| blob | 3d34b92cfb1b22ecc5cc4da5e34f775bd54a3fce |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2013 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. */
40 /* The number of nested classes being processed. If we are not in the
41 scope of any class, this is zero. */
45 /* In order to deal with nested classes, we keep a stack of classes.
46 The topmost entry is the innermost class, and is the entry at index
47 CURRENT_CLASS_DEPTH */
50 /* The name of the class. */
51 tree name;
53 /* The _TYPE node for the class. */
54 tree type;
56 /* The access specifier pending for new declarations in the scope of
57 this class. */
58 tree access;
60 /* If were defining TYPE, the names used in this class. */
61 splay_tree names_used;
63 /* Nonzero if this class is no longer open, because of a call to
64 push_to_top_level. */
69 {
70 /* The base for which we're building initializers. */
71 tree binfo;
72 /* The type of the most-derived type. */
73 tree derived;
74 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
75 unless ctor_vtbl_p is true. */
76 tree rtti_binfo;
77 /* The negative-index vtable initializers built up so far. These
78 are in order from least negative index to most negative index. */
80 /* The binfo for the virtual base for which we're building
81 vcall offset initializers. */
82 tree vbase;
83 /* The functions in vbase for which we have already provided vcall
84 offsets. */
86 /* The vtable index of the next vcall or vbase offset. */
87 tree index;
88 /* Nonzero if we are building the initializer for the primary
89 vtable. */
91 /* Nonzero if we are building the initializer for a construction
92 vtable. */
94 /* True when adding vcall offset entries to the vtable. False when
95 merely computing the indices. */
99 /* The type of a function passed to walk_subobject_offsets. */
102 /* The stack itself. This is a dynamically resized array. The
103 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
107 /* The size of the largest empty class seen in this translation unit. */
110 /* An array of all local classes present in this translation unit, in
111 declaration order. */
193 tree *);
203 splay_tree_key k2);
212 /* Variables shared between class.c and call.c. */
222 /* Convert to or from a base subobject. EXPR is an expression of type
223 `A' or `A*', an expression of type `B' or `B*' is returned. To
224 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
225 the B base instance within A. To convert base A to derived B, CODE
226 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
227 In this latter case, A must not be a morally virtual base of B.
228 NONNULL is true if EXPR is known to be non-NULL (this is only
229 needed when EXPR is of pointer type). CV qualifiers are preserved
230 from EXPR. */
232 tree
234 tree expr,
235 tree binfo,
237 tsubst_flags_t complain)
238 {
241 tree probe;
242 tree offset;
243 tree target_type;
245 tree ptr_target_type;
255 {
261 }
269 {
270 /* This can happen when adjust_result_of_qualified_name_lookup can't
271 find a unique base binfo in a call to a member function. We
272 couldn't give the diagnostic then since we might have been calling
273 a static member function, so we do it now. */
275 {
279 }
281 }
288 /* Nothing to do. */
292 {
294 {
296 {
299 "pointer to derived class %qT because the base is "
301 else
305 }
306 else
307 {
313 else
317 }
318 }
320 }
323 /* This must happen before the call to save_expr. */
325 else
331 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
332 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
333 expression returned matches the input. */
334 target_type = cp_build_qualified_type
338 /* Do we need to look in the vtable for the real offset? */
341 /* Don't bother with the calculations inside sizeof; they'll ICE if the
342 source type is incomplete and the pointer value doesn't matter. In a
343 template (even in fold_non_dependent_expr), we don't have vtables set
344 up properly yet, and the value doesn't matter there either; we're just
345 interested in the result of overload resolution. */
348 {
353 }
355 /* If we're in an NSDMI, we don't have the full constructor context yet
356 that we need for converting to a virtual base, so just build a stub
357 CONVERT_EXPR and expand it later in bot_replace. */
360 {
366 }
368 /* Do we need to check for a null pointer? */
370 {
371 /* If we know the conversion will not actually change the value
372 of EXPR, then we can avoid testing the expression for NULL.
373 We have to avoid generating a COMPONENT_REF for a base class
374 field, because other parts of the compiler know that such
375 expressions are always non-NULL. */
379 }
381 /* Protect against multiple evaluation if necessary. */
385 /* Now that we've saved expr, build the real null test. */
387 {
391 }
393 /* If this is a simple base reference, express it as a COMPONENT_REF. */
395 /* We don't build base fields for empty bases, and they aren't very
396 interesting to the optimizers anyway. */
398 {
405 }
408 {
409 /* Going via virtual base V_BINFO. We need the static offset
410 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
411 V_BINFO. That offset is an entry in D_BINFO's vtable. */
412 tree v_offset;
415 {
416 /* In a base member initializer, we cannot rely on the
417 vtable being set up. We have to indirect via the
418 vtt_parm. */
419 tree t;
425 }
426 else
428 complain),
434 v_offset);
446 /* Negative fixed_type_p means this is a constructor or destructor;
447 virtual base layout is fixed in in-charge [cd]tors, but not in
448 base [cd]tors. */
452 v_offset,
455 else
457 }
465 {
470 }
471 else
477 out:
483 }
485 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
486 Perform a derived-to-base conversion by recursively building up a
487 sequence of COMPONENT_REFs to the appropriate base fields. */
489 static tree
491 {
494 tree field;
497 {
498 tree temp;
502 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
503 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
504 an lvalue in the front end; only _DECLs and _REFs are lvalues
505 in the back end. */
511 }
513 /* Recurse. */
518 /* Is this the base field created by build_base_field? */
522 /* If we're looking for a field in the most-derived class,
523 also check the field offset; we can have two base fields
524 of the same type if one is an indirect virtual base and one
525 is a direct non-virtual base. */
529 {
530 /* We don't use build_class_member_access_expr here, as that
531 has unnecessary checks, and more importantly results in
532 recursive calls to dfs_walk_once. */
540 /* Mark the expression const or volatile, as appropriate.
541 Even though we've dealt with the type above, we still have
542 to mark the expression itself. */
549 }
551 /* Didn't find the base field?!? */
553 }
555 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
556 type is a class type or a pointer to a class type. In the former
557 case, TYPE is also a class type; in the latter it is another
558 pointer type. If CHECK_ACCESS is true, an error message is emitted
559 if TYPE is inaccessible. If OBJECT has pointer type, the value is
560 assumed to be non-NULL. */
562 tree
564 tsubst_flags_t complain)
565 {
566 tree binfo;
567 tree object_type;
570 {
573 }
574 else
583 }
585 /* EXPR is an expression with unqualified class type. BASE is a base
586 binfo of that class type. Returns EXPR, converted to the BASE
587 type. This function assumes that EXPR is the most derived class;
588 therefore virtual bases can be found at their static offsets. */
590 tree
592 {
593 tree expr_type;
597 {
598 /* If this is a non-empty base, use a COMPONENT_REF. */
602 /* We use fold_build2 and fold_convert below to simplify the trees
603 provided to the optimizers. It is not safe to call these functions
604 when processing a template because they do not handle C++-specific
605 trees. */
613 }
616 }
618 \f
619 tree
621 {
627 /* First, convert to the requested type. */
632 /* Second, the requested type may not be the owner of its own vptr.
633 If not, convert to the base class that owns it. We cannot use
634 convert_to_base here, because VCONTEXT may appear more than once
635 in the inheritance hierarchy of TYPE, and thus direct conversion
636 between the types may be ambiguous. Following the path back up
637 one step at a time via primary bases avoids the problem. */
641 {
644 }
647 }
649 /* Given an object INSTANCE, return an expression which yields the
650 vtable element corresponding to INDEX. There are many special
651 cases for INSTANCE which we take care of here, mainly to avoid
652 creating extra tree nodes when we don't have to. */
654 static tree
656 {
657 tree aref;
660 /* Try to figure out what a reference refers to, and
661 access its virtual function table directly. */
669 {
674 }
683 }
685 tree
687 {
691 }
693 /* Given a stable object pointer INSTANCE_PTR, return an expression which
694 yields a function pointer corresponding to vtable element INDEX. */
696 tree
698 {
699 tree aref;
702 tf_warning_or_error),
703 idx);
705 /* When using function descriptors, the address of the
706 vtable entry is treated as a function pointer. */
711 /* Remember this as a method reference, for later devirtualization. */
715 }
717 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
718 for the given TYPE. */
720 static tree
722 {
724 }
726 /* DECL is an entity associated with TYPE, like a virtual table or an
727 implicitly generated constructor. Determine whether or not DECL
728 should have external or internal linkage at the object file
729 level. This routine does not deal with COMDAT linkage and other
730 similar complexities; it simply sets TREE_PUBLIC if it possible for
731 entities in other translation units to contain copies of DECL, in
732 the abstract. */
734 void
736 {
739 }
741 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
742 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
743 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
745 static tree
747 {
748 tree decl;
751 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
752 now to avoid confusion in mangle_decl. */
761 /* At one time the vtable info was grabbed 2 words at a time. This
762 fails on sparc unless you have 8-byte alignment. (tiemann) */
766 /* The vtable has not been defined -- yet. */
770 /* Mark the VAR_DECL node representing the vtable itself as a
771 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
772 is rather important that such things be ignored because any
773 effort to actually generate DWARF for them will run into
774 trouble when/if we encounter code like:
776 #pragma interface
777 struct S { virtual void member (); };
779 because the artificial declaration of the vtable itself (as
780 manufactured by the g++ front end) will say that the vtable is
781 a static member of `S' but only *after* the debug output for
782 the definition of `S' has already been output. This causes
783 grief because the DWARF entry for the definition of the vtable
784 will try to refer back to an earlier *declaration* of the
785 vtable as a static member of `S' and there won't be one. We
786 might be able to arrange to have the "vtable static member"
787 attached to the member list for `S' before the debug info for
788 `S' get written (which would solve the problem) but that would
789 require more intrusive changes to the g++ front end. */
793 }
795 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
796 or even complete. If this does not exist, create it. If COMPLETE is
797 nonzero, then complete the definition of it -- that will render it
798 impossible to actually build the vtable, but is useful to get at those
799 which are known to exist in the runtime. */
801 tree
803 {
804 tree decl;
813 {
816 }
819 }
821 /* Build the primary virtual function table for TYPE. If BINFO is
822 non-NULL, build the vtable starting with the initial approximation
823 that it is the same as the one which is the head of the association
824 list. Returns a nonzero value if a new vtable is actually
825 created. */
827 static int
829 {
830 tree decl;
831 tree virtuals;
836 {
838 /* We have already created a vtable for this base, so there's
839 no need to do it again. */
846 }
847 else
848 {
851 }
854 {
857 }
859 /* Initialize the association list for this type, based
860 on our first approximation. */
865 }
867 /* Give BINFO a new virtual function table which is initialized
868 with a skeleton-copy of its original initialization. The only
869 entry that changes is the `delta' entry, so we can really
870 share a lot of structure.
872 FOR_TYPE is the most derived type which caused this table to
873 be needed.
875 Returns nonzero if we haven't met BINFO before.
877 The order in which vtables are built (by calling this function) for
878 an object must remain the same, otherwise a binary incompatibility
879 can result. */
881 static int
883 {
885 /* We already created a vtable for this base. There's no need to
886 do it again. */
889 /* Remember that we've created a vtable for this BINFO, so that we
890 don't try to do so again. */
893 /* Make fresh virtual list, so we can smash it later. */
896 /* Secondary vtables are laid out as part of the same structure as
897 the primary vtable. */
900 }
902 /* Create a new vtable for BINFO which is the hierarchy dominated by
903 T. Return nonzero if we actually created a new vtable. */
905 static int
907 {
909 /* In this case, it is *type*'s vtable we are modifying. We start
910 with the approximation that its vtable is that of the
911 immediate base class. */
913 else
914 /* This is our very own copy of `basetype' to play with. Later,
915 we will fill in all the virtual functions that override the
916 virtual functions in these base classes which are not defined
917 by the current type. */
919 }
921 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
922 (which is in the hierarchy dominated by T) list FNDECL as its
923 BV_FN. DELTA is the required constant adjustment from the `this'
924 pointer where the vtable entry appears to the `this' required when
925 the function is actually called. */
927 static void
929 tree binfo,
930 tree fndecl,
931 tree delta,
933 {
934 tree v;
940 {
941 /* We need a new vtable for BINFO. */
943 {
944 /* If we really did make a new vtable, we also made a copy
945 of the BINFO_VIRTUALS list. Now, we have to find the
946 corresponding entry in that list. */
951 }
956 }
957 }
959 \f
960 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
961 the USING_DECL naming METHOD. Returns true if the method could be
962 added to the method vec. */
964 bool
966 {
968 tree overload;
974 tree current_fns;
975 tree fns;
988 {
989 /* Make a new method vector. We start with 8 entries. We must
990 allocate at least two (for constructors and destructors), and
991 we're going to end up with an assignment operator at some
992 point as well. */
994 /* Create slots for constructors and destructors. */
998 }
1000 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1003 /* Constructors and destructors go in special slots. */
1007 {
1011 {
1017 type);
1018 }
1019 }
1020 else
1021 {
1022 tree m;
1025 /* See if we already have an entry with this name. */
1029 {
1032 {
1037 }
1041 {
1044 }
1049 }
1050 }
1053 /* Check to see if we've already got this method. */
1055 {
1057 tree fn_type;
1058 tree method_type;
1059 tree parms1;
1060 tree parms2;
1065 /* [over.load] Member function declarations with the
1066 same name and the same parameter types cannot be
1067 overloaded if any of them is a static member
1068 function declaration.
1070 [over.load] Member function declarations with the same name and
1071 the same parameter-type-list as well as member function template
1072 declarations with the same name, the same parameter-type-list, and
1073 the same template parameter lists cannot be overloaded if any of
1074 them, but not all, have a ref-qualifier.
1076 [namespace.udecl] When a using-declaration brings names
1077 from a base class into a derived class scope, member
1078 functions in the derived class override and/or hide member
1079 functions with the same name and parameter types in a base
1080 class (rather than conflicting). */
1086 /* Compare the quals on the 'this' parm. Don't compare
1087 the whole types, as used functions are treated as
1088 coming from the using class in overload resolution. */
1091 /* Either both or neither need to be ref-qualified for
1092 differing quals to allow overloading. */
1099 /* For templates, the return type and template parameters
1100 must be identical. */
1117 {
1118 /* For function versions, their parms and types match
1119 but they are not duplicates. Record function versions
1120 as and when they are found. extern "C" functions are
1121 not treated as versions. */
1127 {
1128 /* Mark functions as versions if necessary. Modify the mangled
1129 decl name if necessary. */
1131 {
1135 }
1137 {
1141 }
1144 }
1146 {
1148 {
1155 }
1156 /* Otherwise defer to the other function. */
1158 }
1160 {
1162 /* Defer to the local function. */
1164 }
1165 else
1166 {
1169 }
1171 /* We don't call duplicate_decls here to merge the
1172 declarations because that will confuse things if the
1173 methods have inline definitions. In particular, we
1174 will crash while processing the definitions. */
1176 }
1177 }
1179 /* A class should never have more than one destructor. */
1183 /* Add the new binding. */
1185 {
1188 }
1189 else
1198 {
1201 /* We only expect to add few methods in the COMPLETE_P case, so
1202 just make room for one more method in that case. */
1205 else
1211 else
1213 }
1214 else
1215 /* Replace the current slot. */
1218 }
1220 /* Subroutines of finish_struct. */
1222 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1223 legit, otherwise return 0. */
1225 static int
1227 {
1228 tree elem;
1237 {
1239 {
1243 else
1246 }
1247 else
1248 {
1249 /* They're changing the access to the same thing they changed
1250 it to before. That's OK. */
1251 ;
1252 }
1253 }
1254 else
1255 {
1257 tf_warning_or_error);
1260 }
1262 }
1264 /* Process the USING_DECL, which is a member of T. */
1266 static void
1268 {
1271 tree access
1276 tree old_value;
1281 tf_warning_or_error);
1283 {
1289 else
1291 }
1299 ;
1301 {
1303 /* It's OK to use functions from a base when there are functions with
1305 else
1306 {
1311 }
1312 }
1314 {
1318 }
1320 /* Make type T see field decl FDECL with access ACCESS. */
1323 {
1326 }
1327 else
1329 }
1330 \f
1331 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1332 types with abi tags, add the corresponding identifiers to the VEC in
1333 *DATA and set IDENTIFIER_MARKED. */
1335 struct abi_tag_data
1336 {
1337 tree t;
1338 tree subob;
1339 };
1341 static tree
1343 {
1348 {
1352 {
1356 {
1358 {
1363 }
1364 else
1365 {
1372 }
1373 }
1374 }
1375 }
1377 }
1379 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1380 complete) template arguments. */
1382 static void
1384 {
1387 {
1390 {
1394 }
1395 }
1397 /* Also mark ABI tags from template arguments. */
1399 {
1402 {
1405 {
1409 }
1410 }
1411 }
1412 }
1414 /* Check that class T has all the abi tags that subobject SUBOB has, or
1415 warn if not. */
1417 static void
1419 {
1428 }
1430 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1431 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1432 properties of the bases. */
1434 static void
1438 {
1442 tree base_binfo;
1443 tree binfo;
1453 {
1462 /* If any base class is non-literal, so is the derived class. */
1466 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1467 here because the case of virtual functions but non-virtual
1468 dtor is handled in finish_struct_1. */
1473 /* If the base class doesn't have copy constructors or
1474 assignment operators that take const references, then the
1475 derived class cannot have such a member automatically
1476 generated. */
1485 /* A virtual base does not effect nearly emptiness. */
1486 ;
1488 {
1490 /* And if there is more than one nearly empty base, then the
1491 derived class is not nearly empty either. */
1493 else
1494 /* Remember we've seen one. */
1496 }
1498 /* If the base class is not empty or nearly empty, then this
1499 class cannot be nearly empty. */
1502 /* A lot of properties from the bases also apply to the derived
1503 class. */
1521 /* A standard-layout class is a class that:
1522 ...
1523 * has no non-standard-layout base classes, */
1526 {
1527 tree basefield;
1528 /* ...has no base classes of the same type as the first non-static
1529 data member... */
1531 && (same_type_ignoring_top_level_qualifiers_p
1534 else
1535 /* ...either has no non-static data members in the most-derived
1536 class and at most one base class with non-static data
1537 members, or has no base classes with non-static data
1538 members */
1542 {
1545 else
1548 }
1549 }
1551 /* Don't bother collecting tm attributes if transactional memory
1552 support is not enabled. */
1554 {
1558 }
1561 }
1563 /* If one of the base classes had TM attributes, and the current class
1564 doesn't define its own, then the current class inherits one. */
1566 {
1569 }
1570 }
1572 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1573 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1574 that have had a nearly-empty virtual primary base stolen by some
1575 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1576 T. */
1578 static void
1580 {
1584 tree base_binfo;
1586 /* Determine the primary bases of our bases. */
1589 {
1592 /* See if we're the non-virtual primary of our inheritance
1593 chain. */
1595 {
1602 /* We are the primary binfo. */
1604 }
1605 /* Determine if we have a virtual primary base, and mark it so.
1606 */
1608 {
1612 /* Someone already claimed this base. */
1614 else
1615 {
1616 tree delta;
1621 /* A virtual binfo might have been copied from within
1622 another hierarchy. As we're about to use it as a
1623 primary base, make sure the offsets match. */
1631 }
1632 }
1633 }
1635 /* First look for a dynamic direct non-virtual base. */
1637 {
1641 {
1644 }
1645 }
1647 /* A "nearly-empty" virtual base class can be the primary base
1648 class, if no non-virtual polymorphic base can be found. Look for
1649 a nearly-empty virtual dynamic base that is not already a primary
1650 base of something in the hierarchy. If there is no such base,
1651 just pick the first nearly-empty virtual base. */
1657 {
1659 {
1660 /* Found one that is not primary. */
1663 }
1665 /* Remember the first candidate. */
1667 }
1669 found:
1670 /* If we've got a primary base, use it. */
1672 {
1677 /* We are stealing a primary base. */
1681 {
1682 tree delta;
1685 /* A virtual binfo might have been copied from within
1686 another hierarchy. As we're about to use it as a primary
1687 base, make sure the offsets match. */
1692 }
1699 }
1700 }
1702 /* Update the variant types of T. */
1704 void
1706 {
1707 tree variants;
1713 variants;
1715 {
1716 /* These fields are in the _TYPE part of the node, not in
1717 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1727 /* Copy whatever these are holding today. */
1731 }
1732 }
1734 /* Early variant fixups: we apply attributes at the beginning of the class
1735 definition, and we need to fix up any variants that have already been
1736 made via elaborated-type-specifier so that check_qualified_type works. */
1738 void
1740 {
1741 tree variants;
1747 variants;
1749 {
1750 /* These are the two fields that check_qualified_type looks at and
1751 are affected by attributes. */
1754 }
1755 }
1756 \f
1757 /* Set memoizing fields and bits of T (and its variants) for later
1758 use. */
1760 static void
1762 {
1763 /* Fix up variants (if any). */
1767 /* For a class w/o baseclasses, 'finish_struct' has set
1768 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1769 Similarly for a class whose base classes do not have vtables.
1770 When neither of these is true, we might have removed abstract
1771 virtuals (by providing a definition), added some (by declaring
1772 new ones), or redeclared ones from a base class. We need to
1773 recalculate what's really an abstract virtual at this point (by
1774 looking in the vtables). */
1777 /* If this type has a copy constructor or a destructor, force its
1778 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1779 nonzero. This will cause it to be passed by invisible reference
1780 and prevent it from being returned in a register. */
1783 {
1784 tree variants;
1787 {
1790 }
1791 }
1792 }
1794 /* Issue warnings about T having private constructors, but no friends,
1795 and so forth.
1797 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1798 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1799 non-private static member functions. */
1801 static void
1803 {
1806 tree fn;
1809 /* If the class has friends, those entities might create and
1810 access instances, so we should not warn. */
1813 /* We will have warned when the template was declared; there's
1814 no need to warn on every instantiation. */
1816 /* There's no reason to even consider warning about this
1817 class. */
1820 /* We only issue one warning, if more than one applies, because
1821 otherwise, on code like:
1823 class A {
1824 // Oops - forgot `public:'
1825 A();
1826 A(const A&);
1827 ~A();
1828 };
1830 we warn several times about essentially the same problem. */
1832 /* Check to see if all (non-constructor, non-destructor) member
1833 functions are private. (Since there are no friends or
1834 non-private statics, we can't ever call any of the private member
1835 functions.) */
1837 /* We're not interested in compiler-generated methods; they don't
1838 provide any way to call private members. */
1840 {
1842 {
1844 /* A non-private static member function is just like a
1845 friend; it can create and invoke private member
1846 functions, and be accessed without a class
1847 instance. */
1851 /* Keep searching for a static member function. */
1852 }
1855 }
1858 {
1859 /* There are no non-private methods, and there's at least one
1860 private member function that isn't a constructor or
1861 destructor. (If all the private members are
1862 constructors/destructors we want to use the code below that
1863 issues error messages specifically referring to
1864 constructors/destructors.) */
1870 {
1873 }
1875 {
1879 }
1880 }
1882 /* Even if some of the member functions are non-private, the class
1883 won't be useful for much if all the constructors or destructors
1884 are private: such an object can never be created or destroyed. */
1887 {
1890 t);
1892 }
1894 /* Warn about classes that have private constructors and no friends. */
1896 /* Implicitly generated constructors are always public. */
1899 {
1902 /* If a non-template class does not define a copy
1903 constructor, one is defined for it, enabling it to avoid
1904 this warning. For a template class, this does not
1905 happen, and so we would normally get a warning on:
1907 template <class T> class C { private: C(); };
1909 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1910 complete non-template or fully instantiated classes have this
1911 flag set. */
1914 else
1916 {
1918 /* Ideally, we wouldn't count copy constructors (or, in
1919 fact, any constructor that takes an argument of the
1920 class type as a parameter) because such things cannot
1921 be used to construct an instance of the class unless
1922 you already have one. But, for now at least, we're
1923 more generous. */
1925 {
1928 }
1929 }
1932 {
1935 t);
1937 }
1938 }
1939 }
1942 gt_pointer_operator new_value;
1946 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1948 static int
1950 {
1963 }
1965 /* This routine compares two fields like method_name_cmp but using the
1966 pointer operator in resort_field_decl_data. */
1968 static int
1970 {
1979 {
1986 }
1988 }
1990 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1992 void
1995 gt_pointer_operator new_value,
1997 {
2001 tree fn;
2003 /* The type conversion ops have to live at the front of the vec, so we
2004 can't sort them. */
2012 {
2016 resort_method_name_cmp);
2017 }
2018 }
2020 /* Warn about duplicate methods in fn_fields.
2022 Sort methods that are not special (i.e., constructors, destructors,
2023 and type conversion operators) so that we can find them faster in
2024 search. */
2026 static void
2028 {
2029 tree fn_fields;
2039 /* Clear DECL_IN_AGGR_P for all functions. */
2044 /* Issue warnings about private constructors and such. If there are
2045 no methods, then some public defaults are generated. */
2048 /* The type conversion ops have to live at the front of the vec, so we
2049 can't sort them. */
2058 }
2060 /* Make BINFO's vtable have N entries, including RTTI entries,
2061 vbase and vcall offsets, etc. Set its type and call the back end
2062 to lay it out. */
2064 static void
2066 {
2067 tree atype;
2068 tree vtable;
2073 /* We may have to grow the vtable. */
2076 {
2080 }
2081 }
2083 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2084 have the same signature. */
2086 int
2088 {
2089 /* One destructor overrides another if they are the same kind of
2090 destructor. */
2094 /* But a non-destructor never overrides a destructor, nor vice
2095 versa, nor do different kinds of destructors override
2096 one-another. For example, a complete object destructor does not
2097 override a deleting destructor. */
2106 {
2114 }
2116 }
2118 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2119 subobject. */
2121 static bool
2123 {
2124 tree probe;
2127 {
2131 /* If we meet a virtual base, we can't follow the inheritance
2132 any more. See if the complete type of DERIVED contains
2133 such a virtual base. */
2136 }
2138 }
2141 /* The function for which we are trying to find a final overrider. */
2142 tree fn;
2143 /* The base class in which the function was declared. */
2144 tree declaring_base;
2145 /* The candidate overriders. */
2146 tree candidates;
2147 /* Path to most derived. */
2151 /* Add the overrider along the current path to FFOD->CANDIDATES.
2152 Returns true if an overrider was found; false otherwise. */
2154 static bool
2158 {
2159 tree method;
2161 /* If BINFO is not the most derived type, try a more derived class.
2162 A definition there will overrider a definition here. */
2164 {
2165 depth--;
2169 }
2173 {
2176 /* Remove any candidates overridden by this new function. */
2178 {
2179 /* If *CANDIDATE overrides METHOD, then METHOD
2180 cannot override anything else on the list. */
2183 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2186 else
2188 }
2190 /* Add the new function. */
2193 }
2196 }
2198 /* Called from find_final_overrider via dfs_walk. */
2200 static tree
2202 {
2210 }
2212 static tree
2214 {
2219 }
2221 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2222 FN and whose TREE_VALUE is the binfo for the base where the
2223 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2224 DERIVED) is the base object in which FN is declared. */
2226 static tree
2228 {
2229 find_final_overrider_data ffod;
2231 /* Getting this right is a little tricky. This is valid:
2233 struct S { virtual void f (); };
2234 struct T { virtual void f (); };
2235 struct U : public S, public T { };
2237 even though calling `f' in `U' is ambiguous. But,
2239 struct R { virtual void f(); };
2240 struct S : virtual public R { virtual void f (); };
2241 struct T : virtual public R { virtual void f (); };
2242 struct U : public S, public T { };
2244 is not -- there's no way to decide whether to put `S::f' or
2245 `T::f' in the vtable for `R'.
2247 The solution is to look at all paths to BINFO. If we find
2248 different overriders along any two, then there is a problem. */
2252 /* Determine the depth of the hierarchy. */
2263 /* If there was no winner, issue an error message. */
2268 }
2270 /* Return the index of the vcall offset for FN when TYPE is used as a
2271 virtual base. */
2273 static tree
2275 {
2277 tree_pair_p p;
2285 /* There should always be an appropriate index. */
2287 }
2289 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2290 dominated by T. FN is the old function; VIRTUALS points to the
2291 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2292 of that entry in the list. */
2294 static void
2297 {
2298 tree b;
2299 tree overrider;
2300 tree delta;
2301 tree virtual_base;
2302 tree first_defn;
2308 /* Find the nearest primary base (possibly binfo itself) which defines
2309 this function; this is the class the caller will convert to when
2310 calling FN through BINFO. */
2312 {
2317 /* The nearest definition is from a lost primary. */
2320 }
2323 /* Find the final overrider. */
2326 {
2329 }
2332 /* Check for adjusting covariant return types. */
2340 /* If the overrider is invalid, don't even try. */
2342 {
2343 /* If FN is a covariant thunk, we must figure out the adjustment
2344 to the final base FN was converting to. As OVERRIDER_TARGET might
2345 also be converting to the return type of FN, we have to
2346 combine the two conversions here. */
2353 {
2357 }
2358 else
2362 /* Find the equivalent binfo within the return type of the
2363 overriding function. We will want the vbase offset from
2364 there. */
2366 over_return);
2369 {
2370 /* There was no existing virtual thunk (which takes
2371 precedence). So find the binfo of the base function's
2372 return type within the overriding function's return type.
2373 We cannot call lookup base here, because we're inside a
2374 dfs_walk, and will therefore clobber the BINFO_MARKED
2375 flags. Fortunately we know the covariancy is valid (it
2376 has already been checked), so we can just iterate along
2377 the binfos, which have been chained in inheritance graph
2378 order. Of course it is lame that we have to repeat the
2379 search here anyway -- we should really be caching pieces
2380 of the vtable and avoiding this repeated work. */
2383 /* Find the base binfo within the overriding function's
2384 return type. We will always find a thunk_binfo, except
2385 when the covariancy is invalid (which we will have
2386 already diagnosed). */
2389 thunk_binfo;
2395 /* See if virtual inheritance is involved. */
2397 virtual_offset;
2404 {
2408 {
2409 /* We convert via virtual base. Adjust the fixed
2410 offset to be from there. */
2411 offset =
2415 }
2417 /* There was an existing fixed offset, this must be
2418 from the base just converted to, and the base the
2419 FN was thunking to. */
2421 else
2423 }
2424 }
2427 /* Replace the overriding function with a covariant thunk. We
2428 will emit the overriding function in its own slot as
2429 well. */
2432 }
2433 else
2437 /* If we need a covariant thunk, then we may need to adjust first_defn.
2438 The ABI specifies that the thunks emitted with a function are
2439 determined by which bases the function overrides, so we need to be
2440 sure that we're using a thunk for some overridden base; even if we
2441 know that the necessary this adjustment is zero, there may not be an
2442 appropriate zero-this-adjusment thunk for us to use since thunks for
2443 overriding virtual bases always use the vcall offset.
2445 Furthermore, just choosing any base that overrides this function isn't
2446 quite right, as this slot won't be used for calls through a type that
2447 puts a covariant thunk here. Calling the function through such a type
2448 will use a different slot, and that slot is the one that determines
2449 the thunk emitted for that base.
2451 So, keep looking until we find the base that we're really overriding
2452 in this slot: the nearest primary base that doesn't use a covariant
2453 thunk in this slot. */
2455 {
2457 /* We already know that the overrider needs a covariant thunk. */
2460 {
2467 }
2469 }
2471 /* Assume that we will produce a thunk that convert all the way to
2472 the final overrider, and not to an intermediate virtual base. */
2475 /* See if we can convert to an intermediate virtual base first, and then
2476 use the vcall offset located there to finish the conversion. */
2478 {
2479 /* If we find the final overrider, then we can stop
2480 walking. */
2485 /* If we find a virtual base, and we haven't yet found the
2486 overrider, then there is a virtual base between the
2487 declaring base (first_defn) and the final overrider. */
2489 {
2492 }
2493 }
2495 /* Compute the constant adjustment to the `this' pointer. The
2496 `this' pointer, when this function is called, will point at BINFO
2497 (or one of its primary bases, which are at the same offset). */
2499 /* The `this' pointer needs to be adjusted from the declaration to
2500 the nearest virtual base. */
2505 /* If the nearest definition is in a lost primary, we don't need an
2506 entry in our vtable. Except possibly in a constructor vtable,
2507 if we happen to get our primary back. In that case, the offset
2508 will be zero, as it will be a primary base. */
2510 else
2511 /* The `this' pointer needs to be adjusted from pointing to
2512 BINFO to pointing at the base where the final overrider
2513 appears. */
2524 else
2528 }
2530 /* Called from modify_all_vtables via dfs_walk. */
2532 static tree
2534 {
2536 tree virtuals;
2537 tree old_virtuals;
2541 /* A base without a vtable needs no modification, and its bases
2542 are uninteresting. */
2547 /* Don't do the primary vtable, if it's new. */
2551 /* There's no need to modify the vtable for a non-virtual primary
2552 base; we're not going to use that vtable anyhow. We do still
2553 need to do this for virtual primary bases, as they could become
2554 non-primary in a construction vtable. */
2559 /* Now, go through each of the virtual functions in the virtual
2560 function table for BINFO. Find the final overrider, and update
2561 the BINFO_VIRTUALS list appropriately. */
2564 virtuals;
2568 binfo,
2573 }
2575 /* Update all of the primary and secondary vtables for T. Create new
2576 vtables as required, and initialize their RTTI information. Each
2577 of the functions in VIRTUALS is declared in T and may override a
2578 virtual function from a base class; find and modify the appropriate
2579 entries to point to the overriding functions. Returns a list, in
2580 declaration order, of the virtual functions that are declared in T,
2581 but do not appear in the primary base class vtable, and which
2582 should therefore be appended to the end of the vtable for T. */
2584 static tree
2586 {
2590 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2594 /* Update all of the vtables. */
2597 /* Add virtual functions not already in our primary vtable. These
2598 will be both those introduced by this class, and those overridden
2599 from secondary bases. It does not include virtuals merely
2600 inherited from secondary bases. */
2602 {
2607 {
2608 /* We don't need to adjust the `this' pointer when
2609 calling this function. */
2613 /* This is a function not already in our vtable. Keep it. */
2615 }
2616 else
2617 /* We've already got an entry for this function. Skip it. */
2619 }
2622 }
2624 /* Get the base virtual function declarations in T that have the
2625 indicated NAME. */
2627 static tree
2629 {
2630 tree methods;
2635 /* Find virtual functions in T with the indicated NAME. */
2639 methods;
2641 {
2647 }
2653 {
2656 base_fndecls);
2657 }
2660 }
2662 /* If this declaration supersedes the declaration of
2663 a method declared virtual in the base class, then
2664 mark this field as being virtual as well. */
2666 void
2668 {
2671 /* In [temp.mem] we have:
2673 A specialization of a member function template does not
2674 override a virtual function from a base class. */
2681 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2682 the error_mark_node so that we know it is an overriding
2683 function. */
2684 {
2687 }
2690 {
2696 }
2701 }
2703 /* Warn about hidden virtual functions that are not overridden in t.
2704 We know that constructors and destructors don't apply. */
2706 static void
2708 {
2710 tree fns;
2713 /* We go through each separately named virtual function. */
2717 {
2718 tree fn;
2719 tree name;
2720 tree fndecl;
2721 tree base_fndecls;
2722 tree base_binfo;
2723 tree binfo;
2726 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2727 have the same name. Figure out what name that is. */
2729 /* There are no possibly hidden functions yet. */
2731 /* Iterate through all of the base classes looking for possibly
2732 hidden functions. */
2735 {
2738 base_fndecls);
2739 }
2741 /* If there are no functions to hide, continue. */
2745 /* Remove any overridden functions. */
2747 {
2750 {
2754 /* If the method from the base class has the same
2755 signature as the method from the derived class, it
2756 has been overridden. */
2759 else
2761 }
2762 }
2764 /* Now give a warning for all base functions without overriders,
2765 as they are hidden. */
2767 {
2768 /* Here we know it is a hider, and no overrider exists. */
2772 }
2773 }
2774 }
2776 /* Recursive helper for finish_struct_anon. */
2778 static void
2780 {
2784 {
2785 /* We're generally only interested in entities the user
2786 declared, but we also find nested classes by noticing
2787 the TYPE_DECL that we create implicitly. You're
2788 allowed to put one anonymous union inside another,
2789 though, so we explicitly tolerate that. We use
2790 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2791 we also allow unnamed types used for defining fields. */
2798 {
2800 {
2803 "%q+#D invalid; an anonymous union can "
2805 else
2807 "%q+#D invalid; an anonymous struct can "
2809 }
2811 }
2814 {
2816 {
2820 else
2823 }
2825 {
2829 else
2832 }
2833 }
2838 /* Recurse into the anonymous aggregates to handle correctly
2839 access control (c++/24926):
2841 class A {
2842 union {
2843 union {
2844 int i;
2845 };
2846 };
2847 };
2849 int j=A().i; */
2853 }
2854 }
2856 /* Check for things that are invalid. There are probably plenty of other
2857 things we should check for also. */
2859 static void
2861 {
2863 {
2872 }
2873 }
2875 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2876 will be used later during class template instantiation.
2877 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2878 a non-static member data (FIELD_DECL), a member function
2879 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2880 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2881 When FRIEND_P is nonzero, T is either a friend class
2882 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2883 (FUNCTION_DECL, TEMPLATE_DECL). */
2885 void
2887 {
2888 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2893 }
2895 /* This function is called from declare_virt_assop_and_dtor via
2896 dfs_walk_all.
2898 DATA is a type that direcly or indirectly inherits the base
2899 represented by BINFO. If BINFO contains a virtual assignment [copy
2900 assignment or move assigment] operator or a virtual constructor,
2901 declare that function in DATA if it hasn't been already declared. */
2903 static tree
2905 {
2913 /* A base without a vtable needs no modification, and its bases
2914 are uninteresting. */
2918 /* If this is a primary base, then we have already looked at the
2919 virtual functions of its vtable. */
2923 {
2927 {
2932 }
2936 }
2939 }
2941 /* If the class type T has a direct or indirect base that contains a
2942 virtual assignment operator or a virtual destructor, declare that
2943 function in T if it hasn't been already declared. */
2945 static void
2947 {
2955 dfs_declare_virt_assop_and_dtor,
2957 }
2959 /* Declare the inheriting constructor for class T inherited from base
2960 constructor CTOR with the parameter array PARMS of size NPARMS. */
2962 static void
2964 {
2965 /* We don't declare an inheriting ctor that would be a default,
2966 copy or move ctor for derived or base. */
2971 {
2975 }
2983 {
2986 }
2987 }
2989 /* Declare all the inheriting constructors for class T inherited from base
2990 constructor CTOR. */
2992 static void
2994 {
3000 {
3004 }
3007 {
3011 }
3012 }
3014 /* Create default constructors, assignment operators, and so forth for
3015 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3016 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3017 the class cannot have a default constructor, copy constructor
3018 taking a const reference argument, or an assignment operator taking
3019 a const reference, respectively. */
3021 static void
3025 {
3033 /* Destructor. */
3035 {
3036 /* In general, we create destructors lazily. */
3041 /* But if this is a Java class, any non-trivial destructor is
3042 invalid, even if compiler-generated. Therefore, if the
3043 destructor is non-trivial we create it now. */
3045 }
3047 /* [class.ctor]
3049 If there is no user-declared constructor for a class, a default
3050 constructor is implicitly declared. */
3052 {
3057 /* This might force the declaration. */
3059 }
3061 /* [class.ctor]
3063 If a class definition does not explicitly declare a copy
3064 constructor, one is declared implicitly. */
3066 {
3072 }
3074 /* If there is no assignment operator, one will be created if and
3075 when it is needed. For now, just record whether or not the type
3076 of the parameter to the assignment operator will be a const or
3077 non-const reference. */
3079 {
3085 }
3087 /* We can't be lazy about declaring functions that might override
3088 a virtual function from a base class. */
3092 {
3096 {
3097 /* declare, then remove the decl */
3106 }
3107 else
3109 }
3110 }
3112 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3113 count the number of fields in TYPE, including anonymous union
3114 members. */
3116 static int
3118 {
3119 tree x;
3122 {
3125 else
3127 }
3129 }
3131 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3132 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3133 elts, starting at offset IDX. */
3135 static int
3137 {
3138 tree x;
3140 {
3143 else
3145 }
3147 }
3149 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3150 starting at offset IDX. */
3152 static int
3156 {
3157 tree values;
3161 }
3163 /* FIELD is a bit-field. We are finishing the processing for its
3164 enclosing type. Issue any appropriate messages and set appropriate
3165 flags. Returns false if an error has been diagnosed. */
3167 static bool
3169 {
3171 tree w;
3173 /* Extract the declared width of the bitfield, which has been
3174 temporarily stashed in DECL_INITIAL. */
3177 /* Remove the bit-field width indicator so that the rest of the
3178 compiler does not treat that value as an initializer. */
3181 /* Detect invalid bit-field type. */
3183 {
3186 }
3187 else
3188 {
3190 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3193 /* detect invalid field size. */
3199 {
3202 }
3204 {
3207 }
3209 {
3212 }
3224 }
3227 {
3231 }
3232 else
3233 {
3234 /* Non-bit-fields are aligned for their type. */
3238 }
3239 }
3241 /* FIELD is a non bit-field. We are finishing the processing for its
3242 enclosing type T. Issue any appropriate messages and set appropriate
3243 flags. */
3245 static void
3247 tree t,
3251 {
3254 /* In C++98 an anonymous union cannot contain any fields which would change
3255 the settings of CANT_HAVE_CONST_CTOR and friends. */
3257 ;
3258 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3259 structs. So, we recurse through their fields here. */
3261 {
3262 tree fields;
3268 }
3269 /* Check members with class type for constructors, destructors,
3270 etc. */
3272 {
3273 /* Never let anything with uninheritable virtuals
3274 make it through without complaint. */
3278 {
3283 field);
3288 field);
3290 {
3294 }
3295 }
3296 else
3297 {
3310 }
3319 }
3324 {
3325 /* `build_class_init_list' does not recognize
3326 non-FIELD_DECLs. */
3330 }
3331 }
3333 /* Check the data members (both static and non-static), class-scoped
3334 typedefs, etc., appearing in the declaration of T. Issue
3335 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3336 declaration order) of access declarations; each TREE_VALUE in this
3337 list is a USING_DECL.
3339 In addition, set the following flags:
3341 EMPTY_P
3342 The class is empty, i.e., contains no non-static data members.
3344 CANT_HAVE_CONST_CTOR_P
3345 This class cannot have an implicitly generated copy constructor
3346 taking a const reference.
3348 CANT_HAVE_CONST_ASN_REF
3349 This class cannot have an implicitly generated assignment
3350 operator taking a const reference.
3352 All of these flags should be initialized before calling this
3353 function.
3355 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3356 fields can be added by adding to this chain. */
3358 static void
3362 {
3370 /* Assume there are no access declarations. */
3372 /* Assume this class has no pointer members. */
3374 /* Assume none of the members of this class have default
3375 initializations. */
3379 {
3387 {
3388 /* Save the access declarations for our caller. */
3391 }
3397 /* If we've gotten this far, it's a data member, possibly static,
3398 or an enumerator. */
3402 /* When this goes into scope, it will be a non-local reference. */
3406 {
3407 /* [class.union]
3409 If a union contains a static data member, or a member of
3410 reference type, the program is ill-formed. */
3412 {
3415 }
3417 {
3422 }
3423 }
3425 /* Perform error checking that did not get done in
3426 grokdeclarator. */
3428 {
3432 }
3434 {
3438 }
3446 /* Now it can only be a FIELD_DECL. */
3451 /* If at least one non-static data member is non-literal, the whole
3452 class becomes non-literal. Note: if the type is incomplete we
3453 will complain later on. */
3457 /* A standard-layout class is a class that:
3458 ...
3459 has the same access control (Clause 11) for all non-static data members,
3460 ... */
3467 /* If this is of reference type, check if it needs an init. */
3469 {
3475 /* ARM $12.6.2: [A member initializer list] (or, for an
3476 aggregate, initialization by a brace-enclosed list) is the
3477 only way to initialize nonstatic const and reference
3478 members. */
3481 }
3486 {
3488 {
3489 warning
3492 x);
3494 }
3498 }
3501 /* We don't treat zero-width bitfields as making a class
3502 non-empty. */
3503 ;
3504 else
3505 {
3506 /* The class is non-empty. */
3508 /* The class is not even nearly empty. */
3510 /* If one of the data members contains an empty class,
3511 so does T. */
3515 }
3517 /* This is used by -Weffc++ (see below). Warn only for pointers
3518 to members which might hold dynamic memory. So do not warn
3519 for pointers to functions or pointers to members. */
3525 {
3530 }
3536 {
3538 {
3542 }
3544 {
3548 }
3549 }
3552 /* DR 148 now allows pointers to members (which are POD themselves),
3553 to be allowed in POD structs. */
3562 /* We set DECL_C_BIT_FIELD in grokbitfield.
3563 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3566 cant_have_const_ctor_p,
3567 no_const_asn_ref_p,
3570 /* Now that we've removed bit-field widths from DECL_INITIAL,
3571 anything left in DECL_INITIAL is an NSDMI that makes the class
3572 non-aggregate. */
3576 /* If any field is const, the structure type is pseudo-const. */
3578 {
3583 /* ARM $12.6.2: [A member initializer list] (or, for an
3584 aggregate, initialization by a brace-enclosed list) is the
3585 only way to initialize nonstatic const and reference
3586 members. */
3589 }
3590 /* A field that is pseudo-const makes the structure likewise. */
3592 {
3597 }
3599 /* Core issue 80: A nonstatic data member is required to have a
3600 different name from the class iff the class has a
3601 user-declared constructor. */
3605 }
3607 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3608 it should also define a copy constructor and an assignment operator to
3609 implement the correct copy semantic (deep vs shallow, etc.). As it is
3610 not feasible to check whether the constructors do allocate dynamic memory
3611 and store it within members, we approximate the warning like this:
3613 -- Warn only if there are members which are pointers
3614 -- Warn only if there is a non-trivial constructor (otherwise,
3615 there cannot be memory allocated).
3616 -- Warn only if there is a non-trivial destructor. We assume that the
3617 user at least implemented the cleanup correctly, and a destructor
3618 is needed to free dynamic memory.
3620 This seems enough for practical purposes. */
3622 && has_pointers
3626 {
3630 {
3635 }
3639 }
3641 /* Non-static data member initializers make the default constructor
3642 non-trivial. */
3644 {
3647 }
3649 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3653 /* Check anonymous struct/anonymous union fields. */
3656 /* We've built up the list of access declarations in reverse order.
3657 Fix that now. */
3659 }
3661 /* If TYPE is an empty class type, records its OFFSET in the table of
3662 OFFSETS. */
3664 static int
3666 {
3667 splay_tree_node n;
3672 /* Record the location of this empty object in OFFSETS. */
3680 type,
3684 }
3686 /* Returns nonzero if TYPE is an empty class type and there is
3687 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3689 static int
3691 {
3692 splay_tree_node n;
3693 tree t;
3698 /* Record the location of this empty object in OFFSETS. */
3708 }
3710 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3711 F for every subobject, passing it the type, offset, and table of
3712 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3713 be traversed.
3715 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3716 than MAX_OFFSET will not be walked.
3718 If F returns a nonzero value, the traversal ceases, and that value
3719 is returned. Otherwise, returns zero. */
3721 static int
3723 subobject_offset_fn f,
3724 tree offset,
3725 splay_tree offsets,
3726 tree max_offset,
3728 {
3732 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3733 stop. */
3741 {
3745 }
3748 {
3749 tree field;
3750 tree binfo;
3753 /* Avoid recursing into objects that are not interesting. */
3757 /* Record the location of TYPE. */
3762 /* Iterate through the direct base classes of TYPE. */
3766 {
3767 tree binfo_offset;
3780 offset,
3782 else
3783 {
3784 tree orig_binfo;
3785 /* We cannot rely on BINFO_OFFSET being set for the base
3786 class yet, but the offsets for direct non-virtual
3787 bases can be calculated by going back to the TYPE. */
3790 offset,
3792 }
3795 f,
3796 binfo_offset,
3797 offsets,
3798 max_offset,
3803 }
3806 {
3810 /* Iterate through the virtual base classes of TYPE. In G++
3811 3.2, we included virtual bases in the direct base class
3812 loop above, which results in incorrect results; the
3813 correct offsets for virtual bases are only known when
3814 working with the most derived type. */
3818 {
3820 f,
3822 offset,
3824 offsets,
3825 max_offset,
3829 }
3830 else
3831 {
3832 /* We still have to walk the primary base, if it is
3833 virtual. (If it is non-virtual, then it was walked
3834 above.) */
3840 {
3841 r = (walk_subobject_offsets
3846 }
3847 }
3848 }
3850 /* Iterate through the fields of TYPE. */
3855 {
3856 tree field_offset;
3860 else
3861 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3865 f,
3867 offset,
3868 field_offset),
3869 offsets,
3870 max_offset,
3874 }
3875 }
3877 {
3880 tree index;
3882 /* Avoid recursing into objects that are not interesting. */
3887 /* Step through each of the elements in the array. */
3889 /* G++ 3.2 had an off-by-one error here. */
3894 {
3896 f,
3897 offset,
3898 offsets,
3899 max_offset,
3905 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3906 there's no point in iterating through the remaining
3907 elements of the array. */
3910 }
3911 }
3914 }
3916 /* Record all of the empty subobjects of TYPE (either a type or a
3917 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3918 is being placed at OFFSET; otherwise, it is a base class that is
3919 being placed at OFFSET. */
3921 static void
3923 tree offset,
3924 splay_tree offsets,
3926 {
3927 tree max_offset;
3928 /* If recording subobjects for a non-static data member or a
3929 non-empty base class , we do not need to record offsets beyond
3930 the size of the biggest empty class. Additional data members
3931 will go at the end of the class. Additional base classes will go
3932 either at offset zero (if empty, in which case they cannot
3933 overlap with offsets past the size of the biggest empty class) or
3934 at the end of the class.
3936 However, if we are placing an empty base class, then we must record
3937 all offsets, as either the empty class is at offset zero (where
3938 other empty classes might later be placed) or at the end of the
3939 class (where other objects might then be placed, so other empty
3940 subobjects might later overlap). */
3944 else
3948 }
3950 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3951 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3952 virtual bases of TYPE are examined. */
3954 static int
3956 tree offset,
3957 splay_tree offsets,
3959 {
3960 splay_tree_node max_node;
3962 /* Get the node in OFFSETS that indicates the maximum offset where
3963 an empty subobject is located. */
3965 /* If there aren't any empty subobjects, then there's no point in
3966 performing this check. */
3972 vbases_p);
3973 }
3975 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3976 non-static data member of the type indicated by RLI. BINFO is the
3977 binfo corresponding to the base subobject, OFFSETS maps offsets to
3978 types already located at those offsets. This function determines
3979 the position of the DECL. */
3981 static void
3983 tree decl,
3984 tree binfo,
3985 splay_tree offsets)
3986 {
3989 tree type;
3992 {
3993 /* For the purposes of determining layout conflicts, we want to
3994 use the class type of BINFO; TREE_TYPE (DECL) will be the
3995 CLASSTYPE_AS_BASE version, which does not contain entries for
3996 zero-sized bases. */
3999 }
4000 else
4001 {
4004 }
4006 /* Try to place the field. It may take more than one try if we have
4007 a hard time placing the field without putting two objects of the
4008 same type at the same address. */
4010 {
4013 /* Place this field. */
4017 /* We have to check to see whether or not there is already
4018 something of the same type at the offset we're about to use.
4019 For example, consider:
4021 struct S {};
4022 struct T : public S { int i; };
4023 struct U : public S, public T {};
4025 Here, we put S at offset zero in U. Then, we can't put T at
4026 offset zero -- its S component would be at the same address
4027 as the S we already allocated. So, we have to skip ahead.
4028 Since all data members, including those whose type is an
4029 empty class, have nonzero size, any overlap can happen only
4030 with a direct or indirect base-class -- it can't happen with
4031 a data member. */
4032 /* In a union, overlap is permitted; all members are placed at
4033 offset zero. */
4036 /* G++ 3.2 did not check for overlaps when placing a non-empty
4037 virtual base. */
4042 {
4043 /* Strip off the size allocated to this field. That puts us
4044 at the first place we could have put the field with
4045 proper alignment. */
4048 /* Bump up by the alignment required for the type. */
4049 rli->bitpos
4055 }
4056 else
4057 /* There was no conflict. We're done laying out this field. */
4059 }
4061 /* Now that we know where it will be placed, update its
4062 BINFO_OFFSET. */
4064 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4065 this point because their BINFO_OFFSET is copied from another
4066 hierarchy. Therefore, we may not need to add the entire
4067 OFFSET. */
4073 }
4075 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4077 static int
4079 tree offset,
4081 {
4083 }
4085 /* Layout the empty base BINFO. EOC indicates the byte currently just
4086 past the end of the class, and should be correctly aligned for a
4087 class of the type indicated by BINFO; OFFSETS gives the offsets of
4088 the empty bases allocated so far. T is the most derived
4089 type. Return nonzero iff we added it at the end. */
4091 static bool
4094 {
4095 tree alignment;
4099 /* This routine should only be used for empty classes. */
4104 {
4106 propagate_binfo_offsets
4109 else
4111 "offset of empty base %qT may not be ABI-compliant and may"
4114 }
4116 /* This is an empty base class. We first try to put it at offset
4117 zero. */
4120 offsets,
4122 {
4123 /* That didn't work. Now, we move forward from the next
4124 available spot in the class. */
4128 {
4131 offsets,
4133 /* We finally found a spot where there's no overlap. */
4136 /* There's overlap here, too. Bump along to the next spot. */
4138 }
4139 }
4142 {
4147 }
4150 }
4152 /* Layout the base given by BINFO in the class indicated by RLI.
4153 *BASE_ALIGN is a running maximum of the alignments of
4154 any base class. OFFSETS gives the location of empty base
4155 subobjects. T is the most derived type. Return nonzero if the new
4156 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4157 *NEXT_FIELD, unless BINFO is for an empty base class.
4159 Returns the location at which the next field should be inserted. */
4164 {
4169 /* This error is now reported in xref_tag, thus giving better
4170 location information. */
4173 /* Place the base class. */
4175 {
4176 tree decl;
4178 /* The containing class is non-empty because it has a non-empty
4179 base class. */
4182 /* Create the FIELD_DECL. */
4189 {
4197 /* Try to place the field. It may take more than one try if we
4198 have a hard time placing the field without putting two
4199 objects of the same type at the same address. */
4201 /* Add the new FIELD_DECL to the list of fields for T. */
4205 }
4206 }
4207 else
4208 {
4209 tree eoc;
4212 /* On some platforms (ARM), even empty classes will not be
4213 byte-aligned. */
4218 /* A nearly-empty class "has no proper base class that is empty,
4219 not morally virtual, and at an offset other than zero." */
4221 {
4224 /* The check above (used in G++ 3.2) is insufficient because
4225 an empty class placed at offset zero might itself have an
4226 empty base at a nonzero offset. */
4228 empty_base_at_nonzero_offset_p,
4229 size_zero_node,
4233 {
4236 else
4238 "class %qT will be considered nearly empty in a "
4240 }
4241 }
4243 /* We do not create a FIELD_DECL for empty base classes because
4244 it might overlap some other field. We want to be able to
4245 create CONSTRUCTORs for the class by iterating over the
4246 FIELD_DECLs, and the back end does not handle overlapping
4247 FIELD_DECLs. */
4249 /* An empty virtual base causes a class to be non-empty
4250 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4251 here because that was already done when the virtual table
4252 pointer was created. */
4253 }
4255 /* Record the offsets of BINFO and its base subobjects. */
4258 offsets,
4262 }
4264 /* Layout all of the non-virtual base classes. Record empty
4265 subobjects in OFFSETS. T is the most derived type. Return nonzero
4266 if the type cannot be nearly empty. The fields created
4267 corresponding to the base classes will be inserted at
4268 *NEXT_FIELD. */
4270 static void
4273 {
4274 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4275 subobjects. */
4280 /* The primary base class is always allocated first. */
4285 /* Now allocate the rest of the bases. */
4287 {
4288 tree base_binfo;
4292 /* The primary base was already allocated above, so we don't
4293 need to allocate it again here. */
4297 /* Virtual bases are added at the end (a primary virtual base
4298 will have already been added). */
4304 }
4305 }
4307 /* Go through the TYPE_METHODS of T issuing any appropriate
4308 diagnostics, figuring out which methods override which other
4309 methods, and so forth. */
4311 static void
4313 {
4314 tree x;
4317 {
4321 /* The name of the field is the original field name
4322 Save this in auxiliary field for later overloading. */
4324 {
4328 }
4329 /* All user-provided destructors are non-trivial.
4330 Constructors and assignment ops are handled in
4331 grok_special_member_properties. */
4334 }
4335 }
4337 /* FN is a constructor or destructor. Clone the declaration to create
4338 a specialized in-charge or not-in-charge version, as indicated by
4339 NAME. */
4341 static tree
4343 {
4344 tree parms;
4345 tree clone;
4347 /* Copy the function. */
4349 /* Reset the function name. */
4352 /* Remember where this function came from. */
4354 /* Make it easy to find the CLONE given the FN. */
4358 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4360 {
4367 }
4370 /* There's no pending inline data for this function. */
4374 /* The base-class destructor is not virtual. */
4376 {
4380 }
4382 /* If there was an in-charge parameter, drop it from the function
4383 type. */
4385 {
4386 tree basetype;
4387 tree parmtypes;
4388 tree exceptions;
4393 /* Skip the `this' parameter. */
4395 /* Skip the in-charge parameter. */
4397 /* And the VTT parm, in a complete [cd]tor. */
4401 /* If this is subobject constructor or destructor, add the vtt
4402 parameter. */
4406 parmtypes);
4409 exceptions);
4413 }
4415 /* Copy the function parameters. */
4417 /* Remove the in-charge parameter. */
4419 {
4423 }
4424 /* And the VTT parm, in a complete [cd]tor. */
4426 {
4429 else
4430 {
4434 }
4435 }
4438 {
4441 }
4443 /* Create the RTL for this function. */
4451 }
4453 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4454 not invoke this function directly.
4456 For a non-thunk function, returns the address of the slot for storing
4457 the function it is a clone of. Otherwise returns NULL_TREE.
4459 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4460 cloned_function is unset. This is to support the separate
4461 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4462 on a template makes sense, but not the former. */
4464 tree *
4466 {
4474 {
4475 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4478 else
4479 #endif
4481 }
4486 else
4488 }
4490 /* Produce declarations for all appropriate clones of FN. If
4491 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4492 CLASTYPE_METHOD_VEC as well. */
4494 void
4496 {
4497 tree clone;
4499 /* Avoid inappropriate cloning. */
4505 {
4506 /* For each constructor, we need two variants: an in-charge version
4507 and a not-in-charge version. */
4514 }
4515 else
4516 {
4519 /* For each destructor, we need three variants: an in-charge
4520 version, a not-in-charge version, and an in-charge deleting
4521 version. We clone the deleting version first because that
4522 means it will go second on the TYPE_METHODS list -- and that
4523 corresponds to the correct layout order in the virtual
4524 function table.
4526 For a non-virtual destructor, we do not build a deleting
4527 destructor. */
4529 {
4533 }
4540 }
4542 /* Note that this is an abstract function that is never emitted. */
4544 }
4546 /* DECL is an in charge constructor, which is being defined. This will
4547 have had an in class declaration, from whence clones were
4548 declared. An out-of-class definition can specify additional default
4549 arguments. As it is the clones that are involved in overload
4550 resolution, we must propagate the information from the DECL to its
4551 clones. */
4553 void
4555 {
4556 tree clone;
4560 {
4567 /* Skip the 'this' parameter. */
4583 {
4588 {
4589 /* A default parameter has been added. Adjust the
4590 clone's parameters. */
4594 tree type;
4599 {
4602 clone_parms);
4604 }
4607 clone_parms);
4616 }
4617 }
4619 }
4620 }
4622 /* For each of the constructors and destructors in T, create an
4623 in-charge and not-in-charge variant. */
4625 static void
4627 {
4628 tree fns;
4630 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4631 out now. */
4639 }
4641 /* Deduce noexcept for a destructor DTOR. */
4643 void
4645 {
4647 {
4654 }
4655 }
4657 /* For each destructor in T, deduce noexcept:
4659 12.4/3: A declaration of a destructor that does not have an
4660 exception-specification is implicitly considered to have the
4661 same exception-specification as an implicit declaration (15.4). */
4663 static void
4665 {
4666 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4667 out now. */
4673 /* Avoid early exit from synthesized_method_walk (c++/57645). */
4680 }
4682 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4683 of TYPE for virtual functions which FNDECL overrides. Return a
4684 mask of the tm attributes found therein. */
4686 static int
4688 {
4690 tree base_binfo;
4694 {
4704 else
4706 }
4709 }
4711 /* Subroutine of set_method_tm_attributes. Handle the checks and
4712 inheritance for one virtual method FNDECL. */
4714 static void
4716 {
4717 tree tm_attr;
4722 /* If FNDECL doesn't actually override anything (i.e. T is the
4723 class that first declares FNDECL virtual), then we're done. */
4730 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4731 tm_pure must match exactly, otherwise no weakening of
4732 tm_safe > tm_callable > nothing. */
4733 /* ??? The tm_pure attribute didn't make the transition to the
4734 multivendor language spec. */
4736 {
4738 {
4741 }
4742 }
4743 /* If the overridden function is tm_pure, then FNDECL must be. */
4746 /* Look for base class combinations that cannot be satisfied. */
4748 {
4754 }
4755 /* If FNDECL did not declare an attribute, then inherit the most
4756 restrictive one. */
4758 {
4760 }
4761 /* Otherwise validate that we're not weaker than a function
4762 that is being overridden. */
4763 else
4764 {
4768 }
4771 err_override:
4775 }
4777 /* For each of the methods in T, propagate a class-level tm attribute. */
4779 static void
4781 {
4784 /* Don't bother collecting tm attributes if transactional memory
4785 support is not enabled. */
4789 /* Process virtual methods first, as they inherit directly from the
4790 base virtual function and also require validation of new attributes. */
4792 {
4793 tree vchain;
4796 {
4801 }
4802 }
4804 /* If the class doesn't have an attribute, nothing more to do. */
4809 /* Any method that does not yet have a tm attribute inherits
4810 the one from the class. */
4812 {
4815 }
4816 }
4818 /* Returns true iff class T has a user-defined constructor other than
4819 the default constructor. */
4821 bool
4823 {
4824 tree fns;
4830 {
4837 }
4840 }
4842 /* Returns the defaulted constructor if T has one. Otherwise, returns
4843 NULL_TREE. */
4845 tree
4847 {
4854 {
4858 {
4864 }
4865 }
4868 }
4870 /* Returns true iff FN is a user-provided function, i.e. user-declared
4871 and not defaulted at its first declaration; or explicit, private,
4872 protected, or non-const. */
4874 bool
4876 {
4879 else
4882 }
4884 /* Returns true iff class T has a user-provided constructor. */
4886 bool
4888 {
4889 tree fns;
4897 /* This can happen in error cases; avoid crashing. */
4906 }
4908 /* Returns true iff class T has a user-provided default constructor. */
4910 bool
4912 {
4913 tree fns;
4919 {
4925 }
4928 }
4930 /* TYPE is being used as a virtual base, and has a non-trivial move
4931 assignment. Return true if this is due to there being a user-provided
4932 move assignment in TYPE or one of its subobjects; if there isn't, then
4933 multiple move assignment can't cause any harm. */
4935 bool
4937 {
4938 /* Does the type itself have a user-provided move assignment operator? */
4942 {
4946 }
4948 /* Do any of its bases? */
4950 tree base_binfo;
4955 /* Or non-static data members? */
4957 {
4962 }
4964 /* Seems not. */
4966 }
4968 /* If default-initialization leaves part of TYPE uninitialized, returns
4969 a DECL for the field or TYPE itself (DR 253). */
4971 tree
4973 {
4984 {
4988 }
4993 {
4997 }
5000 }
5002 /* Returns true iff for class T, a trivial synthesized default constructor
5003 would be constexpr. */
5005 bool
5007 {
5008 /* A defaulted trivial default constructor is constexpr
5009 if there is nothing to initialize. */
5012 }
5014 /* Returns true iff class T has a constexpr default constructor. */
5016 bool
5018 {
5019 tree fns;
5022 {
5023 /* The caller should have stripped an enclosing array. */
5026 }
5028 {
5031 /* Non-trivial, we need to check subobject constructors. */
5033 }
5036 }
5038 /* Returns true iff class TYPE has a virtual destructor. */
5040 bool
5042 {
5043 tree dtor;
5051 }
5053 /* Returns true iff class T has a move constructor. */
5055 bool
5057 {
5058 tree fns;
5061 {
5064 }
5074 }
5076 /* Returns true iff class T has a move assignment operator. */
5078 bool
5080 {
5081 tree fns;
5084 {
5087 }
5095 }
5097 /* Returns true iff class T has a move constructor that was explicitly
5098 declared in the class body. Note that this is different from
5099 "user-provided", which doesn't include functions that are defaulted in
5100 the class. */
5102 bool
5104 {
5105 tree fns;
5114 {
5118 }
5121 }
5123 /* Returns true iff class T has a move assignment operator that was
5124 explicitly declared in the class body. */
5126 bool
5128 {
5129 tree fns;
5136 {
5140 }
5143 }
5145 /* Nonzero if we need to build up a constructor call when initializing an
5146 object of this class, either because it has a user-provided constructor
5147 or because it doesn't have a default constructor (so we need to give an
5148 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5149 what you care about is whether or not an object can be produced by a
5150 constructor (e.g. so we don't set TREE_READONLY on const variables of
5151 such type); use this function when what you care about is whether or not
5152 to try to call a constructor to create an object. The latter case is
5153 the former plus some cases of constructors that cannot be called. */
5155 bool
5157 {
5158 tree inner;
5164 }
5166 /* Remove all zero-width bit-fields from T. */
5168 static void
5170 {
5175 {
5178 /* We should not be confused by the fact that grokbitfield
5179 temporarily sets the width of the bit field into
5180 DECL_INITIAL (*fieldsp).
5181 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5182 to that width. */
5185 else
5187 }
5188 }
5190 /* Returns TRUE iff we need a cookie when dynamically allocating an
5191 array whose elements have the indicated class TYPE. */
5193 static bool
5195 {
5196 tree fns;
5201 /* If there's a non-trivial destructor, we need a cookie. In order
5202 to iterate through the array calling the destructor for each
5203 element, we'll have to know how many elements there are. */
5207 /* If the usual deallocation function is a two-argument whose second
5208 argument is of type `size_t', then we have to pass the size of
5209 the array to the deallocation function, so we will need to store
5210 a cookie. */
5214 /* If there are no `operator []' members, or the lookup is
5215 ambiguous, then we don't need a cookie. */
5218 /* Loop through all of the functions. */
5220 {
5221 tree fn;
5222 tree second_parm;
5224 /* Select the current function. */
5226 /* See if this function is a one-argument delete function. If
5227 it is, then it will be the usual deallocation function. */
5231 /* Do not consider this function if its second argument is an
5232 ellipsis. */
5235 /* Otherwise, if we have a two-argument function and the second
5236 argument is `size_t', it will be the usual deallocation
5237 function -- unless there is one-argument function, too. */
5241 }
5244 }
5246 /* Finish computing the `literal type' property of class type T.
5248 At this point, we have already processed base classes and
5249 non-static data members. We need to check whether the copy
5250 constructor is trivial, the destructor is trivial, and there
5251 is a trivial default constructor or at least one constexpr
5252 constructor other than the copy constructor. */
5254 static void
5256 {
5257 tree fn;
5273 {
5276 {
5280 }
5281 }
5282 }
5284 /* T is a non-literal type used in a context which requires a constant
5285 expression. Explain why it isn't literal. */
5287 void
5289 {
5299 /* Already explained. */
5308 {
5310 "default constructor, and has no constexpr constructor that "
5314 {
5315 /* Note that we can't simply call locate_ctor because when the
5316 constructor is deleted it just returns NULL_TREE. */
5317 tree fns;
5319 {
5326 {
5329 else
5332 }
5333 }
5334 }
5335 }
5336 else
5337 {
5341 {
5344 {
5349 }
5350 }
5352 {
5353 tree ftype;
5358 {
5363 }
5364 }
5365 }
5366 }
5368 /* Check the validity of the bases and members declared in T. Add any
5369 implicitly-generated functions (like copy-constructors and
5370 assignment operators). Compute various flag bits (like
5371 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5372 level: i.e., independently of the ABI in use. */
5374 static void
5376 {
5377 /* Nonzero if the implicitly generated copy constructor should take
5378 a non-const reference argument. */
5380 /* Nonzero if the implicitly generated assignment operator
5381 should take a non-const reference argument. */
5383 tree access_decls;
5386 tree fn;
5388 /* By default, we use const reference arguments and generate default
5389 constructors. */
5393 /* Check all the base-classes. */
5397 /* Deduce noexcept on destructors. This needs to happen after we've set
5398 triviality flags appropriately for our bases. */
5402 /* Check all the method declarations. */
5405 /* Save the initial values of these flags which only indicate whether
5406 or not the class has user-provided functions. As we analyze the
5407 bases and members we can set these flags for other reasons. */
5411 /* Check all the data member declarations. We cannot call
5412 check_field_decls until we have called check_bases check_methods,
5413 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5414 being set appropriately. */
5419 /* A nearly-empty class has to be vptr-containing; a nearly empty
5420 class contains just a vptr. */
5424 /* Do some bookkeeping that will guide the generation of implicitly
5425 declared member functions. */
5428 /* We need to call a constructor for this class if it has a
5429 user-provided constructor, or if the default constructor is going
5430 to initialize the vptr. (This is not an if-and-only-if;
5431 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5432 themselves need constructing.) */
5435 /* [dcl.init.aggr]
5437 An aggregate is an array or a class with no user-provided
5438 constructors ... and no virtual functions.
5440 Again, other conditions for being an aggregate are checked
5441 elsewhere. */
5444 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5445 retain the old definition internally for ABI reasons. */
5454 /* If the class has no user-declared constructor, but does have
5455 non-static const or reference data members that can never be
5456 initialized, issue a warning. */
5458 /* Classes with user-declared constructors are presumed to
5459 initialize these members. */
5461 /* Aggregates can be initialized with brace-enclosed
5462 initializers. */
5464 {
5465 tree field;
5468 {
5469 tree type;
5484 }
5485 }
5487 /* Synthesize any needed methods. */
5489 cant_have_const_ctor,
5490 no_const_asn_ref);
5492 /* Check defaulted declarations here so we have cant_have_const_ctor
5493 and don't need to worry about clones. */
5496 {
5499 {
5500 bool imp_const_p
5506 /* If the function is defaulted outside the class, we just
5507 give the synthesis error. */
5510 }
5512 }
5515 {
5516 /* "The closure type associated with a lambda-expression has a deleted
5517 default constructor and a deleted copy assignment operator." */
5523 /* "This class type is not an aggregate." */
5525 }
5527 /* Compute the 'literal type' property before we
5528 do anything with non-static member functions. */
5531 /* Create the in-charge and not-in-charge variants of constructors
5532 and destructors. */
5535 /* Process the using-declarations. */
5539 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5542 /* Figure out whether or not we will need a cookie when dynamically
5543 allocating an array of this type. */
5546 }
5548 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5549 accordingly. If a new vfield was created (because T doesn't have a
5550 primary base class), then the newly created field is returned. It
5551 is not added to the TYPE_FIELDS list; it is the caller's
5552 responsibility to do that. Accumulate declared virtual functions
5553 on VIRTUALS_P. */
5555 static tree
5557 {
5558 tree fn;
5560 /* Collect the virtual functions declared in T. */
5564 {
5573 }
5575 /* If we couldn't find an appropriate base class, create a new field
5576 here. Even if there weren't any new virtual functions, we might need a
5577 new virtual function table if we're supposed to include vptrs in
5578 all classes that need them. */
5580 {
5581 /* We build this decl with vtbl_ptr_type_node, which is a
5582 `vtable_entry_type*'. It might seem more precise to use
5583 `vtable_entry_type (*)[N]' where N is the number of virtual
5584 functions. However, that would require the vtable pointer in
5585 base classes to have a different type than the vtable pointer
5586 in derived classes. We could make that happen, but that
5587 still wouldn't solve all the problems. In particular, the
5588 type-based alias analysis code would decide that assignments
5589 to the base class vtable pointer can't alias assignments to
5590 the derived class vtable pointer, since they have different
5591 types. Thus, in a derived class destructor, where the base
5592 class constructor was inlined, we could generate bad code for
5593 setting up the vtable pointer.
5595 Therefore, we use one type for all vtable pointers. We still
5596 use a type-correct type; it's just doesn't indicate the array
5597 bounds. That's better than using `void*' or some such; it's
5598 cleaner, and it let's the alias analysis code know that these
5599 stores cannot alias stores to void*! */
5600 tree field;
5613 /* This class is non-empty. */
5617 }
5620 }
5622 /* Add OFFSET to all base types of BINFO which is a base in the
5623 hierarchy dominated by T.
5625 OFFSET, which is a type offset, is number of bytes. */
5627 static void
5629 {
5631 tree primary_binfo;
5632 tree base_binfo;
5634 /* Update BINFO's offset. */
5639 offset));
5641 /* Find the primary base class. */
5647 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5648 downwards. */
5650 {
5651 /* Don't do the primary base twice. */
5659 }
5660 }
5662 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5663 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5664 empty subobjects of T. */
5666 static void
5668 {
5669 tree vbase;
5678 {
5679 /* In G++ 3.2, we incorrectly rounded the size before laying out
5680 the virtual bases. */
5682 #ifdef STRUCTURE_SIZE_BOUNDARY
5683 /* Packed structures don't need to have minimum size. */
5686 #endif
5690 }
5692 /* Find the last field. The artificial fields created for virtual
5693 bases will go after the last extant field to date. */
5698 /* Go through the virtual bases, allocating space for each virtual
5699 base that is not already a primary base class. These are
5700 allocated in inheritance graph order. */
5702 {
5707 {
5710 /* This virtual base is not a primary base of any class in the
5711 hierarchy, so we have to add space for it. */
5715 /* If the first virtual base might have been placed at a
5716 lower address, had we started from CLASSTYPE_SIZE, rather
5717 than TYPE_SIZE, issue a warning. There can be both false
5718 positives and false negatives from this warning in rare
5719 cases; to deal with all the possibilities would probably
5720 require performing both layout algorithms and comparing
5721 the results which is not particularly tractable. */
5723 && first_vbase
5724 && (tree_int_cst_lt
5729 bitsize_unit_node),
5732 "offset of virtual base %qT is not ABI-compliant and "
5734 basetype);
5737 }
5738 }
5739 }
5741 /* Returns the offset of the byte just past the end of the base class
5742 BINFO. */
5744 static tree
5746 {
5747 tree size;
5752 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5753 allocate some space for it. It cannot have virtual bases, so
5754 TYPE_SIZE_UNIT is fine. */
5756 else
5760 }
5762 /* Returns the offset of the byte just past the end of the base class
5763 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5764 only non-virtual bases are included. */
5766 static tree
5768 {
5771 tree binfo;
5772 tree base_binfo;
5773 tree offset;
5778 {
5788 }
5790 /* G++ 3.2 did not check indirect virtual bases. */
5794 {
5798 }
5801 }
5803 /* Warn about bases of T that are inaccessible because they are
5804 ambiguous. For example:
5806 struct S {};
5807 struct T : public S {};
5808 struct U : public S, public T {};
5810 Here, `(S*) new U' is not allowed because there are two `S'
5811 subobjects of U. */
5813 static void
5815 {
5818 tree basetype;
5819 tree binfo;
5820 tree base_binfo;
5822 /* If there are no repeated bases, nothing can be ambiguous. */
5826 /* Check direct bases. */
5829 {
5835 }
5837 /* Check for ambiguous virtual bases. */
5841 {
5847 }
5848 }
5850 /* Compare two INTEGER_CSTs K1 and K2. */
5852 static int
5854 {
5856 }
5858 /* Increase the size indicated in RLI to account for empty classes
5859 that are "off the end" of the class. */
5861 static void
5863 {
5864 tree eoc;
5865 tree rli_size;
5867 /* It might be the case that we grew the class to allocate a
5868 zero-sized base class. That won't be reflected in RLI, yet,
5869 because we are willing to overlay multiple bases at the same
5870 offset. However, now we need to make sure that RLI is big enough
5871 to reflect the entire class. */
5877 {
5879 /* In version 1 of the ABI, the size of a class that ends with
5880 a bitfield was not rounded up to a whole multiple of a
5881 byte. Because rli_size_unit_so_far returns only the number
5882 of fully allocated bytes, any extra bits were not included
5883 in the size. */
5885 else
5886 /* The size should have been rounded to a whole byte. */
5889 rli->bitpos
5898 }
5899 }
5901 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5902 BINFO_OFFSETs for all of the base-classes. Position the vtable
5903 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5905 static void
5907 {
5908 tree non_static_data_members;
5909 tree field;
5910 tree vptr;
5911 record_layout_info rli;
5912 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5913 types that appear at that offset. */
5914 splay_tree empty_base_offsets;
5915 /* True if the last field laid out was a bit-field. */
5917 /* The location at which the next field should be inserted. */
5919 /* T, as a base class. */
5920 tree base_t;
5922 /* Keep track of the first non-static data member. */
5925 /* Start laying out the record. */
5928 /* Mark all the primary bases in the hierarchy. */
5931 /* Create a pointer to our virtual function table. */
5934 /* The vptr is always the first thing in the class. */
5936 {
5941 }
5942 else
5945 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5950 /* Layout the non-static data members. */
5952 {
5953 tree type;
5954 tree padding;
5956 /* We still pass things that aren't non-static data members to
5957 the back end, in case it wants to do something with them. */
5959 {
5961 /* If the static data member has incomplete type, keep track
5962 of it so that it can be completed later. (The handling
5963 of pending statics in finish_record_layout is
5964 insufficient; consider:
5966 struct S1;
5967 struct S2 { static S1 s1; };
5969 At this point, finish_record_layout will be called, but
5970 S1 is still incomplete.) */
5972 {
5974 /* The visibility of static data members is determined
5975 at their point of declaration, not their point of
5976 definition. */
5978 }
5980 }
5988 /* If this field is a bit-field whose width is greater than its
5989 type, then there are some special rules for allocating
5990 it. */
5993 {
5995 tree integer_type;
5997 /* We must allocate the bits as if suitably aligned for the
5998 longest integer type that fits in this many bits. type
5999 of the field. Then, we are supposed to use the left over
6000 bits as additional padding. */
6009 /* ITK now indicates a type that is too large for the
6010 field. We have to back up by one to find the largest
6011 type that fits. */
6012 do
6013 {
6018 /* Figure out how much additional padding is required. GCC
6019 3.2 always created a padding field, even if it had zero
6020 width. */
6023 {
6025 /* In a union, the padding field must have the full width
6026 of the bit-field; all fields start at offset zero. */
6028 else
6029 {
6032 "ABI-compliant and may change in a future "
6034 t);
6037 }
6038 }
6039 #ifdef PCC_BITFIELD_TYPE_MATTERS
6040 /* An unnamed bitfield does not normally affect the
6041 alignment of the containing class on a target where
6042 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6043 make any exceptions for unnamed bitfields when the
6044 bitfields are longer than their types. Therefore, we
6045 temporarily give the field a name. */
6047 {
6050 }
6051 #endif
6056 empty_base_offsets);
6059 /* Now that layout has been performed, set the size of the
6060 field to the size of its declared type; the rest of the
6061 field is effectively invisible. */
6063 /* We must also reset the DECL_MODE of the field. */
6068 /* Versions of G++ before G++ 3.4 did not reset the
6069 DECL_MODE. */
6071 "the offset of %qD may not be ABI-compliant and may "
6073 }
6074 else
6076 empty_base_offsets);
6078 /* Remember the location of any empty classes in FIELD. */
6082 empty_base_offsets,
6085 /* If a bit-field does not immediately follow another bit-field,
6086 and yet it starts in the middle of a byte, we have failed to
6087 comply with the ABI. */
6090 /* The TREE_NO_WARNING flag gets set by Objective-C when
6091 laying out an Objective-C class. The ObjC ABI differs
6092 from the C++ ABI, and so we do not want a warning
6093 here. */
6095 && !last_field_was_bitfield
6098 bitsize_unit_node)))
6102 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
6103 offset of the field. */
6110 "classes to be placed at different locations in a "
6113 /* The middle end uses the type of expressions to determine the
6114 possible range of expression values. In order to optimize
6115 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6116 must be made aware of the width of "i", via its type.
6118 Because C++ does not have integer types of arbitrary width,
6119 we must (for the purposes of the front end) convert from the
6120 type assigned here to the declared type of the bitfield
6121 whenever a bitfield expression is used as an rvalue.
6122 Similarly, when assigning a value to a bitfield, the value
6123 must be converted to the type given the bitfield here. */
6125 {
6130 {
6137 }
6138 }
6140 /* If we needed additional padding after this field, add it
6141 now. */
6143 {
6144 tree padding_field;
6147 FIELD_DECL,
6148 NULL_TREE,
6149 char_type_node);
6156 NULL_TREE,
6157 empty_base_offsets);
6158 }
6161 }
6164 {
6165 /* Make sure that we are on a byte boundary so that the size of
6166 the class without virtual bases will always be a round number
6167 of bytes. */
6170 }
6172 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6173 padding. */
6177 /* Delete all zero-width bit-fields from the list of fields. Now
6178 that the type is laid out they are no longer important. */
6181 /* Create the version of T used for virtual bases. We do not use
6182 make_class_type for this version; this is an artificial type. For
6183 a POD type, we just reuse T. */
6185 {
6188 /* Set the size and alignment for the new type. In G++ 3.2, all
6189 empty classes were considered to have size zero when used as
6190 base classes. */
6192 {
6197 "layout of classes derived from empty class %qT "
6199 t);
6200 }
6201 else
6202 {
6203 tree eoc;
6205 /* If the ABI version is not at least two, and the last
6206 field was a bit-field, RLI may not be on a byte
6207 boundary. In particular, rli_size_unit_so_far might
6208 indicate the last complete byte, while rli_size_so_far
6209 indicates the total number of bits used. Therefore,
6210 rli_size_so_far, rather than rli_size_unit_so_far, is
6211 used to compute TYPE_SIZE_UNIT. */
6219 eoc);
6226 }
6230 /* Copy the fields from T. */
6234 {
6236 FIELD_DECL,
6246 }
6248 /* Record the base version of the type. */
6251 }
6252 else
6255 /* Every empty class contains an empty class. */
6259 /* Set the TYPE_DECL for this type to contain the right
6260 value for DECL_OFFSET, so that we can use it as part
6261 of a COMPONENT_REF for multiple inheritance. */
6264 /* Now fix up any virtual base class types that we left lying
6265 around. We must get these done before we try to lay out the
6266 virtual function table. As a side-effect, this will remove the
6267 base subobject fields. */
6270 /* Make sure that empty classes are reflected in RLI at this
6271 point. */
6274 /* Make sure not to create any structures with zero size. */
6280 /* If this is a non-POD, declaring it packed makes a difference to how it
6281 can be used as a field; don't let finalize_record_size undo it. */
6285 /* Let the back end lay out the type. */
6294 /* Warn about bases that can't be talked about due to ambiguity. */
6297 /* Now that we're done with layout, give the base fields the real types. */
6302 /* Clean up. */
6309 }
6311 /* Determine the "key method" for the class type indicated by TYPE,
6312 and set CLASSTYPE_KEY_METHOD accordingly. */
6314 void
6316 {
6317 tree method;
6320 || processing_template_decl
6325 /* The key method is the first non-pure virtual function that is not
6326 inline at the point of class definition. On some targets the
6327 key function may not be inline; those targets should not call
6328 this function until the end of the translation unit. */
6334 {
6337 }
6340 }
6343 /* Allocate and return an instance of struct sorted_fields_type with
6344 N fields. */
6348 {
6355 }
6358 /* Perform processing required when the definition of T (a class type)
6359 is complete. */
6361 void
6363 {
6364 tree x;
6365 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6369 {
6374 }
6376 /* If this type was previously laid out as a forward reference,
6377 make sure we lay it out again. */
6381 /* Make assumptions about the class; we'll reset the flags if
6382 necessary. */
6388 /* Do end-of-class semantic processing: checking the validity of the
6389 bases and members and add implicitly generated methods. */
6392 /* Find the key method. */
6394 {
6395 /* The Itanium C++ ABI permits the key method to be chosen when
6396 the class is defined -- even though the key method so
6397 selected may later turn out to be an inline function. On
6398 some systems (such as ARM Symbian OS) the key method cannot
6399 be determined until the end of the translation unit. On such
6400 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6401 will cause the class to be added to KEYED_CLASSES. Then, in
6402 finish_file we will determine the key method. */
6406 /* If a polymorphic class has no key method, we may emit the vtable
6407 in every translation unit where the class definition appears. */
6410 }
6412 /* Layout the class itself. */
6415 /* We use the base type for trivial assignments, and hence it
6416 needs a mode. */
6421 /* If necessary, create the primary vtable for this class. */
6423 {
6424 /* We must enter these virtuals into the table. */
6428 /* Here we know enough to change the type of our virtual
6429 function table, but we will wait until later this function. */
6432 /* If we're warning about ABI tags, check the types of the new
6433 virtual functions. */
6437 }
6440 {
6442 tree fn;
6449 /* Add entries for virtual functions introduced by this class. */
6453 /* Set DECL_VINDEX for all functions declared in this class. */
6455 fn;
6457 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6459 {
6463 /* A thunk. We should never be calling this entry directly
6464 from this vtable -- we'd use the entry for the non
6465 thunk base function. */
6469 }
6470 }
6475 /* Complete the rtl for any static member objects of the type we're
6476 working on. */
6483 /* Done with FIELDS...now decide whether to sort these for
6484 faster lookups later.
6486 We use a small number because most searches fail (succeeding
6487 ultimately as the search bores through the inheritance
6488 hierarchy), and we want this failure to occur quickly. */
6492 /* Complain if one of the field types requires lower visibility. */
6495 /* Make the rtl for any new vtables we have created, and unmark
6496 the base types we marked. */
6499 /* Build the VTT for T. */
6502 /* This warning does not make sense for Java classes, since they
6503 cannot have destructors. */
6505 {
6506 tree dtor;
6510 if it were virtual, we would have created it by now. */
6511 !dtor
6520 "%q#T has virtual functions and accessible"
6522 }
6529 /* Class layout, assignment of virtual table slots, etc., is now
6530 complete. Give the back end a chance to tweak the visibility of
6531 the class or perform any other required target modifications. */
6541 /* Finish debugging output for this type. */
6545 {
6548 {
6551 }
6553 {
6556 else
6557 {
6560 }
6562 }
6564 {
6566 "the type of the first field has a different ABI from the "
6569 }
6570 }
6571 }
6573 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6574 equal to THRESHOLD or greater than THRESHOLD. */
6576 static void
6578 {
6581 {
6586 }
6587 }
6589 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6591 void
6593 {
6596 {
6598 int n_fields
6609 }
6610 }
6612 /* When T was built up, the member declarations were added in reverse
6613 order. Rearrange them to declaration order. */
6615 void
6617 {
6618 tree next;
6619 tree prev;
6620 tree x;
6622 /* The following lists are all in reverse order. Put them in
6623 declaration order now. */
6627 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6628 reverse order, so we can't just use nreverse. */
6633 {
6637 }
6639 {
6643 }
6644 }
6646 tree
6648 {
6651 /* Now that we've got all the field declarations, reverse everything
6652 as necessary. */
6657 /* Nadger the current location so that diagnostics point to the start of
6658 the struct, not the end. */
6662 {
6663 tree x;
6669 /* We need to emit an error message if this type was used as a parameter
6670 and it is an abstract type, even if it is a template. We construct
6671 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6672 account and we call complete_vars with this type, which will check
6673 the PARM_DECLS. Note that while the type is being defined,
6674 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6675 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6681 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6682 an enclosing scope is a template class, so that this function be
6683 found by lookup_fnfields_1 when the using declaration is not
6684 instantiated yet. */
6687 {
6692 }
6694 /* Remember current #pragma pack value. */
6697 /* Fix up any variants we've already built. */
6699 {
6704 }
6705 }
6706 else
6715 else
6719 /* Lambdas are defined by the LAMBDA_EXPR. */
6724 }
6725 \f
6726 /* Hash table to avoid endless recursion when handling references. */
6729 /* Return the dynamic type of INSTANCE, if known.
6730 Used to determine whether the virtual function table is needed
6731 or not.
6733 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6734 of our knowledge of its type. *NONNULL should be initialized
6735 before this function is called. */
6737 static tree
6739 {
6740 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6743 {
6747 else
6751 /* This is a call to a constructor, hence it's never zero. */
6753 {
6757 }
6761 /* This is a call to a constructor, hence it's never zero. */
6763 {
6767 }
6776 /* Propagate nonnull. */
6781 CASE_CONVERT:
6787 {
6788 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6789 with a real object -- given &p->f, p can still be null. */
6791 /* ??? Probably should check DECL_WEAK here. */
6794 }
6798 /* If this component is really a base class reference, then the field
6799 itself isn't definitive. */
6808 {
6812 }
6813 /* fall through... */
6818 {
6822 }
6824 {
6828 /* if we're in a ctor or dtor, we know our type. If
6829 current_class_ptr is set but we aren't in a function, we're in
6830 an NSDMI (and therefore a constructor). */
6835 {
6839 }
6840 }
6842 {
6843 /* We only need one hash table because it is always left empty. */
6847 /* Reference variables should be references to objects. */
6851 /* Enter the INSTANCE in a table to prevent recursion; a
6852 variable's initializer may refer to the variable
6853 itself. */
6858 {
6859 tree type;
6868 }
6869 }
6874 }
6875 #undef RECUR
6876 }
6878 /* Return nonzero if the dynamic type of INSTANCE is known, and
6879 equivalent to the static type. We also handle the case where
6880 INSTANCE is really a pointer. Return negative if this is a
6881 ctor/dtor. There the dynamic type is known, but this might not be
6882 the most derived base of the original object, and hence virtual
6883 bases may not be laid out according to this type.
6885 Used to determine whether the virtual function table is needed
6886 or not.
6888 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6889 of our knowledge of its type. *NONNULL should be initialized
6890 before this function is called. */
6892 int
6894 {
6897 tree fixed;
6899 /* processing_template_decl can be false in a template if we're in
6900 fold_non_dependent_expr, but we still want to suppress this check. */
6902 {
6903 /* In a template we only care about the type of the result. */
6907 }
6917 }
6919 \f
6920 void
6922 {
6925 current_class_stack
6933 }
6935 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6937 static void
6939 {
6940 tree type;
6942 /* We are re-entering the same class we just left, so we don't
6943 have to search the whole inheritance matrix to find all the
6944 decls to bind again. Instead, we install the cached
6945 class_shadowed list and walk through it binding names. */
6948 /* Restore IDENTIFIER_TYPE_VALUE. */
6950 type;
6953 }
6955 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6956 appropriate for TYPE.
6958 So that we may avoid calls to lookup_name, we cache the _TYPE
6959 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6961 For multiple inheritance, we perform a two-pass depth-first search
6962 of the type lattice. */
6964 void
6966 {
6967 class_stack_node_t csn;
6971 /* Make sure there is enough room for the new entry on the stack. */
6973 {
6975 current_class_stack
6977 current_class_stack_size);
6978 }
6980 /* Insert a new entry on the class stack. */
6987 current_class_depth++;
6989 /* Now set up the new type. */
6995 /* By default, things in classes are private, while things in
6996 structures or unions are public. */
6998 ? access_private_node
7004 {
7005 /* Forcibly remove any old class remnants. */
7007 }
7013 else
7015 }
7017 /* When we exit a toplevel class scope, we save its binding level so
7018 that we can restore it quickly. Here, we've entered some other
7019 class, so we must invalidate our cache. */
7021 void
7023 {
7025 }
7027 /* Get out of the current class scope. If we were in a class scope
7028 previously, that is the one popped to. */
7030 void
7032 {
7035 current_class_depth--;
7041 }
7043 /* Mark the top of the class stack as hidden. */
7045 void
7047 {
7050 }
7052 /* Mark the top of the class stack as un-hidden. */
7054 void
7056 {
7059 }
7061 /* Returns 1 if the class type currently being defined is either T or
7062 a nested type of T. */
7064 bool
7066 {
7074 /* We start looking from 1 because entry 0 is from global scope,
7075 and has no type. */
7077 {
7078 tree c;
7081 else
7082 {
7086 }
7091 }
7093 }
7095 /* If either current_class_type or one of its enclosing classes are derived
7096 from T, return the appropriate type. Used to determine how we found
7097 something via unqualified lookup. */
7099 tree
7101 {
7104 /* The bases of a dependent type are unknown. */
7115 {
7120 }
7123 }
7125 /* Returns the innermost class type which is not a lambda closure type. */
7127 tree
7129 {
7132 /* We start looking from 1 because entry 0 is from global scope,
7133 and has no type. */
7135 {
7136 tree c;
7139 else
7140 {
7144 }
7149 }
7151 }
7153 /* When entering a class scope, all enclosing class scopes' names with
7154 static meaning (static variables, static functions, types and
7155 enumerators) have to be visible. This recursive function calls
7156 pushclass for all enclosing class contexts until global or a local
7157 scope is reached. TYPE is the enclosed class. */
7159 void
7161 {
7162 /* A namespace might be passed in error cases, like A::B:C. */
7170 }
7172 /* Undoes a push_nested_class call. */
7174 void
7176 {
7182 }
7184 /* Returns the number of extern "LANG" blocks we are nested within. */
7186 int
7188 {
7190 }
7192 /* Set global variables CURRENT_LANG_NAME to appropriate value
7193 so that behavior of name-mangling machinery is correct. */
7195 void
7197 {
7201 {
7203 }
7205 {
7207 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7208 (See record_builtin_java_type in decl.c.) However, that causes
7209 incorrect debug entries if these types are actually used.
7210 So we re-enable debug output after extern "Java". */
7219 }
7221 {
7223 }
7224 else
7226 }
7228 /* Get out of the current language scope. */
7230 void
7232 {
7234 }
7235 \f
7236 /* Type instantiation routines. */
7238 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7239 matches the TARGET_TYPE. If there is no satisfactory match, return
7240 error_mark_node, and issue an error & warning messages under
7241 control of FLAGS. Permit pointers to member function if FLAGS
7242 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7243 a template-id, and EXPLICIT_TARGS are the explicitly provided
7244 template arguments.
7246 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7247 is the base path used to reference those member functions. If
7248 the address is resolved to a member function, access checks will be
7249 performed and errors issued if appropriate. */
7251 static tree
7253 tree overload,
7254 tsubst_flags_t flags,
7256 tree explicit_targs,
7257 tree access_path)
7258 {
7259 /* Here's what the standard says:
7261 [over.over]
7263 If the name is a function template, template argument deduction
7264 is done, and if the argument deduction succeeds, the deduced
7265 arguments are used to generate a single template function, which
7266 is added to the set of overloaded functions considered.
7268 Non-member functions and static member functions match targets of
7269 type "pointer-to-function" or "reference-to-function." Nonstatic
7270 member functions match targets of type "pointer-to-member
7271 function;" the function type of the pointer to member is used to
7272 select the member function from the set of overloaded member
7273 functions. If a nonstatic member function is selected, the
7274 reference to the overloaded function name is required to have the
7275 form of a pointer to member as described in 5.3.1.
7277 If more than one function is selected, any template functions in
7278 the set are eliminated if the set also contains a non-template
7279 function, and any given template function is eliminated if the
7280 set contains a second template function that is more specialized
7281 than the first according to the partial ordering rules 14.5.5.2.
7282 After such eliminations, if any, there shall remain exactly one
7283 selected function. */
7286 /* We store the matches in a TREE_LIST rooted here. The functions
7287 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7288 interoperability with most_specialized_instantiation. */
7290 tree fn;
7291 tree target_fn_type;
7293 /* By the time we get here, we should be seeing only real
7294 pointer-to-member types, not the internal POINTER_TYPE to
7295 METHOD_TYPE representation. */
7301 /* Check that the TARGET_TYPE is reasonable. */
7306 /* This is OK, too. */
7309 /* This is OK, too. This comes from a conversion to reference
7310 type. */
7312 else
7313 {
7319 }
7321 /* Non-member functions and static member functions match targets of type
7322 "pointer-to-function" or "reference-to-function." Nonstatic member
7323 functions match targets of type "pointer-to-member-function;" the
7324 function type of the pointer to member is used to select the member
7325 function from the set of overloaded member functions.
7327 So figure out the FUNCTION_TYPE that we want to match against. */
7330 /* If we can find a non-template function that matches, we can just
7331 use it. There's no point in generating template instantiations
7332 if we're just going to throw them out anyhow. But, of course, we
7333 can only do this when we don't *need* a template function. */
7335 {
7336 tree fns;
7339 {
7343 /* We're not looking for templates just yet. */
7348 /* We're looking for a non-static member, and this isn't
7349 one, or vice versa. */
7352 /* Ignore functions which haven't been explicitly
7353 declared. */
7357 /* See if there's a match. */
7360 }
7361 }
7363 /* Now, if we've already got a match (or matches), there's no need
7364 to proceed to the template functions. But, if we don't have a
7365 match we need to look at them, too. */
7367 {
7368 tree target_arg_types;
7369 tree target_ret_type;
7370 tree fns;
7373 tree arg;
7387 {
7389 tree instantiation;
7390 tree targs;
7393 /* We're only looking for templates. */
7398 /* We're not looking for a non-static member, and this is
7399 one, or vice versa. */
7404 /* If the template has a deduced return type, don't expose it to
7405 template argument deduction. */
7409 /* Try to do argument deduction. */
7416 /* Instantiation failed. */
7419 /* And now force instantiation to do return type deduction. */
7421 {
7427 }
7429 /* See if there's a match. */
7434 }
7436 /* Now, remove all but the most specialized of the matches. */
7438 {
7443 NULL_TREE,
7444 NULL_TREE);
7445 }
7446 }
7448 /* Now we should have exactly one function in MATCHES. */
7450 {
7451 /* There were *no* matches. */
7453 {
7456 target_type);
7459 }
7461 }
7463 {
7464 /* There were too many matches. First check if they're all
7465 the same function. */
7470 /* For multi-versioned functions, more than one match is just fine and
7471 decls_match will return false as they are different. */
7479 {
7481 {
7484 target_type);
7486 /* Since print_candidates expects the functions in the
7487 TREE_VALUE slot, we flip them here. */
7492 }
7495 }
7496 }
7498 /* Good, exactly one match. Now, convert it to the correct type. */
7503 {
7511 {
7514 }
7515 }
7517 /* If a pointer to a function that is multi-versioned is requested, the
7518 pointer to the dispatcher function is returned instead. This works
7519 well because indirectly calling the function will dispatch the right
7520 function version at run-time. */
7522 {
7526 /* Mark all the versions corresponding to the dispatcher as used. */
7529 }
7531 /* If we're doing overload resolution purely for the purpose of
7532 determining conversion sequences, we should not consider the
7533 function used. If this conversion sequence is selected, the
7534 function will be marked as used at this point. */
7536 {
7537 /* Make =delete work with SFINAE. */
7542 }
7544 /* We could not check access to member functions when this
7545 expression was originally created since we did not know at that
7546 time to which function the expression referred. */
7548 {
7551 }
7555 else
7556 {
7557 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7558 will mark the function as addressed, but here we must do it
7559 explicitly. */
7563 }
7564 }
7566 /* This function will instantiate the type of the expression given in
7567 RHS to match the type of LHSTYPE. If errors exist, then return
7568 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7569 we complain on errors. If we are not complaining, never modify rhs,
7570 as overload resolution wants to try many possible instantiations, in
7571 the hope that at least one will work.
7573 For non-recursive calls, LHSTYPE should be a function, pointer to
7574 function, or a pointer to member function. */
7576 tree
7578 {
7585 {
7589 }
7592 {
7599 /* Microsoft allows `A::f' to be resolved to a
7600 pointer-to-member. */
7601 ;
7602 else
7603 {
7608 }
7609 }
7612 {
7615 }
7617 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7618 deduce any type information. */
7620 {
7624 }
7626 /* There only a few kinds of expressions that may have a type
7627 dependent on overload resolution. */
7633 /* This should really only be used when attempting to distinguish
7634 what sort of a pointer to function we have. For now, any
7635 arithmetic operation which is not supported on pointers
7636 is rejected as an error. */
7639 {
7641 {
7647 /* Do not lose object's side effects. */
7651 }
7658 /* This can happen if we are forming a pointer-to-member for a
7659 member template. */
7662 /* Fall through. */
7665 {
7669 return
7673 }
7677 return
7681 access_path);
7684 {
7689 }
7696 }
7698 }
7699 \f
7700 /* Return the name of the virtual function pointer field
7701 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7702 this may have to look back through base types to find the
7703 ultimate field name. (For single inheritance, these could
7704 all be the same name. Who knows for multiple inheritance). */
7706 static tree
7708 {
7715 {
7721 }
7729 }
7731 void
7733 {
7740 {
7745 }
7746 }
7748 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7749 according to [class]:
7750 The class-name is also inserted
7751 into the scope of the class itself. For purposes of access checking,
7752 the inserted class name is treated as if it were a public member name. */
7754 void
7756 {
7759 tree saved_cas;
7774 }
7776 /* Returns 1 if TYPE contains only padding bytes. */
7778 int
7780 {
7787 /* In G++ 3.2, whether or not a class was empty was determined by
7788 looking at its size. */
7791 else
7793 }
7795 /* Returns true if TYPE contains an empty class. */
7797 static bool
7799 {
7803 {
7804 tree field;
7805 tree binfo;
7806 tree base_binfo;
7818 }
7822 }
7824 /* Returns true if TYPE contains no actual data, just various
7825 possible combinations of empty classes and possibly a vptr. */
7827 bool
7829 {
7831 {
7832 tree field;
7833 tree binfo;
7834 tree base_binfo;
7837 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7838 out, but we'd like to be able to check this before then. */
7852 }
7856 }
7858 /* Note that NAME was looked up while the current class was being
7859 defined and that the result of that lookup was DECL. */
7861 void
7863 {
7864 splay_tree names_used;
7866 /* If we're not defining a class, there's nothing to do. */
7872 /* If there's already a binding for this NAME, then we don't have
7873 anything to worry about. */
7886 }
7888 /* Note that NAME was declared (as DECL) in the current class. Check
7889 to see that the declaration is valid. */
7891 void
7893 {
7894 splay_tree names_used;
7895 splay_tree_node n;
7897 /* Look to see if we ever used this name. */
7898 names_used
7902 /* The C language allows members to be declared with a type of the same
7903 name, and the C++ standard says this diagnostic is not required. So
7904 allow it in extern "C" blocks unless predantic is specified.
7905 Allow it in all cases if -ms-extensions is specified. */
7911 {
7912 /* [basic.scope.class]
7914 A name N used in a class S shall refer to the same declaration
7915 in its context and when re-evaluated in the completed scope of
7916 S. */
7920 }
7921 }
7923 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7924 Secondary vtables are merged with primary vtables; this function
7925 will return the VAR_DECL for the primary vtable. */
7927 tree
7929 {
7930 tree decl;
7934 {
7937 }
7941 }
7944 /* Returns the binfo for the primary base of BINFO. If the resulting
7945 BINFO is a virtual base, and it is inherited elsewhere in the
7946 hierarchy, then the returned binfo might not be the primary base of
7947 BINFO in the complete object. Check BINFO_PRIMARY_P or
7948 BINFO_LOST_PRIMARY_P to be sure. */
7950 static tree
7952 {
7953 tree primary_base;
7960 }
7962 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7964 static int
7966 {
7970 }
7972 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7973 INDENT should be zero when called from the top level; it is
7974 incremented recursively. IGO indicates the next expected BINFO in
7975 inheritance graph ordering. */
7977 static tree
7980 tree binfo,
7981 tree igo,
7983 {
7985 tree base_binfo;
7993 {
7996 }
8011 {
8015 TFF_PLAIN_IDENTIFIER),
8017 }
8019 {
8022 }
8027 {
8031 {
8035 TFF_PLAIN_IDENTIFIER));
8036 }
8038 {
8042 TFF_PLAIN_IDENTIFIER));
8043 }
8045 {
8049 TFF_PLAIN_IDENTIFIER));
8050 }
8052 {
8056 TFF_PLAIN_IDENTIFIER));
8057 }
8061 }
8067 }
8069 /* Dump the BINFO hierarchy for T. */
8071 static void
8073 {
8085 }
8087 /* Debug interface to hierarchy dumping. */
8089 void
8091 {
8093 }
8095 static void
8097 {
8102 {
8105 }
8106 }
8108 static void
8110 {
8111 tree value;
8113 HOST_WIDE_INT elt;
8121 TFF_PLAIN_IDENTIFIER));
8128 }
8130 static void
8132 {
8140 {
8147 {
8152 }
8156 }
8159 }
8161 static void
8163 {
8171 {
8176 }
8179 }
8181 /* Dump a function or thunk and its thunkees. */
8183 static void
8185 {
8188 tree thunks;
8196 {
8206 else
8212 }
8216 }
8218 /* Dump the thunks for FN. */
8220 void
8222 {
8224 }
8226 /* Virtual function table initialization. */
8228 /* Create all the necessary vtables for T and its base classes. */
8230 static void
8232 {
8233 tree vbase;
8237 /* We lay out the primary and secondary vtables in one contiguous
8238 vtable. The primary vtable is first, followed by the non-virtual
8239 secondary vtables in inheritance graph order. */
8243 /* Then come the virtual bases, also in inheritance graph order. */
8245 {
8249 }
8253 }
8255 /* Initialize the vtable for BINFO with the INITS. */
8257 static void
8259 {
8260 tree decl;
8266 }
8268 /* Build the VTT (virtual table table) for T.
8269 A class requires a VTT if it has virtual bases.
8271 This holds
8272 1 - primary virtual pointer for complete object T
8273 2 - secondary VTTs for each direct non-virtual base of T which requires a
8274 VTT
8275 3 - secondary virtual pointers for each direct or indirect base of T which
8276 has virtual bases or is reachable via a virtual path from T.
8277 4 - secondary VTTs for each direct or indirect virtual base of T.
8279 Secondary VTTs look like complete object VTTs without part 4. */
8281 static void
8283 {
8284 tree type;
8285 tree vtt;
8286 tree index;
8289 /* Build up the initializers for the VTT. */
8294 /* If we didn't need a VTT, we're done. */
8298 /* Figure out the type of the VTT. */
8302 /* Now, build the VTT object itself. */
8305 /* Add the VTT to the vtables list. */
8310 }
8312 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8313 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8314 and CHAIN the vtable pointer for this binfo after construction is
8315 complete. VALUE can also be another BINFO, in which case we recurse. */
8317 static tree
8319 {
8320 tree vt;
8323 {
8329 else
8331 }
8334 }
8336 /* Data for secondary VTT initialization. */
8338 {
8339 /* Is this the primary VTT? */
8342 /* Current index into the VTT. */
8343 tree index;
8345 /* Vector of initializers built up. */
8348 /* The type being constructed by this secondary VTT. */
8349 tree type_being_constructed;
8352 /* Recursively build the VTT-initializer for BINFO (which is in the
8353 hierarchy dominated by T). INITS points to the end of the initializer
8354 list to date. INDEX is the VTT index where the next element will be
8355 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8356 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8357 for virtual bases of T. When it is not so, we build the constructor
8358 vtables for the BINFO-in-T variant. */
8360 static void
8363 {
8365 tree b;
8366 tree init;
8367 secondary_vptr_vtt_init_data data;
8370 /* We only need VTTs for subobjects with virtual bases. */
8374 /* We need to use a construction vtable if this is not the primary
8375 VTT. */
8377 {
8380 /* Record the offset in the VTT where this sub-VTT can be found. */
8382 }
8384 /* Add the address of the primary vtable for the complete object. */
8388 {
8391 }
8394 /* Recursively add the secondary VTTs for non-virtual bases. */
8399 /* Add secondary virtual pointers for all subobjects of BINFO with
8400 either virtual bases or reachable along a virtual path, except
8401 subobjects that are non-virtual primary bases. */
8411 /* data.inits might have grown as we added secondary virtual pointers.
8412 Make sure our caller knows about the new vector. */
8416 /* Add the secondary VTTs for virtual bases in inheritance graph
8417 order. */
8419 {
8424 }
8425 else
8426 /* Remove the ctor vtables we created. */
8428 }
8430 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8431 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8433 static tree
8435 {
8438 /* We don't care about bases that don't have vtables. */
8442 /* We're only interested in proper subobjects of the type being
8443 constructed. */
8447 /* We're only interested in bases with virtual bases or reachable
8448 via a virtual path from the type being constructed. */
8453 /* We're not interested in non-virtual primary bases. */
8457 /* Record the index where this secondary vptr can be found. */
8459 {
8464 {
8465 /* It's a primary virtual base, and this is not a
8466 construction vtable. Find the base this is primary of in
8467 the inheritance graph, and use that base's vtable
8468 now. */
8471 }
8472 }
8474 /* Add the initializer for the secondary vptr itself. */
8477 /* Advance the vtt index. */
8482 }
8484 /* Called from build_vtt_inits via dfs_walk. After building
8485 constructor vtables and generating the sub-vtt from them, we need
8486 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8487 binfo of the base whose sub vtt was generated. */
8489 static tree
8491 {
8495 /* If this class has no vtable, none of its bases do. */
8499 /* This might be a primary base, so have no vtable in this
8500 hierarchy. */
8503 /* If we scribbled the construction vtable vptr into BINFO, clear it
8504 out now. */
8510 }
8512 /* Build the construction vtable group for BINFO which is in the
8513 hierarchy dominated by T. */
8515 static void
8517 {
8518 tree type;
8519 tree vtbl;
8520 tree id;
8521 tree vbase;
8524 /* See if we've already created this construction vtable group. */
8530 /* Build a version of VTBL (with the wrong type) for use in
8531 constructing the addresses of secondary vtables in the
8532 construction vtable group. */
8535 /* Don't export construction vtables from shared libraries. Even on
8536 targets that don't support hidden visibility, this tells
8537 can_refer_decl_in_current_unit_p not to assume that it's safe to
8538 access from a different compilation unit (bz 54314). */
8546 /* Add the vtables for each of our virtual bases using the vbase in T
8547 binfo. */
8549 vbase;
8551 {
8552 tree b;
8559 }
8561 /* Figure out the type of the construction vtable. */
8568 /* Initialize the construction vtable. */
8572 }
8574 /* Add the vtbl initializers for BINFO (and its bases other than
8575 non-virtual primaries) to the list of INITS. BINFO is in the
8576 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8577 the constructor the vtbl inits should be accumulated for. (If this
8578 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8579 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8580 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8581 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8582 but are not necessarily the same in terms of layout. */
8584 static void
8586 tree orig_binfo,
8587 tree rtti_binfo,
8588 tree vtbl,
8589 tree t,
8591 {
8593 tree base_binfo;
8598 /* If it doesn't have a vptr, we don't do anything. */
8602 /* If we're building a construction vtable, we're not interested in
8603 subobjects that don't require construction vtables. */
8609 /* Build the initializers for the BINFO-in-T vtable. */
8612 /* Walk the BINFO and its bases. We walk in preorder so that as we
8613 initialize each vtable we can figure out at what offset the
8614 secondary vtable lies from the primary vtable. We can't use
8615 dfs_walk here because we need to iterate through bases of BINFO
8616 and RTTI_BINFO simultaneously. */
8618 {
8619 /* Skip virtual bases. */
8625 inits);
8626 }
8627 }
8629 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8630 BINFO vtable to L. */
8632 static void
8634 tree orig_binfo,
8635 tree rtti_binfo,
8636 tree orig_vtbl,
8637 tree t,
8639 {
8646 {
8647 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8648 primary virtual base. If it is not the same primary in
8649 the hierarchy of T, we'll need to generate a ctor vtable
8650 for it, to place at its location in T. If it is the same
8651 primary, we still need a VTT entry for the vtable, but it
8652 should point to the ctor vtable for the base it is a
8653 primary for within the sub-hierarchy of RTTI_BINFO.
8655 There are three possible cases:
8657 1) We are in the same place.
8658 2) We are a primary base within a lost primary virtual base of
8659 RTTI_BINFO.
8660 3) We are primary to something not a base of RTTI_BINFO. */
8662 tree b;
8665 /* First, look through the bases we are primary to for RTTI_BINFO
8666 or a virtual base. */
8669 {
8674 }
8675 /* If we run out of primary links, keep looking down our
8676 inheritance chain; we might be an indirect primary. */
8680 found:
8682 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8683 base B and it is a base of RTTI_BINFO, this is case 2. In
8684 either case, we share our vtable with LAST, i.e. the
8685 derived-most base within B of which we are a primary. */
8688 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8689 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8690 binfo_ctor_vtable after everything's been set up. */
8693 /* Otherwise, this is case 3 and we get our own. */
8694 }
8701 {
8702 tree index;
8705 /* Add the initializer for this vtable. */
8709 /* Figure out the position to which the VPTR should point. */
8715 }
8718 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8719 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8720 straighten this out. */
8723 /* Throw away any unneeded intializers. */
8725 else
8726 /* For an ordinary vtable, set BINFO_VTABLE. */
8728 }
8732 /* Construct the initializer for BINFO's virtual function table. BINFO
8733 is part of the hierarchy dominated by T. If we're building a
8734 construction vtable, the ORIG_BINFO is the binfo we should use to
8735 find the actual function pointers to put in the vtable - but they
8736 can be overridden on the path to most-derived in the graph that
8737 ORIG_BINFO belongs. Otherwise,
8738 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8739 BINFO that should be indicated by the RTTI information in the
8740 vtable; it will be a base class of T, rather than T itself, if we
8741 are building a construction vtable.
8743 The value returned is a TREE_LIST suitable for wrapping in a
8744 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8745 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8746 number of non-function entries in the vtable.
8748 It might seem that this function should never be called with a
8749 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8750 base is always subsumed by a derived class vtable. However, when
8751 we are building construction vtables, we do build vtables for
8752 primary bases; we need these while the primary base is being
8753 constructed. */
8755 static void
8757 tree orig_binfo,
8758 tree t,
8759 tree rtti_binfo,
8762 {
8763 tree v;
8764 vtbl_init_data vid;
8766 tree vbinfo;
8770 /* Initialize VID. */
8778 /* The first vbase or vcall offset is at index -3 in the vtable. */
8781 /* Add entries to the vtable for RTTI. */
8784 /* Create an array for keeping track of the functions we've
8785 processed. When we see multiple functions with the same
8786 signature, we share the vcall offsets. */
8788 /* Add the vcall and vbase offset entries. */
8791 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8792 build_vbase_offset_vtbl_entries. */
8797 /* If the target requires padding between data entries, add that now. */
8799 {
8804 /* Move data entries into their new positions and add padding
8805 after the new positions. Iterate backwards so we don't
8806 overwrite entries that we would need to process later. */
8809 ix--)
8810 {
8818 {
8822 null_pointer_node);
8823 }
8824 }
8825 }
8830 /* The initializers for virtual functions were built up in reverse
8831 order. Straighten them out and add them to the running list in one
8832 step. */
8841 /* Go through all the ordinary virtual functions, building up
8842 initializers. */
8844 {
8845 tree delta;
8846 tree vcall_index;
8853 {
8857 {
8860 }
8862 }
8864 /* If the only definition of this function signature along our
8865 primary base chain is from a lost primary, this vtable slot will
8866 never be used, so just zero it out. This is important to avoid
8867 requiring extra thunks which cannot be generated with the function.
8869 We first check this in update_vtable_entry_for_fn, so we handle
8870 restored primary bases properly; we also need to do it here so we
8871 zero out unused slots in ctor vtables, rather than filling them
8872 with erroneous values (though harmless, apart from relocation
8873 costs). */
8878 {
8879 /* Pull the offset for `this', and the function to call, out of
8880 the list. */
8887 /* You can't call an abstract virtual function; it's abstract.
8888 So, we replace these functions with __pure_virtual. */
8890 {
8893 {
8895 abort_fndecl_addr
8899 }
8900 }
8901 /* Likewise for deleted virtuals. */
8903 {
8912 }
8913 else
8914 {
8916 {
8920 }
8921 /* Take the address of the function, considering it to be of an
8922 appropriate generic type. */
8926 }
8927 }
8929 /* And add it to the chain of initializers. */
8931 {
8936 else
8938 {
8944 }
8945 }
8946 else
8948 }
8949 }
8951 /* Adds to vid->inits the initializers for the vbase and vcall
8952 offsets in BINFO, which is in the hierarchy dominated by T. */
8954 static void
8956 {
8957 tree b;
8959 /* If this is a derived class, we must first create entries
8960 corresponding to the primary base class. */
8965 /* Add the vbase entries for this base. */
8967 /* Add the vcall entries for this base. */
8969 }
8971 /* Returns the initializers for the vbase offset entries in the vtable
8972 for BINFO (which is part of the class hierarchy dominated by T), in
8973 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8974 where the next vbase offset will go. */
8976 static void
8978 {
8979 tree vbase;
8980 tree t;
8981 tree non_primary_binfo;
8983 /* If there are no virtual baseclasses, then there is nothing to
8984 do. */
8990 /* We might be a primary base class. Go up the inheritance hierarchy
8991 until we find the most derived class of which we are a primary base:
8992 it is the offset of that which we need to use. */
8995 {
8996 tree b;
8998 /* If we have reached a virtual base, then it must be a primary
8999 base (possibly multi-level) of vid->binfo, or we wouldn't
9000 have called build_vcall_and_vbase_vtbl_entries for it. But it
9001 might be a lost primary, so just skip down to vid->binfo. */
9003 {
9006 }
9012 }
9014 /* Go through the virtual bases, adding the offsets. */
9016 vbase;
9018 {
9019 tree b;
9020 tree delta;
9025 /* Find the instance of this virtual base in the complete
9026 object. */
9029 /* If we've already got an offset for this virtual base, we
9030 don't need another one. */
9035 /* Figure out where we can find this vbase offset. */
9044 /* The vbase offset had better be the same. */
9047 /* The next vbase will come at a more negative offset. */
9051 /* The initializer is the delta from BINFO to this virtual base.
9052 The vbase offsets go in reverse inheritance-graph order, and
9053 we are walking in inheritance graph order so these end up in
9054 the right order. */
9061 }
9062 }
9064 /* Adds the initializers for the vcall offset entries in the vtable
9065 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9066 to VID->INITS. */
9068 static void
9070 {
9071 /* We only need these entries if this base is a virtual base. We
9072 compute the indices -- but do not add to the vtable -- when
9073 building the main vtable for a class. */
9076 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9077 correspond to VID->DERIVED), we are building a primary
9078 construction virtual table. Since this is a primary
9079 virtual table, we do not need the vcall offsets for
9080 BINFO. */
9082 {
9083 /* We need a vcall offset for each of the virtual functions in this
9084 vtable. For example:
9086 class A { virtual void f (); };
9087 class B1 : virtual public A { virtual void f (); };
9088 class B2 : virtual public A { virtual void f (); };
9089 class C: public B1, public B2 { virtual void f (); };
9091 A C object has a primary base of B1, which has a primary base of A. A
9092 C also has a secondary base of B2, which no longer has a primary base
9093 of A. So the B2-in-C construction vtable needs a secondary vtable for
9094 A, which will adjust the A* to a B2* to call f. We have no way of
9095 knowing what (or even whether) this offset will be when we define B2,
9096 so we store this "vcall offset" in the A sub-vtable and look it up in
9097 a "virtual thunk" for B2::f.
9099 We need entries for all the functions in our primary vtable and
9100 in our non-virtual bases' secondary vtables. */
9102 /* If we are just computing the vcall indices -- but do not need
9103 the actual entries -- not that. */
9106 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9108 }
9109 }
9111 /* Build vcall offsets, starting with those for BINFO. */
9113 static void
9115 {
9117 tree primary_binfo;
9118 tree base_binfo;
9120 /* Don't walk into virtual bases -- except, of course, for the
9121 virtual base for which we are building vcall offsets. Any
9122 primary virtual base will have already had its offsets generated
9123 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9127 /* If BINFO has a primary base, process it first. */
9132 /* Add BINFO itself to the list. */
9135 /* Scan the non-primary bases of BINFO. */
9139 }
9141 /* Called from build_vcall_offset_vtbl_entries_r. */
9143 static void
9145 {
9146 /* Make entries for the rest of the virtuals. */
9148 {
9149 tree orig_fn;
9151 /* The ABI requires that the methods be processed in declaration
9152 order. G++ 3.2 used the order in the vtable. */
9154 orig_fn;
9158 }
9159 else
9160 {
9161 tree derived_virtuals;
9162 tree base_virtuals;
9163 tree orig_virtuals;
9164 /* If BINFO is a primary base, the most derived class which has
9165 BINFO as a primary base; otherwise, just BINFO. */
9166 tree non_primary_binfo;
9168 /* We might be a primary base class. Go up the inheritance hierarchy
9169 until we find the most derived class of which we are a primary base:
9170 it is the BINFO_VIRTUALS there that we need to consider. */
9173 {
9174 tree b;
9176 /* If we have reached a virtual base, then it must be vid->vbase,
9177 because we ignore other virtual bases in
9178 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9179 base (possibly multi-level) of vid->binfo, or we wouldn't
9180 have called build_vcall_and_vbase_vtbl_entries for it. But it
9181 might be a lost primary, so just skip down to vid->binfo. */
9183 {
9187 }
9193 }
9196 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9197 where rtti_binfo is the most derived type. */
9198 non_primary_binfo
9204 base_virtuals;
9208 {
9209 tree orig_fn;
9211 /* Find the declaration that originally caused this function to
9212 be present in BINFO_TYPE (binfo). */
9215 /* When processing BINFO, we only want to generate vcall slots for
9216 function slots introduced in BINFO. So don't try to generate
9217 one if the function isn't even defined in BINFO. */
9222 }
9223 }
9224 }
9226 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9228 static void
9230 {
9232 tree vcall_offset;
9233 tree derived_entry;
9235 /* If there is already an entry for a function with the same
9236 signature as FN, then we do not need a second vcall offset.
9237 Check the list of functions already present in the derived
9238 class vtable. */
9240 {
9242 /* We only use one vcall offset for virtual destructors,
9243 even though there are two virtual table entries. */
9247 }
9249 /* If we are building these vcall offsets as part of building
9250 the vtable for the most derived class, remember the vcall
9251 offset. */
9253 {
9256 }
9258 /* The next vcall offset will be found at a more negative
9259 offset. */
9263 /* Keep track of this function. */
9267 {
9268 tree base;
9269 tree fn;
9271 /* Find the overriding function. */
9275 else
9276 {
9279 /* The vbase we're working on is a primary base of
9280 vid->binfo. But it might be a lost primary, so its
9281 BINFO_OFFSET might be wrong, so we just use the
9282 BINFO_OFFSET from vid->binfo. */
9288 vcall_offset);
9289 }
9290 /* Add the initializer to the vtable. */
9292 }
9293 }
9295 /* Return vtbl initializers for the RTTI entries corresponding to the
9296 BINFO's vtable. The RTTI entries should indicate the object given
9297 by VID->rtti_binfo. */
9299 static void
9301 {
9302 tree b;
9303 tree t;
9304 tree offset;
9305 tree decl;
9306 tree init;
9310 /* To find the complete object, we will first convert to our most
9311 primary base, and then add the offset in the vtbl to that value. */
9315 {
9316 tree primary_base;
9322 }
9326 /* The second entry is the address of the typeinfo object. */
9329 else
9332 /* Convert the declaration to a type that can be stored in the
9333 vtable. */
9337 /* Add the offset-to-top entry. It comes earlier in the vtable than
9338 the typeinfo entry. Convert the offset to look like a
9339 function pointer, so that we can put it in the vtable. */
9342 }
9344 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9345 accessibility. */
9347 bool
9349 {
9352 }
9354 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9356 bool
9358 {
9362 }
9364 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9365 class between them, if any. */
9367 tree
9369 {
9381 {
9384 }
9388 }