1 /* Functions related to invoking methods and overloaded functions. 2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 4 2010, 2011, 2012 5 Free Software Foundation, Inc. 6 Contributed by Michael Tiemann (tiemann@cygnus.com) and 7 modified by Brendan Kehoe (brendan@cygnus.com). 8 9 This file is part of GCC. 10 11 GCC is free software; you can redistribute it and/or modify 12 it under the terms of the GNU General Public License as published by 13 the Free Software Foundation; either version 3, or (at your option) 14 any later version. 15 16 GCC is distributed in the hope that it will be useful, 17 but WITHOUT ANY WARRANTY; without even the implied warranty of 18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 GNU General Public License for more details. 20 21 You should have received a copy of the GNU General Public License 22 along with GCC; see the file COPYING3. If not see 23 <http://www.gnu.org/licenses/>. */ 24 25 26 /* High-level class interface. */ 27 28 #include "config.h" 29 #include "system.h" 30 #include "coretypes.h" 31 #include "tm.h" 32 #include "tree.h" 33 #include "cp-tree.h" 34 #include "output.h" 35 #include "flags.h" 36 #include "toplev.h" 37 #include "diagnostic-core.h" 38 #include "intl.h" 39 #include "target.h" 40 #include "convert.h" 41 #include "langhooks.h" 42 #include "c-family/c-objc.h" 43 #include "timevar.h" 44 45 /* The various kinds of conversion. */ 46 47 typedef enum conversion_kind { 48 ck_identity, 49 ck_lvalue, 50 ck_qual, 51 ck_std, 52 ck_ptr, 53 ck_pmem, 54 ck_base, 55 ck_ref_bind, 56 ck_user, 57 ck_ambig, 58 ck_list, 59 ck_aggr, 60 ck_rvalue 61 } conversion_kind; 62 63 /* The rank of the conversion. Order of the enumerals matters; better 64 conversions should come earlier in the list. */ 65 66 typedef enum conversion_rank { 67 cr_identity, 68 cr_exact, 69 cr_promotion, 70 cr_std, 71 cr_pbool, 72 cr_user, 73 cr_ellipsis, 74 cr_bad 75 } conversion_rank; 76 77 /* An implicit conversion sequence, in the sense of [over.best.ics]. 78 The first conversion to be performed is at the end of the chain. 79 That conversion is always a cr_identity conversion. */ 80 81 typedef struct conversion conversion; 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. */ 97 BOOL_BITFIELD need_temporary_p : 1; 98 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion 99 from a pointer-to-derived to pointer-to-base is being performed. */ 100 BOOL_BITFIELD base_p : 1; 101 /* If KIND is ck_ref_bind, true when either an lvalue reference is 102 being bound to an lvalue expression or an rvalue reference is 103 being bound to an rvalue expression. If KIND is ck_rvalue, 104 true when we should treat an lvalue as an rvalue (12.8p33). If 105 KIND is ck_base, always false. */ 106 BOOL_BITFIELD rvaluedness_matches_p: 1; 107 BOOL_BITFIELD check_narrowing: 1; 108 /* The type of the expression resulting from the conversion. */ 109 tree type; 110 union { 111 /* The next conversion in the chain. Since the conversions are 112 arranged from outermost to innermost, the NEXT conversion will 113 actually be performed before this conversion. This variant is 114 used only when KIND is neither ck_identity, ck_ambig nor 115 ck_list. Please use the next_conversion function instead 116 of using this field directly. */ 117 conversion *next; 118 /* The expression at the beginning of the conversion chain. This 119 variant is used only if KIND is ck_identity or ck_ambig. */ 120 tree expr; 121 /* The array of conversions for an initializer_list, so this 122 variant is used only when KIN D is ck_list. */ 123 conversion **list; 124 } u; 125 /* The function candidate corresponding to this conversion 126 sequence. This field is only used if KIND is ck_user. */ 127 struct z_candidate *cand; 128 }; 129 130 #define CONVERSION_RANK(NODE) \ 131 ((NODE)->bad_p ? cr_bad \ 132 : (NODE)->ellipsis_p ? cr_ellipsis \ 133 : (NODE)->user_conv_p ? cr_user \ 134 : (NODE)->rank) 135 136 #define BAD_CONVERSION_RANK(NODE) \ 137 ((NODE)->ellipsis_p ? cr_ellipsis \ 138 : (NODE)->user_conv_p ? cr_user \ 139 : (NODE)->rank) 140 141 static struct obstack conversion_obstack; 142 static bool conversion_obstack_initialized; 143 struct rejection_reason; 144 145 static struct z_candidate * tourney (struct z_candidate *); 146 static int equal_functions (tree, tree); 147 static int joust (struct z_candidate *, struct z_candidate *, bool); 148 static int compare_ics (conversion *, conversion *); 149 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t); 150 static tree build_java_interface_fn_ref (tree, tree); 151 #define convert_like(CONV, EXPR, COMPLAIN) \ 152 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \ 153 /*issue_conversion_warnings=*/true, \ 154 /*c_cast_p=*/false, (COMPLAIN)) 155 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \ 156 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \ 157 /*issue_conversion_warnings=*/true, \ 158 /*c_cast_p=*/false, (COMPLAIN)) 159 static tree convert_like_real (conversion *, tree, tree, int, int, bool, 160 bool, tsubst_flags_t); 161 static void op_error (enum tree_code, enum tree_code, tree, tree, 162 tree, bool); 163 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int); 164 static void print_z_candidate (const char *, struct z_candidate *); 165 static void print_z_candidates (location_t, struct z_candidate *); 166 static tree build_this (tree); 167 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *); 168 static bool any_strictly_viable (struct z_candidate *); 169 static struct z_candidate *add_template_candidate 170 (struct z_candidate **, tree, tree, tree, tree, const VEC(tree,gc) *, 171 tree, tree, tree, int, unification_kind_t); 172 static struct z_candidate *add_template_candidate_real 173 (struct z_candidate **, tree, tree, tree, tree, const VEC(tree,gc) *, 174 tree, tree, tree, int, tree, unification_kind_t); 175 static struct z_candidate *add_template_conv_candidate 176 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree, 177 tree, tree); 178 static void add_builtin_candidates 179 (struct z_candidate **, enum tree_code, enum tree_code, 180 tree, tree *, int); 181 static void add_builtin_candidate 182 (struct z_candidate **, enum tree_code, enum tree_code, 183 tree, tree, tree, tree *, tree *, int); 184 static bool is_complete (tree); 185 static void build_builtin_candidate 186 (struct z_candidate **, tree, tree, tree, tree *, tree *, 187 int); 188 static struct z_candidate *add_conv_candidate 189 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree, 190 tree); 191 static struct z_candidate *add_function_candidate 192 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree, 193 tree, int); 194 static conversion *implicit_conversion (tree, tree, tree, bool, int); 195 static conversion *standard_conversion (tree, tree, tree, bool, int); 196 static conversion *reference_binding (tree, tree, tree, bool, int); 197 static conversion *build_conv (conversion_kind, tree, conversion *); 198 static conversion *build_list_conv (tree, tree, int); 199 static conversion *next_conversion (conversion *); 200 static bool is_subseq (conversion *, conversion *); 201 static conversion *maybe_handle_ref_bind (conversion **); 202 static void maybe_handle_implicit_object (conversion **); 203 static struct z_candidate *add_candidate 204 (struct z_candidate **, tree, tree, const VEC(tree,gc) *, size_t, 205 conversion **, tree, tree, int, struct rejection_reason *); 206 static tree source_type (conversion *); 207 static void add_warning (struct z_candidate *, struct z_candidate *); 208 static bool reference_compatible_p (tree, tree); 209 static conversion *direct_reference_binding (tree, conversion *); 210 static bool promoted_arithmetic_type_p (tree); 211 static conversion *conditional_conversion (tree, tree); 212 static char *name_as_c_string (tree, tree, bool *); 213 static tree prep_operand (tree); 214 static void add_candidates (tree, tree, const VEC(tree,gc) *, tree, tree, bool, 215 tree, tree, int, struct z_candidate **); 216 static conversion *merge_conversion_sequences (conversion *, conversion *); 217 static bool magic_varargs_p (tree); 218 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t); 219 220 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE. 221 NAME can take many forms... */ 222 223 bool 224 check_dtor_name (tree basetype, tree name) 225 { 226 /* Just accept something we've already complained about. */ 227 if (name == error_mark_node) 228 return true; 229 230 if (TREE_CODE (name) == TYPE_DECL) 231 name = TREE_TYPE (name); 232 else if (TYPE_P (name)) 233 /* OK */; 234 else if (TREE_CODE (name) == IDENTIFIER_NODE) 235 { 236 if ((MAYBE_CLASS_TYPE_P (basetype) 237 && name == constructor_name (basetype)) 238 || (TREE_CODE (basetype) == ENUMERAL_TYPE 239 && name == TYPE_IDENTIFIER (basetype))) 240 return true; 241 else 242 name = get_type_value (name); 243 } 244 else 245 { 246 /* In the case of: 247 248 template <class T> struct S { ~S(); }; 249 int i; 250 i.~S(); 251 252 NAME will be a class template. */ 253 gcc_assert (DECL_CLASS_TEMPLATE_P (name)); 254 return false; 255 } 256 257 if (!name || name == error_mark_node) 258 return false; 259 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name)); 260 } 261 262 /* We want the address of a function or method. We avoid creating a 263 pointer-to-member function. */ 264 265 tree 266 build_addr_func (tree function) 267 { 268 tree type = TREE_TYPE (function); 269 270 /* We have to do these by hand to avoid real pointer to member 271 functions. */ 272 if (TREE_CODE (type) == METHOD_TYPE) 273 { 274 if (TREE_CODE (function) == OFFSET_REF) 275 { 276 tree object = build_address (TREE_OPERAND (function, 0)); 277 return get_member_function_from_ptrfunc (&object, 278 TREE_OPERAND (function, 1)); 279 } 280 function = build_address (function); 281 } 282 else 283 function = decay_conversion (function); 284 285 return function; 286 } 287 288 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or 289 POINTER_TYPE to those. Note, pointer to member function types 290 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are 291 two variants. build_call_a is the primitive taking an array of 292 arguments, while build_call_n is a wrapper that handles varargs. */ 293 294 tree 295 build_call_n (tree function, int n, ...) 296 { 297 if (n == 0) 298 return build_call_a (function, 0, NULL); 299 else 300 { 301 tree *argarray = XALLOCAVEC (tree, n); 302 va_list ap; 303 int i; 304 305 va_start (ap, n); 306 for (i = 0; i < n; i++) 307 argarray[i] = va_arg (ap, tree); 308 va_end (ap); 309 return build_call_a (function, n, argarray); 310 } 311 } 312 313 /* Update various flags in cfun and the call itself based on what is being 314 called. Split out of build_call_a so that bot_manip can use it too. */ 315 316 void 317 set_flags_from_callee (tree call) 318 { 319 int nothrow; 320 tree decl = get_callee_fndecl (call); 321 322 /* We check both the decl and the type; a function may be known not to 323 throw without being declared throw(). */ 324 nothrow = ((decl && TREE_NOTHROW (decl)) 325 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (call))))); 326 327 if (!nothrow && at_function_scope_p () && cfun && cp_function_chain) 328 cp_function_chain->can_throw = 1; 329 330 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain) 331 current_function_returns_abnormally = 1; 332 333 TREE_NOTHROW (call) = nothrow; 334 } 335 336 tree 337 build_call_a (tree function, int n, tree *argarray) 338 { 339 tree decl; 340 tree result_type; 341 tree fntype; 342 int i; 343 344 function = build_addr_func (function); 345 346 gcc_assert (TYPE_PTR_P (TREE_TYPE (function))); 347 fntype = TREE_TYPE (TREE_TYPE (function)); 348 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE 349 || TREE_CODE (fntype) == METHOD_TYPE); 350 result_type = TREE_TYPE (fntype); 351 /* An rvalue has no cv-qualifiers. */ 352 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type)) 353 result_type = cv_unqualified (result_type); 354 355 function = build_call_array_loc (input_location, 356 result_type, function, n, argarray); 357 set_flags_from_callee (function); 358 359 decl = get_callee_fndecl (function); 360 361 if (decl && !TREE_USED (decl)) 362 { 363 /* We invoke build_call directly for several library 364 functions. These may have been declared normally if 365 we're building libgcc, so we can't just check 366 DECL_ARTIFICIAL. */ 367 gcc_assert (DECL_ARTIFICIAL (decl) 368 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)), 369 "__", 2)); 370 mark_used (decl); 371 } 372 373 if (decl && TREE_DEPRECATED (decl)) 374 warn_deprecated_use (decl, NULL_TREE); 375 require_complete_eh_spec_types (fntype, decl); 376 377 TREE_HAS_CONSTRUCTOR (function) = (decl && DECL_CONSTRUCTOR_P (decl)); 378 379 /* Don't pass empty class objects by value. This is useful 380 for tags in STL, which are used to control overload resolution. 381 We don't need to handle other cases of copying empty classes. */ 382 if (! decl || ! DECL_BUILT_IN (decl)) 383 for (i = 0; i < n; i++) 384 { 385 tree arg = CALL_EXPR_ARG (function, i); 386 if (is_empty_class (TREE_TYPE (arg)) 387 && ! TREE_ADDRESSABLE (TREE_TYPE (arg))) 388 { 389 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (arg)); 390 arg = build2 (COMPOUND_EXPR, TREE_TYPE (t), arg, t); 391 CALL_EXPR_ARG (function, i) = arg; 392 } 393 } 394 395 return function; 396 } 397 398 /* Build something of the form ptr->method (args) 399 or object.method (args). This can also build 400 calls to constructors, and find friends. 401 402 Member functions always take their class variable 403 as a pointer. 404 405 INSTANCE is a class instance. 406 407 NAME is the name of the method desired, usually an IDENTIFIER_NODE. 408 409 PARMS help to figure out what that NAME really refers to. 410 411 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE 412 down to the real instance type to use for access checking. We need this 413 information to get protected accesses correct. 414 415 FLAGS is the logical disjunction of zero or more LOOKUP_ 416 flags. See cp-tree.h for more info. 417 418 If this is all OK, calls build_function_call with the resolved 419 member function. 420 421 This function must also handle being called to perform 422 initialization, promotion/coercion of arguments, and 423 instantiation of default parameters. 424 425 Note that NAME may refer to an instance variable name. If 426 `operator()()' is defined for the type of that field, then we return 427 that result. */ 428 429 /* New overloading code. */ 430 431 typedef struct z_candidate z_candidate; 432 433 typedef struct candidate_warning candidate_warning; 434 struct candidate_warning { 435 z_candidate *loser; 436 candidate_warning *next; 437 }; 438 439 /* Information for providing diagnostics about why overloading failed. */ 440 441 enum rejection_reason_code { 442 rr_none, 443 rr_arity, 444 rr_explicit_conversion, 445 rr_template_conversion, 446 rr_arg_conversion, 447 rr_bad_arg_conversion, 448 rr_template_unification, 449 rr_template_instantiation, 450 rr_invalid_copy 451 }; 452 453 struct conversion_info { 454 /* The index of the argument, 0-based. */ 455 int n_arg; 456 /* The type of the actual argument. */ 457 tree from_type; 458 /* The type of the formal argument. */ 459 tree to_type; 460 }; 461 462 struct rejection_reason { 463 enum rejection_reason_code code; 464 union { 465 /* Information about an arity mismatch. */ 466 struct { 467 /* The expected number of arguments. */ 468 int expected; 469 /* The actual number of arguments in the call. */ 470 int actual; 471 /* Whether the call was a varargs call. */ 472 bool call_varargs_p; 473 } arity; 474 /* Information about an argument conversion mismatch. */ 475 struct conversion_info conversion; 476 /* Same, but for bad argument conversions. */ 477 struct conversion_info bad_conversion; 478 /* Information about template unification failures. These are the 479 parameters passed to fn_type_unification. */ 480 struct { 481 tree tmpl; 482 tree explicit_targs; 483 tree targs; 484 const tree *args; 485 unsigned int nargs; 486 tree return_type; 487 unification_kind_t strict; 488 int flags; 489 } template_unification; 490 /* Information about template instantiation failures. These are the 491 parameters passed to instantiate_template. */ 492 struct { 493 tree tmpl; 494 tree targs; 495 } template_instantiation; 496 } u; 497 }; 498 499 struct z_candidate { 500 /* The FUNCTION_DECL that will be called if this candidate is 501 selected by overload resolution. */ 502 tree fn; 503 /* If not NULL_TREE, the first argument to use when calling this 504 function. */ 505 tree first_arg; 506 /* The rest of the arguments to use when calling this function. If 507 there are no further arguments this may be NULL or it may be an 508 empty vector. */ 509 const VEC(tree,gc) *args; 510 /* The implicit conversion sequences for each of the arguments to 511 FN. */ 512 conversion **convs; 513 /* The number of implicit conversion sequences. */ 514 size_t num_convs; 515 /* If FN is a user-defined conversion, the standard conversion 516 sequence from the type returned by FN to the desired destination 517 type. */ 518 conversion *second_conv; 519 int viable; 520 struct rejection_reason *reason; 521 /* If FN is a member function, the binfo indicating the path used to 522 qualify the name of FN at the call site. This path is used to 523 determine whether or not FN is accessible if it is selected by 524 overload resolution. The DECL_CONTEXT of FN will always be a 525 (possibly improper) base of this binfo. */ 526 tree access_path; 527 /* If FN is a non-static member function, the binfo indicating the 528 subobject to which the `this' pointer should be converted if FN 529 is selected by overload resolution. The type pointed to by 530 the `this' pointer must correspond to the most derived class 531 indicated by the CONVERSION_PATH. */ 532 tree conversion_path; 533 tree template_decl; 534 tree explicit_targs; 535 candidate_warning *warnings; 536 z_candidate *next; 537 }; 538 539 /* Returns true iff T is a null pointer constant in the sense of 540 [conv.ptr]. */ 541 542 bool 543 null_ptr_cst_p (tree t) 544 { 545 /* [conv.ptr] 546 547 A null pointer constant is an integral constant expression 548 (_expr.const_) rvalue of integer type that evaluates to zero or 549 an rvalue of type std::nullptr_t. */ 550 if (NULLPTR_TYPE_P (TREE_TYPE (t))) 551 return true; 552 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t))) 553 { 554 /* Core issue 903 says only literal 0 is a null pointer constant. */ 555 if (cxx_dialect < cxx0x) 556 t = integral_constant_value (t); 557 STRIP_NOPS (t); 558 if (integer_zerop (t) && !TREE_OVERFLOW (t)) 559 return true; 560 } 561 return false; 562 } 563 564 /* Returns true iff T is a null member pointer value (4.11). */ 565 566 bool 567 null_member_pointer_value_p (tree t) 568 { 569 tree type = TREE_TYPE (t); 570 if (!type) 571 return false; 572 else if (TYPE_PTRMEMFUNC_P (type)) 573 return (TREE_CODE (t) == CONSTRUCTOR 574 && integer_zerop (CONSTRUCTOR_ELT (t, 0)->value)); 575 else if (TYPE_PTRMEM_P (type)) 576 return integer_all_onesp (t); 577 else 578 return false; 579 } 580 581 /* Returns nonzero if PARMLIST consists of only default parms, 582 ellipsis, and/or undeduced parameter packs. */ 583 584 bool 585 sufficient_parms_p (const_tree parmlist) 586 { 587 for (; parmlist && parmlist != void_list_node; 588 parmlist = TREE_CHAIN (parmlist)) 589 if (!TREE_PURPOSE (parmlist) 590 && !PACK_EXPANSION_P (TREE_VALUE (parmlist))) 591 return false; 592 return true; 593 } 594 595 /* Allocate N bytes of memory from the conversion obstack. The memory 596 is zeroed before being returned. */ 597 598 static void * 599 conversion_obstack_alloc (size_t n) 600 { 601 void *p; 602 if (!conversion_obstack_initialized) 603 { 604 gcc_obstack_init (&conversion_obstack); 605 conversion_obstack_initialized = true; 606 } 607 p = obstack_alloc (&conversion_obstack, n); 608 memset (p, 0, n); 609 return p; 610 } 611 612 /* Allocate rejection reasons. */ 613 614 static struct rejection_reason * 615 alloc_rejection (enum rejection_reason_code code) 616 { 617 struct rejection_reason *p; 618 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p); 619 p->code = code; 620 return p; 621 } 622 623 static struct rejection_reason * 624 arity_rejection (tree first_arg, int expected, int actual) 625 { 626 struct rejection_reason *r = alloc_rejection (rr_arity); 627 int adjust = first_arg != NULL_TREE; 628 r->u.arity.expected = expected - adjust; 629 r->u.arity.actual = actual - adjust; 630 return r; 631 } 632 633 static struct rejection_reason * 634 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to) 635 { 636 struct rejection_reason *r = alloc_rejection (rr_arg_conversion); 637 int adjust = first_arg != NULL_TREE; 638 r->u.conversion.n_arg = n_arg - adjust; 639 r->u.conversion.from_type = from; 640 r->u.conversion.to_type = to; 641 return r; 642 } 643 644 static struct rejection_reason * 645 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to) 646 { 647 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion); 648 int adjust = first_arg != NULL_TREE; 649 r->u.bad_conversion.n_arg = n_arg - adjust; 650 r->u.bad_conversion.from_type = from; 651 r->u.bad_conversion.to_type = to; 652 return r; 653 } 654 655 static struct rejection_reason * 656 explicit_conversion_rejection (tree from, tree to) 657 { 658 struct rejection_reason *r = alloc_rejection (rr_explicit_conversion); 659 r->u.conversion.n_arg = 0; 660 r->u.conversion.from_type = from; 661 r->u.conversion.to_type = to; 662 return r; 663 } 664 665 static struct rejection_reason * 666 template_conversion_rejection (tree from, tree to) 667 { 668 struct rejection_reason *r = alloc_rejection (rr_template_conversion); 669 r->u.conversion.n_arg = 0; 670 r->u.conversion.from_type = from; 671 r->u.conversion.to_type = to; 672 return r; 673 } 674 675 static struct rejection_reason * 676 template_unification_rejection (tree tmpl, tree explicit_targs, tree targs, 677 const tree *args, unsigned int nargs, 678 tree return_type, unification_kind_t strict, 679 int flags) 680 { 681 size_t args_n_bytes = sizeof (*args) * nargs; 682 tree *args1 = (tree *) conversion_obstack_alloc (args_n_bytes); 683 struct rejection_reason *r = alloc_rejection (rr_template_unification); 684 r->u.template_unification.tmpl = tmpl; 685 r->u.template_unification.explicit_targs = explicit_targs; 686 r->u.template_unification.targs = targs; 687 /* Copy args to our own storage. */ 688 memcpy (args1, args, args_n_bytes); 689 r->u.template_unification.args = args1; 690 r->u.template_unification.nargs = nargs; 691 r->u.template_unification.return_type = return_type; 692 r->u.template_unification.strict = strict; 693 r->u.template_unification.flags = flags; 694 return r; 695 } 696 697 static struct rejection_reason * 698 template_unification_error_rejection (void) 699 { 700 return alloc_rejection (rr_template_unification); 701 } 702 703 static struct rejection_reason * 704 template_instantiation_rejection (tree tmpl, tree targs) 705 { 706 struct rejection_reason *r = alloc_rejection (rr_template_instantiation); 707 r->u.template_instantiation.tmpl = tmpl; 708 r->u.template_instantiation.targs = targs; 709 return r; 710 } 711 712 static struct rejection_reason * 713 invalid_copy_with_fn_template_rejection (void) 714 { 715 struct rejection_reason *r = alloc_rejection (rr_invalid_copy); 716 return r; 717 } 718 719 /* Dynamically allocate a conversion. */ 720 721 static conversion * 722 alloc_conversion (conversion_kind kind) 723 { 724 conversion *c; 725 c = (conversion *) conversion_obstack_alloc (sizeof (conversion)); 726 c->kind = kind; 727 return c; 728 } 729 730 #ifdef ENABLE_CHECKING 731 732 /* Make sure that all memory on the conversion obstack has been 733 freed. */ 734 735 void 736 validate_conversion_obstack (void) 737 { 738 if (conversion_obstack_initialized) 739 gcc_assert ((obstack_next_free (&conversion_obstack) 740 == obstack_base (&conversion_obstack))); 741 } 742 743 #endif /* ENABLE_CHECKING */ 744 745 /* Dynamically allocate an array of N conversions. */ 746 747 static conversion ** 748 alloc_conversions (size_t n) 749 { 750 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *)); 751 } 752 753 static conversion * 754 build_conv (conversion_kind code, tree type, conversion *from) 755 { 756 conversion *t; 757 conversion_rank rank = CONVERSION_RANK (from); 758 759 /* Note that the caller is responsible for filling in t->cand for 760 user-defined conversions. */ 761 t = alloc_conversion (code); 762 t->type = type; 763 t->u.next = from; 764 765 switch (code) 766 { 767 case ck_ptr: 768 case ck_pmem: 769 case ck_base: 770 case ck_std: 771 if (rank < cr_std) 772 rank = cr_std; 773 break; 774 775 case ck_qual: 776 if (rank < cr_exact) 777 rank = cr_exact; 778 break; 779 780 default: 781 break; 782 } 783 t->rank = rank; 784 t->user_conv_p = (code == ck_user || from->user_conv_p); 785 t->bad_p = from->bad_p; 786 t->base_p = false; 787 return t; 788 } 789 790 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 791 specialization of std::initializer_list<T>, if such a conversion is 792 possible. */ 793 794 static conversion * 795 build_list_conv (tree type, tree ctor, int flags) 796 { 797 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0); 798 unsigned len = CONSTRUCTOR_NELTS (ctor); 799 conversion **subconvs = alloc_conversions (len); 800 conversion *t; 801 unsigned i; 802 tree val; 803 804 /* Within a list-initialization we can have more user-defined 805 conversions. */ 806 flags &= ~LOOKUP_NO_CONVERSION; 807 /* But no narrowing conversions. */ 808 flags |= LOOKUP_NO_NARROWING; 809 810 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 811 { 812 conversion *sub 813 = implicit_conversion (elttype, TREE_TYPE (val), val, 814 false, flags); 815 if (sub == NULL) 816 return NULL; 817 818 subconvs[i] = sub; 819 } 820 821 t = alloc_conversion (ck_list); 822 t->type = type; 823 t->u.list = subconvs; 824 t->rank = cr_exact; 825 826 for (i = 0; i < len; ++i) 827 { 828 conversion *sub = subconvs[i]; 829 if (sub->rank > t->rank) 830 t->rank = sub->rank; 831 if (sub->user_conv_p) 832 t->user_conv_p = true; 833 if (sub->bad_p) 834 t->bad_p = true; 835 } 836 837 return t; 838 } 839 840 /* Return the next conversion of the conversion chain (if applicable), 841 or NULL otherwise. Please use this function instead of directly 842 accessing fields of struct conversion. */ 843 844 static conversion * 845 next_conversion (conversion *conv) 846 { 847 if (conv == NULL 848 || conv->kind == ck_identity 849 || conv->kind == ck_ambig 850 || conv->kind == ck_list) 851 return NULL; 852 return conv->u.next; 853 } 854 855 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list, 856 is a valid aggregate initializer for array type ATYPE. */ 857 858 static bool 859 can_convert_array (tree atype, tree ctor, int flags) 860 { 861 unsigned i; 862 tree elttype = TREE_TYPE (atype); 863 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i) 864 { 865 tree val = CONSTRUCTOR_ELT (ctor, i)->value; 866 bool ok; 867 if (TREE_CODE (elttype) == ARRAY_TYPE 868 && TREE_CODE (val) == CONSTRUCTOR) 869 ok = can_convert_array (elttype, val, flags); 870 else 871 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags); 872 if (!ok) 873 return false; 874 } 875 return true; 876 } 877 878 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 879 aggregate class, if such a conversion is possible. */ 880 881 static conversion * 882 build_aggr_conv (tree type, tree ctor, int flags) 883 { 884 unsigned HOST_WIDE_INT i = 0; 885 conversion *c; 886 tree field = next_initializable_field (TYPE_FIELDS (type)); 887 tree empty_ctor = NULL_TREE; 888 889 for (; field; field = next_initializable_field (DECL_CHAIN (field))) 890 { 891 tree ftype = TREE_TYPE (field); 892 tree val; 893 bool ok; 894 895 if (i < CONSTRUCTOR_NELTS (ctor)) 896 val = CONSTRUCTOR_ELT (ctor, i)->value; 897 else 898 { 899 if (empty_ctor == NULL_TREE) 900 empty_ctor = build_constructor (init_list_type_node, NULL); 901 val = empty_ctor; 902 } 903 ++i; 904 905 if (TREE_CODE (ftype) == ARRAY_TYPE 906 && TREE_CODE (val) == CONSTRUCTOR) 907 ok = can_convert_array (ftype, val, flags); 908 else 909 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags); 910 911 if (!ok) 912 return NULL; 913 914 if (TREE_CODE (type) == UNION_TYPE) 915 break; 916 } 917 918 if (i < CONSTRUCTOR_NELTS (ctor)) 919 return NULL; 920 921 c = alloc_conversion (ck_aggr); 922 c->type = type; 923 c->rank = cr_exact; 924 c->user_conv_p = true; 925 c->u.next = NULL; 926 return c; 927 } 928 929 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 930 array type, if such a conversion is possible. */ 931 932 static conversion * 933 build_array_conv (tree type, tree ctor, int flags) 934 { 935 conversion *c; 936 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 937 tree elttype = TREE_TYPE (type); 938 unsigned i; 939 tree val; 940 bool bad = false; 941 bool user = false; 942 enum conversion_rank rank = cr_exact; 943 944 if (TYPE_DOMAIN (type)) 945 { 946 unsigned HOST_WIDE_INT alen = tree_low_cst (array_type_nelts_top (type), 1); 947 if (alen < len) 948 return NULL; 949 } 950 951 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 952 { 953 conversion *sub 954 = implicit_conversion (elttype, TREE_TYPE (val), val, 955 false, flags); 956 if (sub == NULL) 957 return NULL; 958 959 if (sub->rank > rank) 960 rank = sub->rank; 961 if (sub->user_conv_p) 962 user = true; 963 if (sub->bad_p) 964 bad = true; 965 } 966 967 c = alloc_conversion (ck_aggr); 968 c->type = type; 969 c->rank = rank; 970 c->user_conv_p = user; 971 c->bad_p = bad; 972 c->u.next = NULL; 973 return c; 974 } 975 976 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 977 complex type, if such a conversion is possible. */ 978 979 static conversion * 980 build_complex_conv (tree type, tree ctor, int flags) 981 { 982 conversion *c; 983 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 984 tree elttype = TREE_TYPE (type); 985 unsigned i; 986 tree val; 987 bool bad = false; 988 bool user = false; 989 enum conversion_rank rank = cr_exact; 990 991 if (len != 2) 992 return NULL; 993 994 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 995 { 996 conversion *sub 997 = implicit_conversion (elttype, TREE_TYPE (val), val, 998 false, flags); 999 if (sub == NULL) 1000 return NULL; 1001 1002 if (sub->rank > rank) 1003 rank = sub->rank; 1004 if (sub->user_conv_p) 1005 user = true; 1006 if (sub->bad_p) 1007 bad = true; 1008 } 1009 1010 c = alloc_conversion (ck_aggr); 1011 c->type = type; 1012 c->rank = rank; 1013 c->user_conv_p = user; 1014 c->bad_p = bad; 1015 c->u.next = NULL; 1016 return c; 1017 } 1018 1019 /* Build a representation of the identity conversion from EXPR to 1020 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */ 1021 1022 static conversion * 1023 build_identity_conv (tree type, tree expr) 1024 { 1025 conversion *c; 1026 1027 c = alloc_conversion (ck_identity); 1028 c->type = type; 1029 c->u.expr = expr; 1030 1031 return c; 1032 } 1033 1034 /* Converting from EXPR to TYPE was ambiguous in the sense that there 1035 were multiple user-defined conversions to accomplish the job. 1036 Build a conversion that indicates that ambiguity. */ 1037 1038 static conversion * 1039 build_ambiguous_conv (tree type, tree expr) 1040 { 1041 conversion *c; 1042 1043 c = alloc_conversion (ck_ambig); 1044 c->type = type; 1045 c->u.expr = expr; 1046 1047 return c; 1048 } 1049 1050 tree 1051 strip_top_quals (tree t) 1052 { 1053 if (TREE_CODE (t) == ARRAY_TYPE) 1054 return t; 1055 return cp_build_qualified_type (t, 0); 1056 } 1057 1058 /* Returns the standard conversion path (see [conv]) from type FROM to type 1059 TO, if any. For proper handling of null pointer constants, you must 1060 also pass the expression EXPR to convert from. If C_CAST_P is true, 1061 this conversion is coming from a C-style cast. */ 1062 1063 static conversion * 1064 standard_conversion (tree to, tree from, tree expr, bool c_cast_p, 1065 int flags) 1066 { 1067 enum tree_code fcode, tcode; 1068 conversion *conv; 1069 bool fromref = false; 1070 tree qualified_to; 1071 1072 to = non_reference (to); 1073 if (TREE_CODE (from) == REFERENCE_TYPE) 1074 { 1075 fromref = true; 1076 from = TREE_TYPE (from); 1077 } 1078 qualified_to = to; 1079 to = strip_top_quals (to); 1080 from = strip_top_quals (from); 1081 1082 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to)) 1083 && expr && type_unknown_p (expr)) 1084 { 1085 tsubst_flags_t tflags = tf_conv; 1086 if (!(flags & LOOKUP_PROTECT)) 1087 tflags |= tf_no_access_control; 1088 expr = instantiate_type (to, expr, tflags); 1089 if (expr == error_mark_node) 1090 return NULL; 1091 from = TREE_TYPE (expr); 1092 } 1093 1094 fcode = TREE_CODE (from); 1095 tcode = TREE_CODE (to); 1096 1097 conv = build_identity_conv (from, expr); 1098 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE) 1099 { 1100 from = type_decays_to (from); 1101 fcode = TREE_CODE (from); 1102 conv = build_conv (ck_lvalue, from, conv); 1103 } 1104 else if (fromref || (expr && lvalue_p (expr))) 1105 { 1106 if (expr) 1107 { 1108 tree bitfield_type; 1109 bitfield_type = is_bitfield_expr_with_lowered_type (expr); 1110 if (bitfield_type) 1111 { 1112 from = strip_top_quals (bitfield_type); 1113 fcode = TREE_CODE (from); 1114 } 1115 } 1116 conv = build_conv (ck_rvalue, from, conv); 1117 if (flags & LOOKUP_PREFER_RVALUE) 1118 conv->rvaluedness_matches_p = true; 1119 } 1120 1121 /* Allow conversion between `__complex__' data types. */ 1122 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE) 1123 { 1124 /* The standard conversion sequence to convert FROM to TO is 1125 the standard conversion sequence to perform componentwise 1126 conversion. */ 1127 conversion *part_conv = standard_conversion 1128 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags); 1129 1130 if (part_conv) 1131 { 1132 conv = build_conv (part_conv->kind, to, conv); 1133 conv->rank = part_conv->rank; 1134 } 1135 else 1136 conv = NULL; 1137 1138 return conv; 1139 } 1140 1141 if (same_type_p (from, to)) 1142 { 1143 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue) 1144 conv->type = qualified_to; 1145 return conv; 1146 } 1147 1148 /* [conv.ptr] 1149 A null pointer constant can be converted to a pointer type; ... A 1150 null pointer constant of integral type can be converted to an 1151 rvalue of type std::nullptr_t. */ 1152 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to) 1153 || NULLPTR_TYPE_P (to)) 1154 && expr && null_ptr_cst_p (expr)) 1155 conv = build_conv (ck_std, to, conv); 1156 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE) 1157 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE)) 1158 { 1159 /* For backwards brain damage compatibility, allow interconversion of 1160 pointers and integers with a pedwarn. */ 1161 conv = build_conv (ck_std, to, conv); 1162 conv->bad_p = true; 1163 } 1164 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE) 1165 { 1166 /* For backwards brain damage compatibility, allow interconversion of 1167 enums and integers with a pedwarn. */ 1168 conv = build_conv (ck_std, to, conv); 1169 conv->bad_p = true; 1170 } 1171 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE) 1172 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from))) 1173 { 1174 tree to_pointee; 1175 tree from_pointee; 1176 1177 if (tcode == POINTER_TYPE 1178 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from), 1179 TREE_TYPE (to))) 1180 ; 1181 else if (VOID_TYPE_P (TREE_TYPE (to)) 1182 && !TYPE_PTRMEM_P (from) 1183 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE) 1184 { 1185 tree nfrom = TREE_TYPE (from); 1186 from = build_pointer_type 1187 (cp_build_qualified_type (void_type_node, 1188 cp_type_quals (nfrom))); 1189 conv = build_conv (ck_ptr, from, conv); 1190 } 1191 else if (TYPE_PTRMEM_P (from)) 1192 { 1193 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from); 1194 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to); 1195 1196 if (DERIVED_FROM_P (fbase, tbase) 1197 && (same_type_ignoring_top_level_qualifiers_p 1198 (TYPE_PTRMEM_POINTED_TO_TYPE (from), 1199 TYPE_PTRMEM_POINTED_TO_TYPE (to)))) 1200 { 1201 from = build_ptrmem_type (tbase, 1202 TYPE_PTRMEM_POINTED_TO_TYPE (from)); 1203 conv = build_conv (ck_pmem, from, conv); 1204 } 1205 else if (!same_type_p (fbase, tbase)) 1206 return NULL; 1207 } 1208 else if (CLASS_TYPE_P (TREE_TYPE (from)) 1209 && CLASS_TYPE_P (TREE_TYPE (to)) 1210 /* [conv.ptr] 1211 1212 An rvalue of type "pointer to cv D," where D is a 1213 class type, can be converted to an rvalue of type 1214 "pointer to cv B," where B is a base class (clause 1215 _class.derived_) of D. If B is an inaccessible 1216 (clause _class.access_) or ambiguous 1217 (_class.member.lookup_) base class of D, a program 1218 that necessitates this conversion is ill-formed. 1219 Therefore, we use DERIVED_FROM_P, and do not check 1220 access or uniqueness. */ 1221 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from))) 1222 { 1223 from = 1224 cp_build_qualified_type (TREE_TYPE (to), 1225 cp_type_quals (TREE_TYPE (from))); 1226 from = build_pointer_type (from); 1227 conv = build_conv (ck_ptr, from, conv); 1228 conv->base_p = true; 1229 } 1230 1231 if (tcode == POINTER_TYPE) 1232 { 1233 to_pointee = TREE_TYPE (to); 1234 from_pointee = TREE_TYPE (from); 1235 } 1236 else 1237 { 1238 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to); 1239 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from); 1240 } 1241 1242 if (same_type_p (from, to)) 1243 /* OK */; 1244 else if (c_cast_p && comp_ptr_ttypes_const (to, from)) 1245 /* In a C-style cast, we ignore CV-qualification because we 1246 are allowed to perform a static_cast followed by a 1247 const_cast. */ 1248 conv = build_conv (ck_qual, to, conv); 1249 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee)) 1250 conv = build_conv (ck_qual, to, conv); 1251 else if (expr && string_conv_p (to, expr, 0)) 1252 /* converting from string constant to char *. */ 1253 conv = build_conv (ck_qual, to, conv); 1254 /* Allow conversions among compatible ObjC pointer types (base 1255 conversions have been already handled above). */ 1256 else if (c_dialect_objc () 1257 && objc_compare_types (to, from, -4, NULL_TREE)) 1258 conv = build_conv (ck_ptr, to, conv); 1259 else if (ptr_reasonably_similar (to_pointee, from_pointee)) 1260 { 1261 conv = build_conv (ck_ptr, to, conv); 1262 conv->bad_p = true; 1263 } 1264 else 1265 return NULL; 1266 1267 from = to; 1268 } 1269 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from)) 1270 { 1271 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from)); 1272 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to)); 1273 tree fbase = class_of_this_parm (fromfn); 1274 tree tbase = class_of_this_parm (tofn); 1275 1276 if (!DERIVED_FROM_P (fbase, tbase) 1277 || !same_type_p (static_fn_type (fromfn), 1278 static_fn_type (tofn))) 1279 return NULL; 1280 1281 from = build_memfn_type (fromfn, tbase, cp_type_quals (tbase)); 1282 from = build_ptrmemfunc_type (build_pointer_type (from)); 1283 conv = build_conv (ck_pmem, from, conv); 1284 conv->base_p = true; 1285 } 1286 else if (tcode == BOOLEAN_TYPE) 1287 { 1288 /* [conv.bool] 1289 1290 An rvalue of arithmetic, unscoped enumeration, pointer, or 1291 pointer to member type can be converted to an rvalue of type 1292 bool. ... An rvalue of type std::nullptr_t can be converted 1293 to an rvalue of type bool; */ 1294 if (ARITHMETIC_TYPE_P (from) 1295 || UNSCOPED_ENUM_P (from) 1296 || fcode == POINTER_TYPE 1297 || TYPE_PTR_TO_MEMBER_P (from) 1298 || NULLPTR_TYPE_P (from)) 1299 { 1300 conv = build_conv (ck_std, to, conv); 1301 if (fcode == POINTER_TYPE 1302 || TYPE_PTRMEM_P (from) 1303 || (TYPE_PTRMEMFUNC_P (from) 1304 && conv->rank < cr_pbool) 1305 || NULLPTR_TYPE_P (from)) 1306 conv->rank = cr_pbool; 1307 return conv; 1308 } 1309 1310 return NULL; 1311 } 1312 /* We don't check for ENUMERAL_TYPE here because there are no standard 1313 conversions to enum type. */ 1314 /* As an extension, allow conversion to complex type. */ 1315 else if (ARITHMETIC_TYPE_P (to)) 1316 { 1317 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE) 1318 || SCOPED_ENUM_P (from)) 1319 return NULL; 1320 conv = build_conv (ck_std, to, conv); 1321 1322 /* Give this a better rank if it's a promotion. */ 1323 if (same_type_p (to, type_promotes_to (from)) 1324 && conv->u.next->rank <= cr_promotion) 1325 conv->rank = cr_promotion; 1326 } 1327 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE 1328 && vector_types_convertible_p (from, to, false)) 1329 return build_conv (ck_std, to, conv); 1330 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from) 1331 && is_properly_derived_from (from, to)) 1332 { 1333 if (conv->kind == ck_rvalue) 1334 conv = conv->u.next; 1335 conv = build_conv (ck_base, to, conv); 1336 /* The derived-to-base conversion indicates the initialization 1337 of a parameter with base type from an object of a derived 1338 type. A temporary object is created to hold the result of 1339 the conversion unless we're binding directly to a reference. */ 1340 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND); 1341 } 1342 else 1343 return NULL; 1344 1345 if (flags & LOOKUP_NO_NARROWING) 1346 conv->check_narrowing = true; 1347 1348 return conv; 1349 } 1350 1351 /* Returns nonzero if T1 is reference-related to T2. */ 1352 1353 bool 1354 reference_related_p (tree t1, tree t2) 1355 { 1356 if (t1 == error_mark_node || t2 == error_mark_node) 1357 return false; 1358 1359 t1 = TYPE_MAIN_VARIANT (t1); 1360 t2 = TYPE_MAIN_VARIANT (t2); 1361 1362 /* [dcl.init.ref] 1363 1364 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related 1365 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class 1366 of T2. */ 1367 return (same_type_p (t1, t2) 1368 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 1369 && DERIVED_FROM_P (t1, t2))); 1370 } 1371 1372 /* Returns nonzero if T1 is reference-compatible with T2. */ 1373 1374 static bool 1375 reference_compatible_p (tree t1, tree t2) 1376 { 1377 /* [dcl.init.ref] 1378 1379 "cv1 T1" is reference compatible with "cv2 T2" if T1 is 1380 reference-related to T2 and cv1 is the same cv-qualification as, 1381 or greater cv-qualification than, cv2. */ 1382 return (reference_related_p (t1, t2) 1383 && at_least_as_qualified_p (t1, t2)); 1384 } 1385 1386 /* A reference of the indicated TYPE is being bound directly to the 1387 expression represented by the implicit conversion sequence CONV. 1388 Return a conversion sequence for this binding. */ 1389 1390 static conversion * 1391 direct_reference_binding (tree type, conversion *conv) 1392 { 1393 tree t; 1394 1395 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE); 1396 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE); 1397 1398 t = TREE_TYPE (type); 1399 1400 /* [over.ics.rank] 1401 1402 When a parameter of reference type binds directly 1403 (_dcl.init.ref_) to an argument expression, the implicit 1404 conversion sequence is the identity conversion, unless the 1405 argument expression has a type that is a derived class of the 1406 parameter type, in which case the implicit conversion sequence is 1407 a derived-to-base Conversion. 1408 1409 If the parameter binds directly to the result of applying a 1410 conversion function to the argument expression, the implicit 1411 conversion sequence is a user-defined conversion sequence 1412 (_over.ics.user_), with the second standard conversion sequence 1413 either an identity conversion or, if the conversion function 1414 returns an entity of a type that is a derived class of the 1415 parameter type, a derived-to-base conversion. */ 1416 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type)) 1417 { 1418 /* Represent the derived-to-base conversion. */ 1419 conv = build_conv (ck_base, t, conv); 1420 /* We will actually be binding to the base-class subobject in 1421 the derived class, so we mark this conversion appropriately. 1422 That way, convert_like knows not to generate a temporary. */ 1423 conv->need_temporary_p = false; 1424 } 1425 return build_conv (ck_ref_bind, type, conv); 1426 } 1427 1428 /* Returns the conversion path from type FROM to reference type TO for 1429 purposes of reference binding. For lvalue binding, either pass a 1430 reference type to FROM or an lvalue expression to EXPR. If the 1431 reference will be bound to a temporary, NEED_TEMPORARY_P is set for 1432 the conversion returned. If C_CAST_P is true, this 1433 conversion is coming from a C-style cast. */ 1434 1435 static conversion * 1436 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags) 1437 { 1438 conversion *conv = NULL; 1439 tree to = TREE_TYPE (rto); 1440 tree from = rfrom; 1441 tree tfrom; 1442 bool related_p; 1443 bool compatible_p; 1444 cp_lvalue_kind gl_kind; 1445 bool is_lvalue; 1446 1447 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr)) 1448 { 1449 expr = instantiate_type (to, expr, tf_none); 1450 if (expr == error_mark_node) 1451 return NULL; 1452 from = TREE_TYPE (expr); 1453 } 1454 1455 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1456 { 1457 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS); 1458 conv = implicit_conversion (to, from, expr, c_cast_p, 1459 flags); 1460 if (!CLASS_TYPE_P (to) 1461 && CONSTRUCTOR_NELTS (expr) == 1) 1462 { 1463 expr = CONSTRUCTOR_ELT (expr, 0)->value; 1464 if (error_operand_p (expr)) 1465 return NULL; 1466 from = TREE_TYPE (expr); 1467 } 1468 } 1469 1470 if (TREE_CODE (from) == REFERENCE_TYPE) 1471 { 1472 from = TREE_TYPE (from); 1473 if (!TYPE_REF_IS_RVALUE (rfrom) 1474 || TREE_CODE (from) == FUNCTION_TYPE) 1475 gl_kind = clk_ordinary; 1476 else 1477 gl_kind = clk_rvalueref; 1478 } 1479 else if (expr) 1480 { 1481 gl_kind = lvalue_kind (expr); 1482 if (gl_kind & clk_class) 1483 /* A class prvalue is not a glvalue. */ 1484 gl_kind = clk_none; 1485 } 1486 else 1487 gl_kind = clk_none; 1488 is_lvalue = gl_kind && !(gl_kind & clk_rvalueref); 1489 1490 tfrom = from; 1491 if ((gl_kind & clk_bitfield) != 0) 1492 tfrom = unlowered_expr_type (expr); 1493 1494 /* Figure out whether or not the types are reference-related and 1495 reference compatible. We have do do this after stripping 1496 references from FROM. */ 1497 related_p = reference_related_p (to, tfrom); 1498 /* If this is a C cast, first convert to an appropriately qualified 1499 type, so that we can later do a const_cast to the desired type. */ 1500 if (related_p && c_cast_p 1501 && !at_least_as_qualified_p (to, tfrom)) 1502 to = cp_build_qualified_type (to, cp_type_quals (tfrom)); 1503 compatible_p = reference_compatible_p (to, tfrom); 1504 1505 /* Directly bind reference when target expression's type is compatible with 1506 the reference and expression is an lvalue. In DR391, the wording in 1507 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for 1508 const and rvalue references to rvalues of compatible class type. 1509 We should also do direct bindings for non-class xvalues. */ 1510 if (compatible_p 1511 && (is_lvalue 1512 || (((CP_TYPE_CONST_NON_VOLATILE_P (to) 1513 && !(flags & LOOKUP_NO_RVAL_BIND)) 1514 || TYPE_REF_IS_RVALUE (rto)) 1515 && (gl_kind 1516 || (!(flags & LOOKUP_NO_TEMP_BIND) 1517 && (CLASS_TYPE_P (from) 1518 || TREE_CODE (from) == ARRAY_TYPE)))))) 1519 { 1520 /* [dcl.init.ref] 1521 1522 If the initializer expression 1523 1524 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1" 1525 is reference-compatible with "cv2 T2," 1526 1527 the reference is bound directly to the initializer expression 1528 lvalue. 1529 1530 [...] 1531 If the initializer expression is an rvalue, with T2 a class type, 1532 and "cv1 T1" is reference-compatible with "cv2 T2", the reference 1533 is bound to the object represented by the rvalue or to a sub-object 1534 within that object. */ 1535 1536 conv = build_identity_conv (tfrom, expr); 1537 conv = direct_reference_binding (rto, conv); 1538 1539 if (flags & LOOKUP_PREFER_RVALUE) 1540 /* The top-level caller requested that we pretend that the lvalue 1541 be treated as an rvalue. */ 1542 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1543 else if (TREE_CODE (rfrom) == REFERENCE_TYPE) 1544 /* Handle rvalue reference to function properly. */ 1545 conv->rvaluedness_matches_p 1546 = (TYPE_REF_IS_RVALUE (rto) == TYPE_REF_IS_RVALUE (rfrom)); 1547 else 1548 conv->rvaluedness_matches_p 1549 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue); 1550 1551 if ((gl_kind & clk_bitfield) != 0 1552 || ((gl_kind & clk_packed) != 0 && !TYPE_PACKED (to))) 1553 /* For the purposes of overload resolution, we ignore the fact 1554 this expression is a bitfield or packed field. (In particular, 1555 [over.ics.ref] says specifically that a function with a 1556 non-const reference parameter is viable even if the 1557 argument is a bitfield.) 1558 1559 However, when we actually call the function we must create 1560 a temporary to which to bind the reference. If the 1561 reference is volatile, or isn't const, then we cannot make 1562 a temporary, so we just issue an error when the conversion 1563 actually occurs. */ 1564 conv->need_temporary_p = true; 1565 1566 /* Don't allow binding of lvalues (other than function lvalues) to 1567 rvalue references. */ 1568 if (is_lvalue && TYPE_REF_IS_RVALUE (rto) 1569 && TREE_CODE (to) != FUNCTION_TYPE 1570 && !(flags & LOOKUP_PREFER_RVALUE)) 1571 conv->bad_p = true; 1572 1573 return conv; 1574 } 1575 /* [class.conv.fct] A conversion function is never used to convert a 1576 (possibly cv-qualified) object to the (possibly cv-qualified) same 1577 object type (or a reference to it), to a (possibly cv-qualified) base 1578 class of that type (or a reference to it).... */ 1579 else if (CLASS_TYPE_P (from) && !related_p 1580 && !(flags & LOOKUP_NO_CONVERSION)) 1581 { 1582 /* [dcl.init.ref] 1583 1584 If the initializer expression 1585 1586 -- has a class type (i.e., T2 is a class type) can be 1587 implicitly converted to an lvalue of type "cv3 T3," where 1588 "cv1 T1" is reference-compatible with "cv3 T3". (this 1589 conversion is selected by enumerating the applicable 1590 conversion functions (_over.match.ref_) and choosing the 1591 best one through overload resolution. (_over.match_). 1592 1593 the reference is bound to the lvalue result of the conversion 1594 in the second case. */ 1595 z_candidate *cand = build_user_type_conversion_1 (rto, expr, flags); 1596 if (cand) 1597 return cand->second_conv; 1598 } 1599 1600 /* From this point on, we conceptually need temporaries, even if we 1601 elide them. Only the cases above are "direct bindings". */ 1602 if (flags & LOOKUP_NO_TEMP_BIND) 1603 return NULL; 1604 1605 /* [over.ics.rank] 1606 1607 When a parameter of reference type is not bound directly to an 1608 argument expression, the conversion sequence is the one required 1609 to convert the argument expression to the underlying type of the 1610 reference according to _over.best.ics_. Conceptually, this 1611 conversion sequence corresponds to copy-initializing a temporary 1612 of the underlying type with the argument expression. Any 1613 difference in top-level cv-qualification is subsumed by the 1614 initialization itself and does not constitute a conversion. */ 1615 1616 /* [dcl.init.ref] 1617 1618 Otherwise, the reference shall be to a non-volatile const type. 1619 1620 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */ 1621 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto)) 1622 return NULL; 1623 1624 /* [dcl.init.ref] 1625 1626 Otherwise, a temporary of type "cv1 T1" is created and 1627 initialized from the initializer expression using the rules for a 1628 non-reference copy initialization. If T1 is reference-related to 1629 T2, cv1 must be the same cv-qualification as, or greater 1630 cv-qualification than, cv2; otherwise, the program is ill-formed. */ 1631 if (related_p && !at_least_as_qualified_p (to, from)) 1632 return NULL; 1633 1634 /* We're generating a temporary now, but don't bind any more in the 1635 conversion (specifically, don't slice the temporary returned by a 1636 conversion operator). */ 1637 flags |= LOOKUP_NO_TEMP_BIND; 1638 1639 /* Core issue 899: When [copy-]initializing a temporary to be bound 1640 to the first parameter of a copy constructor (12.8) called with 1641 a single argument in the context of direct-initialization, 1642 explicit conversion functions are also considered. 1643 1644 So don't set LOOKUP_ONLYCONVERTING in that case. */ 1645 if (!(flags & LOOKUP_COPY_PARM)) 1646 flags |= LOOKUP_ONLYCONVERTING; 1647 1648 if (!conv) 1649 conv = implicit_conversion (to, from, expr, c_cast_p, 1650 flags); 1651 if (!conv) 1652 return NULL; 1653 1654 conv = build_conv (ck_ref_bind, rto, conv); 1655 /* This reference binding, unlike those above, requires the 1656 creation of a temporary. */ 1657 conv->need_temporary_p = true; 1658 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1659 1660 return conv; 1661 } 1662 1663 /* Returns the implicit conversion sequence (see [over.ics]) from type 1664 FROM to type TO. The optional expression EXPR may affect the 1665 conversion. FLAGS are the usual overloading flags. If C_CAST_P is 1666 true, this conversion is coming from a C-style cast. */ 1667 1668 static conversion * 1669 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p, 1670 int flags) 1671 { 1672 conversion *conv; 1673 1674 if (from == error_mark_node || to == error_mark_node 1675 || expr == error_mark_node) 1676 return NULL; 1677 1678 /* Other flags only apply to the primary function in overload 1679 resolution, or after we've chosen one. */ 1680 flags &= (LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION|LOOKUP_COPY_PARM 1681 |LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND|LOOKUP_PREFER_RVALUE 1682 |LOOKUP_NO_NARROWING|LOOKUP_PROTECT); 1683 1684 if (TREE_CODE (to) == REFERENCE_TYPE) 1685 conv = reference_binding (to, from, expr, c_cast_p, flags); 1686 else 1687 conv = standard_conversion (to, from, expr, c_cast_p, flags); 1688 1689 if (conv) 1690 return conv; 1691 1692 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1693 { 1694 if (is_std_init_list (to)) 1695 return build_list_conv (to, expr, flags); 1696 1697 /* As an extension, allow list-initialization of _Complex. */ 1698 if (TREE_CODE (to) == COMPLEX_TYPE) 1699 { 1700 conv = build_complex_conv (to, expr, flags); 1701 if (conv) 1702 return conv; 1703 } 1704 1705 /* Allow conversion from an initializer-list with one element to a 1706 scalar type. */ 1707 if (SCALAR_TYPE_P (to)) 1708 { 1709 int nelts = CONSTRUCTOR_NELTS (expr); 1710 tree elt; 1711 1712 if (nelts == 0) 1713 elt = build_value_init (to, tf_none); 1714 else if (nelts == 1) 1715 elt = CONSTRUCTOR_ELT (expr, 0)->value; 1716 else 1717 elt = error_mark_node; 1718 1719 conv = implicit_conversion (to, TREE_TYPE (elt), elt, 1720 c_cast_p, flags); 1721 if (conv) 1722 { 1723 conv->check_narrowing = true; 1724 if (BRACE_ENCLOSED_INITIALIZER_P (elt)) 1725 /* Too many levels of braces, i.e. '{{1}}'. */ 1726 conv->bad_p = true; 1727 return conv; 1728 } 1729 } 1730 else if (TREE_CODE (to) == ARRAY_TYPE) 1731 return build_array_conv (to, expr, flags); 1732 } 1733 1734 if (expr != NULL_TREE 1735 && (MAYBE_CLASS_TYPE_P (from) 1736 || MAYBE_CLASS_TYPE_P (to)) 1737 && (flags & LOOKUP_NO_CONVERSION) == 0) 1738 { 1739 struct z_candidate *cand; 1740 1741 if (CLASS_TYPE_P (to) 1742 && BRACE_ENCLOSED_INITIALIZER_P (expr) 1743 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))) 1744 return build_aggr_conv (to, expr, flags); 1745 1746 cand = build_user_type_conversion_1 (to, expr, flags); 1747 if (cand) 1748 conv = cand->second_conv; 1749 1750 /* We used to try to bind a reference to a temporary here, but that 1751 is now handled after the recursive call to this function at the end 1752 of reference_binding. */ 1753 return conv; 1754 } 1755 1756 return NULL; 1757 } 1758 1759 /* Add a new entry to the list of candidates. Used by the add_*_candidate 1760 functions. ARGS will not be changed until a single candidate is 1761 selected. */ 1762 1763 static struct z_candidate * 1764 add_candidate (struct z_candidate **candidates, 1765 tree fn, tree first_arg, const VEC(tree,gc) *args, 1766 size_t num_convs, conversion **convs, 1767 tree access_path, tree conversion_path, 1768 int viable, struct rejection_reason *reason) 1769 { 1770 struct z_candidate *cand = (struct z_candidate *) 1771 conversion_obstack_alloc (sizeof (struct z_candidate)); 1772 1773 cand->fn = fn; 1774 cand->first_arg = first_arg; 1775 cand->args = args; 1776 cand->convs = convs; 1777 cand->num_convs = num_convs; 1778 cand->access_path = access_path; 1779 cand->conversion_path = conversion_path; 1780 cand->viable = viable; 1781 cand->reason = reason; 1782 cand->next = *candidates; 1783 *candidates = cand; 1784 1785 return cand; 1786 } 1787 1788 /* Return the number of remaining arguments in the parameter list 1789 beginning with ARG. */ 1790 1791 static int 1792 remaining_arguments (tree arg) 1793 { 1794 int n; 1795 1796 for (n = 0; arg != NULL_TREE && arg != void_list_node; 1797 arg = TREE_CHAIN (arg)) 1798 n++; 1799 1800 return n; 1801 } 1802 1803 /* Create an overload candidate for the function or method FN called 1804 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES. 1805 FLAGS is passed on to implicit_conversion. 1806 1807 This does not change ARGS. 1808 1809 CTYPE, if non-NULL, is the type we want to pretend this function 1810 comes from for purposes of overload resolution. */ 1811 1812 static struct z_candidate * 1813 add_function_candidate (struct z_candidate **candidates, 1814 tree fn, tree ctype, tree first_arg, 1815 const VEC(tree,gc) *args, tree access_path, 1816 tree conversion_path, int flags) 1817 { 1818 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn)); 1819 int i, len; 1820 conversion **convs; 1821 tree parmnode; 1822 tree orig_first_arg = first_arg; 1823 int skip; 1824 int viable = 1; 1825 struct rejection_reason *reason = NULL; 1826 1827 /* At this point we should not see any functions which haven't been 1828 explicitly declared, except for friend functions which will have 1829 been found using argument dependent lookup. */ 1830 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn)); 1831 1832 /* The `this', `in_chrg' and VTT arguments to constructors are not 1833 considered in overload resolution. */ 1834 if (DECL_CONSTRUCTOR_P (fn)) 1835 { 1836 parmlist = skip_artificial_parms_for (fn, parmlist); 1837 skip = num_artificial_parms_for (fn); 1838 if (skip > 0 && first_arg != NULL_TREE) 1839 { 1840 --skip; 1841 first_arg = NULL_TREE; 1842 } 1843 } 1844 else 1845 skip = 0; 1846 1847 len = VEC_length (tree, args) - skip + (first_arg != NULL_TREE ? 1 : 0); 1848 convs = alloc_conversions (len); 1849 1850 /* 13.3.2 - Viable functions [over.match.viable] 1851 First, to be a viable function, a candidate function shall have enough 1852 parameters to agree in number with the arguments in the list. 1853 1854 We need to check this first; otherwise, checking the ICSes might cause 1855 us to produce an ill-formed template instantiation. */ 1856 1857 parmnode = parmlist; 1858 for (i = 0; i < len; ++i) 1859 { 1860 if (parmnode == NULL_TREE || parmnode == void_list_node) 1861 break; 1862 parmnode = TREE_CHAIN (parmnode); 1863 } 1864 1865 if ((i < len && parmnode) 1866 || !sufficient_parms_p (parmnode)) 1867 { 1868 int remaining = remaining_arguments (parmnode); 1869 viable = 0; 1870 reason = arity_rejection (first_arg, i + remaining, len); 1871 } 1872 /* When looking for a function from a subobject from an implicit 1873 copy/move constructor/operator=, don't consider anything that takes (a 1874 reference to) an unrelated type. See c++/44909 and core 1092. */ 1875 else if (parmlist && (flags & LOOKUP_DEFAULTED)) 1876 { 1877 if (DECL_CONSTRUCTOR_P (fn)) 1878 i = 1; 1879 else if (DECL_ASSIGNMENT_OPERATOR_P (fn) 1880 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR) 1881 i = 2; 1882 else 1883 i = 0; 1884 if (i && len == i) 1885 { 1886 parmnode = chain_index (i-1, parmlist); 1887 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)), 1888 ctype)) 1889 viable = 0; 1890 } 1891 1892 /* This only applies at the top level. */ 1893 flags &= ~LOOKUP_DEFAULTED; 1894 } 1895 1896 if (! viable) 1897 goto out; 1898 1899 /* Second, for F to be a viable function, there shall exist for each 1900 argument an implicit conversion sequence that converts that argument 1901 to the corresponding parameter of F. */ 1902 1903 parmnode = parmlist; 1904 1905 for (i = 0; i < len; ++i) 1906 { 1907 tree arg, argtype, to_type; 1908 conversion *t; 1909 int is_this; 1910 1911 if (parmnode == void_list_node) 1912 break; 1913 1914 if (i == 0 && first_arg != NULL_TREE) 1915 arg = first_arg; 1916 else 1917 arg = VEC_index (tree, args, 1918 i + skip - (first_arg != NULL_TREE ? 1 : 0)); 1919 argtype = lvalue_type (arg); 1920 1921 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 1922 && ! DECL_CONSTRUCTOR_P (fn)); 1923 1924 if (parmnode) 1925 { 1926 tree parmtype = TREE_VALUE (parmnode); 1927 int lflags = flags; 1928 1929 parmnode = TREE_CHAIN (parmnode); 1930 1931 /* The type of the implicit object parameter ('this') for 1932 overload resolution is not always the same as for the 1933 function itself; conversion functions are considered to 1934 be members of the class being converted, and functions 1935 introduced by a using-declaration are considered to be 1936 members of the class that uses them. 1937 1938 Since build_over_call ignores the ICS for the `this' 1939 parameter, we can just change the parm type. */ 1940 if (ctype && is_this) 1941 { 1942 parmtype = cp_build_qualified_type 1943 (ctype, cp_type_quals (TREE_TYPE (parmtype))); 1944 parmtype = build_pointer_type (parmtype); 1945 } 1946 1947 /* Core issue 899: When [copy-]initializing a temporary to be bound 1948 to the first parameter of a copy constructor (12.8) called with 1949 a single argument in the context of direct-initialization, 1950 explicit conversion functions are also considered. 1951 1952 So set LOOKUP_COPY_PARM to let reference_binding know that 1953 it's being called in that context. We generalize the above 1954 to handle move constructors and template constructors as well; 1955 the standardese should soon be updated similarly. */ 1956 if (ctype && i == 0 && (len-skip == 1) 1957 && DECL_CONSTRUCTOR_P (fn) 1958 && parmtype != error_mark_node 1959 && (same_type_ignoring_top_level_qualifiers_p 1960 (non_reference (parmtype), ctype))) 1961 { 1962 if (!(flags & LOOKUP_ONLYCONVERTING)) 1963 lflags |= LOOKUP_COPY_PARM; 1964 /* We allow user-defined conversions within init-lists, but 1965 don't list-initialize the copy parm, as that would mean 1966 using two levels of braces for the same type. */ 1967 if ((flags & LOOKUP_LIST_INIT_CTOR) 1968 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 1969 lflags |= LOOKUP_NO_CONVERSION; 1970 } 1971 else 1972 lflags |= LOOKUP_ONLYCONVERTING; 1973 1974 t = implicit_conversion (parmtype, argtype, arg, 1975 /*c_cast_p=*/false, lflags); 1976 to_type = parmtype; 1977 } 1978 else 1979 { 1980 t = build_identity_conv (argtype, arg); 1981 t->ellipsis_p = true; 1982 to_type = argtype; 1983 } 1984 1985 if (t && is_this) 1986 t->this_p = true; 1987 1988 convs[i] = t; 1989 if (! t) 1990 { 1991 viable = 0; 1992 reason = arg_conversion_rejection (first_arg, i, argtype, to_type); 1993 break; 1994 } 1995 1996 if (t->bad_p) 1997 { 1998 viable = -1; 1999 reason = bad_arg_conversion_rejection (first_arg, i, argtype, to_type); 2000 } 2001 } 2002 2003 out: 2004 return add_candidate (candidates, fn, orig_first_arg, args, len, convs, 2005 access_path, conversion_path, viable, reason); 2006 } 2007 2008 /* Create an overload candidate for the conversion function FN which will 2009 be invoked for expression OBJ, producing a pointer-to-function which 2010 will in turn be called with the argument list FIRST_ARG/ARGLIST, 2011 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is 2012 passed on to implicit_conversion. 2013 2014 Actually, we don't really care about FN; we care about the type it 2015 converts to. There may be multiple conversion functions that will 2016 convert to that type, and we rely on build_user_type_conversion_1 to 2017 choose the best one; so when we create our candidate, we record the type 2018 instead of the function. */ 2019 2020 static struct z_candidate * 2021 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj, 2022 tree first_arg, const VEC(tree,gc) *arglist, 2023 tree access_path, tree conversion_path) 2024 { 2025 tree totype = TREE_TYPE (TREE_TYPE (fn)); 2026 int i, len, viable, flags; 2027 tree parmlist, parmnode; 2028 conversion **convs; 2029 struct rejection_reason *reason; 2030 2031 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; ) 2032 parmlist = TREE_TYPE (parmlist); 2033 parmlist = TYPE_ARG_TYPES (parmlist); 2034 2035 len = VEC_length (tree, arglist) + (first_arg != NULL_TREE ? 1 : 0) + 1; 2036 convs = alloc_conversions (len); 2037 parmnode = parmlist; 2038 viable = 1; 2039 flags = LOOKUP_IMPLICIT; 2040 reason = NULL; 2041 2042 /* Don't bother looking up the same type twice. */ 2043 if (*candidates && (*candidates)->fn == totype) 2044 return NULL; 2045 2046 for (i = 0; i < len; ++i) 2047 { 2048 tree arg, argtype, convert_type = NULL_TREE; 2049 conversion *t; 2050 2051 if (i == 0) 2052 arg = obj; 2053 else if (i == 1 && first_arg != NULL_TREE) 2054 arg = first_arg; 2055 else 2056 arg = VEC_index (tree, arglist, 2057 i - (first_arg != NULL_TREE ? 1 : 0) - 1); 2058 argtype = lvalue_type (arg); 2059 2060 if (i == 0) 2061 { 2062 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false, 2063 flags); 2064 convert_type = totype; 2065 } 2066 else if (parmnode == void_list_node) 2067 break; 2068 else if (parmnode) 2069 { 2070 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg, 2071 /*c_cast_p=*/false, flags); 2072 convert_type = TREE_VALUE (parmnode); 2073 } 2074 else 2075 { 2076 t = build_identity_conv (argtype, arg); 2077 t->ellipsis_p = true; 2078 convert_type = argtype; 2079 } 2080 2081 convs[i] = t; 2082 if (! t) 2083 break; 2084 2085 if (t->bad_p) 2086 { 2087 viable = -1; 2088 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtype, convert_type); 2089 } 2090 2091 if (i == 0) 2092 continue; 2093 2094 if (parmnode) 2095 parmnode = TREE_CHAIN (parmnode); 2096 } 2097 2098 if (i < len 2099 || ! sufficient_parms_p (parmnode)) 2100 { 2101 int remaining = remaining_arguments (parmnode); 2102 viable = 0; 2103 reason = arity_rejection (NULL_TREE, i + remaining, len); 2104 } 2105 2106 return add_candidate (candidates, totype, first_arg, arglist, len, convs, 2107 access_path, conversion_path, viable, reason); 2108 } 2109 2110 static void 2111 build_builtin_candidate (struct z_candidate **candidates, tree fnname, 2112 tree type1, tree type2, tree *args, tree *argtypes, 2113 int flags) 2114 { 2115 conversion *t; 2116 conversion **convs; 2117 size_t num_convs; 2118 int viable = 1, i; 2119 tree types[2]; 2120 struct rejection_reason *reason = NULL; 2121 2122 types[0] = type1; 2123 types[1] = type2; 2124 2125 num_convs = args[2] ? 3 : (args[1] ? 2 : 1); 2126 convs = alloc_conversions (num_convs); 2127 2128 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit 2129 conversion ops are allowed. We handle that here by just checking for 2130 boolean_type_node because other operators don't ask for it. COND_EXPR 2131 also does contextual conversion to bool for the first operand, but we 2132 handle that in build_conditional_expr, and type1 here is operand 2. */ 2133 if (type1 != boolean_type_node) 2134 flags |= LOOKUP_ONLYCONVERTING; 2135 2136 for (i = 0; i < 2; ++i) 2137 { 2138 if (! args[i]) 2139 break; 2140 2141 t = implicit_conversion (types[i], argtypes[i], args[i], 2142 /*c_cast_p=*/false, flags); 2143 if (! t) 2144 { 2145 viable = 0; 2146 /* We need something for printing the candidate. */ 2147 t = build_identity_conv (types[i], NULL_TREE); 2148 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]); 2149 } 2150 else if (t->bad_p) 2151 { 2152 viable = 0; 2153 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]); 2154 } 2155 convs[i] = t; 2156 } 2157 2158 /* For COND_EXPR we rearranged the arguments; undo that now. */ 2159 if (args[2]) 2160 { 2161 convs[2] = convs[1]; 2162 convs[1] = convs[0]; 2163 t = implicit_conversion (boolean_type_node, argtypes[2], args[2], 2164 /*c_cast_p=*/false, flags); 2165 if (t) 2166 convs[0] = t; 2167 else 2168 { 2169 viable = 0; 2170 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2], 2171 boolean_type_node); 2172 } 2173 } 2174 2175 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL, 2176 num_convs, convs, 2177 /*access_path=*/NULL_TREE, 2178 /*conversion_path=*/NULL_TREE, 2179 viable, reason); 2180 } 2181 2182 static bool 2183 is_complete (tree t) 2184 { 2185 return COMPLETE_TYPE_P (complete_type (t)); 2186 } 2187 2188 /* Returns nonzero if TYPE is a promoted arithmetic type. */ 2189 2190 static bool 2191 promoted_arithmetic_type_p (tree type) 2192 { 2193 /* [over.built] 2194 2195 In this section, the term promoted integral type is used to refer 2196 to those integral types which are preserved by integral promotion 2197 (including e.g. int and long but excluding e.g. char). 2198 Similarly, the term promoted arithmetic type refers to promoted 2199 integral types plus floating types. */ 2200 return ((CP_INTEGRAL_TYPE_P (type) 2201 && same_type_p (type_promotes_to (type), type)) 2202 || TREE_CODE (type) == REAL_TYPE); 2203 } 2204 2205 /* Create any builtin operator overload candidates for the operator in 2206 question given the converted operand types TYPE1 and TYPE2. The other 2207 args are passed through from add_builtin_candidates to 2208 build_builtin_candidate. 2209 2210 TYPE1 and TYPE2 may not be permissible, and we must filter them. 2211 If CODE is requires candidates operands of the same type of the kind 2212 of which TYPE1 and TYPE2 are, we add both candidates 2213 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */ 2214 2215 static void 2216 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code, 2217 enum tree_code code2, tree fnname, tree type1, 2218 tree type2, tree *args, tree *argtypes, int flags) 2219 { 2220 switch (code) 2221 { 2222 case POSTINCREMENT_EXPR: 2223 case POSTDECREMENT_EXPR: 2224 args[1] = integer_zero_node; 2225 type2 = integer_type_node; 2226 break; 2227 default: 2228 break; 2229 } 2230 2231 switch (code) 2232 { 2233 2234 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2235 and VQ is either volatile or empty, there exist candidate operator 2236 functions of the form 2237 VQ T& operator++(VQ T&); 2238 T operator++(VQ T&, int); 2239 5 For every pair T, VQ), where T is an enumeration type or an arithmetic 2240 type other than bool, and VQ is either volatile or empty, there exist 2241 candidate operator functions of the form 2242 VQ T& operator--(VQ T&); 2243 T operator--(VQ T&, int); 2244 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified 2245 complete object type, and VQ is either volatile or empty, there exist 2246 candidate operator functions of the form 2247 T*VQ& operator++(T*VQ&); 2248 T*VQ& operator--(T*VQ&); 2249 T* operator++(T*VQ&, int); 2250 T* operator--(T*VQ&, int); */ 2251 2252 case POSTDECREMENT_EXPR: 2253 case PREDECREMENT_EXPR: 2254 if (TREE_CODE (type1) == BOOLEAN_TYPE) 2255 return; 2256 case POSTINCREMENT_EXPR: 2257 case PREINCREMENT_EXPR: 2258 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1)) 2259 { 2260 type1 = build_reference_type (type1); 2261 break; 2262 } 2263 return; 2264 2265 /* 7 For every cv-qualified or cv-unqualified object type T, there 2266 exist candidate operator functions of the form 2267 2268 T& operator*(T*); 2269 2270 8 For every function type T, there exist candidate operator functions of 2271 the form 2272 T& operator*(T*); */ 2273 2274 case INDIRECT_REF: 2275 if (TREE_CODE (type1) == POINTER_TYPE 2276 && !uses_template_parms (TREE_TYPE (type1)) 2277 && (TYPE_PTROB_P (type1) 2278 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)) 2279 break; 2280 return; 2281 2282 /* 9 For every type T, there exist candidate operator functions of the form 2283 T* operator+(T*); 2284 2285 10For every promoted arithmetic type T, there exist candidate operator 2286 functions of the form 2287 T operator+(T); 2288 T operator-(T); */ 2289 2290 case UNARY_PLUS_EXPR: /* unary + */ 2291 if (TREE_CODE (type1) == POINTER_TYPE) 2292 break; 2293 case NEGATE_EXPR: 2294 if (ARITHMETIC_TYPE_P (type1)) 2295 break; 2296 return; 2297 2298 /* 11For every promoted integral type T, there exist candidate operator 2299 functions of the form 2300 T operator~(T); */ 2301 2302 case BIT_NOT_EXPR: 2303 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1)) 2304 break; 2305 return; 2306 2307 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1 2308 is the same type as C2 or is a derived class of C2, T is a complete 2309 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 2310 there exist candidate operator functions of the form 2311 CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 2312 where CV12 is the union of CV1 and CV2. */ 2313 2314 case MEMBER_REF: 2315 if (TREE_CODE (type1) == POINTER_TYPE 2316 && TYPE_PTR_TO_MEMBER_P (type2)) 2317 { 2318 tree c1 = TREE_TYPE (type1); 2319 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2); 2320 2321 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1) 2322 && (TYPE_PTRMEMFUNC_P (type2) 2323 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2)))) 2324 break; 2325 } 2326 return; 2327 2328 /* 13For every pair of promoted arithmetic types L and R, there exist can- 2329 didate operator functions of the form 2330 LR operator*(L, R); 2331 LR operator/(L, R); 2332 LR operator+(L, R); 2333 LR operator-(L, R); 2334 bool operator<(L, R); 2335 bool operator>(L, R); 2336 bool operator<=(L, R); 2337 bool operator>=(L, R); 2338 bool operator==(L, R); 2339 bool operator!=(L, R); 2340 where LR is the result of the usual arithmetic conversions between 2341 types L and R. 2342 2343 14For every pair of types T and I, where T is a cv-qualified or cv- 2344 unqualified complete object type and I is a promoted integral type, 2345 there exist candidate operator functions of the form 2346 T* operator+(T*, I); 2347 T& operator[](T*, I); 2348 T* operator-(T*, I); 2349 T* operator+(I, T*); 2350 T& operator[](I, T*); 2351 2352 15For every T, where T is a pointer to complete object type, there exist 2353 candidate operator functions of the form112) 2354 ptrdiff_t operator-(T, T); 2355 2356 16For every pointer or enumeration type T, there exist candidate operator 2357 functions of the form 2358 bool operator<(T, T); 2359 bool operator>(T, T); 2360 bool operator<=(T, T); 2361 bool operator>=(T, T); 2362 bool operator==(T, T); 2363 bool operator!=(T, T); 2364 2365 17For every pointer to member type T, there exist candidate operator 2366 functions of the form 2367 bool operator==(T, T); 2368 bool operator!=(T, T); */ 2369 2370 case MINUS_EXPR: 2371 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2)) 2372 break; 2373 if (TYPE_PTROB_P (type1) 2374 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2375 { 2376 type2 = ptrdiff_type_node; 2377 break; 2378 } 2379 case MULT_EXPR: 2380 case TRUNC_DIV_EXPR: 2381 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2382 break; 2383 return; 2384 2385 case EQ_EXPR: 2386 case NE_EXPR: 2387 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2388 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))) 2389 break; 2390 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1])) 2391 { 2392 type2 = type1; 2393 break; 2394 } 2395 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0])) 2396 { 2397 type1 = type2; 2398 break; 2399 } 2400 /* Fall through. */ 2401 case LT_EXPR: 2402 case GT_EXPR: 2403 case LE_EXPR: 2404 case GE_EXPR: 2405 case MAX_EXPR: 2406 case MIN_EXPR: 2407 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2408 break; 2409 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2410 break; 2411 if (TREE_CODE (type1) == ENUMERAL_TYPE 2412 && TREE_CODE (type2) == ENUMERAL_TYPE) 2413 break; 2414 if (TYPE_PTR_P (type1) 2415 && null_ptr_cst_p (args[1]) 2416 && !uses_template_parms (type1)) 2417 { 2418 type2 = type1; 2419 break; 2420 } 2421 if (null_ptr_cst_p (args[0]) 2422 && TYPE_PTR_P (type2) 2423 && !uses_template_parms (type2)) 2424 { 2425 type1 = type2; 2426 break; 2427 } 2428 return; 2429 2430 case PLUS_EXPR: 2431 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2432 break; 2433 case ARRAY_REF: 2434 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2)) 2435 { 2436 type1 = ptrdiff_type_node; 2437 break; 2438 } 2439 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2440 { 2441 type2 = ptrdiff_type_node; 2442 break; 2443 } 2444 return; 2445 2446 /* 18For every pair of promoted integral types L and R, there exist candi- 2447 date operator functions of the form 2448 LR operator%(L, R); 2449 LR operator&(L, R); 2450 LR operator^(L, R); 2451 LR operator|(L, R); 2452 L operator<<(L, R); 2453 L operator>>(L, R); 2454 where LR is the result of the usual arithmetic conversions between 2455 types L and R. */ 2456 2457 case TRUNC_MOD_EXPR: 2458 case BIT_AND_EXPR: 2459 case BIT_IOR_EXPR: 2460 case BIT_XOR_EXPR: 2461 case LSHIFT_EXPR: 2462 case RSHIFT_EXPR: 2463 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2464 break; 2465 return; 2466 2467 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration 2468 type, VQ is either volatile or empty, and R is a promoted arithmetic 2469 type, there exist candidate operator functions of the form 2470 VQ L& operator=(VQ L&, R); 2471 VQ L& operator*=(VQ L&, R); 2472 VQ L& operator/=(VQ L&, R); 2473 VQ L& operator+=(VQ L&, R); 2474 VQ L& operator-=(VQ L&, R); 2475 2476 20For every pair T, VQ), where T is any type and VQ is either volatile 2477 or empty, there exist candidate operator functions of the form 2478 T*VQ& operator=(T*VQ&, T*); 2479 2480 21For every pair T, VQ), where T is a pointer to member type and VQ is 2481 either volatile or empty, there exist candidate operator functions of 2482 the form 2483 VQ T& operator=(VQ T&, T); 2484 2485 22For every triple T, VQ, I), where T is a cv-qualified or cv- 2486 unqualified complete object type, VQ is either volatile or empty, and 2487 I is a promoted integral type, there exist candidate operator func- 2488 tions of the form 2489 T*VQ& operator+=(T*VQ&, I); 2490 T*VQ& operator-=(T*VQ&, I); 2491 2492 23For every triple L, VQ, R), where L is an integral or enumeration 2493 type, VQ is either volatile or empty, and R is a promoted integral 2494 type, there exist candidate operator functions of the form 2495 2496 VQ L& operator%=(VQ L&, R); 2497 VQ L& operator<<=(VQ L&, R); 2498 VQ L& operator>>=(VQ L&, R); 2499 VQ L& operator&=(VQ L&, R); 2500 VQ L& operator^=(VQ L&, R); 2501 VQ L& operator|=(VQ L&, R); */ 2502 2503 case MODIFY_EXPR: 2504 switch (code2) 2505 { 2506 case PLUS_EXPR: 2507 case MINUS_EXPR: 2508 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2509 { 2510 type2 = ptrdiff_type_node; 2511 break; 2512 } 2513 case MULT_EXPR: 2514 case TRUNC_DIV_EXPR: 2515 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2516 break; 2517 return; 2518 2519 case TRUNC_MOD_EXPR: 2520 case BIT_AND_EXPR: 2521 case BIT_IOR_EXPR: 2522 case BIT_XOR_EXPR: 2523 case LSHIFT_EXPR: 2524 case RSHIFT_EXPR: 2525 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2526 break; 2527 return; 2528 2529 case NOP_EXPR: 2530 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2531 break; 2532 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2533 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2534 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)) 2535 || ((TYPE_PTRMEMFUNC_P (type1) 2536 || TREE_CODE (type1) == POINTER_TYPE) 2537 && null_ptr_cst_p (args[1]))) 2538 { 2539 type2 = type1; 2540 break; 2541 } 2542 return; 2543 2544 default: 2545 gcc_unreachable (); 2546 } 2547 type1 = build_reference_type (type1); 2548 break; 2549 2550 case COND_EXPR: 2551 /* [over.built] 2552 2553 For every pair of promoted arithmetic types L and R, there 2554 exist candidate operator functions of the form 2555 2556 LR operator?(bool, L, R); 2557 2558 where LR is the result of the usual arithmetic conversions 2559 between types L and R. 2560 2561 For every type T, where T is a pointer or pointer-to-member 2562 type, there exist candidate operator functions of the form T 2563 operator?(bool, T, T); */ 2564 2565 if (promoted_arithmetic_type_p (type1) 2566 && promoted_arithmetic_type_p (type2)) 2567 /* That's OK. */ 2568 break; 2569 2570 /* Otherwise, the types should be pointers. */ 2571 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1)) 2572 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2))) 2573 return; 2574 2575 /* We don't check that the two types are the same; the logic 2576 below will actually create two candidates; one in which both 2577 parameter types are TYPE1, and one in which both parameter 2578 types are TYPE2. */ 2579 break; 2580 2581 case REALPART_EXPR: 2582 case IMAGPART_EXPR: 2583 if (ARITHMETIC_TYPE_P (type1)) 2584 break; 2585 return; 2586 2587 default: 2588 gcc_unreachable (); 2589 } 2590 2591 /* If we're dealing with two pointer types or two enumeral types, 2592 we need candidates for both of them. */ 2593 if (type2 && !same_type_p (type1, type2) 2594 && TREE_CODE (type1) == TREE_CODE (type2) 2595 && (TREE_CODE (type1) == REFERENCE_TYPE 2596 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2597 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)) 2598 || TYPE_PTRMEMFUNC_P (type1) 2599 || MAYBE_CLASS_TYPE_P (type1) 2600 || TREE_CODE (type1) == ENUMERAL_TYPE)) 2601 { 2602 if (TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1)) 2603 { 2604 tree cptype = composite_pointer_type (type1, type2, 2605 error_mark_node, 2606 error_mark_node, 2607 CPO_CONVERSION, 2608 tf_none); 2609 if (cptype != error_mark_node) 2610 { 2611 build_builtin_candidate 2612 (candidates, fnname, cptype, cptype, args, argtypes, flags); 2613 return; 2614 } 2615 } 2616 2617 build_builtin_candidate 2618 (candidates, fnname, type1, type1, args, argtypes, flags); 2619 build_builtin_candidate 2620 (candidates, fnname, type2, type2, args, argtypes, flags); 2621 return; 2622 } 2623 2624 build_builtin_candidate 2625 (candidates, fnname, type1, type2, args, argtypes, flags); 2626 } 2627 2628 tree 2629 type_decays_to (tree type) 2630 { 2631 if (TREE_CODE (type) == ARRAY_TYPE) 2632 return build_pointer_type (TREE_TYPE (type)); 2633 if (TREE_CODE (type) == FUNCTION_TYPE) 2634 return build_pointer_type (type); 2635 return type; 2636 } 2637 2638 /* There are three conditions of builtin candidates: 2639 2640 1) bool-taking candidates. These are the same regardless of the input. 2641 2) pointer-pair taking candidates. These are generated for each type 2642 one of the input types converts to. 2643 3) arithmetic candidates. According to the standard, we should generate 2644 all of these, but I'm trying not to... 2645 2646 Here we generate a superset of the possible candidates for this particular 2647 case. That is a subset of the full set the standard defines, plus some 2648 other cases which the standard disallows. add_builtin_candidate will 2649 filter out the invalid set. */ 2650 2651 static void 2652 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code, 2653 enum tree_code code2, tree fnname, tree *args, 2654 int flags) 2655 { 2656 int ref1, i; 2657 int enum_p = 0; 2658 tree type, argtypes[3], t; 2659 /* TYPES[i] is the set of possible builtin-operator parameter types 2660 we will consider for the Ith argument. */ 2661 VEC(tree,gc) *types[2]; 2662 unsigned ix; 2663 2664 for (i = 0; i < 3; ++i) 2665 { 2666 if (args[i]) 2667 argtypes[i] = unlowered_expr_type (args[i]); 2668 else 2669 argtypes[i] = NULL_TREE; 2670 } 2671 2672 switch (code) 2673 { 2674 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2675 and VQ is either volatile or empty, there exist candidate operator 2676 functions of the form 2677 VQ T& operator++(VQ T&); */ 2678 2679 case POSTINCREMENT_EXPR: 2680 case PREINCREMENT_EXPR: 2681 case POSTDECREMENT_EXPR: 2682 case PREDECREMENT_EXPR: 2683 case MODIFY_EXPR: 2684 ref1 = 1; 2685 break; 2686 2687 /* 24There also exist candidate operator functions of the form 2688 bool operator!(bool); 2689 bool operator&&(bool, bool); 2690 bool operator||(bool, bool); */ 2691 2692 case TRUTH_NOT_EXPR: 2693 build_builtin_candidate 2694 (candidates, fnname, boolean_type_node, 2695 NULL_TREE, args, argtypes, flags); 2696 return; 2697 2698 case TRUTH_ORIF_EXPR: 2699 case TRUTH_ANDIF_EXPR: 2700 build_builtin_candidate 2701 (candidates, fnname, boolean_type_node, 2702 boolean_type_node, args, argtypes, flags); 2703 return; 2704 2705 case ADDR_EXPR: 2706 case COMPOUND_EXPR: 2707 case COMPONENT_REF: 2708 return; 2709 2710 case COND_EXPR: 2711 case EQ_EXPR: 2712 case NE_EXPR: 2713 case LT_EXPR: 2714 case LE_EXPR: 2715 case GT_EXPR: 2716 case GE_EXPR: 2717 enum_p = 1; 2718 /* Fall through. */ 2719 2720 default: 2721 ref1 = 0; 2722 } 2723 2724 types[0] = make_tree_vector (); 2725 types[1] = make_tree_vector (); 2726 2727 for (i = 0; i < 2; ++i) 2728 { 2729 if (! args[i]) 2730 ; 2731 else if (MAYBE_CLASS_TYPE_P (argtypes[i])) 2732 { 2733 tree convs; 2734 2735 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR) 2736 return; 2737 2738 convs = lookup_conversions (argtypes[i]); 2739 2740 if (code == COND_EXPR) 2741 { 2742 if (real_lvalue_p (args[i])) 2743 VEC_safe_push (tree, gc, types[i], 2744 build_reference_type (argtypes[i])); 2745 2746 VEC_safe_push (tree, gc, types[i], 2747 TYPE_MAIN_VARIANT (argtypes[i])); 2748 } 2749 2750 else if (! convs) 2751 return; 2752 2753 for (; convs; convs = TREE_CHAIN (convs)) 2754 { 2755 type = TREE_TYPE (convs); 2756 2757 if (i == 0 && ref1 2758 && (TREE_CODE (type) != REFERENCE_TYPE 2759 || CP_TYPE_CONST_P (TREE_TYPE (type)))) 2760 continue; 2761 2762 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE) 2763 VEC_safe_push (tree, gc, types[i], type); 2764 2765 type = non_reference (type); 2766 if (i != 0 || ! ref1) 2767 { 2768 type = cv_unqualified (type_decays_to (type)); 2769 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE) 2770 VEC_safe_push (tree, gc, types[i], type); 2771 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 2772 type = type_promotes_to (type); 2773 } 2774 2775 if (! vec_member (type, types[i])) 2776 VEC_safe_push (tree, gc, types[i], type); 2777 } 2778 } 2779 else 2780 { 2781 if (code == COND_EXPR && real_lvalue_p (args[i])) 2782 VEC_safe_push (tree, gc, types[i], 2783 build_reference_type (argtypes[i])); 2784 type = non_reference (argtypes[i]); 2785 if (i != 0 || ! ref1) 2786 { 2787 type = cv_unqualified (type_decays_to (type)); 2788 if (enum_p && UNSCOPED_ENUM_P (type)) 2789 VEC_safe_push (tree, gc, types[i], type); 2790 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 2791 type = type_promotes_to (type); 2792 } 2793 VEC_safe_push (tree, gc, types[i], type); 2794 } 2795 } 2796 2797 /* Run through the possible parameter types of both arguments, 2798 creating candidates with those parameter types. */ 2799 FOR_EACH_VEC_ELT_REVERSE (tree, types[0], ix, t) 2800 { 2801 unsigned jx; 2802 tree u; 2803 2804 if (!VEC_empty (tree, types[1])) 2805 FOR_EACH_VEC_ELT_REVERSE (tree, types[1], jx, u) 2806 add_builtin_candidate 2807 (candidates, code, code2, fnname, t, 2808 u, args, argtypes, flags); 2809 else 2810 add_builtin_candidate 2811 (candidates, code, code2, fnname, t, 2812 NULL_TREE, args, argtypes, flags); 2813 } 2814 2815 release_tree_vector (types[0]); 2816 release_tree_vector (types[1]); 2817 } 2818 2819 2820 /* If TMPL can be successfully instantiated as indicated by 2821 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES. 2822 2823 TMPL is the template. EXPLICIT_TARGS are any explicit template 2824 arguments. ARGLIST is the arguments provided at the call-site. 2825 This does not change ARGLIST. The RETURN_TYPE is the desired type 2826 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are 2827 as for add_function_candidate. If an OBJ is supplied, FLAGS and 2828 CTYPE are ignored, and OBJ is as for add_conv_candidate. */ 2829 2830 static struct z_candidate* 2831 add_template_candidate_real (struct z_candidate **candidates, tree tmpl, 2832 tree ctype, tree explicit_targs, tree first_arg, 2833 const VEC(tree,gc) *arglist, tree return_type, 2834 tree access_path, tree conversion_path, 2835 int flags, tree obj, unification_kind_t strict) 2836 { 2837 int ntparms = DECL_NTPARMS (tmpl); 2838 tree targs = make_tree_vec (ntparms); 2839 unsigned int len = VEC_length (tree, arglist); 2840 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len; 2841 unsigned int skip_without_in_chrg = 0; 2842 tree first_arg_without_in_chrg = first_arg; 2843 tree *args_without_in_chrg; 2844 unsigned int nargs_without_in_chrg; 2845 unsigned int ia, ix; 2846 tree arg; 2847 struct z_candidate *cand; 2848 int i; 2849 tree fn; 2850 struct rejection_reason *reason = NULL; 2851 int errs; 2852 2853 /* We don't do deduction on the in-charge parameter, the VTT 2854 parameter or 'this'. */ 2855 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl)) 2856 { 2857 if (first_arg_without_in_chrg != NULL_TREE) 2858 first_arg_without_in_chrg = NULL_TREE; 2859 else 2860 ++skip_without_in_chrg; 2861 } 2862 2863 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl) 2864 || DECL_BASE_CONSTRUCTOR_P (tmpl)) 2865 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl))) 2866 { 2867 if (first_arg_without_in_chrg != NULL_TREE) 2868 first_arg_without_in_chrg = NULL_TREE; 2869 else 2870 ++skip_without_in_chrg; 2871 } 2872 2873 if (len < skip_without_in_chrg) 2874 return NULL; 2875 2876 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0) 2877 + (len - skip_without_in_chrg)); 2878 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg); 2879 ia = 0; 2880 if (first_arg_without_in_chrg != NULL_TREE) 2881 { 2882 args_without_in_chrg[ia] = first_arg_without_in_chrg; 2883 ++ia; 2884 } 2885 for (ix = skip_without_in_chrg; 2886 VEC_iterate (tree, arglist, ix, arg); 2887 ++ix) 2888 { 2889 args_without_in_chrg[ia] = arg; 2890 ++ia; 2891 } 2892 gcc_assert (ia == nargs_without_in_chrg); 2893 2894 errs = errorcount+sorrycount; 2895 i = fn_type_unification (tmpl, explicit_targs, targs, 2896 args_without_in_chrg, 2897 nargs_without_in_chrg, 2898 return_type, strict, flags, false); 2899 2900 if (i != 0) 2901 { 2902 /* Don't repeat unification later if it already resulted in errors. */ 2903 if (errorcount+sorrycount == errs) 2904 reason = template_unification_rejection (tmpl, explicit_targs, 2905 targs, args_without_in_chrg, 2906 nargs_without_in_chrg, 2907 return_type, strict, flags); 2908 else 2909 reason = template_unification_error_rejection (); 2910 goto fail; 2911 } 2912 2913 fn = instantiate_template (tmpl, targs, tf_none); 2914 if (fn == error_mark_node) 2915 { 2916 reason = template_instantiation_rejection (tmpl, targs); 2917 goto fail; 2918 } 2919 2920 /* In [class.copy]: 2921 2922 A member function template is never instantiated to perform the 2923 copy of a class object to an object of its class type. 2924 2925 It's a little unclear what this means; the standard explicitly 2926 does allow a template to be used to copy a class. For example, 2927 in: 2928 2929 struct A { 2930 A(A&); 2931 template <class T> A(const T&); 2932 }; 2933 const A f (); 2934 void g () { A a (f ()); } 2935 2936 the member template will be used to make the copy. The section 2937 quoted above appears in the paragraph that forbids constructors 2938 whose only parameter is (a possibly cv-qualified variant of) the 2939 class type, and a logical interpretation is that the intent was 2940 to forbid the instantiation of member templates which would then 2941 have that form. */ 2942 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2) 2943 { 2944 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn); 2945 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)), 2946 ctype)) 2947 { 2948 reason = invalid_copy_with_fn_template_rejection (); 2949 goto fail; 2950 } 2951 } 2952 2953 if (obj != NULL_TREE) 2954 /* Aha, this is a conversion function. */ 2955 cand = add_conv_candidate (candidates, fn, obj, first_arg, arglist, 2956 access_path, conversion_path); 2957 else 2958 cand = add_function_candidate (candidates, fn, ctype, 2959 first_arg, arglist, access_path, 2960 conversion_path, flags); 2961 if (DECL_TI_TEMPLATE (fn) != tmpl) 2962 /* This situation can occur if a member template of a template 2963 class is specialized. Then, instantiate_template might return 2964 an instantiation of the specialization, in which case the 2965 DECL_TI_TEMPLATE field will point at the original 2966 specialization. For example: 2967 2968 template <class T> struct S { template <class U> void f(U); 2969 template <> void f(int) {}; }; 2970 S<double> sd; 2971 sd.f(3); 2972 2973 Here, TMPL will be template <class U> S<double>::f(U). 2974 And, instantiate template will give us the specialization 2975 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field 2976 for this will point at template <class T> template <> S<T>::f(int), 2977 so that we can find the definition. For the purposes of 2978 overload resolution, however, we want the original TMPL. */ 2979 cand->template_decl = build_template_info (tmpl, targs); 2980 else 2981 cand->template_decl = DECL_TEMPLATE_INFO (fn); 2982 cand->explicit_targs = explicit_targs; 2983 2984 return cand; 2985 fail: 2986 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL, 2987 access_path, conversion_path, 0, reason); 2988 } 2989 2990 2991 static struct z_candidate * 2992 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype, 2993 tree explicit_targs, tree first_arg, 2994 const VEC(tree,gc) *arglist, tree return_type, 2995 tree access_path, tree conversion_path, int flags, 2996 unification_kind_t strict) 2997 { 2998 return 2999 add_template_candidate_real (candidates, tmpl, ctype, 3000 explicit_targs, first_arg, arglist, 3001 return_type, access_path, conversion_path, 3002 flags, NULL_TREE, strict); 3003 } 3004 3005 3006 static struct z_candidate * 3007 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl, 3008 tree obj, tree first_arg, 3009 const VEC(tree,gc) *arglist, 3010 tree return_type, tree access_path, 3011 tree conversion_path) 3012 { 3013 return 3014 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE, 3015 first_arg, arglist, return_type, access_path, 3016 conversion_path, 0, obj, DEDUCE_CONV); 3017 } 3018 3019 /* The CANDS are the set of candidates that were considered for 3020 overload resolution. Return the set of viable candidates, or CANDS 3021 if none are viable. If any of the candidates were viable, set 3022 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be 3023 considered viable only if it is strictly viable. */ 3024 3025 static struct z_candidate* 3026 splice_viable (struct z_candidate *cands, 3027 bool strict_p, 3028 bool *any_viable_p) 3029 { 3030 struct z_candidate *viable; 3031 struct z_candidate **last_viable; 3032 struct z_candidate **cand; 3033 3034 /* Be strict inside templates, since build_over_call won't actually 3035 do the conversions to get pedwarns. */ 3036 if (processing_template_decl) 3037 strict_p = true; 3038 3039 viable = NULL; 3040 last_viable = &viable; 3041 *any_viable_p = false; 3042 3043 cand = &cands; 3044 while (*cand) 3045 { 3046 struct z_candidate *c = *cand; 3047 if (strict_p ? c->viable == 1 : c->viable) 3048 { 3049 *last_viable = c; 3050 *cand = c->next; 3051 c->next = NULL; 3052 last_viable = &c->next; 3053 *any_viable_p = true; 3054 } 3055 else 3056 cand = &c->next; 3057 } 3058 3059 return viable ? viable : cands; 3060 } 3061 3062 static bool 3063 any_strictly_viable (struct z_candidate *cands) 3064 { 3065 for (; cands; cands = cands->next) 3066 if (cands->viable == 1) 3067 return true; 3068 return false; 3069 } 3070 3071 /* OBJ is being used in an expression like "OBJ.f (...)". In other 3072 words, it is about to become the "this" pointer for a member 3073 function call. Take the address of the object. */ 3074 3075 static tree 3076 build_this (tree obj) 3077 { 3078 /* In a template, we are only concerned about the type of the 3079 expression, so we can take a shortcut. */ 3080 if (processing_template_decl) 3081 return build_address (obj); 3082 3083 return cp_build_addr_expr (obj, tf_warning_or_error); 3084 } 3085 3086 /* Returns true iff functions are equivalent. Equivalent functions are 3087 not '==' only if one is a function-local extern function or if 3088 both are extern "C". */ 3089 3090 static inline int 3091 equal_functions (tree fn1, tree fn2) 3092 { 3093 if (TREE_CODE (fn1) != TREE_CODE (fn2)) 3094 return 0; 3095 if (TREE_CODE (fn1) == TEMPLATE_DECL) 3096 return fn1 == fn2; 3097 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2) 3098 || DECL_EXTERN_C_FUNCTION_P (fn1)) 3099 return decls_match (fn1, fn2); 3100 return fn1 == fn2; 3101 } 3102 3103 /* Print information about a candidate being rejected due to INFO. */ 3104 3105 static void 3106 print_conversion_rejection (location_t loc, struct conversion_info *info) 3107 { 3108 if (info->n_arg == -1) 3109 /* Conversion of implicit `this' argument failed. */ 3110 inform (loc, " no known conversion for implicit " 3111 "%<this%> parameter from %qT to %qT", 3112 info->from_type, info->to_type); 3113 else 3114 inform (loc, " no known conversion for argument %d from %qT to %qT", 3115 info->n_arg+1, info->from_type, info->to_type); 3116 } 3117 3118 /* Print information about a candidate with WANT parameters and we found 3119 HAVE. */ 3120 3121 static void 3122 print_arity_information (location_t loc, unsigned int have, unsigned int want) 3123 { 3124 inform_n (loc, want, 3125 " candidate expects %d argument, %d provided", 3126 " candidate expects %d arguments, %d provided", 3127 want, have); 3128 } 3129 3130 /* Print information about one overload candidate CANDIDATE. MSGSTR 3131 is the text to print before the candidate itself. 3132 3133 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected 3134 to have been run through gettext by the caller. This wart makes 3135 life simpler in print_z_candidates and for the translators. */ 3136 3137 static void 3138 print_z_candidate (const char *msgstr, struct z_candidate *candidate) 3139 { 3140 const char *msg = (msgstr == NULL 3141 ? "" 3142 : ACONCAT ((msgstr, " ", NULL))); 3143 location_t loc = location_of (candidate->fn); 3144 3145 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE) 3146 { 3147 if (candidate->num_convs == 3) 3148 inform (input_location, "%s%D(%T, %T, %T) <built-in>", msg, candidate->fn, 3149 candidate->convs[0]->type, 3150 candidate->convs[1]->type, 3151 candidate->convs[2]->type); 3152 else if (candidate->num_convs == 2) 3153 inform (input_location, "%s%D(%T, %T) <built-in>", msg, candidate->fn, 3154 candidate->convs[0]->type, 3155 candidate->convs[1]->type); 3156 else 3157 inform (input_location, "%s%D(%T) <built-in>", msg, candidate->fn, 3158 candidate->convs[0]->type); 3159 } 3160 else if (TYPE_P (candidate->fn)) 3161 inform (input_location, "%s%T <conversion>", msg, candidate->fn); 3162 else if (candidate->viable == -1) 3163 inform (loc, "%s%#D <near match>", msg, candidate->fn); 3164 else if (DECL_DELETED_FN (STRIP_TEMPLATE (candidate->fn))) 3165 inform (loc, "%s%#D <deleted>", msg, candidate->fn); 3166 else 3167 inform (loc, "%s%#D", msg, candidate->fn); 3168 /* Give the user some information about why this candidate failed. */ 3169 if (candidate->reason != NULL) 3170 { 3171 struct rejection_reason *r = candidate->reason; 3172 3173 switch (r->code) 3174 { 3175 case rr_arity: 3176 print_arity_information (loc, r->u.arity.actual, 3177 r->u.arity.expected); 3178 break; 3179 case rr_arg_conversion: 3180 print_conversion_rejection (loc, &r->u.conversion); 3181 break; 3182 case rr_bad_arg_conversion: 3183 print_conversion_rejection (loc, &r->u.bad_conversion); 3184 break; 3185 case rr_explicit_conversion: 3186 inform (loc, " return type %qT of explicit conversion function " 3187 "cannot be converted to %qT with a qualification " 3188 "conversion", r->u.conversion.from_type, 3189 r->u.conversion.to_type); 3190 break; 3191 case rr_template_conversion: 3192 inform (loc, " conversion from return type %qT of template " 3193 "conversion function specialization to %qT is not an " 3194 "exact match", r->u.conversion.from_type, 3195 r->u.conversion.to_type); 3196 break; 3197 case rr_template_unification: 3198 /* We use template_unification_error_rejection if unification caused 3199 actual non-SFINAE errors, in which case we don't need to repeat 3200 them here. */ 3201 if (r->u.template_unification.tmpl == NULL_TREE) 3202 { 3203 inform (loc, " substitution of deduced template arguments " 3204 "resulted in errors seen above"); 3205 break; 3206 } 3207 /* Re-run template unification with diagnostics. */ 3208 inform (loc, " template argument deduction/substitution failed:"); 3209 fn_type_unification (r->u.template_unification.tmpl, 3210 r->u.template_unification.explicit_targs, 3211 r->u.template_unification.targs, 3212 r->u.template_unification.args, 3213 r->u.template_unification.nargs, 3214 r->u.template_unification.return_type, 3215 r->u.template_unification.strict, 3216 r->u.template_unification.flags, 3217 true); 3218 break; 3219 case rr_template_instantiation: 3220 /* Re-run template instantiation with diagnostics. */ 3221 instantiate_template (r->u.template_instantiation.tmpl, 3222 r->u.template_instantiation.targs, 3223 tf_warning_or_error); 3224 break; 3225 case rr_invalid_copy: 3226 inform (loc, 3227 " a constructor taking a single argument of its own " 3228 "class type is invalid"); 3229 break; 3230 case rr_none: 3231 default: 3232 /* This candidate didn't have any issues or we failed to 3233 handle a particular code. Either way... */ 3234 gcc_unreachable (); 3235 } 3236 } 3237 } 3238 3239 static void 3240 print_z_candidates (location_t loc, struct z_candidate *candidates) 3241 { 3242 struct z_candidate *cand1; 3243 struct z_candidate **cand2; 3244 int n_candidates; 3245 3246 if (!candidates) 3247 return; 3248 3249 /* Remove non-viable deleted candidates. */ 3250 cand1 = candidates; 3251 for (cand2 = &cand1; *cand2; ) 3252 { 3253 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL 3254 && !(*cand2)->viable 3255 && DECL_DELETED_FN ((*cand2)->fn)) 3256 *cand2 = (*cand2)->next; 3257 else 3258 cand2 = &(*cand2)->next; 3259 } 3260 /* ...if there are any non-deleted ones. */ 3261 if (cand1) 3262 candidates = cand1; 3263 3264 /* There may be duplicates in the set of candidates. We put off 3265 checking this condition as long as possible, since we have no way 3266 to eliminate duplicates from a set of functions in less than n^2 3267 time. Now we are about to emit an error message, so it is more 3268 permissible to go slowly. */ 3269 for (cand1 = candidates; cand1; cand1 = cand1->next) 3270 { 3271 tree fn = cand1->fn; 3272 /* Skip builtin candidates and conversion functions. */ 3273 if (!DECL_P (fn)) 3274 continue; 3275 cand2 = &cand1->next; 3276 while (*cand2) 3277 { 3278 if (DECL_P ((*cand2)->fn) 3279 && equal_functions (fn, (*cand2)->fn)) 3280 *cand2 = (*cand2)->next; 3281 else 3282 cand2 = &(*cand2)->next; 3283 } 3284 } 3285 3286 for (n_candidates = 0, cand1 = candidates; cand1; cand1 = cand1->next) 3287 n_candidates++; 3288 3289 inform_n (loc, n_candidates, "candidate is:", "candidates are:"); 3290 for (; candidates; candidates = candidates->next) 3291 print_z_candidate (NULL, candidates); 3292 } 3293 3294 /* USER_SEQ is a user-defined conversion sequence, beginning with a 3295 USER_CONV. STD_SEQ is the standard conversion sequence applied to 3296 the result of the conversion function to convert it to the final 3297 desired type. Merge the two sequences into a single sequence, 3298 and return the merged sequence. */ 3299 3300 static conversion * 3301 merge_conversion_sequences (conversion *user_seq, conversion *std_seq) 3302 { 3303 conversion **t; 3304 bool bad = user_seq->bad_p; 3305 3306 gcc_assert (user_seq->kind == ck_user); 3307 3308 /* Find the end of the second conversion sequence. */ 3309 for (t = &std_seq; (*t)->kind != ck_identity; t = &((*t)->u.next)) 3310 { 3311 /* The entire sequence is a user-conversion sequence. */ 3312 (*t)->user_conv_p = true; 3313 if (bad) 3314 (*t)->bad_p = true; 3315 } 3316 3317 /* Replace the identity conversion with the user conversion 3318 sequence. */ 3319 *t = user_seq; 3320 3321 return std_seq; 3322 } 3323 3324 /* Handle overload resolution for initializing an object of class type from 3325 an initializer list. First we look for a suitable constructor that 3326 takes a std::initializer_list; if we don't find one, we then look for a 3327 non-list constructor. 3328 3329 Parameters are as for add_candidates, except that the arguments are in 3330 the form of a CONSTRUCTOR (the initializer list) rather than a VEC, and 3331 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */ 3332 3333 static void 3334 add_list_candidates (tree fns, tree first_arg, 3335 tree init_list, tree totype, 3336 tree explicit_targs, bool template_only, 3337 tree conversion_path, tree access_path, 3338 int flags, 3339 struct z_candidate **candidates) 3340 { 3341 VEC(tree,gc) *args; 3342 3343 gcc_assert (*candidates == NULL); 3344 3345 /* We're looking for a ctor for list-initialization. */ 3346 flags |= LOOKUP_LIST_INIT_CTOR; 3347 /* And we don't allow narrowing conversions. We also use this flag to 3348 avoid the copy constructor call for copy-list-initialization. */ 3349 flags |= LOOKUP_NO_NARROWING; 3350 3351 /* Always use the default constructor if the list is empty (DR 990). */ 3352 if (CONSTRUCTOR_NELTS (init_list) == 0 3353 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 3354 ; 3355 /* If the class has a list ctor, try passing the list as a single 3356 argument first, but only consider list ctors. */ 3357 else if (TYPE_HAS_LIST_CTOR (totype)) 3358 { 3359 flags |= LOOKUP_LIST_ONLY; 3360 args = make_tree_vector_single (init_list); 3361 add_candidates (fns, first_arg, args, NULL_TREE, 3362 explicit_targs, template_only, conversion_path, 3363 access_path, flags, candidates); 3364 if (any_strictly_viable (*candidates)) 3365 return; 3366 } 3367 3368 args = ctor_to_vec (init_list); 3369 3370 /* We aren't looking for list-ctors anymore. */ 3371 flags &= ~LOOKUP_LIST_ONLY; 3372 /* We allow more user-defined conversions within an init-list. */ 3373 flags &= ~LOOKUP_NO_CONVERSION; 3374 3375 add_candidates (fns, first_arg, args, NULL_TREE, 3376 explicit_targs, template_only, conversion_path, 3377 access_path, flags, candidates); 3378 } 3379 3380 /* Returns the best overload candidate to perform the requested 3381 conversion. This function is used for three the overloading situations 3382 described in [over.match.copy], [over.match.conv], and [over.match.ref]. 3383 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as 3384 per [dcl.init.ref], so we ignore temporary bindings. */ 3385 3386 static struct z_candidate * 3387 build_user_type_conversion_1 (tree totype, tree expr, int flags) 3388 { 3389 struct z_candidate *candidates, *cand; 3390 tree fromtype; 3391 tree ctors = NULL_TREE; 3392 tree conv_fns = NULL_TREE; 3393 conversion *conv = NULL; 3394 tree first_arg = NULL_TREE; 3395 VEC(tree,gc) *args = NULL; 3396 bool any_viable_p; 3397 int convflags; 3398 3399 if (!expr) 3400 return NULL; 3401 3402 fromtype = TREE_TYPE (expr); 3403 3404 /* We represent conversion within a hierarchy using RVALUE_CONV and 3405 BASE_CONV, as specified by [over.best.ics]; these become plain 3406 constructor calls, as specified in [dcl.init]. */ 3407 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype) 3408 || !DERIVED_FROM_P (totype, fromtype)); 3409 3410 if (MAYBE_CLASS_TYPE_P (totype)) 3411 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid 3412 creating a garbage BASELINK; constructors can't be inherited. */ 3413 ctors = lookup_fnfields_slot (totype, complete_ctor_identifier); 3414 3415 if (MAYBE_CLASS_TYPE_P (fromtype)) 3416 { 3417 tree to_nonref = non_reference (totype); 3418 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) || 3419 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype) 3420 && DERIVED_FROM_P (to_nonref, fromtype))) 3421 { 3422 /* [class.conv.fct] A conversion function is never used to 3423 convert a (possibly cv-qualified) object to the (possibly 3424 cv-qualified) same object type (or a reference to it), to a 3425 (possibly cv-qualified) base class of that type (or a 3426 reference to it)... */ 3427 } 3428 else 3429 conv_fns = lookup_conversions (fromtype); 3430 } 3431 3432 candidates = 0; 3433 flags |= LOOKUP_NO_CONVERSION; 3434 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3435 flags |= LOOKUP_NO_NARROWING; 3436 3437 /* It's OK to bind a temporary for converting constructor arguments, but 3438 not in converting the return value of a conversion operator. */ 3439 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION); 3440 flags &= ~LOOKUP_NO_TEMP_BIND; 3441 3442 if (ctors) 3443 { 3444 int ctorflags = flags; 3445 3446 first_arg = build_int_cst (build_pointer_type (totype), 0); 3447 3448 /* We should never try to call the abstract or base constructor 3449 from here. */ 3450 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors)) 3451 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors))); 3452 3453 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3454 { 3455 /* List-initialization. */ 3456 add_list_candidates (ctors, first_arg, expr, totype, NULL_TREE, 3457 false, TYPE_BINFO (totype), TYPE_BINFO (totype), 3458 ctorflags, &candidates); 3459 } 3460 else 3461 { 3462 args = make_tree_vector_single (expr); 3463 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false, 3464 TYPE_BINFO (totype), TYPE_BINFO (totype), 3465 ctorflags, &candidates); 3466 } 3467 3468 for (cand = candidates; cand; cand = cand->next) 3469 { 3470 cand->second_conv = build_identity_conv (totype, NULL_TREE); 3471 3472 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't 3473 set, then this is copy-initialization. In that case, "The 3474 result of the call is then used to direct-initialize the 3475 object that is the destination of the copy-initialization." 3476 [dcl.init] 3477 3478 We represent this in the conversion sequence with an 3479 rvalue conversion, which means a constructor call. */ 3480 if (TREE_CODE (totype) != REFERENCE_TYPE 3481 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3482 cand->second_conv 3483 = build_conv (ck_rvalue, totype, cand->second_conv); 3484 } 3485 } 3486 3487 if (conv_fns) 3488 first_arg = build_this (expr); 3489 3490 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns)) 3491 { 3492 tree conversion_path = TREE_PURPOSE (conv_fns); 3493 struct z_candidate *old_candidates; 3494 3495 /* If we are called to convert to a reference type, we are trying to 3496 find a direct binding, so don't even consider temporaries. If 3497 we don't find a direct binding, the caller will try again to 3498 look for a temporary binding. */ 3499 if (TREE_CODE (totype) == REFERENCE_TYPE) 3500 convflags |= LOOKUP_NO_TEMP_BIND; 3501 3502 old_candidates = candidates; 3503 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype, 3504 NULL_TREE, false, 3505 conversion_path, TYPE_BINFO (fromtype), 3506 flags, &candidates); 3507 3508 for (cand = candidates; cand != old_candidates; cand = cand->next) 3509 { 3510 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn)); 3511 conversion *ics 3512 = implicit_conversion (totype, 3513 rettype, 3514 0, 3515 /*c_cast_p=*/false, convflags); 3516 3517 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is 3518 copy-initialization. In that case, "The result of the 3519 call is then used to direct-initialize the object that is 3520 the destination of the copy-initialization." [dcl.init] 3521 3522 We represent this in the conversion sequence with an 3523 rvalue conversion, which means a constructor call. But 3524 don't add a second rvalue conversion if there's already 3525 one there. Which there really shouldn't be, but it's 3526 harmless since we'd add it here anyway. */ 3527 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue 3528 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3529 ics = build_conv (ck_rvalue, totype, ics); 3530 3531 cand->second_conv = ics; 3532 3533 if (!ics) 3534 { 3535 cand->viable = 0; 3536 cand->reason = arg_conversion_rejection (NULL_TREE, -1, 3537 rettype, totype); 3538 } 3539 else if (DECL_NONCONVERTING_P (cand->fn) 3540 && ics->rank > cr_exact) 3541 { 3542 /* 13.3.1.5: For direct-initialization, those explicit 3543 conversion functions that are not hidden within S and 3544 yield type T or a type that can be converted to type T 3545 with a qualification conversion (4.4) are also candidate 3546 functions. */ 3547 /* 13.3.1.6 doesn't have a parallel restriction, but it should; 3548 I've raised this issue with the committee. --jason 9/2011 */ 3549 cand->viable = -1; 3550 cand->reason = explicit_conversion_rejection (rettype, totype); 3551 } 3552 else if (cand->viable == 1 && ics->bad_p) 3553 { 3554 cand->viable = -1; 3555 cand->reason 3556 = bad_arg_conversion_rejection (NULL_TREE, -1, 3557 rettype, totype); 3558 } 3559 else if (primary_template_instantiation_p (cand->fn) 3560 && ics->rank > cr_exact) 3561 { 3562 /* 13.3.3.1.2: If the user-defined conversion is specified by 3563 a specialization of a conversion function template, the 3564 second standard conversion sequence shall have exact match 3565 rank. */ 3566 cand->viable = -1; 3567 cand->reason = template_conversion_rejection (rettype, totype); 3568 } 3569 } 3570 } 3571 3572 candidates = splice_viable (candidates, pedantic, &any_viable_p); 3573 if (!any_viable_p) 3574 { 3575 if (args) 3576 release_tree_vector (args); 3577 return NULL; 3578 } 3579 3580 cand = tourney (candidates); 3581 if (cand == 0) 3582 { 3583 if (flags & LOOKUP_COMPLAIN) 3584 { 3585 error ("conversion from %qT to %qT is ambiguous", 3586 fromtype, totype); 3587 print_z_candidates (location_of (expr), candidates); 3588 } 3589 3590 cand = candidates; /* any one will do */ 3591 cand->second_conv = build_ambiguous_conv (totype, expr); 3592 cand->second_conv->user_conv_p = true; 3593 if (!any_strictly_viable (candidates)) 3594 cand->second_conv->bad_p = true; 3595 /* If there are viable candidates, don't set ICS_BAD_FLAG; an 3596 ambiguous conversion is no worse than another user-defined 3597 conversion. */ 3598 3599 return cand; 3600 } 3601 3602 /* Build the user conversion sequence. */ 3603 conv = build_conv 3604 (ck_user, 3605 (DECL_CONSTRUCTOR_P (cand->fn) 3606 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))), 3607 build_identity_conv (TREE_TYPE (expr), expr)); 3608 conv->cand = cand; 3609 if (cand->viable == -1) 3610 conv->bad_p = true; 3611 3612 /* Remember that this was a list-initialization. */ 3613 if (flags & LOOKUP_NO_NARROWING) 3614 conv->check_narrowing = true; 3615 3616 /* Combine it with the second conversion sequence. */ 3617 cand->second_conv = merge_conversion_sequences (conv, 3618 cand->second_conv); 3619 3620 return cand; 3621 } 3622 3623 /* Wrapper for above. */ 3624 3625 tree 3626 build_user_type_conversion (tree totype, tree expr, int flags) 3627 { 3628 struct z_candidate *cand; 3629 tree ret; 3630 3631 bool subtime = timevar_cond_start (TV_OVERLOAD); 3632 cand = build_user_type_conversion_1 (totype, expr, flags); 3633 3634 if (cand) 3635 { 3636 if (cand->second_conv->kind == ck_ambig) 3637 ret = error_mark_node; 3638 else 3639 { 3640 expr = convert_like (cand->second_conv, expr, tf_warning_or_error); 3641 ret = convert_from_reference (expr); 3642 } 3643 } 3644 else 3645 ret = NULL_TREE; 3646 3647 timevar_cond_stop (TV_OVERLOAD, subtime); 3648 return ret; 3649 } 3650 3651 /* Subroutine of convert_nontype_argument. 3652 3653 EXPR is an argument for a template non-type parameter of integral or 3654 enumeration type. Do any necessary conversions (that are permitted for 3655 non-type arguments) to convert it to the parameter type. 3656 3657 If conversion is successful, returns the converted expression; 3658 otherwise, returns error_mark_node. */ 3659 3660 tree 3661 build_integral_nontype_arg_conv (tree type, tree expr, tsubst_flags_t complain) 3662 { 3663 conversion *conv; 3664 void *p; 3665 tree t; 3666 3667 if (error_operand_p (expr)) 3668 return error_mark_node; 3669 3670 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type)); 3671 3672 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 3673 p = conversion_obstack_alloc (0); 3674 3675 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 3676 /*c_cast_p=*/false, 3677 LOOKUP_IMPLICIT); 3678 3679 /* for a non-type template-parameter of integral or 3680 enumeration type, integral promotions (4.5) and integral 3681 conversions (4.7) are applied. */ 3682 /* It should be sufficient to check the outermost conversion step, since 3683 there are no qualification conversions to integer type. */ 3684 if (conv) 3685 switch (conv->kind) 3686 { 3687 /* A conversion function is OK. If it isn't constexpr, we'll 3688 complain later that the argument isn't constant. */ 3689 case ck_user: 3690 /* The lvalue-to-rvalue conversion is OK. */ 3691 case ck_rvalue: 3692 case ck_identity: 3693 break; 3694 3695 case ck_std: 3696 t = conv->u.next->type; 3697 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t)) 3698 break; 3699 3700 if (complain & tf_error) 3701 error ("conversion from %qT to %qT not considered for " 3702 "non-type template argument", t, type); 3703 /* and fall through. */ 3704 3705 default: 3706 conv = NULL; 3707 break; 3708 } 3709 3710 if (conv) 3711 expr = convert_like (conv, expr, complain); 3712 else 3713 expr = error_mark_node; 3714 3715 /* Free all the conversions we allocated. */ 3716 obstack_free (&conversion_obstack, p); 3717 3718 return expr; 3719 } 3720 3721 /* Do any initial processing on the arguments to a function call. */ 3722 3723 static VEC(tree,gc) * 3724 resolve_args (VEC(tree,gc) *args, tsubst_flags_t complain) 3725 { 3726 unsigned int ix; 3727 tree arg; 3728 3729 FOR_EACH_VEC_ELT (tree, args, ix, arg) 3730 { 3731 if (error_operand_p (arg)) 3732 return NULL; 3733 else if (VOID_TYPE_P (TREE_TYPE (arg))) 3734 { 3735 if (complain & tf_error) 3736 error ("invalid use of void expression"); 3737 return NULL; 3738 } 3739 else if (invalid_nonstatic_memfn_p (arg, tf_warning_or_error)) 3740 return NULL; 3741 } 3742 return args; 3743 } 3744 3745 /* Perform overload resolution on FN, which is called with the ARGS. 3746 3747 Return the candidate function selected by overload resolution, or 3748 NULL if the event that overload resolution failed. In the case 3749 that overload resolution fails, *CANDIDATES will be the set of 3750 candidates considered, and ANY_VIABLE_P will be set to true or 3751 false to indicate whether or not any of the candidates were 3752 viable. 3753 3754 The ARGS should already have gone through RESOLVE_ARGS before this 3755 function is called. */ 3756 3757 static struct z_candidate * 3758 perform_overload_resolution (tree fn, 3759 const VEC(tree,gc) *args, 3760 struct z_candidate **candidates, 3761 bool *any_viable_p) 3762 { 3763 struct z_candidate *cand; 3764 tree explicit_targs; 3765 int template_only; 3766 3767 bool subtime = timevar_cond_start (TV_OVERLOAD); 3768 3769 explicit_targs = NULL_TREE; 3770 template_only = 0; 3771 3772 *candidates = NULL; 3773 *any_viable_p = true; 3774 3775 /* Check FN. */ 3776 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 3777 || TREE_CODE (fn) == TEMPLATE_DECL 3778 || TREE_CODE (fn) == OVERLOAD 3779 || TREE_CODE (fn) == TEMPLATE_ID_EXPR); 3780 3781 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 3782 { 3783 explicit_targs = TREE_OPERAND (fn, 1); 3784 fn = TREE_OPERAND (fn, 0); 3785 template_only = 1; 3786 } 3787 3788 /* Add the various candidate functions. */ 3789 add_candidates (fn, NULL_TREE, args, NULL_TREE, 3790 explicit_targs, template_only, 3791 /*conversion_path=*/NULL_TREE, 3792 /*access_path=*/NULL_TREE, 3793 LOOKUP_NORMAL, 3794 candidates); 3795 3796 *candidates = splice_viable (*candidates, pedantic, any_viable_p); 3797 if (*any_viable_p) 3798 cand = tourney (*candidates); 3799 else 3800 cand = NULL; 3801 3802 timevar_cond_stop (TV_OVERLOAD, subtime); 3803 return cand; 3804 } 3805 3806 /* Print an error message about being unable to build a call to FN with 3807 ARGS. ANY_VIABLE_P indicates whether any candidate functions could 3808 be located; CANDIDATES is a possibly empty list of such 3809 functions. */ 3810 3811 static void 3812 print_error_for_call_failure (tree fn, VEC(tree,gc) *args, bool any_viable_p, 3813 struct z_candidate *candidates) 3814 { 3815 tree name = DECL_NAME (OVL_CURRENT (fn)); 3816 location_t loc = location_of (name); 3817 3818 if (!any_viable_p) 3819 error_at (loc, "no matching function for call to %<%D(%A)%>", 3820 name, build_tree_list_vec (args)); 3821 else 3822 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous", 3823 name, build_tree_list_vec (args)); 3824 if (candidates) 3825 print_z_candidates (loc, candidates); 3826 } 3827 3828 /* Return an expression for a call to FN (a namespace-scope function, 3829 or a static member function) with the ARGS. This may change 3830 ARGS. */ 3831 3832 tree 3833 build_new_function_call (tree fn, VEC(tree,gc) **args, bool koenig_p, 3834 tsubst_flags_t complain) 3835 { 3836 struct z_candidate *candidates, *cand; 3837 bool any_viable_p; 3838 void *p; 3839 tree result; 3840 3841 if (args != NULL && *args != NULL) 3842 { 3843 *args = resolve_args (*args, complain); 3844 if (*args == NULL) 3845 return error_mark_node; 3846 } 3847 3848 if (flag_tm) 3849 tm_malloc_replacement (fn); 3850 3851 /* If this function was found without using argument dependent 3852 lookup, then we want to ignore any undeclared friend 3853 functions. */ 3854 if (!koenig_p) 3855 { 3856 tree orig_fn = fn; 3857 3858 fn = remove_hidden_names (fn); 3859 if (!fn) 3860 { 3861 if (complain & tf_error) 3862 print_error_for_call_failure (orig_fn, *args, false, NULL); 3863 return error_mark_node; 3864 } 3865 } 3866 3867 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 3868 p = conversion_obstack_alloc (0); 3869 3870 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p); 3871 3872 if (!cand) 3873 { 3874 if (complain & tf_error) 3875 { 3876 if (!any_viable_p && candidates && ! candidates->next 3877 && (TREE_CODE (candidates->fn) == FUNCTION_DECL)) 3878 return cp_build_function_call_vec (candidates->fn, args, complain); 3879 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 3880 fn = TREE_OPERAND (fn, 0); 3881 print_error_for_call_failure (fn, *args, any_viable_p, candidates); 3882 } 3883 result = error_mark_node; 3884 } 3885 else 3886 { 3887 int flags = LOOKUP_NORMAL; 3888 /* If fn is template_id_expr, the call has explicit template arguments 3889 (e.g. func<int>(5)), communicate this info to build_over_call 3890 through flags so that later we can use it to decide whether to warn 3891 about peculiar null pointer conversion. */ 3892 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 3893 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 3894 result = build_over_call (cand, flags, complain); 3895 } 3896 3897 /* Free all the conversions we allocated. */ 3898 obstack_free (&conversion_obstack, p); 3899 3900 return result; 3901 } 3902 3903 /* Build a call to a global operator new. FNNAME is the name of the 3904 operator (either "operator new" or "operator new[]") and ARGS are 3905 the arguments provided. This may change ARGS. *SIZE points to the 3906 total number of bytes required by the allocation, and is updated if 3907 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should 3908 be used. If this function determines that no cookie should be 3909 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is 3910 non-NULL, it will be set, upon return, to the allocation function 3911 called. */ 3912 3913 tree 3914 build_operator_new_call (tree fnname, VEC(tree,gc) **args, 3915 tree *size, tree *cookie_size, 3916 tree *fn) 3917 { 3918 tree fns; 3919 struct z_candidate *candidates; 3920 struct z_candidate *cand; 3921 bool any_viable_p; 3922 3923 if (fn) 3924 *fn = NULL_TREE; 3925 VEC_safe_insert (tree, gc, *args, 0, *size); 3926 *args = resolve_args (*args, tf_warning_or_error); 3927 if (*args == NULL) 3928 return error_mark_node; 3929 3930 /* Based on: 3931 3932 [expr.new] 3933 3934 If this lookup fails to find the name, or if the allocated type 3935 is not a class type, the allocation function's name is looked 3936 up in the global scope. 3937 3938 we disregard block-scope declarations of "operator new". */ 3939 fns = lookup_function_nonclass (fnname, *args, /*block_p=*/false); 3940 3941 /* Figure out what function is being called. */ 3942 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p); 3943 3944 /* If no suitable function could be found, issue an error message 3945 and give up. */ 3946 if (!cand) 3947 { 3948 print_error_for_call_failure (fns, *args, any_viable_p, candidates); 3949 return error_mark_node; 3950 } 3951 3952 /* If a cookie is required, add some extra space. Whether 3953 or not a cookie is required cannot be determined until 3954 after we know which function was called. */ 3955 if (*cookie_size) 3956 { 3957 bool use_cookie = true; 3958 if (!abi_version_at_least (2)) 3959 { 3960 /* In G++ 3.2, the check was implemented incorrectly; it 3961 looked at the placement expression, rather than the 3962 type of the function. */ 3963 if (VEC_length (tree, *args) == 2 3964 && same_type_p (TREE_TYPE (VEC_index (tree, *args, 1)), 3965 ptr_type_node)) 3966 use_cookie = false; 3967 } 3968 else 3969 { 3970 tree arg_types; 3971 3972 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 3973 /* Skip the size_t parameter. */ 3974 arg_types = TREE_CHAIN (arg_types); 3975 /* Check the remaining parameters (if any). */ 3976 if (arg_types 3977 && TREE_CHAIN (arg_types) == void_list_node 3978 && same_type_p (TREE_VALUE (arg_types), 3979 ptr_type_node)) 3980 use_cookie = false; 3981 } 3982 /* If we need a cookie, adjust the number of bytes allocated. */ 3983 if (use_cookie) 3984 { 3985 /* Update the total size. */ 3986 *size = size_binop (PLUS_EXPR, *size, *cookie_size); 3987 /* Update the argument list to reflect the adjusted size. */ 3988 VEC_replace (tree, *args, 0, *size); 3989 } 3990 else 3991 *cookie_size = NULL_TREE; 3992 } 3993 3994 /* Tell our caller which function we decided to call. */ 3995 if (fn) 3996 *fn = cand->fn; 3997 3998 /* Build the CALL_EXPR. */ 3999 return build_over_call (cand, LOOKUP_NORMAL, tf_warning_or_error); 4000 } 4001 4002 /* Build a new call to operator(). This may change ARGS. */ 4003 4004 static tree 4005 build_op_call_1 (tree obj, VEC(tree,gc) **args, tsubst_flags_t complain) 4006 { 4007 struct z_candidate *candidates = 0, *cand; 4008 tree fns, convs, first_mem_arg = NULL_TREE; 4009 tree type = TREE_TYPE (obj); 4010 bool any_viable_p; 4011 tree result = NULL_TREE; 4012 void *p; 4013 4014 if (error_operand_p (obj)) 4015 return error_mark_node; 4016 4017 obj = prep_operand (obj); 4018 4019 if (TYPE_PTRMEMFUNC_P (type)) 4020 { 4021 if (complain & tf_error) 4022 /* It's no good looking for an overloaded operator() on a 4023 pointer-to-member-function. */ 4024 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj); 4025 return error_mark_node; 4026 } 4027 4028 if (TYPE_BINFO (type)) 4029 { 4030 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1); 4031 if (fns == error_mark_node) 4032 return error_mark_node; 4033 } 4034 else 4035 fns = NULL_TREE; 4036 4037 if (args != NULL && *args != NULL) 4038 { 4039 *args = resolve_args (*args, complain); 4040 if (*args == NULL) 4041 return error_mark_node; 4042 } 4043 4044 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4045 p = conversion_obstack_alloc (0); 4046 4047 if (fns) 4048 { 4049 first_mem_arg = build_this (obj); 4050 4051 add_candidates (BASELINK_FUNCTIONS (fns), 4052 first_mem_arg, *args, NULL_TREE, 4053 NULL_TREE, false, 4054 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns), 4055 LOOKUP_NORMAL, &candidates); 4056 } 4057 4058 convs = lookup_conversions (type); 4059 4060 for (; convs; convs = TREE_CHAIN (convs)) 4061 { 4062 tree fns = TREE_VALUE (convs); 4063 tree totype = TREE_TYPE (convs); 4064 4065 if ((TREE_CODE (totype) == POINTER_TYPE 4066 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE) 4067 || (TREE_CODE (totype) == REFERENCE_TYPE 4068 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE) 4069 || (TREE_CODE (totype) == REFERENCE_TYPE 4070 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE 4071 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE)) 4072 for (; fns; fns = OVL_NEXT (fns)) 4073 { 4074 tree fn = OVL_CURRENT (fns); 4075 4076 if (DECL_NONCONVERTING_P (fn)) 4077 continue; 4078 4079 if (TREE_CODE (fn) == TEMPLATE_DECL) 4080 add_template_conv_candidate 4081 (&candidates, fn, obj, NULL_TREE, *args, totype, 4082 /*access_path=*/NULL_TREE, 4083 /*conversion_path=*/NULL_TREE); 4084 else 4085 add_conv_candidate (&candidates, fn, obj, NULL_TREE, 4086 *args, /*conversion_path=*/NULL_TREE, 4087 /*access_path=*/NULL_TREE); 4088 } 4089 } 4090 4091 candidates = splice_viable (candidates, pedantic, &any_viable_p); 4092 if (!any_viable_p) 4093 { 4094 if (complain & tf_error) 4095 { 4096 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), 4097 build_tree_list_vec (*args)); 4098 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4099 } 4100 result = error_mark_node; 4101 } 4102 else 4103 { 4104 cand = tourney (candidates); 4105 if (cand == 0) 4106 { 4107 if (complain & tf_error) 4108 { 4109 error ("call of %<(%T) (%A)%> is ambiguous", 4110 TREE_TYPE (obj), build_tree_list_vec (*args)); 4111 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4112 } 4113 result = error_mark_node; 4114 } 4115 /* Since cand->fn will be a type, not a function, for a conversion 4116 function, we must be careful not to unconditionally look at 4117 DECL_NAME here. */ 4118 else if (TREE_CODE (cand->fn) == FUNCTION_DECL 4119 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR) 4120 result = build_over_call (cand, LOOKUP_NORMAL, complain); 4121 else 4122 { 4123 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1, 4124 complain); 4125 obj = convert_from_reference (obj); 4126 result = cp_build_function_call_vec (obj, args, complain); 4127 } 4128 } 4129 4130 /* Free all the conversions we allocated. */ 4131 obstack_free (&conversion_obstack, p); 4132 4133 return result; 4134 } 4135 4136 /* Wrapper for above. */ 4137 4138 tree 4139 build_op_call (tree obj, VEC(tree,gc) **args, tsubst_flags_t complain) 4140 { 4141 tree ret; 4142 bool subtime = timevar_cond_start (TV_OVERLOAD); 4143 ret = build_op_call_1 (obj, args, complain); 4144 timevar_cond_stop (TV_OVERLOAD, subtime); 4145 return ret; 4146 } 4147 4148 static void 4149 op_error (enum tree_code code, enum tree_code code2, 4150 tree arg1, tree arg2, tree arg3, bool match) 4151 { 4152 const char *opname; 4153 4154 if (code == MODIFY_EXPR) 4155 opname = assignment_operator_name_info[code2].name; 4156 else 4157 opname = operator_name_info[code].name; 4158 4159 switch (code) 4160 { 4161 case COND_EXPR: 4162 if (match) 4163 error ("ambiguous overload for ternary %<operator?:%> " 4164 "in %<%E ? %E : %E%>", arg1, arg2, arg3); 4165 else 4166 error ("no match for ternary %<operator?:%> " 4167 "in %<%E ? %E : %E%>", arg1, arg2, arg3); 4168 break; 4169 4170 case POSTINCREMENT_EXPR: 4171 case POSTDECREMENT_EXPR: 4172 if (match) 4173 error ("ambiguous overload for %<operator%s%> in %<%E%s%>", 4174 opname, arg1, opname); 4175 else 4176 error ("no match for %<operator%s%> in %<%E%s%>", 4177 opname, arg1, opname); 4178 break; 4179 4180 case ARRAY_REF: 4181 if (match) 4182 error ("ambiguous overload for %<operator[]%> in %<%E[%E]%>", 4183 arg1, arg2); 4184 else 4185 error ("no match for %<operator[]%> in %<%E[%E]%>", 4186 arg1, arg2); 4187 break; 4188 4189 case REALPART_EXPR: 4190 case IMAGPART_EXPR: 4191 if (match) 4192 error ("ambiguous overload for %qs in %<%s %E%>", 4193 opname, opname, arg1); 4194 else 4195 error ("no match for %qs in %<%s %E%>", 4196 opname, opname, arg1); 4197 break; 4198 4199 default: 4200 if (arg2) 4201 if (match) 4202 error ("ambiguous overload for %<operator%s%> in %<%E %s %E%>", 4203 opname, arg1, opname, arg2); 4204 else 4205 error ("no match for %<operator%s%> in %<%E %s %E%>", 4206 opname, arg1, opname, arg2); 4207 else 4208 if (match) 4209 error ("ambiguous overload for %<operator%s%> in %<%s%E%>", 4210 opname, opname, arg1); 4211 else 4212 error ("no match for %<operator%s%> in %<%s%E%>", 4213 opname, opname, arg1); 4214 break; 4215 } 4216 } 4217 4218 /* Return the implicit conversion sequence that could be used to 4219 convert E1 to E2 in [expr.cond]. */ 4220 4221 static conversion * 4222 conditional_conversion (tree e1, tree e2) 4223 { 4224 tree t1 = non_reference (TREE_TYPE (e1)); 4225 tree t2 = non_reference (TREE_TYPE (e2)); 4226 conversion *conv; 4227 bool good_base; 4228 4229 /* [expr.cond] 4230 4231 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be 4232 implicitly converted (clause _conv_) to the type "lvalue reference to 4233 T2", subject to the constraint that in the conversion the 4234 reference must bind directly (_dcl.init.ref_) to an lvalue. */ 4235 if (real_lvalue_p (e2)) 4236 { 4237 conv = implicit_conversion (build_reference_type (t2), 4238 t1, 4239 e1, 4240 /*c_cast_p=*/false, 4241 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND 4242 |LOOKUP_ONLYCONVERTING); 4243 if (conv) 4244 return conv; 4245 } 4246 4247 /* [expr.cond] 4248 4249 If E1 and E2 have class type, and the underlying class types are 4250 the same or one is a base class of the other: E1 can be converted 4251 to match E2 if the class of T2 is the same type as, or a base 4252 class of, the class of T1, and the cv-qualification of T2 is the 4253 same cv-qualification as, or a greater cv-qualification than, the 4254 cv-qualification of T1. If the conversion is applied, E1 is 4255 changed to an rvalue of type T2 that still refers to the original 4256 source class object (or the appropriate subobject thereof). */ 4257 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 4258 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2))) 4259 { 4260 if (good_base && at_least_as_qualified_p (t2, t1)) 4261 { 4262 conv = build_identity_conv (t1, e1); 4263 if (!same_type_p (TYPE_MAIN_VARIANT (t1), 4264 TYPE_MAIN_VARIANT (t2))) 4265 conv = build_conv (ck_base, t2, conv); 4266 else 4267 conv = build_conv (ck_rvalue, t2, conv); 4268 return conv; 4269 } 4270 else 4271 return NULL; 4272 } 4273 else 4274 /* [expr.cond] 4275 4276 Otherwise: E1 can be converted to match E2 if E1 can be implicitly 4277 converted to the type that expression E2 would have if E2 were 4278 converted to an rvalue (or the type it has, if E2 is an rvalue). */ 4279 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false, 4280 LOOKUP_IMPLICIT); 4281 } 4282 4283 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three 4284 arguments to the conditional expression. */ 4285 4286 static tree 4287 build_conditional_expr_1 (tree arg1, tree arg2, tree arg3, 4288 tsubst_flags_t complain) 4289 { 4290 tree arg2_type; 4291 tree arg3_type; 4292 tree result = NULL_TREE; 4293 tree result_type = NULL_TREE; 4294 bool lvalue_p = true; 4295 struct z_candidate *candidates = 0; 4296 struct z_candidate *cand; 4297 void *p; 4298 4299 /* As a G++ extension, the second argument to the conditional can be 4300 omitted. (So that `a ? : c' is roughly equivalent to `a ? a : 4301 c'.) If the second operand is omitted, make sure it is 4302 calculated only once. */ 4303 if (!arg2) 4304 { 4305 if (complain & tf_error) 4306 pedwarn (input_location, OPT_pedantic, 4307 "ISO C++ forbids omitting the middle term of a ?: expression"); 4308 4309 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */ 4310 if (real_lvalue_p (arg1)) 4311 arg2 = arg1 = stabilize_reference (arg1); 4312 else 4313 arg2 = arg1 = save_expr (arg1); 4314 } 4315 4316 /* [expr.cond] 4317 4318 The first expression is implicitly converted to bool (clause 4319 _conv_). */ 4320 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain, 4321 LOOKUP_NORMAL); 4322 4323 /* If something has already gone wrong, just pass that fact up the 4324 tree. */ 4325 if (error_operand_p (arg1) 4326 || error_operand_p (arg2) 4327 || error_operand_p (arg3)) 4328 return error_mark_node; 4329 4330 /* [expr.cond] 4331 4332 If either the second or the third operand has type (possibly 4333 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_), 4334 array-to-pointer (_conv.array_), and function-to-pointer 4335 (_conv.func_) standard conversions are performed on the second 4336 and third operands. */ 4337 arg2_type = unlowered_expr_type (arg2); 4338 arg3_type = unlowered_expr_type (arg3); 4339 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type)) 4340 { 4341 /* Do the conversions. We don't these for `void' type arguments 4342 since it can't have any effect and since decay_conversion 4343 does not handle that case gracefully. */ 4344 if (!VOID_TYPE_P (arg2_type)) 4345 arg2 = decay_conversion (arg2); 4346 if (!VOID_TYPE_P (arg3_type)) 4347 arg3 = decay_conversion (arg3); 4348 arg2_type = TREE_TYPE (arg2); 4349 arg3_type = TREE_TYPE (arg3); 4350 4351 /* [expr.cond] 4352 4353 One of the following shall hold: 4354 4355 --The second or the third operand (but not both) is a 4356 throw-expression (_except.throw_); the result is of the 4357 type of the other and is an rvalue. 4358 4359 --Both the second and the third operands have type void; the 4360 result is of type void and is an rvalue. 4361 4362 We must avoid calling force_rvalue for expressions of type 4363 "void" because it will complain that their value is being 4364 used. */ 4365 if (TREE_CODE (arg2) == THROW_EXPR 4366 && TREE_CODE (arg3) != THROW_EXPR) 4367 { 4368 if (!VOID_TYPE_P (arg3_type)) 4369 { 4370 arg3 = force_rvalue (arg3, complain); 4371 if (arg3 == error_mark_node) 4372 return error_mark_node; 4373 } 4374 arg3_type = TREE_TYPE (arg3); 4375 result_type = arg3_type; 4376 } 4377 else if (TREE_CODE (arg2) != THROW_EXPR 4378 && TREE_CODE (arg3) == THROW_EXPR) 4379 { 4380 if (!VOID_TYPE_P (arg2_type)) 4381 { 4382 arg2 = force_rvalue (arg2, complain); 4383 if (arg2 == error_mark_node) 4384 return error_mark_node; 4385 } 4386 arg2_type = TREE_TYPE (arg2); 4387 result_type = arg2_type; 4388 } 4389 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type)) 4390 result_type = void_type_node; 4391 else 4392 { 4393 if (complain & tf_error) 4394 { 4395 if (VOID_TYPE_P (arg2_type)) 4396 error ("second operand to the conditional operator " 4397 "is of type %<void%>, " 4398 "but the third operand is neither a throw-expression " 4399 "nor of type %<void%>"); 4400 else 4401 error ("third operand to the conditional operator " 4402 "is of type %<void%>, " 4403 "but the second operand is neither a throw-expression " 4404 "nor of type %<void%>"); 4405 } 4406 return error_mark_node; 4407 } 4408 4409 lvalue_p = false; 4410 goto valid_operands; 4411 } 4412 /* [expr.cond] 4413 4414 Otherwise, if the second and third operand have different types, 4415 and either has (possibly cv-qualified) class type, an attempt is 4416 made to convert each of those operands to the type of the other. */ 4417 else if (!same_type_p (arg2_type, arg3_type) 4418 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type))) 4419 { 4420 conversion *conv2; 4421 conversion *conv3; 4422 4423 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4424 p = conversion_obstack_alloc (0); 4425 4426 conv2 = conditional_conversion (arg2, arg3); 4427 conv3 = conditional_conversion (arg3, arg2); 4428 4429 /* [expr.cond] 4430 4431 If both can be converted, or one can be converted but the 4432 conversion is ambiguous, the program is ill-formed. If 4433 neither can be converted, the operands are left unchanged and 4434 further checking is performed as described below. If exactly 4435 one conversion is possible, that conversion is applied to the 4436 chosen operand and the converted operand is used in place of 4437 the original operand for the remainder of this section. */ 4438 if ((conv2 && !conv2->bad_p 4439 && conv3 && !conv3->bad_p) 4440 || (conv2 && conv2->kind == ck_ambig) 4441 || (conv3 && conv3->kind == ck_ambig)) 4442 { 4443 error ("operands to ?: have different types %qT and %qT", 4444 arg2_type, arg3_type); 4445 result = error_mark_node; 4446 } 4447 else if (conv2 && (!conv2->bad_p || !conv3)) 4448 { 4449 arg2 = convert_like (conv2, arg2, complain); 4450 arg2 = convert_from_reference (arg2); 4451 arg2_type = TREE_TYPE (arg2); 4452 /* Even if CONV2 is a valid conversion, the result of the 4453 conversion may be invalid. For example, if ARG3 has type 4454 "volatile X", and X does not have a copy constructor 4455 accepting a "volatile X&", then even if ARG2 can be 4456 converted to X, the conversion will fail. */ 4457 if (error_operand_p (arg2)) 4458 result = error_mark_node; 4459 } 4460 else if (conv3 && (!conv3->bad_p || !conv2)) 4461 { 4462 arg3 = convert_like (conv3, arg3, complain); 4463 arg3 = convert_from_reference (arg3); 4464 arg3_type = TREE_TYPE (arg3); 4465 if (error_operand_p (arg3)) 4466 result = error_mark_node; 4467 } 4468 4469 /* Free all the conversions we allocated. */ 4470 obstack_free (&conversion_obstack, p); 4471 4472 if (result) 4473 return result; 4474 4475 /* If, after the conversion, both operands have class type, 4476 treat the cv-qualification of both operands as if it were the 4477 union of the cv-qualification of the operands. 4478 4479 The standard is not clear about what to do in this 4480 circumstance. For example, if the first operand has type 4481 "const X" and the second operand has a user-defined 4482 conversion to "volatile X", what is the type of the second 4483 operand after this step? Making it be "const X" (matching 4484 the first operand) seems wrong, as that discards the 4485 qualification without actually performing a copy. Leaving it 4486 as "volatile X" seems wrong as that will result in the 4487 conditional expression failing altogether, even though, 4488 according to this step, the one operand could be converted to 4489 the type of the other. */ 4490 if ((conv2 || conv3) 4491 && CLASS_TYPE_P (arg2_type) 4492 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type)) 4493 arg2_type = arg3_type = 4494 cp_build_qualified_type (arg2_type, 4495 cp_type_quals (arg2_type) 4496 | cp_type_quals (arg3_type)); 4497 } 4498 4499 /* [expr.cond] 4500 4501 If the second and third operands are lvalues and have the same 4502 type, the result is of that type and is an lvalue. */ 4503 if (real_lvalue_p (arg2) 4504 && real_lvalue_p (arg3) 4505 && same_type_p (arg2_type, arg3_type)) 4506 { 4507 result_type = arg2_type; 4508 arg2 = mark_lvalue_use (arg2); 4509 arg3 = mark_lvalue_use (arg3); 4510 goto valid_operands; 4511 } 4512 4513 /* [expr.cond] 4514 4515 Otherwise, the result is an rvalue. If the second and third 4516 operand do not have the same type, and either has (possibly 4517 cv-qualified) class type, overload resolution is used to 4518 determine the conversions (if any) to be applied to the operands 4519 (_over.match.oper_, _over.built_). */ 4520 lvalue_p = false; 4521 if (!same_type_p (arg2_type, arg3_type) 4522 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type))) 4523 { 4524 tree args[3]; 4525 conversion *conv; 4526 bool any_viable_p; 4527 4528 /* Rearrange the arguments so that add_builtin_candidate only has 4529 to know about two args. In build_builtin_candidate, the 4530 arguments are unscrambled. */ 4531 args[0] = arg2; 4532 args[1] = arg3; 4533 args[2] = arg1; 4534 add_builtin_candidates (&candidates, 4535 COND_EXPR, 4536 NOP_EXPR, 4537 ansi_opname (COND_EXPR), 4538 args, 4539 LOOKUP_NORMAL); 4540 4541 /* [expr.cond] 4542 4543 If the overload resolution fails, the program is 4544 ill-formed. */ 4545 candidates = splice_viable (candidates, pedantic, &any_viable_p); 4546 if (!any_viable_p) 4547 { 4548 if (complain & tf_error) 4549 { 4550 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE); 4551 print_z_candidates (location_of (arg1), candidates); 4552 } 4553 return error_mark_node; 4554 } 4555 cand = tourney (candidates); 4556 if (!cand) 4557 { 4558 if (complain & tf_error) 4559 { 4560 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE); 4561 print_z_candidates (location_of (arg1), candidates); 4562 } 4563 return error_mark_node; 4564 } 4565 4566 /* [expr.cond] 4567 4568 Otherwise, the conversions thus determined are applied, and 4569 the converted operands are used in place of the original 4570 operands for the remainder of this section. */ 4571 conv = cand->convs[0]; 4572 arg1 = convert_like (conv, arg1, complain); 4573 conv = cand->convs[1]; 4574 arg2 = convert_like (conv, arg2, complain); 4575 arg2_type = TREE_TYPE (arg2); 4576 conv = cand->convs[2]; 4577 arg3 = convert_like (conv, arg3, complain); 4578 arg3_type = TREE_TYPE (arg3); 4579 } 4580 4581 /* [expr.cond] 4582 4583 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_), 4584 and function-to-pointer (_conv.func_) standard conversions are 4585 performed on the second and third operands. 4586 4587 We need to force the lvalue-to-rvalue conversion here for class types, 4588 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues 4589 that isn't wrapped with a TARGET_EXPR plays havoc with exception 4590 regions. */ 4591 4592 arg2 = force_rvalue (arg2, complain); 4593 if (!CLASS_TYPE_P (arg2_type)) 4594 arg2_type = TREE_TYPE (arg2); 4595 4596 arg3 = force_rvalue (arg3, complain); 4597 if (!CLASS_TYPE_P (arg3_type)) 4598 arg3_type = TREE_TYPE (arg3); 4599 4600 if (arg2 == error_mark_node || arg3 == error_mark_node) 4601 return error_mark_node; 4602 4603 /* [expr.cond] 4604 4605 After those conversions, one of the following shall hold: 4606 4607 --The second and third operands have the same type; the result is of 4608 that type. */ 4609 if (same_type_p (arg2_type, arg3_type)) 4610 result_type = arg2_type; 4611 /* [expr.cond] 4612 4613 --The second and third operands have arithmetic or enumeration 4614 type; the usual arithmetic conversions are performed to bring 4615 them to a common type, and the result is of that type. */ 4616 else if ((ARITHMETIC_TYPE_P (arg2_type) 4617 || UNSCOPED_ENUM_P (arg2_type)) 4618 && (ARITHMETIC_TYPE_P (arg3_type) 4619 || UNSCOPED_ENUM_P (arg3_type))) 4620 { 4621 /* In this case, there is always a common type. */ 4622 result_type = type_after_usual_arithmetic_conversions (arg2_type, 4623 arg3_type); 4624 do_warn_double_promotion (result_type, arg2_type, arg3_type, 4625 "implicit conversion from %qT to %qT to " 4626 "match other result of conditional", 4627 input_location); 4628 4629 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE 4630 && TREE_CODE (arg3_type) == ENUMERAL_TYPE) 4631 { 4632 if (complain & tf_warning) 4633 warning (OPT_Wenum_compare, 4634 "enumeral mismatch in conditional expression: %qT vs %qT", 4635 arg2_type, arg3_type); 4636 } 4637 else if (extra_warnings 4638 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE 4639 && !same_type_p (arg3_type, type_promotes_to (arg2_type))) 4640 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE 4641 && !same_type_p (arg2_type, type_promotes_to (arg3_type))))) 4642 { 4643 if (complain & tf_warning) 4644 warning (0, 4645 "enumeral and non-enumeral type in conditional expression"); 4646 } 4647 4648 arg2 = perform_implicit_conversion (result_type, arg2, complain); 4649 arg3 = perform_implicit_conversion (result_type, arg3, complain); 4650 } 4651 /* [expr.cond] 4652 4653 --The second and third operands have pointer type, or one has 4654 pointer type and the other is a null pointer constant; pointer 4655 conversions (_conv.ptr_) and qualification conversions 4656 (_conv.qual_) are performed to bring them to their composite 4657 pointer type (_expr.rel_). The result is of the composite 4658 pointer type. 4659 4660 --The second and third operands have pointer to member type, or 4661 one has pointer to member type and the other is a null pointer 4662 constant; pointer to member conversions (_conv.mem_) and 4663 qualification conversions (_conv.qual_) are performed to bring 4664 them to a common type, whose cv-qualification shall match the 4665 cv-qualification of either the second or the third operand. 4666 The result is of the common type. */ 4667 else if ((null_ptr_cst_p (arg2) 4668 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type))) 4669 || (null_ptr_cst_p (arg3) 4670 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type))) 4671 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type)) 4672 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type)) 4673 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type))) 4674 { 4675 result_type = composite_pointer_type (arg2_type, arg3_type, arg2, 4676 arg3, CPO_CONDITIONAL_EXPR, 4677 complain); 4678 if (result_type == error_mark_node) 4679 return error_mark_node; 4680 arg2 = perform_implicit_conversion (result_type, arg2, complain); 4681 arg3 = perform_implicit_conversion (result_type, arg3, complain); 4682 } 4683 4684 if (!result_type) 4685 { 4686 if (complain & tf_error) 4687 error ("operands to ?: have different types %qT and %qT", 4688 arg2_type, arg3_type); 4689 return error_mark_node; 4690 } 4691 4692 valid_operands: 4693 result = build3 (COND_EXPR, result_type, arg1, arg2, arg3); 4694 if (!cp_unevaluated_operand) 4695 /* Avoid folding within decltype (c++/42013) and noexcept. */ 4696 result = fold_if_not_in_template (result); 4697 4698 /* We can't use result_type below, as fold might have returned a 4699 throw_expr. */ 4700 4701 if (!lvalue_p) 4702 { 4703 /* Expand both sides into the same slot, hopefully the target of 4704 the ?: expression. We used to check for TARGET_EXPRs here, 4705 but now we sometimes wrap them in NOP_EXPRs so the test would 4706 fail. */ 4707 if (CLASS_TYPE_P (TREE_TYPE (result))) 4708 result = get_target_expr (result); 4709 /* If this expression is an rvalue, but might be mistaken for an 4710 lvalue, we must add a NON_LVALUE_EXPR. */ 4711 result = rvalue (result); 4712 } 4713 4714 return result; 4715 } 4716 4717 /* Wrapper for above. */ 4718 4719 tree 4720 build_conditional_expr (tree arg1, tree arg2, tree arg3, 4721 tsubst_flags_t complain) 4722 { 4723 tree ret; 4724 bool subtime = timevar_cond_start (TV_OVERLOAD); 4725 ret = build_conditional_expr_1 (arg1, arg2, arg3, complain); 4726 timevar_cond_stop (TV_OVERLOAD, subtime); 4727 return ret; 4728 } 4729 4730 /* OPERAND is an operand to an expression. Perform necessary steps 4731 required before using it. If OPERAND is NULL_TREE, NULL_TREE is 4732 returned. */ 4733 4734 static tree 4735 prep_operand (tree operand) 4736 { 4737 if (operand) 4738 { 4739 if (CLASS_TYPE_P (TREE_TYPE (operand)) 4740 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand))) 4741 /* Make sure the template type is instantiated now. */ 4742 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand))); 4743 } 4744 4745 return operand; 4746 } 4747 4748 /* Add each of the viable functions in FNS (a FUNCTION_DECL or 4749 OVERLOAD) to the CANDIDATES, returning an updated list of 4750 CANDIDATES. The ARGS are the arguments provided to the call; 4751 if FIRST_ARG is non-null it is the implicit object argument, 4752 otherwise the first element of ARGS is used if needed. The 4753 EXPLICIT_TARGS are explicit template arguments provided. 4754 TEMPLATE_ONLY is true if only template functions should be 4755 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for 4756 add_function_candidate. */ 4757 4758 static void 4759 add_candidates (tree fns, tree first_arg, const VEC(tree,gc) *args, 4760 tree return_type, 4761 tree explicit_targs, bool template_only, 4762 tree conversion_path, tree access_path, 4763 int flags, 4764 struct z_candidate **candidates) 4765 { 4766 tree ctype; 4767 const VEC(tree,gc) *non_static_args; 4768 bool check_list_ctor; 4769 bool check_converting; 4770 unification_kind_t strict; 4771 tree fn; 4772 4773 if (!fns) 4774 return; 4775 4776 /* Precalculate special handling of constructors and conversion ops. */ 4777 fn = OVL_CURRENT (fns); 4778 if (DECL_CONV_FN_P (fn)) 4779 { 4780 check_list_ctor = false; 4781 check_converting = !!(flags & LOOKUP_ONLYCONVERTING); 4782 if (flags & LOOKUP_NO_CONVERSION) 4783 /* We're doing return_type(x). */ 4784 strict = DEDUCE_CONV; 4785 else 4786 /* We're doing x.operator return_type(). */ 4787 strict = DEDUCE_EXACT; 4788 /* [over.match.funcs] For conversion functions, the function 4789 is considered to be a member of the class of the implicit 4790 object argument for the purpose of defining the type of 4791 the implicit object parameter. */ 4792 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (first_arg))); 4793 } 4794 else 4795 { 4796 if (DECL_CONSTRUCTOR_P (fn)) 4797 { 4798 check_list_ctor = !!(flags & LOOKUP_LIST_ONLY); 4799 /* For list-initialization we consider explicit constructors 4800 and complain if one is chosen. */ 4801 check_converting 4802 = ((flags & (LOOKUP_ONLYCONVERTING|LOOKUP_LIST_INIT_CTOR)) 4803 == LOOKUP_ONLYCONVERTING); 4804 } 4805 else 4806 { 4807 check_list_ctor = false; 4808 check_converting = false; 4809 } 4810 strict = DEDUCE_CALL; 4811 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE; 4812 } 4813 4814 if (first_arg) 4815 non_static_args = args; 4816 else 4817 /* Delay creating the implicit this parameter until it is needed. */ 4818 non_static_args = NULL; 4819 4820 for (; fns; fns = OVL_NEXT (fns)) 4821 { 4822 tree fn_first_arg; 4823 const VEC(tree,gc) *fn_args; 4824 4825 fn = OVL_CURRENT (fns); 4826 4827 if (check_converting && DECL_NONCONVERTING_P (fn)) 4828 continue; 4829 if (check_list_ctor && !is_list_ctor (fn)) 4830 continue; 4831 4832 /* Figure out which set of arguments to use. */ 4833 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) 4834 { 4835 /* If this function is a non-static member and we didn't get an 4836 implicit object argument, move it out of args. */ 4837 if (first_arg == NULL_TREE) 4838 { 4839 unsigned int ix; 4840 tree arg; 4841 VEC(tree,gc) *tempvec 4842 = VEC_alloc (tree, gc, VEC_length (tree, args) - 1); 4843 for (ix = 1; VEC_iterate (tree, args, ix, arg); ++ix) 4844 VEC_quick_push (tree, tempvec, arg); 4845 non_static_args = tempvec; 4846 first_arg = build_this (VEC_index (tree, args, 0)); 4847 } 4848 4849 fn_first_arg = first_arg; 4850 fn_args = non_static_args; 4851 } 4852 else 4853 { 4854 /* Otherwise, just use the list of arguments provided. */ 4855 fn_first_arg = NULL_TREE; 4856 fn_args = args; 4857 } 4858 4859 if (TREE_CODE (fn) == TEMPLATE_DECL) 4860 add_template_candidate (candidates, 4861 fn, 4862 ctype, 4863 explicit_targs, 4864 fn_first_arg, 4865 fn_args, 4866 return_type, 4867 access_path, 4868 conversion_path, 4869 flags, 4870 strict); 4871 else if (!template_only) 4872 add_function_candidate (candidates, 4873 fn, 4874 ctype, 4875 fn_first_arg, 4876 fn_args, 4877 access_path, 4878 conversion_path, 4879 flags); 4880 } 4881 } 4882 4883 static tree 4884 build_new_op_1 (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3, 4885 tree *overload, tsubst_flags_t complain) 4886 { 4887 struct z_candidate *candidates = 0, *cand; 4888 VEC(tree,gc) *arglist; 4889 tree fnname; 4890 tree args[3]; 4891 tree result = NULL_TREE; 4892 bool result_valid_p = false; 4893 enum tree_code code2 = NOP_EXPR; 4894 enum tree_code code_orig_arg1 = ERROR_MARK; 4895 enum tree_code code_orig_arg2 = ERROR_MARK; 4896 conversion *conv; 4897 void *p; 4898 bool strict_p; 4899 bool any_viable_p; 4900 4901 if (error_operand_p (arg1) 4902 || error_operand_p (arg2) 4903 || error_operand_p (arg3)) 4904 return error_mark_node; 4905 4906 if (code == MODIFY_EXPR) 4907 { 4908 code2 = TREE_CODE (arg3); 4909 arg3 = NULL_TREE; 4910 fnname = ansi_assopname (code2); 4911 } 4912 else 4913 fnname = ansi_opname (code); 4914 4915 arg1 = prep_operand (arg1); 4916 4917 switch (code) 4918 { 4919 case NEW_EXPR: 4920 case VEC_NEW_EXPR: 4921 case VEC_DELETE_EXPR: 4922 case DELETE_EXPR: 4923 /* Use build_op_new_call and build_op_delete_call instead. */ 4924 gcc_unreachable (); 4925 4926 case CALL_EXPR: 4927 /* Use build_op_call instead. */ 4928 gcc_unreachable (); 4929 4930 case TRUTH_ORIF_EXPR: 4931 case TRUTH_ANDIF_EXPR: 4932 case TRUTH_AND_EXPR: 4933 case TRUTH_OR_EXPR: 4934 /* These are saved for the sake of warn_logical_operator. */ 4935 code_orig_arg1 = TREE_CODE (arg1); 4936 code_orig_arg2 = TREE_CODE (arg2); 4937 4938 default: 4939 break; 4940 } 4941 4942 arg2 = prep_operand (arg2); 4943 arg3 = prep_operand (arg3); 4944 4945 if (code == COND_EXPR) 4946 /* Use build_conditional_expr instead. */ 4947 gcc_unreachable (); 4948 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1)) 4949 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2)))) 4950 goto builtin; 4951 4952 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR) 4953 arg2 = integer_zero_node; 4954 4955 arglist = VEC_alloc (tree, gc, 3); 4956 VEC_quick_push (tree, arglist, arg1); 4957 if (arg2 != NULL_TREE) 4958 VEC_quick_push (tree, arglist, arg2); 4959 if (arg3 != NULL_TREE) 4960 VEC_quick_push (tree, arglist, arg3); 4961 4962 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4963 p = conversion_obstack_alloc (0); 4964 4965 /* Add namespace-scope operators to the list of functions to 4966 consider. */ 4967 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true), 4968 NULL_TREE, arglist, NULL_TREE, 4969 NULL_TREE, false, NULL_TREE, NULL_TREE, 4970 flags, &candidates); 4971 /* Add class-member operators to the candidate set. */ 4972 if (CLASS_TYPE_P (TREE_TYPE (arg1))) 4973 { 4974 tree fns; 4975 4976 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1); 4977 if (fns == error_mark_node) 4978 { 4979 result = error_mark_node; 4980 goto user_defined_result_ready; 4981 } 4982 if (fns) 4983 add_candidates (BASELINK_FUNCTIONS (fns), 4984 NULL_TREE, arglist, NULL_TREE, 4985 NULL_TREE, false, 4986 BASELINK_BINFO (fns), 4987 BASELINK_ACCESS_BINFO (fns), 4988 flags, &candidates); 4989 } 4990 4991 args[0] = arg1; 4992 args[1] = arg2; 4993 args[2] = NULL_TREE; 4994 4995 add_builtin_candidates (&candidates, code, code2, fnname, args, flags); 4996 4997 switch (code) 4998 { 4999 case COMPOUND_EXPR: 5000 case ADDR_EXPR: 5001 /* For these, the built-in candidates set is empty 5002 [over.match.oper]/3. We don't want non-strict matches 5003 because exact matches are always possible with built-in 5004 operators. The built-in candidate set for COMPONENT_REF 5005 would be empty too, but since there are no such built-in 5006 operators, we accept non-strict matches for them. */ 5007 strict_p = true; 5008 break; 5009 5010 default: 5011 strict_p = pedantic; 5012 break; 5013 } 5014 5015 candidates = splice_viable (candidates, strict_p, &any_viable_p); 5016 if (!any_viable_p) 5017 { 5018 switch (code) 5019 { 5020 case POSTINCREMENT_EXPR: 5021 case POSTDECREMENT_EXPR: 5022 /* Don't try anything fancy if we're not allowed to produce 5023 errors. */ 5024 if (!(complain & tf_error)) 5025 return error_mark_node; 5026 5027 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't 5028 distinguish between prefix and postfix ++ and 5029 operator++() was used for both, so we allow this with 5030 -fpermissive. */ 5031 if (flags & LOOKUP_COMPLAIN) 5032 { 5033 const char *msg = (flag_permissive) 5034 ? G_("no %<%D(int)%> declared for postfix %qs," 5035 " trying prefix operator instead") 5036 : G_("no %<%D(int)%> declared for postfix %qs"); 5037 permerror (input_location, msg, fnname, 5038 operator_name_info[code].name); 5039 } 5040 5041 if (!flag_permissive) 5042 return error_mark_node; 5043 5044 if (code == POSTINCREMENT_EXPR) 5045 code = PREINCREMENT_EXPR; 5046 else 5047 code = PREDECREMENT_EXPR; 5048 result = build_new_op_1 (code, flags, arg1, NULL_TREE, NULL_TREE, 5049 overload, complain); 5050 break; 5051 5052 /* The caller will deal with these. */ 5053 case ADDR_EXPR: 5054 case COMPOUND_EXPR: 5055 case COMPONENT_REF: 5056 result = NULL_TREE; 5057 result_valid_p = true; 5058 break; 5059 5060 default: 5061 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error)) 5062 { 5063 /* If one of the arguments of the operator represents 5064 an invalid use of member function pointer, try to report 5065 a meaningful error ... */ 5066 if (invalid_nonstatic_memfn_p (arg1, tf_error) 5067 || invalid_nonstatic_memfn_p (arg2, tf_error) 5068 || invalid_nonstatic_memfn_p (arg3, tf_error)) 5069 /* We displayed the error message. */; 5070 else 5071 { 5072 /* ... Otherwise, report the more generic 5073 "no matching operator found" error */ 5074 op_error (code, code2, arg1, arg2, arg3, FALSE); 5075 print_z_candidates (input_location, candidates); 5076 } 5077 } 5078 result = error_mark_node; 5079 break; 5080 } 5081 } 5082 else 5083 { 5084 cand = tourney (candidates); 5085 if (cand == 0) 5086 { 5087 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error)) 5088 { 5089 op_error (code, code2, arg1, arg2, arg3, TRUE); 5090 print_z_candidates (input_location, candidates); 5091 } 5092 result = error_mark_node; 5093 } 5094 else if (TREE_CODE (cand->fn) == FUNCTION_DECL) 5095 { 5096 if (overload) 5097 *overload = cand->fn; 5098 5099 if (resolve_args (arglist, complain) == NULL) 5100 result = error_mark_node; 5101 else 5102 result = build_over_call (cand, LOOKUP_NORMAL, complain); 5103 } 5104 else 5105 { 5106 /* Give any warnings we noticed during overload resolution. */ 5107 if (cand->warnings && (complain & tf_warning)) 5108 { 5109 struct candidate_warning *w; 5110 for (w = cand->warnings; w; w = w->next) 5111 joust (cand, w->loser, 1); 5112 } 5113 5114 /* Check for comparison of different enum types. */ 5115 switch (code) 5116 { 5117 case GT_EXPR: 5118 case LT_EXPR: 5119 case GE_EXPR: 5120 case LE_EXPR: 5121 case EQ_EXPR: 5122 case NE_EXPR: 5123 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE 5124 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE 5125 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1)) 5126 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))) 5127 && (complain & tf_warning)) 5128 { 5129 warning (OPT_Wenum_compare, 5130 "comparison between %q#T and %q#T", 5131 TREE_TYPE (arg1), TREE_TYPE (arg2)); 5132 } 5133 break; 5134 default: 5135 break; 5136 } 5137 5138 /* We need to strip any leading REF_BIND so that bitfields 5139 don't cause errors. This should not remove any important 5140 conversions, because builtins don't apply to class 5141 objects directly. */ 5142 conv = cand->convs[0]; 5143 if (conv->kind == ck_ref_bind) 5144 conv = conv->u.next; 5145 arg1 = convert_like (conv, arg1, complain); 5146 5147 if (arg2) 5148 { 5149 /* We need to call warn_logical_operator before 5150 converting arg2 to a boolean_type. */ 5151 if (complain & tf_warning) 5152 warn_logical_operator (input_location, code, boolean_type_node, 5153 code_orig_arg1, arg1, 5154 code_orig_arg2, arg2); 5155 5156 conv = cand->convs[1]; 5157 if (conv->kind == ck_ref_bind) 5158 conv = conv->u.next; 5159 arg2 = convert_like (conv, arg2, complain); 5160 } 5161 if (arg3) 5162 { 5163 conv = cand->convs[2]; 5164 if (conv->kind == ck_ref_bind) 5165 conv = conv->u.next; 5166 arg3 = convert_like (conv, arg3, complain); 5167 } 5168 5169 } 5170 } 5171 5172 user_defined_result_ready: 5173 5174 /* Free all the conversions we allocated. */ 5175 obstack_free (&conversion_obstack, p); 5176 5177 if (result || result_valid_p) 5178 return result; 5179 5180 builtin: 5181 switch (code) 5182 { 5183 case MODIFY_EXPR: 5184 return cp_build_modify_expr (arg1, code2, arg2, complain); 5185 5186 case INDIRECT_REF: 5187 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain); 5188 5189 case TRUTH_ANDIF_EXPR: 5190 case TRUTH_ORIF_EXPR: 5191 case TRUTH_AND_EXPR: 5192 case TRUTH_OR_EXPR: 5193 warn_logical_operator (input_location, code, boolean_type_node, 5194 code_orig_arg1, arg1, code_orig_arg2, arg2); 5195 /* Fall through. */ 5196 case PLUS_EXPR: 5197 case MINUS_EXPR: 5198 case MULT_EXPR: 5199 case TRUNC_DIV_EXPR: 5200 case GT_EXPR: 5201 case LT_EXPR: 5202 case GE_EXPR: 5203 case LE_EXPR: 5204 case EQ_EXPR: 5205 case NE_EXPR: 5206 case MAX_EXPR: 5207 case MIN_EXPR: 5208 case LSHIFT_EXPR: 5209 case RSHIFT_EXPR: 5210 case TRUNC_MOD_EXPR: 5211 case BIT_AND_EXPR: 5212 case BIT_IOR_EXPR: 5213 case BIT_XOR_EXPR: 5214 return cp_build_binary_op (input_location, code, arg1, arg2, complain); 5215 5216 case UNARY_PLUS_EXPR: 5217 case NEGATE_EXPR: 5218 case BIT_NOT_EXPR: 5219 case TRUTH_NOT_EXPR: 5220 case PREINCREMENT_EXPR: 5221 case POSTINCREMENT_EXPR: 5222 case PREDECREMENT_EXPR: 5223 case POSTDECREMENT_EXPR: 5224 case REALPART_EXPR: 5225 case IMAGPART_EXPR: 5226 case ABS_EXPR: 5227 return cp_build_unary_op (code, arg1, candidates != 0, complain); 5228 5229 case ARRAY_REF: 5230 return cp_build_array_ref (input_location, arg1, arg2, complain); 5231 5232 case MEMBER_REF: 5233 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_NULL, 5234 complain), 5235 arg2); 5236 5237 /* The caller will deal with these. */ 5238 case ADDR_EXPR: 5239 case COMPONENT_REF: 5240 case COMPOUND_EXPR: 5241 return NULL_TREE; 5242 5243 default: 5244 gcc_unreachable (); 5245 } 5246 return NULL_TREE; 5247 } 5248 5249 /* Wrapper for above. */ 5250 5251 tree 5252 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3, 5253 tree *overload, tsubst_flags_t complain) 5254 { 5255 tree ret; 5256 bool subtime = timevar_cond_start (TV_OVERLOAD); 5257 ret = build_new_op_1 (code, flags, arg1, arg2, arg3, overload, complain); 5258 timevar_cond_stop (TV_OVERLOAD, subtime); 5259 return ret; 5260 } 5261 5262 /* Returns true iff T, an element of an OVERLOAD chain, is a usual 5263 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */ 5264 5265 static bool 5266 non_placement_deallocation_fn_p (tree t) 5267 { 5268 /* A template instance is never a usual deallocation function, 5269 regardless of its signature. */ 5270 if (TREE_CODE (t) == TEMPLATE_DECL 5271 || primary_template_instantiation_p (t)) 5272 return false; 5273 5274 /* If a class T has a member deallocation function named operator delete 5275 with exactly one parameter, then that function is a usual 5276 (non-placement) deallocation function. If class T does not declare 5277 such an operator delete but does declare a member deallocation 5278 function named operator delete with exactly two parameters, the second 5279 of which has type std::size_t (18.2), then this function is a usual 5280 deallocation function. */ 5281 t = FUNCTION_ARG_CHAIN (t); 5282 if (t == void_list_node 5283 || (t && same_type_p (TREE_VALUE (t), size_type_node) 5284 && TREE_CHAIN (t) == void_list_node)) 5285 return true; 5286 return false; 5287 } 5288 5289 /* Build a call to operator delete. This has to be handled very specially, 5290 because the restrictions on what signatures match are different from all 5291 other call instances. For a normal delete, only a delete taking (void *) 5292 or (void *, size_t) is accepted. For a placement delete, only an exact 5293 match with the placement new is accepted. 5294 5295 CODE is either DELETE_EXPR or VEC_DELETE_EXPR. 5296 ADDR is the pointer to be deleted. 5297 SIZE is the size of the memory block to be deleted. 5298 GLOBAL_P is true if the delete-expression should not consider 5299 class-specific delete operators. 5300 PLACEMENT is the corresponding placement new call, or NULL_TREE. 5301 5302 If this call to "operator delete" is being generated as part to 5303 deallocate memory allocated via a new-expression (as per [expr.new] 5304 which requires that if the initialization throws an exception then 5305 we call a deallocation function), then ALLOC_FN is the allocation 5306 function. */ 5307 5308 tree 5309 build_op_delete_call (enum tree_code code, tree addr, tree size, 5310 bool global_p, tree placement, 5311 tree alloc_fn) 5312 { 5313 tree fn = NULL_TREE; 5314 tree fns, fnname, type, t; 5315 5316 if (addr == error_mark_node) 5317 return error_mark_node; 5318 5319 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr))); 5320 5321 fnname = ansi_opname (code); 5322 5323 if (CLASS_TYPE_P (type) 5324 && COMPLETE_TYPE_P (complete_type (type)) 5325 && !global_p) 5326 /* In [class.free] 5327 5328 If the result of the lookup is ambiguous or inaccessible, or if 5329 the lookup selects a placement deallocation function, the 5330 program is ill-formed. 5331 5332 Therefore, we ask lookup_fnfields to complain about ambiguity. */ 5333 { 5334 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1); 5335 if (fns == error_mark_node) 5336 return error_mark_node; 5337 } 5338 else 5339 fns = NULL_TREE; 5340 5341 if (fns == NULL_TREE) 5342 fns = lookup_name_nonclass (fnname); 5343 5344 /* Strip const and volatile from addr. */ 5345 addr = cp_convert (ptr_type_node, addr); 5346 5347 if (placement) 5348 { 5349 /* "A declaration of a placement deallocation function matches the 5350 declaration of a placement allocation function if it has the same 5351 number of parameters and, after parameter transformations (8.3.5), 5352 all parameter types except the first are identical." 5353 5354 So we build up the function type we want and ask instantiate_type 5355 to get it for us. */ 5356 t = FUNCTION_ARG_CHAIN (alloc_fn); 5357 t = tree_cons (NULL_TREE, ptr_type_node, t); 5358 t = build_function_type (void_type_node, t); 5359 5360 fn = instantiate_type (t, fns, tf_none); 5361 if (fn == error_mark_node) 5362 return NULL_TREE; 5363 5364 if (BASELINK_P (fn)) 5365 fn = BASELINK_FUNCTIONS (fn); 5366 5367 /* "If the lookup finds the two-parameter form of a usual deallocation 5368 function (3.7.4.2) and that function, considered as a placement 5369 deallocation function, would have been selected as a match for the 5370 allocation function, the program is ill-formed." */ 5371 if (non_placement_deallocation_fn_p (fn)) 5372 { 5373 /* But if the class has an operator delete (void *), then that is 5374 the usual deallocation function, so we shouldn't complain 5375 about using the operator delete (void *, size_t). */ 5376 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns; 5377 t; t = OVL_NEXT (t)) 5378 { 5379 tree elt = OVL_CURRENT (t); 5380 if (non_placement_deallocation_fn_p (elt) 5381 && FUNCTION_ARG_CHAIN (elt) == void_list_node) 5382 goto ok; 5383 } 5384 permerror (0, "non-placement deallocation function %q+D", fn); 5385 permerror (input_location, "selected for placement delete"); 5386 ok:; 5387 } 5388 } 5389 else 5390 /* "Any non-placement deallocation function matches a non-placement 5391 allocation function. If the lookup finds a single matching 5392 deallocation function, that function will be called; otherwise, no 5393 deallocation function will be called." */ 5394 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns; 5395 t; t = OVL_NEXT (t)) 5396 { 5397 tree elt = OVL_CURRENT (t); 5398 if (non_placement_deallocation_fn_p (elt)) 5399 { 5400 fn = elt; 5401 /* "If a class T has a member deallocation function named 5402 operator delete with exactly one parameter, then that 5403 function is a usual (non-placement) deallocation 5404 function. If class T does not declare such an operator 5405 delete but does declare a member deallocation function named 5406 operator delete with exactly two parameters, the second of 5407 which has type std::size_t (18.2), then this function is a 5408 usual deallocation function." 5409 5410 So (void*) beats (void*, size_t). */ 5411 if (FUNCTION_ARG_CHAIN (fn) == void_list_node) 5412 break; 5413 } 5414 } 5415 5416 /* If we have a matching function, call it. */ 5417 if (fn) 5418 { 5419 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 5420 5421 /* If the FN is a member function, make sure that it is 5422 accessible. */ 5423 if (BASELINK_P (fns)) 5424 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn); 5425 5426 /* Core issue 901: It's ok to new a type with deleted delete. */ 5427 if (DECL_DELETED_FN (fn) && alloc_fn) 5428 return NULL_TREE; 5429 5430 if (placement) 5431 { 5432 /* The placement args might not be suitable for overload 5433 resolution at this point, so build the call directly. */ 5434 int nargs = call_expr_nargs (placement); 5435 tree *argarray = XALLOCAVEC (tree, nargs); 5436 int i; 5437 argarray[0] = addr; 5438 for (i = 1; i < nargs; i++) 5439 argarray[i] = CALL_EXPR_ARG (placement, i); 5440 mark_used (fn); 5441 return build_cxx_call (fn, nargs, argarray); 5442 } 5443 else 5444 { 5445 tree ret; 5446 VEC(tree,gc) *args = VEC_alloc (tree, gc, 2); 5447 VEC_quick_push (tree, args, addr); 5448 if (FUNCTION_ARG_CHAIN (fn) != void_list_node) 5449 VEC_quick_push (tree, args, size); 5450 ret = cp_build_function_call_vec (fn, &args, tf_warning_or_error); 5451 VEC_free (tree, gc, args); 5452 return ret; 5453 } 5454 } 5455 5456 /* [expr.new] 5457 5458 If no unambiguous matching deallocation function can be found, 5459 propagating the exception does not cause the object's memory to 5460 be freed. */ 5461 if (alloc_fn) 5462 { 5463 if (!placement) 5464 warning (0, "no corresponding deallocation function for %qD", 5465 alloc_fn); 5466 return NULL_TREE; 5467 } 5468 5469 error ("no suitable %<operator %s%> for %qT", 5470 operator_name_info[(int)code].name, type); 5471 return error_mark_node; 5472 } 5473 5474 /* If the current scope isn't allowed to access DECL along 5475 BASETYPE_PATH, give an error. The most derived class in 5476 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is 5477 the declaration to use in the error diagnostic. */ 5478 5479 bool 5480 enforce_access (tree basetype_path, tree decl, tree diag_decl) 5481 { 5482 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO); 5483 5484 if (!accessible_p (basetype_path, decl, true)) 5485 { 5486 if (TREE_PRIVATE (decl)) 5487 error ("%q+#D is private", diag_decl); 5488 else if (TREE_PROTECTED (decl)) 5489 error ("%q+#D is protected", diag_decl); 5490 else 5491 error ("%q+#D is inaccessible", diag_decl); 5492 error ("within this context"); 5493 return false; 5494 } 5495 5496 return true; 5497 } 5498 5499 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a 5500 bitwise or of LOOKUP_* values. If any errors are warnings are 5501 generated, set *DIAGNOSTIC_FN to "error" or "warning", 5502 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN 5503 to NULL. */ 5504 5505 static tree 5506 build_temp (tree expr, tree type, int flags, 5507 diagnostic_t *diagnostic_kind, tsubst_flags_t complain) 5508 { 5509 int savew, savee; 5510 VEC(tree,gc) *args; 5511 5512 savew = warningcount, savee = errorcount; 5513 args = make_tree_vector_single (expr); 5514 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 5515 &args, type, flags, complain); 5516 release_tree_vector (args); 5517 if (warningcount > savew) 5518 *diagnostic_kind = DK_WARNING; 5519 else if (errorcount > savee) 5520 *diagnostic_kind = DK_ERROR; 5521 else 5522 *diagnostic_kind = DK_UNSPECIFIED; 5523 return expr; 5524 } 5525 5526 /* Perform warnings about peculiar, but valid, conversions from/to NULL. 5527 EXPR is implicitly converted to type TOTYPE. 5528 FN and ARGNUM are used for diagnostics. */ 5529 5530 static void 5531 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum) 5532 { 5533 /* Issue warnings about peculiar, but valid, uses of NULL. */ 5534 if (expr == null_node && TREE_CODE (totype) != BOOLEAN_TYPE 5535 && ARITHMETIC_TYPE_P (totype)) 5536 { 5537 if (fn) 5538 warning_at (input_location, OPT_Wconversion_null, 5539 "passing NULL to non-pointer argument %P of %qD", 5540 argnum, fn); 5541 else 5542 warning_at (input_location, OPT_Wconversion_null, 5543 "converting to non-pointer type %qT from NULL", totype); 5544 } 5545 5546 /* Issue warnings if "false" is converted to a NULL pointer */ 5547 else if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE 5548 && TYPE_PTR_P (totype)) 5549 { 5550 if (fn) 5551 warning_at (input_location, OPT_Wconversion_null, 5552 "converting %<false%> to pointer type for argument %P " 5553 "of %qD", argnum, fn); 5554 else 5555 warning_at (input_location, OPT_Wconversion_null, 5556 "converting %<false%> to pointer type %qT", totype); 5557 } 5558 } 5559 5560 /* Perform the conversions in CONVS on the expression EXPR. FN and 5561 ARGNUM are used for diagnostics. ARGNUM is zero based, -1 5562 indicates the `this' argument of a method. INNER is nonzero when 5563 being called to continue a conversion chain. It is negative when a 5564 reference binding will be applied, positive otherwise. If 5565 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious 5566 conversions will be emitted if appropriate. If C_CAST_P is true, 5567 this conversion is coming from a C-style cast; in that case, 5568 conversions to inaccessible bases are permitted. */ 5569 5570 static tree 5571 convert_like_real (conversion *convs, tree expr, tree fn, int argnum, 5572 int inner, bool issue_conversion_warnings, 5573 bool c_cast_p, tsubst_flags_t complain) 5574 { 5575 tree totype = convs->type; 5576 diagnostic_t diag_kind; 5577 int flags; 5578 5579 if (convs->bad_p && !(complain & tf_error)) 5580 return error_mark_node; 5581 5582 if (convs->bad_p 5583 && convs->kind != ck_user 5584 && convs->kind != ck_list 5585 && convs->kind != ck_ambig 5586 && (convs->kind != ck_ref_bind 5587 || convs->user_conv_p) 5588 && convs->kind != ck_rvalue 5589 && convs->kind != ck_base) 5590 { 5591 conversion *t = convs; 5592 5593 /* Give a helpful error if this is bad because of excess braces. */ 5594 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 5595 && SCALAR_TYPE_P (totype) 5596 && CONSTRUCTOR_NELTS (expr) > 0 5597 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value)) 5598 permerror (input_location, "too many braces around initializer for %qT", totype); 5599 5600 for (; t ; t = next_conversion (t)) 5601 { 5602 if (t->kind == ck_user && t->cand->reason) 5603 { 5604 permerror (input_location, "invalid user-defined conversion " 5605 "from %qT to %qT", TREE_TYPE (expr), totype); 5606 print_z_candidate ("candidate is:", t->cand); 5607 expr = convert_like_real (t, expr, fn, argnum, 1, 5608 /*issue_conversion_warnings=*/false, 5609 /*c_cast_p=*/false, 5610 complain); 5611 if (convs->kind == ck_ref_bind) 5612 return convert_to_reference (totype, expr, CONV_IMPLICIT, 5613 LOOKUP_NORMAL, NULL_TREE); 5614 else 5615 return cp_convert (totype, expr); 5616 } 5617 else if (t->kind == ck_user || !t->bad_p) 5618 { 5619 expr = convert_like_real (t, expr, fn, argnum, 1, 5620 /*issue_conversion_warnings=*/false, 5621 /*c_cast_p=*/false, 5622 complain); 5623 break; 5624 } 5625 else if (t->kind == ck_ambig) 5626 return convert_like_real (t, expr, fn, argnum, 1, 5627 /*issue_conversion_warnings=*/false, 5628 /*c_cast_p=*/false, 5629 complain); 5630 else if (t->kind == ck_identity) 5631 break; 5632 } 5633 5634 permerror (input_location, "invalid conversion from %qT to %qT", 5635 TREE_TYPE (expr), totype); 5636 if (fn) 5637 permerror (DECL_SOURCE_LOCATION (fn), 5638 " initializing argument %P of %qD", argnum, fn); 5639 5640 return cp_convert (totype, expr); 5641 } 5642 5643 if (issue_conversion_warnings && (complain & tf_warning)) 5644 conversion_null_warnings (totype, expr, fn, argnum); 5645 5646 switch (convs->kind) 5647 { 5648 case ck_user: 5649 { 5650 struct z_candidate *cand = convs->cand; 5651 tree convfn = cand->fn; 5652 unsigned i; 5653 5654 /* If we're initializing from {}, it's value-initialization. */ 5655 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 5656 && CONSTRUCTOR_NELTS (expr) == 0 5657 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 5658 { 5659 bool direct = CONSTRUCTOR_IS_DIRECT_INIT (expr); 5660 expr = build_value_init (totype, complain); 5661 expr = get_target_expr_sfinae (expr, complain); 5662 if (expr != error_mark_node) 5663 { 5664 TARGET_EXPR_LIST_INIT_P (expr) = true; 5665 TARGET_EXPR_DIRECT_INIT_P (expr) = direct; 5666 } 5667 return expr; 5668 } 5669 5670 expr = mark_rvalue_use (expr); 5671 5672 /* When converting from an init list we consider explicit 5673 constructors, but actually trying to call one is an error. */ 5674 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn) 5675 /* Unless this is for direct-list-initialization. */ 5676 && !(BRACE_ENCLOSED_INITIALIZER_P (expr) 5677 && CONSTRUCTOR_IS_DIRECT_INIT (expr)) 5678 /* Unless we're calling it for value-initialization from an 5679 empty list, since that is handled separately in 8.5.4. */ 5680 && cand->num_convs > 0) 5681 { 5682 error ("converting to %qT from initializer list would use " 5683 "explicit constructor %qD", totype, convfn); 5684 } 5685 5686 /* Set user_conv_p on the argument conversions, so rvalue/base 5687 handling knows not to allow any more UDCs. */ 5688 for (i = 0; i < cand->num_convs; ++i) 5689 cand->convs[i]->user_conv_p = true; 5690 5691 expr = build_over_call (cand, LOOKUP_NORMAL, complain); 5692 5693 /* If this is a constructor or a function returning an aggr type, 5694 we need to build up a TARGET_EXPR. */ 5695 if (DECL_CONSTRUCTOR_P (convfn)) 5696 { 5697 expr = build_cplus_new (totype, expr, complain); 5698 5699 /* Remember that this was list-initialization. */ 5700 if (convs->check_narrowing && expr != error_mark_node) 5701 TARGET_EXPR_LIST_INIT_P (expr) = true; 5702 } 5703 5704 return expr; 5705 } 5706 case ck_identity: 5707 expr = mark_rvalue_use (expr); 5708 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 5709 { 5710 int nelts = CONSTRUCTOR_NELTS (expr); 5711 if (nelts == 0) 5712 expr = build_value_init (totype, complain); 5713 else if (nelts == 1) 5714 expr = CONSTRUCTOR_ELT (expr, 0)->value; 5715 else 5716 gcc_unreachable (); 5717 } 5718 5719 if (type_unknown_p (expr)) 5720 expr = instantiate_type (totype, expr, complain); 5721 /* Convert a constant to its underlying value, unless we are 5722 about to bind it to a reference, in which case we need to 5723 leave it as an lvalue. */ 5724 if (inner >= 0) 5725 { 5726 expr = decl_constant_value_safe (expr); 5727 if (expr == null_node && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype)) 5728 /* If __null has been converted to an integer type, we do not 5729 want to warn about uses of EXPR as an integer, rather than 5730 as a pointer. */ 5731 expr = build_int_cst (totype, 0); 5732 } 5733 return expr; 5734 case ck_ambig: 5735 /* We leave bad_p off ck_ambig because overload resolution considers 5736 it valid, it just fails when we try to perform it. So we need to 5737 check complain here, too. */ 5738 if (complain & tf_error) 5739 { 5740 /* Call build_user_type_conversion again for the error. */ 5741 build_user_type_conversion (totype, convs->u.expr, LOOKUP_NORMAL); 5742 if (fn) 5743 error (" initializing argument %P of %q+D", argnum, fn); 5744 } 5745 return error_mark_node; 5746 5747 case ck_list: 5748 { 5749 /* Conversion to std::initializer_list<T>. */ 5750 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0); 5751 tree new_ctor = build_constructor (init_list_type_node, NULL); 5752 unsigned len = CONSTRUCTOR_NELTS (expr); 5753 tree array, val, field; 5754 VEC(constructor_elt,gc) *vec = NULL; 5755 unsigned ix; 5756 5757 /* Convert all the elements. */ 5758 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val) 5759 { 5760 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum, 5761 1, false, false, complain); 5762 if (sub == error_mark_node) 5763 return sub; 5764 if (!BRACE_ENCLOSED_INITIALIZER_P (val)) 5765 check_narrowing (TREE_TYPE (sub), val); 5766 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub); 5767 if (!TREE_CONSTANT (sub)) 5768 TREE_CONSTANT (new_ctor) = false; 5769 } 5770 /* Build up the array. */ 5771 elttype = cp_build_qualified_type 5772 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST); 5773 array = build_array_of_n_type (elttype, len); 5774 array = finish_compound_literal (array, new_ctor, complain); 5775 /* Take the address explicitly rather than via decay_conversion 5776 to avoid the error about taking the address of a temporary. */ 5777 array = cp_build_addr_expr (array, complain); 5778 array = cp_convert (build_pointer_type (elttype), array); 5779 5780 /* Build up the initializer_list object. */ 5781 totype = complete_type (totype); 5782 field = next_initializable_field (TYPE_FIELDS (totype)); 5783 CONSTRUCTOR_APPEND_ELT (vec, field, array); 5784 field = next_initializable_field (DECL_CHAIN (field)); 5785 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len)); 5786 new_ctor = build_constructor (totype, vec); 5787 return get_target_expr (new_ctor); 5788 } 5789 5790 case ck_aggr: 5791 if (TREE_CODE (totype) == COMPLEX_TYPE) 5792 { 5793 tree real = CONSTRUCTOR_ELT (expr, 0)->value; 5794 tree imag = CONSTRUCTOR_ELT (expr, 1)->value; 5795 real = perform_implicit_conversion (TREE_TYPE (totype), 5796 real, complain); 5797 imag = perform_implicit_conversion (TREE_TYPE (totype), 5798 imag, complain); 5799 expr = build2 (COMPLEX_EXPR, totype, real, imag); 5800 return fold_if_not_in_template (expr); 5801 } 5802 return get_target_expr (digest_init (totype, expr, complain)); 5803 5804 default: 5805 break; 5806 }; 5807 5808 expr = convert_like_real (convs->u.next, expr, fn, argnum, 5809 convs->kind == ck_ref_bind ? -1 : 1, 5810 convs->kind == ck_ref_bind ? issue_conversion_warnings : false, 5811 c_cast_p, 5812 complain); 5813 if (expr == error_mark_node) 5814 return error_mark_node; 5815 5816 switch (convs->kind) 5817 { 5818 case ck_rvalue: 5819 expr = decay_conversion (expr); 5820 if (! MAYBE_CLASS_TYPE_P (totype)) 5821 return expr; 5822 /* Else fall through. */ 5823 case ck_base: 5824 if (convs->kind == ck_base && !convs->need_temporary_p) 5825 { 5826 /* We are going to bind a reference directly to a base-class 5827 subobject of EXPR. */ 5828 /* Build an expression for `*((base*) &expr)'. */ 5829 expr = cp_build_addr_expr (expr, complain); 5830 expr = convert_to_base (expr, build_pointer_type (totype), 5831 !c_cast_p, /*nonnull=*/true, complain); 5832 expr = cp_build_indirect_ref (expr, RO_IMPLICIT_CONVERSION, complain); 5833 return expr; 5834 } 5835 5836 /* Copy-initialization where the cv-unqualified version of the source 5837 type is the same class as, or a derived class of, the class of the 5838 destination [is treated as direct-initialization]. [dcl.init] */ 5839 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING; 5840 if (convs->user_conv_p) 5841 /* This conversion is being done in the context of a user-defined 5842 conversion (i.e. the second step of copy-initialization), so 5843 don't allow any more. */ 5844 flags |= LOOKUP_NO_CONVERSION; 5845 if (convs->rvaluedness_matches_p) 5846 flags |= LOOKUP_PREFER_RVALUE; 5847 if (TREE_CODE (expr) == TARGET_EXPR 5848 && TARGET_EXPR_LIST_INIT_P (expr)) 5849 /* Copy-list-initialization doesn't actually involve a copy. */ 5850 return expr; 5851 expr = build_temp (expr, totype, flags, &diag_kind, complain); 5852 if (diag_kind && fn && complain) 5853 emit_diagnostic (diag_kind, DECL_SOURCE_LOCATION (fn), 0, 5854 " initializing argument %P of %qD", argnum, fn); 5855 return build_cplus_new (totype, expr, complain); 5856 5857 case ck_ref_bind: 5858 { 5859 tree ref_type = totype; 5860 5861 if (convs->bad_p && !convs->u.next->bad_p) 5862 { 5863 gcc_assert (TYPE_REF_IS_RVALUE (ref_type) 5864 && real_lvalue_p (expr)); 5865 5866 error ("cannot bind %qT lvalue to %qT", 5867 TREE_TYPE (expr), totype); 5868 if (fn) 5869 error (" initializing argument %P of %q+D", argnum, fn); 5870 return error_mark_node; 5871 } 5872 5873 /* If necessary, create a temporary. 5874 5875 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases 5876 that need temporaries, even when their types are reference 5877 compatible with the type of reference being bound, so the 5878 upcoming call to cp_build_addr_expr doesn't fail. */ 5879 if (convs->need_temporary_p 5880 || TREE_CODE (expr) == CONSTRUCTOR 5881 || TREE_CODE (expr) == VA_ARG_EXPR) 5882 { 5883 /* Otherwise, a temporary of type "cv1 T1" is created and 5884 initialized from the initializer expression using the rules 5885 for a non-reference copy-initialization (8.5). */ 5886 5887 tree type = TREE_TYPE (ref_type); 5888 cp_lvalue_kind lvalue = real_lvalue_p (expr); 5889 5890 gcc_assert (same_type_ignoring_top_level_qualifiers_p 5891 (type, convs->u.next->type)); 5892 if (!CP_TYPE_CONST_NON_VOLATILE_P (type) 5893 && !TYPE_REF_IS_RVALUE (ref_type)) 5894 { 5895 /* If the reference is volatile or non-const, we 5896 cannot create a temporary. */ 5897 if (lvalue & clk_bitfield) 5898 error ("cannot bind bitfield %qE to %qT", 5899 expr, ref_type); 5900 else if (lvalue & clk_packed) 5901 error ("cannot bind packed field %qE to %qT", 5902 expr, ref_type); 5903 else 5904 error ("cannot bind rvalue %qE to %qT", expr, ref_type); 5905 return error_mark_node; 5906 } 5907 /* If the source is a packed field, and we must use a copy 5908 constructor, then building the target expr will require 5909 binding the field to the reference parameter to the 5910 copy constructor, and we'll end up with an infinite 5911 loop. If we can use a bitwise copy, then we'll be 5912 OK. */ 5913 if ((lvalue & clk_packed) 5914 && CLASS_TYPE_P (type) 5915 && type_has_nontrivial_copy_init (type)) 5916 { 5917 error ("cannot bind packed field %qE to %qT", 5918 expr, ref_type); 5919 return error_mark_node; 5920 } 5921 if (lvalue & clk_bitfield) 5922 { 5923 expr = convert_bitfield_to_declared_type (expr); 5924 expr = fold_convert (type, expr); 5925 } 5926 expr = build_target_expr_with_type (expr, type, complain); 5927 } 5928 5929 /* Take the address of the thing to which we will bind the 5930 reference. */ 5931 expr = cp_build_addr_expr (expr, complain); 5932 if (expr == error_mark_node) 5933 return error_mark_node; 5934 5935 /* Convert it to a pointer to the type referred to by the 5936 reference. This will adjust the pointer if a derived to 5937 base conversion is being performed. */ 5938 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)), 5939 expr); 5940 /* Convert the pointer to the desired reference type. */ 5941 return build_nop (ref_type, expr); 5942 } 5943 5944 case ck_lvalue: 5945 return decay_conversion (expr); 5946 5947 case ck_qual: 5948 /* Warn about deprecated conversion if appropriate. */ 5949 string_conv_p (totype, expr, 1); 5950 break; 5951 5952 case ck_ptr: 5953 if (convs->base_p) 5954 expr = convert_to_base (expr, totype, !c_cast_p, 5955 /*nonnull=*/false, complain); 5956 return build_nop (totype, expr); 5957 5958 case ck_pmem: 5959 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false, 5960 c_cast_p, complain); 5961 5962 default: 5963 break; 5964 } 5965 5966 if (convs->check_narrowing) 5967 check_narrowing (totype, expr); 5968 5969 if (issue_conversion_warnings && (complain & tf_warning)) 5970 expr = convert_and_check (totype, expr); 5971 else 5972 expr = convert (totype, expr); 5973 5974 return expr; 5975 } 5976 5977 /* ARG is being passed to a varargs function. Perform any conversions 5978 required. Return the converted value. */ 5979 5980 tree 5981 convert_arg_to_ellipsis (tree arg) 5982 { 5983 tree arg_type; 5984 5985 /* [expr.call] 5986 5987 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer 5988 standard conversions are performed. */ 5989 arg = decay_conversion (arg); 5990 arg_type = TREE_TYPE (arg); 5991 /* [expr.call] 5992 5993 If the argument has integral or enumeration type that is subject 5994 to the integral promotions (_conv.prom_), or a floating point 5995 type that is subject to the floating point promotion 5996 (_conv.fpprom_), the value of the argument is converted to the 5997 promoted type before the call. */ 5998 if (TREE_CODE (arg_type) == REAL_TYPE 5999 && (TYPE_PRECISION (arg_type) 6000 < TYPE_PRECISION (double_type_node)) 6001 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type))) 6002 { 6003 if (warn_double_promotion && !c_inhibit_evaluation_warnings) 6004 warning (OPT_Wdouble_promotion, 6005 "implicit conversion from %qT to %qT when passing " 6006 "argument to function", 6007 arg_type, double_type_node); 6008 arg = convert_to_real (double_type_node, arg); 6009 } 6010 else if (NULLPTR_TYPE_P (arg_type)) 6011 arg = null_pointer_node; 6012 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type)) 6013 { 6014 if (SCOPED_ENUM_P (arg_type) && !abi_version_at_least (6)) 6015 { 6016 warning (OPT_Wabi, "scoped enum %qT will not promote to an " 6017 "integral type in a future version of GCC", arg_type); 6018 arg = cp_convert (ENUM_UNDERLYING_TYPE (arg_type), arg); 6019 } 6020 arg = perform_integral_promotions (arg); 6021 } 6022 6023 arg = require_complete_type (arg); 6024 arg_type = TREE_TYPE (arg); 6025 6026 if (arg != error_mark_node 6027 /* In a template (or ill-formed code), we can have an incomplete type 6028 even after require_complete_type, in which case we don't know 6029 whether it has trivial copy or not. */ 6030 && COMPLETE_TYPE_P (arg_type)) 6031 { 6032 /* Build up a real lvalue-to-rvalue conversion in case the 6033 copy constructor is trivial but not callable. */ 6034 if (!cp_unevaluated_operand && CLASS_TYPE_P (arg_type)) 6035 force_rvalue (arg, tf_warning_or_error); 6036 6037 /* [expr.call] 5.2.2/7: 6038 Passing a potentially-evaluated argument of class type (Clause 9) 6039 with a non-trivial copy constructor or a non-trivial destructor 6040 with no corresponding parameter is conditionally-supported, with 6041 implementation-defined semantics. 6042 6043 We used to just warn here and do a bitwise copy, but now 6044 cp_expr_size will abort if we try to do that. 6045 6046 If the call appears in the context of a sizeof expression, 6047 it is not potentially-evaluated. */ 6048 if (cp_unevaluated_operand == 0 6049 && (type_has_nontrivial_copy_init (arg_type) 6050 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type))) 6051 error ("cannot pass objects of non-trivially-copyable " 6052 "type %q#T through %<...%>", arg_type); 6053 } 6054 6055 return arg; 6056 } 6057 6058 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */ 6059 6060 tree 6061 build_x_va_arg (tree expr, tree type) 6062 { 6063 if (processing_template_decl) 6064 return build_min (VA_ARG_EXPR, type, expr); 6065 6066 type = complete_type_or_else (type, NULL_TREE); 6067 6068 if (expr == error_mark_node || !type) 6069 return error_mark_node; 6070 6071 expr = mark_lvalue_use (expr); 6072 6073 if (type_has_nontrivial_copy_init (type) 6074 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type) 6075 || TREE_CODE (type) == REFERENCE_TYPE) 6076 { 6077 /* Remove reference types so we don't ICE later on. */ 6078 tree type1 = non_reference (type); 6079 /* conditionally-supported behavior [expr.call] 5.2.2/7. */ 6080 error ("cannot receive objects of non-trivially-copyable type %q#T " 6081 "through %<...%>; ", type); 6082 expr = convert (build_pointer_type (type1), null_node); 6083 expr = cp_build_indirect_ref (expr, RO_NULL, tf_warning_or_error); 6084 return expr; 6085 } 6086 6087 return build_va_arg (input_location, expr, type); 6088 } 6089 6090 /* TYPE has been given to va_arg. Apply the default conversions which 6091 would have happened when passed via ellipsis. Return the promoted 6092 type, or the passed type if there is no change. */ 6093 6094 tree 6095 cxx_type_promotes_to (tree type) 6096 { 6097 tree promote; 6098 6099 /* Perform the array-to-pointer and function-to-pointer 6100 conversions. */ 6101 type = type_decays_to (type); 6102 6103 promote = type_promotes_to (type); 6104 if (same_type_p (type, promote)) 6105 promote = type; 6106 6107 return promote; 6108 } 6109 6110 /* ARG is a default argument expression being passed to a parameter of 6111 the indicated TYPE, which is a parameter to FN. PARMNUM is the 6112 zero-based argument number. Do any required conversions. Return 6113 the converted value. */ 6114 6115 static GTY(()) VEC(tree,gc) *default_arg_context; 6116 void 6117 push_defarg_context (tree fn) 6118 { VEC_safe_push (tree, gc, default_arg_context, fn); } 6119 void 6120 pop_defarg_context (void) 6121 { VEC_pop (tree, default_arg_context); } 6122 6123 tree 6124 convert_default_arg (tree type, tree arg, tree fn, int parmnum) 6125 { 6126 int i; 6127 tree t; 6128 6129 /* See through clones. */ 6130 fn = DECL_ORIGIN (fn); 6131 6132 /* Detect recursion. */ 6133 FOR_EACH_VEC_ELT (tree, default_arg_context, i, t) 6134 if (t == fn) 6135 { 6136 error ("recursive evaluation of default argument for %q#D", fn); 6137 return error_mark_node; 6138 } 6139 6140 /* If the ARG is an unparsed default argument expression, the 6141 conversion cannot be performed. */ 6142 if (TREE_CODE (arg) == DEFAULT_ARG) 6143 { 6144 error ("call to %qD uses the default argument for parameter %P, which " 6145 "is not yet defined", fn, parmnum); 6146 return error_mark_node; 6147 } 6148 6149 push_defarg_context (fn); 6150 6151 if (fn && DECL_TEMPLATE_INFO (fn)) 6152 arg = tsubst_default_argument (fn, type, arg); 6153 6154 /* Due to: 6155 6156 [dcl.fct.default] 6157 6158 The names in the expression are bound, and the semantic 6159 constraints are checked, at the point where the default 6160 expressions appears. 6161 6162 we must not perform access checks here. */ 6163 push_deferring_access_checks (dk_no_check); 6164 /* We must make a copy of ARG, in case subsequent processing 6165 alters any part of it. */ 6166 arg = break_out_target_exprs (arg); 6167 if (TREE_CODE (arg) == CONSTRUCTOR) 6168 { 6169 arg = digest_init (type, arg, tf_warning_or_error); 6170 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT, 6171 ICR_DEFAULT_ARGUMENT, fn, parmnum, 6172 tf_warning_or_error); 6173 } 6174 else 6175 { 6176 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT, 6177 ICR_DEFAULT_ARGUMENT, fn, parmnum, 6178 tf_warning_or_error); 6179 arg = convert_for_arg_passing (type, arg); 6180 } 6181 pop_deferring_access_checks(); 6182 6183 pop_defarg_context (); 6184 6185 return arg; 6186 } 6187 6188 /* Returns the type which will really be used for passing an argument of 6189 type TYPE. */ 6190 6191 tree 6192 type_passed_as (tree type) 6193 { 6194 /* Pass classes with copy ctors by invisible reference. */ 6195 if (TREE_ADDRESSABLE (type)) 6196 { 6197 type = build_reference_type (type); 6198 /* There are no other pointers to this temporary. */ 6199 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT); 6200 } 6201 else if (targetm.calls.promote_prototypes (type) 6202 && INTEGRAL_TYPE_P (type) 6203 && COMPLETE_TYPE_P (type) 6204 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type), 6205 TYPE_SIZE (integer_type_node))) 6206 type = integer_type_node; 6207 6208 return type; 6209 } 6210 6211 /* Actually perform the appropriate conversion. */ 6212 6213 tree 6214 convert_for_arg_passing (tree type, tree val) 6215 { 6216 tree bitfield_type; 6217 6218 /* If VAL is a bitfield, then -- since it has already been converted 6219 to TYPE -- it cannot have a precision greater than TYPE. 6220 6221 If it has a smaller precision, we must widen it here. For 6222 example, passing "int f:3;" to a function expecting an "int" will 6223 not result in any conversion before this point. 6224 6225 If the precision is the same we must not risk widening. For 6226 example, the COMPONENT_REF for a 32-bit "long long" bitfield will 6227 often have type "int", even though the C++ type for the field is 6228 "long long". If the value is being passed to a function 6229 expecting an "int", then no conversions will be required. But, 6230 if we call convert_bitfield_to_declared_type, the bitfield will 6231 be converted to "long long". */ 6232 bitfield_type = is_bitfield_expr_with_lowered_type (val); 6233 if (bitfield_type 6234 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)) 6235 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val); 6236 6237 if (val == error_mark_node) 6238 ; 6239 /* Pass classes with copy ctors by invisible reference. */ 6240 else if (TREE_ADDRESSABLE (type)) 6241 val = build1 (ADDR_EXPR, build_reference_type (type), val); 6242 else if (targetm.calls.promote_prototypes (type) 6243 && INTEGRAL_TYPE_P (type) 6244 && COMPLETE_TYPE_P (type) 6245 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type), 6246 TYPE_SIZE (integer_type_node))) 6247 val = perform_integral_promotions (val); 6248 if (warn_missing_format_attribute) 6249 { 6250 tree rhstype = TREE_TYPE (val); 6251 const enum tree_code coder = TREE_CODE (rhstype); 6252 const enum tree_code codel = TREE_CODE (type); 6253 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 6254 && coder == codel 6255 && check_missing_format_attribute (type, rhstype)) 6256 warning (OPT_Wmissing_format_attribute, 6257 "argument of function call might be a candidate for a format attribute"); 6258 } 6259 return val; 6260 } 6261 6262 /* Returns true iff FN is a function with magic varargs, i.e. ones for 6263 which no conversions at all should be done. This is true for some 6264 builtins which don't act like normal functions. */ 6265 6266 static bool 6267 magic_varargs_p (tree fn) 6268 { 6269 if (DECL_BUILT_IN (fn)) 6270 switch (DECL_FUNCTION_CODE (fn)) 6271 { 6272 case BUILT_IN_CLASSIFY_TYPE: 6273 case BUILT_IN_CONSTANT_P: 6274 case BUILT_IN_NEXT_ARG: 6275 case BUILT_IN_VA_START: 6276 return true; 6277 6278 default:; 6279 return lookup_attribute ("type generic", 6280 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0; 6281 } 6282 6283 return false; 6284 } 6285 6286 /* Subroutine of the various build_*_call functions. Overload resolution 6287 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly. 6288 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a 6289 bitmask of various LOOKUP_* flags which apply to the call itself. */ 6290 6291 static tree 6292 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) 6293 { 6294 tree fn = cand->fn; 6295 const VEC(tree,gc) *args = cand->args; 6296 tree first_arg = cand->first_arg; 6297 conversion **convs = cand->convs; 6298 conversion *conv; 6299 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn)); 6300 int parmlen; 6301 tree val; 6302 int i = 0; 6303 int j = 0; 6304 unsigned int arg_index = 0; 6305 int is_method = 0; 6306 int nargs; 6307 tree *argarray; 6308 bool already_used = false; 6309 6310 /* In a template, there is no need to perform all of the work that 6311 is normally done. We are only interested in the type of the call 6312 expression, i.e., the return type of the function. Any semantic 6313 errors will be deferred until the template is instantiated. */ 6314 if (processing_template_decl) 6315 { 6316 tree expr; 6317 tree return_type; 6318 const tree *argarray; 6319 unsigned int nargs; 6320 6321 return_type = TREE_TYPE (TREE_TYPE (fn)); 6322 nargs = VEC_length (tree, args); 6323 if (first_arg == NULL_TREE) 6324 argarray = VEC_address (tree, CONST_CAST (VEC(tree,gc) *, args)); 6325 else 6326 { 6327 tree *alcarray; 6328 unsigned int ix; 6329 tree arg; 6330 6331 ++nargs; 6332 alcarray = XALLOCAVEC (tree, nargs); 6333 alcarray[0] = first_arg; 6334 FOR_EACH_VEC_ELT (tree, args, ix, arg) 6335 alcarray[ix + 1] = arg; 6336 argarray = alcarray; 6337 } 6338 expr = build_call_array_loc (input_location, 6339 return_type, build_addr_func (fn), nargs, 6340 argarray); 6341 if (TREE_THIS_VOLATILE (fn) && cfun) 6342 current_function_returns_abnormally = 1; 6343 return convert_from_reference (expr); 6344 } 6345 6346 /* Give any warnings we noticed during overload resolution. */ 6347 if (cand->warnings && (complain & tf_warning)) 6348 { 6349 struct candidate_warning *w; 6350 for (w = cand->warnings; w; w = w->next) 6351 joust (cand, w->loser, 1); 6352 } 6353 6354 /* Make =delete work with SFINAE. */ 6355 if (DECL_DELETED_FN (fn) && !(complain & tf_error)) 6356 return error_mark_node; 6357 6358 if (DECL_FUNCTION_MEMBER_P (fn)) 6359 { 6360 tree access_fn; 6361 /* If FN is a template function, two cases must be considered. 6362 For example: 6363 6364 struct A { 6365 protected: 6366 template <class T> void f(); 6367 }; 6368 template <class T> struct B { 6369 protected: 6370 void g(); 6371 }; 6372 struct C : A, B<int> { 6373 using A::f; // #1 6374 using B<int>::g; // #2 6375 }; 6376 6377 In case #1 where `A::f' is a member template, DECL_ACCESS is 6378 recorded in the primary template but not in its specialization. 6379 We check access of FN using its primary template. 6380 6381 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply 6382 because it is a member of class template B, DECL_ACCESS is 6383 recorded in the specialization `B<int>::g'. We cannot use its 6384 primary template because `B<T>::g' and `B<int>::g' may have 6385 different access. */ 6386 if (DECL_TEMPLATE_INFO (fn) 6387 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn))) 6388 access_fn = DECL_TI_TEMPLATE (fn); 6389 else 6390 access_fn = fn; 6391 if (flags & LOOKUP_SPECULATIVE) 6392 { 6393 if (!speculative_access_check (cand->access_path, access_fn, fn, 6394 !!(flags & LOOKUP_COMPLAIN))) 6395 return error_mark_node; 6396 } 6397 else 6398 perform_or_defer_access_check (cand->access_path, access_fn, fn); 6399 } 6400 6401 /* If we're checking for implicit delete, don't bother with argument 6402 conversions. */ 6403 if (flags & LOOKUP_SPECULATIVE) 6404 { 6405 if (DECL_DELETED_FN (fn)) 6406 { 6407 if (flags & LOOKUP_COMPLAIN) 6408 mark_used (fn); 6409 return error_mark_node; 6410 } 6411 if (cand->viable == 1) 6412 return fn; 6413 else if (!(flags & LOOKUP_COMPLAIN)) 6414 /* Reject bad conversions now. */ 6415 return error_mark_node; 6416 /* else continue to get conversion error. */ 6417 } 6418 6419 /* Find maximum size of vector to hold converted arguments. */ 6420 parmlen = list_length (parm); 6421 nargs = VEC_length (tree, args) + (first_arg != NULL_TREE ? 1 : 0); 6422 if (parmlen > nargs) 6423 nargs = parmlen; 6424 argarray = XALLOCAVEC (tree, nargs); 6425 6426 /* The implicit parameters to a constructor are not considered by overload 6427 resolution, and must be of the proper type. */ 6428 if (DECL_CONSTRUCTOR_P (fn)) 6429 { 6430 if (first_arg != NULL_TREE) 6431 { 6432 argarray[j++] = first_arg; 6433 first_arg = NULL_TREE; 6434 } 6435 else 6436 { 6437 argarray[j++] = VEC_index (tree, args, arg_index); 6438 ++arg_index; 6439 } 6440 parm = TREE_CHAIN (parm); 6441 /* We should never try to call the abstract constructor. */ 6442 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn)); 6443 6444 if (DECL_HAS_VTT_PARM_P (fn)) 6445 { 6446 argarray[j++] = VEC_index (tree, args, arg_index); 6447 ++arg_index; 6448 parm = TREE_CHAIN (parm); 6449 } 6450 } 6451 /* Bypass access control for 'this' parameter. */ 6452 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 6453 { 6454 tree parmtype = TREE_VALUE (parm); 6455 tree arg = (first_arg != NULL_TREE 6456 ? first_arg 6457 : VEC_index (tree, args, arg_index)); 6458 tree argtype = TREE_TYPE (arg); 6459 tree converted_arg; 6460 tree base_binfo; 6461 6462 if (convs[i]->bad_p) 6463 { 6464 if (complain & tf_error) 6465 permerror (input_location, "passing %qT as %<this%> argument of %q#D discards qualifiers", 6466 TREE_TYPE (argtype), fn); 6467 else 6468 return error_mark_node; 6469 } 6470 6471 /* See if the function member or the whole class type is declared 6472 final and the call can be devirtualized. */ 6473 if (DECL_FINAL_P (fn) 6474 || CLASSTYPE_FINAL (TYPE_METHOD_BASETYPE (TREE_TYPE (fn)))) 6475 flags |= LOOKUP_NONVIRTUAL; 6476 6477 /* [class.mfct.nonstatic]: If a nonstatic member function of a class 6478 X is called for an object that is not of type X, or of a type 6479 derived from X, the behavior is undefined. 6480 6481 So we can assume that anything passed as 'this' is non-null, and 6482 optimize accordingly. */ 6483 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE); 6484 /* Convert to the base in which the function was declared. */ 6485 gcc_assert (cand->conversion_path != NULL_TREE); 6486 converted_arg = build_base_path (PLUS_EXPR, 6487 arg, 6488 cand->conversion_path, 6489 1, complain); 6490 /* Check that the base class is accessible. */ 6491 if (!accessible_base_p (TREE_TYPE (argtype), 6492 BINFO_TYPE (cand->conversion_path), true)) 6493 error ("%qT is not an accessible base of %qT", 6494 BINFO_TYPE (cand->conversion_path), 6495 TREE_TYPE (argtype)); 6496 /* If fn was found by a using declaration, the conversion path 6497 will be to the derived class, not the base declaring fn. We 6498 must convert from derived to base. */ 6499 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)), 6500 TREE_TYPE (parmtype), ba_unique, NULL); 6501 converted_arg = build_base_path (PLUS_EXPR, converted_arg, 6502 base_binfo, 1, complain); 6503 6504 argarray[j++] = converted_arg; 6505 parm = TREE_CHAIN (parm); 6506 if (first_arg != NULL_TREE) 6507 first_arg = NULL_TREE; 6508 else 6509 ++arg_index; 6510 ++i; 6511 is_method = 1; 6512 } 6513 6514 gcc_assert (first_arg == NULL_TREE); 6515 for (; arg_index < VEC_length (tree, args) && parm; 6516 parm = TREE_CHAIN (parm), ++arg_index, ++i) 6517 { 6518 tree type = TREE_VALUE (parm); 6519 tree arg = VEC_index (tree, args, arg_index); 6520 bool conversion_warning = true; 6521 6522 conv = convs[i]; 6523 6524 /* If the argument is NULL and used to (implicitly) instantiate a 6525 template function (and bind one of the template arguments to 6526 the type of 'long int'), we don't want to warn about passing NULL 6527 to non-pointer argument. 6528 For example, if we have this template function: 6529 6530 template<typename T> void func(T x) {} 6531 6532 we want to warn (when -Wconversion is enabled) in this case: 6533 6534 void foo() { 6535 func<int>(NULL); 6536 } 6537 6538 but not in this case: 6539 6540 void foo() { 6541 func(NULL); 6542 } 6543 */ 6544 if (arg == null_node 6545 && DECL_TEMPLATE_INFO (fn) 6546 && cand->template_decl 6547 && !(flags & LOOKUP_EXPLICIT_TMPL_ARGS)) 6548 conversion_warning = false; 6549 6550 /* Warn about initializer_list deduction that isn't currently in the 6551 working draft. */ 6552 if (cxx_dialect > cxx98 6553 && flag_deduce_init_list 6554 && cand->template_decl 6555 && is_std_init_list (non_reference (type)) 6556 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 6557 { 6558 tree tmpl = TI_TEMPLATE (cand->template_decl); 6559 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn)); 6560 tree patparm = get_pattern_parm (realparm, tmpl); 6561 tree pattype = TREE_TYPE (patparm); 6562 if (PACK_EXPANSION_P (pattype)) 6563 pattype = PACK_EXPANSION_PATTERN (pattype); 6564 pattype = non_reference (pattype); 6565 6566 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM 6567 && (cand->explicit_targs == NULL_TREE 6568 || (TREE_VEC_LENGTH (cand->explicit_targs) 6569 <= TEMPLATE_TYPE_IDX (pattype)))) 6570 { 6571 pedwarn (input_location, 0, "deducing %qT as %qT", 6572 non_reference (TREE_TYPE (patparm)), 6573 non_reference (type)); 6574 pedwarn (input_location, 0, " in call to %q+D", cand->fn); 6575 pedwarn (input_location, 0, 6576 " (you can disable this with -fno-deduce-init-list)"); 6577 } 6578 } 6579 6580 val = convert_like_with_context (conv, arg, fn, i-is_method, 6581 conversion_warning 6582 ? complain 6583 : complain & (~tf_warning)); 6584 6585 val = convert_for_arg_passing (type, val); 6586 if (val == error_mark_node) 6587 return error_mark_node; 6588 else 6589 argarray[j++] = val; 6590 } 6591 6592 /* Default arguments */ 6593 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++) 6594 { 6595 if (TREE_VALUE (parm) == error_mark_node) 6596 return error_mark_node; 6597 argarray[j++] = convert_default_arg (TREE_VALUE (parm), 6598 TREE_PURPOSE (parm), 6599 fn, i - is_method); 6600 } 6601 6602 /* Ellipsis */ 6603 for (; arg_index < VEC_length (tree, args); ++arg_index) 6604 { 6605 tree a = VEC_index (tree, args, arg_index); 6606 if (magic_varargs_p (fn)) 6607 /* Do no conversions for magic varargs. */ 6608 a = mark_type_use (a); 6609 else 6610 a = convert_arg_to_ellipsis (a); 6611 argarray[j++] = a; 6612 } 6613 6614 gcc_assert (j <= nargs); 6615 nargs = j; 6616 6617 check_function_arguments (TREE_TYPE (fn), nargs, argarray); 6618 6619 /* Avoid actually calling copy constructors and copy assignment operators, 6620 if possible. */ 6621 6622 if (! flag_elide_constructors) 6623 /* Do things the hard way. */; 6624 else if (cand->num_convs == 1 6625 && (DECL_COPY_CONSTRUCTOR_P (fn) 6626 || DECL_MOVE_CONSTRUCTOR_P (fn))) 6627 { 6628 tree targ; 6629 tree arg = argarray[num_artificial_parms_for (fn)]; 6630 tree fa; 6631 bool trivial = trivial_fn_p (fn); 6632 6633 /* Pull out the real argument, disregarding const-correctness. */ 6634 targ = arg; 6635 while (CONVERT_EXPR_P (targ) 6636 || TREE_CODE (targ) == NON_LVALUE_EXPR) 6637 targ = TREE_OPERAND (targ, 0); 6638 if (TREE_CODE (targ) == ADDR_EXPR) 6639 { 6640 targ = TREE_OPERAND (targ, 0); 6641 if (!same_type_ignoring_top_level_qualifiers_p 6642 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ))) 6643 targ = NULL_TREE; 6644 } 6645 else 6646 targ = NULL_TREE; 6647 6648 if (targ) 6649 arg = targ; 6650 else 6651 arg = cp_build_indirect_ref (arg, RO_NULL, complain); 6652 6653 /* [class.copy]: the copy constructor is implicitly defined even if 6654 the implementation elided its use. */ 6655 if (!trivial || DECL_DELETED_FN (fn)) 6656 { 6657 mark_used (fn); 6658 already_used = true; 6659 } 6660 6661 /* If we're creating a temp and we already have one, don't create a 6662 new one. If we're not creating a temp but we get one, use 6663 INIT_EXPR to collapse the temp into our target. Otherwise, if the 6664 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a 6665 temp or an INIT_EXPR otherwise. */ 6666 fa = argarray[0]; 6667 if (integer_zerop (fa)) 6668 { 6669 if (TREE_CODE (arg) == TARGET_EXPR) 6670 return arg; 6671 else if (trivial) 6672 return force_target_expr (DECL_CONTEXT (fn), arg, complain); 6673 } 6674 else if (TREE_CODE (arg) == TARGET_EXPR || trivial) 6675 { 6676 tree to = stabilize_reference (cp_build_indirect_ref (fa, RO_NULL, 6677 complain)); 6678 6679 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg); 6680 return val; 6681 } 6682 } 6683 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR 6684 && trivial_fn_p (fn) 6685 && !DECL_DELETED_FN (fn)) 6686 { 6687 tree to = stabilize_reference 6688 (cp_build_indirect_ref (argarray[0], RO_NULL, complain)); 6689 tree type = TREE_TYPE (to); 6690 tree as_base = CLASSTYPE_AS_BASE (type); 6691 tree arg = argarray[1]; 6692 6693 if (is_really_empty_class (type)) 6694 { 6695 /* Avoid copying empty classes. */ 6696 val = build2 (COMPOUND_EXPR, void_type_node, to, arg); 6697 TREE_NO_WARNING (val) = 1; 6698 val = build2 (COMPOUND_EXPR, type, val, to); 6699 TREE_NO_WARNING (val) = 1; 6700 } 6701 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base))) 6702 { 6703 arg = cp_build_indirect_ref (arg, RO_NULL, complain); 6704 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg); 6705 } 6706 else 6707 { 6708 /* We must only copy the non-tail padding parts. */ 6709 tree arg0, arg2, t; 6710 tree array_type, alias_set; 6711 6712 arg2 = TYPE_SIZE_UNIT (as_base); 6713 arg0 = cp_build_addr_expr (to, complain); 6714 6715 array_type = build_array_type (char_type_node, 6716 build_index_type 6717 (size_binop (MINUS_EXPR, 6718 arg2, size_int (1)))); 6719 alias_set = build_int_cst (build_pointer_type (type), 0); 6720 t = build2 (MODIFY_EXPR, void_type_node, 6721 build2 (MEM_REF, array_type, arg0, alias_set), 6722 build2 (MEM_REF, array_type, arg, alias_set)); 6723 val = build2 (COMPOUND_EXPR, TREE_TYPE (to), t, to); 6724 TREE_NO_WARNING (val) = 1; 6725 } 6726 6727 return val; 6728 } 6729 else if (DECL_DESTRUCTOR_P (fn) 6730 && trivial_fn_p (fn) 6731 && !DECL_DELETED_FN (fn)) 6732 return fold_convert (void_type_node, argarray[0]); 6733 /* FIXME handle trivial default constructor, too. */ 6734 6735 if (!already_used) 6736 mark_used (fn); 6737 6738 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0) 6739 { 6740 tree t; 6741 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])), 6742 DECL_CONTEXT (fn), 6743 ba_any, NULL); 6744 gcc_assert (binfo && binfo != error_mark_node); 6745 6746 /* Warn about deprecated virtual functions now, since we're about 6747 to throw away the decl. */ 6748 if (TREE_DEPRECATED (fn)) 6749 warn_deprecated_use (fn, NULL_TREE); 6750 6751 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1, 6752 complain); 6753 if (TREE_SIDE_EFFECTS (argarray[0])) 6754 argarray[0] = save_expr (argarray[0]); 6755 t = build_pointer_type (TREE_TYPE (fn)); 6756 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn))) 6757 fn = build_java_interface_fn_ref (fn, argarray[0]); 6758 else 6759 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn)); 6760 TREE_TYPE (fn) = t; 6761 } 6762 else 6763 fn = build_addr_func (fn); 6764 6765 return build_cxx_call (fn, nargs, argarray); 6766 } 6767 6768 /* Build and return a call to FN, using NARGS arguments in ARGARRAY. 6769 This function performs no overload resolution, conversion, or other 6770 high-level operations. */ 6771 6772 tree 6773 build_cxx_call (tree fn, int nargs, tree *argarray) 6774 { 6775 tree fndecl; 6776 6777 /* Remember roughly where this call is. */ 6778 location_t loc = EXPR_LOC_OR_HERE (fn); 6779 fn = build_call_a (fn, nargs, argarray); 6780 SET_EXPR_LOCATION (fn, loc); 6781 6782 fndecl = get_callee_fndecl (fn); 6783 6784 /* Check that arguments to builtin functions match the expectations. */ 6785 if (fndecl 6786 && DECL_BUILT_IN (fndecl) 6787 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL 6788 && !check_builtin_function_arguments (fndecl, nargs, argarray)) 6789 return error_mark_node; 6790 6791 /* Some built-in function calls will be evaluated at compile-time in 6792 fold (). */ 6793 fn = fold_if_not_in_template (fn); 6794 6795 if (VOID_TYPE_P (TREE_TYPE (fn))) 6796 return fn; 6797 6798 fn = require_complete_type (fn); 6799 if (fn == error_mark_node) 6800 return error_mark_node; 6801 6802 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn))) 6803 fn = build_cplus_new (TREE_TYPE (fn), fn, tf_warning_or_error); 6804 return convert_from_reference (fn); 6805 } 6806 6807 static GTY(()) tree java_iface_lookup_fn; 6808 6809 /* Make an expression which yields the address of the Java interface 6810 method FN. This is achieved by generating a call to libjava's 6811 _Jv_LookupInterfaceMethodIdx(). */ 6812 6813 static tree 6814 build_java_interface_fn_ref (tree fn, tree instance) 6815 { 6816 tree lookup_fn, method, idx; 6817 tree klass_ref, iface, iface_ref; 6818 int i; 6819 6820 if (!java_iface_lookup_fn) 6821 { 6822 tree ftype = build_function_type_list (ptr_type_node, 6823 ptr_type_node, ptr_type_node, 6824 java_int_type_node, NULL_TREE); 6825 java_iface_lookup_fn 6826 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx", ftype, 6827 0, NOT_BUILT_IN, NULL, NULL_TREE); 6828 } 6829 6830 /* Look up the pointer to the runtime java.lang.Class object for `instance'. 6831 This is the first entry in the vtable. */ 6832 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, RO_NULL, 6833 tf_warning_or_error), 6834 integer_zero_node); 6835 6836 /* Get the java.lang.Class pointer for the interface being called. */ 6837 iface = DECL_CONTEXT (fn); 6838 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false); 6839 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL 6840 || DECL_CONTEXT (iface_ref) != iface) 6841 { 6842 error ("could not find class$ field in java interface type %qT", 6843 iface); 6844 return error_mark_node; 6845 } 6846 iface_ref = build_address (iface_ref); 6847 iface_ref = convert (build_pointer_type (iface), iface_ref); 6848 6849 /* Determine the itable index of FN. */ 6850 i = 1; 6851 for (method = TYPE_METHODS (iface); method; method = DECL_CHAIN (method)) 6852 { 6853 if (!DECL_VIRTUAL_P (method)) 6854 continue; 6855 if (fn == method) 6856 break; 6857 i++; 6858 } 6859 idx = build_int_cst (NULL_TREE, i); 6860 6861 lookup_fn = build1 (ADDR_EXPR, 6862 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)), 6863 java_iface_lookup_fn); 6864 return build_call_nary (ptr_type_node, lookup_fn, 6865 3, klass_ref, iface_ref, idx); 6866 } 6867 6868 /* Returns the value to use for the in-charge parameter when making a 6869 call to a function with the indicated NAME. 6870 6871 FIXME:Can't we find a neater way to do this mapping? */ 6872 6873 tree 6874 in_charge_arg_for_name (tree name) 6875 { 6876 if (name == base_ctor_identifier 6877 || name == base_dtor_identifier) 6878 return integer_zero_node; 6879 else if (name == complete_ctor_identifier) 6880 return integer_one_node; 6881 else if (name == complete_dtor_identifier) 6882 return integer_two_node; 6883 else if (name == deleting_dtor_identifier) 6884 return integer_three_node; 6885 6886 /* This function should only be called with one of the names listed 6887 above. */ 6888 gcc_unreachable (); 6889 return NULL_TREE; 6890 } 6891 6892 /* Build a call to a constructor, destructor, or an assignment 6893 operator for INSTANCE, an expression with class type. NAME 6894 indicates the special member function to call; *ARGS are the 6895 arguments. ARGS may be NULL. This may change ARGS. BINFO 6896 indicates the base of INSTANCE that is to be passed as the `this' 6897 parameter to the member function called. 6898 6899 FLAGS are the LOOKUP_* flags to use when processing the call. 6900 6901 If NAME indicates a complete object constructor, INSTANCE may be 6902 NULL_TREE. In this case, the caller will call build_cplus_new to 6903 store the newly constructed object into a VAR_DECL. */ 6904 6905 tree 6906 build_special_member_call (tree instance, tree name, VEC(tree,gc) **args, 6907 tree binfo, int flags, tsubst_flags_t complain) 6908 { 6909 tree fns; 6910 /* The type of the subobject to be constructed or destroyed. */ 6911 tree class_type; 6912 VEC(tree,gc) *allocated = NULL; 6913 tree ret; 6914 6915 gcc_assert (name == complete_ctor_identifier 6916 || name == base_ctor_identifier 6917 || name == complete_dtor_identifier 6918 || name == base_dtor_identifier 6919 || name == deleting_dtor_identifier 6920 || name == ansi_assopname (NOP_EXPR)); 6921 if (TYPE_P (binfo)) 6922 { 6923 /* Resolve the name. */ 6924 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain)) 6925 return error_mark_node; 6926 6927 binfo = TYPE_BINFO (binfo); 6928 } 6929 6930 gcc_assert (binfo != NULL_TREE); 6931 6932 class_type = BINFO_TYPE (binfo); 6933 6934 /* Handle the special case where INSTANCE is NULL_TREE. */ 6935 if (name == complete_ctor_identifier && !instance) 6936 { 6937 instance = build_int_cst (build_pointer_type (class_type), 0); 6938 instance = build1 (INDIRECT_REF, class_type, instance); 6939 } 6940 else 6941 { 6942 if (name == complete_dtor_identifier 6943 || name == base_dtor_identifier 6944 || name == deleting_dtor_identifier) 6945 gcc_assert (args == NULL || VEC_empty (tree, *args)); 6946 6947 /* Convert to the base class, if necessary. */ 6948 if (!same_type_ignoring_top_level_qualifiers_p 6949 (TREE_TYPE (instance), BINFO_TYPE (binfo))) 6950 { 6951 if (name != ansi_assopname (NOP_EXPR)) 6952 /* For constructors and destructors, either the base is 6953 non-virtual, or it is virtual but we are doing the 6954 conversion from a constructor or destructor for the 6955 complete object. In either case, we can convert 6956 statically. */ 6957 instance = convert_to_base_statically (instance, binfo); 6958 else 6959 /* However, for assignment operators, we must convert 6960 dynamically if the base is virtual. */ 6961 instance = build_base_path (PLUS_EXPR, instance, 6962 binfo, /*nonnull=*/1, complain); 6963 } 6964 } 6965 6966 gcc_assert (instance != NULL_TREE); 6967 6968 fns = lookup_fnfields (binfo, name, 1); 6969 6970 /* When making a call to a constructor or destructor for a subobject 6971 that uses virtual base classes, pass down a pointer to a VTT for 6972 the subobject. */ 6973 if ((name == base_ctor_identifier 6974 || name == base_dtor_identifier) 6975 && CLASSTYPE_VBASECLASSES (class_type)) 6976 { 6977 tree vtt; 6978 tree sub_vtt; 6979 6980 /* If the current function is a complete object constructor 6981 or destructor, then we fetch the VTT directly. 6982 Otherwise, we look it up using the VTT we were given. */ 6983 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type)); 6984 vtt = decay_conversion (vtt); 6985 vtt = build3 (COND_EXPR, TREE_TYPE (vtt), 6986 build2 (EQ_EXPR, boolean_type_node, 6987 current_in_charge_parm, integer_zero_node), 6988 current_vtt_parm, 6989 vtt); 6990 if (BINFO_SUBVTT_INDEX (binfo)) 6991 sub_vtt = fold_build_pointer_plus (vtt, BINFO_SUBVTT_INDEX (binfo)); 6992 else 6993 sub_vtt = vtt; 6994 6995 if (args == NULL) 6996 { 6997 allocated = make_tree_vector (); 6998 args = &allocated; 6999 } 7000 7001 VEC_safe_insert (tree, gc, *args, 0, sub_vtt); 7002 } 7003 7004 ret = build_new_method_call (instance, fns, args, 7005 TYPE_BINFO (BINFO_TYPE (binfo)), 7006 flags, /*fn=*/NULL, 7007 complain); 7008 7009 if (allocated != NULL) 7010 release_tree_vector (allocated); 7011 7012 return ret; 7013 } 7014 7015 /* Return the NAME, as a C string. The NAME indicates a function that 7016 is a member of TYPE. *FREE_P is set to true if the caller must 7017 free the memory returned. 7018 7019 Rather than go through all of this, we should simply set the names 7020 of constructors and destructors appropriately, and dispense with 7021 ctor_identifier, dtor_identifier, etc. */ 7022 7023 static char * 7024 name_as_c_string (tree name, tree type, bool *free_p) 7025 { 7026 char *pretty_name; 7027 7028 /* Assume that we will not allocate memory. */ 7029 *free_p = false; 7030 /* Constructors and destructors are special. */ 7031 if (IDENTIFIER_CTOR_OR_DTOR_P (name)) 7032 { 7033 pretty_name 7034 = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type)))); 7035 /* For a destructor, add the '~'. */ 7036 if (name == complete_dtor_identifier 7037 || name == base_dtor_identifier 7038 || name == deleting_dtor_identifier) 7039 { 7040 pretty_name = concat ("~", pretty_name, NULL); 7041 /* Remember that we need to free the memory allocated. */ 7042 *free_p = true; 7043 } 7044 } 7045 else if (IDENTIFIER_TYPENAME_P (name)) 7046 { 7047 pretty_name = concat ("operator ", 7048 type_as_string_translate (TREE_TYPE (name), 7049 TFF_PLAIN_IDENTIFIER), 7050 NULL); 7051 /* Remember that we need to free the memory allocated. */ 7052 *free_p = true; 7053 } 7054 else 7055 pretty_name = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (name))); 7056 7057 return pretty_name; 7058 } 7059 7060 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will 7061 be set, upon return, to the function called. ARGS may be NULL. 7062 This may change ARGS. */ 7063 7064 static tree 7065 build_new_method_call_1 (tree instance, tree fns, VEC(tree,gc) **args, 7066 tree conversion_path, int flags, 7067 tree *fn_p, tsubst_flags_t complain) 7068 { 7069 struct z_candidate *candidates = 0, *cand; 7070 tree explicit_targs = NULL_TREE; 7071 tree basetype = NULL_TREE; 7072 tree access_binfo; 7073 tree optype; 7074 tree first_mem_arg = NULL_TREE; 7075 tree instance_ptr; 7076 tree name; 7077 bool skip_first_for_error; 7078 VEC(tree,gc) *user_args; 7079 tree call; 7080 tree fn; 7081 int template_only = 0; 7082 bool any_viable_p; 7083 tree orig_instance; 7084 tree orig_fns; 7085 VEC(tree,gc) *orig_args = NULL; 7086 void *p; 7087 7088 gcc_assert (instance != NULL_TREE); 7089 7090 /* We don't know what function we're going to call, yet. */ 7091 if (fn_p) 7092 *fn_p = NULL_TREE; 7093 7094 if (error_operand_p (instance) 7095 || !fns || error_operand_p (fns)) 7096 return error_mark_node; 7097 7098 if (!BASELINK_P (fns)) 7099 { 7100 if (complain & tf_error) 7101 error ("call to non-function %qD", fns); 7102 return error_mark_node; 7103 } 7104 7105 orig_instance = instance; 7106 orig_fns = fns; 7107 7108 /* Dismantle the baselink to collect all the information we need. */ 7109 if (!conversion_path) 7110 conversion_path = BASELINK_BINFO (fns); 7111 access_binfo = BASELINK_ACCESS_BINFO (fns); 7112 optype = BASELINK_OPTYPE (fns); 7113 fns = BASELINK_FUNCTIONS (fns); 7114 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR) 7115 { 7116 explicit_targs = TREE_OPERAND (fns, 1); 7117 fns = TREE_OPERAND (fns, 0); 7118 template_only = 1; 7119 } 7120 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL 7121 || TREE_CODE (fns) == TEMPLATE_DECL 7122 || TREE_CODE (fns) == OVERLOAD); 7123 fn = get_first_fn (fns); 7124 name = DECL_NAME (fn); 7125 7126 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance)); 7127 gcc_assert (CLASS_TYPE_P (basetype)); 7128 7129 if (processing_template_decl) 7130 { 7131 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args); 7132 instance = build_non_dependent_expr (instance); 7133 if (args != NULL) 7134 make_args_non_dependent (*args); 7135 } 7136 7137 user_args = args == NULL ? NULL : *args; 7138 /* Under DR 147 A::A() is an invalid constructor call, 7139 not a functional cast. */ 7140 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 7141 { 7142 if (! (complain & tf_error)) 7143 return error_mark_node; 7144 7145 permerror (input_location, 7146 "cannot call constructor %<%T::%D%> directly", 7147 basetype, name); 7148 permerror (input_location, " for a function-style cast, remove the " 7149 "redundant %<::%D%>", name); 7150 call = build_functional_cast (basetype, build_tree_list_vec (user_args), 7151 complain); 7152 return call; 7153 } 7154 7155 /* Figure out whether to skip the first argument for the error 7156 message we will display to users if an error occurs. We don't 7157 want to display any compiler-generated arguments. The "this" 7158 pointer hasn't been added yet. However, we must remove the VTT 7159 pointer if this is a call to a base-class constructor or 7160 destructor. */ 7161 skip_first_for_error = false; 7162 if (IDENTIFIER_CTOR_OR_DTOR_P (name)) 7163 { 7164 /* Callers should explicitly indicate whether they want to construct 7165 the complete object or just the part without virtual bases. */ 7166 gcc_assert (name != ctor_identifier); 7167 /* Similarly for destructors. */ 7168 gcc_assert (name != dtor_identifier); 7169 /* Remove the VTT pointer, if present. */ 7170 if ((name == base_ctor_identifier || name == base_dtor_identifier) 7171 && CLASSTYPE_VBASECLASSES (basetype)) 7172 skip_first_for_error = true; 7173 } 7174 7175 /* Process the argument list. */ 7176 if (args != NULL && *args != NULL) 7177 { 7178 *args = resolve_args (*args, complain); 7179 if (*args == NULL) 7180 return error_mark_node; 7181 } 7182 7183 instance_ptr = build_this (instance); 7184 7185 /* It's OK to call destructors and constructors on cv-qualified objects. 7186 Therefore, convert the INSTANCE_PTR to the unqualified type, if 7187 necessary. */ 7188 if (DECL_DESTRUCTOR_P (fn) 7189 || DECL_CONSTRUCTOR_P (fn)) 7190 { 7191 tree type = build_pointer_type (basetype); 7192 if (!same_type_p (type, TREE_TYPE (instance_ptr))) 7193 instance_ptr = build_nop (type, instance_ptr); 7194 } 7195 if (DECL_DESTRUCTOR_P (fn)) 7196 name = complete_dtor_identifier; 7197 7198 first_mem_arg = instance_ptr; 7199 7200 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 7201 p = conversion_obstack_alloc (0); 7202 7203 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form 7204 initializer, not T({ }). */ 7205 if (DECL_CONSTRUCTOR_P (fn) && args != NULL && !VEC_empty (tree, *args) 7206 && BRACE_ENCLOSED_INITIALIZER_P (VEC_index (tree, *args, 0)) 7207 && CONSTRUCTOR_IS_DIRECT_INIT (VEC_index (tree, *args, 0))) 7208 { 7209 tree init_list = VEC_index (tree, *args, 0); 7210 tree init = NULL_TREE; 7211 7212 gcc_assert (VEC_length (tree, *args) == 1 7213 && !(flags & LOOKUP_ONLYCONVERTING)); 7214 7215 /* If the initializer list has no elements and T is a class type with 7216 a default constructor, the object is value-initialized. Handle 7217 this here so we don't need to handle it wherever we use 7218 build_special_member_call. */ 7219 if (CONSTRUCTOR_NELTS (init_list) == 0 7220 && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype) 7221 /* For a user-provided default constructor, use the normal 7222 mechanisms so that protected access works. */ 7223 && !type_has_user_provided_default_constructor (basetype) 7224 && !processing_template_decl) 7225 init = build_value_init (basetype, complain); 7226 7227 /* If BASETYPE is an aggregate, we need to do aggregate 7228 initialization. */ 7229 else if (CP_AGGREGATE_TYPE_P (basetype)) 7230 init = digest_init (basetype, init_list, complain); 7231 7232 if (init) 7233 { 7234 tree ob; 7235 if (integer_zerop (instance_ptr)) 7236 return get_target_expr_sfinae (init, complain); 7237 ob = build_fold_indirect_ref (instance_ptr); 7238 init = build2 (INIT_EXPR, TREE_TYPE (ob), ob, init); 7239 TREE_SIDE_EFFECTS (init) = true; 7240 return init; 7241 } 7242 7243 /* Otherwise go ahead with overload resolution. */ 7244 add_list_candidates (fns, first_mem_arg, init_list, 7245 basetype, explicit_targs, template_only, 7246 conversion_path, access_binfo, flags, &candidates); 7247 } 7248 else 7249 { 7250 add_candidates (fns, first_mem_arg, user_args, optype, 7251 explicit_targs, template_only, conversion_path, 7252 access_binfo, flags, &candidates); 7253 } 7254 any_viable_p = false; 7255 candidates = splice_viable (candidates, pedantic, &any_viable_p); 7256 7257 if (!any_viable_p) 7258 { 7259 if (complain & tf_error) 7260 { 7261 if (!COMPLETE_OR_OPEN_TYPE_P (basetype)) 7262 cxx_incomplete_type_error (instance_ptr, basetype); 7263 else if (optype) 7264 error ("no matching function for call to %<%T::operator %T(%A)%#V%>", 7265 basetype, optype, build_tree_list_vec (user_args), 7266 TREE_TYPE (TREE_TYPE (instance_ptr))); 7267 else 7268 { 7269 char *pretty_name; 7270 bool free_p; 7271 tree arglist; 7272 7273 pretty_name = name_as_c_string (name, basetype, &free_p); 7274 arglist = build_tree_list_vec (user_args); 7275 if (skip_first_for_error) 7276 arglist = TREE_CHAIN (arglist); 7277 error ("no matching function for call to %<%T::%s(%A)%#V%>", 7278 basetype, pretty_name, arglist, 7279 TREE_TYPE (TREE_TYPE (instance_ptr))); 7280 if (free_p) 7281 free (pretty_name); 7282 } 7283 print_z_candidates (location_of (name), candidates); 7284 } 7285 call = error_mark_node; 7286 } 7287 else 7288 { 7289 cand = tourney (candidates); 7290 if (cand == 0) 7291 { 7292 char *pretty_name; 7293 bool free_p; 7294 tree arglist; 7295 7296 if (complain & tf_error) 7297 { 7298 pretty_name = name_as_c_string (name, basetype, &free_p); 7299 arglist = build_tree_list_vec (user_args); 7300 if (skip_first_for_error) 7301 arglist = TREE_CHAIN (arglist); 7302 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name, 7303 arglist); 7304 print_z_candidates (location_of (name), candidates); 7305 if (free_p) 7306 free (pretty_name); 7307 } 7308 call = error_mark_node; 7309 } 7310 else 7311 { 7312 fn = cand->fn; 7313 7314 if (!(flags & LOOKUP_NONVIRTUAL) 7315 && DECL_PURE_VIRTUAL_P (fn) 7316 && instance == current_class_ref 7317 && (DECL_CONSTRUCTOR_P (current_function_decl) 7318 || DECL_DESTRUCTOR_P (current_function_decl)) 7319 && (complain & tf_warning)) 7320 /* This is not an error, it is runtime undefined 7321 behavior. */ 7322 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ? 7323 "pure virtual %q#D called from constructor" 7324 : "pure virtual %q#D called from destructor"), 7325 fn); 7326 7327 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE 7328 && is_dummy_object (instance_ptr)) 7329 { 7330 if (complain & tf_error) 7331 error ("cannot call member function %qD without object", 7332 fn); 7333 call = error_mark_node; 7334 } 7335 else 7336 { 7337 /* Optimize away vtable lookup if we know that this function 7338 can't be overridden. */ 7339 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL) 7340 && resolves_to_fixed_type_p (instance, 0)) 7341 flags |= LOOKUP_NONVIRTUAL; 7342 if (explicit_targs) 7343 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 7344 /* Now we know what function is being called. */ 7345 if (fn_p) 7346 *fn_p = fn; 7347 /* Build the actual CALL_EXPR. */ 7348 call = build_over_call (cand, flags, complain); 7349 /* In an expression of the form `a->f()' where `f' turns 7350 out to be a static member function, `a' is 7351 none-the-less evaluated. */ 7352 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE 7353 && !is_dummy_object (instance_ptr) 7354 && TREE_SIDE_EFFECTS (instance_ptr)) 7355 call = build2 (COMPOUND_EXPR, TREE_TYPE (call), 7356 instance_ptr, call); 7357 else if (call != error_mark_node 7358 && DECL_DESTRUCTOR_P (cand->fn) 7359 && !VOID_TYPE_P (TREE_TYPE (call))) 7360 /* An explicit call of the form "x->~X()" has type 7361 "void". However, on platforms where destructors 7362 return "this" (i.e., those where 7363 targetm.cxx.cdtor_returns_this is true), such calls 7364 will appear to have a return value of pointer type 7365 to the low-level call machinery. We do not want to 7366 change the low-level machinery, since we want to be 7367 able to optimize "delete f()" on such platforms as 7368 "operator delete(~X(f()))" (rather than generating 7369 "t = f(), ~X(t), operator delete (t)"). */ 7370 call = build_nop (void_type_node, call); 7371 } 7372 } 7373 } 7374 7375 if (processing_template_decl && call != error_mark_node) 7376 { 7377 bool cast_to_void = false; 7378 7379 if (TREE_CODE (call) == COMPOUND_EXPR) 7380 call = TREE_OPERAND (call, 1); 7381 else if (TREE_CODE (call) == NOP_EXPR) 7382 { 7383 cast_to_void = true; 7384 call = TREE_OPERAND (call, 0); 7385 } 7386 if (TREE_CODE (call) == INDIRECT_REF) 7387 call = TREE_OPERAND (call, 0); 7388 call = (build_min_non_dep_call_vec 7389 (call, 7390 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)), 7391 orig_instance, orig_fns, NULL_TREE), 7392 orig_args)); 7393 call = convert_from_reference (call); 7394 if (cast_to_void) 7395 call = build_nop (void_type_node, call); 7396 } 7397 7398 /* Free all the conversions we allocated. */ 7399 obstack_free (&conversion_obstack, p); 7400 7401 if (orig_args != NULL) 7402 release_tree_vector (orig_args); 7403 7404 return call; 7405 } 7406 7407 /* Wrapper for above. */ 7408 7409 tree 7410 build_new_method_call (tree instance, tree fns, VEC(tree,gc) **args, 7411 tree conversion_path, int flags, 7412 tree *fn_p, tsubst_flags_t complain) 7413 { 7414 tree ret; 7415 bool subtime = timevar_cond_start (TV_OVERLOAD); 7416 ret = build_new_method_call_1 (instance, fns, args, conversion_path, flags, 7417 fn_p, complain); 7418 timevar_cond_stop (TV_OVERLOAD, subtime); 7419 return ret; 7420 } 7421 7422 /* Returns true iff standard conversion sequence ICS1 is a proper 7423 subsequence of ICS2. */ 7424 7425 static bool 7426 is_subseq (conversion *ics1, conversion *ics2) 7427 { 7428 /* We can assume that a conversion of the same code 7429 between the same types indicates a subsequence since we only get 7430 here if the types we are converting from are the same. */ 7431 7432 while (ics1->kind == ck_rvalue 7433 || ics1->kind == ck_lvalue) 7434 ics1 = ics1->u.next; 7435 7436 while (1) 7437 { 7438 while (ics2->kind == ck_rvalue 7439 || ics2->kind == ck_lvalue) 7440 ics2 = ics2->u.next; 7441 7442 if (ics2->kind == ck_user 7443 || ics2->kind == ck_ambig 7444 || ics2->kind == ck_aggr 7445 || ics2->kind == ck_list 7446 || ics2->kind == ck_identity) 7447 /* At this point, ICS1 cannot be a proper subsequence of 7448 ICS2. We can get a USER_CONV when we are comparing the 7449 second standard conversion sequence of two user conversion 7450 sequences. */ 7451 return false; 7452 7453 ics2 = ics2->u.next; 7454 7455 if (ics2->kind == ics1->kind 7456 && same_type_p (ics2->type, ics1->type) 7457 && same_type_p (ics2->u.next->type, 7458 ics1->u.next->type)) 7459 return true; 7460 } 7461 } 7462 7463 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may 7464 be any _TYPE nodes. */ 7465 7466 bool 7467 is_properly_derived_from (tree derived, tree base) 7468 { 7469 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base)) 7470 return false; 7471 7472 /* We only allow proper derivation here. The DERIVED_FROM_P macro 7473 considers every class derived from itself. */ 7474 return (!same_type_ignoring_top_level_qualifiers_p (derived, base) 7475 && DERIVED_FROM_P (base, derived)); 7476 } 7477 7478 /* We build the ICS for an implicit object parameter as a pointer 7479 conversion sequence. However, such a sequence should be compared 7480 as if it were a reference conversion sequence. If ICS is the 7481 implicit conversion sequence for an implicit object parameter, 7482 modify it accordingly. */ 7483 7484 static void 7485 maybe_handle_implicit_object (conversion **ics) 7486 { 7487 if ((*ics)->this_p) 7488 { 7489 /* [over.match.funcs] 7490 7491 For non-static member functions, the type of the 7492 implicit object parameter is "reference to cv X" 7493 where X is the class of which the function is a 7494 member and cv is the cv-qualification on the member 7495 function declaration. */ 7496 conversion *t = *ics; 7497 tree reference_type; 7498 7499 /* The `this' parameter is a pointer to a class type. Make the 7500 implicit conversion talk about a reference to that same class 7501 type. */ 7502 reference_type = TREE_TYPE (t->type); 7503 reference_type = build_reference_type (reference_type); 7504 7505 if (t->kind == ck_qual) 7506 t = t->u.next; 7507 if (t->kind == ck_ptr) 7508 t = t->u.next; 7509 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE); 7510 t = direct_reference_binding (reference_type, t); 7511 t->this_p = 1; 7512 t->rvaluedness_matches_p = 0; 7513 *ics = t; 7514 } 7515 } 7516 7517 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion, 7518 and return the initial reference binding conversion. Otherwise, 7519 leave *ICS unchanged and return NULL. */ 7520 7521 static conversion * 7522 maybe_handle_ref_bind (conversion **ics) 7523 { 7524 if ((*ics)->kind == ck_ref_bind) 7525 { 7526 conversion *old_ics = *ics; 7527 *ics = old_ics->u.next; 7528 (*ics)->user_conv_p = old_ics->user_conv_p; 7529 return old_ics; 7530 } 7531 7532 return NULL; 7533 } 7534 7535 /* Compare two implicit conversion sequences according to the rules set out in 7536 [over.ics.rank]. Return values: 7537 7538 1: ics1 is better than ics2 7539 -1: ics2 is better than ics1 7540 0: ics1 and ics2 are indistinguishable */ 7541 7542 static int 7543 compare_ics (conversion *ics1, conversion *ics2) 7544 { 7545 tree from_type1; 7546 tree from_type2; 7547 tree to_type1; 7548 tree to_type2; 7549 tree deref_from_type1 = NULL_TREE; 7550 tree deref_from_type2 = NULL_TREE; 7551 tree deref_to_type1 = NULL_TREE; 7552 tree deref_to_type2 = NULL_TREE; 7553 conversion_rank rank1, rank2; 7554 7555 /* REF_BINDING is nonzero if the result of the conversion sequence 7556 is a reference type. In that case REF_CONV is the reference 7557 binding conversion. */ 7558 conversion *ref_conv1; 7559 conversion *ref_conv2; 7560 7561 /* Handle implicit object parameters. */ 7562 maybe_handle_implicit_object (&ics1); 7563 maybe_handle_implicit_object (&ics2); 7564 7565 /* Handle reference parameters. */ 7566 ref_conv1 = maybe_handle_ref_bind (&ics1); 7567 ref_conv2 = maybe_handle_ref_bind (&ics2); 7568 7569 /* List-initialization sequence L1 is a better conversion sequence than 7570 list-initialization sequence L2 if L1 converts to 7571 std::initializer_list<X> for some X and L2 does not. */ 7572 if (ics1->kind == ck_list && ics2->kind != ck_list) 7573 return 1; 7574 if (ics2->kind == ck_list && ics1->kind != ck_list) 7575 return -1; 7576 7577 /* [over.ics.rank] 7578 7579 When comparing the basic forms of implicit conversion sequences (as 7580 defined in _over.best.ics_) 7581 7582 --a standard conversion sequence (_over.ics.scs_) is a better 7583 conversion sequence than a user-defined conversion sequence 7584 or an ellipsis conversion sequence, and 7585 7586 --a user-defined conversion sequence (_over.ics.user_) is a 7587 better conversion sequence than an ellipsis conversion sequence 7588 (_over.ics.ellipsis_). */ 7589 rank1 = CONVERSION_RANK (ics1); 7590 rank2 = CONVERSION_RANK (ics2); 7591 7592 if (rank1 > rank2) 7593 return -1; 7594 else if (rank1 < rank2) 7595 return 1; 7596 7597 if (rank1 == cr_bad) 7598 { 7599 /* Both ICS are bad. We try to make a decision based on what would 7600 have happened if they'd been good. This is not an extension, 7601 we'll still give an error when we build up the call; this just 7602 helps us give a more helpful error message. */ 7603 rank1 = BAD_CONVERSION_RANK (ics1); 7604 rank2 = BAD_CONVERSION_RANK (ics2); 7605 7606 if (rank1 > rank2) 7607 return -1; 7608 else if (rank1 < rank2) 7609 return 1; 7610 7611 /* We couldn't make up our minds; try to figure it out below. */ 7612 } 7613 7614 if (ics1->ellipsis_p) 7615 /* Both conversions are ellipsis conversions. */ 7616 return 0; 7617 7618 /* User-defined conversion sequence U1 is a better conversion sequence 7619 than another user-defined conversion sequence U2 if they contain the 7620 same user-defined conversion operator or constructor and if the sec- 7621 ond standard conversion sequence of U1 is better than the second 7622 standard conversion sequence of U2. */ 7623 7624 /* Handle list-conversion with the same code even though it isn't always 7625 ranked as a user-defined conversion and it doesn't have a second 7626 standard conversion sequence; it will still have the desired effect. 7627 Specifically, we need to do the reference binding comparison at the 7628 end of this function. */ 7629 7630 if (ics1->user_conv_p || ics1->kind == ck_list || ics1->kind == ck_aggr) 7631 { 7632 conversion *t1; 7633 conversion *t2; 7634 7635 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next) 7636 if (t1->kind == ck_ambig || t1->kind == ck_aggr 7637 || t1->kind == ck_list) 7638 break; 7639 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next) 7640 if (t2->kind == ck_ambig || t2->kind == ck_aggr 7641 || t2->kind == ck_list) 7642 break; 7643 7644 if (t1->kind != t2->kind) 7645 return 0; 7646 else if (t1->kind == ck_user) 7647 { 7648 if (t1->cand->fn != t2->cand->fn) 7649 return 0; 7650 } 7651 else 7652 { 7653 /* For ambiguous or aggregate conversions, use the target type as 7654 a proxy for the conversion function. */ 7655 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type)) 7656 return 0; 7657 } 7658 7659 /* We can just fall through here, after setting up 7660 FROM_TYPE1 and FROM_TYPE2. */ 7661 from_type1 = t1->type; 7662 from_type2 = t2->type; 7663 } 7664 else 7665 { 7666 conversion *t1; 7667 conversion *t2; 7668 7669 /* We're dealing with two standard conversion sequences. 7670 7671 [over.ics.rank] 7672 7673 Standard conversion sequence S1 is a better conversion 7674 sequence than standard conversion sequence S2 if 7675 7676 --S1 is a proper subsequence of S2 (comparing the conversion 7677 sequences in the canonical form defined by _over.ics.scs_, 7678 excluding any Lvalue Transformation; the identity 7679 conversion sequence is considered to be a subsequence of 7680 any non-identity conversion sequence */ 7681 7682 t1 = ics1; 7683 while (t1->kind != ck_identity) 7684 t1 = t1->u.next; 7685 from_type1 = t1->type; 7686 7687 t2 = ics2; 7688 while (t2->kind != ck_identity) 7689 t2 = t2->u.next; 7690 from_type2 = t2->type; 7691 } 7692 7693 /* One sequence can only be a subsequence of the other if they start with 7694 the same type. They can start with different types when comparing the 7695 second standard conversion sequence in two user-defined conversion 7696 sequences. */ 7697 if (same_type_p (from_type1, from_type2)) 7698 { 7699 if (is_subseq (ics1, ics2)) 7700 return 1; 7701 if (is_subseq (ics2, ics1)) 7702 return -1; 7703 } 7704 7705 /* [over.ics.rank] 7706 7707 Or, if not that, 7708 7709 --the rank of S1 is better than the rank of S2 (by the rules 7710 defined below): 7711 7712 Standard conversion sequences are ordered by their ranks: an Exact 7713 Match is a better conversion than a Promotion, which is a better 7714 conversion than a Conversion. 7715 7716 Two conversion sequences with the same rank are indistinguishable 7717 unless one of the following rules applies: 7718 7719 --A conversion that does not a convert a pointer, pointer to member, 7720 or std::nullptr_t to bool is better than one that does. 7721 7722 The ICS_STD_RANK automatically handles the pointer-to-bool rule, 7723 so that we do not have to check it explicitly. */ 7724 if (ics1->rank < ics2->rank) 7725 return 1; 7726 else if (ics2->rank < ics1->rank) 7727 return -1; 7728 7729 to_type1 = ics1->type; 7730 to_type2 = ics2->type; 7731 7732 /* A conversion from scalar arithmetic type to complex is worse than a 7733 conversion between scalar arithmetic types. */ 7734 if (same_type_p (from_type1, from_type2) 7735 && ARITHMETIC_TYPE_P (from_type1) 7736 && ARITHMETIC_TYPE_P (to_type1) 7737 && ARITHMETIC_TYPE_P (to_type2) 7738 && ((TREE_CODE (to_type1) == COMPLEX_TYPE) 7739 != (TREE_CODE (to_type2) == COMPLEX_TYPE))) 7740 { 7741 if (TREE_CODE (to_type1) == COMPLEX_TYPE) 7742 return -1; 7743 else 7744 return 1; 7745 } 7746 7747 if (TYPE_PTR_P (from_type1) 7748 && TYPE_PTR_P (from_type2) 7749 && TYPE_PTR_P (to_type1) 7750 && TYPE_PTR_P (to_type2)) 7751 { 7752 deref_from_type1 = TREE_TYPE (from_type1); 7753 deref_from_type2 = TREE_TYPE (from_type2); 7754 deref_to_type1 = TREE_TYPE (to_type1); 7755 deref_to_type2 = TREE_TYPE (to_type2); 7756 } 7757 /* The rules for pointers to members A::* are just like the rules 7758 for pointers A*, except opposite: if B is derived from A then 7759 A::* converts to B::*, not vice versa. For that reason, we 7760 switch the from_ and to_ variables here. */ 7761 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2) 7762 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2)) 7763 || (TYPE_PTRMEMFUNC_P (from_type1) 7764 && TYPE_PTRMEMFUNC_P (from_type2) 7765 && TYPE_PTRMEMFUNC_P (to_type1) 7766 && TYPE_PTRMEMFUNC_P (to_type2))) 7767 { 7768 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1); 7769 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2); 7770 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1); 7771 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2); 7772 } 7773 7774 if (deref_from_type1 != NULL_TREE 7775 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1)) 7776 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2))) 7777 { 7778 /* This was one of the pointer or pointer-like conversions. 7779 7780 [over.ics.rank] 7781 7782 --If class B is derived directly or indirectly from class A, 7783 conversion of B* to A* is better than conversion of B* to 7784 void*, and conversion of A* to void* is better than 7785 conversion of B* to void*. */ 7786 if (TREE_CODE (deref_to_type1) == VOID_TYPE 7787 && TREE_CODE (deref_to_type2) == VOID_TYPE) 7788 { 7789 if (is_properly_derived_from (deref_from_type1, 7790 deref_from_type2)) 7791 return -1; 7792 else if (is_properly_derived_from (deref_from_type2, 7793 deref_from_type1)) 7794 return 1; 7795 } 7796 else if (TREE_CODE (deref_to_type1) == VOID_TYPE 7797 || TREE_CODE (deref_to_type2) == VOID_TYPE) 7798 { 7799 if (same_type_p (deref_from_type1, deref_from_type2)) 7800 { 7801 if (TREE_CODE (deref_to_type2) == VOID_TYPE) 7802 { 7803 if (is_properly_derived_from (deref_from_type1, 7804 deref_to_type1)) 7805 return 1; 7806 } 7807 /* We know that DEREF_TO_TYPE1 is `void' here. */ 7808 else if (is_properly_derived_from (deref_from_type1, 7809 deref_to_type2)) 7810 return -1; 7811 } 7812 } 7813 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1)) 7814 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2))) 7815 { 7816 /* [over.ics.rank] 7817 7818 --If class B is derived directly or indirectly from class A 7819 and class C is derived directly or indirectly from B, 7820 7821 --conversion of C* to B* is better than conversion of C* to 7822 A*, 7823 7824 --conversion of B* to A* is better than conversion of C* to 7825 A* */ 7826 if (same_type_p (deref_from_type1, deref_from_type2)) 7827 { 7828 if (is_properly_derived_from (deref_to_type1, 7829 deref_to_type2)) 7830 return 1; 7831 else if (is_properly_derived_from (deref_to_type2, 7832 deref_to_type1)) 7833 return -1; 7834 } 7835 else if (same_type_p (deref_to_type1, deref_to_type2)) 7836 { 7837 if (is_properly_derived_from (deref_from_type2, 7838 deref_from_type1)) 7839 return 1; 7840 else if (is_properly_derived_from (deref_from_type1, 7841 deref_from_type2)) 7842 return -1; 7843 } 7844 } 7845 } 7846 else if (CLASS_TYPE_P (non_reference (from_type1)) 7847 && same_type_p (from_type1, from_type2)) 7848 { 7849 tree from = non_reference (from_type1); 7850 7851 /* [over.ics.rank] 7852 7853 --binding of an expression of type C to a reference of type 7854 B& is better than binding an expression of type C to a 7855 reference of type A& 7856 7857 --conversion of C to B is better than conversion of C to A, */ 7858 if (is_properly_derived_from (from, to_type1) 7859 && is_properly_derived_from (from, to_type2)) 7860 { 7861 if (is_properly_derived_from (to_type1, to_type2)) 7862 return 1; 7863 else if (is_properly_derived_from (to_type2, to_type1)) 7864 return -1; 7865 } 7866 } 7867 else if (CLASS_TYPE_P (non_reference (to_type1)) 7868 && same_type_p (to_type1, to_type2)) 7869 { 7870 tree to = non_reference (to_type1); 7871 7872 /* [over.ics.rank] 7873 7874 --binding of an expression of type B to a reference of type 7875 A& is better than binding an expression of type C to a 7876 reference of type A&, 7877 7878 --conversion of B to A is better than conversion of C to A */ 7879 if (is_properly_derived_from (from_type1, to) 7880 && is_properly_derived_from (from_type2, to)) 7881 { 7882 if (is_properly_derived_from (from_type2, from_type1)) 7883 return 1; 7884 else if (is_properly_derived_from (from_type1, from_type2)) 7885 return -1; 7886 } 7887 } 7888 7889 /* [over.ics.rank] 7890 7891 --S1 and S2 differ only in their qualification conversion and yield 7892 similar types T1 and T2 (_conv.qual_), respectively, and the cv- 7893 qualification signature of type T1 is a proper subset of the cv- 7894 qualification signature of type T2 */ 7895 if (ics1->kind == ck_qual 7896 && ics2->kind == ck_qual 7897 && same_type_p (from_type1, from_type2)) 7898 { 7899 int result = comp_cv_qual_signature (to_type1, to_type2); 7900 if (result != 0) 7901 return result; 7902 } 7903 7904 /* [over.ics.rank] 7905 7906 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers 7907 to an implicit object parameter, and either S1 binds an lvalue reference 7908 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue 7909 reference to an rvalue and S2 binds an lvalue reference 7910 (C++0x draft standard, 13.3.3.2) 7911 7912 --S1 and S2 are reference bindings (_dcl.init.ref_), and the 7913 types to which the references refer are the same type except for 7914 top-level cv-qualifiers, and the type to which the reference 7915 initialized by S2 refers is more cv-qualified than the type to 7916 which the reference initialized by S1 refers. 7917 7918 DR 1328 [over.match.best]: the context is an initialization by 7919 conversion function for direct reference binding (13.3.1.6) of a 7920 reference to function type, the return type of F1 is the same kind of 7921 reference (i.e. lvalue or rvalue) as the reference being initialized, 7922 and the return type of F2 is not. */ 7923 7924 if (ref_conv1 && ref_conv2) 7925 { 7926 if (!ref_conv1->this_p && !ref_conv2->this_p 7927 && (ref_conv1->rvaluedness_matches_p 7928 != ref_conv2->rvaluedness_matches_p) 7929 && (same_type_p (ref_conv1->type, ref_conv2->type) 7930 || (TYPE_REF_IS_RVALUE (ref_conv1->type) 7931 != TYPE_REF_IS_RVALUE (ref_conv2->type)))) 7932 { 7933 return (ref_conv1->rvaluedness_matches_p 7934 - ref_conv2->rvaluedness_matches_p); 7935 } 7936 7937 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2)) 7938 return comp_cv_qualification (TREE_TYPE (ref_conv2->type), 7939 TREE_TYPE (ref_conv1->type)); 7940 } 7941 7942 /* Neither conversion sequence is better than the other. */ 7943 return 0; 7944 } 7945 7946 /* The source type for this standard conversion sequence. */ 7947 7948 static tree 7949 source_type (conversion *t) 7950 { 7951 for (;; t = t->u.next) 7952 { 7953 if (t->kind == ck_user 7954 || t->kind == ck_ambig 7955 || t->kind == ck_identity) 7956 return t->type; 7957 } 7958 gcc_unreachable (); 7959 } 7960 7961 /* Note a warning about preferring WINNER to LOSER. We do this by storing 7962 a pointer to LOSER and re-running joust to produce the warning if WINNER 7963 is actually used. */ 7964 7965 static void 7966 add_warning (struct z_candidate *winner, struct z_candidate *loser) 7967 { 7968 candidate_warning *cw = (candidate_warning *) 7969 conversion_obstack_alloc (sizeof (candidate_warning)); 7970 cw->loser = loser; 7971 cw->next = winner->warnings; 7972 winner->warnings = cw; 7973 } 7974 7975 /* Compare two candidates for overloading as described in 7976 [over.match.best]. Return values: 7977 7978 1: cand1 is better than cand2 7979 -1: cand2 is better than cand1 7980 0: cand1 and cand2 are indistinguishable */ 7981 7982 static int 7983 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn) 7984 { 7985 int winner = 0; 7986 int off1 = 0, off2 = 0; 7987 size_t i; 7988 size_t len; 7989 7990 /* Candidates that involve bad conversions are always worse than those 7991 that don't. */ 7992 if (cand1->viable > cand2->viable) 7993 return 1; 7994 if (cand1->viable < cand2->viable) 7995 return -1; 7996 7997 /* If we have two pseudo-candidates for conversions to the same type, 7998 or two candidates for the same function, arbitrarily pick one. */ 7999 if (cand1->fn == cand2->fn 8000 && (IS_TYPE_OR_DECL_P (cand1->fn))) 8001 return 1; 8002 8003 /* a viable function F1 8004 is defined to be a better function than another viable function F2 if 8005 for all arguments i, ICSi(F1) is not a worse conversion sequence than 8006 ICSi(F2), and then */ 8007 8008 /* for some argument j, ICSj(F1) is a better conversion sequence than 8009 ICSj(F2) */ 8010 8011 /* For comparing static and non-static member functions, we ignore 8012 the implicit object parameter of the non-static function. The 8013 standard says to pretend that the static function has an object 8014 parm, but that won't work with operator overloading. */ 8015 len = cand1->num_convs; 8016 if (len != cand2->num_convs) 8017 { 8018 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn); 8019 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn); 8020 8021 if (DECL_CONSTRUCTOR_P (cand1->fn) 8022 && is_list_ctor (cand1->fn) != is_list_ctor (cand2->fn)) 8023 /* We're comparing a near-match list constructor and a near-match 8024 non-list constructor. Just treat them as unordered. */ 8025 return 0; 8026 8027 gcc_assert (static_1 != static_2); 8028 8029 if (static_1) 8030 off2 = 1; 8031 else 8032 { 8033 off1 = 1; 8034 --len; 8035 } 8036 } 8037 8038 for (i = 0; i < len; ++i) 8039 { 8040 conversion *t1 = cand1->convs[i + off1]; 8041 conversion *t2 = cand2->convs[i + off2]; 8042 int comp = compare_ics (t1, t2); 8043 8044 if (comp != 0) 8045 { 8046 if (warn_sign_promo 8047 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2) 8048 == cr_std + cr_promotion) 8049 && t1->kind == ck_std 8050 && t2->kind == ck_std 8051 && TREE_CODE (t1->type) == INTEGER_TYPE 8052 && TREE_CODE (t2->type) == INTEGER_TYPE 8053 && (TYPE_PRECISION (t1->type) 8054 == TYPE_PRECISION (t2->type)) 8055 && (TYPE_UNSIGNED (t1->u.next->type) 8056 || (TREE_CODE (t1->u.next->type) 8057 == ENUMERAL_TYPE))) 8058 { 8059 tree type = t1->u.next->type; 8060 tree type1, type2; 8061 struct z_candidate *w, *l; 8062 if (comp > 0) 8063 type1 = t1->type, type2 = t2->type, 8064 w = cand1, l = cand2; 8065 else 8066 type1 = t2->type, type2 = t1->type, 8067 w = cand2, l = cand1; 8068 8069 if (warn) 8070 { 8071 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT", 8072 type, type1, type2); 8073 warning (OPT_Wsign_promo, " in call to %qD", w->fn); 8074 } 8075 else 8076 add_warning (w, l); 8077 } 8078 8079 if (winner && comp != winner) 8080 { 8081 winner = 0; 8082 goto tweak; 8083 } 8084 winner = comp; 8085 } 8086 } 8087 8088 /* warn about confusing overload resolution for user-defined conversions, 8089 either between a constructor and a conversion op, or between two 8090 conversion ops. */ 8091 if (winner && warn_conversion && cand1->second_conv 8092 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn)) 8093 && winner != compare_ics (cand1->second_conv, cand2->second_conv)) 8094 { 8095 struct z_candidate *w, *l; 8096 bool give_warning = false; 8097 8098 if (winner == 1) 8099 w = cand1, l = cand2; 8100 else 8101 w = cand2, l = cand1; 8102 8103 /* We don't want to complain about `X::operator T1 ()' 8104 beating `X::operator T2 () const', when T2 is a no less 8105 cv-qualified version of T1. */ 8106 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn) 8107 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn)) 8108 { 8109 tree t = TREE_TYPE (TREE_TYPE (l->fn)); 8110 tree f = TREE_TYPE (TREE_TYPE (w->fn)); 8111 8112 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t)) 8113 { 8114 t = TREE_TYPE (t); 8115 f = TREE_TYPE (f); 8116 } 8117 if (!comp_ptr_ttypes (t, f)) 8118 give_warning = true; 8119 } 8120 else 8121 give_warning = true; 8122 8123 if (!give_warning) 8124 /*NOP*/; 8125 else if (warn) 8126 { 8127 tree source = source_type (w->convs[0]); 8128 if (! DECL_CONSTRUCTOR_P (w->fn)) 8129 source = TREE_TYPE (source); 8130 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn) 8131 && warning (OPT_Wconversion, " for conversion from %qT to %qT", 8132 source, w->second_conv->type)) 8133 { 8134 inform (input_location, " because conversion sequence for the argument is better"); 8135 } 8136 } 8137 else 8138 add_warning (w, l); 8139 } 8140 8141 if (winner) 8142 return winner; 8143 8144 /* DR 495 moved this tiebreaker above the template ones. */ 8145 /* or, if not that, 8146 the context is an initialization by user-defined conversion (see 8147 _dcl.init_ and _over.match.user_) and the standard conversion 8148 sequence from the return type of F1 to the destination type (i.e., 8149 the type of the entity being initialized) is a better conversion 8150 sequence than the standard conversion sequence from the return type 8151 of F2 to the destination type. */ 8152 8153 if (cand1->second_conv) 8154 { 8155 winner = compare_ics (cand1->second_conv, cand2->second_conv); 8156 if (winner) 8157 return winner; 8158 } 8159 8160 /* or, if not that, 8161 F1 is a non-template function and F2 is a template function 8162 specialization. */ 8163 8164 if (!cand1->template_decl && cand2->template_decl) 8165 return 1; 8166 else if (cand1->template_decl && !cand2->template_decl) 8167 return -1; 8168 8169 /* or, if not that, 8170 F1 and F2 are template functions and the function template for F1 is 8171 more specialized than the template for F2 according to the partial 8172 ordering rules. */ 8173 8174 if (cand1->template_decl && cand2->template_decl) 8175 { 8176 winner = more_specialized_fn 8177 (TI_TEMPLATE (cand1->template_decl), 8178 TI_TEMPLATE (cand2->template_decl), 8179 /* [temp.func.order]: The presence of unused ellipsis and default 8180 arguments has no effect on the partial ordering of function 8181 templates. add_function_candidate() will not have 8182 counted the "this" argument for constructors. */ 8183 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn)); 8184 if (winner) 8185 return winner; 8186 } 8187 8188 /* Check whether we can discard a builtin candidate, either because we 8189 have two identical ones or matching builtin and non-builtin candidates. 8190 8191 (Pedantically in the latter case the builtin which matched the user 8192 function should not be added to the overload set, but we spot it here. 8193 8194 [over.match.oper] 8195 ... the builtin candidates include ... 8196 - do not have the same parameter type list as any non-template 8197 non-member candidate. */ 8198 8199 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE 8200 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE) 8201 { 8202 for (i = 0; i < len; ++i) 8203 if (!same_type_p (cand1->convs[i]->type, 8204 cand2->convs[i]->type)) 8205 break; 8206 if (i == cand1->num_convs) 8207 { 8208 if (cand1->fn == cand2->fn) 8209 /* Two built-in candidates; arbitrarily pick one. */ 8210 return 1; 8211 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE) 8212 /* cand1 is built-in; prefer cand2. */ 8213 return -1; 8214 else 8215 /* cand2 is built-in; prefer cand1. */ 8216 return 1; 8217 } 8218 } 8219 8220 /* If the two function declarations represent the same function (this can 8221 happen with declarations in multiple scopes and arg-dependent lookup), 8222 arbitrarily choose one. But first make sure the default args we're 8223 using match. */ 8224 if (DECL_P (cand1->fn) && DECL_P (cand2->fn) 8225 && equal_functions (cand1->fn, cand2->fn)) 8226 { 8227 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn)); 8228 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn)); 8229 8230 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn)); 8231 8232 for (i = 0; i < len; ++i) 8233 { 8234 /* Don't crash if the fn is variadic. */ 8235 if (!parms1) 8236 break; 8237 parms1 = TREE_CHAIN (parms1); 8238 parms2 = TREE_CHAIN (parms2); 8239 } 8240 8241 if (off1) 8242 parms1 = TREE_CHAIN (parms1); 8243 else if (off2) 8244 parms2 = TREE_CHAIN (parms2); 8245 8246 for (; parms1; ++i) 8247 { 8248 if (!cp_tree_equal (TREE_PURPOSE (parms1), 8249 TREE_PURPOSE (parms2))) 8250 { 8251 if (warn) 8252 { 8253 permerror (input_location, "default argument mismatch in " 8254 "overload resolution"); 8255 inform (input_location, 8256 " candidate 1: %q+#F", cand1->fn); 8257 inform (input_location, 8258 " candidate 2: %q+#F", cand2->fn); 8259 } 8260 else 8261 add_warning (cand1, cand2); 8262 break; 8263 } 8264 parms1 = TREE_CHAIN (parms1); 8265 parms2 = TREE_CHAIN (parms2); 8266 } 8267 8268 return 1; 8269 } 8270 8271 tweak: 8272 8273 /* Extension: If the worst conversion for one candidate is worse than the 8274 worst conversion for the other, take the first. */ 8275 if (!pedantic) 8276 { 8277 conversion_rank rank1 = cr_identity, rank2 = cr_identity; 8278 struct z_candidate *w = 0, *l = 0; 8279 8280 for (i = 0; i < len; ++i) 8281 { 8282 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1) 8283 rank1 = CONVERSION_RANK (cand1->convs[i+off1]); 8284 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2) 8285 rank2 = CONVERSION_RANK (cand2->convs[i + off2]); 8286 } 8287 if (rank1 < rank2) 8288 winner = 1, w = cand1, l = cand2; 8289 if (rank1 > rank2) 8290 winner = -1, w = cand2, l = cand1; 8291 if (winner) 8292 { 8293 /* Don't choose a deleted function over ambiguity. */ 8294 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn)) 8295 return 0; 8296 if (warn) 8297 { 8298 pedwarn (input_location, 0, 8299 "ISO C++ says that these are ambiguous, even " 8300 "though the worst conversion for the first is better than " 8301 "the worst conversion for the second:"); 8302 print_z_candidate (_("candidate 1:"), w); 8303 print_z_candidate (_("candidate 2:"), l); 8304 } 8305 else 8306 add_warning (w, l); 8307 return winner; 8308 } 8309 } 8310 8311 gcc_assert (!winner); 8312 return 0; 8313 } 8314 8315 /* Given a list of candidates for overloading, find the best one, if any. 8316 This algorithm has a worst case of O(2n) (winner is last), and a best 8317 case of O(n/2) (totally ambiguous); much better than a sorting 8318 algorithm. */ 8319 8320 static struct z_candidate * 8321 tourney (struct z_candidate *candidates) 8322 { 8323 struct z_candidate *champ = candidates, *challenger; 8324 int fate; 8325 int champ_compared_to_predecessor = 0; 8326 8327 /* Walk through the list once, comparing each current champ to the next 8328 candidate, knocking out a candidate or two with each comparison. */ 8329 8330 for (challenger = champ->next; challenger; ) 8331 { 8332 fate = joust (champ, challenger, 0); 8333 if (fate == 1) 8334 challenger = challenger->next; 8335 else 8336 { 8337 if (fate == 0) 8338 { 8339 champ = challenger->next; 8340 if (champ == 0) 8341 return NULL; 8342 champ_compared_to_predecessor = 0; 8343 } 8344 else 8345 { 8346 champ = challenger; 8347 champ_compared_to_predecessor = 1; 8348 } 8349 8350 challenger = champ->next; 8351 } 8352 } 8353 8354 /* Make sure the champ is better than all the candidates it hasn't yet 8355 been compared to. */ 8356 8357 for (challenger = candidates; 8358 challenger != champ 8359 && !(champ_compared_to_predecessor && challenger->next == champ); 8360 challenger = challenger->next) 8361 { 8362 fate = joust (champ, challenger, 0); 8363 if (fate != 1) 8364 return NULL; 8365 } 8366 8367 return champ; 8368 } 8369 8370 /* Returns nonzero if things of type FROM can be converted to TO. */ 8371 8372 bool 8373 can_convert (tree to, tree from) 8374 { 8375 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT); 8376 } 8377 8378 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */ 8379 8380 bool 8381 can_convert_arg (tree to, tree from, tree arg, int flags) 8382 { 8383 conversion *t; 8384 void *p; 8385 bool ok_p; 8386 8387 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8388 p = conversion_obstack_alloc (0); 8389 8390 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 8391 flags); 8392 ok_p = (t && !t->bad_p); 8393 8394 /* Free all the conversions we allocated. */ 8395 obstack_free (&conversion_obstack, p); 8396 8397 return ok_p; 8398 } 8399 8400 /* Like can_convert_arg, but allows dubious conversions as well. */ 8401 8402 bool 8403 can_convert_arg_bad (tree to, tree from, tree arg, int flags) 8404 { 8405 conversion *t; 8406 void *p; 8407 8408 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8409 p = conversion_obstack_alloc (0); 8410 /* Try to perform the conversion. */ 8411 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 8412 flags); 8413 /* Free all the conversions we allocated. */ 8414 obstack_free (&conversion_obstack, p); 8415 8416 return t != NULL; 8417 } 8418 8419 /* Convert EXPR to TYPE. Return the converted expression. 8420 8421 Note that we allow bad conversions here because by the time we get to 8422 this point we are committed to doing the conversion. If we end up 8423 doing a bad conversion, convert_like will complain. */ 8424 8425 tree 8426 perform_implicit_conversion_flags (tree type, tree expr, tsubst_flags_t complain, int flags) 8427 { 8428 conversion *conv; 8429 void *p; 8430 8431 if (error_operand_p (expr)) 8432 return error_mark_node; 8433 8434 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8435 p = conversion_obstack_alloc (0); 8436 8437 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 8438 /*c_cast_p=*/false, 8439 flags); 8440 8441 if (!conv) 8442 { 8443 if (complain & tf_error) 8444 { 8445 /* If expr has unknown type, then it is an overloaded function. 8446 Call instantiate_type to get good error messages. */ 8447 if (TREE_TYPE (expr) == unknown_type_node) 8448 instantiate_type (type, expr, complain); 8449 else if (invalid_nonstatic_memfn_p (expr, complain)) 8450 /* We gave an error. */; 8451 else 8452 error ("could not convert %qE from %qT to %qT", expr, 8453 TREE_TYPE (expr), type); 8454 } 8455 expr = error_mark_node; 8456 } 8457 else if (processing_template_decl && conv->kind != ck_identity) 8458 { 8459 /* In a template, we are only concerned about determining the 8460 type of non-dependent expressions, so we do not have to 8461 perform the actual conversion. But for initializers, we 8462 need to be able to perform it at instantiation 8463 (or fold_non_dependent_expr) time. */ 8464 expr = build1 (IMPLICIT_CONV_EXPR, type, expr); 8465 if (!(flags & LOOKUP_ONLYCONVERTING)) 8466 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true; 8467 } 8468 else 8469 expr = convert_like (conv, expr, complain); 8470 8471 /* Free all the conversions we allocated. */ 8472 obstack_free (&conversion_obstack, p); 8473 8474 return expr; 8475 } 8476 8477 tree 8478 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain) 8479 { 8480 return perform_implicit_conversion_flags (type, expr, complain, LOOKUP_IMPLICIT); 8481 } 8482 8483 /* Convert EXPR to TYPE (as a direct-initialization) if that is 8484 permitted. If the conversion is valid, the converted expression is 8485 returned. Otherwise, NULL_TREE is returned, except in the case 8486 that TYPE is a class type; in that case, an error is issued. If 8487 C_CAST_P is true, then this direct-initialization is taking 8488 place as part of a static_cast being attempted as part of a C-style 8489 cast. */ 8490 8491 tree 8492 perform_direct_initialization_if_possible (tree type, 8493 tree expr, 8494 bool c_cast_p, 8495 tsubst_flags_t complain) 8496 { 8497 conversion *conv; 8498 void *p; 8499 8500 if (type == error_mark_node || error_operand_p (expr)) 8501 return error_mark_node; 8502 /* [dcl.init] 8503 8504 If the destination type is a (possibly cv-qualified) class type: 8505 8506 -- If the initialization is direct-initialization ..., 8507 constructors are considered. ... If no constructor applies, or 8508 the overload resolution is ambiguous, the initialization is 8509 ill-formed. */ 8510 if (CLASS_TYPE_P (type)) 8511 { 8512 VEC(tree,gc) *args = make_tree_vector_single (expr); 8513 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 8514 &args, type, LOOKUP_NORMAL, complain); 8515 release_tree_vector (args); 8516 return build_cplus_new (type, expr, complain); 8517 } 8518 8519 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8520 p = conversion_obstack_alloc (0); 8521 8522 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 8523 c_cast_p, 8524 LOOKUP_NORMAL); 8525 if (!conv || conv->bad_p) 8526 expr = NULL_TREE; 8527 else 8528 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0, 8529 /*issue_conversion_warnings=*/false, 8530 c_cast_p, 8531 complain); 8532 8533 /* Free all the conversions we allocated. */ 8534 obstack_free (&conversion_obstack, p); 8535 8536 return expr; 8537 } 8538 8539 /* When initializing a reference that lasts longer than a full-expression, 8540 this special rule applies: 8541 8542 [class.temporary] 8543 8544 The temporary to which the reference is bound or the temporary 8545 that is the complete object to which the reference is bound 8546 persists for the lifetime of the reference. 8547 8548 The temporaries created during the evaluation of the expression 8549 initializing the reference, except the temporary to which the 8550 reference is bound, are destroyed at the end of the 8551 full-expression in which they are created. 8552 8553 In that case, we store the converted expression into a new 8554 VAR_DECL in a new scope. 8555 8556 However, we want to be careful not to create temporaries when 8557 they are not required. For example, given: 8558 8559 struct B {}; 8560 struct D : public B {}; 8561 D f(); 8562 const B& b = f(); 8563 8564 there is no need to copy the return value from "f"; we can just 8565 extend its lifetime. Similarly, given: 8566 8567 struct S {}; 8568 struct T { operator S(); }; 8569 T t; 8570 const S& s = t; 8571 8572 we can extend the lifetime of the return value of the conversion 8573 operator. 8574 8575 The next several functions are involved in this lifetime extension. */ 8576 8577 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference 8578 is being bound to a temporary. Create and return a new VAR_DECL 8579 with the indicated TYPE; this variable will store the value to 8580 which the reference is bound. */ 8581 8582 tree 8583 make_temporary_var_for_ref_to_temp (tree decl, tree type) 8584 { 8585 tree var; 8586 8587 /* Create the variable. */ 8588 var = create_temporary_var (type); 8589 8590 /* Register the variable. */ 8591 if (TREE_STATIC (decl)) 8592 { 8593 /* Namespace-scope or local static; give it a mangled name. */ 8594 /* FIXME share comdat with decl? */ 8595 tree name; 8596 8597 TREE_STATIC (var) = 1; 8598 name = mangle_ref_init_variable (decl); 8599 DECL_NAME (var) = name; 8600 SET_DECL_ASSEMBLER_NAME (var, name); 8601 var = pushdecl_top_level (var); 8602 } 8603 else 8604 /* Create a new cleanup level if necessary. */ 8605 maybe_push_cleanup_level (type); 8606 8607 return var; 8608 } 8609 8610 /* EXPR is the initializer for a variable DECL of reference or 8611 std::initializer_list type. Create, push and return a new VAR_DECL 8612 for the initializer so that it will live as long as DECL. Any 8613 cleanup for the new variable is returned through CLEANUP, and the 8614 code to initialize the new variable is returned through INITP. */ 8615 8616 static tree 8617 set_up_extended_ref_temp (tree decl, tree expr, VEC(tree,gc) **cleanups, 8618 tree *initp) 8619 { 8620 tree init; 8621 tree type; 8622 tree var; 8623 8624 /* Create the temporary variable. */ 8625 type = TREE_TYPE (expr); 8626 var = make_temporary_var_for_ref_to_temp (decl, type); 8627 layout_decl (var, 0); 8628 /* If the rvalue is the result of a function call it will be 8629 a TARGET_EXPR. If it is some other construct (such as a 8630 member access expression where the underlying object is 8631 itself the result of a function call), turn it into a 8632 TARGET_EXPR here. It is important that EXPR be a 8633 TARGET_EXPR below since otherwise the INIT_EXPR will 8634 attempt to make a bitwise copy of EXPR to initialize 8635 VAR. */ 8636 if (TREE_CODE (expr) != TARGET_EXPR) 8637 expr = get_target_expr (expr); 8638 8639 if (TREE_CODE (decl) == FIELD_DECL 8640 && extra_warnings && !TREE_NO_WARNING (decl)) 8641 { 8642 warning (OPT_Wextra, "a temporary bound to %qD only persists " 8643 "until the constructor exits", decl); 8644 TREE_NO_WARNING (decl) = true; 8645 } 8646 8647 /* Recursively extend temps in this initializer. */ 8648 TARGET_EXPR_INITIAL (expr) 8649 = extend_ref_init_temps (decl, TARGET_EXPR_INITIAL (expr), cleanups); 8650 8651 /* If the initializer is constant, put it in DECL_INITIAL so we get 8652 static initialization and use in constant expressions. */ 8653 init = maybe_constant_init (expr); 8654 if (TREE_CONSTANT (init)) 8655 { 8656 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type)) 8657 { 8658 /* 5.19 says that a constant expression can include an 8659 lvalue-rvalue conversion applied to "a glvalue of literal type 8660 that refers to a non-volatile temporary object initialized 8661 with a constant expression". Rather than try to communicate 8662 that this VAR_DECL is a temporary, just mark it constexpr. 8663 8664 Currently this is only useful for initializer_list temporaries, 8665 since reference vars can't appear in constant expressions. */ 8666 DECL_DECLARED_CONSTEXPR_P (var) = true; 8667 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true; 8668 TREE_CONSTANT (var) = true; 8669 } 8670 DECL_INITIAL (var) = init; 8671 init = NULL_TREE; 8672 } 8673 else 8674 /* Create the INIT_EXPR that will initialize the temporary 8675 variable. */ 8676 init = build2 (INIT_EXPR, type, var, expr); 8677 if (at_function_scope_p ()) 8678 { 8679 add_decl_expr (var); 8680 8681 if (TREE_STATIC (var)) 8682 init = add_stmt_to_compound (init, register_dtor_fn (var)); 8683 else 8684 { 8685 tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error); 8686 if (cleanup) 8687 VEC_safe_push (tree, gc, *cleanups, cleanup); 8688 } 8689 8690 /* We must be careful to destroy the temporary only 8691 after its initialization has taken place. If the 8692 initialization throws an exception, then the 8693 destructor should not be run. We cannot simply 8694 transform INIT into something like: 8695 8696 (INIT, ({ CLEANUP_STMT; })) 8697 8698 because emit_local_var always treats the 8699 initializer as a full-expression. Thus, the 8700 destructor would run too early; it would run at the 8701 end of initializing the reference variable, rather 8702 than at the end of the block enclosing the 8703 reference variable. 8704 8705 The solution is to pass back a cleanup expression 8706 which the caller is responsible for attaching to 8707 the statement tree. */ 8708 } 8709 else 8710 { 8711 rest_of_decl_compilation (var, /*toplev=*/1, at_eof); 8712 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 8713 static_aggregates = tree_cons (NULL_TREE, var, 8714 static_aggregates); 8715 } 8716 8717 *initp = init; 8718 return var; 8719 } 8720 8721 /* Convert EXPR to the indicated reference TYPE, in a way suitable for 8722 initializing a variable of that TYPE. */ 8723 8724 tree 8725 initialize_reference (tree type, tree expr, 8726 int flags, tsubst_flags_t complain) 8727 { 8728 conversion *conv; 8729 void *p; 8730 8731 if (type == error_mark_node || error_operand_p (expr)) 8732 return error_mark_node; 8733 8734 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8735 p = conversion_obstack_alloc (0); 8736 8737 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false, 8738 flags); 8739 if (!conv || conv->bad_p) 8740 { 8741 if (complain & tf_error) 8742 { 8743 if (conv) 8744 convert_like (conv, expr, complain); 8745 else if (!CP_TYPE_CONST_P (TREE_TYPE (type)) 8746 && !TYPE_REF_IS_RVALUE (type) 8747 && !real_lvalue_p (expr)) 8748 error ("invalid initialization of non-const reference of " 8749 "type %qT from an rvalue of type %qT", 8750 type, TREE_TYPE (expr)); 8751 else 8752 error ("invalid initialization of reference of type " 8753 "%qT from expression of type %qT", type, 8754 TREE_TYPE (expr)); 8755 } 8756 return error_mark_node; 8757 } 8758 8759 gcc_assert (conv->kind == ck_ref_bind); 8760 8761 /* Perform the conversion. */ 8762 expr = convert_like (conv, expr, complain); 8763 8764 /* Free all the conversions we allocated. */ 8765 obstack_free (&conversion_obstack, p); 8766 8767 return expr; 8768 } 8769 8770 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer, 8771 which is bound either to a reference or a std::initializer_list. */ 8772 8773 static tree 8774 extend_ref_init_temps_1 (tree decl, tree init, VEC(tree,gc) **cleanups) 8775 { 8776 tree sub = init; 8777 tree *p; 8778 STRIP_NOPS (sub); 8779 if (TREE_CODE (sub) == COMPOUND_EXPR) 8780 { 8781 TREE_OPERAND (sub, 1) 8782 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups); 8783 return init; 8784 } 8785 if (TREE_CODE (sub) != ADDR_EXPR) 8786 return init; 8787 /* Deal with binding to a subobject. */ 8788 for (p = &TREE_OPERAND (sub, 0); TREE_CODE (*p) == COMPONENT_REF; ) 8789 p = &TREE_OPERAND (*p, 0); 8790 if (TREE_CODE (*p) == TARGET_EXPR) 8791 { 8792 tree subinit = NULL_TREE; 8793 *p = set_up_extended_ref_temp (decl, *p, cleanups, &subinit); 8794 if (subinit) 8795 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), subinit, init); 8796 } 8797 return init; 8798 } 8799 8800 /* INIT is part of the initializer for DECL. If there are any 8801 reference or initializer lists being initialized, extend their 8802 lifetime to match that of DECL. */ 8803 8804 tree 8805 extend_ref_init_temps (tree decl, tree init, VEC(tree,gc) **cleanups) 8806 { 8807 tree type = TREE_TYPE (init); 8808 if (processing_template_decl) 8809 return init; 8810 if (TREE_CODE (type) == REFERENCE_TYPE) 8811 init = extend_ref_init_temps_1 (decl, init, cleanups); 8812 else if (is_std_init_list (type)) 8813 { 8814 /* The temporary array underlying a std::initializer_list 8815 is handled like a reference temporary. */ 8816 tree ctor = init; 8817 if (TREE_CODE (ctor) == TARGET_EXPR) 8818 ctor = TARGET_EXPR_INITIAL (ctor); 8819 if (TREE_CODE (ctor) == CONSTRUCTOR) 8820 { 8821 tree array = CONSTRUCTOR_ELT (ctor, 0)->value; 8822 array = extend_ref_init_temps_1 (decl, array, cleanups); 8823 CONSTRUCTOR_ELT (ctor, 0)->value = array; 8824 } 8825 } 8826 else if (TREE_CODE (init) == CONSTRUCTOR) 8827 { 8828 unsigned i; 8829 constructor_elt *p; 8830 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (init); 8831 FOR_EACH_VEC_ELT (constructor_elt, elts, i, p) 8832 p->value = extend_ref_init_temps (decl, p->value, cleanups); 8833 } 8834 8835 return init; 8836 } 8837 8838 /* Returns true iff an initializer for TYPE could contain temporaries that 8839 need to be extended because they are bound to references or 8840 std::initializer_list. */ 8841 8842 bool 8843 type_has_extended_temps (tree type) 8844 { 8845 type = strip_array_types (type); 8846 if (TREE_CODE (type) == REFERENCE_TYPE) 8847 return true; 8848 if (CLASS_TYPE_P (type)) 8849 { 8850 tree f; 8851 if (is_std_init_list (type)) 8852 return true; 8853 for (f = next_initializable_field (TYPE_FIELDS (type)); 8854 f; f = next_initializable_field (DECL_CHAIN (f))) 8855 if (type_has_extended_temps (TREE_TYPE (f))) 8856 return true; 8857 } 8858 return false; 8859 } 8860 8861 /* Returns true iff TYPE is some variant of std::initializer_list. */ 8862 8863 bool 8864 is_std_init_list (tree type) 8865 { 8866 /* Look through typedefs. */ 8867 if (!TYPE_P (type)) 8868 return false; 8869 type = TYPE_MAIN_VARIANT (type); 8870 return (CLASS_TYPE_P (type) 8871 && CP_TYPE_CONTEXT (type) == std_node 8872 && strcmp (TYPE_NAME_STRING (type), "initializer_list") == 0); 8873 } 8874 8875 /* Returns true iff DECL is a list constructor: i.e. a constructor which 8876 will accept an argument list of a single std::initializer_list<T>. */ 8877 8878 bool 8879 is_list_ctor (tree decl) 8880 { 8881 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl); 8882 tree arg; 8883 8884 if (!args || args == void_list_node) 8885 return false; 8886 8887 arg = non_reference (TREE_VALUE (args)); 8888 if (!is_std_init_list (arg)) 8889 return false; 8890 8891 args = TREE_CHAIN (args); 8892 8893 if (args && args != void_list_node && !TREE_PURPOSE (args)) 8894 /* There are more non-defaulted parms. */ 8895 return false; 8896 8897 return true; 8898 } 8899 8900 #include "gt-cp-call.h" 8901