| blob | 010ed25ea36363b0d104db5825e1aaa0609f0ff5 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2014 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. */
44 /* The number of nested classes being processed. If we are not in the
45 scope of any class, this is zero. */
49 /* In order to deal with nested classes, we keep a stack of classes.
50 The topmost entry is the innermost class, and is the entry at index
51 CURRENT_CLASS_DEPTH */
54 /* The name of the class. */
55 tree name;
57 /* The _TYPE node for the class. */
58 tree type;
60 /* The access specifier pending for new declarations in the scope of
61 this class. */
62 tree access;
64 /* If were defining TYPE, the names used in this class. */
65 splay_tree names_used;
67 /* Nonzero if this class is no longer open, because of a call to
68 push_to_top_level. */
73 {
74 /* The base for which we're building initializers. */
75 tree binfo;
76 /* The type of the most-derived type. */
77 tree derived;
78 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
79 unless ctor_vtbl_p is true. */
80 tree rtti_binfo;
81 /* The negative-index vtable initializers built up so far. These
82 are in order from least negative index to most negative index. */
84 /* The binfo for the virtual base for which we're building
85 vcall offset initializers. */
86 tree vbase;
87 /* The functions in vbase for which we have already provided vcall
88 offsets. */
90 /* The vtable index of the next vcall or vbase offset. */
91 tree index;
92 /* Nonzero if we are building the initializer for the primary
93 vtable. */
95 /* Nonzero if we are building the initializer for a construction
96 vtable. */
98 /* True when adding vcall offset entries to the vtable. False when
99 merely computing the indices. */
103 /* The type of a function passed to walk_subobject_offsets. */
106 /* The stack itself. This is a dynamically resized array. The
107 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
111 /* The size of the largest empty class seen in this translation unit. */
114 /* An array of all local classes present in this translation unit, in
115 declaration order. */
198 tree *);
208 splay_tree_key k2);
216 /* Variables shared between class.c and call.c. */
226 /* Convert to or from a base subobject. EXPR is an expression of type
227 `A' or `A*', an expression of type `B' or `B*' is returned. To
228 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
229 the B base instance within A. To convert base A to derived B, CODE
230 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
231 In this latter case, A must not be a morally virtual base of B.
232 NONNULL is true if EXPR is known to be non-NULL (this is only
233 needed when EXPR is of pointer type). CV qualifiers are preserved
234 from EXPR. */
236 tree
238 tree expr,
239 tree binfo,
241 tsubst_flags_t complain)
242 {
245 tree probe;
246 tree offset;
247 tree target_type;
249 tree ptr_target_type;
259 {
265 }
273 {
274 /* This can happen when adjust_result_of_qualified_name_lookup can't
275 find a unique base binfo in a call to a member function. We
276 couldn't give the diagnostic then since we might have been calling
277 a static member function, so we do it now. */
279 {
283 }
285 }
292 /* Nothing to do. */
296 {
298 {
300 {
303 "pointer to derived class %qT because the base is "
305 else
309 }
310 else
311 {
317 else
321 }
322 }
324 }
327 /* This must happen before the call to save_expr. */
329 else
335 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
336 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
337 expression returned matches the input. */
338 target_type = cp_build_qualified_type
342 /* Do we need to look in the vtable for the real offset? */
345 /* Don't bother with the calculations inside sizeof; they'll ICE if the
346 source type is incomplete and the pointer value doesn't matter. In a
347 template (even in fold_non_dependent_expr), we don't have vtables set
348 up properly yet, and the value doesn't matter there either; we're just
349 interested in the result of overload resolution. */
352 {
357 }
359 /* If we're in an NSDMI, we don't have the full constructor context yet
360 that we need for converting to a virtual base, so just build a stub
361 CONVERT_EXPR and expand it later in bot_replace. */
364 {
370 }
372 /* Do we need to check for a null pointer? */
374 {
375 /* If we know the conversion will not actually change the value
376 of EXPR, then we can avoid testing the expression for NULL.
377 We have to avoid generating a COMPONENT_REF for a base class
378 field, because other parts of the compiler know that such
379 expressions are always non-NULL. */
383 }
385 /* Protect against multiple evaluation if necessary. */
389 /* Now that we've saved expr, build the real null test. */
391 {
395 }
397 /* If this is a simple base reference, express it as a COMPONENT_REF. */
399 /* We don't build base fields for empty bases, and they aren't very
400 interesting to the optimizers anyway. */
402 {
409 }
412 {
413 /* Going via virtual base V_BINFO. We need the static offset
414 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
415 V_BINFO. That offset is an entry in D_BINFO's vtable. */
416 tree v_offset;
419 {
420 /* In a base member initializer, we cannot rely on the
421 vtable being set up. We have to indirect via the
422 vtt_parm. */
423 tree t;
429 }
430 else
432 complain),
441 v_offset);
453 /* Negative fixed_type_p means this is a constructor or destructor;
454 virtual base layout is fixed in in-charge [cd]tors, but not in
455 base [cd]tors. */
459 v_offset,
462 else
464 }
472 {
477 }
478 else
484 out:
490 }
492 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
493 Perform a derived-to-base conversion by recursively building up a
494 sequence of COMPONENT_REFs to the appropriate base fields. */
496 static tree
498 {
501 tree field;
504 {
505 tree temp;
509 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
510 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
511 an lvalue in the front end; only _DECLs and _REFs are lvalues
512 in the back end. */
518 }
520 /* Recurse. */
525 /* Is this the base field created by build_base_field? */
529 /* If we're looking for a field in the most-derived class,
530 also check the field offset; we can have two base fields
531 of the same type if one is an indirect virtual base and one
532 is a direct non-virtual base. */
536 {
537 /* We don't use build_class_member_access_expr here, as that
538 has unnecessary checks, and more importantly results in
539 recursive calls to dfs_walk_once. */
547 /* Mark the expression const or volatile, as appropriate.
548 Even though we've dealt with the type above, we still have
549 to mark the expression itself. */
556 }
558 /* Didn't find the base field?!? */
560 }
562 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
563 type is a class type or a pointer to a class type. In the former
564 case, TYPE is also a class type; in the latter it is another
565 pointer type. If CHECK_ACCESS is true, an error message is emitted
566 if TYPE is inaccessible. If OBJECT has pointer type, the value is
567 assumed to be non-NULL. */
569 tree
571 tsubst_flags_t complain)
572 {
573 tree binfo;
574 tree object_type;
577 {
580 }
581 else
590 }
592 /* EXPR is an expression with unqualified class type. BASE is a base
593 binfo of that class type. Returns EXPR, converted to the BASE
594 type. This function assumes that EXPR is the most derived class;
595 therefore virtual bases can be found at their static offsets. */
597 tree
599 {
600 tree expr_type;
604 {
605 /* If this is a non-empty base, use a COMPONENT_REF. */
609 /* We use fold_build2 and fold_convert below to simplify the trees
610 provided to the optimizers. It is not safe to call these functions
611 when processing a template because they do not handle C++-specific
612 trees. */
620 }
623 }
625 \f
626 tree
628 {
632 /* Can happen in case of duplicate base types (c++/59082). */
636 /* First, convert to the requested type. */
641 /* Second, the requested type may not be the owner of its own vptr.
642 If not, convert to the base class that owns it. We cannot use
643 convert_to_base here, because VCONTEXT may appear more than once
644 in the inheritance hierarchy of TYPE, and thus direct conversion
645 between the types may be ambiguous. Following the path back up
646 one step at a time via primary bases avoids the problem. */
650 {
653 }
656 }
658 /* Given an object INSTANCE, return an expression which yields the
659 vtable element corresponding to INDEX. There are many special
660 cases for INSTANCE which we take care of here, mainly to avoid
661 creating extra tree nodes when we don't have to. */
663 static tree
665 {
666 tree aref;
669 /* Try to figure out what a reference refers to, and
670 access its virtual function table directly. */
678 {
683 }
692 }
694 tree
696 {
700 }
702 /* Given a stable object pointer INSTANCE_PTR, return an expression which
703 yields a function pointer corresponding to vtable element INDEX. */
705 tree
707 {
708 tree aref;
711 tf_warning_or_error),
712 idx);
714 /* When using function descriptors, the address of the
715 vtable entry is treated as a function pointer. */
720 /* Remember this as a method reference, for later devirtualization. */
724 }
726 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
727 for the given TYPE. */
729 static tree
731 {
733 }
735 /* DECL is an entity associated with TYPE, like a virtual table or an
736 implicitly generated constructor. Determine whether or not DECL
737 should have external or internal linkage at the object file
738 level. This routine does not deal with COMDAT linkage and other
739 similar complexities; it simply sets TREE_PUBLIC if it possible for
740 entities in other translation units to contain copies of DECL, in
741 the abstract. */
743 void
745 {
748 }
750 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
751 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
752 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
754 static tree
756 {
757 tree decl;
760 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
761 now to avoid confusion in mangle_decl. */
772 /* The vtable has not been defined -- yet. */
776 /* Mark the VAR_DECL node representing the vtable itself as a
777 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
778 is rather important that such things be ignored because any
779 effort to actually generate DWARF for them will run into
780 trouble when/if we encounter code like:
782 #pragma interface
783 struct S { virtual void member (); };
785 because the artificial declaration of the vtable itself (as
786 manufactured by the g++ front end) will say that the vtable is
787 a static member of `S' but only *after* the debug output for
788 the definition of `S' has already been output. This causes
789 grief because the DWARF entry for the definition of the vtable
790 will try to refer back to an earlier *declaration* of the
791 vtable as a static member of `S' and there won't be one. We
792 might be able to arrange to have the "vtable static member"
793 attached to the member list for `S' before the debug info for
794 `S' get written (which would solve the problem) but that would
795 require more intrusive changes to the g++ front end. */
799 }
801 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
802 or even complete. If this does not exist, create it. If COMPLETE is
803 nonzero, then complete the definition of it -- that will render it
804 impossible to actually build the vtable, but is useful to get at those
805 which are known to exist in the runtime. */
807 tree
809 {
810 tree decl;
819 {
822 }
825 }
827 /* Build the primary virtual function table for TYPE. If BINFO is
828 non-NULL, build the vtable starting with the initial approximation
829 that it is the same as the one which is the head of the association
830 list. Returns a nonzero value if a new vtable is actually
831 created. */
833 static int
835 {
836 tree decl;
837 tree virtuals;
842 {
844 /* We have already created a vtable for this base, so there's
845 no need to do it again. */
852 }
853 else
854 {
857 }
860 {
863 }
865 /* Initialize the association list for this type, based
866 on our first approximation. */
871 }
873 /* Give BINFO a new virtual function table which is initialized
874 with a skeleton-copy of its original initialization. The only
875 entry that changes is the `delta' entry, so we can really
876 share a lot of structure.
878 FOR_TYPE is the most derived type which caused this table to
879 be needed.
881 Returns nonzero if we haven't met BINFO before.
883 The order in which vtables are built (by calling this function) for
884 an object must remain the same, otherwise a binary incompatibility
885 can result. */
887 static int
889 {
891 /* We already created a vtable for this base. There's no need to
892 do it again. */
895 /* Remember that we've created a vtable for this BINFO, so that we
896 don't try to do so again. */
899 /* Make fresh virtual list, so we can smash it later. */
902 /* Secondary vtables are laid out as part of the same structure as
903 the primary vtable. */
906 }
908 /* Create a new vtable for BINFO which is the hierarchy dominated by
909 T. Return nonzero if we actually created a new vtable. */
911 static int
913 {
915 /* In this case, it is *type*'s vtable we are modifying. We start
916 with the approximation that its vtable is that of the
917 immediate base class. */
919 else
920 /* This is our very own copy of `basetype' to play with. Later,
921 we will fill in all the virtual functions that override the
922 virtual functions in these base classes which are not defined
923 by the current type. */
925 }
927 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
928 (which is in the hierarchy dominated by T) list FNDECL as its
929 BV_FN. DELTA is the required constant adjustment from the `this'
930 pointer where the vtable entry appears to the `this' required when
931 the function is actually called. */
933 static void
935 tree binfo,
936 tree fndecl,
937 tree delta,
939 {
940 tree v;
946 {
947 /* We need a new vtable for BINFO. */
949 {
950 /* If we really did make a new vtable, we also made a copy
951 of the BINFO_VIRTUALS list. Now, we have to find the
952 corresponding entry in that list. */
957 }
962 }
963 }
965 \f
966 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
967 the USING_DECL naming METHOD. Returns true if the method could be
968 added to the method vec. */
970 bool
972 {
974 tree overload;
980 tree current_fns;
981 tree fns;
994 {
995 /* Make a new method vector. We start with 8 entries. We must
996 allocate at least two (for constructors and destructors), and
997 we're going to end up with an assignment operator at some
998 point as well. */
1000 /* Create slots for constructors and destructors. */
1004 }
1006 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1009 /* Constructors and destructors go in special slots. */
1013 {
1017 {
1023 type);
1024 }
1025 }
1026 else
1027 {
1028 tree m;
1031 /* See if we already have an entry with this name. */
1035 {
1038 {
1043 }
1047 {
1050 }
1055 }
1056 }
1059 /* Check to see if we've already got this method. */
1061 {
1063 tree fn_type;
1064 tree method_type;
1065 tree parms1;
1066 tree parms2;
1071 /* [over.load] Member function declarations with the
1072 same name and the same parameter types cannot be
1073 overloaded if any of them is a static member
1074 function declaration.
1076 [over.load] Member function declarations with the same name and
1077 the same parameter-type-list as well as member function template
1078 declarations with the same name, the same parameter-type-list, and
1079 the same template parameter lists cannot be overloaded if any of
1080 them, but not all, have a ref-qualifier.
1082 [namespace.udecl] When a using-declaration brings names
1083 from a base class into a derived class scope, member
1084 functions in the derived class override and/or hide member
1085 functions with the same name and parameter types in a base
1086 class (rather than conflicting). */
1092 /* Compare the quals on the 'this' parm. Don't compare
1093 the whole types, as used functions are treated as
1094 coming from the using class in overload resolution. */
1097 /* Either both or neither need to be ref-qualified for
1098 differing quals to allow overloading. */
1105 /* For templates, the return type and template parameters
1106 must be identical. */
1123 {
1124 /* For function versions, their parms and types match
1125 but they are not duplicates. Record function versions
1126 as and when they are found. extern "C" functions are
1127 not treated as versions. */
1133 {
1134 /* Mark functions as versions if necessary. Modify the mangled
1135 decl name if necessary. */
1137 {
1141 }
1143 {
1147 }
1150 }
1152 {
1154 {
1161 }
1162 /* Otherwise defer to the other function. */
1164 }
1166 {
1168 /* Defer to the local function. */
1170 }
1171 else
1172 {
1175 }
1177 /* We don't call duplicate_decls here to merge the
1178 declarations because that will confuse things if the
1179 methods have inline definitions. In particular, we
1180 will crash while processing the definitions. */
1182 }
1183 }
1185 /* A class should never have more than one destructor. */
1189 /* Add the new binding. */
1191 {
1194 }
1195 else
1204 {
1207 /* We only expect to add few methods in the COMPLETE_P case, so
1208 just make room for one more method in that case. */
1211 else
1217 else
1219 }
1220 else
1221 /* Replace the current slot. */
1224 }
1226 /* Subroutines of finish_struct. */
1228 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1229 legit, otherwise return 0. */
1231 static int
1233 {
1234 tree elem;
1243 {
1245 {
1249 else
1252 }
1253 else
1254 {
1255 /* They're changing the access to the same thing they changed
1256 it to before. That's OK. */
1257 ;
1258 }
1259 }
1260 else
1261 {
1263 tf_warning_or_error);
1266 }
1268 }
1270 /* Process the USING_DECL, which is a member of T. */
1272 static void
1274 {
1277 tree access
1282 tree old_value;
1287 tf_warning_or_error);
1289 {
1295 else
1297 }
1305 ;
1307 {
1309 /* It's OK to use functions from a base when there are functions with
1311 else
1312 {
1317 }
1318 }
1320 {
1324 }
1326 /* Make type T see field decl FDECL with access ACCESS. */
1329 {
1332 }
1333 else
1335 }
1336 \f
1337 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1338 types with abi tags, add the corresponding identifiers to the VEC in
1339 *DATA and set IDENTIFIER_MARKED. */
1341 struct abi_tag_data
1342 {
1343 tree t;
1344 tree subob;
1345 // error_mark_node to get diagnostics; otherwise collect missing tags here
1346 tree tags;
1347 };
1349 static tree
1351 {
1355 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1356 anyway, but let's make sure of it. */
1360 {
1364 {
1368 {
1370 {
1371 /* We're collecting tags from template arguments. */
1377 /* Don't inherit this tag multiple times. */
1379 }
1381 /* Otherwise we're diagnosing missing tags. */
1383 {
1388 }
1389 else
1390 {
1394 {
1398 }
1399 }
1400 }
1401 }
1402 }
1404 }
1406 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1407 complete) template arguments. */
1409 static void
1411 {
1414 {
1417 {
1421 }
1422 }
1423 }
1425 /* Check that class T has all the abi tags that subobject SUBOB has, or
1426 warn if not. */
1428 static void
1430 {
1439 }
1441 void
1443 {
1453 {
1456 {
1460 }
1461 }
1463 // If we found some tags on our template arguments, add them to our
1464 // abi_tag attribute.
1466 {
1470 else
1474 }
1477 }
1479 /* Return true, iff class T has a non-virtual destructor that is
1480 accessible from outside the class heirarchy (i.e. is public, or
1481 there's a suitable friend. */
1483 static bool
1485 {
1488 /* An implicitly declared destructor is always public. And,
1489 if it were virtual, we would have created it by now. */
1504 }
1506 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1507 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1508 properties of the bases. */
1510 static void
1514 {
1518 tree base_binfo;
1519 tree binfo;
1529 {
1538 /* If any base class is non-literal, so is the derived class. */
1542 /* If the base class doesn't have copy constructors or
1543 assignment operators that take const references, then the
1544 derived class cannot have such a member automatically
1545 generated. */
1554 /* A virtual base does not effect nearly emptiness. */
1555 ;
1557 {
1559 /* And if there is more than one nearly empty base, then the
1560 derived class is not nearly empty either. */
1562 else
1563 /* Remember we've seen one. */
1565 }
1567 /* If the base class is not empty or nearly empty, then this
1568 class cannot be nearly empty. */
1571 /* A lot of properties from the bases also apply to the derived
1572 class. */
1589 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1592 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1596 /* A standard-layout class is a class that:
1597 ...
1598 * has no non-standard-layout base classes, */
1601 {
1602 tree basefield;
1603 /* ...has no base classes of the same type as the first non-static
1604 data member... */
1606 && (same_type_ignoring_top_level_qualifiers_p
1609 else
1610 /* ...either has no non-static data members in the most-derived
1611 class and at most one base class with non-static data
1612 members, or has no base classes with non-static data
1613 members */
1617 {
1620 else
1623 }
1624 }
1626 /* Don't bother collecting tm attributes if transactional memory
1627 support is not enabled. */
1629 {
1633 }
1636 }
1638 /* If one of the base classes had TM attributes, and the current class
1639 doesn't define its own, then the current class inherits one. */
1641 {
1644 }
1645 }
1647 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1648 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1649 that have had a nearly-empty virtual primary base stolen by some
1650 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1651 T. */
1653 static void
1655 {
1659 tree base_binfo;
1661 /* Determine the primary bases of our bases. */
1664 {
1667 /* See if we're the non-virtual primary of our inheritance
1668 chain. */
1670 {
1677 /* We are the primary binfo. */
1679 }
1680 /* Determine if we have a virtual primary base, and mark it so.
1681 */
1683 {
1687 /* Someone already claimed this base. */
1689 else
1690 {
1691 tree delta;
1696 /* A virtual binfo might have been copied from within
1697 another hierarchy. As we're about to use it as a
1698 primary base, make sure the offsets match. */
1706 }
1707 }
1708 }
1710 /* First look for a dynamic direct non-virtual base. */
1712 {
1716 {
1719 }
1720 }
1722 /* A "nearly-empty" virtual base class can be the primary base
1723 class, if no non-virtual polymorphic base can be found. Look for
1724 a nearly-empty virtual dynamic base that is not already a primary
1725 base of something in the hierarchy. If there is no such base,
1726 just pick the first nearly-empty virtual base. */
1732 {
1734 {
1735 /* Found one that is not primary. */
1738 }
1740 /* Remember the first candidate. */
1742 }
1744 found:
1745 /* If we've got a primary base, use it. */
1747 {
1752 /* We are stealing a primary base. */
1756 {
1757 tree delta;
1760 /* A virtual binfo might have been copied from within
1761 another hierarchy. As we're about to use it as a primary
1762 base, make sure the offsets match. */
1767 }
1774 }
1775 }
1777 /* Update the variant types of T. */
1779 void
1781 {
1782 tree variants;
1788 variants;
1790 {
1791 /* These fields are in the _TYPE part of the node, not in
1792 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1802 /* Copy whatever these are holding today. */
1806 }
1807 }
1809 /* Early variant fixups: we apply attributes at the beginning of the class
1810 definition, and we need to fix up any variants that have already been
1811 made via elaborated-type-specifier so that check_qualified_type works. */
1813 void
1815 {
1816 tree variants;
1822 variants;
1824 {
1825 /* These are the two fields that check_qualified_type looks at and
1826 are affected by attributes. */
1829 }
1830 }
1831 \f
1832 /* Set memoizing fields and bits of T (and its variants) for later
1833 use. */
1835 static void
1837 {
1838 /* Fix up variants (if any). */
1842 /* For a class w/o baseclasses, 'finish_struct' has set
1843 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1844 Similarly for a class whose base classes do not have vtables.
1845 When neither of these is true, we might have removed abstract
1846 virtuals (by providing a definition), added some (by declaring
1847 new ones), or redeclared ones from a base class. We need to
1848 recalculate what's really an abstract virtual at this point (by
1849 looking in the vtables). */
1852 /* If this type has a copy constructor or a destructor, force its
1853 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1854 nonzero. This will cause it to be passed by invisible reference
1855 and prevent it from being returned in a register. */
1858 {
1859 tree variants;
1862 {
1865 }
1866 }
1867 }
1869 /* Issue warnings about T having private constructors, but no friends,
1870 and so forth.
1872 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1873 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1874 non-private static member functions. */
1876 static void
1878 {
1881 tree fn;
1884 /* If the class has friends, those entities might create and
1885 access instances, so we should not warn. */
1888 /* We will have warned when the template was declared; there's
1889 no need to warn on every instantiation. */
1891 /* There's no reason to even consider warning about this
1892 class. */
1895 /* We only issue one warning, if more than one applies, because
1896 otherwise, on code like:
1898 class A {
1899 // Oops - forgot `public:'
1900 A();
1901 A(const A&);
1902 ~A();
1903 };
1905 we warn several times about essentially the same problem. */
1907 /* Check to see if all (non-constructor, non-destructor) member
1908 functions are private. (Since there are no friends or
1909 non-private statics, we can't ever call any of the private member
1910 functions.) */
1912 /* We're not interested in compiler-generated methods; they don't
1913 provide any way to call private members. */
1915 {
1917 {
1919 /* A non-private static member function is just like a
1920 friend; it can create and invoke private member
1921 functions, and be accessed without a class
1922 instance. */
1926 /* Keep searching for a static member function. */
1927 }
1930 }
1933 {
1934 /* There are no non-private methods, and there's at least one
1935 private member function that isn't a constructor or
1936 destructor. (If all the private members are
1937 constructors/destructors we want to use the code below that
1938 issues error messages specifically referring to
1939 constructors/destructors.) */
1945 {
1948 }
1950 {
1954 }
1955 }
1957 /* Even if some of the member functions are non-private, the class
1958 won't be useful for much if all the constructors or destructors
1959 are private: such an object can never be created or destroyed. */
1962 {
1965 t);
1967 }
1969 /* Warn about classes that have private constructors and no friends. */
1971 /* Implicitly generated constructors are always public. */
1974 {
1977 /* If a non-template class does not define a copy
1978 constructor, one is defined for it, enabling it to avoid
1979 this warning. For a template class, this does not
1980 happen, and so we would normally get a warning on:
1982 template <class T> class C { private: C(); };
1984 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1985 complete non-template or fully instantiated classes have this
1986 flag set. */
1989 else
1991 {
1993 /* Ideally, we wouldn't count copy constructors (or, in
1994 fact, any constructor that takes an argument of the
1995 class type as a parameter) because such things cannot
1996 be used to construct an instance of the class unless
1997 you already have one. But, for now at least, we're
1998 more generous. */
2000 {
2003 }
2004 }
2007 {
2010 t);
2012 }
2013 }
2014 }
2017 gt_pointer_operator new_value;
2021 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2023 static int
2025 {
2038 }
2040 /* This routine compares two fields like method_name_cmp but using the
2041 pointer operator in resort_field_decl_data. */
2043 static int
2045 {
2054 {
2061 }
2063 }
2065 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2067 void
2070 gt_pointer_operator new_value,
2072 {
2076 tree fn;
2078 /* The type conversion ops have to live at the front of the vec, so we
2079 can't sort them. */
2087 {
2091 resort_method_name_cmp);
2092 }
2093 }
2095 /* Warn about duplicate methods in fn_fields.
2097 Sort methods that are not special (i.e., constructors, destructors,
2098 and type conversion operators) so that we can find them faster in
2099 search. */
2101 static void
2103 {
2104 tree fn_fields;
2114 /* Clear DECL_IN_AGGR_P for all functions. */
2119 /* Issue warnings about private constructors and such. If there are
2120 no methods, then some public defaults are generated. */
2123 /* The type conversion ops have to live at the front of the vec, so we
2124 can't sort them. */
2133 }
2135 /* Make BINFO's vtable have N entries, including RTTI entries,
2136 vbase and vcall offsets, etc. Set its type and call the back end
2137 to lay it out. */
2139 static void
2141 {
2142 tree atype;
2143 tree vtable;
2148 /* We may have to grow the vtable. */
2151 {
2155 }
2156 }
2158 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2159 have the same signature. */
2161 int
2163 {
2164 /* One destructor overrides another if they are the same kind of
2165 destructor. */
2169 /* But a non-destructor never overrides a destructor, nor vice
2170 versa, nor do different kinds of destructors override
2171 one-another. For example, a complete object destructor does not
2172 override a deleting destructor. */
2181 {
2189 }
2191 }
2193 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2194 subobject. */
2196 static bool
2198 {
2199 tree probe;
2202 {
2206 /* If we meet a virtual base, we can't follow the inheritance
2207 any more. See if the complete type of DERIVED contains
2208 such a virtual base. */
2211 }
2213 }
2216 /* The function for which we are trying to find a final overrider. */
2217 tree fn;
2218 /* The base class in which the function was declared. */
2219 tree declaring_base;
2220 /* The candidate overriders. */
2221 tree candidates;
2222 /* Path to most derived. */
2226 /* Add the overrider along the current path to FFOD->CANDIDATES.
2227 Returns true if an overrider was found; false otherwise. */
2229 static bool
2233 {
2234 tree method;
2236 /* If BINFO is not the most derived type, try a more derived class.
2237 A definition there will overrider a definition here. */
2239 {
2240 depth--;
2244 }
2248 {
2251 /* Remove any candidates overridden by this new function. */
2253 {
2254 /* If *CANDIDATE overrides METHOD, then METHOD
2255 cannot override anything else on the list. */
2258 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2261 else
2263 }
2265 /* Add the new function. */
2268 }
2271 }
2273 /* Called from find_final_overrider via dfs_walk. */
2275 static tree
2277 {
2285 }
2287 static tree
2289 {
2294 }
2296 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2297 FN and whose TREE_VALUE is the binfo for the base where the
2298 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2299 DERIVED) is the base object in which FN is declared. */
2301 static tree
2303 {
2304 find_final_overrider_data ffod;
2306 /* Getting this right is a little tricky. This is valid:
2308 struct S { virtual void f (); };
2309 struct T { virtual void f (); };
2310 struct U : public S, public T { };
2312 even though calling `f' in `U' is ambiguous. But,
2314 struct R { virtual void f(); };
2315 struct S : virtual public R { virtual void f (); };
2316 struct T : virtual public R { virtual void f (); };
2317 struct U : public S, public T { };
2319 is not -- there's no way to decide whether to put `S::f' or
2320 `T::f' in the vtable for `R'.
2322 The solution is to look at all paths to BINFO. If we find
2323 different overriders along any two, then there is a problem. */
2327 /* Determine the depth of the hierarchy. */
2338 /* If there was no winner, issue an error message. */
2343 }
2345 /* Return the index of the vcall offset for FN when TYPE is used as a
2346 virtual base. */
2348 static tree
2350 {
2352 tree_pair_p p;
2360 /* There should always be an appropriate index. */
2362 }
2364 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2365 dominated by T. FN is the old function; VIRTUALS points to the
2366 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2367 of that entry in the list. */
2369 static void
2372 {
2373 tree b;
2374 tree overrider;
2375 tree delta;
2376 tree virtual_base;
2377 tree first_defn;
2383 /* Find the nearest primary base (possibly binfo itself) which defines
2384 this function; this is the class the caller will convert to when
2385 calling FN through BINFO. */
2387 {
2392 /* The nearest definition is from a lost primary. */
2395 }
2398 /* Find the final overrider. */
2401 {
2404 }
2407 /* Check for adjusting covariant return types. */
2415 /* If the overrider is invalid, don't even try. */
2417 {
2418 /* If FN is a covariant thunk, we must figure out the adjustment
2419 to the final base FN was converting to. As OVERRIDER_TARGET might
2420 also be converting to the return type of FN, we have to
2421 combine the two conversions here. */
2428 {
2432 }
2433 else
2437 /* Find the equivalent binfo within the return type of the
2438 overriding function. We will want the vbase offset from
2439 there. */
2441 over_return);
2444 {
2445 /* There was no existing virtual thunk (which takes
2446 precedence). So find the binfo of the base function's
2447 return type within the overriding function's return type.
2448 We cannot call lookup base here, because we're inside a
2449 dfs_walk, and will therefore clobber the BINFO_MARKED
2450 flags. Fortunately we know the covariancy is valid (it
2451 has already been checked), so we can just iterate along
2452 the binfos, which have been chained in inheritance graph
2453 order. Of course it is lame that we have to repeat the
2454 search here anyway -- we should really be caching pieces
2455 of the vtable and avoiding this repeated work. */
2458 /* Find the base binfo within the overriding function's
2459 return type. We will always find a thunk_binfo, except
2460 when the covariancy is invalid (which we will have
2461 already diagnosed). */
2464 thunk_binfo;
2470 /* See if virtual inheritance is involved. */
2472 virtual_offset;
2479 {
2483 {
2484 /* We convert via virtual base. Adjust the fixed
2485 offset to be from there. */
2486 offset =
2490 }
2492 /* There was an existing fixed offset, this must be
2493 from the base just converted to, and the base the
2494 FN was thunking to. */
2496 else
2498 }
2499 }
2502 /* Replace the overriding function with a covariant thunk. We
2503 will emit the overriding function in its own slot as
2504 well. */
2507 }
2508 else
2512 /* If we need a covariant thunk, then we may need to adjust first_defn.
2513 The ABI specifies that the thunks emitted with a function are
2514 determined by which bases the function overrides, so we need to be
2515 sure that we're using a thunk for some overridden base; even if we
2516 know that the necessary this adjustment is zero, there may not be an
2517 appropriate zero-this-adjusment thunk for us to use since thunks for
2518 overriding virtual bases always use the vcall offset.
2520 Furthermore, just choosing any base that overrides this function isn't
2521 quite right, as this slot won't be used for calls through a type that
2522 puts a covariant thunk here. Calling the function through such a type
2523 will use a different slot, and that slot is the one that determines
2524 the thunk emitted for that base.
2526 So, keep looking until we find the base that we're really overriding
2527 in this slot: the nearest primary base that doesn't use a covariant
2528 thunk in this slot. */
2530 {
2532 /* We already know that the overrider needs a covariant thunk. */
2535 {
2542 }
2544 }
2546 /* Assume that we will produce a thunk that convert all the way to
2547 the final overrider, and not to an intermediate virtual base. */
2550 /* See if we can convert to an intermediate virtual base first, and then
2551 use the vcall offset located there to finish the conversion. */
2553 {
2554 /* If we find the final overrider, then we can stop
2555 walking. */
2560 /* If we find a virtual base, and we haven't yet found the
2561 overrider, then there is a virtual base between the
2562 declaring base (first_defn) and the final overrider. */
2564 {
2567 }
2568 }
2570 /* Compute the constant adjustment to the `this' pointer. The
2571 `this' pointer, when this function is called, will point at BINFO
2572 (or one of its primary bases, which are at the same offset). */
2574 /* The `this' pointer needs to be adjusted from the declaration to
2575 the nearest virtual base. */
2580 /* If the nearest definition is in a lost primary, we don't need an
2581 entry in our vtable. Except possibly in a constructor vtable,
2582 if we happen to get our primary back. In that case, the offset
2583 will be zero, as it will be a primary base. */
2585 else
2586 /* The `this' pointer needs to be adjusted from pointing to
2587 BINFO to pointing at the base where the final overrider
2588 appears. */
2599 else
2603 }
2605 /* Called from modify_all_vtables via dfs_walk. */
2607 static tree
2609 {
2611 tree virtuals;
2612 tree old_virtuals;
2616 /* A base without a vtable needs no modification, and its bases
2617 are uninteresting. */
2622 /* Don't do the primary vtable, if it's new. */
2626 /* There's no need to modify the vtable for a non-virtual primary
2627 base; we're not going to use that vtable anyhow. We do still
2628 need to do this for virtual primary bases, as they could become
2629 non-primary in a construction vtable. */
2634 /* Now, go through each of the virtual functions in the virtual
2635 function table for BINFO. Find the final overrider, and update
2636 the BINFO_VIRTUALS list appropriately. */
2639 virtuals;
2643 binfo,
2648 }
2650 /* Update all of the primary and secondary vtables for T. Create new
2651 vtables as required, and initialize their RTTI information. Each
2652 of the functions in VIRTUALS is declared in T and may override a
2653 virtual function from a base class; find and modify the appropriate
2654 entries to point to the overriding functions. Returns a list, in
2655 declaration order, of the virtual functions that are declared in T,
2656 but do not appear in the primary base class vtable, and which
2657 should therefore be appended to the end of the vtable for T. */
2659 static tree
2661 {
2665 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2669 /* Update all of the vtables. */
2672 /* Add virtual functions not already in our primary vtable. These
2673 will be both those introduced by this class, and those overridden
2674 from secondary bases. It does not include virtuals merely
2675 inherited from secondary bases. */
2677 {
2682 {
2683 /* We don't need to adjust the `this' pointer when
2684 calling this function. */
2688 /* This is a function not already in our vtable. Keep it. */
2690 }
2691 else
2692 /* We've already got an entry for this function. Skip it. */
2694 }
2697 }
2699 /* Get the base virtual function declarations in T that have the
2700 indicated NAME. */
2702 static tree
2704 {
2705 tree methods;
2710 /* Find virtual functions in T with the indicated NAME. */
2714 methods;
2716 {
2722 }
2728 {
2731 base_fndecls);
2732 }
2735 }
2737 /* If this declaration supersedes the declaration of
2738 a method declared virtual in the base class, then
2739 mark this field as being virtual as well. */
2741 void
2743 {
2746 /* In [temp.mem] we have:
2748 A specialization of a member function template does not
2749 override a virtual function from a base class. */
2756 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2757 the error_mark_node so that we know it is an overriding
2758 function. */
2759 {
2762 }
2765 {
2771 }
2776 }
2778 /* Warn about hidden virtual functions that are not overridden in t.
2779 We know that constructors and destructors don't apply. */
2781 static void
2783 {
2785 tree fns;
2788 /* We go through each separately named virtual function. */
2792 {
2793 tree fn;
2794 tree name;
2795 tree fndecl;
2796 tree base_fndecls;
2797 tree base_binfo;
2798 tree binfo;
2801 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2802 have the same name. Figure out what name that is. */
2804 /* There are no possibly hidden functions yet. */
2806 /* Iterate through all of the base classes looking for possibly
2807 hidden functions. */
2810 {
2813 base_fndecls);
2814 }
2816 /* If there are no functions to hide, continue. */
2820 /* Remove any overridden functions. */
2822 {
2825 {
2829 /* If the method from the base class has the same
2830 signature as the method from the derived class, it
2831 has been overridden. */
2834 else
2836 }
2837 }
2839 /* Now give a warning for all base functions without overriders,
2840 as they are hidden. */
2842 {
2843 /* Here we know it is a hider, and no overrider exists. */
2847 }
2848 }
2849 }
2851 /* Recursive helper for finish_struct_anon. */
2853 static void
2855 {
2859 {
2860 /* We're generally only interested in entities the user
2861 declared, but we also find nested classes by noticing
2862 the TYPE_DECL that we create implicitly. You're
2863 allowed to put one anonymous union inside another,
2864 though, so we explicitly tolerate that. We use
2865 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2866 we also allow unnamed types used for defining fields. */
2873 {
2874 /* We already complained about static data members in
2875 finish_static_data_member_decl. */
2877 {
2880 "%q+#D invalid; an anonymous union can "
2882 else
2884 "%q+#D invalid; an anonymous struct can "
2886 }
2888 }
2891 {
2893 {
2897 else
2900 }
2902 {
2906 else
2909 }
2910 }
2915 /* Recurse into the anonymous aggregates to handle correctly
2916 access control (c++/24926):
2918 class A {
2919 union {
2920 union {
2921 int i;
2922 };
2923 };
2924 };
2926 int j=A().i; */
2930 }
2931 }
2933 /* Check for things that are invalid. There are probably plenty of other
2934 things we should check for also. */
2936 static void
2938 {
2940 {
2949 }
2950 }
2952 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2953 will be used later during class template instantiation.
2954 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2955 a non-static member data (FIELD_DECL), a member function
2956 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2957 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2958 When FRIEND_P is nonzero, T is either a friend class
2959 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2960 (FUNCTION_DECL, TEMPLATE_DECL). */
2962 void
2964 {
2965 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2970 }
2972 /* This function is called from declare_virt_assop_and_dtor via
2973 dfs_walk_all.
2975 DATA is a type that direcly or indirectly inherits the base
2976 represented by BINFO. If BINFO contains a virtual assignment [copy
2977 assignment or move assigment] operator or a virtual constructor,
2978 declare that function in DATA if it hasn't been already declared. */
2980 static tree
2982 {
2990 /* A base without a vtable needs no modification, and its bases
2991 are uninteresting. */
2995 /* If this is a primary base, then we have already looked at the
2996 virtual functions of its vtable. */
3000 {
3004 {
3009 }
3013 }
3016 }
3018 /* If the class type T has a direct or indirect base that contains a
3019 virtual assignment operator or a virtual destructor, declare that
3020 function in T if it hasn't been already declared. */
3022 static void
3024 {
3032 dfs_declare_virt_assop_and_dtor,
3034 }
3036 /* Declare the inheriting constructor for class T inherited from base
3037 constructor CTOR with the parameter array PARMS of size NPARMS. */
3039 static void
3041 {
3042 /* We don't declare an inheriting ctor that would be a default,
3043 copy or move ctor for derived or base. */
3048 {
3052 }
3060 {
3063 }
3064 }
3066 /* Declare all the inheriting constructors for class T inherited from base
3067 constructor CTOR. */
3069 static void
3071 {
3077 {
3081 }
3084 {
3088 }
3089 }
3091 /* Create default constructors, assignment operators, and so forth for
3092 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3093 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3094 the class cannot have a default constructor, copy constructor
3095 taking a const reference argument, or an assignment operator taking
3096 a const reference, respectively. */
3098 static void
3102 {
3110 /* Destructor. */
3112 {
3113 /* In general, we create destructors lazily. */
3118 /* But if this is a Java class, any non-trivial destructor is
3119 invalid, even if compiler-generated. Therefore, if the
3120 destructor is non-trivial we create it now. */
3122 }
3124 /* [class.ctor]
3126 If there is no user-declared constructor for a class, a default
3127 constructor is implicitly declared. */
3129 {
3134 /* This might force the declaration. */
3136 }
3138 /* [class.ctor]
3140 If a class definition does not explicitly declare a copy
3141 constructor, one is declared implicitly. */
3143 {
3149 }
3151 /* If there is no assignment operator, one will be created if and
3152 when it is needed. For now, just record whether or not the type
3153 of the parameter to the assignment operator will be a const or
3154 non-const reference. */
3156 {
3162 }
3164 /* We can't be lazy about declaring functions that might override
3165 a virtual function from a base class. */
3169 {
3173 {
3174 /* declare, then remove the decl */
3183 }
3184 else
3186 }
3187 }
3189 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3190 count the number of fields in TYPE, including anonymous union
3191 members. */
3193 static int
3195 {
3196 tree x;
3199 {
3202 else
3204 }
3206 }
3208 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3209 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3210 elts, starting at offset IDX. */
3212 static int
3214 {
3215 tree x;
3217 {
3220 else
3222 }
3224 }
3226 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3227 starting at offset IDX. */
3229 static int
3233 {
3234 tree values;
3238 }
3240 /* FIELD is a bit-field. We are finishing the processing for its
3241 enclosing type. Issue any appropriate messages and set appropriate
3242 flags. Returns false if an error has been diagnosed. */
3244 static bool
3246 {
3248 tree w;
3250 /* Extract the declared width of the bitfield, which has been
3251 temporarily stashed in DECL_INITIAL. */
3254 /* Remove the bit-field width indicator so that the rest of the
3255 compiler does not treat that value as an initializer. */
3258 /* Detect invalid bit-field type. */
3260 {
3263 }
3264 else
3265 {
3267 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3270 /* detect invalid field size. */
3276 {
3279 }
3281 {
3284 }
3286 {
3289 }
3301 }
3304 {
3308 }
3309 else
3310 {
3311 /* Non-bit-fields are aligned for their type. */
3315 }
3316 }
3318 /* FIELD is a non bit-field. We are finishing the processing for its
3319 enclosing type T. Issue any appropriate messages and set appropriate
3320 flags. */
3322 static void
3324 tree t,
3328 {
3331 /* In C++98 an anonymous union cannot contain any fields which would change
3332 the settings of CANT_HAVE_CONST_CTOR and friends. */
3334 ;
3335 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3336 structs. So, we recurse through their fields here. */
3338 {
3339 tree fields;
3345 }
3346 /* Check members with class type for constructors, destructors,
3347 etc. */
3349 {
3350 /* Never let anything with uninheritable virtuals
3351 make it through without complaint. */
3355 {
3360 field);
3365 field);
3367 {
3371 }
3372 }
3373 else
3374 {
3387 }
3396 }
3401 {
3402 /* `build_class_init_list' does not recognize
3403 non-FIELD_DECLs. */
3407 }
3408 }
3410 /* Check the data members (both static and non-static), class-scoped
3411 typedefs, etc., appearing in the declaration of T. Issue
3412 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3413 declaration order) of access declarations; each TREE_VALUE in this
3414 list is a USING_DECL.
3416 In addition, set the following flags:
3418 EMPTY_P
3419 The class is empty, i.e., contains no non-static data members.
3421 CANT_HAVE_CONST_CTOR_P
3422 This class cannot have an implicitly generated copy constructor
3423 taking a const reference.
3425 CANT_HAVE_CONST_ASN_REF
3426 This class cannot have an implicitly generated assignment
3427 operator taking a const reference.
3429 All of these flags should be initialized before calling this
3430 function.
3432 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3433 fields can be added by adding to this chain. */
3435 static void
3439 {
3447 /* Assume there are no access declarations. */
3449 /* Assume this class has no pointer members. */
3451 /* Assume none of the members of this class have default
3452 initializations. */
3456 {
3464 {
3465 /* Save the access declarations for our caller. */
3468 }
3474 /* If we've gotten this far, it's a data member, possibly static,
3475 or an enumerator. */
3479 /* When this goes into scope, it will be a non-local reference. */
3484 {
3485 /* [class.union] (C++98)
3487 If a union contains a static data member, or a member of
3488 reference type, the program is ill-formed.
3490 In C++11 this limitation doesn't exist anymore. */
3492 {
3496 }
3498 {
3502 }
3503 }
3505 /* Perform error checking that did not get done in
3506 grokdeclarator. */
3508 {
3512 }
3514 {
3518 }
3526 /* Now it can only be a FIELD_DECL. */
3531 /* If at least one non-static data member is non-literal, the whole
3532 class becomes non-literal. Per Core/1453, volatile non-static
3533 data members and base classes are also not allowed.
3534 Note: if the type is incomplete we will complain later on. */
3539 /* A standard-layout class is a class that:
3540 ...
3541 has the same access control (Clause 11) for all non-static data members,
3542 ... */
3549 /* If this is of reference type, check if it needs an init. */
3551 {
3557 /* ARM $12.6.2: [A member initializer list] (or, for an
3558 aggregate, initialization by a brace-enclosed list) is the
3559 only way to initialize nonstatic const and reference
3560 members. */
3563 }
3568 {
3570 {
3571 warning
3574 x);
3576 }
3580 }
3583 /* We don't treat zero-width bitfields as making a class
3584 non-empty. */
3585 ;
3586 else
3587 {
3588 /* The class is non-empty. */
3590 /* The class is not even nearly empty. */
3592 /* If one of the data members contains an empty class,
3593 so does T. */
3597 }
3599 /* This is used by -Weffc++ (see below). Warn only for pointers
3600 to members which might hold dynamic memory. So do not warn
3601 for pointers to functions or pointers to members. */
3607 {
3612 }
3618 {
3620 {
3624 }
3626 {
3630 }
3631 }
3634 /* DR 148 now allows pointers to members (which are POD themselves),
3635 to be allowed in POD structs. */
3644 /* We set DECL_C_BIT_FIELD in grokbitfield.
3645 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3648 cant_have_const_ctor_p,
3649 no_const_asn_ref_p,
3652 /* Now that we've removed bit-field widths from DECL_INITIAL,
3653 anything left in DECL_INITIAL is an NSDMI that makes the class
3654 non-aggregate. */
3658 /* If any field is const, the structure type is pseudo-const. */
3660 {
3665 /* ARM $12.6.2: [A member initializer list] (or, for an
3666 aggregate, initialization by a brace-enclosed list) is the
3667 only way to initialize nonstatic const and reference
3668 members. */
3671 }
3672 /* A field that is pseudo-const makes the structure likewise. */
3674 {
3679 }
3681 /* Core issue 80: A nonstatic data member is required to have a
3682 different name from the class iff the class has a
3683 user-declared constructor. */
3687 }
3689 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3690 it should also define a copy constructor and an assignment operator to
3691 implement the correct copy semantic (deep vs shallow, etc.). As it is
3692 not feasible to check whether the constructors do allocate dynamic memory
3693 and store it within members, we approximate the warning like this:
3695 -- Warn only if there are members which are pointers
3696 -- Warn only if there is a non-trivial constructor (otherwise,
3697 there cannot be memory allocated).
3698 -- Warn only if there is a non-trivial destructor. We assume that the
3699 user at least implemented the cleanup correctly, and a destructor
3700 is needed to free dynamic memory.
3702 This seems enough for practical purposes. */
3704 && has_pointers
3708 {
3712 {
3717 }
3721 }
3723 /* Non-static data member initializers make the default constructor
3724 non-trivial. */
3726 {
3729 }
3731 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3735 /* Check anonymous struct/anonymous union fields. */
3738 /* We've built up the list of access declarations in reverse order.
3739 Fix that now. */
3741 }
3743 /* If TYPE is an empty class type, records its OFFSET in the table of
3744 OFFSETS. */
3746 static int
3748 {
3749 splay_tree_node n;
3754 /* Record the location of this empty object in OFFSETS. */
3762 type,
3766 }
3768 /* Returns nonzero if TYPE is an empty class type and there is
3769 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3771 static int
3773 {
3774 splay_tree_node n;
3775 tree t;
3780 /* Record the location of this empty object in OFFSETS. */
3790 }
3792 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3793 F for every subobject, passing it the type, offset, and table of
3794 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3795 be traversed.
3797 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3798 than MAX_OFFSET will not be walked.
3800 If F returns a nonzero value, the traversal ceases, and that value
3801 is returned. Otherwise, returns zero. */
3803 static int
3805 subobject_offset_fn f,
3806 tree offset,
3807 splay_tree offsets,
3808 tree max_offset,
3810 {
3814 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3815 stop. */
3823 {
3826 }
3829 {
3830 tree field;
3831 tree binfo;
3834 /* Avoid recursing into objects that are not interesting. */
3838 /* Record the location of TYPE. */
3843 /* Iterate through the direct base classes of TYPE. */
3847 {
3848 tree binfo_offset;
3853 tree orig_binfo;
3854 /* We cannot rely on BINFO_OFFSET being set for the base
3855 class yet, but the offsets for direct non-virtual
3856 bases can be calculated by going back to the TYPE. */
3859 offset,
3863 f,
3864 binfo_offset,
3865 offsets,
3866 max_offset,
3870 }
3873 {
3877 /* Iterate through the virtual base classes of TYPE. In G++
3878 3.2, we included virtual bases in the direct base class
3879 loop above, which results in incorrect results; the
3880 correct offsets for virtual bases are only known when
3881 working with the most derived type. */
3885 {
3887 f,
3889 offset,
3891 offsets,
3892 max_offset,
3896 }
3897 else
3898 {
3899 /* We still have to walk the primary base, if it is
3900 virtual. (If it is non-virtual, then it was walked
3901 above.) */
3907 {
3908 r = (walk_subobject_offsets
3913 }
3914 }
3915 }
3917 /* Iterate through the fields of TYPE. */
3922 {
3923 tree field_offset;
3928 f,
3930 offset,
3931 field_offset),
3932 offsets,
3933 max_offset,
3937 }
3938 }
3940 {
3943 tree index;
3945 /* Avoid recursing into objects that are not interesting. */
3950 /* Step through each of the elements in the array. */
3954 {
3956 f,
3957 offset,
3958 offsets,
3959 max_offset,
3965 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3966 there's no point in iterating through the remaining
3967 elements of the array. */
3970 }
3971 }
3974 }
3976 /* Record all of the empty subobjects of TYPE (either a type or a
3977 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3978 is being placed at OFFSET; otherwise, it is a base class that is
3979 being placed at OFFSET. */
3981 static void
3983 tree offset,
3984 splay_tree offsets,
3986 {
3987 tree max_offset;
3988 /* If recording subobjects for a non-static data member or a
3989 non-empty base class , we do not need to record offsets beyond
3990 the size of the biggest empty class. Additional data members
3991 will go at the end of the class. Additional base classes will go
3992 either at offset zero (if empty, in which case they cannot
3993 overlap with offsets past the size of the biggest empty class) or
3994 at the end of the class.
3996 However, if we are placing an empty base class, then we must record
3997 all offsets, as either the empty class is at offset zero (where
3998 other empty classes might later be placed) or at the end of the
3999 class (where other objects might then be placed, so other empty
4000 subobjects might later overlap). */
4004 else
4008 }
4010 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4011 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4012 virtual bases of TYPE are examined. */
4014 static int
4016 tree offset,
4017 splay_tree offsets,
4019 {
4020 splay_tree_node max_node;
4022 /* Get the node in OFFSETS that indicates the maximum offset where
4023 an empty subobject is located. */
4025 /* If there aren't any empty subobjects, then there's no point in
4026 performing this check. */
4032 vbases_p);
4033 }
4035 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4036 non-static data member of the type indicated by RLI. BINFO is the
4037 binfo corresponding to the base subobject, OFFSETS maps offsets to
4038 types already located at those offsets. This function determines
4039 the position of the DECL. */
4041 static void
4043 tree decl,
4044 tree binfo,
4045 splay_tree offsets)
4046 {
4049 tree type;
4052 {
4053 /* For the purposes of determining layout conflicts, we want to
4054 use the class type of BINFO; TREE_TYPE (DECL) will be the
4055 CLASSTYPE_AS_BASE version, which does not contain entries for
4056 zero-sized bases. */
4059 }
4060 else
4061 {
4064 }
4066 /* Try to place the field. It may take more than one try if we have
4067 a hard time placing the field without putting two objects of the
4068 same type at the same address. */
4070 {
4073 /* Place this field. */
4077 /* We have to check to see whether or not there is already
4078 something of the same type at the offset we're about to use.
4079 For example, consider:
4081 struct S {};
4082 struct T : public S { int i; };
4083 struct U : public S, public T {};
4085 Here, we put S at offset zero in U. Then, we can't put T at
4086 offset zero -- its S component would be at the same address
4087 as the S we already allocated. So, we have to skip ahead.
4088 Since all data members, including those whose type is an
4089 empty class, have nonzero size, any overlap can happen only
4090 with a direct or indirect base-class -- it can't happen with
4091 a data member. */
4092 /* In a union, overlap is permitted; all members are placed at
4093 offset zero. */
4098 {
4099 /* Strip off the size allocated to this field. That puts us
4100 at the first place we could have put the field with
4101 proper alignment. */
4104 /* Bump up by the alignment required for the type. */
4105 rli->bitpos
4111 }
4112 else
4113 /* There was no conflict. We're done laying out this field. */
4115 }
4117 /* Now that we know where it will be placed, update its
4118 BINFO_OFFSET. */
4120 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4121 this point because their BINFO_OFFSET is copied from another
4122 hierarchy. Therefore, we may not need to add the entire
4123 OFFSET. */
4129 }
4131 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4133 static int
4135 tree offset,
4137 {
4139 }
4141 /* Layout the empty base BINFO. EOC indicates the byte currently just
4142 past the end of the class, and should be correctly aligned for a
4143 class of the type indicated by BINFO; OFFSETS gives the offsets of
4144 the empty bases allocated so far. T is the most derived
4145 type. Return nonzero iff we added it at the end. */
4147 static bool
4150 {
4151 tree alignment;
4155 /* This routine should only be used for empty classes. */
4160 propagate_binfo_offsets
4164 /* This is an empty base class. We first try to put it at offset
4165 zero. */
4168 offsets,
4170 {
4171 /* That didn't work. Now, we move forward from the next
4172 available spot in the class. */
4176 {
4179 offsets,
4181 /* We finally found a spot where there's no overlap. */
4184 /* There's overlap here, too. Bump along to the next spot. */
4186 }
4187 }
4190 {
4195 }
4198 }
4200 /* Layout the base given by BINFO in the class indicated by RLI.
4201 *BASE_ALIGN is a running maximum of the alignments of
4202 any base class. OFFSETS gives the location of empty base
4203 subobjects. T is the most derived type. Return nonzero if the new
4204 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4205 *NEXT_FIELD, unless BINFO is for an empty base class.
4207 Returns the location at which the next field should be inserted. */
4212 {
4217 /* This error is now reported in xref_tag, thus giving better
4218 location information. */
4221 /* Place the base class. */
4223 {
4224 tree decl;
4226 /* The containing class is non-empty because it has a non-empty
4227 base class. */
4230 /* Create the FIELD_DECL. */
4237 {
4245 /* Try to place the field. It may take more than one try if we
4246 have a hard time placing the field without putting two
4247 objects of the same type at the same address. */
4249 /* Add the new FIELD_DECL to the list of fields for T. */
4253 }
4254 }
4255 else
4256 {
4257 tree eoc;
4260 /* On some platforms (ARM), even empty classes will not be
4261 byte-aligned. */
4266 /* A nearly-empty class "has no proper base class that is empty,
4267 not morally virtual, and at an offset other than zero." */
4269 {
4272 /* The check above (used in G++ 3.2) is insufficient because
4273 an empty class placed at offset zero might itself have an
4274 empty base at a nonzero offset. */
4276 empty_base_at_nonzero_offset_p,
4277 size_zero_node,
4282 }
4284 /* We do not create a FIELD_DECL for empty base classes because
4285 it might overlap some other field. We want to be able to
4286 create CONSTRUCTORs for the class by iterating over the
4287 FIELD_DECLs, and the back end does not handle overlapping
4288 FIELD_DECLs. */
4290 /* An empty virtual base causes a class to be non-empty
4291 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4292 here because that was already done when the virtual table
4293 pointer was created. */
4294 }
4296 /* Record the offsets of BINFO and its base subobjects. */
4299 offsets,
4303 }
4305 /* Layout all of the non-virtual base classes. Record empty
4306 subobjects in OFFSETS. T is the most derived type. Return nonzero
4307 if the type cannot be nearly empty. The fields created
4308 corresponding to the base classes will be inserted at
4309 *NEXT_FIELD. */
4311 static void
4314 {
4315 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4316 subobjects. */
4321 /* The primary base class is always allocated first. */
4326 /* Now allocate the rest of the bases. */
4328 {
4329 tree base_binfo;
4333 /* The primary base was already allocated above, so we don't
4334 need to allocate it again here. */
4338 /* Virtual bases are added at the end (a primary virtual base
4339 will have already been added). */
4345 }
4346 }
4348 /* Go through the TYPE_METHODS of T issuing any appropriate
4349 diagnostics, figuring out which methods override which other
4350 methods, and so forth. */
4352 static void
4354 {
4355 tree x;
4358 {
4362 /* The name of the field is the original field name
4363 Save this in auxiliary field for later overloading. */
4365 {
4369 }
4370 /* All user-provided destructors are non-trivial.
4371 Constructors and assignment ops are handled in
4372 grok_special_member_properties. */
4375 }
4376 }
4378 /* FN is a constructor or destructor. Clone the declaration to create
4379 a specialized in-charge or not-in-charge version, as indicated by
4380 NAME. */
4382 static tree
4384 {
4385 tree parms;
4386 tree clone;
4388 /* Copy the function. */
4390 /* Reset the function name. */
4392 /* Remember where this function came from. */
4394 /* Make it easy to find the CLONE given the FN. */
4398 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4400 {
4407 }
4411 /* There's no pending inline data for this function. */
4415 /* The base-class destructor is not virtual. */
4417 {
4421 }
4423 /* If there was an in-charge parameter, drop it from the function
4424 type. */
4426 {
4427 tree basetype;
4428 tree parmtypes;
4429 tree exceptions;
4434 /* Skip the `this' parameter. */
4436 /* Skip the in-charge parameter. */
4438 /* And the VTT parm, in a complete [cd]tor. */
4442 /* If this is subobject constructor or destructor, add the vtt
4443 parameter. */
4447 parmtypes);
4450 exceptions);
4454 }
4456 /* Copy the function parameters. */
4458 /* Remove the in-charge parameter. */
4460 {
4464 }
4465 /* And the VTT parm, in a complete [cd]tor. */
4467 {
4470 else
4471 {
4475 }
4476 }
4479 {
4482 }
4484 /* Create the RTL for this function. */
4492 }
4494 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4495 not invoke this function directly.
4497 For a non-thunk function, returns the address of the slot for storing
4498 the function it is a clone of. Otherwise returns NULL_TREE.
4500 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4501 cloned_function is unset. This is to support the separate
4502 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4503 on a template makes sense, but not the former. */
4505 tree *
4507 {
4515 {
4516 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4519 else
4520 #endif
4522 }
4527 else
4529 }
4531 /* Produce declarations for all appropriate clones of FN. If
4532 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4533 CLASTYPE_METHOD_VEC as well. */
4535 void
4537 {
4538 tree clone;
4540 /* Avoid inappropriate cloning. */
4546 {
4547 /* For each constructor, we need two variants: an in-charge version
4548 and a not-in-charge version. */
4555 }
4556 else
4557 {
4560 /* For each destructor, we need three variants: an in-charge
4561 version, a not-in-charge version, and an in-charge deleting
4562 version. We clone the deleting version first because that
4563 means it will go second on the TYPE_METHODS list -- and that
4564 corresponds to the correct layout order in the virtual
4565 function table.
4567 For a non-virtual destructor, we do not build a deleting
4568 destructor. */
4570 {
4574 }
4581 }
4583 /* Note that this is an abstract function that is never emitted. */
4585 }
4587 /* DECL is an in charge constructor, which is being defined. This will
4588 have had an in class declaration, from whence clones were
4589 declared. An out-of-class definition can specify additional default
4590 arguments. As it is the clones that are involved in overload
4591 resolution, we must propagate the information from the DECL to its
4592 clones. */
4594 void
4596 {
4597 tree clone;
4601 {
4608 /* Skip the 'this' parameter. */
4624 {
4629 {
4630 /* A default parameter has been added. Adjust the
4631 clone's parameters. */
4635 tree type;
4640 {
4643 clone_parms);
4645 }
4648 clone_parms);
4657 }
4658 }
4660 }
4661 }
4663 /* For each of the constructors and destructors in T, create an
4664 in-charge and not-in-charge variant. */
4666 static void
4668 {
4669 tree fns;
4671 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4672 out now. */
4680 }
4682 /* Deduce noexcept for a destructor DTOR. */
4684 void
4686 {
4688 {
4691 }
4692 }
4694 /* For each destructor in T, deduce noexcept:
4696 12.4/3: A declaration of a destructor that does not have an
4697 exception-specification is implicitly considered to have the
4698 same exception-specification as an implicit declaration (15.4). */
4700 static void
4702 {
4703 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4704 out now. */
4710 }
4712 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4713 of TYPE for virtual functions which FNDECL overrides. Return a
4714 mask of the tm attributes found therein. */
4716 static int
4718 {
4720 tree base_binfo;
4724 {
4734 else
4736 }
4739 }
4741 /* Subroutine of set_method_tm_attributes. Handle the checks and
4742 inheritance for one virtual method FNDECL. */
4744 static void
4746 {
4747 tree tm_attr;
4752 /* If FNDECL doesn't actually override anything (i.e. T is the
4753 class that first declares FNDECL virtual), then we're done. */
4760 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4761 tm_pure must match exactly, otherwise no weakening of
4762 tm_safe > tm_callable > nothing. */
4763 /* ??? The tm_pure attribute didn't make the transition to the
4764 multivendor language spec. */
4766 {
4768 {
4771 }
4772 }
4773 /* If the overridden function is tm_pure, then FNDECL must be. */
4776 /* Look for base class combinations that cannot be satisfied. */
4778 {
4784 }
4785 /* If FNDECL did not declare an attribute, then inherit the most
4786 restrictive one. */
4788 {
4790 }
4791 /* Otherwise validate that we're not weaker than a function
4792 that is being overridden. */
4793 else
4794 {
4798 }
4801 err_override:
4805 }
4807 /* For each of the methods in T, propagate a class-level tm attribute. */
4809 static void
4811 {
4814 /* Don't bother collecting tm attributes if transactional memory
4815 support is not enabled. */
4819 /* Process virtual methods first, as they inherit directly from the
4820 base virtual function and also require validation of new attributes. */
4822 {
4823 tree vchain;
4826 {
4831 }
4832 }
4834 /* If the class doesn't have an attribute, nothing more to do. */
4839 /* Any method that does not yet have a tm attribute inherits
4840 the one from the class. */
4842 {
4845 }
4846 }
4848 /* Returns true iff class T has a user-defined constructor other than
4849 the default constructor. */
4851 bool
4853 {
4854 tree fns;
4860 {
4867 }
4870 }
4872 /* Returns the defaulted constructor if T has one. Otherwise, returns
4873 NULL_TREE. */
4875 tree
4877 {
4884 {
4888 {
4894 }
4895 }
4898 }
4900 /* Returns true iff FN is a user-provided function, i.e. user-declared
4901 and not defaulted at its first declaration; or explicit, private,
4902 protected, or non-const. */
4904 bool
4906 {
4909 else
4913 }
4915 /* Returns true iff class T has a user-provided constructor. */
4917 bool
4919 {
4920 tree fns;
4928 /* This can happen in error cases; avoid crashing. */
4937 }
4939 /* Returns true iff class T has a user-provided default constructor. */
4941 bool
4943 {
4944 tree fns;
4950 {
4956 }
4959 }
4961 /* TYPE is being used as a virtual base, and has a non-trivial move
4962 assignment. Return true if this is due to there being a user-provided
4963 move assignment in TYPE or one of its subobjects; if there isn't, then
4964 multiple move assignment can't cause any harm. */
4966 bool
4968 {
4969 /* Does the type itself have a user-provided move assignment operator? */
4973 {
4977 }
4979 /* Do any of its bases? */
4981 tree base_binfo;
4986 /* Or non-static data members? */
4988 {
4993 }
4995 /* Seems not. */
4997 }
4999 /* If default-initialization leaves part of TYPE uninitialized, returns
5000 a DECL for the field or TYPE itself (DR 253). */
5002 tree
5004 {
5015 {
5019 }
5024 {
5028 }
5031 }
5033 /* Returns true iff for class T, a trivial synthesized default constructor
5034 would be constexpr. */
5036 bool
5038 {
5039 /* A defaulted trivial default constructor is constexpr
5040 if there is nothing to initialize. */
5043 }
5045 /* Returns true iff class T has a constexpr default constructor. */
5047 bool
5049 {
5050 tree fns;
5053 {
5054 /* The caller should have stripped an enclosing array. */
5057 }
5059 {
5062 /* Non-trivial, we need to check subobject constructors. */
5064 }
5067 }
5069 /* Returns true iff class TYPE has a virtual destructor. */
5071 bool
5073 {
5074 tree dtor;
5082 }
5084 /* Returns true iff class T has a move constructor. */
5086 bool
5088 {
5089 tree fns;
5092 {
5095 }
5105 }
5107 /* Returns true iff class T has a move assignment operator. */
5109 bool
5111 {
5112 tree fns;
5115 {
5118 }
5126 }
5128 /* Returns true iff class T has a move constructor that was explicitly
5129 declared in the class body. Note that this is different from
5130 "user-provided", which doesn't include functions that are defaulted in
5131 the class. */
5133 bool
5135 {
5136 tree fns;
5145 {
5149 }
5152 }
5154 /* Returns true iff class T has a move assignment operator that was
5155 explicitly declared in the class body. */
5157 bool
5159 {
5160 tree fns;
5167 {
5171 }
5174 }
5176 /* Nonzero if we need to build up a constructor call when initializing an
5177 object of this class, either because it has a user-declared constructor
5178 or because it doesn't have a default constructor (so we need to give an
5179 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5180 what you care about is whether or not an object can be produced by a
5181 constructor (e.g. so we don't set TREE_READONLY on const variables of
5182 such type); use this function when what you care about is whether or not
5183 to try to call a constructor to create an object. The latter case is
5184 the former plus some cases of constructors that cannot be called. */
5186 bool
5188 {
5189 tree inner;
5199 /* A user-declared constructor might be private, and a constructor might
5200 be trivial but deleted. */
5203 {
5208 }
5210 }
5212 /* Like type_build_ctor_call, but for destructors. */
5214 bool
5216 {
5217 tree inner;
5226 /* A user-declared destructor might be private, and a destructor might
5227 be trivial but deleted. */
5230 {
5235 }
5237 }
5239 /* Remove all zero-width bit-fields from T. */
5241 static void
5243 {
5248 {
5251 /* We should not be confused by the fact that grokbitfield
5252 temporarily sets the width of the bit field into
5253 DECL_INITIAL (*fieldsp).
5254 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5255 to that width. */
5258 else
5260 }
5261 }
5263 /* Returns TRUE iff we need a cookie when dynamically allocating an
5264 array whose elements have the indicated class TYPE. */
5266 static bool
5268 {
5269 tree fns;
5274 /* If there's a non-trivial destructor, we need a cookie. In order
5275 to iterate through the array calling the destructor for each
5276 element, we'll have to know how many elements there are. */
5280 /* If the usual deallocation function is a two-argument whose second
5281 argument is of type `size_t', then we have to pass the size of
5282 the array to the deallocation function, so we will need to store
5283 a cookie. */
5287 /* If there are no `operator []' members, or the lookup is
5288 ambiguous, then we don't need a cookie. */
5291 /* Loop through all of the functions. */
5293 {
5294 tree fn;
5295 tree second_parm;
5297 /* Select the current function. */
5299 /* See if this function is a one-argument delete function. If
5300 it is, then it will be the usual deallocation function. */
5304 /* Do not consider this function if its second argument is an
5305 ellipsis. */
5308 /* Otherwise, if we have a two-argument function and the second
5309 argument is `size_t', it will be the usual deallocation
5310 function -- unless there is one-argument function, too. */
5314 }
5317 }
5319 /* Finish computing the `literal type' property of class type T.
5321 At this point, we have already processed base classes and
5322 non-static data members. We need to check whether the copy
5323 constructor is trivial, the destructor is trivial, and there
5324 is a trivial default constructor or at least one constexpr
5325 constructor other than the copy constructor. */
5327 static void
5329 {
5330 tree fn;
5346 {
5349 {
5353 }
5354 }
5355 }
5357 /* T is a non-literal type used in a context which requires a constant
5358 expression. Explain why it isn't literal. */
5360 void
5362 {
5372 /* Already explained. */
5381 {
5383 "default constructor, and has no constexpr constructor that "
5387 {
5388 /* Note that we can't simply call locate_ctor because when the
5389 constructor is deleted it just returns NULL_TREE. */
5390 tree fns;
5392 {
5399 {
5402 else
5405 }
5406 }
5407 }
5408 }
5409 else
5410 {
5414 {
5417 {
5422 }
5423 }
5425 {
5426 tree ftype;
5431 {
5436 }
5440 }
5441 }
5442 }
5444 /* Check the validity of the bases and members declared in T. Add any
5445 implicitly-generated functions (like copy-constructors and
5446 assignment operators). Compute various flag bits (like
5447 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5448 level: i.e., independently of the ABI in use. */
5450 static void
5452 {
5453 /* Nonzero if the implicitly generated copy constructor should take
5454 a non-const reference argument. */
5456 /* Nonzero if the implicitly generated assignment operator
5457 should take a non-const reference argument. */
5459 tree access_decls;
5462 tree fn;
5464 /* By default, we use const reference arguments and generate default
5465 constructors. */
5469 /* Check all the base-classes. */
5473 /* Deduce noexcept on destructors. This needs to happen after we've set
5474 triviality flags appropriately for our bases. */
5478 /* Check all the method declarations. */
5481 /* Save the initial values of these flags which only indicate whether
5482 or not the class has user-provided functions. As we analyze the
5483 bases and members we can set these flags for other reasons. */
5487 /* Check all the data member declarations. We cannot call
5488 check_field_decls until we have called check_bases check_methods,
5489 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5490 being set appropriately. */
5495 /* A nearly-empty class has to be vptr-containing; a nearly empty
5496 class contains just a vptr. */
5500 /* Do some bookkeeping that will guide the generation of implicitly
5501 declared member functions. */
5504 /* We need to call a constructor for this class if it has a
5505 user-provided constructor, or if the default constructor is going
5506 to initialize the vptr. (This is not an if-and-only-if;
5507 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5508 themselves need constructing.) */
5511 /* [dcl.init.aggr]
5513 An aggregate is an array or a class with no user-provided
5514 constructors ... and no virtual functions.
5516 Again, other conditions for being an aggregate are checked
5517 elsewhere. */
5520 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5521 retain the old definition internally for ABI reasons. */
5530 /* Warn if a public base of a polymorphic type has an accessible
5531 non-virtual destructor. It is only now that we know the class is
5532 polymorphic. Although a polymorphic base will have a already
5533 been diagnosed during its definition, we warn on use too. */
5535 {
5538 tree base_binfo;
5542 {
5550 basetype);
5551 }
5552 }
5554 /* If the class has no user-declared constructor, but does have
5555 non-static const or reference data members that can never be
5556 initialized, issue a warning. */
5558 /* Classes with user-declared constructors are presumed to
5559 initialize these members. */
5561 /* Aggregates can be initialized with brace-enclosed
5562 initializers. */
5564 {
5565 tree field;
5568 {
5569 tree type;
5584 }
5585 }
5587 /* Synthesize any needed methods. */
5589 cant_have_const_ctor,
5590 no_const_asn_ref);
5592 /* Check defaulted declarations here so we have cant_have_const_ctor
5593 and don't need to worry about clones. */
5596 {
5599 {
5600 bool imp_const_p
5606 /* If the function is defaulted outside the class, we just
5607 give the synthesis error. */
5610 }
5612 }
5615 {
5616 /* "The closure type associated with a lambda-expression has a deleted
5617 default constructor and a deleted copy assignment operator." */
5623 /* "This class type is not an aggregate." */
5625 }
5627 /* Compute the 'literal type' property before we
5628 do anything with non-static member functions. */
5631 /* Create the in-charge and not-in-charge variants of constructors
5632 and destructors. */
5635 /* Process the using-declarations. */
5639 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5642 /* Figure out whether or not we will need a cookie when dynamically
5643 allocating an array of this type. */
5646 }
5648 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5649 accordingly. If a new vfield was created (because T doesn't have a
5650 primary base class), then the newly created field is returned. It
5651 is not added to the TYPE_FIELDS list; it is the caller's
5652 responsibility to do that. Accumulate declared virtual functions
5653 on VIRTUALS_P. */
5655 static tree
5657 {
5658 tree fn;
5660 /* Collect the virtual functions declared in T. */
5665 {
5674 }
5676 /* If we couldn't find an appropriate base class, create a new field
5677 here. Even if there weren't any new virtual functions, we might need a
5678 new virtual function table if we're supposed to include vptrs in
5679 all classes that need them. */
5681 {
5682 /* We build this decl with vtbl_ptr_type_node, which is a
5683 `vtable_entry_type*'. It might seem more precise to use
5684 `vtable_entry_type (*)[N]' where N is the number of virtual
5685 functions. However, that would require the vtable pointer in
5686 base classes to have a different type than the vtable pointer
5687 in derived classes. We could make that happen, but that
5688 still wouldn't solve all the problems. In particular, the
5689 type-based alias analysis code would decide that assignments
5690 to the base class vtable pointer can't alias assignments to
5691 the derived class vtable pointer, since they have different
5692 types. Thus, in a derived class destructor, where the base
5693 class constructor was inlined, we could generate bad code for
5694 setting up the vtable pointer.
5696 Therefore, we use one type for all vtable pointers. We still
5697 use a type-correct type; it's just doesn't indicate the array
5698 bounds. That's better than using `void*' or some such; it's
5699 cleaner, and it let's the alias analysis code know that these
5700 stores cannot alias stores to void*! */
5701 tree field;
5714 /* This class is non-empty. */
5718 }
5721 }
5723 /* Add OFFSET to all base types of BINFO which is a base in the
5724 hierarchy dominated by T.
5726 OFFSET, which is a type offset, is number of bytes. */
5728 static void
5730 {
5732 tree primary_binfo;
5733 tree base_binfo;
5735 /* Update BINFO's offset. */
5740 offset));
5742 /* Find the primary base class. */
5748 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5749 downwards. */
5751 {
5752 /* Don't do the primary base twice. */
5760 }
5761 }
5763 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5764 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5765 empty subobjects of T. */
5767 static void
5769 {
5770 tree vbase;
5777 /* Find the last field. The artificial fields created for virtual
5778 bases will go after the last extant field to date. */
5783 /* Go through the virtual bases, allocating space for each virtual
5784 base that is not already a primary base class. These are
5785 allocated in inheritance graph order. */
5787 {
5792 {
5793 /* This virtual base is not a primary base of any class in the
5794 hierarchy, so we have to add space for it. */
5797 }
5798 }
5799 }
5801 /* Returns the offset of the byte just past the end of the base class
5802 BINFO. */
5804 static tree
5806 {
5807 tree size;
5812 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5813 allocate some space for it. It cannot have virtual bases, so
5814 TYPE_SIZE_UNIT is fine. */
5816 else
5820 }
5822 /* Returns the offset of the byte just past the end of the base class
5823 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5824 only non-virtual bases are included. */
5826 static tree
5828 {
5831 tree binfo;
5832 tree base_binfo;
5833 tree offset;
5838 {
5848 }
5853 {
5857 }
5860 }
5862 /* Warn about bases of T that are inaccessible because they are
5863 ambiguous. For example:
5865 struct S {};
5866 struct T : public S {};
5867 struct U : public S, public T {};
5869 Here, `(S*) new U' is not allowed because there are two `S'
5870 subobjects of U. */
5872 static void
5874 {
5877 tree basetype;
5878 tree binfo;
5879 tree base_binfo;
5881 /* If there are no repeated bases, nothing can be ambiguous. */
5885 /* Check direct bases. */
5888 {
5894 }
5896 /* Check for ambiguous virtual bases. */
5900 {
5906 }
5907 }
5909 /* Compare two INTEGER_CSTs K1 and K2. */
5911 static int
5913 {
5915 }
5917 /* Increase the size indicated in RLI to account for empty classes
5918 that are "off the end" of the class. */
5920 static void
5922 {
5923 tree eoc;
5924 tree rli_size;
5926 /* It might be the case that we grew the class to allocate a
5927 zero-sized base class. That won't be reflected in RLI, yet,
5928 because we are willing to overlay multiple bases at the same
5929 offset. However, now we need to make sure that RLI is big enough
5930 to reflect the entire class. */
5936 {
5937 /* The size should have been rounded to a whole byte. */
5940 rli->bitpos
5949 }
5950 }
5952 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5953 BINFO_OFFSETs for all of the base-classes. Position the vtable
5954 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5956 static void
5958 {
5959 tree non_static_data_members;
5960 tree field;
5961 tree vptr;
5962 record_layout_info rli;
5963 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5964 types that appear at that offset. */
5965 splay_tree empty_base_offsets;
5966 /* True if the last field laid out was a bit-field. */
5968 /* The location at which the next field should be inserted. */
5970 /* T, as a base class. */
5971 tree base_t;
5973 /* Keep track of the first non-static data member. */
5976 /* Start laying out the record. */
5979 /* Mark all the primary bases in the hierarchy. */
5982 /* Create a pointer to our virtual function table. */
5985 /* The vptr is always the first thing in the class. */
5987 {
5992 }
5993 else
5996 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6001 /* Layout the non-static data members. */
6003 {
6004 tree type;
6005 tree padding;
6007 /* We still pass things that aren't non-static data members to
6008 the back end, in case it wants to do something with them. */
6010 {
6012 /* If the static data member has incomplete type, keep track
6013 of it so that it can be completed later. (The handling
6014 of pending statics in finish_record_layout is
6015 insufficient; consider:
6017 struct S1;
6018 struct S2 { static S1 s1; };
6020 At this point, finish_record_layout will be called, but
6021 S1 is still incomplete.) */
6023 {
6025 /* The visibility of static data members is determined
6026 at their point of declaration, not their point of
6027 definition. */
6029 }
6031 }
6039 /* If this field is a bit-field whose width is greater than its
6040 type, then there are some special rules for allocating
6041 it. */
6044 {
6046 tree integer_type;
6048 /* We must allocate the bits as if suitably aligned for the
6049 longest integer type that fits in this many bits. type
6050 of the field. Then, we are supposed to use the left over
6051 bits as additional padding. */
6060 /* ITK now indicates a type that is too large for the
6061 field. We have to back up by one to find the largest
6062 type that fits. */
6063 do
6064 {
6069 /* Figure out how much additional padding is required. */
6071 {
6073 /* In a union, the padding field must have the full width
6074 of the bit-field; all fields start at offset zero. */
6076 else
6079 }
6080 #ifdef PCC_BITFIELD_TYPE_MATTERS
6081 /* An unnamed bitfield does not normally affect the
6082 alignment of the containing class on a target where
6083 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6084 make any exceptions for unnamed bitfields when the
6085 bitfields are longer than their types. Therefore, we
6086 temporarily give the field a name. */
6088 {
6091 }
6092 #endif
6097 empty_base_offsets);
6100 /* Now that layout has been performed, set the size of the
6101 field to the size of its declared type; the rest of the
6102 field is effectively invisible. */
6104 /* We must also reset the DECL_MODE of the field. */
6106 }
6107 else
6109 empty_base_offsets);
6111 /* Remember the location of any empty classes in FIELD. */
6114 empty_base_offsets,
6117 /* If a bit-field does not immediately follow another bit-field,
6118 and yet it starts in the middle of a byte, we have failed to
6119 comply with the ABI. */
6122 /* The TREE_NO_WARNING flag gets set by Objective-C when
6123 laying out an Objective-C class. The ObjC ABI differs
6124 from the C++ ABI, and so we do not want a warning
6125 here. */
6127 && !last_field_was_bitfield
6130 bitsize_unit_node)))
6134 /* The middle end uses the type of expressions to determine the
6135 possible range of expression values. In order to optimize
6136 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6137 must be made aware of the width of "i", via its type.
6139 Because C++ does not have integer types of arbitrary width,
6140 we must (for the purposes of the front end) convert from the
6141 type assigned here to the declared type of the bitfield
6142 whenever a bitfield expression is used as an rvalue.
6143 Similarly, when assigning a value to a bitfield, the value
6144 must be converted to the type given the bitfield here. */
6146 {
6151 {
6158 }
6159 }
6161 /* If we needed additional padding after this field, add it
6162 now. */
6164 {
6165 tree padding_field;
6168 FIELD_DECL,
6169 NULL_TREE,
6170 char_type_node);
6177 NULL_TREE,
6178 empty_base_offsets);
6179 }
6182 }
6185 {
6186 /* Make sure that we are on a byte boundary so that the size of
6187 the class without virtual bases will always be a round number
6188 of bytes. */
6191 }
6193 /* Delete all zero-width bit-fields from the list of fields. Now
6194 that the type is laid out they are no longer important. */
6197 /* Create the version of T used for virtual bases. We do not use
6198 make_class_type for this version; this is an artificial type. For
6199 a POD type, we just reuse T. */
6201 {
6204 /* Set the size and alignment for the new type. */
6205 tree eoc;
6207 /* If the ABI version is not at least two, and the last
6208 field was a bit-field, RLI may not be on a byte
6209 boundary. In particular, rli_size_unit_so_far might
6210 indicate the last complete byte, while rli_size_so_far
6211 indicates the total number of bits used. Therefore,
6212 rli_size_so_far, rather than rli_size_unit_so_far, is
6213 used to compute TYPE_SIZE_UNIT. */
6221 eoc);
6231 /* Copy the fields from T. */
6235 {
6237 FIELD_DECL,
6247 }
6249 /* Record the base version of the type. */
6252 }
6253 else
6256 /* Every empty class contains an empty class. */
6260 /* Set the TYPE_DECL for this type to contain the right
6261 value for DECL_OFFSET, so that we can use it as part
6262 of a COMPONENT_REF for multiple inheritance. */
6265 /* Now fix up any virtual base class types that we left lying
6266 around. We must get these done before we try to lay out the
6267 virtual function table. As a side-effect, this will remove the
6268 base subobject fields. */
6271 /* Make sure that empty classes are reflected in RLI at this
6272 point. */
6275 /* Make sure not to create any structures with zero size. */
6281 /* If this is a non-POD, declaring it packed makes a difference to how it
6282 can be used as a field; don't let finalize_record_size undo it. */
6286 /* Let the back end lay out the type. */
6295 /* Warn about bases that can't be talked about due to ambiguity. */
6298 /* Now that we're done with layout, give the base fields the real types. */
6303 /* Clean up. */
6310 }
6312 /* Determine the "key method" for the class type indicated by TYPE,
6313 and set CLASSTYPE_KEY_METHOD accordingly. */
6315 void
6317 {
6318 tree method;
6321 || processing_template_decl
6326 /* The key method is the first non-pure virtual function that is not
6327 inline at the point of class definition. On some targets the
6328 key function may not be inline; those targets should not call
6329 this function until the end of the translation unit. */
6336 {
6339 }
6342 }
6345 /* Allocate and return an instance of struct sorted_fields_type with
6346 N fields. */
6350 {
6357 }
6360 /* Perform processing required when the definition of T (a class type)
6361 is complete. */
6363 void
6365 {
6366 tree x;
6367 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6371 {
6376 }
6378 /* If this type was previously laid out as a forward reference,
6379 make sure we lay it out again. */
6383 /* Make assumptions about the class; we'll reset the flags if
6384 necessary. */
6390 /* Do end-of-class semantic processing: checking the validity of the
6391 bases and members and add implicitly generated methods. */
6394 /* Find the key method. */
6396 {
6397 /* The Itanium C++ ABI permits the key method to be chosen when
6398 the class is defined -- even though the key method so
6399 selected may later turn out to be an inline function. On
6400 some systems (such as ARM Symbian OS) the key method cannot
6401 be determined until the end of the translation unit. On such
6402 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6403 will cause the class to be added to KEYED_CLASSES. Then, in
6404 finish_file we will determine the key method. */
6408 /* If a polymorphic class has no key method, we may emit the vtable
6409 in every translation unit where the class definition appears. If
6410 we're devirtualizing, we can look into the vtable even if we
6411 aren't emitting it. */
6414 }
6416 /* Layout the class itself. */
6419 /* We use the base type for trivial assignments, and hence it
6420 needs a mode. */
6425 /* If necessary, create the primary vtable for this class. */
6427 {
6428 /* We must enter these virtuals into the table. */
6432 /* Here we know enough to change the type of our virtual
6433 function table, but we will wait until later this function. */
6436 /* If we're warning about ABI tags, check the types of the new
6437 virtual functions. */
6441 }
6444 {
6446 tree fn;
6453 /* Add entries for virtual functions introduced by this class. */
6457 /* Set DECL_VINDEX for all functions declared in this class. */
6459 fn;
6461 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6463 {
6467 /* A thunk. We should never be calling this entry directly
6468 from this vtable -- we'd use the entry for the non
6469 thunk base function. */
6473 }
6474 }
6479 /* Complete the rtl for any static member objects of the type we're
6480 working on. */
6487 /* Done with FIELDS...now decide whether to sort these for
6488 faster lookups later.
6490 We use a small number because most searches fail (succeeding
6491 ultimately as the search bores through the inheritance
6492 hierarchy), and we want this failure to occur quickly. */
6496 /* Complain if one of the field types requires lower visibility. */
6499 /* Make the rtl for any new vtables we have created, and unmark
6500 the base types we marked. */
6503 /* Build the VTT for T. */
6506 /* This warning does not make sense for Java classes, since they
6507 cannot have destructors. */
6512 "%q#T has virtual functions and accessible"
6520 /* Class layout, assignment of virtual table slots, etc., is now
6521 complete. Give the back end a chance to tweak the visibility of
6522 the class or perform any other required target modifications. */
6532 /* Finish debugging output for this type. */
6536 {
6539 {
6542 }
6544 {
6547 else
6548 {
6551 }
6553 }
6555 {
6557 "the type of the first field has a different ABI from the "
6560 }
6561 }
6562 }
6564 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6565 equal to THRESHOLD or greater than THRESHOLD. */
6567 static void
6569 {
6572 {
6577 }
6578 }
6580 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6582 void
6584 {
6587 {
6589 int n_fields
6600 }
6601 }
6603 /* When T was built up, the member declarations were added in reverse
6604 order. Rearrange them to declaration order. */
6606 void
6608 {
6609 tree next;
6610 tree prev;
6611 tree x;
6613 /* The following lists are all in reverse order. Put them in
6614 declaration order now. */
6618 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6619 reverse order, so we can't just use nreverse. */
6624 {
6628 }
6630 {
6634 }
6635 }
6637 tree
6639 {
6642 /* Now that we've got all the field declarations, reverse everything
6643 as necessary. */
6648 /* Nadger the current location so that diagnostics point to the start of
6649 the struct, not the end. */
6653 {
6654 tree x;
6660 /* We need to emit an error message if this type was used as a parameter
6661 and it is an abstract type, even if it is a template. We construct
6662 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6663 account and we call complete_vars with this type, which will check
6664 the PARM_DECLS. Note that while the type is being defined,
6665 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6666 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6672 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6673 an enclosing scope is a template class, so that this function be
6674 found by lookup_fnfields_1 when the using declaration is not
6675 instantiated yet. */
6678 {
6683 }
6685 /* Remember current #pragma pack value. */
6688 /* Fix up any variants we've already built. */
6690 {
6695 }
6696 }
6697 else
6701 {
6702 /* People keep complaining that the compiler crashes on an invalid
6703 definition of initializer_list, so I guess we should explicitly
6704 reject it. What the compiler internals care about is that it's a
6705 template and has a pointer field followed by an integer field. */
6708 {
6711 {
6715 }
6716 }
6720 }
6728 else
6732 /* Lambdas are defined by the LAMBDA_EXPR. */
6737 }
6738 \f
6739 /* Hash table to avoid endless recursion when handling references. */
6742 /* Return the dynamic type of INSTANCE, if known.
6743 Used to determine whether the virtual function table is needed
6744 or not.
6746 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6747 of our knowledge of its type. *NONNULL should be initialized
6748 before this function is called. */
6750 static tree
6752 {
6753 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6756 {
6760 else
6764 /* This is a call to a constructor, hence it's never zero. */
6766 {
6770 }
6774 /* This is a call to a constructor, hence it's never zero. */
6776 {
6780 }
6789 /* Propagate nonnull. */
6794 CASE_CONVERT:
6800 {
6801 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6802 with a real object -- given &p->f, p can still be null. */
6804 /* ??? Probably should check DECL_WEAK here. */
6807 }
6811 /* If this component is really a base class reference, then the field
6812 itself isn't definitive. */
6821 {
6825 }
6826 /* fall through... */
6831 {
6835 }
6837 {
6841 /* if we're in a ctor or dtor, we know our type. If
6842 current_class_ptr is set but we aren't in a function, we're in
6843 an NSDMI (and therefore a constructor). */
6848 {
6852 }
6853 }
6855 {
6856 /* We only need one hash table because it is always left empty. */
6858 fixed_type_or_null_ref_ht
6861 /* Reference variables should be references to objects. */
6865 /* Enter the INSTANCE in a table to prevent recursion; a
6866 variable's initializer may refer to the variable
6867 itself. */
6872 {
6873 tree type;
6882 }
6883 }
6888 }
6889 #undef RECUR
6890 }
6892 /* Return nonzero if the dynamic type of INSTANCE is known, and
6893 equivalent to the static type. We also handle the case where
6894 INSTANCE is really a pointer. Return negative if this is a
6895 ctor/dtor. There the dynamic type is known, but this might not be
6896 the most derived base of the original object, and hence virtual
6897 bases may not be laid out according to this type.
6899 Used to determine whether the virtual function table is needed
6900 or not.
6902 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6903 of our knowledge of its type. *NONNULL should be initialized
6904 before this function is called. */
6906 int
6908 {
6911 tree fixed;
6913 /* processing_template_decl can be false in a template if we're in
6914 fold_non_dependent_expr, but we still want to suppress this check. */
6916 {
6917 /* In a template we only care about the type of the result. */
6921 }
6931 }
6933 \f
6934 void
6936 {
6939 current_class_stack
6947 }
6949 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6951 static void
6953 {
6954 tree type;
6956 /* We are re-entering the same class we just left, so we don't
6957 have to search the whole inheritance matrix to find all the
6958 decls to bind again. Instead, we install the cached
6959 class_shadowed list and walk through it binding names. */
6962 /* Restore IDENTIFIER_TYPE_VALUE. */
6964 type;
6967 }
6969 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6970 appropriate for TYPE.
6972 So that we may avoid calls to lookup_name, we cache the _TYPE
6973 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6975 For multiple inheritance, we perform a two-pass depth-first search
6976 of the type lattice. */
6978 void
6980 {
6981 class_stack_node_t csn;
6985 /* Make sure there is enough room for the new entry on the stack. */
6987 {
6989 current_class_stack
6991 current_class_stack_size);
6992 }
6994 /* Insert a new entry on the class stack. */
7001 current_class_depth++;
7003 /* Now set up the new type. */
7009 /* By default, things in classes are private, while things in
7010 structures or unions are public. */
7012 ? access_private_node
7018 {
7019 /* Forcibly remove any old class remnants. */
7021 }
7027 else
7029 }
7031 /* When we exit a toplevel class scope, we save its binding level so
7032 that we can restore it quickly. Here, we've entered some other
7033 class, so we must invalidate our cache. */
7035 void
7037 {
7039 }
7041 /* Get out of the current class scope. If we were in a class scope
7042 previously, that is the one popped to. */
7044 void
7046 {
7049 current_class_depth--;
7055 }
7057 /* Mark the top of the class stack as hidden. */
7059 void
7061 {
7064 }
7066 /* Mark the top of the class stack as un-hidden. */
7068 void
7070 {
7073 }
7075 /* Returns 1 if the class type currently being defined is either T or
7076 a nested type of T. */
7078 bool
7080 {
7088 /* We start looking from 1 because entry 0 is from global scope,
7089 and has no type. */
7091 {
7092 tree c;
7095 else
7096 {
7100 }
7105 }
7107 }
7109 /* If either current_class_type or one of its enclosing classes are derived
7110 from T, return the appropriate type. Used to determine how we found
7111 something via unqualified lookup. */
7113 tree
7115 {
7118 /* The bases of a dependent type are unknown. */
7129 {
7134 }
7137 }
7139 /* Return the outermost enclosing class type that is still open, or
7140 NULL_TREE. */
7142 tree
7144 {
7151 {
7158 }
7160 }
7162 /* Returns the innermost class type which is not a lambda closure type. */
7164 tree
7166 {
7169 /* We start looking from 1 because entry 0 is from global scope,
7170 and has no type. */
7172 {
7173 tree c;
7176 else
7177 {
7181 }
7186 }
7188 }
7190 /* When entering a class scope, all enclosing class scopes' names with
7191 static meaning (static variables, static functions, types and
7192 enumerators) have to be visible. This recursive function calls
7193 pushclass for all enclosing class contexts until global or a local
7194 scope is reached. TYPE is the enclosed class. */
7196 void
7198 {
7199 /* A namespace might be passed in error cases, like A::B:C. */
7207 }
7209 /* Undoes a push_nested_class call. */
7211 void
7213 {
7219 }
7221 /* Returns the number of extern "LANG" blocks we are nested within. */
7223 int
7225 {
7227 }
7229 /* Set global variables CURRENT_LANG_NAME to appropriate value
7230 so that behavior of name-mangling machinery is correct. */
7232 void
7234 {
7238 {
7240 }
7242 {
7244 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7245 (See record_builtin_java_type in decl.c.) However, that causes
7246 incorrect debug entries if these types are actually used.
7247 So we re-enable debug output after extern "Java". */
7256 }
7258 {
7260 }
7261 else
7263 }
7265 /* Get out of the current language scope. */
7267 void
7269 {
7271 }
7272 \f
7273 /* Type instantiation routines. */
7275 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7276 matches the TARGET_TYPE. If there is no satisfactory match, return
7277 error_mark_node, and issue an error & warning messages under
7278 control of FLAGS. Permit pointers to member function if FLAGS
7279 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7280 a template-id, and EXPLICIT_TARGS are the explicitly provided
7281 template arguments.
7283 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7284 is the base path used to reference those member functions. If
7285 the address is resolved to a member function, access checks will be
7286 performed and errors issued if appropriate. */
7288 static tree
7290 tree overload,
7291 tsubst_flags_t flags,
7293 tree explicit_targs,
7294 tree access_path)
7295 {
7296 /* Here's what the standard says:
7298 [over.over]
7300 If the name is a function template, template argument deduction
7301 is done, and if the argument deduction succeeds, the deduced
7302 arguments are used to generate a single template function, which
7303 is added to the set of overloaded functions considered.
7305 Non-member functions and static member functions match targets of
7306 type "pointer-to-function" or "reference-to-function." Nonstatic
7307 member functions match targets of type "pointer-to-member
7308 function;" the function type of the pointer to member is used to
7309 select the member function from the set of overloaded member
7310 functions. If a nonstatic member function is selected, the
7311 reference to the overloaded function name is required to have the
7312 form of a pointer to member as described in 5.3.1.
7314 If more than one function is selected, any template functions in
7315 the set are eliminated if the set also contains a non-template
7316 function, and any given template function is eliminated if the
7317 set contains a second template function that is more specialized
7318 than the first according to the partial ordering rules 14.5.5.2.
7319 After such eliminations, if any, there shall remain exactly one
7320 selected function. */
7323 /* We store the matches in a TREE_LIST rooted here. The functions
7324 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7325 interoperability with most_specialized_instantiation. */
7327 tree fn;
7328 tree target_fn_type;
7330 /* By the time we get here, we should be seeing only real
7331 pointer-to-member types, not the internal POINTER_TYPE to
7332 METHOD_TYPE representation. */
7338 /* Check that the TARGET_TYPE is reasonable. */
7343 /* This is OK, too. */
7346 /* This is OK, too. This comes from a conversion to reference
7347 type. */
7349 else
7350 {
7356 }
7358 /* Non-member functions and static member functions match targets of type
7359 "pointer-to-function" or "reference-to-function." Nonstatic member
7360 functions match targets of type "pointer-to-member-function;" the
7361 function type of the pointer to member is used to select the member
7362 function from the set of overloaded member functions.
7364 So figure out the FUNCTION_TYPE that we want to match against. */
7367 /* If we can find a non-template function that matches, we can just
7368 use it. There's no point in generating template instantiations
7369 if we're just going to throw them out anyhow. But, of course, we
7370 can only do this when we don't *need* a template function. */
7372 {
7373 tree fns;
7376 {
7380 /* We're not looking for templates just yet. */
7385 /* We're looking for a non-static member, and this isn't
7386 one, or vice versa. */
7389 /* Ignore functions which haven't been explicitly
7390 declared. */
7394 /* See if there's a match. */
7397 }
7398 }
7400 /* Now, if we've already got a match (or matches), there's no need
7401 to proceed to the template functions. But, if we don't have a
7402 match we need to look at them, too. */
7404 {
7405 tree target_arg_types;
7406 tree target_ret_type;
7407 tree fns;
7410 tree arg;
7424 {
7426 tree instantiation;
7427 tree targs;
7430 /* We're only looking for templates. */
7435 /* We're not looking for a non-static member, and this is
7436 one, or vice versa. */
7441 /* If the template has a deduced return type, don't expose it to
7442 template argument deduction. */
7446 /* Try to do argument deduction. */
7453 /* Instantiation failed. */
7456 /* And now force instantiation to do return type deduction. */
7458 {
7464 }
7466 /* See if there's a match. */
7469 }
7471 /* Now, remove all but the most specialized of the matches. */
7473 {
7478 NULL_TREE,
7479 NULL_TREE);
7480 }
7481 }
7483 /* Now we should have exactly one function in MATCHES. */
7485 {
7486 /* There were *no* matches. */
7488 {
7491 target_type);
7494 }
7496 }
7498 {
7499 /* There were too many matches. First check if they're all
7500 the same function. */
7505 /* For multi-versioned functions, more than one match is just fine and
7506 decls_match will return false as they are different. */
7514 {
7516 {
7519 target_type);
7521 /* Since print_candidates expects the functions in the
7522 TREE_VALUE slot, we flip them here. */
7527 }
7530 }
7531 }
7533 /* Good, exactly one match. Now, convert it to the correct type. */
7538 {
7546 {
7549 }
7550 }
7552 /* If a pointer to a function that is multi-versioned is requested, the
7553 pointer to the dispatcher function is returned instead. This works
7554 well because indirectly calling the function will dispatch the right
7555 function version at run-time. */
7557 {
7561 /* Mark all the versions corresponding to the dispatcher as used. */
7564 }
7566 /* If we're doing overload resolution purely for the purpose of
7567 determining conversion sequences, we should not consider the
7568 function used. If this conversion sequence is selected, the
7569 function will be marked as used at this point. */
7571 {
7572 /* Make =delete work with SFINAE. */
7577 }
7579 /* We could not check access to member functions when this
7580 expression was originally created since we did not know at that
7581 time to which function the expression referred. */
7583 {
7586 }
7590 else
7591 {
7592 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7593 will mark the function as addressed, but here we must do it
7594 explicitly. */
7598 }
7599 }
7601 /* This function will instantiate the type of the expression given in
7602 RHS to match the type of LHSTYPE. If errors exist, then return
7603 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7604 we complain on errors. If we are not complaining, never modify rhs,
7605 as overload resolution wants to try many possible instantiations, in
7606 the hope that at least one will work.
7608 For non-recursive calls, LHSTYPE should be a function, pointer to
7609 function, or a pointer to member function. */
7611 tree
7613 {
7620 {
7624 }
7627 {
7634 /* Microsoft allows `A::f' to be resolved to a
7635 pointer-to-member. */
7636 ;
7637 else
7638 {
7643 }
7644 }
7647 {
7650 }
7652 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7653 deduce any type information. */
7655 {
7659 }
7661 /* There only a few kinds of expressions that may have a type
7662 dependent on overload resolution. */
7668 /* This should really only be used when attempting to distinguish
7669 what sort of a pointer to function we have. For now, any
7670 arithmetic operation which is not supported on pointers
7671 is rejected as an error. */
7674 {
7676 {
7682 /* Do not lose object's side effects. */
7686 }
7693 /* This can happen if we are forming a pointer-to-member for a
7694 member template. */
7697 /* Fall through. */
7700 {
7704 return
7708 }
7712 return
7716 access_path);
7719 {
7724 }
7731 }
7733 }
7734 \f
7735 /* Return the name of the virtual function pointer field
7736 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7737 this may have to look back through base types to find the
7738 ultimate field name. (For single inheritance, these could
7739 all be the same name. Who knows for multiple inheritance). */
7741 static tree
7743 {
7750 {
7756 }
7764 }
7766 void
7768 {
7775 {
7780 }
7781 }
7783 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7784 according to [class]:
7785 The class-name is also inserted
7786 into the scope of the class itself. For purposes of access checking,
7787 the inserted class name is treated as if it were a public member name. */
7789 void
7791 {
7794 tree saved_cas;
7809 }
7811 /* Returns 1 if TYPE contains only padding bytes. */
7813 int
7815 {
7823 }
7825 /* Returns true if TYPE contains no actual data, just various
7826 possible combinations of empty classes and possibly a vptr. */
7828 bool
7830 {
7832 {
7833 tree field;
7834 tree binfo;
7835 tree base_binfo;
7838 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7839 out, but we'd like to be able to check this before then. */
7853 }
7857 }
7859 /* Note that NAME was looked up while the current class was being
7860 defined and that the result of that lookup was DECL. */
7862 void
7864 {
7865 splay_tree names_used;
7867 /* If we're not defining a class, there's nothing to do. */
7873 /* If there's already a binding for this NAME, then we don't have
7874 anything to worry about. */
7887 }
7889 /* Note that NAME was declared (as DECL) in the current class. Check
7890 to see that the declaration is valid. */
7892 void
7894 {
7895 splay_tree names_used;
7896 splay_tree_node n;
7898 /* Look to see if we ever used this name. */
7899 names_used
7903 /* The C language allows members to be declared with a type of the same
7904 name, and the C++ standard says this diagnostic is not required. So
7905 allow it in extern "C" blocks unless predantic is specified.
7906 Allow it in all cases if -ms-extensions is specified. */
7912 {
7913 /* [basic.scope.class]
7915 A name N used in a class S shall refer to the same declaration
7916 in its context and when re-evaluated in the completed scope of
7917 S. */
7921 }
7922 }
7924 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7925 Secondary vtables are merged with primary vtables; this function
7926 will return the VAR_DECL for the primary vtable. */
7928 tree
7930 {
7931 tree decl;
7935 {
7938 }
7942 }
7945 /* Returns the binfo for the primary base of BINFO. If the resulting
7946 BINFO is a virtual base, and it is inherited elsewhere in the
7947 hierarchy, then the returned binfo might not be the primary base of
7948 BINFO in the complete object. Check BINFO_PRIMARY_P or
7949 BINFO_LOST_PRIMARY_P to be sure. */
7951 static tree
7953 {
7954 tree primary_base;
7961 }
7963 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7965 static int
7967 {
7971 }
7973 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7974 INDENT should be zero when called from the top level; it is
7975 incremented recursively. IGO indicates the next expected BINFO in
7976 inheritance graph ordering. */
7978 static tree
7981 tree binfo,
7982 tree igo,
7984 {
7986 tree base_binfo;
7994 {
7997 }
8012 {
8016 TFF_PLAIN_IDENTIFIER),
8018 }
8020 {
8023 }
8028 {
8032 {
8036 TFF_PLAIN_IDENTIFIER));
8037 }
8039 {
8043 TFF_PLAIN_IDENTIFIER));
8044 }
8046 {
8050 TFF_PLAIN_IDENTIFIER));
8051 }
8053 {
8057 TFF_PLAIN_IDENTIFIER));
8058 }
8062 }
8068 }
8070 /* Dump the BINFO hierarchy for T. */
8072 static void
8074 {
8086 }
8088 /* Debug interface to hierarchy dumping. */
8090 void
8092 {
8094 }
8096 static void
8098 {
8103 {
8105 }
8106 }
8108 static void
8110 {
8111 tree value;
8113 HOST_WIDE_INT elt;
8121 TFF_PLAIN_IDENTIFIER));
8128 }
8130 static void
8132 {
8140 {
8147 {
8152 }
8156 }
8157 }
8159 static void
8161 {
8169 {
8174 }
8175 }
8177 /* Dump a function or thunk and its thunkees. */
8179 static void
8181 {
8184 tree thunks;
8192 {
8202 else
8208 }
8212 }
8214 /* Dump the thunks for FN. */
8216 void
8218 {
8220 }
8222 /* Virtual function table initialization. */
8224 /* Create all the necessary vtables for T and its base classes. */
8226 static void
8228 {
8229 tree vbase;
8233 /* We lay out the primary and secondary vtables in one contiguous
8234 vtable. The primary vtable is first, followed by the non-virtual
8235 secondary vtables in inheritance graph order. */
8239 /* Then come the virtual bases, also in inheritance graph order. */
8241 {
8245 }
8249 }
8251 /* Initialize the vtable for BINFO with the INITS. */
8253 static void
8255 {
8256 tree decl;
8262 }
8264 /* Build the VTT (virtual table table) for T.
8265 A class requires a VTT if it has virtual bases.
8267 This holds
8268 1 - primary virtual pointer for complete object T
8269 2 - secondary VTTs for each direct non-virtual base of T which requires a
8270 VTT
8271 3 - secondary virtual pointers for each direct or indirect base of T which
8272 has virtual bases or is reachable via a virtual path from T.
8273 4 - secondary VTTs for each direct or indirect virtual base of T.
8275 Secondary VTTs look like complete object VTTs without part 4. */
8277 static void
8279 {
8280 tree type;
8281 tree vtt;
8282 tree index;
8285 /* Build up the initializers for the VTT. */
8290 /* If we didn't need a VTT, we're done. */
8294 /* Figure out the type of the VTT. */
8298 /* Now, build the VTT object itself. */
8301 /* Add the VTT to the vtables list. */
8306 }
8308 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8309 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8310 and CHAIN the vtable pointer for this binfo after construction is
8311 complete. VALUE can also be another BINFO, in which case we recurse. */
8313 static tree
8315 {
8316 tree vt;
8319 {
8325 else
8327 }
8330 }
8332 /* Data for secondary VTT initialization. */
8334 {
8335 /* Is this the primary VTT? */
8338 /* Current index into the VTT. */
8339 tree index;
8341 /* Vector of initializers built up. */
8344 /* The type being constructed by this secondary VTT. */
8345 tree type_being_constructed;
8348 /* Recursively build the VTT-initializer for BINFO (which is in the
8349 hierarchy dominated by T). INITS points to the end of the initializer
8350 list to date. INDEX is the VTT index where the next element will be
8351 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8352 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8353 for virtual bases of T. When it is not so, we build the constructor
8354 vtables for the BINFO-in-T variant. */
8356 static void
8359 {
8361 tree b;
8362 tree init;
8363 secondary_vptr_vtt_init_data data;
8366 /* We only need VTTs for subobjects with virtual bases. */
8370 /* We need to use a construction vtable if this is not the primary
8371 VTT. */
8373 {
8376 /* Record the offset in the VTT where this sub-VTT can be found. */
8378 }
8380 /* Add the address of the primary vtable for the complete object. */
8384 {
8387 }
8390 /* Recursively add the secondary VTTs for non-virtual bases. */
8395 /* Add secondary virtual pointers for all subobjects of BINFO with
8396 either virtual bases or reachable along a virtual path, except
8397 subobjects that are non-virtual primary bases. */
8407 /* data.inits might have grown as we added secondary virtual pointers.
8408 Make sure our caller knows about the new vector. */
8412 /* Add the secondary VTTs for virtual bases in inheritance graph
8413 order. */
8415 {
8420 }
8421 else
8422 /* Remove the ctor vtables we created. */
8424 }
8426 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8427 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8429 static tree
8431 {
8434 /* We don't care about bases that don't have vtables. */
8438 /* We're only interested in proper subobjects of the type being
8439 constructed. */
8443 /* We're only interested in bases with virtual bases or reachable
8444 via a virtual path from the type being constructed. */
8449 /* We're not interested in non-virtual primary bases. */
8453 /* Record the index where this secondary vptr can be found. */
8455 {
8460 {
8461 /* It's a primary virtual base, and this is not a
8462 construction vtable. Find the base this is primary of in
8463 the inheritance graph, and use that base's vtable
8464 now. */
8467 }
8468 }
8470 /* Add the initializer for the secondary vptr itself. */
8473 /* Advance the vtt index. */
8478 }
8480 /* Called from build_vtt_inits via dfs_walk. After building
8481 constructor vtables and generating the sub-vtt from them, we need
8482 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8483 binfo of the base whose sub vtt was generated. */
8485 static tree
8487 {
8491 /* If this class has no vtable, none of its bases do. */
8495 /* This might be a primary base, so have no vtable in this
8496 hierarchy. */
8499 /* If we scribbled the construction vtable vptr into BINFO, clear it
8500 out now. */
8506 }
8508 /* Build the construction vtable group for BINFO which is in the
8509 hierarchy dominated by T. */
8511 static void
8513 {
8514 tree type;
8515 tree vtbl;
8516 tree id;
8517 tree vbase;
8520 /* See if we've already created this construction vtable group. */
8526 /* Build a version of VTBL (with the wrong type) for use in
8527 constructing the addresses of secondary vtables in the
8528 construction vtable group. */
8531 /* Don't export construction vtables from shared libraries. Even on
8532 targets that don't support hidden visibility, this tells
8533 can_refer_decl_in_current_unit_p not to assume that it's safe to
8534 access from a different compilation unit (bz 54314). */
8542 /* Add the vtables for each of our virtual bases using the vbase in T
8543 binfo. */
8545 vbase;
8547 {
8548 tree b;
8555 }
8557 /* Figure out the type of the construction vtable. */
8564 /* Initialize the construction vtable. */
8568 }
8570 /* Add the vtbl initializers for BINFO (and its bases other than
8571 non-virtual primaries) to the list of INITS. BINFO is in the
8572 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8573 the constructor the vtbl inits should be accumulated for. (If this
8574 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8575 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8576 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8577 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8578 but are not necessarily the same in terms of layout. */
8580 static void
8582 tree orig_binfo,
8583 tree rtti_binfo,
8584 tree vtbl,
8585 tree t,
8587 {
8589 tree base_binfo;
8594 /* If it doesn't have a vptr, we don't do anything. */
8598 /* If we're building a construction vtable, we're not interested in
8599 subobjects that don't require construction vtables. */
8605 /* Build the initializers for the BINFO-in-T vtable. */
8608 /* Walk the BINFO and its bases. We walk in preorder so that as we
8609 initialize each vtable we can figure out at what offset the
8610 secondary vtable lies from the primary vtable. We can't use
8611 dfs_walk here because we need to iterate through bases of BINFO
8612 and RTTI_BINFO simultaneously. */
8614 {
8615 /* Skip virtual bases. */
8621 inits);
8622 }
8623 }
8625 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8626 BINFO vtable to L. */
8628 static void
8630 tree orig_binfo,
8631 tree rtti_binfo,
8632 tree orig_vtbl,
8633 tree t,
8635 {
8642 {
8643 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8644 primary virtual base. If it is not the same primary in
8645 the hierarchy of T, we'll need to generate a ctor vtable
8646 for it, to place at its location in T. If it is the same
8647 primary, we still need a VTT entry for the vtable, but it
8648 should point to the ctor vtable for the base it is a
8649 primary for within the sub-hierarchy of RTTI_BINFO.
8651 There are three possible cases:
8653 1) We are in the same place.
8654 2) We are a primary base within a lost primary virtual base of
8655 RTTI_BINFO.
8656 3) We are primary to something not a base of RTTI_BINFO. */
8658 tree b;
8661 /* First, look through the bases we are primary to for RTTI_BINFO
8662 or a virtual base. */
8665 {
8670 }
8671 /* If we run out of primary links, keep looking down our
8672 inheritance chain; we might be an indirect primary. */
8676 found:
8678 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8679 base B and it is a base of RTTI_BINFO, this is case 2. In
8680 either case, we share our vtable with LAST, i.e. the
8681 derived-most base within B of which we are a primary. */
8684 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8685 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8686 binfo_ctor_vtable after everything's been set up. */
8689 /* Otherwise, this is case 3 and we get our own. */
8690 }
8697 {
8698 tree index;
8701 /* Add the initializer for this vtable. */
8705 /* Figure out the position to which the VPTR should point. */
8711 }
8714 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8715 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8716 straighten this out. */
8719 /* Throw away any unneeded intializers. */
8721 else
8722 /* For an ordinary vtable, set BINFO_VTABLE. */
8724 }
8728 /* Construct the initializer for BINFO's virtual function table. BINFO
8729 is part of the hierarchy dominated by T. If we're building a
8730 construction vtable, the ORIG_BINFO is the binfo we should use to
8731 find the actual function pointers to put in the vtable - but they
8732 can be overridden on the path to most-derived in the graph that
8733 ORIG_BINFO belongs. Otherwise,
8734 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8735 BINFO that should be indicated by the RTTI information in the
8736 vtable; it will be a base class of T, rather than T itself, if we
8737 are building a construction vtable.
8739 The value returned is a TREE_LIST suitable for wrapping in a
8740 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8741 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8742 number of non-function entries in the vtable.
8744 It might seem that this function should never be called with a
8745 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8746 base is always subsumed by a derived class vtable. However, when
8747 we are building construction vtables, we do build vtables for
8748 primary bases; we need these while the primary base is being
8749 constructed. */
8751 static void
8753 tree orig_binfo,
8754 tree t,
8755 tree rtti_binfo,
8758 {
8759 tree v;
8760 vtbl_init_data vid;
8762 tree vbinfo;
8766 /* Initialize VID. */
8774 /* The first vbase or vcall offset is at index -3 in the vtable. */
8777 /* Add entries to the vtable for RTTI. */
8780 /* Create an array for keeping track of the functions we've
8781 processed. When we see multiple functions with the same
8782 signature, we share the vcall offsets. */
8784 /* Add the vcall and vbase offset entries. */
8787 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8788 build_vbase_offset_vtbl_entries. */
8793 /* If the target requires padding between data entries, add that now. */
8795 {
8800 /* Move data entries into their new positions and add padding
8801 after the new positions. Iterate backwards so we don't
8802 overwrite entries that we would need to process later. */
8805 ix--)
8806 {
8814 {
8818 null_pointer_node);
8819 }
8820 }
8821 }
8826 /* The initializers for virtual functions were built up in reverse
8827 order. Straighten them out and add them to the running list in one
8828 step. */
8837 /* Go through all the ordinary virtual functions, building up
8838 initializers. */
8840 {
8841 tree delta;
8842 tree vcall_index;
8849 {
8853 {
8856 }
8858 }
8860 /* If the only definition of this function signature along our
8861 primary base chain is from a lost primary, this vtable slot will
8862 never be used, so just zero it out. This is important to avoid
8863 requiring extra thunks which cannot be generated with the function.
8865 We first check this in update_vtable_entry_for_fn, so we handle
8866 restored primary bases properly; we also need to do it here so we
8867 zero out unused slots in ctor vtables, rather than filling them
8868 with erroneous values (though harmless, apart from relocation
8869 costs). */
8874 {
8875 /* Pull the offset for `this', and the function to call, out of
8876 the list. */
8883 /* You can't call an abstract virtual function; it's abstract.
8884 So, we replace these functions with __pure_virtual. */
8886 {
8889 {
8891 abort_fndecl_addr
8895 }
8896 }
8897 /* Likewise for deleted virtuals. */
8899 {
8908 }
8909 else
8910 {
8912 {
8916 }
8917 /* Take the address of the function, considering it to be of an
8918 appropriate generic type. */
8922 /* Don't refer to a virtual destructor from a constructor
8923 vtable or a vtable for an abstract class, since destroying
8924 an object under construction is undefined behavior and we
8925 don't want it to be considered a candidate for speculative
8926 devirtualization. But do create the thunk for ABI
8927 compliance. */
8932 }
8933 }
8935 /* And add it to the chain of initializers. */
8937 {
8942 else
8944 {
8950 }
8951 }
8952 else
8954 }
8955 }
8957 /* Adds to vid->inits the initializers for the vbase and vcall
8958 offsets in BINFO, which is in the hierarchy dominated by T. */
8960 static void
8962 {
8963 tree b;
8965 /* If this is a derived class, we must first create entries
8966 corresponding to the primary base class. */
8971 /* Add the vbase entries for this base. */
8973 /* Add the vcall entries for this base. */
8975 }
8977 /* Returns the initializers for the vbase offset entries in the vtable
8978 for BINFO (which is part of the class hierarchy dominated by T), in
8979 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8980 where the next vbase offset will go. */
8982 static void
8984 {
8985 tree vbase;
8986 tree t;
8987 tree non_primary_binfo;
8989 /* If there are no virtual baseclasses, then there is nothing to
8990 do. */
8996 /* We might be a primary base class. Go up the inheritance hierarchy
8997 until we find the most derived class of which we are a primary base:
8998 it is the offset of that which we need to use. */
9001 {
9002 tree b;
9004 /* If we have reached a virtual base, then it must be a primary
9005 base (possibly multi-level) of vid->binfo, or we wouldn't
9006 have called build_vcall_and_vbase_vtbl_entries for it. But it
9007 might be a lost primary, so just skip down to vid->binfo. */
9009 {
9012 }
9018 }
9020 /* Go through the virtual bases, adding the offsets. */
9022 vbase;
9024 {
9025 tree b;
9026 tree delta;
9031 /* Find the instance of this virtual base in the complete
9032 object. */
9035 /* If we've already got an offset for this virtual base, we
9036 don't need another one. */
9041 /* Figure out where we can find this vbase offset. */
9050 /* The vbase offset had better be the same. */
9053 /* The next vbase will come at a more negative offset. */
9057 /* The initializer is the delta from BINFO to this virtual base.
9058 The vbase offsets go in reverse inheritance-graph order, and
9059 we are walking in inheritance graph order so these end up in
9060 the right order. */
9067 }
9068 }
9070 /* Adds the initializers for the vcall offset entries in the vtable
9071 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9072 to VID->INITS. */
9074 static void
9076 {
9077 /* We only need these entries if this base is a virtual base. We
9078 compute the indices -- but do not add to the vtable -- when
9079 building the main vtable for a class. */
9082 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9083 correspond to VID->DERIVED), we are building a primary
9084 construction virtual table. Since this is a primary
9085 virtual table, we do not need the vcall offsets for
9086 BINFO. */
9088 {
9089 /* We need a vcall offset for each of the virtual functions in this
9090 vtable. For example:
9092 class A { virtual void f (); };
9093 class B1 : virtual public A { virtual void f (); };
9094 class B2 : virtual public A { virtual void f (); };
9095 class C: public B1, public B2 { virtual void f (); };
9097 A C object has a primary base of B1, which has a primary base of A. A
9098 C also has a secondary base of B2, which no longer has a primary base
9099 of A. So the B2-in-C construction vtable needs a secondary vtable for
9100 A, which will adjust the A* to a B2* to call f. We have no way of
9101 knowing what (or even whether) this offset will be when we define B2,
9102 so we store this "vcall offset" in the A sub-vtable and look it up in
9103 a "virtual thunk" for B2::f.
9105 We need entries for all the functions in our primary vtable and
9106 in our non-virtual bases' secondary vtables. */
9108 /* If we are just computing the vcall indices -- but do not need
9109 the actual entries -- not that. */
9112 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9114 }
9115 }
9117 /* Build vcall offsets, starting with those for BINFO. */
9119 static void
9121 {
9123 tree primary_binfo;
9124 tree base_binfo;
9126 /* Don't walk into virtual bases -- except, of course, for the
9127 virtual base for which we are building vcall offsets. Any
9128 primary virtual base will have already had its offsets generated
9129 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9133 /* If BINFO has a primary base, process it first. */
9138 /* Add BINFO itself to the list. */
9141 /* Scan the non-primary bases of BINFO. */
9145 }
9147 /* Called from build_vcall_offset_vtbl_entries_r. */
9149 static void
9151 {
9152 /* Make entries for the rest of the virtuals. */
9153 tree orig_fn;
9155 /* The ABI requires that the methods be processed in declaration
9156 order. */
9158 orig_fn;
9162 }
9164 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9166 static void
9168 {
9170 tree vcall_offset;
9171 tree derived_entry;
9173 /* If there is already an entry for a function with the same
9174 signature as FN, then we do not need a second vcall offset.
9175 Check the list of functions already present in the derived
9176 class vtable. */
9178 {
9180 /* We only use one vcall offset for virtual destructors,
9181 even though there are two virtual table entries. */
9185 }
9187 /* If we are building these vcall offsets as part of building
9188 the vtable for the most derived class, remember the vcall
9189 offset. */
9191 {
9194 }
9196 /* The next vcall offset will be found at a more negative
9197 offset. */
9201 /* Keep track of this function. */
9205 {
9206 tree base;
9207 tree fn;
9209 /* Find the overriding function. */
9213 else
9214 {
9217 /* The vbase we're working on is a primary base of
9218 vid->binfo. But it might be a lost primary, so its
9219 BINFO_OFFSET might be wrong, so we just use the
9220 BINFO_OFFSET from vid->binfo. */
9226 vcall_offset);
9227 }
9228 /* Add the initializer to the vtable. */
9230 }
9231 }
9233 /* Return vtbl initializers for the RTTI entries corresponding to the
9234 BINFO's vtable. The RTTI entries should indicate the object given
9235 by VID->rtti_binfo. */
9237 static void
9239 {
9240 tree b;
9241 tree t;
9242 tree offset;
9243 tree decl;
9244 tree init;
9248 /* To find the complete object, we will first convert to our most
9249 primary base, and then add the offset in the vtbl to that value. */
9253 {
9254 tree primary_base;
9260 }
9264 /* The second entry is the address of the typeinfo object. */
9267 else
9270 /* Convert the declaration to a type that can be stored in the
9271 vtable. */
9275 /* Add the offset-to-top entry. It comes earlier in the vtable than
9276 the typeinfo entry. Convert the offset to look like a
9277 function pointer, so that we can put it in the vtable. */
9280 }
9282 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9283 accessibility. */
9285 bool
9287 {
9290 }
9292 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9294 bool
9296 {
9300 }
9302 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9303 class between them, if any. */
9305 tree
9307 {
9319 {
9322 }
9326 }