1 /* Breadth-first and depth-first routines for
2 searching multiple-inheritance lattice for GNU C++.
3 Copyright (C) 1987-2021 Free Software Foundation, Inc.
4 Contributed by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* High-level class interface. */
26 #include "coretypes.h"
30 #include "spellcheck-tree.h"
31 #include "stringpool.h"
34 static int is_subobject_of_p (tree
, tree
);
35 static tree
dfs_lookup_base (tree
, void *);
36 static tree
dfs_dcast_hint_pre (tree
, void *);
37 static tree
dfs_dcast_hint_post (tree
, void *);
38 static tree
dfs_debug_mark (tree
, void *);
39 static int check_hidden_convs (tree
, int, int, tree
, tree
, tree
);
40 static tree
split_conversions (tree
, tree
, tree
, tree
);
41 static int lookup_conversions_r (tree
, int, int, tree
, tree
, tree
*);
42 static int look_for_overrides_r (tree
, tree
);
43 static tree
lookup_field_r (tree
, void *);
44 static tree
dfs_accessible_post (tree
, void *);
45 static tree
dfs_walk_once_accessible (tree
, bool,
46 tree (*pre_fn
) (tree
, void *),
47 tree (*post_fn
) (tree
, void *),
49 static tree
dfs_access_in_type (tree
, void *);
50 static access_kind
access_in_type (tree
, tree
);
51 static tree
dfs_get_pure_virtuals (tree
, void *);
54 /* Data for lookup_base and its workers. */
56 struct lookup_base_data_s
58 tree t
; /* type being searched. */
59 tree base
; /* The base type we're looking for. */
60 tree binfo
; /* Found binfo. */
61 bool via_virtual
; /* Found via a virtual path. */
62 bool ambiguous
; /* Found multiply ambiguous */
63 bool repeated_base
; /* Whether there are repeated bases in the
65 bool want_any
; /* Whether we want any matching binfo. */
68 /* Worker function for lookup_base. See if we've found the desired
69 base and update DATA_ (a pointer to LOOKUP_BASE_DATA_S). */
72 dfs_lookup_base (tree binfo
, void *data_
)
74 struct lookup_base_data_s
*data
= (struct lookup_base_data_s
*) data_
;
76 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo
), data
->base
))
82 = binfo_via_virtual (data
->binfo
, data
->t
) != NULL_TREE
;
84 if (!data
->repeated_base
)
85 /* If there are no repeated bases, we can stop now. */
88 if (data
->want_any
&& !data
->via_virtual
)
89 /* If this is a non-virtual base, then we can't do
93 return dfs_skip_bases
;
97 gcc_assert (binfo
!= data
->binfo
);
99 /* We've found more than one matching binfo. */
102 /* This is immediately ambiguous. */
103 data
->binfo
= NULL_TREE
;
104 data
->ambiguous
= true;
105 return error_mark_node
;
108 /* Prefer one via a non-virtual path. */
109 if (!binfo_via_virtual (binfo
, data
->t
))
112 data
->via_virtual
= false;
116 /* There must be repeated bases, otherwise we'd have stopped
117 on the first base we found. */
118 return dfs_skip_bases
;
125 /* Returns true if type BASE is accessible in T. (BASE is known to be
126 a (possibly non-proper) base class of T.) If CONSIDER_LOCAL_P is
127 true, consider any special access of the current scope, or access
128 bestowed by friendship. */
131 accessible_base_p (tree t
, tree base
, bool consider_local_p
)
135 /* [class.access.base]
137 A base class is said to be accessible if an invented public
138 member of the base class is accessible.
140 If BASE is a non-proper base, this condition is trivially
142 if (same_type_p (t
, base
))
144 /* Rather than inventing a public member, we use the implicit
145 public typedef created in the scope of every class. */
146 decl
= TYPE_FIELDS (base
);
147 while (!DECL_SELF_REFERENCE_P (decl
))
148 decl
= DECL_CHAIN (decl
);
149 while (ANON_AGGR_TYPE_P (t
))
150 t
= TYPE_CONTEXT (t
);
151 return accessible_p (t
, decl
, consider_local_p
);
154 /* Lookup BASE in the hierarchy dominated by T. Do access checking as
155 ACCESS specifies. Return the binfo we discover. If KIND_PTR is
156 non-NULL, fill with information about what kind of base we
159 If the base is inaccessible, or ambiguous, then error_mark_node is
160 returned. If the tf_error bit of COMPLAIN is not set, no error
164 lookup_base (tree t
, tree base
, base_access access
,
165 base_kind
*kind_ptr
, tsubst_flags_t complain
)
171 /* "Nothing" is definitely not derived from Base. */
175 *kind_ptr
= bk_not_base
;
179 if (t
== error_mark_node
|| base
== error_mark_node
)
182 *kind_ptr
= bk_not_base
;
183 return error_mark_node
;
185 gcc_assert (TYPE_P (base
));
194 t
= complete_type (TYPE_MAIN_VARIANT (t
));
195 if (dependent_type_p (t
))
196 if (tree open
= currently_open_class (t
))
198 t_binfo
= TYPE_BINFO (t
);
201 base
= TYPE_MAIN_VARIANT (base
);
203 /* If BASE is incomplete, it can't be a base of T--and instantiating it
204 might cause an error. */
205 if (t_binfo
&& CLASS_TYPE_P (base
) && COMPLETE_OR_OPEN_TYPE_P (base
))
207 struct lookup_base_data_s data
;
211 data
.binfo
= NULL_TREE
;
212 data
.ambiguous
= data
.via_virtual
= false;
213 data
.repeated_base
= CLASSTYPE_REPEATED_BASE_P (t
);
214 data
.want_any
= access
== ba_any
;
216 dfs_walk_once (t_binfo
, dfs_lookup_base
, NULL
, &data
);
220 bk
= data
.ambiguous
? bk_ambig
: bk_not_base
;
221 else if (binfo
== t_binfo
)
223 else if (data
.via_virtual
)
234 /* Check that the base is unambiguous and accessible. */
235 if (access
!= ba_any
)
242 if (complain
& tf_error
)
243 error ("%qT is an ambiguous base of %qT", base
, t
);
244 binfo
= error_mark_node
;
248 if ((access
& ba_check_bit
)
249 /* If BASE is incomplete, then BASE and TYPE are probably
250 the same, in which case BASE is accessible. If they
251 are not the same, then TYPE is invalid. In that case,
252 there's no need to issue another error here, and
253 there's no implicit typedef to use in the code that
254 follows, so we skip the check. */
255 && COMPLETE_TYPE_P (base
)
256 && !accessible_base_p (t
, base
, !(access
& ba_ignore_scope
)))
258 if (complain
& tf_error
)
259 error ("%qT is an inaccessible base of %qT", base
, t
);
260 binfo
= error_mark_node
;
261 bk
= bk_inaccessible
;
272 /* Data for dcast_base_hint walker. */
276 tree subtype
; /* The base type we're looking for. */
277 int virt_depth
; /* Number of virtual bases encountered from most
279 tree offset
; /* Best hint offset discovered so far. */
280 bool repeated_base
; /* Whether there are repeated bases in the
284 /* Worker for dcast_base_hint. Search for the base type being cast
288 dfs_dcast_hint_pre (tree binfo
, void *data_
)
290 struct dcast_data_s
*data
= (struct dcast_data_s
*) data_
;
292 if (BINFO_VIRTUAL_P (binfo
))
295 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo
), data
->subtype
))
297 if (data
->virt_depth
)
299 data
->offset
= ssize_int (-1);
303 data
->offset
= ssize_int (-3);
305 data
->offset
= BINFO_OFFSET (binfo
);
307 return data
->repeated_base
? dfs_skip_bases
: data
->offset
;
313 /* Worker for dcast_base_hint. Track the virtual depth. */
316 dfs_dcast_hint_post (tree binfo
, void *data_
)
318 struct dcast_data_s
*data
= (struct dcast_data_s
*) data_
;
320 if (BINFO_VIRTUAL_P (binfo
))
326 /* The dynamic cast runtime needs a hint about how the static SUBTYPE type
327 started from is related to the required TARGET type, in order to optimize
328 the inheritance graph search. This information is independent of the
329 current context, and ignores private paths, hence get_base_distance is
330 inappropriate. Return a TREE specifying the base offset, BOFF.
331 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF,
332 and there are no public virtual SUBTYPE bases.
333 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
334 BOFF == -2, SUBTYPE is not a public base.
335 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */
338 dcast_base_hint (tree subtype
, tree target
)
340 struct dcast_data_s data
;
342 data
.subtype
= subtype
;
344 data
.offset
= NULL_TREE
;
345 data
.repeated_base
= CLASSTYPE_REPEATED_BASE_P (target
);
347 dfs_walk_once_accessible (TYPE_BINFO (target
), /*friends=*/false,
348 dfs_dcast_hint_pre
, dfs_dcast_hint_post
, &data
);
349 return data
.offset
? data
.offset
: ssize_int (-2);
352 /* Search for a member with name NAME in a multiple inheritance
353 lattice specified by TYPE. If it does not exist, return NULL_TREE.
354 If the member is ambiguously referenced, return `error_mark_node'.
355 Otherwise, return a DECL with the indicated name. If WANT_TYPE is
356 true, type declarations are preferred. */
358 /* Return the FUNCTION_DECL, RECORD_TYPE, UNION_TYPE, or
359 NAMESPACE_DECL corresponding to the innermost non-block scope. */
364 /* There are a number of cases we need to be aware of here:
365 current_class_type current_function_decl
372 Those last two make life interesting. If we're in a function which is
373 itself inside a class, we need decls to go into the fn's decls (our
374 second case below). But if we're in a class and the class itself is
375 inside a function, we need decls to go into the decls for the class. To
376 achieve this last goal, we must see if, when both current_class_ptr and
377 current_function_decl are set, the class was declared inside that
378 function. If so, we know to put the decls into the class's scope. */
379 if (current_function_decl
&& current_class_type
380 && ((DECL_FUNCTION_MEMBER_P (current_function_decl
)
381 && same_type_p (DECL_CONTEXT (current_function_decl
),
383 || (DECL_FRIEND_CONTEXT (current_function_decl
)
384 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl
),
385 current_class_type
))))
386 return current_function_decl
;
388 if (current_class_type
)
389 return current_class_type
;
391 if (current_function_decl
)
392 return current_function_decl
;
394 return current_namespace
;
397 /* Returns nonzero if we are currently in a function scope. Note
398 that this function returns zero if we are within a local class, but
399 not within a member function body of the local class. */
402 at_function_scope_p (void)
404 tree cs
= current_scope ();
405 /* Also check cfun to make sure that we're really compiling
406 this function (as opposed to having set current_function_decl
407 for access checking or some such). */
408 return (cs
&& TREE_CODE (cs
) == FUNCTION_DECL
409 && cfun
&& cfun
->decl
== current_function_decl
);
412 /* Returns true if the innermost active scope is a class scope. */
415 at_class_scope_p (void)
417 tree cs
= current_scope ();
418 return cs
&& TYPE_P (cs
);
421 /* Returns true if the innermost active scope is a namespace scope. */
424 at_namespace_scope_p (void)
426 tree cs
= current_scope ();
427 return cs
&& TREE_CODE (cs
) == NAMESPACE_DECL
;
430 /* Return the scope of DECL, as appropriate when doing name-lookup. */
433 context_for_name_lookup (tree decl
)
437 For the purposes of name lookup, after the anonymous union
438 definition, the members of the anonymous union are considered to
439 have been defined in the scope in which the anonymous union is
441 tree context
= DECL_CONTEXT (decl
);
443 while (context
&& TYPE_P (context
)
444 && (ANON_AGGR_TYPE_P (context
) || UNSCOPED_ENUM_P (context
)))
445 context
= TYPE_CONTEXT (context
);
447 context
= global_namespace
;
452 /* Returns true iff DECL is declared in TYPE. */
455 member_declared_in_type (tree decl
, tree type
)
457 /* A normal declaration obviously counts. */
458 if (context_for_name_lookup (decl
) == type
)
460 /* So does a using or access declaration. */
461 if (DECL_LANG_SPECIFIC (decl
) && !DECL_DISCRIMINATOR_P (decl
)
462 && purpose_member (type
, DECL_ACCESS (decl
)))
467 /* The accessibility routines use BINFO_ACCESS for scratch space
468 during the computation of the accessibility of some declaration. */
470 /* Avoid walking up past a declaration of the member. */
473 dfs_access_in_type_pre (tree binfo
, void *data
)
475 tree decl
= (tree
) data
;
476 tree type
= BINFO_TYPE (binfo
);
477 if (member_declared_in_type (decl
, type
))
478 return dfs_skip_bases
;
482 #define BINFO_ACCESS(NODE) \
483 ((access_kind) ((TREE_PUBLIC (NODE) << 1) | TREE_PRIVATE (NODE)))
485 /* Set the access associated with NODE to ACCESS. */
487 #define SET_BINFO_ACCESS(NODE, ACCESS) \
488 ((TREE_PUBLIC (NODE) = ((ACCESS) & 2) != 0), \
489 (TREE_PRIVATE (NODE) = ((ACCESS) & 1) != 0))
491 /* Called from access_in_type via dfs_walk. Calculate the access to
492 DATA (which is really a DECL) in BINFO. */
495 dfs_access_in_type (tree binfo
, void *data
)
497 tree decl
= (tree
) data
;
498 tree type
= BINFO_TYPE (binfo
);
499 access_kind access
= ak_none
;
501 if (context_for_name_lookup (decl
) == type
)
503 /* If we have descended to the scope of DECL, just note the
504 appropriate access. */
505 if (TREE_PRIVATE (decl
))
507 else if (TREE_PROTECTED (decl
))
508 access
= ak_protected
;
514 /* First, check for an access-declaration that gives us more
515 access to the DECL. */
516 if (DECL_LANG_SPECIFIC (decl
) && !DECL_DISCRIMINATOR_P (decl
))
518 tree decl_access
= purpose_member (type
, DECL_ACCESS (decl
));
522 decl_access
= TREE_VALUE (decl_access
);
524 if (decl_access
== access_public_node
)
526 else if (decl_access
== access_protected_node
)
527 access
= ak_protected
;
528 else if (decl_access
== access_private_node
)
539 vec
<tree
, va_gc
> *accesses
;
541 /* Otherwise, scan our baseclasses, and pick the most favorable
543 accesses
= BINFO_BASE_ACCESSES (binfo
);
544 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
546 tree base_access
= (*accesses
)[i
];
547 access_kind base_access_now
= BINFO_ACCESS (base_binfo
);
549 if (base_access_now
== ak_none
|| base_access_now
== ak_private
)
550 /* If it was not accessible in the base, or only
551 accessible as a private member, we can't access it
553 base_access_now
= ak_none
;
554 else if (base_access
== access_protected_node
)
555 /* Public and protected members in the base become
557 base_access_now
= ak_protected
;
558 else if (base_access
== access_private_node
)
559 /* Public and protected members in the base become
561 base_access_now
= ak_private
;
563 /* See if the new access, via this base, gives more
564 access than our previous best access. */
565 if (base_access_now
!= ak_none
566 && (access
== ak_none
|| base_access_now
< access
))
568 access
= base_access_now
;
570 /* If the new access is public, we can't do better. */
571 if (access
== ak_public
)
578 /* Note the access to DECL in TYPE. */
579 SET_BINFO_ACCESS (binfo
, access
);
584 /* Return the access to DECL in TYPE. */
587 access_in_type (tree type
, tree decl
)
589 tree binfo
= TYPE_BINFO (type
);
591 /* We must take into account
595 If a name can be reached by several paths through a multiple
596 inheritance graph, the access is that of the path that gives
599 The algorithm we use is to make a post-order depth-first traversal
600 of the base-class hierarchy. As we come up the tree, we annotate
601 each node with the most lenient access. */
602 dfs_walk_once (binfo
, dfs_access_in_type_pre
, dfs_access_in_type
, decl
);
604 return BINFO_ACCESS (binfo
);
607 /* Returns nonzero if it is OK to access DECL named in TYPE through an object
608 of OTYPE in the context of DERIVED. */
611 protected_accessible_p (tree decl
, tree derived
, tree type
, tree otype
)
613 /* We're checking this clause from [class.access.base]
615 m as a member of N is protected, and the reference occurs in a
616 member or friend of class N, or in a member or friend of a
617 class P derived from N, where m as a member of P is public, private
620 Here DERIVED is a possible P, DECL is m and TYPE is N. */
622 /* If DERIVED isn't derived from N, then it can't be a P. */
623 if (!DERIVED_FROM_P (type
, derived
))
626 /* DECL_NONSTATIC_MEMBER_P won't work for USING_DECLs. */
627 decl
= strip_using_decl (decl
);
628 /* We don't expect or support dependent decls. */
629 gcc_assert (TREE_CODE (decl
) != USING_DECL
);
633 When a friend or a member function of a derived class references
634 a protected non-static member of a base class, an access check
635 applies in addition to those described earlier in clause
636 _class.access_) Except when forming a pointer to member
637 (_expr.unary.op_), the access must be through a pointer to,
638 reference to, or object of the derived class itself (or any class
639 derived from that class) (_expr.ref_). If the access is to form
640 a pointer to member, the nested-name-specifier shall name the
641 derived class (or any class derived from that class). */
642 if (DECL_NONSTATIC_MEMBER_P (decl
)
643 && !DERIVED_FROM_P (derived
, otype
))
649 /* Returns nonzero if SCOPE is a type or a friend of a type which would be able
650 to access DECL through TYPE. OTYPE is the type of the object. */
653 friend_accessible_p (tree scope
, tree decl
, tree type
, tree otype
)
655 /* We're checking this clause from [class.access.base]
657 m as a member of N is protected, and the reference occurs in a
658 member or friend of class N, or in a member or friend of a
659 class P derived from N, where m as a member of P is public, private
662 Here DECL is m and TYPE is N. SCOPE is the current context,
663 and we check all its possible Ps. */
664 tree befriending_classes
;
670 if (is_global_friend (scope
))
673 /* Is SCOPE itself a suitable P? */
674 if (TYPE_P (scope
) && protected_accessible_p (decl
, scope
, type
, otype
))
677 if (DECL_DECLARES_FUNCTION_P (scope
))
678 befriending_classes
= DECL_BEFRIENDING_CLASSES (scope
);
679 else if (TYPE_P (scope
))
680 befriending_classes
= CLASSTYPE_BEFRIENDING_CLASSES (scope
);
684 for (t
= befriending_classes
; t
; t
= TREE_CHAIN (t
))
685 if (protected_accessible_p (decl
, TREE_VALUE (t
), type
, otype
))
688 /* Nested classes have the same access as their enclosing types, as
689 per DR 45 (this is a change from C++98). */
691 if (friend_accessible_p (TYPE_CONTEXT (scope
), decl
, type
, otype
))
694 if (DECL_DECLARES_FUNCTION_P (scope
))
696 /* Perhaps this SCOPE is a member of a class which is a
698 if (DECL_CLASS_SCOPE_P (scope
)
699 && friend_accessible_p (DECL_CONTEXT (scope
), decl
, type
, otype
))
701 /* Perhaps SCOPE is a friend function defined inside a class from which
702 DECL is accessible. Checking this is necessary only when the class
703 is dependent, for otherwise add_friend will already have added the
704 class to SCOPE's DECL_BEFRIENDING_CLASSES. */
705 if (tree fctx
= DECL_FRIEND_CONTEXT (scope
))
706 if (dependent_type_p (fctx
)
707 && protected_accessible_p (decl
, fctx
, type
, otype
))
711 /* Maybe scope's template is a friend. */
712 if (tree tinfo
= get_template_info (scope
))
714 tree tmpl
= TI_TEMPLATE (tinfo
);
715 if (DECL_CLASS_TEMPLATE_P (tmpl
))
716 tmpl
= TREE_TYPE (tmpl
);
718 tmpl
= DECL_TEMPLATE_RESULT (tmpl
);
721 /* Increment processing_template_decl to make sure that
722 dependent_type_p works correctly. */
723 ++processing_template_decl
;
724 int ret
= friend_accessible_p (tmpl
, decl
, type
, otype
);
725 --processing_template_decl
;
731 /* If is_friend is true, we should have found a befriending class. */
732 gcc_checking_assert (!is_friend (type
, scope
));
737 struct dfs_accessible_data
743 /* Avoid walking up past a declaration of the member. */
746 dfs_accessible_pre (tree binfo
, void *data
)
748 dfs_accessible_data
*d
= (dfs_accessible_data
*)data
;
749 tree type
= BINFO_TYPE (binfo
);
750 if (member_declared_in_type (d
->decl
, type
))
751 return dfs_skip_bases
;
755 /* Called via dfs_walk_once_accessible from accessible_p */
758 dfs_accessible_post (tree binfo
, void *data
)
760 /* access_in_type already set BINFO_ACCESS for us. */
761 access_kind access
= BINFO_ACCESS (binfo
);
762 tree N
= BINFO_TYPE (binfo
);
763 dfs_accessible_data
*d
= (dfs_accessible_data
*)data
;
765 tree scope
= current_nonlambda_scope ();
767 /* A member m is accessible at the point R when named in class N if */
774 /* m as a member of N is public, or */
779 /* m as a member of N is private, and R occurs in a member or friend of
781 if (scope
&& TREE_CODE (scope
) != NAMESPACE_DECL
782 && is_friend (N
, scope
))
789 /* m as a member of N is protected, and R occurs in a member or friend
790 of class N, or in a member or friend of a class P derived from N,
791 where m as a member of P is public, private, or protected */
792 if (friend_accessible_p (scope
, decl
, N
, d
->object_type
))
802 /* Like accessible_p below, but within a template returns true iff DECL is
803 accessible in TYPE to all possible instantiations of the template. */
806 accessible_in_template_p (tree type
, tree decl
)
808 int save_ptd
= processing_template_decl
;
809 processing_template_decl
= 0;
810 int val
= accessible_p (type
, decl
, false);
811 processing_template_decl
= save_ptd
;
815 /* DECL is a declaration from a base class of TYPE, which was the
816 class used to name DECL. Return nonzero if, in the current
817 context, DECL is accessible. If TYPE is actually a BINFO node,
818 then we can tell in what context the access is occurring by looking
819 at the most derived class along the path indicated by BINFO. If
820 CONSIDER_LOCAL is true, do consider special access the current
821 scope or friendship thereof we might have. */
824 accessible_p (tree type
, tree decl
, bool consider_local_p
)
829 /* If this declaration is in a block or namespace scope, there's no
831 if (!TYPE_P (context_for_name_lookup (decl
)))
834 /* There is no need to perform access checks inside a thunk. */
835 if (current_function_decl
&& DECL_THUNK_P (current_function_decl
))
838 tree otype
= NULL_TREE
;
841 /* When accessing a non-static member, the most derived type in the
842 binfo chain is the type of the object; remember that type for
843 protected_accessible_p. */
844 for (tree b
= type
; b
; b
= BINFO_INHERITANCE_CHAIN (b
))
845 otype
= BINFO_TYPE (b
);
846 type
= BINFO_TYPE (type
);
851 /* [class.access.base]
853 A member m is accessible when named in class N if
855 --m as a member of N is public, or
857 --m as a member of N is private, and the reference occurs in a
858 member or friend of class N, or
860 --m as a member of N is protected, and the reference occurs in a
861 member or friend of class N, or in a member or friend of a
862 class P derived from N, where m as a member of P is public, private or
865 --there exists a base class B of N that is accessible at the point
866 of reference, and m is accessible when named in class B.
868 We walk the base class hierarchy, checking these conditions. */
870 /* We walk using TYPE_BINFO (type) because access_in_type will set
871 BINFO_ACCESS on it and its bases. */
872 binfo
= TYPE_BINFO (type
);
874 /* Compute the accessibility of DECL in the class hierarchy
875 dominated by type. */
876 access
= access_in_type (type
, decl
);
877 if (access
== ak_public
)
880 /* If we aren't considering the point of reference, only the first bullet
882 if (!consider_local_p
)
885 dfs_accessible_data d
= { decl
, otype
};
887 /* Walk the hierarchy again, looking for a base class that allows
889 return dfs_walk_once_accessible (binfo
, /*friends=*/true,
891 dfs_accessible_post
, &d
)
895 struct lookup_field_info
{
896 /* The type in which we're looking. */
898 /* The name of the field for which we're looking. */
900 /* If non-NULL, the current result of the lookup. */
902 /* The path to RVAL. */
904 /* If non-NULL, the lookup was ambiguous, and this is a list of the
907 /* If nonzero, we are looking for types, not data members. */
909 /* If something went wrong, a message indicating what. */
913 /* Nonzero for a class member means that it is shared between all objects
916 [class.member.lookup]:If the resulting set of declarations are not all
917 from sub-objects of the same type, or the set has a non-static member
918 and includes members from distinct sub-objects, there is an ambiguity
919 and the program is ill-formed.
921 This function checks that T contains no non-static members. */
924 shared_member_p (tree t
)
926 if (VAR_P (t
) || TREE_CODE (t
) == TYPE_DECL \
927 || TREE_CODE (t
) == CONST_DECL
)
929 if (is_overloaded_fn (t
))
931 for (ovl_iterator
iter (get_fns (t
)); iter
; ++iter
)
933 tree decl
= strip_using_decl (*iter
);
934 /* We don't expect or support dependent decls. */
935 gcc_assert (TREE_CODE (decl
) != USING_DECL
);
936 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl
))
944 /* Routine to see if the sub-object denoted by the binfo PARENT can be
945 found as a base class and sub-object of the object denoted by
949 is_subobject_of_p (tree parent
, tree binfo
)
953 for (probe
= parent
; probe
; probe
= BINFO_INHERITANCE_CHAIN (probe
))
957 if (BINFO_VIRTUAL_P (probe
))
958 return (binfo_for_vbase (BINFO_TYPE (probe
), BINFO_TYPE (binfo
))
964 /* DATA is really a struct lookup_field_info. Look for a field with
965 the name indicated there in BINFO. If this function returns a
966 non-NULL value it is the result of the lookup. Called from
967 lookup_field via breadth_first_search. */
970 lookup_field_r (tree binfo
, void *data
)
972 struct lookup_field_info
*lfi
= (struct lookup_field_info
*) data
;
973 tree type
= BINFO_TYPE (binfo
);
974 tree nval
= NULL_TREE
;
976 /* If this is a dependent base, don't look in it. */
977 if (BINFO_DEPENDENT_BASE_P (binfo
))
980 /* If this base class is hidden by the best-known value so far, we
981 don't need to look. */
982 if (lfi
->rval_binfo
&& BINFO_INHERITANCE_CHAIN (binfo
) == lfi
->rval_binfo
983 && !BINFO_VIRTUAL_P (binfo
))
984 return dfs_skip_bases
;
986 nval
= get_class_binding (type
, lfi
->name
, lfi
->want_type
);
988 /* If there is no declaration with the indicated name in this type,
989 then there's nothing to do. */
993 /* If the lookup already found a match, and the new value doesn't
994 hide the old one, we might have an ambiguity. */
996 && !is_subobject_of_p (lfi
->rval_binfo
, binfo
))
999 if (nval
== lfi
->rval
&& shared_member_p (nval
))
1000 /* The two things are really the same. */
1002 else if (is_subobject_of_p (binfo
, lfi
->rval_binfo
))
1003 /* The previous value hides the new one. */
1007 /* We have a real ambiguity. We keep a chain of all the
1009 if (!lfi
->ambiguous
&& lfi
->rval
)
1011 /* This is the first time we noticed an ambiguity. Add
1012 what we previously thought was a reasonable candidate
1014 lfi
->ambiguous
= tree_cons (NULL_TREE
, lfi
->rval
, NULL_TREE
);
1015 TREE_TYPE (lfi
->ambiguous
) = error_mark_node
;
1018 /* Add the new value. */
1019 lfi
->ambiguous
= tree_cons (NULL_TREE
, nval
, lfi
->ambiguous
);
1020 TREE_TYPE (lfi
->ambiguous
) = error_mark_node
;
1021 lfi
->errstr
= G_("request for member %qD is ambiguous");
1027 lfi
->rval_binfo
= binfo
;
1031 /* Don't look for constructors or destructors in base classes. */
1032 if (IDENTIFIER_CDTOR_P (lfi
->name
))
1033 return dfs_skip_bases
;
1037 /* Return a "baselink" with BASELINK_BINFO, BASELINK_ACCESS_BINFO,
1038 BASELINK_FUNCTIONS, and BASELINK_OPTYPE set to BINFO, ACCESS_BINFO,
1039 FUNCTIONS, and OPTYPE respectively. */
1042 build_baselink (tree binfo
, tree access_binfo
, tree functions
, tree optype
)
1046 gcc_assert (OVL_P (functions
) || TREE_CODE (functions
) == TEMPLATE_ID_EXPR
);
1047 gcc_assert (!optype
|| TYPE_P (optype
));
1048 gcc_assert (TREE_TYPE (functions
));
1050 baselink
= make_node (BASELINK
);
1051 TREE_TYPE (baselink
) = TREE_TYPE (functions
);
1052 BASELINK_BINFO (baselink
) = binfo
;
1053 BASELINK_ACCESS_BINFO (baselink
) = access_binfo
;
1054 BASELINK_FUNCTIONS (baselink
) = functions
;
1055 BASELINK_OPTYPE (baselink
) = optype
;
1060 /* Look for a member named NAME in an inheritance lattice dominated by
1061 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it
1062 is 1, we enforce accessibility. If PROTECT is zero, then, for an
1063 ambiguous lookup, we return NULL. If PROTECT is 1, we issue error
1064 messages about inaccessible or ambiguous lookup. If PROTECT is 2,
1065 we return a TREE_LIST whose TREE_TYPE is error_mark_node and whose
1066 TREE_VALUEs are the list of ambiguous candidates.
1068 WANT_TYPE is 1 when we should only return TYPE_DECLs.
1070 If nothing can be found return NULL_TREE and do not issue an error.
1072 If non-NULL, failure information is written back to AFI. */
1075 lookup_member (tree xbasetype
, tree name
, int protect
, bool want_type
,
1076 tsubst_flags_t complain
, access_failure_info
*afi
)
1078 tree rval
, rval_binfo
= NULL_TREE
;
1079 tree type
= NULL_TREE
, basetype_path
= NULL_TREE
;
1080 struct lookup_field_info lfi
;
1082 /* rval_binfo is the binfo associated with the found member, note,
1083 this can be set with useful information, even when rval is not
1084 set, because it must deal with ALL members, not just non-function
1085 members. It is used for ambiguity checking and the hidden
1086 checks. Whereas rval is only set if a proper (not hidden)
1087 non-function member is found. */
1089 const char *errstr
= 0;
1091 if (name
== error_mark_node
1092 || xbasetype
== NULL_TREE
1093 || xbasetype
== error_mark_node
)
1096 gcc_assert (identifier_p (name
));
1098 if (TREE_CODE (xbasetype
) == TREE_BINFO
)
1100 type
= BINFO_TYPE (xbasetype
);
1101 basetype_path
= xbasetype
;
1105 if (!RECORD_OR_UNION_CODE_P (TREE_CODE (xbasetype
)))
1108 xbasetype
= NULL_TREE
;
1111 type
= complete_type (type
);
1113 /* Make sure we're looking for a member of the current instantiation in the
1114 right partial specialization. */
1115 if (dependent_type_p (type
))
1116 if (tree t
= currently_open_class (type
))
1120 basetype_path
= TYPE_BINFO (type
);
1125 memset (&lfi
, 0, sizeof (lfi
));
1128 lfi
.want_type
= want_type
;
1129 dfs_walk_all (basetype_path
, &lookup_field_r
, NULL
, &lfi
);
1131 rval_binfo
= lfi
.rval_binfo
;
1133 type
= BINFO_TYPE (rval_binfo
);
1134 errstr
= lfi
.errstr
;
1136 /* If we are not interested in ambiguities, don't report them;
1137 just return NULL_TREE. */
1138 if (!protect
&& lfi
.ambiguous
)
1144 return lfi
.ambiguous
;
1151 In the case of overloaded function names, access control is
1152 applied to the function selected by overloaded resolution.
1154 We cannot check here, even if RVAL is only a single non-static
1155 member function, since we do not know what the "this" pointer
1158 class A { protected: void f(); };
1159 class B : public A {
1166 only the first call to "f" is valid. However, if the function is
1167 static, we can check. */
1169 && !really_overloaded_fn (rval
))
1171 tree decl
= is_overloaded_fn (rval
) ? get_first_fn (rval
) : rval
;
1172 decl
= strip_using_decl (decl
);
1173 /* A dependent USING_DECL will be checked after tsubsting. */
1174 if (TREE_CODE (decl
) != USING_DECL
1175 && !DECL_NONSTATIC_MEMBER_FUNCTION_P (decl
)
1176 && !perform_or_defer_access_check (basetype_path
, decl
, decl
,
1178 rval
= error_mark_node
;
1181 if (errstr
&& protect
)
1183 if (complain
& tf_error
)
1185 error (errstr
, name
, type
);
1187 print_candidates (lfi
.ambiguous
);
1189 rval
= error_mark_node
;
1192 if (rval
&& is_overloaded_fn (rval
))
1193 rval
= build_baselink (rval_binfo
, basetype_path
, rval
,
1194 (IDENTIFIER_CONV_OP_P (name
)
1195 ? TREE_TYPE (name
): NULL_TREE
));
1199 /* Helper class for lookup_member_fuzzy. */
1201 class lookup_field_fuzzy_info
1204 lookup_field_fuzzy_info (bool want_type_p
) :
1205 m_want_type_p (want_type_p
), m_candidates () {}
1207 void fuzzy_lookup_field (tree type
);
1209 /* If true, we are looking for types, not data members. */
1211 /* The result: a vec of identifiers. */
1212 auto_vec
<tree
> m_candidates
;
1215 /* Locate all fields within TYPE, append them to m_candidates. */
1218 lookup_field_fuzzy_info::fuzzy_lookup_field (tree type
)
1220 if (!CLASS_TYPE_P (type
))
1223 for (tree field
= TYPE_FIELDS (type
); field
; field
= DECL_CHAIN (field
))
1225 if (m_want_type_p
&& !DECL_DECLARES_TYPE_P (field
))
1228 if (!DECL_NAME (field
))
1231 if (is_lambda_ignored_entity (field
))
1234 m_candidates
.safe_push (DECL_NAME (field
));
1239 /* Helper function for lookup_member_fuzzy, called via dfs_walk_all
1240 DATA is really a lookup_field_fuzzy_info. Look for a field with
1241 the name indicated there in BINFO. Gathers pertinent identifiers into
1245 lookup_field_fuzzy_r (tree binfo
, void *data
)
1247 lookup_field_fuzzy_info
*lffi
= (lookup_field_fuzzy_info
*) data
;
1248 tree type
= BINFO_TYPE (binfo
);
1250 lffi
->fuzzy_lookup_field (type
);
1255 /* Like lookup_member, but try to find the closest match for NAME,
1256 rather than an exact match, and return an identifier (or NULL_TREE).
1260 lookup_member_fuzzy (tree xbasetype
, tree name
, bool want_type_p
)
1262 tree type
= NULL_TREE
, basetype_path
= NULL_TREE
;
1263 class lookup_field_fuzzy_info
lffi (want_type_p
);
1265 /* rval_binfo is the binfo associated with the found member, note,
1266 this can be set with useful information, even when rval is not
1267 set, because it must deal with ALL members, not just non-function
1268 members. It is used for ambiguity checking and the hidden
1269 checks. Whereas rval is only set if a proper (not hidden)
1270 non-function member is found. */
1272 if (name
== error_mark_node
1273 || xbasetype
== NULL_TREE
1274 || xbasetype
== error_mark_node
)
1277 gcc_assert (identifier_p (name
));
1279 if (TREE_CODE (xbasetype
) == TREE_BINFO
)
1281 type
= BINFO_TYPE (xbasetype
);
1282 basetype_path
= xbasetype
;
1286 if (!RECORD_OR_UNION_CODE_P (TREE_CODE (xbasetype
)))
1289 xbasetype
= NULL_TREE
;
1292 type
= complete_type (type
);
1294 /* Make sure we're looking for a member of the current instantiation in the
1295 right partial specialization. */
1296 if (flag_concepts
&& dependent_type_p (type
))
1297 type
= currently_open_class (type
);
1300 basetype_path
= TYPE_BINFO (type
);
1305 /* Populate lffi.m_candidates. */
1306 dfs_walk_all (basetype_path
, &lookup_field_fuzzy_r
, NULL
, &lffi
);
1308 return find_closest_identifier (name
, &lffi
.m_candidates
);
1311 /* Like lookup_member, except that if we find a function member we
1312 return NULL_TREE. */
1315 lookup_field (tree xbasetype
, tree name
, int protect
, bool want_type
)
1317 tree rval
= lookup_member (xbasetype
, name
, protect
, want_type
,
1318 tf_warning_or_error
);
1320 /* Ignore functions, but propagate the ambiguity list. */
1321 if (!error_operand_p (rval
)
1322 && (rval
&& BASELINK_P (rval
)))
1328 /* Like lookup_member, except that if we find a non-function member we
1329 return NULL_TREE. */
1332 lookup_fnfields (tree xbasetype
, tree name
, int protect
,
1333 tsubst_flags_t complain
)
1335 tree rval
= lookup_member (xbasetype
, name
, protect
, /*want_type=*/false,
1338 /* Ignore non-functions, but propagate the ambiguity list. */
1339 if (!error_operand_p (rval
)
1340 && (rval
&& !BASELINK_P (rval
)))
1346 /* DECL is the result of a qualified name lookup. QUALIFYING_SCOPE is
1347 the class or namespace used to qualify the name. CONTEXT_CLASS is
1348 the class corresponding to the object in which DECL will be used.
1349 Return a possibly modified version of DECL that takes into account
1352 In particular, consider an expression like `B::m' in the context of
1353 a derived class `D'. If `B::m' has been resolved to a BASELINK,
1354 then the most derived class indicated by the BASELINK_BINFO will be
1355 `B', not `D'. This function makes that adjustment. */
1358 adjust_result_of_qualified_name_lookup (tree decl
,
1359 tree qualifying_scope
,
1362 if (context_class
&& context_class
!= error_mark_node
1363 && CLASS_TYPE_P (context_class
)
1364 && CLASS_TYPE_P (qualifying_scope
)
1365 && DERIVED_FROM_P (qualifying_scope
, context_class
)
1366 && BASELINK_P (decl
))
1370 /* Look for the QUALIFYING_SCOPE as a base of the CONTEXT_CLASS.
1371 Because we do not yet know which function will be chosen by
1372 overload resolution, we cannot yet check either accessibility
1373 or ambiguity -- in either case, the choice of a static member
1374 function might make the usage valid. */
1375 base
= lookup_base (context_class
, qualifying_scope
,
1376 ba_unique
, NULL
, tf_none
);
1377 if (base
&& base
!= error_mark_node
)
1379 BASELINK_ACCESS_BINFO (decl
) = base
;
1381 = lookup_base (base
, BINFO_TYPE (BASELINK_BINFO (decl
)),
1382 ba_unique
, NULL
, tf_none
);
1383 if (decl_binfo
&& decl_binfo
!= error_mark_node
)
1384 BASELINK_BINFO (decl
) = decl_binfo
;
1388 if (BASELINK_P (decl
))
1389 BASELINK_QUALIFIED_P (decl
) = true;
1395 /* Walk the class hierarchy within BINFO, in a depth-first traversal.
1396 PRE_FN is called in preorder, while POST_FN is called in postorder.
1397 If PRE_FN returns DFS_SKIP_BASES, child binfos will not be
1398 walked. If PRE_FN or POST_FN returns a different non-NULL value,
1399 that value is immediately returned and the walk is terminated. One
1400 of PRE_FN and POST_FN can be NULL. At each node, PRE_FN and
1401 POST_FN are passed the binfo to examine and the caller's DATA
1402 value. All paths are walked, thus virtual and morally virtual
1403 binfos can be multiply walked. */
1406 dfs_walk_all (tree binfo
, tree (*pre_fn
) (tree
, void *),
1407 tree (*post_fn
) (tree
, void *), void *data
)
1413 /* Call the pre-order walking function. */
1416 rval
= pre_fn (binfo
, data
);
1419 if (rval
== dfs_skip_bases
)
1425 /* Find the next child binfo to walk. */
1426 for (ix
= 0; BINFO_BASE_ITERATE (binfo
, ix
, base_binfo
); ix
++)
1428 rval
= dfs_walk_all (base_binfo
, pre_fn
, post_fn
, data
);
1434 /* Call the post-order walking function. */
1437 rval
= post_fn (binfo
, data
);
1438 gcc_assert (rval
!= dfs_skip_bases
);
1445 /* Worker for dfs_walk_once. This behaves as dfs_walk_all, except
1446 that binfos are walked at most once. */
1449 dfs_walk_once_r (tree binfo
, tree (*pre_fn
) (tree
, void *),
1450 tree (*post_fn
) (tree
, void *), hash_set
<tree
> *pset
,
1457 /* Call the pre-order walking function. */
1460 rval
= pre_fn (binfo
, data
);
1463 if (rval
== dfs_skip_bases
)
1470 /* Find the next child binfo to walk. */
1471 for (ix
= 0; BINFO_BASE_ITERATE (binfo
, ix
, base_binfo
); ix
++)
1473 if (BINFO_VIRTUAL_P (base_binfo
))
1474 if (pset
->add (base_binfo
))
1477 rval
= dfs_walk_once_r (base_binfo
, pre_fn
, post_fn
, pset
, data
);
1483 /* Call the post-order walking function. */
1486 rval
= post_fn (binfo
, data
);
1487 gcc_assert (rval
!= dfs_skip_bases
);
1494 /* Like dfs_walk_all, except that binfos are not multiply walked. For
1495 non-diamond shaped hierarchies this is the same as dfs_walk_all.
1496 For diamond shaped hierarchies we must mark the virtual bases, to
1497 avoid multiple walks. */
1500 dfs_walk_once (tree binfo
, tree (*pre_fn
) (tree
, void *),
1501 tree (*post_fn
) (tree
, void *), void *data
)
1503 static int active
= 0; /* We must not be called recursively. */
1506 gcc_assert (pre_fn
|| post_fn
);
1507 gcc_assert (!active
);
1510 if (!CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo
)))
1511 /* We are not diamond shaped, and therefore cannot encounter the
1512 same binfo twice. */
1513 rval
= dfs_walk_all (binfo
, pre_fn
, post_fn
, data
);
1516 hash_set
<tree
> pset
;
1517 rval
= dfs_walk_once_r (binfo
, pre_fn
, post_fn
, &pset
, data
);
1525 /* Worker function for dfs_walk_once_accessible. Behaves like
1526 dfs_walk_once_r, except (a) FRIENDS_P is true if special
1527 access given by the current context should be considered, (b) ONCE
1528 indicates whether bases should be marked during traversal. */
1531 dfs_walk_once_accessible_r (tree binfo
, bool friends_p
, hash_set
<tree
> *pset
,
1532 tree (*pre_fn
) (tree
, void *),
1533 tree (*post_fn
) (tree
, void *), void *data
)
1535 tree rval
= NULL_TREE
;
1539 /* Call the pre-order walking function. */
1542 rval
= pre_fn (binfo
, data
);
1545 if (rval
== dfs_skip_bases
)
1552 /* Find the next child binfo to walk. */
1553 for (ix
= 0; BINFO_BASE_ITERATE (binfo
, ix
, base_binfo
); ix
++)
1555 bool mark
= pset
&& BINFO_VIRTUAL_P (base_binfo
);
1557 if (mark
&& pset
->contains (base_binfo
))
1560 /* If the base is inherited via private or protected
1561 inheritance, then we can't see it, unless we are a friend of
1562 the current binfo. */
1563 if (BINFO_BASE_ACCESS (binfo
, ix
) != access_public_node
)
1568 scope
= current_scope ();
1570 || TREE_CODE (scope
) == NAMESPACE_DECL
1571 || !is_friend (BINFO_TYPE (binfo
), scope
))
1576 pset
->add (base_binfo
);
1578 rval
= dfs_walk_once_accessible_r (base_binfo
, friends_p
, pset
,
1579 pre_fn
, post_fn
, data
);
1585 /* Call the post-order walking function. */
1588 rval
= post_fn (binfo
, data
);
1589 gcc_assert (rval
!= dfs_skip_bases
);
1596 /* Like dfs_walk_once except that only accessible bases are walked.
1597 FRIENDS_P indicates whether friendship of the local context
1598 should be considered when determining accessibility. */
1601 dfs_walk_once_accessible (tree binfo
, bool friends_p
,
1602 tree (*pre_fn
) (tree
, void *),
1603 tree (*post_fn
) (tree
, void *), void *data
)
1605 hash_set
<tree
> *pset
= NULL
;
1606 if (CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo
)))
1607 pset
= new hash_set
<tree
>;
1608 tree rval
= dfs_walk_once_accessible_r (binfo
, friends_p
, pset
,
1609 pre_fn
, post_fn
, data
);
1616 /* Return true iff the code of T is CODE, and it has compatible
1620 matches_code_and_type_p (tree t
, enum tree_code code
, tree type
)
1622 if (TREE_CODE (t
) != code
)
1624 if (!cxx_types_compatible_p (TREE_TYPE (t
), type
))
1629 /* Subroutine of direct_accessor_p and reference_accessor_p.
1630 Determine if COMPONENT_REF is a simple field lookup of this->FIELD_DECL.
1631 We expect a tree of the form:
1636 <field_decl (FIELD_DECL)>>>. */
1639 field_access_p (tree component_ref
, tree field_decl
, tree field_type
)
1641 if (!matches_code_and_type_p (component_ref
, COMPONENT_REF
, field_type
))
1644 tree indirect_ref
= TREE_OPERAND (component_ref
, 0);
1645 if (!INDIRECT_REF_P (indirect_ref
))
1648 tree ptr
= STRIP_NOPS (TREE_OPERAND (indirect_ref
, 0));
1649 if (!is_this_parameter (ptr
))
1652 /* Must access the correct field. */
1653 if (TREE_OPERAND (component_ref
, 1) != field_decl
)
1658 /* Subroutine of field_accessor_p.
1660 Assuming that INIT_EXPR has already had its code and type checked,
1661 determine if it is a simple accessor for FIELD_DECL
1662 (of type FIELD_TYPE).
1664 Specifically, a simple accessor within struct S of the form:
1665 T get_field () { return m_field; }
1666 should have a constexpr_fn_retval (saved_tree) of the form:
1674 <field_decl (FIELD_DECL)>>>>>. */
1677 direct_accessor_p (tree init_expr
, tree field_decl
, tree field_type
)
1679 tree result_decl
= TREE_OPERAND (init_expr
, 0);
1680 if (!matches_code_and_type_p (result_decl
, RESULT_DECL
, field_type
))
1683 tree component_ref
= STRIP_NOPS (TREE_OPERAND (init_expr
, 1));
1684 if (!field_access_p (component_ref
, field_decl
, field_type
))
1690 /* Subroutine of field_accessor_p.
1692 Assuming that INIT_EXPR has already had its code and type checked,
1693 determine if it is a "reference" accessor for FIELD_DECL
1694 (of type FIELD_REFERENCE_TYPE).
1696 Specifically, a simple accessor within struct S of the form:
1697 T& get_field () { return m_field; }
1698 should have a constexpr_fn_retval (saved_tree) of the form:
1707 <field (FIELD_DECL)>>>>>>. */
1709 reference_accessor_p (tree init_expr
, tree field_decl
, tree field_type
,
1710 tree field_reference_type
)
1712 tree result_decl
= TREE_OPERAND (init_expr
, 0);
1713 if (!matches_code_and_type_p (result_decl
, RESULT_DECL
, field_reference_type
))
1716 tree field_pointer_type
= build_pointer_type (field_type
);
1717 tree addr_expr
= STRIP_NOPS (TREE_OPERAND (init_expr
, 1));
1718 if (!matches_code_and_type_p (addr_expr
, ADDR_EXPR
, field_pointer_type
))
1721 tree component_ref
= STRIP_NOPS (TREE_OPERAND (addr_expr
, 0));
1723 if (!field_access_p (component_ref
, field_decl
, field_type
))
1729 /* Return true if FN is an accessor method for FIELD_DECL.
1730 i.e. a method of the form { return FIELD; }, with no
1733 If CONST_P, then additionally require that FN be a const
1737 field_accessor_p (tree fn
, tree field_decl
, bool const_p
)
1739 if (TREE_CODE (fn
) != FUNCTION_DECL
)
1742 /* We don't yet support looking up static data, just fields. */
1743 if (TREE_CODE (field_decl
) != FIELD_DECL
)
1746 tree fntype
= TREE_TYPE (fn
);
1747 if (TREE_CODE (fntype
) != METHOD_TYPE
)
1750 /* If the field is accessed via a const "this" argument, verify
1751 that the "this" parameter is const. */
1754 tree this_class
= class_of_this_parm (fntype
);
1755 if (!TYPE_READONLY (this_class
))
1759 tree saved_tree
= DECL_SAVED_TREE (fn
);
1761 if (saved_tree
== NULL_TREE
)
1764 /* Attempt to extract a single return value from the function,
1766 tree retval
= constexpr_fn_retval (saved_tree
);
1767 if (retval
== NULL_TREE
|| retval
== error_mark_node
)
1769 /* Require an INIT_EXPR. */
1770 if (TREE_CODE (retval
) != INIT_EXPR
)
1772 tree init_expr
= retval
;
1774 /* Determine if this is a simple accessor within struct S of the form:
1775 T get_field () { return m_field; }. */
1776 tree field_type
= TREE_TYPE (field_decl
);
1777 if (cxx_types_compatible_p (TREE_TYPE (init_expr
), field_type
))
1778 return direct_accessor_p (init_expr
, field_decl
, field_type
);
1780 /* Failing that, determine if it is an accessor of the form:
1781 T& get_field () { return m_field; }. */
1782 tree field_reference_type
= cp_build_reference_type (field_type
, false);
1783 if (cxx_types_compatible_p (TREE_TYPE (init_expr
), field_reference_type
))
1784 return reference_accessor_p (init_expr
, field_decl
, field_type
,
1785 field_reference_type
);
1790 /* Callback data for dfs_locate_field_accessor_pre. */
1792 class locate_field_data
1795 locate_field_data (tree field_decl_
, bool const_p_
)
1796 : field_decl (field_decl_
), const_p (const_p_
) {}
1802 /* Return a FUNCTION_DECL that is an "accessor" method for DATA, a FIELD_DECL,
1803 callable via binfo, if one exists, otherwise return NULL_TREE.
1805 Callback for dfs_walk_once_accessible for use within
1806 locate_field_accessor. */
1809 dfs_locate_field_accessor_pre (tree binfo
, void *data
)
1811 locate_field_data
*lfd
= (locate_field_data
*)data
;
1812 tree type
= BINFO_TYPE (binfo
);
1814 vec
<tree
, va_gc
> *member_vec
;
1818 if (!CLASS_TYPE_P (type
))
1821 member_vec
= CLASSTYPE_MEMBER_VEC (type
);
1825 for (i
= 0; vec_safe_iterate (member_vec
, i
, &fn
); ++i
)
1827 if (field_accessor_p (fn
, lfd
->field_decl
, lfd
->const_p
))
1833 /* Return a FUNCTION_DECL that is an "accessor" method for FIELD_DECL,
1834 callable via BASETYPE_PATH, if one exists, otherwise return NULL_TREE. */
1837 locate_field_accessor (tree basetype_path
, tree field_decl
, bool const_p
)
1839 if (TREE_CODE (basetype_path
) != TREE_BINFO
)
1842 /* Walk the hierarchy, looking for a method of some base class that allows
1843 access to the field. */
1844 locate_field_data
lfd (field_decl
, const_p
);
1845 return dfs_walk_once_accessible (basetype_path
, /*friends=*/true,
1846 dfs_locate_field_accessor_pre
,
1850 /* Check throw specifier of OVERRIDER is at least as strict as
1851 the one of BASEFN. */
1854 maybe_check_overriding_exception_spec (tree overrider
, tree basefn
)
1856 maybe_instantiate_noexcept (basefn
);
1857 maybe_instantiate_noexcept (overrider
);
1858 tree base_throw
= TYPE_RAISES_EXCEPTIONS (TREE_TYPE (basefn
));
1859 tree over_throw
= TYPE_RAISES_EXCEPTIONS (TREE_TYPE (overrider
));
1861 if (DECL_INVALID_OVERRIDER_P (overrider
))
1864 /* Can't check this yet. Pretend this is fine and let
1865 noexcept_override_late_checks check this later. */
1866 if (UNPARSED_NOEXCEPT_SPEC_P (base_throw
)
1867 || UNPARSED_NOEXCEPT_SPEC_P (over_throw
))
1870 if (!comp_except_specs (base_throw
, over_throw
, ce_derived
))
1872 auto_diagnostic_group d
;
1873 error ("looser exception specification on overriding virtual function "
1874 "%q+#F", overrider
);
1875 inform (DECL_SOURCE_LOCATION (basefn
),
1876 "overridden function is %q#F", basefn
);
1877 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1883 /* Check that virtual overrider OVERRIDER is acceptable for base function
1884 BASEFN. Issue diagnostic, and return zero, if unacceptable. */
1887 check_final_overrider (tree overrider
, tree basefn
)
1889 tree over_type
= TREE_TYPE (overrider
);
1890 tree base_type
= TREE_TYPE (basefn
);
1891 tree over_return
= fndecl_declared_return_type (overrider
);
1892 tree base_return
= fndecl_declared_return_type (basefn
);
1896 if (DECL_INVALID_OVERRIDER_P (overrider
))
1899 if (same_type_p (base_return
, over_return
))
1901 else if ((CLASS_TYPE_P (over_return
) && CLASS_TYPE_P (base_return
))
1902 || (TREE_CODE (base_return
) == TREE_CODE (over_return
)
1903 && INDIRECT_TYPE_P (base_return
)))
1905 /* Potentially covariant. */
1906 unsigned base_quals
, over_quals
;
1908 fail
= !INDIRECT_TYPE_P (base_return
);
1911 fail
= cp_type_quals (base_return
) != cp_type_quals (over_return
);
1913 base_return
= TREE_TYPE (base_return
);
1914 over_return
= TREE_TYPE (over_return
);
1916 base_quals
= cp_type_quals (base_return
);
1917 over_quals
= cp_type_quals (over_return
);
1919 if ((base_quals
& over_quals
) != over_quals
)
1922 if (CLASS_TYPE_P (base_return
) && CLASS_TYPE_P (over_return
))
1924 /* Strictly speaking, the standard requires the return type to be
1925 complete even if it only differs in cv-quals, but that seems
1926 like a bug in the wording. */
1927 if (!same_type_ignoring_top_level_qualifiers_p (base_return
,
1930 tree binfo
= lookup_base (over_return
, base_return
,
1931 ba_check
, NULL
, tf_none
);
1933 if (!binfo
|| binfo
== error_mark_node
)
1937 else if (can_convert_standard (TREE_TYPE (base_type
),
1938 TREE_TYPE (over_type
),
1939 tf_warning_or_error
))
1940 /* GNU extension, allow trivial pointer conversions such as
1941 converting to void *, or qualification conversion. */
1943 auto_diagnostic_group d
;
1944 if (pedwarn (DECL_SOURCE_LOCATION (overrider
), 0,
1945 "invalid covariant return type for %q#D", overrider
))
1946 inform (DECL_SOURCE_LOCATION (basefn
),
1947 "overridden function is %q#D", basefn
);
1958 auto_diagnostic_group d
;
1960 error ("invalid covariant return type for %q+#D", overrider
);
1962 error ("conflicting return type specified for %q+#D", overrider
);
1963 inform (DECL_SOURCE_LOCATION (basefn
),
1964 "overridden function is %q#D", basefn
);
1965 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1969 if (!maybe_check_overriding_exception_spec (overrider
, basefn
))
1972 /* Check for conflicting type attributes. But leave transaction_safe for
1973 set_one_vmethod_tm_attributes. */
1974 if (!comp_type_attributes (over_type
, base_type
)
1975 && !tx_safe_fn_type_p (base_type
)
1976 && !tx_safe_fn_type_p (over_type
))
1978 auto_diagnostic_group d
;
1979 error ("conflicting type attributes specified for %q+#D", overrider
);
1980 inform (DECL_SOURCE_LOCATION (basefn
),
1981 "overridden function is %q#D", basefn
);
1982 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1986 /* A consteval virtual function shall not override a virtual function that is
1987 not consteval. A consteval virtual function shall not be overridden by a
1988 virtual function that is not consteval. */
1989 if (DECL_IMMEDIATE_FUNCTION_P (overrider
)
1990 != DECL_IMMEDIATE_FUNCTION_P (basefn
))
1992 auto_diagnostic_group d
;
1993 if (DECL_IMMEDIATE_FUNCTION_P (overrider
))
1994 error ("%<consteval%> function %q+D overriding non-%<consteval%> "
1995 "function", overrider
);
1997 error ("non-%<consteval%> function %q+D overriding %<consteval%> "
1998 "function", overrider
);
1999 inform (DECL_SOURCE_LOCATION (basefn
),
2000 "overridden function is %qD", basefn
);
2001 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
2005 /* A function declared transaction_safe_dynamic that overrides a function
2006 declared transaction_safe (but not transaction_safe_dynamic) is
2008 if (tx_safe_fn_type_p (base_type
)
2009 && lookup_attribute ("transaction_safe_dynamic",
2010 DECL_ATTRIBUTES (overrider
))
2011 && !lookup_attribute ("transaction_safe_dynamic",
2012 DECL_ATTRIBUTES (basefn
)))
2014 auto_diagnostic_group d
;
2015 error_at (DECL_SOURCE_LOCATION (overrider
),
2016 "%qD declared %<transaction_safe_dynamic%>", overrider
);
2017 inform (DECL_SOURCE_LOCATION (basefn
),
2018 "overriding %qD declared %<transaction_safe%>", basefn
);
2021 if (DECL_DELETED_FN (basefn
) != DECL_DELETED_FN (overrider
))
2023 if (DECL_DELETED_FN (overrider
))
2025 auto_diagnostic_group d
;
2026 error ("deleted function %q+D overriding non-deleted function",
2028 inform (DECL_SOURCE_LOCATION (basefn
),
2029 "overridden function is %qD", basefn
);
2030 maybe_explain_implicit_delete (overrider
);
2034 auto_diagnostic_group d
;
2035 error ("non-deleted function %q+D overriding deleted function",
2037 inform (DECL_SOURCE_LOCATION (basefn
),
2038 "overridden function is %qD", basefn
);
2042 if (DECL_FINAL_P (basefn
))
2044 auto_diagnostic_group d
;
2045 error ("virtual function %q+D overriding final function", overrider
);
2046 inform (DECL_SOURCE_LOCATION (basefn
),
2047 "overridden function is %qD", basefn
);
2053 /* Given a class TYPE, and a function decl FNDECL, look for
2054 virtual functions in TYPE's hierarchy which FNDECL overrides.
2055 We do not look in TYPE itself, only its bases.
2057 Returns nonzero, if we find any. Set FNDECL's DECL_VIRTUAL_P, if we
2058 find that it overrides anything.
2060 We check that every function which is overridden, is correctly
2064 look_for_overrides (tree type
, tree fndecl
)
2066 tree binfo
= TYPE_BINFO (type
);
2071 /* A constructor for a class T does not override a function T
2073 if (DECL_CONSTRUCTOR_P (fndecl
))
2076 for (ix
= 0; BINFO_BASE_ITERATE (binfo
, ix
, base_binfo
); ix
++)
2078 tree basetype
= BINFO_TYPE (base_binfo
);
2080 if (TYPE_POLYMORPHIC_P (basetype
))
2081 found
+= look_for_overrides_r (basetype
, fndecl
);
2086 /* Look in TYPE for virtual functions with the same signature as
2090 look_for_overrides_here (tree type
, tree fndecl
)
2092 tree ovl
= get_class_binding (type
, DECL_NAME (fndecl
));
2094 for (ovl_iterator
iter (ovl
); iter
; ++iter
)
2098 if (!DECL_VIRTUAL_P (fn
))
2099 /* Not a virtual. */;
2100 else if (DECL_CONTEXT (fn
) != type
)
2101 /* Introduced with a using declaration. */;
2102 else if (DECL_STATIC_FUNCTION_P (fndecl
))
2104 tree btypes
= TYPE_ARG_TYPES (TREE_TYPE (fn
));
2105 tree dtypes
= TYPE_ARG_TYPES (TREE_TYPE (fndecl
));
2106 if (compparms (TREE_CHAIN (btypes
), dtypes
))
2109 else if (same_signature_p (fndecl
, fn
))
2116 /* Look in TYPE for virtual functions overridden by FNDECL. Check both
2117 TYPE itself and its bases. */
2120 look_for_overrides_r (tree type
, tree fndecl
)
2122 tree fn
= look_for_overrides_here (type
, fndecl
);
2125 if (DECL_STATIC_FUNCTION_P (fndecl
))
2127 /* A static member function cannot match an inherited
2128 virtual member function. */
2129 auto_diagnostic_group d
;
2130 error ("%q+#D cannot be declared", fndecl
);
2131 error (" since %q+#D declared in base class", fn
);
2135 /* It's definitely virtual, even if not explicitly set. */
2136 DECL_VIRTUAL_P (fndecl
) = 1;
2137 check_final_overrider (fndecl
, fn
);
2142 /* We failed to find one declared in this class. Look in its bases. */
2143 return look_for_overrides (type
, fndecl
);
2146 /* Called via dfs_walk from dfs_get_pure_virtuals. */
2149 dfs_get_pure_virtuals (tree binfo
, void *data
)
2151 tree type
= (tree
) data
;
2153 /* We're not interested in primary base classes; the derived class
2154 of which they are a primary base will contain the information we
2156 if (!BINFO_PRIMARY_P (binfo
))
2160 for (virtuals
= BINFO_VIRTUALS (binfo
);
2162 virtuals
= TREE_CHAIN (virtuals
))
2163 if (DECL_PURE_VIRTUAL_P (BV_FN (virtuals
)))
2164 vec_safe_push (CLASSTYPE_PURE_VIRTUALS (type
), BV_FN (virtuals
));
2170 /* Set CLASSTYPE_PURE_VIRTUALS for TYPE. */
2173 get_pure_virtuals (tree type
)
2175 /* Clear the CLASSTYPE_PURE_VIRTUALS list; whatever is already there
2176 is going to be overridden. */
2177 CLASSTYPE_PURE_VIRTUALS (type
) = NULL
;
2178 /* Now, run through all the bases which are not primary bases, and
2179 collect the pure virtual functions. We look at the vtable in
2180 each class to determine what pure virtual functions are present.
2181 (A primary base is not interesting because the derived class of
2182 which it is a primary base will contain vtable entries for the
2183 pure virtuals in the base class. */
2184 dfs_walk_once (TYPE_BINFO (type
), NULL
, dfs_get_pure_virtuals
, type
);
2187 /* Debug info for C++ classes can get very large; try to avoid
2188 emitting it everywhere.
2190 Note that this optimization wins even when the target supports
2191 BINCL (if only slightly), and reduces the amount of work for the
2195 maybe_suppress_debug_info (tree t
)
2197 if (write_symbols
== NO_DEBUG
)
2200 /* We might have set this earlier in cp_finish_decl. */
2201 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 0;
2203 /* Always emit the information for each class every time. */
2204 if (flag_emit_class_debug_always
)
2207 /* If we already know how we're handling this class, handle debug info
2209 if (CLASSTYPE_INTERFACE_KNOWN (t
))
2211 if (CLASSTYPE_INTERFACE_ONLY (t
))
2212 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 1;
2213 /* else don't set it. */
2215 /* If the class has a vtable, write out the debug info along with
2217 else if (TYPE_CONTAINS_VPTR_P (t
))
2218 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 1;
2220 /* Otherwise, just emit the debug info normally. */
2223 /* Note that we want debugging information for a base class of a class
2224 whose vtable is being emitted. Normally, this would happen because
2225 calling the constructor for a derived class implies calling the
2226 constructors for all bases, which involve initializing the
2227 appropriate vptr with the vtable for the base class; but in the
2228 presence of optimization, this initialization may be optimized
2229 away, so we tell finish_vtable_vardecl that we want the debugging
2230 information anyway. */
2233 dfs_debug_mark (tree binfo
, void * /*data*/)
2235 tree t
= BINFO_TYPE (binfo
);
2237 if (CLASSTYPE_DEBUG_REQUESTED (t
))
2238 return dfs_skip_bases
;
2240 CLASSTYPE_DEBUG_REQUESTED (t
) = 1;
2245 /* Write out the debugging information for TYPE, whose vtable is being
2246 emitted. Also walk through our bases and note that we want to
2247 write out information for them. This avoids the problem of not
2248 writing any debug info for intermediate basetypes whose
2249 constructors, and thus the references to their vtables, and thus
2250 the vtables themselves, were optimized away. */
2253 note_debug_info_needed (tree type
)
2255 if (TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type
)))
2257 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type
)) = 0;
2258 rest_of_type_compilation (type
, namespace_bindings_p ());
2261 dfs_walk_all (TYPE_BINFO (type
), dfs_debug_mark
, NULL
, 0);
2264 /* Helper for lookup_conversions_r. TO_TYPE is the type converted to
2265 by a conversion op in base BINFO. VIRTUAL_DEPTH is nonzero if
2266 BINFO is morally virtual, and VIRTUALNESS is nonzero if virtual
2267 bases have been encountered already in the tree walk. PARENT_CONVS
2268 is the list of lists of conversion functions that could hide CONV
2269 and OTHER_CONVS is the list of lists of conversion functions that
2270 could hide or be hidden by CONV, should virtualness be involved in
2271 the hierarchy. Merely checking the conversion op's name is not
2272 enough because two conversion operators to the same type can have
2273 different names. Return nonzero if we are visible. */
2276 check_hidden_convs (tree binfo
, int virtual_depth
, int virtualness
,
2277 tree to_type
, tree parent_convs
, tree other_convs
)
2281 /* See if we are hidden by a parent conversion. */
2282 for (level
= parent_convs
; level
; level
= TREE_CHAIN (level
))
2283 for (probe
= TREE_VALUE (level
); probe
; probe
= TREE_CHAIN (probe
))
2284 if (same_type_p (to_type
, TREE_TYPE (probe
)))
2287 if (virtual_depth
|| virtualness
)
2289 /* In a virtual hierarchy, we could be hidden, or could hide a
2290 conversion function on the other_convs list. */
2291 for (level
= other_convs
; level
; level
= TREE_CHAIN (level
))
2297 if (!(virtual_depth
|| TREE_STATIC (level
)))
2298 /* Neither is morally virtual, so cannot hide each other. */
2301 if (!TREE_VALUE (level
))
2302 /* They evaporated away already. */
2305 they_hide_us
= (virtual_depth
2306 && original_binfo (binfo
, TREE_PURPOSE (level
)));
2307 we_hide_them
= (!they_hide_us
&& TREE_STATIC (level
)
2308 && original_binfo (TREE_PURPOSE (level
), binfo
));
2310 if (!(we_hide_them
|| they_hide_us
))
2311 /* Neither is within the other, so no hiding can occur. */
2314 for (prev
= &TREE_VALUE (level
), other
= *prev
; other
;)
2316 if (same_type_p (to_type
, TREE_TYPE (other
)))
2319 /* We are hidden. */
2324 /* We hide the other one. */
2325 other
= TREE_CHAIN (other
);
2330 prev
= &TREE_CHAIN (other
);
2338 /* Helper for lookup_conversions_r. PARENT_CONVS is a list of lists
2339 of conversion functions, the first slot will be for the current
2340 binfo, if MY_CONVS is non-NULL. CHILD_CONVS is the list of lists
2341 of conversion functions from children of the current binfo,
2342 concatenated with conversions from elsewhere in the hierarchy --
2343 that list begins with OTHER_CONVS. Return a single list of lists
2344 containing only conversions from the current binfo and its
2348 split_conversions (tree my_convs
, tree parent_convs
,
2349 tree child_convs
, tree other_convs
)
2354 /* Remove the original other_convs portion from child_convs. */
2355 for (prev
= NULL
, t
= child_convs
;
2356 t
!= other_convs
; prev
= t
, t
= TREE_CHAIN (t
))
2360 TREE_CHAIN (prev
) = NULL_TREE
;
2362 child_convs
= NULL_TREE
;
2364 /* Attach the child convs to any we had at this level. */
2367 my_convs
= parent_convs
;
2368 TREE_CHAIN (my_convs
) = child_convs
;
2371 my_convs
= child_convs
;
2376 /* Worker for lookup_conversions. Lookup conversion functions in
2377 BINFO and its children. VIRTUAL_DEPTH is nonzero, if BINFO is in a
2378 morally virtual base, and VIRTUALNESS is nonzero, if we've
2379 encountered virtual bases already in the tree walk. PARENT_CONVS
2380 is a list of conversions within parent binfos. OTHER_CONVS are
2381 conversions found elsewhere in the tree. Return the conversions
2382 found within this portion of the graph in CONVS. Return nonzero if
2383 we encountered virtualness. We keep template and non-template
2384 conversions separate, to avoid unnecessary type comparisons.
2386 The located conversion functions are held in lists of lists. The
2387 TREE_VALUE of the outer list is the list of conversion functions
2388 found in a particular binfo. The TREE_PURPOSE of both the outer
2389 and inner lists is the binfo at which those conversions were
2390 found. TREE_STATIC is set for those lists within of morally
2391 virtual binfos. The TREE_VALUE of the inner list is the conversion
2392 function or overload itself. The TREE_TYPE of each inner list node
2393 is the converted-to type. */
2396 lookup_conversions_r (tree binfo
, int virtual_depth
, int virtualness
,
2397 tree parent_convs
, tree other_convs
, tree
*convs
)
2399 int my_virtualness
= 0;
2400 tree my_convs
= NULL_TREE
;
2401 tree child_convs
= NULL_TREE
;
2403 /* If we have no conversion operators, then don't look. */
2404 if (!TYPE_HAS_CONVERSION (BINFO_TYPE (binfo
)))
2411 if (BINFO_VIRTUAL_P (binfo
))
2414 /* First, locate the unhidden ones at this level. */
2415 if (tree conv
= get_class_binding (BINFO_TYPE (binfo
), conv_op_identifier
))
2416 for (ovl_iterator
iter (conv
); iter
; ++iter
)
2419 tree type
= DECL_CONV_FN_TYPE (fn
);
2421 if (TREE_CODE (fn
) != TEMPLATE_DECL
&& type_uses_auto (type
))
2424 type
= DECL_CONV_FN_TYPE (fn
);
2427 if (check_hidden_convs (binfo
, virtual_depth
, virtualness
,
2428 type
, parent_convs
, other_convs
))
2430 my_convs
= tree_cons (binfo
, fn
, my_convs
);
2431 TREE_TYPE (my_convs
) = type
;
2434 TREE_STATIC (my_convs
) = 1;
2442 parent_convs
= tree_cons (binfo
, my_convs
, parent_convs
);
2444 TREE_STATIC (parent_convs
) = 1;
2447 child_convs
= other_convs
;
2449 /* Now iterate over each base, looking for more conversions. */
2452 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
2455 unsigned base_virtualness
;
2457 base_virtualness
= lookup_conversions_r (base_binfo
,
2458 virtual_depth
, virtualness
,
2459 parent_convs
, child_convs
,
2461 if (base_virtualness
)
2462 my_virtualness
= virtualness
= 1;
2463 child_convs
= chainon (base_convs
, child_convs
);
2466 *convs
= split_conversions (my_convs
, parent_convs
,
2467 child_convs
, other_convs
);
2469 return my_virtualness
;
2472 /* Return a TREE_LIST containing all the non-hidden user-defined
2473 conversion functions for TYPE (and its base-classes). The
2474 TREE_VALUE of each node is the FUNCTION_DECL of the conversion
2475 function. The TREE_PURPOSE is the BINFO from which the conversion
2476 functions in this node were selected. This function is effectively
2477 performing a set of member lookups as lookup_fnfield does, but
2478 using the type being converted to as the unique key, rather than the
2482 lookup_conversions (tree type
)
2486 complete_type (type
);
2487 if (!CLASS_TYPE_P (type
) || !TYPE_BINFO (type
))
2490 lookup_conversions_r (TYPE_BINFO (type
), 0, 0, NULL_TREE
, NULL_TREE
, &convs
);
2492 tree list
= NULL_TREE
;
2494 /* Flatten the list-of-lists */
2495 for (; convs
; convs
= TREE_CHAIN (convs
))
2499 for (probe
= TREE_VALUE (convs
); probe
; probe
= next
)
2501 next
= TREE_CHAIN (probe
);
2503 TREE_CHAIN (probe
) = list
;
2511 /* Returns the binfo of the first direct or indirect virtual base derived
2512 from BINFO, or NULL if binfo is not via virtual. */
2515 binfo_from_vbase (tree binfo
)
2517 for (; binfo
; binfo
= BINFO_INHERITANCE_CHAIN (binfo
))
2519 if (BINFO_VIRTUAL_P (binfo
))
2525 /* Returns the binfo of the first direct or indirect virtual base derived
2526 from BINFO up to the TREE_TYPE, LIMIT, or NULL if binfo is not
2530 binfo_via_virtual (tree binfo
, tree limit
)
2532 if (limit
&& !CLASSTYPE_VBASECLASSES (limit
))
2533 /* LIMIT has no virtual bases, so BINFO cannot be via one. */
2536 for (; binfo
&& !SAME_BINFO_TYPE_P (BINFO_TYPE (binfo
), limit
);
2537 binfo
= BINFO_INHERITANCE_CHAIN (binfo
))
2539 if (BINFO_VIRTUAL_P (binfo
))
2545 /* BINFO is for a base class in some hierarchy. Return true iff it is a
2549 binfo_direct_p (tree binfo
)
2551 tree d_binfo
= BINFO_INHERITANCE_CHAIN (binfo
);
2552 if (BINFO_INHERITANCE_CHAIN (d_binfo
))
2553 /* A second inheritance chain means indirect. */
2555 if (!BINFO_VIRTUAL_P (binfo
))
2556 /* Non-virtual, so only one inheritance chain means direct. */
2558 /* A virtual base looks like a direct base, so we need to look through the
2559 direct bases to see if it's there. */
2561 for (int i
= 0; BINFO_BASE_ITERATE (d_binfo
, i
, b_binfo
); ++i
)
2562 if (b_binfo
== binfo
)
2567 /* BINFO is a base binfo in the complete type BINFO_TYPE (HERE).
2568 Find the equivalent binfo within whatever graph HERE is located.
2569 This is the inverse of original_binfo. */
2572 copied_binfo (tree binfo
, tree here
)
2574 tree result
= NULL_TREE
;
2576 if (BINFO_VIRTUAL_P (binfo
))
2580 for (t
= here
; BINFO_INHERITANCE_CHAIN (t
);
2581 t
= BINFO_INHERITANCE_CHAIN (t
))
2584 result
= binfo_for_vbase (BINFO_TYPE (binfo
), BINFO_TYPE (t
));
2586 else if (BINFO_INHERITANCE_CHAIN (binfo
))
2592 cbinfo
= copied_binfo (BINFO_INHERITANCE_CHAIN (binfo
), here
);
2593 for (ix
= 0; BINFO_BASE_ITERATE (cbinfo
, ix
, base_binfo
); ix
++)
2594 if (SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo
), BINFO_TYPE (binfo
)))
2596 result
= base_binfo
;
2602 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (here
), BINFO_TYPE (binfo
)));
2606 gcc_assert (result
);
2611 binfo_for_vbase (tree base
, tree t
)
2615 vec
<tree
, va_gc
> *vbases
;
2617 for (vbases
= CLASSTYPE_VBASECLASSES (t
), ix
= 0;
2618 vec_safe_iterate (vbases
, ix
, &binfo
); ix
++)
2619 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo
), base
))
2624 /* BINFO is some base binfo of HERE, within some other
2625 hierarchy. Return the equivalent binfo, but in the hierarchy
2626 dominated by HERE. This is the inverse of copied_binfo. If BINFO
2627 is not a base binfo of HERE, returns NULL_TREE. */
2630 original_binfo (tree binfo
, tree here
)
2634 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo
), BINFO_TYPE (here
)))
2636 else if (BINFO_VIRTUAL_P (binfo
))
2637 result
= (CLASSTYPE_VBASECLASSES (BINFO_TYPE (here
))
2638 ? binfo_for_vbase (BINFO_TYPE (binfo
), BINFO_TYPE (here
))
2640 else if (BINFO_INHERITANCE_CHAIN (binfo
))
2644 base_binfos
= original_binfo (BINFO_INHERITANCE_CHAIN (binfo
), here
);
2650 for (ix
= 0; (base_binfo
= BINFO_BASE_BINFO (base_binfos
, ix
)); ix
++)
2651 if (SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo
),
2652 BINFO_TYPE (binfo
)))
2654 result
= base_binfo
;
2663 /* True iff TYPE has any dependent bases (and therefore we can't say
2664 definitively that another class is not a base of an instantiation of
2668 any_dependent_bases_p (tree type
)
2670 if (!type
|| !CLASS_TYPE_P (type
) || !uses_template_parms (type
))
2673 /* If we haven't set TYPE_BINFO yet, we don't know anything about the bases.
2674 Return false because in this situation we aren't actually looking up names
2675 in the scope of the class, so it doesn't matter whether it has dependent
2677 if (!TYPE_BINFO (type
))
2682 FOR_EACH_VEC_SAFE_ELT (BINFO_BASE_BINFOS (TYPE_BINFO (type
)), i
, base_binfo
)
2683 if (BINFO_DEPENDENT_BASE_P (base_binfo
))