| blob | 0d7a1db4d18f74f689ed8d69d4a3cc1d1caa0f49 |
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. */
45 /* The number of nested classes being processed. If we are not in the
46 scope of any class, this is zero. */
50 /* In order to deal with nested classes, we keep a stack of classes.
51 The topmost entry is the innermost class, and is the entry at index
52 CURRENT_CLASS_DEPTH */
55 /* The name of the class. */
56 tree name;
58 /* The _TYPE node for the class. */
59 tree type;
61 /* The access specifier pending for new declarations in the scope of
62 this class. */
63 tree access;
65 /* If were defining TYPE, the names used in this class. */
66 splay_tree names_used;
68 /* Nonzero if this class is no longer open, because of a call to
69 push_to_top_level. */
74 {
75 /* The base for which we're building initializers. */
76 tree binfo;
77 /* The type of the most-derived type. */
78 tree derived;
79 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
80 unless ctor_vtbl_p is true. */
81 tree rtti_binfo;
82 /* The negative-index vtable initializers built up so far. These
83 are in order from least negative index to most negative index. */
85 /* The binfo for the virtual base for which we're building
86 vcall offset initializers. */
87 tree vbase;
88 /* The functions in vbase for which we have already provided vcall
89 offsets. */
91 /* The vtable index of the next vcall or vbase offset. */
92 tree index;
93 /* Nonzero if we are building the initializer for the primary
94 vtable. */
96 /* Nonzero if we are building the initializer for a construction
97 vtable. */
99 /* True when adding vcall offset entries to the vtable. False when
100 merely computing the indices. */
104 /* The type of a function passed to walk_subobject_offsets. */
107 /* The stack itself. This is a dynamically resized array. The
108 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
112 /* The size of the largest empty class seen in this translation unit. */
115 /* An array of all local classes present in this translation unit, in
116 declaration order. */
199 tree *);
209 splay_tree_key k2);
218 /* Variables shared between class.c and call.c. */
228 /* Convert to or from a base subobject. EXPR is an expression of type
229 `A' or `A*', an expression of type `B' or `B*' is returned. To
230 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
231 the B base instance within A. To convert base A to derived B, CODE
232 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
233 In this latter case, A must not be a morally virtual base of B.
234 NONNULL is true if EXPR is known to be non-NULL (this is only
235 needed when EXPR is of pointer type). CV qualifiers are preserved
236 from EXPR. */
238 tree
240 tree expr,
241 tree binfo,
243 tsubst_flags_t complain)
244 {
247 tree probe;
248 tree offset;
249 tree target_type;
251 tree ptr_target_type;
261 {
267 }
275 {
276 /* This can happen when adjust_result_of_qualified_name_lookup can't
277 find a unique base binfo in a call to a member function. We
278 couldn't give the diagnostic then since we might have been calling
279 a static member function, so we do it now. */
281 {
285 }
287 }
294 /* Nothing to do. */
298 {
300 {
302 {
305 "pointer to derived class %qT because the base is "
307 else
311 }
312 else
313 {
319 else
323 }
324 }
326 }
329 /* This must happen before the call to save_expr. */
331 else
337 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
338 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
339 expression returned matches the input. */
340 target_type = cp_build_qualified_type
344 /* Do we need to look in the vtable for the real offset? */
347 /* Don't bother with the calculations inside sizeof; they'll ICE if the
348 source type is incomplete and the pointer value doesn't matter. In a
349 template (even in fold_non_dependent_expr), we don't have vtables set
350 up properly yet, and the value doesn't matter there either; we're just
351 interested in the result of overload resolution. */
354 {
359 }
361 /* If we're in an NSDMI, we don't have the full constructor context yet
362 that we need for converting to a virtual base, so just build a stub
363 CONVERT_EXPR and expand it later in bot_replace. */
366 {
372 }
374 /* Do we need to check for a null pointer? */
376 {
377 /* If we know the conversion will not actually change the value
378 of EXPR, then we can avoid testing the expression for NULL.
379 We have to avoid generating a COMPONENT_REF for a base class
380 field, because other parts of the compiler know that such
381 expressions are always non-NULL. */
385 }
387 /* Protect against multiple evaluation if necessary. */
391 /* Now that we've saved expr, build the real null test. */
393 {
397 }
399 /* If this is a simple base reference, express it as a COMPONENT_REF. */
401 /* We don't build base fields for empty bases, and they aren't very
402 interesting to the optimizers anyway. */
404 {
411 }
414 {
415 /* Going via virtual base V_BINFO. We need the static offset
416 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
417 V_BINFO. That offset is an entry in D_BINFO's vtable. */
418 tree v_offset;
421 {
422 /* In a base member initializer, we cannot rely on the
423 vtable being set up. We have to indirect via the
424 vtt_parm. */
425 tree t;
431 }
432 else
434 complain),
443 v_offset);
455 /* Negative fixed_type_p means this is a constructor or destructor;
456 virtual base layout is fixed in in-charge [cd]tors, but not in
457 base [cd]tors. */
461 v_offset,
464 else
466 }
474 {
479 }
480 else
486 out:
492 }
494 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
495 Perform a derived-to-base conversion by recursively building up a
496 sequence of COMPONENT_REFs to the appropriate base fields. */
498 static tree
500 {
503 tree field;
506 {
507 tree temp;
511 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
512 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
513 an lvalue in the front end; only _DECLs and _REFs are lvalues
514 in the back end. */
520 }
522 /* Recurse. */
527 /* Is this the base field created by build_base_field? */
531 /* If we're looking for a field in the most-derived class,
532 also check the field offset; we can have two base fields
533 of the same type if one is an indirect virtual base and one
534 is a direct non-virtual base. */
538 {
539 /* We don't use build_class_member_access_expr here, as that
540 has unnecessary checks, and more importantly results in
541 recursive calls to dfs_walk_once. */
549 /* Mark the expression const or volatile, as appropriate.
550 Even though we've dealt with the type above, we still have
551 to mark the expression itself. */
558 }
560 /* Didn't find the base field?!? */
562 }
564 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
565 type is a class type or a pointer to a class type. In the former
566 case, TYPE is also a class type; in the latter it is another
567 pointer type. If CHECK_ACCESS is true, an error message is emitted
568 if TYPE is inaccessible. If OBJECT has pointer type, the value is
569 assumed to be non-NULL. */
571 tree
573 tsubst_flags_t complain)
574 {
575 tree binfo;
576 tree object_type;
579 {
582 }
583 else
592 }
594 /* EXPR is an expression with unqualified class type. BASE is a base
595 binfo of that class type. Returns EXPR, converted to the BASE
596 type. This function assumes that EXPR is the most derived class;
597 therefore virtual bases can be found at their static offsets. */
599 tree
601 {
602 tree expr_type;
606 {
607 /* If this is a non-empty base, use a COMPONENT_REF. */
611 /* We use fold_build2 and fold_convert below to simplify the trees
612 provided to the optimizers. It is not safe to call these functions
613 when processing a template because they do not handle C++-specific
614 trees. */
622 }
625 }
627 \f
628 tree
630 {
634 /* Can happen in case of duplicate base types (c++/59082). */
638 /* First, convert to the requested type. */
643 /* Second, the requested type may not be the owner of its own vptr.
644 If not, convert to the base class that owns it. We cannot use
645 convert_to_base here, because VCONTEXT may appear more than once
646 in the inheritance hierarchy of TYPE, and thus direct conversion
647 between the types may be ambiguous. Following the path back up
648 one step at a time via primary bases avoids the problem. */
652 {
655 }
658 }
660 /* Given an object INSTANCE, return an expression which yields the
661 vtable element corresponding to INDEX. There are many special
662 cases for INSTANCE which we take care of here, mainly to avoid
663 creating extra tree nodes when we don't have to. */
665 static tree
667 {
668 tree aref;
671 /* Try to figure out what a reference refers to, and
672 access its virtual function table directly. */
680 {
685 }
694 }
696 tree
698 {
702 }
704 /* Given a stable object pointer INSTANCE_PTR, return an expression which
705 yields a function pointer corresponding to vtable element INDEX. */
707 tree
709 {
710 tree aref;
713 tf_warning_or_error),
714 idx);
716 /* When using function descriptors, the address of the
717 vtable entry is treated as a function pointer. */
722 /* Remember this as a method reference, for later devirtualization. */
726 }
728 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
729 for the given TYPE. */
731 static tree
733 {
735 }
737 /* DECL is an entity associated with TYPE, like a virtual table or an
738 implicitly generated constructor. Determine whether or not DECL
739 should have external or internal linkage at the object file
740 level. This routine does not deal with COMDAT linkage and other
741 similar complexities; it simply sets TREE_PUBLIC if it possible for
742 entities in other translation units to contain copies of DECL, in
743 the abstract. */
745 void
747 {
750 }
752 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
753 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
754 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
756 static tree
758 {
759 tree decl;
762 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
763 now to avoid confusion in mangle_decl. */
774 /* The vtable has not been defined -- yet. */
778 /* Mark the VAR_DECL node representing the vtable itself as a
779 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
780 is rather important that such things be ignored because any
781 effort to actually generate DWARF for them will run into
782 trouble when/if we encounter code like:
784 #pragma interface
785 struct S { virtual void member (); };
787 because the artificial declaration of the vtable itself (as
788 manufactured by the g++ front end) will say that the vtable is
789 a static member of `S' but only *after* the debug output for
790 the definition of `S' has already been output. This causes
791 grief because the DWARF entry for the definition of the vtable
792 will try to refer back to an earlier *declaration* of the
793 vtable as a static member of `S' and there won't be one. We
794 might be able to arrange to have the "vtable static member"
795 attached to the member list for `S' before the debug info for
796 `S' get written (which would solve the problem) but that would
797 require more intrusive changes to the g++ front end. */
801 }
803 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
804 or even complete. If this does not exist, create it. If COMPLETE is
805 nonzero, then complete the definition of it -- that will render it
806 impossible to actually build the vtable, but is useful to get at those
807 which are known to exist in the runtime. */
809 tree
811 {
812 tree decl;
821 {
824 }
827 }
829 /* Build the primary virtual function table for TYPE. If BINFO is
830 non-NULL, build the vtable starting with the initial approximation
831 that it is the same as the one which is the head of the association
832 list. Returns a nonzero value if a new vtable is actually
833 created. */
835 static int
837 {
838 tree decl;
839 tree virtuals;
844 {
846 /* We have already created a vtable for this base, so there's
847 no need to do it again. */
854 }
855 else
856 {
859 }
862 {
865 }
867 /* Initialize the association list for this type, based
868 on our first approximation. */
873 }
875 /* Give BINFO a new virtual function table which is initialized
876 with a skeleton-copy of its original initialization. The only
877 entry that changes is the `delta' entry, so we can really
878 share a lot of structure.
880 FOR_TYPE is the most derived type which caused this table to
881 be needed.
883 Returns nonzero if we haven't met BINFO before.
885 The order in which vtables are built (by calling this function) for
886 an object must remain the same, otherwise a binary incompatibility
887 can result. */
889 static int
891 {
893 /* We already created a vtable for this base. There's no need to
894 do it again. */
897 /* Remember that we've created a vtable for this BINFO, so that we
898 don't try to do so again. */
901 /* Make fresh virtual list, so we can smash it later. */
904 /* Secondary vtables are laid out as part of the same structure as
905 the primary vtable. */
908 }
910 /* Create a new vtable for BINFO which is the hierarchy dominated by
911 T. Return nonzero if we actually created a new vtable. */
913 static int
915 {
917 /* In this case, it is *type*'s vtable we are modifying. We start
918 with the approximation that its vtable is that of the
919 immediate base class. */
921 else
922 /* This is our very own copy of `basetype' to play with. Later,
923 we will fill in all the virtual functions that override the
924 virtual functions in these base classes which are not defined
925 by the current type. */
927 }
929 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
930 (which is in the hierarchy dominated by T) list FNDECL as its
931 BV_FN. DELTA is the required constant adjustment from the `this'
932 pointer where the vtable entry appears to the `this' required when
933 the function is actually called. */
935 static void
937 tree binfo,
938 tree fndecl,
939 tree delta,
941 {
942 tree v;
948 {
949 /* We need a new vtable for BINFO. */
951 {
952 /* If we really did make a new vtable, we also made a copy
953 of the BINFO_VIRTUALS list. Now, we have to find the
954 corresponding entry in that list. */
959 }
964 }
965 }
967 // Returns the template associated with the member FN or
968 // NULL if the declaration is neither a template nor temploid.
971 {
977 }
979 // Returns true if NEWDECL and OLDDECL are member functions with with
980 // different constraints. If NEWDECL and OLDDECL are non-template members
981 // or specializations of non-template members, the overloads are
982 // differentiated by the template constraints.
983 //
984 // Note that the types of the functions are assumed to be equivalent.
987 {
991 // If neither is a template or temploid, then they cannot
992 // be constrained declarations.
995 else
997 }
999 \f
1000 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
1001 the USING_DECL naming METHOD. Returns true if the method could be
1002 added to the method vec. */
1004 bool
1006 {
1008 tree overload;
1014 tree current_fns;
1015 tree fns;
1028 {
1029 /* Make a new method vector. We start with 8 entries. We must
1030 allocate at least two (for constructors and destructors), and
1031 we're going to end up with an assignment operator at some
1032 point as well. */
1034 /* Create slots for constructors and destructors. */
1038 }
1040 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1043 /* Constructors and destructors go in special slots. */
1047 {
1051 {
1057 type);
1058 }
1059 }
1060 else
1061 {
1062 tree m;
1065 /* See if we already have an entry with this name. */
1069 {
1072 {
1077 }
1081 {
1084 }
1089 }
1090 }
1093 /* Check to see if we've already got this method. */
1095 {
1097 tree fn_type;
1098 tree method_type;
1099 tree parms1;
1100 tree parms2;
1105 /* [over.load] Member function declarations with the
1106 same name and the same parameter types cannot be
1107 overloaded if any of them is a static member
1108 function declaration.
1110 [over.load] Member function declarations with the same name and
1111 the same parameter-type-list as well as member function template
1112 declarations with the same name, the same parameter-type-list, and
1113 the same template parameter lists cannot be overloaded if any of
1114 them, but not all, have a ref-qualifier.
1116 [namespace.udecl] When a using-declaration brings names
1117 from a base class into a derived class scope, member
1118 functions in the derived class override and/or hide member
1119 functions with the same name and parameter types in a base
1120 class (rather than conflicting). */
1126 /* Compare the quals on the 'this' parm. Don't compare
1127 the whole types, as used functions are treated as
1128 coming from the using class in overload resolution. */
1131 /* Either both or neither need to be ref-qualified for
1132 differing quals to allow overloading. */
1139 /* For templates, the return type and template parameters
1140 must be identical. */
1157 {
1158 /* For function versions, their parms and types match
1159 but they are not duplicates. Record function versions
1160 as and when they are found. extern "C" functions are
1161 not treated as versions. */
1167 {
1168 /* Mark functions as versions if necessary. Modify the mangled
1169 decl name if necessary. */
1171 {
1175 }
1177 {
1181 }
1184 }
1186 {
1188 {
1195 }
1196 /* Otherwise defer to the other function. */
1198 }
1200 {
1202 /* Defer to the local function. */
1204 }
1207 else
1208 {
1211 }
1213 /* We don't call duplicate_decls here to merge the
1214 declarations because that will confuse things if the
1215 methods have inline definitions. In particular, we
1216 will crash while processing the definitions. */
1218 }
1219 }
1221 /* A class should never have more than one destructor. */
1225 /* Add the new binding. */
1227 {
1230 }
1231 else
1240 {
1243 /* We only expect to add few methods in the COMPLETE_P case, so
1244 just make room for one more method in that case. */
1247 else
1253 else
1255 }
1256 else
1257 /* Replace the current slot. */
1260 }
1262 /* Subroutines of finish_struct. */
1264 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1265 legit, otherwise return 0. */
1267 static int
1269 {
1270 tree elem;
1279 {
1281 {
1285 else
1288 }
1289 else
1290 {
1291 /* They're changing the access to the same thing they changed
1292 it to before. That's OK. */
1293 ;
1294 }
1295 }
1296 else
1297 {
1299 tf_warning_or_error);
1302 }
1304 }
1306 /* Process the USING_DECL, which is a member of T. */
1308 static void
1310 {
1313 tree access
1318 tree old_value;
1323 tf_warning_or_error);
1325 {
1331 else
1333 }
1341 ;
1343 {
1345 /* It's OK to use functions from a base when there are functions with
1347 else
1348 {
1353 }
1354 }
1356 {
1360 }
1362 /* Make type T see field decl FDECL with access ACCESS. */
1365 {
1368 }
1369 else
1371 }
1372 \f
1373 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1374 types with abi tags, add the corresponding identifiers to the VEC in
1375 *DATA and set IDENTIFIER_MARKED. */
1377 struct abi_tag_data
1378 {
1379 tree t;
1380 tree subob;
1381 // error_mark_node to get diagnostics; otherwise collect missing tags here
1382 tree tags;
1383 };
1385 static tree
1387 {
1391 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1392 anyway, but let's make sure of it. */
1396 {
1400 {
1404 {
1406 {
1407 /* We're collecting tags from template arguments. */
1413 /* Don't inherit this tag multiple times. */
1415 }
1417 /* Otherwise we're diagnosing missing tags. */
1419 {
1424 }
1425 else
1426 {
1430 {
1434 }
1435 }
1436 }
1437 }
1438 }
1440 }
1442 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1443 complete) template arguments. */
1445 static void
1447 {
1450 {
1453 {
1457 }
1458 }
1459 }
1461 /* Check that class T has all the abi tags that subobject SUBOB has, or
1462 warn if not. */
1464 static void
1466 {
1475 }
1477 void
1479 {
1488 {
1491 {
1495 }
1496 }
1498 // If we found some tags on our template arguments, add them to our
1499 // abi_tag attribute.
1501 {
1505 else
1509 }
1512 }
1514 /* Return true, iff class T has a non-virtual destructor that is
1515 accessible from outside the class heirarchy (i.e. is public, or
1516 there's a suitable friend. */
1518 static bool
1520 {
1523 /* An implicitly declared destructor is always public. And,
1524 if it were virtual, we would have created it by now. */
1539 }
1541 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1542 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1543 properties of the bases. */
1545 static void
1549 {
1553 tree base_binfo;
1554 tree binfo;
1564 {
1573 /* If any base class is non-literal, so is the derived class. */
1577 /* If the base class doesn't have copy constructors or
1578 assignment operators that take const references, then the
1579 derived class cannot have such a member automatically
1580 generated. */
1589 /* A virtual base does not effect nearly emptiness. */
1590 ;
1592 {
1594 /* And if there is more than one nearly empty base, then the
1595 derived class is not nearly empty either. */
1597 else
1598 /* Remember we've seen one. */
1600 }
1602 /* If the base class is not empty or nearly empty, then this
1603 class cannot be nearly empty. */
1606 /* A lot of properties from the bases also apply to the derived
1607 class. */
1624 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1627 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1631 /* A standard-layout class is a class that:
1632 ...
1633 * has no non-standard-layout base classes, */
1636 {
1637 tree basefield;
1638 /* ...has no base classes of the same type as the first non-static
1639 data member... */
1641 && (same_type_ignoring_top_level_qualifiers_p
1644 else
1645 /* ...either has no non-static data members in the most-derived
1646 class and at most one base class with non-static data
1647 members, or has no base classes with non-static data
1648 members */
1652 {
1655 else
1658 }
1659 }
1661 /* Don't bother collecting tm attributes if transactional memory
1662 support is not enabled. */
1664 {
1668 }
1671 }
1673 /* If one of the base classes had TM attributes, and the current class
1674 doesn't define its own, then the current class inherits one. */
1676 {
1679 }
1680 }
1682 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1683 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1684 that have had a nearly-empty virtual primary base stolen by some
1685 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1686 T. */
1688 static void
1690 {
1694 tree base_binfo;
1696 /* Determine the primary bases of our bases. */
1699 {
1702 /* See if we're the non-virtual primary of our inheritance
1703 chain. */
1705 {
1712 /* We are the primary binfo. */
1714 }
1715 /* Determine if we have a virtual primary base, and mark it so.
1716 */
1718 {
1722 /* Someone already claimed this base. */
1724 else
1725 {
1726 tree delta;
1731 /* A virtual binfo might have been copied from within
1732 another hierarchy. As we're about to use it as a
1733 primary base, make sure the offsets match. */
1741 }
1742 }
1743 }
1745 /* First look for a dynamic direct non-virtual base. */
1747 {
1751 {
1754 }
1755 }
1757 /* A "nearly-empty" virtual base class can be the primary base
1758 class, if no non-virtual polymorphic base can be found. Look for
1759 a nearly-empty virtual dynamic base that is not already a primary
1760 base of something in the hierarchy. If there is no such base,
1761 just pick the first nearly-empty virtual base. */
1767 {
1769 {
1770 /* Found one that is not primary. */
1773 }
1775 /* Remember the first candidate. */
1777 }
1779 found:
1780 /* If we've got a primary base, use it. */
1782 {
1787 /* We are stealing a primary base. */
1791 {
1792 tree delta;
1795 /* A virtual binfo might have been copied from within
1796 another hierarchy. As we're about to use it as a primary
1797 base, make sure the offsets match. */
1802 }
1809 }
1810 }
1812 /* Update the variant types of T. */
1814 void
1816 {
1817 tree variants;
1823 variants;
1825 {
1826 /* These fields are in the _TYPE part of the node, not in
1827 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1837 /* Copy whatever these are holding today. */
1841 }
1842 }
1844 /* Early variant fixups: we apply attributes at the beginning of the class
1845 definition, and we need to fix up any variants that have already been
1846 made via elaborated-type-specifier so that check_qualified_type works. */
1848 void
1850 {
1851 tree variants;
1857 variants;
1859 {
1860 /* These are the two fields that check_qualified_type looks at and
1861 are affected by attributes. */
1864 }
1865 }
1866 \f
1867 /* Set memoizing fields and bits of T (and its variants) for later
1868 use. */
1870 static void
1872 {
1873 /* Fix up variants (if any). */
1877 /* For a class w/o baseclasses, 'finish_struct' has set
1878 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1879 Similarly for a class whose base classes do not have vtables.
1880 When neither of these is true, we might have removed abstract
1881 virtuals (by providing a definition), added some (by declaring
1882 new ones), or redeclared ones from a base class. We need to
1883 recalculate what's really an abstract virtual at this point (by
1884 looking in the vtables). */
1887 /* If this type has a copy constructor or a destructor, force its
1888 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1889 nonzero. This will cause it to be passed by invisible reference
1890 and prevent it from being returned in a register. */
1893 {
1894 tree variants;
1897 {
1900 }
1901 }
1902 }
1904 /* Issue warnings about T having private constructors, but no friends,
1905 and so forth.
1907 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1908 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1909 non-private static member functions. */
1911 static void
1913 {
1916 tree fn;
1919 /* If the class has friends, those entities might create and
1920 access instances, so we should not warn. */
1923 /* We will have warned when the template was declared; there's
1924 no need to warn on every instantiation. */
1926 /* There's no reason to even consider warning about this
1927 class. */
1930 /* We only issue one warning, if more than one applies, because
1931 otherwise, on code like:
1933 class A {
1934 // Oops - forgot `public:'
1935 A();
1936 A(const A&);
1937 ~A();
1938 };
1940 we warn several times about essentially the same problem. */
1942 /* Check to see if all (non-constructor, non-destructor) member
1943 functions are private. (Since there are no friends or
1944 non-private statics, we can't ever call any of the private member
1945 functions.) */
1947 /* We're not interested in compiler-generated methods; they don't
1948 provide any way to call private members. */
1950 {
1952 {
1954 /* A non-private static member function is just like a
1955 friend; it can create and invoke private member
1956 functions, and be accessed without a class
1957 instance. */
1961 /* Keep searching for a static member function. */
1962 }
1965 }
1968 {
1969 /* There are no non-private methods, and there's at least one
1970 private member function that isn't a constructor or
1971 destructor. (If all the private members are
1972 constructors/destructors we want to use the code below that
1973 issues error messages specifically referring to
1974 constructors/destructors.) */
1980 {
1983 }
1985 {
1989 }
1990 }
1992 /* Even if some of the member functions are non-private, the class
1993 won't be useful for much if all the constructors or destructors
1994 are private: such an object can never be created or destroyed. */
1997 {
2000 t);
2002 }
2004 /* Warn about classes that have private constructors and no friends. */
2006 /* Implicitly generated constructors are always public. */
2009 {
2012 /* If a non-template class does not define a copy
2013 constructor, one is defined for it, enabling it to avoid
2014 this warning. For a template class, this does not
2015 happen, and so we would normally get a warning on:
2017 template <class T> class C { private: C(); };
2019 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2020 complete non-template or fully instantiated classes have this
2021 flag set. */
2024 else
2026 {
2028 /* Ideally, we wouldn't count copy constructors (or, in
2029 fact, any constructor that takes an argument of the
2030 class type as a parameter) because such things cannot
2031 be used to construct an instance of the class unless
2032 you already have one. But, for now at least, we're
2033 more generous. */
2035 {
2038 }
2039 }
2042 {
2045 t);
2047 }
2048 }
2049 }
2052 gt_pointer_operator new_value;
2056 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2058 static int
2060 {
2073 }
2075 /* This routine compares two fields like method_name_cmp but using the
2076 pointer operator in resort_field_decl_data. */
2078 static int
2080 {
2089 {
2096 }
2098 }
2100 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2102 void
2105 gt_pointer_operator new_value,
2107 {
2111 tree fn;
2113 /* The type conversion ops have to live at the front of the vec, so we
2114 can't sort them. */
2122 {
2126 resort_method_name_cmp);
2127 }
2128 }
2130 /* Warn about duplicate methods in fn_fields.
2132 Sort methods that are not special (i.e., constructors, destructors,
2133 and type conversion operators) so that we can find them faster in
2134 search. */
2136 static void
2138 {
2139 tree fn_fields;
2149 /* Clear DECL_IN_AGGR_P for all functions. */
2154 /* Issue warnings about private constructors and such. If there are
2155 no methods, then some public defaults are generated. */
2158 /* The type conversion ops have to live at the front of the vec, so we
2159 can't sort them. */
2168 }
2170 /* Make BINFO's vtable have N entries, including RTTI entries,
2171 vbase and vcall offsets, etc. Set its type and call the back end
2172 to lay it out. */
2174 static void
2176 {
2177 tree atype;
2178 tree vtable;
2183 /* We may have to grow the vtable. */
2186 {
2190 }
2191 }
2193 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2194 have the same signature. */
2196 int
2198 {
2199 /* One destructor overrides another if they are the same kind of
2200 destructor. */
2204 /* But a non-destructor never overrides a destructor, nor vice
2205 versa, nor do different kinds of destructors override
2206 one-another. For example, a complete object destructor does not
2207 override a deleting destructor. */
2216 {
2224 }
2226 }
2228 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2229 subobject. */
2231 static bool
2233 {
2234 tree probe;
2237 {
2241 /* If we meet a virtual base, we can't follow the inheritance
2242 any more. See if the complete type of DERIVED contains
2243 such a virtual base. */
2246 }
2248 }
2251 /* The function for which we are trying to find a final overrider. */
2252 tree fn;
2253 /* The base class in which the function was declared. */
2254 tree declaring_base;
2255 /* The candidate overriders. */
2256 tree candidates;
2257 /* Path to most derived. */
2261 /* Add the overrider along the current path to FFOD->CANDIDATES.
2262 Returns true if an overrider was found; false otherwise. */
2264 static bool
2268 {
2269 tree method;
2271 /* If BINFO is not the most derived type, try a more derived class.
2272 A definition there will overrider a definition here. */
2274 {
2275 depth--;
2279 }
2283 {
2286 /* Remove any candidates overridden by this new function. */
2288 {
2289 /* If *CANDIDATE overrides METHOD, then METHOD
2290 cannot override anything else on the list. */
2293 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2296 else
2298 }
2300 /* Add the new function. */
2303 }
2306 }
2308 /* Called from find_final_overrider via dfs_walk. */
2310 static tree
2312 {
2320 }
2322 static tree
2324 {
2329 }
2331 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2332 FN and whose TREE_VALUE is the binfo for the base where the
2333 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2334 DERIVED) is the base object in which FN is declared. */
2336 static tree
2338 {
2339 find_final_overrider_data ffod;
2341 /* Getting this right is a little tricky. This is valid:
2343 struct S { virtual void f (); };
2344 struct T { virtual void f (); };
2345 struct U : public S, public T { };
2347 even though calling `f' in `U' is ambiguous. But,
2349 struct R { virtual void f(); };
2350 struct S : virtual public R { virtual void f (); };
2351 struct T : virtual public R { virtual void f (); };
2352 struct U : public S, public T { };
2354 is not -- there's no way to decide whether to put `S::f' or
2355 `T::f' in the vtable for `R'.
2357 The solution is to look at all paths to BINFO. If we find
2358 different overriders along any two, then there is a problem. */
2362 /* Determine the depth of the hierarchy. */
2373 /* If there was no winner, issue an error message. */
2378 }
2380 /* Return the index of the vcall offset for FN when TYPE is used as a
2381 virtual base. */
2383 static tree
2385 {
2387 tree_pair_p p;
2395 /* There should always be an appropriate index. */
2397 }
2399 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2400 dominated by T. FN is the old function; VIRTUALS points to the
2401 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2402 of that entry in the list. */
2404 static void
2407 {
2408 tree b;
2409 tree overrider;
2410 tree delta;
2411 tree virtual_base;
2412 tree first_defn;
2418 /* Find the nearest primary base (possibly binfo itself) which defines
2419 this function; this is the class the caller will convert to when
2420 calling FN through BINFO. */
2422 {
2427 /* The nearest definition is from a lost primary. */
2430 }
2433 /* Find the final overrider. */
2436 {
2439 }
2442 /* Check for adjusting covariant return types. */
2450 /* If the overrider is invalid, don't even try. */
2452 {
2453 /* If FN is a covariant thunk, we must figure out the adjustment
2454 to the final base FN was converting to. As OVERRIDER_TARGET might
2455 also be converting to the return type of FN, we have to
2456 combine the two conversions here. */
2463 {
2467 }
2468 else
2472 /* Find the equivalent binfo within the return type of the
2473 overriding function. We will want the vbase offset from
2474 there. */
2476 over_return);
2479 {
2480 /* There was no existing virtual thunk (which takes
2481 precedence). So find the binfo of the base function's
2482 return type within the overriding function's return type.
2483 We cannot call lookup base here, because we're inside a
2484 dfs_walk, and will therefore clobber the BINFO_MARKED
2485 flags. Fortunately we know the covariancy is valid (it
2486 has already been checked), so we can just iterate along
2487 the binfos, which have been chained in inheritance graph
2488 order. Of course it is lame that we have to repeat the
2489 search here anyway -- we should really be caching pieces
2490 of the vtable and avoiding this repeated work. */
2493 /* Find the base binfo within the overriding function's
2494 return type. We will always find a thunk_binfo, except
2495 when the covariancy is invalid (which we will have
2496 already diagnosed). */
2499 thunk_binfo;
2505 /* See if virtual inheritance is involved. */
2507 virtual_offset;
2514 {
2518 {
2519 /* We convert via virtual base. Adjust the fixed
2520 offset to be from there. */
2521 offset =
2525 }
2527 /* There was an existing fixed offset, this must be
2528 from the base just converted to, and the base the
2529 FN was thunking to. */
2531 else
2533 }
2534 }
2537 /* Replace the overriding function with a covariant thunk. We
2538 will emit the overriding function in its own slot as
2539 well. */
2542 }
2543 else
2547 /* If we need a covariant thunk, then we may need to adjust first_defn.
2548 The ABI specifies that the thunks emitted with a function are
2549 determined by which bases the function overrides, so we need to be
2550 sure that we're using a thunk for some overridden base; even if we
2551 know that the necessary this adjustment is zero, there may not be an
2552 appropriate zero-this-adjusment thunk for us to use since thunks for
2553 overriding virtual bases always use the vcall offset.
2555 Furthermore, just choosing any base that overrides this function isn't
2556 quite right, as this slot won't be used for calls through a type that
2557 puts a covariant thunk here. Calling the function through such a type
2558 will use a different slot, and that slot is the one that determines
2559 the thunk emitted for that base.
2561 So, keep looking until we find the base that we're really overriding
2562 in this slot: the nearest primary base that doesn't use a covariant
2563 thunk in this slot. */
2565 {
2567 /* We already know that the overrider needs a covariant thunk. */
2570 {
2577 }
2579 }
2581 /* Assume that we will produce a thunk that convert all the way to
2582 the final overrider, and not to an intermediate virtual base. */
2585 /* See if we can convert to an intermediate virtual base first, and then
2586 use the vcall offset located there to finish the conversion. */
2588 {
2589 /* If we find the final overrider, then we can stop
2590 walking. */
2595 /* If we find a virtual base, and we haven't yet found the
2596 overrider, then there is a virtual base between the
2597 declaring base (first_defn) and the final overrider. */
2599 {
2602 }
2603 }
2605 /* Compute the constant adjustment to the `this' pointer. The
2606 `this' pointer, when this function is called, will point at BINFO
2607 (or one of its primary bases, which are at the same offset). */
2609 /* The `this' pointer needs to be adjusted from the declaration to
2610 the nearest virtual base. */
2615 /* If the nearest definition is in a lost primary, we don't need an
2616 entry in our vtable. Except possibly in a constructor vtable,
2617 if we happen to get our primary back. In that case, the offset
2618 will be zero, as it will be a primary base. */
2620 else
2621 /* The `this' pointer needs to be adjusted from pointing to
2622 BINFO to pointing at the base where the final overrider
2623 appears. */
2634 else
2638 }
2640 /* Called from modify_all_vtables via dfs_walk. */
2642 static tree
2644 {
2646 tree virtuals;
2647 tree old_virtuals;
2651 /* A base without a vtable needs no modification, and its bases
2652 are uninteresting. */
2657 /* Don't do the primary vtable, if it's new. */
2661 /* There's no need to modify the vtable for a non-virtual primary
2662 base; we're not going to use that vtable anyhow. We do still
2663 need to do this for virtual primary bases, as they could become
2664 non-primary in a construction vtable. */
2669 /* Now, go through each of the virtual functions in the virtual
2670 function table for BINFO. Find the final overrider, and update
2671 the BINFO_VIRTUALS list appropriately. */
2674 virtuals;
2678 binfo,
2683 }
2685 /* Update all of the primary and secondary vtables for T. Create new
2686 vtables as required, and initialize their RTTI information. Each
2687 of the functions in VIRTUALS is declared in T and may override a
2688 virtual function from a base class; find and modify the appropriate
2689 entries to point to the overriding functions. Returns a list, in
2690 declaration order, of the virtual functions that are declared in T,
2691 but do not appear in the primary base class vtable, and which
2692 should therefore be appended to the end of the vtable for T. */
2694 static tree
2696 {
2700 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2704 /* Update all of the vtables. */
2707 /* Add virtual functions not already in our primary vtable. These
2708 will be both those introduced by this class, and those overridden
2709 from secondary bases. It does not include virtuals merely
2710 inherited from secondary bases. */
2712 {
2717 {
2718 /* We don't need to adjust the `this' pointer when
2719 calling this function. */
2723 /* This is a function not already in our vtable. Keep it. */
2725 }
2726 else
2727 /* We've already got an entry for this function. Skip it. */
2729 }
2732 }
2734 /* Get the base virtual function declarations in T that have the
2735 indicated NAME. */
2737 static tree
2739 {
2740 tree methods;
2745 /* Find virtual functions in T with the indicated NAME. */
2749 methods;
2751 {
2757 }
2763 {
2766 base_fndecls);
2767 }
2770 }
2772 /* If this declaration supersedes the declaration of
2773 a method declared virtual in the base class, then
2774 mark this field as being virtual as well. */
2776 void
2778 {
2781 /* In [temp.mem] we have:
2783 A specialization of a member function template does not
2784 override a virtual function from a base class. */
2791 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2792 the error_mark_node so that we know it is an overriding
2793 function. */
2794 {
2797 }
2800 {
2806 }
2811 }
2813 /* Warn about hidden virtual functions that are not overridden in t.
2814 We know that constructors and destructors don't apply. */
2816 static void
2818 {
2820 tree fns;
2823 /* We go through each separately named virtual function. */
2827 {
2828 tree fn;
2829 tree name;
2830 tree fndecl;
2831 tree base_fndecls;
2832 tree base_binfo;
2833 tree binfo;
2836 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2837 have the same name. Figure out what name that is. */
2839 /* There are no possibly hidden functions yet. */
2841 /* Iterate through all of the base classes looking for possibly
2842 hidden functions. */
2845 {
2848 base_fndecls);
2849 }
2851 /* If there are no functions to hide, continue. */
2855 /* Remove any overridden functions. */
2857 {
2860 {
2864 /* If the method from the base class has the same
2865 signature as the method from the derived class, it
2866 has been overridden. */
2869 else
2871 }
2872 }
2874 /* Now give a warning for all base functions without overriders,
2875 as they are hidden. */
2877 {
2878 /* Here we know it is a hider, and no overrider exists. */
2882 }
2883 }
2884 }
2886 /* Recursive helper for finish_struct_anon. */
2888 static void
2890 {
2894 {
2895 /* We're generally only interested in entities the user
2896 declared, but we also find nested classes by noticing
2897 the TYPE_DECL that we create implicitly. You're
2898 allowed to put one anonymous union inside another,
2899 though, so we explicitly tolerate that. We use
2900 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2901 we also allow unnamed types used for defining fields. */
2908 {
2909 /* We already complained about static data members in
2910 finish_static_data_member_decl. */
2912 {
2915 "%q+#D invalid; an anonymous union can "
2917 else
2919 "%q+#D invalid; an anonymous struct can "
2921 }
2923 }
2926 {
2928 {
2932 else
2935 }
2937 {
2941 else
2944 }
2945 }
2950 /* Recurse into the anonymous aggregates to handle correctly
2951 access control (c++/24926):
2953 class A {
2954 union {
2955 union {
2956 int i;
2957 };
2958 };
2959 };
2961 int j=A().i; */
2965 }
2966 }
2968 /* Check for things that are invalid. There are probably plenty of other
2969 things we should check for also. */
2971 static void
2973 {
2975 {
2984 }
2985 }
2987 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2988 will be used later during class template instantiation.
2989 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2990 a non-static member data (FIELD_DECL), a member function
2991 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2992 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2993 When FRIEND_P is nonzero, T is either a friend class
2994 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2995 (FUNCTION_DECL, TEMPLATE_DECL). */
2997 void
2999 {
3000 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3005 }
3007 /* This function is called from declare_virt_assop_and_dtor via
3008 dfs_walk_all.
3010 DATA is a type that direcly or indirectly inherits the base
3011 represented by BINFO. If BINFO contains a virtual assignment [copy
3012 assignment or move assigment] operator or a virtual constructor,
3013 declare that function in DATA if it hasn't been already declared. */
3015 static tree
3017 {
3025 /* A base without a vtable needs no modification, and its bases
3026 are uninteresting. */
3030 /* If this is a primary base, then we have already looked at the
3031 virtual functions of its vtable. */
3035 {
3039 {
3044 }
3048 }
3051 }
3053 /* If the class type T has a direct or indirect base that contains a
3054 virtual assignment operator or a virtual destructor, declare that
3055 function in T if it hasn't been already declared. */
3057 static void
3059 {
3067 dfs_declare_virt_assop_and_dtor,
3069 }
3071 /* Declare the inheriting constructor for class T inherited from base
3072 constructor CTOR with the parameter array PARMS of size NPARMS. */
3074 static void
3076 {
3077 /* We don't declare an inheriting ctor that would be a default,
3078 copy or move ctor for derived or base. */
3083 {
3087 }
3095 {
3098 }
3099 }
3101 /* Declare all the inheriting constructors for class T inherited from base
3102 constructor CTOR. */
3104 static void
3106 {
3112 {
3116 }
3119 {
3123 }
3124 }
3126 /* Create default constructors, assignment operators, and so forth for
3127 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3128 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3129 the class cannot have a default constructor, copy constructor
3130 taking a const reference argument, or an assignment operator taking
3131 a const reference, respectively. */
3133 static void
3137 {
3145 /* Destructor. */
3147 {
3148 /* In general, we create destructors lazily. */
3153 /* But if this is a Java class, any non-trivial destructor is
3154 invalid, even if compiler-generated. Therefore, if the
3155 destructor is non-trivial we create it now. */
3157 }
3159 /* [class.ctor]
3161 If there is no user-declared constructor for a class, a default
3162 constructor is implicitly declared. */
3164 {
3169 /* This might force the declaration. */
3171 }
3173 /* [class.ctor]
3175 If a class definition does not explicitly declare a copy
3176 constructor, one is declared implicitly. */
3178 {
3184 }
3186 /* If there is no assignment operator, one will be created if and
3187 when it is needed. For now, just record whether or not the type
3188 of the parameter to the assignment operator will be a const or
3189 non-const reference. */
3191 {
3197 }
3199 /* We can't be lazy about declaring functions that might override
3200 a virtual function from a base class. */
3204 {
3208 {
3209 /* declare, then remove the decl */
3218 }
3219 else
3221 }
3222 }
3224 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3225 count the number of fields in TYPE, including anonymous union
3226 members. */
3228 static int
3230 {
3231 tree x;
3234 {
3237 else
3239 }
3241 }
3243 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3244 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3245 elts, starting at offset IDX. */
3247 static int
3249 {
3250 tree x;
3252 {
3255 else
3257 }
3259 }
3261 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3262 starting at offset IDX. */
3264 static int
3268 {
3269 tree values;
3273 }
3275 /* FIELD is a bit-field. We are finishing the processing for its
3276 enclosing type. Issue any appropriate messages and set appropriate
3277 flags. Returns false if an error has been diagnosed. */
3279 static bool
3281 {
3283 tree w;
3285 /* Extract the declared width of the bitfield, which has been
3286 temporarily stashed in DECL_INITIAL. */
3289 /* Remove the bit-field width indicator so that the rest of the
3290 compiler does not treat that value as an initializer. */
3293 /* Detect invalid bit-field type. */
3295 {
3298 }
3299 else
3300 {
3302 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3305 /* detect invalid field size. */
3311 {
3314 }
3316 {
3319 }
3321 {
3324 }
3336 }
3339 {
3343 }
3344 else
3345 {
3346 /* Non-bit-fields are aligned for their type. */
3350 }
3351 }
3353 /* FIELD is a non bit-field. We are finishing the processing for its
3354 enclosing type T. Issue any appropriate messages and set appropriate
3355 flags. */
3357 static void
3359 tree t,
3363 {
3366 /* In C++98 an anonymous union cannot contain any fields which would change
3367 the settings of CANT_HAVE_CONST_CTOR and friends. */
3369 ;
3370 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3371 structs. So, we recurse through their fields here. */
3373 {
3374 tree fields;
3380 }
3381 /* Check members with class type for constructors, destructors,
3382 etc. */
3384 {
3385 /* Never let anything with uninheritable virtuals
3386 make it through without complaint. */
3390 {
3395 field);
3400 field);
3402 {
3406 }
3407 }
3408 else
3409 {
3422 }
3431 }
3436 {
3437 /* `build_class_init_list' does not recognize
3438 non-FIELD_DECLs. */
3442 }
3443 }
3445 /* Check the data members (both static and non-static), class-scoped
3446 typedefs, etc., appearing in the declaration of T. Issue
3447 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3448 declaration order) of access declarations; each TREE_VALUE in this
3449 list is a USING_DECL.
3451 In addition, set the following flags:
3453 EMPTY_P
3454 The class is empty, i.e., contains no non-static data members.
3456 CANT_HAVE_CONST_CTOR_P
3457 This class cannot have an implicitly generated copy constructor
3458 taking a const reference.
3460 CANT_HAVE_CONST_ASN_REF
3461 This class cannot have an implicitly generated assignment
3462 operator taking a const reference.
3464 All of these flags should be initialized before calling this
3465 function.
3467 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3468 fields can be added by adding to this chain. */
3470 static void
3474 {
3482 /* Assume there are no access declarations. */
3484 /* Assume this class has no pointer members. */
3486 /* Assume none of the members of this class have default
3487 initializations. */
3491 {
3499 {
3500 /* Save the access declarations for our caller. */
3503 }
3509 /* If we've gotten this far, it's a data member, possibly static,
3510 or an enumerator. */
3514 /* When this goes into scope, it will be a non-local reference. */
3519 {
3520 /* [class.union] (C++98)
3522 If a union contains a static data member, or a member of
3523 reference type, the program is ill-formed.
3525 In C++11 this limitation doesn't exist anymore. */
3527 {
3531 }
3533 {
3537 }
3538 }
3540 /* Perform error checking that did not get done in
3541 grokdeclarator. */
3543 {
3547 }
3549 {
3553 }
3561 /* Now it can only be a FIELD_DECL. */
3566 /* If at least one non-static data member is non-literal, the whole
3567 class becomes non-literal. Note: if the type is incomplete we
3568 will complain later on. */
3572 /* A standard-layout class is a class that:
3573 ...
3574 has the same access control (Clause 11) for all non-static data members,
3575 ... */
3582 /* If this is of reference type, check if it needs an init. */
3584 {
3590 /* ARM $12.6.2: [A member initializer list] (or, for an
3591 aggregate, initialization by a brace-enclosed list) is the
3592 only way to initialize nonstatic const and reference
3593 members. */
3596 }
3601 {
3603 {
3604 warning
3607 x);
3609 }
3613 }
3616 /* We don't treat zero-width bitfields as making a class
3617 non-empty. */
3618 ;
3619 else
3620 {
3621 /* The class is non-empty. */
3623 /* The class is not even nearly empty. */
3625 /* If one of the data members contains an empty class,
3626 so does T. */
3630 }
3632 /* This is used by -Weffc++ (see below). Warn only for pointers
3633 to members which might hold dynamic memory. So do not warn
3634 for pointers to functions or pointers to members. */
3640 {
3645 }
3651 {
3653 {
3657 }
3659 {
3663 }
3664 }
3667 /* DR 148 now allows pointers to members (which are POD themselves),
3668 to be allowed in POD structs. */
3677 /* We set DECL_C_BIT_FIELD in grokbitfield.
3678 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3681 cant_have_const_ctor_p,
3682 no_const_asn_ref_p,
3685 /* Now that we've removed bit-field widths from DECL_INITIAL,
3686 anything left in DECL_INITIAL is an NSDMI that makes the class
3687 non-aggregate. */
3691 /* If any field is const, the structure type is pseudo-const. */
3693 {
3698 /* ARM $12.6.2: [A member initializer list] (or, for an
3699 aggregate, initialization by a brace-enclosed list) is the
3700 only way to initialize nonstatic const and reference
3701 members. */
3704 }
3705 /* A field that is pseudo-const makes the structure likewise. */
3707 {
3712 }
3714 /* Core issue 80: A nonstatic data member is required to have a
3715 different name from the class iff the class has a
3716 user-declared constructor. */
3720 }
3722 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3723 it should also define a copy constructor and an assignment operator to
3724 implement the correct copy semantic (deep vs shallow, etc.). As it is
3725 not feasible to check whether the constructors do allocate dynamic memory
3726 and store it within members, we approximate the warning like this:
3728 -- Warn only if there are members which are pointers
3729 -- Warn only if there is a non-trivial constructor (otherwise,
3730 there cannot be memory allocated).
3731 -- Warn only if there is a non-trivial destructor. We assume that the
3732 user at least implemented the cleanup correctly, and a destructor
3733 is needed to free dynamic memory.
3735 This seems enough for practical purposes. */
3737 && has_pointers
3741 {
3745 {
3750 }
3754 }
3756 /* Non-static data member initializers make the default constructor
3757 non-trivial. */
3759 {
3762 }
3764 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3768 /* Check anonymous struct/anonymous union fields. */
3771 /* We've built up the list of access declarations in reverse order.
3772 Fix that now. */
3774 }
3776 /* If TYPE is an empty class type, records its OFFSET in the table of
3777 OFFSETS. */
3779 static int
3781 {
3782 splay_tree_node n;
3787 /* Record the location of this empty object in OFFSETS. */
3795 type,
3799 }
3801 /* Returns nonzero if TYPE is an empty class type and there is
3802 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3804 static int
3806 {
3807 splay_tree_node n;
3808 tree t;
3813 /* Record the location of this empty object in OFFSETS. */
3823 }
3825 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3826 F for every subobject, passing it the type, offset, and table of
3827 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3828 be traversed.
3830 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3831 than MAX_OFFSET will not be walked.
3833 If F returns a nonzero value, the traversal ceases, and that value
3834 is returned. Otherwise, returns zero. */
3836 static int
3838 subobject_offset_fn f,
3839 tree offset,
3840 splay_tree offsets,
3841 tree max_offset,
3843 {
3847 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3848 stop. */
3856 {
3859 }
3862 {
3863 tree field;
3864 tree binfo;
3867 /* Avoid recursing into objects that are not interesting. */
3871 /* Record the location of TYPE. */
3876 /* Iterate through the direct base classes of TYPE. */
3880 {
3881 tree binfo_offset;
3886 tree orig_binfo;
3887 /* We cannot rely on BINFO_OFFSET being set for the base
3888 class yet, but the offsets for direct non-virtual
3889 bases can be calculated by going back to the TYPE. */
3892 offset,
3896 f,
3897 binfo_offset,
3898 offsets,
3899 max_offset,
3903 }
3906 {
3910 /* Iterate through the virtual base classes of TYPE. In G++
3911 3.2, we included virtual bases in the direct base class
3912 loop above, which results in incorrect results; the
3913 correct offsets for virtual bases are only known when
3914 working with the most derived type. */
3918 {
3920 f,
3922 offset,
3924 offsets,
3925 max_offset,
3929 }
3930 else
3931 {
3932 /* We still have to walk the primary base, if it is
3933 virtual. (If it is non-virtual, then it was walked
3934 above.) */
3940 {
3941 r = (walk_subobject_offsets
3946 }
3947 }
3948 }
3950 /* Iterate through the fields of TYPE. */
3955 {
3956 tree field_offset;
3961 f,
3963 offset,
3964 field_offset),
3965 offsets,
3966 max_offset,
3970 }
3971 }
3973 {
3976 tree index;
3978 /* Avoid recursing into objects that are not interesting. */
3983 /* Step through each of the elements in the array. */
3987 {
3989 f,
3990 offset,
3991 offsets,
3992 max_offset,
3998 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3999 there's no point in iterating through the remaining
4000 elements of the array. */
4003 }
4004 }
4007 }
4009 /* Record all of the empty subobjects of TYPE (either a type or a
4010 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4011 is being placed at OFFSET; otherwise, it is a base class that is
4012 being placed at OFFSET. */
4014 static void
4016 tree offset,
4017 splay_tree offsets,
4019 {
4020 tree max_offset;
4021 /* If recording subobjects for a non-static data member or a
4022 non-empty base class , we do not need to record offsets beyond
4023 the size of the biggest empty class. Additional data members
4024 will go at the end of the class. Additional base classes will go
4025 either at offset zero (if empty, in which case they cannot
4026 overlap with offsets past the size of the biggest empty class) or
4027 at the end of the class.
4029 However, if we are placing an empty base class, then we must record
4030 all offsets, as either the empty class is at offset zero (where
4031 other empty classes might later be placed) or at the end of the
4032 class (where other objects might then be placed, so other empty
4033 subobjects might later overlap). */
4037 else
4041 }
4043 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4044 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4045 virtual bases of TYPE are examined. */
4047 static int
4049 tree offset,
4050 splay_tree offsets,
4052 {
4053 splay_tree_node max_node;
4055 /* Get the node in OFFSETS that indicates the maximum offset where
4056 an empty subobject is located. */
4058 /* If there aren't any empty subobjects, then there's no point in
4059 performing this check. */
4065 vbases_p);
4066 }
4068 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4069 non-static data member of the type indicated by RLI. BINFO is the
4070 binfo corresponding to the base subobject, OFFSETS maps offsets to
4071 types already located at those offsets. This function determines
4072 the position of the DECL. */
4074 static void
4076 tree decl,
4077 tree binfo,
4078 splay_tree offsets)
4079 {
4082 tree type;
4085 {
4086 /* For the purposes of determining layout conflicts, we want to
4087 use the class type of BINFO; TREE_TYPE (DECL) will be the
4088 CLASSTYPE_AS_BASE version, which does not contain entries for
4089 zero-sized bases. */
4092 }
4093 else
4094 {
4097 }
4099 /* Try to place the field. It may take more than one try if we have
4100 a hard time placing the field without putting two objects of the
4101 same type at the same address. */
4103 {
4106 /* Place this field. */
4110 /* We have to check to see whether or not there is already
4111 something of the same type at the offset we're about to use.
4112 For example, consider:
4114 struct S {};
4115 struct T : public S { int i; };
4116 struct U : public S, public T {};
4118 Here, we put S at offset zero in U. Then, we can't put T at
4119 offset zero -- its S component would be at the same address
4120 as the S we already allocated. So, we have to skip ahead.
4121 Since all data members, including those whose type is an
4122 empty class, have nonzero size, any overlap can happen only
4123 with a direct or indirect base-class -- it can't happen with
4124 a data member. */
4125 /* In a union, overlap is permitted; all members are placed at
4126 offset zero. */
4131 {
4132 /* Strip off the size allocated to this field. That puts us
4133 at the first place we could have put the field with
4134 proper alignment. */
4137 /* Bump up by the alignment required for the type. */
4138 rli->bitpos
4144 }
4145 else
4146 /* There was no conflict. We're done laying out this field. */
4148 }
4150 /* Now that we know where it will be placed, update its
4151 BINFO_OFFSET. */
4153 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4154 this point because their BINFO_OFFSET is copied from another
4155 hierarchy. Therefore, we may not need to add the entire
4156 OFFSET. */
4162 }
4164 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4166 static int
4168 tree offset,
4170 {
4172 }
4174 /* Layout the empty base BINFO. EOC indicates the byte currently just
4175 past the end of the class, and should be correctly aligned for a
4176 class of the type indicated by BINFO; OFFSETS gives the offsets of
4177 the empty bases allocated so far. T is the most derived
4178 type. Return nonzero iff we added it at the end. */
4180 static bool
4183 {
4184 tree alignment;
4188 /* This routine should only be used for empty classes. */
4193 propagate_binfo_offsets
4197 /* This is an empty base class. We first try to put it at offset
4198 zero. */
4201 offsets,
4203 {
4204 /* That didn't work. Now, we move forward from the next
4205 available spot in the class. */
4209 {
4212 offsets,
4214 /* We finally found a spot where there's no overlap. */
4217 /* There's overlap here, too. Bump along to the next spot. */
4219 }
4220 }
4223 {
4228 }
4231 }
4233 /* Layout the base given by BINFO in the class indicated by RLI.
4234 *BASE_ALIGN is a running maximum of the alignments of
4235 any base class. OFFSETS gives the location of empty base
4236 subobjects. T is the most derived type. Return nonzero if the new
4237 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4238 *NEXT_FIELD, unless BINFO is for an empty base class.
4240 Returns the location at which the next field should be inserted. */
4245 {
4250 /* This error is now reported in xref_tag, thus giving better
4251 location information. */
4254 /* Place the base class. */
4256 {
4257 tree decl;
4259 /* The containing class is non-empty because it has a non-empty
4260 base class. */
4263 /* Create the FIELD_DECL. */
4270 {
4278 /* Try to place the field. It may take more than one try if we
4279 have a hard time placing the field without putting two
4280 objects of the same type at the same address. */
4282 /* Add the new FIELD_DECL to the list of fields for T. */
4286 }
4287 }
4288 else
4289 {
4290 tree eoc;
4293 /* On some platforms (ARM), even empty classes will not be
4294 byte-aligned. */
4299 /* A nearly-empty class "has no proper base class that is empty,
4300 not morally virtual, and at an offset other than zero." */
4302 {
4305 /* The check above (used in G++ 3.2) is insufficient because
4306 an empty class placed at offset zero might itself have an
4307 empty base at a nonzero offset. */
4309 empty_base_at_nonzero_offset_p,
4310 size_zero_node,
4315 }
4317 /* We do not create a FIELD_DECL for empty base classes because
4318 it might overlap some other field. We want to be able to
4319 create CONSTRUCTORs for the class by iterating over the
4320 FIELD_DECLs, and the back end does not handle overlapping
4321 FIELD_DECLs. */
4323 /* An empty virtual base causes a class to be non-empty
4324 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4325 here because that was already done when the virtual table
4326 pointer was created. */
4327 }
4329 /* Record the offsets of BINFO and its base subobjects. */
4332 offsets,
4336 }
4338 /* Layout all of the non-virtual base classes. Record empty
4339 subobjects in OFFSETS. T is the most derived type. Return nonzero
4340 if the type cannot be nearly empty. The fields created
4341 corresponding to the base classes will be inserted at
4342 *NEXT_FIELD. */
4344 static void
4347 {
4348 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4349 subobjects. */
4354 /* The primary base class is always allocated first. */
4359 /* Now allocate the rest of the bases. */
4361 {
4362 tree base_binfo;
4366 /* The primary base was already allocated above, so we don't
4367 need to allocate it again here. */
4371 /* Virtual bases are added at the end (a primary virtual base
4372 will have already been added). */
4378 }
4379 }
4381 /* Go through the TYPE_METHODS of T issuing any appropriate
4382 diagnostics, figuring out which methods override which other
4383 methods, and so forth. */
4385 static void
4387 {
4388 tree x;
4391 {
4395 /* The name of the field is the original field name
4396 Save this in auxiliary field for later overloading. */
4398 {
4402 }
4403 /* All user-provided destructors are non-trivial.
4404 Constructors and assignment ops are handled in
4405 grok_special_member_properties. */
4408 }
4409 }
4411 /* FN is a constructor or destructor. Clone the declaration to create
4412 a specialized in-charge or not-in-charge version, as indicated by
4413 NAME. */
4415 static tree
4417 {
4418 tree parms;
4419 tree clone;
4421 /* Copy the function. */
4423 /* Reset the function name. */
4426 /* Remember where this function came from. */
4428 /* Make it easy to find the CLONE given the FN. */
4432 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4434 {
4441 }
4444 /* There's no pending inline data for this function. */
4448 /* The base-class destructor is not virtual. */
4450 {
4454 }
4456 /* If there was an in-charge parameter, drop it from the function
4457 type. */
4459 {
4460 tree basetype;
4461 tree parmtypes;
4462 tree exceptions;
4467 /* Skip the `this' parameter. */
4469 /* Skip the in-charge parameter. */
4471 /* And the VTT parm, in a complete [cd]tor. */
4475 /* If this is subobject constructor or destructor, add the vtt
4476 parameter. */
4480 parmtypes);
4483 exceptions);
4487 }
4489 /* Copy the function parameters. */
4491 /* Remove the in-charge parameter. */
4493 {
4497 }
4498 /* And the VTT parm, in a complete [cd]tor. */
4500 {
4503 else
4504 {
4508 }
4509 }
4512 {
4515 }
4517 /* Create the RTL for this function. */
4525 }
4527 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4528 not invoke this function directly.
4530 For a non-thunk function, returns the address of the slot for storing
4531 the function it is a clone of. Otherwise returns NULL_TREE.
4533 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4534 cloned_function is unset. This is to support the separate
4535 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4536 on a template makes sense, but not the former. */
4538 tree *
4540 {
4548 {
4549 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4552 else
4553 #endif
4555 }
4560 else
4562 }
4564 /* Produce declarations for all appropriate clones of FN. If
4565 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4566 CLASTYPE_METHOD_VEC as well. */
4568 void
4570 {
4571 tree clone;
4573 /* Avoid inappropriate cloning. */
4579 {
4580 /* For each constructor, we need two variants: an in-charge version
4581 and a not-in-charge version. */
4588 }
4589 else
4590 {
4593 /* For each destructor, we need three variants: an in-charge
4594 version, a not-in-charge version, and an in-charge deleting
4595 version. We clone the deleting version first because that
4596 means it will go second on the TYPE_METHODS list -- and that
4597 corresponds to the correct layout order in the virtual
4598 function table.
4600 For a non-virtual destructor, we do not build a deleting
4601 destructor. */
4603 {
4607 }
4614 }
4616 /* Note that this is an abstract function that is never emitted. */
4618 }
4620 /* DECL is an in charge constructor, which is being defined. This will
4621 have had an in class declaration, from whence clones were
4622 declared. An out-of-class definition can specify additional default
4623 arguments. As it is the clones that are involved in overload
4624 resolution, we must propagate the information from the DECL to its
4625 clones. */
4627 void
4629 {
4630 tree clone;
4634 {
4641 /* Skip the 'this' parameter. */
4657 {
4662 {
4663 /* A default parameter has been added. Adjust the
4664 clone's parameters. */
4668 tree type;
4673 {
4676 clone_parms);
4678 }
4681 clone_parms);
4690 }
4691 }
4693 }
4694 }
4696 /* For each of the constructors and destructors in T, create an
4697 in-charge and not-in-charge variant. */
4699 static void
4701 {
4702 tree fns;
4704 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4705 out now. */
4713 }
4715 /* Deduce noexcept for a destructor DTOR. */
4717 void
4719 {
4721 {
4724 }
4725 }
4727 /* For each destructor in T, deduce noexcept:
4729 12.4/3: A declaration of a destructor that does not have an
4730 exception-specification is implicitly considered to have the
4731 same exception-specification as an implicit declaration (15.4). */
4733 static void
4735 {
4736 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4737 out now. */
4743 }
4745 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4746 of TYPE for virtual functions which FNDECL overrides. Return a
4747 mask of the tm attributes found therein. */
4749 static int
4751 {
4753 tree base_binfo;
4757 {
4767 else
4769 }
4772 }
4774 /* Subroutine of set_method_tm_attributes. Handle the checks and
4775 inheritance for one virtual method FNDECL. */
4777 static void
4779 {
4780 tree tm_attr;
4785 /* If FNDECL doesn't actually override anything (i.e. T is the
4786 class that first declares FNDECL virtual), then we're done. */
4793 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4794 tm_pure must match exactly, otherwise no weakening of
4795 tm_safe > tm_callable > nothing. */
4796 /* ??? The tm_pure attribute didn't make the transition to the
4797 multivendor language spec. */
4799 {
4801 {
4804 }
4805 }
4806 /* If the overridden function is tm_pure, then FNDECL must be. */
4809 /* Look for base class combinations that cannot be satisfied. */
4811 {
4817 }
4818 /* If FNDECL did not declare an attribute, then inherit the most
4819 restrictive one. */
4821 {
4823 }
4824 /* Otherwise validate that we're not weaker than a function
4825 that is being overridden. */
4826 else
4827 {
4831 }
4834 err_override:
4838 }
4840 /* For each of the methods in T, propagate a class-level tm attribute. */
4842 static void
4844 {
4847 /* Don't bother collecting tm attributes if transactional memory
4848 support is not enabled. */
4852 /* Process virtual methods first, as they inherit directly from the
4853 base virtual function and also require validation of new attributes. */
4855 {
4856 tree vchain;
4859 {
4864 }
4865 }
4867 /* If the class doesn't have an attribute, nothing more to do. */
4872 /* Any method that does not yet have a tm attribute inherits
4873 the one from the class. */
4875 {
4878 }
4879 }
4881 /* Returns true iff class T has a user-defined constructor other than
4882 the default constructor. */
4884 bool
4886 {
4887 tree fns;
4893 {
4900 }
4903 }
4905 /* Returns the defaulted constructor if T has one. Otherwise, returns
4906 NULL_TREE. */
4908 tree
4910 {
4917 {
4921 {
4927 }
4928 }
4931 }
4933 /* Returns true iff FN is a user-provided function, i.e. user-declared
4934 and not defaulted at its first declaration; or explicit, private,
4935 protected, or non-const. */
4937 bool
4939 {
4942 else
4946 }
4948 /* Returns true iff class T has a user-provided constructor. */
4950 bool
4952 {
4953 tree fns;
4961 /* This can happen in error cases; avoid crashing. */
4970 }
4972 /* Returns true iff class T has a user-provided default constructor. */
4974 bool
4976 {
4977 tree fns;
4983 {
4989 }
4992 }
4994 /* TYPE is being used as a virtual base, and has a non-trivial move
4995 assignment. Return true if this is due to there being a user-provided
4996 move assignment in TYPE or one of its subobjects; if there isn't, then
4997 multiple move assignment can't cause any harm. */
4999 bool
5001 {
5002 /* Does the type itself have a user-provided move assignment operator? */
5006 {
5010 }
5012 /* Do any of its bases? */
5014 tree base_binfo;
5019 /* Or non-static data members? */
5021 {
5026 }
5028 /* Seems not. */
5030 }
5032 /* If default-initialization leaves part of TYPE uninitialized, returns
5033 a DECL for the field or TYPE itself (DR 253). */
5035 tree
5037 {
5048 {
5052 }
5057 {
5061 }
5064 }
5066 /* Returns true iff for class T, a trivial synthesized default constructor
5067 would be constexpr. */
5069 bool
5071 {
5072 /* A defaulted trivial default constructor is constexpr
5073 if there is nothing to initialize. */
5076 }
5078 /* Returns true iff class T has a constexpr default constructor. */
5080 bool
5082 {
5083 tree fns;
5086 {
5087 /* The caller should have stripped an enclosing array. */
5090 }
5092 {
5095 /* Non-trivial, we need to check subobject constructors. */
5097 }
5100 }
5102 /* Returns true iff class TYPE has a virtual destructor. */
5104 bool
5106 {
5107 tree dtor;
5115 }
5117 /* Returns true iff class T has a move constructor. */
5119 bool
5121 {
5122 tree fns;
5125 {
5128 }
5138 }
5140 /* Returns true iff class T has a move assignment operator. */
5142 bool
5144 {
5145 tree fns;
5148 {
5151 }
5159 }
5161 /* Returns true iff class T has a move constructor that was explicitly
5162 declared in the class body. Note that this is different from
5163 "user-provided", which doesn't include functions that are defaulted in
5164 the class. */
5166 bool
5168 {
5169 tree fns;
5178 {
5182 }
5185 }
5187 /* Returns true iff class T has a move assignment operator that was
5188 explicitly declared in the class body. */
5190 bool
5192 {
5193 tree fns;
5200 {
5204 }
5207 }
5209 /* Nonzero if we need to build up a constructor call when initializing an
5210 object of this class, either because it has a user-declared constructor
5211 or because it doesn't have a default constructor (so we need to give an
5212 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5213 what you care about is whether or not an object can be produced by a
5214 constructor (e.g. so we don't set TREE_READONLY on const variables of
5215 such type); use this function when what you care about is whether or not
5216 to try to call a constructor to create an object. The latter case is
5217 the former plus some cases of constructors that cannot be called. */
5219 bool
5221 {
5222 tree inner;
5232 /* A user-declared constructor might be private, and a constructor might
5233 be trivial but deleted. */
5236 {
5241 }
5243 }
5245 /* Like type_build_ctor_call, but for destructors. */
5247 bool
5249 {
5250 tree inner;
5259 /* A user-declared destructor might be private, and a destructor might
5260 be trivial but deleted. */
5263 {
5268 }
5270 }
5272 /* Remove all zero-width bit-fields from T. */
5274 static void
5276 {
5281 {
5284 /* We should not be confused by the fact that grokbitfield
5285 temporarily sets the width of the bit field into
5286 DECL_INITIAL (*fieldsp).
5287 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5288 to that width. */
5291 else
5293 }
5294 }
5296 /* Returns TRUE iff we need a cookie when dynamically allocating an
5297 array whose elements have the indicated class TYPE. */
5299 static bool
5301 {
5302 tree fns;
5307 /* If there's a non-trivial destructor, we need a cookie. In order
5308 to iterate through the array calling the destructor for each
5309 element, we'll have to know how many elements there are. */
5313 /* If the usual deallocation function is a two-argument whose second
5314 argument is of type `size_t', then we have to pass the size of
5315 the array to the deallocation function, so we will need to store
5316 a cookie. */
5320 /* If there are no `operator []' members, or the lookup is
5321 ambiguous, then we don't need a cookie. */
5324 /* Loop through all of the functions. */
5326 {
5327 tree fn;
5328 tree second_parm;
5330 /* Select the current function. */
5332 /* See if this function is a one-argument delete function. If
5333 it is, then it will be the usual deallocation function. */
5337 /* Do not consider this function if its second argument is an
5338 ellipsis. */
5341 /* Otherwise, if we have a two-argument function and the second
5342 argument is `size_t', it will be the usual deallocation
5343 function -- unless there is one-argument function, too. */
5347 }
5350 }
5352 /* Finish computing the `literal type' property of class type T.
5354 At this point, we have already processed base classes and
5355 non-static data members. We need to check whether the copy
5356 constructor is trivial, the destructor is trivial, and there
5357 is a trivial default constructor or at least one constexpr
5358 constructor other than the copy constructor. */
5360 static void
5362 {
5363 tree fn;
5379 {
5382 {
5386 }
5387 }
5388 }
5390 /* T is a non-literal type used in a context which requires a constant
5391 expression. Explain why it isn't literal. */
5393 void
5395 {
5405 /* Already explained. */
5414 {
5416 "default constructor, and has no constexpr constructor that "
5420 {
5421 /* Note that we can't simply call locate_ctor because when the
5422 constructor is deleted it just returns NULL_TREE. */
5423 tree fns;
5425 {
5432 {
5435 else
5438 }
5439 }
5440 }
5441 }
5442 else
5443 {
5447 {
5450 {
5455 }
5456 }
5458 {
5459 tree ftype;
5464 {
5469 }
5470 }
5471 }
5472 }
5474 /* Check the validity of the bases and members declared in T. Add any
5475 implicitly-generated functions (like copy-constructors and
5476 assignment operators). Compute various flag bits (like
5477 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5478 level: i.e., independently of the ABI in use. */
5480 static void
5482 {
5483 /* Nonzero if the implicitly generated copy constructor should take
5484 a non-const reference argument. */
5486 /* Nonzero if the implicitly generated assignment operator
5487 should take a non-const reference argument. */
5489 tree access_decls;
5492 tree fn;
5494 /* Pick up any abi_tags from our template arguments before checking. */
5497 /* By default, we use const reference arguments and generate default
5498 constructors. */
5502 /* Check all the base-classes. */
5506 /* Deduce noexcept on destructors. This needs to happen after we've set
5507 triviality flags appropriately for our bases. */
5511 /* Check all the method declarations. */
5514 /* Save the initial values of these flags which only indicate whether
5515 or not the class has user-provided functions. As we analyze the
5516 bases and members we can set these flags for other reasons. */
5520 /* Check all the data member declarations. We cannot call
5521 check_field_decls until we have called check_bases check_methods,
5522 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5523 being set appropriately. */
5528 /* A nearly-empty class has to be vptr-containing; a nearly empty
5529 class contains just a vptr. */
5533 /* Do some bookkeeping that will guide the generation of implicitly
5534 declared member functions. */
5537 /* We need to call a constructor for this class if it has a
5538 user-provided constructor, or if the default constructor is going
5539 to initialize the vptr. (This is not an if-and-only-if;
5540 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5541 themselves need constructing.) */
5544 /* [dcl.init.aggr]
5546 An aggregate is an array or a class with no user-provided
5547 constructors ... and no virtual functions.
5549 Again, other conditions for being an aggregate are checked
5550 elsewhere. */
5553 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5554 retain the old definition internally for ABI reasons. */
5563 /* Warn if a public base of a polymorphic type has an accessible
5564 non-virtual destructor. It is only now that we know the class is
5565 polymorphic. Although a polymorphic base will have a already
5566 been diagnosed during its definition, we warn on use too. */
5568 {
5571 tree base_binfo;
5575 {
5583 basetype);
5584 }
5585 }
5587 /* If the class has no user-declared constructor, but does have
5588 non-static const or reference data members that can never be
5589 initialized, issue a warning. */
5591 /* Classes with user-declared constructors are presumed to
5592 initialize these members. */
5594 /* Aggregates can be initialized with brace-enclosed
5595 initializers. */
5597 {
5598 tree field;
5601 {
5602 tree type;
5617 }
5618 }
5620 /* Synthesize any needed methods. */
5622 cant_have_const_ctor,
5623 no_const_asn_ref);
5625 /* Check defaulted declarations here so we have cant_have_const_ctor
5626 and don't need to worry about clones. */
5629 {
5632 {
5633 bool imp_const_p
5639 /* If the function is defaulted outside the class, we just
5640 give the synthesis error. */
5643 }
5645 }
5648 {
5649 /* "The closure type associated with a lambda-expression has a deleted
5650 default constructor and a deleted copy assignment operator." */
5656 /* "This class type is not an aggregate." */
5658 }
5660 /* Compute the 'literal type' property before we
5661 do anything with non-static member functions. */
5664 /* Create the in-charge and not-in-charge variants of constructors
5665 and destructors. */
5668 /* Process the using-declarations. */
5672 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5675 /* Figure out whether or not we will need a cookie when dynamically
5676 allocating an array of this type. */
5679 }
5681 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5682 accordingly. If a new vfield was created (because T doesn't have a
5683 primary base class), then the newly created field is returned. It
5684 is not added to the TYPE_FIELDS list; it is the caller's
5685 responsibility to do that. Accumulate declared virtual functions
5686 on VIRTUALS_P. */
5688 static tree
5690 {
5691 tree fn;
5693 /* Collect the virtual functions declared in T. */
5698 {
5707 }
5709 /* If we couldn't find an appropriate base class, create a new field
5710 here. Even if there weren't any new virtual functions, we might need a
5711 new virtual function table if we're supposed to include vptrs in
5712 all classes that need them. */
5714 {
5715 /* We build this decl with vtbl_ptr_type_node, which is a
5716 `vtable_entry_type*'. It might seem more precise to use
5717 `vtable_entry_type (*)[N]' where N is the number of virtual
5718 functions. However, that would require the vtable pointer in
5719 base classes to have a different type than the vtable pointer
5720 in derived classes. We could make that happen, but that
5721 still wouldn't solve all the problems. In particular, the
5722 type-based alias analysis code would decide that assignments
5723 to the base class vtable pointer can't alias assignments to
5724 the derived class vtable pointer, since they have different
5725 types. Thus, in a derived class destructor, where the base
5726 class constructor was inlined, we could generate bad code for
5727 setting up the vtable pointer.
5729 Therefore, we use one type for all vtable pointers. We still
5730 use a type-correct type; it's just doesn't indicate the array
5731 bounds. That's better than using `void*' or some such; it's
5732 cleaner, and it let's the alias analysis code know that these
5733 stores cannot alias stores to void*! */
5734 tree field;
5747 /* This class is non-empty. */
5751 }
5754 }
5756 /* Add OFFSET to all base types of BINFO which is a base in the
5757 hierarchy dominated by T.
5759 OFFSET, which is a type offset, is number of bytes. */
5761 static void
5763 {
5765 tree primary_binfo;
5766 tree base_binfo;
5768 /* Update BINFO's offset. */
5773 offset));
5775 /* Find the primary base class. */
5781 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5782 downwards. */
5784 {
5785 /* Don't do the primary base twice. */
5793 }
5794 }
5796 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5797 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5798 empty subobjects of T. */
5800 static void
5802 {
5803 tree vbase;
5810 /* Find the last field. The artificial fields created for virtual
5811 bases will go after the last extant field to date. */
5816 /* Go through the virtual bases, allocating space for each virtual
5817 base that is not already a primary base class. These are
5818 allocated in inheritance graph order. */
5820 {
5825 {
5826 /* This virtual base is not a primary base of any class in the
5827 hierarchy, so we have to add space for it. */
5830 }
5831 }
5832 }
5834 /* Returns the offset of the byte just past the end of the base class
5835 BINFO. */
5837 static tree
5839 {
5840 tree size;
5845 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5846 allocate some space for it. It cannot have virtual bases, so
5847 TYPE_SIZE_UNIT is fine. */
5849 else
5853 }
5855 /* Returns the offset of the byte just past the end of the base class
5856 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5857 only non-virtual bases are included. */
5859 static tree
5861 {
5864 tree binfo;
5865 tree base_binfo;
5866 tree offset;
5871 {
5881 }
5886 {
5890 }
5893 }
5895 /* Warn about bases of T that are inaccessible because they are
5896 ambiguous. For example:
5898 struct S {};
5899 struct T : public S {};
5900 struct U : public S, public T {};
5902 Here, `(S*) new U' is not allowed because there are two `S'
5903 subobjects of U. */
5905 static void
5907 {
5910 tree basetype;
5911 tree binfo;
5912 tree base_binfo;
5914 /* If there are no repeated bases, nothing can be ambiguous. */
5918 /* Check direct bases. */
5921 {
5927 }
5929 /* Check for ambiguous virtual bases. */
5933 {
5939 }
5940 }
5942 /* Compare two INTEGER_CSTs K1 and K2. */
5944 static int
5946 {
5948 }
5950 /* Increase the size indicated in RLI to account for empty classes
5951 that are "off the end" of the class. */
5953 static void
5955 {
5956 tree eoc;
5957 tree rli_size;
5959 /* It might be the case that we grew the class to allocate a
5960 zero-sized base class. That won't be reflected in RLI, yet,
5961 because we are willing to overlay multiple bases at the same
5962 offset. However, now we need to make sure that RLI is big enough
5963 to reflect the entire class. */
5969 {
5970 /* The size should have been rounded to a whole byte. */
5973 rli->bitpos
5982 }
5983 }
5985 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5986 BINFO_OFFSETs for all of the base-classes. Position the vtable
5987 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5989 static void
5991 {
5992 tree non_static_data_members;
5993 tree field;
5994 tree vptr;
5995 record_layout_info rli;
5996 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5997 types that appear at that offset. */
5998 splay_tree empty_base_offsets;
5999 /* True if the last field laid out was a bit-field. */
6001 /* The location at which the next field should be inserted. */
6003 /* T, as a base class. */
6004 tree base_t;
6006 /* Keep track of the first non-static data member. */
6009 /* Start laying out the record. */
6012 /* Mark all the primary bases in the hierarchy. */
6015 /* Create a pointer to our virtual function table. */
6018 /* The vptr is always the first thing in the class. */
6020 {
6025 }
6026 else
6029 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6034 /* Layout the non-static data members. */
6036 {
6037 tree type;
6038 tree padding;
6040 /* We still pass things that aren't non-static data members to
6041 the back end, in case it wants to do something with them. */
6043 {
6045 /* If the static data member has incomplete type, keep track
6046 of it so that it can be completed later. (The handling
6047 of pending statics in finish_record_layout is
6048 insufficient; consider:
6050 struct S1;
6051 struct S2 { static S1 s1; };
6053 At this point, finish_record_layout will be called, but
6054 S1 is still incomplete.) */
6056 {
6058 /* The visibility of static data members is determined
6059 at their point of declaration, not their point of
6060 definition. */
6062 }
6064 }
6072 /* If this field is a bit-field whose width is greater than its
6073 type, then there are some special rules for allocating
6074 it. */
6077 {
6079 tree integer_type;
6081 /* We must allocate the bits as if suitably aligned for the
6082 longest integer type that fits in this many bits. type
6083 of the field. Then, we are supposed to use the left over
6084 bits as additional padding. */
6093 /* ITK now indicates a type that is too large for the
6094 field. We have to back up by one to find the largest
6095 type that fits. */
6096 do
6097 {
6102 /* Figure out how much additional padding is required. */
6104 {
6106 /* In a union, the padding field must have the full width
6107 of the bit-field; all fields start at offset zero. */
6109 else
6112 }
6113 #ifdef PCC_BITFIELD_TYPE_MATTERS
6114 /* An unnamed bitfield does not normally affect the
6115 alignment of the containing class on a target where
6116 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6117 make any exceptions for unnamed bitfields when the
6118 bitfields are longer than their types. Therefore, we
6119 temporarily give the field a name. */
6121 {
6124 }
6125 #endif
6130 empty_base_offsets);
6133 /* Now that layout has been performed, set the size of the
6134 field to the size of its declared type; the rest of the
6135 field is effectively invisible. */
6137 /* We must also reset the DECL_MODE of the field. */
6139 }
6140 else
6142 empty_base_offsets);
6144 /* Remember the location of any empty classes in FIELD. */
6147 empty_base_offsets,
6150 /* If a bit-field does not immediately follow another bit-field,
6151 and yet it starts in the middle of a byte, we have failed to
6152 comply with the ABI. */
6155 /* The TREE_NO_WARNING flag gets set by Objective-C when
6156 laying out an Objective-C class. The ObjC ABI differs
6157 from the C++ ABI, and so we do not want a warning
6158 here. */
6160 && !last_field_was_bitfield
6163 bitsize_unit_node)))
6167 /* The middle end uses the type of expressions to determine the
6168 possible range of expression values. In order to optimize
6169 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6170 must be made aware of the width of "i", via its type.
6172 Because C++ does not have integer types of arbitrary width,
6173 we must (for the purposes of the front end) convert from the
6174 type assigned here to the declared type of the bitfield
6175 whenever a bitfield expression is used as an rvalue.
6176 Similarly, when assigning a value to a bitfield, the value
6177 must be converted to the type given the bitfield here. */
6179 {
6184 {
6191 }
6192 }
6194 /* If we needed additional padding after this field, add it
6195 now. */
6197 {
6198 tree padding_field;
6201 FIELD_DECL,
6202 NULL_TREE,
6203 char_type_node);
6210 NULL_TREE,
6211 empty_base_offsets);
6212 }
6215 }
6218 {
6219 /* Make sure that we are on a byte boundary so that the size of
6220 the class without virtual bases will always be a round number
6221 of bytes. */
6224 }
6226 /* Delete all zero-width bit-fields from the list of fields. Now
6227 that the type is laid out they are no longer important. */
6230 /* Create the version of T used for virtual bases. We do not use
6231 make_class_type for this version; this is an artificial type. For
6232 a POD type, we just reuse T. */
6234 {
6237 /* Set the size and alignment for the new type. */
6238 tree eoc;
6240 /* If the ABI version is not at least two, and the last
6241 field was a bit-field, RLI may not be on a byte
6242 boundary. In particular, rli_size_unit_so_far might
6243 indicate the last complete byte, while rli_size_so_far
6244 indicates the total number of bits used. Therefore,
6245 rli_size_so_far, rather than rli_size_unit_so_far, is
6246 used to compute TYPE_SIZE_UNIT. */
6254 eoc);
6264 /* Copy the fields from T. */
6268 {
6270 FIELD_DECL,
6280 }
6282 /* Record the base version of the type. */
6285 }
6286 else
6289 /* Every empty class contains an empty class. */
6293 /* Set the TYPE_DECL for this type to contain the right
6294 value for DECL_OFFSET, so that we can use it as part
6295 of a COMPONENT_REF for multiple inheritance. */
6298 /* Now fix up any virtual base class types that we left lying
6299 around. We must get these done before we try to lay out the
6300 virtual function table. As a side-effect, this will remove the
6301 base subobject fields. */
6304 /* Make sure that empty classes are reflected in RLI at this
6305 point. */
6308 /* Make sure not to create any structures with zero size. */
6314 /* If this is a non-POD, declaring it packed makes a difference to how it
6315 can be used as a field; don't let finalize_record_size undo it. */
6319 /* Let the back end lay out the type. */
6328 /* Warn about bases that can't be talked about due to ambiguity. */
6331 /* Now that we're done with layout, give the base fields the real types. */
6336 /* Clean up. */
6343 }
6345 /* Determine the "key method" for the class type indicated by TYPE,
6346 and set CLASSTYPE_KEY_METHOD accordingly. */
6348 void
6350 {
6351 tree method;
6354 || processing_template_decl
6359 /* The key method is the first non-pure virtual function that is not
6360 inline at the point of class definition. On some targets the
6361 key function may not be inline; those targets should not call
6362 this function until the end of the translation unit. */
6369 {
6372 }
6375 }
6378 /* Allocate and return an instance of struct sorted_fields_type with
6379 N fields. */
6383 {
6390 }
6393 /* Perform processing required when the definition of T (a class type)
6394 is complete. */
6396 void
6398 {
6399 tree x;
6400 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6404 {
6409 }
6411 /* If this type was previously laid out as a forward reference,
6412 make sure we lay it out again. */
6416 /* Make assumptions about the class; we'll reset the flags if
6417 necessary. */
6423 /* Do end-of-class semantic processing: checking the validity of the
6424 bases and members and add implicitly generated methods. */
6427 /* Find the key method. */
6429 {
6430 /* The Itanium C++ ABI permits the key method to be chosen when
6431 the class is defined -- even though the key method so
6432 selected may later turn out to be an inline function. On
6433 some systems (such as ARM Symbian OS) the key method cannot
6434 be determined until the end of the translation unit. On such
6435 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6436 will cause the class to be added to KEYED_CLASSES. Then, in
6437 finish_file we will determine the key method. */
6441 /* If a polymorphic class has no key method, we may emit the vtable
6442 in every translation unit where the class definition appears. */
6445 }
6447 /* Layout the class itself. */
6450 /* We use the base type for trivial assignments, and hence it
6451 needs a mode. */
6456 /* If necessary, create the primary vtable for this class. */
6458 {
6459 /* We must enter these virtuals into the table. */
6463 /* Here we know enough to change the type of our virtual
6464 function table, but we will wait until later this function. */
6467 /* If we're warning about ABI tags, check the types of the new
6468 virtual functions. */
6472 }
6475 {
6477 tree fn;
6484 /* Add entries for virtual functions introduced by this class. */
6488 /* Set DECL_VINDEX for all functions declared in this class. */
6490 fn;
6492 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6494 {
6498 /* A thunk. We should never be calling this entry directly
6499 from this vtable -- we'd use the entry for the non
6500 thunk base function. */
6504 }
6505 }
6510 /* Complete the rtl for any static member objects of the type we're
6511 working on. */
6518 /* Done with FIELDS...now decide whether to sort these for
6519 faster lookups later.
6521 We use a small number because most searches fail (succeeding
6522 ultimately as the search bores through the inheritance
6523 hierarchy), and we want this failure to occur quickly. */
6527 /* Complain if one of the field types requires lower visibility. */
6530 /* Make the rtl for any new vtables we have created, and unmark
6531 the base types we marked. */
6534 /* Build the VTT for T. */
6537 /* This warning does not make sense for Java classes, since they
6538 cannot have destructors. */
6542 "%q#T has virtual functions and accessible"
6550 /* Class layout, assignment of virtual table slots, etc., is now
6551 complete. Give the back end a chance to tweak the visibility of
6552 the class or perform any other required target modifications. */
6562 /* Finish debugging output for this type. */
6566 {
6569 {
6572 }
6574 {
6577 else
6578 {
6581 }
6583 }
6585 {
6587 "the type of the first field has a different ABI from the "
6590 }
6591 }
6592 }
6594 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6595 equal to THRESHOLD or greater than THRESHOLD. */
6597 static void
6599 {
6602 {
6607 }
6608 }
6610 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6612 void
6614 {
6617 {
6619 int n_fields
6630 }
6631 }
6633 /* When T was built up, the member declarations were added in reverse
6634 order. Rearrange them to declaration order. */
6636 void
6638 {
6639 tree next;
6640 tree prev;
6641 tree x;
6643 /* The following lists are all in reverse order. Put them in
6644 declaration order now. */
6648 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6649 reverse order, so we can't just use nreverse. */
6654 {
6658 }
6660 {
6664 }
6665 }
6667 tree
6669 {
6672 /* Now that we've got all the field declarations, reverse everything
6673 as necessary. */
6678 /* Nadger the current location so that diagnostics point to the start of
6679 the struct, not the end. */
6683 {
6684 tree x;
6690 /* We need to emit an error message if this type was used as a parameter
6691 and it is an abstract type, even if it is a template. We construct
6692 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6693 account and we call complete_vars with this type, which will check
6694 the PARM_DECLS. Note that while the type is being defined,
6695 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6696 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6702 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6703 an enclosing scope is a template class, so that this function be
6704 found by lookup_fnfields_1 when the using declaration is not
6705 instantiated yet. */
6708 {
6713 }
6715 /* Remember current #pragma pack value. */
6718 /* Fix up any variants we've already built. */
6720 {
6725 }
6726 }
6727 else
6736 else
6740 /* Lambdas are defined by the LAMBDA_EXPR. */
6745 }
6746 \f
6747 /* Hash table to avoid endless recursion when handling references. */
6750 /* Return the dynamic type of INSTANCE, if known.
6751 Used to determine whether the virtual function table is needed
6752 or not.
6754 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6755 of our knowledge of its type. *NONNULL should be initialized
6756 before this function is called. */
6758 static tree
6760 {
6761 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6764 {
6768 else
6772 /* This is a call to a constructor, hence it's never zero. */
6774 {
6778 }
6782 /* This is a call to a constructor, hence it's never zero. */
6784 {
6788 }
6797 /* Propagate nonnull. */
6802 CASE_CONVERT:
6808 {
6809 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6810 with a real object -- given &p->f, p can still be null. */
6812 /* ??? Probably should check DECL_WEAK here. */
6815 }
6819 /* If this component is really a base class reference, then the field
6820 itself isn't definitive. */
6829 {
6833 }
6834 /* fall through... */
6839 {
6843 }
6845 {
6849 /* if we're in a ctor or dtor, we know our type. If
6850 current_class_ptr is set but we aren't in a function, we're in
6851 an NSDMI (and therefore a constructor). */
6856 {
6860 }
6861 }
6863 {
6864 /* We only need one hash table because it is always left empty. */
6866 fixed_type_or_null_ref_ht
6869 /* Reference variables should be references to objects. */
6873 /* Enter the INSTANCE in a table to prevent recursion; a
6874 variable's initializer may refer to the variable
6875 itself. */
6880 {
6881 tree type;
6890 }
6891 }
6896 }
6897 #undef RECUR
6898 }
6900 /* Return nonzero if the dynamic type of INSTANCE is known, and
6901 equivalent to the static type. We also handle the case where
6902 INSTANCE is really a pointer. Return negative if this is a
6903 ctor/dtor. There the dynamic type is known, but this might not be
6904 the most derived base of the original object, and hence virtual
6905 bases may not be laid out according to this type.
6907 Used to determine whether the virtual function table is needed
6908 or not.
6910 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6911 of our knowledge of its type. *NONNULL should be initialized
6912 before this function is called. */
6914 int
6916 {
6919 tree fixed;
6921 /* processing_template_decl can be false in a template if we're in
6922 fold_non_dependent_expr, but we still want to suppress this check. */
6924 {
6925 /* In a template we only care about the type of the result. */
6929 }
6939 }
6941 \f
6942 void
6944 {
6947 current_class_stack
6955 }
6957 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6959 static void
6961 {
6962 tree type;
6964 /* We are re-entering the same class we just left, so we don't
6965 have to search the whole inheritance matrix to find all the
6966 decls to bind again. Instead, we install the cached
6967 class_shadowed list and walk through it binding names. */
6970 /* Restore IDENTIFIER_TYPE_VALUE. */
6972 type;
6975 }
6977 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6978 appropriate for TYPE.
6980 So that we may avoid calls to lookup_name, we cache the _TYPE
6981 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6983 For multiple inheritance, we perform a two-pass depth-first search
6984 of the type lattice. */
6986 void
6988 {
6989 class_stack_node_t csn;
6993 /* Make sure there is enough room for the new entry on the stack. */
6995 {
6997 current_class_stack
6999 current_class_stack_size);
7000 }
7002 /* Insert a new entry on the class stack. */
7009 current_class_depth++;
7011 /* Now set up the new type. */
7017 /* By default, things in classes are private, while things in
7018 structures or unions are public. */
7020 ? access_private_node
7026 {
7027 /* Forcibly remove any old class remnants. */
7029 }
7035 else
7037 }
7039 /* When we exit a toplevel class scope, we save its binding level so
7040 that we can restore it quickly. Here, we've entered some other
7041 class, so we must invalidate our cache. */
7043 void
7045 {
7047 }
7049 /* Get out of the current class scope. If we were in a class scope
7050 previously, that is the one popped to. */
7052 void
7054 {
7057 current_class_depth--;
7063 }
7065 /* Mark the top of the class stack as hidden. */
7067 void
7069 {
7072 }
7074 /* Mark the top of the class stack as un-hidden. */
7076 void
7078 {
7081 }
7083 /* Returns 1 if the class type currently being defined is either T or
7084 a nested type of T. */
7086 bool
7088 {
7096 /* We start looking from 1 because entry 0 is from global scope,
7097 and has no type. */
7099 {
7100 tree c;
7103 else
7104 {
7108 }
7113 }
7115 }
7117 /* If either current_class_type or one of its enclosing classes are derived
7118 from T, return the appropriate type. Used to determine how we found
7119 something via unqualified lookup. */
7121 tree
7123 {
7126 /* The bases of a dependent type are unknown. */
7137 {
7142 }
7145 }
7147 /* Returns the innermost class type which is not a lambda closure type. */
7149 tree
7151 {
7154 /* We start looking from 1 because entry 0 is from global scope,
7155 and has no type. */
7157 {
7158 tree c;
7161 else
7162 {
7166 }
7171 }
7173 }
7175 /* When entering a class scope, all enclosing class scopes' names with
7176 static meaning (static variables, static functions, types and
7177 enumerators) have to be visible. This recursive function calls
7178 pushclass for all enclosing class contexts until global or a local
7179 scope is reached. TYPE is the enclosed class. */
7181 void
7183 {
7184 /* A namespace might be passed in error cases, like A::B:C. */
7192 }
7194 /* Undoes a push_nested_class call. */
7196 void
7198 {
7204 }
7206 /* Returns the number of extern "LANG" blocks we are nested within. */
7208 int
7210 {
7212 }
7214 /* Set global variables CURRENT_LANG_NAME to appropriate value
7215 so that behavior of name-mangling machinery is correct. */
7217 void
7219 {
7223 {
7225 }
7227 {
7229 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7230 (See record_builtin_java_type in decl.c.) However, that causes
7231 incorrect debug entries if these types are actually used.
7232 So we re-enable debug output after extern "Java". */
7241 }
7243 {
7245 }
7246 else
7248 }
7250 /* Get out of the current language scope. */
7252 void
7254 {
7256 }
7257 \f
7258 /* Type instantiation routines. */
7260 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7261 matches the TARGET_TYPE. If there is no satisfactory match, return
7262 error_mark_node, and issue an error & warning messages under
7263 control of FLAGS. Permit pointers to member function if FLAGS
7264 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7265 a template-id, and EXPLICIT_TARGS are the explicitly provided
7266 template arguments.
7268 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7269 is the base path used to reference those member functions. If
7270 the address is resolved to a member function, access checks will be
7271 performed and errors issued if appropriate. */
7273 static tree
7275 tree overload,
7276 tsubst_flags_t flags,
7278 tree explicit_targs,
7279 tree access_path)
7280 {
7281 /* Here's what the standard says:
7283 [over.over]
7285 If the name is a function template, template argument deduction
7286 is done, and if the argument deduction succeeds, the deduced
7287 arguments are used to generate a single template function, which
7288 is added to the set of overloaded functions considered.
7290 Non-member functions and static member functions match targets of
7291 type "pointer-to-function" or "reference-to-function." Nonstatic
7292 member functions match targets of type "pointer-to-member
7293 function;" the function type of the pointer to member is used to
7294 select the member function from the set of overloaded member
7295 functions. If a nonstatic member function is selected, the
7296 reference to the overloaded function name is required to have the
7297 form of a pointer to member as described in 5.3.1.
7299 If more than one function is selected, any template functions in
7300 the set are eliminated if the set also contains a non-template
7301 function, and any given template function is eliminated if the
7302 set contains a second template function that is more specialized
7303 than the first according to the partial ordering rules 14.5.5.2.
7304 After such eliminations, if any, there shall remain exactly one
7305 selected function. */
7308 /* We store the matches in a TREE_LIST rooted here. The functions
7309 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7310 interoperability with most_specialized_instantiation. */
7312 tree fn;
7313 tree target_fn_type;
7315 /* By the time we get here, we should be seeing only real
7316 pointer-to-member types, not the internal POINTER_TYPE to
7317 METHOD_TYPE representation. */
7323 /* Check that the TARGET_TYPE is reasonable. */
7328 /* This is OK, too. */
7331 /* This is OK, too. This comes from a conversion to reference
7332 type. */
7334 else
7335 {
7341 }
7343 /* Non-member functions and static member functions match targets of type
7344 "pointer-to-function" or "reference-to-function." Nonstatic member
7345 functions match targets of type "pointer-to-member-function;" the
7346 function type of the pointer to member is used to select the member
7347 function from the set of overloaded member functions.
7349 So figure out the FUNCTION_TYPE that we want to match against. */
7352 /* If we can find a non-template function that matches, we can just
7353 use it. There's no point in generating template instantiations
7354 if we're just going to throw them out anyhow. But, of course, we
7355 can only do this when we don't *need* a template function. */
7357 {
7358 tree fns;
7361 {
7365 /* We're not looking for templates just yet. */
7370 /* We're looking for a non-static member, and this isn't
7371 one, or vice versa. */
7374 /* Ignore functions which haven't been explicitly
7375 declared. */
7379 /* See if there's a match. */
7382 }
7383 }
7385 /* Now, if we've already got a match (or matches), there's no need
7386 to proceed to the template functions. But, if we don't have a
7387 match we need to look at them, too. */
7389 {
7390 tree target_arg_types;
7391 tree target_ret_type;
7392 tree fns;
7395 tree arg;
7409 {
7411 tree instantiation;
7412 tree targs;
7415 /* We're only looking for templates. */
7420 /* We're not looking for a non-static member, and this is
7421 one, or vice versa. */
7426 /* If the template has a deduced return type, don't expose it to
7427 template argument deduction. */
7431 /* Try to do argument deduction. */
7438 /* Instantiation failed. */
7441 /* And now force instantiation to do return type deduction. */
7443 {
7449 }
7451 /* See if there's a match. */
7454 }
7456 /* Now, remove all but the most specialized of the matches. */
7458 {
7463 NULL_TREE,
7464 NULL_TREE);
7465 }
7466 }
7468 /* Now we should have exactly one function in MATCHES. */
7470 {
7471 /* There were *no* matches. */
7473 {
7476 target_type);
7479 }
7481 }
7483 {
7484 /* There were too many matches. First check if they're all
7485 the same function. */
7490 /* For multi-versioned functions, more than one match is just fine and
7491 decls_match will return false as they are different. */
7499 {
7501 {
7504 target_type);
7506 /* Since print_candidates expects the functions in the
7507 TREE_VALUE slot, we flip them here. */
7512 }
7515 }
7516 }
7518 /* Good, exactly one match. Now, convert it to the correct type. */
7523 {
7531 {
7534 }
7535 }
7537 /* If a pointer to a function that is multi-versioned is requested, the
7538 pointer to the dispatcher function is returned instead. This works
7539 well because indirectly calling the function will dispatch the right
7540 function version at run-time. */
7542 {
7546 /* Mark all the versions corresponding to the dispatcher as used. */
7549 }
7551 /* If we're doing overload resolution purely for the purpose of
7552 determining conversion sequences, we should not consider the
7553 function used. If this conversion sequence is selected, the
7554 function will be marked as used at this point. */
7556 {
7557 /* Make =delete work with SFINAE. */
7562 }
7564 /* We could not check access to member functions when this
7565 expression was originally created since we did not know at that
7566 time to which function the expression referred. */
7568 {
7571 }
7575 else
7576 {
7577 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7578 will mark the function as addressed, but here we must do it
7579 explicitly. */
7583 }
7584 }
7586 /* This function will instantiate the type of the expression given in
7587 RHS to match the type of LHSTYPE. If errors exist, then return
7588 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7589 we complain on errors. If we are not complaining, never modify rhs,
7590 as overload resolution wants to try many possible instantiations, in
7591 the hope that at least one will work.
7593 For non-recursive calls, LHSTYPE should be a function, pointer to
7594 function, or a pointer to member function. */
7596 tree
7598 {
7605 {
7609 }
7612 {
7619 /* Microsoft allows `A::f' to be resolved to a
7620 pointer-to-member. */
7621 ;
7622 else
7623 {
7628 }
7629 }
7632 {
7635 }
7637 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7638 deduce any type information. */
7640 {
7644 }
7646 /* There only a few kinds of expressions that may have a type
7647 dependent on overload resolution. */
7653 /* This should really only be used when attempting to distinguish
7654 what sort of a pointer to function we have. For now, any
7655 arithmetic operation which is not supported on pointers
7656 is rejected as an error. */
7659 {
7661 {
7667 /* Do not lose object's side effects. */
7671 }
7678 /* This can happen if we are forming a pointer-to-member for a
7679 member template. */
7682 /* Fall through. */
7685 {
7689 return
7693 }
7697 return
7701 access_path);
7704 {
7709 }
7716 }
7718 }
7719 \f
7720 /* Return the name of the virtual function pointer field
7721 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7722 this may have to look back through base types to find the
7723 ultimate field name. (For single inheritance, these could
7724 all be the same name. Who knows for multiple inheritance). */
7726 static tree
7728 {
7735 {
7741 }
7749 }
7751 void
7753 {
7760 {
7765 }
7766 }
7768 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7769 according to [class]:
7770 The class-name is also inserted
7771 into the scope of the class itself. For purposes of access checking,
7772 the inserted class name is treated as if it were a public member name. */
7774 void
7776 {
7779 tree saved_cas;
7794 }
7796 /* Returns 1 if TYPE contains only padding bytes. */
7798 int
7800 {
7808 }
7810 /* Returns true if TYPE contains an empty class. */
7812 static bool
7814 {
7818 {
7819 tree field;
7820 tree binfo;
7821 tree base_binfo;
7833 }
7837 }
7839 /* Returns true if TYPE contains no actual data, just various
7840 possible combinations of empty classes and possibly a vptr. */
7842 bool
7844 {
7846 {
7847 tree field;
7848 tree binfo;
7849 tree base_binfo;
7852 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7853 out, but we'd like to be able to check this before then. */
7867 }
7871 }
7873 /* Note that NAME was looked up while the current class was being
7874 defined and that the result of that lookup was DECL. */
7876 void
7878 {
7879 splay_tree names_used;
7881 /* If we're not defining a class, there's nothing to do. */
7887 /* If there's already a binding for this NAME, then we don't have
7888 anything to worry about. */
7901 }
7903 /* Note that NAME was declared (as DECL) in the current class. Check
7904 to see that the declaration is valid. */
7906 void
7908 {
7909 splay_tree names_used;
7910 splay_tree_node n;
7912 /* Look to see if we ever used this name. */
7913 names_used
7917 /* The C language allows members to be declared with a type of the same
7918 name, and the C++ standard says this diagnostic is not required. So
7919 allow it in extern "C" blocks unless predantic is specified.
7920 Allow it in all cases if -ms-extensions is specified. */
7926 {
7927 /* [basic.scope.class]
7929 A name N used in a class S shall refer to the same declaration
7930 in its context and when re-evaluated in the completed scope of
7931 S. */
7935 }
7936 }
7938 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7939 Secondary vtables are merged with primary vtables; this function
7940 will return the VAR_DECL for the primary vtable. */
7942 tree
7944 {
7945 tree decl;
7949 {
7952 }
7956 }
7959 /* Returns the binfo for the primary base of BINFO. If the resulting
7960 BINFO is a virtual base, and it is inherited elsewhere in the
7961 hierarchy, then the returned binfo might not be the primary base of
7962 BINFO in the complete object. Check BINFO_PRIMARY_P or
7963 BINFO_LOST_PRIMARY_P to be sure. */
7965 static tree
7967 {
7968 tree primary_base;
7975 }
7977 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7979 static int
7981 {
7985 }
7987 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7988 INDENT should be zero when called from the top level; it is
7989 incremented recursively. IGO indicates the next expected BINFO in
7990 inheritance graph ordering. */
7992 static tree
7995 tree binfo,
7996 tree igo,
7998 {
8000 tree base_binfo;
8008 {
8011 }
8026 {
8030 TFF_PLAIN_IDENTIFIER),
8032 }
8034 {
8037 }
8042 {
8046 {
8050 TFF_PLAIN_IDENTIFIER));
8051 }
8053 {
8057 TFF_PLAIN_IDENTIFIER));
8058 }
8060 {
8064 TFF_PLAIN_IDENTIFIER));
8065 }
8067 {
8071 TFF_PLAIN_IDENTIFIER));
8072 }
8076 }
8082 }
8084 /* Dump the BINFO hierarchy for T. */
8086 static void
8088 {
8100 }
8102 /* Debug interface to hierarchy dumping. */
8104 void
8106 {
8108 }
8110 static void
8112 {
8117 {
8119 }
8120 }
8122 static void
8124 {
8125 tree value;
8127 HOST_WIDE_INT elt;
8135 TFF_PLAIN_IDENTIFIER));
8142 }
8144 static void
8146 {
8154 {
8161 {
8166 }
8170 }
8171 }
8173 static void
8175 {
8183 {
8188 }
8189 }
8191 /* Dump a function or thunk and its thunkees. */
8193 static void
8195 {
8198 tree thunks;
8206 {
8216 else
8222 }
8226 }
8228 /* Dump the thunks for FN. */
8230 void
8232 {
8234 }
8236 /* Virtual function table initialization. */
8238 /* Create all the necessary vtables for T and its base classes. */
8240 static void
8242 {
8243 tree vbase;
8247 /* We lay out the primary and secondary vtables in one contiguous
8248 vtable. The primary vtable is first, followed by the non-virtual
8249 secondary vtables in inheritance graph order. */
8253 /* Then come the virtual bases, also in inheritance graph order. */
8255 {
8259 }
8263 }
8265 /* Initialize the vtable for BINFO with the INITS. */
8267 static void
8269 {
8270 tree decl;
8276 }
8278 /* Build the VTT (virtual table table) for T.
8279 A class requires a VTT if it has virtual bases.
8281 This holds
8282 1 - primary virtual pointer for complete object T
8283 2 - secondary VTTs for each direct non-virtual base of T which requires a
8284 VTT
8285 3 - secondary virtual pointers for each direct or indirect base of T which
8286 has virtual bases or is reachable via a virtual path from T.
8287 4 - secondary VTTs for each direct or indirect virtual base of T.
8289 Secondary VTTs look like complete object VTTs without part 4. */
8291 static void
8293 {
8294 tree type;
8295 tree vtt;
8296 tree index;
8299 /* Build up the initializers for the VTT. */
8304 /* If we didn't need a VTT, we're done. */
8308 /* Figure out the type of the VTT. */
8312 /* Now, build the VTT object itself. */
8315 /* Add the VTT to the vtables list. */
8320 }
8322 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8323 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8324 and CHAIN the vtable pointer for this binfo after construction is
8325 complete. VALUE can also be another BINFO, in which case we recurse. */
8327 static tree
8329 {
8330 tree vt;
8333 {
8339 else
8341 }
8344 }
8346 /* Data for secondary VTT initialization. */
8348 {
8349 /* Is this the primary VTT? */
8352 /* Current index into the VTT. */
8353 tree index;
8355 /* Vector of initializers built up. */
8358 /* The type being constructed by this secondary VTT. */
8359 tree type_being_constructed;
8362 /* Recursively build the VTT-initializer for BINFO (which is in the
8363 hierarchy dominated by T). INITS points to the end of the initializer
8364 list to date. INDEX is the VTT index where the next element will be
8365 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8366 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8367 for virtual bases of T. When it is not so, we build the constructor
8368 vtables for the BINFO-in-T variant. */
8370 static void
8373 {
8375 tree b;
8376 tree init;
8377 secondary_vptr_vtt_init_data data;
8380 /* We only need VTTs for subobjects with virtual bases. */
8384 /* We need to use a construction vtable if this is not the primary
8385 VTT. */
8387 {
8390 /* Record the offset in the VTT where this sub-VTT can be found. */
8392 }
8394 /* Add the address of the primary vtable for the complete object. */
8398 {
8401 }
8404 /* Recursively add the secondary VTTs for non-virtual bases. */
8409 /* Add secondary virtual pointers for all subobjects of BINFO with
8410 either virtual bases or reachable along a virtual path, except
8411 subobjects that are non-virtual primary bases. */
8421 /* data.inits might have grown as we added secondary virtual pointers.
8422 Make sure our caller knows about the new vector. */
8426 /* Add the secondary VTTs for virtual bases in inheritance graph
8427 order. */
8429 {
8434 }
8435 else
8436 /* Remove the ctor vtables we created. */
8438 }
8440 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8441 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8443 static tree
8445 {
8448 /* We don't care about bases that don't have vtables. */
8452 /* We're only interested in proper subobjects of the type being
8453 constructed. */
8457 /* We're only interested in bases with virtual bases or reachable
8458 via a virtual path from the type being constructed. */
8463 /* We're not interested in non-virtual primary bases. */
8467 /* Record the index where this secondary vptr can be found. */
8469 {
8474 {
8475 /* It's a primary virtual base, and this is not a
8476 construction vtable. Find the base this is primary of in
8477 the inheritance graph, and use that base's vtable
8478 now. */
8481 }
8482 }
8484 /* Add the initializer for the secondary vptr itself. */
8487 /* Advance the vtt index. */
8492 }
8494 /* Called from build_vtt_inits via dfs_walk. After building
8495 constructor vtables and generating the sub-vtt from them, we need
8496 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8497 binfo of the base whose sub vtt was generated. */
8499 static tree
8501 {
8505 /* If this class has no vtable, none of its bases do. */
8509 /* This might be a primary base, so have no vtable in this
8510 hierarchy. */
8513 /* If we scribbled the construction vtable vptr into BINFO, clear it
8514 out now. */
8520 }
8522 /* Build the construction vtable group for BINFO which is in the
8523 hierarchy dominated by T. */
8525 static void
8527 {
8528 tree type;
8529 tree vtbl;
8530 tree id;
8531 tree vbase;
8534 /* See if we've already created this construction vtable group. */
8540 /* Build a version of VTBL (with the wrong type) for use in
8541 constructing the addresses of secondary vtables in the
8542 construction vtable group. */
8545 /* Don't export construction vtables from shared libraries. Even on
8546 targets that don't support hidden visibility, this tells
8547 can_refer_decl_in_current_unit_p not to assume that it's safe to
8548 access from a different compilation unit (bz 54314). */
8556 /* Add the vtables for each of our virtual bases using the vbase in T
8557 binfo. */
8559 vbase;
8561 {
8562 tree b;
8569 }
8571 /* Figure out the type of the construction vtable. */
8578 /* Initialize the construction vtable. */
8582 }
8584 /* Add the vtbl initializers for BINFO (and its bases other than
8585 non-virtual primaries) to the list of INITS. BINFO is in the
8586 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8587 the constructor the vtbl inits should be accumulated for. (If this
8588 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8589 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8590 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8591 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8592 but are not necessarily the same in terms of layout. */
8594 static void
8596 tree orig_binfo,
8597 tree rtti_binfo,
8598 tree vtbl,
8599 tree t,
8601 {
8603 tree base_binfo;
8608 /* If it doesn't have a vptr, we don't do anything. */
8612 /* If we're building a construction vtable, we're not interested in
8613 subobjects that don't require construction vtables. */
8619 /* Build the initializers for the BINFO-in-T vtable. */
8622 /* Walk the BINFO and its bases. We walk in preorder so that as we
8623 initialize each vtable we can figure out at what offset the
8624 secondary vtable lies from the primary vtable. We can't use
8625 dfs_walk here because we need to iterate through bases of BINFO
8626 and RTTI_BINFO simultaneously. */
8628 {
8629 /* Skip virtual bases. */
8635 inits);
8636 }
8637 }
8639 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8640 BINFO vtable to L. */
8642 static void
8644 tree orig_binfo,
8645 tree rtti_binfo,
8646 tree orig_vtbl,
8647 tree t,
8649 {
8656 {
8657 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8658 primary virtual base. If it is not the same primary in
8659 the hierarchy of T, we'll need to generate a ctor vtable
8660 for it, to place at its location in T. If it is the same
8661 primary, we still need a VTT entry for the vtable, but it
8662 should point to the ctor vtable for the base it is a
8663 primary for within the sub-hierarchy of RTTI_BINFO.
8665 There are three possible cases:
8667 1) We are in the same place.
8668 2) We are a primary base within a lost primary virtual base of
8669 RTTI_BINFO.
8670 3) We are primary to something not a base of RTTI_BINFO. */
8672 tree b;
8675 /* First, look through the bases we are primary to for RTTI_BINFO
8676 or a virtual base. */
8679 {
8684 }
8685 /* If we run out of primary links, keep looking down our
8686 inheritance chain; we might be an indirect primary. */
8690 found:
8692 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8693 base B and it is a base of RTTI_BINFO, this is case 2. In
8694 either case, we share our vtable with LAST, i.e. the
8695 derived-most base within B of which we are a primary. */
8698 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8699 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8700 binfo_ctor_vtable after everything's been set up. */
8703 /* Otherwise, this is case 3 and we get our own. */
8704 }
8711 {
8712 tree index;
8715 /* Add the initializer for this vtable. */
8719 /* Figure out the position to which the VPTR should point. */
8725 }
8728 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8729 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8730 straighten this out. */
8733 /* Throw away any unneeded intializers. */
8735 else
8736 /* For an ordinary vtable, set BINFO_VTABLE. */
8738 }
8742 /* Construct the initializer for BINFO's virtual function table. BINFO
8743 is part of the hierarchy dominated by T. If we're building a
8744 construction vtable, the ORIG_BINFO is the binfo we should use to
8745 find the actual function pointers to put in the vtable - but they
8746 can be overridden on the path to most-derived in the graph that
8747 ORIG_BINFO belongs. Otherwise,
8748 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8749 BINFO that should be indicated by the RTTI information in the
8750 vtable; it will be a base class of T, rather than T itself, if we
8751 are building a construction vtable.
8753 The value returned is a TREE_LIST suitable for wrapping in a
8754 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8755 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8756 number of non-function entries in the vtable.
8758 It might seem that this function should never be called with a
8759 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8760 base is always subsumed by a derived class vtable. However, when
8761 we are building construction vtables, we do build vtables for
8762 primary bases; we need these while the primary base is being
8763 constructed. */
8765 static void
8767 tree orig_binfo,
8768 tree t,
8769 tree rtti_binfo,
8772 {
8773 tree v;
8774 vtbl_init_data vid;
8776 tree vbinfo;
8780 /* Initialize VID. */
8788 /* The first vbase or vcall offset is at index -3 in the vtable. */
8791 /* Add entries to the vtable for RTTI. */
8794 /* Create an array for keeping track of the functions we've
8795 processed. When we see multiple functions with the same
8796 signature, we share the vcall offsets. */
8798 /* Add the vcall and vbase offset entries. */
8801 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8802 build_vbase_offset_vtbl_entries. */
8807 /* If the target requires padding between data entries, add that now. */
8809 {
8814 /* Move data entries into their new positions and add padding
8815 after the new positions. Iterate backwards so we don't
8816 overwrite entries that we would need to process later. */
8819 ix--)
8820 {
8828 {
8832 null_pointer_node);
8833 }
8834 }
8835 }
8840 /* The initializers for virtual functions were built up in reverse
8841 order. Straighten them out and add them to the running list in one
8842 step. */
8851 /* Go through all the ordinary virtual functions, building up
8852 initializers. */
8854 {
8855 tree delta;
8856 tree vcall_index;
8863 {
8867 {
8870 }
8872 }
8874 /* If the only definition of this function signature along our
8875 primary base chain is from a lost primary, this vtable slot will
8876 never be used, so just zero it out. This is important to avoid
8877 requiring extra thunks which cannot be generated with the function.
8879 We first check this in update_vtable_entry_for_fn, so we handle
8880 restored primary bases properly; we also need to do it here so we
8881 zero out unused slots in ctor vtables, rather than filling them
8882 with erroneous values (though harmless, apart from relocation
8883 costs). */
8888 {
8889 /* Pull the offset for `this', and the function to call, out of
8890 the list. */
8897 /* You can't call an abstract virtual function; it's abstract.
8898 So, we replace these functions with __pure_virtual. */
8900 {
8903 {
8905 abort_fndecl_addr
8909 }
8910 }
8911 /* Likewise for deleted virtuals. */
8913 {
8922 }
8923 else
8924 {
8926 {
8930 }
8931 /* Take the address of the function, considering it to be of an
8932 appropriate generic type. */
8936 /* Don't refer to a virtual destructor from a constructor
8937 vtable or a vtable for an abstract class, since destroying
8938 an object under construction is undefined behavior and we
8939 don't want it to be considered a candidate for speculative
8940 devirtualization. But do create the thunk for ABI
8941 compliance. */
8946 }
8947 }
8949 /* And add it to the chain of initializers. */
8951 {
8956 else
8958 {
8964 }
8965 }
8966 else
8968 }
8969 }
8971 /* Adds to vid->inits the initializers for the vbase and vcall
8972 offsets in BINFO, which is in the hierarchy dominated by T. */
8974 static void
8976 {
8977 tree b;
8979 /* If this is a derived class, we must first create entries
8980 corresponding to the primary base class. */
8985 /* Add the vbase entries for this base. */
8987 /* Add the vcall entries for this base. */
8989 }
8991 /* Returns the initializers for the vbase offset entries in the vtable
8992 for BINFO (which is part of the class hierarchy dominated by T), in
8993 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8994 where the next vbase offset will go. */
8996 static void
8998 {
8999 tree vbase;
9000 tree t;
9001 tree non_primary_binfo;
9003 /* If there are no virtual baseclasses, then there is nothing to
9004 do. */
9010 /* We might be a primary base class. Go up the inheritance hierarchy
9011 until we find the most derived class of which we are a primary base:
9012 it is the offset of that which we need to use. */
9015 {
9016 tree b;
9018 /* If we have reached a virtual base, then it must be a primary
9019 base (possibly multi-level) of vid->binfo, or we wouldn't
9020 have called build_vcall_and_vbase_vtbl_entries for it. But it
9021 might be a lost primary, so just skip down to vid->binfo. */
9023 {
9026 }
9032 }
9034 /* Go through the virtual bases, adding the offsets. */
9036 vbase;
9038 {
9039 tree b;
9040 tree delta;
9045 /* Find the instance of this virtual base in the complete
9046 object. */
9049 /* If we've already got an offset for this virtual base, we
9050 don't need another one. */
9055 /* Figure out where we can find this vbase offset. */
9064 /* The vbase offset had better be the same. */
9067 /* The next vbase will come at a more negative offset. */
9071 /* The initializer is the delta from BINFO to this virtual base.
9072 The vbase offsets go in reverse inheritance-graph order, and
9073 we are walking in inheritance graph order so these end up in
9074 the right order. */
9081 }
9082 }
9084 /* Adds the initializers for the vcall offset entries in the vtable
9085 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9086 to VID->INITS. */
9088 static void
9090 {
9091 /* We only need these entries if this base is a virtual base. We
9092 compute the indices -- but do not add to the vtable -- when
9093 building the main vtable for a class. */
9096 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9097 correspond to VID->DERIVED), we are building a primary
9098 construction virtual table. Since this is a primary
9099 virtual table, we do not need the vcall offsets for
9100 BINFO. */
9102 {
9103 /* We need a vcall offset for each of the virtual functions in this
9104 vtable. For example:
9106 class A { virtual void f (); };
9107 class B1 : virtual public A { virtual void f (); };
9108 class B2 : virtual public A { virtual void f (); };
9109 class C: public B1, public B2 { virtual void f (); };
9111 A C object has a primary base of B1, which has a primary base of A. A
9112 C also has a secondary base of B2, which no longer has a primary base
9113 of A. So the B2-in-C construction vtable needs a secondary vtable for
9114 A, which will adjust the A* to a B2* to call f. We have no way of
9115 knowing what (or even whether) this offset will be when we define B2,
9116 so we store this "vcall offset" in the A sub-vtable and look it up in
9117 a "virtual thunk" for B2::f.
9119 We need entries for all the functions in our primary vtable and
9120 in our non-virtual bases' secondary vtables. */
9122 /* If we are just computing the vcall indices -- but do not need
9123 the actual entries -- not that. */
9126 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9128 }
9129 }
9131 /* Build vcall offsets, starting with those for BINFO. */
9133 static void
9135 {
9137 tree primary_binfo;
9138 tree base_binfo;
9140 /* Don't walk into virtual bases -- except, of course, for the
9141 virtual base for which we are building vcall offsets. Any
9142 primary virtual base will have already had its offsets generated
9143 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9147 /* If BINFO has a primary base, process it first. */
9152 /* Add BINFO itself to the list. */
9155 /* Scan the non-primary bases of BINFO. */
9159 }
9161 /* Called from build_vcall_offset_vtbl_entries_r. */
9163 static void
9165 {
9166 /* Make entries for the rest of the virtuals. */
9167 tree orig_fn;
9169 /* The ABI requires that the methods be processed in declaration
9170 order. */
9172 orig_fn;
9176 }
9178 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9180 static void
9182 {
9184 tree vcall_offset;
9185 tree derived_entry;
9187 /* If there is already an entry for a function with the same
9188 signature as FN, then we do not need a second vcall offset.
9189 Check the list of functions already present in the derived
9190 class vtable. */
9192 {
9194 /* We only use one vcall offset for virtual destructors,
9195 even though there are two virtual table entries. */
9199 }
9201 /* If we are building these vcall offsets as part of building
9202 the vtable for the most derived class, remember the vcall
9203 offset. */
9205 {
9208 }
9210 /* The next vcall offset will be found at a more negative
9211 offset. */
9215 /* Keep track of this function. */
9219 {
9220 tree base;
9221 tree fn;
9223 /* Find the overriding function. */
9227 else
9228 {
9231 /* The vbase we're working on is a primary base of
9232 vid->binfo. But it might be a lost primary, so its
9233 BINFO_OFFSET might be wrong, so we just use the
9234 BINFO_OFFSET from vid->binfo. */
9240 vcall_offset);
9241 }
9242 /* Add the initializer to the vtable. */
9244 }
9245 }
9247 /* Return vtbl initializers for the RTTI entries corresponding to the
9248 BINFO's vtable. The RTTI entries should indicate the object given
9249 by VID->rtti_binfo. */
9251 static void
9253 {
9254 tree b;
9255 tree t;
9256 tree offset;
9257 tree decl;
9258 tree init;
9262 /* To find the complete object, we will first convert to our most
9263 primary base, and then add the offset in the vtbl to that value. */
9267 {
9268 tree primary_base;
9274 }
9278 /* The second entry is the address of the typeinfo object. */
9281 else
9284 /* Convert the declaration to a type that can be stored in the
9285 vtable. */
9289 /* Add the offset-to-top entry. It comes earlier in the vtable than
9290 the typeinfo entry. Convert the offset to look like a
9291 function pointer, so that we can put it in the vtable. */
9294 }
9296 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9297 accessibility. */
9299 bool
9301 {
9304 }
9306 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9308 bool
9310 {
9314 }
9316 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9317 class between them, if any. */
9319 tree
9321 {
9333 {
9336 }
9340 }