| blob | b5b5b8b5cee9ca84de51618f4dea99c631b556b0 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2015 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com)
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
22 /* High-level class interface. */
46 /* The number of nested classes being processed. If we are not in the
47 scope of any class, this is zero. */
51 /* In order to deal with nested classes, we keep a stack of classes.
52 The topmost entry is the innermost class, and is the entry at index
53 CURRENT_CLASS_DEPTH */
56 /* The name of the class. */
57 tree name;
59 /* The _TYPE node for the class. */
60 tree type;
62 /* The access specifier pending for new declarations in the scope of
63 this class. */
64 tree access;
66 /* If were defining TYPE, the names used in this class. */
67 splay_tree names_used;
69 /* Nonzero if this class is no longer open, because of a call to
70 push_to_top_level. */
75 {
76 /* The base for which we're building initializers. */
77 tree binfo;
78 /* The type of the most-derived type. */
79 tree derived;
80 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
81 unless ctor_vtbl_p is true. */
82 tree rtti_binfo;
83 /* The negative-index vtable initializers built up so far. These
84 are in order from least negative index to most negative index. */
86 /* The binfo for the virtual base for which we're building
87 vcall offset initializers. */
88 tree vbase;
89 /* The functions in vbase for which we have already provided vcall
90 offsets. */
92 /* The vtable index of the next vcall or vbase offset. */
93 tree index;
94 /* Nonzero if we are building the initializer for the primary
95 vtable. */
97 /* Nonzero if we are building the initializer for a construction
98 vtable. */
100 /* True when adding vcall offset entries to the vtable. False when
101 merely computing the indices. */
105 /* The type of a function passed to walk_subobject_offsets. */
108 /* The stack itself. This is a dynamically resized array. The
109 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
113 /* The size of the largest empty class seen in this translation unit. */
116 /* An array of all local classes present in this translation unit, in
117 declaration order. */
200 tree *);
210 splay_tree_key k2);
218 /* Variables shared between class.c and call.c. */
228 /* Convert to or from a base subobject. EXPR is an expression of type
229 `A' or `A*', an expression of type `B' or `B*' is returned. To
230 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
231 the B base instance within A. To convert base A to derived B, CODE
232 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
233 In this latter case, A must not be a morally virtual base of B.
234 NONNULL is true if EXPR is known to be non-NULL (this is only
235 needed when EXPR is of pointer type). CV qualifiers are preserved
236 from EXPR. */
238 tree
240 tree expr,
241 tree binfo,
243 tsubst_flags_t complain)
244 {
247 tree probe;
248 tree offset;
249 tree target_type;
251 tree ptr_target_type;
262 {
268 }
276 {
277 /* This can happen when adjust_result_of_qualified_name_lookup can't
278 find a unique base binfo in a call to a member function. We
279 couldn't give the diagnostic then since we might have been calling
280 a static member function, so we do it now. */
282 {
286 }
288 }
295 /* Nothing to do. */
299 {
301 {
303 {
306 "pointer to derived class %qT because the base is "
308 else
312 }
313 else
314 {
320 else
324 }
325 }
327 }
330 {
332 /* This must happen before the call to save_expr. */
334 }
335 else
341 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
342 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
343 expression returned matches the input. */
344 target_type = cp_build_qualified_type
348 /* Do we need to look in the vtable for the real offset? */
351 /* Don't bother with the calculations inside sizeof; they'll ICE if the
352 source type is incomplete and the pointer value doesn't matter. In a
353 template (even in instantiate_non_dependent_expr), we don't have vtables
354 set up properly yet, and the value doesn't matter there either; we're
355 just interested in the result of overload resolution. */
358 {
361 }
363 /* If we're in an NSDMI, we don't have the full constructor context yet
364 that we need for converting to a virtual base, so just build a stub
365 CONVERT_EXPR and expand it later in bot_replace. */
368 {
372 }
374 /* Do we need to check for a null pointer? */
376 {
377 /* If we know the conversion will not actually change the value
378 of EXPR, then we can avoid testing the expression for NULL.
379 We have to avoid generating a COMPONENT_REF for a base class
380 field, because other parts of the compiler know that such
381 expressions are always non-NULL. */
385 }
387 /* Protect against multiple evaluation if necessary. */
391 /* Now that we've saved expr, build the real null test. */
393 {
397 }
399 /* If this is a simple base reference, express it as a COMPONENT_REF. */
401 /* We don't build base fields for empty bases, and they aren't very
402 interesting to the optimizers anyway. */
404 {
413 }
416 {
417 /* Going via virtual base V_BINFO. We need the static offset
418 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
419 V_BINFO. That offset is an entry in D_BINFO's vtable. */
420 tree v_offset;
423 {
424 /* In a base member initializer, we cannot rely on the
425 vtable being set up. We have to indirect via the
426 vtt_parm. */
427 tree t;
433 }
434 else
435 {
438 {
443 }
445 complain),
447 }
455 v_offset);
467 /* Negative fixed_type_p means this is a constructor or destructor;
468 virtual base layout is fixed in in-charge [cd]tors, but not in
469 base [cd]tors. */
473 v_offset,
476 else
478 }
486 {
491 }
492 else
495 indout:
497 {
501 }
503 out:
509 }
511 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
512 Perform a derived-to-base conversion by recursively building up a
513 sequence of COMPONENT_REFs to the appropriate base fields. */
515 static tree
517 {
520 tree field;
523 {
524 tree temp;
528 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
529 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
530 an lvalue in the front end; only _DECLs and _REFs are lvalues
531 in the back end. */
537 }
539 /* Recurse. */
544 /* Is this the base field created by build_base_field? */
548 /* If we're looking for a field in the most-derived class,
549 also check the field offset; we can have two base fields
550 of the same type if one is an indirect virtual base and one
551 is a direct non-virtual base. */
555 {
556 /* We don't use build_class_member_access_expr here, as that
557 has unnecessary checks, and more importantly results in
558 recursive calls to dfs_walk_once. */
566 /* Mark the expression const or volatile, as appropriate.
567 Even though we've dealt with the type above, we still have
568 to mark the expression itself. */
575 }
577 /* Didn't find the base field?!? */
579 }
581 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
582 type is a class type or a pointer to a class type. In the former
583 case, TYPE is also a class type; in the latter it is another
584 pointer type. If CHECK_ACCESS is true, an error message is emitted
585 if TYPE is inaccessible. If OBJECT has pointer type, the value is
586 assumed to be non-NULL. */
588 tree
590 tsubst_flags_t complain)
591 {
592 tree binfo;
593 tree object_type;
596 {
599 }
600 else
609 }
611 /* EXPR is an expression with unqualified class type. BASE is a base
612 binfo of that class type. Returns EXPR, converted to the BASE
613 type. This function assumes that EXPR is the most derived class;
614 therefore virtual bases can be found at their static offsets. */
616 tree
618 {
619 tree expr_type;
623 {
624 /* If this is a non-empty base, use a COMPONENT_REF. */
628 /* We use fold_build2 and fold_convert below to simplify the trees
629 provided to the optimizers. It is not safe to call these functions
630 when processing a template because they do not handle C++-specific
631 trees. */
639 }
642 }
644 \f
645 tree
647 {
651 /* Can happen in case of duplicate base types (c++/59082). */
655 /* First, convert to the requested type. */
660 /* Second, the requested type may not be the owner of its own vptr.
661 If not, convert to the base class that owns it. We cannot use
662 convert_to_base here, because VCONTEXT may appear more than once
663 in the inheritance hierarchy of TYPE, and thus direct conversion
664 between the types may be ambiguous. Following the path back up
665 one step at a time via primary bases avoids the problem. */
669 {
672 }
675 }
677 /* Given an object INSTANCE, return an expression which yields the
678 vtable element corresponding to INDEX. There are many special
679 cases for INSTANCE which we take care of here, mainly to avoid
680 creating extra tree nodes when we don't have to. */
682 static tree
684 {
685 tree aref;
688 /* Try to figure out what a reference refers to, and
689 access its virtual function table directly. */
697 {
702 }
711 }
713 tree
715 {
719 }
721 /* Given a stable object pointer INSTANCE_PTR, return an expression which
722 yields a function pointer corresponding to vtable element INDEX. */
724 tree
726 {
727 tree aref;
730 tf_warning_or_error),
731 idx);
733 /* When using function descriptors, the address of the
734 vtable entry is treated as a function pointer. */
739 /* Remember this as a method reference, for later devirtualization. */
743 }
745 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
746 for the given TYPE. */
748 static tree
750 {
752 }
754 /* DECL is an entity associated with TYPE, like a virtual table or an
755 implicitly generated constructor. Determine whether or not DECL
756 should have external or internal linkage at the object file
757 level. This routine does not deal with COMDAT linkage and other
758 similar complexities; it simply sets TREE_PUBLIC if it possible for
759 entities in other translation units to contain copies of DECL, in
760 the abstract. */
762 void
764 {
767 }
769 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
770 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
771 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
773 static tree
775 {
776 tree decl;
779 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
780 now to avoid confusion in mangle_decl. */
791 /* The vtable has not been defined -- yet. */
795 /* Mark the VAR_DECL node representing the vtable itself as a
796 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
797 is rather important that such things be ignored because any
798 effort to actually generate DWARF for them will run into
799 trouble when/if we encounter code like:
801 #pragma interface
802 struct S { virtual void member (); };
804 because the artificial declaration of the vtable itself (as
805 manufactured by the g++ front end) will say that the vtable is
806 a static member of `S' but only *after* the debug output for
807 the definition of `S' has already been output. This causes
808 grief because the DWARF entry for the definition of the vtable
809 will try to refer back to an earlier *declaration* of the
810 vtable as a static member of `S' and there won't be one. We
811 might be able to arrange to have the "vtable static member"
812 attached to the member list for `S' before the debug info for
813 `S' get written (which would solve the problem) but that would
814 require more intrusive changes to the g++ front end. */
818 }
820 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
821 or even complete. If this does not exist, create it. If COMPLETE is
822 nonzero, then complete the definition of it -- that will render it
823 impossible to actually build the vtable, but is useful to get at those
824 which are known to exist in the runtime. */
826 tree
828 {
829 tree decl;
838 {
841 }
844 }
846 /* Build the primary virtual function table for TYPE. If BINFO is
847 non-NULL, build the vtable starting with the initial approximation
848 that it is the same as the one which is the head of the association
849 list. Returns a nonzero value if a new vtable is actually
850 created. */
852 static int
854 {
855 tree decl;
856 tree virtuals;
861 {
863 /* We have already created a vtable for this base, so there's
864 no need to do it again. */
871 }
872 else
873 {
876 }
879 {
882 }
884 /* Initialize the association list for this type, based
885 on our first approximation. */
890 }
892 /* Give BINFO a new virtual function table which is initialized
893 with a skeleton-copy of its original initialization. The only
894 entry that changes is the `delta' entry, so we can really
895 share a lot of structure.
897 FOR_TYPE is the most derived type which caused this table to
898 be needed.
900 Returns nonzero if we haven't met BINFO before.
902 The order in which vtables are built (by calling this function) for
903 an object must remain the same, otherwise a binary incompatibility
904 can result. */
906 static int
908 {
910 /* We already created a vtable for this base. There's no need to
911 do it again. */
914 /* Remember that we've created a vtable for this BINFO, so that we
915 don't try to do so again. */
918 /* Make fresh virtual list, so we can smash it later. */
921 /* Secondary vtables are laid out as part of the same structure as
922 the primary vtable. */
925 }
927 /* Create a new vtable for BINFO which is the hierarchy dominated by
928 T. Return nonzero if we actually created a new vtable. */
930 static int
932 {
934 /* In this case, it is *type*'s vtable we are modifying. We start
935 with the approximation that its vtable is that of the
936 immediate base class. */
938 else
939 /* This is our very own copy of `basetype' to play with. Later,
940 we will fill in all the virtual functions that override the
941 virtual functions in these base classes which are not defined
942 by the current type. */
944 }
946 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
947 (which is in the hierarchy dominated by T) list FNDECL as its
948 BV_FN. DELTA is the required constant adjustment from the `this'
949 pointer where the vtable entry appears to the `this' required when
950 the function is actually called. */
952 static void
954 tree binfo,
955 tree fndecl,
956 tree delta,
958 {
959 tree v;
965 {
966 /* We need a new vtable for BINFO. */
968 {
969 /* If we really did make a new vtable, we also made a copy
970 of the BINFO_VIRTUALS list. Now, we have to find the
971 corresponding entry in that list. */
976 }
981 }
982 }
984 \f
985 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
986 the USING_DECL naming METHOD. Returns true if the method could be
987 added to the method vec. */
989 bool
991 {
993 tree overload;
999 tree current_fns;
1000 tree fns;
1013 {
1014 /* Make a new method vector. We start with 8 entries. We must
1015 allocate at least two (for constructors and destructors), and
1016 we're going to end up with an assignment operator at some
1017 point as well. */
1019 /* Create slots for constructors and destructors. */
1023 }
1025 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1028 /* Constructors and destructors go in special slots. */
1032 {
1036 {
1042 type);
1043 }
1044 }
1045 else
1046 {
1047 tree m;
1050 /* See if we already have an entry with this name. */
1054 {
1057 {
1062 }
1066 {
1069 }
1074 }
1075 }
1078 /* Check to see if we've already got this method. */
1080 {
1082 tree fn_type;
1083 tree method_type;
1084 tree parms1;
1085 tree parms2;
1090 /* [over.load] Member function declarations with the
1091 same name and the same parameter types cannot be
1092 overloaded if any of them is a static member
1093 function declaration.
1095 [over.load] Member function declarations with the same name and
1096 the same parameter-type-list as well as member function template
1097 declarations with the same name, the same parameter-type-list, and
1098 the same template parameter lists cannot be overloaded if any of
1099 them, but not all, have a ref-qualifier.
1101 [namespace.udecl] When a using-declaration brings names
1102 from a base class into a derived class scope, member
1103 functions in the derived class override and/or hide member
1104 functions with the same name and parameter types in a base
1105 class (rather than conflicting). */
1111 /* Compare the quals on the 'this' parm. Don't compare
1112 the whole types, as used functions are treated as
1113 coming from the using class in overload resolution. */
1116 /* Either both or neither need to be ref-qualified for
1117 differing quals to allow overloading. */
1124 /* For templates, the return type and template parameters
1125 must be identical. */
1142 {
1143 /* For function versions, their parms and types match
1144 but they are not duplicates. Record function versions
1145 as and when they are found. extern "C" functions are
1146 not treated as versions. */
1152 {
1153 /* Mark functions as versions if necessary. Modify the mangled
1154 decl name if necessary. */
1156 {
1160 }
1162 {
1166 }
1169 }
1171 {
1173 {
1180 }
1181 /* Otherwise defer to the other function. */
1183 }
1185 {
1187 /* Defer to the local function. */
1189 }
1190 else
1191 {
1194 }
1196 /* We don't call duplicate_decls here to merge the
1197 declarations because that will confuse things if the
1198 methods have inline definitions. In particular, we
1199 will crash while processing the definitions. */
1201 }
1202 }
1204 /* A class should never have more than one destructor. */
1208 /* Add the new binding. */
1210 {
1213 }
1214 else
1223 {
1226 /* We only expect to add few methods in the COMPLETE_P case, so
1227 just make room for one more method in that case. */
1230 else
1236 else
1238 }
1239 else
1240 /* Replace the current slot. */
1243 }
1245 /* Subroutines of finish_struct. */
1247 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1248 legit, otherwise return 0. */
1250 static int
1252 {
1253 tree elem;
1262 {
1264 {
1268 else
1271 }
1272 else
1273 {
1274 /* They're changing the access to the same thing they changed
1275 it to before. That's OK. */
1276 ;
1277 }
1278 }
1279 else
1280 {
1282 tf_warning_or_error);
1285 }
1287 }
1289 /* Process the USING_DECL, which is a member of T. */
1291 static void
1293 {
1296 tree access
1301 tree old_value;
1306 tf_warning_or_error);
1308 {
1314 else
1316 }
1324 ;
1326 {
1328 /* It's OK to use functions from a base when there are functions with
1330 else
1331 {
1336 }
1337 }
1339 {
1343 }
1345 /* Make type T see field decl FDECL with access ACCESS. */
1348 {
1351 }
1352 else
1354 }
1355 \f
1356 /* Data structure for find_abi_tags_r, below. */
1358 struct abi_tag_data
1359 {
1363 };
1365 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1366 in the context of P. TAG can be either an identifier (the DECL_NAME of
1367 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1369 static void
1371 {
1373 {
1375 {
1376 /* We're collecting tags from template arguments or from
1377 the type of a variable or function return type. */
1380 /* Don't inherit this tag multiple times. */
1384 {
1385 /* Tags inherited from type template arguments are only used
1386 to avoid warnings. */
1389 }
1390 /* For functions and variables we want to warn, too. */
1391 }
1393 /* Otherwise we're diagnosing missing tags. */
1395 {
1400 }
1402 {
1406 }
1408 {
1413 }
1414 else
1415 {
1419 {
1423 }
1424 }
1425 }
1426 }
1428 /* Find all the ABI tags in the attribute list ATTR and either call
1429 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1431 static void
1433 {
1440 {
1445 else
1447 }
1448 }
1450 /* Find all the ABI tags on T and its enclosing scopes and either call
1451 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1453 static void
1455 {
1457 {
1458 tree attr;
1460 {
1463 }
1464 else
1465 {
1468 }
1470 }
1471 }
1473 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1474 types with ABI tags, add the corresponding identifiers to the VEC in
1475 *DATA and set IDENTIFIER_MARKED. */
1477 static tree
1479 {
1483 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1484 anyway, but let's make sure of it. */
1492 }
1494 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1495 IDENTIFIER_MARKED on its ABI tags. */
1497 static tree
1499 {
1503 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1504 anyway, but let's make sure of it. */
1512 }
1514 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1515 scopes. */
1517 static void
1519 {
1522 {
1525 {
1526 /* Template arguments are part of the signature. */
1529 {
1532 }
1533 }
1535 /* A function's parameter types are part of the signature, so
1536 we don't need to inherit any tags that are also in them. */
1541 }
1542 }
1544 /* Check that T has all the ABI tags that subobject SUBOB has, or
1545 warn if not. If T is a (variable or function) declaration, also
1546 add any missing tags. */
1548 static void
1550 {
1558 /* No need to worry about things local to this TU. */
1571 {
1575 else
1579 }
1582 }
1584 /* Check that DECL has all the ABI tags that are used in parts of its type
1585 that are not reflected in its mangled name. */
1587 void
1589 {
1595 }
1597 void
1599 {
1609 {
1612 {
1616 }
1617 }
1619 // If we found some tags on our template arguments, add them to our
1620 // abi_tag attribute.
1622 {
1626 else
1630 }
1633 }
1635 /* Return true, iff class T has a non-virtual destructor that is
1636 accessible from outside the class heirarchy (i.e. is public, or
1637 there's a suitable friend. */
1639 static bool
1641 {
1644 /* An implicitly declared destructor is always public. And,
1645 if it were virtual, we would have created it by now. */
1660 }
1662 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1663 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1664 properties of the bases. */
1666 static void
1670 {
1674 tree base_binfo;
1675 tree binfo;
1685 {
1694 /* If any base class is non-literal, so is the derived class. */
1698 /* If the base class doesn't have copy constructors or
1699 assignment operators that take const references, then the
1700 derived class cannot have such a member automatically
1701 generated. */
1710 /* A virtual base does not effect nearly emptiness. */
1711 ;
1713 {
1715 /* And if there is more than one nearly empty base, then the
1716 derived class is not nearly empty either. */
1718 else
1719 /* Remember we've seen one. */
1721 }
1723 /* If the base class is not empty or nearly empty, then this
1724 class cannot be nearly empty. */
1727 /* A lot of properties from the bases also apply to the derived
1728 class. */
1745 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1748 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1752 /* A standard-layout class is a class that:
1753 ...
1754 * has no non-standard-layout base classes, */
1757 {
1758 tree basefield;
1759 /* ...has no base classes of the same type as the first non-static
1760 data member... */
1762 && (same_type_ignoring_top_level_qualifiers_p
1765 else
1766 /* ...either has no non-static data members in the most-derived
1767 class and at most one base class with non-static data
1768 members, or has no base classes with non-static data
1769 members */
1773 {
1776 else
1779 }
1780 }
1782 /* Don't bother collecting tm attributes if transactional memory
1783 support is not enabled. */
1785 {
1789 }
1792 }
1794 /* If one of the base classes had TM attributes, and the current class
1795 doesn't define its own, then the current class inherits one. */
1797 {
1800 }
1801 }
1803 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1804 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1805 that have had a nearly-empty virtual primary base stolen by some
1806 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1807 T. */
1809 static void
1811 {
1815 tree base_binfo;
1817 /* Determine the primary bases of our bases. */
1820 {
1823 /* See if we're the non-virtual primary of our inheritance
1824 chain. */
1826 {
1833 /* We are the primary binfo. */
1835 }
1836 /* Determine if we have a virtual primary base, and mark it so.
1837 */
1839 {
1843 /* Someone already claimed this base. */
1845 else
1846 {
1847 tree delta;
1852 /* A virtual binfo might have been copied from within
1853 another hierarchy. As we're about to use it as a
1854 primary base, make sure the offsets match. */
1862 }
1863 }
1864 }
1866 /* First look for a dynamic direct non-virtual base. */
1868 {
1872 {
1875 }
1876 }
1878 /* A "nearly-empty" virtual base class can be the primary base
1879 class, if no non-virtual polymorphic base can be found. Look for
1880 a nearly-empty virtual dynamic base that is not already a primary
1881 base of something in the hierarchy. If there is no such base,
1882 just pick the first nearly-empty virtual base. */
1888 {
1890 {
1891 /* Found one that is not primary. */
1894 }
1896 /* Remember the first candidate. */
1898 }
1900 found:
1901 /* If we've got a primary base, use it. */
1903 {
1908 /* We are stealing a primary base. */
1912 {
1913 tree delta;
1916 /* A virtual binfo might have been copied from within
1917 another hierarchy. As we're about to use it as a primary
1918 base, make sure the offsets match. */
1923 }
1930 }
1931 }
1933 /* Update the variant types of T. */
1935 void
1937 {
1938 tree variants;
1944 variants;
1946 {
1947 /* These fields are in the _TYPE part of the node, not in
1948 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1958 /* Copy whatever these are holding today. */
1961 }
1962 }
1964 /* Early variant fixups: we apply attributes at the beginning of the class
1965 definition, and we need to fix up any variants that have already been
1966 made via elaborated-type-specifier so that check_qualified_type works. */
1968 void
1970 {
1971 tree variants;
1981 variants;
1983 {
1984 /* These are the two fields that check_qualified_type looks at and
1985 are affected by attributes. */
1990 else
1993 }
1994 }
1995 \f
1996 /* Set memoizing fields and bits of T (and its variants) for later
1997 use. */
1999 static void
2001 {
2002 /* Fix up variants (if any). */
2006 /* For a class w/o baseclasses, 'finish_struct' has set
2007 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2008 Similarly for a class whose base classes do not have vtables.
2009 When neither of these is true, we might have removed abstract
2010 virtuals (by providing a definition), added some (by declaring
2011 new ones), or redeclared ones from a base class. We need to
2012 recalculate what's really an abstract virtual at this point (by
2013 looking in the vtables). */
2016 /* If this type has a copy constructor or a destructor, force its
2017 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2018 nonzero. This will cause it to be passed by invisible reference
2019 and prevent it from being returned in a register. */
2022 {
2023 tree variants;
2026 {
2029 }
2030 }
2031 }
2033 /* Issue warnings about T having private constructors, but no friends,
2034 and so forth.
2036 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2037 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2038 non-private static member functions. */
2040 static void
2042 {
2045 tree fn;
2048 /* If the class has friends, those entities might create and
2049 access instances, so we should not warn. */
2052 /* We will have warned when the template was declared; there's
2053 no need to warn on every instantiation. */
2055 /* There's no reason to even consider warning about this
2056 class. */
2059 /* We only issue one warning, if more than one applies, because
2060 otherwise, on code like:
2062 class A {
2063 // Oops - forgot `public:'
2064 A();
2065 A(const A&);
2066 ~A();
2067 };
2069 we warn several times about essentially the same problem. */
2071 /* Check to see if all (non-constructor, non-destructor) member
2072 functions are private. (Since there are no friends or
2073 non-private statics, we can't ever call any of the private member
2074 functions.) */
2076 /* We're not interested in compiler-generated methods; they don't
2077 provide any way to call private members. */
2079 {
2081 {
2083 /* A non-private static member function is just like a
2084 friend; it can create and invoke private member
2085 functions, and be accessed without a class
2086 instance. */
2090 /* Keep searching for a static member function. */
2091 }
2094 }
2097 {
2098 /* There are no non-private methods, and there's at least one
2099 private member function that isn't a constructor or
2100 destructor. (If all the private members are
2101 constructors/destructors we want to use the code below that
2102 issues error messages specifically referring to
2103 constructors/destructors.) */
2109 {
2112 }
2114 {
2118 }
2119 }
2121 /* Even if some of the member functions are non-private, the class
2122 won't be useful for much if all the constructors or destructors
2123 are private: such an object can never be created or destroyed. */
2126 {
2129 t);
2131 }
2133 /* Warn about classes that have private constructors and no friends. */
2135 /* Implicitly generated constructors are always public. */
2138 {
2141 /* If a non-template class does not define a copy
2142 constructor, one is defined for it, enabling it to avoid
2143 this warning. For a template class, this does not
2144 happen, and so we would normally get a warning on:
2146 template <class T> class C { private: C(); };
2148 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2149 complete non-template or fully instantiated classes have this
2150 flag set. */
2153 else
2155 {
2157 /* Ideally, we wouldn't count copy constructors (or, in
2158 fact, any constructor that takes an argument of the
2159 class type as a parameter) because such things cannot
2160 be used to construct an instance of the class unless
2161 you already have one. But, for now at least, we're
2162 more generous. */
2164 {
2167 }
2168 }
2171 {
2174 t);
2176 }
2177 }
2178 }
2181 gt_pointer_operator new_value;
2185 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2187 static int
2189 {
2202 }
2204 /* This routine compares two fields like method_name_cmp but using the
2205 pointer operator in resort_field_decl_data. */
2207 static int
2209 {
2218 {
2225 }
2227 }
2229 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2231 void
2234 gt_pointer_operator new_value,
2236 {
2240 tree fn;
2242 /* The type conversion ops have to live at the front of the vec, so we
2243 can't sort them. */
2251 {
2255 resort_method_name_cmp);
2256 }
2257 }
2259 /* Warn about duplicate methods in fn_fields.
2261 Sort methods that are not special (i.e., constructors, destructors,
2262 and type conversion operators) so that we can find them faster in
2263 search. */
2265 static void
2267 {
2268 tree fn_fields;
2278 /* Clear DECL_IN_AGGR_P for all functions. */
2283 /* Issue warnings about private constructors and such. If there are
2284 no methods, then some public defaults are generated. */
2287 /* The type conversion ops have to live at the front of the vec, so we
2288 can't sort them. */
2297 }
2299 /* Make BINFO's vtable have N entries, including RTTI entries,
2300 vbase and vcall offsets, etc. Set its type and call the back end
2301 to lay it out. */
2303 static void
2305 {
2306 tree atype;
2307 tree vtable;
2312 /* We may have to grow the vtable. */
2315 {
2319 }
2320 }
2322 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2323 have the same signature. */
2325 int
2327 {
2328 /* One destructor overrides another if they are the same kind of
2329 destructor. */
2333 /* But a non-destructor never overrides a destructor, nor vice
2334 versa, nor do different kinds of destructors override
2335 one-another. For example, a complete object destructor does not
2336 override a deleting destructor. */
2345 {
2353 }
2355 }
2357 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2358 subobject. */
2360 static bool
2362 {
2363 tree probe;
2366 {
2370 /* If we meet a virtual base, we can't follow the inheritance
2371 any more. See if the complete type of DERIVED contains
2372 such a virtual base. */
2375 }
2377 }
2380 /* The function for which we are trying to find a final overrider. */
2381 tree fn;
2382 /* The base class in which the function was declared. */
2383 tree declaring_base;
2384 /* The candidate overriders. */
2385 tree candidates;
2386 /* Path to most derived. */
2390 /* Add the overrider along the current path to FFOD->CANDIDATES.
2391 Returns true if an overrider was found; false otherwise. */
2393 static bool
2397 {
2398 tree method;
2400 /* If BINFO is not the most derived type, try a more derived class.
2401 A definition there will overrider a definition here. */
2403 {
2404 depth--;
2408 }
2412 {
2415 /* Remove any candidates overridden by this new function. */
2417 {
2418 /* If *CANDIDATE overrides METHOD, then METHOD
2419 cannot override anything else on the list. */
2422 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2425 else
2427 }
2429 /* Add the new function. */
2432 }
2435 }
2437 /* Called from find_final_overrider via dfs_walk. */
2439 static tree
2441 {
2449 }
2451 static tree
2453 {
2458 }
2460 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2461 FN and whose TREE_VALUE is the binfo for the base where the
2462 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2463 DERIVED) is the base object in which FN is declared. */
2465 static tree
2467 {
2468 find_final_overrider_data ffod;
2470 /* Getting this right is a little tricky. This is valid:
2472 struct S { virtual void f (); };
2473 struct T { virtual void f (); };
2474 struct U : public S, public T { };
2476 even though calling `f' in `U' is ambiguous. But,
2478 struct R { virtual void f(); };
2479 struct S : virtual public R { virtual void f (); };
2480 struct T : virtual public R { virtual void f (); };
2481 struct U : public S, public T { };
2483 is not -- there's no way to decide whether to put `S::f' or
2484 `T::f' in the vtable for `R'.
2486 The solution is to look at all paths to BINFO. If we find
2487 different overriders along any two, then there is a problem. */
2491 /* Determine the depth of the hierarchy. */
2502 /* If there was no winner, issue an error message. */
2507 }
2509 /* Return the index of the vcall offset for FN when TYPE is used as a
2510 virtual base. */
2512 static tree
2514 {
2516 tree_pair_p p;
2524 /* There should always be an appropriate index. */
2526 }
2528 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2529 dominated by T. FN is the old function; VIRTUALS points to the
2530 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2531 of that entry in the list. */
2533 static void
2536 {
2537 tree b;
2538 tree overrider;
2539 tree delta;
2540 tree virtual_base;
2541 tree first_defn;
2547 /* Find the nearest primary base (possibly binfo itself) which defines
2548 this function; this is the class the caller will convert to when
2549 calling FN through BINFO. */
2551 {
2556 /* The nearest definition is from a lost primary. */
2559 }
2562 /* Find the final overrider. */
2565 {
2568 }
2571 /* Check for adjusting covariant return types. */
2579 /* If the overrider is invalid, don't even try. */
2581 {
2582 /* If FN is a covariant thunk, we must figure out the adjustment
2583 to the final base FN was converting to. As OVERRIDER_TARGET might
2584 also be converting to the return type of FN, we have to
2585 combine the two conversions here. */
2592 {
2596 }
2597 else
2601 /* Find the equivalent binfo within the return type of the
2602 overriding function. We will want the vbase offset from
2603 there. */
2605 over_return);
2608 {
2609 /* There was no existing virtual thunk (which takes
2610 precedence). So find the binfo of the base function's
2611 return type within the overriding function's return type.
2612 We cannot call lookup base here, because we're inside a
2613 dfs_walk, and will therefore clobber the BINFO_MARKED
2614 flags. Fortunately we know the covariancy is valid (it
2615 has already been checked), so we can just iterate along
2616 the binfos, which have been chained in inheritance graph
2617 order. Of course it is lame that we have to repeat the
2618 search here anyway -- we should really be caching pieces
2619 of the vtable and avoiding this repeated work. */
2622 /* Find the base binfo within the overriding function's
2623 return type. We will always find a thunk_binfo, except
2624 when the covariancy is invalid (which we will have
2625 already diagnosed). */
2628 thunk_binfo;
2634 /* See if virtual inheritance is involved. */
2636 virtual_offset;
2643 {
2647 {
2648 /* We convert via virtual base. Adjust the fixed
2649 offset to be from there. */
2650 offset =
2654 }
2656 /* There was an existing fixed offset, this must be
2657 from the base just converted to, and the base the
2658 FN was thunking to. */
2660 else
2662 }
2663 }
2666 /* Replace the overriding function with a covariant thunk. We
2667 will emit the overriding function in its own slot as
2668 well. */
2671 }
2672 else
2676 /* If we need a covariant thunk, then we may need to adjust first_defn.
2677 The ABI specifies that the thunks emitted with a function are
2678 determined by which bases the function overrides, so we need to be
2679 sure that we're using a thunk for some overridden base; even if we
2680 know that the necessary this adjustment is zero, there may not be an
2681 appropriate zero-this-adjusment thunk for us to use since thunks for
2682 overriding virtual bases always use the vcall offset.
2684 Furthermore, just choosing any base that overrides this function isn't
2685 quite right, as this slot won't be used for calls through a type that
2686 puts a covariant thunk here. Calling the function through such a type
2687 will use a different slot, and that slot is the one that determines
2688 the thunk emitted for that base.
2690 So, keep looking until we find the base that we're really overriding
2691 in this slot: the nearest primary base that doesn't use a covariant
2692 thunk in this slot. */
2694 {
2696 /* We already know that the overrider needs a covariant thunk. */
2699 {
2706 }
2708 }
2710 /* Assume that we will produce a thunk that convert all the way to
2711 the final overrider, and not to an intermediate virtual base. */
2714 /* See if we can convert to an intermediate virtual base first, and then
2715 use the vcall offset located there to finish the conversion. */
2717 {
2718 /* If we find the final overrider, then we can stop
2719 walking. */
2724 /* If we find a virtual base, and we haven't yet found the
2725 overrider, then there is a virtual base between the
2726 declaring base (first_defn) and the final overrider. */
2728 {
2731 }
2732 }
2734 /* Compute the constant adjustment to the `this' pointer. The
2735 `this' pointer, when this function is called, will point at BINFO
2736 (or one of its primary bases, which are at the same offset). */
2738 /* The `this' pointer needs to be adjusted from the declaration to
2739 the nearest virtual base. */
2744 /* If the nearest definition is in a lost primary, we don't need an
2745 entry in our vtable. Except possibly in a constructor vtable,
2746 if we happen to get our primary back. In that case, the offset
2747 will be zero, as it will be a primary base. */
2749 else
2750 /* The `this' pointer needs to be adjusted from pointing to
2751 BINFO to pointing at the base where the final overrider
2752 appears. */
2763 else
2767 }
2769 /* Called from modify_all_vtables via dfs_walk. */
2771 static tree
2773 {
2775 tree virtuals;
2776 tree old_virtuals;
2780 /* A base without a vtable needs no modification, and its bases
2781 are uninteresting. */
2786 /* Don't do the primary vtable, if it's new. */
2790 /* There's no need to modify the vtable for a non-virtual primary
2791 base; we're not going to use that vtable anyhow. We do still
2792 need to do this for virtual primary bases, as they could become
2793 non-primary in a construction vtable. */
2798 /* Now, go through each of the virtual functions in the virtual
2799 function table for BINFO. Find the final overrider, and update
2800 the BINFO_VIRTUALS list appropriately. */
2803 virtuals;
2807 binfo,
2812 }
2814 /* Update all of the primary and secondary vtables for T. Create new
2815 vtables as required, and initialize their RTTI information. Each
2816 of the functions in VIRTUALS is declared in T and may override a
2817 virtual function from a base class; find and modify the appropriate
2818 entries to point to the overriding functions. Returns a list, in
2819 declaration order, of the virtual functions that are declared in T,
2820 but do not appear in the primary base class vtable, and which
2821 should therefore be appended to the end of the vtable for T. */
2823 static tree
2825 {
2829 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2833 /* Update all of the vtables. */
2836 /* Add virtual functions not already in our primary vtable. These
2837 will be both those introduced by this class, and those overridden
2838 from secondary bases. It does not include virtuals merely
2839 inherited from secondary bases. */
2841 {
2846 {
2847 /* We don't need to adjust the `this' pointer when
2848 calling this function. */
2852 /* This is a function not already in our vtable. Keep it. */
2854 }
2855 else
2856 /* We've already got an entry for this function. Skip it. */
2858 }
2861 }
2863 /* Get the base virtual function declarations in T that have the
2864 indicated NAME. */
2866 static void
2868 {
2869 tree methods;
2873 /* Find virtual functions in T with the indicated NAME. */
2878 methods;
2880 {
2885 {
2888 }
2889 }
2895 {
2898 }
2899 }
2901 /* If this declaration supersedes the declaration of
2902 a method declared virtual in the base class, then
2903 mark this field as being virtual as well. */
2905 void
2907 {
2910 /* In [temp.mem] we have:
2912 A specialization of a member function template does not
2913 override a virtual function from a base class. */
2920 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2921 the error_mark_node so that we know it is an overriding
2922 function. */
2923 {
2930 }
2933 {
2939 }
2944 }
2946 /* Warn about hidden virtual functions that are not overridden in t.
2947 We know that constructors and destructors don't apply. */
2949 static void
2951 {
2953 tree fns;
2956 /* We go through each separately named virtual function. */
2960 {
2961 tree fn;
2962 tree name;
2963 tree fndecl;
2964 tree base_binfo;
2965 tree binfo;
2968 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2969 have the same name. Figure out what name that is. */
2971 /* There are no possibly hidden functions yet. */
2973 /* Iterate through all of the base classes looking for possibly
2974 hidden functions. */
2977 {
2980 }
2982 /* If there are no functions to hide, continue. */
2986 /* Remove any overridden functions. */
2988 {
2992 {
2993 /* If the method from the base class has the same
2994 signature as the method from the derived class, it
2995 has been overridden. */
3000 }
3001 }
3003 /* Now give a warning for all base functions without overriders,
3004 as they are hidden. */
3006 tree base_fndecl;
3009 {
3010 /* Here we know it is a hider, and no overrider exists. */
3013 }
3014 }
3015 }
3017 /* Recursive helper for finish_struct_anon. */
3019 static void
3021 {
3025 {
3026 /* We're generally only interested in entities the user
3027 declared, but we also find nested classes by noticing
3028 the TYPE_DECL that we create implicitly. You're
3029 allowed to put one anonymous union inside another,
3030 though, so we explicitly tolerate that. We use
3031 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
3032 we also allow unnamed types used for defining fields. */
3039 {
3040 /* We already complained about static data members in
3041 finish_static_data_member_decl. */
3043 {
3046 "%q+#D invalid; an anonymous union can "
3048 else
3050 "%q+#D invalid; an anonymous struct can "
3052 }
3054 }
3057 {
3059 {
3063 else
3066 }
3068 {
3072 else
3075 }
3076 }
3081 /* Recurse into the anonymous aggregates to handle correctly
3082 access control (c++/24926):
3084 class A {
3085 union {
3086 union {
3087 int i;
3088 };
3089 };
3090 };
3092 int j=A().i; */
3096 }
3097 }
3099 /* Check for things that are invalid. There are probably plenty of other
3100 things we should check for also. */
3102 static void
3104 {
3106 {
3115 }
3116 }
3118 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3119 will be used later during class template instantiation.
3120 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3121 a non-static member data (FIELD_DECL), a member function
3122 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3123 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3124 When FRIEND_P is nonzero, T is either a friend class
3125 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3126 (FUNCTION_DECL, TEMPLATE_DECL). */
3128 void
3130 {
3131 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3136 }
3138 /* This function is called from declare_virt_assop_and_dtor via
3139 dfs_walk_all.
3141 DATA is a type that direcly or indirectly inherits the base
3142 represented by BINFO. If BINFO contains a virtual assignment [copy
3143 assignment or move assigment] operator or a virtual constructor,
3144 declare that function in DATA if it hasn't been already declared. */
3146 static tree
3148 {
3156 /* A base without a vtable needs no modification, and its bases
3157 are uninteresting. */
3161 /* If this is a primary base, then we have already looked at the
3162 virtual functions of its vtable. */
3166 {
3170 {
3175 }
3179 }
3182 }
3184 /* If the class type T has a direct or indirect base that contains a
3185 virtual assignment operator or a virtual destructor, declare that
3186 function in T if it hasn't been already declared. */
3188 static void
3190 {
3198 dfs_declare_virt_assop_and_dtor,
3200 }
3202 /* Declare the inheriting constructor for class T inherited from base
3203 constructor CTOR with the parameter array PARMS of size NPARMS. */
3205 static void
3207 {
3208 /* We don't declare an inheriting ctor that would be a default,
3209 copy or move ctor for derived or base. */
3214 {
3218 }
3227 {
3230 }
3231 }
3233 /* Declare all the inheriting constructors for class T inherited from base
3234 constructor CTOR. */
3236 static void
3238 {
3244 {
3248 }
3251 {
3255 }
3256 }
3258 /* Create default constructors, assignment operators, and so forth for
3259 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3260 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3261 the class cannot have a default constructor, copy constructor
3262 taking a const reference argument, or an assignment operator taking
3263 a const reference, respectively. */
3265 static void
3269 {
3277 /* Destructor. */
3279 {
3280 /* In general, we create destructors lazily. */
3285 /* But if this is a Java class, any non-trivial destructor is
3286 invalid, even if compiler-generated. Therefore, if the
3287 destructor is non-trivial we create it now. */
3289 }
3291 /* [class.ctor]
3293 If there is no user-declared constructor for a class, a default
3294 constructor is implicitly declared. */
3296 {
3301 /* This might force the declaration. */
3303 }
3305 /* [class.ctor]
3307 If a class definition does not explicitly declare a copy
3308 constructor, one is declared implicitly. */
3310 {
3316 }
3318 /* If there is no assignment operator, one will be created if and
3319 when it is needed. For now, just record whether or not the type
3320 of the parameter to the assignment operator will be a const or
3321 non-const reference. */
3323 {
3329 }
3331 /* We can't be lazy about declaring functions that might override
3332 a virtual function from a base class. */
3336 {
3340 {
3341 /* declare, then remove the decl */
3350 }
3351 else
3353 }
3354 }
3356 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3357 count the number of fields in TYPE, including anonymous union
3358 members. */
3360 static int
3362 {
3363 tree x;
3366 {
3369 else
3371 }
3373 }
3375 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3376 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3377 elts, starting at offset IDX. */
3379 static int
3381 {
3382 tree x;
3384 {
3387 else
3389 }
3391 }
3393 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3394 starting at offset IDX. */
3396 static int
3400 {
3401 tree values;
3405 }
3407 /* FIELD is a bit-field. We are finishing the processing for its
3408 enclosing type. Issue any appropriate messages and set appropriate
3409 flags. Returns false if an error has been diagnosed. */
3411 static bool
3413 {
3415 tree w;
3417 /* Extract the declared width of the bitfield, which has been
3418 temporarily stashed in DECL_INITIAL. */
3421 /* Remove the bit-field width indicator so that the rest of the
3422 compiler does not treat that value as an initializer. */
3425 /* Detect invalid bit-field type. */
3427 {
3430 }
3431 else
3432 {
3434 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3437 /* detect invalid field size. */
3443 {
3446 }
3448 {
3451 }
3453 {
3456 }
3468 }
3471 {
3475 }
3476 else
3477 {
3478 /* Non-bit-fields are aligned for their type. */
3482 }
3483 }
3485 /* FIELD is a non bit-field. We are finishing the processing for its
3486 enclosing type T. Issue any appropriate messages and set appropriate
3487 flags. */
3489 static void
3491 tree t,
3495 {
3498 /* In C++98 an anonymous union cannot contain any fields which would change
3499 the settings of CANT_HAVE_CONST_CTOR and friends. */
3501 ;
3502 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3503 structs. So, we recurse through their fields here. */
3505 {
3506 tree fields;
3512 }
3513 /* Check members with class type for constructors, destructors,
3514 etc. */
3516 {
3517 /* Never let anything with uninheritable virtuals
3518 make it through without complaint. */
3522 {
3527 field);
3532 field);
3534 {
3538 }
3539 }
3540 else
3541 {
3554 }
3563 }
3568 {
3569 /* `build_class_init_list' does not recognize
3570 non-FIELD_DECLs. */
3574 }
3575 }
3577 /* Check the data members (both static and non-static), class-scoped
3578 typedefs, etc., appearing in the declaration of T. Issue
3579 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3580 declaration order) of access declarations; each TREE_VALUE in this
3581 list is a USING_DECL.
3583 In addition, set the following flags:
3585 EMPTY_P
3586 The class is empty, i.e., contains no non-static data members.
3588 CANT_HAVE_CONST_CTOR_P
3589 This class cannot have an implicitly generated copy constructor
3590 taking a const reference.
3592 CANT_HAVE_CONST_ASN_REF
3593 This class cannot have an implicitly generated assignment
3594 operator taking a const reference.
3596 All of these flags should be initialized before calling this
3597 function.
3599 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3600 fields can be added by adding to this chain. */
3602 static void
3606 {
3614 /* Assume there are no access declarations. */
3616 /* Assume this class has no pointer members. */
3618 /* Assume none of the members of this class have default
3619 initializations. */
3623 {
3631 {
3632 /* Save the access declarations for our caller. */
3635 }
3641 /* If we've gotten this far, it's a data member, possibly static,
3642 or an enumerator. */
3646 /* When this goes into scope, it will be a non-local reference. */
3651 {
3652 /* [class.union] (C++98)
3654 If a union contains a static data member, or a member of
3655 reference type, the program is ill-formed.
3657 In C++11 this limitation doesn't exist anymore. */
3659 {
3663 }
3665 {
3669 }
3670 }
3672 /* Perform error checking that did not get done in
3673 grokdeclarator. */
3675 {
3679 }
3681 {
3685 }
3693 /* Now it can only be a FIELD_DECL. */
3698 /* If at least one non-static data member is non-literal, the whole
3699 class becomes non-literal. Per Core/1453, volatile non-static
3700 data members and base classes are also not allowed.
3701 Note: if the type is incomplete we will complain later on. */
3706 /* A standard-layout class is a class that:
3707 ...
3708 has the same access control (Clause 11) for all non-static data members,
3709 ... */
3716 /* If this is of reference type, check if it needs an init. */
3718 {
3724 {
3725 /* ARM $12.6.2: [A member initializer list] (or, for an
3726 aggregate, initialization by a brace-enclosed list) is the
3727 only way to initialize nonstatic const and reference
3728 members. */
3731 }
3732 }
3737 {
3739 {
3740 warning
3743 x);
3745 }
3749 }
3752 /* We don't treat zero-width bitfields as making a class
3753 non-empty. */
3754 ;
3755 else
3756 {
3757 /* The class is non-empty. */
3759 /* The class is not even nearly empty. */
3761 /* If one of the data members contains an empty class,
3762 so does T. */
3766 }
3768 /* This is used by -Weffc++ (see below). Warn only for pointers
3769 to members which might hold dynamic memory. So do not warn
3770 for pointers to functions or pointers to members. */
3776 {
3781 }
3787 {
3789 {
3793 }
3795 {
3799 }
3800 }
3803 /* DR 148 now allows pointers to members (which are POD themselves),
3804 to be allowed in POD structs. */
3813 /* We set DECL_C_BIT_FIELD in grokbitfield.
3814 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3817 cant_have_const_ctor_p,
3818 no_const_asn_ref_p,
3821 /* Now that we've removed bit-field widths from DECL_INITIAL,
3822 anything left in DECL_INITIAL is an NSDMI that makes the class
3823 non-aggregate in C++11. */
3827 /* If any field is const, the structure type is pseudo-const. */
3829 {
3834 {
3835 /* ARM $12.6.2: [A member initializer list] (or, for an
3836 aggregate, initialization by a brace-enclosed list) is the
3837 only way to initialize nonstatic const and reference
3838 members. */
3841 }
3842 }
3843 /* A field that is pseudo-const makes the structure likewise. */
3845 {
3850 }
3852 /* Core issue 80: A nonstatic data member is required to have a
3853 different name from the class iff the class has a
3854 user-declared constructor. */
3858 }
3860 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3861 it should also define a copy constructor and an assignment operator to
3862 implement the correct copy semantic (deep vs shallow, etc.). As it is
3863 not feasible to check whether the constructors do allocate dynamic memory
3864 and store it within members, we approximate the warning like this:
3866 -- Warn only if there are members which are pointers
3867 -- Warn only if there is a non-trivial constructor (otherwise,
3868 there cannot be memory allocated).
3869 -- Warn only if there is a non-trivial destructor. We assume that the
3870 user at least implemented the cleanup correctly, and a destructor
3871 is needed to free dynamic memory.
3873 This seems enough for practical purposes. */
3875 && has_pointers
3879 {
3883 {
3888 }
3892 }
3894 /* Non-static data member initializers make the default constructor
3895 non-trivial. */
3897 {
3900 }
3902 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3906 /* Check anonymous struct/anonymous union fields. */
3909 /* We've built up the list of access declarations in reverse order.
3910 Fix that now. */
3912 }
3914 /* If TYPE is an empty class type, records its OFFSET in the table of
3915 OFFSETS. */
3917 static int
3919 {
3920 splay_tree_node n;
3925 /* Record the location of this empty object in OFFSETS. */
3933 type,
3937 }
3939 /* Returns nonzero if TYPE is an empty class type and there is
3940 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3942 static int
3944 {
3945 splay_tree_node n;
3946 tree t;
3951 /* Record the location of this empty object in OFFSETS. */
3961 }
3963 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3964 F for every subobject, passing it the type, offset, and table of
3965 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3966 be traversed.
3968 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3969 than MAX_OFFSET will not be walked.
3971 If F returns a nonzero value, the traversal ceases, and that value
3972 is returned. Otherwise, returns zero. */
3974 static int
3976 subobject_offset_fn f,
3977 tree offset,
3978 splay_tree offsets,
3979 tree max_offset,
3981 {
3985 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3986 stop. */
3994 {
3997 }
4000 {
4001 tree field;
4002 tree binfo;
4005 /* Avoid recursing into objects that are not interesting. */
4009 /* Record the location of TYPE. */
4014 /* Iterate through the direct base classes of TYPE. */
4018 {
4019 tree binfo_offset;
4024 tree orig_binfo;
4025 /* We cannot rely on BINFO_OFFSET being set for the base
4026 class yet, but the offsets for direct non-virtual
4027 bases can be calculated by going back to the TYPE. */
4030 offset,
4034 f,
4035 binfo_offset,
4036 offsets,
4037 max_offset,
4041 }
4044 {
4048 /* Iterate through the virtual base classes of TYPE. In G++
4049 3.2, we included virtual bases in the direct base class
4050 loop above, which results in incorrect results; the
4051 correct offsets for virtual bases are only known when
4052 working with the most derived type. */
4056 {
4058 f,
4060 offset,
4062 offsets,
4063 max_offset,
4067 }
4068 else
4069 {
4070 /* We still have to walk the primary base, if it is
4071 virtual. (If it is non-virtual, then it was walked
4072 above.) */
4078 {
4079 r = (walk_subobject_offsets
4084 }
4085 }
4086 }
4088 /* Iterate through the fields of TYPE. */
4093 {
4094 tree field_offset;
4099 f,
4101 offset,
4102 field_offset),
4103 offsets,
4104 max_offset,
4108 }
4109 }
4111 {
4114 tree index;
4116 /* Avoid recursing into objects that are not interesting. */
4121 /* Step through each of the elements in the array. */
4125 {
4127 f,
4128 offset,
4129 offsets,
4130 max_offset,
4136 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4137 there's no point in iterating through the remaining
4138 elements of the array. */
4141 }
4142 }
4145 }
4147 /* Record all of the empty subobjects of TYPE (either a type or a
4148 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4149 is being placed at OFFSET; otherwise, it is a base class that is
4150 being placed at OFFSET. */
4152 static void
4154 tree offset,
4155 splay_tree offsets,
4157 {
4158 tree max_offset;
4159 /* If recording subobjects for a non-static data member or a
4160 non-empty base class , we do not need to record offsets beyond
4161 the size of the biggest empty class. Additional data members
4162 will go at the end of the class. Additional base classes will go
4163 either at offset zero (if empty, in which case they cannot
4164 overlap with offsets past the size of the biggest empty class) or
4165 at the end of the class.
4167 However, if we are placing an empty base class, then we must record
4168 all offsets, as either the empty class is at offset zero (where
4169 other empty classes might later be placed) or at the end of the
4170 class (where other objects might then be placed, so other empty
4171 subobjects might later overlap). */
4175 else
4179 }
4181 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4182 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4183 virtual bases of TYPE are examined. */
4185 static int
4187 tree offset,
4188 splay_tree offsets,
4190 {
4191 splay_tree_node max_node;
4193 /* Get the node in OFFSETS that indicates the maximum offset where
4194 an empty subobject is located. */
4196 /* If there aren't any empty subobjects, then there's no point in
4197 performing this check. */
4203 vbases_p);
4204 }
4206 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4207 non-static data member of the type indicated by RLI. BINFO is the
4208 binfo corresponding to the base subobject, OFFSETS maps offsets to
4209 types already located at those offsets. This function determines
4210 the position of the DECL. */
4212 static void
4214 tree decl,
4215 tree binfo,
4216 splay_tree offsets)
4217 {
4220 tree type;
4223 {
4224 /* For the purposes of determining layout conflicts, we want to
4225 use the class type of BINFO; TREE_TYPE (DECL) will be the
4226 CLASSTYPE_AS_BASE version, which does not contain entries for
4227 zero-sized bases. */
4230 }
4231 else
4232 {
4235 }
4237 /* Try to place the field. It may take more than one try if we have
4238 a hard time placing the field without putting two objects of the
4239 same type at the same address. */
4241 {
4244 /* Place this field. */
4248 /* We have to check to see whether or not there is already
4249 something of the same type at the offset we're about to use.
4250 For example, consider:
4252 struct S {};
4253 struct T : public S { int i; };
4254 struct U : public S, public T {};
4256 Here, we put S at offset zero in U. Then, we can't put T at
4257 offset zero -- its S component would be at the same address
4258 as the S we already allocated. So, we have to skip ahead.
4259 Since all data members, including those whose type is an
4260 empty class, have nonzero size, any overlap can happen only
4261 with a direct or indirect base-class -- it can't happen with
4262 a data member. */
4263 /* In a union, overlap is permitted; all members are placed at
4264 offset zero. */
4269 {
4270 /* Strip off the size allocated to this field. That puts us
4271 at the first place we could have put the field with
4272 proper alignment. */
4275 /* Bump up by the alignment required for the type. */
4276 rli->bitpos
4282 }
4285 {
4286 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4287 the offset wasn't aligned like a pointer when we started to
4288 layout this field, that affects its position. */
4291 {
4294 "alignment of %qD increased in -fabi-version=9 "
4296 else
4299 }
4301 }
4302 else
4303 /* There was no conflict. We're done laying out this field. */
4305 }
4307 /* Now that we know where it will be placed, update its
4308 BINFO_OFFSET. */
4310 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4311 this point because their BINFO_OFFSET is copied from another
4312 hierarchy. Therefore, we may not need to add the entire
4313 OFFSET. */
4319 }
4321 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4323 static int
4325 tree offset,
4327 {
4329 }
4331 /* Layout the empty base BINFO. EOC indicates the byte currently just
4332 past the end of the class, and should be correctly aligned for a
4333 class of the type indicated by BINFO; OFFSETS gives the offsets of
4334 the empty bases allocated so far. T is the most derived
4335 type. Return nonzero iff we added it at the end. */
4337 static bool
4340 {
4341 tree alignment;
4345 /* This routine should only be used for empty classes. */
4350 propagate_binfo_offsets
4354 /* This is an empty base class. We first try to put it at offset
4355 zero. */
4358 offsets,
4360 {
4361 /* That didn't work. Now, we move forward from the next
4362 available spot in the class. */
4366 {
4369 offsets,
4371 /* We finally found a spot where there's no overlap. */
4374 /* There's overlap here, too. Bump along to the next spot. */
4376 }
4377 }
4380 {
4385 }
4388 }
4390 /* Layout the base given by BINFO in the class indicated by RLI.
4391 *BASE_ALIGN is a running maximum of the alignments of
4392 any base class. OFFSETS gives the location of empty base
4393 subobjects. T is the most derived type. Return nonzero if the new
4394 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4395 *NEXT_FIELD, unless BINFO is for an empty base class.
4397 Returns the location at which the next field should be inserted. */
4402 {
4407 /* This error is now reported in xref_tag, thus giving better
4408 location information. */
4411 /* Place the base class. */
4413 {
4414 tree decl;
4416 /* The containing class is non-empty because it has a non-empty
4417 base class. */
4420 /* Create the FIELD_DECL. */
4427 {
4435 /* Try to place the field. It may take more than one try if we
4436 have a hard time placing the field without putting two
4437 objects of the same type at the same address. */
4439 /* Add the new FIELD_DECL to the list of fields for T. */
4443 }
4444 }
4445 else
4446 {
4447 tree eoc;
4450 /* On some platforms (ARM), even empty classes will not be
4451 byte-aligned. */
4456 /* A nearly-empty class "has no proper base class that is empty,
4457 not morally virtual, and at an offset other than zero." */
4459 {
4462 /* The check above (used in G++ 3.2) is insufficient because
4463 an empty class placed at offset zero might itself have an
4464 empty base at a nonzero offset. */
4466 empty_base_at_nonzero_offset_p,
4467 size_zero_node,
4472 }
4474 /* We do not create a FIELD_DECL for empty base classes because
4475 it might overlap some other field. We want to be able to
4476 create CONSTRUCTORs for the class by iterating over the
4477 FIELD_DECLs, and the back end does not handle overlapping
4478 FIELD_DECLs. */
4480 /* An empty virtual base causes a class to be non-empty
4481 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4482 here because that was already done when the virtual table
4483 pointer was created. */
4484 }
4486 /* Record the offsets of BINFO and its base subobjects. */
4489 offsets,
4493 }
4495 /* Layout all of the non-virtual base classes. Record empty
4496 subobjects in OFFSETS. T is the most derived type. Return nonzero
4497 if the type cannot be nearly empty. The fields created
4498 corresponding to the base classes will be inserted at
4499 *NEXT_FIELD. */
4501 static void
4504 {
4505 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4506 subobjects. */
4511 /* The primary base class is always allocated first. */
4516 /* Now allocate the rest of the bases. */
4518 {
4519 tree base_binfo;
4523 /* The primary base was already allocated above, so we don't
4524 need to allocate it again here. */
4528 /* Virtual bases are added at the end (a primary virtual base
4529 will have already been added). */
4535 }
4536 }
4538 /* Go through the TYPE_METHODS of T issuing any appropriate
4539 diagnostics, figuring out which methods override which other
4540 methods, and so forth. */
4542 static void
4544 {
4545 tree x;
4548 {
4552 /* The name of the field is the original field name
4553 Save this in auxiliary field for later overloading. */
4555 {
4559 }
4560 /* All user-provided destructors are non-trivial.
4561 Constructors and assignment ops are handled in
4562 grok_special_member_properties. */
4565 }
4566 }
4568 /* FN is a constructor or destructor. Clone the declaration to create
4569 a specialized in-charge or not-in-charge version, as indicated by
4570 NAME. */
4572 static tree
4574 {
4575 tree parms;
4576 tree clone;
4578 /* Copy the function. */
4580 /* Reset the function name. */
4582 /* Remember where this function came from. */
4584 /* Make it easy to find the CLONE given the FN. */
4588 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4590 {
4597 }
4601 /* There's no pending inline data for this function. */
4605 /* The base-class destructor is not virtual. */
4607 {
4611 }
4613 /* If there was an in-charge parameter, drop it from the function
4614 type. */
4616 {
4617 tree basetype;
4618 tree parmtypes;
4619 tree exceptions;
4624 /* Skip the `this' parameter. */
4626 /* Skip the in-charge parameter. */
4628 /* And the VTT parm, in a complete [cd]tor. */
4632 /* If this is subobject constructor or destructor, add the vtt
4633 parameter. */
4637 parmtypes);
4640 exceptions);
4644 }
4646 /* Copy the function parameters. */
4648 /* Remove the in-charge parameter. */
4650 {
4654 }
4655 /* And the VTT parm, in a complete [cd]tor. */
4657 {
4660 else
4661 {
4665 }
4666 }
4669 {
4672 }
4674 /* Create the RTL for this function. */
4682 }
4684 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4685 not invoke this function directly.
4687 For a non-thunk function, returns the address of the slot for storing
4688 the function it is a clone of. Otherwise returns NULL_TREE.
4690 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4691 cloned_function is unset. This is to support the separate
4692 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4693 on a template makes sense, but not the former. */
4695 tree *
4697 {
4705 {
4706 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4709 else
4710 #endif
4712 }
4717 else
4719 }
4721 /* Produce declarations for all appropriate clones of FN. If
4722 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4723 CLASTYPE_METHOD_VEC as well. */
4725 void
4727 {
4728 tree clone;
4730 /* Avoid inappropriate cloning. */
4736 {
4737 /* For each constructor, we need two variants: an in-charge version
4738 and a not-in-charge version. */
4745 }
4746 else
4747 {
4750 /* For each destructor, we need three variants: an in-charge
4751 version, a not-in-charge version, and an in-charge deleting
4752 version. We clone the deleting version first because that
4753 means it will go second on the TYPE_METHODS list -- and that
4754 corresponds to the correct layout order in the virtual
4755 function table.
4757 For a non-virtual destructor, we do not build a deleting
4758 destructor. */
4760 {
4764 }
4771 }
4773 /* Note that this is an abstract function that is never emitted. */
4775 }
4777 /* DECL is an in charge constructor, which is being defined. This will
4778 have had an in class declaration, from whence clones were
4779 declared. An out-of-class definition can specify additional default
4780 arguments. As it is the clones that are involved in overload
4781 resolution, we must propagate the information from the DECL to its
4782 clones. */
4784 void
4786 {
4787 tree clone;
4791 {
4798 /* Skip the 'this' parameter. */
4814 {
4819 {
4820 /* A default parameter has been added. Adjust the
4821 clone's parameters. */
4825 tree type;
4830 {
4833 clone_parms);
4835 }
4838 clone_parms);
4847 }
4848 }
4850 }
4851 }
4853 /* For each of the constructors and destructors in T, create an
4854 in-charge and not-in-charge variant. */
4856 static void
4858 {
4859 tree fns;
4861 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4862 out now. */
4870 }
4872 /* Deduce noexcept for a destructor DTOR. */
4874 void
4876 {
4878 {
4881 }
4882 }
4884 /* For each destructor in T, deduce noexcept:
4886 12.4/3: A declaration of a destructor that does not have an
4887 exception-specification is implicitly considered to have the
4888 same exception-specification as an implicit declaration (15.4). */
4890 static void
4892 {
4893 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4894 out now. */
4900 }
4902 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4903 of TYPE for virtual functions which FNDECL overrides. Return a
4904 mask of the tm attributes found therein. */
4906 static int
4908 {
4910 tree base_binfo;
4914 {
4924 else
4926 }
4929 }
4931 /* Subroutine of set_method_tm_attributes. Handle the checks and
4932 inheritance for one virtual method FNDECL. */
4934 static void
4936 {
4937 tree tm_attr;
4942 /* If FNDECL doesn't actually override anything (i.e. T is the
4943 class that first declares FNDECL virtual), then we're done. */
4950 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4951 tm_pure must match exactly, otherwise no weakening of
4952 tm_safe > tm_callable > nothing. */
4953 /* ??? The tm_pure attribute didn't make the transition to the
4954 multivendor language spec. */
4956 {
4958 {
4961 }
4962 }
4963 /* If the overridden function is tm_pure, then FNDECL must be. */
4966 /* Look for base class combinations that cannot be satisfied. */
4968 {
4974 }
4975 /* If FNDECL did not declare an attribute, then inherit the most
4976 restrictive one. */
4978 {
4980 }
4981 /* Otherwise validate that we're not weaker than a function
4982 that is being overridden. */
4983 else
4984 {
4988 }
4991 err_override:
4995 }
4997 /* For each of the methods in T, propagate a class-level tm attribute. */
4999 static void
5001 {
5004 /* Don't bother collecting tm attributes if transactional memory
5005 support is not enabled. */
5009 /* Process virtual methods first, as they inherit directly from the
5010 base virtual function and also require validation of new attributes. */
5012 {
5013 tree vchain;
5016 {
5021 }
5022 }
5024 /* If the class doesn't have an attribute, nothing more to do. */
5029 /* Any method that does not yet have a tm attribute inherits
5030 the one from the class. */
5032 {
5035 }
5036 }
5038 /* Returns true iff class T has a user-defined constructor other than
5039 the default constructor. */
5041 bool
5043 {
5044 tree fns;
5050 {
5057 }
5060 }
5062 /* Returns the defaulted constructor if T has one. Otherwise, returns
5063 NULL_TREE. */
5065 tree
5067 {
5074 {
5078 {
5084 }
5085 }
5088 }
5090 /* Returns true iff FN is a user-provided function, i.e. user-declared
5091 and not defaulted at its first declaration; or explicit, private,
5092 protected, or non-const. */
5094 bool
5096 {
5099 else
5103 }
5105 /* Returns true iff class T has a user-provided constructor. */
5107 bool
5109 {
5110 tree fns;
5118 /* This can happen in error cases; avoid crashing. */
5127 }
5129 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5130 declared or explicitly defaulted in the class body) default
5131 constructor. */
5133 bool
5135 {
5136 tree fns;
5144 {
5150 }
5153 }
5155 /* TYPE is being used as a virtual base, and has a non-trivial move
5156 assignment. Return true if this is due to there being a user-provided
5157 move assignment in TYPE or one of its subobjects; if there isn't, then
5158 multiple move assignment can't cause any harm. */
5160 bool
5162 {
5163 /* Does the type itself have a user-provided move assignment operator? */
5167 {
5171 }
5173 /* Do any of its bases? */
5175 tree base_binfo;
5180 /* Or non-static data members? */
5182 {
5187 }
5189 /* Seems not. */
5191 }
5193 /* If default-initialization leaves part of TYPE uninitialized, returns
5194 a DECL for the field or TYPE itself (DR 253). */
5196 tree
5198 {
5209 {
5213 }
5218 {
5222 }
5225 }
5227 /* Returns true iff for class T, a trivial synthesized default constructor
5228 would be constexpr. */
5230 bool
5232 {
5233 /* A defaulted trivial default constructor is constexpr
5234 if there is nothing to initialize. */
5237 }
5239 /* Returns true iff class T has a constexpr default constructor. */
5241 bool
5243 {
5244 tree fns;
5247 {
5248 /* The caller should have stripped an enclosing array. */
5251 }
5253 {
5256 /* Non-trivial, we need to check subobject constructors. */
5258 }
5261 }
5263 /* Returns true iff class TYPE has a virtual destructor. */
5265 bool
5267 {
5268 tree dtor;
5276 }
5278 /* Returns true iff class T has a move constructor. */
5280 bool
5282 {
5283 tree fns;
5286 {
5289 }
5299 }
5301 /* Returns true iff class T has a move assignment operator. */
5303 bool
5305 {
5306 tree fns;
5309 {
5312 }
5320 }
5322 /* Returns true iff class T has a move constructor that was explicitly
5323 declared in the class body. Note that this is different from
5324 "user-provided", which doesn't include functions that are defaulted in
5325 the class. */
5327 bool
5329 {
5330 tree fns;
5339 {
5343 }
5346 }
5348 /* Returns true iff class T has a move assignment operator that was
5349 explicitly declared in the class body. */
5351 bool
5353 {
5354 tree fns;
5361 {
5365 }
5368 }
5370 /* Nonzero if we need to build up a constructor call when initializing an
5371 object of this class, either because it has a user-declared constructor
5372 or because it doesn't have a default constructor (so we need to give an
5373 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5374 what you care about is whether or not an object can be produced by a
5375 constructor (e.g. so we don't set TREE_READONLY on const variables of
5376 such type); use this function when what you care about is whether or not
5377 to try to call a constructor to create an object. The latter case is
5378 the former plus some cases of constructors that cannot be called. */
5380 bool
5382 {
5383 tree inner;
5393 /* A user-declared constructor might be private, and a constructor might
5394 be trivial but deleted. */
5397 {
5402 }
5404 }
5406 /* Like type_build_ctor_call, but for destructors. */
5408 bool
5410 {
5411 tree inner;
5420 /* A user-declared destructor might be private, and a destructor might
5421 be trivial but deleted. */
5424 {
5429 }
5431 }
5433 /* Remove all zero-width bit-fields from T. */
5435 static void
5437 {
5442 {
5445 /* We should not be confused by the fact that grokbitfield
5446 temporarily sets the width of the bit field into
5447 DECL_INITIAL (*fieldsp).
5448 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5449 to that width. */
5453 else
5455 }
5456 }
5458 /* Returns TRUE iff we need a cookie when dynamically allocating an
5459 array whose elements have the indicated class TYPE. */
5461 static bool
5463 {
5464 tree fns;
5469 /* If there's a non-trivial destructor, we need a cookie. In order
5470 to iterate through the array calling the destructor for each
5471 element, we'll have to know how many elements there are. */
5475 /* If the usual deallocation function is a two-argument whose second
5476 argument is of type `size_t', then we have to pass the size of
5477 the array to the deallocation function, so we will need to store
5478 a cookie. */
5482 /* If there are no `operator []' members, or the lookup is
5483 ambiguous, then we don't need a cookie. */
5486 /* Loop through all of the functions. */
5488 {
5489 tree fn;
5490 tree second_parm;
5492 /* Select the current function. */
5494 /* See if this function is a one-argument delete function. If
5495 it is, then it will be the usual deallocation function. */
5499 /* Do not consider this function if its second argument is an
5500 ellipsis. */
5503 /* Otherwise, if we have a two-argument function and the second
5504 argument is `size_t', it will be the usual deallocation
5505 function -- unless there is one-argument function, too. */
5509 }
5512 }
5514 /* Finish computing the `literal type' property of class type T.
5516 At this point, we have already processed base classes and
5517 non-static data members. We need to check whether the copy
5518 constructor is trivial, the destructor is trivial, and there
5519 is a trivial default constructor or at least one constexpr
5520 constructor other than the copy constructor. */
5522 static void
5524 {
5525 tree fn;
5541 {
5544 {
5548 }
5549 }
5550 }
5552 /* T is a non-literal type used in a context which requires a constant
5553 expression. Explain why it isn't literal. */
5555 void
5557 {
5567 /* Already explained. */
5576 {
5578 "default constructor, and has no constexpr constructor that "
5581 {
5582 /* Note that we can't simply call locate_ctor because when the
5583 constructor is deleted it just returns NULL_TREE. */
5584 tree fns;
5586 {
5593 {
5596 else
5599 }
5600 }
5601 }
5602 }
5603 else
5604 {
5608 {
5611 {
5616 }
5617 }
5619 {
5620 tree ftype;
5625 {
5630 }
5634 }
5635 }
5636 }
5638 /* Check the validity of the bases and members declared in T. Add any
5639 implicitly-generated functions (like copy-constructors and
5640 assignment operators). Compute various flag bits (like
5641 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5642 level: i.e., independently of the ABI in use. */
5644 static void
5646 {
5647 /* Nonzero if the implicitly generated copy constructor should take
5648 a non-const reference argument. */
5650 /* Nonzero if the implicitly generated assignment operator
5651 should take a non-const reference argument. */
5653 tree access_decls;
5656 tree fn;
5658 /* By default, we use const reference arguments and generate default
5659 constructors. */
5663 /* Check all the base-classes. */
5667 /* Deduce noexcept on destructors. This needs to happen after we've set
5668 triviality flags appropriately for our bases. */
5672 /* Check all the method declarations. */
5675 /* Save the initial values of these flags which only indicate whether
5676 or not the class has user-provided functions. As we analyze the
5677 bases and members we can set these flags for other reasons. */
5681 /* Check all the data member declarations. We cannot call
5682 check_field_decls until we have called check_bases check_methods,
5683 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5684 being set appropriately. */
5689 /* A nearly-empty class has to be vptr-containing; a nearly empty
5690 class contains just a vptr. */
5694 /* Do some bookkeeping that will guide the generation of implicitly
5695 declared member functions. */
5698 /* We need to call a constructor for this class if it has a
5699 user-provided constructor, or if the default constructor is going
5700 to initialize the vptr. (This is not an if-and-only-if;
5701 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5702 themselves need constructing.) */
5705 /* [dcl.init.aggr]
5707 An aggregate is an array or a class with no user-provided
5708 constructors ... and no virtual functions.
5710 Again, other conditions for being an aggregate are checked
5711 elsewhere. */
5714 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5715 retain the old definition internally for ABI reasons. */
5724 /* If the only explicitly declared default constructor is user-provided,
5725 set TYPE_HAS_COMPLEX_DFLT. */
5731 /* Warn if a public base of a polymorphic type has an accessible
5732 non-virtual destructor. It is only now that we know the class is
5733 polymorphic. Although a polymorphic base will have a already
5734 been diagnosed during its definition, we warn on use too. */
5736 {
5739 tree base_binfo;
5743 {
5751 basetype);
5752 }
5753 }
5755 /* If the class has no user-declared constructor, but does have
5756 non-static const or reference data members that can never be
5757 initialized, issue a warning. */
5759 /* Classes with user-declared constructors are presumed to
5760 initialize these members. */
5762 /* Aggregates can be initialized with brace-enclosed
5763 initializers. */
5765 {
5766 tree field;
5769 {
5770 tree type;
5785 }
5786 }
5788 /* Synthesize any needed methods. */
5790 cant_have_const_ctor,
5791 no_const_asn_ref);
5793 /* Check defaulted declarations here so we have cant_have_const_ctor
5794 and don't need to worry about clones. */
5797 {
5800 {
5801 bool imp_const_p
5807 /* If the function is defaulted outside the class, we just
5808 give the synthesis error. */
5811 }
5813 }
5816 {
5817 /* "This class type is not an aggregate." */
5819 }
5821 /* Compute the 'literal type' property before we
5822 do anything with non-static member functions. */
5825 /* Create the in-charge and not-in-charge variants of constructors
5826 and destructors. */
5829 /* Process the using-declarations. */
5833 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5836 /* Figure out whether or not we will need a cookie when dynamically
5837 allocating an array of this type. */
5840 }
5842 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5843 accordingly. If a new vfield was created (because T doesn't have a
5844 primary base class), then the newly created field is returned. It
5845 is not added to the TYPE_FIELDS list; it is the caller's
5846 responsibility to do that. Accumulate declared virtual functions
5847 on VIRTUALS_P. */
5849 static tree
5851 {
5852 tree fn;
5854 /* Collect the virtual functions declared in T. */
5859 {
5868 }
5870 /* If we couldn't find an appropriate base class, create a new field
5871 here. Even if there weren't any new virtual functions, we might need a
5872 new virtual function table if we're supposed to include vptrs in
5873 all classes that need them. */
5875 {
5876 /* We build this decl with vtbl_ptr_type_node, which is a
5877 `vtable_entry_type*'. It might seem more precise to use
5878 `vtable_entry_type (*)[N]' where N is the number of virtual
5879 functions. However, that would require the vtable pointer in
5880 base classes to have a different type than the vtable pointer
5881 in derived classes. We could make that happen, but that
5882 still wouldn't solve all the problems. In particular, the
5883 type-based alias analysis code would decide that assignments
5884 to the base class vtable pointer can't alias assignments to
5885 the derived class vtable pointer, since they have different
5886 types. Thus, in a derived class destructor, where the base
5887 class constructor was inlined, we could generate bad code for
5888 setting up the vtable pointer.
5890 Therefore, we use one type for all vtable pointers. We still
5891 use a type-correct type; it's just doesn't indicate the array
5892 bounds. That's better than using `void*' or some such; it's
5893 cleaner, and it let's the alias analysis code know that these
5894 stores cannot alias stores to void*! */
5895 tree field;
5908 /* This class is non-empty. */
5912 }
5915 }
5917 /* Add OFFSET to all base types of BINFO which is a base in the
5918 hierarchy dominated by T.
5920 OFFSET, which is a type offset, is number of bytes. */
5922 static void
5924 {
5926 tree primary_binfo;
5927 tree base_binfo;
5929 /* Update BINFO's offset. */
5934 offset));
5936 /* Find the primary base class. */
5942 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5943 downwards. */
5945 {
5946 /* Don't do the primary base twice. */
5954 }
5955 }
5957 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5958 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5959 empty subobjects of T. */
5961 static void
5963 {
5964 tree vbase;
5971 /* Find the last field. The artificial fields created for virtual
5972 bases will go after the last extant field to date. */
5977 /* Go through the virtual bases, allocating space for each virtual
5978 base that is not already a primary base class. These are
5979 allocated in inheritance graph order. */
5981 {
5986 {
5987 /* This virtual base is not a primary base of any class in the
5988 hierarchy, so we have to add space for it. */
5991 }
5992 }
5993 }
5995 /* Returns the offset of the byte just past the end of the base class
5996 BINFO. */
5998 static tree
6000 {
6001 tree size;
6006 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6007 allocate some space for it. It cannot have virtual bases, so
6008 TYPE_SIZE_UNIT is fine. */
6010 else
6014 }
6016 /* Returns the offset of the byte just past the end of the base class
6017 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
6018 only non-virtual bases are included. */
6020 static tree
6022 {
6025 tree binfo;
6026 tree base_binfo;
6027 tree offset;
6032 {
6042 }
6047 {
6051 }
6054 }
6056 /* Warn about bases of T that are inaccessible because they are
6057 ambiguous. For example:
6059 struct S {};
6060 struct T : public S {};
6061 struct U : public S, public T {};
6063 Here, `(S*) new U' is not allowed because there are two `S'
6064 subobjects of U. */
6066 static void
6068 {
6071 tree basetype;
6072 tree binfo;
6073 tree base_binfo;
6075 /* If there are no repeated bases, nothing can be ambiguous. */
6079 /* Check direct bases. */
6082 {
6088 }
6090 /* Check for ambiguous virtual bases. */
6094 {
6100 }
6101 }
6103 /* Compare two INTEGER_CSTs K1 and K2. */
6105 static int
6107 {
6109 }
6111 /* Increase the size indicated in RLI to account for empty classes
6112 that are "off the end" of the class. */
6114 static void
6116 {
6117 tree eoc;
6118 tree rli_size;
6120 /* It might be the case that we grew the class to allocate a
6121 zero-sized base class. That won't be reflected in RLI, yet,
6122 because we are willing to overlay multiple bases at the same
6123 offset. However, now we need to make sure that RLI is big enough
6124 to reflect the entire class. */
6130 {
6131 /* The size should have been rounded to a whole byte. */
6134 rli->bitpos
6143 }
6144 }
6146 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6147 BINFO_OFFSETs for all of the base-classes. Position the vtable
6148 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6150 static void
6152 {
6153 tree non_static_data_members;
6154 tree field;
6155 tree vptr;
6156 record_layout_info rli;
6157 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6158 types that appear at that offset. */
6159 splay_tree empty_base_offsets;
6160 /* True if the last field laid out was a bit-field. */
6162 /* The location at which the next field should be inserted. */
6164 /* T, as a base class. */
6165 tree base_t;
6167 /* Keep track of the first non-static data member. */
6170 /* Start laying out the record. */
6173 /* Mark all the primary bases in the hierarchy. */
6176 /* Create a pointer to our virtual function table. */
6179 /* The vptr is always the first thing in the class. */
6181 {
6186 }
6187 else
6190 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6195 /* Layout the non-static data members. */
6197 {
6198 tree type;
6199 tree padding;
6201 /* We still pass things that aren't non-static data members to
6202 the back end, in case it wants to do something with them. */
6204 {
6206 /* If the static data member has incomplete type, keep track
6207 of it so that it can be completed later. (The handling
6208 of pending statics in finish_record_layout is
6209 insufficient; consider:
6211 struct S1;
6212 struct S2 { static S1 s1; };
6214 At this point, finish_record_layout will be called, but
6215 S1 is still incomplete.) */
6217 {
6219 /* The visibility of static data members is determined
6220 at their point of declaration, not their point of
6221 definition. */
6223 }
6225 }
6233 /* If this field is a bit-field whose width is greater than its
6234 type, then there are some special rules for allocating
6235 it. */
6238 {
6240 tree integer_type;
6242 /* We must allocate the bits as if suitably aligned for the
6243 longest integer type that fits in this many bits. type
6244 of the field. Then, we are supposed to use the left over
6245 bits as additional padding. */
6254 /* ITK now indicates a type that is too large for the
6255 field. We have to back up by one to find the largest
6256 type that fits. */
6257 do
6258 {
6263 /* Figure out how much additional padding is required. */
6265 {
6267 /* In a union, the padding field must have the full width
6268 of the bit-field; all fields start at offset zero. */
6270 else
6273 }
6275 /* An unnamed bitfield does not normally affect the
6276 alignment of the containing class on a target where
6277 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6278 make any exceptions for unnamed bitfields when the
6279 bitfields are longer than their types. Therefore, we
6280 temporarily give the field a name. */
6282 {
6285 }
6291 empty_base_offsets);
6294 /* Now that layout has been performed, set the size of the
6295 field to the size of its declared type; the rest of the
6296 field is effectively invisible. */
6298 /* We must also reset the DECL_MODE of the field. */
6300 }
6301 else
6303 empty_base_offsets);
6305 /* Remember the location of any empty classes in FIELD. */
6308 empty_base_offsets,
6311 /* If a bit-field does not immediately follow another bit-field,
6312 and yet it starts in the middle of a byte, we have failed to
6313 comply with the ABI. */
6316 /* The TREE_NO_WARNING flag gets set by Objective-C when
6317 laying out an Objective-C class. The ObjC ABI differs
6318 from the C++ ABI, and so we do not want a warning
6319 here. */
6321 && !last_field_was_bitfield
6324 bitsize_unit_node)))
6328 /* The middle end uses the type of expressions to determine the
6329 possible range of expression values. In order to optimize
6330 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6331 must be made aware of the width of "i", via its type.
6333 Because C++ does not have integer types of arbitrary width,
6334 we must (for the purposes of the front end) convert from the
6335 type assigned here to the declared type of the bitfield
6336 whenever a bitfield expression is used as an rvalue.
6337 Similarly, when assigning a value to a bitfield, the value
6338 must be converted to the type given the bitfield here. */
6340 {
6345 {
6352 }
6353 }
6355 /* If we needed additional padding after this field, add it
6356 now. */
6358 {
6359 tree padding_field;
6362 FIELD_DECL,
6363 NULL_TREE,
6364 char_type_node);
6371 NULL_TREE,
6372 empty_base_offsets);
6373 }
6376 }
6379 {
6380 /* Make sure that we are on a byte boundary so that the size of
6381 the class without virtual bases will always be a round number
6382 of bytes. */
6385 }
6387 /* Delete all zero-width bit-fields from the list of fields. Now
6388 that the type is laid out they are no longer important. */
6391 /* Create the version of T used for virtual bases. We do not use
6392 make_class_type for this version; this is an artificial type. For
6393 a POD type, we just reuse T. */
6395 {
6398 /* Set the size and alignment for the new type. */
6399 tree eoc;
6401 /* If the ABI version is not at least two, and the last
6402 field was a bit-field, RLI may not be on a byte
6403 boundary. In particular, rli_size_unit_so_far might
6404 indicate the last complete byte, while rli_size_so_far
6405 indicates the total number of bits used. Therefore,
6406 rli_size_so_far, rather than rli_size_unit_so_far, is
6407 used to compute TYPE_SIZE_UNIT. */
6415 eoc);
6425 /* Copy the fields from T. */
6429 {
6431 FIELD_DECL,
6441 }
6443 /* Record the base version of the type. */
6446 }
6447 else
6450 /* Every empty class contains an empty class. */
6454 /* Set the TYPE_DECL for this type to contain the right
6455 value for DECL_OFFSET, so that we can use it as part
6456 of a COMPONENT_REF for multiple inheritance. */
6459 /* Now fix up any virtual base class types that we left lying
6460 around. We must get these done before we try to lay out the
6461 virtual function table. As a side-effect, this will remove the
6462 base subobject fields. */
6465 /* Make sure that empty classes are reflected in RLI at this
6466 point. */
6469 /* Make sure not to create any structures with zero size. */
6475 /* If this is a non-POD, declaring it packed makes a difference to how it
6476 can be used as a field; don't let finalize_record_size undo it. */
6480 /* Let the back end lay out the type. */
6489 /* Warn about bases that can't be talked about due to ambiguity. */
6492 /* Now that we're done with layout, give the base fields the real types. */
6497 /* Clean up. */
6504 }
6506 /* Determine the "key method" for the class type indicated by TYPE,
6507 and set CLASSTYPE_KEY_METHOD accordingly. */
6509 void
6511 {
6512 tree method;
6515 || processing_template_decl
6520 /* The key method is the first non-pure virtual function that is not
6521 inline at the point of class definition. On some targets the
6522 key function may not be inline; those targets should not call
6523 this function until the end of the translation unit. */
6530 {
6533 }
6536 }
6539 /* Allocate and return an instance of struct sorted_fields_type with
6540 N fields. */
6544 {
6551 }
6554 /* Perform processing required when the definition of T (a class type)
6555 is complete. */
6557 void
6559 {
6560 tree x;
6561 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6565 {
6570 }
6572 /* If this type was previously laid out as a forward reference,
6573 make sure we lay it out again. */
6577 /* Make assumptions about the class; we'll reset the flags if
6578 necessary. */
6584 /* Do end-of-class semantic processing: checking the validity of the
6585 bases and members and add implicitly generated methods. */
6588 /* Find the key method. */
6590 {
6591 /* The Itanium C++ ABI permits the key method to be chosen when
6592 the class is defined -- even though the key method so
6593 selected may later turn out to be an inline function. On
6594 some systems (such as ARM Symbian OS) the key method cannot
6595 be determined until the end of the translation unit. On such
6596 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6597 will cause the class to be added to KEYED_CLASSES. Then, in
6598 finish_file we will determine the key method. */
6602 /* If a polymorphic class has no key method, we may emit the vtable
6603 in every translation unit where the class definition appears. If
6604 we're devirtualizing, we can look into the vtable even if we
6605 aren't emitting it. */
6608 }
6610 /* Layout the class itself. */
6613 /* We use the base type for trivial assignments, and hence it
6614 needs a mode. */
6619 /* If necessary, create the primary vtable for this class. */
6621 {
6622 /* We must enter these virtuals into the table. */
6626 /* Here we know enough to change the type of our virtual
6627 function table, but we will wait until later this function. */
6630 /* If we're warning about ABI tags, check the types of the new
6631 virtual functions. */
6635 }
6638 {
6640 tree fn;
6647 /* Add entries for virtual functions introduced by this class. */
6651 /* Set DECL_VINDEX for all functions declared in this class. */
6653 fn;
6655 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6657 {
6661 /* A thunk. We should never be calling this entry directly
6662 from this vtable -- we'd use the entry for the non
6663 thunk base function. */
6667 }
6668 }
6673 /* Complete the rtl for any static member objects of the type we're
6674 working on. */
6681 /* Done with FIELDS...now decide whether to sort these for
6682 faster lookups later.
6684 We use a small number because most searches fail (succeeding
6685 ultimately as the search bores through the inheritance
6686 hierarchy), and we want this failure to occur quickly. */
6690 /* Complain if one of the field types requires lower visibility. */
6693 /* Make the rtl for any new vtables we have created, and unmark
6694 the base types we marked. */
6697 /* Build the VTT for T. */
6700 /* This warning does not make sense for Java classes, since they
6701 cannot have destructors. */
6706 "%q#T has virtual functions and accessible"
6714 /* Class layout, assignment of virtual table slots, etc., is now
6715 complete. Give the back end a chance to tweak the visibility of
6716 the class or perform any other required target modifications. */
6726 /* Finish debugging output for this type. */
6730 {
6733 {
6736 }
6738 {
6741 else
6742 {
6745 }
6747 }
6749 {
6751 "the type of the first field has a different ABI from the "
6754 }
6755 }
6756 }
6758 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6759 equal to THRESHOLD or greater than THRESHOLD. */
6761 static void
6763 {
6766 {
6771 }
6772 }
6774 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6776 void
6778 {
6781 {
6783 int n_fields
6794 }
6795 }
6797 /* When T was built up, the member declarations were added in reverse
6798 order. Rearrange them to declaration order. */
6800 void
6802 {
6803 tree next;
6804 tree prev;
6805 tree x;
6807 /* The following lists are all in reverse order. Put them in
6808 declaration order now. */
6812 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6813 reverse order, so we can't just use nreverse. */
6818 {
6822 }
6824 {
6828 }
6829 }
6831 tree
6833 {
6836 /* Now that we've got all the field declarations, reverse everything
6837 as necessary. */
6843 /* Nadger the current location so that diagnostics point to the start of
6844 the struct, not the end. */
6848 {
6849 tree x;
6855 /* We need to emit an error message if this type was used as a parameter
6856 and it is an abstract type, even if it is a template. We construct
6857 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6858 account and we call complete_vars with this type, which will check
6859 the PARM_DECLS. Note that while the type is being defined,
6860 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6861 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6867 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6868 an enclosing scope is a template class, so that this function be
6869 found by lookup_fnfields_1 when the using declaration is not
6870 instantiated yet. */
6873 {
6878 }
6880 /* Remember current #pragma pack value. */
6883 /* Fix up any variants we've already built. */
6885 {
6890 }
6891 }
6892 else
6896 {
6897 /* People keep complaining that the compiler crashes on an invalid
6898 definition of initializer_list, so I guess we should explicitly
6899 reject it. What the compiler internals care about is that it's a
6900 template and has a pointer field followed by an integer field. */
6903 {
6906 {
6910 }
6911 }
6914 "definition of std::initializer_list does not match "
6916 }
6924 else
6928 /* Lambdas are defined by the LAMBDA_EXPR. */
6933 }
6934 \f
6935 /* Hash table to avoid endless recursion when handling references. */
6938 /* Return the dynamic type of INSTANCE, if known.
6939 Used to determine whether the virtual function table is needed
6940 or not.
6942 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6943 of our knowledge of its type. *NONNULL should be initialized
6944 before this function is called. */
6946 static tree
6948 {
6949 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6952 {
6956 else
6960 /* This is a call to a constructor, hence it's never zero. */
6962 {
6966 }
6970 /* This is a call to a constructor, hence it's never zero. */
6972 {
6976 }
6985 /* Propagate nonnull. */
6990 CASE_CONVERT:
6996 {
6997 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6998 with a real object -- given &p->f, p can still be null. */
7000 /* ??? Probably should check DECL_WEAK here. */
7003 }
7007 /* If this component is really a base class reference, then the field
7008 itself isn't definitive. */
7017 {
7021 }
7022 /* fall through... */
7027 {
7031 }
7033 {
7037 /* if we're in a ctor or dtor, we know our type. If
7038 current_class_ptr is set but we aren't in a function, we're in
7039 an NSDMI (and therefore a constructor). */
7044 {
7048 }
7049 }
7051 {
7052 /* We only need one hash table because it is always left empty. */
7054 fixed_type_or_null_ref_ht
7057 /* Reference variables should be references to objects. */
7061 /* Enter the INSTANCE in a table to prevent recursion; a
7062 variable's initializer may refer to the variable
7063 itself. */
7068 {
7069 tree type;
7078 }
7079 }
7084 }
7085 #undef RECUR
7086 }
7088 /* Return nonzero if the dynamic type of INSTANCE is known, and
7089 equivalent to the static type. We also handle the case where
7090 INSTANCE is really a pointer. Return negative if this is a
7091 ctor/dtor. There the dynamic type is known, but this might not be
7092 the most derived base of the original object, and hence virtual
7093 bases may not be laid out according to this type.
7095 Used to determine whether the virtual function table is needed
7096 or not.
7098 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7099 of our knowledge of its type. *NONNULL should be initialized
7100 before this function is called. */
7102 int
7104 {
7107 tree fixed;
7109 /* processing_template_decl can be false in a template if we're in
7110 instantiate_non_dependent_expr, but we still want to suppress
7111 this check. */
7113 {
7114 /* In a template we only care about the type of the result. */
7118 }
7128 }
7130 \f
7131 void
7133 {
7136 current_class_stack
7144 }
7146 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7148 static void
7150 {
7151 tree type;
7153 /* We are re-entering the same class we just left, so we don't
7154 have to search the whole inheritance matrix to find all the
7155 decls to bind again. Instead, we install the cached
7156 class_shadowed list and walk through it binding names. */
7159 /* Restore IDENTIFIER_TYPE_VALUE. */
7161 type;
7164 }
7166 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7167 appropriate for TYPE.
7169 So that we may avoid calls to lookup_name, we cache the _TYPE
7170 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7172 For multiple inheritance, we perform a two-pass depth-first search
7173 of the type lattice. */
7175 void
7177 {
7178 class_stack_node_t csn;
7182 /* Make sure there is enough room for the new entry on the stack. */
7184 {
7186 current_class_stack
7188 current_class_stack_size);
7189 }
7191 /* Insert a new entry on the class stack. */
7198 current_class_depth++;
7200 /* Now set up the new type. */
7206 /* By default, things in classes are private, while things in
7207 structures or unions are public. */
7209 ? access_private_node
7215 {
7216 /* Forcibly remove any old class remnants. */
7218 }
7224 else
7226 }
7228 /* When we exit a toplevel class scope, we save its binding level so
7229 that we can restore it quickly. Here, we've entered some other
7230 class, so we must invalidate our cache. */
7232 void
7234 {
7236 }
7238 /* Get out of the current class scope. If we were in a class scope
7239 previously, that is the one popped to. */
7241 void
7243 {
7246 current_class_depth--;
7252 }
7254 /* Mark the top of the class stack as hidden. */
7256 void
7258 {
7261 }
7263 /* Mark the top of the class stack as un-hidden. */
7265 void
7267 {
7270 }
7272 /* Returns 1 if the class type currently being defined is either T or
7273 a nested type of T. */
7275 bool
7277 {
7285 /* We start looking from 1 because entry 0 is from global scope,
7286 and has no type. */
7288 {
7289 tree c;
7292 else
7293 {
7297 }
7302 }
7304 }
7306 /* If either current_class_type or one of its enclosing classes are derived
7307 from T, return the appropriate type. Used to determine how we found
7308 something via unqualified lookup. */
7310 tree
7312 {
7315 /* The bases of a dependent type are unknown. */
7326 {
7331 }
7334 }
7336 /* Return the outermost enclosing class type that is still open, or
7337 NULL_TREE. */
7339 tree
7341 {
7348 {
7355 }
7357 }
7359 /* Returns the innermost class type which is not a lambda closure type. */
7361 tree
7363 {
7366 /* We start looking from 1 because entry 0 is from global scope,
7367 and has no type. */
7369 {
7370 tree c;
7373 else
7374 {
7378 }
7383 }
7385 }
7387 /* When entering a class scope, all enclosing class scopes' names with
7388 static meaning (static variables, static functions, types and
7389 enumerators) have to be visible. This recursive function calls
7390 pushclass for all enclosing class contexts until global or a local
7391 scope is reached. TYPE is the enclosed class. */
7393 void
7395 {
7396 /* A namespace might be passed in error cases, like A::B:C. */
7404 }
7406 /* Undoes a push_nested_class call. */
7408 void
7410 {
7416 }
7418 /* Returns the number of extern "LANG" blocks we are nested within. */
7420 int
7422 {
7424 }
7426 /* Set global variables CURRENT_LANG_NAME to appropriate value
7427 so that behavior of name-mangling machinery is correct. */
7429 void
7431 {
7435 {
7437 }
7439 {
7441 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7442 (See record_builtin_java_type in decl.c.) However, that causes
7443 incorrect debug entries if these types are actually used.
7444 So we re-enable debug output after extern "Java". */
7453 }
7455 {
7457 }
7458 else
7460 }
7462 /* Get out of the current language scope. */
7464 void
7466 {
7468 }
7469 \f
7470 /* Type instantiation routines. */
7472 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7473 matches the TARGET_TYPE. If there is no satisfactory match, return
7474 error_mark_node, and issue an error & warning messages under
7475 control of FLAGS. Permit pointers to member function if FLAGS
7476 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7477 a template-id, and EXPLICIT_TARGS are the explicitly provided
7478 template arguments.
7480 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7481 is the base path used to reference those member functions. If
7482 the address is resolved to a member function, access checks will be
7483 performed and errors issued if appropriate. */
7485 static tree
7487 tree overload,
7488 tsubst_flags_t complain,
7490 tree explicit_targs,
7491 tree access_path)
7492 {
7493 /* Here's what the standard says:
7495 [over.over]
7497 If the name is a function template, template argument deduction
7498 is done, and if the argument deduction succeeds, the deduced
7499 arguments are used to generate a single template function, which
7500 is added to the set of overloaded functions considered.
7502 Non-member functions and static member functions match targets of
7503 type "pointer-to-function" or "reference-to-function." Nonstatic
7504 member functions match targets of type "pointer-to-member
7505 function;" the function type of the pointer to member is used to
7506 select the member function from the set of overloaded member
7507 functions. If a nonstatic member function is selected, the
7508 reference to the overloaded function name is required to have the
7509 form of a pointer to member as described in 5.3.1.
7511 If more than one function is selected, any template functions in
7512 the set are eliminated if the set also contains a non-template
7513 function, and any given template function is eliminated if the
7514 set contains a second template function that is more specialized
7515 than the first according to the partial ordering rules 14.5.5.2.
7516 After such eliminations, if any, there shall remain exactly one
7517 selected function. */
7520 /* We store the matches in a TREE_LIST rooted here. The functions
7521 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7522 interoperability with most_specialized_instantiation. */
7524 tree fn;
7525 tree target_fn_type;
7527 /* By the time we get here, we should be seeing only real
7528 pointer-to-member types, not the internal POINTER_TYPE to
7529 METHOD_TYPE representation. */
7535 /* Check that the TARGET_TYPE is reasonable. */
7540 /* This is OK, too. */
7543 /* This is OK, too. This comes from a conversion to reference
7544 type. */
7546 else
7547 {
7553 }
7555 /* Non-member functions and static member functions match targets of type
7556 "pointer-to-function" or "reference-to-function." Nonstatic member
7557 functions match targets of type "pointer-to-member-function;" the
7558 function type of the pointer to member is used to select the member
7559 function from the set of overloaded member functions.
7561 So figure out the FUNCTION_TYPE that we want to match against. */
7564 /* If we can find a non-template function that matches, we can just
7565 use it. There's no point in generating template instantiations
7566 if we're just going to throw them out anyhow. But, of course, we
7567 can only do this when we don't *need* a template function. */
7569 {
7570 tree fns;
7573 {
7577 /* We're not looking for templates just yet. */
7582 /* We're looking for a non-static member, and this isn't
7583 one, or vice versa. */
7586 /* Ignore functions which haven't been explicitly
7587 declared. */
7591 /* See if there's a match. */
7594 }
7595 }
7597 /* Now, if we've already got a match (or matches), there's no need
7598 to proceed to the template functions. But, if we don't have a
7599 match we need to look at them, too. */
7601 {
7602 tree target_arg_types;
7603 tree target_ret_type;
7604 tree fns;
7607 tree arg;
7621 {
7623 tree instantiation;
7624 tree targs;
7627 /* We're only looking for templates. */
7632 /* We're not looking for a non-static member, and this is
7633 one, or vice versa. */
7638 /* If the template has a deduced return type, don't expose it to
7639 template argument deduction. */
7643 /* Try to do argument deduction. */
7650 /* Instantiation failed. */
7653 /* And now force instantiation to do return type deduction. */
7655 {
7661 }
7663 /* See if there's a match. */
7666 }
7668 /* Now, remove all but the most specialized of the matches. */
7670 {
7675 NULL_TREE,
7676 NULL_TREE);
7677 }
7678 }
7680 /* Now we should have exactly one function in MATCHES. */
7682 {
7683 /* There were *no* matches. */
7685 {
7688 target_type);
7691 }
7693 }
7695 {
7696 /* There were too many matches. First check if they're all
7697 the same function. */
7702 /* For multi-versioned functions, more than one match is just fine and
7703 decls_match will return false as they are different. */
7711 {
7713 {
7716 target_type);
7718 /* Since print_candidates expects the functions in the
7719 TREE_VALUE slot, we flip them here. */
7724 }
7727 }
7728 }
7730 /* Good, exactly one match. Now, convert it to the correct type. */
7735 {
7743 {
7746 }
7747 }
7749 /* If a pointer to a function that is multi-versioned is requested, the
7750 pointer to the dispatcher function is returned instead. This works
7751 well because indirectly calling the function will dispatch the right
7752 function version at run-time. */
7754 {
7758 /* Mark all the versions corresponding to the dispatcher as used. */
7761 }
7763 /* If we're doing overload resolution purely for the purpose of
7764 determining conversion sequences, we should not consider the
7765 function used. If this conversion sequence is selected, the
7766 function will be marked as used at this point. */
7768 {
7769 /* Make =delete work with SFINAE. */
7774 }
7776 /* We could not check access to member functions when this
7777 expression was originally created since we did not know at that
7778 time to which function the expression referred. */
7780 {
7783 }
7787 else
7788 {
7789 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7790 will mark the function as addressed, but here we must do it
7791 explicitly. */
7795 }
7796 }
7798 /* This function will instantiate the type of the expression given in
7799 RHS to match the type of LHSTYPE. If errors exist, then return
7800 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
7801 we complain on errors. If we are not complaining, never modify rhs,
7802 as overload resolution wants to try many possible instantiations, in
7803 the hope that at least one will work.
7805 For non-recursive calls, LHSTYPE should be a function, pointer to
7806 function, or a pointer to member function. */
7808 tree
7810 {
7817 {
7821 }
7824 {
7831 /* Microsoft allows `A::f' to be resolved to a
7832 pointer-to-member. */
7833 ;
7834 else
7835 {
7840 }
7841 }
7844 {
7847 }
7849 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7850 deduce any type information. */
7852 {
7856 }
7858 /* There only a few kinds of expressions that may have a type
7859 dependent on overload resolution. */
7865 /* This should really only be used when attempting to distinguish
7866 what sort of a pointer to function we have. For now, any
7867 arithmetic operation which is not supported on pointers
7868 is rejected as an error. */
7871 {
7873 {
7879 /* Do not lose object's side effects. */
7883 }
7890 /* This can happen if we are forming a pointer-to-member for a
7891 member template. */
7894 /* Fall through. */
7897 {
7901 return
7905 }
7909 return
7913 access_path);
7916 {
7921 }
7928 }
7930 }
7931 \f
7932 /* Return the name of the virtual function pointer field
7933 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7934 this may have to look back through base types to find the
7935 ultimate field name. (For single inheritance, these could
7936 all be the same name. Who knows for multiple inheritance). */
7938 static tree
7940 {
7947 {
7953 }
7961 }
7963 void
7965 {
7972 {
7977 }
7978 }
7980 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7981 according to [class]:
7982 The class-name is also inserted
7983 into the scope of the class itself. For purposes of access checking,
7984 the inserted class name is treated as if it were a public member name. */
7986 void
7988 {
7991 tree saved_cas;
8006 }
8008 /* Returns 1 if TYPE contains only padding bytes. */
8010 int
8012 {
8020 }
8022 /* Returns true if TYPE contains no actual data, just various
8023 possible combinations of empty classes and possibly a vptr. */
8025 bool
8027 {
8029 {
8030 tree field;
8031 tree binfo;
8032 tree base_binfo;
8035 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8036 out, but we'd like to be able to check this before then. */
8050 }
8054 }
8056 /* Note that NAME was looked up while the current class was being
8057 defined and that the result of that lookup was DECL. */
8059 void
8061 {
8062 splay_tree names_used;
8064 /* If we're not defining a class, there's nothing to do. */
8070 /* If there's already a binding for this NAME, then we don't have
8071 anything to worry about. */
8084 }
8086 /* Note that NAME was declared (as DECL) in the current class. Check
8087 to see that the declaration is valid. */
8089 void
8091 {
8092 splay_tree names_used;
8093 splay_tree_node n;
8095 /* Look to see if we ever used this name. */
8096 names_used
8100 /* The C language allows members to be declared with a type of the same
8101 name, and the C++ standard says this diagnostic is not required. So
8102 allow it in extern "C" blocks unless predantic is specified.
8103 Allow it in all cases if -ms-extensions is specified. */
8109 {
8110 /* [basic.scope.class]
8112 A name N used in a class S shall refer to the same declaration
8113 in its context and when re-evaluated in the completed scope of
8114 S. */
8118 }
8119 }
8121 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8122 Secondary vtables are merged with primary vtables; this function
8123 will return the VAR_DECL for the primary vtable. */
8125 tree
8127 {
8128 tree decl;
8132 {
8135 }
8139 }
8142 /* Returns the binfo for the primary base of BINFO. If the resulting
8143 BINFO is a virtual base, and it is inherited elsewhere in the
8144 hierarchy, then the returned binfo might not be the primary base of
8145 BINFO in the complete object. Check BINFO_PRIMARY_P or
8146 BINFO_LOST_PRIMARY_P to be sure. */
8148 static tree
8150 {
8151 tree primary_base;
8158 }
8160 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8162 static int
8164 {
8168 }
8170 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8171 INDENT should be zero when called from the top level; it is
8172 incremented recursively. IGO indicates the next expected BINFO in
8173 inheritance graph ordering. */
8175 static tree
8178 tree binfo,
8179 tree igo,
8181 {
8183 tree base_binfo;
8191 {
8194 }
8209 {
8213 TFF_PLAIN_IDENTIFIER),
8215 }
8217 {
8220 }
8225 {
8229 {
8233 TFF_PLAIN_IDENTIFIER));
8234 }
8236 {
8240 TFF_PLAIN_IDENTIFIER));
8241 }
8243 {
8247 TFF_PLAIN_IDENTIFIER));
8248 }
8250 {
8254 TFF_PLAIN_IDENTIFIER));
8255 }
8259 }
8265 }
8267 /* Dump the BINFO hierarchy for T. */
8269 static void
8271 {
8283 }
8285 /* Debug interface to hierarchy dumping. */
8287 void
8289 {
8291 }
8293 static void
8295 {
8300 {
8302 }
8303 }
8305 static void
8307 {
8308 tree value;
8310 HOST_WIDE_INT elt;
8318 TFF_PLAIN_IDENTIFIER));
8325 }
8327 static void
8329 {
8337 {
8344 {
8349 }
8353 }
8354 }
8356 static void
8358 {
8366 {
8371 }
8372 }
8374 /* Dump a function or thunk and its thunkees. */
8376 static void
8378 {
8381 tree thunks;
8389 {
8399 else
8405 }
8409 }
8411 /* Dump the thunks for FN. */
8413 void
8415 {
8417 }
8419 /* Virtual function table initialization. */
8421 /* Create all the necessary vtables for T and its base classes. */
8423 static void
8425 {
8426 tree vbase;
8430 /* We lay out the primary and secondary vtables in one contiguous
8431 vtable. The primary vtable is first, followed by the non-virtual
8432 secondary vtables in inheritance graph order. */
8436 /* Then come the virtual bases, also in inheritance graph order. */
8438 {
8442 }
8446 }
8448 /* Initialize the vtable for BINFO with the INITS. */
8450 static void
8452 {
8453 tree decl;
8459 }
8461 /* Build the VTT (virtual table table) for T.
8462 A class requires a VTT if it has virtual bases.
8464 This holds
8465 1 - primary virtual pointer for complete object T
8466 2 - secondary VTTs for each direct non-virtual base of T which requires a
8467 VTT
8468 3 - secondary virtual pointers for each direct or indirect base of T which
8469 has virtual bases or is reachable via a virtual path from T.
8470 4 - secondary VTTs for each direct or indirect virtual base of T.
8472 Secondary VTTs look like complete object VTTs without part 4. */
8474 static void
8476 {
8477 tree type;
8478 tree vtt;
8479 tree index;
8482 /* Build up the initializers for the VTT. */
8487 /* If we didn't need a VTT, we're done. */
8491 /* Figure out the type of the VTT. */
8495 /* Now, build the VTT object itself. */
8498 /* Add the VTT to the vtables list. */
8503 }
8505 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8506 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8507 and CHAIN the vtable pointer for this binfo after construction is
8508 complete. VALUE can also be another BINFO, in which case we recurse. */
8510 static tree
8512 {
8513 tree vt;
8516 {
8522 else
8524 }
8527 }
8529 /* Data for secondary VTT initialization. */
8531 {
8532 /* Is this the primary VTT? */
8535 /* Current index into the VTT. */
8536 tree index;
8538 /* Vector of initializers built up. */
8541 /* The type being constructed by this secondary VTT. */
8542 tree type_being_constructed;
8545 /* Recursively build the VTT-initializer for BINFO (which is in the
8546 hierarchy dominated by T). INITS points to the end of the initializer
8547 list to date. INDEX is the VTT index where the next element will be
8548 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8549 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8550 for virtual bases of T. When it is not so, we build the constructor
8551 vtables for the BINFO-in-T variant. */
8553 static void
8556 {
8558 tree b;
8559 tree init;
8560 secondary_vptr_vtt_init_data data;
8563 /* We only need VTTs for subobjects with virtual bases. */
8567 /* We need to use a construction vtable if this is not the primary
8568 VTT. */
8570 {
8573 /* Record the offset in the VTT where this sub-VTT can be found. */
8575 }
8577 /* Add the address of the primary vtable for the complete object. */
8581 {
8584 }
8587 /* Recursively add the secondary VTTs for non-virtual bases. */
8592 /* Add secondary virtual pointers for all subobjects of BINFO with
8593 either virtual bases or reachable along a virtual path, except
8594 subobjects that are non-virtual primary bases. */
8604 /* data.inits might have grown as we added secondary virtual pointers.
8605 Make sure our caller knows about the new vector. */
8609 /* Add the secondary VTTs for virtual bases in inheritance graph
8610 order. */
8612 {
8617 }
8618 else
8619 /* Remove the ctor vtables we created. */
8621 }
8623 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8624 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8626 static tree
8628 {
8631 /* We don't care about bases that don't have vtables. */
8635 /* We're only interested in proper subobjects of the type being
8636 constructed. */
8640 /* We're only interested in bases with virtual bases or reachable
8641 via a virtual path from the type being constructed. */
8646 /* We're not interested in non-virtual primary bases. */
8650 /* Record the index where this secondary vptr can be found. */
8652 {
8657 {
8658 /* It's a primary virtual base, and this is not a
8659 construction vtable. Find the base this is primary of in
8660 the inheritance graph, and use that base's vtable
8661 now. */
8664 }
8665 }
8667 /* Add the initializer for the secondary vptr itself. */
8670 /* Advance the vtt index. */
8675 }
8677 /* Called from build_vtt_inits via dfs_walk. After building
8678 constructor vtables and generating the sub-vtt from them, we need
8679 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8680 binfo of the base whose sub vtt was generated. */
8682 static tree
8684 {
8688 /* If this class has no vtable, none of its bases do. */
8692 /* This might be a primary base, so have no vtable in this
8693 hierarchy. */
8696 /* If we scribbled the construction vtable vptr into BINFO, clear it
8697 out now. */
8703 }
8705 /* Build the construction vtable group for BINFO which is in the
8706 hierarchy dominated by T. */
8708 static void
8710 {
8711 tree type;
8712 tree vtbl;
8713 tree id;
8714 tree vbase;
8717 /* See if we've already created this construction vtable group. */
8723 /* Build a version of VTBL (with the wrong type) for use in
8724 constructing the addresses of secondary vtables in the
8725 construction vtable group. */
8728 /* Don't export construction vtables from shared libraries. Even on
8729 targets that don't support hidden visibility, this tells
8730 can_refer_decl_in_current_unit_p not to assume that it's safe to
8731 access from a different compilation unit (bz 54314). */
8739 /* Add the vtables for each of our virtual bases using the vbase in T
8740 binfo. */
8742 vbase;
8744 {
8745 tree b;
8752 }
8754 /* Figure out the type of the construction vtable. */
8761 /* Initialize the construction vtable. */
8765 }
8767 /* Add the vtbl initializers for BINFO (and its bases other than
8768 non-virtual primaries) to the list of INITS. BINFO is in the
8769 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8770 the constructor the vtbl inits should be accumulated for. (If this
8771 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8772 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8773 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8774 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8775 but are not necessarily the same in terms of layout. */
8777 static void
8779 tree orig_binfo,
8780 tree rtti_binfo,
8781 tree vtbl,
8782 tree t,
8784 {
8786 tree base_binfo;
8791 /* If it doesn't have a vptr, we don't do anything. */
8795 /* If we're building a construction vtable, we're not interested in
8796 subobjects that don't require construction vtables. */
8802 /* Build the initializers for the BINFO-in-T vtable. */
8805 /* Walk the BINFO and its bases. We walk in preorder so that as we
8806 initialize each vtable we can figure out at what offset the
8807 secondary vtable lies from the primary vtable. We can't use
8808 dfs_walk here because we need to iterate through bases of BINFO
8809 and RTTI_BINFO simultaneously. */
8811 {
8812 /* Skip virtual bases. */
8818 inits);
8819 }
8820 }
8822 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8823 BINFO vtable to L. */
8825 static void
8827 tree orig_binfo,
8828 tree rtti_binfo,
8829 tree orig_vtbl,
8830 tree t,
8832 {
8839 {
8840 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8841 primary virtual base. If it is not the same primary in
8842 the hierarchy of T, we'll need to generate a ctor vtable
8843 for it, to place at its location in T. If it is the same
8844 primary, we still need a VTT entry for the vtable, but it
8845 should point to the ctor vtable for the base it is a
8846 primary for within the sub-hierarchy of RTTI_BINFO.
8848 There are three possible cases:
8850 1) We are in the same place.
8851 2) We are a primary base within a lost primary virtual base of
8852 RTTI_BINFO.
8853 3) We are primary to something not a base of RTTI_BINFO. */
8855 tree b;
8858 /* First, look through the bases we are primary to for RTTI_BINFO
8859 or a virtual base. */
8862 {
8867 }
8868 /* If we run out of primary links, keep looking down our
8869 inheritance chain; we might be an indirect primary. */
8873 found:
8875 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8876 base B and it is a base of RTTI_BINFO, this is case 2. In
8877 either case, we share our vtable with LAST, i.e. the
8878 derived-most base within B of which we are a primary. */
8881 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8882 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8883 binfo_ctor_vtable after everything's been set up. */
8886 /* Otherwise, this is case 3 and we get our own. */
8887 }
8894 {
8895 tree index;
8898 /* Add the initializer for this vtable. */
8902 /* Figure out the position to which the VPTR should point. */
8908 }
8911 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8912 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8913 straighten this out. */
8916 /* Throw away any unneeded intializers. */
8918 else
8919 /* For an ordinary vtable, set BINFO_VTABLE. */
8921 }
8925 /* Construct the initializer for BINFO's virtual function table. BINFO
8926 is part of the hierarchy dominated by T. If we're building a
8927 construction vtable, the ORIG_BINFO is the binfo we should use to
8928 find the actual function pointers to put in the vtable - but they
8929 can be overridden on the path to most-derived in the graph that
8930 ORIG_BINFO belongs. Otherwise,
8931 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8932 BINFO that should be indicated by the RTTI information in the
8933 vtable; it will be a base class of T, rather than T itself, if we
8934 are building a construction vtable.
8936 The value returned is a TREE_LIST suitable for wrapping in a
8937 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8938 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8939 number of non-function entries in the vtable.
8941 It might seem that this function should never be called with a
8942 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8943 base is always subsumed by a derived class vtable. However, when
8944 we are building construction vtables, we do build vtables for
8945 primary bases; we need these while the primary base is being
8946 constructed. */
8948 static void
8950 tree orig_binfo,
8951 tree t,
8952 tree rtti_binfo,
8955 {
8956 tree v;
8957 vtbl_init_data vid;
8959 tree vbinfo;
8963 /* Initialize VID. */
8971 /* The first vbase or vcall offset is at index -3 in the vtable. */
8974 /* Add entries to the vtable for RTTI. */
8977 /* Create an array for keeping track of the functions we've
8978 processed. When we see multiple functions with the same
8979 signature, we share the vcall offsets. */
8981 /* Add the vcall and vbase offset entries. */
8984 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8985 build_vbase_offset_vtbl_entries. */
8990 /* If the target requires padding between data entries, add that now. */
8992 {
8997 /* Move data entries into their new positions and add padding
8998 after the new positions. Iterate backwards so we don't
8999 overwrite entries that we would need to process later. */
9002 ix--)
9003 {
9011 {
9015 null_pointer_node);
9016 }
9017 }
9018 }
9023 /* The initializers for virtual functions were built up in reverse
9024 order. Straighten them out and add them to the running list in one
9025 step. */
9034 /* Go through all the ordinary virtual functions, building up
9035 initializers. */
9037 {
9038 tree delta;
9039 tree vcall_index;
9046 {
9050 {
9053 }
9055 }
9057 /* If the only definition of this function signature along our
9058 primary base chain is from a lost primary, this vtable slot will
9059 never be used, so just zero it out. This is important to avoid
9060 requiring extra thunks which cannot be generated with the function.
9062 We first check this in update_vtable_entry_for_fn, so we handle
9063 restored primary bases properly; we also need to do it here so we
9064 zero out unused slots in ctor vtables, rather than filling them
9065 with erroneous values (though harmless, apart from relocation
9066 costs). */
9071 {
9072 /* Pull the offset for `this', and the function to call, out of
9073 the list. */
9080 /* You can't call an abstract virtual function; it's abstract.
9081 So, we replace these functions with __pure_virtual. */
9083 {
9086 {
9088 abort_fndecl_addr
9092 }
9093 }
9094 /* Likewise for deleted virtuals. */
9096 {
9105 }
9106 else
9107 {
9109 {
9113 }
9114 /* Take the address of the function, considering it to be of an
9115 appropriate generic type. */
9119 /* Don't refer to a virtual destructor from a constructor
9120 vtable or a vtable for an abstract class, since destroying
9121 an object under construction is undefined behavior and we
9122 don't want it to be considered a candidate for speculative
9123 devirtualization. But do create the thunk for ABI
9124 compliance. */
9129 }
9130 }
9132 /* And add it to the chain of initializers. */
9134 {
9139 else
9141 {
9147 }
9148 }
9149 else
9151 }
9152 }
9154 /* Adds to vid->inits the initializers for the vbase and vcall
9155 offsets in BINFO, which is in the hierarchy dominated by T. */
9157 static void
9159 {
9160 tree b;
9162 /* If this is a derived class, we must first create entries
9163 corresponding to the primary base class. */
9168 /* Add the vbase entries for this base. */
9170 /* Add the vcall entries for this base. */
9172 }
9174 /* Returns the initializers for the vbase offset entries in the vtable
9175 for BINFO (which is part of the class hierarchy dominated by T), in
9176 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9177 where the next vbase offset will go. */
9179 static void
9181 {
9182 tree vbase;
9183 tree t;
9184 tree non_primary_binfo;
9186 /* If there are no virtual baseclasses, then there is nothing to
9187 do. */
9193 /* We might be a primary base class. Go up the inheritance hierarchy
9194 until we find the most derived class of which we are a primary base:
9195 it is the offset of that which we need to use. */
9198 {
9199 tree b;
9201 /* If we have reached a virtual base, then it must be a primary
9202 base (possibly multi-level) of vid->binfo, or we wouldn't
9203 have called build_vcall_and_vbase_vtbl_entries for it. But it
9204 might be a lost primary, so just skip down to vid->binfo. */
9206 {
9209 }
9215 }
9217 /* Go through the virtual bases, adding the offsets. */
9219 vbase;
9221 {
9222 tree b;
9223 tree delta;
9228 /* Find the instance of this virtual base in the complete
9229 object. */
9232 /* If we've already got an offset for this virtual base, we
9233 don't need another one. */
9238 /* Figure out where we can find this vbase offset. */
9247 /* The vbase offset had better be the same. */
9250 /* The next vbase will come at a more negative offset. */
9254 /* The initializer is the delta from BINFO to this virtual base.
9255 The vbase offsets go in reverse inheritance-graph order, and
9256 we are walking in inheritance graph order so these end up in
9257 the right order. */
9264 }
9265 }
9267 /* Adds the initializers for the vcall offset entries in the vtable
9268 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9269 to VID->INITS. */
9271 static void
9273 {
9274 /* We only need these entries if this base is a virtual base. We
9275 compute the indices -- but do not add to the vtable -- when
9276 building the main vtable for a class. */
9279 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9280 correspond to VID->DERIVED), we are building a primary
9281 construction virtual table. Since this is a primary
9282 virtual table, we do not need the vcall offsets for
9283 BINFO. */
9285 {
9286 /* We need a vcall offset for each of the virtual functions in this
9287 vtable. For example:
9289 class A { virtual void f (); };
9290 class B1 : virtual public A { virtual void f (); };
9291 class B2 : virtual public A { virtual void f (); };
9292 class C: public B1, public B2 { virtual void f (); };
9294 A C object has a primary base of B1, which has a primary base of A. A
9295 C also has a secondary base of B2, which no longer has a primary base
9296 of A. So the B2-in-C construction vtable needs a secondary vtable for
9297 A, which will adjust the A* to a B2* to call f. We have no way of
9298 knowing what (or even whether) this offset will be when we define B2,
9299 so we store this "vcall offset" in the A sub-vtable and look it up in
9300 a "virtual thunk" for B2::f.
9302 We need entries for all the functions in our primary vtable and
9303 in our non-virtual bases' secondary vtables. */
9305 /* If we are just computing the vcall indices -- but do not need
9306 the actual entries -- not that. */
9309 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9311 }
9312 }
9314 /* Build vcall offsets, starting with those for BINFO. */
9316 static void
9318 {
9320 tree primary_binfo;
9321 tree base_binfo;
9323 /* Don't walk into virtual bases -- except, of course, for the
9324 virtual base for which we are building vcall offsets. Any
9325 primary virtual base will have already had its offsets generated
9326 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9330 /* If BINFO has a primary base, process it first. */
9335 /* Add BINFO itself to the list. */
9338 /* Scan the non-primary bases of BINFO. */
9342 }
9344 /* Called from build_vcall_offset_vtbl_entries_r. */
9346 static void
9348 {
9349 /* Make entries for the rest of the virtuals. */
9350 tree orig_fn;
9352 /* The ABI requires that the methods be processed in declaration
9353 order. */
9355 orig_fn;
9359 }
9361 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9363 static void
9365 {
9367 tree vcall_offset;
9368 tree derived_entry;
9370 /* If there is already an entry for a function with the same
9371 signature as FN, then we do not need a second vcall offset.
9372 Check the list of functions already present in the derived
9373 class vtable. */
9375 {
9377 /* We only use one vcall offset for virtual destructors,
9378 even though there are two virtual table entries. */
9382 }
9384 /* If we are building these vcall offsets as part of building
9385 the vtable for the most derived class, remember the vcall
9386 offset. */
9388 {
9391 }
9393 /* The next vcall offset will be found at a more negative
9394 offset. */
9398 /* Keep track of this function. */
9402 {
9403 tree base;
9404 tree fn;
9406 /* Find the overriding function. */
9410 else
9411 {
9414 /* The vbase we're working on is a primary base of
9415 vid->binfo. But it might be a lost primary, so its
9416 BINFO_OFFSET might be wrong, so we just use the
9417 BINFO_OFFSET from vid->binfo. */
9423 vcall_offset);
9424 }
9425 /* Add the initializer to the vtable. */
9427 }
9428 }
9430 /* Return vtbl initializers for the RTTI entries corresponding to the
9431 BINFO's vtable. The RTTI entries should indicate the object given
9432 by VID->rtti_binfo. */
9434 static void
9436 {
9437 tree b;
9438 tree t;
9439 tree offset;
9440 tree decl;
9441 tree init;
9445 /* To find the complete object, we will first convert to our most
9446 primary base, and then add the offset in the vtbl to that value. */
9450 {
9451 tree primary_base;
9457 }
9461 /* The second entry is the address of the typeinfo object. */
9464 else
9467 /* Convert the declaration to a type that can be stored in the
9468 vtable. */
9472 /* Add the offset-to-top entry. It comes earlier in the vtable than
9473 the typeinfo entry. Convert the offset to look like a
9474 function pointer, so that we can put it in the vtable. */
9477 }
9479 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9480 accessibility. */
9482 bool
9484 {
9487 }
9489 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9491 bool
9493 {
9497 }
9499 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9500 class between them, if any. */
9502 tree
9504 {
9516 {
9519 }
9523 }