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, 2007, 2008, 2009 5 Free Software Foundation, Inc. 6 Contributed by Michael Tiemann (tiemann@cygnus.com) 7 8This file is part of GCC. 9 10GCC is free software; you can redistribute it and/or modify 11it under the terms of the GNU General Public License as published by 12the Free Software Foundation; either version 3, or (at your option) 13any later version. 14 15GCC is distributed in the hope that it will be useful, 16but WITHOUT ANY WARRANTY; without even the implied warranty of 17MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18GNU General Public License for more details. 19 20You should have received a copy of the GNU General Public License 21along with GCC; see the file COPYING3. If not see 22<http://www.gnu.org/licenses/>. */ 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 "intl.h" 33#include "obstack.h" 34#include "flags.h" 35#include "rtl.h" 36#include "output.h" 37#include "toplev.h" 38#include "target.h" 39 40static int is_subobject_of_p (tree, tree); 41static tree dfs_lookup_base (tree, void *); 42static tree dfs_dcast_hint_pre (tree, void *); 43static tree dfs_dcast_hint_post (tree, void *); 44static tree dfs_debug_mark (tree, void *); 45static tree dfs_walk_once_r (tree, tree (*pre_fn) (tree, void *), 46 tree (*post_fn) (tree, void *), void *data); 47static void dfs_unmark_r (tree); 48static int check_hidden_convs (tree, int, int, tree, tree, tree); 49static tree split_conversions (tree, tree, tree, tree); 50static int lookup_conversions_r (tree, int, int, 51 tree, tree, tree, tree, tree *, tree *); 52static int look_for_overrides_r (tree, tree); 53static tree lookup_field_r (tree, void *); 54static tree dfs_accessible_post (tree, void *); 55static tree dfs_walk_once_accessible_r (tree, bool, bool, 56 tree (*pre_fn) (tree, void *), 57 tree (*post_fn) (tree, void *), 58 void *data); 59static tree dfs_walk_once_accessible (tree, bool, 60 tree (*pre_fn) (tree, void *), 61 tree (*post_fn) (tree, void *), 62 void *data); 63static tree dfs_access_in_type (tree, void *); 64static access_kind access_in_type (tree, tree); 65static int protected_accessible_p (tree, tree, tree); 66static int friend_accessible_p (tree, tree, tree); 67static tree dfs_get_pure_virtuals (tree, void *); 68 69 70/* Variables for gathering statistics. */ 71#ifdef GATHER_STATISTICS 72static int n_fields_searched; 73static int n_calls_lookup_field, n_calls_lookup_field_1; 74static int n_calls_lookup_fnfields, n_calls_lookup_fnfields_1; 75static int n_calls_get_base_type; 76static int n_outer_fields_searched; 77static int n_contexts_saved; 78#endif /* GATHER_STATISTICS */ 79 80 81/* Data for lookup_base and its workers. */ 82 83struct lookup_base_data_s 84{ 85 tree t; /* type being searched. */ 86 tree base; /* The base type we're looking for. */ 87 tree binfo; /* Found binfo. */ 88 bool via_virtual; /* Found via a virtual path. */ 89 bool ambiguous; /* Found multiply ambiguous */ 90 bool repeated_base; /* Whether there are repeated bases in the 91 hierarchy. */ 92 bool want_any; /* Whether we want any matching binfo. */ 93}; 94 95/* Worker function for lookup_base. See if we've found the desired 96 base and update DATA_ (a pointer to LOOKUP_BASE_DATA_S). */ 97 98static tree 99dfs_lookup_base (tree binfo, void *data_) 100{ 101 struct lookup_base_data_s *data = (struct lookup_base_data_s *) data_; 102 103 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->base)) 104 { 105 if (!data->binfo) 106 { 107 data->binfo = binfo; 108 data->via_virtual 109 = binfo_via_virtual (data->binfo, data->t) != NULL_TREE; 110 111 if (!data->repeated_base) 112 /* If there are no repeated bases, we can stop now. */ 113 return binfo; 114 115 if (data->want_any && !data->via_virtual) 116 /* If this is a non-virtual base, then we can't do 117 better. */ 118 return binfo; 119 120 return dfs_skip_bases; 121 } 122 else 123 { 124 gcc_assert (binfo != data->binfo); 125 126 /* We've found more than one matching binfo. */ 127 if (!data->want_any) 128 { 129 /* This is immediately ambiguous. */ 130 data->binfo = NULL_TREE; 131 data->ambiguous = true; 132 return error_mark_node; 133 } 134 135 /* Prefer one via a non-virtual path. */ 136 if (!binfo_via_virtual (binfo, data->t)) 137 { 138 data->binfo = binfo; 139 data->via_virtual = false; 140 return binfo; 141 } 142 143 /* There must be repeated bases, otherwise we'd have stopped 144 on the first base we found. */ 145 return dfs_skip_bases; 146 } 147 } 148 149 return NULL_TREE; 150} 151 152/* Returns true if type BASE is accessible in T. (BASE is known to be 153 a (possibly non-proper) base class of T.) If CONSIDER_LOCAL_P is 154 true, consider any special access of the current scope, or access 155 bestowed by friendship. */ 156 157bool 158accessible_base_p (tree t, tree base, bool consider_local_p) 159{ 160 tree decl; 161 162 /* [class.access.base] 163 164 A base class is said to be accessible if an invented public 165 member of the base class is accessible. 166 167 If BASE is a non-proper base, this condition is trivially 168 true. */ 169 if (same_type_p (t, base)) 170 return true; 171 /* Rather than inventing a public member, we use the implicit 172 public typedef created in the scope of every class. */ 173 decl = TYPE_FIELDS (base); 174 while (!DECL_SELF_REFERENCE_P (decl)) 175 decl = TREE_CHAIN (decl); 176 while (ANON_AGGR_TYPE_P (t)) 177 t = TYPE_CONTEXT (t); 178 return accessible_p (t, decl, consider_local_p); 179} 180 181/* Lookup BASE in the hierarchy dominated by T. Do access checking as 182 ACCESS specifies. Return the binfo we discover. If KIND_PTR is 183 non-NULL, fill with information about what kind of base we 184 discovered. 185 186 If the base is inaccessible, or ambiguous, and the ba_quiet bit is 187 not set in ACCESS, then an error is issued and error_mark_node is 188 returned. If the ba_quiet bit is set, then no error is issued and 189 NULL_TREE is returned. */ 190 191tree 192lookup_base (tree t, tree base, base_access access, base_kind *kind_ptr) 193{ 194 tree binfo; 195 tree t_binfo; 196 base_kind bk; 197 198 if (t == error_mark_node || base == error_mark_node) 199 { 200 if (kind_ptr) 201 *kind_ptr = bk_not_base; 202 return error_mark_node; 203 } 204 gcc_assert (TYPE_P (base)); 205 206 if (!TYPE_P (t)) 207 { 208 t_binfo = t; 209 t = BINFO_TYPE (t); 210 } 211 else 212 { 213 t = complete_type (TYPE_MAIN_VARIANT (t)); 214 t_binfo = TYPE_BINFO (t); 215 } 216 217 base = TYPE_MAIN_VARIANT (base); 218 219 /* If BASE is incomplete, it can't be a base of T--and instantiating it 220 might cause an error. */ 221 if (t_binfo && CLASS_TYPE_P (base) 222 && (COMPLETE_TYPE_P (base) || TYPE_BEING_DEFINED (base))) 223 { 224 struct lookup_base_data_s data; 225 226 data.t = t; 227 data.base = base; 228 data.binfo = NULL_TREE; 229 data.ambiguous = data.via_virtual = false; 230 data.repeated_base = CLASSTYPE_REPEATED_BASE_P (t); 231 data.want_any = access == ba_any; 232 233 dfs_walk_once (t_binfo, dfs_lookup_base, NULL, &data); 234 binfo = data.binfo; 235 236 if (!binfo) 237 bk = data.ambiguous ? bk_ambig : bk_not_base; 238 else if (binfo == t_binfo) 239 bk = bk_same_type; 240 else if (data.via_virtual) 241 bk = bk_via_virtual; 242 else 243 bk = bk_proper_base; 244 } 245 else 246 { 247 binfo = NULL_TREE; 248 bk = bk_not_base; 249 } 250 251 /* Check that the base is unambiguous and accessible. */ 252 if (access != ba_any) 253 switch (bk) 254 { 255 case bk_not_base: 256 break; 257 258 case bk_ambig: 259 if (!(access & ba_quiet)) 260 { 261 error ("%qT is an ambiguous base of %qT", base, t); 262 binfo = error_mark_node; 263 } 264 break; 265 266 default: 267 if ((access & ba_check_bit) 268 /* If BASE is incomplete, then BASE and TYPE are probably 269 the same, in which case BASE is accessible. If they 270 are not the same, then TYPE is invalid. In that case, 271 there's no need to issue another error here, and 272 there's no implicit typedef to use in the code that 273 follows, so we skip the check. */ 274 && COMPLETE_TYPE_P (base) 275 && !accessible_base_p (t, base, !(access & ba_ignore_scope))) 276 { 277 if (!(access & ba_quiet)) 278 { 279 error ("%qT is an inaccessible base of %qT", base, t); 280 binfo = error_mark_node; 281 } 282 else 283 binfo = NULL_TREE; 284 bk = bk_inaccessible; 285 } 286 break; 287 } 288 289 if (kind_ptr) 290 *kind_ptr = bk; 291 292 return binfo; 293} 294 295/* Data for dcast_base_hint walker. */ 296 297struct dcast_data_s 298{ 299 tree subtype; /* The base type we're looking for. */ 300 int virt_depth; /* Number of virtual bases encountered from most 301 derived. */ 302 tree offset; /* Best hint offset discovered so far. */ 303 bool repeated_base; /* Whether there are repeated bases in the 304 hierarchy. */ 305}; 306 307/* Worker for dcast_base_hint. Search for the base type being cast 308 from. */ 309 310static tree 311dfs_dcast_hint_pre (tree binfo, void *data_) 312{ 313 struct dcast_data_s *data = (struct dcast_data_s *) data_; 314 315 if (BINFO_VIRTUAL_P (binfo)) 316 data->virt_depth++; 317 318 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->subtype)) 319 { 320 if (data->virt_depth) 321 { 322 data->offset = ssize_int (-1); 323 return data->offset; 324 } 325 if (data->offset) 326 data->offset = ssize_int (-3); 327 else 328 data->offset = BINFO_OFFSET (binfo); 329 330 return data->repeated_base ? dfs_skip_bases : data->offset; 331 } 332 333 return NULL_TREE; 334} 335 336/* Worker for dcast_base_hint. Track the virtual depth. */ 337 338static tree 339dfs_dcast_hint_post (tree binfo, void *data_) 340{ 341 struct dcast_data_s *data = (struct dcast_data_s *) data_; 342 343 if (BINFO_VIRTUAL_P (binfo)) 344 data->virt_depth--; 345 346 return NULL_TREE; 347} 348 349/* The dynamic cast runtime needs a hint about how the static SUBTYPE type 350 started from is related to the required TARGET type, in order to optimize 351 the inheritance graph search. This information is independent of the 352 current context, and ignores private paths, hence get_base_distance is 353 inappropriate. Return a TREE specifying the base offset, BOFF. 354 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF, 355 and there are no public virtual SUBTYPE bases. 356 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases. 357 BOFF == -2, SUBTYPE is not a public base. 358 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */ 359 360tree 361dcast_base_hint (tree subtype, tree target) 362{ 363 struct dcast_data_s data; 364 365 data.subtype = subtype; 366 data.virt_depth = 0; 367 data.offset = NULL_TREE; 368 data.repeated_base = CLASSTYPE_REPEATED_BASE_P (target); 369 370 dfs_walk_once_accessible (TYPE_BINFO (target), /*friends=*/false, 371 dfs_dcast_hint_pre, dfs_dcast_hint_post, &data); 372 return data.offset ? data.offset : ssize_int (-2); 373} 374 375/* Search for a member with name NAME in a multiple inheritance 376 lattice specified by TYPE. If it does not exist, return NULL_TREE. 377 If the member is ambiguously referenced, return `error_mark_node'. 378 Otherwise, return a DECL with the indicated name. If WANT_TYPE is 379 true, type declarations are preferred. */ 380 381/* Do a 1-level search for NAME as a member of TYPE. The caller must 382 figure out whether it can access this field. (Since it is only one 383 level, this is reasonable.) */ 384 385tree 386lookup_field_1 (tree type, tree name, bool want_type) 387{ 388 tree field; 389 390 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM 391 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM 392 || TREE_CODE (type) == TYPENAME_TYPE) 393 /* The TYPE_FIELDS of a TEMPLATE_TYPE_PARM and 394 BOUND_TEMPLATE_TEMPLATE_PARM are not fields at all; 395 instead TYPE_FIELDS is the TEMPLATE_PARM_INDEX. (Miraculously, 396 the code often worked even when we treated the index as a list 397 of fields!) 398 The TYPE_FIELDS of TYPENAME_TYPE is its TYPENAME_TYPE_FULLNAME. */ 399 return NULL_TREE; 400 401 if (CLASSTYPE_SORTED_FIELDS (type)) 402 { 403 tree *fields = &CLASSTYPE_SORTED_FIELDS (type)->elts[0]; 404 int lo = 0, hi = CLASSTYPE_SORTED_FIELDS (type)->len; 405 int i; 406 407 while (lo < hi) 408 { 409 i = (lo + hi) / 2; 410 411#ifdef GATHER_STATISTICS 412 n_fields_searched++; 413#endif /* GATHER_STATISTICS */ 414 415 if (DECL_NAME (fields[i]) > name) 416 hi = i; 417 else if (DECL_NAME (fields[i]) < name) 418 lo = i + 1; 419 else 420 { 421 field = NULL_TREE; 422 423 /* We might have a nested class and a field with the 424 same name; we sorted them appropriately via 425 field_decl_cmp, so just look for the first or last 426 field with this name. */ 427 if (want_type) 428 { 429 do 430 field = fields[i--]; 431 while (i >= lo && DECL_NAME (fields[i]) == name); 432 if (TREE_CODE (field) != TYPE_DECL 433 && !DECL_CLASS_TEMPLATE_P (field)) 434 field = NULL_TREE; 435 } 436 else 437 { 438 do 439 field = fields[i++]; 440 while (i < hi && DECL_NAME (fields[i]) == name); 441 } 442 return field; 443 } 444 } 445 return NULL_TREE; 446 } 447 448 field = TYPE_FIELDS (type); 449 450#ifdef GATHER_STATISTICS 451 n_calls_lookup_field_1++; 452#endif /* GATHER_STATISTICS */ 453 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 454 { 455#ifdef GATHER_STATISTICS 456 n_fields_searched++; 457#endif /* GATHER_STATISTICS */ 458 gcc_assert (DECL_P (field)); 459 if (DECL_NAME (field) == NULL_TREE 460 && ANON_AGGR_TYPE_P (TREE_TYPE (field))) 461 { 462 tree temp = lookup_field_1 (TREE_TYPE (field), name, want_type); 463 if (temp) 464 return temp; 465 } 466 if (TREE_CODE (field) == USING_DECL) 467 { 468 /* We generally treat class-scope using-declarations as 469 ARM-style access specifications, because support for the 470 ISO semantics has not been implemented. So, in general, 471 there's no reason to return a USING_DECL, and the rest of 472 the compiler cannot handle that. Once the class is 473 defined, USING_DECLs are purged from TYPE_FIELDS; see 474 handle_using_decl. However, we make special efforts to 475 make using-declarations in class templates and class 476 template partial specializations work correctly. */ 477 if (!DECL_DEPENDENT_P (field)) 478 continue; 479 } 480 481 if (DECL_NAME (field) == name 482 && (!want_type 483 || TREE_CODE (field) == TYPE_DECL 484 || DECL_CLASS_TEMPLATE_P (field))) 485 return field; 486 } 487 /* Not found. */ 488 if (name == vptr_identifier) 489 { 490 /* Give the user what s/he thinks s/he wants. */ 491 if (TYPE_POLYMORPHIC_P (type)) 492 return TYPE_VFIELD (type); 493 } 494 return NULL_TREE; 495} 496 497/* Return the FUNCTION_DECL, RECORD_TYPE, UNION_TYPE, or 498 NAMESPACE_DECL corresponding to the innermost non-block scope. */ 499 500tree 501current_scope (void) 502{ 503 /* There are a number of cases we need to be aware of here: 504 current_class_type current_function_decl 505 global NULL NULL 506 fn-local NULL SET 507 class-local SET NULL 508 class->fn SET SET 509 fn->class SET SET 510 511 Those last two make life interesting. If we're in a function which is 512 itself inside a class, we need decls to go into the fn's decls (our 513 second case below). But if we're in a class and the class itself is 514 inside a function, we need decls to go into the decls for the class. To 515 achieve this last goal, we must see if, when both current_class_ptr and 516 current_function_decl are set, the class was declared inside that 517 function. If so, we know to put the decls into the class's scope. */ 518 if (current_function_decl && current_class_type 519 && ((DECL_FUNCTION_MEMBER_P (current_function_decl) 520 && same_type_p (DECL_CONTEXT (current_function_decl), 521 current_class_type)) 522 || (DECL_FRIEND_CONTEXT (current_function_decl) 523 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl), 524 current_class_type)))) 525 return current_function_decl; 526 if (current_class_type) 527 return current_class_type; 528 if (current_function_decl) 529 return current_function_decl; 530 return current_namespace; 531} 532 533/* Returns nonzero if we are currently in a function scope. Note 534 that this function returns zero if we are within a local class, but 535 not within a member function body of the local class. */ 536 537int 538at_function_scope_p (void) 539{ 540 tree cs = current_scope (); 541 return cs && TREE_CODE (cs) == FUNCTION_DECL; 542} 543 544/* Returns true if the innermost active scope is a class scope. */ 545 546bool 547at_class_scope_p (void) 548{ 549 tree cs = current_scope (); 550 return cs && TYPE_P (cs); 551} 552 553/* Returns true if the innermost active scope is a namespace scope. */ 554 555bool 556at_namespace_scope_p (void) 557{ 558 tree cs = current_scope (); 559 return cs && TREE_CODE (cs) == NAMESPACE_DECL; 560} 561 562/* Return the scope of DECL, as appropriate when doing name-lookup. */ 563 564tree 565context_for_name_lookup (tree decl) 566{ 567 /* [class.union] 568 569 For the purposes of name lookup, after the anonymous union 570 definition, the members of the anonymous union are considered to 571 have been defined in the scope in which the anonymous union is 572 declared. */ 573 tree context = DECL_CONTEXT (decl); 574 575 while (context && TYPE_P (context) && ANON_AGGR_TYPE_P (context)) 576 context = TYPE_CONTEXT (context); 577 if (!context) 578 context = global_namespace; 579 580 return context; 581} 582 583/* The accessibility routines use BINFO_ACCESS for scratch space 584 during the computation of the accessibility of some declaration. */ 585 586#define BINFO_ACCESS(NODE) \ 587 ((access_kind) ((TREE_PUBLIC (NODE) << 1) | TREE_PRIVATE (NODE))) 588 589/* Set the access associated with NODE to ACCESS. */ 590 591#define SET_BINFO_ACCESS(NODE, ACCESS) \ 592 ((TREE_PUBLIC (NODE) = ((ACCESS) & 2) != 0), \ 593 (TREE_PRIVATE (NODE) = ((ACCESS) & 1) != 0)) 594 595/* Called from access_in_type via dfs_walk. Calculate the access to 596 DATA (which is really a DECL) in BINFO. */ 597 598static tree 599dfs_access_in_type (tree binfo, void *data) 600{ 601 tree decl = (tree) data; 602 tree type = BINFO_TYPE (binfo); 603 access_kind access = ak_none; 604 605 if (context_for_name_lookup (decl) == type) 606 { 607 /* If we have descended to the scope of DECL, just note the 608 appropriate access. */ 609 if (TREE_PRIVATE (decl)) 610 access = ak_private; 611 else if (TREE_PROTECTED (decl)) 612 access = ak_protected; 613 else 614 access = ak_public; 615 } 616 else 617 { 618 /* First, check for an access-declaration that gives us more 619 access to the DECL. The CONST_DECL for an enumeration 620 constant will not have DECL_LANG_SPECIFIC, and thus no 621 DECL_ACCESS. */ 622 if (DECL_LANG_SPECIFIC (decl) && !DECL_DISCRIMINATOR_P (decl)) 623 { 624 tree decl_access = purpose_member (type, DECL_ACCESS (decl)); 625 626 if (decl_access) 627 { 628 decl_access = TREE_VALUE (decl_access); 629 630 if (decl_access == access_public_node) 631 access = ak_public; 632 else if (decl_access == access_protected_node) 633 access = ak_protected; 634 else if (decl_access == access_private_node) 635 access = ak_private; 636 else 637 gcc_unreachable (); 638 } 639 } 640 641 if (!access) 642 { 643 int i; 644 tree base_binfo; 645 VEC(tree,gc) *accesses; 646 647 /* Otherwise, scan our baseclasses, and pick the most favorable 648 access. */ 649 accesses = BINFO_BASE_ACCESSES (binfo); 650 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 651 { 652 tree base_access = VEC_index (tree, accesses, i); 653 access_kind base_access_now = BINFO_ACCESS (base_binfo); 654 655 if (base_access_now == ak_none || base_access_now == ak_private) 656 /* If it was not accessible in the base, or only 657 accessible as a private member, we can't access it 658 all. */ 659 base_access_now = ak_none; 660 else if (base_access == access_protected_node) 661 /* Public and protected members in the base become 662 protected here. */ 663 base_access_now = ak_protected; 664 else if (base_access == access_private_node) 665 /* Public and protected members in the base become 666 private here. */ 667 base_access_now = ak_private; 668 669 /* See if the new access, via this base, gives more 670 access than our previous best access. */ 671 if (base_access_now != ak_none 672 && (access == ak_none || base_access_now < access)) 673 { 674 access = base_access_now; 675 676 /* If the new access is public, we can't do better. */ 677 if (access == ak_public) 678 break; 679 } 680 } 681 } 682 } 683 684 /* Note the access to DECL in TYPE. */ 685 SET_BINFO_ACCESS (binfo, access); 686 687 return NULL_TREE; 688} 689 690/* Return the access to DECL in TYPE. */ 691 692static access_kind 693access_in_type (tree type, tree decl) 694{ 695 tree binfo = TYPE_BINFO (type); 696 697 /* We must take into account 698 699 [class.paths] 700 701 If a name can be reached by several paths through a multiple 702 inheritance graph, the access is that of the path that gives 703 most access. 704 705 The algorithm we use is to make a post-order depth-first traversal 706 of the base-class hierarchy. As we come up the tree, we annotate 707 each node with the most lenient access. */ 708 dfs_walk_once (binfo, NULL, dfs_access_in_type, decl); 709 710 return BINFO_ACCESS (binfo); 711} 712 713/* Returns nonzero if it is OK to access DECL through an object 714 indicated by BINFO in the context of DERIVED. */ 715 716static int 717protected_accessible_p (tree decl, tree derived, tree binfo) 718{ 719 access_kind access; 720 721 /* We're checking this clause from [class.access.base] 722 723 m as a member of N is protected, and the reference occurs in a 724 member or friend of class N, or in a member or friend of a 725 class P derived from N, where m as a member of P is public, private 726 or protected. 727 728 Here DERIVED is a possible P, DECL is m and BINFO_TYPE (binfo) is N. */ 729 730 /* If DERIVED isn't derived from N, then it can't be a P. */ 731 if (!DERIVED_FROM_P (BINFO_TYPE (binfo), derived)) 732 return 0; 733 734 access = access_in_type (derived, decl); 735 736 /* If m is inaccessible in DERIVED, then it's not a P. */ 737 if (access == ak_none) 738 return 0; 739 740 /* [class.protected] 741 742 When a friend or a member function of a derived class references 743 a protected nonstatic member of a base class, an access check 744 applies in addition to those described earlier in clause 745 _class.access_) Except when forming a pointer to member 746 (_expr.unary.op_), the access must be through a pointer to, 747 reference to, or object of the derived class itself (or any class 748 derived from that class) (_expr.ref_). If the access is to form 749 a pointer to member, the nested-name-specifier shall name the 750 derived class (or any class derived from that class). */ 751 if (DECL_NONSTATIC_MEMBER_P (decl)) 752 { 753 /* We can tell through what the reference is occurring by 754 chasing BINFO up to the root. */ 755 tree t = binfo; 756 while (BINFO_INHERITANCE_CHAIN (t)) 757 t = BINFO_INHERITANCE_CHAIN (t); 758 759 if (!DERIVED_FROM_P (derived, BINFO_TYPE (t))) 760 return 0; 761 } 762 763 return 1; 764} 765 766/* Returns nonzero if SCOPE is a friend of a type which would be able 767 to access DECL through the object indicated by BINFO. */ 768 769static int 770friend_accessible_p (tree scope, tree decl, tree binfo) 771{ 772 tree befriending_classes; 773 tree t; 774 775 if (!scope) 776 return 0; 777 778 if (TREE_CODE (scope) == FUNCTION_DECL 779 || DECL_FUNCTION_TEMPLATE_P (scope)) 780 befriending_classes = DECL_BEFRIENDING_CLASSES (scope); 781 else if (TYPE_P (scope)) 782 befriending_classes = CLASSTYPE_BEFRIENDING_CLASSES (scope); 783 else 784 return 0; 785 786 for (t = befriending_classes; t; t = TREE_CHAIN (t)) 787 if (protected_accessible_p (decl, TREE_VALUE (t), binfo)) 788 return 1; 789 790 /* Nested classes have the same access as their enclosing types, as 791 per DR 45 (this is a change from the standard). */ 792 if (TYPE_P (scope)) 793 for (t = TYPE_CONTEXT (scope); t && TYPE_P (t); t = TYPE_CONTEXT (t)) 794 if (protected_accessible_p (decl, t, binfo)) 795 return 1; 796 797 if (TREE_CODE (scope) == FUNCTION_DECL 798 || DECL_FUNCTION_TEMPLATE_P (scope)) 799 { 800 /* Perhaps this SCOPE is a member of a class which is a 801 friend. */ 802 if (DECL_CLASS_SCOPE_P (scope) 803 && friend_accessible_p (DECL_CONTEXT (scope), decl, binfo)) 804 return 1; 805 806 /* Or an instantiation of something which is a friend. */ 807 if (DECL_TEMPLATE_INFO (scope)) 808 { 809 int ret; 810 /* Increment processing_template_decl to make sure that 811 dependent_type_p works correctly. */ 812 ++processing_template_decl; 813 ret = friend_accessible_p (DECL_TI_TEMPLATE (scope), decl, binfo); 814 --processing_template_decl; 815 return ret; 816 } 817 } 818 819 return 0; 820} 821 822/* Called via dfs_walk_once_accessible from accessible_p */ 823 824static tree 825dfs_accessible_post (tree binfo, void *data ATTRIBUTE_UNUSED) 826{ 827 if (BINFO_ACCESS (binfo) != ak_none) 828 { 829 tree scope = current_scope (); 830 if (scope && TREE_CODE (scope) != NAMESPACE_DECL 831 && is_friend (BINFO_TYPE (binfo), scope)) 832 return binfo; 833 } 834 835 return NULL_TREE; 836} 837 838/* DECL is a declaration from a base class of TYPE, which was the 839 class used to name DECL. Return nonzero if, in the current 840 context, DECL is accessible. If TYPE is actually a BINFO node, 841 then we can tell in what context the access is occurring by looking 842 at the most derived class along the path indicated by BINFO. If 843 CONSIDER_LOCAL is true, do consider special access the current 844 scope or friendship thereof we might have. */ 845 846int 847accessible_p (tree type, tree decl, bool consider_local_p) 848{ 849 tree binfo; 850 tree scope; 851 access_kind access; 852 853 /* Nonzero if it's OK to access DECL if it has protected 854 accessibility in TYPE. */ 855 int protected_ok = 0; 856 857 /* If this declaration is in a block or namespace scope, there's no 858 access control. */ 859 if (!TYPE_P (context_for_name_lookup (decl))) 860 return 1; 861 862 /* There is no need to perform access checks inside a thunk. */ 863 scope = current_scope (); 864 if (scope && DECL_THUNK_P (scope)) 865 return 1; 866 867 /* In a template declaration, we cannot be sure whether the 868 particular specialization that is instantiated will be a friend 869 or not. Therefore, all access checks are deferred until 870 instantiation. However, PROCESSING_TEMPLATE_DECL is set in the 871 parameter list for a template (because we may see dependent types 872 in default arguments for template parameters), and access 873 checking should be performed in the outermost parameter list. */ 874 if (processing_template_decl 875 && (!processing_template_parmlist || processing_template_decl > 1)) 876 return 1; 877 878 if (!TYPE_P (type)) 879 { 880 binfo = type; 881 type = BINFO_TYPE (type); 882 } 883 else 884 binfo = TYPE_BINFO (type); 885 886 /* [class.access.base] 887 888 A member m is accessible when named in class N if 889 890 --m as a member of N is public, or 891 892 --m as a member of N is private, and the reference occurs in a 893 member or friend of class N, or 894 895 --m as a member of N is protected, and the reference occurs in a 896 member or friend of class N, or in a member or friend of a 897 class P derived from N, where m as a member of P is private or 898 protected, or 899 900 --there exists a base class B of N that is accessible at the point 901 of reference, and m is accessible when named in class B. 902 903 We walk the base class hierarchy, checking these conditions. */ 904 905 if (consider_local_p) 906 { 907 /* Figure out where the reference is occurring. Check to see if 908 DECL is private or protected in this scope, since that will 909 determine whether protected access is allowed. */ 910 if (current_class_type) 911 protected_ok = protected_accessible_p (decl, 912 current_class_type, binfo); 913 914 /* Now, loop through the classes of which we are a friend. */ 915 if (!protected_ok) 916 protected_ok = friend_accessible_p (scope, decl, binfo); 917 } 918 919 /* Standardize the binfo that access_in_type will use. We don't 920 need to know what path was chosen from this point onwards. */ 921 binfo = TYPE_BINFO (type); 922 923 /* Compute the accessibility of DECL in the class hierarchy 924 dominated by type. */ 925 access = access_in_type (type, decl); 926 if (access == ak_public 927 || (access == ak_protected && protected_ok)) 928 return 1; 929 930 if (!consider_local_p) 931 return 0; 932 933 /* Walk the hierarchy again, looking for a base class that allows 934 access. */ 935 return dfs_walk_once_accessible (binfo, /*friends=*/true, 936 NULL, dfs_accessible_post, NULL) 937 != NULL_TREE; 938} 939 940struct lookup_field_info { 941 /* The type in which we're looking. */ 942 tree type; 943 /* The name of the field for which we're looking. */ 944 tree name; 945 /* If non-NULL, the current result of the lookup. */ 946 tree rval; 947 /* The path to RVAL. */ 948 tree rval_binfo; 949 /* If non-NULL, the lookup was ambiguous, and this is a list of the 950 candidates. */ 951 tree ambiguous; 952 /* If nonzero, we are looking for types, not data members. */ 953 int want_type; 954 /* If something went wrong, a message indicating what. */ 955 const char *errstr; 956}; 957 958/* Nonzero for a class member means that it is shared between all objects 959 of that class. 960 961 [class.member.lookup]:If the resulting set of declarations are not all 962 from sub-objects of the same type, or the set has a nonstatic member 963 and includes members from distinct sub-objects, there is an ambiguity 964 and the program is ill-formed. 965 966 This function checks that T contains no nonstatic members. */ 967 968int 969shared_member_p (tree t) 970{ 971 if (TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == TYPE_DECL \ 972 || TREE_CODE (t) == CONST_DECL) 973 return 1; 974 if (is_overloaded_fn (t)) 975 { 976 for (; t; t = OVL_NEXT (t)) 977 { 978 tree fn = OVL_CURRENT (t); 979 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) 980 return 0; 981 } 982 return 1; 983 } 984 return 0; 985} 986 987/* Routine to see if the sub-object denoted by the binfo PARENT can be 988 found as a base class and sub-object of the object denoted by 989 BINFO. */ 990 991static int 992is_subobject_of_p (tree parent, tree binfo) 993{ 994 tree probe; 995 996 for (probe = parent; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) 997 { 998 if (probe == binfo) 999 return 1; 1000 if (BINFO_VIRTUAL_P (probe)) 1001 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (binfo)) 1002 != NULL_TREE); 1003 } 1004 return 0; 1005} 1006 1007/* DATA is really a struct lookup_field_info. Look for a field with 1008 the name indicated there in BINFO. If this function returns a 1009 non-NULL value it is the result of the lookup. Called from 1010 lookup_field via breadth_first_search. */ 1011 1012static tree 1013lookup_field_r (tree binfo, void *data) 1014{ 1015 struct lookup_field_info *lfi = (struct lookup_field_info *) data; 1016 tree type = BINFO_TYPE (binfo); 1017 tree nval = NULL_TREE; 1018 1019 /* If this is a dependent base, don't look in it. */ 1020 if (BINFO_DEPENDENT_BASE_P (binfo)) 1021 return NULL_TREE; 1022 1023 /* If this base class is hidden by the best-known value so far, we 1024 don't need to look. */ 1025 if (lfi->rval_binfo && BINFO_INHERITANCE_CHAIN (binfo) == lfi->rval_binfo 1026 && !BINFO_VIRTUAL_P (binfo)) 1027 return dfs_skip_bases; 1028 1029 /* First, look for a function. There can't be a function and a data 1030 member with the same name, and if there's a function and a type 1031 with the same name, the type is hidden by the function. */ 1032 if (!lfi->want_type) 1033 { 1034 int idx = lookup_fnfields_1 (type, lfi->name); 1035 if (idx >= 0) 1036 nval = VEC_index (tree, CLASSTYPE_METHOD_VEC (type), idx); 1037 } 1038 1039 if (!nval) 1040 /* Look for a data member or type. */ 1041 nval = lookup_field_1 (type, lfi->name, lfi->want_type); 1042 1043 /* If there is no declaration with the indicated name in this type, 1044 then there's nothing to do. */ 1045 if (!nval) 1046 goto done; 1047 1048 /* If we're looking up a type (as with an elaborated type specifier) 1049 we ignore all non-types we find. */ 1050 if (lfi->want_type && TREE_CODE (nval) != TYPE_DECL 1051 && !DECL_CLASS_TEMPLATE_P (nval)) 1052 { 1053 if (lfi->name == TYPE_IDENTIFIER (type)) 1054 { 1055 /* If the aggregate has no user defined constructors, we allow 1056 it to have fields with the same name as the enclosing type. 1057 If we are looking for that name, find the corresponding 1058 TYPE_DECL. */ 1059 for (nval = TREE_CHAIN (nval); nval; nval = TREE_CHAIN (nval)) 1060 if (DECL_NAME (nval) == lfi->name 1061 && TREE_CODE (nval) == TYPE_DECL) 1062 break; 1063 } 1064 else 1065 nval = NULL_TREE; 1066 if (!nval && CLASSTYPE_NESTED_UTDS (type) != NULL) 1067 { 1068 binding_entry e = binding_table_find (CLASSTYPE_NESTED_UTDS (type), 1069 lfi->name); 1070 if (e != NULL) 1071 nval = TYPE_MAIN_DECL (e->type); 1072 else 1073 goto done; 1074 } 1075 } 1076 1077 /* If the lookup already found a match, and the new value doesn't 1078 hide the old one, we might have an ambiguity. */ 1079 if (lfi->rval_binfo 1080 && !is_subobject_of_p (lfi->rval_binfo, binfo)) 1081 1082 { 1083 if (nval == lfi->rval && shared_member_p (nval)) 1084 /* The two things are really the same. */ 1085 ; 1086 else if (is_subobject_of_p (binfo, lfi->rval_binfo)) 1087 /* The previous value hides the new one. */ 1088 ; 1089 else 1090 { 1091 /* We have a real ambiguity. We keep a chain of all the 1092 candidates. */ 1093 if (!lfi->ambiguous && lfi->rval) 1094 { 1095 /* This is the first time we noticed an ambiguity. Add 1096 what we previously thought was a reasonable candidate 1097 to the list. */ 1098 lfi->ambiguous = tree_cons (NULL_TREE, lfi->rval, NULL_TREE); 1099 TREE_TYPE (lfi->ambiguous) = error_mark_node; 1100 } 1101 1102 /* Add the new value. */ 1103 lfi->ambiguous = tree_cons (NULL_TREE, nval, lfi->ambiguous); 1104 TREE_TYPE (lfi->ambiguous) = error_mark_node; 1105 lfi->errstr = G_("request for member %qD is ambiguous"); 1106 } 1107 } 1108 else 1109 { 1110 lfi->rval = nval; 1111 lfi->rval_binfo = binfo; 1112 } 1113 1114 done: 1115 /* Don't look for constructors or destructors in base classes. */ 1116 if (IDENTIFIER_CTOR_OR_DTOR_P (lfi->name)) 1117 return dfs_skip_bases; 1118 return NULL_TREE; 1119} 1120 1121/* Return a "baselink" with BASELINK_BINFO, BASELINK_ACCESS_BINFO, 1122 BASELINK_FUNCTIONS, and BASELINK_OPTYPE set to BINFO, ACCESS_BINFO, 1123 FUNCTIONS, and OPTYPE respectively. */ 1124 1125tree 1126build_baselink (tree binfo, tree access_binfo, tree functions, tree optype) 1127{ 1128 tree baselink; 1129 1130 gcc_assert (TREE_CODE (functions) == FUNCTION_DECL 1131 || TREE_CODE (functions) == TEMPLATE_DECL 1132 || TREE_CODE (functions) == TEMPLATE_ID_EXPR 1133 || TREE_CODE (functions) == OVERLOAD); 1134 gcc_assert (!optype || TYPE_P (optype)); 1135 gcc_assert (TREE_TYPE (functions)); 1136 1137 baselink = make_node (BASELINK); 1138 TREE_TYPE (baselink) = TREE_TYPE (functions); 1139 BASELINK_BINFO (baselink) = binfo; 1140 BASELINK_ACCESS_BINFO (baselink) = access_binfo; 1141 BASELINK_FUNCTIONS (baselink) = functions; 1142 BASELINK_OPTYPE (baselink) = optype; 1143 1144 return baselink; 1145} 1146 1147/* Look for a member named NAME in an inheritance lattice dominated by 1148 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it 1149 is 1, we enforce accessibility. If PROTECT is zero, then, for an 1150 ambiguous lookup, we return NULL. If PROTECT is 1, we issue error 1151 messages about inaccessible or ambiguous lookup. If PROTECT is 2, 1152 we return a TREE_LIST whose TREE_TYPE is error_mark_node and whose 1153 TREE_VALUEs are the list of ambiguous candidates. 1154 1155 WANT_TYPE is 1 when we should only return TYPE_DECLs. 1156 1157 If nothing can be found return NULL_TREE and do not issue an error. */ 1158 1159tree 1160lookup_member (tree xbasetype, tree name, int protect, bool want_type) 1161{ 1162 tree rval, rval_binfo = NULL_TREE; 1163 tree type = NULL_TREE, basetype_path = NULL_TREE; 1164 struct lookup_field_info lfi; 1165 1166 /* rval_binfo is the binfo associated with the found member, note, 1167 this can be set with useful information, even when rval is not 1168 set, because it must deal with ALL members, not just non-function 1169 members. It is used for ambiguity checking and the hidden 1170 checks. Whereas rval is only set if a proper (not hidden) 1171 non-function member is found. */ 1172 1173 const char *errstr = 0; 1174 1175 if (name == error_mark_node) 1176 return NULL_TREE; 1177 1178 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE); 1179 1180 if (TREE_CODE (xbasetype) == TREE_BINFO) 1181 { 1182 type = BINFO_TYPE (xbasetype); 1183 basetype_path = xbasetype; 1184 } 1185 else 1186 { 1187 if (!RECORD_OR_UNION_CODE_P (TREE_CODE (xbasetype))) 1188 return NULL_TREE; 1189 type = xbasetype; 1190 xbasetype = NULL_TREE; 1191 } 1192 1193 type = complete_type (type); 1194 if (!basetype_path) 1195 basetype_path = TYPE_BINFO (type); 1196 1197 if (!basetype_path) 1198 return NULL_TREE; 1199 1200#ifdef GATHER_STATISTICS 1201 n_calls_lookup_field++; 1202#endif /* GATHER_STATISTICS */ 1203 1204 memset (&lfi, 0, sizeof (lfi)); 1205 lfi.type = type; 1206 lfi.name = name; 1207 lfi.want_type = want_type; 1208 dfs_walk_all (basetype_path, &lookup_field_r, NULL, &lfi); 1209 rval = lfi.rval; 1210 rval_binfo = lfi.rval_binfo; 1211 if (rval_binfo) 1212 type = BINFO_TYPE (rval_binfo); 1213 errstr = lfi.errstr; 1214 1215 /* If we are not interested in ambiguities, don't report them; 1216 just return NULL_TREE. */ 1217 if (!protect && lfi.ambiguous) 1218 return NULL_TREE; 1219 1220 if (protect == 2) 1221 { 1222 if (lfi.ambiguous) 1223 return lfi.ambiguous; 1224 else 1225 protect = 0; 1226 } 1227 1228 /* [class.access] 1229 1230 In the case of overloaded function names, access control is 1231 applied to the function selected by overloaded resolution. 1232 1233 We cannot check here, even if RVAL is only a single non-static 1234 member function, since we do not know what the "this" pointer 1235 will be. For: 1236 1237 class A { protected: void f(); }; 1238 class B : public A { 1239 void g(A *p) { 1240 f(); // OK 1241 p->f(); // Not OK. 1242 } 1243 }; 1244 1245 only the first call to "f" is valid. However, if the function is 1246 static, we can check. */ 1247 if (rval && protect 1248 && !really_overloaded_fn (rval) 1249 && !(TREE_CODE (rval) == FUNCTION_DECL 1250 && DECL_NONSTATIC_MEMBER_FUNCTION_P (rval))) 1251 perform_or_defer_access_check (basetype_path, rval, rval); 1252 1253 if (errstr && protect) 1254 { 1255 error (errstr, name, type); 1256 if (lfi.ambiguous) 1257 print_candidates (lfi.ambiguous); 1258 rval = error_mark_node; 1259 } 1260 1261 if (rval && is_overloaded_fn (rval)) 1262 rval = build_baselink (rval_binfo, basetype_path, rval, 1263 (IDENTIFIER_TYPENAME_P (name) 1264 ? TREE_TYPE (name): NULL_TREE)); 1265 return rval; 1266} 1267 1268/* Like lookup_member, except that if we find a function member we 1269 return NULL_TREE. */ 1270 1271tree 1272lookup_field (tree xbasetype, tree name, int protect, bool want_type) 1273{ 1274 tree rval = lookup_member (xbasetype, name, protect, want_type); 1275 1276 /* Ignore functions, but propagate the ambiguity list. */ 1277 if (!error_operand_p (rval) 1278 && (rval && BASELINK_P (rval))) 1279 return NULL_TREE; 1280 1281 return rval; 1282} 1283 1284/* Like lookup_member, except that if we find a non-function member we 1285 return NULL_TREE. */ 1286 1287tree 1288lookup_fnfields (tree xbasetype, tree name, int protect) 1289{ 1290 tree rval = lookup_member (xbasetype, name, protect, /*want_type=*/false); 1291 1292 /* Ignore non-functions, but propagate the ambiguity list. */ 1293 if (!error_operand_p (rval) 1294 && (rval && !BASELINK_P (rval))) 1295 return NULL_TREE; 1296 1297 return rval; 1298} 1299 1300/* Return the index in the CLASSTYPE_METHOD_VEC for CLASS_TYPE 1301 corresponding to "operator TYPE ()", or -1 if there is no such 1302 operator. Only CLASS_TYPE itself is searched; this routine does 1303 not scan the base classes of CLASS_TYPE. */ 1304 1305static int 1306lookup_conversion_operator (tree class_type, tree type) 1307{ 1308 int tpl_slot = -1; 1309 1310 if (TYPE_HAS_CONVERSION (class_type)) 1311 { 1312 int i; 1313 tree fn; 1314 VEC(tree,gc) *methods = CLASSTYPE_METHOD_VEC (class_type); 1315 1316 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT; 1317 VEC_iterate (tree, methods, i, fn); ++i) 1318 { 1319 /* All the conversion operators come near the beginning of 1320 the class. Therefore, if FN is not a conversion 1321 operator, there is no matching conversion operator in 1322 CLASS_TYPE. */ 1323 fn = OVL_CURRENT (fn); 1324 if (!DECL_CONV_FN_P (fn)) 1325 break; 1326 1327 if (TREE_CODE (fn) == TEMPLATE_DECL) 1328 /* All the templated conversion functions are on the same 1329 slot, so remember it. */ 1330 tpl_slot = i; 1331 else if (same_type_p (DECL_CONV_FN_TYPE (fn), type)) 1332 return i; 1333 } 1334 } 1335 1336 return tpl_slot; 1337} 1338 1339/* TYPE is a class type. Return the index of the fields within 1340 the method vector with name NAME, or -1 is no such field exists. */ 1341 1342int 1343lookup_fnfields_1 (tree type, tree name) 1344{ 1345 VEC(tree,gc) *method_vec; 1346 tree fn; 1347 tree tmp; 1348 size_t i; 1349 1350 if (!CLASS_TYPE_P (type)) 1351 return -1; 1352 1353 if (COMPLETE_TYPE_P (type)) 1354 { 1355 if ((name == ctor_identifier 1356 || name == base_ctor_identifier 1357 || name == complete_ctor_identifier)) 1358 { 1359 if (CLASSTYPE_LAZY_DEFAULT_CTOR (type)) 1360 lazily_declare_fn (sfk_constructor, type); 1361 if (CLASSTYPE_LAZY_COPY_CTOR (type)) 1362 lazily_declare_fn (sfk_copy_constructor, type); 1363 if (CLASSTYPE_LAZY_MOVE_CTOR (type)) 1364 lazily_declare_fn (sfk_move_constructor, type); 1365 } 1366 else if (name == ansi_assopname(NOP_EXPR) 1367 && CLASSTYPE_LAZY_ASSIGNMENT_OP (type)) 1368 lazily_declare_fn (sfk_assignment_operator, type); 1369 else if ((name == dtor_identifier 1370 || name == base_dtor_identifier 1371 || name == complete_dtor_identifier 1372 || name == deleting_dtor_identifier) 1373 && CLASSTYPE_LAZY_DESTRUCTOR (type)) 1374 lazily_declare_fn (sfk_destructor, type); 1375 } 1376 1377 method_vec = CLASSTYPE_METHOD_VEC (type); 1378 if (!method_vec) 1379 return -1; 1380 1381#ifdef GATHER_STATISTICS 1382 n_calls_lookup_fnfields_1++; 1383#endif /* GATHER_STATISTICS */ 1384 1385 /* Constructors are first... */ 1386 if (name == ctor_identifier) 1387 { 1388 fn = CLASSTYPE_CONSTRUCTORS (type); 1389 return fn ? CLASSTYPE_CONSTRUCTOR_SLOT : -1; 1390 } 1391 /* and destructors are second. */ 1392 if (name == dtor_identifier) 1393 { 1394 fn = CLASSTYPE_DESTRUCTORS (type); 1395 return fn ? CLASSTYPE_DESTRUCTOR_SLOT : -1; 1396 } 1397 if (IDENTIFIER_TYPENAME_P (name)) 1398 return lookup_conversion_operator (type, TREE_TYPE (name)); 1399 1400 /* Skip the conversion operators. */ 1401 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT; 1402 VEC_iterate (tree, method_vec, i, fn); 1403 ++i) 1404 if (!DECL_CONV_FN_P (OVL_CURRENT (fn))) 1405 break; 1406 1407 /* If the type is complete, use binary search. */ 1408 if (COMPLETE_TYPE_P (type)) 1409 { 1410 int lo; 1411 int hi; 1412 1413 lo = i; 1414 hi = VEC_length (tree, method_vec); 1415 while (lo < hi) 1416 { 1417 i = (lo + hi) / 2; 1418 1419#ifdef GATHER_STATISTICS 1420 n_outer_fields_searched++; 1421#endif /* GATHER_STATISTICS */ 1422 1423 tmp = VEC_index (tree, method_vec, i); 1424 tmp = DECL_NAME (OVL_CURRENT (tmp)); 1425 if (tmp > name) 1426 hi = i; 1427 else if (tmp < name) 1428 lo = i + 1; 1429 else 1430 return i; 1431 } 1432 } 1433 else 1434 for (; VEC_iterate (tree, method_vec, i, fn); ++i) 1435 { 1436#ifdef GATHER_STATISTICS 1437 n_outer_fields_searched++; 1438#endif /* GATHER_STATISTICS */ 1439 if (DECL_NAME (OVL_CURRENT (fn)) == name) 1440 return i; 1441 } 1442 1443 return -1; 1444} 1445 1446/* Like lookup_fnfields_1, except that the name is extracted from 1447 FUNCTION, which is a FUNCTION_DECL or a TEMPLATE_DECL. */ 1448 1449int 1450class_method_index_for_fn (tree class_type, tree function) 1451{ 1452 gcc_assert (TREE_CODE (function) == FUNCTION_DECL 1453 || DECL_FUNCTION_TEMPLATE_P (function)); 1454 1455 return lookup_fnfields_1 (class_type, 1456 DECL_CONSTRUCTOR_P (function) ? ctor_identifier : 1457 DECL_DESTRUCTOR_P (function) ? dtor_identifier : 1458 DECL_NAME (function)); 1459} 1460 1461 1462/* DECL is the result of a qualified name lookup. QUALIFYING_SCOPE is 1463 the class or namespace used to qualify the name. CONTEXT_CLASS is 1464 the class corresponding to the object in which DECL will be used. 1465 Return a possibly modified version of DECL that takes into account 1466 the CONTEXT_CLASS. 1467 1468 In particular, consider an expression like `B::m' in the context of 1469 a derived class `D'. If `B::m' has been resolved to a BASELINK, 1470 then the most derived class indicated by the BASELINK_BINFO will be 1471 `B', not `D'. This function makes that adjustment. */ 1472 1473tree 1474adjust_result_of_qualified_name_lookup (tree decl, 1475 tree qualifying_scope, 1476 tree context_class) 1477{ 1478 if (context_class && context_class != error_mark_node 1479 && CLASS_TYPE_P (context_class) 1480 && CLASS_TYPE_P (qualifying_scope) 1481 && DERIVED_FROM_P (qualifying_scope, context_class) 1482 && BASELINK_P (decl)) 1483 { 1484 tree base; 1485 1486 /* Look for the QUALIFYING_SCOPE as a base of the CONTEXT_CLASS. 1487 Because we do not yet know which function will be chosen by 1488 overload resolution, we cannot yet check either accessibility 1489 or ambiguity -- in either case, the choice of a static member 1490 function might make the usage valid. */ 1491 base = lookup_base (context_class, qualifying_scope, 1492 ba_unique | ba_quiet, NULL); 1493 if (base) 1494 { 1495 BASELINK_ACCESS_BINFO (decl) = base; 1496 BASELINK_BINFO (decl) 1497 = lookup_base (base, BINFO_TYPE (BASELINK_BINFO (decl)), 1498 ba_unique | ba_quiet, 1499 NULL); 1500 } 1501 } 1502 1503 return decl; 1504} 1505 1506 1507/* Walk the class hierarchy within BINFO, in a depth-first traversal. 1508 PRE_FN is called in preorder, while POST_FN is called in postorder. 1509 If PRE_FN returns DFS_SKIP_BASES, child binfos will not be 1510 walked. If PRE_FN or POST_FN returns a different non-NULL value, 1511 that value is immediately returned and the walk is terminated. One 1512 of PRE_FN and POST_FN can be NULL. At each node, PRE_FN and 1513 POST_FN are passed the binfo to examine and the caller's DATA 1514 value. All paths are walked, thus virtual and morally virtual 1515 binfos can be multiply walked. */ 1516 1517tree 1518dfs_walk_all (tree binfo, tree (*pre_fn) (tree, void *), 1519 tree (*post_fn) (tree, void *), void *data) 1520{ 1521 tree rval; 1522 unsigned ix; 1523 tree base_binfo; 1524 1525 /* Call the pre-order walking function. */ 1526 if (pre_fn) 1527 { 1528 rval = pre_fn (binfo, data); 1529 if (rval) 1530 { 1531 if (rval == dfs_skip_bases) 1532 goto skip_bases; 1533 return rval; 1534 } 1535 } 1536 1537 /* Find the next child binfo to walk. */ 1538 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 1539 { 1540 rval = dfs_walk_all (base_binfo, pre_fn, post_fn, data); 1541 if (rval) 1542 return rval; 1543 } 1544 1545 skip_bases: 1546 /* Call the post-order walking function. */ 1547 if (post_fn) 1548 { 1549 rval = post_fn (binfo, data); 1550 gcc_assert (rval != dfs_skip_bases); 1551 return rval; 1552 } 1553 1554 return NULL_TREE; 1555} 1556 1557/* Worker for dfs_walk_once. This behaves as dfs_walk_all, except 1558 that binfos are walked at most once. */ 1559 1560static tree 1561dfs_walk_once_r (tree binfo, tree (*pre_fn) (tree, void *), 1562 tree (*post_fn) (tree, void *), void *data) 1563{ 1564 tree rval; 1565 unsigned ix; 1566 tree base_binfo; 1567 1568 /* Call the pre-order walking function. */ 1569 if (pre_fn) 1570 { 1571 rval = pre_fn (binfo, data); 1572 if (rval) 1573 { 1574 if (rval == dfs_skip_bases) 1575 goto skip_bases; 1576 1577 return rval; 1578 } 1579 } 1580 1581 /* Find the next child binfo to walk. */ 1582 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 1583 { 1584 if (BINFO_VIRTUAL_P (base_binfo)) 1585 { 1586 if (BINFO_MARKED (base_binfo)) 1587 continue; 1588 BINFO_MARKED (base_binfo) = 1; 1589 } 1590 1591 rval = dfs_walk_once_r (base_binfo, pre_fn, post_fn, data); 1592 if (rval) 1593 return rval; 1594 } 1595 1596 skip_bases: 1597 /* Call the post-order walking function. */ 1598 if (post_fn) 1599 { 1600 rval = post_fn (binfo, data); 1601 gcc_assert (rval != dfs_skip_bases); 1602 return rval; 1603 } 1604 1605 return NULL_TREE; 1606} 1607 1608/* Worker for dfs_walk_once. Recursively unmark the virtual base binfos of 1609 BINFO. */ 1610 1611static void 1612dfs_unmark_r (tree binfo) 1613{ 1614 unsigned ix; 1615 tree base_binfo; 1616 1617 /* Process the basetypes. */ 1618 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 1619 { 1620 if (BINFO_VIRTUAL_P (base_binfo)) 1621 { 1622 if (!BINFO_MARKED (base_binfo)) 1623 continue; 1624 BINFO_MARKED (base_binfo) = 0; 1625 } 1626 /* Only walk, if it can contain more virtual bases. */ 1627 if (CLASSTYPE_VBASECLASSES (BINFO_TYPE (base_binfo))) 1628 dfs_unmark_r (base_binfo); 1629 } 1630} 1631 1632/* Like dfs_walk_all, except that binfos are not multiply walked. For 1633 non-diamond shaped hierarchies this is the same as dfs_walk_all. 1634 For diamond shaped hierarchies we must mark the virtual bases, to 1635 avoid multiple walks. */ 1636 1637tree 1638dfs_walk_once (tree binfo, tree (*pre_fn) (tree, void *), 1639 tree (*post_fn) (tree, void *), void *data) 1640{ 1641 static int active = 0; /* We must not be called recursively. */ 1642 tree rval; 1643 1644 gcc_assert (pre_fn || post_fn); 1645 gcc_assert (!active); 1646 active++; 1647 1648 if (!CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo))) 1649 /* We are not diamond shaped, and therefore cannot encounter the 1650 same binfo twice. */ 1651 rval = dfs_walk_all (binfo, pre_fn, post_fn, data); 1652 else 1653 { 1654 rval = dfs_walk_once_r (binfo, pre_fn, post_fn, data); 1655 if (!BINFO_INHERITANCE_CHAIN (binfo)) 1656 { 1657 /* We are at the top of the hierarchy, and can use the 1658 CLASSTYPE_VBASECLASSES list for unmarking the virtual 1659 bases. */ 1660 VEC(tree,gc) *vbases; 1661 unsigned ix; 1662 tree base_binfo; 1663 1664 for (vbases = CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)), ix = 0; 1665 VEC_iterate (tree, vbases, ix, base_binfo); ix++) 1666 BINFO_MARKED (base_binfo) = 0; 1667 } 1668 else 1669 dfs_unmark_r (binfo); 1670 } 1671 1672 active--; 1673 1674 return rval; 1675} 1676 1677/* Worker function for dfs_walk_once_accessible. Behaves like 1678 dfs_walk_once_r, except (a) FRIENDS_P is true if special 1679 access given by the current context should be considered, (b) ONCE 1680 indicates whether bases should be marked during traversal. */ 1681 1682static tree 1683dfs_walk_once_accessible_r (tree binfo, bool friends_p, bool once, 1684 tree (*pre_fn) (tree, void *), 1685 tree (*post_fn) (tree, void *), void *data) 1686{ 1687 tree rval = NULL_TREE; 1688 unsigned ix; 1689 tree base_binfo; 1690 1691 /* Call the pre-order walking function. */ 1692 if (pre_fn) 1693 { 1694 rval = pre_fn (binfo, data); 1695 if (rval) 1696 { 1697 if (rval == dfs_skip_bases) 1698 goto skip_bases; 1699 1700 return rval; 1701 } 1702 } 1703 1704 /* Find the next child binfo to walk. */ 1705 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 1706 { 1707 bool mark = once && BINFO_VIRTUAL_P (base_binfo); 1708 1709 if (mark && BINFO_MARKED (base_binfo)) 1710 continue; 1711 1712 /* If the base is inherited via private or protected 1713 inheritance, then we can't see it, unless we are a friend of 1714 the current binfo. */ 1715 if (BINFO_BASE_ACCESS (binfo, ix) != access_public_node) 1716 { 1717 tree scope; 1718 if (!friends_p) 1719 continue; 1720 scope = current_scope (); 1721 if (!scope 1722 || TREE_CODE (scope) == NAMESPACE_DECL 1723 || !is_friend (BINFO_TYPE (binfo), scope)) 1724 continue; 1725 } 1726 1727 if (mark) 1728 BINFO_MARKED (base_binfo) = 1; 1729 1730 rval = dfs_walk_once_accessible_r (base_binfo, friends_p, once, 1731 pre_fn, post_fn, data); 1732 if (rval) 1733 return rval; 1734 } 1735 1736 skip_bases: 1737 /* Call the post-order walking function. */ 1738 if (post_fn) 1739 { 1740 rval = post_fn (binfo, data); 1741 gcc_assert (rval != dfs_skip_bases); 1742 return rval; 1743 } 1744 1745 return NULL_TREE; 1746} 1747 1748/* Like dfs_walk_once except that only accessible bases are walked. 1749 FRIENDS_P indicates whether friendship of the local context 1750 should be considered when determining accessibility. */ 1751 1752static tree 1753dfs_walk_once_accessible (tree binfo, bool friends_p, 1754 tree (*pre_fn) (tree, void *), 1755 tree (*post_fn) (tree, void *), void *data) 1756{ 1757 bool diamond_shaped = CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo)); 1758 tree rval = dfs_walk_once_accessible_r (binfo, friends_p, diamond_shaped, 1759 pre_fn, post_fn, data); 1760 1761 if (diamond_shaped) 1762 { 1763 if (!BINFO_INHERITANCE_CHAIN (binfo)) 1764 { 1765 /* We are at the top of the hierarchy, and can use the 1766 CLASSTYPE_VBASECLASSES list for unmarking the virtual 1767 bases. */ 1768 VEC(tree,gc) *vbases; 1769 unsigned ix; 1770 tree base_binfo; 1771 1772 for (vbases = CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)), ix = 0; 1773 VEC_iterate (tree, vbases, ix, base_binfo); ix++) 1774 BINFO_MARKED (base_binfo) = 0; 1775 } 1776 else 1777 dfs_unmark_r (binfo); 1778 } 1779 return rval; 1780} 1781 1782/* Check that virtual overrider OVERRIDER is acceptable for base function 1783 BASEFN. Issue diagnostic, and return zero, if unacceptable. */ 1784 1785static int 1786check_final_overrider (tree overrider, tree basefn) 1787{ 1788 tree over_type = TREE_TYPE (overrider); 1789 tree base_type = TREE_TYPE (basefn); 1790 tree over_return = TREE_TYPE (over_type); 1791 tree base_return = TREE_TYPE (base_type); 1792 tree over_throw = TYPE_RAISES_EXCEPTIONS (over_type); 1793 tree base_throw = TYPE_RAISES_EXCEPTIONS (base_type); 1794 int fail = 0; 1795 1796 if (DECL_INVALID_OVERRIDER_P (overrider)) 1797 return 0; 1798 1799 if (same_type_p (base_return, over_return)) 1800 /* OK */; 1801 else if ((CLASS_TYPE_P (over_return) && CLASS_TYPE_P (base_return)) 1802 || (TREE_CODE (base_return) == TREE_CODE (over_return) 1803 && POINTER_TYPE_P (base_return))) 1804 { 1805 /* Potentially covariant. */ 1806 unsigned base_quals, over_quals; 1807 1808 fail = !POINTER_TYPE_P (base_return); 1809 if (!fail) 1810 { 1811 fail = cp_type_quals (base_return) != cp_type_quals (over_return); 1812 1813 base_return = TREE_TYPE (base_return); 1814 over_return = TREE_TYPE (over_return); 1815 } 1816 base_quals = cp_type_quals (base_return); 1817 over_quals = cp_type_quals (over_return); 1818 1819 if ((base_quals & over_quals) != over_quals) 1820 fail = 1; 1821 1822 if (CLASS_TYPE_P (base_return) && CLASS_TYPE_P (over_return)) 1823 { 1824 tree binfo = lookup_base (over_return, base_return, 1825 ba_check | ba_quiet, NULL); 1826 1827 if (!binfo) 1828 fail = 1; 1829 } 1830 else if (!pedantic 1831 && can_convert (TREE_TYPE (base_type), TREE_TYPE (over_type))) 1832 /* GNU extension, allow trivial pointer conversions such as 1833 converting to void *, or qualification conversion. */ 1834 { 1835 /* can_convert will permit user defined conversion from a 1836 (reference to) class type. We must reject them. */ 1837 over_return = non_reference (TREE_TYPE (over_type)); 1838 if (CLASS_TYPE_P (over_return)) 1839 fail = 2; 1840 else 1841 { 1842 warning (0, "deprecated covariant return type for %q+#D", 1843 overrider); 1844 warning (0, " overriding %q+#D", basefn); 1845 } 1846 } 1847 else 1848 fail = 2; 1849 } 1850 else 1851 fail = 2; 1852 if (!fail) 1853 /* OK */; 1854 else 1855 { 1856 if (fail == 1) 1857 { 1858 error ("invalid covariant return type for %q+#D", overrider); 1859 error (" overriding %q+#D", basefn); 1860 } 1861 else 1862 { 1863 error ("conflicting return type specified for %q+#D", overrider); 1864 error (" overriding %q+#D", basefn); 1865 } 1866 DECL_INVALID_OVERRIDER_P (overrider) = 1; 1867 return 0; 1868 } 1869 1870 /* Check throw specifier is at least as strict. */ 1871 if (!comp_except_specs (base_throw, over_throw, 0)) 1872 { 1873 error ("looser throw specifier for %q+#F", overrider); 1874 error (" overriding %q+#F", basefn); 1875 DECL_INVALID_OVERRIDER_P (overrider) = 1; 1876 return 0; 1877 } 1878 1879 /* Check for conflicting type attributes. */ 1880 if (!targetm.comp_type_attributes (over_type, base_type)) 1881 { 1882 error ("conflicting type attributes specified for %q+#D", overrider); 1883 error (" overriding %q+#D", basefn); 1884 DECL_INVALID_OVERRIDER_P (overrider) = 1; 1885 return 0; 1886 } 1887 1888 if (DECL_DELETED_FN (basefn) != DECL_DELETED_FN (overrider)) 1889 { 1890 if (DECL_DELETED_FN (overrider)) 1891 { 1892 error ("deleted function %q+D", overrider); 1893 error ("overriding non-deleted function %q+D", basefn); 1894 } 1895 else 1896 { 1897 error ("non-deleted function %q+D", overrider); 1898 error ("overriding deleted function %q+D", basefn); 1899 } 1900 return 0; 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