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 if (TREE_CODE (ftype) == REFERENCE_TYPE) 898 /* Value-initialization of reference is ill-formed. */ 899 return NULL; 900 else 901 { 902 if (empty_ctor == NULL_TREE) 903 empty_ctor = build_constructor (init_list_type_node, NULL); 904 val = empty_ctor; 905 } 906 ++i; 907 908 if (TREE_CODE (ftype) == ARRAY_TYPE 909 && TREE_CODE (val) == CONSTRUCTOR) 910 ok = can_convert_array (ftype, val, flags); 911 else 912 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags); 913 914 if (!ok) 915 return NULL; 916 917 if (TREE_CODE (type) == UNION_TYPE) 918 break; 919 } 920 921 if (i < CONSTRUCTOR_NELTS (ctor)) 922 return NULL; 923 924 c = alloc_conversion (ck_aggr); 925 c->type = type; 926 c->rank = cr_exact; 927 c->user_conv_p = true; 928 c->u.next = NULL; 929 return c; 930 } 931 932 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 933 array type, if such a conversion is possible. */ 934 935 static conversion * 936 build_array_conv (tree type, tree ctor, int flags) 937 { 938 conversion *c; 939 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 940 tree elttype = TREE_TYPE (type); 941 unsigned i; 942 tree val; 943 bool bad = false; 944 bool user = false; 945 enum conversion_rank rank = cr_exact; 946 947 if (TYPE_DOMAIN (type)) 948 { 949 unsigned HOST_WIDE_INT alen = tree_low_cst (array_type_nelts_top (type), 1); 950 if (alen < len) 951 return NULL; 952 } 953 954 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 955 { 956 conversion *sub 957 = implicit_conversion (elttype, TREE_TYPE (val), val, 958 false, flags); 959 if (sub == NULL) 960 return NULL; 961 962 if (sub->rank > rank) 963 rank = sub->rank; 964 if (sub->user_conv_p) 965 user = true; 966 if (sub->bad_p) 967 bad = true; 968 } 969 970 c = alloc_conversion (ck_aggr); 971 c->type = type; 972 c->rank = rank; 973 c->user_conv_p = user; 974 c->bad_p = bad; 975 c->u.next = NULL; 976 return c; 977 } 978 979 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 980 complex type, if such a conversion is possible. */ 981 982 static conversion * 983 build_complex_conv (tree type, tree ctor, int flags) 984 { 985 conversion *c; 986 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 987 tree elttype = TREE_TYPE (type); 988 unsigned i; 989 tree val; 990 bool bad = false; 991 bool user = false; 992 enum conversion_rank rank = cr_exact; 993 994 if (len != 2) 995 return NULL; 996 997 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 998 { 999 conversion *sub 1000 = implicit_conversion (elttype, TREE_TYPE (val), val, 1001 false, flags); 1002 if (sub == NULL) 1003 return NULL; 1004 1005 if (sub->rank > rank) 1006 rank = sub->rank; 1007 if (sub->user_conv_p) 1008 user = true; 1009 if (sub->bad_p) 1010 bad = true; 1011 } 1012 1013 c = alloc_conversion (ck_aggr); 1014 c->type = type; 1015 c->rank = rank; 1016 c->user_conv_p = user; 1017 c->bad_p = bad; 1018 c->u.next = NULL; 1019 return c; 1020 } 1021 1022 /* Build a representation of the identity conversion from EXPR to 1023 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */ 1024 1025 static conversion * 1026 build_identity_conv (tree type, tree expr) 1027 { 1028 conversion *c; 1029 1030 c = alloc_conversion (ck_identity); 1031 c->type = type; 1032 c->u.expr = expr; 1033 1034 return c; 1035 } 1036 1037 /* Converting from EXPR to TYPE was ambiguous in the sense that there 1038 were multiple user-defined conversions to accomplish the job. 1039 Build a conversion that indicates that ambiguity. */ 1040 1041 static conversion * 1042 build_ambiguous_conv (tree type, tree expr) 1043 { 1044 conversion *c; 1045 1046 c = alloc_conversion (ck_ambig); 1047 c->type = type; 1048 c->u.expr = expr; 1049 1050 return c; 1051 } 1052 1053 tree 1054 strip_top_quals (tree t) 1055 { 1056 if (TREE_CODE (t) == ARRAY_TYPE) 1057 return t; 1058 return cp_build_qualified_type (t, 0); 1059 } 1060 1061 /* Returns the standard conversion path (see [conv]) from type FROM to type 1062 TO, if any. For proper handling of null pointer constants, you must 1063 also pass the expression EXPR to convert from. If C_CAST_P is true, 1064 this conversion is coming from a C-style cast. */ 1065 1066 static conversion * 1067 standard_conversion (tree to, tree from, tree expr, bool c_cast_p, 1068 int flags) 1069 { 1070 enum tree_code fcode, tcode; 1071 conversion *conv; 1072 bool fromref = false; 1073 tree qualified_to; 1074 1075 to = non_reference (to); 1076 if (TREE_CODE (from) == REFERENCE_TYPE) 1077 { 1078 fromref = true; 1079 from = TREE_TYPE (from); 1080 } 1081 qualified_to = to; 1082 to = strip_top_quals (to); 1083 from = strip_top_quals (from); 1084 1085 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to)) 1086 && expr && type_unknown_p (expr)) 1087 { 1088 tsubst_flags_t tflags = tf_conv; 1089 if (!(flags & LOOKUP_PROTECT)) 1090 tflags |= tf_no_access_control; 1091 expr = instantiate_type (to, expr, tflags); 1092 if (expr == error_mark_node) 1093 return NULL; 1094 from = TREE_TYPE (expr); 1095 } 1096 1097 fcode = TREE_CODE (from); 1098 tcode = TREE_CODE (to); 1099 1100 conv = build_identity_conv (from, expr); 1101 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE) 1102 { 1103 from = type_decays_to (from); 1104 fcode = TREE_CODE (from); 1105 conv = build_conv (ck_lvalue, from, conv); 1106 } 1107 else if (fromref || (expr && lvalue_p (expr))) 1108 { 1109 if (expr) 1110 { 1111 tree bitfield_type; 1112 bitfield_type = is_bitfield_expr_with_lowered_type (expr); 1113 if (bitfield_type) 1114 { 1115 from = strip_top_quals (bitfield_type); 1116 fcode = TREE_CODE (from); 1117 } 1118 } 1119 conv = build_conv (ck_rvalue, from, conv); 1120 if (flags & LOOKUP_PREFER_RVALUE) 1121 conv->rvaluedness_matches_p = true; 1122 } 1123 1124 /* Allow conversion between `__complex__' data types. */ 1125 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE) 1126 { 1127 /* The standard conversion sequence to convert FROM to TO is 1128 the standard conversion sequence to perform componentwise 1129 conversion. */ 1130 conversion *part_conv = standard_conversion 1131 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags); 1132 1133 if (part_conv) 1134 { 1135 conv = build_conv (part_conv->kind, to, conv); 1136 conv->rank = part_conv->rank; 1137 } 1138 else 1139 conv = NULL; 1140 1141 return conv; 1142 } 1143 1144 if (same_type_p (from, to)) 1145 { 1146 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue) 1147 conv->type = qualified_to; 1148 return conv; 1149 } 1150 1151 /* [conv.ptr] 1152 A null pointer constant can be converted to a pointer type; ... A 1153 null pointer constant of integral type can be converted to an 1154 rvalue of type std::nullptr_t. */ 1155 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to) 1156 || NULLPTR_TYPE_P (to)) 1157 && expr && null_ptr_cst_p (expr)) 1158 conv = build_conv (ck_std, to, conv); 1159 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE) 1160 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE)) 1161 { 1162 /* For backwards brain damage compatibility, allow interconversion of 1163 pointers and integers with a pedwarn. */ 1164 conv = build_conv (ck_std, to, conv); 1165 conv->bad_p = true; 1166 } 1167 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE) 1168 { 1169 /* For backwards brain damage compatibility, allow interconversion of 1170 enums and integers with a pedwarn. */ 1171 conv = build_conv (ck_std, to, conv); 1172 conv->bad_p = true; 1173 } 1174 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE) 1175 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from))) 1176 { 1177 tree to_pointee; 1178 tree from_pointee; 1179 1180 if (tcode == POINTER_TYPE 1181 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from), 1182 TREE_TYPE (to))) 1183 ; 1184 else if (VOID_TYPE_P (TREE_TYPE (to)) 1185 && !TYPE_PTRMEM_P (from) 1186 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE) 1187 { 1188 tree nfrom = TREE_TYPE (from); 1189 from = build_pointer_type 1190 (cp_build_qualified_type (void_type_node, 1191 cp_type_quals (nfrom))); 1192 conv = build_conv (ck_ptr, from, conv); 1193 } 1194 else if (TYPE_PTRMEM_P (from)) 1195 { 1196 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from); 1197 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to); 1198 1199 if (DERIVED_FROM_P (fbase, tbase) 1200 && (same_type_ignoring_top_level_qualifiers_p 1201 (TYPE_PTRMEM_POINTED_TO_TYPE (from), 1202 TYPE_PTRMEM_POINTED_TO_TYPE (to)))) 1203 { 1204 from = build_ptrmem_type (tbase, 1205 TYPE_PTRMEM_POINTED_TO_TYPE (from)); 1206 conv = build_conv (ck_pmem, from, conv); 1207 } 1208 else if (!same_type_p (fbase, tbase)) 1209 return NULL; 1210 } 1211 else if (CLASS_TYPE_P (TREE_TYPE (from)) 1212 && CLASS_TYPE_P (TREE_TYPE (to)) 1213 /* [conv.ptr] 1214 1215 An rvalue of type "pointer to cv D," where D is a 1216 class type, can be converted to an rvalue of type 1217 "pointer to cv B," where B is a base class (clause 1218 _class.derived_) of D. If B is an inaccessible 1219 (clause _class.access_) or ambiguous 1220 (_class.member.lookup_) base class of D, a program 1221 that necessitates this conversion is ill-formed. 1222 Therefore, we use DERIVED_FROM_P, and do not check 1223 access or uniqueness. */ 1224 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from))) 1225 { 1226 from = 1227 cp_build_qualified_type (TREE_TYPE (to), 1228 cp_type_quals (TREE_TYPE (from))); 1229 from = build_pointer_type (from); 1230 conv = build_conv (ck_ptr, from, conv); 1231 conv->base_p = true; 1232 } 1233 1234 if (tcode == POINTER_TYPE) 1235 { 1236 to_pointee = TREE_TYPE (to); 1237 from_pointee = TREE_TYPE (from); 1238 } 1239 else 1240 { 1241 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to); 1242 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from); 1243 } 1244 1245 if (same_type_p (from, to)) 1246 /* OK */; 1247 else if (c_cast_p && comp_ptr_ttypes_const (to, from)) 1248 /* In a C-style cast, we ignore CV-qualification because we 1249 are allowed to perform a static_cast followed by a 1250 const_cast. */ 1251 conv = build_conv (ck_qual, to, conv); 1252 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee)) 1253 conv = build_conv (ck_qual, to, conv); 1254 else if (expr && string_conv_p (to, expr, 0)) 1255 /* converting from string constant to char *. */ 1256 conv = build_conv (ck_qual, to, conv); 1257 /* Allow conversions among compatible ObjC pointer types (base 1258 conversions have been already handled above). */ 1259 else if (c_dialect_objc () 1260 && objc_compare_types (to, from, -4, NULL_TREE)) 1261 conv = build_conv (ck_ptr, to, conv); 1262 else if (ptr_reasonably_similar (to_pointee, from_pointee)) 1263 { 1264 conv = build_conv (ck_ptr, to, conv); 1265 conv->bad_p = true; 1266 } 1267 else 1268 return NULL; 1269 1270 from = to; 1271 } 1272 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from)) 1273 { 1274 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from)); 1275 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to)); 1276 tree fbase = class_of_this_parm (fromfn); 1277 tree tbase = class_of_this_parm (tofn); 1278 1279 if (!DERIVED_FROM_P (fbase, tbase) 1280 || !same_type_p (static_fn_type (fromfn), 1281 static_fn_type (tofn))) 1282 return NULL; 1283 1284 from = build_memfn_type (fromfn, tbase, cp_type_quals (tbase)); 1285 from = build_ptrmemfunc_type (build_pointer_type (from)); 1286 conv = build_conv (ck_pmem, from, conv); 1287 conv->base_p = true; 1288 } 1289 else if (tcode == BOOLEAN_TYPE) 1290 { 1291 /* [conv.bool] 1292 1293 An rvalue of arithmetic, unscoped enumeration, pointer, or 1294 pointer to member type can be converted to an rvalue of type 1295 bool. ... An rvalue of type std::nullptr_t can be converted 1296 to an rvalue of type bool; */ 1297 if (ARITHMETIC_TYPE_P (from) 1298 || UNSCOPED_ENUM_P (from) 1299 || fcode == POINTER_TYPE 1300 || TYPE_PTR_TO_MEMBER_P (from) 1301 || NULLPTR_TYPE_P (from)) 1302 { 1303 conv = build_conv (ck_std, to, conv); 1304 if (fcode == POINTER_TYPE 1305 || TYPE_PTRMEM_P (from) 1306 || (TYPE_PTRMEMFUNC_P (from) 1307 && conv->rank < cr_pbool) 1308 || NULLPTR_TYPE_P (from)) 1309 conv->rank = cr_pbool; 1310 return conv; 1311 } 1312 1313 return NULL; 1314 } 1315 /* We don't check for ENUMERAL_TYPE here because there are no standard 1316 conversions to enum type. */ 1317 /* As an extension, allow conversion to complex type. */ 1318 else if (ARITHMETIC_TYPE_P (to)) 1319 { 1320 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE) 1321 || SCOPED_ENUM_P (from)) 1322 return NULL; 1323 conv = build_conv (ck_std, to, conv); 1324 1325 /* Give this a better rank if it's a promotion. */ 1326 if (same_type_p (to, type_promotes_to (from)) 1327 && conv->u.next->rank <= cr_promotion) 1328 conv->rank = cr_promotion; 1329 } 1330 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE 1331 && vector_types_convertible_p (from, to, false)) 1332 return build_conv (ck_std, to, conv); 1333 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from) 1334 && is_properly_derived_from (from, to)) 1335 { 1336 if (conv->kind == ck_rvalue) 1337 conv = conv->u.next; 1338 conv = build_conv (ck_base, to, conv); 1339 /* The derived-to-base conversion indicates the initialization 1340 of a parameter with base type from an object of a derived 1341 type. A temporary object is created to hold the result of 1342 the conversion unless we're binding directly to a reference. */ 1343 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND); 1344 } 1345 else 1346 return NULL; 1347 1348 if (flags & LOOKUP_NO_NARROWING) 1349 conv->check_narrowing = true; 1350 1351 return conv; 1352 } 1353 1354 /* Returns nonzero if T1 is reference-related to T2. */ 1355 1356 bool 1357 reference_related_p (tree t1, tree t2) 1358 { 1359 if (t1 == error_mark_node || t2 == error_mark_node) 1360 return false; 1361 1362 t1 = TYPE_MAIN_VARIANT (t1); 1363 t2 = TYPE_MAIN_VARIANT (t2); 1364 1365 /* [dcl.init.ref] 1366 1367 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related 1368 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class 1369 of T2. */ 1370 return (same_type_p (t1, t2) 1371 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 1372 && DERIVED_FROM_P (t1, t2))); 1373 } 1374 1375 /* Returns nonzero if T1 is reference-compatible with T2. */ 1376 1377 static bool 1378 reference_compatible_p (tree t1, tree t2) 1379 { 1380 /* [dcl.init.ref] 1381 1382 "cv1 T1" is reference compatible with "cv2 T2" if T1 is 1383 reference-related to T2 and cv1 is the same cv-qualification as, 1384 or greater cv-qualification than, cv2. */ 1385 return (reference_related_p (t1, t2) 1386 && at_least_as_qualified_p (t1, t2)); 1387 } 1388 1389 /* A reference of the indicated TYPE is being bound directly to the 1390 expression represented by the implicit conversion sequence CONV. 1391 Return a conversion sequence for this binding. */ 1392 1393 static conversion * 1394 direct_reference_binding (tree type, conversion *conv) 1395 { 1396 tree t; 1397 1398 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE); 1399 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE); 1400 1401 t = TREE_TYPE (type); 1402 1403 /* [over.ics.rank] 1404 1405 When a parameter of reference type binds directly 1406 (_dcl.init.ref_) to an argument expression, the implicit 1407 conversion sequence is the identity conversion, unless the 1408 argument expression has a type that is a derived class of the 1409 parameter type, in which case the implicit conversion sequence is 1410 a derived-to-base Conversion. 1411 1412 If the parameter binds directly to the result of applying a 1413 conversion function to the argument expression, the implicit 1414 conversion sequence is a user-defined conversion sequence 1415 (_over.ics.user_), with the second standard conversion sequence 1416 either an identity conversion or, if the conversion function 1417 returns an entity of a type that is a derived class of the 1418 parameter type, a derived-to-base conversion. */ 1419 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type)) 1420 { 1421 /* Represent the derived-to-base conversion. */ 1422 conv = build_conv (ck_base, t, conv); 1423 /* We will actually be binding to the base-class subobject in 1424 the derived class, so we mark this conversion appropriately. 1425 That way, convert_like knows not to generate a temporary. */ 1426 conv->need_temporary_p = false; 1427 } 1428 return build_conv (ck_ref_bind, type, conv); 1429 } 1430 1431 /* Returns the conversion path from type FROM to reference type TO for 1432 purposes of reference binding. For lvalue binding, either pass a 1433 reference type to FROM or an lvalue expression to EXPR. If the 1434 reference will be bound to a temporary, NEED_TEMPORARY_P is set for 1435 the conversion returned. If C_CAST_P is true, this 1436 conversion is coming from a C-style cast. */ 1437 1438 static conversion * 1439 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags) 1440 { 1441 conversion *conv = NULL; 1442 tree to = TREE_TYPE (rto); 1443 tree from = rfrom; 1444 tree tfrom; 1445 bool related_p; 1446 bool compatible_p; 1447 cp_lvalue_kind gl_kind; 1448 bool is_lvalue; 1449 1450 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr)) 1451 { 1452 expr = instantiate_type (to, expr, tf_none); 1453 if (expr == error_mark_node) 1454 return NULL; 1455 from = TREE_TYPE (expr); 1456 } 1457 1458 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1459 { 1460 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS); 1461 conv = implicit_conversion (to, from, expr, c_cast_p, 1462 flags); 1463 if (!CLASS_TYPE_P (to) 1464 && CONSTRUCTOR_NELTS (expr) == 1) 1465 { 1466 expr = CONSTRUCTOR_ELT (expr, 0)->value; 1467 if (error_operand_p (expr)) 1468 return NULL; 1469 from = TREE_TYPE (expr); 1470 } 1471 } 1472 1473 if (TREE_CODE (from) == REFERENCE_TYPE) 1474 { 1475 from = TREE_TYPE (from); 1476 if (!TYPE_REF_IS_RVALUE (rfrom) 1477 || TREE_CODE (from) == FUNCTION_TYPE) 1478 gl_kind = clk_ordinary; 1479 else 1480 gl_kind = clk_rvalueref; 1481 } 1482 else if (expr) 1483 { 1484 gl_kind = lvalue_kind (expr); 1485 if (gl_kind & clk_class) 1486 /* A class prvalue is not a glvalue. */ 1487 gl_kind = clk_none; 1488 } 1489 else 1490 gl_kind = clk_none; 1491 is_lvalue = gl_kind && !(gl_kind & clk_rvalueref); 1492 1493 tfrom = from; 1494 if ((gl_kind & clk_bitfield) != 0) 1495 tfrom = unlowered_expr_type (expr); 1496 1497 /* Figure out whether or not the types are reference-related and 1498 reference compatible. We have do do this after stripping 1499 references from FROM. */ 1500 related_p = reference_related_p (to, tfrom); 1501 /* If this is a C cast, first convert to an appropriately qualified 1502 type, so that we can later do a const_cast to the desired type. */ 1503 if (related_p && c_cast_p 1504 && !at_least_as_qualified_p (to, tfrom)) 1505 to = cp_build_qualified_type (to, cp_type_quals (tfrom)); 1506 compatible_p = reference_compatible_p (to, tfrom); 1507 1508 /* Directly bind reference when target expression's type is compatible with 1509 the reference and expression is an lvalue. In DR391, the wording in 1510 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for 1511 const and rvalue references to rvalues of compatible class type. 1512 We should also do direct bindings for non-class xvalues. */ 1513 if (compatible_p 1514 && (is_lvalue 1515 || (((CP_TYPE_CONST_NON_VOLATILE_P (to) 1516 && !(flags & LOOKUP_NO_RVAL_BIND)) 1517 || TYPE_REF_IS_RVALUE (rto)) 1518 && (gl_kind 1519 || (!(flags & LOOKUP_NO_TEMP_BIND) 1520 && (CLASS_TYPE_P (from) 1521 || TREE_CODE (from) == ARRAY_TYPE)))))) 1522 { 1523 /* [dcl.init.ref] 1524 1525 If the initializer expression 1526 1527 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1" 1528 is reference-compatible with "cv2 T2," 1529 1530 the reference is bound directly to the initializer expression 1531 lvalue. 1532 1533 [...] 1534 If the initializer expression is an rvalue, with T2 a class type, 1535 and "cv1 T1" is reference-compatible with "cv2 T2", the reference 1536 is bound to the object represented by the rvalue or to a sub-object 1537 within that object. */ 1538 1539 conv = build_identity_conv (tfrom, expr); 1540 conv = direct_reference_binding (rto, conv); 1541 1542 if (flags & LOOKUP_PREFER_RVALUE) 1543 /* The top-level caller requested that we pretend that the lvalue 1544 be treated as an rvalue. */ 1545 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1546 else if (TREE_CODE (rfrom) == REFERENCE_TYPE) 1547 /* Handle rvalue reference to function properly. */ 1548 conv->rvaluedness_matches_p 1549 = (TYPE_REF_IS_RVALUE (rto) == TYPE_REF_IS_RVALUE (rfrom)); 1550 else 1551 conv->rvaluedness_matches_p 1552 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue); 1553 1554 if ((gl_kind & clk_bitfield) != 0 1555 || ((gl_kind & clk_packed) != 0 && !TYPE_PACKED (to))) 1556 /* For the purposes of overload resolution, we ignore the fact 1557 this expression is a bitfield or packed field. (In particular, 1558 [over.ics.ref] says specifically that a function with a 1559 non-const reference parameter is viable even if the 1560 argument is a bitfield.) 1561 1562 However, when we actually call the function we must create 1563 a temporary to which to bind the reference. If the 1564 reference is volatile, or isn't const, then we cannot make 1565 a temporary, so we just issue an error when the conversion 1566 actually occurs. */ 1567 conv->need_temporary_p = true; 1568 1569 /* Don't allow binding of lvalues (other than function lvalues) to 1570 rvalue references. */ 1571 if (is_lvalue && TYPE_REF_IS_RVALUE (rto) 1572 && TREE_CODE (to) != FUNCTION_TYPE 1573 && !(flags & LOOKUP_PREFER_RVALUE)) 1574 conv->bad_p = true; 1575 1576 return conv; 1577 } 1578 /* [class.conv.fct] A conversion function is never used to convert a 1579 (possibly cv-qualified) object to the (possibly cv-qualified) same 1580 object type (or a reference to it), to a (possibly cv-qualified) base 1581 class of that type (or a reference to it).... */ 1582 else if (CLASS_TYPE_P (from) && !related_p 1583 && !(flags & LOOKUP_NO_CONVERSION)) 1584 { 1585 /* [dcl.init.ref] 1586 1587 If the initializer expression 1588 1589 -- has a class type (i.e., T2 is a class type) can be 1590 implicitly converted to an lvalue of type "cv3 T3," where 1591 "cv1 T1" is reference-compatible with "cv3 T3". (this 1592 conversion is selected by enumerating the applicable 1593 conversion functions (_over.match.ref_) and choosing the 1594 best one through overload resolution. (_over.match_). 1595 1596 the reference is bound to the lvalue result of the conversion 1597 in the second case. */ 1598 z_candidate *cand = build_user_type_conversion_1 (rto, expr, flags); 1599 if (cand) 1600 return cand->second_conv; 1601 } 1602 1603 /* From this point on, we conceptually need temporaries, even if we 1604 elide them. Only the cases above are "direct bindings". */ 1605 if (flags & LOOKUP_NO_TEMP_BIND) 1606 return NULL; 1607 1608 /* [over.ics.rank] 1609 1610 When a parameter of reference type is not bound directly to an 1611 argument expression, the conversion sequence is the one required 1612 to convert the argument expression to the underlying type of the 1613 reference according to _over.best.ics_. Conceptually, this 1614 conversion sequence corresponds to copy-initializing a temporary 1615 of the underlying type with the argument expression. Any 1616 difference in top-level cv-qualification is subsumed by the 1617 initialization itself and does not constitute a conversion. */ 1618 1619 /* [dcl.init.ref] 1620 1621 Otherwise, the reference shall be to a non-volatile const type. 1622 1623 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */ 1624 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto)) 1625 return NULL; 1626 1627 /* [dcl.init.ref] 1628 1629 Otherwise, a temporary of type "cv1 T1" is created and 1630 initialized from the initializer expression using the rules for a 1631 non-reference copy initialization. If T1 is reference-related to 1632 T2, cv1 must be the same cv-qualification as, or greater 1633 cv-qualification than, cv2; otherwise, the program is ill-formed. */ 1634 if (related_p && !at_least_as_qualified_p (to, from)) 1635 return NULL; 1636 1637 /* We're generating a temporary now, but don't bind any more in the 1638 conversion (specifically, don't slice the temporary returned by a 1639 conversion operator). */ 1640 flags |= LOOKUP_NO_TEMP_BIND; 1641 1642 /* Core issue 899: When [copy-]initializing a temporary to be bound 1643 to the first parameter of a copy constructor (12.8) called with 1644 a single argument in the context of direct-initialization, 1645 explicit conversion functions are also considered. 1646 1647 So don't set LOOKUP_ONLYCONVERTING in that case. */ 1648 if (!(flags & LOOKUP_COPY_PARM)) 1649 flags |= LOOKUP_ONLYCONVERTING; 1650 1651 if (!conv) 1652 conv = implicit_conversion (to, from, expr, c_cast_p, 1653 flags); 1654 if (!conv) 1655 return NULL; 1656 1657 conv = build_conv (ck_ref_bind, rto, conv); 1658 /* This reference binding, unlike those above, requires the 1659 creation of a temporary. */ 1660 conv->need_temporary_p = true; 1661 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1662 1663 return conv; 1664 } 1665 1666 /* Returns the implicit conversion sequence (see [over.ics]) from type 1667 FROM to type TO. The optional expression EXPR may affect the 1668 conversion. FLAGS are the usual overloading flags. If C_CAST_P is 1669 true, this conversion is coming from a C-style cast. */ 1670 1671 static conversion * 1672 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p, 1673 int flags) 1674 { 1675 conversion *conv; 1676 1677 if (from == error_mark_node || to == error_mark_node 1678 || expr == error_mark_node) 1679 return NULL; 1680 1681 /* Other flags only apply to the primary function in overload 1682 resolution, or after we've chosen one. */ 1683 flags &= (LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION|LOOKUP_COPY_PARM 1684 |LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND|LOOKUP_PREFER_RVALUE 1685 |LOOKUP_NO_NARROWING|LOOKUP_PROTECT); 1686 1687 if (TREE_CODE (to) == REFERENCE_TYPE) 1688 conv = reference_binding (to, from, expr, c_cast_p, flags); 1689 else 1690 conv = standard_conversion (to, from, expr, c_cast_p, flags); 1691 1692 if (conv) 1693 return conv; 1694 1695 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1696 { 1697 if (is_std_init_list (to)) 1698 return build_list_conv (to, expr, flags); 1699 1700 /* As an extension, allow list-initialization of _Complex. */ 1701 if (TREE_CODE (to) == COMPLEX_TYPE) 1702 { 1703 conv = build_complex_conv (to, expr, flags); 1704 if (conv) 1705 return conv; 1706 } 1707 1708 /* Allow conversion from an initializer-list with one element to a 1709 scalar type. */ 1710 if (SCALAR_TYPE_P (to)) 1711 { 1712 int nelts = CONSTRUCTOR_NELTS (expr); 1713 tree elt; 1714 1715 if (nelts == 0) 1716 elt = build_value_init (to, tf_none); 1717 else if (nelts == 1) 1718 elt = CONSTRUCTOR_ELT (expr, 0)->value; 1719 else 1720 elt = error_mark_node; 1721 1722 conv = implicit_conversion (to, TREE_TYPE (elt), elt, 1723 c_cast_p, flags); 1724 if (conv) 1725 { 1726 conv->check_narrowing = true; 1727 if (BRACE_ENCLOSED_INITIALIZER_P (elt)) 1728 /* Too many levels of braces, i.e. '{{1}}'. */ 1729 conv->bad_p = true; 1730 return conv; 1731 } 1732 } 1733 else if (TREE_CODE (to) == ARRAY_TYPE) 1734 return build_array_conv (to, expr, flags); 1735 } 1736 1737 if (expr != NULL_TREE 1738 && (MAYBE_CLASS_TYPE_P (from) 1739 || MAYBE_CLASS_TYPE_P (to)) 1740 && (flags & LOOKUP_NO_CONVERSION) == 0) 1741 { 1742 struct z_candidate *cand; 1743 1744 if (CLASS_TYPE_P (to) 1745 && BRACE_ENCLOSED_INITIALIZER_P (expr) 1746 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))) 1747 return build_aggr_conv (to, expr, flags); 1748 1749 cand = build_user_type_conversion_1 (to, expr, flags); 1750 if (cand) 1751 conv = cand->second_conv; 1752 1753 /* We used to try to bind a reference to a temporary here, but that 1754 is now handled after the recursive call to this function at the end 1755 of reference_binding. */ 1756 return conv; 1757 } 1758 1759 return NULL; 1760 } 1761 1762 /* Add a new entry to the list of candidates. Used by the add_*_candidate 1763 functions. ARGS will not be changed until a single candidate is 1764 selected. */ 1765 1766 static struct z_candidate * 1767 add_candidate (struct z_candidate **candidates, 1768 tree fn, tree first_arg, const VEC(tree,gc) *args, 1769 size_t num_convs, conversion **convs, 1770 tree access_path, tree conversion_path, 1771 int viable, struct rejection_reason *reason) 1772 { 1773 struct z_candidate *cand = (struct z_candidate *) 1774 conversion_obstack_alloc (sizeof (struct z_candidate)); 1775 1776 cand->fn = fn; 1777 cand->first_arg = first_arg; 1778 cand->args = args; 1779 cand->convs = convs; 1780 cand->num_convs = num_convs; 1781 cand->access_path = access_path; 1782 cand->conversion_path = conversion_path; 1783 cand->viable = viable; 1784 cand->reason = reason; 1785 cand->next = *candidates; 1786 *candidates = cand; 1787 1788 return cand; 1789 } 1790 1791 /* Return the number of remaining arguments in the parameter list 1792 beginning with ARG. */ 1793 1794 static int 1795 remaining_arguments (tree arg) 1796 { 1797 int n; 1798 1799 for (n = 0; arg != NULL_TREE && arg != void_list_node; 1800 arg = TREE_CHAIN (arg)) 1801 n++; 1802 1803 return n; 1804 } 1805 1806 /* Create an overload candidate for the function or method FN called 1807 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES. 1808 FLAGS is passed on to implicit_conversion. 1809 1810 This does not change ARGS. 1811 1812 CTYPE, if non-NULL, is the type we want to pretend this function 1813 comes from for purposes of overload resolution. */ 1814 1815 static struct z_candidate * 1816 add_function_candidate (struct z_candidate **candidates, 1817 tree fn, tree ctype, tree first_arg, 1818 const VEC(tree,gc) *args, tree access_path, 1819 tree conversion_path, int flags) 1820 { 1821 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn)); 1822 int i, len; 1823 conversion **convs; 1824 tree parmnode; 1825 tree orig_first_arg = first_arg; 1826 int skip; 1827 int viable = 1; 1828 struct rejection_reason *reason = NULL; 1829 1830 /* At this point we should not see any functions which haven't been 1831 explicitly declared, except for friend functions which will have 1832 been found using argument dependent lookup. */ 1833 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn)); 1834 1835 /* The `this', `in_chrg' and VTT arguments to constructors are not 1836 considered in overload resolution. */ 1837 if (DECL_CONSTRUCTOR_P (fn)) 1838 { 1839 parmlist = skip_artificial_parms_for (fn, parmlist); 1840 skip = num_artificial_parms_for (fn); 1841 if (skip > 0 && first_arg != NULL_TREE) 1842 { 1843 --skip; 1844 first_arg = NULL_TREE; 1845 } 1846 } 1847 else 1848 skip = 0; 1849 1850 len = VEC_length (tree, args) - skip + (first_arg != NULL_TREE ? 1 : 0); 1851 convs = alloc_conversions (len); 1852 1853 /* 13.3.2 - Viable functions [over.match.viable] 1854 First, to be a viable function, a candidate function shall have enough 1855 parameters to agree in number with the arguments in the list. 1856 1857 We need to check this first; otherwise, checking the ICSes might cause 1858 us to produce an ill-formed template instantiation. */ 1859 1860 parmnode = parmlist; 1861 for (i = 0; i < len; ++i) 1862 { 1863 if (parmnode == NULL_TREE || parmnode == void_list_node) 1864 break; 1865 parmnode = TREE_CHAIN (parmnode); 1866 } 1867 1868 if ((i < len && parmnode) 1869 || !sufficient_parms_p (parmnode)) 1870 { 1871 int remaining = remaining_arguments (parmnode); 1872 viable = 0; 1873 reason = arity_rejection (first_arg, i + remaining, len); 1874 } 1875 /* When looking for a function from a subobject from an implicit 1876 copy/move constructor/operator=, don't consider anything that takes (a 1877 reference to) an unrelated type. See c++/44909 and core 1092. */ 1878 else if (parmlist && (flags & LOOKUP_DEFAULTED)) 1879 { 1880 if (DECL_CONSTRUCTOR_P (fn)) 1881 i = 1; 1882 else if (DECL_ASSIGNMENT_OPERATOR_P (fn) 1883 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR) 1884 i = 2; 1885 else 1886 i = 0; 1887 if (i && len == i) 1888 { 1889 parmnode = chain_index (i-1, parmlist); 1890 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)), 1891 ctype)) 1892 viable = 0; 1893 } 1894 1895 /* This only applies at the top level. */ 1896 flags &= ~LOOKUP_DEFAULTED; 1897 } 1898 1899 if (! viable) 1900 goto out; 1901 1902 /* Second, for F to be a viable function, there shall exist for each 1903 argument an implicit conversion sequence that converts that argument 1904 to the corresponding parameter of F. */ 1905 1906 parmnode = parmlist; 1907 1908 for (i = 0; i < len; ++i) 1909 { 1910 tree arg, argtype, to_type; 1911 conversion *t; 1912 int is_this; 1913 1914 if (parmnode == void_list_node) 1915 break; 1916 1917 if (i == 0 && first_arg != NULL_TREE) 1918 arg = first_arg; 1919 else 1920 arg = VEC_index (tree, args, 1921 i + skip - (first_arg != NULL_TREE ? 1 : 0)); 1922 argtype = lvalue_type (arg); 1923 1924 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 1925 && ! DECL_CONSTRUCTOR_P (fn)); 1926 1927 if (parmnode) 1928 { 1929 tree parmtype = TREE_VALUE (parmnode); 1930 int lflags = flags; 1931 1932 parmnode = TREE_CHAIN (parmnode); 1933 1934 /* The type of the implicit object parameter ('this') for 1935 overload resolution is not always the same as for the 1936 function itself; conversion functions are considered to 1937 be members of the class being converted, and functions 1938 introduced by a using-declaration are considered to be 1939 members of the class that uses them. 1940 1941 Since build_over_call ignores the ICS for the `this' 1942 parameter, we can just change the parm type. */ 1943 if (ctype && is_this) 1944 { 1945 parmtype = cp_build_qualified_type 1946 (ctype, cp_type_quals (TREE_TYPE (parmtype))); 1947 parmtype = build_pointer_type (parmtype); 1948 } 1949 1950 /* Core issue 899: When [copy-]initializing a temporary to be bound 1951 to the first parameter of a copy constructor (12.8) called with 1952 a single argument in the context of direct-initialization, 1953 explicit conversion functions are also considered. 1954 1955 So set LOOKUP_COPY_PARM to let reference_binding know that 1956 it's being called in that context. We generalize the above 1957 to handle move constructors and template constructors as well; 1958 the standardese should soon be updated similarly. */ 1959 if (ctype && i == 0 && (len-skip == 1) 1960 && DECL_CONSTRUCTOR_P (fn) 1961 && parmtype != error_mark_node 1962 && (same_type_ignoring_top_level_qualifiers_p 1963 (non_reference (parmtype), ctype))) 1964 { 1965 if (!(flags & LOOKUP_ONLYCONVERTING)) 1966 lflags |= LOOKUP_COPY_PARM; 1967 /* We allow user-defined conversions within init-lists, but 1968 don't list-initialize the copy parm, as that would mean 1969 using two levels of braces for the same type. */ 1970 if ((flags & LOOKUP_LIST_INIT_CTOR) 1971 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 1972 lflags |= LOOKUP_NO_CONVERSION; 1973 } 1974 else 1975 lflags |= LOOKUP_ONLYCONVERTING; 1976 1977 t = implicit_conversion (parmtype, argtype, arg, 1978 /*c_cast_p=*/false, lflags); 1979 to_type = parmtype; 1980 } 1981 else 1982 { 1983 t = build_identity_conv (argtype, arg); 1984 t->ellipsis_p = true; 1985 to_type = argtype; 1986 } 1987 1988 if (t && is_this) 1989 t->this_p = true; 1990 1991 convs[i] = t; 1992 if (! t) 1993 { 1994 viable = 0; 1995 reason = arg_conversion_rejection (first_arg, i, argtype, to_type); 1996 break; 1997 } 1998 1999 if (t->bad_p) 2000 { 2001 viable = -1; 2002 reason = bad_arg_conversion_rejection (first_arg, i, argtype, to_type); 2003 } 2004 } 2005 2006 out: 2007 return add_candidate (candidates, fn, orig_first_arg, args, len, convs, 2008 access_path, conversion_path, viable, reason); 2009 } 2010 2011 /* Create an overload candidate for the conversion function FN which will 2012 be invoked for expression OBJ, producing a pointer-to-function which 2013 will in turn be called with the argument list FIRST_ARG/ARGLIST, 2014 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is 2015 passed on to implicit_conversion. 2016 2017 Actually, we don't really care about FN; we care about the type it 2018 converts to. There may be multiple conversion functions that will 2019 convert to that type, and we rely on build_user_type_conversion_1 to 2020 choose the best one; so when we create our candidate, we record the type 2021 instead of the function. */ 2022 2023 static struct z_candidate * 2024 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj, 2025 tree first_arg, const VEC(tree,gc) *arglist, 2026 tree access_path, tree conversion_path) 2027 { 2028 tree totype = TREE_TYPE (TREE_TYPE (fn)); 2029 int i, len, viable, flags; 2030 tree parmlist, parmnode; 2031 conversion **convs; 2032 struct rejection_reason *reason; 2033 2034 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; ) 2035 parmlist = TREE_TYPE (parmlist); 2036 parmlist = TYPE_ARG_TYPES (parmlist); 2037 2038 len = VEC_length (tree, arglist) + (first_arg != NULL_TREE ? 1 : 0) + 1; 2039 convs = alloc_conversions (len); 2040 parmnode = parmlist; 2041 viable = 1; 2042 flags = LOOKUP_IMPLICIT; 2043 reason = NULL; 2044 2045 /* Don't bother looking up the same type twice. */ 2046 if (*candidates && (*candidates)->fn == totype) 2047 return NULL; 2048 2049 for (i = 0; i < len; ++i) 2050 { 2051 tree arg, argtype, convert_type = NULL_TREE; 2052 conversion *t; 2053 2054 if (i == 0) 2055 arg = obj; 2056 else if (i == 1 && first_arg != NULL_TREE) 2057 arg = first_arg; 2058 else 2059 arg = VEC_index (tree, arglist, 2060 i - (first_arg != NULL_TREE ? 1 : 0) - 1); 2061 argtype = lvalue_type (arg); 2062 2063 if (i == 0) 2064 { 2065 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false, 2066 flags); 2067 convert_type = totype; 2068 } 2069 else if (parmnode == void_list_node) 2070 break; 2071 else if (parmnode) 2072 { 2073 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg, 2074 /*c_cast_p=*/false, flags); 2075 convert_type = TREE_VALUE (parmnode); 2076 } 2077 else 2078 { 2079 t = build_identity_conv (argtype, arg); 2080 t->ellipsis_p = true; 2081 convert_type = argtype; 2082 } 2083 2084 convs[i] = t; 2085 if (! t) 2086 break; 2087 2088 if (t->bad_p) 2089 { 2090 viable = -1; 2091 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtype, convert_type); 2092 } 2093 2094 if (i == 0) 2095 continue; 2096 2097 if (parmnode) 2098 parmnode = TREE_CHAIN (parmnode); 2099 } 2100 2101 if (i < len 2102 || ! sufficient_parms_p (parmnode)) 2103 { 2104 int remaining = remaining_arguments (parmnode); 2105 viable = 0; 2106 reason = arity_rejection (NULL_TREE, i + remaining, len); 2107 } 2108 2109 return add_candidate (candidates, totype, first_arg, arglist, len, convs, 2110 access_path, conversion_path, viable, reason); 2111 } 2112 2113 static void 2114 build_builtin_candidate (struct z_candidate **candidates, tree fnname, 2115 tree type1, tree type2, tree *args, tree *argtypes, 2116 int flags) 2117 { 2118 conversion *t; 2119 conversion **convs; 2120 size_t num_convs; 2121 int viable = 1, i; 2122 tree types[2]; 2123 struct rejection_reason *reason = NULL; 2124 2125 types[0] = type1; 2126 types[1] = type2; 2127 2128 num_convs = args[2] ? 3 : (args[1] ? 2 : 1); 2129 convs = alloc_conversions (num_convs); 2130 2131 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit 2132 conversion ops are allowed. We handle that here by just checking for 2133 boolean_type_node because other operators don't ask for it. COND_EXPR 2134 also does contextual conversion to bool for the first operand, but we 2135 handle that in build_conditional_expr, and type1 here is operand 2. */ 2136 if (type1 != boolean_type_node) 2137 flags |= LOOKUP_ONLYCONVERTING; 2138 2139 for (i = 0; i < 2; ++i) 2140 { 2141 if (! args[i]) 2142 break; 2143 2144 t = implicit_conversion (types[i], argtypes[i], args[i], 2145 /*c_cast_p=*/false, flags); 2146 if (! t) 2147 { 2148 viable = 0; 2149 /* We need something for printing the candidate. */ 2150 t = build_identity_conv (types[i], NULL_TREE); 2151 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]); 2152 } 2153 else if (t->bad_p) 2154 { 2155 viable = 0; 2156 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]); 2157 } 2158 convs[i] = t; 2159 } 2160 2161 /* For COND_EXPR we rearranged the arguments; undo that now. */ 2162 if (args[2]) 2163 { 2164 convs[2] = convs[1]; 2165 convs[1] = convs[0]; 2166 t = implicit_conversion (boolean_type_node, argtypes[2], args[2], 2167 /*c_cast_p=*/false, flags); 2168 if (t) 2169 convs[0] = t; 2170 else 2171 { 2172 viable = 0; 2173 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2], 2174 boolean_type_node); 2175 } 2176 } 2177 2178 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL, 2179 num_convs, convs, 2180 /*access_path=*/NULL_TREE, 2181 /*conversion_path=*/NULL_TREE, 2182 viable, reason); 2183 } 2184 2185 static bool 2186 is_complete (tree t) 2187 { 2188 return COMPLETE_TYPE_P (complete_type (t)); 2189 } 2190 2191 /* Returns nonzero if TYPE is a promoted arithmetic type. */ 2192 2193 static bool 2194 promoted_arithmetic_type_p (tree type) 2195 { 2196 /* [over.built] 2197 2198 In this section, the term promoted integral type is used to refer 2199 to those integral types which are preserved by integral promotion 2200 (including e.g. int and long but excluding e.g. char). 2201 Similarly, the term promoted arithmetic type refers to promoted 2202 integral types plus floating types. */ 2203 return ((CP_INTEGRAL_TYPE_P (type) 2204 && same_type_p (type_promotes_to (type), type)) 2205 || TREE_CODE (type) == REAL_TYPE); 2206 } 2207 2208 /* Create any builtin operator overload candidates for the operator in 2209 question given the converted operand types TYPE1 and TYPE2. The other 2210 args are passed through from add_builtin_candidates to 2211 build_builtin_candidate. 2212 2213 TYPE1 and TYPE2 may not be permissible, and we must filter them. 2214 If CODE is requires candidates operands of the same type of the kind 2215 of which TYPE1 and TYPE2 are, we add both candidates 2216 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */ 2217 2218 static void 2219 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code, 2220 enum tree_code code2, tree fnname, tree type1, 2221 tree type2, tree *args, tree *argtypes, int flags) 2222 { 2223 switch (code) 2224 { 2225 case POSTINCREMENT_EXPR: 2226 case POSTDECREMENT_EXPR: 2227 args[1] = integer_zero_node; 2228 type2 = integer_type_node; 2229 break; 2230 default: 2231 break; 2232 } 2233 2234 switch (code) 2235 { 2236 2237 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2238 and VQ is either volatile or empty, there exist candidate operator 2239 functions of the form 2240 VQ T& operator++(VQ T&); 2241 T operator++(VQ T&, int); 2242 5 For every pair T, VQ), where T is an enumeration type or an arithmetic 2243 type other than bool, and VQ is either volatile or empty, there exist 2244 candidate operator functions of the form 2245 VQ T& operator--(VQ T&); 2246 T operator--(VQ T&, int); 2247 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified 2248 complete object type, and VQ is either volatile or empty, there exist 2249 candidate operator functions of the form 2250 T*VQ& operator++(T*VQ&); 2251 T*VQ& operator--(T*VQ&); 2252 T* operator++(T*VQ&, int); 2253 T* operator--(T*VQ&, int); */ 2254 2255 case POSTDECREMENT_EXPR: 2256 case PREDECREMENT_EXPR: 2257 if (TREE_CODE (type1) == BOOLEAN_TYPE) 2258 return; 2259 case POSTINCREMENT_EXPR: 2260 case PREINCREMENT_EXPR: 2261 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1)) 2262 { 2263 type1 = build_reference_type (type1); 2264 break; 2265 } 2266 return; 2267 2268 /* 7 For every cv-qualified or cv-unqualified object type T, there 2269 exist candidate operator functions of the form 2270 2271 T& operator*(T*); 2272 2273 8 For every function type T, there exist candidate operator functions of 2274 the form 2275 T& operator*(T*); */ 2276 2277 case INDIRECT_REF: 2278 if (TREE_CODE (type1) == POINTER_TYPE 2279 && !uses_template_parms (TREE_TYPE (type1)) 2280 && (TYPE_PTROB_P (type1) 2281 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)) 2282 break; 2283 return; 2284 2285 /* 9 For every type T, there exist candidate operator functions of the form 2286 T* operator+(T*); 2287 2288 10For every promoted arithmetic type T, there exist candidate operator 2289 functions of the form 2290 T operator+(T); 2291 T operator-(T); */ 2292 2293 case UNARY_PLUS_EXPR: /* unary + */ 2294 if (TREE_CODE (type1) == POINTER_TYPE) 2295 break; 2296 case NEGATE_EXPR: 2297 if (ARITHMETIC_TYPE_P (type1)) 2298 break; 2299 return; 2300 2301 /* 11For every promoted integral type T, there exist candidate operator 2302 functions of the form 2303 T operator~(T); */ 2304 2305 case BIT_NOT_EXPR: 2306 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1)) 2307 break; 2308 return; 2309 2310 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1 2311 is the same type as C2 or is a derived class of C2, T is a complete 2312 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 2313 there exist candidate operator functions of the form 2314 CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 2315 where CV12 is the union of CV1 and CV2. */ 2316 2317 case MEMBER_REF: 2318 if (TREE_CODE (type1) == POINTER_TYPE 2319 && TYPE_PTR_TO_MEMBER_P (type2)) 2320 { 2321 tree c1 = TREE_TYPE (type1); 2322 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2); 2323 2324 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1) 2325 && (TYPE_PTRMEMFUNC_P (type2) 2326 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2)))) 2327 break; 2328 } 2329 return; 2330 2331 /* 13For every pair of promoted arithmetic types L and R, there exist can- 2332 didate operator functions of the form 2333 LR operator*(L, R); 2334 LR operator/(L, R); 2335 LR operator+(L, R); 2336 LR operator-(L, R); 2337 bool operator<(L, R); 2338 bool operator>(L, R); 2339 bool operator<=(L, R); 2340 bool operator>=(L, R); 2341 bool operator==(L, R); 2342 bool operator!=(L, R); 2343 where LR is the result of the usual arithmetic conversions between 2344 types L and R. 2345 2346 14For every pair of types T and I, where T is a cv-qualified or cv- 2347 unqualified complete object type and I is a promoted integral type, 2348 there exist candidate operator functions of the form 2349 T* operator+(T*, I); 2350 T& operator[](T*, I); 2351 T* operator-(T*, I); 2352 T* operator+(I, T*); 2353 T& operator[](I, T*); 2354 2355 15For every T, where T is a pointer to complete object type, there exist 2356 candidate operator functions of the form112) 2357 ptrdiff_t operator-(T, T); 2358 2359 16For every pointer or enumeration type T, there exist candidate operator 2360 functions of the form 2361 bool operator<(T, T); 2362 bool operator>(T, T); 2363 bool operator<=(T, T); 2364 bool operator>=(T, T); 2365 bool operator==(T, T); 2366 bool operator!=(T, T); 2367 2368 17For every pointer to member type T, there exist candidate operator 2369 functions of the form 2370 bool operator==(T, T); 2371 bool operator!=(T, T); */ 2372 2373 case MINUS_EXPR: 2374 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2)) 2375 break; 2376 if (TYPE_PTROB_P (type1) 2377 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2378 { 2379 type2 = ptrdiff_type_node; 2380 break; 2381 } 2382 case MULT_EXPR: 2383 case TRUNC_DIV_EXPR: 2384 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2385 break; 2386 return; 2387 2388 case EQ_EXPR: 2389 case NE_EXPR: 2390 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2391 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))) 2392 break; 2393 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1])) 2394 { 2395 type2 = type1; 2396 break; 2397 } 2398 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0])) 2399 { 2400 type1 = type2; 2401 break; 2402 } 2403 /* Fall through. */ 2404 case LT_EXPR: 2405 case GT_EXPR: 2406 case LE_EXPR: 2407 case GE_EXPR: 2408 case MAX_EXPR: 2409 case MIN_EXPR: 2410 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2411 break; 2412 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2413 break; 2414 if (TREE_CODE (type1) == ENUMERAL_TYPE 2415 && TREE_CODE (type2) == ENUMERAL_TYPE) 2416 break; 2417 if (TYPE_PTR_P (type1) 2418 && null_ptr_cst_p (args[1]) 2419 && !uses_template_parms (type1)) 2420 { 2421 type2 = type1; 2422 break; 2423 } 2424 if (null_ptr_cst_p (args[0]) 2425 && TYPE_PTR_P (type2) 2426 && !uses_template_parms (type2)) 2427 { 2428 type1 = type2; 2429 break; 2430 } 2431 return; 2432 2433 case PLUS_EXPR: 2434 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2435 break; 2436 case ARRAY_REF: 2437 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2)) 2438 { 2439 type1 = ptrdiff_type_node; 2440 break; 2441 } 2442 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2443 { 2444 type2 = ptrdiff_type_node; 2445 break; 2446 } 2447 return; 2448 2449 /* 18For every pair of promoted integral types L and R, there exist candi- 2450 date operator functions of the form 2451 LR operator%(L, R); 2452 LR operator&(L, R); 2453 LR operator^(L, R); 2454 LR operator|(L, R); 2455 L operator<<(L, R); 2456 L operator>>(L, R); 2457 where LR is the result of the usual arithmetic conversions between 2458 types L and R. */ 2459 2460 case TRUNC_MOD_EXPR: 2461 case BIT_AND_EXPR: 2462 case BIT_IOR_EXPR: 2463 case BIT_XOR_EXPR: 2464 case LSHIFT_EXPR: 2465 case RSHIFT_EXPR: 2466 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2467 break; 2468 return; 2469 2470 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration 2471 type, VQ is either volatile or empty, and R is a promoted arithmetic 2472 type, there exist candidate operator functions of the form 2473 VQ L& operator=(VQ L&, R); 2474 VQ L& operator*=(VQ L&, R); 2475 VQ L& operator/=(VQ L&, R); 2476 VQ L& operator+=(VQ L&, R); 2477 VQ L& operator-=(VQ L&, R); 2478 2479 20For every pair T, VQ), where T is any type and VQ is either volatile 2480 or empty, there exist candidate operator functions of the form 2481 T*VQ& operator=(T*VQ&, T*); 2482 2483 21For every pair T, VQ), where T is a pointer to member type and VQ is 2484 either volatile or empty, there exist candidate operator functions of 2485 the form 2486 VQ T& operator=(VQ T&, T); 2487 2488 22For every triple T, VQ, I), where T is a cv-qualified or cv- 2489 unqualified complete object type, VQ is either volatile or empty, and 2490 I is a promoted integral type, there exist candidate operator func- 2491 tions of the form 2492 T*VQ& operator+=(T*VQ&, I); 2493 T*VQ& operator-=(T*VQ&, I); 2494 2495 23For every triple L, VQ, R), where L is an integral or enumeration 2496 type, VQ is either volatile or empty, and R is a promoted integral 2497 type, there exist candidate operator functions of the form 2498 2499 VQ L& operator%=(VQ L&, R); 2500 VQ L& operator<<=(VQ L&, R); 2501 VQ L& operator>>=(VQ L&, R); 2502 VQ L& operator&=(VQ L&, R); 2503 VQ L& operator^=(VQ L&, R); 2504 VQ L& operator|=(VQ L&, R); */ 2505 2506 case MODIFY_EXPR: 2507 switch (code2) 2508 { 2509 case PLUS_EXPR: 2510 case MINUS_EXPR: 2511 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2512 { 2513 type2 = ptrdiff_type_node; 2514 break; 2515 } 2516 case MULT_EXPR: 2517 case TRUNC_DIV_EXPR: 2518 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2519 break; 2520 return; 2521 2522 case TRUNC_MOD_EXPR: 2523 case BIT_AND_EXPR: 2524 case BIT_IOR_EXPR: 2525 case BIT_XOR_EXPR: 2526 case LSHIFT_EXPR: 2527 case RSHIFT_EXPR: 2528 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2529 break; 2530 return; 2531 2532 case NOP_EXPR: 2533 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2534 break; 2535 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2536 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2537 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)) 2538 || ((TYPE_PTRMEMFUNC_P (type1) 2539 || TREE_CODE (type1) == POINTER_TYPE) 2540 && null_ptr_cst_p (args[1]))) 2541 { 2542 type2 = type1; 2543 break; 2544 } 2545 return; 2546 2547 default: 2548 gcc_unreachable (); 2549 } 2550 type1 = build_reference_type (type1); 2551 break; 2552 2553 case COND_EXPR: 2554 /* [over.built] 2555 2556 For every pair of promoted arithmetic types L and R, there 2557 exist candidate operator functions of the form 2558 2559 LR operator?(bool, L, R); 2560 2561 where LR is the result of the usual arithmetic conversions 2562 between types L and R. 2563 2564 For every type T, where T is a pointer or pointer-to-member 2565 type, there exist candidate operator functions of the form T 2566 operator?(bool, T, T); */ 2567 2568 if (promoted_arithmetic_type_p (type1) 2569 && promoted_arithmetic_type_p (type2)) 2570 /* That's OK. */ 2571 break; 2572 2573 /* Otherwise, the types should be pointers. */ 2574 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1)) 2575 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2))) 2576 return; 2577 2578 /* We don't check that the two types are the same; the logic 2579 below will actually create two candidates; one in which both 2580 parameter types are TYPE1, and one in which both parameter 2581 types are TYPE2. */ 2582 break; 2583 2584 case REALPART_EXPR: 2585 case IMAGPART_EXPR: 2586 if (ARITHMETIC_TYPE_P (type1)) 2587 break; 2588 return; 2589 2590 default: 2591 gcc_unreachable (); 2592 } 2593 2594 /* If we're dealing with two pointer types or two enumeral types, 2595 we need candidates for both of them. */ 2596 if (type2 && !same_type_p (type1, type2) 2597 && TREE_CODE (type1) == TREE_CODE (type2) 2598 && (TREE_CODE (type1) == REFERENCE_TYPE 2599 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2600 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)) 2601 || TYPE_PTRMEMFUNC_P (type1) 2602 || MAYBE_CLASS_TYPE_P (type1) 2603 || TREE_CODE (type1) == ENUMERAL_TYPE)) 2604 { 2605 if (TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1)) 2606 { 2607 tree cptype = composite_pointer_type (type1, type2, 2608 error_mark_node, 2609 error_mark_node, 2610 CPO_CONVERSION, 2611 tf_none); 2612 if (cptype != error_mark_node) 2613 { 2614 build_builtin_candidate 2615 (candidates, fnname, cptype, cptype, args, argtypes, flags); 2616 return; 2617 } 2618 } 2619 2620 build_builtin_candidate 2621 (candidates, fnname, type1, type1, args, argtypes, flags); 2622 build_builtin_candidate 2623 (candidates, fnname, type2, type2, args, argtypes, flags); 2624 return; 2625 } 2626 2627 build_builtin_candidate 2628 (candidates, fnname, type1, type2, args, argtypes, flags); 2629 } 2630 2631 tree 2632 type_decays_to (tree type) 2633 { 2634 if (TREE_CODE (type) == ARRAY_TYPE) 2635 return build_pointer_type (TREE_TYPE (type)); 2636 if (TREE_CODE (type) == FUNCTION_TYPE) 2637 return build_pointer_type (type); 2638 return type; 2639 } 2640 2641 /* There are three conditions of builtin candidates: 2642 2643 1) bool-taking candidates. These are the same regardless of the input. 2644 2) pointer-pair taking candidates. These are generated for each type 2645 one of the input types converts to. 2646 3) arithmetic candidates. According to the standard, we should generate 2647 all of these, but I'm trying not to... 2648 2649 Here we generate a superset of the possible candidates for this particular 2650 case. That is a subset of the full set the standard defines, plus some 2651 other cases which the standard disallows. add_builtin_candidate will 2652 filter out the invalid set. */ 2653 2654 static void 2655 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code, 2656 enum tree_code code2, tree fnname, tree *args, 2657 int flags) 2658 { 2659 int ref1, i; 2660 int enum_p = 0; 2661 tree type, argtypes[3], t; 2662 /* TYPES[i] is the set of possible builtin-operator parameter types 2663 we will consider for the Ith argument. */ 2664 VEC(tree,gc) *types[2]; 2665 unsigned ix; 2666 2667 for (i = 0; i < 3; ++i) 2668 { 2669 if (args[i]) 2670 argtypes[i] = unlowered_expr_type (args[i]); 2671 else 2672 argtypes[i] = NULL_TREE; 2673 } 2674 2675 switch (code) 2676 { 2677 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2678 and VQ is either volatile or empty, there exist candidate operator 2679 functions of the form 2680 VQ T& operator++(VQ T&); */ 2681 2682 case POSTINCREMENT_EXPR: 2683 case PREINCREMENT_EXPR: 2684 case POSTDECREMENT_EXPR: 2685 case PREDECREMENT_EXPR: 2686 case MODIFY_EXPR: 2687 ref1 = 1; 2688 break; 2689 2690 /* 24There also exist candidate operator functions of the form 2691 bool operator!(bool); 2692 bool operator&&(bool, bool); 2693 bool operator||(bool, bool); */ 2694 2695 case TRUTH_NOT_EXPR: 2696 build_builtin_candidate 2697 (candidates, fnname, boolean_type_node, 2698 NULL_TREE, args, argtypes, flags); 2699 return; 2700 2701 case TRUTH_ORIF_EXPR: 2702 case TRUTH_ANDIF_EXPR: 2703 build_builtin_candidate 2704 (candidates, fnname, boolean_type_node, 2705 boolean_type_node, args, argtypes, flags); 2706 return; 2707 2708 case ADDR_EXPR: 2709 case COMPOUND_EXPR: 2710 case COMPONENT_REF: 2711 return; 2712 2713 case COND_EXPR: 2714 case EQ_EXPR: 2715 case NE_EXPR: 2716 case LT_EXPR: 2717 case LE_EXPR: 2718 case GT_EXPR: 2719 case GE_EXPR: 2720 enum_p = 1; 2721 /* Fall through. */ 2722 2723 default: 2724 ref1 = 0; 2725 } 2726 2727 types[0] = make_tree_vector (); 2728 types[1] = make_tree_vector (); 2729 2730 for (i = 0; i < 2; ++i) 2731 { 2732 if (! args[i]) 2733 ; 2734 else if (MAYBE_CLASS_TYPE_P (argtypes[i])) 2735 { 2736 tree convs; 2737 2738 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR) 2739 return; 2740 2741 convs = lookup_conversions (argtypes[i]); 2742 2743 if (code == COND_EXPR) 2744 { 2745 if (real_lvalue_p (args[i])) 2746 VEC_safe_push (tree, gc, types[i], 2747 build_reference_type (argtypes[i])); 2748 2749 VEC_safe_push (tree, gc, types[i], 2750 TYPE_MAIN_VARIANT (argtypes[i])); 2751 } 2752 2753 else if (! convs) 2754 return; 2755 2756 for (; convs; convs = TREE_CHAIN (convs)) 2757 { 2758 type = TREE_TYPE (convs); 2759 2760 if (i == 0 && ref1 2761 && (TREE_CODE (type) != REFERENCE_TYPE 2762 || CP_TYPE_CONST_P (TREE_TYPE (type)))) 2763 continue; 2764 2765 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE) 2766 VEC_safe_push (tree, gc, types[i], type); 2767 2768 type = non_reference (type); 2769 if (i != 0 || ! ref1) 2770 { 2771 type = cv_unqualified (type_decays_to (type)); 2772 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE) 2773 VEC_safe_push (tree, gc, types[i], type); 2774 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 2775 type = type_promotes_to (type); 2776 } 2777 2778 if (! vec_member (type, types[i])) 2779 VEC_safe_push (tree, gc, types[i], type); 2780 } 2781 } 2782 else 2783 { 2784 if (code == COND_EXPR && real_lvalue_p (args[i])) 2785 VEC_safe_push (tree, gc, types[i], 2786 build_reference_type (argtypes[i])); 2787 type = non_reference (argtypes[i]); 2788 if (i != 0 || ! ref1) 2789 { 2790 type = cv_unqualified (type_decays_to (type)); 2791 if (enum_p && UNSCOPED_ENUM_P (type)) 2792 VEC_safe_push (tree, gc, types[i], type); 2793 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 2794 type = type_promotes_to (type); 2795 } 2796 VEC_safe_push (tree, gc, types[i], type); 2797 } 2798 } 2799 2800 /* Run through the possible parameter types of both arguments, 2801 creating candidates with those parameter types. */ 2802 FOR_EACH_VEC_ELT_REVERSE (tree, types[0], ix, t) 2803 { 2804 unsigned jx; 2805 tree u; 2806 2807 if (!VEC_empty (tree, types[1])) 2808 FOR_EACH_VEC_ELT_REVERSE (tree, types[1], jx, u) 2809 add_builtin_candidate 2810 (candidates, code, code2, fnname, t, 2811 u, args, argtypes, flags); 2812 else 2813 add_builtin_candidate 2814 (candidates, code, code2, fnname, t, 2815 NULL_TREE, args, argtypes, flags); 2816 } 2817 2818 release_tree_vector (types[0]); 2819 release_tree_vector (types[1]); 2820 } 2821 2822 2823 /* If TMPL can be successfully instantiated as indicated by 2824 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES. 2825 2826 TMPL is the template. EXPLICIT_TARGS are any explicit template 2827 arguments. ARGLIST is the arguments provided at the call-site. 2828 This does not change ARGLIST. The RETURN_TYPE is the desired type 2829 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are 2830 as for add_function_candidate. If an OBJ is supplied, FLAGS and 2831 CTYPE are ignored, and OBJ is as for add_conv_candidate. */ 2832 2833 static struct z_candidate* 2834 add_template_candidate_real (struct z_candidate **candidates, tree tmpl, 2835 tree ctype, tree explicit_targs, tree first_arg, 2836 const VEC(tree,gc) *arglist, tree return_type, 2837 tree access_path, tree conversion_path, 2838 int flags, tree obj, unification_kind_t strict) 2839 { 2840 int ntparms = DECL_NTPARMS (tmpl); 2841 tree targs = make_tree_vec (ntparms); 2842 unsigned int len = VEC_length (tree, arglist); 2843 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len; 2844 unsigned int skip_without_in_chrg = 0; 2845 tree first_arg_without_in_chrg = first_arg; 2846 tree *args_without_in_chrg; 2847 unsigned int nargs_without_in_chrg; 2848 unsigned int ia, ix; 2849 tree arg; 2850 struct z_candidate *cand; 2851 int i; 2852 tree fn; 2853 struct rejection_reason *reason = NULL; 2854 int errs; 2855 2856 /* We don't do deduction on the in-charge parameter, the VTT 2857 parameter or 'this'. */ 2858 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl)) 2859 { 2860 if (first_arg_without_in_chrg != NULL_TREE) 2861 first_arg_without_in_chrg = NULL_TREE; 2862 else 2863 ++skip_without_in_chrg; 2864 } 2865 2866 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl) 2867 || DECL_BASE_CONSTRUCTOR_P (tmpl)) 2868 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl))) 2869 { 2870 if (first_arg_without_in_chrg != NULL_TREE) 2871 first_arg_without_in_chrg = NULL_TREE; 2872 else 2873 ++skip_without_in_chrg; 2874 } 2875 2876 if (len < skip_without_in_chrg) 2877 return NULL; 2878 2879 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0) 2880 + (len - skip_without_in_chrg)); 2881 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg); 2882 ia = 0; 2883 if (first_arg_without_in_chrg != NULL_TREE) 2884 { 2885 args_without_in_chrg[ia] = first_arg_without_in_chrg; 2886 ++ia; 2887 } 2888 for (ix = skip_without_in_chrg; 2889 VEC_iterate (tree, arglist, ix, arg); 2890 ++ix) 2891 { 2892 args_without_in_chrg[ia] = arg; 2893 ++ia; 2894 } 2895 gcc_assert (ia == nargs_without_in_chrg); 2896 2897 errs = errorcount+sorrycount; 2898 i = fn_type_unification (tmpl, explicit_targs, targs, 2899 args_without_in_chrg, 2900 nargs_without_in_chrg, 2901 return_type, strict, flags, false); 2902 2903 if (i != 0) 2904 { 2905 /* Don't repeat unification later if it already resulted in errors. */ 2906 if (errorcount+sorrycount == errs) 2907 reason = template_unification_rejection (tmpl, explicit_targs, 2908 targs, args_without_in_chrg, 2909 nargs_without_in_chrg, 2910 return_type, strict, flags); 2911 else 2912 reason = template_unification_error_rejection (); 2913 goto fail; 2914 } 2915 2916 fn = instantiate_template (tmpl, targs, tf_none); 2917 if (fn == error_mark_node) 2918 { 2919 reason = template_instantiation_rejection (tmpl, targs); 2920 goto fail; 2921 } 2922 2923 /* In [class.copy]: 2924 2925 A member function template is never instantiated to perform the 2926 copy of a class object to an object of its class type. 2927 2928 It's a little unclear what this means; the standard explicitly 2929 does allow a template to be used to copy a class. For example, 2930 in: 2931 2932 struct A { 2933 A(A&); 2934 template <class T> A(const T&); 2935 }; 2936 const A f (); 2937 void g () { A a (f ()); } 2938 2939 the member template will be used to make the copy. The section 2940 quoted above appears in the paragraph that forbids constructors 2941 whose only parameter is (a possibly cv-qualified variant of) the 2942 class type, and a logical interpretation is that the intent was 2943 to forbid the instantiation of member templates which would then 2944 have that form. */ 2945 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2) 2946 { 2947 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn); 2948 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)), 2949 ctype)) 2950 { 2951 reason = invalid_copy_with_fn_template_rejection (); 2952 goto fail; 2953 } 2954 } 2955 2956 if (obj != NULL_TREE) 2957 /* Aha, this is a conversion function. */ 2958 cand = add_conv_candidate (candidates, fn, obj, first_arg, arglist, 2959 access_path, conversion_path); 2960 else 2961 cand = add_function_candidate (candidates, fn, ctype, 2962 first_arg, arglist, access_path, 2963 conversion_path, flags); 2964 if (DECL_TI_TEMPLATE (fn) != tmpl) 2965 /* This situation can occur if a member template of a template 2966 class is specialized. Then, instantiate_template might return 2967 an instantiation of the specialization, in which case the 2968 DECL_TI_TEMPLATE field will point at the original 2969 specialization. For example: 2970 2971 template <class T> struct S { template <class U> void f(U); 2972 template <> void f(int) {}; }; 2973 S<double> sd; 2974 sd.f(3); 2975 2976 Here, TMPL will be template <class U> S<double>::f(U). 2977 And, instantiate template will give us the specialization 2978 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field 2979 for this will point at template <class T> template <> S<T>::f(int), 2980 so that we can find the definition. For the purposes of 2981 overload resolution, however, we want the original TMPL. */ 2982 cand->template_decl = build_template_info (tmpl, targs); 2983 else 2984 cand->template_decl = DECL_TEMPLATE_INFO (fn); 2985 cand->explicit_targs = explicit_targs; 2986 2987 return cand; 2988 fail: 2989 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL, 2990 access_path, conversion_path, 0, reason); 2991 } 2992 2993 2994 static struct z_candidate * 2995 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype, 2996 tree explicit_targs, tree first_arg, 2997 const VEC(tree,gc) *arglist, tree return_type, 2998 tree access_path, tree conversion_path, int flags, 2999 unification_kind_t strict) 3000 { 3001 return 3002 add_template_candidate_real (candidates, tmpl, ctype, 3003 explicit_targs, first_arg, arglist, 3004 return_type, access_path, conversion_path, 3005 flags, NULL_TREE, strict); 3006 } 3007 3008 3009 static struct z_candidate * 3010 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl, 3011 tree obj, tree first_arg, 3012 const VEC(tree,gc) *arglist, 3013 tree return_type, tree access_path, 3014 tree conversion_path) 3015 { 3016 return 3017 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE, 3018 first_arg, arglist, return_type, access_path, 3019 conversion_path, 0, obj, DEDUCE_CONV); 3020 } 3021 3022 /* The CANDS are the set of candidates that were considered for 3023 overload resolution. Return the set of viable candidates, or CANDS 3024 if none are viable. If any of the candidates were viable, set 3025 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be 3026 considered viable only if it is strictly viable. */ 3027 3028 static struct z_candidate* 3029 splice_viable (struct z_candidate *cands, 3030 bool strict_p, 3031 bool *any_viable_p) 3032 { 3033 struct z_candidate *viable; 3034 struct z_candidate **last_viable; 3035 struct z_candidate **cand; 3036 3037 /* Be strict inside templates, since build_over_call won't actually 3038 do the conversions to get pedwarns. */ 3039 if (processing_template_decl) 3040 strict_p = true; 3041 3042 viable = NULL; 3043 last_viable = &viable; 3044 *any_viable_p = false; 3045 3046 cand = &cands; 3047 while (*cand) 3048 { 3049 struct z_candidate *c = *cand; 3050 if (strict_p ? c->viable == 1 : c->viable) 3051 { 3052 *last_viable = c; 3053 *cand = c->next; 3054 c->next = NULL; 3055 last_viable = &c->next; 3056 *any_viable_p = true; 3057 } 3058 else 3059 cand = &c->next; 3060 } 3061 3062 return viable ? viable : cands; 3063 } 3064 3065 static bool 3066 any_strictly_viable (struct z_candidate *cands) 3067 { 3068 for (; cands; cands = cands->next) 3069 if (cands->viable == 1) 3070 return true; 3071 return false; 3072 } 3073 3074 /* OBJ is being used in an expression like "OBJ.f (...)". In other 3075 words, it is about to become the "this" pointer for a member 3076 function call. Take the address of the object. */ 3077 3078 static tree 3079 build_this (tree obj) 3080 { 3081 /* In a template, we are only concerned about the type of the 3082 expression, so we can take a shortcut. */ 3083 if (processing_template_decl) 3084 return build_address (obj); 3085 3086 return cp_build_addr_expr (obj, tf_warning_or_error); 3087 } 3088 3089 /* Returns true iff functions are equivalent. Equivalent functions are 3090 not '==' only if one is a function-local extern function or if 3091 both are extern "C". */ 3092 3093 static inline int 3094 equal_functions (tree fn1, tree fn2) 3095 { 3096 if (TREE_CODE (fn1) != TREE_CODE (fn2)) 3097 return 0; 3098 if (TREE_CODE (fn1) == TEMPLATE_DECL) 3099 return fn1 == fn2; 3100 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2) 3101 || DECL_EXTERN_C_FUNCTION_P (fn1)) 3102 return decls_match (fn1, fn2); 3103 return fn1 == fn2; 3104 } 3105 3106 /* Print information about a candidate being rejected due to INFO. */ 3107 3108 static void 3109 print_conversion_rejection (location_t loc, struct conversion_info *info) 3110 { 3111 if (info->n_arg == -1) 3112 /* Conversion of implicit `this' argument failed. */ 3113 inform (loc, " no known conversion for implicit " 3114 "%<this%> parameter from %qT to %qT", 3115 info->from_type, info->to_type); 3116 else 3117 inform (loc, " no known conversion for argument %d from %qT to %qT", 3118 info->n_arg+1, info->from_type, info->to_type); 3119 } 3120 3121 /* Print information about a candidate with WANT parameters and we found 3122 HAVE. */ 3123 3124 static void 3125 print_arity_information (location_t loc, unsigned int have, unsigned int want) 3126 { 3127 inform_n (loc, want, 3128 " candidate expects %d argument, %d provided", 3129 " candidate expects %d arguments, %d provided", 3130 want, have); 3131 } 3132 3133 /* Print information about one overload candidate CANDIDATE. MSGSTR 3134 is the text to print before the candidate itself. 3135 3136 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected 3137 to have been run through gettext by the caller. This wart makes 3138 life simpler in print_z_candidates and for the translators. */ 3139 3140 static void 3141 print_z_candidate (const char *msgstr, struct z_candidate *candidate) 3142 { 3143 const char *msg = (msgstr == NULL 3144 ? "" 3145 : ACONCAT ((msgstr, " ", NULL))); 3146 location_t loc = location_of (candidate->fn); 3147 3148 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE) 3149 { 3150 if (candidate->num_convs == 3) 3151 inform (input_location, "%s%D(%T, %T, %T) <built-in>", msg, candidate->fn, 3152 candidate->convs[0]->type, 3153 candidate->convs[1]->type, 3154 candidate->convs[2]->type); 3155 else if (candidate->num_convs == 2) 3156 inform (input_location, "%s%D(%T, %T) <built-in>", msg, candidate->fn, 3157 candidate->convs[0]->type, 3158 candidate->convs[1]->type); 3159 else 3160 inform (input_location, "%s%D(%T) <built-in>", msg, candidate->fn, 3161 candidate->convs[0]->type); 3162 } 3163 else if (TYPE_P (candidate->fn)) 3164 inform (input_location, "%s%T <conversion>", msg, candidate->fn); 3165 else if (candidate->viable == -1) 3166 inform (loc, "%s%#D <near match>", msg, candidate->fn); 3167 else if (DECL_DELETED_FN (STRIP_TEMPLATE (candidate->fn))) 3168 inform (loc, "%s%#D <deleted>", msg, candidate->fn); 3169 else 3170 inform (loc, "%s%#D", msg, candidate->fn); 3171 /* Give the user some information about why this candidate failed. */ 3172 if (candidate->reason != NULL) 3173 { 3174 struct rejection_reason *r = candidate->reason; 3175 3176 switch (r->code) 3177 { 3178 case rr_arity: 3179 print_arity_information (loc, r->u.arity.actual, 3180 r->u.arity.expected); 3181 break; 3182 case rr_arg_conversion: 3183 print_conversion_rejection (loc, &r->u.conversion); 3184 break; 3185 case rr_bad_arg_conversion: 3186 print_conversion_rejection (loc, &r->u.bad_conversion); 3187 break; 3188 case rr_explicit_conversion: 3189 inform (loc, " return type %qT of explicit conversion function " 3190 "cannot be converted to %qT with a qualification " 3191 "conversion", r->u.conversion.from_type, 3192 r->u.conversion.to_type); 3193 break; 3194 case rr_template_conversion: 3195 inform (loc, " conversion from return type %qT of template " 3196 "conversion function specialization to %qT is not an " 3197 "exact match", r->u.conversion.from_type, 3198 r->u.conversion.to_type); 3199 break; 3200 case rr_template_unification: 3201 /* We use template_unification_error_rejection if unification caused 3202 actual non-SFINAE errors, in which case we don't need to repeat 3203 them here. */ 3204 if (r->u.template_unification.tmpl == NULL_TREE) 3205 { 3206 inform (loc, " substitution of deduced template arguments " 3207 "resulted in errors seen above"); 3208 break; 3209 } 3210 /* Re-run template unification with diagnostics. */ 3211 inform (loc, " template argument deduction/substitution failed:"); 3212 fn_type_unification (r->u.template_unification.tmpl, 3213 r->u.template_unification.explicit_targs, 3214 r->u.template_unification.targs, 3215 r->u.template_unification.args, 3216 r->u.template_unification.nargs, 3217 r->u.template_unification.return_type, 3218 r->u.template_unification.strict, 3219 r->u.template_unification.flags, 3220 true); 3221 break; 3222 case rr_template_instantiation: 3223 /* Re-run template instantiation with diagnostics. */ 3224 instantiate_template (r->u.template_instantiation.tmpl, 3225 r->u.template_instantiation.targs, 3226 tf_warning_or_error); 3227 break; 3228 case rr_invalid_copy: 3229 inform (loc, 3230 " a constructor taking a single argument of its own " 3231 "class type is invalid"); 3232 break; 3233 case rr_none: 3234 default: 3235 /* This candidate didn't have any issues or we failed to 3236 handle a particular code. Either way... */ 3237 gcc_unreachable (); 3238 } 3239 } 3240 } 3241 3242 static void 3243 print_z_candidates (location_t loc, struct z_candidate *candidates) 3244 { 3245 struct z_candidate *cand1; 3246 struct z_candidate **cand2; 3247 int n_candidates; 3248 3249 if (!candidates) 3250 return; 3251 3252 /* Remove non-viable deleted candidates. */ 3253 cand1 = candidates; 3254 for (cand2 = &cand1; *cand2; ) 3255 { 3256 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL 3257 && !(*cand2)->viable 3258 && DECL_DELETED_FN ((*cand2)->fn)) 3259 *cand2 = (*cand2)->next; 3260 else 3261 cand2 = &(*cand2)->next; 3262 } 3263 /* ...if there are any non-deleted ones. */ 3264 if (cand1) 3265 candidates = cand1; 3266 3267 /* There may be duplicates in the set of candidates. We put off 3268 checking this condition as long as possible, since we have no way 3269 to eliminate duplicates from a set of functions in less than n^2 3270 time. Now we are about to emit an error message, so it is more 3271 permissible to go slowly. */ 3272 for (cand1 = candidates; cand1; cand1 = cand1->next) 3273 { 3274 tree fn = cand1->fn; 3275 /* Skip builtin candidates and conversion functions. */ 3276 if (!DECL_P (fn)) 3277 continue; 3278 cand2 = &cand1->next; 3279 while (*cand2) 3280 { 3281 if (DECL_P ((*cand2)->fn) 3282 && equal_functions (fn, (*cand2)->fn)) 3283 *cand2 = (*cand2)->next; 3284 else 3285 cand2 = &(*cand2)->next; 3286 } 3287 } 3288 3289 for (n_candidates = 0, cand1 = candidates; cand1; cand1 = cand1->next) 3290 n_candidates++; 3291 3292 inform_n (loc, n_candidates, "candidate is:", "candidates are:"); 3293 for (; candidates; candidates = candidates->next) 3294 print_z_candidate (NULL, candidates); 3295 } 3296 3297 /* USER_SEQ is a user-defined conversion sequence, beginning with a 3298 USER_CONV. STD_SEQ is the standard conversion sequence applied to 3299 the result of the conversion function to convert it to the final 3300 desired type. Merge the two sequences into a single sequence, 3301 and return the merged sequence. */ 3302 3303 static conversion * 3304 merge_conversion_sequences (conversion *user_seq, conversion *std_seq) 3305 { 3306 conversion **t; 3307 bool bad = user_seq->bad_p; 3308 3309 gcc_assert (user_seq->kind == ck_user); 3310 3311 /* Find the end of the second conversion sequence. */ 3312 for (t = &std_seq; (*t)->kind != ck_identity; t = &((*t)->u.next)) 3313 { 3314 /* The entire sequence is a user-conversion sequence. */ 3315 (*t)->user_conv_p = true; 3316 if (bad) 3317 (*t)->bad_p = true; 3318 } 3319 3320 /* Replace the identity conversion with the user conversion 3321 sequence. */ 3322 *t = user_seq; 3323 3324 return std_seq; 3325 } 3326 3327 /* Handle overload resolution for initializing an object of class type from 3328 an initializer list. First we look for a suitable constructor that 3329 takes a std::initializer_list; if we don't find one, we then look for a 3330 non-list constructor. 3331 3332 Parameters are as for add_candidates, except that the arguments are in 3333 the form of a CONSTRUCTOR (the initializer list) rather than a VEC, and 3334 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */ 3335 3336 static void 3337 add_list_candidates (tree fns, tree first_arg, 3338 tree init_list, tree totype, 3339 tree explicit_targs, bool template_only, 3340 tree conversion_path, tree access_path, 3341 int flags, 3342 struct z_candidate **candidates) 3343 { 3344 VEC(tree,gc) *args; 3345 3346 gcc_assert (*candidates == NULL); 3347 3348 /* We're looking for a ctor for list-initialization. */ 3349 flags |= LOOKUP_LIST_INIT_CTOR; 3350 /* And we don't allow narrowing conversions. We also use this flag to 3351 avoid the copy constructor call for copy-list-initialization. */ 3352 flags |= LOOKUP_NO_NARROWING; 3353 3354 /* Always use the default constructor if the list is empty (DR 990). */ 3355 if (CONSTRUCTOR_NELTS (init_list) == 0 3356 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 3357 ; 3358 /* If the class has a list ctor, try passing the list as a single 3359 argument first, but only consider list ctors. */ 3360 else if (TYPE_HAS_LIST_CTOR (totype)) 3361 { 3362 flags |= LOOKUP_LIST_ONLY; 3363 args = make_tree_vector_single (init_list); 3364 add_candidates (fns, first_arg, args, NULL_TREE, 3365 explicit_targs, template_only, conversion_path, 3366 access_path, flags, candidates); 3367 if (any_strictly_viable (*candidates)) 3368 return; 3369 } 3370 3371 args = ctor_to_vec (init_list); 3372 3373 /* We aren't looking for list-ctors anymore. */ 3374 flags &= ~LOOKUP_LIST_ONLY; 3375 /* We allow more user-defined conversions within an init-list. */ 3376 flags &= ~LOOKUP_NO_CONVERSION; 3377 3378 add_candidates (fns, first_arg, args, NULL_TREE, 3379 explicit_targs, template_only, conversion_path, 3380 access_path, flags, candidates); 3381 } 3382 3383 /* Returns the best overload candidate to perform the requested 3384 conversion. This function is used for three the overloading situations 3385 described in [over.match.copy], [over.match.conv], and [over.match.ref]. 3386 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as 3387 per [dcl.init.ref], so we ignore temporary bindings. */ 3388 3389 static struct z_candidate * 3390 build_user_type_conversion_1 (tree totype, tree expr, int flags) 3391 { 3392 struct z_candidate *candidates, *cand; 3393 tree fromtype; 3394 tree ctors = NULL_TREE; 3395 tree conv_fns = NULL_TREE; 3396 conversion *conv = NULL; 3397 tree first_arg = NULL_TREE; 3398 VEC(tree,gc) *args = NULL; 3399 bool any_viable_p; 3400 int convflags; 3401 3402 if (!expr) 3403 return NULL; 3404 3405 fromtype = TREE_TYPE (expr); 3406 3407 /* We represent conversion within a hierarchy using RVALUE_CONV and 3408 BASE_CONV, as specified by [over.best.ics]; these become plain 3409 constructor calls, as specified in [dcl.init]. */ 3410 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype) 3411 || !DERIVED_FROM_P (totype, fromtype)); 3412 3413 if (MAYBE_CLASS_TYPE_P (totype)) 3414 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid 3415 creating a garbage BASELINK; constructors can't be inherited. */ 3416 ctors = lookup_fnfields_slot (totype, complete_ctor_identifier); 3417 3418 if (MAYBE_CLASS_TYPE_P (fromtype)) 3419 { 3420 tree to_nonref = non_reference (totype); 3421 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) || 3422 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype) 3423 && DERIVED_FROM_P (to_nonref, fromtype))) 3424 { 3425 /* [class.conv.fct] A conversion function is never used to 3426 convert a (possibly cv-qualified) object to the (possibly 3427 cv-qualified) same object type (or a reference to it), to a 3428 (possibly cv-qualified) base class of that type (or a 3429 reference to it)... */ 3430 } 3431 else 3432 conv_fns = lookup_conversions (fromtype); 3433 } 3434 3435 candidates = 0; 3436 flags |= LOOKUP_NO_CONVERSION; 3437 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3438 flags |= LOOKUP_NO_NARROWING; 3439 3440 /* It's OK to bind a temporary for converting constructor arguments, but 3441 not in converting the return value of a conversion operator. */ 3442 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION); 3443 flags &= ~LOOKUP_NO_TEMP_BIND; 3444 3445 if (ctors) 3446 { 3447 int ctorflags = flags; 3448 3449 first_arg = build_int_cst (build_pointer_type (totype), 0); 3450 3451 /* We should never try to call the abstract or base constructor 3452 from here. */ 3453 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors)) 3454 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors))); 3455 3456 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3457 { 3458 /* List-initialization. */ 3459 add_list_candidates (ctors, first_arg, expr, totype, NULL_TREE, 3460 false, TYPE_BINFO (totype), TYPE_BINFO (totype), 3461 ctorflags, &candidates); 3462 } 3463 else 3464 { 3465 args = make_tree_vector_single (expr); 3466 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false, 3467 TYPE_BINFO (totype), TYPE_BINFO (totype), 3468 ctorflags, &candidates); 3469 } 3470 3471 for (cand = candidates; cand; cand = cand->next) 3472 { 3473 cand->second_conv = build_identity_conv (totype, NULL_TREE); 3474 3475 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't 3476 set, then this is copy-initialization. In that case, "The 3477 result of the call is then used to direct-initialize the 3478 object that is the destination of the copy-initialization." 3479 [dcl.init] 3480 3481 We represent this in the conversion sequence with an 3482 rvalue conversion, which means a constructor call. */ 3483 if (TREE_CODE (totype) != REFERENCE_TYPE 3484 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3485 cand->second_conv 3486 = build_conv (ck_rvalue, totype, cand->second_conv); 3487 } 3488 } 3489 3490 if (conv_fns) 3491 first_arg = build_this (expr); 3492 3493 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns)) 3494 { 3495 tree conversion_path = TREE_PURPOSE (conv_fns); 3496 struct z_candidate *old_candidates; 3497 3498 /* If we are called to convert to a reference type, we are trying to 3499 find a direct binding, so don't even consider temporaries. If 3500 we don't find a direct binding, the caller will try again to 3501 look for a temporary binding. */ 3502 if (TREE_CODE (totype) == REFERENCE_TYPE) 3503 convflags |= LOOKUP_NO_TEMP_BIND; 3504 3505 old_candidates = candidates; 3506 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype, 3507 NULL_TREE, false, 3508 conversion_path, TYPE_BINFO (fromtype), 3509 flags, &candidates); 3510 3511 for (cand = candidates; cand != old_candidates; cand = cand->next) 3512 { 3513 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn)); 3514 conversion *ics 3515 = implicit_conversion (totype, 3516 rettype, 3517 0, 3518 /*c_cast_p=*/false, convflags); 3519 3520 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is 3521 copy-initialization. In that case, "The result of the 3522 call is then used to direct-initialize the object that is 3523 the destination of the copy-initialization." [dcl.init] 3524 3525 We represent this in the conversion sequence with an 3526 rvalue conversion, which means a constructor call. But 3527 don't add a second rvalue conversion if there's already 3528 one there. Which there really shouldn't be, but it's 3529 harmless since we'd add it here anyway. */ 3530 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue 3531 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3532 ics = build_conv (ck_rvalue, totype, ics); 3533 3534 cand->second_conv = ics; 3535 3536 if (!ics) 3537 { 3538 cand->viable = 0; 3539 cand->reason = arg_conversion_rejection (NULL_TREE, -1, 3540 rettype, totype); 3541 } 3542 else if (DECL_NONCONVERTING_P (cand->fn) 3543 && ics->rank > cr_exact) 3544 { 3545 /* 13.3.1.5: For direct-initialization, those explicit 3546 conversion functions that are not hidden within S and 3547 yield type T or a type that can be converted to type T 3548 with a qualification conversion (4.4) are also candidate 3549 functions. */ 3550 /* 13.3.1.6 doesn't have a parallel restriction, but it should; 3551 I've raised this issue with the committee. --jason 9/2011 */ 3552 cand->viable = -1; 3553 cand->reason = explicit_conversion_rejection (rettype, totype); 3554 } 3555 else if (cand->viable == 1 && ics->bad_p) 3556 { 3557 cand->viable = -1; 3558 cand->reason 3559 = bad_arg_conversion_rejection (NULL_TREE, -1, 3560 rettype, totype); 3561 } 3562 else if (primary_template_instantiation_p (cand->fn) 3563 && ics->rank > cr_exact) 3564 { 3565 /* 13.3.3.1.2: If the user-defined conversion is specified by 3566 a specialization of a conversion function template, the 3567 second standard conversion sequence shall have exact match 3568 rank. */ 3569 cand->viable = -1; 3570 cand->reason = template_conversion_rejection (rettype, totype); 3571 } 3572 } 3573 } 3574 3575 candidates = splice_viable (candidates, pedantic, &any_viable_p); 3576 if (!any_viable_p) 3577 { 3578 if (args) 3579 release_tree_vector (args); 3580 return NULL; 3581 } 3582 3583 cand = tourney (candidates); 3584 if (cand == 0) 3585 { 3586 if (flags & LOOKUP_COMPLAIN) 3587 { 3588 error ("conversion from %qT to %qT is ambiguous", 3589 fromtype, totype); 3590 print_z_candidates (location_of (expr), candidates); 3591 } 3592 3593 cand = candidates; /* any one will do */ 3594 cand->second_conv = build_ambiguous_conv (totype, expr); 3595 cand->second_conv->user_conv_p = true; 3596 if (!any_strictly_viable (candidates)) 3597 cand->second_conv->bad_p = true; 3598 /* If there are viable candidates, don't set ICS_BAD_FLAG; an 3599 ambiguous conversion is no worse than another user-defined 3600 conversion. */ 3601 3602 return cand; 3603 } 3604 3605 /* Build the user conversion sequence. */ 3606 conv = build_conv 3607 (ck_user, 3608 (DECL_CONSTRUCTOR_P (cand->fn) 3609 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))), 3610 build_identity_conv (TREE_TYPE (expr), expr)); 3611 conv->cand = cand; 3612 if (cand->viable == -1) 3613 conv->bad_p = true; 3614 3615 /* Remember that this was a list-initialization. */ 3616 if (flags & LOOKUP_NO_NARROWING) 3617 conv->check_narrowing = true; 3618 3619 /* Combine it with the second conversion sequence. */ 3620 cand->second_conv = merge_conversion_sequences (conv, 3621 cand->second_conv); 3622 3623 return cand; 3624 } 3625 3626 /* Wrapper for above. */ 3627 3628 tree 3629 build_user_type_conversion (tree totype, tree expr, int flags) 3630 { 3631 struct z_candidate *cand; 3632 tree ret; 3633 3634 bool subtime = timevar_cond_start (TV_OVERLOAD); 3635 cand = build_user_type_conversion_1 (totype, expr, flags); 3636 3637 if (cand) 3638 { 3639 if (cand->second_conv->kind == ck_ambig) 3640 ret = error_mark_node; 3641 else 3642 { 3643 expr = convert_like (cand->second_conv, expr, tf_warning_or_error); 3644 ret = convert_from_reference (expr); 3645 } 3646 } 3647 else 3648 ret = NULL_TREE; 3649 3650 timevar_cond_stop (TV_OVERLOAD, subtime); 3651 return ret; 3652 } 3653 3654 /* Subroutine of convert_nontype_argument. 3655 3656 EXPR is an argument for a template non-type parameter of integral or 3657 enumeration type. Do any necessary conversions (that are permitted for 3658 non-type arguments) to convert it to the parameter type. 3659 3660 If conversion is successful, returns the converted expression; 3661 otherwise, returns error_mark_node. */ 3662 3663 tree 3664 build_integral_nontype_arg_conv (tree type, tree expr, tsubst_flags_t complain) 3665 { 3666 conversion *conv; 3667 void *p; 3668 tree t; 3669 3670 if (error_operand_p (expr)) 3671 return error_mark_node; 3672 3673 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type)); 3674 3675 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 3676 p = conversion_obstack_alloc (0); 3677 3678 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 3679 /*c_cast_p=*/false, 3680 LOOKUP_IMPLICIT); 3681 3682 /* for a non-type template-parameter of integral or 3683 enumeration type, integral promotions (4.5) and integral 3684 conversions (4.7) are applied. */ 3685 /* It should be sufficient to check the outermost conversion step, since 3686 there are no qualification conversions to integer type. */ 3687 if (conv) 3688 switch (conv->kind) 3689 { 3690 /* A conversion function is OK. If it isn't constexpr, we'll 3691 complain later that the argument isn't constant. */ 3692 case ck_user: 3693 /* The lvalue-to-rvalue conversion is OK. */ 3694 case ck_rvalue: 3695 case ck_identity: 3696 break; 3697 3698 case ck_std: 3699 t = conv->u.next->type; 3700 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t)) 3701 break; 3702 3703 if (complain & tf_error) 3704 error ("conversion from %qT to %qT not considered for " 3705 "non-type template argument", t, type); 3706 /* and fall through. */ 3707 3708 default: 3709 conv = NULL; 3710 break; 3711 } 3712 3713 if (conv) 3714 expr = convert_like (conv, expr, complain); 3715 else 3716 expr = error_mark_node; 3717 3718 /* Free all the conversions we allocated. */ 3719 obstack_free (&conversion_obstack, p); 3720 3721 return expr; 3722 } 3723 3724 /* Do any initial processing on the arguments to a function call. */ 3725 3726 static VEC(tree,gc) * 3727 resolve_args (VEC(tree,gc) *args, tsubst_flags_t complain) 3728 { 3729 unsigned int ix; 3730 tree arg; 3731 3732 FOR_EACH_VEC_ELT (tree, args, ix, arg) 3733 { 3734 if (error_operand_p (arg)) 3735 return NULL; 3736 else if (VOID_TYPE_P (TREE_TYPE (arg))) 3737 { 3738 if (complain & tf_error) 3739 error ("invalid use of void expression"); 3740 return NULL; 3741 } 3742 else if (invalid_nonstatic_memfn_p (arg, tf_warning_or_error)) 3743 return NULL; 3744 } 3745 return args; 3746 } 3747 3748 /* Perform overload resolution on FN, which is called with the ARGS. 3749 3750 Return the candidate function selected by overload resolution, or 3751 NULL if the event that overload resolution failed. In the case 3752 that overload resolution fails, *CANDIDATES will be the set of 3753 candidates considered, and ANY_VIABLE_P will be set to true or 3754 false to indicate whether or not any of the candidates were 3755 viable. 3756 3757 The ARGS should already have gone through RESOLVE_ARGS before this 3758 function is called. */ 3759 3760 static struct z_candidate * 3761 perform_overload_resolution (tree fn, 3762 const VEC(tree,gc) *args, 3763 struct z_candidate **candidates, 3764 bool *any_viable_p) 3765 { 3766 struct z_candidate *cand; 3767 tree explicit_targs; 3768 int template_only; 3769 3770 bool subtime = timevar_cond_start (TV_OVERLOAD); 3771 3772 explicit_targs = NULL_TREE; 3773 template_only = 0; 3774 3775 *candidates = NULL; 3776 *any_viable_p = true; 3777 3778 /* Check FN. */ 3779 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 3780 || TREE_CODE (fn) == TEMPLATE_DECL 3781 || TREE_CODE (fn) == OVERLOAD 3782 || TREE_CODE (fn) == TEMPLATE_ID_EXPR); 3783 3784 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 3785 { 3786 explicit_targs = TREE_OPERAND (fn, 1); 3787 fn = TREE_OPERAND (fn, 0); 3788 template_only = 1; 3789 } 3790 3791 /* Add the various candidate functions. */ 3792 add_candidates (fn, NULL_TREE, args, NULL_TREE, 3793 explicit_targs, template_only, 3794 /*conversion_path=*/NULL_TREE, 3795 /*access_path=*/NULL_TREE, 3796 LOOKUP_NORMAL, 3797 candidates); 3798 3799 *candidates = splice_viable (*candidates, pedantic, any_viable_p); 3800 if (*any_viable_p) 3801 cand = tourney (*candidates); 3802 else 3803 cand = NULL; 3804 3805 timevar_cond_stop (TV_OVERLOAD, subtime); 3806 return cand; 3807 } 3808 3809 /* Print an error message about being unable to build a call to FN with 3810 ARGS. ANY_VIABLE_P indicates whether any candidate functions could 3811 be located; CANDIDATES is a possibly empty list of such 3812 functions. */ 3813 3814 static void 3815 print_error_for_call_failure (tree fn, VEC(tree,gc) *args, bool any_viable_p, 3816 struct z_candidate *candidates) 3817 { 3818 tree name = DECL_NAME (OVL_CURRENT (fn)); 3819 location_t loc = location_of (name); 3820 3821 if (!any_viable_p) 3822 error_at (loc, "no matching function for call to %<%D(%A)%>", 3823 name, build_tree_list_vec (args)); 3824 else 3825 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous", 3826 name, build_tree_list_vec (args)); 3827 if (candidates) 3828 print_z_candidates (loc, candidates); 3829 } 3830 3831 /* Return an expression for a call to FN (a namespace-scope function, 3832 or a static member function) with the ARGS. This may change 3833 ARGS. */ 3834 3835 tree 3836 build_new_function_call (tree fn, VEC(tree,gc) **args, bool koenig_p, 3837 tsubst_flags_t complain) 3838 { 3839 struct z_candidate *candidates, *cand; 3840 bool any_viable_p; 3841 void *p; 3842 tree result; 3843 3844 if (args != NULL && *args != NULL) 3845 { 3846 *args = resolve_args (*args, complain); 3847 if (*args == NULL) 3848 return error_mark_node; 3849 } 3850 3851 if (flag_tm) 3852 tm_malloc_replacement (fn); 3853 3854 /* If this function was found without using argument dependent 3855 lookup, then we want to ignore any undeclared friend 3856 functions. */ 3857 if (!koenig_p) 3858 { 3859 tree orig_fn = fn; 3860 3861 fn = remove_hidden_names (fn); 3862 if (!fn) 3863 { 3864 if (complain & tf_error) 3865 print_error_for_call_failure (orig_fn, *args, false, NULL); 3866 return error_mark_node; 3867 } 3868 } 3869 3870 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 3871 p = conversion_obstack_alloc (0); 3872 3873 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p); 3874 3875 if (!cand) 3876 { 3877 if (complain & tf_error) 3878 { 3879 if (!any_viable_p && candidates && ! candidates->next 3880 && (TREE_CODE (candidates->fn) == FUNCTION_DECL)) 3881 return cp_build_function_call_vec (candidates->fn, args, complain); 3882 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 3883 fn = TREE_OPERAND (fn, 0); 3884 print_error_for_call_failure (fn, *args, any_viable_p, candidates); 3885 } 3886 result = error_mark_node; 3887 } 3888 else 3889 { 3890 int flags = LOOKUP_NORMAL; 3891 /* If fn is template_id_expr, the call has explicit template arguments 3892 (e.g. func<int>(5)), communicate this info to build_over_call 3893 through flags so that later we can use it to decide whether to warn 3894 about peculiar null pointer conversion. */ 3895 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 3896 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 3897 result = build_over_call (cand, flags, complain); 3898 } 3899 3900 /* Free all the conversions we allocated. */ 3901 obstack_free (&conversion_obstack, p); 3902 3903 return result; 3904 } 3905 3906 /* Build a call to a global operator new. FNNAME is the name of the 3907 operator (either "operator new" or "operator new[]") and ARGS are 3908 the arguments provided. This may change ARGS. *SIZE points to the 3909 total number of bytes required by the allocation, and is updated if 3910 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should 3911 be used. If this function determines that no cookie should be 3912 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is 3913 non-NULL, it will be set, upon return, to the allocation function 3914 called. */ 3915 3916 tree 3917 build_operator_new_call (tree fnname, VEC(tree,gc) **args, 3918 tree *size, tree *cookie_size, 3919 tree *fn) 3920 { 3921 tree fns; 3922 struct z_candidate *candidates; 3923 struct z_candidate *cand; 3924 bool any_viable_p; 3925 3926 if (fn) 3927 *fn = NULL_TREE; 3928 VEC_safe_insert (tree, gc, *args, 0, *size); 3929 *args = resolve_args (*args, tf_warning_or_error); 3930 if (*args == NULL) 3931 return error_mark_node; 3932 3933 /* Based on: 3934 3935 [expr.new] 3936 3937 If this lookup fails to find the name, or if the allocated type 3938 is not a class type, the allocation function's name is looked 3939 up in the global scope. 3940 3941 we disregard block-scope declarations of "operator new". */ 3942 fns = lookup_function_nonclass (fnname, *args, /*block_p=*/false); 3943 3944 /* Figure out what function is being called. */ 3945 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p); 3946 3947 /* If no suitable function could be found, issue an error message 3948 and give up. */ 3949 if (!cand) 3950 { 3951 print_error_for_call_failure (fns, *args, any_viable_p, candidates); 3952 return error_mark_node; 3953 } 3954 3955 /* If a cookie is required, add some extra space. Whether 3956 or not a cookie is required cannot be determined until 3957 after we know which function was called. */ 3958 if (*cookie_size) 3959 { 3960 bool use_cookie = true; 3961 if (!abi_version_at_least (2)) 3962 { 3963 /* In G++ 3.2, the check was implemented incorrectly; it 3964 looked at the placement expression, rather than the 3965 type of the function. */ 3966 if (VEC_length (tree, *args) == 2 3967 && same_type_p (TREE_TYPE (VEC_index (tree, *args, 1)), 3968 ptr_type_node)) 3969 use_cookie = false; 3970 } 3971 else 3972 { 3973 tree arg_types; 3974 3975 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 3976 /* Skip the size_t parameter. */ 3977 arg_types = TREE_CHAIN (arg_types); 3978 /* Check the remaining parameters (if any). */ 3979 if (arg_types 3980 && TREE_CHAIN (arg_types) == void_list_node 3981 && same_type_p (TREE_VALUE (arg_types), 3982 ptr_type_node)) 3983 use_cookie = false; 3984 } 3985 /* If we need a cookie, adjust the number of bytes allocated. */ 3986 if (use_cookie) 3987 { 3988 /* Update the total size. */ 3989 *size = size_binop (PLUS_EXPR, *size, *cookie_size); 3990 /* Update the argument list to reflect the adjusted size. */ 3991 VEC_replace (tree, *args, 0, *size); 3992 } 3993 else 3994 *cookie_size = NULL_TREE; 3995 } 3996 3997 /* Tell our caller which function we decided to call. */ 3998 if (fn) 3999 *fn = cand->fn; 4000 4001 /* Build the CALL_EXPR. */ 4002 return build_over_call (cand, LOOKUP_NORMAL, tf_warning_or_error); 4003 } 4004 4005 /* Build a new call to operator(). This may change ARGS. */ 4006 4007 static tree 4008 build_op_call_1 (tree obj, VEC(tree,gc) **args, tsubst_flags_t complain) 4009 { 4010 struct z_candidate *candidates = 0, *cand; 4011 tree fns, convs, first_mem_arg = NULL_TREE; 4012 tree type = TREE_TYPE (obj); 4013 bool any_viable_p; 4014 tree result = NULL_TREE; 4015 void *p; 4016 4017 if (error_operand_p (obj)) 4018 return error_mark_node; 4019 4020 obj = prep_operand (obj); 4021 4022 if (TYPE_PTRMEMFUNC_P (type)) 4023 { 4024 if (complain & tf_error) 4025 /* It's no good looking for an overloaded operator() on a 4026 pointer-to-member-function. */ 4027 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj); 4028 return error_mark_node; 4029 } 4030 4031 if (TYPE_BINFO (type)) 4032 { 4033 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1); 4034 if (fns == error_mark_node) 4035 return error_mark_node; 4036 } 4037 else 4038 fns = NULL_TREE; 4039 4040 if (args != NULL && *args != NULL) 4041 { 4042 *args = resolve_args (*args, complain); 4043 if (*args == NULL) 4044 return error_mark_node; 4045 } 4046 4047 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4048 p = conversion_obstack_alloc (0); 4049 4050 if (fns) 4051 { 4052 first_mem_arg = build_this (obj); 4053 4054 add_candidates (BASELINK_FUNCTIONS (fns), 4055 first_mem_arg, *args, NULL_TREE, 4056 NULL_TREE, false, 4057 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns), 4058 LOOKUP_NORMAL, &candidates); 4059 } 4060 4061 convs = lookup_conversions (type); 4062 4063 for (; convs; convs = TREE_CHAIN (convs)) 4064 { 4065 tree fns = TREE_VALUE (convs); 4066 tree totype = TREE_TYPE (convs); 4067 4068 if ((TREE_CODE (totype) == POINTER_TYPE 4069 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE) 4070 || (TREE_CODE (totype) == REFERENCE_TYPE 4071 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE) 4072 || (TREE_CODE (totype) == REFERENCE_TYPE 4073 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE 4074 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE)) 4075 for (; fns; fns = OVL_NEXT (fns)) 4076 { 4077 tree fn = OVL_CURRENT (fns); 4078 4079 if (DECL_NONCONVERTING_P (fn)) 4080 continue; 4081 4082 if (TREE_CODE (fn) == TEMPLATE_DECL) 4083 add_template_conv_candidate 4084 (&candidates, fn, obj, NULL_TREE, *args, totype, 4085 /*access_path=*/NULL_TREE, 4086 /*conversion_path=*/NULL_TREE); 4087 else 4088 add_conv_candidate (&candidates, fn, obj, NULL_TREE, 4089 *args, /*conversion_path=*/NULL_TREE, 4090 /*access_path=*/NULL_TREE); 4091 } 4092 } 4093 4094 candidates = splice_viable (candidates, pedantic, &any_viable_p); 4095 if (!any_viable_p) 4096 { 4097 if (complain & tf_error) 4098 { 4099 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), 4100 build_tree_list_vec (*args)); 4101 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4102 } 4103 result = error_mark_node; 4104 } 4105 else 4106 { 4107 cand = tourney (candidates); 4108 if (cand == 0) 4109 { 4110 if (complain & tf_error) 4111 { 4112 error ("call of %<(%T) (%A)%> is ambiguous", 4113 TREE_TYPE (obj), build_tree_list_vec (*args)); 4114 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4115 } 4116 result = error_mark_node; 4117 } 4118 /* Since cand->fn will be a type, not a function, for a conversion 4119 function, we must be careful not to unconditionally look at 4120 DECL_NAME here. */ 4121 else if (TREE_CODE (cand->fn) == FUNCTION_DECL 4122 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR) 4123 result = build_over_call (cand, LOOKUP_NORMAL, complain); 4124 else 4125 { 4126 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1, 4127 complain); 4128 obj = convert_from_reference (obj); 4129 result = cp_build_function_call_vec (obj, args, complain); 4130 } 4131 } 4132 4133 /* Free all the conversions we allocated. */ 4134 obstack_free (&conversion_obstack, p); 4135 4136 return result; 4137 } 4138 4139 /* Wrapper for above. */ 4140 4141 tree 4142 build_op_call (tree obj, VEC(tree,gc) **args, tsubst_flags_t complain) 4143 { 4144 tree ret; 4145 bool subtime = timevar_cond_start (TV_OVERLOAD); 4146 ret = build_op_call_1 (obj, args, complain); 4147 timevar_cond_stop (TV_OVERLOAD, subtime); 4148 return ret; 4149 } 4150 4151 static void 4152 op_error (enum tree_code code, enum tree_code code2, 4153 tree arg1, tree arg2, tree arg3, bool match) 4154 { 4155 const char *opname; 4156 4157 if (code == MODIFY_EXPR) 4158 opname = assignment_operator_name_info[code2].name; 4159 else 4160 opname = operator_name_info[code].name; 4161 4162 switch (code) 4163 { 4164 case COND_EXPR: 4165 if (match) 4166 error ("ambiguous overload for ternary %<operator?:%> " 4167 "in %<%E ? %E : %E%>", arg1, arg2, arg3); 4168 else 4169 error ("no match for ternary %<operator?:%> " 4170 "in %<%E ? %E : %E%>", arg1, arg2, arg3); 4171 break; 4172 4173 case POSTINCREMENT_EXPR: 4174 case POSTDECREMENT_EXPR: 4175 if (match) 4176 error ("ambiguous overload for %<operator%s%> in %<%E%s%>", 4177 opname, arg1, opname); 4178 else 4179 error ("no match for %<operator%s%> in %<%E%s%>", 4180 opname, arg1, opname); 4181 break; 4182 4183 case ARRAY_REF: 4184 if (match) 4185 error ("ambiguous overload for %<operator[]%> in %<%E[%E]%>", 4186 arg1, arg2); 4187 else 4188 error ("no match for %<operator[]%> in %<%E[%E]%>", 4189 arg1, arg2); 4190 break; 4191 4192 case REALPART_EXPR: 4193 case IMAGPART_EXPR: 4194 if (match) 4195 error ("ambiguous overload for %qs in %<%s %E%>", 4196 opname, opname, arg1); 4197 else 4198 error ("no match for %qs in %<%s %E%>", 4199 opname, opname, arg1); 4200 break; 4201 4202 default: 4203 if (arg2) 4204 if (match) 4205 error ("ambiguous overload for %<operator%s%> in %<%E %s %E%>", 4206 opname, arg1, opname, arg2); 4207 else 4208 error ("no match for %<operator%s%> in %<%E %s %E%>", 4209 opname, arg1, opname, arg2); 4210 else 4211 if (match) 4212 error ("ambiguous overload for %<operator%s%> in %<%s%E%>", 4213 opname, opname, arg1); 4214 else 4215 error ("no match for %<operator%s%> in %<%s%E%>", 4216 opname, opname, arg1); 4217 break; 4218 } 4219 } 4220 4221 /* Return the implicit conversion sequence that could be used to 4222 convert E1 to E2 in [expr.cond]. */ 4223 4224 static conversion * 4225 conditional_conversion (tree e1, tree e2) 4226 { 4227 tree t1 = non_reference (TREE_TYPE (e1)); 4228 tree t2 = non_reference (TREE_TYPE (e2)); 4229 conversion *conv; 4230 bool good_base; 4231 4232 /* [expr.cond] 4233 4234 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be 4235 implicitly converted (clause _conv_) to the type "lvalue reference to 4236 T2", subject to the constraint that in the conversion the 4237 reference must bind directly (_dcl.init.ref_) to an lvalue. */ 4238 if (real_lvalue_p (e2)) 4239 { 4240 conv = implicit_conversion (build_reference_type (t2), 4241 t1, 4242 e1, 4243 /*c_cast_p=*/false, 4244 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND 4245 |LOOKUP_ONLYCONVERTING); 4246 if (conv) 4247 return conv; 4248 } 4249 4250 /* [expr.cond] 4251 4252 If E1 and E2 have class type, and the underlying class types are 4253 the same or one is a base class of the other: E1 can be converted 4254 to match E2 if the class of T2 is the same type as, or a base 4255 class of, the class of T1, and the cv-qualification of T2 is the 4256 same cv-qualification as, or a greater cv-qualification than, the 4257 cv-qualification of T1. If the conversion is applied, E1 is 4258 changed to an rvalue of type T2 that still refers to the original 4259 source class object (or the appropriate subobject thereof). */ 4260 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 4261 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2))) 4262 { 4263 if (good_base && at_least_as_qualified_p (t2, t1)) 4264 { 4265 conv = build_identity_conv (t1, e1); 4266 if (!same_type_p (TYPE_MAIN_VARIANT (t1), 4267 TYPE_MAIN_VARIANT (t2))) 4268 conv = build_conv (ck_base, t2, conv); 4269 else 4270 conv = build_conv (ck_rvalue, t2, conv); 4271 return conv; 4272 } 4273 else 4274 return NULL; 4275 } 4276 else 4277 /* [expr.cond] 4278 4279 Otherwise: E1 can be converted to match E2 if E1 can be implicitly 4280 converted to the type that expression E2 would have if E2 were 4281 converted to an rvalue (or the type it has, if E2 is an rvalue). */ 4282 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false, 4283 LOOKUP_IMPLICIT); 4284 } 4285 4286 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three 4287 arguments to the conditional expression. */ 4288 4289 static tree 4290 build_conditional_expr_1 (tree arg1, tree arg2, tree arg3, 4291 tsubst_flags_t complain) 4292 { 4293 tree arg2_type; 4294 tree arg3_type; 4295 tree result = NULL_TREE; 4296 tree result_type = NULL_TREE; 4297 bool lvalue_p = true; 4298 struct z_candidate *candidates = 0; 4299 struct z_candidate *cand; 4300 void *p; 4301 4302 /* As a G++ extension, the second argument to the conditional can be 4303 omitted. (So that `a ? : c' is roughly equivalent to `a ? a : 4304 c'.) If the second operand is omitted, make sure it is 4305 calculated only once. */ 4306 if (!arg2) 4307 { 4308 if (complain & tf_error) 4309 pedwarn (input_location, OPT_pedantic, 4310 "ISO C++ forbids omitting the middle term of a ?: expression"); 4311 4312 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */ 4313 if (real_lvalue_p (arg1)) 4314 arg2 = arg1 = stabilize_reference (arg1); 4315 else 4316 arg2 = arg1 = save_expr (arg1); 4317 } 4318 4319 /* [expr.cond] 4320 4321 The first expression is implicitly converted to bool (clause 4322 _conv_). */ 4323 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain, 4324 LOOKUP_NORMAL); 4325 4326 /* If something has already gone wrong, just pass that fact up the 4327 tree. */ 4328 if (error_operand_p (arg1) 4329 || error_operand_p (arg2) 4330 || error_operand_p (arg3)) 4331 return error_mark_node; 4332 4333 /* [expr.cond] 4334 4335 If either the second or the third operand has type (possibly 4336 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_), 4337 array-to-pointer (_conv.array_), and function-to-pointer 4338 (_conv.func_) standard conversions are performed on the second 4339 and third operands. */ 4340 arg2_type = unlowered_expr_type (arg2); 4341 arg3_type = unlowered_expr_type (arg3); 4342 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type)) 4343 { 4344 /* Do the conversions. We don't these for `void' type arguments 4345 since it can't have any effect and since decay_conversion 4346 does not handle that case gracefully. */ 4347 if (!VOID_TYPE_P (arg2_type)) 4348 arg2 = decay_conversion (arg2); 4349 if (!VOID_TYPE_P (arg3_type)) 4350 arg3 = decay_conversion (arg3); 4351 arg2_type = TREE_TYPE (arg2); 4352 arg3_type = TREE_TYPE (arg3); 4353 4354 /* [expr.cond] 4355 4356 One of the following shall hold: 4357 4358 --The second or the third operand (but not both) is a 4359 throw-expression (_except.throw_); the result is of the 4360 type of the other and is an rvalue. 4361 4362 --Both the second and the third operands have type void; the 4363 result is of type void and is an rvalue. 4364 4365 We must avoid calling force_rvalue for expressions of type 4366 "void" because it will complain that their value is being 4367 used. */ 4368 if (TREE_CODE (arg2) == THROW_EXPR 4369 && TREE_CODE (arg3) != THROW_EXPR) 4370 { 4371 if (!VOID_TYPE_P (arg3_type)) 4372 { 4373 arg3 = force_rvalue (arg3, complain); 4374 if (arg3 == error_mark_node) 4375 return error_mark_node; 4376 } 4377 arg3_type = TREE_TYPE (arg3); 4378 result_type = arg3_type; 4379 } 4380 else if (TREE_CODE (arg2) != THROW_EXPR 4381 && TREE_CODE (arg3) == THROW_EXPR) 4382 { 4383 if (!VOID_TYPE_P (arg2_type)) 4384 { 4385 arg2 = force_rvalue (arg2, complain); 4386 if (arg2 == error_mark_node) 4387 return error_mark_node; 4388 } 4389 arg2_type = TREE_TYPE (arg2); 4390 result_type = arg2_type; 4391 } 4392 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type)) 4393 result_type = void_type_node; 4394 else 4395 { 4396 if (complain & tf_error) 4397 { 4398 if (VOID_TYPE_P (arg2_type)) 4399 error ("second operand to the conditional operator " 4400 "is of type %<void%>, " 4401 "but the third operand is neither a throw-expression " 4402 "nor of type %<void%>"); 4403 else 4404 error ("third operand to the conditional operator " 4405 "is of type %<void%>, " 4406 "but the second operand is neither a throw-expression " 4407 "nor of type %<void%>"); 4408 } 4409 return error_mark_node; 4410 } 4411 4412 lvalue_p = false; 4413 goto valid_operands; 4414 } 4415 /* [expr.cond] 4416 4417 Otherwise, if the second and third operand have different types, 4418 and either has (possibly cv-qualified) class type, an attempt is 4419 made to convert each of those operands to the type of the other. */ 4420 else if (!same_type_p (arg2_type, arg3_type) 4421 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type))) 4422 { 4423 conversion *conv2; 4424 conversion *conv3; 4425 4426 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4427 p = conversion_obstack_alloc (0); 4428 4429 conv2 = conditional_conversion (arg2, arg3); 4430 conv3 = conditional_conversion (arg3, arg2); 4431 4432 /* [expr.cond] 4433 4434 If both can be converted, or one can be converted but the 4435 conversion is ambiguous, the program is ill-formed. If 4436 neither can be converted, the operands are left unchanged and 4437 further checking is performed as described below. If exactly 4438 one conversion is possible, that conversion is applied to the 4439 chosen operand and the converted operand is used in place of 4440 the original operand for the remainder of this section. */ 4441 if ((conv2 && !conv2->bad_p 4442 && conv3 && !conv3->bad_p) 4443 || (conv2 && conv2->kind == ck_ambig) 4444 || (conv3 && conv3->kind == ck_ambig)) 4445 { 4446 error ("operands to ?: have different types %qT and %qT", 4447 arg2_type, arg3_type); 4448 result = error_mark_node; 4449 } 4450 else if (conv2 && (!conv2->bad_p || !conv3)) 4451 { 4452 arg2 = convert_like (conv2, arg2, complain); 4453 arg2 = convert_from_reference (arg2); 4454 arg2_type = TREE_TYPE (arg2); 4455 /* Even if CONV2 is a valid conversion, the result of the 4456 conversion may be invalid. For example, if ARG3 has type 4457 "volatile X", and X does not have a copy constructor 4458 accepting a "volatile X&", then even if ARG2 can be 4459 converted to X, the conversion will fail. */ 4460 if (error_operand_p (arg2)) 4461 result = error_mark_node; 4462 } 4463 else if (conv3 && (!conv3->bad_p || !conv2)) 4464 { 4465 arg3 = convert_like (conv3, arg3, complain); 4466 arg3 = convert_from_reference (arg3); 4467 arg3_type = TREE_TYPE (arg3); 4468 if (error_operand_p (arg3)) 4469 result = error_mark_node; 4470 } 4471 4472 /* Free all the conversions we allocated. */ 4473 obstack_free (&conversion_obstack, p); 4474 4475 if (result) 4476 return result; 4477 4478 /* If, after the conversion, both operands have class type, 4479 treat the cv-qualification of both operands as if it were the 4480 union of the cv-qualification of the operands. 4481 4482 The standard is not clear about what to do in this 4483 circumstance. For example, if the first operand has type 4484 "const X" and the second operand has a user-defined 4485 conversion to "volatile X", what is the type of the second 4486 operand after this step? Making it be "const X" (matching 4487 the first operand) seems wrong, as that discards the 4488 qualification without actually performing a copy. Leaving it 4489 as "volatile X" seems wrong as that will result in the 4490 conditional expression failing altogether, even though, 4491 according to this step, the one operand could be converted to 4492 the type of the other. */ 4493 if ((conv2 || conv3) 4494 && CLASS_TYPE_P (arg2_type) 4495 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type)) 4496 arg2_type = arg3_type = 4497 cp_build_qualified_type (arg2_type, 4498 cp_type_quals (arg2_type) 4499 | cp_type_quals (arg3_type)); 4500 } 4501 4502 /* [expr.cond] 4503 4504 If the second and third operands are lvalues and have the same 4505 type, the result is of that type and is an lvalue. */ 4506 if (real_lvalue_p (arg2) 4507 && real_lvalue_p (arg3) 4508 && same_type_p (arg2_type, arg3_type)) 4509 { 4510 result_type = arg2_type; 4511 arg2 = mark_lvalue_use (arg2); 4512 arg3 = mark_lvalue_use (arg3); 4513 goto valid_operands; 4514 } 4515 4516 /* [expr.cond] 4517 4518 Otherwise, the result is an rvalue. If the second and third 4519 operand do not have the same type, and either has (possibly 4520 cv-qualified) class type, overload resolution is used to 4521 determine the conversions (if any) to be applied to the operands 4522 (_over.match.oper_, _over.built_). */ 4523 lvalue_p = false; 4524 if (!same_type_p (arg2_type, arg3_type) 4525 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type))) 4526 { 4527 tree args[3]; 4528 conversion *conv; 4529 bool any_viable_p; 4530 4531 /* Rearrange the arguments so that add_builtin_candidate only has 4532 to know about two args. In build_builtin_candidate, the 4533 arguments are unscrambled. */ 4534 args[0] = arg2; 4535 args[1] = arg3; 4536 args[2] = arg1; 4537 add_builtin_candidates (&candidates, 4538 COND_EXPR, 4539 NOP_EXPR, 4540 ansi_opname (COND_EXPR), 4541 args, 4542 LOOKUP_NORMAL); 4543 4544 /* [expr.cond] 4545 4546 If the overload resolution fails, the program is 4547 ill-formed. */ 4548 candidates = splice_viable (candidates, pedantic, &any_viable_p); 4549 if (!any_viable_p) 4550 { 4551 if (complain & tf_error) 4552 { 4553 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE); 4554 print_z_candidates (location_of (arg1), candidates); 4555 } 4556 return error_mark_node; 4557 } 4558 cand = tourney (candidates); 4559 if (!cand) 4560 { 4561 if (complain & tf_error) 4562 { 4563 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE); 4564 print_z_candidates (location_of (arg1), candidates); 4565 } 4566 return error_mark_node; 4567 } 4568 4569 /* [expr.cond] 4570 4571 Otherwise, the conversions thus determined are applied, and 4572 the converted operands are used in place of the original 4573 operands for the remainder of this section. */ 4574 conv = cand->convs[0]; 4575 arg1 = convert_like (conv, arg1, complain); 4576 conv = cand->convs[1]; 4577 arg2 = convert_like (conv, arg2, complain); 4578 arg2_type = TREE_TYPE (arg2); 4579 conv = cand->convs[2]; 4580 arg3 = convert_like (conv, arg3, complain); 4581 arg3_type = TREE_TYPE (arg3); 4582 } 4583 4584 /* [expr.cond] 4585 4586 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_), 4587 and function-to-pointer (_conv.func_) standard conversions are 4588 performed on the second and third operands. 4589 4590 We need to force the lvalue-to-rvalue conversion here for class types, 4591 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues 4592 that isn't wrapped with a TARGET_EXPR plays havoc with exception 4593 regions. */ 4594 4595 arg2 = force_rvalue (arg2, complain); 4596 if (!CLASS_TYPE_P (arg2_type)) 4597 arg2_type = TREE_TYPE (arg2); 4598 4599 arg3 = force_rvalue (arg3, complain); 4600 if (!CLASS_TYPE_P (arg3_type)) 4601 arg3_type = TREE_TYPE (arg3); 4602 4603 if (arg2 == error_mark_node || arg3 == error_mark_node) 4604 return error_mark_node; 4605 4606 /* [expr.cond] 4607 4608 After those conversions, one of the following shall hold: 4609 4610 --The second and third operands have the same type; the result is of 4611 that type. */ 4612 if (same_type_p (arg2_type, arg3_type)) 4613 result_type = arg2_type; 4614 /* [expr.cond] 4615 4616 --The second and third operands have arithmetic or enumeration 4617 type; the usual arithmetic conversions are performed to bring 4618 them to a common type, and the result is of that type. */ 4619 else if ((ARITHMETIC_TYPE_P (arg2_type) 4620 || UNSCOPED_ENUM_P (arg2_type)) 4621 && (ARITHMETIC_TYPE_P (arg3_type) 4622 || UNSCOPED_ENUM_P (arg3_type))) 4623 { 4624 /* In this case, there is always a common type. */ 4625 result_type = type_after_usual_arithmetic_conversions (arg2_type, 4626 arg3_type); 4627 do_warn_double_promotion (result_type, arg2_type, arg3_type, 4628 "implicit conversion from %qT to %qT to " 4629 "match other result of conditional", 4630 input_location); 4631 4632 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE 4633 && TREE_CODE (arg3_type) == ENUMERAL_TYPE) 4634 { 4635 if (complain & tf_warning) 4636 warning (OPT_Wenum_compare, 4637 "enumeral mismatch in conditional expression: %qT vs %qT", 4638 arg2_type, arg3_type); 4639 } 4640 else if (extra_warnings 4641 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE 4642 && !same_type_p (arg3_type, type_promotes_to (arg2_type))) 4643 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE 4644 && !same_type_p (arg2_type, type_promotes_to (arg3_type))))) 4645 { 4646 if (complain & tf_warning) 4647 warning (0, 4648 "enumeral and non-enumeral type in conditional expression"); 4649 } 4650 4651 arg2 = perform_implicit_conversion (result_type, arg2, complain); 4652 arg3 = perform_implicit_conversion (result_type, arg3, complain); 4653 } 4654 /* [expr.cond] 4655 4656 --The second and third operands have pointer type, or one has 4657 pointer type and the other is a null pointer constant; pointer 4658 conversions (_conv.ptr_) and qualification conversions 4659 (_conv.qual_) are performed to bring them to their composite 4660 pointer type (_expr.rel_). The result is of the composite 4661 pointer type. 4662 4663 --The second and third operands have pointer to member type, or 4664 one has pointer to member type and the other is a null pointer 4665 constant; pointer to member conversions (_conv.mem_) and 4666 qualification conversions (_conv.qual_) are performed to bring 4667 them to a common type, whose cv-qualification shall match the 4668 cv-qualification of either the second or the third operand. 4669 The result is of the common type. */ 4670 else if ((null_ptr_cst_p (arg2) 4671 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type))) 4672 || (null_ptr_cst_p (arg3) 4673 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type))) 4674 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type)) 4675 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type)) 4676 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type))) 4677 { 4678 result_type = composite_pointer_type (arg2_type, arg3_type, arg2, 4679 arg3, CPO_CONDITIONAL_EXPR, 4680 complain); 4681 if (result_type == error_mark_node) 4682 return error_mark_node; 4683 arg2 = perform_implicit_conversion (result_type, arg2, complain); 4684 arg3 = perform_implicit_conversion (result_type, arg3, complain); 4685 } 4686 4687 if (!result_type) 4688 { 4689 if (complain & tf_error) 4690 error ("operands to ?: have different types %qT and %qT", 4691 arg2_type, arg3_type); 4692 return error_mark_node; 4693 } 4694 4695 valid_operands: 4696 result = build3 (COND_EXPR, result_type, arg1, arg2, arg3); 4697 if (!cp_unevaluated_operand) 4698 /* Avoid folding within decltype (c++/42013) and noexcept. */ 4699 result = fold_if_not_in_template (result); 4700 4701 /* We can't use result_type below, as fold might have returned a 4702 throw_expr. */ 4703 4704 if (!lvalue_p) 4705 { 4706 /* Expand both sides into the same slot, hopefully the target of 4707 the ?: expression. We used to check for TARGET_EXPRs here, 4708 but now we sometimes wrap them in NOP_EXPRs so the test would 4709 fail. */ 4710 if (CLASS_TYPE_P (TREE_TYPE (result))) 4711 result = get_target_expr (result); 4712 /* If this expression is an rvalue, but might be mistaken for an 4713 lvalue, we must add a NON_LVALUE_EXPR. */ 4714 result = rvalue (result); 4715 } 4716 4717 return result; 4718 } 4719 4720 /* Wrapper for above. */ 4721 4722 tree 4723 build_conditional_expr (tree arg1, tree arg2, tree arg3, 4724 tsubst_flags_t complain) 4725 { 4726 tree ret; 4727 bool subtime = timevar_cond_start (TV_OVERLOAD); 4728 ret = build_conditional_expr_1 (arg1, arg2, arg3, complain); 4729 timevar_cond_stop (TV_OVERLOAD, subtime); 4730 return ret; 4731 } 4732 4733 /* OPERAND is an operand to an expression. Perform necessary steps 4734 required before using it. If OPERAND is NULL_TREE, NULL_TREE is 4735 returned. */ 4736 4737 static tree 4738 prep_operand (tree operand) 4739 { 4740 if (operand) 4741 { 4742 if (CLASS_TYPE_P (TREE_TYPE (operand)) 4743 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand))) 4744 /* Make sure the template type is instantiated now. */ 4745 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand))); 4746 } 4747 4748 return operand; 4749 } 4750 4751 /* Add each of the viable functions in FNS (a FUNCTION_DECL or 4752 OVERLOAD) to the CANDIDATES, returning an updated list of 4753 CANDIDATES. The ARGS are the arguments provided to the call; 4754 if FIRST_ARG is non-null it is the implicit object argument, 4755 otherwise the first element of ARGS is used if needed. The 4756 EXPLICIT_TARGS are explicit template arguments provided. 4757 TEMPLATE_ONLY is true if only template functions should be 4758 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for 4759 add_function_candidate. */ 4760 4761 static void 4762 add_candidates (tree fns, tree first_arg, const VEC(tree,gc) *args, 4763 tree return_type, 4764 tree explicit_targs, bool template_only, 4765 tree conversion_path, tree access_path, 4766 int flags, 4767 struct z_candidate **candidates) 4768 { 4769 tree ctype; 4770 const VEC(tree,gc) *non_static_args; 4771 bool check_list_ctor; 4772 bool check_converting; 4773 unification_kind_t strict; 4774 tree fn; 4775 4776 if (!fns) 4777 return; 4778 4779 /* Precalculate special handling of constructors and conversion ops. */ 4780 fn = OVL_CURRENT (fns); 4781 if (DECL_CONV_FN_P (fn)) 4782 { 4783 check_list_ctor = false; 4784 check_converting = !!(flags & LOOKUP_ONLYCONVERTING); 4785 if (flags & LOOKUP_NO_CONVERSION) 4786 /* We're doing return_type(x). */ 4787 strict = DEDUCE_CONV; 4788 else 4789 /* We're doing x.operator return_type(). */ 4790 strict = DEDUCE_EXACT; 4791 /* [over.match.funcs] For conversion functions, the function 4792 is considered to be a member of the class of the implicit 4793 object argument for the purpose of defining the type of 4794 the implicit object parameter. */ 4795 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (first_arg))); 4796 } 4797 else 4798 { 4799 if (DECL_CONSTRUCTOR_P (fn)) 4800 { 4801 check_list_ctor = !!(flags & LOOKUP_LIST_ONLY); 4802 /* For list-initialization we consider explicit constructors 4803 and complain if one is chosen. */ 4804 check_converting 4805 = ((flags & (LOOKUP_ONLYCONVERTING|LOOKUP_LIST_INIT_CTOR)) 4806 == LOOKUP_ONLYCONVERTING); 4807 } 4808 else 4809 { 4810 check_list_ctor = false; 4811 check_converting = false; 4812 } 4813 strict = DEDUCE_CALL; 4814 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE; 4815 } 4816 4817 if (first_arg) 4818 non_static_args = args; 4819 else 4820 /* Delay creating the implicit this parameter until it is needed. */ 4821 non_static_args = NULL; 4822 4823 for (; fns; fns = OVL_NEXT (fns)) 4824 { 4825 tree fn_first_arg; 4826 const VEC(tree,gc) *fn_args; 4827 4828 fn = OVL_CURRENT (fns); 4829 4830 if (check_converting && DECL_NONCONVERTING_P (fn)) 4831 continue; 4832 if (check_list_ctor && !is_list_ctor (fn)) 4833 continue; 4834 4835 /* Figure out which set of arguments to use. */ 4836 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) 4837 { 4838 /* If this function is a non-static member and we didn't get an 4839 implicit object argument, move it out of args. */ 4840 if (first_arg == NULL_TREE) 4841 { 4842 unsigned int ix; 4843 tree arg; 4844 VEC(tree,gc) *tempvec 4845 = VEC_alloc (tree, gc, VEC_length (tree, args) - 1); 4846 for (ix = 1; VEC_iterate (tree, args, ix, arg); ++ix) 4847 VEC_quick_push (tree, tempvec, arg); 4848 non_static_args = tempvec; 4849 first_arg = build_this (VEC_index (tree, args, 0)); 4850 } 4851 4852 fn_first_arg = first_arg; 4853 fn_args = non_static_args; 4854 } 4855 else 4856 { 4857 /* Otherwise, just use the list of arguments provided. */ 4858 fn_first_arg = NULL_TREE; 4859 fn_args = args; 4860 } 4861 4862 if (TREE_CODE (fn) == TEMPLATE_DECL) 4863 add_template_candidate (candidates, 4864 fn, 4865 ctype, 4866 explicit_targs, 4867 fn_first_arg, 4868 fn_args, 4869 return_type, 4870 access_path, 4871 conversion_path, 4872 flags, 4873 strict); 4874 else if (!template_only) 4875 add_function_candidate (candidates, 4876 fn, 4877 ctype, 4878 fn_first_arg, 4879 fn_args, 4880 access_path, 4881 conversion_path, 4882 flags); 4883 } 4884 } 4885 4886 static tree 4887 build_new_op_1 (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3, 4888 tree *overload, tsubst_flags_t complain) 4889 { 4890 struct z_candidate *candidates = 0, *cand; 4891 VEC(tree,gc) *arglist; 4892 tree fnname; 4893 tree args[3]; 4894 tree result = NULL_TREE; 4895 bool result_valid_p = false; 4896 enum tree_code code2 = NOP_EXPR; 4897 enum tree_code code_orig_arg1 = ERROR_MARK; 4898 enum tree_code code_orig_arg2 = ERROR_MARK; 4899 conversion *conv; 4900 void *p; 4901 bool strict_p; 4902 bool any_viable_p; 4903 4904 if (error_operand_p (arg1) 4905 || error_operand_p (arg2) 4906 || error_operand_p (arg3)) 4907 return error_mark_node; 4908 4909 if (code == MODIFY_EXPR) 4910 { 4911 code2 = TREE_CODE (arg3); 4912 arg3 = NULL_TREE; 4913 fnname = ansi_assopname (code2); 4914 } 4915 else 4916 fnname = ansi_opname (code); 4917 4918 arg1 = prep_operand (arg1); 4919 4920 switch (code) 4921 { 4922 case NEW_EXPR: 4923 case VEC_NEW_EXPR: 4924 case VEC_DELETE_EXPR: 4925 case DELETE_EXPR: 4926 /* Use build_op_new_call and build_op_delete_call instead. */ 4927 gcc_unreachable (); 4928 4929 case CALL_EXPR: 4930 /* Use build_op_call instead. */ 4931 gcc_unreachable (); 4932 4933 case TRUTH_ORIF_EXPR: 4934 case TRUTH_ANDIF_EXPR: 4935 case TRUTH_AND_EXPR: 4936 case TRUTH_OR_EXPR: 4937 /* These are saved for the sake of warn_logical_operator. */ 4938 code_orig_arg1 = TREE_CODE (arg1); 4939 code_orig_arg2 = TREE_CODE (arg2); 4940 4941 default: 4942 break; 4943 } 4944 4945 arg2 = prep_operand (arg2); 4946 arg3 = prep_operand (arg3); 4947 4948 if (code == COND_EXPR) 4949 /* Use build_conditional_expr instead. */ 4950 gcc_unreachable (); 4951 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1)) 4952 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2)))) 4953 goto builtin; 4954 4955 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR) 4956 arg2 = integer_zero_node; 4957 4958 arglist = VEC_alloc (tree, gc, 3); 4959 VEC_quick_push (tree, arglist, arg1); 4960 if (arg2 != NULL_TREE) 4961 VEC_quick_push (tree, arglist, arg2); 4962 if (arg3 != NULL_TREE) 4963 VEC_quick_push (tree, arglist, arg3); 4964 4965 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4966 p = conversion_obstack_alloc (0); 4967 4968 /* Add namespace-scope operators to the list of functions to 4969 consider. */ 4970 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true), 4971 NULL_TREE, arglist, NULL_TREE, 4972 NULL_TREE, false, NULL_TREE, NULL_TREE, 4973 flags, &candidates); 4974 /* Add class-member operators to the candidate set. */ 4975 if (CLASS_TYPE_P (TREE_TYPE (arg1))) 4976 { 4977 tree fns; 4978 4979 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1); 4980 if (fns == error_mark_node) 4981 { 4982 result = error_mark_node; 4983 goto user_defined_result_ready; 4984 } 4985 if (fns) 4986 add_candidates (BASELINK_FUNCTIONS (fns), 4987 NULL_TREE, arglist, NULL_TREE, 4988 NULL_TREE, false, 4989 BASELINK_BINFO (fns), 4990 BASELINK_ACCESS_BINFO (fns), 4991 flags, &candidates); 4992 } 4993 4994 args[0] = arg1; 4995 args[1] = arg2; 4996 args[2] = NULL_TREE; 4997 4998 add_builtin_candidates (&candidates, code, code2, fnname, args, flags); 4999 5000 switch (code) 5001 { 5002 case COMPOUND_EXPR: 5003 case ADDR_EXPR: 5004 /* For these, the built-in candidates set is empty 5005 [over.match.oper]/3. We don't want non-strict matches 5006 because exact matches are always possible with built-in 5007 operators. The built-in candidate set for COMPONENT_REF 5008 would be empty too, but since there are no such built-in 5009 operators, we accept non-strict matches for them. */ 5010 strict_p = true; 5011 break; 5012 5013 default: 5014 strict_p = pedantic; 5015 break; 5016 } 5017 5018 candidates = splice_viable (candidates, strict_p, &any_viable_p); 5019 if (!any_viable_p) 5020 { 5021 switch (code) 5022 { 5023 case POSTINCREMENT_EXPR: 5024 case POSTDECREMENT_EXPR: 5025 /* Don't try anything fancy if we're not allowed to produce 5026 errors. */ 5027 if (!(complain & tf_error)) 5028 return error_mark_node; 5029 5030 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't 5031 distinguish between prefix and postfix ++ and 5032 operator++() was used for both, so we allow this with 5033 -fpermissive. */ 5034 if (flags & LOOKUP_COMPLAIN) 5035 { 5036 const char *msg = (flag_permissive) 5037 ? G_("no %<%D(int)%> declared for postfix %qs," 5038 " trying prefix operator instead") 5039 : G_("no %<%D(int)%> declared for postfix %qs"); 5040 permerror (input_location, msg, fnname, 5041 operator_name_info[code].name); 5042 } 5043 5044 if (!flag_permissive) 5045 return error_mark_node; 5046 5047 if (code == POSTINCREMENT_EXPR) 5048 code = PREINCREMENT_EXPR; 5049 else 5050 code = PREDECREMENT_EXPR; 5051 result = build_new_op_1 (code, flags, arg1, NULL_TREE, NULL_TREE, 5052 overload, complain); 5053 break; 5054 5055 /* The caller will deal with these. */ 5056 case ADDR_EXPR: 5057 case COMPOUND_EXPR: 5058 case COMPONENT_REF: 5059 result = NULL_TREE; 5060 result_valid_p = true; 5061 break; 5062 5063 default: 5064 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error)) 5065 { 5066 /* If one of the arguments of the operator represents 5067 an invalid use of member function pointer, try to report 5068 a meaningful error ... */ 5069 if (invalid_nonstatic_memfn_p (arg1, tf_error) 5070 || invalid_nonstatic_memfn_p (arg2, tf_error) 5071 || invalid_nonstatic_memfn_p (arg3, tf_error)) 5072 /* We displayed the error message. */; 5073 else 5074 { 5075 /* ... Otherwise, report the more generic 5076 "no matching operator found" error */ 5077 op_error (code, code2, arg1, arg2, arg3, FALSE); 5078 print_z_candidates (input_location, candidates); 5079 } 5080 } 5081 result = error_mark_node; 5082 break; 5083 } 5084 } 5085 else 5086 { 5087 cand = tourney (candidates); 5088 if (cand == 0) 5089 { 5090 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error)) 5091 { 5092 op_error (code, code2, arg1, arg2, arg3, TRUE); 5093 print_z_candidates (input_location, candidates); 5094 } 5095 result = error_mark_node; 5096 } 5097 else if (TREE_CODE (cand->fn) == FUNCTION_DECL) 5098 { 5099 if (overload) 5100 *overload = cand->fn; 5101 5102 if (resolve_args (arglist, complain) == NULL) 5103 result = error_mark_node; 5104 else 5105 result = build_over_call (cand, LOOKUP_NORMAL, complain); 5106 } 5107 else 5108 { 5109 /* Give any warnings we noticed during overload resolution. */ 5110 if (cand->warnings && (complain & tf_warning)) 5111 { 5112 struct candidate_warning *w; 5113 for (w = cand->warnings; w; w = w->next) 5114 joust (cand, w->loser, 1); 5115 } 5116 5117 /* Check for comparison of different enum types. */ 5118 switch (code) 5119 { 5120 case GT_EXPR: 5121 case LT_EXPR: 5122 case GE_EXPR: 5123 case LE_EXPR: 5124 case EQ_EXPR: 5125 case NE_EXPR: 5126 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE 5127 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE 5128 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1)) 5129 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))) 5130 && (complain & tf_warning)) 5131 { 5132 warning (OPT_Wenum_compare, 5133 "comparison between %q#T and %q#T", 5134 TREE_TYPE (arg1), TREE_TYPE (arg2)); 5135 } 5136 break; 5137 default: 5138 break; 5139 } 5140 5141 /* We need to strip any leading REF_BIND so that bitfields 5142 don't cause errors. This should not remove any important 5143 conversions, because builtins don't apply to class 5144 objects directly. */ 5145 conv = cand->convs[0]; 5146 if (conv->kind == ck_ref_bind) 5147 conv = conv->u.next; 5148 arg1 = convert_like (conv, arg1, complain); 5149 5150 if (arg2) 5151 { 5152 /* We need to call warn_logical_operator before 5153 converting arg2 to a boolean_type. */ 5154 if (complain & tf_warning) 5155 warn_logical_operator (input_location, code, boolean_type_node, 5156 code_orig_arg1, arg1, 5157 code_orig_arg2, arg2); 5158 5159 conv = cand->convs[1]; 5160 if (conv->kind == ck_ref_bind) 5161 conv = conv->u.next; 5162 arg2 = convert_like (conv, arg2, complain); 5163 } 5164 if (arg3) 5165 { 5166 conv = cand->convs[2]; 5167 if (conv->kind == ck_ref_bind) 5168 conv = conv->u.next; 5169 arg3 = convert_like (conv, arg3, complain); 5170 } 5171 5172 } 5173 } 5174 5175 user_defined_result_ready: 5176 5177 /* Free all the conversions we allocated. */ 5178 obstack_free (&conversion_obstack, p); 5179 5180 if (result || result_valid_p) 5181 return result; 5182 5183 builtin: 5184 switch (code) 5185 { 5186 case MODIFY_EXPR: 5187 return cp_build_modify_expr (arg1, code2, arg2, complain); 5188 5189 case INDIRECT_REF: 5190 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain); 5191 5192 case TRUTH_ANDIF_EXPR: 5193 case TRUTH_ORIF_EXPR: 5194 case TRUTH_AND_EXPR: 5195 case TRUTH_OR_EXPR: 5196 warn_logical_operator (input_location, code, boolean_type_node, 5197 code_orig_arg1, arg1, code_orig_arg2, arg2); 5198 /* Fall through. */ 5199 case PLUS_EXPR: 5200 case MINUS_EXPR: 5201 case MULT_EXPR: 5202 case TRUNC_DIV_EXPR: 5203 case GT_EXPR: 5204 case LT_EXPR: 5205 case GE_EXPR: 5206 case LE_EXPR: 5207 case EQ_EXPR: 5208 case NE_EXPR: 5209 case MAX_EXPR: 5210 case MIN_EXPR: 5211 case LSHIFT_EXPR: 5212 case RSHIFT_EXPR: 5213 case TRUNC_MOD_EXPR: 5214 case BIT_AND_EXPR: 5215 case BIT_IOR_EXPR: 5216 case BIT_XOR_EXPR: 5217 return cp_build_binary_op (input_location, code, arg1, arg2, complain); 5218 5219 case UNARY_PLUS_EXPR: 5220 case NEGATE_EXPR: 5221 case BIT_NOT_EXPR: 5222 case TRUTH_NOT_EXPR: 5223 case PREINCREMENT_EXPR: 5224 case POSTINCREMENT_EXPR: 5225 case PREDECREMENT_EXPR: 5226 case POSTDECREMENT_EXPR: 5227 case REALPART_EXPR: 5228 case IMAGPART_EXPR: 5229 case ABS_EXPR: 5230 return cp_build_unary_op (code, arg1, candidates != 0, complain); 5231 5232 case ARRAY_REF: 5233 return cp_build_array_ref (input_location, arg1, arg2, complain); 5234 5235 case MEMBER_REF: 5236 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_NULL, 5237 complain), 5238 arg2); 5239 5240 /* The caller will deal with these. */ 5241 case ADDR_EXPR: 5242 case COMPONENT_REF: 5243 case COMPOUND_EXPR: 5244 return NULL_TREE; 5245 5246 default: 5247 gcc_unreachable (); 5248 } 5249 return NULL_TREE; 5250 } 5251 5252 /* Wrapper for above. */ 5253 5254 tree 5255 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3, 5256 tree *overload, tsubst_flags_t complain) 5257 { 5258 tree ret; 5259 bool subtime = timevar_cond_start (TV_OVERLOAD); 5260 ret = build_new_op_1 (code, flags, arg1, arg2, arg3, overload, complain); 5261 timevar_cond_stop (TV_OVERLOAD, subtime); 5262 return ret; 5263 } 5264 5265 /* Returns true iff T, an element of an OVERLOAD chain, is a usual 5266 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */ 5267 5268 static bool 5269 non_placement_deallocation_fn_p (tree t) 5270 { 5271 /* A template instance is never a usual deallocation function, 5272 regardless of its signature. */ 5273 if (TREE_CODE (t) == TEMPLATE_DECL 5274 || primary_template_instantiation_p (t)) 5275 return false; 5276 5277 /* If a class T has a member deallocation function named operator delete 5278 with exactly one parameter, then that function is a usual 5279 (non-placement) deallocation function. If class T does not declare 5280 such an operator delete but does declare a member deallocation 5281 function named operator delete with exactly two parameters, the second 5282 of which has type std::size_t (18.2), then this function is a usual 5283 deallocation function. */ 5284 t = FUNCTION_ARG_CHAIN (t); 5285 if (t == void_list_node 5286 || (t && same_type_p (TREE_VALUE (t), size_type_node) 5287 && TREE_CHAIN (t) == void_list_node)) 5288 return true; 5289 return false; 5290 } 5291 5292 /* Build a call to operator delete. This has to be handled very specially, 5293 because the restrictions on what signatures match are different from all 5294 other call instances. For a normal delete, only a delete taking (void *) 5295 or (void *, size_t) is accepted. For a placement delete, only an exact 5296 match with the placement new is accepted. 5297 5298 CODE is either DELETE_EXPR or VEC_DELETE_EXPR. 5299 ADDR is the pointer to be deleted. 5300 SIZE is the size of the memory block to be deleted. 5301 GLOBAL_P is true if the delete-expression should not consider 5302 class-specific delete operators. 5303 PLACEMENT is the corresponding placement new call, or NULL_TREE. 5304 5305 If this call to "operator delete" is being generated as part to 5306 deallocate memory allocated via a new-expression (as per [expr.new] 5307 which requires that if the initialization throws an exception then 5308 we call a deallocation function), then ALLOC_FN is the allocation 5309 function. */ 5310 5311 tree 5312 build_op_delete_call (enum tree_code code, tree addr, tree size, 5313 bool global_p, tree placement, 5314 tree alloc_fn) 5315 { 5316 tree fn = NULL_TREE; 5317 tree fns, fnname, type, t; 5318 5319 if (addr == error_mark_node) 5320 return error_mark_node; 5321 5322 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr))); 5323 5324 fnname = ansi_opname (code); 5325 5326 if (CLASS_TYPE_P (type) 5327 && COMPLETE_TYPE_P (complete_type (type)) 5328 && !global_p) 5329 /* In [class.free] 5330 5331 If the result of the lookup is ambiguous or inaccessible, or if 5332 the lookup selects a placement deallocation function, the 5333 program is ill-formed. 5334 5335 Therefore, we ask lookup_fnfields to complain about ambiguity. */ 5336 { 5337 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1); 5338 if (fns == error_mark_node) 5339 return error_mark_node; 5340 } 5341 else 5342 fns = NULL_TREE; 5343 5344 if (fns == NULL_TREE) 5345 fns = lookup_name_nonclass (fnname); 5346 5347 /* Strip const and volatile from addr. */ 5348 addr = cp_convert (ptr_type_node, addr); 5349 5350 if (placement) 5351 { 5352 /* "A declaration of a placement deallocation function matches the 5353 declaration of a placement allocation function if it has the same 5354 number of parameters and, after parameter transformations (8.3.5), 5355 all parameter types except the first are identical." 5356 5357 So we build up the function type we want and ask instantiate_type 5358 to get it for us. */ 5359 t = FUNCTION_ARG_CHAIN (alloc_fn); 5360 t = tree_cons (NULL_TREE, ptr_type_node, t); 5361 t = build_function_type (void_type_node, t); 5362 5363 fn = instantiate_type (t, fns, tf_none); 5364 if (fn == error_mark_node) 5365 return NULL_TREE; 5366 5367 if (BASELINK_P (fn)) 5368 fn = BASELINK_FUNCTIONS (fn); 5369 5370 /* "If the lookup finds the two-parameter form of a usual deallocation 5371 function (3.7.4.2) and that function, considered as a placement 5372 deallocation function, would have been selected as a match for the 5373 allocation function, the program is ill-formed." */ 5374 if (non_placement_deallocation_fn_p (fn)) 5375 { 5376 /* But if the class has an operator delete (void *), then that is 5377 the usual deallocation function, so we shouldn't complain 5378 about using the operator delete (void *, size_t). */ 5379 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns; 5380 t; t = OVL_NEXT (t)) 5381 { 5382 tree elt = OVL_CURRENT (t); 5383 if (non_placement_deallocation_fn_p (elt) 5384 && FUNCTION_ARG_CHAIN (elt) == void_list_node) 5385 goto ok; 5386 } 5387 permerror (0, "non-placement deallocation function %q+D", fn); 5388 permerror (input_location, "selected for placement delete"); 5389 ok:; 5390 } 5391 } 5392 else 5393 /* "Any non-placement deallocation function matches a non-placement 5394 allocation function. If the lookup finds a single matching 5395 deallocation function, that function will be called; otherwise, no 5396 deallocation function will be called." */ 5397 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns; 5398 t; t = OVL_NEXT (t)) 5399 { 5400 tree elt = OVL_CURRENT (t); 5401 if (non_placement_deallocation_fn_p (elt)) 5402 { 5403 fn = elt; 5404 /* "If a class T has a member deallocation function named 5405 operator delete with exactly one parameter, then that 5406 function is a usual (non-placement) deallocation 5407 function. If class T does not declare such an operator 5408 delete but does declare a member deallocation function named 5409 operator delete with exactly two parameters, the second of 5410 which has type std::size_t (18.2), then this function is a 5411 usual deallocation function." 5412 5413 So (void*) beats (void*, size_t). */ 5414 if (FUNCTION_ARG_CHAIN (fn) == void_list_node) 5415 break; 5416 } 5417 } 5418 5419 /* If we have a matching function, call it. */ 5420 if (fn) 5421 { 5422 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 5423 5424 /* If the FN is a member function, make sure that it is 5425 accessible. */ 5426 if (BASELINK_P (fns)) 5427 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn); 5428 5429 /* Core issue 901: It's ok to new a type with deleted delete. */ 5430 if (DECL_DELETED_FN (fn) && alloc_fn) 5431 return NULL_TREE; 5432 5433 if (placement) 5434 { 5435 /* The placement args might not be suitable for overload 5436 resolution at this point, so build the call directly. */ 5437 int nargs = call_expr_nargs (placement); 5438 tree *argarray = XALLOCAVEC (tree, nargs); 5439 int i; 5440 argarray[0] = addr; 5441 for (i = 1; i < nargs; i++) 5442 argarray[i] = CALL_EXPR_ARG (placement, i); 5443 mark_used (fn); 5444 return build_cxx_call (fn, nargs, argarray); 5445 } 5446 else 5447 { 5448 tree ret; 5449 VEC(tree,gc) *args = VEC_alloc (tree, gc, 2); 5450 VEC_quick_push (tree, args, addr); 5451 if (FUNCTION_ARG_CHAIN (fn) != void_list_node) 5452 VEC_quick_push (tree, args, size); 5453 ret = cp_build_function_call_vec (fn, &args, tf_warning_or_error); 5454 VEC_free (tree, gc, args); 5455 return ret; 5456 } 5457 } 5458 5459 /* [expr.new] 5460 5461 If no unambiguous matching deallocation function can be found, 5462 propagating the exception does not cause the object's memory to 5463 be freed. */ 5464 if (alloc_fn) 5465 { 5466 if (!placement) 5467 warning (0, "no corresponding deallocation function for %qD", 5468 alloc_fn); 5469 return NULL_TREE; 5470 } 5471 5472 error ("no suitable %<operator %s%> for %qT", 5473 operator_name_info[(int)code].name, type); 5474 return error_mark_node; 5475 } 5476 5477 /* If the current scope isn't allowed to access DECL along 5478 BASETYPE_PATH, give an error. The most derived class in 5479 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is 5480 the declaration to use in the error diagnostic. */ 5481 5482 bool 5483 enforce_access (tree basetype_path, tree decl, tree diag_decl) 5484 { 5485 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO); 5486 5487 if (!accessible_p (basetype_path, decl, true)) 5488 { 5489 if (TREE_PRIVATE (decl)) 5490 error ("%q+#D is private", diag_decl); 5491 else if (TREE_PROTECTED (decl)) 5492 error ("%q+#D is protected", diag_decl); 5493 else 5494 error ("%q+#D is inaccessible", diag_decl); 5495 error ("within this context"); 5496 return false; 5497 } 5498 5499 return true; 5500 } 5501 5502 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a 5503 bitwise or of LOOKUP_* values. If any errors are warnings are 5504 generated, set *DIAGNOSTIC_FN to "error" or "warning", 5505 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN 5506 to NULL. */ 5507 5508 static tree 5509 build_temp (tree expr, tree type, int flags, 5510 diagnostic_t *diagnostic_kind, tsubst_flags_t complain) 5511 { 5512 int savew, savee; 5513 VEC(tree,gc) *args; 5514 5515 savew = warningcount, savee = errorcount; 5516 args = make_tree_vector_single (expr); 5517 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 5518 &args, type, flags, complain); 5519 release_tree_vector (args); 5520 if (warningcount > savew) 5521 *diagnostic_kind = DK_WARNING; 5522 else if (errorcount > savee) 5523 *diagnostic_kind = DK_ERROR; 5524 else 5525 *diagnostic_kind = DK_UNSPECIFIED; 5526 return expr; 5527 } 5528 5529 /* Perform warnings about peculiar, but valid, conversions from/to NULL. 5530 EXPR is implicitly converted to type TOTYPE. 5531 FN and ARGNUM are used for diagnostics. */ 5532 5533 static void 5534 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum) 5535 { 5536 /* Issue warnings about peculiar, but valid, uses of NULL. */ 5537 if (expr == null_node && TREE_CODE (totype) != BOOLEAN_TYPE 5538 && ARITHMETIC_TYPE_P (totype)) 5539 { 5540 if (fn) 5541 warning_at (input_location, OPT_Wconversion_null, 5542 "passing NULL to non-pointer argument %P of %qD", 5543 argnum, fn); 5544 else 5545 warning_at (input_location, OPT_Wconversion_null, 5546 "converting to non-pointer type %qT from NULL", totype); 5547 } 5548 5549 /* Issue warnings if "false" is converted to a NULL pointer */ 5550 else if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE 5551 && TYPE_PTR_P (totype)) 5552 { 5553 if (fn) 5554 warning_at (input_location, OPT_Wconversion_null, 5555 "converting %<false%> to pointer type for argument %P " 5556 "of %qD", argnum, fn); 5557 else 5558 warning_at (input_location, OPT_Wconversion_null, 5559 "converting %<false%> to pointer type %qT", totype); 5560 } 5561 } 5562 5563 /* Perform the conversions in CONVS on the expression EXPR. FN and 5564 ARGNUM are used for diagnostics. ARGNUM is zero based, -1 5565 indicates the `this' argument of a method. INNER is nonzero when 5566 being called to continue a conversion chain. It is negative when a 5567 reference binding will be applied, positive otherwise. If 5568 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious 5569 conversions will be emitted if appropriate. If C_CAST_P is true, 5570 this conversion is coming from a C-style cast; in that case, 5571 conversions to inaccessible bases are permitted. */ 5572 5573 static tree 5574 convert_like_real (conversion *convs, tree expr, tree fn, int argnum, 5575 int inner, bool issue_conversion_warnings, 5576 bool c_cast_p, tsubst_flags_t complain) 5577 { 5578 tree totype = convs->type; 5579 diagnostic_t diag_kind; 5580 int flags; 5581 5582 if (convs->bad_p && !(complain & tf_error)) 5583 return error_mark_node; 5584 5585 if (convs->bad_p 5586 && convs->kind != ck_user 5587 && convs->kind != ck_list 5588 && convs->kind != ck_ambig 5589 && (convs->kind != ck_ref_bind 5590 || convs->user_conv_p) 5591 && convs->kind != ck_rvalue 5592 && convs->kind != ck_base) 5593 { 5594 conversion *t = convs; 5595 5596 /* Give a helpful error if this is bad because of excess braces. */ 5597 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 5598 && SCALAR_TYPE_P (totype) 5599 && CONSTRUCTOR_NELTS (expr) > 0 5600 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value)) 5601 permerror (input_location, "too many braces around initializer for %qT", totype); 5602 5603 for (; t ; t = next_conversion (t)) 5604 { 5605 if (t->kind == ck_user && t->cand->reason) 5606 { 5607 permerror (input_location, "invalid user-defined conversion " 5608 "from %qT to %qT", TREE_TYPE (expr), totype); 5609 print_z_candidate ("candidate is:", t->cand); 5610 expr = convert_like_real (t, expr, fn, argnum, 1, 5611 /*issue_conversion_warnings=*/false, 5612 /*c_cast_p=*/false, 5613 complain); 5614 if (convs->kind == ck_ref_bind) 5615 return convert_to_reference (totype, expr, CONV_IMPLICIT, 5616 LOOKUP_NORMAL, NULL_TREE); 5617 else 5618 return cp_convert (totype, expr); 5619 } 5620 else if (t->kind == ck_user || !t->bad_p) 5621 { 5622 expr = convert_like_real (t, expr, fn, argnum, 1, 5623 /*issue_conversion_warnings=*/false, 5624 /*c_cast_p=*/false, 5625 complain); 5626 break; 5627 } 5628 else if (t->kind == ck_ambig) 5629 return convert_like_real (t, expr, fn, argnum, 1, 5630 /*issue_conversion_warnings=*/false, 5631 /*c_cast_p=*/false, 5632 complain); 5633 else if (t->kind == ck_identity) 5634 break; 5635 } 5636 5637 permerror (input_location, "invalid conversion from %qT to %qT", 5638 TREE_TYPE (expr), totype); 5639 if (fn) 5640 permerror (DECL_SOURCE_LOCATION (fn), 5641 " initializing argument %P of %qD", argnum, fn); 5642 5643 return cp_convert (totype, expr); 5644 } 5645 5646 if (issue_conversion_warnings && (complain & tf_warning)) 5647 conversion_null_warnings (totype, expr, fn, argnum); 5648 5649 switch (convs->kind) 5650 { 5651 case ck_user: 5652 { 5653 struct z_candidate *cand = convs->cand; 5654 tree convfn = cand->fn; 5655 unsigned i; 5656 5657 /* If we're initializing from {}, it's value-initialization. */ 5658 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 5659 && CONSTRUCTOR_NELTS (expr) == 0 5660 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 5661 { 5662 bool direct = CONSTRUCTOR_IS_DIRECT_INIT (expr); 5663 expr = build_value_init (totype, complain); 5664 expr = get_target_expr_sfinae (expr, complain); 5665 if (expr != error_mark_node) 5666 { 5667 TARGET_EXPR_LIST_INIT_P (expr) = true; 5668 TARGET_EXPR_DIRECT_INIT_P (expr) = direct; 5669 } 5670 return expr; 5671 } 5672 5673 expr = mark_rvalue_use (expr); 5674 5675 /* When converting from an init list we consider explicit 5676 constructors, but actually trying to call one is an error. */ 5677 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn) 5678 /* Unless this is for direct-list-initialization. */ 5679 && !(BRACE_ENCLOSED_INITIALIZER_P (expr) 5680 && CONSTRUCTOR_IS_DIRECT_INIT (expr)) 5681 /* Unless we're calling it for value-initialization from an 5682 empty list, since that is handled separately in 8.5.4. */ 5683 && cand->num_convs > 0) 5684 { 5685 error ("converting to %qT from initializer list would use " 5686 "explicit constructor %qD", totype, convfn); 5687 } 5688 5689 /* Set user_conv_p on the argument conversions, so rvalue/base 5690 handling knows not to allow any more UDCs. */ 5691 for (i = 0; i < cand->num_convs; ++i) 5692 cand->convs[i]->user_conv_p = true; 5693 5694 expr = build_over_call (cand, LOOKUP_NORMAL, complain); 5695 5696 /* If this is a constructor or a function returning an aggr type, 5697 we need to build up a TARGET_EXPR. */ 5698 if (DECL_CONSTRUCTOR_P (convfn)) 5699 { 5700 expr = build_cplus_new (totype, expr, complain); 5701 5702 /* Remember that this was list-initialization. */ 5703 if (convs->check_narrowing && expr != error_mark_node) 5704 TARGET_EXPR_LIST_INIT_P (expr) = true; 5705 } 5706 5707 return expr; 5708 } 5709 case ck_identity: 5710 expr = mark_rvalue_use (expr); 5711 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 5712 { 5713 int nelts = CONSTRUCTOR_NELTS (expr); 5714 if (nelts == 0) 5715 expr = build_value_init (totype, complain); 5716 else if (nelts == 1) 5717 expr = CONSTRUCTOR_ELT (expr, 0)->value; 5718 else 5719 gcc_unreachable (); 5720 } 5721 5722 if (type_unknown_p (expr)) 5723 expr = instantiate_type (totype, expr, complain); 5724 /* Convert a constant to its underlying value, unless we are 5725 about to bind it to a reference, in which case we need to 5726 leave it as an lvalue. */ 5727 if (inner >= 0) 5728 { 5729 expr = decl_constant_value_safe (expr); 5730 if (expr == null_node && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype)) 5731 /* If __null has been converted to an integer type, we do not 5732 want to warn about uses of EXPR as an integer, rather than 5733 as a pointer. */ 5734 expr = build_int_cst (totype, 0); 5735 } 5736 return expr; 5737 case ck_ambig: 5738 /* We leave bad_p off ck_ambig because overload resolution considers 5739 it valid, it just fails when we try to perform it. So we need to 5740 check complain here, too. */ 5741 if (complain & tf_error) 5742 { 5743 /* Call build_user_type_conversion again for the error. */ 5744 build_user_type_conversion (totype, convs->u.expr, LOOKUP_NORMAL); 5745 if (fn) 5746 error (" initializing argument %P of %q+D", argnum, fn); 5747 } 5748 return error_mark_node; 5749 5750 case ck_list: 5751 { 5752 /* Conversion to std::initializer_list<T>. */ 5753 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0); 5754 tree new_ctor = build_constructor (init_list_type_node, NULL); 5755 unsigned len = CONSTRUCTOR_NELTS (expr); 5756 tree array, val, field; 5757 VEC(constructor_elt,gc) *vec = NULL; 5758 unsigned ix; 5759 5760 /* Convert all the elements. */ 5761 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val) 5762 { 5763 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum, 5764 1, false, false, complain); 5765 if (sub == error_mark_node) 5766 return sub; 5767 if (!BRACE_ENCLOSED_INITIALIZER_P (val)) 5768 check_narrowing (TREE_TYPE (sub), val); 5769 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub); 5770 if (!TREE_CONSTANT (sub)) 5771 TREE_CONSTANT (new_ctor) = false; 5772 } 5773 /* Build up the array. */ 5774 elttype = cp_build_qualified_type 5775 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST); 5776 array = build_array_of_n_type (elttype, len); 5777 array = finish_compound_literal (array, new_ctor, complain); 5778 /* Take the address explicitly rather than via decay_conversion 5779 to avoid the error about taking the address of a temporary. */ 5780 array = cp_build_addr_expr (array, complain); 5781 array = cp_convert (build_pointer_type (elttype), array); 5782 5783 /* Build up the initializer_list object. */ 5784 totype = complete_type (totype); 5785 field = next_initializable_field (TYPE_FIELDS (totype)); 5786 CONSTRUCTOR_APPEND_ELT (vec, field, array); 5787 field = next_initializable_field (DECL_CHAIN (field)); 5788 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len)); 5789 new_ctor = build_constructor (totype, vec); 5790 return get_target_expr (new_ctor); 5791 } 5792 5793 case ck_aggr: 5794 if (TREE_CODE (totype) == COMPLEX_TYPE) 5795 { 5796 tree real = CONSTRUCTOR_ELT (expr, 0)->value; 5797 tree imag = CONSTRUCTOR_ELT (expr, 1)->value; 5798 real = perform_implicit_conversion (TREE_TYPE (totype), 5799 real, complain); 5800 imag = perform_implicit_conversion (TREE_TYPE (totype), 5801 imag, complain); 5802 expr = build2 (COMPLEX_EXPR, totype, real, imag); 5803 return fold_if_not_in_template (expr); 5804 } 5805 return get_target_expr (digest_init (totype, expr, complain)); 5806 5807 default: 5808 break; 5809 }; 5810 5811 expr = convert_like_real (convs->u.next, expr, fn, argnum, 5812 convs->kind == ck_ref_bind ? -1 : 1, 5813 convs->kind == ck_ref_bind ? issue_conversion_warnings : false, 5814 c_cast_p, 5815 complain); 5816 if (expr == error_mark_node) 5817 return error_mark_node; 5818 5819 switch (convs->kind) 5820 { 5821 case ck_rvalue: 5822 expr = decay_conversion (expr); 5823 if (! MAYBE_CLASS_TYPE_P (totype)) 5824 return expr; 5825 /* Else fall through. */ 5826 case ck_base: 5827 if (convs->kind == ck_base && !convs->need_temporary_p) 5828 { 5829 /* We are going to bind a reference directly to a base-class 5830 subobject of EXPR. */ 5831 /* Build an expression for `*((base*) &expr)'. */ 5832 expr = cp_build_addr_expr (expr, complain); 5833 expr = convert_to_base (expr, build_pointer_type (totype), 5834 !c_cast_p, /*nonnull=*/true, complain); 5835 expr = cp_build_indirect_ref (expr, RO_IMPLICIT_CONVERSION, complain); 5836 return expr; 5837 } 5838 5839 /* Copy-initialization where the cv-unqualified version of the source 5840 type is the same class as, or a derived class of, the class of the 5841 destination [is treated as direct-initialization]. [dcl.init] */ 5842 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING; 5843 if (convs->user_conv_p) 5844 /* This conversion is being done in the context of a user-defined 5845 conversion (i.e. the second step of copy-initialization), so 5846 don't allow any more. */ 5847 flags |= LOOKUP_NO_CONVERSION; 5848 if (convs->rvaluedness_matches_p) 5849 flags |= LOOKUP_PREFER_RVALUE; 5850 if (TREE_CODE (expr) == TARGET_EXPR 5851 && TARGET_EXPR_LIST_INIT_P (expr)) 5852 /* Copy-list-initialization doesn't actually involve a copy. */ 5853 return expr; 5854 expr = build_temp (expr, totype, flags, &diag_kind, complain); 5855 if (diag_kind && fn && complain) 5856 emit_diagnostic (diag_kind, DECL_SOURCE_LOCATION (fn), 0, 5857 " initializing argument %P of %qD", argnum, fn); 5858 return build_cplus_new (totype, expr, complain); 5859 5860 case ck_ref_bind: 5861 { 5862 tree ref_type = totype; 5863 5864 if (convs->bad_p && !convs->u.next->bad_p) 5865 { 5866 gcc_assert (TYPE_REF_IS_RVALUE (ref_type) 5867 && real_lvalue_p (expr)); 5868 5869 error ("cannot bind %qT lvalue to %qT", 5870 TREE_TYPE (expr), totype); 5871 if (fn) 5872 error (" initializing argument %P of %q+D", argnum, fn); 5873 return error_mark_node; 5874 } 5875 5876 /* If necessary, create a temporary. 5877 5878 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases 5879 that need temporaries, even when their types are reference 5880 compatible with the type of reference being bound, so the 5881 upcoming call to cp_build_addr_expr doesn't fail. */ 5882 if (convs->need_temporary_p 5883 || TREE_CODE (expr) == CONSTRUCTOR 5884 || TREE_CODE (expr) == VA_ARG_EXPR) 5885 { 5886 /* Otherwise, a temporary of type "cv1 T1" is created and 5887 initialized from the initializer expression using the rules 5888 for a non-reference copy-initialization (8.5). */ 5889 5890 tree type = TREE_TYPE (ref_type); 5891 cp_lvalue_kind lvalue = real_lvalue_p (expr); 5892 5893 gcc_assert (same_type_ignoring_top_level_qualifiers_p 5894 (type, convs->u.next->type)); 5895 if (!CP_TYPE_CONST_NON_VOLATILE_P (type) 5896 && !TYPE_REF_IS_RVALUE (ref_type)) 5897 { 5898 /* If the reference is volatile or non-const, we 5899 cannot create a temporary. */ 5900 if (lvalue & clk_bitfield) 5901 error ("cannot bind bitfield %qE to %qT", 5902 expr, ref_type); 5903 else if (lvalue & clk_packed) 5904 error ("cannot bind packed field %qE to %qT", 5905 expr, ref_type); 5906 else 5907 error ("cannot bind rvalue %qE to %qT", expr, ref_type); 5908 return error_mark_node; 5909 } 5910 /* If the source is a packed field, and we must use a copy 5911 constructor, then building the target expr will require 5912 binding the field to the reference parameter to the 5913 copy constructor, and we'll end up with an infinite 5914 loop. If we can use a bitwise copy, then we'll be 5915 OK. */ 5916 if ((lvalue & clk_packed) 5917 && CLASS_TYPE_P (type) 5918 && type_has_nontrivial_copy_init (type)) 5919 { 5920 error ("cannot bind packed field %qE to %qT", 5921 expr, ref_type); 5922 return error_mark_node; 5923 } 5924 if (lvalue & clk_bitfield) 5925 { 5926 expr = convert_bitfield_to_declared_type (expr); 5927 expr = fold_convert (type, expr); 5928 } 5929 expr = build_target_expr_with_type (expr, type, complain); 5930 } 5931 5932 /* Take the address of the thing to which we will bind the 5933 reference. */ 5934 expr = cp_build_addr_expr (expr, complain); 5935 if (expr == error_mark_node) 5936 return error_mark_node; 5937 5938 /* Convert it to a pointer to the type referred to by the 5939 reference. This will adjust the pointer if a derived to 5940 base conversion is being performed. */ 5941 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)), 5942 expr); 5943 /* Convert the pointer to the desired reference type. */ 5944 return build_nop (ref_type, expr); 5945 } 5946 5947 case ck_lvalue: 5948 return decay_conversion (expr); 5949 5950 case ck_qual: 5951 /* Warn about deprecated conversion if appropriate. */ 5952 string_conv_p (totype, expr, 1); 5953 break; 5954 5955 case ck_ptr: 5956 if (convs->base_p) 5957 expr = convert_to_base (expr, totype, !c_cast_p, 5958 /*nonnull=*/false, complain); 5959 return build_nop (totype, expr); 5960 5961 case ck_pmem: 5962 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false, 5963 c_cast_p, complain); 5964 5965 default: 5966 break; 5967 } 5968 5969 if (convs->check_narrowing) 5970 check_narrowing (totype, expr); 5971 5972 if (issue_conversion_warnings && (complain & tf_warning)) 5973 expr = convert_and_check (totype, expr); 5974 else 5975 expr = convert (totype, expr); 5976 5977 return expr; 5978 } 5979 5980 /* ARG is being passed to a varargs function. Perform any conversions 5981 required. Return the converted value. */ 5982 5983 tree 5984 convert_arg_to_ellipsis (tree arg) 5985 { 5986 tree arg_type; 5987 5988 /* [expr.call] 5989 5990 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer 5991 standard conversions are performed. */ 5992 arg = decay_conversion (arg); 5993 arg_type = TREE_TYPE (arg); 5994 /* [expr.call] 5995 5996 If the argument has integral or enumeration type that is subject 5997 to the integral promotions (_conv.prom_), or a floating point 5998 type that is subject to the floating point promotion 5999 (_conv.fpprom_), the value of the argument is converted to the 6000 promoted type before the call. */ 6001 if (TREE_CODE (arg_type) == REAL_TYPE 6002 && (TYPE_PRECISION (arg_type) 6003 < TYPE_PRECISION (double_type_node)) 6004 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type))) 6005 { 6006 if (warn_double_promotion && !c_inhibit_evaluation_warnings) 6007 warning (OPT_Wdouble_promotion, 6008 "implicit conversion from %qT to %qT when passing " 6009 "argument to function", 6010 arg_type, double_type_node); 6011 arg = convert_to_real (double_type_node, arg); 6012 } 6013 else if (NULLPTR_TYPE_P (arg_type)) 6014 arg = null_pointer_node; 6015 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type)) 6016 { 6017 if (SCOPED_ENUM_P (arg_type) && !abi_version_at_least (6)) 6018 { 6019 warning (OPT_Wabi, "scoped enum %qT will not promote to an " 6020 "integral type in a future version of GCC", arg_type); 6021 arg = cp_convert (ENUM_UNDERLYING_TYPE (arg_type), arg); 6022 } 6023 arg = perform_integral_promotions (arg); 6024 } 6025 6026 arg = require_complete_type (arg); 6027 arg_type = TREE_TYPE (arg); 6028 6029 if (arg != error_mark_node 6030 /* In a template (or ill-formed code), we can have an incomplete type 6031 even after require_complete_type, in which case we don't know 6032 whether it has trivial copy or not. */ 6033 && COMPLETE_TYPE_P (arg_type)) 6034 { 6035 /* Build up a real lvalue-to-rvalue conversion in case the 6036 copy constructor is trivial but not callable. */ 6037 if (!cp_unevaluated_operand && CLASS_TYPE_P (arg_type)) 6038 force_rvalue (arg, tf_warning_or_error); 6039 6040 /* [expr.call] 5.2.2/7: 6041 Passing a potentially-evaluated argument of class type (Clause 9) 6042 with a non-trivial copy constructor or a non-trivial destructor 6043 with no corresponding parameter is conditionally-supported, with 6044 implementation-defined semantics. 6045 6046 We used to just warn here and do a bitwise copy, but now 6047 cp_expr_size will abort if we try to do that. 6048 6049 If the call appears in the context of a sizeof expression, 6050 it is not potentially-evaluated. */ 6051 if (cp_unevaluated_operand == 0 6052 && (type_has_nontrivial_copy_init (arg_type) 6053 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type))) 6054 error ("cannot pass objects of non-trivially-copyable " 6055 "type %q#T through %<...%>", arg_type); 6056 } 6057 6058 return arg; 6059 } 6060 6061 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */ 6062 6063 tree 6064 build_x_va_arg (tree expr, tree type) 6065 { 6066 if (processing_template_decl) 6067 return build_min (VA_ARG_EXPR, type, expr); 6068 6069 type = complete_type_or_else (type, NULL_TREE); 6070 6071 if (expr == error_mark_node || !type) 6072 return error_mark_node; 6073 6074 expr = mark_lvalue_use (expr); 6075 6076 if (type_has_nontrivial_copy_init (type) 6077 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type) 6078 || TREE_CODE (type) == REFERENCE_TYPE) 6079 { 6080 /* Remove reference types so we don't ICE later on. */ 6081 tree type1 = non_reference (type); 6082 /* conditionally-supported behavior [expr.call] 5.2.2/7. */ 6083 error ("cannot receive objects of non-trivially-copyable type %q#T " 6084 "through %<...%>; ", type); 6085 expr = convert (build_pointer_type (type1), null_node); 6086 expr = cp_build_indirect_ref (expr, RO_NULL, tf_warning_or_error); 6087 return expr; 6088 } 6089 6090 return build_va_arg (input_location, expr, type); 6091 } 6092 6093 /* TYPE has been given to va_arg. Apply the default conversions which 6094 would have happened when passed via ellipsis. Return the promoted 6095 type, or the passed type if there is no change. */ 6096 6097 tree 6098 cxx_type_promotes_to (tree type) 6099 { 6100 tree promote; 6101 6102 /* Perform the array-to-pointer and function-to-pointer 6103 conversions. */ 6104 type = type_decays_to (type); 6105 6106 promote = type_promotes_to (type); 6107 if (same_type_p (type, promote)) 6108 promote = type; 6109 6110 return promote; 6111 } 6112 6113 /* ARG is a default argument expression being passed to a parameter of 6114 the indicated TYPE, which is a parameter to FN. PARMNUM is the 6115 zero-based argument number. Do any required conversions. Return 6116 the converted value. */ 6117 6118 static GTY(()) VEC(tree,gc) *default_arg_context; 6119 void 6120 push_defarg_context (tree fn) 6121 { VEC_safe_push (tree, gc, default_arg_context, fn); } 6122 void 6123 pop_defarg_context (void) 6124 { VEC_pop (tree, default_arg_context); } 6125 6126 tree 6127 convert_default_arg (tree type, tree arg, tree fn, int parmnum) 6128 { 6129 int i; 6130 tree t; 6131 6132 /* See through clones. */ 6133 fn = DECL_ORIGIN (fn); 6134 6135 /* Detect recursion. */ 6136 FOR_EACH_VEC_ELT (tree, default_arg_context, i, t) 6137 if (t == fn) 6138 { 6139 error ("recursive evaluation of default argument for %q#D", fn); 6140 return error_mark_node; 6141 } 6142 6143 /* If the ARG is an unparsed default argument expression, the 6144 conversion cannot be performed. */ 6145 if (TREE_CODE (arg) == DEFAULT_ARG) 6146 { 6147 error ("call to %qD uses the default argument for parameter %P, which " 6148 "is not yet defined", fn, parmnum); 6149 return error_mark_node; 6150 } 6151 6152 push_defarg_context (fn); 6153 6154 if (fn && DECL_TEMPLATE_INFO (fn)) 6155 arg = tsubst_default_argument (fn, type, arg); 6156 6157 /* Due to: 6158 6159 [dcl.fct.default] 6160 6161 The names in the expression are bound, and the semantic 6162 constraints are checked, at the point where the default 6163 expressions appears. 6164 6165 we must not perform access checks here. */ 6166 push_deferring_access_checks (dk_no_check); 6167 /* We must make a copy of ARG, in case subsequent processing 6168 alters any part of it. */ 6169 arg = break_out_target_exprs (arg); 6170 if (TREE_CODE (arg) == CONSTRUCTOR) 6171 { 6172 arg = digest_init (type, arg, tf_warning_or_error); 6173 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT, 6174 ICR_DEFAULT_ARGUMENT, fn, parmnum, 6175 tf_warning_or_error); 6176 } 6177 else 6178 { 6179 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT, 6180 ICR_DEFAULT_ARGUMENT, fn, parmnum, 6181 tf_warning_or_error); 6182 arg = convert_for_arg_passing (type, arg); 6183 } 6184 pop_deferring_access_checks(); 6185 6186 pop_defarg_context (); 6187 6188 return arg; 6189 } 6190 6191 /* Returns the type which will really be used for passing an argument of 6192 type TYPE. */ 6193 6194 tree 6195 type_passed_as (tree type) 6196 { 6197 /* Pass classes with copy ctors by invisible reference. */ 6198 if (TREE_ADDRESSABLE (type)) 6199 { 6200 type = build_reference_type (type); 6201 /* There are no other pointers to this temporary. */ 6202 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT); 6203 } 6204 else if (targetm.calls.promote_prototypes (type) 6205 && INTEGRAL_TYPE_P (type) 6206 && COMPLETE_TYPE_P (type) 6207 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type), 6208 TYPE_SIZE (integer_type_node))) 6209 type = integer_type_node; 6210 6211 return type; 6212 } 6213 6214 /* Actually perform the appropriate conversion. */ 6215 6216 tree 6217 convert_for_arg_passing (tree type, tree val) 6218 { 6219 tree bitfield_type; 6220 6221 /* If VAL is a bitfield, then -- since it has already been converted 6222 to TYPE -- it cannot have a precision greater than TYPE. 6223 6224 If it has a smaller precision, we must widen it here. For 6225 example, passing "int f:3;" to a function expecting an "int" will 6226 not result in any conversion before this point. 6227 6228 If the precision is the same we must not risk widening. For 6229 example, the COMPONENT_REF for a 32-bit "long long" bitfield will 6230 often have type "int", even though the C++ type for the field is 6231 "long long". If the value is being passed to a function 6232 expecting an "int", then no conversions will be required. But, 6233 if we call convert_bitfield_to_declared_type, the bitfield will 6234 be converted to "long long". */ 6235 bitfield_type = is_bitfield_expr_with_lowered_type (val); 6236 if (bitfield_type 6237 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)) 6238 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val); 6239 6240 if (val == error_mark_node) 6241 ; 6242 /* Pass classes with copy ctors by invisible reference. */ 6243 else if (TREE_ADDRESSABLE (type)) 6244 val = build1 (ADDR_EXPR, build_reference_type (type), val); 6245 else if (targetm.calls.promote_prototypes (type) 6246 && INTEGRAL_TYPE_P (type) 6247 && COMPLETE_TYPE_P (type) 6248 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type), 6249 TYPE_SIZE (integer_type_node))) 6250 val = perform_integral_promotions (val); 6251 if (warn_missing_format_attribute) 6252 { 6253 tree rhstype = TREE_TYPE (val); 6254 const enum tree_code coder = TREE_CODE (rhstype); 6255 const enum tree_code codel = TREE_CODE (type); 6256 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 6257 && coder == codel 6258 && check_missing_format_attribute (type, rhstype)) 6259 warning (OPT_Wmissing_format_attribute, 6260 "argument of function call might be a candidate for a format attribute"); 6261 } 6262 return val; 6263 } 6264 6265 /* Returns true iff FN is a function with magic varargs, i.e. ones for 6266 which no conversions at all should be done. This is true for some 6267 builtins which don't act like normal functions. */ 6268 6269 static bool 6270 magic_varargs_p (tree fn) 6271 { 6272 if (DECL_BUILT_IN (fn)) 6273 switch (DECL_FUNCTION_CODE (fn)) 6274 { 6275 case BUILT_IN_CLASSIFY_TYPE: 6276 case BUILT_IN_CONSTANT_P: 6277 case BUILT_IN_NEXT_ARG: 6278 case BUILT_IN_VA_START: 6279 return true; 6280 6281 default:; 6282 return lookup_attribute ("type generic", 6283 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0; 6284 } 6285 6286 return false; 6287 } 6288 6289 /* Subroutine of the various build_*_call functions. Overload resolution 6290 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly. 6291 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a 6292 bitmask of various LOOKUP_* flags which apply to the call itself. */ 6293 6294 static tree 6295 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) 6296 { 6297 tree fn = cand->fn; 6298 const VEC(tree,gc) *args = cand->args; 6299 tree first_arg = cand->first_arg; 6300 conversion **convs = cand->convs; 6301 conversion *conv; 6302 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn)); 6303 int parmlen; 6304 tree val; 6305 int i = 0; 6306 int j = 0; 6307 unsigned int arg_index = 0; 6308 int is_method = 0; 6309 int nargs; 6310 tree *argarray; 6311 bool already_used = false; 6312 6313 /* In a template, there is no need to perform all of the work that 6314 is normally done. We are only interested in the type of the call 6315 expression, i.e., the return type of the function. Any semantic 6316 errors will be deferred until the template is instantiated. */ 6317 if (processing_template_decl) 6318 { 6319 tree expr; 6320 tree return_type; 6321 const tree *argarray; 6322 unsigned int nargs; 6323 6324 return_type = TREE_TYPE (TREE_TYPE (fn)); 6325 nargs = VEC_length (tree, args); 6326 if (first_arg == NULL_TREE) 6327 argarray = VEC_address (tree, CONST_CAST (VEC(tree,gc) *, args)); 6328 else 6329 { 6330 tree *alcarray; 6331 unsigned int ix; 6332 tree arg; 6333 6334 ++nargs; 6335 alcarray = XALLOCAVEC (tree, nargs); 6336 alcarray[0] = first_arg; 6337 FOR_EACH_VEC_ELT (tree, args, ix, arg) 6338 alcarray[ix + 1] = arg; 6339 argarray = alcarray; 6340 } 6341 expr = build_call_array_loc (input_location, 6342 return_type, build_addr_func (fn), nargs, 6343 argarray); 6344 if (TREE_THIS_VOLATILE (fn) && cfun) 6345 current_function_returns_abnormally = 1; 6346 return convert_from_reference (expr); 6347 } 6348 6349 /* Give any warnings we noticed during overload resolution. */ 6350 if (cand->warnings && (complain & tf_warning)) 6351 { 6352 struct candidate_warning *w; 6353 for (w = cand->warnings; w; w = w->next) 6354 joust (cand, w->loser, 1); 6355 } 6356 6357 /* Make =delete work with SFINAE. */ 6358 if (DECL_DELETED_FN (fn) && !(complain & tf_error)) 6359 return error_mark_node; 6360 6361 if (DECL_FUNCTION_MEMBER_P (fn)) 6362 { 6363 tree access_fn; 6364 /* If FN is a template function, two cases must be considered. 6365 For example: 6366 6367 struct A { 6368 protected: 6369 template <class T> void f(); 6370 }; 6371 template <class T> struct B { 6372 protected: 6373 void g(); 6374 }; 6375 struct C : A, B<int> { 6376 using A::f; // #1 6377 using B<int>::g; // #2 6378 }; 6379 6380 In case #1 where `A::f' is a member template, DECL_ACCESS is 6381 recorded in the primary template but not in its specialization. 6382 We check access of FN using its primary template. 6383 6384 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply 6385 because it is a member of class template B, DECL_ACCESS is 6386 recorded in the specialization `B<int>::g'. We cannot use its 6387 primary template because `B<T>::g' and `B<int>::g' may have 6388 different access. */ 6389 if (DECL_TEMPLATE_INFO (fn) 6390 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn))) 6391 access_fn = DECL_TI_TEMPLATE (fn); 6392 else 6393 access_fn = fn; 6394 if (flags & LOOKUP_SPECULATIVE) 6395 { 6396 if (!speculative_access_check (cand->access_path, access_fn, fn, 6397 !!(flags & LOOKUP_COMPLAIN))) 6398 return error_mark_node; 6399 } 6400 else 6401 perform_or_defer_access_check (cand->access_path, access_fn, fn); 6402 } 6403 6404 /* If we're checking for implicit delete, don't bother with argument 6405 conversions. */ 6406 if (flags & LOOKUP_SPECULATIVE) 6407 { 6408 if (DECL_DELETED_FN (fn)) 6409 { 6410 if (flags & LOOKUP_COMPLAIN) 6411 mark_used (fn); 6412 return error_mark_node; 6413 } 6414 if (cand->viable == 1) 6415 return fn; 6416 else if (!(flags & LOOKUP_COMPLAIN)) 6417 /* Reject bad conversions now. */ 6418 return error_mark_node; 6419 /* else continue to get conversion error. */ 6420 } 6421 6422 /* Find maximum size of vector to hold converted arguments. */ 6423 parmlen = list_length (parm); 6424 nargs = VEC_length (tree, args) + (first_arg != NULL_TREE ? 1 : 0); 6425 if (parmlen > nargs) 6426 nargs = parmlen; 6427 argarray = XALLOCAVEC (tree, nargs); 6428 6429 /* The implicit parameters to a constructor are not considered by overload 6430 resolution, and must be of the proper type. */ 6431 if (DECL_CONSTRUCTOR_P (fn)) 6432 { 6433 if (first_arg != NULL_TREE) 6434 { 6435 argarray[j++] = first_arg; 6436 first_arg = NULL_TREE; 6437 } 6438 else 6439 { 6440 argarray[j++] = VEC_index (tree, args, arg_index); 6441 ++arg_index; 6442 } 6443 parm = TREE_CHAIN (parm); 6444 /* We should never try to call the abstract constructor. */ 6445 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn)); 6446 6447 if (DECL_HAS_VTT_PARM_P (fn)) 6448 { 6449 argarray[j++] = VEC_index (tree, args, arg_index); 6450 ++arg_index; 6451 parm = TREE_CHAIN (parm); 6452 } 6453 } 6454 /* Bypass access control for 'this' parameter. */ 6455 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 6456 { 6457 tree parmtype = TREE_VALUE (parm); 6458 tree arg = (first_arg != NULL_TREE 6459 ? first_arg 6460 : VEC_index (tree, args, arg_index)); 6461 tree argtype = TREE_TYPE (arg); 6462 tree converted_arg; 6463 tree base_binfo; 6464 6465 if (convs[i]->bad_p) 6466 { 6467 if (complain & tf_error) 6468 permerror (input_location, "passing %qT as %<this%> argument of %q#D discards qualifiers", 6469 TREE_TYPE (argtype), fn); 6470 else 6471 return error_mark_node; 6472 } 6473 6474 /* See if the function member or the whole class type is declared 6475 final and the call can be devirtualized. */ 6476 if (DECL_FINAL_P (fn) 6477 || CLASSTYPE_FINAL (TYPE_METHOD_BASETYPE (TREE_TYPE (fn)))) 6478 flags |= LOOKUP_NONVIRTUAL; 6479 6480 /* [class.mfct.nonstatic]: If a nonstatic member function of a class 6481 X is called for an object that is not of type X, or of a type 6482 derived from X, the behavior is undefined. 6483 6484 So we can assume that anything passed as 'this' is non-null, and 6485 optimize accordingly. */ 6486 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE); 6487 /* Convert to the base in which the function was declared. */ 6488 gcc_assert (cand->conversion_path != NULL_TREE); 6489 converted_arg = build_base_path (PLUS_EXPR, 6490 arg, 6491 cand->conversion_path, 6492 1, complain); 6493 /* Check that the base class is accessible. */ 6494 if (!accessible_base_p (TREE_TYPE (argtype), 6495 BINFO_TYPE (cand->conversion_path), true)) 6496 error ("%qT is not an accessible base of %qT", 6497 BINFO_TYPE (cand->conversion_path), 6498 TREE_TYPE (argtype)); 6499 /* If fn was found by a using declaration, the conversion path 6500 will be to the derived class, not the base declaring fn. We 6501 must convert from derived to base. */ 6502 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)), 6503 TREE_TYPE (parmtype), ba_unique, NULL); 6504 converted_arg = build_base_path (PLUS_EXPR, converted_arg, 6505 base_binfo, 1, complain); 6506 6507 argarray[j++] = converted_arg; 6508 parm = TREE_CHAIN (parm); 6509 if (first_arg != NULL_TREE) 6510 first_arg = NULL_TREE; 6511 else 6512 ++arg_index; 6513 ++i; 6514 is_method = 1; 6515 } 6516 6517 gcc_assert (first_arg == NULL_TREE); 6518 for (; arg_index < VEC_length (tree, args) && parm; 6519 parm = TREE_CHAIN (parm), ++arg_index, ++i) 6520 { 6521 tree type = TREE_VALUE (parm); 6522 tree arg = VEC_index (tree, args, arg_index); 6523 bool conversion_warning = true; 6524 6525 conv = convs[i]; 6526 6527 /* If the argument is NULL and used to (implicitly) instantiate a 6528 template function (and bind one of the template arguments to 6529 the type of 'long int'), we don't want to warn about passing NULL 6530 to non-pointer argument. 6531 For example, if we have this template function: 6532 6533 template<typename T> void func(T x) {} 6534 6535 we want to warn (when -Wconversion is enabled) in this case: 6536 6537 void foo() { 6538 func<int>(NULL); 6539 } 6540 6541 but not in this case: 6542 6543 void foo() { 6544 func(NULL); 6545 } 6546 */ 6547 if (arg == null_node 6548 && DECL_TEMPLATE_INFO (fn) 6549 && cand->template_decl 6550 && !(flags & LOOKUP_EXPLICIT_TMPL_ARGS)) 6551 conversion_warning = false; 6552 6553 /* Warn about initializer_list deduction that isn't currently in the 6554 working draft. */ 6555 if (cxx_dialect > cxx98 6556 && flag_deduce_init_list 6557 && cand->template_decl 6558 && is_std_init_list (non_reference (type)) 6559 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 6560 { 6561 tree tmpl = TI_TEMPLATE (cand->template_decl); 6562 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn)); 6563 tree patparm = get_pattern_parm (realparm, tmpl); 6564 tree pattype = TREE_TYPE (patparm); 6565 if (PACK_EXPANSION_P (pattype)) 6566 pattype = PACK_EXPANSION_PATTERN (pattype); 6567 pattype = non_reference (pattype); 6568 6569 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM 6570 && (cand->explicit_targs == NULL_TREE 6571 || (TREE_VEC_LENGTH (cand->explicit_targs) 6572 <= TEMPLATE_TYPE_IDX (pattype)))) 6573 { 6574 pedwarn (input_location, 0, "deducing %qT as %qT", 6575 non_reference (TREE_TYPE (patparm)), 6576 non_reference (type)); 6577 pedwarn (input_location, 0, " in call to %q+D", cand->fn); 6578 pedwarn (input_location, 0, 6579 " (you can disable this with -fno-deduce-init-list)"); 6580 } 6581 } 6582 6583 val = convert_like_with_context (conv, arg, fn, i-is_method, 6584 conversion_warning 6585 ? complain 6586 : complain & (~tf_warning)); 6587 6588 val = convert_for_arg_passing (type, val); 6589 if (val == error_mark_node) 6590 return error_mark_node; 6591 else 6592 argarray[j++] = val; 6593 } 6594 6595 /* Default arguments */ 6596 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++) 6597 { 6598 if (TREE_VALUE (parm) == error_mark_node) 6599 return error_mark_node; 6600 argarray[j++] = convert_default_arg (TREE_VALUE (parm), 6601 TREE_PURPOSE (parm), 6602 fn, i - is_method); 6603 } 6604 6605 /* Ellipsis */ 6606 for (; arg_index < VEC_length (tree, args); ++arg_index) 6607 { 6608 tree a = VEC_index (tree, args, arg_index); 6609 if (magic_varargs_p (fn)) 6610 /* Do no conversions for magic varargs. */ 6611 a = mark_type_use (a); 6612 else 6613 a = convert_arg_to_ellipsis (a); 6614 argarray[j++] = a; 6615 } 6616 6617 gcc_assert (j <= nargs); 6618 nargs = j; 6619 6620 check_function_arguments (TREE_TYPE (fn), nargs, argarray); 6621 6622 /* Avoid actually calling copy constructors and copy assignment operators, 6623 if possible. */ 6624 6625 if (! flag_elide_constructors) 6626 /* Do things the hard way. */; 6627 else if (cand->num_convs == 1 6628 && (DECL_COPY_CONSTRUCTOR_P (fn) 6629 || DECL_MOVE_CONSTRUCTOR_P (fn))) 6630 { 6631 tree targ; 6632 tree arg = argarray[num_artificial_parms_for (fn)]; 6633 tree fa; 6634 bool trivial = trivial_fn_p (fn); 6635 6636 /* Pull out the real argument, disregarding const-correctness. */ 6637 targ = arg; 6638 while (CONVERT_EXPR_P (targ) 6639 || TREE_CODE (targ) == NON_LVALUE_EXPR) 6640 targ = TREE_OPERAND (targ, 0); 6641 if (TREE_CODE (targ) == ADDR_EXPR) 6642 { 6643 targ = TREE_OPERAND (targ, 0); 6644 if (!same_type_ignoring_top_level_qualifiers_p 6645 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ))) 6646 targ = NULL_TREE; 6647 } 6648 else 6649 targ = NULL_TREE; 6650 6651 if (targ) 6652 arg = targ; 6653 else 6654 arg = cp_build_indirect_ref (arg, RO_NULL, complain); 6655 6656 /* [class.copy]: the copy constructor is implicitly defined even if 6657 the implementation elided its use. */ 6658 if (!trivial || DECL_DELETED_FN (fn)) 6659 { 6660 mark_used (fn); 6661 already_used = true; 6662 } 6663 6664 /* If we're creating a temp and we already have one, don't create a 6665 new one. If we're not creating a temp but we get one, use 6666 INIT_EXPR to collapse the temp into our target. Otherwise, if the 6667 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a 6668 temp or an INIT_EXPR otherwise. */ 6669 fa = argarray[0]; 6670 if (integer_zerop (fa)) 6671 { 6672 if (TREE_CODE (arg) == TARGET_EXPR) 6673 return arg; 6674 else if (trivial) 6675 return force_target_expr (DECL_CONTEXT (fn), arg, complain); 6676 } 6677 else if (TREE_CODE (arg) == TARGET_EXPR || trivial) 6678 { 6679 tree to = stabilize_reference (cp_build_indirect_ref (fa, RO_NULL, 6680 complain)); 6681 6682 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg); 6683 return val; 6684 } 6685 } 6686 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR 6687 && trivial_fn_p (fn) 6688 && !DECL_DELETED_FN (fn)) 6689 { 6690 tree to = stabilize_reference 6691 (cp_build_indirect_ref (argarray[0], RO_NULL, complain)); 6692 tree type = TREE_TYPE (to); 6693 tree as_base = CLASSTYPE_AS_BASE (type); 6694 tree arg = argarray[1]; 6695 6696 if (is_really_empty_class (type)) 6697 { 6698 /* Avoid copying empty classes. */ 6699 val = build2 (COMPOUND_EXPR, void_type_node, to, arg); 6700 TREE_NO_WARNING (val) = 1; 6701 val = build2 (COMPOUND_EXPR, type, val, to); 6702 TREE_NO_WARNING (val) = 1; 6703 } 6704 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base))) 6705 { 6706 arg = cp_build_indirect_ref (arg, RO_NULL, complain); 6707 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg); 6708 } 6709 else 6710 { 6711 /* We must only copy the non-tail padding parts. */ 6712 tree arg0, arg2, t; 6713 tree array_type, alias_set; 6714 6715 arg2 = TYPE_SIZE_UNIT (as_base); 6716 arg0 = cp_build_addr_expr (to, complain); 6717 6718 array_type = build_array_type (char_type_node, 6719 build_index_type 6720 (size_binop (MINUS_EXPR, 6721 arg2, size_int (1)))); 6722 alias_set = build_int_cst (build_pointer_type (type), 0); 6723 t = build2 (MODIFY_EXPR, void_type_node, 6724 build2 (MEM_REF, array_type, arg0, alias_set), 6725 build2 (MEM_REF, array_type, arg, alias_set)); 6726 val = build2 (COMPOUND_EXPR, TREE_TYPE (to), t, to); 6727 TREE_NO_WARNING (val) = 1; 6728 } 6729 6730 return val; 6731 } 6732 else if (DECL_DESTRUCTOR_P (fn) 6733 && trivial_fn_p (fn) 6734 && !DECL_DELETED_FN (fn)) 6735 return fold_convert (void_type_node, argarray[0]); 6736 /* FIXME handle trivial default constructor, too. */ 6737 6738 if (!already_used) 6739 mark_used (fn); 6740 6741 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0) 6742 { 6743 tree t; 6744 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])), 6745 DECL_CONTEXT (fn), 6746 ba_any, NULL); 6747 gcc_assert (binfo && binfo != error_mark_node); 6748 6749 /* Warn about deprecated virtual functions now, since we're about 6750 to throw away the decl. */ 6751 if (TREE_DEPRECATED (fn)) 6752 warn_deprecated_use (fn, NULL_TREE); 6753 6754 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1, 6755 complain); 6756 if (TREE_SIDE_EFFECTS (argarray[0])) 6757 argarray[0] = save_expr (argarray[0]); 6758 t = build_pointer_type (TREE_TYPE (fn)); 6759 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn))) 6760 fn = build_java_interface_fn_ref (fn, argarray[0]); 6761 else 6762 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn)); 6763 TREE_TYPE (fn) = t; 6764 } 6765 else 6766 fn = build_addr_func (fn); 6767 6768 return build_cxx_call (fn, nargs, argarray); 6769 } 6770 6771 /* Build and return a call to FN, using NARGS arguments in ARGARRAY. 6772 This function performs no overload resolution, conversion, or other 6773 high-level operations. */ 6774 6775 tree 6776 build_cxx_call (tree fn, int nargs, tree *argarray) 6777 { 6778 tree fndecl; 6779 6780 /* Remember roughly where this call is. */ 6781 location_t loc = EXPR_LOC_OR_HERE (fn); 6782 fn = build_call_a (fn, nargs, argarray); 6783 SET_EXPR_LOCATION (fn, loc); 6784 6785 fndecl = get_callee_fndecl (fn); 6786 6787 /* Check that arguments to builtin functions match the expectations. */ 6788 if (fndecl 6789 && DECL_BUILT_IN (fndecl) 6790 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL 6791 && !check_builtin_function_arguments (fndecl, nargs, argarray)) 6792 return error_mark_node; 6793 6794 /* Some built-in function calls will be evaluated at compile-time in 6795 fold (). */ 6796 fn = fold_if_not_in_template (fn); 6797 6798 if (VOID_TYPE_P (TREE_TYPE (fn))) 6799 return fn; 6800 6801 fn = require_complete_type (fn); 6802 if (fn == error_mark_node) 6803 return error_mark_node; 6804 6805 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn))) 6806 fn = build_cplus_new (TREE_TYPE (fn), fn, tf_warning_or_error); 6807 return convert_from_reference (fn); 6808 } 6809 6810 static GTY(()) tree java_iface_lookup_fn; 6811 6812 /* Make an expression which yields the address of the Java interface 6813 method FN. This is achieved by generating a call to libjava's 6814 _Jv_LookupInterfaceMethodIdx(). */ 6815 6816 static tree 6817 build_java_interface_fn_ref (tree fn, tree instance) 6818 { 6819 tree lookup_fn, method, idx; 6820 tree klass_ref, iface, iface_ref; 6821 int i; 6822 6823 if (!java_iface_lookup_fn) 6824 { 6825 tree ftype = build_function_type_list (ptr_type_node, 6826 ptr_type_node, ptr_type_node, 6827 java_int_type_node, NULL_TREE); 6828 java_iface_lookup_fn 6829 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx", ftype, 6830 0, NOT_BUILT_IN, NULL, NULL_TREE); 6831 } 6832 6833 /* Look up the pointer to the runtime java.lang.Class object for `instance'. 6834 This is the first entry in the vtable. */ 6835 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, RO_NULL, 6836 tf_warning_or_error), 6837 integer_zero_node); 6838 6839 /* Get the java.lang.Class pointer for the interface being called. */ 6840 iface = DECL_CONTEXT (fn); 6841 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false); 6842 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL 6843 || DECL_CONTEXT (iface_ref) != iface) 6844 { 6845 error ("could not find class$ field in java interface type %qT", 6846 iface); 6847 return error_mark_node; 6848 } 6849 iface_ref = build_address (iface_ref); 6850 iface_ref = convert (build_pointer_type (iface), iface_ref); 6851 6852 /* Determine the itable index of FN. */ 6853 i = 1; 6854 for (method = TYPE_METHODS (iface); method; method = DECL_CHAIN (method)) 6855 { 6856 if (!DECL_VIRTUAL_P (method)) 6857 continue; 6858 if (fn == method) 6859 break; 6860 i++; 6861 } 6862 idx = build_int_cst (NULL_TREE, i); 6863 6864 lookup_fn = build1 (ADDR_EXPR, 6865 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)), 6866 java_iface_lookup_fn); 6867 return build_call_nary (ptr_type_node, lookup_fn, 6868 3, klass_ref, iface_ref, idx); 6869 } 6870 6871 /* Returns the value to use for the in-charge parameter when making a 6872 call to a function with the indicated NAME. 6873 6874 FIXME:Can't we find a neater way to do this mapping? */ 6875 6876 tree 6877 in_charge_arg_for_name (tree name) 6878 { 6879 if (name == base_ctor_identifier 6880 || name == base_dtor_identifier) 6881 return integer_zero_node; 6882 else if (name == complete_ctor_identifier) 6883 return integer_one_node; 6884 else if (name == complete_dtor_identifier) 6885 return integer_two_node; 6886 else if (name == deleting_dtor_identifier) 6887 return integer_three_node; 6888 6889 /* This function should only be called with one of the names listed 6890 above. */ 6891 gcc_unreachable (); 6892 return NULL_TREE; 6893 } 6894 6895 /* Build a call to a constructor, destructor, or an assignment 6896 operator for INSTANCE, an expression with class type. NAME 6897 indicates the special member function to call; *ARGS are the 6898 arguments. ARGS may be NULL. This may change ARGS. BINFO 6899 indicates the base of INSTANCE that is to be passed as the `this' 6900 parameter to the member function called. 6901 6902 FLAGS are the LOOKUP_* flags to use when processing the call. 6903 6904 If NAME indicates a complete object constructor, INSTANCE may be 6905 NULL_TREE. In this case, the caller will call build_cplus_new to 6906 store the newly constructed object into a VAR_DECL. */ 6907 6908 tree 6909 build_special_member_call (tree instance, tree name, VEC(tree,gc) **args, 6910 tree binfo, int flags, tsubst_flags_t complain) 6911 { 6912 tree fns; 6913 /* The type of the subobject to be constructed or destroyed. */ 6914 tree class_type; 6915 VEC(tree,gc) *allocated = NULL; 6916 tree ret; 6917 6918 gcc_assert (name == complete_ctor_identifier 6919 || name == base_ctor_identifier 6920 || name == complete_dtor_identifier 6921 || name == base_dtor_identifier 6922 || name == deleting_dtor_identifier 6923 || name == ansi_assopname (NOP_EXPR)); 6924 if (TYPE_P (binfo)) 6925 { 6926 /* Resolve the name. */ 6927 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain)) 6928 return error_mark_node; 6929 6930 binfo = TYPE_BINFO (binfo); 6931 } 6932 6933 gcc_assert (binfo != NULL_TREE); 6934 6935 class_type = BINFO_TYPE (binfo); 6936 6937 /* Handle the special case where INSTANCE is NULL_TREE. */ 6938 if (name == complete_ctor_identifier && !instance) 6939 { 6940 instance = build_int_cst (build_pointer_type (class_type), 0); 6941 instance = build1 (INDIRECT_REF, class_type, instance); 6942 } 6943 else 6944 { 6945 if (name == complete_dtor_identifier 6946 || name == base_dtor_identifier 6947 || name == deleting_dtor_identifier) 6948 gcc_assert (args == NULL || VEC_empty (tree, *args)); 6949 6950 /* Convert to the base class, if necessary. */ 6951 if (!same_type_ignoring_top_level_qualifiers_p 6952 (TREE_TYPE (instance), BINFO_TYPE (binfo))) 6953 { 6954 if (name != ansi_assopname (NOP_EXPR)) 6955 /* For constructors and destructors, either the base is 6956 non-virtual, or it is virtual but we are doing the 6957 conversion from a constructor or destructor for the 6958 complete object. In either case, we can convert 6959 statically. */ 6960 instance = convert_to_base_statically (instance, binfo); 6961 else 6962 /* However, for assignment operators, we must convert 6963 dynamically if the base is virtual. */ 6964 instance = build_base_path (PLUS_EXPR, instance, 6965 binfo, /*nonnull=*/1, complain); 6966 } 6967 } 6968 6969 gcc_assert (instance != NULL_TREE); 6970 6971 fns = lookup_fnfields (binfo, name, 1); 6972 6973 /* When making a call to a constructor or destructor for a subobject 6974 that uses virtual base classes, pass down a pointer to a VTT for 6975 the subobject. */ 6976 if ((name == base_ctor_identifier 6977 || name == base_dtor_identifier) 6978 && CLASSTYPE_VBASECLASSES (class_type)) 6979 { 6980 tree vtt; 6981 tree sub_vtt; 6982 6983 /* If the current function is a complete object constructor 6984 or destructor, then we fetch the VTT directly. 6985 Otherwise, we look it up using the VTT we were given. */ 6986 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type)); 6987 vtt = decay_conversion (vtt); 6988 vtt = build3 (COND_EXPR, TREE_TYPE (vtt), 6989 build2 (EQ_EXPR, boolean_type_node, 6990 current_in_charge_parm, integer_zero_node), 6991 current_vtt_parm, 6992 vtt); 6993 if (BINFO_SUBVTT_INDEX (binfo)) 6994 sub_vtt = fold_build_pointer_plus (vtt, BINFO_SUBVTT_INDEX (binfo)); 6995 else 6996 sub_vtt = vtt; 6997 6998 if (args == NULL) 6999 { 7000 allocated = make_tree_vector (); 7001 args = &allocated; 7002 } 7003 7004 VEC_safe_insert (tree, gc, *args, 0, sub_vtt); 7005 } 7006 7007 ret = build_new_method_call (instance, fns, args, 7008 TYPE_BINFO (BINFO_TYPE (binfo)), 7009 flags, /*fn=*/NULL, 7010 complain); 7011 7012 if (allocated != NULL) 7013 release_tree_vector (allocated); 7014 7015 return ret; 7016 } 7017 7018 /* Return the NAME, as a C string. The NAME indicates a function that 7019 is a member of TYPE. *FREE_P is set to true if the caller must 7020 free the memory returned. 7021 7022 Rather than go through all of this, we should simply set the names 7023 of constructors and destructors appropriately, and dispense with 7024 ctor_identifier, dtor_identifier, etc. */ 7025 7026 static char * 7027 name_as_c_string (tree name, tree type, bool *free_p) 7028 { 7029 char *pretty_name; 7030 7031 /* Assume that we will not allocate memory. */ 7032 *free_p = false; 7033 /* Constructors and destructors are special. */ 7034 if (IDENTIFIER_CTOR_OR_DTOR_P (name)) 7035 { 7036 pretty_name 7037 = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type)))); 7038 /* For a destructor, add the '~'. */ 7039 if (name == complete_dtor_identifier 7040 || name == base_dtor_identifier 7041 || name == deleting_dtor_identifier) 7042 { 7043 pretty_name = concat ("~", pretty_name, NULL); 7044 /* Remember that we need to free the memory allocated. */ 7045 *free_p = true; 7046 } 7047 } 7048 else if (IDENTIFIER_TYPENAME_P (name)) 7049 { 7050 pretty_name = concat ("operator ", 7051 type_as_string_translate (TREE_TYPE (name), 7052 TFF_PLAIN_IDENTIFIER), 7053 NULL); 7054 /* Remember that we need to free the memory allocated. */ 7055 *free_p = true; 7056 } 7057 else 7058 pretty_name = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (name))); 7059 7060 return pretty_name; 7061 } 7062 7063 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will 7064 be set, upon return, to the function called. ARGS may be NULL. 7065 This may change ARGS. */ 7066 7067 static tree 7068 build_new_method_call_1 (tree instance, tree fns, VEC(tree,gc) **args, 7069 tree conversion_path, int flags, 7070 tree *fn_p, tsubst_flags_t complain) 7071 { 7072 struct z_candidate *candidates = 0, *cand; 7073 tree explicit_targs = NULL_TREE; 7074 tree basetype = NULL_TREE; 7075 tree access_binfo; 7076 tree optype; 7077 tree first_mem_arg = NULL_TREE; 7078 tree instance_ptr; 7079 tree name; 7080 bool skip_first_for_error; 7081 VEC(tree,gc) *user_args; 7082 tree call; 7083 tree fn; 7084 int template_only = 0; 7085 bool any_viable_p; 7086 tree orig_instance; 7087 tree orig_fns; 7088 VEC(tree,gc) *orig_args = NULL; 7089 void *p; 7090 7091 gcc_assert (instance != NULL_TREE); 7092 7093 /* We don't know what function we're going to call, yet. */ 7094 if (fn_p) 7095 *fn_p = NULL_TREE; 7096 7097 if (error_operand_p (instance) 7098 || !fns || error_operand_p (fns)) 7099 return error_mark_node; 7100 7101 if (!BASELINK_P (fns)) 7102 { 7103 if (complain & tf_error) 7104 error ("call to non-function %qD", fns); 7105 return error_mark_node; 7106 } 7107 7108 orig_instance = instance; 7109 orig_fns = fns; 7110 7111 /* Dismantle the baselink to collect all the information we need. */ 7112 if (!conversion_path) 7113 conversion_path = BASELINK_BINFO (fns); 7114 access_binfo = BASELINK_ACCESS_BINFO (fns); 7115 optype = BASELINK_OPTYPE (fns); 7116 fns = BASELINK_FUNCTIONS (fns); 7117 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR) 7118 { 7119 explicit_targs = TREE_OPERAND (fns, 1); 7120 fns = TREE_OPERAND (fns, 0); 7121 template_only = 1; 7122 } 7123 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL 7124 || TREE_CODE (fns) == TEMPLATE_DECL 7125 || TREE_CODE (fns) == OVERLOAD); 7126 fn = get_first_fn (fns); 7127 name = DECL_NAME (fn); 7128 7129 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance)); 7130 gcc_assert (CLASS_TYPE_P (basetype)); 7131 7132 if (processing_template_decl) 7133 { 7134 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args); 7135 instance = build_non_dependent_expr (instance); 7136 if (args != NULL) 7137 make_args_non_dependent (*args); 7138 } 7139 7140 user_args = args == NULL ? NULL : *args; 7141 /* Under DR 147 A::A() is an invalid constructor call, 7142 not a functional cast. */ 7143 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 7144 { 7145 if (! (complain & tf_error)) 7146 return error_mark_node; 7147 7148 permerror (input_location, 7149 "cannot call constructor %<%T::%D%> directly", 7150 basetype, name); 7151 permerror (input_location, " for a function-style cast, remove the " 7152 "redundant %<::%D%>", name); 7153 call = build_functional_cast (basetype, build_tree_list_vec (user_args), 7154 complain); 7155 return call; 7156 } 7157 7158 /* Figure out whether to skip the first argument for the error 7159 message we will display to users if an error occurs. We don't 7160 want to display any compiler-generated arguments. The "this" 7161 pointer hasn't been added yet. However, we must remove the VTT 7162 pointer if this is a call to a base-class constructor or 7163 destructor. */ 7164 skip_first_for_error = false; 7165 if (IDENTIFIER_CTOR_OR_DTOR_P (name)) 7166 { 7167 /* Callers should explicitly indicate whether they want to construct 7168 the complete object or just the part without virtual bases. */ 7169 gcc_assert (name != ctor_identifier); 7170 /* Similarly for destructors. */ 7171 gcc_assert (name != dtor_identifier); 7172 /* Remove the VTT pointer, if present. */ 7173 if ((name == base_ctor_identifier || name == base_dtor_identifier) 7174 && CLASSTYPE_VBASECLASSES (basetype)) 7175 skip_first_for_error = true; 7176 } 7177 7178 /* Process the argument list. */ 7179 if (args != NULL && *args != NULL) 7180 { 7181 *args = resolve_args (*args, complain); 7182 if (*args == NULL) 7183 return error_mark_node; 7184 } 7185 7186 instance_ptr = build_this (instance); 7187 7188 /* It's OK to call destructors and constructors on cv-qualified objects. 7189 Therefore, convert the INSTANCE_PTR to the unqualified type, if 7190 necessary. */ 7191 if (DECL_DESTRUCTOR_P (fn) 7192 || DECL_CONSTRUCTOR_P (fn)) 7193 { 7194 tree type = build_pointer_type (basetype); 7195 if (!same_type_p (type, TREE_TYPE (instance_ptr))) 7196 instance_ptr = build_nop (type, instance_ptr); 7197 } 7198 if (DECL_DESTRUCTOR_P (fn)) 7199 name = complete_dtor_identifier; 7200 7201 first_mem_arg = instance_ptr; 7202 7203 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 7204 p = conversion_obstack_alloc (0); 7205 7206 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form 7207 initializer, not T({ }). */ 7208 if (DECL_CONSTRUCTOR_P (fn) && args != NULL && !VEC_empty (tree, *args) 7209 && BRACE_ENCLOSED_INITIALIZER_P (VEC_index (tree, *args, 0)) 7210 && CONSTRUCTOR_IS_DIRECT_INIT (VEC_index (tree, *args, 0))) 7211 { 7212 tree init_list = VEC_index (tree, *args, 0); 7213 tree init = NULL_TREE; 7214 7215 gcc_assert (VEC_length (tree, *args) == 1 7216 && !(flags & LOOKUP_ONLYCONVERTING)); 7217 7218 /* If the initializer list has no elements and T is a class type with 7219 a default constructor, the object is value-initialized. Handle 7220 this here so we don't need to handle it wherever we use 7221 build_special_member_call. */ 7222 if (CONSTRUCTOR_NELTS (init_list) == 0 7223 && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype) 7224 /* For a user-provided default constructor, use the normal 7225 mechanisms so that protected access works. */ 7226 && !type_has_user_provided_default_constructor (basetype) 7227 && !processing_template_decl) 7228 init = build_value_init (basetype, complain); 7229 7230 /* If BASETYPE is an aggregate, we need to do aggregate 7231 initialization. */ 7232 else if (CP_AGGREGATE_TYPE_P (basetype)) 7233 init = digest_init (basetype, init_list, complain); 7234 7235 if (init) 7236 { 7237 tree ob; 7238 if (integer_zerop (instance_ptr)) 7239 return get_target_expr_sfinae (init, complain); 7240 ob = build_fold_indirect_ref (instance_ptr); 7241 init = build2 (INIT_EXPR, TREE_TYPE (ob), ob, init); 7242 TREE_SIDE_EFFECTS (init) = true; 7243 return init; 7244 } 7245 7246 /* Otherwise go ahead with overload resolution. */ 7247 add_list_candidates (fns, first_mem_arg, init_list, 7248 basetype, explicit_targs, template_only, 7249 conversion_path, access_binfo, flags, &candidates); 7250 } 7251 else 7252 { 7253 add_candidates (fns, first_mem_arg, user_args, optype, 7254 explicit_targs, template_only, conversion_path, 7255 access_binfo, flags, &candidates); 7256 } 7257 any_viable_p = false; 7258 candidates = splice_viable (candidates, pedantic, &any_viable_p); 7259 7260 if (!any_viable_p) 7261 { 7262 if (complain & tf_error) 7263 { 7264 if (!COMPLETE_OR_OPEN_TYPE_P (basetype)) 7265 cxx_incomplete_type_error (instance_ptr, basetype); 7266 else if (optype) 7267 error ("no matching function for call to %<%T::operator %T(%A)%#V%>", 7268 basetype, optype, build_tree_list_vec (user_args), 7269 TREE_TYPE (TREE_TYPE (instance_ptr))); 7270 else 7271 { 7272 char *pretty_name; 7273 bool free_p; 7274 tree arglist; 7275 7276 pretty_name = name_as_c_string (name, basetype, &free_p); 7277 arglist = build_tree_list_vec (user_args); 7278 if (skip_first_for_error) 7279 arglist = TREE_CHAIN (arglist); 7280 error ("no matching function for call to %<%T::%s(%A)%#V%>", 7281 basetype, pretty_name, arglist, 7282 TREE_TYPE (TREE_TYPE (instance_ptr))); 7283 if (free_p) 7284 free (pretty_name); 7285 } 7286 print_z_candidates (location_of (name), candidates); 7287 } 7288 call = error_mark_node; 7289 } 7290 else 7291 { 7292 cand = tourney (candidates); 7293 if (cand == 0) 7294 { 7295 char *pretty_name; 7296 bool free_p; 7297 tree arglist; 7298 7299 if (complain & tf_error) 7300 { 7301 pretty_name = name_as_c_string (name, basetype, &free_p); 7302 arglist = build_tree_list_vec (user_args); 7303 if (skip_first_for_error) 7304 arglist = TREE_CHAIN (arglist); 7305 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name, 7306 arglist); 7307 print_z_candidates (location_of (name), candidates); 7308 if (free_p) 7309 free (pretty_name); 7310 } 7311 call = error_mark_node; 7312 } 7313 else 7314 { 7315 fn = cand->fn; 7316 7317 if (!(flags & LOOKUP_NONVIRTUAL) 7318 && DECL_PURE_VIRTUAL_P (fn) 7319 && instance == current_class_ref 7320 && (DECL_CONSTRUCTOR_P (current_function_decl) 7321 || DECL_DESTRUCTOR_P (current_function_decl)) 7322 && (complain & tf_warning)) 7323 /* This is not an error, it is runtime undefined 7324 behavior. */ 7325 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ? 7326 "pure virtual %q#D called from constructor" 7327 : "pure virtual %q#D called from destructor"), 7328 fn); 7329 7330 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE 7331 && is_dummy_object (instance_ptr)) 7332 { 7333 if (complain & tf_error) 7334 error ("cannot call member function %qD without object", 7335 fn); 7336 call = error_mark_node; 7337 } 7338 else 7339 { 7340 /* Optimize away vtable lookup if we know that this function 7341 can't be overridden. */ 7342 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL) 7343 && resolves_to_fixed_type_p (instance, 0)) 7344 flags |= LOOKUP_NONVIRTUAL; 7345 if (explicit_targs) 7346 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 7347 /* Now we know what function is being called. */ 7348 if (fn_p) 7349 *fn_p = fn; 7350 /* Build the actual CALL_EXPR. */ 7351 call = build_over_call (cand, flags, complain); 7352 /* In an expression of the form `a->f()' where `f' turns 7353 out to be a static member function, `a' is 7354 none-the-less evaluated. */ 7355 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE 7356 && !is_dummy_object (instance_ptr) 7357 && TREE_SIDE_EFFECTS (instance_ptr)) 7358 call = build2 (COMPOUND_EXPR, TREE_TYPE (call), 7359 instance_ptr, call); 7360 else if (call != error_mark_node 7361 && DECL_DESTRUCTOR_P (cand->fn) 7362 && !VOID_TYPE_P (TREE_TYPE (call))) 7363 /* An explicit call of the form "x->~X()" has type 7364 "void". However, on platforms where destructors 7365 return "this" (i.e., those where 7366 targetm.cxx.cdtor_returns_this is true), such calls 7367 will appear to have a return value of pointer type 7368 to the low-level call machinery. We do not want to 7369 change the low-level machinery, since we want to be 7370 able to optimize "delete f()" on such platforms as 7371 "operator delete(~X(f()))" (rather than generating 7372 "t = f(), ~X(t), operator delete (t)"). */ 7373 call = build_nop (void_type_node, call); 7374 } 7375 } 7376 } 7377 7378 if (processing_template_decl && call != error_mark_node) 7379 { 7380 bool cast_to_void = false; 7381 7382 if (TREE_CODE (call) == COMPOUND_EXPR) 7383 call = TREE_OPERAND (call, 1); 7384 else if (TREE_CODE (call) == NOP_EXPR) 7385 { 7386 cast_to_void = true; 7387 call = TREE_OPERAND (call, 0); 7388 } 7389 if (TREE_CODE (call) == INDIRECT_REF) 7390 call = TREE_OPERAND (call, 0); 7391 call = (build_min_non_dep_call_vec 7392 (call, 7393 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)), 7394 orig_instance, orig_fns, NULL_TREE), 7395 orig_args)); 7396 call = convert_from_reference (call); 7397 if (cast_to_void) 7398 call = build_nop (void_type_node, call); 7399 } 7400 7401 /* Free all the conversions we allocated. */ 7402 obstack_free (&conversion_obstack, p); 7403 7404 if (orig_args != NULL) 7405 release_tree_vector (orig_args); 7406 7407 return call; 7408 } 7409 7410 /* Wrapper for above. */ 7411 7412 tree 7413 build_new_method_call (tree instance, tree fns, VEC(tree,gc) **args, 7414 tree conversion_path, int flags, 7415 tree *fn_p, tsubst_flags_t complain) 7416 { 7417 tree ret; 7418 bool subtime = timevar_cond_start (TV_OVERLOAD); 7419 ret = build_new_method_call_1 (instance, fns, args, conversion_path, flags, 7420 fn_p, complain); 7421 timevar_cond_stop (TV_OVERLOAD, subtime); 7422 return ret; 7423 } 7424 7425 /* Returns true iff standard conversion sequence ICS1 is a proper 7426 subsequence of ICS2. */ 7427 7428 static bool 7429 is_subseq (conversion *ics1, conversion *ics2) 7430 { 7431 /* We can assume that a conversion of the same code 7432 between the same types indicates a subsequence since we only get 7433 here if the types we are converting from are the same. */ 7434 7435 while (ics1->kind == ck_rvalue 7436 || ics1->kind == ck_lvalue) 7437 ics1 = ics1->u.next; 7438 7439 while (1) 7440 { 7441 while (ics2->kind == ck_rvalue 7442 || ics2->kind == ck_lvalue) 7443 ics2 = ics2->u.next; 7444 7445 if (ics2->kind == ck_user 7446 || ics2->kind == ck_ambig 7447 || ics2->kind == ck_aggr 7448 || ics2->kind == ck_list 7449 || ics2->kind == ck_identity) 7450 /* At this point, ICS1 cannot be a proper subsequence of 7451 ICS2. We can get a USER_CONV when we are comparing the 7452 second standard conversion sequence of two user conversion 7453 sequences. */ 7454 return false; 7455 7456 ics2 = ics2->u.next; 7457 7458 if (ics2->kind == ics1->kind 7459 && same_type_p (ics2->type, ics1->type) 7460 && same_type_p (ics2->u.next->type, 7461 ics1->u.next->type)) 7462 return true; 7463 } 7464 } 7465 7466 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may 7467 be any _TYPE nodes. */ 7468 7469 bool 7470 is_properly_derived_from (tree derived, tree base) 7471 { 7472 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base)) 7473 return false; 7474 7475 /* We only allow proper derivation here. The DERIVED_FROM_P macro 7476 considers every class derived from itself. */ 7477 return (!same_type_ignoring_top_level_qualifiers_p (derived, base) 7478 && DERIVED_FROM_P (base, derived)); 7479 } 7480 7481 /* We build the ICS for an implicit object parameter as a pointer 7482 conversion sequence. However, such a sequence should be compared 7483 as if it were a reference conversion sequence. If ICS is the 7484 implicit conversion sequence for an implicit object parameter, 7485 modify it accordingly. */ 7486 7487 static void 7488 maybe_handle_implicit_object (conversion **ics) 7489 { 7490 if ((*ics)->this_p) 7491 { 7492 /* [over.match.funcs] 7493 7494 For non-static member functions, the type of the 7495 implicit object parameter is "reference to cv X" 7496 where X is the class of which the function is a 7497 member and cv is the cv-qualification on the member 7498 function declaration. */ 7499 conversion *t = *ics; 7500 tree reference_type; 7501 7502 /* The `this' parameter is a pointer to a class type. Make the 7503 implicit conversion talk about a reference to that same class 7504 type. */ 7505 reference_type = TREE_TYPE (t->type); 7506 reference_type = build_reference_type (reference_type); 7507 7508 if (t->kind == ck_qual) 7509 t = t->u.next; 7510 if (t->kind == ck_ptr) 7511 t = t->u.next; 7512 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE); 7513 t = direct_reference_binding (reference_type, t); 7514 t->this_p = 1; 7515 t->rvaluedness_matches_p = 0; 7516 *ics = t; 7517 } 7518 } 7519 7520 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion, 7521 and return the initial reference binding conversion. Otherwise, 7522 leave *ICS unchanged and return NULL. */ 7523 7524 static conversion * 7525 maybe_handle_ref_bind (conversion **ics) 7526 { 7527 if ((*ics)->kind == ck_ref_bind) 7528 { 7529 conversion *old_ics = *ics; 7530 *ics = old_ics->u.next; 7531 (*ics)->user_conv_p = old_ics->user_conv_p; 7532 return old_ics; 7533 } 7534 7535 return NULL; 7536 } 7537 7538 /* Compare two implicit conversion sequences according to the rules set out in 7539 [over.ics.rank]. Return values: 7540 7541 1: ics1 is better than ics2 7542 -1: ics2 is better than ics1 7543 0: ics1 and ics2 are indistinguishable */ 7544 7545 static int 7546 compare_ics (conversion *ics1, conversion *ics2) 7547 { 7548 tree from_type1; 7549 tree from_type2; 7550 tree to_type1; 7551 tree to_type2; 7552 tree deref_from_type1 = NULL_TREE; 7553 tree deref_from_type2 = NULL_TREE; 7554 tree deref_to_type1 = NULL_TREE; 7555 tree deref_to_type2 = NULL_TREE; 7556 conversion_rank rank1, rank2; 7557 7558 /* REF_BINDING is nonzero if the result of the conversion sequence 7559 is a reference type. In that case REF_CONV is the reference 7560 binding conversion. */ 7561 conversion *ref_conv1; 7562 conversion *ref_conv2; 7563 7564 /* Handle implicit object parameters. */ 7565 maybe_handle_implicit_object (&ics1); 7566 maybe_handle_implicit_object (&ics2); 7567 7568 /* Handle reference parameters. */ 7569 ref_conv1 = maybe_handle_ref_bind (&ics1); 7570 ref_conv2 = maybe_handle_ref_bind (&ics2); 7571 7572 /* List-initialization sequence L1 is a better conversion sequence than 7573 list-initialization sequence L2 if L1 converts to 7574 std::initializer_list<X> for some X and L2 does not. */ 7575 if (ics1->kind == ck_list && ics2->kind != ck_list) 7576 return 1; 7577 if (ics2->kind == ck_list && ics1->kind != ck_list) 7578 return -1; 7579 7580 /* [over.ics.rank] 7581 7582 When comparing the basic forms of implicit conversion sequences (as 7583 defined in _over.best.ics_) 7584 7585 --a standard conversion sequence (_over.ics.scs_) is a better 7586 conversion sequence than a user-defined conversion sequence 7587 or an ellipsis conversion sequence, and 7588 7589 --a user-defined conversion sequence (_over.ics.user_) is a 7590 better conversion sequence than an ellipsis conversion sequence 7591 (_over.ics.ellipsis_). */ 7592 rank1 = CONVERSION_RANK (ics1); 7593 rank2 = CONVERSION_RANK (ics2); 7594 7595 if (rank1 > rank2) 7596 return -1; 7597 else if (rank1 < rank2) 7598 return 1; 7599 7600 if (rank1 == cr_bad) 7601 { 7602 /* Both ICS are bad. We try to make a decision based on what would 7603 have happened if they'd been good. This is not an extension, 7604 we'll still give an error when we build up the call; this just 7605 helps us give a more helpful error message. */ 7606 rank1 = BAD_CONVERSION_RANK (ics1); 7607 rank2 = BAD_CONVERSION_RANK (ics2); 7608 7609 if (rank1 > rank2) 7610 return -1; 7611 else if (rank1 < rank2) 7612 return 1; 7613 7614 /* We couldn't make up our minds; try to figure it out below. */ 7615 } 7616 7617 if (ics1->ellipsis_p) 7618 /* Both conversions are ellipsis conversions. */ 7619 return 0; 7620 7621 /* User-defined conversion sequence U1 is a better conversion sequence 7622 than another user-defined conversion sequence U2 if they contain the 7623 same user-defined conversion operator or constructor and if the sec- 7624 ond standard conversion sequence of U1 is better than the second 7625 standard conversion sequence of U2. */ 7626 7627 /* Handle list-conversion with the same code even though it isn't always 7628 ranked as a user-defined conversion and it doesn't have a second 7629 standard conversion sequence; it will still have the desired effect. 7630 Specifically, we need to do the reference binding comparison at the 7631 end of this function. */ 7632 7633 if (ics1->user_conv_p || ics1->kind == ck_list || ics1->kind == ck_aggr) 7634 { 7635 conversion *t1; 7636 conversion *t2; 7637 7638 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next) 7639 if (t1->kind == ck_ambig || t1->kind == ck_aggr 7640 || t1->kind == ck_list) 7641 break; 7642 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next) 7643 if (t2->kind == ck_ambig || t2->kind == ck_aggr 7644 || t2->kind == ck_list) 7645 break; 7646 7647 if (t1->kind != t2->kind) 7648 return 0; 7649 else if (t1->kind == ck_user) 7650 { 7651 if (t1->cand->fn != t2->cand->fn) 7652 return 0; 7653 } 7654 else 7655 { 7656 /* For ambiguous or aggregate conversions, use the target type as 7657 a proxy for the conversion function. */ 7658 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type)) 7659 return 0; 7660 } 7661 7662 /* We can just fall through here, after setting up 7663 FROM_TYPE1 and FROM_TYPE2. */ 7664 from_type1 = t1->type; 7665 from_type2 = t2->type; 7666 } 7667 else 7668 { 7669 conversion *t1; 7670 conversion *t2; 7671 7672 /* We're dealing with two standard conversion sequences. 7673 7674 [over.ics.rank] 7675 7676 Standard conversion sequence S1 is a better conversion 7677 sequence than standard conversion sequence S2 if 7678 7679 --S1 is a proper subsequence of S2 (comparing the conversion 7680 sequences in the canonical form defined by _over.ics.scs_, 7681 excluding any Lvalue Transformation; the identity 7682 conversion sequence is considered to be a subsequence of 7683 any non-identity conversion sequence */ 7684 7685 t1 = ics1; 7686 while (t1->kind != ck_identity) 7687 t1 = t1->u.next; 7688 from_type1 = t1->type; 7689 7690 t2 = ics2; 7691 while (t2->kind != ck_identity) 7692 t2 = t2->u.next; 7693 from_type2 = t2->type; 7694 } 7695 7696 /* One sequence can only be a subsequence of the other if they start with 7697 the same type. They can start with different types when comparing the 7698 second standard conversion sequence in two user-defined conversion 7699 sequences. */ 7700 if (same_type_p (from_type1, from_type2)) 7701 { 7702 if (is_subseq (ics1, ics2)) 7703 return 1; 7704 if (is_subseq (ics2, ics1)) 7705 return -1; 7706 } 7707 7708 /* [over.ics.rank] 7709 7710 Or, if not that, 7711 7712 --the rank of S1 is better than the rank of S2 (by the rules 7713 defined below): 7714 7715 Standard conversion sequences are ordered by their ranks: an Exact 7716 Match is a better conversion than a Promotion, which is a better 7717 conversion than a Conversion. 7718 7719 Two conversion sequences with the same rank are indistinguishable 7720 unless one of the following rules applies: 7721 7722 --A conversion that does not a convert a pointer, pointer to member, 7723 or std::nullptr_t to bool is better than one that does. 7724 7725 The ICS_STD_RANK automatically handles the pointer-to-bool rule, 7726 so that we do not have to check it explicitly. */ 7727 if (ics1->rank < ics2->rank) 7728 return 1; 7729 else if (ics2->rank < ics1->rank) 7730 return -1; 7731 7732 to_type1 = ics1->type; 7733 to_type2 = ics2->type; 7734 7735 /* A conversion from scalar arithmetic type to complex is worse than a 7736 conversion between scalar arithmetic types. */ 7737 if (same_type_p (from_type1, from_type2) 7738 && ARITHMETIC_TYPE_P (from_type1) 7739 && ARITHMETIC_TYPE_P (to_type1) 7740 && ARITHMETIC_TYPE_P (to_type2) 7741 && ((TREE_CODE (to_type1) == COMPLEX_TYPE) 7742 != (TREE_CODE (to_type2) == COMPLEX_TYPE))) 7743 { 7744 if (TREE_CODE (to_type1) == COMPLEX_TYPE) 7745 return -1; 7746 else 7747 return 1; 7748 } 7749 7750 if (TYPE_PTR_P (from_type1) 7751 && TYPE_PTR_P (from_type2) 7752 && TYPE_PTR_P (to_type1) 7753 && TYPE_PTR_P (to_type2)) 7754 { 7755 deref_from_type1 = TREE_TYPE (from_type1); 7756 deref_from_type2 = TREE_TYPE (from_type2); 7757 deref_to_type1 = TREE_TYPE (to_type1); 7758 deref_to_type2 = TREE_TYPE (to_type2); 7759 } 7760 /* The rules for pointers to members A::* are just like the rules 7761 for pointers A*, except opposite: if B is derived from A then 7762 A::* converts to B::*, not vice versa. For that reason, we 7763 switch the from_ and to_ variables here. */ 7764 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2) 7765 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2)) 7766 || (TYPE_PTRMEMFUNC_P (from_type1) 7767 && TYPE_PTRMEMFUNC_P (from_type2) 7768 && TYPE_PTRMEMFUNC_P (to_type1) 7769 && TYPE_PTRMEMFUNC_P (to_type2))) 7770 { 7771 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1); 7772 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2); 7773 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1); 7774 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2); 7775 } 7776 7777 if (deref_from_type1 != NULL_TREE 7778 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1)) 7779 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2))) 7780 { 7781 /* This was one of the pointer or pointer-like conversions. 7782 7783 [over.ics.rank] 7784 7785 --If class B is derived directly or indirectly from class A, 7786 conversion of B* to A* is better than conversion of B* to 7787 void*, and conversion of A* to void* is better than 7788 conversion of B* to void*. */ 7789 if (TREE_CODE (deref_to_type1) == VOID_TYPE 7790 && TREE_CODE (deref_to_type2) == VOID_TYPE) 7791 { 7792 if (is_properly_derived_from (deref_from_type1, 7793 deref_from_type2)) 7794 return -1; 7795 else if (is_properly_derived_from (deref_from_type2, 7796 deref_from_type1)) 7797 return 1; 7798 } 7799 else if (TREE_CODE (deref_to_type1) == VOID_TYPE 7800 || TREE_CODE (deref_to_type2) == VOID_TYPE) 7801 { 7802 if (same_type_p (deref_from_type1, deref_from_type2)) 7803 { 7804 if (TREE_CODE (deref_to_type2) == VOID_TYPE) 7805 { 7806 if (is_properly_derived_from (deref_from_type1, 7807 deref_to_type1)) 7808 return 1; 7809 } 7810 /* We know that DEREF_TO_TYPE1 is `void' here. */ 7811 else if (is_properly_derived_from (deref_from_type1, 7812 deref_to_type2)) 7813 return -1; 7814 } 7815 } 7816 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1)) 7817 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2))) 7818 { 7819 /* [over.ics.rank] 7820 7821 --If class B is derived directly or indirectly from class A 7822 and class C is derived directly or indirectly from B, 7823 7824 --conversion of C* to B* is better than conversion of C* to 7825 A*, 7826 7827 --conversion of B* to A* is better than conversion of C* to 7828 A* */ 7829 if (same_type_p (deref_from_type1, deref_from_type2)) 7830 { 7831 if (is_properly_derived_from (deref_to_type1, 7832 deref_to_type2)) 7833 return 1; 7834 else if (is_properly_derived_from (deref_to_type2, 7835 deref_to_type1)) 7836 return -1; 7837 } 7838 else if (same_type_p (deref_to_type1, deref_to_type2)) 7839 { 7840 if (is_properly_derived_from (deref_from_type2, 7841 deref_from_type1)) 7842 return 1; 7843 else if (is_properly_derived_from (deref_from_type1, 7844 deref_from_type2)) 7845 return -1; 7846 } 7847 } 7848 } 7849 else if (CLASS_TYPE_P (non_reference (from_type1)) 7850 && same_type_p (from_type1, from_type2)) 7851 { 7852 tree from = non_reference (from_type1); 7853 7854 /* [over.ics.rank] 7855 7856 --binding of an expression of type C to a reference of type 7857 B& is better than binding an expression of type C to a 7858 reference of type A& 7859 7860 --conversion of C to B is better than conversion of C to A, */ 7861 if (is_properly_derived_from (from, to_type1) 7862 && is_properly_derived_from (from, to_type2)) 7863 { 7864 if (is_properly_derived_from (to_type1, to_type2)) 7865 return 1; 7866 else if (is_properly_derived_from (to_type2, to_type1)) 7867 return -1; 7868 } 7869 } 7870 else if (CLASS_TYPE_P (non_reference (to_type1)) 7871 && same_type_p (to_type1, to_type2)) 7872 { 7873 tree to = non_reference (to_type1); 7874 7875 /* [over.ics.rank] 7876 7877 --binding of an expression of type B to a reference of type 7878 A& is better than binding an expression of type C to a 7879 reference of type A&, 7880 7881 --conversion of B to A is better than conversion of C to A */ 7882 if (is_properly_derived_from (from_type1, to) 7883 && is_properly_derived_from (from_type2, to)) 7884 { 7885 if (is_properly_derived_from (from_type2, from_type1)) 7886 return 1; 7887 else if (is_properly_derived_from (from_type1, from_type2)) 7888 return -1; 7889 } 7890 } 7891 7892 /* [over.ics.rank] 7893 7894 --S1 and S2 differ only in their qualification conversion and yield 7895 similar types T1 and T2 (_conv.qual_), respectively, and the cv- 7896 qualification signature of type T1 is a proper subset of the cv- 7897 qualification signature of type T2 */ 7898 if (ics1->kind == ck_qual 7899 && ics2->kind == ck_qual 7900 && same_type_p (from_type1, from_type2)) 7901 { 7902 int result = comp_cv_qual_signature (to_type1, to_type2); 7903 if (result != 0) 7904 return result; 7905 } 7906 7907 /* [over.ics.rank] 7908 7909 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers 7910 to an implicit object parameter, and either S1 binds an lvalue reference 7911 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue 7912 reference to an rvalue and S2 binds an lvalue reference 7913 (C++0x draft standard, 13.3.3.2) 7914 7915 --S1 and S2 are reference bindings (_dcl.init.ref_), and the 7916 types to which the references refer are the same type except for 7917 top-level cv-qualifiers, and the type to which the reference 7918 initialized by S2 refers is more cv-qualified than the type to 7919 which the reference initialized by S1 refers. 7920 7921 DR 1328 [over.match.best]: the context is an initialization by 7922 conversion function for direct reference binding (13.3.1.6) of a 7923 reference to function type, the return type of F1 is the same kind of 7924 reference (i.e. lvalue or rvalue) as the reference being initialized, 7925 and the return type of F2 is not. */ 7926 7927 if (ref_conv1 && ref_conv2) 7928 { 7929 if (!ref_conv1->this_p && !ref_conv2->this_p 7930 && (ref_conv1->rvaluedness_matches_p 7931 != ref_conv2->rvaluedness_matches_p) 7932 && (same_type_p (ref_conv1->type, ref_conv2->type) 7933 || (TYPE_REF_IS_RVALUE (ref_conv1->type) 7934 != TYPE_REF_IS_RVALUE (ref_conv2->type)))) 7935 { 7936 return (ref_conv1->rvaluedness_matches_p 7937 - ref_conv2->rvaluedness_matches_p); 7938 } 7939 7940 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2)) 7941 return comp_cv_qualification (TREE_TYPE (ref_conv2->type), 7942 TREE_TYPE (ref_conv1->type)); 7943 } 7944 7945 /* Neither conversion sequence is better than the other. */ 7946 return 0; 7947 } 7948 7949 /* The source type for this standard conversion sequence. */ 7950 7951 static tree 7952 source_type (conversion *t) 7953 { 7954 for (;; t = t->u.next) 7955 { 7956 if (t->kind == ck_user 7957 || t->kind == ck_ambig 7958 || t->kind == ck_identity) 7959 return t->type; 7960 } 7961 gcc_unreachable (); 7962 } 7963 7964 /* Note a warning about preferring WINNER to LOSER. We do this by storing 7965 a pointer to LOSER and re-running joust to produce the warning if WINNER 7966 is actually used. */ 7967 7968 static void 7969 add_warning (struct z_candidate *winner, struct z_candidate *loser) 7970 { 7971 candidate_warning *cw = (candidate_warning *) 7972 conversion_obstack_alloc (sizeof (candidate_warning)); 7973 cw->loser = loser; 7974 cw->next = winner->warnings; 7975 winner->warnings = cw; 7976 } 7977 7978 /* Compare two candidates for overloading as described in 7979 [over.match.best]. Return values: 7980 7981 1: cand1 is better than cand2 7982 -1: cand2 is better than cand1 7983 0: cand1 and cand2 are indistinguishable */ 7984 7985 static int 7986 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn) 7987 { 7988 int winner = 0; 7989 int off1 = 0, off2 = 0; 7990 size_t i; 7991 size_t len; 7992 7993 /* Candidates that involve bad conversions are always worse than those 7994 that don't. */ 7995 if (cand1->viable > cand2->viable) 7996 return 1; 7997 if (cand1->viable < cand2->viable) 7998 return -1; 7999 8000 /* If we have two pseudo-candidates for conversions to the same type, 8001 or two candidates for the same function, arbitrarily pick one. */ 8002 if (cand1->fn == cand2->fn 8003 && (IS_TYPE_OR_DECL_P (cand1->fn))) 8004 return 1; 8005 8006 /* a viable function F1 8007 is defined to be a better function than another viable function F2 if 8008 for all arguments i, ICSi(F1) is not a worse conversion sequence than 8009 ICSi(F2), and then */ 8010 8011 /* for some argument j, ICSj(F1) is a better conversion sequence than 8012 ICSj(F2) */ 8013 8014 /* For comparing static and non-static member functions, we ignore 8015 the implicit object parameter of the non-static function. The 8016 standard says to pretend that the static function has an object 8017 parm, but that won't work with operator overloading. */ 8018 len = cand1->num_convs; 8019 if (len != cand2->num_convs) 8020 { 8021 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn); 8022 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn); 8023 8024 if (DECL_CONSTRUCTOR_P (cand1->fn) 8025 && is_list_ctor (cand1->fn) != is_list_ctor (cand2->fn)) 8026 /* We're comparing a near-match list constructor and a near-match 8027 non-list constructor. Just treat them as unordered. */ 8028 return 0; 8029 8030 gcc_assert (static_1 != static_2); 8031 8032 if (static_1) 8033 off2 = 1; 8034 else 8035 { 8036 off1 = 1; 8037 --len; 8038 } 8039 } 8040 8041 for (i = 0; i < len; ++i) 8042 { 8043 conversion *t1 = cand1->convs[i + off1]; 8044 conversion *t2 = cand2->convs[i + off2]; 8045 int comp = compare_ics (t1, t2); 8046 8047 if (comp != 0) 8048 { 8049 if (warn_sign_promo 8050 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2) 8051 == cr_std + cr_promotion) 8052 && t1->kind == ck_std 8053 && t2->kind == ck_std 8054 && TREE_CODE (t1->type) == INTEGER_TYPE 8055 && TREE_CODE (t2->type) == INTEGER_TYPE 8056 && (TYPE_PRECISION (t1->type) 8057 == TYPE_PRECISION (t2->type)) 8058 && (TYPE_UNSIGNED (t1->u.next->type) 8059 || (TREE_CODE (t1->u.next->type) 8060 == ENUMERAL_TYPE))) 8061 { 8062 tree type = t1->u.next->type; 8063 tree type1, type2; 8064 struct z_candidate *w, *l; 8065 if (comp > 0) 8066 type1 = t1->type, type2 = t2->type, 8067 w = cand1, l = cand2; 8068 else 8069 type1 = t2->type, type2 = t1->type, 8070 w = cand2, l = cand1; 8071 8072 if (warn) 8073 { 8074 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT", 8075 type, type1, type2); 8076 warning (OPT_Wsign_promo, " in call to %qD", w->fn); 8077 } 8078 else 8079 add_warning (w, l); 8080 } 8081 8082 if (winner && comp != winner) 8083 { 8084 winner = 0; 8085 goto tweak; 8086 } 8087 winner = comp; 8088 } 8089 } 8090 8091 /* warn about confusing overload resolution for user-defined conversions, 8092 either between a constructor and a conversion op, or between two 8093 conversion ops. */ 8094 if (winner && warn_conversion && cand1->second_conv 8095 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn)) 8096 && winner != compare_ics (cand1->second_conv, cand2->second_conv)) 8097 { 8098 struct z_candidate *w, *l; 8099 bool give_warning = false; 8100 8101 if (winner == 1) 8102 w = cand1, l = cand2; 8103 else 8104 w = cand2, l = cand1; 8105 8106 /* We don't want to complain about `X::operator T1 ()' 8107 beating `X::operator T2 () const', when T2 is a no less 8108 cv-qualified version of T1. */ 8109 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn) 8110 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn)) 8111 { 8112 tree t = TREE_TYPE (TREE_TYPE (l->fn)); 8113 tree f = TREE_TYPE (TREE_TYPE (w->fn)); 8114 8115 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t)) 8116 { 8117 t = TREE_TYPE (t); 8118 f = TREE_TYPE (f); 8119 } 8120 if (!comp_ptr_ttypes (t, f)) 8121 give_warning = true; 8122 } 8123 else 8124 give_warning = true; 8125 8126 if (!give_warning) 8127 /*NOP*/; 8128 else if (warn) 8129 { 8130 tree source = source_type (w->convs[0]); 8131 if (! DECL_CONSTRUCTOR_P (w->fn)) 8132 source = TREE_TYPE (source); 8133 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn) 8134 && warning (OPT_Wconversion, " for conversion from %qT to %qT", 8135 source, w->second_conv->type)) 8136 { 8137 inform (input_location, " because conversion sequence for the argument is better"); 8138 } 8139 } 8140 else 8141 add_warning (w, l); 8142 } 8143 8144 if (winner) 8145 return winner; 8146 8147 /* DR 495 moved this tiebreaker above the template ones. */ 8148 /* or, if not that, 8149 the context is an initialization by user-defined conversion (see 8150 _dcl.init_ and _over.match.user_) and the standard conversion 8151 sequence from the return type of F1 to the destination type (i.e., 8152 the type of the entity being initialized) is a better conversion 8153 sequence than the standard conversion sequence from the return type 8154 of F2 to the destination type. */ 8155 8156 if (cand1->second_conv) 8157 { 8158 winner = compare_ics (cand1->second_conv, cand2->second_conv); 8159 if (winner) 8160 return winner; 8161 } 8162 8163 /* or, if not that, 8164 F1 is a non-template function and F2 is a template function 8165 specialization. */ 8166 8167 if (!cand1->template_decl && cand2->template_decl) 8168 return 1; 8169 else if (cand1->template_decl && !cand2->template_decl) 8170 return -1; 8171 8172 /* or, if not that, 8173 F1 and F2 are template functions and the function template for F1 is 8174 more specialized than the template for F2 according to the partial 8175 ordering rules. */ 8176 8177 if (cand1->template_decl && cand2->template_decl) 8178 { 8179 winner = more_specialized_fn 8180 (TI_TEMPLATE (cand1->template_decl), 8181 TI_TEMPLATE (cand2->template_decl), 8182 /* [temp.func.order]: The presence of unused ellipsis and default 8183 arguments has no effect on the partial ordering of function 8184 templates. add_function_candidate() will not have 8185 counted the "this" argument for constructors. */ 8186 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn)); 8187 if (winner) 8188 return winner; 8189 } 8190 8191 /* Check whether we can discard a builtin candidate, either because we 8192 have two identical ones or matching builtin and non-builtin candidates. 8193 8194 (Pedantically in the latter case the builtin which matched the user 8195 function should not be added to the overload set, but we spot it here. 8196 8197 [over.match.oper] 8198 ... the builtin candidates include ... 8199 - do not have the same parameter type list as any non-template 8200 non-member candidate. */ 8201 8202 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE 8203 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE) 8204 { 8205 for (i = 0; i < len; ++i) 8206 if (!same_type_p (cand1->convs[i]->type, 8207 cand2->convs[i]->type)) 8208 break; 8209 if (i == cand1->num_convs) 8210 { 8211 if (cand1->fn == cand2->fn) 8212 /* Two built-in candidates; arbitrarily pick one. */ 8213 return 1; 8214 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE) 8215 /* cand1 is built-in; prefer cand2. */ 8216 return -1; 8217 else 8218 /* cand2 is built-in; prefer cand1. */ 8219 return 1; 8220 } 8221 } 8222 8223 /* If the two function declarations represent the same function (this can 8224 happen with declarations in multiple scopes and arg-dependent lookup), 8225 arbitrarily choose one. But first make sure the default args we're 8226 using match. */ 8227 if (DECL_P (cand1->fn) && DECL_P (cand2->fn) 8228 && equal_functions (cand1->fn, cand2->fn)) 8229 { 8230 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn)); 8231 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn)); 8232 8233 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn)); 8234 8235 for (i = 0; i < len; ++i) 8236 { 8237 /* Don't crash if the fn is variadic. */ 8238 if (!parms1) 8239 break; 8240 parms1 = TREE_CHAIN (parms1); 8241 parms2 = TREE_CHAIN (parms2); 8242 } 8243 8244 if (off1) 8245 parms1 = TREE_CHAIN (parms1); 8246 else if (off2) 8247 parms2 = TREE_CHAIN (parms2); 8248 8249 for (; parms1; ++i) 8250 { 8251 if (!cp_tree_equal (TREE_PURPOSE (parms1), 8252 TREE_PURPOSE (parms2))) 8253 { 8254 if (warn) 8255 { 8256 permerror (input_location, "default argument mismatch in " 8257 "overload resolution"); 8258 inform (input_location, 8259 " candidate 1: %q+#F", cand1->fn); 8260 inform (input_location, 8261 " candidate 2: %q+#F", cand2->fn); 8262 } 8263 else 8264 add_warning (cand1, cand2); 8265 break; 8266 } 8267 parms1 = TREE_CHAIN (parms1); 8268 parms2 = TREE_CHAIN (parms2); 8269 } 8270 8271 return 1; 8272 } 8273 8274 tweak: 8275 8276 /* Extension: If the worst conversion for one candidate is worse than the 8277 worst conversion for the other, take the first. */ 8278 if (!pedantic) 8279 { 8280 conversion_rank rank1 = cr_identity, rank2 = cr_identity; 8281 struct z_candidate *w = 0, *l = 0; 8282 8283 for (i = 0; i < len; ++i) 8284 { 8285 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1) 8286 rank1 = CONVERSION_RANK (cand1->convs[i+off1]); 8287 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2) 8288 rank2 = CONVERSION_RANK (cand2->convs[i + off2]); 8289 } 8290 if (rank1 < rank2) 8291 winner = 1, w = cand1, l = cand2; 8292 if (rank1 > rank2) 8293 winner = -1, w = cand2, l = cand1; 8294 if (winner) 8295 { 8296 /* Don't choose a deleted function over ambiguity. */ 8297 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn)) 8298 return 0; 8299 if (warn) 8300 { 8301 pedwarn (input_location, 0, 8302 "ISO C++ says that these are ambiguous, even " 8303 "though the worst conversion for the first is better than " 8304 "the worst conversion for the second:"); 8305 print_z_candidate (_("candidate 1:"), w); 8306 print_z_candidate (_("candidate 2:"), l); 8307 } 8308 else 8309 add_warning (w, l); 8310 return winner; 8311 } 8312 } 8313 8314 gcc_assert (!winner); 8315 return 0; 8316 } 8317 8318 /* Given a list of candidates for overloading, find the best one, if any. 8319 This algorithm has a worst case of O(2n) (winner is last), and a best 8320 case of O(n/2) (totally ambiguous); much better than a sorting 8321 algorithm. */ 8322 8323 static struct z_candidate * 8324 tourney (struct z_candidate *candidates) 8325 { 8326 struct z_candidate *champ = candidates, *challenger; 8327 int fate; 8328 int champ_compared_to_predecessor = 0; 8329 8330 /* Walk through the list once, comparing each current champ to the next 8331 candidate, knocking out a candidate or two with each comparison. */ 8332 8333 for (challenger = champ->next; challenger; ) 8334 { 8335 fate = joust (champ, challenger, 0); 8336 if (fate == 1) 8337 challenger = challenger->next; 8338 else 8339 { 8340 if (fate == 0) 8341 { 8342 champ = challenger->next; 8343 if (champ == 0) 8344 return NULL; 8345 champ_compared_to_predecessor = 0; 8346 } 8347 else 8348 { 8349 champ = challenger; 8350 champ_compared_to_predecessor = 1; 8351 } 8352 8353 challenger = champ->next; 8354 } 8355 } 8356 8357 /* Make sure the champ is better than all the candidates it hasn't yet 8358 been compared to. */ 8359 8360 for (challenger = candidates; 8361 challenger != champ 8362 && !(champ_compared_to_predecessor && challenger->next == champ); 8363 challenger = challenger->next) 8364 { 8365 fate = joust (champ, challenger, 0); 8366 if (fate != 1) 8367 return NULL; 8368 } 8369 8370 return champ; 8371 } 8372 8373 /* Returns nonzero if things of type FROM can be converted to TO. */ 8374 8375 bool 8376 can_convert (tree to, tree from) 8377 { 8378 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT); 8379 } 8380 8381 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */ 8382 8383 bool 8384 can_convert_arg (tree to, tree from, tree arg, int flags) 8385 { 8386 conversion *t; 8387 void *p; 8388 bool ok_p; 8389 8390 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8391 p = conversion_obstack_alloc (0); 8392 8393 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 8394 flags); 8395 ok_p = (t && !t->bad_p); 8396 8397 /* Free all the conversions we allocated. */ 8398 obstack_free (&conversion_obstack, p); 8399 8400 return ok_p; 8401 } 8402 8403 /* Like can_convert_arg, but allows dubious conversions as well. */ 8404 8405 bool 8406 can_convert_arg_bad (tree to, tree from, tree arg, int flags) 8407 { 8408 conversion *t; 8409 void *p; 8410 8411 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8412 p = conversion_obstack_alloc (0); 8413 /* Try to perform the conversion. */ 8414 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 8415 flags); 8416 /* Free all the conversions we allocated. */ 8417 obstack_free (&conversion_obstack, p); 8418 8419 return t != NULL; 8420 } 8421 8422 /* Convert EXPR to TYPE. Return the converted expression. 8423 8424 Note that we allow bad conversions here because by the time we get to 8425 this point we are committed to doing the conversion. If we end up 8426 doing a bad conversion, convert_like will complain. */ 8427 8428 tree 8429 perform_implicit_conversion_flags (tree type, tree expr, tsubst_flags_t complain, int flags) 8430 { 8431 conversion *conv; 8432 void *p; 8433 8434 if (error_operand_p (expr)) 8435 return error_mark_node; 8436 8437 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8438 p = conversion_obstack_alloc (0); 8439 8440 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 8441 /*c_cast_p=*/false, 8442 flags); 8443 8444 if (!conv) 8445 { 8446 if (complain & tf_error) 8447 { 8448 /* If expr has unknown type, then it is an overloaded function. 8449 Call instantiate_type to get good error messages. */ 8450 if (TREE_TYPE (expr) == unknown_type_node) 8451 instantiate_type (type, expr, complain); 8452 else if (invalid_nonstatic_memfn_p (expr, complain)) 8453 /* We gave an error. */; 8454 else 8455 error ("could not convert %qE from %qT to %qT", expr, 8456 TREE_TYPE (expr), type); 8457 } 8458 expr = error_mark_node; 8459 } 8460 else if (processing_template_decl && conv->kind != ck_identity) 8461 { 8462 /* In a template, we are only concerned about determining the 8463 type of non-dependent expressions, so we do not have to 8464 perform the actual conversion. But for initializers, we 8465 need to be able to perform it at instantiation 8466 (or fold_non_dependent_expr) time. */ 8467 expr = build1 (IMPLICIT_CONV_EXPR, type, expr); 8468 if (!(flags & LOOKUP_ONLYCONVERTING)) 8469 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true; 8470 } 8471 else 8472 expr = convert_like (conv, expr, complain); 8473 8474 /* Free all the conversions we allocated. */ 8475 obstack_free (&conversion_obstack, p); 8476 8477 return expr; 8478 } 8479 8480 tree 8481 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain) 8482 { 8483 return perform_implicit_conversion_flags (type, expr, complain, LOOKUP_IMPLICIT); 8484 } 8485 8486 /* Convert EXPR to TYPE (as a direct-initialization) if that is 8487 permitted. If the conversion is valid, the converted expression is 8488 returned. Otherwise, NULL_TREE is returned, except in the case 8489 that TYPE is a class type; in that case, an error is issued. If 8490 C_CAST_P is true, then this direct-initialization is taking 8491 place as part of a static_cast being attempted as part of a C-style 8492 cast. */ 8493 8494 tree 8495 perform_direct_initialization_if_possible (tree type, 8496 tree expr, 8497 bool c_cast_p, 8498 tsubst_flags_t complain) 8499 { 8500 conversion *conv; 8501 void *p; 8502 8503 if (type == error_mark_node || error_operand_p (expr)) 8504 return error_mark_node; 8505 /* [dcl.init] 8506 8507 If the destination type is a (possibly cv-qualified) class type: 8508 8509 -- If the initialization is direct-initialization ..., 8510 constructors are considered. ... If no constructor applies, or 8511 the overload resolution is ambiguous, the initialization is 8512 ill-formed. */ 8513 if (CLASS_TYPE_P (type)) 8514 { 8515 VEC(tree,gc) *args = make_tree_vector_single (expr); 8516 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 8517 &args, type, LOOKUP_NORMAL, complain); 8518 release_tree_vector (args); 8519 return build_cplus_new (type, expr, complain); 8520 } 8521 8522 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8523 p = conversion_obstack_alloc (0); 8524 8525 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 8526 c_cast_p, 8527 LOOKUP_NORMAL); 8528 if (!conv || conv->bad_p) 8529 expr = NULL_TREE; 8530 else 8531 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0, 8532 /*issue_conversion_warnings=*/false, 8533 c_cast_p, 8534 complain); 8535 8536 /* Free all the conversions we allocated. */ 8537 obstack_free (&conversion_obstack, p); 8538 8539 return expr; 8540 } 8541 8542 /* When initializing a reference that lasts longer than a full-expression, 8543 this special rule applies: 8544 8545 [class.temporary] 8546 8547 The temporary to which the reference is bound or the temporary 8548 that is the complete object to which the reference is bound 8549 persists for the lifetime of the reference. 8550 8551 The temporaries created during the evaluation of the expression 8552 initializing the reference, except the temporary to which the 8553 reference is bound, are destroyed at the end of the 8554 full-expression in which they are created. 8555 8556 In that case, we store the converted expression into a new 8557 VAR_DECL in a new scope. 8558 8559 However, we want to be careful not to create temporaries when 8560 they are not required. For example, given: 8561 8562 struct B {}; 8563 struct D : public B {}; 8564 D f(); 8565 const B& b = f(); 8566 8567 there is no need to copy the return value from "f"; we can just 8568 extend its lifetime. Similarly, given: 8569 8570 struct S {}; 8571 struct T { operator S(); }; 8572 T t; 8573 const S& s = t; 8574 8575 we can extend the lifetime of the return value of the conversion 8576 operator. 8577 8578 The next several functions are involved in this lifetime extension. */ 8579 8580 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference 8581 is being bound to a temporary. Create and return a new VAR_DECL 8582 with the indicated TYPE; this variable will store the value to 8583 which the reference is bound. */ 8584 8585 tree 8586 make_temporary_var_for_ref_to_temp (tree decl, tree type) 8587 { 8588 tree var; 8589 8590 /* Create the variable. */ 8591 var = create_temporary_var (type); 8592 8593 /* Register the variable. */ 8594 if (TREE_STATIC (decl)) 8595 { 8596 /* Namespace-scope or local static; give it a mangled name. */ 8597 /* FIXME share comdat with decl? */ 8598 tree name; 8599 8600 TREE_STATIC (var) = 1; 8601 name = mangle_ref_init_variable (decl); 8602 DECL_NAME (var) = name; 8603 SET_DECL_ASSEMBLER_NAME (var, name); 8604 var = pushdecl_top_level (var); 8605 } 8606 else 8607 /* Create a new cleanup level if necessary. */ 8608 maybe_push_cleanup_level (type); 8609 8610 return var; 8611 } 8612 8613 /* EXPR is the initializer for a variable DECL of reference or 8614 std::initializer_list type. Create, push and return a new VAR_DECL 8615 for the initializer so that it will live as long as DECL. Any 8616 cleanup for the new variable is returned through CLEANUP, and the 8617 code to initialize the new variable is returned through INITP. */ 8618 8619 static tree 8620 set_up_extended_ref_temp (tree decl, tree expr, VEC(tree,gc) **cleanups, 8621 tree *initp) 8622 { 8623 tree init; 8624 tree type; 8625 tree var; 8626 8627 /* Create the temporary variable. */ 8628 type = TREE_TYPE (expr); 8629 var = make_temporary_var_for_ref_to_temp (decl, type); 8630 layout_decl (var, 0); 8631 /* If the rvalue is the result of a function call it will be 8632 a TARGET_EXPR. If it is some other construct (such as a 8633 member access expression where the underlying object is 8634 itself the result of a function call), turn it into a 8635 TARGET_EXPR here. It is important that EXPR be a 8636 TARGET_EXPR below since otherwise the INIT_EXPR will 8637 attempt to make a bitwise copy of EXPR to initialize 8638 VAR. */ 8639 if (TREE_CODE (expr) != TARGET_EXPR) 8640 expr = get_target_expr (expr); 8641 8642 if (TREE_CODE (decl) == FIELD_DECL 8643 && extra_warnings && !TREE_NO_WARNING (decl)) 8644 { 8645 warning (OPT_Wextra, "a temporary bound to %qD only persists " 8646 "until the constructor exits", decl); 8647 TREE_NO_WARNING (decl) = true; 8648 } 8649 8650 /* Recursively extend temps in this initializer. */ 8651 TARGET_EXPR_INITIAL (expr) 8652 = extend_ref_init_temps (decl, TARGET_EXPR_INITIAL (expr), cleanups); 8653 8654 /* If the initializer is constant, put it in DECL_INITIAL so we get 8655 static initialization and use in constant expressions. */ 8656 init = maybe_constant_init (expr); 8657 if (TREE_CONSTANT (init)) 8658 { 8659 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type)) 8660 { 8661 /* 5.19 says that a constant expression can include an 8662 lvalue-rvalue conversion applied to "a glvalue of literal type 8663 that refers to a non-volatile temporary object initialized 8664 with a constant expression". Rather than try to communicate 8665 that this VAR_DECL is a temporary, just mark it constexpr. 8666 8667 Currently this is only useful for initializer_list temporaries, 8668 since reference vars can't appear in constant expressions. */ 8669 DECL_DECLARED_CONSTEXPR_P (var) = true; 8670 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true; 8671 TREE_CONSTANT (var) = true; 8672 } 8673 DECL_INITIAL (var) = init; 8674 init = NULL_TREE; 8675 } 8676 else 8677 /* Create the INIT_EXPR that will initialize the temporary 8678 variable. */ 8679 init = build2 (INIT_EXPR, type, var, expr); 8680 if (at_function_scope_p ()) 8681 { 8682 add_decl_expr (var); 8683 8684 if (TREE_STATIC (var)) 8685 init = add_stmt_to_compound (init, register_dtor_fn (var)); 8686 else 8687 { 8688 tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error); 8689 if (cleanup) 8690 VEC_safe_push (tree, gc, *cleanups, cleanup); 8691 } 8692 8693 /* We must be careful to destroy the temporary only 8694 after its initialization has taken place. If the 8695 initialization throws an exception, then the 8696 destructor should not be run. We cannot simply 8697 transform INIT into something like: 8698 8699 (INIT, ({ CLEANUP_STMT; })) 8700 8701 because emit_local_var always treats the 8702 initializer as a full-expression. Thus, the 8703 destructor would run too early; it would run at the 8704 end of initializing the reference variable, rather 8705 than at the end of the block enclosing the 8706 reference variable. 8707 8708 The solution is to pass back a cleanup expression 8709 which the caller is responsible for attaching to 8710 the statement tree. */ 8711 } 8712 else 8713 { 8714 rest_of_decl_compilation (var, /*toplev=*/1, at_eof); 8715 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 8716 static_aggregates = tree_cons (NULL_TREE, var, 8717 static_aggregates); 8718 } 8719 8720 *initp = init; 8721 return var; 8722 } 8723 8724 /* Convert EXPR to the indicated reference TYPE, in a way suitable for 8725 initializing a variable of that TYPE. */ 8726 8727 tree 8728 initialize_reference (tree type, tree expr, 8729 int flags, tsubst_flags_t complain) 8730 { 8731 conversion *conv; 8732 void *p; 8733 8734 if (type == error_mark_node || error_operand_p (expr)) 8735 return error_mark_node; 8736 8737 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 8738 p = conversion_obstack_alloc (0); 8739 8740 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false, 8741 flags); 8742 if (!conv || conv->bad_p) 8743 { 8744 if (complain & tf_error) 8745 { 8746 if (conv) 8747 convert_like (conv, expr, complain); 8748 else if (!CP_TYPE_CONST_P (TREE_TYPE (type)) 8749 && !TYPE_REF_IS_RVALUE (type) 8750 && !real_lvalue_p (expr)) 8751 error ("invalid initialization of non-const reference of " 8752 "type %qT from an rvalue of type %qT", 8753 type, TREE_TYPE (expr)); 8754 else 8755 error ("invalid initialization of reference of type " 8756 "%qT from expression of type %qT", type, 8757 TREE_TYPE (expr)); 8758 } 8759 return error_mark_node; 8760 } 8761 8762 gcc_assert (conv->kind == ck_ref_bind); 8763 8764 /* Perform the conversion. */ 8765 expr = convert_like (conv, expr, complain); 8766 8767 /* Free all the conversions we allocated. */ 8768 obstack_free (&conversion_obstack, p); 8769 8770 return expr; 8771 } 8772 8773 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer, 8774 which is bound either to a reference or a std::initializer_list. */ 8775 8776 static tree 8777 extend_ref_init_temps_1 (tree decl, tree init, VEC(tree,gc) **cleanups) 8778 { 8779 tree sub = init; 8780 tree *p; 8781 STRIP_NOPS (sub); 8782 if (TREE_CODE (sub) == COMPOUND_EXPR) 8783 { 8784 TREE_OPERAND (sub, 1) 8785 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups); 8786 return init; 8787 } 8788 if (TREE_CODE (sub) != ADDR_EXPR) 8789 return init; 8790 /* Deal with binding to a subobject. */ 8791 for (p = &TREE_OPERAND (sub, 0); TREE_CODE (*p) == COMPONENT_REF; ) 8792 p = &TREE_OPERAND (*p, 0); 8793 if (TREE_CODE (*p) == TARGET_EXPR) 8794 { 8795 tree subinit = NULL_TREE; 8796 *p = set_up_extended_ref_temp (decl, *p, cleanups, &subinit); 8797 if (subinit) 8798 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), subinit, init); 8799 } 8800 return init; 8801 } 8802 8803 /* INIT is part of the initializer for DECL. If there are any 8804 reference or initializer lists being initialized, extend their 8805 lifetime to match that of DECL. */ 8806 8807 tree 8808 extend_ref_init_temps (tree decl, tree init, VEC(tree,gc) **cleanups) 8809 { 8810 tree type = TREE_TYPE (init); 8811 if (processing_template_decl) 8812 return init; 8813 if (TREE_CODE (type) == REFERENCE_TYPE) 8814 init = extend_ref_init_temps_1 (decl, init, cleanups); 8815 else if (is_std_init_list (type)) 8816 { 8817 /* The temporary array underlying a std::initializer_list 8818 is handled like a reference temporary. */ 8819 tree ctor = init; 8820 if (TREE_CODE (ctor) == TARGET_EXPR) 8821 ctor = TARGET_EXPR_INITIAL (ctor); 8822 if (TREE_CODE (ctor) == CONSTRUCTOR) 8823 { 8824 tree array = CONSTRUCTOR_ELT (ctor, 0)->value; 8825 array = extend_ref_init_temps_1 (decl, array, cleanups); 8826 CONSTRUCTOR_ELT (ctor, 0)->value = array; 8827 } 8828 } 8829 else if (TREE_CODE (init) == CONSTRUCTOR) 8830 { 8831 unsigned i; 8832 constructor_elt *p; 8833 VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (init); 8834 FOR_EACH_VEC_ELT (constructor_elt, elts, i, p) 8835 p->value = extend_ref_init_temps (decl, p->value, cleanups); 8836 } 8837 8838 return init; 8839 } 8840 8841 /* Returns true iff an initializer for TYPE could contain temporaries that 8842 need to be extended because they are bound to references or 8843 std::initializer_list. */ 8844 8845 bool 8846 type_has_extended_temps (tree type) 8847 { 8848 type = strip_array_types (type); 8849 if (TREE_CODE (type) == REFERENCE_TYPE) 8850 return true; 8851 if (CLASS_TYPE_P (type)) 8852 { 8853 tree f; 8854 if (is_std_init_list (type)) 8855 return true; 8856 for (f = next_initializable_field (TYPE_FIELDS (type)); 8857 f; f = next_initializable_field (DECL_CHAIN (f))) 8858 if (type_has_extended_temps (TREE_TYPE (f))) 8859 return true; 8860 } 8861 return false; 8862 } 8863 8864 /* Returns true iff TYPE is some variant of std::initializer_list. */ 8865 8866 bool 8867 is_std_init_list (tree type) 8868 { 8869 /* Look through typedefs. */ 8870 if (!TYPE_P (type)) 8871 return false; 8872 type = TYPE_MAIN_VARIANT (type); 8873 return (CLASS_TYPE_P (type) 8874 && CP_TYPE_CONTEXT (type) == std_node 8875 && strcmp (TYPE_NAME_STRING (type), "initializer_list") == 0); 8876 } 8877 8878 /* Returns true iff DECL is a list constructor: i.e. a constructor which 8879 will accept an argument list of a single std::initializer_list<T>. */ 8880 8881 bool 8882 is_list_ctor (tree decl) 8883 { 8884 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl); 8885 tree arg; 8886 8887 if (!args || args == void_list_node) 8888 return false; 8889 8890 arg = non_reference (TREE_VALUE (args)); 8891 if (!is_std_init_list (arg)) 8892 return false; 8893 8894 args = TREE_CHAIN (args); 8895 8896 if (args && args != void_list_node && !TREE_PURPOSE (args)) 8897 /* There are more non-defaulted parms. */ 8898 return false; 8899 8900 return true; 8901 } 8902 8903 #include "gt-cp-call.h" 8904