1/* Breadth-first and depth-first routines for 2 searching multiple-inheritance lattice for GNU C++. 3 Copyright (C) 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 4 1999, 2000, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. 5 Contributed by Michael Tiemann (tiemann@cygnus.com) 6 7This file is part of GCC. 8 9GCC is free software; you can redistribute it and/or modify 10it under the terms of the GNU General Public License as published by 11the Free Software Foundation; either version 2, or (at your option) 12any later version. 13 14GCC is distributed in the hope that it will be useful, 15but WITHOUT ANY WARRANTY; without even the implied warranty of 16MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17GNU General Public License for more details. 18 19You should have received a copy of the GNU General Public License 20along with GCC; see the file COPYING. If not, write to 21the Free Software Foundation, 51 Franklin Street, Fifth Floor, 22Boston, MA 02110-1301, USA. */ 23 24/* High-level class interface. */ 25 26#include "config.h" 27#include "system.h" 28#include "coretypes.h" 29#include "tm.h" 30#include "tree.h" 31#include "cp-tree.h" 32#include "obstack.h" 33#include "flags.h" 34#include "rtl.h" 35#include "output.h" 36#include "toplev.h" 37 38static int is_subobject_of_p (tree, tree); 39static tree dfs_lookup_base (tree, void *); 40static tree dfs_dcast_hint_pre (tree, void *); 41static tree dfs_dcast_hint_post (tree, void *); 42static tree dfs_debug_mark (tree, void *); 43static tree dfs_walk_once_r (tree, tree (*pre_fn) (tree, void *), 44 tree (*post_fn) (tree, void *), void *data); 45static void dfs_unmark_r (tree); 46static int check_hidden_convs (tree, int, int, tree, tree, tree); 47static tree split_conversions (tree, tree, tree, tree); 48static int lookup_conversions_r (tree, int, int, 49 tree, tree, tree, tree, tree *, tree *); 50static int look_for_overrides_r (tree, tree); 51static tree lookup_field_r (tree, void *); 52static tree dfs_accessible_post (tree, void *); 53static tree dfs_walk_once_accessible_r (tree, bool, bool, 54 tree (*pre_fn) (tree, void *), 55 tree (*post_fn) (tree, void *), 56 void *data); 57static tree dfs_walk_once_accessible (tree, bool, 58 tree (*pre_fn) (tree, void *), 59 tree (*post_fn) (tree, void *), 60 void *data); 61static tree dfs_access_in_type (tree, void *); 62static access_kind access_in_type (tree, tree); 63static int protected_accessible_p (tree, tree, tree); 64static int friend_accessible_p (tree, tree, tree); 65static int template_self_reference_p (tree, tree); 66static tree dfs_get_pure_virtuals (tree, void *); 67 68 69/* Variables for gathering statistics. */ 70#ifdef GATHER_STATISTICS 71static int n_fields_searched; 72static int n_calls_lookup_field, n_calls_lookup_field_1; 73static int n_calls_lookup_fnfields, n_calls_lookup_fnfields_1; 74static int n_calls_get_base_type; 75static int n_outer_fields_searched; 76static int n_contexts_saved; 77#endif /* GATHER_STATISTICS */ 78 79 80/* Data for lookup_base and its workers. */ 81 82struct lookup_base_data_s 83{ 84 tree t; /* type being searched. */ 85 tree base; /* The base type we're looking for. */ 86 tree binfo; /* Found binfo. */ 87 bool via_virtual; /* Found via a virtual path. */ 88 bool ambiguous; /* Found multiply ambiguous */ 89 bool repeated_base; /* Whether there are repeated bases in the 90 hierarchy. */ 91 bool want_any; /* Whether we want any matching binfo. */ 92}; 93 94/* Worker function for lookup_base. See if we've found the desired 95 base and update DATA_ (a pointer to LOOKUP_BASE_DATA_S). */ 96 97static tree 98dfs_lookup_base (tree binfo, void *data_) 99{ 100 struct lookup_base_data_s *data = (struct lookup_base_data_s *) data_; 101 102 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->base)) 103 { 104 if (!data->binfo) 105 { 106 data->binfo = binfo; 107 data->via_virtual 108 = binfo_via_virtual (data->binfo, data->t) != NULL_TREE; 109 110 if (!data->repeated_base) 111 /* If there are no repeated bases, we can stop now. */ 112 return binfo; 113 114 if (data->want_any && !data->via_virtual) 115 /* If this is a non-virtual base, then we can't do 116 better. */ 117 return binfo; 118 119 return dfs_skip_bases; 120 } 121 else 122 { 123 gcc_assert (binfo != data->binfo); 124 125 /* We've found more than one matching binfo. */ 126 if (!data->want_any) 127 { 128 /* This is immediately ambiguous. */ 129 data->binfo = NULL_TREE; 130 data->ambiguous = true; 131 return error_mark_node; 132 } 133 134 /* Prefer one via a non-virtual path. */ 135 if (!binfo_via_virtual (binfo, data->t)) 136 { 137 data->binfo = binfo; 138 data->via_virtual = false; 139 return binfo; 140 } 141 142 /* There must be repeated bases, otherwise we'd have stopped 143 on the first base we found. */ 144 return dfs_skip_bases; 145 } 146 } 147 148 return NULL_TREE; 149} 150 151/* Returns true if type BASE is accessible in T. (BASE is known to be 152 a (possibly non-proper) base class of T.) If CONSIDER_LOCAL_P is 153 true, consider any special access of the current scope, or access 154 bestowed by friendship. */ 155 156bool 157accessible_base_p (tree t, tree base, bool consider_local_p) 158{ 159 tree decl; 160 161 /* [class.access.base] 162 163 A base class is said to be accessible if an invented public 164 member of the base class is accessible. 165 166 If BASE is a non-proper base, this condition is trivially 167 true. */ 168 if (same_type_p (t, base)) 169 return true; 170 /* Rather than inventing a public member, we use the implicit 171 public typedef created in the scope of every class. */ 172 decl = TYPE_FIELDS (base); 173 while (!DECL_SELF_REFERENCE_P (decl)) 174 decl = TREE_CHAIN (decl); 175 while (ANON_AGGR_TYPE_P (t)) 176 t = TYPE_CONTEXT (t); 177 return accessible_p (t, decl, consider_local_p); 178} 179 180/* Lookup BASE in the hierarchy dominated by T. Do access checking as 181 ACCESS specifies. Return the binfo we discover. If KIND_PTR is 182 non-NULL, fill with information about what kind of base we 183 discovered. 184 185 If the base is inaccessible, or ambiguous, and the ba_quiet bit is 186 not set in ACCESS, then an error is issued and error_mark_node is 187 returned. If the ba_quiet bit is set, then no error is issued and 188 NULL_TREE is returned. */ 189 190tree 191lookup_base (tree t, tree base, base_access access, base_kind *kind_ptr) 192{ 193 tree binfo; 194 tree t_binfo; 195 base_kind bk; 196 197 if (t == error_mark_node || base == error_mark_node) 198 { 199 if (kind_ptr) 200 *kind_ptr = bk_not_base; 201 return error_mark_node; 202 } 203 gcc_assert (TYPE_P (base)); 204 205 if (!TYPE_P (t)) 206 { 207 t_binfo = t; 208 t = BINFO_TYPE (t); 209 } 210 else 211 { 212 t = complete_type (TYPE_MAIN_VARIANT (t)); 213 t_binfo = TYPE_BINFO (t); 214 } 215 216 base = complete_type (TYPE_MAIN_VARIANT (base)); 217 218 if (t_binfo) 219 { 220 struct lookup_base_data_s data; 221 222 data.t = t; 223 data.base = base; 224 data.binfo = NULL_TREE; 225 data.ambiguous = data.via_virtual = false; 226 data.repeated_base = CLASSTYPE_REPEATED_BASE_P (t); 227 data.want_any = access == ba_any; 228 229 dfs_walk_once (t_binfo, dfs_lookup_base, NULL, &data); 230 binfo = data.binfo; 231 232 if (!binfo) 233 bk = data.ambiguous ? bk_ambig : bk_not_base; 234 else if (binfo == t_binfo) 235 bk = bk_same_type; 236 else if (data.via_virtual) 237 bk = bk_via_virtual; 238 else 239 bk = bk_proper_base; 240 } 241 else 242 { 243 binfo = NULL_TREE; 244 bk = bk_not_base; 245 } 246 247 /* Check that the base is unambiguous and accessible. */ 248 if (access != ba_any) 249 switch (bk) 250 { 251 case bk_not_base: 252 break; 253 254 case bk_ambig: 255 if (!(access & ba_quiet)) 256 { 257 error ("%qT is an ambiguous base of %qT", base, t); 258 binfo = error_mark_node; 259 } 260 break; 261 262 default: 263 if ((access & ba_check_bit) 264 /* If BASE is incomplete, then BASE and TYPE are probably 265 the same, in which case BASE is accessible. If they 266 are not the same, then TYPE is invalid. In that case, 267 there's no need to issue another error here, and 268 there's no implicit typedef to use in the code that 269 follows, so we skip the check. */ 270 && COMPLETE_TYPE_P (base) 271 && !accessible_base_p (t, base, !(access & ba_ignore_scope))) 272 { 273 if (!(access & ba_quiet)) 274 { 275 error ("%qT is an inaccessible base of %qT", base, t); 276 binfo = error_mark_node; 277 } 278 else 279 binfo = NULL_TREE; 280 bk = bk_inaccessible; 281 } 282 break; 283 } 284 285 if (kind_ptr) 286 *kind_ptr = bk; 287 288 return binfo; 289} 290 291/* Data for dcast_base_hint walker. */ 292 293struct dcast_data_s 294{ 295 tree subtype; /* The base type we're looking for. */ 296 int virt_depth; /* Number of virtual bases encountered from most 297 derived. */ 298 tree offset; /* Best hint offset discovered so far. */ 299 bool repeated_base; /* Whether there are repeated bases in the 300 hierarchy. */ 301}; 302 303/* Worker for dcast_base_hint. Search for the base type being cast 304 from. */ 305 306static tree 307dfs_dcast_hint_pre (tree binfo, void *data_) 308{ 309 struct dcast_data_s *data = (struct dcast_data_s *) data_; 310 311 if (BINFO_VIRTUAL_P (binfo)) 312 data->virt_depth++; 313 314 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->subtype)) 315 { 316 if (data->virt_depth) 317 { 318 data->offset = ssize_int (-1); 319 return data->offset; 320 } 321 if (data->offset) 322 data->offset = ssize_int (-3); 323 else 324 data->offset = BINFO_OFFSET (binfo); 325 326 return data->repeated_base ? dfs_skip_bases : data->offset; 327 } 328 329 return NULL_TREE; 330} 331 332/* Worker for dcast_base_hint. Track the virtual depth. */ 333 334static tree 335dfs_dcast_hint_post (tree binfo, void *data_) 336{ 337 struct dcast_data_s *data = (struct dcast_data_s *) data_; 338 339 if (BINFO_VIRTUAL_P (binfo)) 340 data->virt_depth--; 341 342 return NULL_TREE; 343} 344 345/* The dynamic cast runtime needs a hint about how the static SUBTYPE type 346 started from is related to the required TARGET type, in order to optimize 347 the inheritance graph search. This information is independent of the 348 current context, and ignores private paths, hence get_base_distance is 349 inappropriate. Return a TREE specifying the base offset, BOFF. 350 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF, 351 and there are no public virtual SUBTYPE bases. 352 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases. 353 BOFF == -2, SUBTYPE is not a public base. 354 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */ 355 356tree 357dcast_base_hint (tree subtype, tree target) 358{ 359 struct dcast_data_s data; 360 361 data.subtype = subtype; 362 data.virt_depth = 0; 363 data.offset = NULL_TREE; 364 data.repeated_base = CLASSTYPE_REPEATED_BASE_P (target); 365 366 dfs_walk_once_accessible (TYPE_BINFO (target), /*friends=*/false, 367 dfs_dcast_hint_pre, dfs_dcast_hint_post, &data); 368 return data.offset ? data.offset : ssize_int (-2); 369} 370 371/* Search for a member with name NAME in a multiple inheritance 372 lattice specified by TYPE. If it does not exist, return NULL_TREE. 373 If the member is ambiguously referenced, return `error_mark_node'. 374 Otherwise, return a DECL with the indicated name. If WANT_TYPE is 375 true, type declarations are preferred. */ 376 377/* Do a 1-level search for NAME as a member of TYPE. The caller must 378 figure out whether it can access this field. (Since it is only one 379 level, this is reasonable.) */ 380 381tree 382lookup_field_1 (tree type, tree name, bool want_type) 383{ 384 tree field; 385 386 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM 387 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM 388 || TREE_CODE (type) == TYPENAME_TYPE) 389 /* The TYPE_FIELDS of a TEMPLATE_TYPE_PARM and 390 BOUND_TEMPLATE_TEMPLATE_PARM are not fields at all; 391 instead TYPE_FIELDS is the TEMPLATE_PARM_INDEX. (Miraculously, 392 the code often worked even when we treated the index as a list 393 of fields!) 394 The TYPE_FIELDS of TYPENAME_TYPE is its TYPENAME_TYPE_FULLNAME. */ 395 return NULL_TREE; 396 397 if (TYPE_NAME (type) 398 && DECL_LANG_SPECIFIC (TYPE_NAME (type)) 399 && DECL_SORTED_FIELDS (TYPE_NAME (type))) 400 { 401 tree *fields = &DECL_SORTED_FIELDS (TYPE_NAME (type))->elts[0]; 402 int lo = 0, hi = DECL_SORTED_FIELDS (TYPE_NAME (type))->len; 403 int i; 404 405 while (lo < hi) 406 { 407 i = (lo + hi) / 2; 408 409#ifdef GATHER_STATISTICS 410 n_fields_searched++; 411#endif /* GATHER_STATISTICS */ 412 413 if (DECL_NAME (fields[i]) > name) 414 hi = i; 415 else if (DECL_NAME (fields[i]) < name) 416 lo = i + 1; 417 else 418 { 419 field = NULL_TREE; 420 421 /* We might have a nested class and a field with the 422 same name; we sorted them appropriately via 423 field_decl_cmp, so just look for the first or last 424 field with this name. */ 425 if (want_type) 426 { 427 do 428 field = fields[i--]; 429 while (i >= lo && DECL_NAME (fields[i]) == name); 430 if (TREE_CODE (field) != TYPE_DECL 431 && !DECL_CLASS_TEMPLATE_P (field)) 432 field = NULL_TREE; 433 } 434 else 435 { 436 do 437 field = fields[i++]; 438 while (i < hi && DECL_NAME (fields[i]) == name); 439 } 440 return field; 441 } 442 } 443 return NULL_TREE; 444 } 445 446 field = TYPE_FIELDS (type); 447 448#ifdef GATHER_STATISTICS 449 n_calls_lookup_field_1++; 450#endif /* GATHER_STATISTICS */ 451 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 452 { 453#ifdef GATHER_STATISTICS 454 n_fields_searched++; 455#endif /* GATHER_STATISTICS */ 456 gcc_assert (DECL_P (field)); 457 if (DECL_NAME (field) == NULL_TREE 458 && ANON_AGGR_TYPE_P (TREE_TYPE (field))) 459 { 460 tree temp = lookup_field_1 (TREE_TYPE (field), name, want_type); 461 if (temp) 462 return temp; 463 } 464 if (TREE_CODE (field) == USING_DECL) 465 { 466 /* We generally treat class-scope using-declarations as 467 ARM-style access specifications, because support for the 468 ISO semantics has not been implemented. So, in general, 469 there's no reason to return a USING_DECL, and the rest of 470 the compiler cannot handle that. Once the class is 471 defined, USING_DECLs are purged from TYPE_FIELDS; see 472 handle_using_decl. However, we make special efforts to 473 make using-declarations in class templates and class 474 template partial specializations work correctly. */ 475 if (!DECL_DEPENDENT_P (field)) 476 continue; 477 } 478 479 if (DECL_NAME (field) == name 480 && (!want_type 481 || TREE_CODE (field) == TYPE_DECL 482 || DECL_CLASS_TEMPLATE_P (field))) 483 return field; 484 } 485 /* Not found. */ 486 if (name == vptr_identifier) 487 { 488 /* Give the user what s/he thinks s/he wants. */ 489 if (TYPE_POLYMORPHIC_P (type)) 490 return TYPE_VFIELD (type); 491 } 492 return NULL_TREE; 493} 494 495/* Return the FUNCTION_DECL, RECORD_TYPE, UNION_TYPE, or 496 NAMESPACE_DECL corresponding to the innermost non-block scope. */ 497 498tree 499current_scope (void) 500{ 501 /* There are a number of cases we need to be aware of here: 502 current_class_type current_function_decl 503 global NULL NULL 504 fn-local NULL SET 505 class-local SET NULL 506 class->fn SET SET 507 fn->class SET SET 508 509 Those last two make life interesting. If we're in a function which is 510 itself inside a class, we need decls to go into the fn's decls (our 511 second case below). But if we're in a class and the class itself is 512 inside a function, we need decls to go into the decls for the class. To 513 achieve this last goal, we must see if, when both current_class_ptr and 514 current_function_decl are set, the class was declared inside that 515 function. If so, we know to put the decls into the class's scope. */ 516 if (current_function_decl && current_class_type 517 && ((DECL_FUNCTION_MEMBER_P (current_function_decl) 518 && same_type_p (DECL_CONTEXT (current_function_decl), 519 current_class_type)) 520 || (DECL_FRIEND_CONTEXT (current_function_decl) 521 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl), 522 current_class_type)))) 523 return current_function_decl; 524 if (current_class_type) 525 return current_class_type; 526 if (current_function_decl) 527 return current_function_decl; 528 return current_namespace; 529} 530 531/* Returns nonzero if we are currently in a function scope. Note 532 that this function returns zero if we are within a local class, but 533 not within a member function body of the local class. */ 534 535int 536at_function_scope_p (void) 537{ 538 tree cs = current_scope (); 539 return cs && TREE_CODE (cs) == FUNCTION_DECL; 540} 541 542/* Returns true if the innermost active scope is a class scope. */ 543 544bool 545at_class_scope_p (void) 546{ 547 tree cs = current_scope (); 548 return cs && TYPE_P (cs); 549} 550 551/* Returns true if the innermost active scope is a namespace scope. */ 552 553bool 554at_namespace_scope_p (void) 555{ 556 tree cs = current_scope (); 557 return cs && TREE_CODE (cs) == NAMESPACE_DECL; 558} 559 560/* Return the scope of DECL, as appropriate when doing name-lookup. */ 561 562tree 563context_for_name_lookup (tree decl) 564{ 565 /* [class.union] 566 567 For the purposes of name lookup, after the anonymous union 568 definition, the members of the anonymous union are considered to 569 have been defined in the scope in which the anonymous union is 570 declared. */ 571 tree context = DECL_CONTEXT (decl); 572 573 while (context && TYPE_P (context) && ANON_AGGR_TYPE_P (context)) 574 context = TYPE_CONTEXT (context); 575 if (!context) 576 context = global_namespace; 577 578 return context; 579} 580 581/* The accessibility routines use BINFO_ACCESS for scratch space 582 during the computation of the accessibility of some declaration. */ 583 584#define BINFO_ACCESS(NODE) \ 585 ((access_kind) ((TREE_PUBLIC (NODE) << 1) | TREE_PRIVATE (NODE))) 586 587/* Set the access associated with NODE to ACCESS. */ 588 589#define SET_BINFO_ACCESS(NODE, ACCESS) \ 590 ((TREE_PUBLIC (NODE) = ((ACCESS) & 2) != 0), \ 591 (TREE_PRIVATE (NODE) = ((ACCESS) & 1) != 0)) 592 593/* Called from access_in_type via dfs_walk. Calculate the access to 594 DATA (which is really a DECL) in BINFO. */ 595 596static tree 597dfs_access_in_type (tree binfo, void *data) 598{ 599 tree decl = (tree) data; 600 tree type = BINFO_TYPE (binfo); 601 access_kind access = ak_none; 602 603 if (context_for_name_lookup (decl) == type) 604 { 605 /* If we have descended to the scope of DECL, just note the 606 appropriate access. */ 607 if (TREE_PRIVATE (decl)) 608 access = ak_private; 609 else if (TREE_PROTECTED (decl)) 610 access = ak_protected; 611 else 612 access = ak_public; 613 } 614 else 615 { 616 /* First, check for an access-declaration that gives us more 617 access to the DECL. The CONST_DECL for an enumeration 618 constant will not have DECL_LANG_SPECIFIC, and thus no 619 DECL_ACCESS. */ 620 if (DECL_LANG_SPECIFIC (decl) && !DECL_DISCRIMINATOR_P (decl)) 621 { 622 tree decl_access = purpose_member (type, DECL_ACCESS (decl)); 623 624 if (decl_access) 625 { 626 decl_access = TREE_VALUE (decl_access); 627 628 if (decl_access == access_public_node) 629 access = ak_public; 630 else if (decl_access == access_protected_node) 631 access = ak_protected; 632 else if (decl_access == access_private_node) 633 access = ak_private; 634 else 635 gcc_unreachable (); 636 } 637 } 638 639 if (!access) 640 { 641 int i; 642 tree base_binfo; 643 VEC(tree,gc) *accesses; 644 645 /* Otherwise, scan our baseclasses, and pick the most favorable 646 access. */ 647 accesses = BINFO_BASE_ACCESSES (binfo); 648 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 649 { 650 tree base_access = VEC_index (tree, accesses, i); 651 access_kind base_access_now = BINFO_ACCESS (base_binfo); 652 653 if (base_access_now == ak_none || base_access_now == ak_private) 654 /* If it was not accessible in the base, or only 655 accessible as a private member, we can't access it 656 all. */ 657 base_access_now = ak_none; 658 else if (base_access == access_protected_node) 659 /* Public and protected members in the base become 660 protected here. */ 661 base_access_now = ak_protected; 662 else if (base_access == access_private_node) 663 /* Public and protected members in the base become 664 private here. */ 665 base_access_now = ak_private; 666 667 /* See if the new access, via this base, gives more 668 access than our previous best access. */ 669 if (base_access_now != ak_none 670 && (access == ak_none || base_access_now < access)) 671 { 672 access = base_access_now; 673 674 /* If the new access is public, we can't do better. */ 675 if (access == ak_public) 676 break; 677 } 678 } 679 } 680 } 681 682 /* Note the access to DECL in TYPE. */ 683 SET_BINFO_ACCESS (binfo, access); 684 685 return NULL_TREE; 686} 687 688/* Return the access to DECL in TYPE. */ 689 690static access_kind 691access_in_type (tree type, tree decl) 692{ 693 tree binfo = TYPE_BINFO (type); 694 695 /* We must take into account 696 697 [class.paths] 698 699 If a name can be reached by several paths through a multiple 700 inheritance graph, the access is that of the path that gives 701 most access. 702 703 The algorithm we use is to make a post-order depth-first traversal 704 of the base-class hierarchy. As we come up the tree, we annotate 705 each node with the most lenient access. */ 706 dfs_walk_once (binfo, NULL, dfs_access_in_type, decl); 707 708 return BINFO_ACCESS (binfo); 709} 710 711/* Returns nonzero if it is OK to access DECL through an object 712 indicated by BINFO in the context of DERIVED. */ 713 714static int 715protected_accessible_p (tree decl, tree derived, tree binfo) 716{ 717 access_kind access; 718 719 /* We're checking this clause from [class.access.base] 720 721 m as a member of N is protected, and the reference occurs in a 722 member or friend of class N, or in a member or friend of a 723 class P derived from N, where m as a member of P is private or 724 protected. 725 726 Here DERIVED is a possible P and DECL is m. accessible_p will 727 iterate over various values of N, but the access to m in DERIVED 728 does not change. 729 730 Note that I believe that the passage above is wrong, and should read 731 "...is private or protected or public"; otherwise you get bizarre results 732 whereby a public using-decl can prevent you from accessing a protected 733 member of a base. (jason 2000/02/28) */ 734 735 /* If DERIVED isn't derived from m's class, then it can't be a P. */ 736 if (!DERIVED_FROM_P (context_for_name_lookup (decl), derived)) 737 return 0; 738 739 access = access_in_type (derived, decl); 740 741 /* If m is inaccessible in DERIVED, then it's not a P. */ 742 if (access == ak_none) 743 return 0; 744 745 /* [class.protected] 746 747 When a friend or a member function of a derived class references 748 a protected nonstatic member of a base class, an access check 749 applies in addition to those described earlier in clause 750 _class.access_) Except when forming a pointer to member 751 (_expr.unary.op_), the access must be through a pointer to, 752 reference to, or object of the derived class itself (or any class 753 derived from that class) (_expr.ref_). If the access is to form 754 a pointer to member, the nested-name-specifier shall name the 755 derived class (or any class derived from that class). */ 756 if (DECL_NONSTATIC_MEMBER_P (decl)) 757 { 758 /* We can tell through what the reference is occurring by 759 chasing BINFO up to the root. */ 760 tree t = binfo; 761 while (BINFO_INHERITANCE_CHAIN (t)) 762 t = BINFO_INHERITANCE_CHAIN (t); 763 764 if (!DERIVED_FROM_P (derived, BINFO_TYPE (t))) 765 return 0; 766 } 767 768 return 1; 769} 770 771/* Returns nonzero if SCOPE is a friend of a type which would be able 772 to access DECL through the object indicated by BINFO. */ 773 774static int 775friend_accessible_p (tree scope, tree decl, tree binfo) 776{ 777 tree befriending_classes; 778 tree t; 779 780 if (!scope) 781 return 0; 782 783 if (TREE_CODE (scope) == FUNCTION_DECL 784 || DECL_FUNCTION_TEMPLATE_P (scope)) 785 befriending_classes = DECL_BEFRIENDING_CLASSES (scope); 786 else if (TYPE_P (scope)) 787 befriending_classes = CLASSTYPE_BEFRIENDING_CLASSES (scope); 788 else 789 return 0; 790 791 for (t = befriending_classes; t; t = TREE_CHAIN (t)) 792 if (protected_accessible_p (decl, TREE_VALUE (t), binfo)) 793 return 1; 794 795 /* Nested classes have the same access as their enclosing types, as 796 per DR 45 (this is a change from the standard). */ 797 if (TYPE_P (scope)) 798 for (t = TYPE_CONTEXT (scope); t && TYPE_P (t); t = TYPE_CONTEXT (t)) 799 if (protected_accessible_p (decl, t, binfo)) 800 return 1; 801 802 if (TREE_CODE (scope) == FUNCTION_DECL 803 || DECL_FUNCTION_TEMPLATE_P (scope)) 804 { 805 /* Perhaps this SCOPE is a member of a class which is a 806 friend. */ 807 if (DECL_CLASS_SCOPE_P (scope) 808 && friend_accessible_p (DECL_CONTEXT (scope), decl, binfo)) 809 return 1; 810 811 /* Or an instantiation of something which is a friend. */ 812 if (DECL_TEMPLATE_INFO (scope)) 813 { 814 int ret; 815 /* Increment processing_template_decl to make sure that 816 dependent_type_p works correctly. */ 817 ++processing_template_decl; 818 ret = friend_accessible_p (DECL_TI_TEMPLATE (scope), decl, binfo); 819 --processing_template_decl; 820 return ret; 821 } 822 } 823 824 return 0; 825} 826 827/* Called via dfs_walk_once_accessible from accessible_p */ 828 829static tree 830dfs_accessible_post (tree binfo, void *data ATTRIBUTE_UNUSED) 831{ 832 if (BINFO_ACCESS (binfo) != ak_none) 833 { 834 tree scope = current_scope (); 835 if (scope && TREE_CODE (scope) != NAMESPACE_DECL 836 && is_friend (BINFO_TYPE (binfo), scope)) 837 return binfo; 838 } 839 840 return NULL_TREE; 841} 842 843/* DECL is a declaration from a base class of TYPE, which was the 844 class used to name DECL. Return nonzero if, in the current 845 context, DECL is accessible. If TYPE is actually a BINFO node, 846 then we can tell in what context the access is occurring by looking 847 at the most derived class along the path indicated by BINFO. If 848 CONSIDER_LOCAL is true, do consider special access the current 849 scope or friendship thereof we might have. */ 850 851int 852accessible_p (tree type, tree decl, bool consider_local_p) 853{ 854 tree binfo; 855 tree scope; 856 access_kind access; 857 858 /* Nonzero if it's OK to access DECL if it has protected 859 accessibility in TYPE. */ 860 int protected_ok = 0; 861 862 /* If this declaration is in a block or namespace scope, there's no 863 access control. */ 864 if (!TYPE_P (context_for_name_lookup (decl))) 865 return 1; 866 867 /* There is no need to perform access checks inside a thunk. */ 868 scope = current_scope (); 869 if (scope && DECL_THUNK_P (scope)) 870 return 1; 871 872 /* In a template declaration, we cannot be sure whether the 873 particular specialization that is instantiated will be a friend 874 or not. Therefore, all access checks are deferred until 875 instantiation. However, PROCESSING_TEMPLATE_DECL is set in the 876 parameter list for a template (because we may see dependent types 877 in default arguments for template parameters), and access 878 checking should be performed in the outermost parameter list. */ 879 if (processing_template_decl 880 && (!processing_template_parmlist || processing_template_decl > 1)) 881 return 1; 882 883 if (!TYPE_P (type)) 884 { 885 binfo = type; 886 type = BINFO_TYPE (type); 887 } 888 else 889 binfo = TYPE_BINFO (type); 890 891 /* [class.access.base] 892 893 A member m is accessible when named in class N if 894 895 --m as a member of N is public, or 896 897 --m as a member of N is private, and the reference occurs in a 898 member or friend of class N, or 899 900 --m as a member of N is protected, and the reference occurs in a 901 member or friend of class N, or in a member or friend of a 902 class P derived from N, where m as a member of P is private or 903 protected, or 904 905 --there exists a base class B of N that is accessible at the point 906 of reference, and m is accessible when named in class B. 907 908 We walk the base class hierarchy, checking these conditions. */ 909 910 if (consider_local_p) 911 { 912 /* Figure out where the reference is occurring. Check to see if 913 DECL is private or protected in this scope, since that will 914 determine whether protected access is allowed. */ 915 if (current_class_type) 916 protected_ok = protected_accessible_p (decl, 917 current_class_type, binfo); 918 919 /* Now, loop through the classes of which we are a friend. */ 920 if (!protected_ok) 921 protected_ok = friend_accessible_p (scope, decl, binfo); 922 } 923 924 /* Standardize the binfo that access_in_type will use. We don't 925 need to know what path was chosen from this point onwards. */ 926 binfo = TYPE_BINFO (type); 927 928 /* Compute the accessibility of DECL in the class hierarchy 929 dominated by type. */ 930 access = access_in_type (type, decl); 931 if (access == ak_public 932 || (access == ak_protected && protected_ok)) 933 return 1; 934 935 if (!consider_local_p) 936 return 0; 937 938 /* Walk the hierarchy again, looking for a base class that allows 939 access. */ 940 return dfs_walk_once_accessible (binfo, /*friends=*/true, 941 NULL, dfs_accessible_post, NULL) 942 != NULL_TREE; 943} 944 945struct lookup_field_info { 946 /* The type in which we're looking. */ 947 tree type; 948 /* The name of the field for which we're looking. */ 949 tree name; 950 /* If non-NULL, the current result of the lookup. */ 951 tree rval; 952 /* The path to RVAL. */ 953 tree rval_binfo; 954 /* If non-NULL, the lookup was ambiguous, and this is a list of the 955 candidates. */ 956 tree ambiguous; 957 /* If nonzero, we are looking for types, not data members. */ 958 int want_type; 959 /* If something went wrong, a message indicating what. */ 960 const char *errstr; 961}; 962 963/* Within the scope of a template class, you can refer to the to the 964 current specialization with the name of the template itself. For 965 example: 966 967 template <typename T> struct S { S* sp; } 968 969 Returns nonzero if DECL is such a declaration in a class TYPE. */ 970 971static int 972template_self_reference_p (tree type, tree decl) 973{ 974 return (CLASSTYPE_USE_TEMPLATE (type) 975 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type)) 976 && TREE_CODE (decl) == TYPE_DECL 977 && DECL_ARTIFICIAL (decl) 978 && DECL_NAME (decl) == constructor_name (type)); 979} 980 981/* Nonzero for a class member means that it is shared between all objects 982 of that class. 983 984 [class.member.lookup]:If the resulting set of declarations are not all 985 from sub-objects of the same type, or the set has a nonstatic member 986 and includes members from distinct sub-objects, there is an ambiguity 987 and the program is ill-formed. 988 989 This function checks that T contains no nonstatic members. */ 990 991int 992shared_member_p (tree t) 993{ 994 if (TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == TYPE_DECL \ 995 || TREE_CODE (t) == CONST_DECL) 996 return 1; 997 if (is_overloaded_fn (t)) 998 { 999 for (; t; t = OVL_NEXT (t)) 1000 { 1001 tree fn = OVL_CURRENT (t); 1002 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) 1003 return 0; 1004 } 1005 return 1; 1006 } 1007 return 0; 1008} 1009 1010/* Routine to see if the sub-object denoted by the binfo PARENT can be 1011 found as a base class and sub-object of the object denoted by 1012 BINFO. */ 1013 1014static int 1015is_subobject_of_p (tree parent, tree binfo) 1016{ 1017 tree probe; 1018 1019 for (probe = parent; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) 1020 { 1021 if (probe == binfo) 1022 return 1; 1023 if (BINFO_VIRTUAL_P (probe)) 1024 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (binfo)) 1025 != NULL_TREE); 1026 } 1027 return 0; 1028} 1029 1030/* DATA is really a struct lookup_field_info. Look for a field with 1031 the name indicated there in BINFO. If this function returns a 1032 non-NULL value it is the result of the lookup. Called from 1033 lookup_field via breadth_first_search. */ 1034 1035static tree 1036lookup_field_r (tree binfo, void *data) 1037{ 1038 struct lookup_field_info *lfi = (struct lookup_field_info *) data; 1039 tree type = BINFO_TYPE (binfo); 1040 tree nval = NULL_TREE; 1041 1042 /* If this is a dependent base, don't look in it. */ 1043 if (BINFO_DEPENDENT_BASE_P (binfo)) 1044 return NULL_TREE; 1045 1046 /* If this base class is hidden by the best-known value so far, we 1047 don't need to look. */ 1048 if (lfi->rval_binfo && BINFO_INHERITANCE_CHAIN (binfo) == lfi->rval_binfo 1049 && !BINFO_VIRTUAL_P (binfo)) 1050 return dfs_skip_bases; 1051 1052 /* First, look for a function. There can't be a function and a data 1053 member with the same name, and if there's a function and a type 1054 with the same name, the type is hidden by the function. */ 1055 if (!lfi->want_type) 1056 { 1057 int idx = lookup_fnfields_1 (type, lfi->name); 1058 if (idx >= 0) 1059 nval = VEC_index (tree, CLASSTYPE_METHOD_VEC (type), idx); 1060 } 1061 1062 if (!nval) 1063 /* Look for a data member or type. */ 1064 nval = lookup_field_1 (type, lfi->name, lfi->want_type); 1065 1066 /* If there is no declaration with the indicated name in this type, 1067 then there's nothing to do. */ 1068 if (!nval) 1069 goto done; 1070 1071 /* If we're looking up a type (as with an elaborated type specifier) 1072 we ignore all non-types we find. */ 1073 if (lfi->want_type && TREE_CODE (nval) != TYPE_DECL 1074 && !DECL_CLASS_TEMPLATE_P (nval)) 1075 { 1076 if (lfi->name == TYPE_IDENTIFIER (type)) 1077 { 1078 /* If the aggregate has no user defined constructors, we allow 1079 it to have fields with the same name as the enclosing type. 1080 If we are looking for that name, find the corresponding 1081 TYPE_DECL. */ 1082 for (nval = TREE_CHAIN (nval); nval; nval = TREE_CHAIN (nval)) 1083 if (DECL_NAME (nval) == lfi->name 1084 && TREE_CODE (nval) == TYPE_DECL) 1085 break; 1086 } 1087 else 1088 nval = NULL_TREE; 1089 if (!nval && CLASSTYPE_NESTED_UTDS (type) != NULL) 1090 { 1091 binding_entry e = binding_table_find (CLASSTYPE_NESTED_UTDS (type), 1092 lfi->name); 1093 if (e != NULL) 1094 nval = TYPE_MAIN_DECL (e->type); 1095 else 1096 goto done; 1097 } 1098 } 1099 1100 /* You must name a template base class with a template-id. */ 1101 if (!same_type_p (type, lfi->type) 1102 && template_self_reference_p (type, nval)) 1103 goto done; 1104 1105 /* If the lookup already found a match, and the new value doesn't 1106 hide the old one, we might have an ambiguity. */ 1107 if (lfi->rval_binfo 1108 && !is_subobject_of_p (lfi->rval_binfo, binfo)) 1109 1110 { 1111 if (nval == lfi->rval && shared_member_p (nval)) 1112 /* The two things are really the same. */ 1113 ; 1114 else if (is_subobject_of_p (binfo, lfi->rval_binfo)) 1115 /* The previous value hides the new one. */ 1116 ; 1117 else 1118 { 1119 /* We have a real ambiguity. We keep a chain of all the 1120 candidates. */ 1121 if (!lfi->ambiguous && lfi->rval) 1122 { 1123 /* This is the first time we noticed an ambiguity. Add 1124 what we previously thought was a reasonable candidate 1125 to the list. */ 1126 lfi->ambiguous = tree_cons (NULL_TREE, lfi->rval, NULL_TREE); 1127 TREE_TYPE (lfi->ambiguous) = error_mark_node; 1128 } 1129 1130 /* Add the new value. */ 1131 lfi->ambiguous = tree_cons (NULL_TREE, nval, lfi->ambiguous); 1132 TREE_TYPE (lfi->ambiguous) = error_mark_node; 1133 lfi->errstr = "request for member %qD is ambiguous"; 1134 } 1135 } 1136 else 1137 { 1138 lfi->rval = nval; 1139 lfi->rval_binfo = binfo; 1140 } 1141 1142 done: 1143 /* Don't look for constructors or destructors in base classes. */ 1144 if (IDENTIFIER_CTOR_OR_DTOR_P (lfi->name)) 1145 return dfs_skip_bases; 1146 return NULL_TREE; 1147} 1148 1149/* Return a "baselink" with BASELINK_BINFO, BASELINK_ACCESS_BINFO, 1150 BASELINK_FUNCTIONS, and BASELINK_OPTYPE set to BINFO, ACCESS_BINFO, 1151 FUNCTIONS, and OPTYPE respectively. */ 1152 1153tree 1154build_baselink (tree binfo, tree access_binfo, tree functions, tree optype) 1155{ 1156 tree baselink; 1157 1158 gcc_assert (TREE_CODE (functions) == FUNCTION_DECL 1159 || TREE_CODE (functions) == TEMPLATE_DECL 1160 || TREE_CODE (functions) == TEMPLATE_ID_EXPR 1161 || TREE_CODE (functions) == OVERLOAD); 1162 gcc_assert (!optype || TYPE_P (optype)); 1163 gcc_assert (TREE_TYPE (functions)); 1164 1165 baselink = make_node (BASELINK); 1166 TREE_TYPE (baselink) = TREE_TYPE (functions); 1167 BASELINK_BINFO (baselink) = binfo; 1168 BASELINK_ACCESS_BINFO (baselink) = access_binfo; 1169 BASELINK_FUNCTIONS (baselink) = functions; 1170 BASELINK_OPTYPE (baselink) = optype; 1171 1172 return baselink; 1173} 1174 1175/* Look for a member named NAME in an inheritance lattice dominated by 1176 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it 1177 is 1, we enforce accessibility. If PROTECT is zero, then, for an 1178 ambiguous lookup, we return NULL. If PROTECT is 1, we issue error 1179 messages about inaccessible or ambiguous lookup. If PROTECT is 2, 1180 we return a TREE_LIST whose TREE_TYPE is error_mark_node and whose 1181 TREE_VALUEs are the list of ambiguous candidates. 1182 1183 WANT_TYPE is 1 when we should only return TYPE_DECLs. 1184 1185 If nothing can be found return NULL_TREE and do not issue an error. */ 1186 1187tree 1188lookup_member (tree xbasetype, tree name, int protect, bool want_type) 1189{ 1190 tree rval, rval_binfo = NULL_TREE; 1191 tree type = NULL_TREE, basetype_path = NULL_TREE; 1192 struct lookup_field_info lfi; 1193 1194 /* rval_binfo is the binfo associated with the found member, note, 1195 this can be set with useful information, even when rval is not 1196 set, because it must deal with ALL members, not just non-function 1197 members. It is used for ambiguity checking and the hidden 1198 checks. Whereas rval is only set if a proper (not hidden) 1199 non-function member is found. */ 1200 1201 const char *errstr = 0; 1202 1203 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE); 1204 1205 if (TREE_CODE (xbasetype) == TREE_BINFO) 1206 { 1207 type = BINFO_TYPE (xbasetype); 1208 basetype_path = xbasetype; 1209 } 1210 else 1211 { 1212 if (!IS_AGGR_TYPE_CODE (TREE_CODE (xbasetype))) 1213 return NULL_TREE; 1214 type = xbasetype; 1215 xbasetype = NULL_TREE; 1216 } 1217 1218 type = complete_type (type); 1219 if (!basetype_path) 1220 basetype_path = TYPE_BINFO (type); 1221 1222 if (!basetype_path) 1223 return NULL_TREE; 1224 1225#ifdef GATHER_STATISTICS 1226 n_calls_lookup_field++; 1227#endif /* GATHER_STATISTICS */ 1228 1229 memset (&lfi, 0, sizeof (lfi)); 1230 lfi.type = type; 1231 lfi.name = name; 1232 lfi.want_type = want_type; 1233 dfs_walk_all (basetype_path, &lookup_field_r, NULL, &lfi); 1234 rval = lfi.rval; 1235 rval_binfo = lfi.rval_binfo; 1236 if (rval_binfo) 1237 type = BINFO_TYPE (rval_binfo); 1238 errstr = lfi.errstr; 1239 1240 /* If we are not interested in ambiguities, don't report them; 1241 just return NULL_TREE. */ 1242 if (!protect && lfi.ambiguous) 1243 return NULL_TREE; 1244 1245 if (protect == 2) 1246 { 1247 if (lfi.ambiguous) 1248 return lfi.ambiguous; 1249 else 1250 protect = 0; 1251 } 1252 1253 /* [class.access] 1254 1255 In the case of overloaded function names, access control is 1256 applied to the function selected by overloaded resolution. 1257 1258 We cannot check here, even if RVAL is only a single non-static 1259 member function, since we do not know what the "this" pointer 1260 will be. For: 1261 1262 class A { protected: void f(); }; 1263 class B : public A { 1264 void g(A *p) { 1265 f(); // OK 1266 p->f(); // Not OK. 1267 } 1268 }; 1269 1270 only the first call to "f" is valid. However, if the function is 1271 static, we can check. */ 1272 if (rval && protect 1273 && !really_overloaded_fn (rval) 1274 && !(TREE_CODE (rval) == FUNCTION_DECL 1275 && DECL_NONSTATIC_MEMBER_FUNCTION_P (rval))) 1276 perform_or_defer_access_check (basetype_path, rval, rval); 1277 1278 if (errstr && protect) 1279 { 1280 error (errstr, name, type); 1281 if (lfi.ambiguous) 1282 print_candidates (lfi.ambiguous); 1283 rval = error_mark_node; 1284 } 1285 1286 if (rval && is_overloaded_fn (rval)) 1287 rval = build_baselink (rval_binfo, basetype_path, rval, 1288 (IDENTIFIER_TYPENAME_P (name) 1289 ? TREE_TYPE (name): NULL_TREE)); 1290 return rval; 1291} 1292 1293/* Like lookup_member, except that if we find a function member we 1294 return NULL_TREE. */ 1295 1296tree 1297lookup_field (tree xbasetype, tree name, int protect, bool want_type) 1298{ 1299 tree rval = lookup_member (xbasetype, name, protect, want_type); 1300 1301 /* Ignore functions, but propagate the ambiguity list. */ 1302 if (!error_operand_p (rval) 1303 && (rval && BASELINK_P (rval))) 1304 return NULL_TREE; 1305 1306 return rval; 1307} 1308 1309/* Like lookup_member, except that if we find a non-function member we 1310 return NULL_TREE. */ 1311 1312tree 1313lookup_fnfields (tree xbasetype, tree name, int protect) 1314{ 1315 tree rval = lookup_member (xbasetype, name, protect, /*want_type=*/false); 1316 1317 /* Ignore non-functions, but propagate the ambiguity list. */ 1318 if (!error_operand_p (rval) 1319 && (rval && !BASELINK_P (rval))) 1320 return NULL_TREE; 1321 1322 return rval; 1323} 1324 1325/* Return the index in the CLASSTYPE_METHOD_VEC for CLASS_TYPE 1326 corresponding to "operator TYPE ()", or -1 if there is no such 1327 operator. Only CLASS_TYPE itself is searched; this routine does 1328 not scan the base classes of CLASS_TYPE. */ 1329 1330static int 1331lookup_conversion_operator (tree class_type, tree type) 1332{ 1333 int tpl_slot = -1; 1334 1335 if (TYPE_HAS_CONVERSION (class_type)) 1336 { 1337 int i; 1338 tree fn; 1339 VEC(tree,gc) *methods = CLASSTYPE_METHOD_VEC (class_type); 1340 1341 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT; 1342 VEC_iterate (tree, methods, i, fn); ++i) 1343 { 1344 /* All the conversion operators come near the beginning of 1345 the class. Therefore, if FN is not a conversion 1346 operator, there is no matching conversion operator in 1347 CLASS_TYPE. */ 1348 fn = OVL_CURRENT (fn); 1349 if (!DECL_CONV_FN_P (fn)) 1350 break; 1351 1352 if (TREE_CODE (fn) == TEMPLATE_DECL) 1353 /* All the templated conversion functions are on the same 1354 slot, so remember it. */ 1355 tpl_slot = i; 1356 else if (same_type_p (DECL_CONV_FN_TYPE (fn), type)) 1357 return i; 1358 } 1359 } 1360 1361 return tpl_slot; 1362} 1363 1364/* TYPE is a class type. Return the index of the fields within 1365 the method vector with name NAME, or -1 is no such field exists. */ 1366 1367int 1368lookup_fnfields_1 (tree type, tree name) 1369{ 1370 VEC(tree,gc) *method_vec; 1371 tree fn; 1372 tree tmp; 1373 size_t i; 1374 1375 if (!CLASS_TYPE_P (type)) 1376 return -1; 1377 1378 if (COMPLETE_TYPE_P (type)) 1379 { 1380 if ((name == ctor_identifier 1381 || name == base_ctor_identifier 1382 || name == complete_ctor_identifier)) 1383 { 1384 if (CLASSTYPE_LAZY_DEFAULT_CTOR (type)) 1385 lazily_declare_fn (sfk_constructor, type); 1386 if (CLASSTYPE_LAZY_COPY_CTOR (type)) 1387 lazily_declare_fn (sfk_copy_constructor, type); 1388 } 1389 else if (name == ansi_assopname(NOP_EXPR) 1390 && CLASSTYPE_LAZY_ASSIGNMENT_OP (type)) 1391 lazily_declare_fn (sfk_assignment_operator, type); 1392 else if ((name == dtor_identifier 1393 || name == base_dtor_identifier 1394 || name == complete_dtor_identifier 1395 || name == deleting_dtor_identifier) 1396 && CLASSTYPE_LAZY_DESTRUCTOR (type)) 1397 lazily_declare_fn (sfk_destructor, type); 1398 } 1399 1400 method_vec = CLASSTYPE_METHOD_VEC (type); 1401 if (!method_vec) 1402 return -1; 1403 1404#ifdef GATHER_STATISTICS 1405 n_calls_lookup_fnfields_1++; 1406#endif /* GATHER_STATISTICS */ 1407 1408 /* Constructors are first... */ 1409 if (name == ctor_identifier) 1410 { 1411 fn = CLASSTYPE_CONSTRUCTORS (type); 1412 return fn ? CLASSTYPE_CONSTRUCTOR_SLOT : -1; 1413 } 1414 /* and destructors are second. */ 1415 if (name == dtor_identifier) 1416 { 1417 fn = CLASSTYPE_DESTRUCTORS (type); 1418 return fn ? CLASSTYPE_DESTRUCTOR_SLOT : -1; 1419 } 1420 if (IDENTIFIER_TYPENAME_P (name)) 1421 return lookup_conversion_operator (type, TREE_TYPE (name)); 1422 1423 /* Skip the conversion operators. */ 1424 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT; 1425 VEC_iterate (tree, method_vec, i, fn); 1426 ++i) 1427 if (!DECL_CONV_FN_P (OVL_CURRENT (fn))) 1428 break; 1429 1430 /* If the type is complete, use binary search. */ 1431 if (COMPLETE_TYPE_P (type)) 1432 { 1433 int lo; 1434 int hi; 1435 1436 lo = i; 1437 hi = VEC_length (tree, method_vec); 1438 while (lo < hi) 1439 { 1440 i = (lo + hi) / 2; 1441 1442#ifdef GATHER_STATISTICS 1443 n_outer_fields_searched++; 1444#endif /* GATHER_STATISTICS */ 1445 1446 tmp = VEC_index (tree, method_vec, i); 1447 tmp = DECL_NAME (OVL_CURRENT (tmp)); 1448 if (tmp > name) 1449 hi = i; 1450 else if (tmp < name) 1451 lo = i + 1; 1452 else 1453 return i; 1454 } 1455 } 1456 else 1457 for (; VEC_iterate (tree, method_vec, i, fn); ++i) 1458 { 1459#ifdef GATHER_STATISTICS 1460 n_outer_fields_searched++; 1461#endif /* GATHER_STATISTICS */ 1462 if (DECL_NAME (OVL_CURRENT (fn)) == name) 1463 return i; 1464 } 1465 1466 return -1; 1467} 1468 1469/* Like lookup_fnfields_1, except that the name is extracted from 1470 FUNCTION, which is a FUNCTION_DECL or a TEMPLATE_DECL. */ 1471 1472int 1473class_method_index_for_fn (tree class_type, tree function) 1474{ 1475 gcc_assert (TREE_CODE (function) == FUNCTION_DECL 1476 || DECL_FUNCTION_TEMPLATE_P (function)); 1477 1478 return lookup_fnfields_1 (class_type, 1479 DECL_CONSTRUCTOR_P (function) ? ctor_identifier : 1480 DECL_DESTRUCTOR_P (function) ? dtor_identifier : 1481 DECL_NAME (function)); 1482} 1483 1484 1485/* DECL is the result of a qualified name lookup. QUALIFYING_SCOPE is 1486 the class or namespace used to qualify the name. CONTEXT_CLASS is 1487 the class corresponding to the object in which DECL will be used. 1488 Return a possibly modified version of DECL that takes into account 1489 the CONTEXT_CLASS. 1490 1491 In particular, consider an expression like `B::m' in the context of 1492 a derived class `D'. If `B::m' has been resolved to a BASELINK, 1493 then the most derived class indicated by the BASELINK_BINFO will be 1494 `B', not `D'. This function makes that adjustment. */ 1495 1496tree 1497adjust_result_of_qualified_name_lookup (tree decl, 1498 tree qualifying_scope, 1499 tree context_class) 1500{ 1501 if (context_class && context_class != error_mark_node 1502 && CLASS_TYPE_P (context_class) 1503 && CLASS_TYPE_P (qualifying_scope) 1504 && DERIVED_FROM_P (qualifying_scope, context_class) 1505 && BASELINK_P (decl)) 1506 { 1507 tree base; 1508 1509 /* Look for the QUALIFYING_SCOPE as a base of the CONTEXT_CLASS. 1510 Because we do not yet know which function will be chosen by 1511 overload resolution, we cannot yet check either accessibility 1512 or ambiguity -- in either case, the choice of a static member 1513 function might make the usage valid. */ 1514 base = lookup_base (context_class, qualifying_scope, 1515 ba_unique | ba_quiet, NULL); 1516 if (base) 1517 { 1518 BASELINK_ACCESS_BINFO (decl) = base; 1519 BASELINK_BINFO (decl) 1520 = lookup_base (base, BINFO_TYPE (BASELINK_BINFO (decl)), 1521 ba_unique | ba_quiet, 1522 NULL); 1523 } 1524 } 1525 1526 return decl; 1527} 1528 1529 1530/* Walk the class hierarchy within BINFO, in a depth-first traversal. 1531 PRE_FN is called in preorder, while POST_FN is called in postorder. 1532 If PRE_FN returns DFS_SKIP_BASES, child binfos will not be 1533 walked. If PRE_FN or POST_FN returns a different non-NULL value, 1534 that value is immediately returned and the walk is terminated. One 1535 of PRE_FN and POST_FN can be NULL. At each node, PRE_FN and 1536 POST_FN are passed the binfo to examine and the caller's DATA 1537 value. All paths are walked, thus virtual and morally virtual 1538 binfos can be multiply walked. */ 1539 1540tree 1541dfs_walk_all (tree binfo, tree (*pre_fn) (tree, void *), 1542 tree (*post_fn) (tree, void *), void *data) 1543{ 1544 tree rval; 1545 unsigned ix; 1546 tree base_binfo; 1547 1548 /* Call the pre-order walking function. */ 1549 if (pre_fn) 1550 { 1551 rval = pre_fn (binfo, data); 1552 if (rval) 1553 { 1554 if (rval == dfs_skip_bases) 1555 goto skip_bases; 1556 return rval; 1557 } 1558 } 1559 1560 /* Find the next child binfo to walk. */ 1561 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 1562 { 1563 rval = dfs_walk_all (base_binfo, pre_fn, post_fn, data); 1564 if (rval) 1565 return rval; 1566 } 1567 1568 skip_bases: 1569 /* Call the post-order walking function. */ 1570 if (post_fn) 1571 { 1572 rval = post_fn (binfo, data); 1573 gcc_assert (rval != dfs_skip_bases); 1574 return rval; 1575 } 1576 1577 return NULL_TREE; 1578} 1579 1580/* Worker for dfs_walk_once. This behaves as dfs_walk_all, except 1581 that binfos are walked at most once. */ 1582 1583static tree 1584dfs_walk_once_r (tree binfo, tree (*pre_fn) (tree, void *), 1585 tree (*post_fn) (tree, void *), void *data) 1586{ 1587 tree rval; 1588 unsigned ix; 1589 tree base_binfo; 1590 1591 /* Call the pre-order walking function. */ 1592 if (pre_fn) 1593 { 1594 rval = pre_fn (binfo, data); 1595 if (rval) 1596 { 1597 if (rval == dfs_skip_bases) 1598 goto skip_bases; 1599 1600 return rval; 1601 } 1602 } 1603 1604 /* Find the next child binfo to walk. */ 1605 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 1606 { 1607 if (BINFO_VIRTUAL_P (base_binfo)) 1608 { 1609 if (BINFO_MARKED (base_binfo)) 1610 continue; 1611 BINFO_MARKED (base_binfo) = 1; 1612 } 1613 1614 rval = dfs_walk_once_r (base_binfo, pre_fn, post_fn, data); 1615 if (rval) 1616 return rval; 1617 } 1618 1619 skip_bases: 1620 /* Call the post-order walking function. */ 1621 if (post_fn) 1622 { 1623 rval = post_fn (binfo, data); 1624 gcc_assert (rval != dfs_skip_bases); 1625 return rval; 1626 } 1627 1628 return NULL_TREE; 1629} 1630 1631/* Worker for dfs_walk_once. Recursively unmark the virtual base binfos of 1632 BINFO. */ 1633 1634static void 1635dfs_unmark_r (tree binfo) 1636{ 1637 unsigned ix; 1638 tree base_binfo; 1639 1640 /* Process the basetypes. */ 1641 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 1642 { 1643 if (BINFO_VIRTUAL_P (base_binfo)) 1644 { 1645 if (!BINFO_MARKED (base_binfo)) 1646 continue; 1647 BINFO_MARKED (base_binfo) = 0; 1648 } 1649 /* Only walk, if it can contain more virtual bases. */ 1650 if (CLASSTYPE_VBASECLASSES (BINFO_TYPE (base_binfo))) 1651 dfs_unmark_r (base_binfo); 1652 } 1653} 1654 1655/* Like dfs_walk_all, except that binfos are not multiply walked. For 1656 non-diamond shaped hierarchies this is the same as dfs_walk_all. 1657 For diamond shaped hierarchies we must mark the virtual bases, to 1658 avoid multiple walks. */ 1659 1660tree 1661dfs_walk_once (tree binfo, tree (*pre_fn) (tree, void *), 1662 tree (*post_fn) (tree, void *), void *data) 1663{ 1664 static int active = 0; /* We must not be called recursively. */ 1665 tree rval; 1666 1667 gcc_assert (pre_fn || post_fn); 1668 gcc_assert (!active); 1669 active++; 1670 1671 if (!CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo))) 1672 /* We are not diamond shaped, and therefore cannot encounter the 1673 same binfo twice. */ 1674 rval = dfs_walk_all (binfo, pre_fn, post_fn, data); 1675 else 1676 { 1677 rval = dfs_walk_once_r (binfo, pre_fn, post_fn, data); 1678 if (!BINFO_INHERITANCE_CHAIN (binfo)) 1679 { 1680 /* We are at the top of the hierarchy, and can use the 1681 CLASSTYPE_VBASECLASSES list for unmarking the virtual 1682 bases. */ 1683 VEC(tree,gc) *vbases; 1684 unsigned ix; 1685 tree base_binfo; 1686 1687 for (vbases = CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)), ix = 0; 1688 VEC_iterate (tree, vbases, ix, base_binfo); ix++) 1689 BINFO_MARKED (base_binfo) = 0; 1690 } 1691 else 1692 dfs_unmark_r (binfo); 1693 } 1694 1695 active--; 1696 1697 return rval; 1698} 1699 1700/* Worker function for dfs_walk_once_accessible. Behaves like 1701 dfs_walk_once_r, except (a) FRIENDS_P is true if special 1702 access given by the current context should be considered, (b) ONCE 1703 indicates whether bases should be marked during traversal. */ 1704 1705static tree 1706dfs_walk_once_accessible_r (tree binfo, bool friends_p, bool once, 1707 tree (*pre_fn) (tree, void *), 1708 tree (*post_fn) (tree, void *), void *data) 1709{ 1710 tree rval = NULL_TREE; 1711 unsigned ix; 1712 tree base_binfo; 1713 1714 /* Call the pre-order walking function. */ 1715 if (pre_fn) 1716 { 1717 rval = pre_fn (binfo, data); 1718 if (rval) 1719 { 1720 if (rval == dfs_skip_bases) 1721 goto skip_bases; 1722 1723 return rval; 1724 } 1725 } 1726 1727 /* Find the next child binfo to walk. */ 1728 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 1729 { 1730 bool mark = once && BINFO_VIRTUAL_P (base_binfo); 1731 1732 if (mark && BINFO_MARKED (base_binfo)) 1733 continue; 1734 1735 /* If the base is inherited via private or protected 1736 inheritance, then we can't see it, unless we are a friend of 1737 the current binfo. */ 1738 if (BINFO_BASE_ACCESS (binfo, ix) != access_public_node) 1739 { 1740 tree scope; 1741 if (!friends_p) 1742 continue; 1743 scope = current_scope (); 1744 if (!scope 1745 || TREE_CODE (scope) == NAMESPACE_DECL 1746 || !is_friend (BINFO_TYPE (binfo), scope)) 1747 continue; 1748 } 1749 1750 if (mark) 1751 BINFO_MARKED (base_binfo) = 1; 1752 1753 rval = dfs_walk_once_accessible_r (base_binfo, friends_p, once, 1754 pre_fn, post_fn, data); 1755 if (rval) 1756 return rval; 1757 } 1758 1759 skip_bases: 1760 /* Call the post-order walking function. */ 1761 if (post_fn) 1762 { 1763 rval = post_fn (binfo, data); 1764 gcc_assert (rval != dfs_skip_bases); 1765 return rval; 1766 } 1767 1768 return NULL_TREE; 1769} 1770 1771/* Like dfs_walk_once except that only accessible bases are walked. 1772 FRIENDS_P indicates whether friendship of the local context 1773 should be considered when determining accessibility. */ 1774 1775static tree 1776dfs_walk_once_accessible (tree binfo, bool friends_p, 1777 tree (*pre_fn) (tree, void *), 1778 tree (*post_fn) (tree, void *), void *data) 1779{ 1780 bool diamond_shaped = CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo)); 1781 tree rval = dfs_walk_once_accessible_r (binfo, friends_p, diamond_shaped, 1782 pre_fn, post_fn, data); 1783 1784 if (diamond_shaped) 1785 { 1786 if (!BINFO_INHERITANCE_CHAIN (binfo)) 1787 { 1788 /* We are at the top of the hierarchy, and can use the 1789 CLASSTYPE_VBASECLASSES list for unmarking the virtual 1790 bases. */ 1791 VEC(tree,gc) *vbases; 1792 unsigned ix; 1793 tree base_binfo; 1794 1795 for (vbases = CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)), ix = 0; 1796 VEC_iterate (tree, vbases, ix, base_binfo); ix++) 1797 BINFO_MARKED (base_binfo) = 0; 1798 } 1799 else 1800 dfs_unmark_r (binfo); 1801 } 1802 return rval; 1803} 1804 1805/* Check that virtual overrider OVERRIDER is acceptable for base function 1806 BASEFN. Issue diagnostic, and return zero, if unacceptable. */ 1807 1808static int 1809check_final_overrider (tree overrider, tree basefn) 1810{ 1811 tree over_type = TREE_TYPE (overrider); 1812 tree base_type = TREE_TYPE (basefn); 1813 tree over_return = TREE_TYPE (over_type); 1814 tree base_return = TREE_TYPE (base_type); 1815 tree over_throw = TYPE_RAISES_EXCEPTIONS (over_type); 1816 tree base_throw = TYPE_RAISES_EXCEPTIONS (base_type); 1817 int fail = 0; 1818 1819 if (DECL_INVALID_OVERRIDER_P (overrider)) 1820 return 0; 1821 1822 if (same_type_p (base_return, over_return)) 1823 /* OK */; 1824 else if ((CLASS_TYPE_P (over_return) && CLASS_TYPE_P (base_return)) 1825 || (TREE_CODE (base_return) == TREE_CODE (over_return) 1826 && POINTER_TYPE_P (base_return))) 1827 { 1828 /* Potentially covariant. */ 1829 unsigned base_quals, over_quals; 1830 1831 fail = !POINTER_TYPE_P (base_return); 1832 if (!fail) 1833 { 1834 fail = cp_type_quals (base_return) != cp_type_quals (over_return); 1835 1836 base_return = TREE_TYPE (base_return); 1837 over_return = TREE_TYPE (over_return); 1838 } 1839 base_quals = cp_type_quals (base_return); 1840 over_quals = cp_type_quals (over_return); 1841 1842 if ((base_quals & over_quals) != over_quals) 1843 fail = 1; 1844 1845 if (CLASS_TYPE_P (base_return) && CLASS_TYPE_P (over_return)) 1846 { 1847 tree binfo = lookup_base (over_return, base_return, 1848 ba_check | ba_quiet, NULL); 1849 1850 if (!binfo) 1851 fail = 1; 1852 } 1853 else if (!pedantic 1854 && can_convert (TREE_TYPE (base_type), TREE_TYPE (over_type))) 1855 /* GNU extension, allow trivial pointer conversions such as 1856 converting to void *, or qualification conversion. */ 1857 { 1858 /* can_convert will permit user defined conversion from a 1859 (reference to) class type. We must reject them. */ 1860 over_return = non_reference (TREE_TYPE (over_type)); 1861 if (CLASS_TYPE_P (over_return)) 1862 fail = 2; 1863 else 1864 { 1865 warning (0, "deprecated covariant return type for %q+#D", 1866 overrider); 1867 warning (0, " overriding %q+#D", basefn); 1868 } 1869 } 1870 else 1871 fail = 2; 1872 } 1873 else 1874 fail = 2; 1875 if (!fail) 1876 /* OK */; 1877 else 1878 { 1879 if (fail == 1) 1880 { 1881 error ("invalid covariant return type for %q+#D", overrider); 1882 error (" overriding %q+#D", basefn); 1883 } 1884 else 1885 { 1886 error ("conflicting return type specified for %q+#D", overrider); 1887 error (" overriding %q+#D", basefn); 1888 } 1889 DECL_INVALID_OVERRIDER_P (overrider) = 1; 1890 return 0; 1891 } 1892 1893 /* Check throw specifier is at least as strict. */ 1894 if (!comp_except_specs (base_throw, over_throw, 0)) 1895 { 1896 error ("looser throw specifier for %q+#F", overrider); 1897 error (" overriding %q+#F", basefn); 1898 DECL_INVALID_OVERRIDER_P (overrider) = 1; 1899 return 0; 1900 } 1901 1902 return 1; 1903} 1904 1905/* Given a class TYPE, and a function decl FNDECL, look for 1906 virtual functions in TYPE's hierarchy which FNDECL overrides. 1907 We do not look in TYPE itself, only its bases. 1908 1909 Returns nonzero, if we find any. Set FNDECL's DECL_VIRTUAL_P, if we 1910 find that it overrides anything. 1911 1912 We check that every function which is overridden, is correctly 1913 overridden. */ 1914 1915int 1916look_for_overrides (tree type, tree fndecl) 1917{ 1918 tree binfo = TYPE_BINFO (type); 1919 tree base_binfo; 1920 int ix; 1921 int found = 0; 1922 1923 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 1924 { 1925 tree basetype = BINFO_TYPE (base_binfo); 1926 1927 if (TYPE_POLYMORPHIC_P (basetype)) 1928 found += look_for_overrides_r (basetype, fndecl); 1929 } 1930 return found; 1931} 1932 1933/* Look in TYPE for virtual functions with the same signature as 1934 FNDECL. */ 1935 1936tree 1937look_for_overrides_here (tree type, tree fndecl) 1938{ 1939 int ix; 1940 1941 /* If there are no methods in TYPE (meaning that only implicitly 1942 declared methods will ever be provided for TYPE), then there are 1943 no virtual functions. */ 1944 if (!CLASSTYPE_METHOD_VEC (type)) 1945 return NULL_TREE; 1946 1947 if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fndecl)) 1948 ix = CLASSTYPE_DESTRUCTOR_SLOT; 1949 else 1950 ix = lookup_fnfields_1 (type, DECL_NAME (fndecl)); 1951 if (ix >= 0) 1952 { 1953 tree fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (type), ix); 1954 1955 for (; fns; fns = OVL_NEXT (fns)) 1956 { 1957 tree fn = OVL_CURRENT (fns); 1958 1959 if (!DECL_VIRTUAL_P (fn)) 1960 /* Not a virtual. */; 1961 else if (DECL_CONTEXT (fn) != type) 1962 /* Introduced with a using declaration. */; 1963 else if (DECL_STATIC_FUNCTION_P (fndecl)) 1964 { 1965 tree btypes = TYPE_ARG_TYPES (TREE_TYPE (fn)); 1966 tree dtypes = TYPE_ARG_TYPES (TREE_TYPE (fndecl)); 1967 if (compparms (TREE_CHAIN (btypes), dtypes)) 1968 return fn; 1969 } 1970 else if (same_signature_p (fndecl, fn)) 1971 return fn; 1972 } 1973 } 1974 return NULL_TREE; 1975} 1976 1977/* Look in TYPE for virtual functions overridden by FNDECL. Check both 1978 TYPE itself and its bases. */ 1979 1980static int 1981look_for_overrides_r (tree type, tree fndecl) 1982{ 1983 tree fn = look_for_overrides_here (type, fndecl); 1984 if (fn) 1985 { 1986 if (DECL_STATIC_FUNCTION_P (fndecl)) 1987 { 1988 /* A static member function cannot match an inherited 1989 virtual member function. */ 1990 error ("%q+#D cannot be declared", fndecl); 1991 error (" since %q+#D declared in base class", fn); 1992 } 1993 else 1994 { 1995 /* It's definitely virtual, even if not explicitly set. */ 1996 DECL_VIRTUAL_P (fndecl) = 1; 1997 check_final_overrider (fndecl, fn); 1998 } 1999 return 1; 2000 } 2001 2002 /* We failed to find one declared in this class. Look in its bases. */ 2003 return look_for_overrides (type, fndecl); 2004} 2005 2006/* Called via dfs_walk from dfs_get_pure_virtuals. */ 2007 2008static tree 2009dfs_get_pure_virtuals (tree binfo, void *data) 2010{ 2011 tree type = (tree) data; 2012 2013 /* We're not interested in primary base classes; the derived class 2014 of which they are a primary base will contain the information we 2015 need. */ 2016 if (!BINFO_PRIMARY_P (binfo)) 2017 { 2018 tree virtuals; 2019 2020 for (virtuals = BINFO_VIRTUALS (binfo); 2021 virtuals; 2022 virtuals = TREE_CHAIN (virtuals)) 2023 if (DECL_PURE_VIRTUAL_P (BV_FN (virtuals))) 2024 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (type), 2025 BV_FN (virtuals)); 2026 } 2027 2028 return NULL_TREE; 2029} 2030 2031/* Set CLASSTYPE_PURE_VIRTUALS for TYPE. */ 2032 2033void 2034get_pure_virtuals (tree type) 2035{ 2036 /* Clear the CLASSTYPE_PURE_VIRTUALS list; whatever is already there 2037 is going to be overridden. */ 2038 CLASSTYPE_PURE_VIRTUALS (type) = NULL; 2039 /* Now, run through all the bases which are not primary bases, and 2040 collect the pure virtual functions. We look at the vtable in 2041 each class to determine what pure virtual functions are present. 2042 (A primary base is not interesting because the derived class of 2043 which it is a primary base will contain vtable entries for the 2044 pure virtuals in the base class. */ 2045 dfs_walk_once (TYPE_BINFO (type), NULL, dfs_get_pure_virtuals, type); 2046} 2047 2048/* Debug info for C++ classes can get very large; try to avoid 2049 emitting it everywhere. 2050 2051 Note that this optimization wins even when the target supports 2052 BINCL (if only slightly), and reduces the amount of work for the 2053 linker. */ 2054 2055void 2056maybe_suppress_debug_info (tree t) 2057{ 2058 if (write_symbols == NO_DEBUG) 2059 return; 2060 2061 /* We might have set this earlier in cp_finish_decl. */ 2062 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 0; 2063 2064 /* Always emit the information for each class every time. */ 2065 if (flag_emit_class_debug_always) 2066 return; 2067 2068 /* If we already know how we're handling this class, handle debug info 2069 the same way. */ 2070 if (CLASSTYPE_INTERFACE_KNOWN (t)) 2071 { 2072 if (CLASSTYPE_INTERFACE_ONLY (t)) 2073 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 1; 2074 /* else don't set it. */ 2075 } 2076 /* If the class has a vtable, write out the debug info along with 2077 the vtable. */ 2078 else if (TYPE_CONTAINS_VPTR_P (t)) 2079 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 1; 2080 2081 /* Otherwise, just emit the debug info normally. */ 2082} 2083 2084/* Note that we want debugging information for a base class of a class 2085 whose vtable is being emitted. Normally, this would happen because 2086 calling the constructor for a derived class implies calling the 2087 constructors for all bases, which involve initializing the 2088 appropriate vptr with the vtable for the base class; but in the 2089 presence of optimization, this initialization may be optimized 2090 away, so we tell finish_vtable_vardecl that we want the debugging 2091 information anyway. */ 2092 2093static tree 2094dfs_debug_mark (tree binfo, void *data ATTRIBUTE_UNUSED) 2095{ 2096 tree t = BINFO_TYPE (binfo); 2097 2098 if (CLASSTYPE_DEBUG_REQUESTED (t)) 2099 return dfs_skip_bases; 2100 2101 CLASSTYPE_DEBUG_REQUESTED (t) = 1; 2102 2103 return NULL_TREE; 2104} 2105 2106/* Write out the debugging information for TYPE, whose vtable is being 2107 emitted. Also walk through our bases and note that we want to 2108 write out information for them. This avoids the problem of not 2109 writing any debug info for intermediate basetypes whose 2110 constructors, and thus the references to their vtables, and thus 2111 the vtables themselves, were optimized away. */ 2112 2113void 2114note_debug_info_needed (tree type) 2115{ 2116 if (TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type))) 2117 { 2118 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type)) = 0; 2119 rest_of_type_compilation (type, toplevel_bindings_p ()); 2120 } 2121 2122 dfs_walk_all (TYPE_BINFO (type), dfs_debug_mark, NULL, 0); 2123} 2124 2125void 2126print_search_statistics (void) 2127{ 2128#ifdef GATHER_STATISTICS 2129 fprintf (stderr, "%d fields searched in %d[%d] calls to lookup_field[_1]\n", 2130 n_fields_searched, n_calls_lookup_field, n_calls_lookup_field_1); 2131 fprintf (stderr, "%d fnfields searched in %d calls to lookup_fnfields\n", 2132 n_outer_fields_searched, n_calls_lookup_fnfields); 2133 fprintf (stderr, "%d calls to get_base_type\n", n_calls_get_base_type); 2134#else /* GATHER_STATISTICS */ 2135 fprintf (stderr, "no search statistics\n"); 2136#endif /* GATHER_STATISTICS */ 2137} 2138 2139void 2140reinit_search_statistics (void) 2141{ 2142#ifdef GATHER_STATISTICS 2143 n_fields_searched = 0; 2144 n_calls_lookup_field = 0, n_calls_lookup_field_1 = 0; 2145 n_calls_lookup_fnfields = 0, n_calls_lookup_fnfields_1 = 0; 2146 n_calls_get_base_type = 0; 2147 n_outer_fields_searched = 0; 2148 n_contexts_saved = 0; 2149#endif /* GATHER_STATISTICS */ 2150} 2151 2152/* Helper for lookup_conversions_r. TO_TYPE is the type converted to 2153 by a conversion op in base BINFO. VIRTUAL_DEPTH is nonzero if 2154 BINFO is morally virtual, and VIRTUALNESS is nonzero if virtual 2155 bases have been encountered already in the tree walk. PARENT_CONVS 2156 is the list of lists of conversion functions that could hide CONV 2157 and OTHER_CONVS is the list of lists of conversion functions that 2158 could hide or be hidden by CONV, should virtualness be involved in 2159 the hierarchy. Merely checking the conversion op's name is not 2160 enough because two conversion operators to the same type can have 2161 different names. Return nonzero if we are visible. */ 2162 2163static int 2164check_hidden_convs (tree binfo, int virtual_depth, int virtualness, 2165 tree to_type, tree parent_convs, tree other_convs) 2166{ 2167 tree level, probe; 2168 2169 /* See if we are hidden by a parent conversion. */ 2170 for (level = parent_convs; level; level = TREE_CHAIN (level)) 2171 for (probe = TREE_VALUE (level); probe; probe = TREE_CHAIN (probe)) 2172 if (same_type_p (to_type, TREE_TYPE (probe))) 2173 return 0; 2174 2175 if (virtual_depth || virtualness) 2176 { 2177 /* In a virtual hierarchy, we could be hidden, or could hide a 2178 conversion function on the other_convs list. */ 2179 for (level = other_convs; level; level = TREE_CHAIN (level)) 2180 { 2181 int we_hide_them; 2182 int they_hide_us; 2183 tree *prev, other; 2184 2185 if (!(virtual_depth || TREE_STATIC (level))) 2186 /* Neither is morally virtual, so cannot hide each other. */ 2187 continue; 2188 2189 if (!TREE_VALUE (level)) 2190 /* They evaporated away already. */ 2191 continue; 2192 2193 they_hide_us = (virtual_depth 2194 && original_binfo (binfo, TREE_PURPOSE (level))); 2195 we_hide_them = (!they_hide_us && TREE_STATIC (level) 2196 && original_binfo (TREE_PURPOSE (level), binfo)); 2197 2198 if (!(we_hide_them || they_hide_us)) 2199 /* Neither is within the other, so no hiding can occur. */ 2200 continue; 2201 2202 for (prev = &TREE_VALUE (level), other = *prev; other;) 2203 { 2204 if (same_type_p (to_type, TREE_TYPE (other))) 2205 { 2206 if (they_hide_us) 2207 /* We are hidden. */ 2208 return 0; 2209 2210 if (we_hide_them) 2211 { 2212 /* We hide the other one. */ 2213 other = TREE_CHAIN (other); 2214 *prev = other; 2215 continue; 2216 } 2217 } 2218 prev = &TREE_CHAIN (other); 2219 other = *prev; 2220 } 2221 } 2222 } 2223 return 1; 2224} 2225 2226/* Helper for lookup_conversions_r. PARENT_CONVS is a list of lists 2227 of conversion functions, the first slot will be for the current 2228 binfo, if MY_CONVS is non-NULL. CHILD_CONVS is the list of lists 2229 of conversion functions from children of the current binfo, 2230 concatenated with conversions from elsewhere in the hierarchy -- 2231 that list begins with OTHER_CONVS. Return a single list of lists 2232 containing only conversions from the current binfo and its 2233 children. */ 2234 2235static tree 2236split_conversions (tree my_convs, tree parent_convs, 2237 tree child_convs, tree other_convs) 2238{ 2239 tree t; 2240 tree prev; 2241 2242 /* Remove the original other_convs portion from child_convs. */ 2243 for (prev = NULL, t = child_convs; 2244 t != other_convs; prev = t, t = TREE_CHAIN (t)) 2245 continue; 2246 2247 if (prev) 2248 TREE_CHAIN (prev) = NULL_TREE; 2249 else 2250 child_convs = NULL_TREE; 2251 2252 /* Attach the child convs to any we had at this level. */ 2253 if (my_convs) 2254 { 2255 my_convs = parent_convs; 2256 TREE_CHAIN (my_convs) = child_convs; 2257 } 2258 else 2259 my_convs = child_convs; 2260 2261 return my_convs; 2262} 2263 2264/* Worker for lookup_conversions. Lookup conversion functions in 2265 BINFO and its children. VIRTUAL_DEPTH is nonzero, if BINFO is in 2266 a morally virtual base, and VIRTUALNESS is nonzero, if we've 2267 encountered virtual bases already in the tree walk. PARENT_CONVS & 2268 PARENT_TPL_CONVS are lists of list of conversions within parent 2269 binfos. OTHER_CONVS and OTHER_TPL_CONVS are conversions found 2270 elsewhere in the tree. Return the conversions found within this 2271 portion of the graph in CONVS and TPL_CONVS. Return nonzero is we 2272 encountered virtualness. We keep template and non-template 2273 conversions separate, to avoid unnecessary type comparisons. 2274 2275 The located conversion functions are held in lists of lists. The 2276 TREE_VALUE of the outer list is the list of conversion functions 2277 found in a particular binfo. The TREE_PURPOSE of both the outer 2278 and inner lists is the binfo at which those conversions were 2279 found. TREE_STATIC is set for those lists within of morally 2280 virtual binfos. The TREE_VALUE of the inner list is the conversion 2281 function or overload itself. The TREE_TYPE of each inner list node 2282 is the converted-to type. */ 2283 2284static int 2285lookup_conversions_r (tree binfo, 2286 int virtual_depth, int virtualness, 2287 tree parent_convs, tree parent_tpl_convs, 2288 tree other_convs, tree other_tpl_convs, 2289 tree *convs, tree *tpl_convs) 2290{ 2291 int my_virtualness = 0; 2292 tree my_convs = NULL_TREE; 2293 tree my_tpl_convs = NULL_TREE; 2294 tree child_convs = NULL_TREE; 2295 tree child_tpl_convs = NULL_TREE; 2296 unsigned i; 2297 tree base_binfo; 2298 VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo)); 2299 tree conv; 2300 2301 /* If we have no conversion operators, then don't look. */ 2302 if (!TYPE_HAS_CONVERSION (BINFO_TYPE (binfo))) 2303 { 2304 *convs = *tpl_convs = NULL_TREE; 2305 2306 return 0; 2307 } 2308 2309 if (BINFO_VIRTUAL_P (binfo)) 2310 virtual_depth++; 2311 2312 /* First, locate the unhidden ones at this level. */ 2313 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT; 2314 VEC_iterate (tree, method_vec, i, conv); 2315 ++i) 2316 { 2317 tree cur = OVL_CURRENT (conv); 2318 2319 if (!DECL_CONV_FN_P (cur)) 2320 break; 2321 2322 if (TREE_CODE (cur) == TEMPLATE_DECL) 2323 { 2324 /* Only template conversions can be overloaded, and we must 2325 flatten them out and check each one individually. */ 2326 tree tpls; 2327 2328 for (tpls = conv; tpls; tpls = OVL_NEXT (tpls)) 2329 { 2330 tree tpl = OVL_CURRENT (tpls); 2331 tree type = DECL_CONV_FN_TYPE (tpl); 2332 2333 if (check_hidden_convs (binfo, virtual_depth, virtualness, 2334 type, parent_tpl_convs, other_tpl_convs)) 2335 { 2336 my_tpl_convs = tree_cons (binfo, tpl, my_tpl_convs); 2337 TREE_TYPE (my_tpl_convs) = type; 2338 if (virtual_depth) 2339 { 2340 TREE_STATIC (my_tpl_convs) = 1; 2341 my_virtualness = 1; 2342 } 2343 } 2344 } 2345 } 2346 else 2347 { 2348 tree name = DECL_NAME (cur); 2349 2350 if (!IDENTIFIER_MARKED (name)) 2351 { 2352 tree type = DECL_CONV_FN_TYPE (cur); 2353 2354 if (check_hidden_convs (binfo, virtual_depth, virtualness, 2355 type, parent_convs, other_convs)) 2356 { 2357 my_convs = tree_cons (binfo, conv, my_convs); 2358 TREE_TYPE (my_convs) = type; 2359 if (virtual_depth) 2360 { 2361 TREE_STATIC (my_convs) = 1; 2362 my_virtualness = 1; 2363 } 2364 IDENTIFIER_MARKED (name) = 1; 2365 } 2366 } 2367 } 2368 } 2369 2370 if (my_convs) 2371 { 2372 parent_convs = tree_cons (binfo, my_convs, parent_convs); 2373 if (virtual_depth) 2374 TREE_STATIC (parent_convs) = 1; 2375 } 2376 2377 if (my_tpl_convs) 2378 { 2379 parent_tpl_convs = tree_cons (binfo, my_tpl_convs, parent_tpl_convs); 2380 if (virtual_depth) 2381 TREE_STATIC (parent_tpl_convs) = 1; 2382 } 2383 2384 child_convs = other_convs; 2385 child_tpl_convs = other_tpl_convs; 2386 2387 /* Now iterate over each base, looking for more conversions. */ 2388 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 2389 { 2390 tree base_convs, base_tpl_convs; 2391 unsigned base_virtualness; 2392 2393 base_virtualness = lookup_conversions_r (base_binfo, 2394 virtual_depth, virtualness, 2395 parent_convs, parent_tpl_convs, 2396 child_convs, child_tpl_convs, 2397 &base_convs, &base_tpl_convs); 2398 if (base_virtualness) 2399 my_virtualness = virtualness = 1; 2400 child_convs = chainon (base_convs, child_convs); 2401 child_tpl_convs = chainon (base_tpl_convs, child_tpl_convs); 2402 } 2403 2404 /* Unmark the conversions found at this level */ 2405 for (conv = my_convs; conv; conv = TREE_CHAIN (conv)) 2406 IDENTIFIER_MARKED (DECL_NAME (OVL_CURRENT (TREE_VALUE (conv)))) = 0; 2407 2408 *convs = split_conversions (my_convs, parent_convs, 2409 child_convs, other_convs); 2410 *tpl_convs = split_conversions (my_tpl_convs, parent_tpl_convs, 2411 child_tpl_convs, other_tpl_convs); 2412 2413 return my_virtualness; 2414} 2415 2416/* Return a TREE_LIST containing all the non-hidden user-defined 2417 conversion functions for TYPE (and its base-classes). The 2418 TREE_VALUE of each node is the FUNCTION_DECL of the conversion 2419 function. The TREE_PURPOSE is the BINFO from which the conversion 2420 functions in this node were selected. This function is effectively 2421 performing a set of member lookups as lookup_fnfield does, but 2422 using the type being converted to as the unique key, rather than the 2423 field name. */ 2424 2425tree 2426lookup_conversions (tree type) 2427{ 2428 tree convs, tpl_convs; 2429 tree list = NULL_TREE; 2430 2431 complete_type (type); 2432 if (!TYPE_BINFO (type)) 2433 return NULL_TREE; 2434 2435 lookup_conversions_r (TYPE_BINFO (type), 0, 0, 2436 NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE, 2437 &convs, &tpl_convs); 2438 2439 /* Flatten the list-of-lists */ 2440 for (; convs; convs = TREE_CHAIN (convs)) 2441 { 2442 tree probe, next; 2443 2444 for (probe = TREE_VALUE (convs); probe; probe = next) 2445 { 2446 next = TREE_CHAIN (probe); 2447 2448 TREE_CHAIN (probe) = list; 2449 list = probe; 2450 } 2451 } 2452 2453 for (; tpl_convs; tpl_convs = TREE_CHAIN (tpl_convs)) 2454 { 2455 tree probe, next; 2456 2457 for (probe = TREE_VALUE (tpl_convs); probe; probe = next) 2458 { 2459 next = TREE_CHAIN (probe); 2460 2461 TREE_CHAIN (probe) = list; 2462 list = probe; 2463 } 2464 } 2465 2466 return list; 2467} 2468 2469/* Returns the binfo of the first direct or indirect virtual base derived 2470 from BINFO, or NULL if binfo is not via virtual. */ 2471 2472tree 2473binfo_from_vbase (tree binfo) 2474{ 2475 for (; binfo; binfo = BINFO_INHERITANCE_CHAIN (binfo)) 2476 { 2477 if (BINFO_VIRTUAL_P (binfo)) 2478 return binfo; 2479 } 2480 return NULL_TREE; 2481} 2482 2483/* Returns the binfo of the first direct or indirect virtual base derived 2484 from BINFO up to the TREE_TYPE, LIMIT, or NULL if binfo is not 2485 via virtual. */ 2486 2487tree 2488binfo_via_virtual (tree binfo, tree limit) 2489{ 2490 if (limit && !CLASSTYPE_VBASECLASSES (limit)) 2491 /* LIMIT has no virtual bases, so BINFO cannot be via one. */ 2492 return NULL_TREE; 2493 2494 for (; binfo && !SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), limit); 2495 binfo = BINFO_INHERITANCE_CHAIN (binfo)) 2496 { 2497 if (BINFO_VIRTUAL_P (binfo)) 2498 return binfo; 2499 } 2500 return NULL_TREE; 2501} 2502 2503/* BINFO is a base binfo in the complete type BINFO_TYPE (HERE). 2504 Find the equivalent binfo within whatever graph HERE is located. 2505 This is the inverse of original_binfo. */ 2506 2507tree 2508copied_binfo (tree binfo, tree here) 2509{ 2510 tree result = NULL_TREE; 2511 2512 if (BINFO_VIRTUAL_P (binfo)) 2513 { 2514 tree t; 2515 2516 for (t = here; BINFO_INHERITANCE_CHAIN (t); 2517 t = BINFO_INHERITANCE_CHAIN (t)) 2518 continue; 2519 2520 result = binfo_for_vbase (BINFO_TYPE (binfo), BINFO_TYPE (t)); 2521 } 2522 else if (BINFO_INHERITANCE_CHAIN (binfo)) 2523 { 2524 tree cbinfo; 2525 tree base_binfo; 2526 int ix; 2527 2528 cbinfo = copied_binfo (BINFO_INHERITANCE_CHAIN (binfo), here); 2529 for (ix = 0; BINFO_BASE_ITERATE (cbinfo, ix, base_binfo); ix++) 2530 if (SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo), BINFO_TYPE (binfo))) 2531 { 2532 result = base_binfo; 2533 break; 2534 } 2535 } 2536 else 2537 { 2538 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (here), BINFO_TYPE (binfo))); 2539 result = here; 2540 } 2541 2542 gcc_assert (result); 2543 return result; 2544} 2545 2546tree 2547binfo_for_vbase (tree base, tree t) 2548{ 2549 unsigned ix; 2550 tree binfo; 2551 VEC(tree,gc) *vbases; 2552 2553 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0; 2554 VEC_iterate (tree, vbases, ix, binfo); ix++) 2555 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), base)) 2556 return binfo; 2557 return NULL; 2558} 2559 2560/* BINFO is some base binfo of HERE, within some other 2561 hierarchy. Return the equivalent binfo, but in the hierarchy 2562 dominated by HERE. This is the inverse of copied_binfo. If BINFO 2563 is not a base binfo of HERE, returns NULL_TREE. */ 2564 2565tree 2566original_binfo (tree binfo, tree here) 2567{ 2568 tree result = NULL; 2569 2570 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (here))) 2571 result = here; 2572 else if (BINFO_VIRTUAL_P (binfo)) 2573 result = (CLASSTYPE_VBASECLASSES (BINFO_TYPE (here)) 2574 ? binfo_for_vbase (BINFO_TYPE (binfo), BINFO_TYPE (here)) 2575 : NULL_TREE); 2576 else if (BINFO_INHERITANCE_CHAIN (binfo)) 2577 { 2578 tree base_binfos; 2579 2580 base_binfos = original_binfo (BINFO_INHERITANCE_CHAIN (binfo), here); 2581 if (base_binfos) 2582 { 2583 int ix; 2584 tree base_binfo; 2585 2586 for (ix = 0; (base_binfo = BINFO_BASE_BINFO (base_binfos, ix)); ix++) 2587 if (SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo), 2588 BINFO_TYPE (binfo))) 2589 { 2590 result = base_binfo; 2591 break; 2592 } 2593 } 2594 } 2595 2596 return result; 2597} 2598 2599