| blob | 09f946fcdf7c45eef7c09dffe99ee71ed49c18a3 |
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 {
1452 {
1455 {
1459 }
1460 }
1462 // If we found some tags on our template arguments, add them to our
1463 // abi_tag attribute.
1465 {
1469 else
1473 }
1476 }
1478 /* Return true, iff class T has a non-virtual destructor that is
1479 accessible from outside the class heirarchy (i.e. is public, or
1480 there's a suitable friend. */
1482 static bool
1484 {
1487 /* An implicitly declared destructor is always public. And,
1488 if it were virtual, we would have created it by now. */
1503 }
1505 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1506 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1507 properties of the bases. */
1509 static void
1513 {
1517 tree base_binfo;
1518 tree binfo;
1528 {
1537 /* If any base class is non-literal, so is the derived class. */
1541 /* If the base class doesn't have copy constructors or
1542 assignment operators that take const references, then the
1543 derived class cannot have such a member automatically
1544 generated. */
1553 /* A virtual base does not effect nearly emptiness. */
1554 ;
1556 {
1558 /* And if there is more than one nearly empty base, then the
1559 derived class is not nearly empty either. */
1561 else
1562 /* Remember we've seen one. */
1564 }
1566 /* If the base class is not empty or nearly empty, then this
1567 class cannot be nearly empty. */
1570 /* A lot of properties from the bases also apply to the derived
1571 class. */
1588 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1591 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1595 /* A standard-layout class is a class that:
1596 ...
1597 * has no non-standard-layout base classes, */
1600 {
1601 tree basefield;
1602 /* ...has no base classes of the same type as the first non-static
1603 data member... */
1605 && (same_type_ignoring_top_level_qualifiers_p
1608 else
1609 /* ...either has no non-static data members in the most-derived
1610 class and at most one base class with non-static data
1611 members, or has no base classes with non-static data
1612 members */
1616 {
1619 else
1622 }
1623 }
1625 /* Don't bother collecting tm attributes if transactional memory
1626 support is not enabled. */
1628 {
1632 }
1635 }
1637 /* If one of the base classes had TM attributes, and the current class
1638 doesn't define its own, then the current class inherits one. */
1640 {
1643 }
1644 }
1646 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1647 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1648 that have had a nearly-empty virtual primary base stolen by some
1649 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1650 T. */
1652 static void
1654 {
1658 tree base_binfo;
1660 /* Determine the primary bases of our bases. */
1663 {
1666 /* See if we're the non-virtual primary of our inheritance
1667 chain. */
1669 {
1676 /* We are the primary binfo. */
1678 }
1679 /* Determine if we have a virtual primary base, and mark it so.
1680 */
1682 {
1686 /* Someone already claimed this base. */
1688 else
1689 {
1690 tree delta;
1695 /* A virtual binfo might have been copied from within
1696 another hierarchy. As we're about to use it as a
1697 primary base, make sure the offsets match. */
1705 }
1706 }
1707 }
1709 /* First look for a dynamic direct non-virtual base. */
1711 {
1715 {
1718 }
1719 }
1721 /* A "nearly-empty" virtual base class can be the primary base
1722 class, if no non-virtual polymorphic base can be found. Look for
1723 a nearly-empty virtual dynamic base that is not already a primary
1724 base of something in the hierarchy. If there is no such base,
1725 just pick the first nearly-empty virtual base. */
1731 {
1733 {
1734 /* Found one that is not primary. */
1737 }
1739 /* Remember the first candidate. */
1741 }
1743 found:
1744 /* If we've got a primary base, use it. */
1746 {
1751 /* We are stealing a primary base. */
1755 {
1756 tree delta;
1759 /* A virtual binfo might have been copied from within
1760 another hierarchy. As we're about to use it as a primary
1761 base, make sure the offsets match. */
1766 }
1773 }
1774 }
1776 /* Update the variant types of T. */
1778 void
1780 {
1781 tree variants;
1787 variants;
1789 {
1790 /* These fields are in the _TYPE part of the node, not in
1791 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1801 /* Copy whatever these are holding today. */
1805 }
1806 }
1808 /* Early variant fixups: we apply attributes at the beginning of the class
1809 definition, and we need to fix up any variants that have already been
1810 made via elaborated-type-specifier so that check_qualified_type works. */
1812 void
1814 {
1815 tree variants;
1821 variants;
1823 {
1824 /* These are the two fields that check_qualified_type looks at and
1825 are affected by attributes. */
1828 }
1829 }
1830 \f
1831 /* Set memoizing fields and bits of T (and its variants) for later
1832 use. */
1834 static void
1836 {
1837 /* Fix up variants (if any). */
1841 /* For a class w/o baseclasses, 'finish_struct' has set
1842 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1843 Similarly for a class whose base classes do not have vtables.
1844 When neither of these is true, we might have removed abstract
1845 virtuals (by providing a definition), added some (by declaring
1846 new ones), or redeclared ones from a base class. We need to
1847 recalculate what's really an abstract virtual at this point (by
1848 looking in the vtables). */
1851 /* If this type has a copy constructor or a destructor, force its
1852 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1853 nonzero. This will cause it to be passed by invisible reference
1854 and prevent it from being returned in a register. */
1857 {
1858 tree variants;
1861 {
1864 }
1865 }
1866 }
1868 /* Issue warnings about T having private constructors, but no friends,
1869 and so forth.
1871 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1872 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1873 non-private static member functions. */
1875 static void
1877 {
1880 tree fn;
1883 /* If the class has friends, those entities might create and
1884 access instances, so we should not warn. */
1887 /* We will have warned when the template was declared; there's
1888 no need to warn on every instantiation. */
1890 /* There's no reason to even consider warning about this
1891 class. */
1894 /* We only issue one warning, if more than one applies, because
1895 otherwise, on code like:
1897 class A {
1898 // Oops - forgot `public:'
1899 A();
1900 A(const A&);
1901 ~A();
1902 };
1904 we warn several times about essentially the same problem. */
1906 /* Check to see if all (non-constructor, non-destructor) member
1907 functions are private. (Since there are no friends or
1908 non-private statics, we can't ever call any of the private member
1909 functions.) */
1911 /* We're not interested in compiler-generated methods; they don't
1912 provide any way to call private members. */
1914 {
1916 {
1918 /* A non-private static member function is just like a
1919 friend; it can create and invoke private member
1920 functions, and be accessed without a class
1921 instance. */
1925 /* Keep searching for a static member function. */
1926 }
1929 }
1932 {
1933 /* There are no non-private methods, and there's at least one
1934 private member function that isn't a constructor or
1935 destructor. (If all the private members are
1936 constructors/destructors we want to use the code below that
1937 issues error messages specifically referring to
1938 constructors/destructors.) */
1944 {
1947 }
1949 {
1953 }
1954 }
1956 /* Even if some of the member functions are non-private, the class
1957 won't be useful for much if all the constructors or destructors
1958 are private: such an object can never be created or destroyed. */
1961 {
1964 t);
1966 }
1968 /* Warn about classes that have private constructors and no friends. */
1970 /* Implicitly generated constructors are always public. */
1973 {
1976 /* If a non-template class does not define a copy
1977 constructor, one is defined for it, enabling it to avoid
1978 this warning. For a template class, this does not
1979 happen, and so we would normally get a warning on:
1981 template <class T> class C { private: C(); };
1983 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1984 complete non-template or fully instantiated classes have this
1985 flag set. */
1988 else
1990 {
1992 /* Ideally, we wouldn't count copy constructors (or, in
1993 fact, any constructor that takes an argument of the
1994 class type as a parameter) because such things cannot
1995 be used to construct an instance of the class unless
1996 you already have one. But, for now at least, we're
1997 more generous. */
1999 {
2002 }
2003 }
2006 {
2009 t);
2011 }
2012 }
2013 }
2016 gt_pointer_operator new_value;
2020 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2022 static int
2024 {
2037 }
2039 /* This routine compares two fields like method_name_cmp but using the
2040 pointer operator in resort_field_decl_data. */
2042 static int
2044 {
2053 {
2060 }
2062 }
2064 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2066 void
2069 gt_pointer_operator new_value,
2071 {
2075 tree fn;
2077 /* The type conversion ops have to live at the front of the vec, so we
2078 can't sort them. */
2086 {
2090 resort_method_name_cmp);
2091 }
2092 }
2094 /* Warn about duplicate methods in fn_fields.
2096 Sort methods that are not special (i.e., constructors, destructors,
2097 and type conversion operators) so that we can find them faster in
2098 search. */
2100 static void
2102 {
2103 tree fn_fields;
2113 /* Clear DECL_IN_AGGR_P for all functions. */
2118 /* Issue warnings about private constructors and such. If there are
2119 no methods, then some public defaults are generated. */
2122 /* The type conversion ops have to live at the front of the vec, so we
2123 can't sort them. */
2132 }
2134 /* Make BINFO's vtable have N entries, including RTTI entries,
2135 vbase and vcall offsets, etc. Set its type and call the back end
2136 to lay it out. */
2138 static void
2140 {
2141 tree atype;
2142 tree vtable;
2147 /* We may have to grow the vtable. */
2150 {
2154 }
2155 }
2157 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2158 have the same signature. */
2160 int
2162 {
2163 /* One destructor overrides another if they are the same kind of
2164 destructor. */
2168 /* But a non-destructor never overrides a destructor, nor vice
2169 versa, nor do different kinds of destructors override
2170 one-another. For example, a complete object destructor does not
2171 override a deleting destructor. */
2180 {
2188 }
2190 }
2192 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2193 subobject. */
2195 static bool
2197 {
2198 tree probe;
2201 {
2205 /* If we meet a virtual base, we can't follow the inheritance
2206 any more. See if the complete type of DERIVED contains
2207 such a virtual base. */
2210 }
2212 }
2215 /* The function for which we are trying to find a final overrider. */
2216 tree fn;
2217 /* The base class in which the function was declared. */
2218 tree declaring_base;
2219 /* The candidate overriders. */
2220 tree candidates;
2221 /* Path to most derived. */
2225 /* Add the overrider along the current path to FFOD->CANDIDATES.
2226 Returns true if an overrider was found; false otherwise. */
2228 static bool
2232 {
2233 tree method;
2235 /* If BINFO is not the most derived type, try a more derived class.
2236 A definition there will overrider a definition here. */
2238 {
2239 depth--;
2243 }
2247 {
2250 /* Remove any candidates overridden by this new function. */
2252 {
2253 /* If *CANDIDATE overrides METHOD, then METHOD
2254 cannot override anything else on the list. */
2257 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2260 else
2262 }
2264 /* Add the new function. */
2267 }
2270 }
2272 /* Called from find_final_overrider via dfs_walk. */
2274 static tree
2276 {
2284 }
2286 static tree
2288 {
2293 }
2295 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2296 FN and whose TREE_VALUE is the binfo for the base where the
2297 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2298 DERIVED) is the base object in which FN is declared. */
2300 static tree
2302 {
2303 find_final_overrider_data ffod;
2305 /* Getting this right is a little tricky. This is valid:
2307 struct S { virtual void f (); };
2308 struct T { virtual void f (); };
2309 struct U : public S, public T { };
2311 even though calling `f' in `U' is ambiguous. But,
2313 struct R { virtual void f(); };
2314 struct S : virtual public R { virtual void f (); };
2315 struct T : virtual public R { virtual void f (); };
2316 struct U : public S, public T { };
2318 is not -- there's no way to decide whether to put `S::f' or
2319 `T::f' in the vtable for `R'.
2321 The solution is to look at all paths to BINFO. If we find
2322 different overriders along any two, then there is a problem. */
2326 /* Determine the depth of the hierarchy. */
2337 /* If there was no winner, issue an error message. */
2342 }
2344 /* Return the index of the vcall offset for FN when TYPE is used as a
2345 virtual base. */
2347 static tree
2349 {
2351 tree_pair_p p;
2359 /* There should always be an appropriate index. */
2361 }
2363 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2364 dominated by T. FN is the old function; VIRTUALS points to the
2365 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2366 of that entry in the list. */
2368 static void
2371 {
2372 tree b;
2373 tree overrider;
2374 tree delta;
2375 tree virtual_base;
2376 tree first_defn;
2382 /* Find the nearest primary base (possibly binfo itself) which defines
2383 this function; this is the class the caller will convert to when
2384 calling FN through BINFO. */
2386 {
2391 /* The nearest definition is from a lost primary. */
2394 }
2397 /* Find the final overrider. */
2400 {
2403 }
2406 /* Check for adjusting covariant return types. */
2414 /* If the overrider is invalid, don't even try. */
2416 {
2417 /* If FN is a covariant thunk, we must figure out the adjustment
2418 to the final base FN was converting to. As OVERRIDER_TARGET might
2419 also be converting to the return type of FN, we have to
2420 combine the two conversions here. */
2427 {
2431 }
2432 else
2436 /* Find the equivalent binfo within the return type of the
2437 overriding function. We will want the vbase offset from
2438 there. */
2440 over_return);
2443 {
2444 /* There was no existing virtual thunk (which takes
2445 precedence). So find the binfo of the base function's
2446 return type within the overriding function's return type.
2447 We cannot call lookup base here, because we're inside a
2448 dfs_walk, and will therefore clobber the BINFO_MARKED
2449 flags. Fortunately we know the covariancy is valid (it
2450 has already been checked), so we can just iterate along
2451 the binfos, which have been chained in inheritance graph
2452 order. Of course it is lame that we have to repeat the
2453 search here anyway -- we should really be caching pieces
2454 of the vtable and avoiding this repeated work. */
2457 /* Find the base binfo within the overriding function's
2458 return type. We will always find a thunk_binfo, except
2459 when the covariancy is invalid (which we will have
2460 already diagnosed). */
2463 thunk_binfo;
2469 /* See if virtual inheritance is involved. */
2471 virtual_offset;
2478 {
2482 {
2483 /* We convert via virtual base. Adjust the fixed
2484 offset to be from there. */
2485 offset =
2489 }
2491 /* There was an existing fixed offset, this must be
2492 from the base just converted to, and the base the
2493 FN was thunking to. */
2495 else
2497 }
2498 }
2501 /* Replace the overriding function with a covariant thunk. We
2502 will emit the overriding function in its own slot as
2503 well. */
2506 }
2507 else
2511 /* If we need a covariant thunk, then we may need to adjust first_defn.
2512 The ABI specifies that the thunks emitted with a function are
2513 determined by which bases the function overrides, so we need to be
2514 sure that we're using a thunk for some overridden base; even if we
2515 know that the necessary this adjustment is zero, there may not be an
2516 appropriate zero-this-adjusment thunk for us to use since thunks for
2517 overriding virtual bases always use the vcall offset.
2519 Furthermore, just choosing any base that overrides this function isn't
2520 quite right, as this slot won't be used for calls through a type that
2521 puts a covariant thunk here. Calling the function through such a type
2522 will use a different slot, and that slot is the one that determines
2523 the thunk emitted for that base.
2525 So, keep looking until we find the base that we're really overriding
2526 in this slot: the nearest primary base that doesn't use a covariant
2527 thunk in this slot. */
2529 {
2531 /* We already know that the overrider needs a covariant thunk. */
2534 {
2541 }
2543 }
2545 /* Assume that we will produce a thunk that convert all the way to
2546 the final overrider, and not to an intermediate virtual base. */
2549 /* See if we can convert to an intermediate virtual base first, and then
2550 use the vcall offset located there to finish the conversion. */
2552 {
2553 /* If we find the final overrider, then we can stop
2554 walking. */
2559 /* If we find a virtual base, and we haven't yet found the
2560 overrider, then there is a virtual base between the
2561 declaring base (first_defn) and the final overrider. */
2563 {
2566 }
2567 }
2569 /* Compute the constant adjustment to the `this' pointer. The
2570 `this' pointer, when this function is called, will point at BINFO
2571 (or one of its primary bases, which are at the same offset). */
2573 /* The `this' pointer needs to be adjusted from the declaration to
2574 the nearest virtual base. */
2579 /* If the nearest definition is in a lost primary, we don't need an
2580 entry in our vtable. Except possibly in a constructor vtable,
2581 if we happen to get our primary back. In that case, the offset
2582 will be zero, as it will be a primary base. */
2584 else
2585 /* The `this' pointer needs to be adjusted from pointing to
2586 BINFO to pointing at the base where the final overrider
2587 appears. */
2598 else
2602 }
2604 /* Called from modify_all_vtables via dfs_walk. */
2606 static tree
2608 {
2610 tree virtuals;
2611 tree old_virtuals;
2615 /* A base without a vtable needs no modification, and its bases
2616 are uninteresting. */
2621 /* Don't do the primary vtable, if it's new. */
2625 /* There's no need to modify the vtable for a non-virtual primary
2626 base; we're not going to use that vtable anyhow. We do still
2627 need to do this for virtual primary bases, as they could become
2628 non-primary in a construction vtable. */
2633 /* Now, go through each of the virtual functions in the virtual
2634 function table for BINFO. Find the final overrider, and update
2635 the BINFO_VIRTUALS list appropriately. */
2638 virtuals;
2642 binfo,
2647 }
2649 /* Update all of the primary and secondary vtables for T. Create new
2650 vtables as required, and initialize their RTTI information. Each
2651 of the functions in VIRTUALS is declared in T and may override a
2652 virtual function from a base class; find and modify the appropriate
2653 entries to point to the overriding functions. Returns a list, in
2654 declaration order, of the virtual functions that are declared in T,
2655 but do not appear in the primary base class vtable, and which
2656 should therefore be appended to the end of the vtable for T. */
2658 static tree
2660 {
2664 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2668 /* Update all of the vtables. */
2671 /* Add virtual functions not already in our primary vtable. These
2672 will be both those introduced by this class, and those overridden
2673 from secondary bases. It does not include virtuals merely
2674 inherited from secondary bases. */
2676 {
2681 {
2682 /* We don't need to adjust the `this' pointer when
2683 calling this function. */
2687 /* This is a function not already in our vtable. Keep it. */
2689 }
2690 else
2691 /* We've already got an entry for this function. Skip it. */
2693 }
2696 }
2698 /* Get the base virtual function declarations in T that have the
2699 indicated NAME. */
2701 static tree
2703 {
2704 tree methods;
2709 /* Find virtual functions in T with the indicated NAME. */
2713 methods;
2715 {
2721 }
2727 {
2730 base_fndecls);
2731 }
2734 }
2736 /* If this declaration supersedes the declaration of
2737 a method declared virtual in the base class, then
2738 mark this field as being virtual as well. */
2740 void
2742 {
2745 /* In [temp.mem] we have:
2747 A specialization of a member function template does not
2748 override a virtual function from a base class. */
2755 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2756 the error_mark_node so that we know it is an overriding
2757 function. */
2758 {
2761 }
2764 {
2770 }
2775 }
2777 /* Warn about hidden virtual functions that are not overridden in t.
2778 We know that constructors and destructors don't apply. */
2780 static void
2782 {
2784 tree fns;
2787 /* We go through each separately named virtual function. */
2791 {
2792 tree fn;
2793 tree name;
2794 tree fndecl;
2795 tree base_fndecls;
2796 tree base_binfo;
2797 tree binfo;
2800 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2801 have the same name. Figure out what name that is. */
2803 /* There are no possibly hidden functions yet. */
2805 /* Iterate through all of the base classes looking for possibly
2806 hidden functions. */
2809 {
2812 base_fndecls);
2813 }
2815 /* If there are no functions to hide, continue. */
2819 /* Remove any overridden functions. */
2821 {
2824 {
2828 /* If the method from the base class has the same
2829 signature as the method from the derived class, it
2830 has been overridden. */
2833 else
2835 }
2836 }
2838 /* Now give a warning for all base functions without overriders,
2839 as they are hidden. */
2841 {
2842 /* Here we know it is a hider, and no overrider exists. */
2846 }
2847 }
2848 }
2850 /* Recursive helper for finish_struct_anon. */
2852 static void
2854 {
2858 {
2859 /* We're generally only interested in entities the user
2860 declared, but we also find nested classes by noticing
2861 the TYPE_DECL that we create implicitly. You're
2862 allowed to put one anonymous union inside another,
2863 though, so we explicitly tolerate that. We use
2864 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2865 we also allow unnamed types used for defining fields. */
2872 {
2873 /* We already complained about static data members in
2874 finish_static_data_member_decl. */
2876 {
2879 "%q+#D invalid; an anonymous union can "
2881 else
2883 "%q+#D invalid; an anonymous struct can "
2885 }
2887 }
2890 {
2892 {
2896 else
2899 }
2901 {
2905 else
2908 }
2909 }
2914 /* Recurse into the anonymous aggregates to handle correctly
2915 access control (c++/24926):
2917 class A {
2918 union {
2919 union {
2920 int i;
2921 };
2922 };
2923 };
2925 int j=A().i; */
2929 }
2930 }
2932 /* Check for things that are invalid. There are probably plenty of other
2933 things we should check for also. */
2935 static void
2937 {
2939 {
2948 }
2949 }
2951 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2952 will be used later during class template instantiation.
2953 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2954 a non-static member data (FIELD_DECL), a member function
2955 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2956 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2957 When FRIEND_P is nonzero, T is either a friend class
2958 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2959 (FUNCTION_DECL, TEMPLATE_DECL). */
2961 void
2963 {
2964 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2969 }
2971 /* This function is called from declare_virt_assop_and_dtor via
2972 dfs_walk_all.
2974 DATA is a type that direcly or indirectly inherits the base
2975 represented by BINFO. If BINFO contains a virtual assignment [copy
2976 assignment or move assigment] operator or a virtual constructor,
2977 declare that function in DATA if it hasn't been already declared. */
2979 static tree
2981 {
2989 /* A base without a vtable needs no modification, and its bases
2990 are uninteresting. */
2994 /* If this is a primary base, then we have already looked at the
2995 virtual functions of its vtable. */
2999 {
3003 {
3008 }
3012 }
3015 }
3017 /* If the class type T has a direct or indirect base that contains a
3018 virtual assignment operator or a virtual destructor, declare that
3019 function in T if it hasn't been already declared. */
3021 static void
3023 {
3031 dfs_declare_virt_assop_and_dtor,
3033 }
3035 /* Declare the inheriting constructor for class T inherited from base
3036 constructor CTOR with the parameter array PARMS of size NPARMS. */
3038 static void
3040 {
3041 /* We don't declare an inheriting ctor that would be a default,
3042 copy or move ctor for derived or base. */
3047 {
3051 }
3059 {
3062 }
3063 }
3065 /* Declare all the inheriting constructors for class T inherited from base
3066 constructor CTOR. */
3068 static void
3070 {
3076 {
3080 }
3083 {
3087 }
3088 }
3090 /* Create default constructors, assignment operators, and so forth for
3091 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3092 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3093 the class cannot have a default constructor, copy constructor
3094 taking a const reference argument, or an assignment operator taking
3095 a const reference, respectively. */
3097 static void
3101 {
3109 /* Destructor. */
3111 {
3112 /* In general, we create destructors lazily. */
3117 /* But if this is a Java class, any non-trivial destructor is
3118 invalid, even if compiler-generated. Therefore, if the
3119 destructor is non-trivial we create it now. */
3121 }
3123 /* [class.ctor]
3125 If there is no user-declared constructor for a class, a default
3126 constructor is implicitly declared. */
3128 {
3133 /* This might force the declaration. */
3135 }
3137 /* [class.ctor]
3139 If a class definition does not explicitly declare a copy
3140 constructor, one is declared implicitly. */
3142 {
3148 }
3150 /* If there is no assignment operator, one will be created if and
3151 when it is needed. For now, just record whether or not the type
3152 of the parameter to the assignment operator will be a const or
3153 non-const reference. */
3155 {
3161 }
3163 /* We can't be lazy about declaring functions that might override
3164 a virtual function from a base class. */
3168 {
3172 {
3173 /* declare, then remove the decl */
3182 }
3183 else
3185 }
3186 }
3188 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3189 count the number of fields in TYPE, including anonymous union
3190 members. */
3192 static int
3194 {
3195 tree x;
3198 {
3201 else
3203 }
3205 }
3207 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3208 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3209 elts, starting at offset IDX. */
3211 static int
3213 {
3214 tree x;
3216 {
3219 else
3221 }
3223 }
3225 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3226 starting at offset IDX. */
3228 static int
3232 {
3233 tree values;
3237 }
3239 /* FIELD is a bit-field. We are finishing the processing for its
3240 enclosing type. Issue any appropriate messages and set appropriate
3241 flags. Returns false if an error has been diagnosed. */
3243 static bool
3245 {
3247 tree w;
3249 /* Extract the declared width of the bitfield, which has been
3250 temporarily stashed in DECL_INITIAL. */
3253 /* Remove the bit-field width indicator so that the rest of the
3254 compiler does not treat that value as an initializer. */
3257 /* Detect invalid bit-field type. */
3259 {
3262 }
3263 else
3264 {
3266 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3269 /* detect invalid field size. */
3275 {
3278 }
3280 {
3283 }
3285 {
3288 }
3300 }
3303 {
3307 }
3308 else
3309 {
3310 /* Non-bit-fields are aligned for their type. */
3314 }
3315 }
3317 /* FIELD is a non bit-field. We are finishing the processing for its
3318 enclosing type T. Issue any appropriate messages and set appropriate
3319 flags. */
3321 static void
3323 tree t,
3327 {
3330 /* In C++98 an anonymous union cannot contain any fields which would change
3331 the settings of CANT_HAVE_CONST_CTOR and friends. */
3333 ;
3334 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3335 structs. So, we recurse through their fields here. */
3337 {
3338 tree fields;
3344 }
3345 /* Check members with class type for constructors, destructors,
3346 etc. */
3348 {
3349 /* Never let anything with uninheritable virtuals
3350 make it through without complaint. */
3354 {
3359 field);
3364 field);
3366 {
3370 }
3371 }
3372 else
3373 {
3386 }
3395 }
3400 {
3401 /* `build_class_init_list' does not recognize
3402 non-FIELD_DECLs. */
3406 }
3407 }
3409 /* Check the data members (both static and non-static), class-scoped
3410 typedefs, etc., appearing in the declaration of T. Issue
3411 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3412 declaration order) of access declarations; each TREE_VALUE in this
3413 list is a USING_DECL.
3415 In addition, set the following flags:
3417 EMPTY_P
3418 The class is empty, i.e., contains no non-static data members.
3420 CANT_HAVE_CONST_CTOR_P
3421 This class cannot have an implicitly generated copy constructor
3422 taking a const reference.
3424 CANT_HAVE_CONST_ASN_REF
3425 This class cannot have an implicitly generated assignment
3426 operator taking a const reference.
3428 All of these flags should be initialized before calling this
3429 function.
3431 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3432 fields can be added by adding to this chain. */
3434 static void
3438 {
3446 /* Assume there are no access declarations. */
3448 /* Assume this class has no pointer members. */
3450 /* Assume none of the members of this class have default
3451 initializations. */
3455 {
3463 {
3464 /* Save the access declarations for our caller. */
3467 }
3473 /* If we've gotten this far, it's a data member, possibly static,
3474 or an enumerator. */
3478 /* When this goes into scope, it will be a non-local reference. */
3483 {
3484 /* [class.union] (C++98)
3486 If a union contains a static data member, or a member of
3487 reference type, the program is ill-formed.
3489 In C++11 this limitation doesn't exist anymore. */
3491 {
3495 }
3497 {
3501 }
3502 }
3504 /* Perform error checking that did not get done in
3505 grokdeclarator. */
3507 {
3511 }
3513 {
3517 }
3525 /* Now it can only be a FIELD_DECL. */
3530 /* If at least one non-static data member is non-literal, the whole
3531 class becomes non-literal. Per Core/1453, volatile non-static
3532 data members and base classes are also not allowed.
3533 Note: if the type is incomplete we will complain later on. */
3538 /* A standard-layout class is a class that:
3539 ...
3540 has the same access control (Clause 11) for all non-static data members,
3541 ... */
3548 /* If this is of reference type, check if it needs an init. */
3550 {
3556 /* ARM $12.6.2: [A member initializer list] (or, for an
3557 aggregate, initialization by a brace-enclosed list) is the
3558 only way to initialize nonstatic const and reference
3559 members. */
3562 }
3567 {
3569 {
3570 warning
3573 x);
3575 }
3579 }
3582 /* We don't treat zero-width bitfields as making a class
3583 non-empty. */
3584 ;
3585 else
3586 {
3587 /* The class is non-empty. */
3589 /* The class is not even nearly empty. */
3591 /* If one of the data members contains an empty class,
3592 so does T. */
3596 }
3598 /* This is used by -Weffc++ (see below). Warn only for pointers
3599 to members which might hold dynamic memory. So do not warn
3600 for pointers to functions or pointers to members. */
3606 {
3611 }
3617 {
3619 {
3623 }
3625 {
3629 }
3630 }
3633 /* DR 148 now allows pointers to members (which are POD themselves),
3634 to be allowed in POD structs. */
3643 /* We set DECL_C_BIT_FIELD in grokbitfield.
3644 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3647 cant_have_const_ctor_p,
3648 no_const_asn_ref_p,
3651 /* Now that we've removed bit-field widths from DECL_INITIAL,
3652 anything left in DECL_INITIAL is an NSDMI that makes the class
3653 non-aggregate. */
3657 /* If any field is const, the structure type is pseudo-const. */
3659 {
3664 /* ARM $12.6.2: [A member initializer list] (or, for an
3665 aggregate, initialization by a brace-enclosed list) is the
3666 only way to initialize nonstatic const and reference
3667 members. */
3670 }
3671 /* A field that is pseudo-const makes the structure likewise. */
3673 {
3678 }
3680 /* Core issue 80: A nonstatic data member is required to have a
3681 different name from the class iff the class has a
3682 user-declared constructor. */
3686 }
3688 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3689 it should also define a copy constructor and an assignment operator to
3690 implement the correct copy semantic (deep vs shallow, etc.). As it is
3691 not feasible to check whether the constructors do allocate dynamic memory
3692 and store it within members, we approximate the warning like this:
3694 -- Warn only if there are members which are pointers
3695 -- Warn only if there is a non-trivial constructor (otherwise,
3696 there cannot be memory allocated).
3697 -- Warn only if there is a non-trivial destructor. We assume that the
3698 user at least implemented the cleanup correctly, and a destructor
3699 is needed to free dynamic memory.
3701 This seems enough for practical purposes. */
3703 && has_pointers
3707 {
3711 {
3716 }
3720 }
3722 /* Non-static data member initializers make the default constructor
3723 non-trivial. */
3725 {
3728 }
3730 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3734 /* Check anonymous struct/anonymous union fields. */
3737 /* We've built up the list of access declarations in reverse order.
3738 Fix that now. */
3740 }
3742 /* If TYPE is an empty class type, records its OFFSET in the table of
3743 OFFSETS. */
3745 static int
3747 {
3748 splay_tree_node n;
3753 /* Record the location of this empty object in OFFSETS. */
3761 type,
3765 }
3767 /* Returns nonzero if TYPE is an empty class type and there is
3768 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3770 static int
3772 {
3773 splay_tree_node n;
3774 tree t;
3779 /* Record the location of this empty object in OFFSETS. */
3789 }
3791 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3792 F for every subobject, passing it the type, offset, and table of
3793 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3794 be traversed.
3796 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3797 than MAX_OFFSET will not be walked.
3799 If F returns a nonzero value, the traversal ceases, and that value
3800 is returned. Otherwise, returns zero. */
3802 static int
3804 subobject_offset_fn f,
3805 tree offset,
3806 splay_tree offsets,
3807 tree max_offset,
3809 {
3813 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3814 stop. */
3822 {
3825 }
3828 {
3829 tree field;
3830 tree binfo;
3833 /* Avoid recursing into objects that are not interesting. */
3837 /* Record the location of TYPE. */
3842 /* Iterate through the direct base classes of TYPE. */
3846 {
3847 tree binfo_offset;
3852 tree orig_binfo;
3853 /* We cannot rely on BINFO_OFFSET being set for the base
3854 class yet, but the offsets for direct non-virtual
3855 bases can be calculated by going back to the TYPE. */
3858 offset,
3862 f,
3863 binfo_offset,
3864 offsets,
3865 max_offset,
3869 }
3872 {
3876 /* Iterate through the virtual base classes of TYPE. In G++
3877 3.2, we included virtual bases in the direct base class
3878 loop above, which results in incorrect results; the
3879 correct offsets for virtual bases are only known when
3880 working with the most derived type. */
3884 {
3886 f,
3888 offset,
3890 offsets,
3891 max_offset,
3895 }
3896 else
3897 {
3898 /* We still have to walk the primary base, if it is
3899 virtual. (If it is non-virtual, then it was walked
3900 above.) */
3906 {
3907 r = (walk_subobject_offsets
3912 }
3913 }
3914 }
3916 /* Iterate through the fields of TYPE. */
3921 {
3922 tree field_offset;
3927 f,
3929 offset,
3930 field_offset),
3931 offsets,
3932 max_offset,
3936 }
3937 }
3939 {
3942 tree index;
3944 /* Avoid recursing into objects that are not interesting. */
3949 /* Step through each of the elements in the array. */
3953 {
3955 f,
3956 offset,
3957 offsets,
3958 max_offset,
3964 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3965 there's no point in iterating through the remaining
3966 elements of the array. */
3969 }
3970 }
3973 }
3975 /* Record all of the empty subobjects of TYPE (either a type or a
3976 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3977 is being placed at OFFSET; otherwise, it is a base class that is
3978 being placed at OFFSET. */
3980 static void
3982 tree offset,
3983 splay_tree offsets,
3985 {
3986 tree max_offset;
3987 /* If recording subobjects for a non-static data member or a
3988 non-empty base class , we do not need to record offsets beyond
3989 the size of the biggest empty class. Additional data members
3990 will go at the end of the class. Additional base classes will go
3991 either at offset zero (if empty, in which case they cannot
3992 overlap with offsets past the size of the biggest empty class) or
3993 at the end of the class.
3995 However, if we are placing an empty base class, then we must record
3996 all offsets, as either the empty class is at offset zero (where
3997 other empty classes might later be placed) or at the end of the
3998 class (where other objects might then be placed, so other empty
3999 subobjects might later overlap). */
4003 else
4007 }
4009 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4010 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4011 virtual bases of TYPE are examined. */
4013 static int
4015 tree offset,
4016 splay_tree offsets,
4018 {
4019 splay_tree_node max_node;
4021 /* Get the node in OFFSETS that indicates the maximum offset where
4022 an empty subobject is located. */
4024 /* If there aren't any empty subobjects, then there's no point in
4025 performing this check. */
4031 vbases_p);
4032 }
4034 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4035 non-static data member of the type indicated by RLI. BINFO is the
4036 binfo corresponding to the base subobject, OFFSETS maps offsets to
4037 types already located at those offsets. This function determines
4038 the position of the DECL. */
4040 static void
4042 tree decl,
4043 tree binfo,
4044 splay_tree offsets)
4045 {
4048 tree type;
4051 {
4052 /* For the purposes of determining layout conflicts, we want to
4053 use the class type of BINFO; TREE_TYPE (DECL) will be the
4054 CLASSTYPE_AS_BASE version, which does not contain entries for
4055 zero-sized bases. */
4058 }
4059 else
4060 {
4063 }
4065 /* Try to place the field. It may take more than one try if we have
4066 a hard time placing the field without putting two objects of the
4067 same type at the same address. */
4069 {
4072 /* Place this field. */
4076 /* We have to check to see whether or not there is already
4077 something of the same type at the offset we're about to use.
4078 For example, consider:
4080 struct S {};
4081 struct T : public S { int i; };
4082 struct U : public S, public T {};
4084 Here, we put S at offset zero in U. Then, we can't put T at
4085 offset zero -- its S component would be at the same address
4086 as the S we already allocated. So, we have to skip ahead.
4087 Since all data members, including those whose type is an
4088 empty class, have nonzero size, any overlap can happen only
4089 with a direct or indirect base-class -- it can't happen with
4090 a data member. */
4091 /* In a union, overlap is permitted; all members are placed at
4092 offset zero. */
4097 {
4098 /* Strip off the size allocated to this field. That puts us
4099 at the first place we could have put the field with
4100 proper alignment. */
4103 /* Bump up by the alignment required for the type. */
4104 rli->bitpos
4110 }
4111 else
4112 /* There was no conflict. We're done laying out this field. */
4114 }
4116 /* Now that we know where it will be placed, update its
4117 BINFO_OFFSET. */
4119 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4120 this point because their BINFO_OFFSET is copied from another
4121 hierarchy. Therefore, we may not need to add the entire
4122 OFFSET. */
4128 }
4130 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4132 static int
4134 tree offset,
4136 {
4138 }
4140 /* Layout the empty base BINFO. EOC indicates the byte currently just
4141 past the end of the class, and should be correctly aligned for a
4142 class of the type indicated by BINFO; OFFSETS gives the offsets of
4143 the empty bases allocated so far. T is the most derived
4144 type. Return nonzero iff we added it at the end. */
4146 static bool
4149 {
4150 tree alignment;
4154 /* This routine should only be used for empty classes. */
4159 propagate_binfo_offsets
4163 /* This is an empty base class. We first try to put it at offset
4164 zero. */
4167 offsets,
4169 {
4170 /* That didn't work. Now, we move forward from the next
4171 available spot in the class. */
4175 {
4178 offsets,
4180 /* We finally found a spot where there's no overlap. */
4183 /* There's overlap here, too. Bump along to the next spot. */
4185 }
4186 }
4189 {
4194 }
4197 }
4199 /* Layout the base given by BINFO in the class indicated by RLI.
4200 *BASE_ALIGN is a running maximum of the alignments of
4201 any base class. OFFSETS gives the location of empty base
4202 subobjects. T is the most derived type. Return nonzero if the new
4203 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4204 *NEXT_FIELD, unless BINFO is for an empty base class.
4206 Returns the location at which the next field should be inserted. */
4211 {
4216 /* This error is now reported in xref_tag, thus giving better
4217 location information. */
4220 /* Place the base class. */
4222 {
4223 tree decl;
4225 /* The containing class is non-empty because it has a non-empty
4226 base class. */
4229 /* Create the FIELD_DECL. */
4236 {
4244 /* Try to place the field. It may take more than one try if we
4245 have a hard time placing the field without putting two
4246 objects of the same type at the same address. */
4248 /* Add the new FIELD_DECL to the list of fields for T. */
4252 }
4253 }
4254 else
4255 {
4256 tree eoc;
4259 /* On some platforms (ARM), even empty classes will not be
4260 byte-aligned. */
4265 /* A nearly-empty class "has no proper base class that is empty,
4266 not morally virtual, and at an offset other than zero." */
4268 {
4271 /* The check above (used in G++ 3.2) is insufficient because
4272 an empty class placed at offset zero might itself have an
4273 empty base at a nonzero offset. */
4275 empty_base_at_nonzero_offset_p,
4276 size_zero_node,
4281 }
4283 /* We do not create a FIELD_DECL for empty base classes because
4284 it might overlap some other field. We want to be able to
4285 create CONSTRUCTORs for the class by iterating over the
4286 FIELD_DECLs, and the back end does not handle overlapping
4287 FIELD_DECLs. */
4289 /* An empty virtual base causes a class to be non-empty
4290 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4291 here because that was already done when the virtual table
4292 pointer was created. */
4293 }
4295 /* Record the offsets of BINFO and its base subobjects. */
4298 offsets,
4302 }
4304 /* Layout all of the non-virtual base classes. Record empty
4305 subobjects in OFFSETS. T is the most derived type. Return nonzero
4306 if the type cannot be nearly empty. The fields created
4307 corresponding to the base classes will be inserted at
4308 *NEXT_FIELD. */
4310 static void
4313 {
4314 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4315 subobjects. */
4320 /* The primary base class is always allocated first. */
4325 /* Now allocate the rest of the bases. */
4327 {
4328 tree base_binfo;
4332 /* The primary base was already allocated above, so we don't
4333 need to allocate it again here. */
4337 /* Virtual bases are added at the end (a primary virtual base
4338 will have already been added). */
4344 }
4345 }
4347 /* Go through the TYPE_METHODS of T issuing any appropriate
4348 diagnostics, figuring out which methods override which other
4349 methods, and so forth. */
4351 static void
4353 {
4354 tree x;
4357 {
4361 /* The name of the field is the original field name
4362 Save this in auxiliary field for later overloading. */
4364 {
4368 }
4369 /* All user-provided destructors are non-trivial.
4370 Constructors and assignment ops are handled in
4371 grok_special_member_properties. */
4374 }
4375 }
4377 /* FN is a constructor or destructor. Clone the declaration to create
4378 a specialized in-charge or not-in-charge version, as indicated by
4379 NAME. */
4381 static tree
4383 {
4384 tree parms;
4385 tree clone;
4387 /* Copy the function. */
4389 /* Reset the function name. */
4391 /* Remember where this function came from. */
4393 /* Make it easy to find the CLONE given the FN. */
4397 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4399 {
4406 }
4410 /* There's no pending inline data for this function. */
4414 /* The base-class destructor is not virtual. */
4416 {
4420 }
4422 /* If there was an in-charge parameter, drop it from the function
4423 type. */
4425 {
4426 tree basetype;
4427 tree parmtypes;
4428 tree exceptions;
4433 /* Skip the `this' parameter. */
4435 /* Skip the in-charge parameter. */
4437 /* And the VTT parm, in a complete [cd]tor. */
4441 /* If this is subobject constructor or destructor, add the vtt
4442 parameter. */
4446 parmtypes);
4449 exceptions);
4453 }
4455 /* Copy the function parameters. */
4457 /* Remove the in-charge parameter. */
4459 {
4463 }
4464 /* And the VTT parm, in a complete [cd]tor. */
4466 {
4469 else
4470 {
4474 }
4475 }
4478 {
4481 }
4483 /* Create the RTL for this function. */
4491 }
4493 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4494 not invoke this function directly.
4496 For a non-thunk function, returns the address of the slot for storing
4497 the function it is a clone of. Otherwise returns NULL_TREE.
4499 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4500 cloned_function is unset. This is to support the separate
4501 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4502 on a template makes sense, but not the former. */
4504 tree *
4506 {
4514 {
4515 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4518 else
4519 #endif
4521 }
4526 else
4528 }
4530 /* Produce declarations for all appropriate clones of FN. If
4531 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4532 CLASTYPE_METHOD_VEC as well. */
4534 void
4536 {
4537 tree clone;
4539 /* Avoid inappropriate cloning. */
4545 {
4546 /* For each constructor, we need two variants: an in-charge version
4547 and a not-in-charge version. */
4554 }
4555 else
4556 {
4559 /* For each destructor, we need three variants: an in-charge
4560 version, a not-in-charge version, and an in-charge deleting
4561 version. We clone the deleting version first because that
4562 means it will go second on the TYPE_METHODS list -- and that
4563 corresponds to the correct layout order in the virtual
4564 function table.
4566 For a non-virtual destructor, we do not build a deleting
4567 destructor. */
4569 {
4573 }
4580 }
4582 /* Note that this is an abstract function that is never emitted. */
4584 }
4586 /* DECL is an in charge constructor, which is being defined. This will
4587 have had an in class declaration, from whence clones were
4588 declared. An out-of-class definition can specify additional default
4589 arguments. As it is the clones that are involved in overload
4590 resolution, we must propagate the information from the DECL to its
4591 clones. */
4593 void
4595 {
4596 tree clone;
4600 {
4607 /* Skip the 'this' parameter. */
4623 {
4628 {
4629 /* A default parameter has been added. Adjust the
4630 clone's parameters. */
4634 tree type;
4639 {
4642 clone_parms);
4644 }
4647 clone_parms);
4656 }
4657 }
4659 }
4660 }
4662 /* For each of the constructors and destructors in T, create an
4663 in-charge and not-in-charge variant. */
4665 static void
4667 {
4668 tree fns;
4670 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4671 out now. */
4679 }
4681 /* Deduce noexcept for a destructor DTOR. */
4683 void
4685 {
4687 {
4690 }
4691 }
4693 /* For each destructor in T, deduce noexcept:
4695 12.4/3: A declaration of a destructor that does not have an
4696 exception-specification is implicitly considered to have the
4697 same exception-specification as an implicit declaration (15.4). */
4699 static void
4701 {
4702 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4703 out now. */
4709 }
4711 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4712 of TYPE for virtual functions which FNDECL overrides. Return a
4713 mask of the tm attributes found therein. */
4715 static int
4717 {
4719 tree base_binfo;
4723 {
4733 else
4735 }
4738 }
4740 /* Subroutine of set_method_tm_attributes. Handle the checks and
4741 inheritance for one virtual method FNDECL. */
4743 static void
4745 {
4746 tree tm_attr;
4751 /* If FNDECL doesn't actually override anything (i.e. T is the
4752 class that first declares FNDECL virtual), then we're done. */
4759 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4760 tm_pure must match exactly, otherwise no weakening of
4761 tm_safe > tm_callable > nothing. */
4762 /* ??? The tm_pure attribute didn't make the transition to the
4763 multivendor language spec. */
4765 {
4767 {
4770 }
4771 }
4772 /* If the overridden function is tm_pure, then FNDECL must be. */
4775 /* Look for base class combinations that cannot be satisfied. */
4777 {
4783 }
4784 /* If FNDECL did not declare an attribute, then inherit the most
4785 restrictive one. */
4787 {
4789 }
4790 /* Otherwise validate that we're not weaker than a function
4791 that is being overridden. */
4792 else
4793 {
4797 }
4800 err_override:
4804 }
4806 /* For each of the methods in T, propagate a class-level tm attribute. */
4808 static void
4810 {
4813 /* Don't bother collecting tm attributes if transactional memory
4814 support is not enabled. */
4818 /* Process virtual methods first, as they inherit directly from the
4819 base virtual function and also require validation of new attributes. */
4821 {
4822 tree vchain;
4825 {
4830 }
4831 }
4833 /* If the class doesn't have an attribute, nothing more to do. */
4838 /* Any method that does not yet have a tm attribute inherits
4839 the one from the class. */
4841 {
4844 }
4845 }
4847 /* Returns true iff class T has a user-defined constructor other than
4848 the default constructor. */
4850 bool
4852 {
4853 tree fns;
4859 {
4866 }
4869 }
4871 /* Returns the defaulted constructor if T has one. Otherwise, returns
4872 NULL_TREE. */
4874 tree
4876 {
4883 {
4887 {
4893 }
4894 }
4897 }
4899 /* Returns true iff FN is a user-provided function, i.e. user-declared
4900 and not defaulted at its first declaration; or explicit, private,
4901 protected, or non-const. */
4903 bool
4905 {
4908 else
4912 }
4914 /* Returns true iff class T has a user-provided constructor. */
4916 bool
4918 {
4919 tree fns;
4927 /* This can happen in error cases; avoid crashing. */
4936 }
4938 /* Returns true iff class T has a user-provided default constructor. */
4940 bool
4942 {
4943 tree fns;
4949 {
4955 }
4958 }
4960 /* TYPE is being used as a virtual base, and has a non-trivial move
4961 assignment. Return true if this is due to there being a user-provided
4962 move assignment in TYPE or one of its subobjects; if there isn't, then
4963 multiple move assignment can't cause any harm. */
4965 bool
4967 {
4968 /* Does the type itself have a user-provided move assignment operator? */
4972 {
4976 }
4978 /* Do any of its bases? */
4980 tree base_binfo;
4985 /* Or non-static data members? */
4987 {
4992 }
4994 /* Seems not. */
4996 }
4998 /* If default-initialization leaves part of TYPE uninitialized, returns
4999 a DECL for the field or TYPE itself (DR 253). */
5001 tree
5003 {
5014 {
5018 }
5023 {
5027 }
5030 }
5032 /* Returns true iff for class T, a trivial synthesized default constructor
5033 would be constexpr. */
5035 bool
5037 {
5038 /* A defaulted trivial default constructor is constexpr
5039 if there is nothing to initialize. */
5042 }
5044 /* Returns true iff class T has a constexpr default constructor. */
5046 bool
5048 {
5049 tree fns;
5052 {
5053 /* The caller should have stripped an enclosing array. */
5056 }
5058 {
5061 /* Non-trivial, we need to check subobject constructors. */
5063 }
5066 }
5068 /* Returns true iff class TYPE has a virtual destructor. */
5070 bool
5072 {
5073 tree dtor;
5081 }
5083 /* Returns true iff class T has a move constructor. */
5085 bool
5087 {
5088 tree fns;
5091 {
5094 }
5104 }
5106 /* Returns true iff class T has a move assignment operator. */
5108 bool
5110 {
5111 tree fns;
5114 {
5117 }
5125 }
5127 /* Returns true iff class T has a move constructor that was explicitly
5128 declared in the class body. Note that this is different from
5129 "user-provided", which doesn't include functions that are defaulted in
5130 the class. */
5132 bool
5134 {
5135 tree fns;
5144 {
5148 }
5151 }
5153 /* Returns true iff class T has a move assignment operator that was
5154 explicitly declared in the class body. */
5156 bool
5158 {
5159 tree fns;
5166 {
5170 }
5173 }
5175 /* Nonzero if we need to build up a constructor call when initializing an
5176 object of this class, either because it has a user-declared constructor
5177 or because it doesn't have a default constructor (so we need to give an
5178 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5179 what you care about is whether or not an object can be produced by a
5180 constructor (e.g. so we don't set TREE_READONLY on const variables of
5181 such type); use this function when what you care about is whether or not
5182 to try to call a constructor to create an object. The latter case is
5183 the former plus some cases of constructors that cannot be called. */
5185 bool
5187 {
5188 tree inner;
5198 /* A user-declared constructor might be private, and a constructor might
5199 be trivial but deleted. */
5202 {
5207 }
5209 }
5211 /* Like type_build_ctor_call, but for destructors. */
5213 bool
5215 {
5216 tree inner;
5225 /* A user-declared destructor might be private, and a destructor might
5226 be trivial but deleted. */
5229 {
5234 }
5236 }
5238 /* Remove all zero-width bit-fields from T. */
5240 static void
5242 {
5247 {
5250 /* We should not be confused by the fact that grokbitfield
5251 temporarily sets the width of the bit field into
5252 DECL_INITIAL (*fieldsp).
5253 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5254 to that width. */
5257 else
5259 }
5260 }
5262 /* Returns TRUE iff we need a cookie when dynamically allocating an
5263 array whose elements have the indicated class TYPE. */
5265 static bool
5267 {
5268 tree fns;
5273 /* If there's a non-trivial destructor, we need a cookie. In order
5274 to iterate through the array calling the destructor for each
5275 element, we'll have to know how many elements there are. */
5279 /* If the usual deallocation function is a two-argument whose second
5280 argument is of type `size_t', then we have to pass the size of
5281 the array to the deallocation function, so we will need to store
5282 a cookie. */
5286 /* If there are no `operator []' members, or the lookup is
5287 ambiguous, then we don't need a cookie. */
5290 /* Loop through all of the functions. */
5292 {
5293 tree fn;
5294 tree second_parm;
5296 /* Select the current function. */
5298 /* See if this function is a one-argument delete function. If
5299 it is, then it will be the usual deallocation function. */
5303 /* Do not consider this function if its second argument is an
5304 ellipsis. */
5307 /* Otherwise, if we have a two-argument function and the second
5308 argument is `size_t', it will be the usual deallocation
5309 function -- unless there is one-argument function, too. */
5313 }
5316 }
5318 /* Finish computing the `literal type' property of class type T.
5320 At this point, we have already processed base classes and
5321 non-static data members. We need to check whether the copy
5322 constructor is trivial, the destructor is trivial, and there
5323 is a trivial default constructor or at least one constexpr
5324 constructor other than the copy constructor. */
5326 static void
5328 {
5329 tree fn;
5345 {
5348 {
5352 }
5353 }
5354 }
5356 /* T is a non-literal type used in a context which requires a constant
5357 expression. Explain why it isn't literal. */
5359 void
5361 {
5371 /* Already explained. */
5380 {
5382 "default constructor, and has no constexpr constructor that "
5386 {
5387 /* Note that we can't simply call locate_ctor because when the
5388 constructor is deleted it just returns NULL_TREE. */
5389 tree fns;
5391 {
5398 {
5401 else
5404 }
5405 }
5406 }
5407 }
5408 else
5409 {
5413 {
5416 {
5421 }
5422 }
5424 {
5425 tree ftype;
5430 {
5435 }
5439 }
5440 }
5441 }
5443 /* Check the validity of the bases and members declared in T. Add any
5444 implicitly-generated functions (like copy-constructors and
5445 assignment operators). Compute various flag bits (like
5446 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5447 level: i.e., independently of the ABI in use. */
5449 static void
5451 {
5452 /* Nonzero if the implicitly generated copy constructor should take
5453 a non-const reference argument. */
5455 /* Nonzero if the implicitly generated assignment operator
5456 should take a non-const reference argument. */
5458 tree access_decls;
5461 tree fn;
5463 /* Pick up any abi_tags from our template arguments before checking. */
5466 /* By default, we use const reference arguments and generate default
5467 constructors. */
5471 /* Check all the base-classes. */
5475 /* Deduce noexcept on destructors. This needs to happen after we've set
5476 triviality flags appropriately for our bases. */
5480 /* Check all the method declarations. */
5483 /* Save the initial values of these flags which only indicate whether
5484 or not the class has user-provided functions. As we analyze the
5485 bases and members we can set these flags for other reasons. */
5489 /* Check all the data member declarations. We cannot call
5490 check_field_decls until we have called check_bases check_methods,
5491 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5492 being set appropriately. */
5497 /* A nearly-empty class has to be vptr-containing; a nearly empty
5498 class contains just a vptr. */
5502 /* Do some bookkeeping that will guide the generation of implicitly
5503 declared member functions. */
5506 /* We need to call a constructor for this class if it has a
5507 user-provided constructor, or if the default constructor is going
5508 to initialize the vptr. (This is not an if-and-only-if;
5509 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5510 themselves need constructing.) */
5513 /* [dcl.init.aggr]
5515 An aggregate is an array or a class with no user-provided
5516 constructors ... and no virtual functions.
5518 Again, other conditions for being an aggregate are checked
5519 elsewhere. */
5522 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5523 retain the old definition internally for ABI reasons. */
5532 /* Warn if a public base of a polymorphic type has an accessible
5533 non-virtual destructor. It is only now that we know the class is
5534 polymorphic. Although a polymorphic base will have a already
5535 been diagnosed during its definition, we warn on use too. */
5537 {
5540 tree base_binfo;
5544 {
5552 basetype);
5553 }
5554 }
5556 /* If the class has no user-declared constructor, but does have
5557 non-static const or reference data members that can never be
5558 initialized, issue a warning. */
5560 /* Classes with user-declared constructors are presumed to
5561 initialize these members. */
5563 /* Aggregates can be initialized with brace-enclosed
5564 initializers. */
5566 {
5567 tree field;
5570 {
5571 tree type;
5586 }
5587 }
5589 /* Synthesize any needed methods. */
5591 cant_have_const_ctor,
5592 no_const_asn_ref);
5594 /* Check defaulted declarations here so we have cant_have_const_ctor
5595 and don't need to worry about clones. */
5598 {
5601 {
5602 bool imp_const_p
5608 /* If the function is defaulted outside the class, we just
5609 give the synthesis error. */
5612 }
5614 }
5617 {
5618 /* "The closure type associated with a lambda-expression has a deleted
5619 default constructor and a deleted copy assignment operator." */
5625 /* "This class type is not an aggregate." */
5627 }
5629 /* Compute the 'literal type' property before we
5630 do anything with non-static member functions. */
5633 /* Create the in-charge and not-in-charge variants of constructors
5634 and destructors. */
5637 /* Process the using-declarations. */
5641 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5644 /* Figure out whether or not we will need a cookie when dynamically
5645 allocating an array of this type. */
5648 }
5650 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5651 accordingly. If a new vfield was created (because T doesn't have a
5652 primary base class), then the newly created field is returned. It
5653 is not added to the TYPE_FIELDS list; it is the caller's
5654 responsibility to do that. Accumulate declared virtual functions
5655 on VIRTUALS_P. */
5657 static tree
5659 {
5660 tree fn;
5662 /* Collect the virtual functions declared in T. */
5667 {
5676 }
5678 /* If we couldn't find an appropriate base class, create a new field
5679 here. Even if there weren't any new virtual functions, we might need a
5680 new virtual function table if we're supposed to include vptrs in
5681 all classes that need them. */
5683 {
5684 /* We build this decl with vtbl_ptr_type_node, which is a
5685 `vtable_entry_type*'. It might seem more precise to use
5686 `vtable_entry_type (*)[N]' where N is the number of virtual
5687 functions. However, that would require the vtable pointer in
5688 base classes to have a different type than the vtable pointer
5689 in derived classes. We could make that happen, but that
5690 still wouldn't solve all the problems. In particular, the
5691 type-based alias analysis code would decide that assignments
5692 to the base class vtable pointer can't alias assignments to
5693 the derived class vtable pointer, since they have different
5694 types. Thus, in a derived class destructor, where the base
5695 class constructor was inlined, we could generate bad code for
5696 setting up the vtable pointer.
5698 Therefore, we use one type for all vtable pointers. We still
5699 use a type-correct type; it's just doesn't indicate the array
5700 bounds. That's better than using `void*' or some such; it's
5701 cleaner, and it let's the alias analysis code know that these
5702 stores cannot alias stores to void*! */
5703 tree field;
5716 /* This class is non-empty. */
5720 }
5723 }
5725 /* Add OFFSET to all base types of BINFO which is a base in the
5726 hierarchy dominated by T.
5728 OFFSET, which is a type offset, is number of bytes. */
5730 static void
5732 {
5734 tree primary_binfo;
5735 tree base_binfo;
5737 /* Update BINFO's offset. */
5742 offset));
5744 /* Find the primary base class. */
5750 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5751 downwards. */
5753 {
5754 /* Don't do the primary base twice. */
5762 }
5763 }
5765 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5766 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5767 empty subobjects of T. */
5769 static void
5771 {
5772 tree vbase;
5779 /* Find the last field. The artificial fields created for virtual
5780 bases will go after the last extant field to date. */
5785 /* Go through the virtual bases, allocating space for each virtual
5786 base that is not already a primary base class. These are
5787 allocated in inheritance graph order. */
5789 {
5794 {
5795 /* This virtual base is not a primary base of any class in the
5796 hierarchy, so we have to add space for it. */
5799 }
5800 }
5801 }
5803 /* Returns the offset of the byte just past the end of the base class
5804 BINFO. */
5806 static tree
5808 {
5809 tree size;
5814 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5815 allocate some space for it. It cannot have virtual bases, so
5816 TYPE_SIZE_UNIT is fine. */
5818 else
5822 }
5824 /* Returns the offset of the byte just past the end of the base class
5825 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5826 only non-virtual bases are included. */
5828 static tree
5830 {
5833 tree binfo;
5834 tree base_binfo;
5835 tree offset;
5840 {
5850 }
5855 {
5859 }
5862 }
5864 /* Warn about bases of T that are inaccessible because they are
5865 ambiguous. For example:
5867 struct S {};
5868 struct T : public S {};
5869 struct U : public S, public T {};
5871 Here, `(S*) new U' is not allowed because there are two `S'
5872 subobjects of U. */
5874 static void
5876 {
5879 tree basetype;
5880 tree binfo;
5881 tree base_binfo;
5883 /* If there are no repeated bases, nothing can be ambiguous. */
5887 /* Check direct bases. */
5890 {
5896 }
5898 /* Check for ambiguous virtual bases. */
5902 {
5908 }
5909 }
5911 /* Compare two INTEGER_CSTs K1 and K2. */
5913 static int
5915 {
5917 }
5919 /* Increase the size indicated in RLI to account for empty classes
5920 that are "off the end" of the class. */
5922 static void
5924 {
5925 tree eoc;
5926 tree rli_size;
5928 /* It might be the case that we grew the class to allocate a
5929 zero-sized base class. That won't be reflected in RLI, yet,
5930 because we are willing to overlay multiple bases at the same
5931 offset. However, now we need to make sure that RLI is big enough
5932 to reflect the entire class. */
5938 {
5939 /* The size should have been rounded to a whole byte. */
5942 rli->bitpos
5951 }
5952 }
5954 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5955 BINFO_OFFSETs for all of the base-classes. Position the vtable
5956 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5958 static void
5960 {
5961 tree non_static_data_members;
5962 tree field;
5963 tree vptr;
5964 record_layout_info rli;
5965 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5966 types that appear at that offset. */
5967 splay_tree empty_base_offsets;
5968 /* True if the last field laid out was a bit-field. */
5970 /* The location at which the next field should be inserted. */
5972 /* T, as a base class. */
5973 tree base_t;
5975 /* Keep track of the first non-static data member. */
5978 /* Start laying out the record. */
5981 /* Mark all the primary bases in the hierarchy. */
5984 /* Create a pointer to our virtual function table. */
5987 /* The vptr is always the first thing in the class. */
5989 {
5994 }
5995 else
5998 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6003 /* Layout the non-static data members. */
6005 {
6006 tree type;
6007 tree padding;
6009 /* We still pass things that aren't non-static data members to
6010 the back end, in case it wants to do something with them. */
6012 {
6014 /* If the static data member has incomplete type, keep track
6015 of it so that it can be completed later. (The handling
6016 of pending statics in finish_record_layout is
6017 insufficient; consider:
6019 struct S1;
6020 struct S2 { static S1 s1; };
6022 At this point, finish_record_layout will be called, but
6023 S1 is still incomplete.) */
6025 {
6027 /* The visibility of static data members is determined
6028 at their point of declaration, not their point of
6029 definition. */
6031 }
6033 }
6041 /* If this field is a bit-field whose width is greater than its
6042 type, then there are some special rules for allocating
6043 it. */
6046 {
6048 tree integer_type;
6050 /* We must allocate the bits as if suitably aligned for the
6051 longest integer type that fits in this many bits. type
6052 of the field. Then, we are supposed to use the left over
6053 bits as additional padding. */
6062 /* ITK now indicates a type that is too large for the
6063 field. We have to back up by one to find the largest
6064 type that fits. */
6065 do
6066 {
6071 /* Figure out how much additional padding is required. */
6073 {
6075 /* In a union, the padding field must have the full width
6076 of the bit-field; all fields start at offset zero. */
6078 else
6081 }
6082 #ifdef PCC_BITFIELD_TYPE_MATTERS
6083 /* An unnamed bitfield does not normally affect the
6084 alignment of the containing class on a target where
6085 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6086 make any exceptions for unnamed bitfields when the
6087 bitfields are longer than their types. Therefore, we
6088 temporarily give the field a name. */
6090 {
6093 }
6094 #endif
6099 empty_base_offsets);
6102 /* Now that layout has been performed, set the size of the
6103 field to the size of its declared type; the rest of the
6104 field is effectively invisible. */
6106 /* We must also reset the DECL_MODE of the field. */
6108 }
6109 else
6111 empty_base_offsets);
6113 /* Remember the location of any empty classes in FIELD. */
6116 empty_base_offsets,
6119 /* If a bit-field does not immediately follow another bit-field,
6120 and yet it starts in the middle of a byte, we have failed to
6121 comply with the ABI. */
6124 /* The TREE_NO_WARNING flag gets set by Objective-C when
6125 laying out an Objective-C class. The ObjC ABI differs
6126 from the C++ ABI, and so we do not want a warning
6127 here. */
6129 && !last_field_was_bitfield
6132 bitsize_unit_node)))
6136 /* The middle end uses the type of expressions to determine the
6137 possible range of expression values. In order to optimize
6138 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6139 must be made aware of the width of "i", via its type.
6141 Because C++ does not have integer types of arbitrary width,
6142 we must (for the purposes of the front end) convert from the
6143 type assigned here to the declared type of the bitfield
6144 whenever a bitfield expression is used as an rvalue.
6145 Similarly, when assigning a value to a bitfield, the value
6146 must be converted to the type given the bitfield here. */
6148 {
6153 {
6160 }
6161 }
6163 /* If we needed additional padding after this field, add it
6164 now. */
6166 {
6167 tree padding_field;
6170 FIELD_DECL,
6171 NULL_TREE,
6172 char_type_node);
6179 NULL_TREE,
6180 empty_base_offsets);
6181 }
6184 }
6187 {
6188 /* Make sure that we are on a byte boundary so that the size of
6189 the class without virtual bases will always be a round number
6190 of bytes. */
6193 }
6195 /* Delete all zero-width bit-fields from the list of fields. Now
6196 that the type is laid out they are no longer important. */
6199 /* Create the version of T used for virtual bases. We do not use
6200 make_class_type for this version; this is an artificial type. For
6201 a POD type, we just reuse T. */
6203 {
6206 /* Set the size and alignment for the new type. */
6207 tree eoc;
6209 /* If the ABI version is not at least two, and the last
6210 field was a bit-field, RLI may not be on a byte
6211 boundary. In particular, rli_size_unit_so_far might
6212 indicate the last complete byte, while rli_size_so_far
6213 indicates the total number of bits used. Therefore,
6214 rli_size_so_far, rather than rli_size_unit_so_far, is
6215 used to compute TYPE_SIZE_UNIT. */
6223 eoc);
6233 /* Copy the fields from T. */
6237 {
6239 FIELD_DECL,
6249 }
6251 /* Record the base version of the type. */
6254 }
6255 else
6258 /* Every empty class contains an empty class. */
6262 /* Set the TYPE_DECL for this type to contain the right
6263 value for DECL_OFFSET, so that we can use it as part
6264 of a COMPONENT_REF for multiple inheritance. */
6267 /* Now fix up any virtual base class types that we left lying
6268 around. We must get these done before we try to lay out the
6269 virtual function table. As a side-effect, this will remove the
6270 base subobject fields. */
6273 /* Make sure that empty classes are reflected in RLI at this
6274 point. */
6277 /* Make sure not to create any structures with zero size. */
6283 /* If this is a non-POD, declaring it packed makes a difference to how it
6284 can be used as a field; don't let finalize_record_size undo it. */
6288 /* Let the back end lay out the type. */
6297 /* Warn about bases that can't be talked about due to ambiguity. */
6300 /* Now that we're done with layout, give the base fields the real types. */
6305 /* Clean up. */
6312 }
6314 /* Determine the "key method" for the class type indicated by TYPE,
6315 and set CLASSTYPE_KEY_METHOD accordingly. */
6317 void
6319 {
6320 tree method;
6323 || processing_template_decl
6328 /* The key method is the first non-pure virtual function that is not
6329 inline at the point of class definition. On some targets the
6330 key function may not be inline; those targets should not call
6331 this function until the end of the translation unit. */
6338 {
6341 }
6344 }
6347 /* Allocate and return an instance of struct sorted_fields_type with
6348 N fields. */
6352 {
6359 }
6362 /* Perform processing required when the definition of T (a class type)
6363 is complete. */
6365 void
6367 {
6368 tree x;
6369 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6373 {
6378 }
6380 /* If this type was previously laid out as a forward reference,
6381 make sure we lay it out again. */
6385 /* Make assumptions about the class; we'll reset the flags if
6386 necessary. */
6392 /* Do end-of-class semantic processing: checking the validity of the
6393 bases and members and add implicitly generated methods. */
6396 /* Find the key method. */
6398 {
6399 /* The Itanium C++ ABI permits the key method to be chosen when
6400 the class is defined -- even though the key method so
6401 selected may later turn out to be an inline function. On
6402 some systems (such as ARM Symbian OS) the key method cannot
6403 be determined until the end of the translation unit. On such
6404 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6405 will cause the class to be added to KEYED_CLASSES. Then, in
6406 finish_file we will determine the key method. */
6410 /* If a polymorphic class has no key method, we may emit the vtable
6411 in every translation unit where the class definition appears. If
6412 we're devirtualizing, we can look into the vtable even if we
6413 aren't emitting it. */
6416 }
6418 /* Layout the class itself. */
6421 /* We use the base type for trivial assignments, and hence it
6422 needs a mode. */
6427 /* If necessary, create the primary vtable for this class. */
6429 {
6430 /* We must enter these virtuals into the table. */
6434 /* Here we know enough to change the type of our virtual
6435 function table, but we will wait until later this function. */
6438 /* If we're warning about ABI tags, check the types of the new
6439 virtual functions. */
6443 }
6446 {
6448 tree fn;
6455 /* Add entries for virtual functions introduced by this class. */
6459 /* Set DECL_VINDEX for all functions declared in this class. */
6461 fn;
6463 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6465 {
6469 /* A thunk. We should never be calling this entry directly
6470 from this vtable -- we'd use the entry for the non
6471 thunk base function. */
6475 }
6476 }
6481 /* Complete the rtl for any static member objects of the type we're
6482 working on. */
6489 /* Done with FIELDS...now decide whether to sort these for
6490 faster lookups later.
6492 We use a small number because most searches fail (succeeding
6493 ultimately as the search bores through the inheritance
6494 hierarchy), and we want this failure to occur quickly. */
6498 /* Complain if one of the field types requires lower visibility. */
6501 /* Make the rtl for any new vtables we have created, and unmark
6502 the base types we marked. */
6505 /* Build the VTT for T. */
6508 /* This warning does not make sense for Java classes, since they
6509 cannot have destructors. */
6513 "%q#T has virtual functions and accessible"
6521 /* Class layout, assignment of virtual table slots, etc., is now
6522 complete. Give the back end a chance to tweak the visibility of
6523 the class or perform any other required target modifications. */
6533 /* Finish debugging output for this type. */
6537 {
6540 {
6543 }
6545 {
6548 else
6549 {
6552 }
6554 }
6556 {
6558 "the type of the first field has a different ABI from the "
6561 }
6562 }
6563 }
6565 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6566 equal to THRESHOLD or greater than THRESHOLD. */
6568 static void
6570 {
6573 {
6578 }
6579 }
6581 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6583 void
6585 {
6588 {
6590 int n_fields
6601 }
6602 }
6604 /* When T was built up, the member declarations were added in reverse
6605 order. Rearrange them to declaration order. */
6607 void
6609 {
6610 tree next;
6611 tree prev;
6612 tree x;
6614 /* The following lists are all in reverse order. Put them in
6615 declaration order now. */
6619 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6620 reverse order, so we can't just use nreverse. */
6625 {
6629 }
6631 {
6635 }
6636 }
6638 tree
6640 {
6643 /* Now that we've got all the field declarations, reverse everything
6644 as necessary. */
6649 /* Nadger the current location so that diagnostics point to the start of
6650 the struct, not the end. */
6654 {
6655 tree x;
6661 /* We need to emit an error message if this type was used as a parameter
6662 and it is an abstract type, even if it is a template. We construct
6663 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6664 account and we call complete_vars with this type, which will check
6665 the PARM_DECLS. Note that while the type is being defined,
6666 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6667 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6673 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6674 an enclosing scope is a template class, so that this function be
6675 found by lookup_fnfields_1 when the using declaration is not
6676 instantiated yet. */
6679 {
6684 }
6686 /* Remember current #pragma pack value. */
6689 /* Fix up any variants we've already built. */
6691 {
6696 }
6697 }
6698 else
6702 {
6703 /* People keep complaining that the compiler crashes on an invalid
6704 definition of initializer_list, so I guess we should explicitly
6705 reject it. What the compiler internals care about is that it's a
6706 template and has a pointer field followed by an integer field. */
6709 {
6712 {
6716 }
6717 }
6721 }
6729 else
6733 /* Lambdas are defined by the LAMBDA_EXPR. */
6738 }
6739 \f
6740 /* Hash table to avoid endless recursion when handling references. */
6743 /* Return the dynamic type of INSTANCE, if known.
6744 Used to determine whether the virtual function table is needed
6745 or not.
6747 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6748 of our knowledge of its type. *NONNULL should be initialized
6749 before this function is called. */
6751 static tree
6753 {
6754 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6757 {
6761 else
6765 /* This is a call to a constructor, hence it's never zero. */
6767 {
6771 }
6775 /* This is a call to a constructor, hence it's never zero. */
6777 {
6781 }
6790 /* Propagate nonnull. */
6795 CASE_CONVERT:
6801 {
6802 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6803 with a real object -- given &p->f, p can still be null. */
6805 /* ??? Probably should check DECL_WEAK here. */
6808 }
6812 /* If this component is really a base class reference, then the field
6813 itself isn't definitive. */
6822 {
6826 }
6827 /* fall through... */
6832 {
6836 }
6838 {
6842 /* if we're in a ctor or dtor, we know our type. If
6843 current_class_ptr is set but we aren't in a function, we're in
6844 an NSDMI (and therefore a constructor). */
6849 {
6853 }
6854 }
6856 {
6857 /* We only need one hash table because it is always left empty. */
6859 fixed_type_or_null_ref_ht
6862 /* Reference variables should be references to objects. */
6866 /* Enter the INSTANCE in a table to prevent recursion; a
6867 variable's initializer may refer to the variable
6868 itself. */
6873 {
6874 tree type;
6883 }
6884 }
6889 }
6890 #undef RECUR
6891 }
6893 /* Return nonzero if the dynamic type of INSTANCE is known, and
6894 equivalent to the static type. We also handle the case where
6895 INSTANCE is really a pointer. Return negative if this is a
6896 ctor/dtor. There the dynamic type is known, but this might not be
6897 the most derived base of the original object, and hence virtual
6898 bases may not be laid out according to this type.
6900 Used to determine whether the virtual function table is needed
6901 or not.
6903 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6904 of our knowledge of its type. *NONNULL should be initialized
6905 before this function is called. */
6907 int
6909 {
6912 tree fixed;
6914 /* processing_template_decl can be false in a template if we're in
6915 fold_non_dependent_expr, but we still want to suppress this check. */
6917 {
6918 /* In a template we only care about the type of the result. */
6922 }
6932 }
6934 \f
6935 void
6937 {
6940 current_class_stack
6948 }
6950 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6952 static void
6954 {
6955 tree type;
6957 /* We are re-entering the same class we just left, so we don't
6958 have to search the whole inheritance matrix to find all the
6959 decls to bind again. Instead, we install the cached
6960 class_shadowed list and walk through it binding names. */
6963 /* Restore IDENTIFIER_TYPE_VALUE. */
6965 type;
6968 }
6970 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6971 appropriate for TYPE.
6973 So that we may avoid calls to lookup_name, we cache the _TYPE
6974 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6976 For multiple inheritance, we perform a two-pass depth-first search
6977 of the type lattice. */
6979 void
6981 {
6982 class_stack_node_t csn;
6986 /* Make sure there is enough room for the new entry on the stack. */
6988 {
6990 current_class_stack
6992 current_class_stack_size);
6993 }
6995 /* Insert a new entry on the class stack. */
7002 current_class_depth++;
7004 /* Now set up the new type. */
7010 /* By default, things in classes are private, while things in
7011 structures or unions are public. */
7013 ? access_private_node
7019 {
7020 /* Forcibly remove any old class remnants. */
7022 }
7028 else
7030 }
7032 /* When we exit a toplevel class scope, we save its binding level so
7033 that we can restore it quickly. Here, we've entered some other
7034 class, so we must invalidate our cache. */
7036 void
7038 {
7040 }
7042 /* Get out of the current class scope. If we were in a class scope
7043 previously, that is the one popped to. */
7045 void
7047 {
7050 current_class_depth--;
7056 }
7058 /* Mark the top of the class stack as hidden. */
7060 void
7062 {
7065 }
7067 /* Mark the top of the class stack as un-hidden. */
7069 void
7071 {
7074 }
7076 /* Returns 1 if the class type currently being defined is either T or
7077 a nested type of T. */
7079 bool
7081 {
7089 /* We start looking from 1 because entry 0 is from global scope,
7090 and has no type. */
7092 {
7093 tree c;
7096 else
7097 {
7101 }
7106 }
7108 }
7110 /* If either current_class_type or one of its enclosing classes are derived
7111 from T, return the appropriate type. Used to determine how we found
7112 something via unqualified lookup. */
7114 tree
7116 {
7119 /* The bases of a dependent type are unknown. */
7130 {
7135 }
7138 }
7140 /* Return the outermost enclosing class type that is still open, or
7141 NULL_TREE. */
7143 tree
7145 {
7152 {
7159 }
7161 }
7163 /* Returns the innermost class type which is not a lambda closure type. */
7165 tree
7167 {
7170 /* We start looking from 1 because entry 0 is from global scope,
7171 and has no type. */
7173 {
7174 tree c;
7177 else
7178 {
7182 }
7187 }
7189 }
7191 /* When entering a class scope, all enclosing class scopes' names with
7192 static meaning (static variables, static functions, types and
7193 enumerators) have to be visible. This recursive function calls
7194 pushclass for all enclosing class contexts until global or a local
7195 scope is reached. TYPE is the enclosed class. */
7197 void
7199 {
7200 /* A namespace might be passed in error cases, like A::B:C. */
7208 }
7210 /* Undoes a push_nested_class call. */
7212 void
7214 {
7220 }
7222 /* Returns the number of extern "LANG" blocks we are nested within. */
7224 int
7226 {
7228 }
7230 /* Set global variables CURRENT_LANG_NAME to appropriate value
7231 so that behavior of name-mangling machinery is correct. */
7233 void
7235 {
7239 {
7241 }
7243 {
7245 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7246 (See record_builtin_java_type in decl.c.) However, that causes
7247 incorrect debug entries if these types are actually used.
7248 So we re-enable debug output after extern "Java". */
7257 }
7259 {
7261 }
7262 else
7264 }
7266 /* Get out of the current language scope. */
7268 void
7270 {
7272 }
7273 \f
7274 /* Type instantiation routines. */
7276 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7277 matches the TARGET_TYPE. If there is no satisfactory match, return
7278 error_mark_node, and issue an error & warning messages under
7279 control of FLAGS. Permit pointers to member function if FLAGS
7280 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7281 a template-id, and EXPLICIT_TARGS are the explicitly provided
7282 template arguments.
7284 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7285 is the base path used to reference those member functions. If
7286 the address is resolved to a member function, access checks will be
7287 performed and errors issued if appropriate. */
7289 static tree
7291 tree overload,
7292 tsubst_flags_t flags,
7294 tree explicit_targs,
7295 tree access_path)
7296 {
7297 /* Here's what the standard says:
7299 [over.over]
7301 If the name is a function template, template argument deduction
7302 is done, and if the argument deduction succeeds, the deduced
7303 arguments are used to generate a single template function, which
7304 is added to the set of overloaded functions considered.
7306 Non-member functions and static member functions match targets of
7307 type "pointer-to-function" or "reference-to-function." Nonstatic
7308 member functions match targets of type "pointer-to-member
7309 function;" the function type of the pointer to member is used to
7310 select the member function from the set of overloaded member
7311 functions. If a nonstatic member function is selected, the
7312 reference to the overloaded function name is required to have the
7313 form of a pointer to member as described in 5.3.1.
7315 If more than one function is selected, any template functions in
7316 the set are eliminated if the set also contains a non-template
7317 function, and any given template function is eliminated if the
7318 set contains a second template function that is more specialized
7319 than the first according to the partial ordering rules 14.5.5.2.
7320 After such eliminations, if any, there shall remain exactly one
7321 selected function. */
7324 /* We store the matches in a TREE_LIST rooted here. The functions
7325 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7326 interoperability with most_specialized_instantiation. */
7328 tree fn;
7329 tree target_fn_type;
7331 /* By the time we get here, we should be seeing only real
7332 pointer-to-member types, not the internal POINTER_TYPE to
7333 METHOD_TYPE representation. */
7339 /* Check that the TARGET_TYPE is reasonable. */
7344 /* This is OK, too. */
7347 /* This is OK, too. This comes from a conversion to reference
7348 type. */
7350 else
7351 {
7357 }
7359 /* Non-member functions and static member functions match targets of type
7360 "pointer-to-function" or "reference-to-function." Nonstatic member
7361 functions match targets of type "pointer-to-member-function;" the
7362 function type of the pointer to member is used to select the member
7363 function from the set of overloaded member functions.
7365 So figure out the FUNCTION_TYPE that we want to match against. */
7368 /* If we can find a non-template function that matches, we can just
7369 use it. There's no point in generating template instantiations
7370 if we're just going to throw them out anyhow. But, of course, we
7371 can only do this when we don't *need* a template function. */
7373 {
7374 tree fns;
7377 {
7381 /* We're not looking for templates just yet. */
7386 /* We're looking for a non-static member, and this isn't
7387 one, or vice versa. */
7390 /* Ignore functions which haven't been explicitly
7391 declared. */
7395 /* See if there's a match. */
7398 }
7399 }
7401 /* Now, if we've already got a match (or matches), there's no need
7402 to proceed to the template functions. But, if we don't have a
7403 match we need to look at them, too. */
7405 {
7406 tree target_arg_types;
7407 tree target_ret_type;
7408 tree fns;
7411 tree arg;
7425 {
7427 tree instantiation;
7428 tree targs;
7431 /* We're only looking for templates. */
7436 /* We're not looking for a non-static member, and this is
7437 one, or vice versa. */
7442 /* If the template has a deduced return type, don't expose it to
7443 template argument deduction. */
7447 /* Try to do argument deduction. */
7454 /* Instantiation failed. */
7457 /* And now force instantiation to do return type deduction. */
7459 {
7465 }
7467 /* See if there's a match. */
7470 }
7472 /* Now, remove all but the most specialized of the matches. */
7474 {
7479 NULL_TREE,
7480 NULL_TREE);
7481 }
7482 }
7484 /* Now we should have exactly one function in MATCHES. */
7486 {
7487 /* There were *no* matches. */
7489 {
7492 target_type);
7495 }
7497 }
7499 {
7500 /* There were too many matches. First check if they're all
7501 the same function. */
7506 /* For multi-versioned functions, more than one match is just fine and
7507 decls_match will return false as they are different. */
7515 {
7517 {
7520 target_type);
7522 /* Since print_candidates expects the functions in the
7523 TREE_VALUE slot, we flip them here. */
7528 }
7531 }
7532 }
7534 /* Good, exactly one match. Now, convert it to the correct type. */
7539 {
7547 {
7550 }
7551 }
7553 /* If a pointer to a function that is multi-versioned is requested, the
7554 pointer to the dispatcher function is returned instead. This works
7555 well because indirectly calling the function will dispatch the right
7556 function version at run-time. */
7558 {
7562 /* Mark all the versions corresponding to the dispatcher as used. */
7565 }
7567 /* If we're doing overload resolution purely for the purpose of
7568 determining conversion sequences, we should not consider the
7569 function used. If this conversion sequence is selected, the
7570 function will be marked as used at this point. */
7572 {
7573 /* Make =delete work with SFINAE. */
7578 }
7580 /* We could not check access to member functions when this
7581 expression was originally created since we did not know at that
7582 time to which function the expression referred. */
7584 {
7587 }
7591 else
7592 {
7593 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7594 will mark the function as addressed, but here we must do it
7595 explicitly. */
7599 }
7600 }
7602 /* This function will instantiate the type of the expression given in
7603 RHS to match the type of LHSTYPE. If errors exist, then return
7604 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7605 we complain on errors. If we are not complaining, never modify rhs,
7606 as overload resolution wants to try many possible instantiations, in
7607 the hope that at least one will work.
7609 For non-recursive calls, LHSTYPE should be a function, pointer to
7610 function, or a pointer to member function. */
7612 tree
7614 {
7621 {
7625 }
7628 {
7635 /* Microsoft allows `A::f' to be resolved to a
7636 pointer-to-member. */
7637 ;
7638 else
7639 {
7644 }
7645 }
7648 {
7651 }
7653 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7654 deduce any type information. */
7656 {
7660 }
7662 /* There only a few kinds of expressions that may have a type
7663 dependent on overload resolution. */
7669 /* This should really only be used when attempting to distinguish
7670 what sort of a pointer to function we have. For now, any
7671 arithmetic operation which is not supported on pointers
7672 is rejected as an error. */
7675 {
7677 {
7683 /* Do not lose object's side effects. */
7687 }
7694 /* This can happen if we are forming a pointer-to-member for a
7695 member template. */
7698 /* Fall through. */
7701 {
7705 return
7709 }
7713 return
7717 access_path);
7720 {
7725 }
7732 }
7734 }
7735 \f
7736 /* Return the name of the virtual function pointer field
7737 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7738 this may have to look back through base types to find the
7739 ultimate field name. (For single inheritance, these could
7740 all be the same name. Who knows for multiple inheritance). */
7742 static tree
7744 {
7751 {
7757 }
7765 }
7767 void
7769 {
7776 {
7781 }
7782 }
7784 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7785 according to [class]:
7786 The class-name is also inserted
7787 into the scope of the class itself. For purposes of access checking,
7788 the inserted class name is treated as if it were a public member name. */
7790 void
7792 {
7795 tree saved_cas;
7810 }
7812 /* Returns 1 if TYPE contains only padding bytes. */
7814 int
7816 {
7824 }
7826 /* Returns true if TYPE contains no actual data, just various
7827 possible combinations of empty classes and possibly a vptr. */
7829 bool
7831 {
7833 {
7834 tree field;
7835 tree binfo;
7836 tree base_binfo;
7839 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7840 out, but we'd like to be able to check this before then. */
7854 }
7858 }
7860 /* Note that NAME was looked up while the current class was being
7861 defined and that the result of that lookup was DECL. */
7863 void
7865 {
7866 splay_tree names_used;
7868 /* If we're not defining a class, there's nothing to do. */
7874 /* If there's already a binding for this NAME, then we don't have
7875 anything to worry about. */
7888 }
7890 /* Note that NAME was declared (as DECL) in the current class. Check
7891 to see that the declaration is valid. */
7893 void
7895 {
7896 splay_tree names_used;
7897 splay_tree_node n;
7899 /* Look to see if we ever used this name. */
7900 names_used
7904 /* The C language allows members to be declared with a type of the same
7905 name, and the C++ standard says this diagnostic is not required. So
7906 allow it in extern "C" blocks unless predantic is specified.
7907 Allow it in all cases if -ms-extensions is specified. */
7913 {
7914 /* [basic.scope.class]
7916 A name N used in a class S shall refer to the same declaration
7917 in its context and when re-evaluated in the completed scope of
7918 S. */
7922 }
7923 }
7925 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7926 Secondary vtables are merged with primary vtables; this function
7927 will return the VAR_DECL for the primary vtable. */
7929 tree
7931 {
7932 tree decl;
7936 {
7939 }
7943 }
7946 /* Returns the binfo for the primary base of BINFO. If the resulting
7947 BINFO is a virtual base, and it is inherited elsewhere in the
7948 hierarchy, then the returned binfo might not be the primary base of
7949 BINFO in the complete object. Check BINFO_PRIMARY_P or
7950 BINFO_LOST_PRIMARY_P to be sure. */
7952 static tree
7954 {
7955 tree primary_base;
7962 }
7964 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7966 static int
7968 {
7972 }
7974 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7975 INDENT should be zero when called from the top level; it is
7976 incremented recursively. IGO indicates the next expected BINFO in
7977 inheritance graph ordering. */
7979 static tree
7982 tree binfo,
7983 tree igo,
7985 {
7987 tree base_binfo;
7995 {
7998 }
8013 {
8017 TFF_PLAIN_IDENTIFIER),
8019 }
8021 {
8024 }
8029 {
8033 {
8037 TFF_PLAIN_IDENTIFIER));
8038 }
8040 {
8044 TFF_PLAIN_IDENTIFIER));
8045 }
8047 {
8051 TFF_PLAIN_IDENTIFIER));
8052 }
8054 {
8058 TFF_PLAIN_IDENTIFIER));
8059 }
8063 }
8069 }
8071 /* Dump the BINFO hierarchy for T. */
8073 static void
8075 {
8087 }
8089 /* Debug interface to hierarchy dumping. */
8091 void
8093 {
8095 }
8097 static void
8099 {
8104 {
8106 }
8107 }
8109 static void
8111 {
8112 tree value;
8114 HOST_WIDE_INT elt;
8122 TFF_PLAIN_IDENTIFIER));
8129 }
8131 static void
8133 {
8141 {
8148 {
8153 }
8157 }
8158 }
8160 static void
8162 {
8170 {
8175 }
8176 }
8178 /* Dump a function or thunk and its thunkees. */
8180 static void
8182 {
8185 tree thunks;
8193 {
8203 else
8209 }
8213 }
8215 /* Dump the thunks for FN. */
8217 void
8219 {
8221 }
8223 /* Virtual function table initialization. */
8225 /* Create all the necessary vtables for T and its base classes. */
8227 static void
8229 {
8230 tree vbase;
8234 /* We lay out the primary and secondary vtables in one contiguous
8235 vtable. The primary vtable is first, followed by the non-virtual
8236 secondary vtables in inheritance graph order. */
8240 /* Then come the virtual bases, also in inheritance graph order. */
8242 {
8246 }
8250 }
8252 /* Initialize the vtable for BINFO with the INITS. */
8254 static void
8256 {
8257 tree decl;
8263 }
8265 /* Build the VTT (virtual table table) for T.
8266 A class requires a VTT if it has virtual bases.
8268 This holds
8269 1 - primary virtual pointer for complete object T
8270 2 - secondary VTTs for each direct non-virtual base of T which requires a
8271 VTT
8272 3 - secondary virtual pointers for each direct or indirect base of T which
8273 has virtual bases or is reachable via a virtual path from T.
8274 4 - secondary VTTs for each direct or indirect virtual base of T.
8276 Secondary VTTs look like complete object VTTs without part 4. */
8278 static void
8280 {
8281 tree type;
8282 tree vtt;
8283 tree index;
8286 /* Build up the initializers for the VTT. */
8291 /* If we didn't need a VTT, we're done. */
8295 /* Figure out the type of the VTT. */
8299 /* Now, build the VTT object itself. */
8302 /* Add the VTT to the vtables list. */
8307 }
8309 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8310 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8311 and CHAIN the vtable pointer for this binfo after construction is
8312 complete. VALUE can also be another BINFO, in which case we recurse. */
8314 static tree
8316 {
8317 tree vt;
8320 {
8326 else
8328 }
8331 }
8333 /* Data for secondary VTT initialization. */
8335 {
8336 /* Is this the primary VTT? */
8339 /* Current index into the VTT. */
8340 tree index;
8342 /* Vector of initializers built up. */
8345 /* The type being constructed by this secondary VTT. */
8346 tree type_being_constructed;
8349 /* Recursively build the VTT-initializer for BINFO (which is in the
8350 hierarchy dominated by T). INITS points to the end of the initializer
8351 list to date. INDEX is the VTT index where the next element will be
8352 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8353 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8354 for virtual bases of T. When it is not so, we build the constructor
8355 vtables for the BINFO-in-T variant. */
8357 static void
8360 {
8362 tree b;
8363 tree init;
8364 secondary_vptr_vtt_init_data data;
8367 /* We only need VTTs for subobjects with virtual bases. */
8371 /* We need to use a construction vtable if this is not the primary
8372 VTT. */
8374 {
8377 /* Record the offset in the VTT where this sub-VTT can be found. */
8379 }
8381 /* Add the address of the primary vtable for the complete object. */
8385 {
8388 }
8391 /* Recursively add the secondary VTTs for non-virtual bases. */
8396 /* Add secondary virtual pointers for all subobjects of BINFO with
8397 either virtual bases or reachable along a virtual path, except
8398 subobjects that are non-virtual primary bases. */
8408 /* data.inits might have grown as we added secondary virtual pointers.
8409 Make sure our caller knows about the new vector. */
8413 /* Add the secondary VTTs for virtual bases in inheritance graph
8414 order. */
8416 {
8421 }
8422 else
8423 /* Remove the ctor vtables we created. */
8425 }
8427 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8428 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8430 static tree
8432 {
8435 /* We don't care about bases that don't have vtables. */
8439 /* We're only interested in proper subobjects of the type being
8440 constructed. */
8444 /* We're only interested in bases with virtual bases or reachable
8445 via a virtual path from the type being constructed. */
8450 /* We're not interested in non-virtual primary bases. */
8454 /* Record the index where this secondary vptr can be found. */
8456 {
8461 {
8462 /* It's a primary virtual base, and this is not a
8463 construction vtable. Find the base this is primary of in
8464 the inheritance graph, and use that base's vtable
8465 now. */
8468 }
8469 }
8471 /* Add the initializer for the secondary vptr itself. */
8474 /* Advance the vtt index. */
8479 }
8481 /* Called from build_vtt_inits via dfs_walk. After building
8482 constructor vtables and generating the sub-vtt from them, we need
8483 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8484 binfo of the base whose sub vtt was generated. */
8486 static tree
8488 {
8492 /* If this class has no vtable, none of its bases do. */
8496 /* This might be a primary base, so have no vtable in this
8497 hierarchy. */
8500 /* If we scribbled the construction vtable vptr into BINFO, clear it
8501 out now. */
8507 }
8509 /* Build the construction vtable group for BINFO which is in the
8510 hierarchy dominated by T. */
8512 static void
8514 {
8515 tree type;
8516 tree vtbl;
8517 tree id;
8518 tree vbase;
8521 /* See if we've already created this construction vtable group. */
8527 /* Build a version of VTBL (with the wrong type) for use in
8528 constructing the addresses of secondary vtables in the
8529 construction vtable group. */
8532 /* Don't export construction vtables from shared libraries. Even on
8533 targets that don't support hidden visibility, this tells
8534 can_refer_decl_in_current_unit_p not to assume that it's safe to
8535 access from a different compilation unit (bz 54314). */
8543 /* Add the vtables for each of our virtual bases using the vbase in T
8544 binfo. */
8546 vbase;
8548 {
8549 tree b;
8556 }
8558 /* Figure out the type of the construction vtable. */
8565 /* Initialize the construction vtable. */
8569 }
8571 /* Add the vtbl initializers for BINFO (and its bases other than
8572 non-virtual primaries) to the list of INITS. BINFO is in the
8573 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8574 the constructor the vtbl inits should be accumulated for. (If this
8575 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8576 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8577 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8578 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8579 but are not necessarily the same in terms of layout. */
8581 static void
8583 tree orig_binfo,
8584 tree rtti_binfo,
8585 tree vtbl,
8586 tree t,
8588 {
8590 tree base_binfo;
8595 /* If it doesn't have a vptr, we don't do anything. */
8599 /* If we're building a construction vtable, we're not interested in
8600 subobjects that don't require construction vtables. */
8606 /* Build the initializers for the BINFO-in-T vtable. */
8609 /* Walk the BINFO and its bases. We walk in preorder so that as we
8610 initialize each vtable we can figure out at what offset the
8611 secondary vtable lies from the primary vtable. We can't use
8612 dfs_walk here because we need to iterate through bases of BINFO
8613 and RTTI_BINFO simultaneously. */
8615 {
8616 /* Skip virtual bases. */
8622 inits);
8623 }
8624 }
8626 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8627 BINFO vtable to L. */
8629 static void
8631 tree orig_binfo,
8632 tree rtti_binfo,
8633 tree orig_vtbl,
8634 tree t,
8636 {
8643 {
8644 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8645 primary virtual base. If it is not the same primary in
8646 the hierarchy of T, we'll need to generate a ctor vtable
8647 for it, to place at its location in T. If it is the same
8648 primary, we still need a VTT entry for the vtable, but it
8649 should point to the ctor vtable for the base it is a
8650 primary for within the sub-hierarchy of RTTI_BINFO.
8652 There are three possible cases:
8654 1) We are in the same place.
8655 2) We are a primary base within a lost primary virtual base of
8656 RTTI_BINFO.
8657 3) We are primary to something not a base of RTTI_BINFO. */
8659 tree b;
8662 /* First, look through the bases we are primary to for RTTI_BINFO
8663 or a virtual base. */
8666 {
8671 }
8672 /* If we run out of primary links, keep looking down our
8673 inheritance chain; we might be an indirect primary. */
8677 found:
8679 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8680 base B and it is a base of RTTI_BINFO, this is case 2. In
8681 either case, we share our vtable with LAST, i.e. the
8682 derived-most base within B of which we are a primary. */
8685 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8686 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8687 binfo_ctor_vtable after everything's been set up. */
8690 /* Otherwise, this is case 3 and we get our own. */
8691 }
8698 {
8699 tree index;
8702 /* Add the initializer for this vtable. */
8706 /* Figure out the position to which the VPTR should point. */
8712 }
8715 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8716 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8717 straighten this out. */
8720 /* Throw away any unneeded intializers. */
8722 else
8723 /* For an ordinary vtable, set BINFO_VTABLE. */
8725 }
8729 /* Construct the initializer for BINFO's virtual function table. BINFO
8730 is part of the hierarchy dominated by T. If we're building a
8731 construction vtable, the ORIG_BINFO is the binfo we should use to
8732 find the actual function pointers to put in the vtable - but they
8733 can be overridden on the path to most-derived in the graph that
8734 ORIG_BINFO belongs. Otherwise,
8735 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8736 BINFO that should be indicated by the RTTI information in the
8737 vtable; it will be a base class of T, rather than T itself, if we
8738 are building a construction vtable.
8740 The value returned is a TREE_LIST suitable for wrapping in a
8741 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8742 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8743 number of non-function entries in the vtable.
8745 It might seem that this function should never be called with a
8746 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8747 base is always subsumed by a derived class vtable. However, when
8748 we are building construction vtables, we do build vtables for
8749 primary bases; we need these while the primary base is being
8750 constructed. */
8752 static void
8754 tree orig_binfo,
8755 tree t,
8756 tree rtti_binfo,
8759 {
8760 tree v;
8761 vtbl_init_data vid;
8763 tree vbinfo;
8767 /* Initialize VID. */
8775 /* The first vbase or vcall offset is at index -3 in the vtable. */
8778 /* Add entries to the vtable for RTTI. */
8781 /* Create an array for keeping track of the functions we've
8782 processed. When we see multiple functions with the same
8783 signature, we share the vcall offsets. */
8785 /* Add the vcall and vbase offset entries. */
8788 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8789 build_vbase_offset_vtbl_entries. */
8794 /* If the target requires padding between data entries, add that now. */
8796 {
8801 /* Move data entries into their new positions and add padding
8802 after the new positions. Iterate backwards so we don't
8803 overwrite entries that we would need to process later. */
8806 ix--)
8807 {
8815 {
8819 null_pointer_node);
8820 }
8821 }
8822 }
8827 /* The initializers for virtual functions were built up in reverse
8828 order. Straighten them out and add them to the running list in one
8829 step. */
8838 /* Go through all the ordinary virtual functions, building up
8839 initializers. */
8841 {
8842 tree delta;
8843 tree vcall_index;
8850 {
8854 {
8857 }
8859 }
8861 /* If the only definition of this function signature along our
8862 primary base chain is from a lost primary, this vtable slot will
8863 never be used, so just zero it out. This is important to avoid
8864 requiring extra thunks which cannot be generated with the function.
8866 We first check this in update_vtable_entry_for_fn, so we handle
8867 restored primary bases properly; we also need to do it here so we
8868 zero out unused slots in ctor vtables, rather than filling them
8869 with erroneous values (though harmless, apart from relocation
8870 costs). */
8875 {
8876 /* Pull the offset for `this', and the function to call, out of
8877 the list. */
8884 /* You can't call an abstract virtual function; it's abstract.
8885 So, we replace these functions with __pure_virtual. */
8887 {
8890 {
8892 abort_fndecl_addr
8896 }
8897 }
8898 /* Likewise for deleted virtuals. */
8900 {
8909 }
8910 else
8911 {
8913 {
8917 }
8918 /* Take the address of the function, considering it to be of an
8919 appropriate generic type. */
8923 /* Don't refer to a virtual destructor from a constructor
8924 vtable or a vtable for an abstract class, since destroying
8925 an object under construction is undefined behavior and we
8926 don't want it to be considered a candidate for speculative
8927 devirtualization. But do create the thunk for ABI
8928 compliance. */
8933 }
8934 }
8936 /* And add it to the chain of initializers. */
8938 {
8943 else
8945 {
8951 }
8952 }
8953 else
8955 }
8956 }
8958 /* Adds to vid->inits the initializers for the vbase and vcall
8959 offsets in BINFO, which is in the hierarchy dominated by T. */
8961 static void
8963 {
8964 tree b;
8966 /* If this is a derived class, we must first create entries
8967 corresponding to the primary base class. */
8972 /* Add the vbase entries for this base. */
8974 /* Add the vcall entries for this base. */
8976 }
8978 /* Returns the initializers for the vbase offset entries in the vtable
8979 for BINFO (which is part of the class hierarchy dominated by T), in
8980 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8981 where the next vbase offset will go. */
8983 static void
8985 {
8986 tree vbase;
8987 tree t;
8988 tree non_primary_binfo;
8990 /* If there are no virtual baseclasses, then there is nothing to
8991 do. */
8997 /* We might be a primary base class. Go up the inheritance hierarchy
8998 until we find the most derived class of which we are a primary base:
8999 it is the offset of that which we need to use. */
9002 {
9003 tree b;
9005 /* If we have reached a virtual base, then it must be a primary
9006 base (possibly multi-level) of vid->binfo, or we wouldn't
9007 have called build_vcall_and_vbase_vtbl_entries for it. But it
9008 might be a lost primary, so just skip down to vid->binfo. */
9010 {
9013 }
9019 }
9021 /* Go through the virtual bases, adding the offsets. */
9023 vbase;
9025 {
9026 tree b;
9027 tree delta;
9032 /* Find the instance of this virtual base in the complete
9033 object. */
9036 /* If we've already got an offset for this virtual base, we
9037 don't need another one. */
9042 /* Figure out where we can find this vbase offset. */
9051 /* The vbase offset had better be the same. */
9054 /* The next vbase will come at a more negative offset. */
9058 /* The initializer is the delta from BINFO to this virtual base.
9059 The vbase offsets go in reverse inheritance-graph order, and
9060 we are walking in inheritance graph order so these end up in
9061 the right order. */
9068 }
9069 }
9071 /* Adds the initializers for the vcall offset entries in the vtable
9072 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9073 to VID->INITS. */
9075 static void
9077 {
9078 /* We only need these entries if this base is a virtual base. We
9079 compute the indices -- but do not add to the vtable -- when
9080 building the main vtable for a class. */
9083 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9084 correspond to VID->DERIVED), we are building a primary
9085 construction virtual table. Since this is a primary
9086 virtual table, we do not need the vcall offsets for
9087 BINFO. */
9089 {
9090 /* We need a vcall offset for each of the virtual functions in this
9091 vtable. For example:
9093 class A { virtual void f (); };
9094 class B1 : virtual public A { virtual void f (); };
9095 class B2 : virtual public A { virtual void f (); };
9096 class C: public B1, public B2 { virtual void f (); };
9098 A C object has a primary base of B1, which has a primary base of A. A
9099 C also has a secondary base of B2, which no longer has a primary base
9100 of A. So the B2-in-C construction vtable needs a secondary vtable for
9101 A, which will adjust the A* to a B2* to call f. We have no way of
9102 knowing what (or even whether) this offset will be when we define B2,
9103 so we store this "vcall offset" in the A sub-vtable and look it up in
9104 a "virtual thunk" for B2::f.
9106 We need entries for all the functions in our primary vtable and
9107 in our non-virtual bases' secondary vtables. */
9109 /* If we are just computing the vcall indices -- but do not need
9110 the actual entries -- not that. */
9113 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9115 }
9116 }
9118 /* Build vcall offsets, starting with those for BINFO. */
9120 static void
9122 {
9124 tree primary_binfo;
9125 tree base_binfo;
9127 /* Don't walk into virtual bases -- except, of course, for the
9128 virtual base for which we are building vcall offsets. Any
9129 primary virtual base will have already had its offsets generated
9130 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9134 /* If BINFO has a primary base, process it first. */
9139 /* Add BINFO itself to the list. */
9142 /* Scan the non-primary bases of BINFO. */
9146 }
9148 /* Called from build_vcall_offset_vtbl_entries_r. */
9150 static void
9152 {
9153 /* Make entries for the rest of the virtuals. */
9154 tree orig_fn;
9156 /* The ABI requires that the methods be processed in declaration
9157 order. */
9159 orig_fn;
9163 }
9165 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9167 static void
9169 {
9171 tree vcall_offset;
9172 tree derived_entry;
9174 /* If there is already an entry for a function with the same
9175 signature as FN, then we do not need a second vcall offset.
9176 Check the list of functions already present in the derived
9177 class vtable. */
9179 {
9181 /* We only use one vcall offset for virtual destructors,
9182 even though there are two virtual table entries. */
9186 }
9188 /* If we are building these vcall offsets as part of building
9189 the vtable for the most derived class, remember the vcall
9190 offset. */
9192 {
9195 }
9197 /* The next vcall offset will be found at a more negative
9198 offset. */
9202 /* Keep track of this function. */
9206 {
9207 tree base;
9208 tree fn;
9210 /* Find the overriding function. */
9214 else
9215 {
9218 /* The vbase we're working on is a primary base of
9219 vid->binfo. But it might be a lost primary, so its
9220 BINFO_OFFSET might be wrong, so we just use the
9221 BINFO_OFFSET from vid->binfo. */
9227 vcall_offset);
9228 }
9229 /* Add the initializer to the vtable. */
9231 }
9232 }
9234 /* Return vtbl initializers for the RTTI entries corresponding to the
9235 BINFO's vtable. The RTTI entries should indicate the object given
9236 by VID->rtti_binfo. */
9238 static void
9240 {
9241 tree b;
9242 tree t;
9243 tree offset;
9244 tree decl;
9245 tree init;
9249 /* To find the complete object, we will first convert to our most
9250 primary base, and then add the offset in the vtbl to that value. */
9254 {
9255 tree primary_base;
9261 }
9265 /* The second entry is the address of the typeinfo object. */
9268 else
9271 /* Convert the declaration to a type that can be stored in the
9272 vtable. */
9276 /* Add the offset-to-top entry. It comes earlier in the vtable than
9277 the typeinfo entry. Convert the offset to look like a
9278 function pointer, so that we can put it in the vtable. */
9281 }
9283 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9284 accessibility. */
9286 bool
9288 {
9291 }
9293 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9295 bool
9297 {
9301 }
9303 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9304 class between them, if any. */
9306 tree
9308 {
9320 {
9323 }
9327 }