| blob | c587e55ac6815e178c34ce2bdd53ee005f1f5384 |
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. */
1520 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1523 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1527 /* A standard-layout class is a class that:
1528 ...
1529 * has no non-standard-layout base classes, */
1532 {
1533 tree basefield;
1534 /* ...has no base classes of the same type as the first non-static
1535 data member... */
1537 && (same_type_ignoring_top_level_qualifiers_p
1540 else
1541 /* ...either has no non-static data members in the most-derived
1542 class and at most one base class with non-static data
1543 members, or has no base classes with non-static data
1544 members */
1548 {
1551 else
1554 }
1555 }
1557 /* Don't bother collecting tm attributes if transactional memory
1558 support is not enabled. */
1560 {
1564 }
1567 }
1569 /* If one of the base classes had TM attributes, and the current class
1570 doesn't define its own, then the current class inherits one. */
1572 {
1575 }
1576 }
1578 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1579 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1580 that have had a nearly-empty virtual primary base stolen by some
1581 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1582 T. */
1584 static void
1586 {
1590 tree base_binfo;
1592 /* Determine the primary bases of our bases. */
1595 {
1598 /* See if we're the non-virtual primary of our inheritance
1599 chain. */
1601 {
1608 /* We are the primary binfo. */
1610 }
1611 /* Determine if we have a virtual primary base, and mark it so.
1612 */
1614 {
1618 /* Someone already claimed this base. */
1620 else
1621 {
1622 tree delta;
1627 /* A virtual binfo might have been copied from within
1628 another hierarchy. As we're about to use it as a
1629 primary base, make sure the offsets match. */
1637 }
1638 }
1639 }
1641 /* First look for a dynamic direct non-virtual base. */
1643 {
1647 {
1650 }
1651 }
1653 /* A "nearly-empty" virtual base class can be the primary base
1654 class, if no non-virtual polymorphic base can be found. Look for
1655 a nearly-empty virtual dynamic base that is not already a primary
1656 base of something in the hierarchy. If there is no such base,
1657 just pick the first nearly-empty virtual base. */
1663 {
1665 {
1666 /* Found one that is not primary. */
1669 }
1671 /* Remember the first candidate. */
1673 }
1675 found:
1676 /* If we've got a primary base, use it. */
1678 {
1683 /* We are stealing a primary base. */
1687 {
1688 tree delta;
1691 /* A virtual binfo might have been copied from within
1692 another hierarchy. As we're about to use it as a primary
1693 base, make sure the offsets match. */
1698 }
1705 }
1706 }
1708 /* Update the variant types of T. */
1710 void
1712 {
1713 tree variants;
1719 variants;
1721 {
1722 /* These fields are in the _TYPE part of the node, not in
1723 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1733 /* Copy whatever these are holding today. */
1737 }
1738 }
1740 /* Early variant fixups: we apply attributes at the beginning of the class
1741 definition, and we need to fix up any variants that have already been
1742 made via elaborated-type-specifier so that check_qualified_type works. */
1744 void
1746 {
1747 tree variants;
1753 variants;
1755 {
1756 /* These are the two fields that check_qualified_type looks at and
1757 are affected by attributes. */
1760 }
1761 }
1762 \f
1763 /* Set memoizing fields and bits of T (and its variants) for later
1764 use. */
1766 static void
1768 {
1769 /* Fix up variants (if any). */
1773 /* For a class w/o baseclasses, 'finish_struct' has set
1774 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1775 Similarly for a class whose base classes do not have vtables.
1776 When neither of these is true, we might have removed abstract
1777 virtuals (by providing a definition), added some (by declaring
1778 new ones), or redeclared ones from a base class. We need to
1779 recalculate what's really an abstract virtual at this point (by
1780 looking in the vtables). */
1783 /* If this type has a copy constructor or a destructor, force its
1784 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1785 nonzero. This will cause it to be passed by invisible reference
1786 and prevent it from being returned in a register. */
1789 {
1790 tree variants;
1793 {
1796 }
1797 }
1798 }
1800 /* Issue warnings about T having private constructors, but no friends,
1801 and so forth.
1803 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1804 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1805 non-private static member functions. */
1807 static void
1809 {
1812 tree fn;
1815 /* If the class has friends, those entities might create and
1816 access instances, so we should not warn. */
1819 /* We will have warned when the template was declared; there's
1820 no need to warn on every instantiation. */
1822 /* There's no reason to even consider warning about this
1823 class. */
1826 /* We only issue one warning, if more than one applies, because
1827 otherwise, on code like:
1829 class A {
1830 // Oops - forgot `public:'
1831 A();
1832 A(const A&);
1833 ~A();
1834 };
1836 we warn several times about essentially the same problem. */
1838 /* Check to see if all (non-constructor, non-destructor) member
1839 functions are private. (Since there are no friends or
1840 non-private statics, we can't ever call any of the private member
1841 functions.) */
1843 /* We're not interested in compiler-generated methods; they don't
1844 provide any way to call private members. */
1846 {
1848 {
1850 /* A non-private static member function is just like a
1851 friend; it can create and invoke private member
1852 functions, and be accessed without a class
1853 instance. */
1857 /* Keep searching for a static member function. */
1858 }
1861 }
1864 {
1865 /* There are no non-private methods, and there's at least one
1866 private member function that isn't a constructor or
1867 destructor. (If all the private members are
1868 constructors/destructors we want to use the code below that
1869 issues error messages specifically referring to
1870 constructors/destructors.) */
1876 {
1879 }
1881 {
1885 }
1886 }
1888 /* Even if some of the member functions are non-private, the class
1889 won't be useful for much if all the constructors or destructors
1890 are private: such an object can never be created or destroyed. */
1893 {
1896 t);
1898 }
1900 /* Warn about classes that have private constructors and no friends. */
1902 /* Implicitly generated constructors are always public. */
1905 {
1908 /* If a non-template class does not define a copy
1909 constructor, one is defined for it, enabling it to avoid
1910 this warning. For a template class, this does not
1911 happen, and so we would normally get a warning on:
1913 template <class T> class C { private: C(); };
1915 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1916 complete non-template or fully instantiated classes have this
1917 flag set. */
1920 else
1922 {
1924 /* Ideally, we wouldn't count copy constructors (or, in
1925 fact, any constructor that takes an argument of the
1926 class type as a parameter) because such things cannot
1927 be used to construct an instance of the class unless
1928 you already have one. But, for now at least, we're
1929 more generous. */
1931 {
1934 }
1935 }
1938 {
1941 t);
1943 }
1944 }
1945 }
1948 gt_pointer_operator new_value;
1952 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1954 static int
1956 {
1969 }
1971 /* This routine compares two fields like method_name_cmp but using the
1972 pointer operator in resort_field_decl_data. */
1974 static int
1976 {
1985 {
1992 }
1994 }
1996 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1998 void
2001 gt_pointer_operator new_value,
2003 {
2007 tree fn;
2009 /* The type conversion ops have to live at the front of the vec, so we
2010 can't sort them. */
2018 {
2022 resort_method_name_cmp);
2023 }
2024 }
2026 /* Warn about duplicate methods in fn_fields.
2028 Sort methods that are not special (i.e., constructors, destructors,
2029 and type conversion operators) so that we can find them faster in
2030 search. */
2032 static void
2034 {
2035 tree fn_fields;
2045 /* Clear DECL_IN_AGGR_P for all functions. */
2050 /* Issue warnings about private constructors and such. If there are
2051 no methods, then some public defaults are generated. */
2054 /* The type conversion ops have to live at the front of the vec, so we
2055 can't sort them. */
2064 }
2066 /* Make BINFO's vtable have N entries, including RTTI entries,
2067 vbase and vcall offsets, etc. Set its type and call the back end
2068 to lay it out. */
2070 static void
2072 {
2073 tree atype;
2074 tree vtable;
2079 /* We may have to grow the vtable. */
2082 {
2086 }
2087 }
2089 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2090 have the same signature. */
2092 int
2094 {
2095 /* One destructor overrides another if they are the same kind of
2096 destructor. */
2100 /* But a non-destructor never overrides a destructor, nor vice
2101 versa, nor do different kinds of destructors override
2102 one-another. For example, a complete object destructor does not
2103 override a deleting destructor. */
2112 {
2120 }
2122 }
2124 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2125 subobject. */
2127 static bool
2129 {
2130 tree probe;
2133 {
2137 /* If we meet a virtual base, we can't follow the inheritance
2138 any more. See if the complete type of DERIVED contains
2139 such a virtual base. */
2142 }
2144 }
2147 /* The function for which we are trying to find a final overrider. */
2148 tree fn;
2149 /* The base class in which the function was declared. */
2150 tree declaring_base;
2151 /* The candidate overriders. */
2152 tree candidates;
2153 /* Path to most derived. */
2157 /* Add the overrider along the current path to FFOD->CANDIDATES.
2158 Returns true if an overrider was found; false otherwise. */
2160 static bool
2164 {
2165 tree method;
2167 /* If BINFO is not the most derived type, try a more derived class.
2168 A definition there will overrider a definition here. */
2170 {
2171 depth--;
2175 }
2179 {
2182 /* Remove any candidates overridden by this new function. */
2184 {
2185 /* If *CANDIDATE overrides METHOD, then METHOD
2186 cannot override anything else on the list. */
2189 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2192 else
2194 }
2196 /* Add the new function. */
2199 }
2202 }
2204 /* Called from find_final_overrider via dfs_walk. */
2206 static tree
2208 {
2216 }
2218 static tree
2220 {
2225 }
2227 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2228 FN and whose TREE_VALUE is the binfo for the base where the
2229 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2230 DERIVED) is the base object in which FN is declared. */
2232 static tree
2234 {
2235 find_final_overrider_data ffod;
2237 /* Getting this right is a little tricky. This is valid:
2239 struct S { virtual void f (); };
2240 struct T { virtual void f (); };
2241 struct U : public S, public T { };
2243 even though calling `f' in `U' is ambiguous. But,
2245 struct R { virtual void f(); };
2246 struct S : virtual public R { virtual void f (); };
2247 struct T : virtual public R { virtual void f (); };
2248 struct U : public S, public T { };
2250 is not -- there's no way to decide whether to put `S::f' or
2251 `T::f' in the vtable for `R'.
2253 The solution is to look at all paths to BINFO. If we find
2254 different overriders along any two, then there is a problem. */
2258 /* Determine the depth of the hierarchy. */
2269 /* If there was no winner, issue an error message. */
2274 }
2276 /* Return the index of the vcall offset for FN when TYPE is used as a
2277 virtual base. */
2279 static tree
2281 {
2283 tree_pair_p p;
2291 /* There should always be an appropriate index. */
2293 }
2295 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2296 dominated by T. FN is the old function; VIRTUALS points to the
2297 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2298 of that entry in the list. */
2300 static void
2303 {
2304 tree b;
2305 tree overrider;
2306 tree delta;
2307 tree virtual_base;
2308 tree first_defn;
2314 /* Find the nearest primary base (possibly binfo itself) which defines
2315 this function; this is the class the caller will convert to when
2316 calling FN through BINFO. */
2318 {
2323 /* The nearest definition is from a lost primary. */
2326 }
2329 /* Find the final overrider. */
2332 {
2335 }
2338 /* Check for adjusting covariant return types. */
2346 /* If the overrider is invalid, don't even try. */
2348 {
2349 /* If FN is a covariant thunk, we must figure out the adjustment
2350 to the final base FN was converting to. As OVERRIDER_TARGET might
2351 also be converting to the return type of FN, we have to
2352 combine the two conversions here. */
2359 {
2363 }
2364 else
2368 /* Find the equivalent binfo within the return type of the
2369 overriding function. We will want the vbase offset from
2370 there. */
2372 over_return);
2375 {
2376 /* There was no existing virtual thunk (which takes
2377 precedence). So find the binfo of the base function's
2378 return type within the overriding function's return type.
2379 We cannot call lookup base here, because we're inside a
2380 dfs_walk, and will therefore clobber the BINFO_MARKED
2381 flags. Fortunately we know the covariancy is valid (it
2382 has already been checked), so we can just iterate along
2383 the binfos, which have been chained in inheritance graph
2384 order. Of course it is lame that we have to repeat the
2385 search here anyway -- we should really be caching pieces
2386 of the vtable and avoiding this repeated work. */
2389 /* Find the base binfo within the overriding function's
2390 return type. We will always find a thunk_binfo, except
2391 when the covariancy is invalid (which we will have
2392 already diagnosed). */
2395 thunk_binfo;
2401 /* See if virtual inheritance is involved. */
2403 virtual_offset;
2410 {
2414 {
2415 /* We convert via virtual base. Adjust the fixed
2416 offset to be from there. */
2417 offset =
2421 }
2423 /* There was an existing fixed offset, this must be
2424 from the base just converted to, and the base the
2425 FN was thunking to. */
2427 else
2429 }
2430 }
2433 /* Replace the overriding function with a covariant thunk. We
2434 will emit the overriding function in its own slot as
2435 well. */
2438 }
2439 else
2443 /* If we need a covariant thunk, then we may need to adjust first_defn.
2444 The ABI specifies that the thunks emitted with a function are
2445 determined by which bases the function overrides, so we need to be
2446 sure that we're using a thunk for some overridden base; even if we
2447 know that the necessary this adjustment is zero, there may not be an
2448 appropriate zero-this-adjusment thunk for us to use since thunks for
2449 overriding virtual bases always use the vcall offset.
2451 Furthermore, just choosing any base that overrides this function isn't
2452 quite right, as this slot won't be used for calls through a type that
2453 puts a covariant thunk here. Calling the function through such a type
2454 will use a different slot, and that slot is the one that determines
2455 the thunk emitted for that base.
2457 So, keep looking until we find the base that we're really overriding
2458 in this slot: the nearest primary base that doesn't use a covariant
2459 thunk in this slot. */
2461 {
2463 /* We already know that the overrider needs a covariant thunk. */
2466 {
2473 }
2475 }
2477 /* Assume that we will produce a thunk that convert all the way to
2478 the final overrider, and not to an intermediate virtual base. */
2481 /* See if we can convert to an intermediate virtual base first, and then
2482 use the vcall offset located there to finish the conversion. */
2484 {
2485 /* If we find the final overrider, then we can stop
2486 walking. */
2491 /* If we find a virtual base, and we haven't yet found the
2492 overrider, then there is a virtual base between the
2493 declaring base (first_defn) and the final overrider. */
2495 {
2498 }
2499 }
2501 /* Compute the constant adjustment to the `this' pointer. The
2502 `this' pointer, when this function is called, will point at BINFO
2503 (or one of its primary bases, which are at the same offset). */
2505 /* The `this' pointer needs to be adjusted from the declaration to
2506 the nearest virtual base. */
2511 /* If the nearest definition is in a lost primary, we don't need an
2512 entry in our vtable. Except possibly in a constructor vtable,
2513 if we happen to get our primary back. In that case, the offset
2514 will be zero, as it will be a primary base. */
2516 else
2517 /* The `this' pointer needs to be adjusted from pointing to
2518 BINFO to pointing at the base where the final overrider
2519 appears. */
2530 else
2534 }
2536 /* Called from modify_all_vtables via dfs_walk. */
2538 static tree
2540 {
2542 tree virtuals;
2543 tree old_virtuals;
2547 /* A base without a vtable needs no modification, and its bases
2548 are uninteresting. */
2553 /* Don't do the primary vtable, if it's new. */
2557 /* There's no need to modify the vtable for a non-virtual primary
2558 base; we're not going to use that vtable anyhow. We do still
2559 need to do this for virtual primary bases, as they could become
2560 non-primary in a construction vtable. */
2565 /* Now, go through each of the virtual functions in the virtual
2566 function table for BINFO. Find the final overrider, and update
2567 the BINFO_VIRTUALS list appropriately. */
2570 virtuals;
2574 binfo,
2579 }
2581 /* Update all of the primary and secondary vtables for T. Create new
2582 vtables as required, and initialize their RTTI information. Each
2583 of the functions in VIRTUALS is declared in T and may override a
2584 virtual function from a base class; find and modify the appropriate
2585 entries to point to the overriding functions. Returns a list, in
2586 declaration order, of the virtual functions that are declared in T,
2587 but do not appear in the primary base class vtable, and which
2588 should therefore be appended to the end of the vtable for T. */
2590 static tree
2592 {
2596 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2600 /* Update all of the vtables. */
2603 /* Add virtual functions not already in our primary vtable. These
2604 will be both those introduced by this class, and those overridden
2605 from secondary bases. It does not include virtuals merely
2606 inherited from secondary bases. */
2608 {
2613 {
2614 /* We don't need to adjust the `this' pointer when
2615 calling this function. */
2619 /* This is a function not already in our vtable. Keep it. */
2621 }
2622 else
2623 /* We've already got an entry for this function. Skip it. */
2625 }
2628 }
2630 /* Get the base virtual function declarations in T that have the
2631 indicated NAME. */
2633 static tree
2635 {
2636 tree methods;
2641 /* Find virtual functions in T with the indicated NAME. */
2645 methods;
2647 {
2653 }
2659 {
2662 base_fndecls);
2663 }
2666 }
2668 /* If this declaration supersedes the declaration of
2669 a method declared virtual in the base class, then
2670 mark this field as being virtual as well. */
2672 void
2674 {
2677 /* In [temp.mem] we have:
2679 A specialization of a member function template does not
2680 override a virtual function from a base class. */
2687 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2688 the error_mark_node so that we know it is an overriding
2689 function. */
2690 {
2693 }
2696 {
2702 }
2707 }
2709 /* Warn about hidden virtual functions that are not overridden in t.
2710 We know that constructors and destructors don't apply. */
2712 static void
2714 {
2716 tree fns;
2719 /* We go through each separately named virtual function. */
2723 {
2724 tree fn;
2725 tree name;
2726 tree fndecl;
2727 tree base_fndecls;
2728 tree base_binfo;
2729 tree binfo;
2732 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2733 have the same name. Figure out what name that is. */
2735 /* There are no possibly hidden functions yet. */
2737 /* Iterate through all of the base classes looking for possibly
2738 hidden functions. */
2741 {
2744 base_fndecls);
2745 }
2747 /* If there are no functions to hide, continue. */
2751 /* Remove any overridden functions. */
2753 {
2756 {
2760 /* If the method from the base class has the same
2761 signature as the method from the derived class, it
2762 has been overridden. */
2765 else
2767 }
2768 }
2770 /* Now give a warning for all base functions without overriders,
2771 as they are hidden. */
2773 {
2774 /* Here we know it is a hider, and no overrider exists. */
2778 }
2779 }
2780 }
2782 /* Recursive helper for finish_struct_anon. */
2784 static void
2786 {
2790 {
2791 /* We're generally only interested in entities the user
2792 declared, but we also find nested classes by noticing
2793 the TYPE_DECL that we create implicitly. You're
2794 allowed to put one anonymous union inside another,
2795 though, so we explicitly tolerate that. We use
2796 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2797 we also allow unnamed types used for defining fields. */
2804 {
2806 {
2809 "%q+#D invalid; an anonymous union can "
2811 else
2813 "%q+#D invalid; an anonymous struct can "
2815 }
2817 }
2820 {
2822 {
2826 else
2829 }
2831 {
2835 else
2838 }
2839 }
2844 /* Recurse into the anonymous aggregates to handle correctly
2845 access control (c++/24926):
2847 class A {
2848 union {
2849 union {
2850 int i;
2851 };
2852 };
2853 };
2855 int j=A().i; */
2859 }
2860 }
2862 /* Check for things that are invalid. There are probably plenty of other
2863 things we should check for also. */
2865 static void
2867 {
2869 {
2878 }
2879 }
2881 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2882 will be used later during class template instantiation.
2883 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2884 a non-static member data (FIELD_DECL), a member function
2885 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2886 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2887 When FRIEND_P is nonzero, T is either a friend class
2888 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2889 (FUNCTION_DECL, TEMPLATE_DECL). */
2891 void
2893 {
2894 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2899 }
2901 /* This function is called from declare_virt_assop_and_dtor via
2902 dfs_walk_all.
2904 DATA is a type that direcly or indirectly inherits the base
2905 represented by BINFO. If BINFO contains a virtual assignment [copy
2906 assignment or move assigment] operator or a virtual constructor,
2907 declare that function in DATA if it hasn't been already declared. */
2909 static tree
2911 {
2919 /* A base without a vtable needs no modification, and its bases
2920 are uninteresting. */
2924 /* If this is a primary base, then we have already looked at the
2925 virtual functions of its vtable. */
2929 {
2933 {
2938 }
2942 }
2945 }
2947 /* If the class type T has a direct or indirect base that contains a
2948 virtual assignment operator or a virtual destructor, declare that
2949 function in T if it hasn't been already declared. */
2951 static void
2953 {
2961 dfs_declare_virt_assop_and_dtor,
2963 }
2965 /* Declare the inheriting constructor for class T inherited from base
2966 constructor CTOR with the parameter array PARMS of size NPARMS. */
2968 static void
2970 {
2971 /* We don't declare an inheriting ctor that would be a default,
2972 copy or move ctor for derived or base. */
2977 {
2981 }
2989 {
2992 }
2993 }
2995 /* Declare all the inheriting constructors for class T inherited from base
2996 constructor CTOR. */
2998 static void
3000 {
3006 {
3010 }
3013 {
3017 }
3018 }
3020 /* Create default constructors, assignment operators, and so forth for
3021 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3022 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3023 the class cannot have a default constructor, copy constructor
3024 taking a const reference argument, or an assignment operator taking
3025 a const reference, respectively. */
3027 static void
3031 {
3039 /* Destructor. */
3041 {
3042 /* In general, we create destructors lazily. */
3047 /* But if this is a Java class, any non-trivial destructor is
3048 invalid, even if compiler-generated. Therefore, if the
3049 destructor is non-trivial we create it now. */
3051 }
3053 /* [class.ctor]
3055 If there is no user-declared constructor for a class, a default
3056 constructor is implicitly declared. */
3058 {
3063 /* This might force the declaration. */
3065 }
3067 /* [class.ctor]
3069 If a class definition does not explicitly declare a copy
3070 constructor, one is declared implicitly. */
3072 {
3078 }
3080 /* If there is no assignment operator, one will be created if and
3081 when it is needed. For now, just record whether or not the type
3082 of the parameter to the assignment operator will be a const or
3083 non-const reference. */
3085 {
3091 }
3093 /* We can't be lazy about declaring functions that might override
3094 a virtual function from a base class. */
3098 {
3102 {
3103 /* declare, then remove the decl */
3112 }
3113 else
3115 }
3116 }
3118 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3119 count the number of fields in TYPE, including anonymous union
3120 members. */
3122 static int
3124 {
3125 tree x;
3128 {
3131 else
3133 }
3135 }
3137 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3138 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3139 elts, starting at offset IDX. */
3141 static int
3143 {
3144 tree x;
3146 {
3149 else
3151 }
3153 }
3155 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3156 starting at offset IDX. */
3158 static int
3162 {
3163 tree values;
3167 }
3169 /* FIELD is a bit-field. We are finishing the processing for its
3170 enclosing type. Issue any appropriate messages and set appropriate
3171 flags. Returns false if an error has been diagnosed. */
3173 static bool
3175 {
3177 tree w;
3179 /* Extract the declared width of the bitfield, which has been
3180 temporarily stashed in DECL_INITIAL. */
3183 /* Remove the bit-field width indicator so that the rest of the
3184 compiler does not treat that value as an initializer. */
3187 /* Detect invalid bit-field type. */
3189 {
3192 }
3193 else
3194 {
3196 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3199 /* detect invalid field size. */
3205 {
3208 }
3210 {
3213 }
3215 {
3218 }
3230 }
3233 {
3237 }
3238 else
3239 {
3240 /* Non-bit-fields are aligned for their type. */
3244 }
3245 }
3247 /* FIELD is a non bit-field. We are finishing the processing for its
3248 enclosing type T. Issue any appropriate messages and set appropriate
3249 flags. */
3251 static void
3253 tree t,
3257 {
3260 /* In C++98 an anonymous union cannot contain any fields which would change
3261 the settings of CANT_HAVE_CONST_CTOR and friends. */
3263 ;
3264 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3265 structs. So, we recurse through their fields here. */
3267 {
3268 tree fields;
3274 }
3275 /* Check members with class type for constructors, destructors,
3276 etc. */
3278 {
3279 /* Never let anything with uninheritable virtuals
3280 make it through without complaint. */
3284 {
3289 field);
3294 field);
3296 {
3300 }
3301 }
3302 else
3303 {
3316 }
3325 }
3330 {
3331 /* `build_class_init_list' does not recognize
3332 non-FIELD_DECLs. */
3336 }
3337 }
3339 /* Check the data members (both static and non-static), class-scoped
3340 typedefs, etc., appearing in the declaration of T. Issue
3341 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3342 declaration order) of access declarations; each TREE_VALUE in this
3343 list is a USING_DECL.
3345 In addition, set the following flags:
3347 EMPTY_P
3348 The class is empty, i.e., contains no non-static data members.
3350 CANT_HAVE_CONST_CTOR_P
3351 This class cannot have an implicitly generated copy constructor
3352 taking a const reference.
3354 CANT_HAVE_CONST_ASN_REF
3355 This class cannot have an implicitly generated assignment
3356 operator taking a const reference.
3358 All of these flags should be initialized before calling this
3359 function.
3361 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3362 fields can be added by adding to this chain. */
3364 static void
3368 {
3376 /* Assume there are no access declarations. */
3378 /* Assume this class has no pointer members. */
3380 /* Assume none of the members of this class have default
3381 initializations. */
3385 {
3393 {
3394 /* Save the access declarations for our caller. */
3397 }
3403 /* If we've gotten this far, it's a data member, possibly static,
3404 or an enumerator. */
3408 /* When this goes into scope, it will be a non-local reference. */
3412 {
3413 /* [class.union]
3415 If a union contains a static data member, or a member of
3416 reference type, the program is ill-formed. */
3418 {
3421 }
3423 {
3428 }
3429 }
3431 /* Perform error checking that did not get done in
3432 grokdeclarator. */
3434 {
3438 }
3440 {
3444 }
3452 /* Now it can only be a FIELD_DECL. */
3457 /* If at least one non-static data member is non-literal, the whole
3458 class becomes non-literal. Note: if the type is incomplete we
3459 will complain later on. */
3463 /* A standard-layout class is a class that:
3464 ...
3465 has the same access control (Clause 11) for all non-static data members,
3466 ... */
3473 /* If this is of reference type, check if it needs an init. */
3475 {
3481 /* ARM $12.6.2: [A member initializer list] (or, for an
3482 aggregate, initialization by a brace-enclosed list) is the
3483 only way to initialize nonstatic const and reference
3484 members. */
3487 }
3492 {
3494 {
3495 warning
3498 x);
3500 }
3504 }
3507 /* We don't treat zero-width bitfields as making a class
3508 non-empty. */
3509 ;
3510 else
3511 {
3512 /* The class is non-empty. */
3514 /* The class is not even nearly empty. */
3516 /* If one of the data members contains an empty class,
3517 so does T. */
3521 }
3523 /* This is used by -Weffc++ (see below). Warn only for pointers
3524 to members which might hold dynamic memory. So do not warn
3525 for pointers to functions or pointers to members. */
3531 {
3536 }
3542 {
3544 {
3548 }
3550 {
3554 }
3555 }
3558 /* DR 148 now allows pointers to members (which are POD themselves),
3559 to be allowed in POD structs. */
3568 /* We set DECL_C_BIT_FIELD in grokbitfield.
3569 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3572 cant_have_const_ctor_p,
3573 no_const_asn_ref_p,
3576 /* Now that we've removed bit-field widths from DECL_INITIAL,
3577 anything left in DECL_INITIAL is an NSDMI that makes the class
3578 non-aggregate. */
3582 /* If any field is const, the structure type is pseudo-const. */
3584 {
3589 /* ARM $12.6.2: [A member initializer list] (or, for an
3590 aggregate, initialization by a brace-enclosed list) is the
3591 only way to initialize nonstatic const and reference
3592 members. */
3595 }
3596 /* A field that is pseudo-const makes the structure likewise. */
3598 {
3603 }
3605 /* Core issue 80: A nonstatic data member is required to have a
3606 different name from the class iff the class has a
3607 user-declared constructor. */
3611 }
3613 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3614 it should also define a copy constructor and an assignment operator to
3615 implement the correct copy semantic (deep vs shallow, etc.). As it is
3616 not feasible to check whether the constructors do allocate dynamic memory
3617 and store it within members, we approximate the warning like this:
3619 -- Warn only if there are members which are pointers
3620 -- Warn only if there is a non-trivial constructor (otherwise,
3621 there cannot be memory allocated).
3622 -- Warn only if there is a non-trivial destructor. We assume that the
3623 user at least implemented the cleanup correctly, and a destructor
3624 is needed to free dynamic memory.
3626 This seems enough for practical purposes. */
3628 && has_pointers
3632 {
3636 {
3641 }
3645 }
3647 /* Non-static data member initializers make the default constructor
3648 non-trivial. */
3650 {
3653 }
3655 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3659 /* Check anonymous struct/anonymous union fields. */
3662 /* We've built up the list of access declarations in reverse order.
3663 Fix that now. */
3665 }
3667 /* If TYPE is an empty class type, records its OFFSET in the table of
3668 OFFSETS. */
3670 static int
3672 {
3673 splay_tree_node n;
3678 /* Record the location of this empty object in OFFSETS. */
3686 type,
3690 }
3692 /* Returns nonzero if TYPE is an empty class type and there is
3693 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3695 static int
3697 {
3698 splay_tree_node n;
3699 tree t;
3704 /* Record the location of this empty object in OFFSETS. */
3714 }
3716 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3717 F for every subobject, passing it the type, offset, and table of
3718 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3719 be traversed.
3721 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3722 than MAX_OFFSET will not be walked.
3724 If F returns a nonzero value, the traversal ceases, and that value
3725 is returned. Otherwise, returns zero. */
3727 static int
3729 subobject_offset_fn f,
3730 tree offset,
3731 splay_tree offsets,
3732 tree max_offset,
3734 {
3738 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3739 stop. */
3747 {
3751 }
3754 {
3755 tree field;
3756 tree binfo;
3759 /* Avoid recursing into objects that are not interesting. */
3763 /* Record the location of TYPE. */
3768 /* Iterate through the direct base classes of TYPE. */
3772 {
3773 tree binfo_offset;
3786 offset,
3788 else
3789 {
3790 tree orig_binfo;
3791 /* We cannot rely on BINFO_OFFSET being set for the base
3792 class yet, but the offsets for direct non-virtual
3793 bases can be calculated by going back to the TYPE. */
3796 offset,
3798 }
3801 f,
3802 binfo_offset,
3803 offsets,
3804 max_offset,
3809 }
3812 {
3816 /* Iterate through the virtual base classes of TYPE. In G++
3817 3.2, we included virtual bases in the direct base class
3818 loop above, which results in incorrect results; the
3819 correct offsets for virtual bases are only known when
3820 working with the most derived type. */
3824 {
3826 f,
3828 offset,
3830 offsets,
3831 max_offset,
3835 }
3836 else
3837 {
3838 /* We still have to walk the primary base, if it is
3839 virtual. (If it is non-virtual, then it was walked
3840 above.) */
3846 {
3847 r = (walk_subobject_offsets
3852 }
3853 }
3854 }
3856 /* Iterate through the fields of TYPE. */
3861 {
3862 tree field_offset;
3866 else
3867 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3871 f,
3873 offset,
3874 field_offset),
3875 offsets,
3876 max_offset,
3880 }
3881 }
3883 {
3886 tree index;
3888 /* Avoid recursing into objects that are not interesting. */
3893 /* Step through each of the elements in the array. */
3895 /* G++ 3.2 had an off-by-one error here. */
3900 {
3902 f,
3903 offset,
3904 offsets,
3905 max_offset,
3911 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3912 there's no point in iterating through the remaining
3913 elements of the array. */
3916 }
3917 }
3920 }
3922 /* Record all of the empty subobjects of TYPE (either a type or a
3923 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3924 is being placed at OFFSET; otherwise, it is a base class that is
3925 being placed at OFFSET. */
3927 static void
3929 tree offset,
3930 splay_tree offsets,
3932 {
3933 tree max_offset;
3934 /* If recording subobjects for a non-static data member or a
3935 non-empty base class , we do not need to record offsets beyond
3936 the size of the biggest empty class. Additional data members
3937 will go at the end of the class. Additional base classes will go
3938 either at offset zero (if empty, in which case they cannot
3939 overlap with offsets past the size of the biggest empty class) or
3940 at the end of the class.
3942 However, if we are placing an empty base class, then we must record
3943 all offsets, as either the empty class is at offset zero (where
3944 other empty classes might later be placed) or at the end of the
3945 class (where other objects might then be placed, so other empty
3946 subobjects might later overlap). */
3950 else
3954 }
3956 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3957 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3958 virtual bases of TYPE are examined. */
3960 static int
3962 tree offset,
3963 splay_tree offsets,
3965 {
3966 splay_tree_node max_node;
3968 /* Get the node in OFFSETS that indicates the maximum offset where
3969 an empty subobject is located. */
3971 /* If there aren't any empty subobjects, then there's no point in
3972 performing this check. */
3978 vbases_p);
3979 }
3981 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3982 non-static data member of the type indicated by RLI. BINFO is the
3983 binfo corresponding to the base subobject, OFFSETS maps offsets to
3984 types already located at those offsets. This function determines
3985 the position of the DECL. */
3987 static void
3989 tree decl,
3990 tree binfo,
3991 splay_tree offsets)
3992 {
3995 tree type;
3998 {
3999 /* For the purposes of determining layout conflicts, we want to
4000 use the class type of BINFO; TREE_TYPE (DECL) will be the
4001 CLASSTYPE_AS_BASE version, which does not contain entries for
4002 zero-sized bases. */
4005 }
4006 else
4007 {
4010 }
4012 /* Try to place the field. It may take more than one try if we have
4013 a hard time placing the field without putting two objects of the
4014 same type at the same address. */
4016 {
4019 /* Place this field. */
4023 /* We have to check to see whether or not there is already
4024 something of the same type at the offset we're about to use.
4025 For example, consider:
4027 struct S {};
4028 struct T : public S { int i; };
4029 struct U : public S, public T {};
4031 Here, we put S at offset zero in U. Then, we can't put T at
4032 offset zero -- its S component would be at the same address
4033 as the S we already allocated. So, we have to skip ahead.
4034 Since all data members, including those whose type is an
4035 empty class, have nonzero size, any overlap can happen only
4036 with a direct or indirect base-class -- it can't happen with
4037 a data member. */
4038 /* In a union, overlap is permitted; all members are placed at
4039 offset zero. */
4042 /* G++ 3.2 did not check for overlaps when placing a non-empty
4043 virtual base. */
4048 {
4049 /* Strip off the size allocated to this field. That puts us
4050 at the first place we could have put the field with
4051 proper alignment. */
4054 /* Bump up by the alignment required for the type. */
4055 rli->bitpos
4061 }
4062 else
4063 /* There was no conflict. We're done laying out this field. */
4065 }
4067 /* Now that we know where it will be placed, update its
4068 BINFO_OFFSET. */
4070 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4071 this point because their BINFO_OFFSET is copied from another
4072 hierarchy. Therefore, we may not need to add the entire
4073 OFFSET. */
4079 }
4081 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4083 static int
4085 tree offset,
4087 {
4089 }
4091 /* Layout the empty base BINFO. EOC indicates the byte currently just
4092 past the end of the class, and should be correctly aligned for a
4093 class of the type indicated by BINFO; OFFSETS gives the offsets of
4094 the empty bases allocated so far. T is the most derived
4095 type. Return nonzero iff we added it at the end. */
4097 static bool
4100 {
4101 tree alignment;
4105 /* This routine should only be used for empty classes. */
4110 {
4112 propagate_binfo_offsets
4115 else
4117 "offset of empty base %qT may not be ABI-compliant and may"
4120 }
4122 /* This is an empty base class. We first try to put it at offset
4123 zero. */
4126 offsets,
4128 {
4129 /* That didn't work. Now, we move forward from the next
4130 available spot in the class. */
4134 {
4137 offsets,
4139 /* We finally found a spot where there's no overlap. */
4142 /* There's overlap here, too. Bump along to the next spot. */
4144 }
4145 }
4148 {
4153 }
4156 }
4158 /* Layout the base given by BINFO in the class indicated by RLI.
4159 *BASE_ALIGN is a running maximum of the alignments of
4160 any base class. OFFSETS gives the location of empty base
4161 subobjects. T is the most derived type. Return nonzero if the new
4162 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4163 *NEXT_FIELD, unless BINFO is for an empty base class.
4165 Returns the location at which the next field should be inserted. */
4170 {
4175 /* This error is now reported in xref_tag, thus giving better
4176 location information. */
4179 /* Place the base class. */
4181 {
4182 tree decl;
4184 /* The containing class is non-empty because it has a non-empty
4185 base class. */
4188 /* Create the FIELD_DECL. */
4195 {
4203 /* Try to place the field. It may take more than one try if we
4204 have a hard time placing the field without putting two
4205 objects of the same type at the same address. */
4207 /* Add the new FIELD_DECL to the list of fields for T. */
4211 }
4212 }
4213 else
4214 {
4215 tree eoc;
4218 /* On some platforms (ARM), even empty classes will not be
4219 byte-aligned. */
4224 /* A nearly-empty class "has no proper base class that is empty,
4225 not morally virtual, and at an offset other than zero." */
4227 {
4230 /* The check above (used in G++ 3.2) is insufficient because
4231 an empty class placed at offset zero might itself have an
4232 empty base at a nonzero offset. */
4234 empty_base_at_nonzero_offset_p,
4235 size_zero_node,
4239 {
4242 else
4244 "class %qT will be considered nearly empty in a "
4246 }
4247 }
4249 /* We do not create a FIELD_DECL for empty base classes because
4250 it might overlap some other field. We want to be able to
4251 create CONSTRUCTORs for the class by iterating over the
4252 FIELD_DECLs, and the back end does not handle overlapping
4253 FIELD_DECLs. */
4255 /* An empty virtual base causes a class to be non-empty
4256 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4257 here because that was already done when the virtual table
4258 pointer was created. */
4259 }
4261 /* Record the offsets of BINFO and its base subobjects. */
4264 offsets,
4268 }
4270 /* Layout all of the non-virtual base classes. Record empty
4271 subobjects in OFFSETS. T is the most derived type. Return nonzero
4272 if the type cannot be nearly empty. The fields created
4273 corresponding to the base classes will be inserted at
4274 *NEXT_FIELD. */
4276 static void
4279 {
4280 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4281 subobjects. */
4286 /* The primary base class is always allocated first. */
4291 /* Now allocate the rest of the bases. */
4293 {
4294 tree base_binfo;
4298 /* The primary base was already allocated above, so we don't
4299 need to allocate it again here. */
4303 /* Virtual bases are added at the end (a primary virtual base
4304 will have already been added). */
4310 }
4311 }
4313 /* Go through the TYPE_METHODS of T issuing any appropriate
4314 diagnostics, figuring out which methods override which other
4315 methods, and so forth. */
4317 static void
4319 {
4320 tree x;
4323 {
4327 /* The name of the field is the original field name
4328 Save this in auxiliary field for later overloading. */
4330 {
4334 }
4335 /* All user-provided destructors are non-trivial.
4336 Constructors and assignment ops are handled in
4337 grok_special_member_properties. */
4340 }
4341 }
4343 /* FN is a constructor or destructor. Clone the declaration to create
4344 a specialized in-charge or not-in-charge version, as indicated by
4345 NAME. */
4347 static tree
4349 {
4350 tree parms;
4351 tree clone;
4353 /* Copy the function. */
4355 /* Reset the function name. */
4358 /* Remember where this function came from. */
4360 /* Make it easy to find the CLONE given the FN. */
4364 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4366 {
4373 }
4376 /* There's no pending inline data for this function. */
4380 /* The base-class destructor is not virtual. */
4382 {
4386 }
4388 /* If there was an in-charge parameter, drop it from the function
4389 type. */
4391 {
4392 tree basetype;
4393 tree parmtypes;
4394 tree exceptions;
4399 /* Skip the `this' parameter. */
4401 /* Skip the in-charge parameter. */
4403 /* And the VTT parm, in a complete [cd]tor. */
4407 /* If this is subobject constructor or destructor, add the vtt
4408 parameter. */
4412 parmtypes);
4415 exceptions);
4419 }
4421 /* Copy the function parameters. */
4423 /* Remove the in-charge parameter. */
4425 {
4429 }
4430 /* And the VTT parm, in a complete [cd]tor. */
4432 {
4435 else
4436 {
4440 }
4441 }
4444 {
4447 }
4449 /* Create the RTL for this function. */
4457 }
4459 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4460 not invoke this function directly.
4462 For a non-thunk function, returns the address of the slot for storing
4463 the function it is a clone of. Otherwise returns NULL_TREE.
4465 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4466 cloned_function is unset. This is to support the separate
4467 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4468 on a template makes sense, but not the former. */
4470 tree *
4472 {
4480 {
4481 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4484 else
4485 #endif
4487 }
4492 else
4494 }
4496 /* Produce declarations for all appropriate clones of FN. If
4497 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4498 CLASTYPE_METHOD_VEC as well. */
4500 void
4502 {
4503 tree clone;
4505 /* Avoid inappropriate cloning. */
4511 {
4512 /* For each constructor, we need two variants: an in-charge version
4513 and a not-in-charge version. */
4520 }
4521 else
4522 {
4525 /* For each destructor, we need three variants: an in-charge
4526 version, a not-in-charge version, and an in-charge deleting
4527 version. We clone the deleting version first because that
4528 means it will go second on the TYPE_METHODS list -- and that
4529 corresponds to the correct layout order in the virtual
4530 function table.
4532 For a non-virtual destructor, we do not build a deleting
4533 destructor. */
4535 {
4539 }
4546 }
4548 /* Note that this is an abstract function that is never emitted. */
4550 }
4552 /* DECL is an in charge constructor, which is being defined. This will
4553 have had an in class declaration, from whence clones were
4554 declared. An out-of-class definition can specify additional default
4555 arguments. As it is the clones that are involved in overload
4556 resolution, we must propagate the information from the DECL to its
4557 clones. */
4559 void
4561 {
4562 tree clone;
4566 {
4573 /* Skip the 'this' parameter. */
4589 {
4594 {
4595 /* A default parameter has been added. Adjust the
4596 clone's parameters. */
4600 tree type;
4605 {
4608 clone_parms);
4610 }
4613 clone_parms);
4622 }
4623 }
4625 }
4626 }
4628 /* For each of the constructors and destructors in T, create an
4629 in-charge and not-in-charge variant. */
4631 static void
4633 {
4634 tree fns;
4636 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4637 out now. */
4645 }
4647 /* Deduce noexcept for a destructor DTOR. */
4649 void
4651 {
4653 {
4660 }
4661 }
4663 /* For each destructor in T, deduce noexcept:
4665 12.4/3: A declaration of a destructor that does not have an
4666 exception-specification is implicitly considered to have the
4667 same exception-specification as an implicit declaration (15.4). */
4669 static void
4671 {
4672 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4673 out now. */
4679 /* Avoid early exit from synthesized_method_walk (c++/57645). */
4686 }
4688 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4689 of TYPE for virtual functions which FNDECL overrides. Return a
4690 mask of the tm attributes found therein. */
4692 static int
4694 {
4696 tree base_binfo;
4700 {
4710 else
4712 }
4715 }
4717 /* Subroutine of set_method_tm_attributes. Handle the checks and
4718 inheritance for one virtual method FNDECL. */
4720 static void
4722 {
4723 tree tm_attr;
4728 /* If FNDECL doesn't actually override anything (i.e. T is the
4729 class that first declares FNDECL virtual), then we're done. */
4736 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4737 tm_pure must match exactly, otherwise no weakening of
4738 tm_safe > tm_callable > nothing. */
4739 /* ??? The tm_pure attribute didn't make the transition to the
4740 multivendor language spec. */
4742 {
4744 {
4747 }
4748 }
4749 /* If the overridden function is tm_pure, then FNDECL must be. */
4752 /* Look for base class combinations that cannot be satisfied. */
4754 {
4760 }
4761 /* If FNDECL did not declare an attribute, then inherit the most
4762 restrictive one. */
4764 {
4766 }
4767 /* Otherwise validate that we're not weaker than a function
4768 that is being overridden. */
4769 else
4770 {
4774 }
4777 err_override:
4781 }
4783 /* For each of the methods in T, propagate a class-level tm attribute. */
4785 static void
4787 {
4790 /* Don't bother collecting tm attributes if transactional memory
4791 support is not enabled. */
4795 /* Process virtual methods first, as they inherit directly from the
4796 base virtual function and also require validation of new attributes. */
4798 {
4799 tree vchain;
4802 {
4807 }
4808 }
4810 /* If the class doesn't have an attribute, nothing more to do. */
4815 /* Any method that does not yet have a tm attribute inherits
4816 the one from the class. */
4818 {
4821 }
4822 }
4824 /* Returns true iff class T has a user-defined constructor other than
4825 the default constructor. */
4827 bool
4829 {
4830 tree fns;
4836 {
4843 }
4846 }
4848 /* Returns the defaulted constructor if T has one. Otherwise, returns
4849 NULL_TREE. */
4851 tree
4853 {
4860 {
4864 {
4870 }
4871 }
4874 }
4876 /* Returns true iff FN is a user-provided function, i.e. user-declared
4877 and not defaulted at its first declaration; or explicit, private,
4878 protected, or non-const. */
4880 bool
4882 {
4885 else
4888 }
4890 /* Returns true iff class T has a user-provided constructor. */
4892 bool
4894 {
4895 tree fns;
4903 /* This can happen in error cases; avoid crashing. */
4912 }
4914 /* Returns true iff class T has a user-provided default constructor. */
4916 bool
4918 {
4919 tree fns;
4925 {
4931 }
4934 }
4936 /* TYPE is being used as a virtual base, and has a non-trivial move
4937 assignment. Return true if this is due to there being a user-provided
4938 move assignment in TYPE or one of its subobjects; if there isn't, then
4939 multiple move assignment can't cause any harm. */
4941 bool
4943 {
4944 /* Does the type itself have a user-provided move assignment operator? */
4948 {
4952 }
4954 /* Do any of its bases? */
4956 tree base_binfo;
4961 /* Or non-static data members? */
4963 {
4968 }
4970 /* Seems not. */
4972 }
4974 /* If default-initialization leaves part of TYPE uninitialized, returns
4975 a DECL for the field or TYPE itself (DR 253). */
4977 tree
4979 {
4990 {
4994 }
4999 {
5003 }
5006 }
5008 /* Returns true iff for class T, a trivial synthesized default constructor
5009 would be constexpr. */
5011 bool
5013 {
5014 /* A defaulted trivial default constructor is constexpr
5015 if there is nothing to initialize. */
5018 }
5020 /* Returns true iff class T has a constexpr default constructor. */
5022 bool
5024 {
5025 tree fns;
5028 {
5029 /* The caller should have stripped an enclosing array. */
5032 }
5034 {
5037 /* Non-trivial, we need to check subobject constructors. */
5039 }
5042 }
5044 /* Returns true iff class TYPE has a virtual destructor. */
5046 bool
5048 {
5049 tree dtor;
5057 }
5059 /* Returns true iff class T has a move constructor. */
5061 bool
5063 {
5064 tree fns;
5067 {
5070 }
5080 }
5082 /* Returns true iff class T has a move assignment operator. */
5084 bool
5086 {
5087 tree fns;
5090 {
5093 }
5101 }
5103 /* Returns true iff class T has a move constructor that was explicitly
5104 declared in the class body. Note that this is different from
5105 "user-provided", which doesn't include functions that are defaulted in
5106 the class. */
5108 bool
5110 {
5111 tree fns;
5120 {
5124 }
5127 }
5129 /* Returns true iff class T has a move assignment operator that was
5130 explicitly declared in the class body. */
5132 bool
5134 {
5135 tree fns;
5142 {
5146 }
5149 }
5151 /* Nonzero if we need to build up a constructor call when initializing an
5152 object of this class, either because it has a user-provided constructor
5153 or because it doesn't have a default constructor (so we need to give an
5154 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5155 what you care about is whether or not an object can be produced by a
5156 constructor (e.g. so we don't set TREE_READONLY on const variables of
5157 such type); use this function when what you care about is whether or not
5158 to try to call a constructor to create an object. The latter case is
5159 the former plus some cases of constructors that cannot be called. */
5161 bool
5163 {
5164 tree inner;
5170 }
5172 /* Remove all zero-width bit-fields from T. */
5174 static void
5176 {
5181 {
5184 /* We should not be confused by the fact that grokbitfield
5185 temporarily sets the width of the bit field into
5186 DECL_INITIAL (*fieldsp).
5187 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5188 to that width. */
5191 else
5193 }
5194 }
5196 /* Returns TRUE iff we need a cookie when dynamically allocating an
5197 array whose elements have the indicated class TYPE. */
5199 static bool
5201 {
5202 tree fns;
5207 /* If there's a non-trivial destructor, we need a cookie. In order
5208 to iterate through the array calling the destructor for each
5209 element, we'll have to know how many elements there are. */
5213 /* If the usual deallocation function is a two-argument whose second
5214 argument is of type `size_t', then we have to pass the size of
5215 the array to the deallocation function, so we will need to store
5216 a cookie. */
5220 /* If there are no `operator []' members, or the lookup is
5221 ambiguous, then we don't need a cookie. */
5224 /* Loop through all of the functions. */
5226 {
5227 tree fn;
5228 tree second_parm;
5230 /* Select the current function. */
5232 /* See if this function is a one-argument delete function. If
5233 it is, then it will be the usual deallocation function. */
5237 /* Do not consider this function if its second argument is an
5238 ellipsis. */
5241 /* Otherwise, if we have a two-argument function and the second
5242 argument is `size_t', it will be the usual deallocation
5243 function -- unless there is one-argument function, too. */
5247 }
5250 }
5252 /* Finish computing the `literal type' property of class type T.
5254 At this point, we have already processed base classes and
5255 non-static data members. We need to check whether the copy
5256 constructor is trivial, the destructor is trivial, and there
5257 is a trivial default constructor or at least one constexpr
5258 constructor other than the copy constructor. */
5260 static void
5262 {
5263 tree fn;
5279 {
5282 {
5286 }
5287 }
5288 }
5290 /* T is a non-literal type used in a context which requires a constant
5291 expression. Explain why it isn't literal. */
5293 void
5295 {
5305 /* Already explained. */
5314 {
5316 "default constructor, and has no constexpr constructor that "
5320 {
5321 /* Note that we can't simply call locate_ctor because when the
5322 constructor is deleted it just returns NULL_TREE. */
5323 tree fns;
5325 {
5332 {
5335 else
5338 }
5339 }
5340 }
5341 }
5342 else
5343 {
5347 {
5350 {
5355 }
5356 }
5358 {
5359 tree ftype;
5364 {
5369 }
5370 }
5371 }
5372 }
5374 /* Check the validity of the bases and members declared in T. Add any
5375 implicitly-generated functions (like copy-constructors and
5376 assignment operators). Compute various flag bits (like
5377 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5378 level: i.e., independently of the ABI in use. */
5380 static void
5382 {
5383 /* Nonzero if the implicitly generated copy constructor should take
5384 a non-const reference argument. */
5386 /* Nonzero if the implicitly generated assignment operator
5387 should take a non-const reference argument. */
5389 tree access_decls;
5392 tree fn;
5394 /* By default, we use const reference arguments and generate default
5395 constructors. */
5399 /* Check all the base-classes. */
5403 /* Deduce noexcept on destructors. This needs to happen after we've set
5404 triviality flags appropriately for our bases. */
5408 /* Check all the method declarations. */
5411 /* Save the initial values of these flags which only indicate whether
5412 or not the class has user-provided functions. As we analyze the
5413 bases and members we can set these flags for other reasons. */
5417 /* Check all the data member declarations. We cannot call
5418 check_field_decls until we have called check_bases check_methods,
5419 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5420 being set appropriately. */
5425 /* A nearly-empty class has to be vptr-containing; a nearly empty
5426 class contains just a vptr. */
5430 /* Do some bookkeeping that will guide the generation of implicitly
5431 declared member functions. */
5434 /* We need to call a constructor for this class if it has a
5435 user-provided constructor, or if the default constructor is going
5436 to initialize the vptr. (This is not an if-and-only-if;
5437 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5438 themselves need constructing.) */
5441 /* [dcl.init.aggr]
5443 An aggregate is an array or a class with no user-provided
5444 constructors ... and no virtual functions.
5446 Again, other conditions for being an aggregate are checked
5447 elsewhere. */
5450 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5451 retain the old definition internally for ABI reasons. */
5460 /* If the class has no user-declared constructor, but does have
5461 non-static const or reference data members that can never be
5462 initialized, issue a warning. */
5464 /* Classes with user-declared constructors are presumed to
5465 initialize these members. */
5467 /* Aggregates can be initialized with brace-enclosed
5468 initializers. */
5470 {
5471 tree field;
5474 {
5475 tree type;
5490 }
5491 }
5493 /* Synthesize any needed methods. */
5495 cant_have_const_ctor,
5496 no_const_asn_ref);
5498 /* Check defaulted declarations here so we have cant_have_const_ctor
5499 and don't need to worry about clones. */
5502 {
5505 {
5506 bool imp_const_p
5512 /* If the function is defaulted outside the class, we just
5513 give the synthesis error. */
5516 }
5518 }
5521 {
5522 /* "The closure type associated with a lambda-expression has a deleted
5523 default constructor and a deleted copy assignment operator." */
5529 /* "This class type is not an aggregate." */
5531 }
5533 /* Compute the 'literal type' property before we
5534 do anything with non-static member functions. */
5537 /* Create the in-charge and not-in-charge variants of constructors
5538 and destructors. */
5541 /* Process the using-declarations. */
5545 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5548 /* Figure out whether or not we will need a cookie when dynamically
5549 allocating an array of this type. */
5552 }
5554 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5555 accordingly. If a new vfield was created (because T doesn't have a
5556 primary base class), then the newly created field is returned. It
5557 is not added to the TYPE_FIELDS list; it is the caller's
5558 responsibility to do that. Accumulate declared virtual functions
5559 on VIRTUALS_P. */
5561 static tree
5563 {
5564 tree fn;
5566 /* Collect the virtual functions declared in T. */
5570 {
5579 }
5581 /* If we couldn't find an appropriate base class, create a new field
5582 here. Even if there weren't any new virtual functions, we might need a
5583 new virtual function table if we're supposed to include vptrs in
5584 all classes that need them. */
5586 {
5587 /* We build this decl with vtbl_ptr_type_node, which is a
5588 `vtable_entry_type*'. It might seem more precise to use
5589 `vtable_entry_type (*)[N]' where N is the number of virtual
5590 functions. However, that would require the vtable pointer in
5591 base classes to have a different type than the vtable pointer
5592 in derived classes. We could make that happen, but that
5593 still wouldn't solve all the problems. In particular, the
5594 type-based alias analysis code would decide that assignments
5595 to the base class vtable pointer can't alias assignments to
5596 the derived class vtable pointer, since they have different
5597 types. Thus, in a derived class destructor, where the base
5598 class constructor was inlined, we could generate bad code for
5599 setting up the vtable pointer.
5601 Therefore, we use one type for all vtable pointers. We still
5602 use a type-correct type; it's just doesn't indicate the array
5603 bounds. That's better than using `void*' or some such; it's
5604 cleaner, and it let's the alias analysis code know that these
5605 stores cannot alias stores to void*! */
5606 tree field;
5619 /* This class is non-empty. */
5623 }
5626 }
5628 /* Add OFFSET to all base types of BINFO which is a base in the
5629 hierarchy dominated by T.
5631 OFFSET, which is a type offset, is number of bytes. */
5633 static void
5635 {
5637 tree primary_binfo;
5638 tree base_binfo;
5640 /* Update BINFO's offset. */
5645 offset));
5647 /* Find the primary base class. */
5653 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5654 downwards. */
5656 {
5657 /* Don't do the primary base twice. */
5665 }
5666 }
5668 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5669 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5670 empty subobjects of T. */
5672 static void
5674 {
5675 tree vbase;
5684 {
5685 /* In G++ 3.2, we incorrectly rounded the size before laying out
5686 the virtual bases. */
5688 #ifdef STRUCTURE_SIZE_BOUNDARY
5689 /* Packed structures don't need to have minimum size. */
5692 #endif
5696 }
5698 /* Find the last field. The artificial fields created for virtual
5699 bases will go after the last extant field to date. */
5704 /* Go through the virtual bases, allocating space for each virtual
5705 base that is not already a primary base class. These are
5706 allocated in inheritance graph order. */
5708 {
5713 {
5716 /* This virtual base is not a primary base of any class in the
5717 hierarchy, so we have to add space for it. */
5721 /* If the first virtual base might have been placed at a
5722 lower address, had we started from CLASSTYPE_SIZE, rather
5723 than TYPE_SIZE, issue a warning. There can be both false
5724 positives and false negatives from this warning in rare
5725 cases; to deal with all the possibilities would probably
5726 require performing both layout algorithms and comparing
5727 the results which is not particularly tractable. */
5729 && first_vbase
5730 && (tree_int_cst_lt
5735 bitsize_unit_node),
5738 "offset of virtual base %qT is not ABI-compliant and "
5740 basetype);
5743 }
5744 }
5745 }
5747 /* Returns the offset of the byte just past the end of the base class
5748 BINFO. */
5750 static tree
5752 {
5753 tree size;
5758 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5759 allocate some space for it. It cannot have virtual bases, so
5760 TYPE_SIZE_UNIT is fine. */
5762 else
5766 }
5768 /* Returns the offset of the byte just past the end of the base class
5769 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5770 only non-virtual bases are included. */
5772 static tree
5774 {
5777 tree binfo;
5778 tree base_binfo;
5779 tree offset;
5784 {
5794 }
5796 /* G++ 3.2 did not check indirect virtual bases. */
5800 {
5804 }
5807 }
5809 /* Warn about bases of T that are inaccessible because they are
5810 ambiguous. For example:
5812 struct S {};
5813 struct T : public S {};
5814 struct U : public S, public T {};
5816 Here, `(S*) new U' is not allowed because there are two `S'
5817 subobjects of U. */
5819 static void
5821 {
5824 tree basetype;
5825 tree binfo;
5826 tree base_binfo;
5828 /* If there are no repeated bases, nothing can be ambiguous. */
5832 /* Check direct bases. */
5835 {
5841 }
5843 /* Check for ambiguous virtual bases. */
5847 {
5853 }
5854 }
5856 /* Compare two INTEGER_CSTs K1 and K2. */
5858 static int
5860 {
5862 }
5864 /* Increase the size indicated in RLI to account for empty classes
5865 that are "off the end" of the class. */
5867 static void
5869 {
5870 tree eoc;
5871 tree rli_size;
5873 /* It might be the case that we grew the class to allocate a
5874 zero-sized base class. That won't be reflected in RLI, yet,
5875 because we are willing to overlay multiple bases at the same
5876 offset. However, now we need to make sure that RLI is big enough
5877 to reflect the entire class. */
5883 {
5885 /* In version 1 of the ABI, the size of a class that ends with
5886 a bitfield was not rounded up to a whole multiple of a
5887 byte. Because rli_size_unit_so_far returns only the number
5888 of fully allocated bytes, any extra bits were not included
5889 in the size. */
5891 else
5892 /* The size should have been rounded to a whole byte. */
5895 rli->bitpos
5904 }
5905 }
5907 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5908 BINFO_OFFSETs for all of the base-classes. Position the vtable
5909 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5911 static void
5913 {
5914 tree non_static_data_members;
5915 tree field;
5916 tree vptr;
5917 record_layout_info rli;
5918 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5919 types that appear at that offset. */
5920 splay_tree empty_base_offsets;
5921 /* True if the last field laid out was a bit-field. */
5923 /* The location at which the next field should be inserted. */
5925 /* T, as a base class. */
5926 tree base_t;
5928 /* Keep track of the first non-static data member. */
5931 /* Start laying out the record. */
5934 /* Mark all the primary bases in the hierarchy. */
5937 /* Create a pointer to our virtual function table. */
5940 /* The vptr is always the first thing in the class. */
5942 {
5947 }
5948 else
5951 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5956 /* Layout the non-static data members. */
5958 {
5959 tree type;
5960 tree padding;
5962 /* We still pass things that aren't non-static data members to
5963 the back end, in case it wants to do something with them. */
5965 {
5967 /* If the static data member has incomplete type, keep track
5968 of it so that it can be completed later. (The handling
5969 of pending statics in finish_record_layout is
5970 insufficient; consider:
5972 struct S1;
5973 struct S2 { static S1 s1; };
5975 At this point, finish_record_layout will be called, but
5976 S1 is still incomplete.) */
5978 {
5980 /* The visibility of static data members is determined
5981 at their point of declaration, not their point of
5982 definition. */
5984 }
5986 }
5994 /* If this field is a bit-field whose width is greater than its
5995 type, then there are some special rules for allocating
5996 it. */
5999 {
6001 tree integer_type;
6003 /* We must allocate the bits as if suitably aligned for the
6004 longest integer type that fits in this many bits. type
6005 of the field. Then, we are supposed to use the left over
6006 bits as additional padding. */
6015 /* ITK now indicates a type that is too large for the
6016 field. We have to back up by one to find the largest
6017 type that fits. */
6018 do
6019 {
6024 /* Figure out how much additional padding is required. GCC
6025 3.2 always created a padding field, even if it had zero
6026 width. */
6029 {
6031 /* In a union, the padding field must have the full width
6032 of the bit-field; all fields start at offset zero. */
6034 else
6035 {
6038 "ABI-compliant and may change in a future "
6040 t);
6043 }
6044 }
6045 #ifdef PCC_BITFIELD_TYPE_MATTERS
6046 /* An unnamed bitfield does not normally affect the
6047 alignment of the containing class on a target where
6048 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6049 make any exceptions for unnamed bitfields when the
6050 bitfields are longer than their types. Therefore, we
6051 temporarily give the field a name. */
6053 {
6056 }
6057 #endif
6062 empty_base_offsets);
6065 /* Now that layout has been performed, set the size of the
6066 field to the size of its declared type; the rest of the
6067 field is effectively invisible. */
6069 /* We must also reset the DECL_MODE of the field. */
6074 /* Versions of G++ before G++ 3.4 did not reset the
6075 DECL_MODE. */
6077 "the offset of %qD may not be ABI-compliant and may "
6079 }
6080 else
6082 empty_base_offsets);
6084 /* Remember the location of any empty classes in FIELD. */
6088 empty_base_offsets,
6091 /* If a bit-field does not immediately follow another bit-field,
6092 and yet it starts in the middle of a byte, we have failed to
6093 comply with the ABI. */
6096 /* The TREE_NO_WARNING flag gets set by Objective-C when
6097 laying out an Objective-C class. The ObjC ABI differs
6098 from the C++ ABI, and so we do not want a warning
6099 here. */
6101 && !last_field_was_bitfield
6104 bitsize_unit_node)))
6108 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
6109 offset of the field. */
6116 "classes to be placed at different locations in a "
6119 /* The middle end uses the type of expressions to determine the
6120 possible range of expression values. In order to optimize
6121 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6122 must be made aware of the width of "i", via its type.
6124 Because C++ does not have integer types of arbitrary width,
6125 we must (for the purposes of the front end) convert from the
6126 type assigned here to the declared type of the bitfield
6127 whenever a bitfield expression is used as an rvalue.
6128 Similarly, when assigning a value to a bitfield, the value
6129 must be converted to the type given the bitfield here. */
6131 {
6136 {
6143 }
6144 }
6146 /* If we needed additional padding after this field, add it
6147 now. */
6149 {
6150 tree padding_field;
6153 FIELD_DECL,
6154 NULL_TREE,
6155 char_type_node);
6162 NULL_TREE,
6163 empty_base_offsets);
6164 }
6167 }
6170 {
6171 /* Make sure that we are on a byte boundary so that the size of
6172 the class without virtual bases will always be a round number
6173 of bytes. */
6176 }
6178 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6179 padding. */
6183 /* Delete all zero-width bit-fields from the list of fields. Now
6184 that the type is laid out they are no longer important. */
6187 /* Create the version of T used for virtual bases. We do not use
6188 make_class_type for this version; this is an artificial type. For
6189 a POD type, we just reuse T. */
6191 {
6194 /* Set the size and alignment for the new type. In G++ 3.2, all
6195 empty classes were considered to have size zero when used as
6196 base classes. */
6198 {
6203 "layout of classes derived from empty class %qT "
6205 t);
6206 }
6207 else
6208 {
6209 tree eoc;
6211 /* If the ABI version is not at least two, and the last
6212 field was a bit-field, RLI may not be on a byte
6213 boundary. In particular, rli_size_unit_so_far might
6214 indicate the last complete byte, while rli_size_so_far
6215 indicates the total number of bits used. Therefore,
6216 rli_size_so_far, rather than rli_size_unit_so_far, is
6217 used to compute TYPE_SIZE_UNIT. */
6225 eoc);
6232 }
6236 /* Copy the fields from T. */
6240 {
6242 FIELD_DECL,
6252 }
6254 /* Record the base version of the type. */
6257 }
6258 else
6261 /* Every empty class contains an empty class. */
6265 /* Set the TYPE_DECL for this type to contain the right
6266 value for DECL_OFFSET, so that we can use it as part
6267 of a COMPONENT_REF for multiple inheritance. */
6270 /* Now fix up any virtual base class types that we left lying
6271 around. We must get these done before we try to lay out the
6272 virtual function table. As a side-effect, this will remove the
6273 base subobject fields. */
6276 /* Make sure that empty classes are reflected in RLI at this
6277 point. */
6280 /* Make sure not to create any structures with zero size. */
6286 /* If this is a non-POD, declaring it packed makes a difference to how it
6287 can be used as a field; don't let finalize_record_size undo it. */
6291 /* Let the back end lay out the type. */
6300 /* Warn about bases that can't be talked about due to ambiguity. */
6303 /* Now that we're done with layout, give the base fields the real types. */
6308 /* Clean up. */
6315 }
6317 /* Determine the "key method" for the class type indicated by TYPE,
6318 and set CLASSTYPE_KEY_METHOD accordingly. */
6320 void
6322 {
6323 tree method;
6326 || processing_template_decl
6331 /* The key method is the first non-pure virtual function that is not
6332 inline at the point of class definition. On some targets the
6333 key function may not be inline; those targets should not call
6334 this function until the end of the translation unit. */
6340 {
6343 }
6346 }
6349 /* Allocate and return an instance of struct sorted_fields_type with
6350 N fields. */
6354 {
6361 }
6364 /* Perform processing required when the definition of T (a class type)
6365 is complete. */
6367 void
6369 {
6370 tree x;
6371 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6375 {
6380 }
6382 /* If this type was previously laid out as a forward reference,
6383 make sure we lay it out again. */
6387 /* Make assumptions about the class; we'll reset the flags if
6388 necessary. */
6394 /* Do end-of-class semantic processing: checking the validity of the
6395 bases and members and add implicitly generated methods. */
6398 /* Find the key method. */
6400 {
6401 /* The Itanium C++ ABI permits the key method to be chosen when
6402 the class is defined -- even though the key method so
6403 selected may later turn out to be an inline function. On
6404 some systems (such as ARM Symbian OS) the key method cannot
6405 be determined until the end of the translation unit. On such
6406 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6407 will cause the class to be added to KEYED_CLASSES. Then, in
6408 finish_file we will determine the key method. */
6412 /* If a polymorphic class has no key method, we may emit the vtable
6413 in every translation unit where the class definition appears. */
6416 }
6418 /* Layout the class itself. */
6421 /* We use the base type for trivial assignments, and hence it
6422 needs a mode. */
6427 /* If necessary, create the primary vtable for this class. */
6429 {
6430 /* We must enter these virtuals into the table. */
6434 /* Here we know enough to change the type of our virtual
6435 function table, but we will wait until later this function. */
6438 /* If we're warning about ABI tags, check the types of the new
6439 virtual functions. */
6443 }
6446 {
6448 tree fn;
6455 /* Add entries for virtual functions introduced by this class. */
6459 /* Set DECL_VINDEX for all functions declared in this class. */
6461 fn;
6463 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6465 {
6469 /* A thunk. We should never be calling this entry directly
6470 from this vtable -- we'd use the entry for the non
6471 thunk base function. */
6475 }
6476 }
6481 /* Complete the rtl for any static member objects of the type we're
6482 working on. */
6489 /* Done with FIELDS...now decide whether to sort these for
6490 faster lookups later.
6492 We use a small number because most searches fail (succeeding
6493 ultimately as the search bores through the inheritance
6494 hierarchy), and we want this failure to occur quickly. */
6498 /* Complain if one of the field types requires lower visibility. */
6501 /* Make the rtl for any new vtables we have created, and unmark
6502 the base types we marked. */
6505 /* Build the VTT for T. */
6508 /* This warning does not make sense for Java classes, since they
6509 cannot have destructors. */
6511 {
6512 tree dtor;
6516 if it were virtual, we would have created it by now. */
6517 !dtor
6526 "%q#T has virtual functions and accessible"
6528 }
6535 /* Class layout, assignment of virtual table slots, etc., is now
6536 complete. Give the back end a chance to tweak the visibility of
6537 the class or perform any other required target modifications. */
6547 /* Finish debugging output for this type. */
6551 {
6554 {
6557 }
6559 {
6562 else
6563 {
6566 }
6568 }
6570 {
6572 "the type of the first field has a different ABI from the "
6575 }
6576 }
6577 }
6579 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6580 equal to THRESHOLD or greater than THRESHOLD. */
6582 static void
6584 {
6587 {
6592 }
6593 }
6595 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6597 void
6599 {
6602 {
6604 int n_fields
6615 }
6616 }
6618 /* When T was built up, the member declarations were added in reverse
6619 order. Rearrange them to declaration order. */
6621 void
6623 {
6624 tree next;
6625 tree prev;
6626 tree x;
6628 /* The following lists are all in reverse order. Put them in
6629 declaration order now. */
6633 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6634 reverse order, so we can't just use nreverse. */
6639 {
6643 }
6645 {
6649 }
6650 }
6652 tree
6654 {
6657 /* Now that we've got all the field declarations, reverse everything
6658 as necessary. */
6663 /* Nadger the current location so that diagnostics point to the start of
6664 the struct, not the end. */
6668 {
6669 tree x;
6675 /* We need to emit an error message if this type was used as a parameter
6676 and it is an abstract type, even if it is a template. We construct
6677 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6678 account and we call complete_vars with this type, which will check
6679 the PARM_DECLS. Note that while the type is being defined,
6680 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6681 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6687 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6688 an enclosing scope is a template class, so that this function be
6689 found by lookup_fnfields_1 when the using declaration is not
6690 instantiated yet. */
6693 {
6698 }
6700 /* Remember current #pragma pack value. */
6703 /* Fix up any variants we've already built. */
6705 {
6710 }
6711 }
6712 else
6721 else
6725 /* Lambdas are defined by the LAMBDA_EXPR. */
6730 }
6731 \f
6732 /* Hash table to avoid endless recursion when handling references. */
6735 /* Return the dynamic type of INSTANCE, if known.
6736 Used to determine whether the virtual function table is needed
6737 or not.
6739 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6740 of our knowledge of its type. *NONNULL should be initialized
6741 before this function is called. */
6743 static tree
6745 {
6746 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6749 {
6753 else
6757 /* This is a call to a constructor, hence it's never zero. */
6759 {
6763 }
6767 /* This is a call to a constructor, hence it's never zero. */
6769 {
6773 }
6782 /* Propagate nonnull. */
6787 CASE_CONVERT:
6793 {
6794 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6795 with a real object -- given &p->f, p can still be null. */
6797 /* ??? Probably should check DECL_WEAK here. */
6800 }
6804 /* If this component is really a base class reference, then the field
6805 itself isn't definitive. */
6814 {
6818 }
6819 /* fall through... */
6824 {
6828 }
6830 {
6834 /* if we're in a ctor or dtor, we know our type. If
6835 current_class_ptr is set but we aren't in a function, we're in
6836 an NSDMI (and therefore a constructor). */
6841 {
6845 }
6846 }
6848 {
6849 /* We only need one hash table because it is always left empty. */
6853 /* Reference variables should be references to objects. */
6857 /* Enter the INSTANCE in a table to prevent recursion; a
6858 variable's initializer may refer to the variable
6859 itself. */
6864 {
6865 tree type;
6874 }
6875 }
6880 }
6881 #undef RECUR
6882 }
6884 /* Return nonzero if the dynamic type of INSTANCE is known, and
6885 equivalent to the static type. We also handle the case where
6886 INSTANCE is really a pointer. Return negative if this is a
6887 ctor/dtor. There the dynamic type is known, but this might not be
6888 the most derived base of the original object, and hence virtual
6889 bases may not be laid out according to this type.
6891 Used to determine whether the virtual function table is needed
6892 or not.
6894 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6895 of our knowledge of its type. *NONNULL should be initialized
6896 before this function is called. */
6898 int
6900 {
6903 tree fixed;
6905 /* processing_template_decl can be false in a template if we're in
6906 fold_non_dependent_expr, but we still want to suppress this check. */
6908 {
6909 /* In a template we only care about the type of the result. */
6913 }
6923 }
6925 \f
6926 void
6928 {
6931 current_class_stack
6939 }
6941 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6943 static void
6945 {
6946 tree type;
6948 /* We are re-entering the same class we just left, so we don't
6949 have to search the whole inheritance matrix to find all the
6950 decls to bind again. Instead, we install the cached
6951 class_shadowed list and walk through it binding names. */
6954 /* Restore IDENTIFIER_TYPE_VALUE. */
6956 type;
6959 }
6961 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6962 appropriate for TYPE.
6964 So that we may avoid calls to lookup_name, we cache the _TYPE
6965 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6967 For multiple inheritance, we perform a two-pass depth-first search
6968 of the type lattice. */
6970 void
6972 {
6973 class_stack_node_t csn;
6977 /* Make sure there is enough room for the new entry on the stack. */
6979 {
6981 current_class_stack
6983 current_class_stack_size);
6984 }
6986 /* Insert a new entry on the class stack. */
6993 current_class_depth++;
6995 /* Now set up the new type. */
7001 /* By default, things in classes are private, while things in
7002 structures or unions are public. */
7004 ? access_private_node
7010 {
7011 /* Forcibly remove any old class remnants. */
7013 }
7019 else
7021 }
7023 /* When we exit a toplevel class scope, we save its binding level so
7024 that we can restore it quickly. Here, we've entered some other
7025 class, so we must invalidate our cache. */
7027 void
7029 {
7031 }
7033 /* Get out of the current class scope. If we were in a class scope
7034 previously, that is the one popped to. */
7036 void
7038 {
7041 current_class_depth--;
7047 }
7049 /* Mark the top of the class stack as hidden. */
7051 void
7053 {
7056 }
7058 /* Mark the top of the class stack as un-hidden. */
7060 void
7062 {
7065 }
7067 /* Returns 1 if the class type currently being defined is either T or
7068 a nested type of T. */
7070 bool
7072 {
7080 /* We start looking from 1 because entry 0 is from global scope,
7081 and has no type. */
7083 {
7084 tree c;
7087 else
7088 {
7092 }
7097 }
7099 }
7101 /* If either current_class_type or one of its enclosing classes are derived
7102 from T, return the appropriate type. Used to determine how we found
7103 something via unqualified lookup. */
7105 tree
7107 {
7110 /* The bases of a dependent type are unknown. */
7121 {
7126 }
7129 }
7131 /* Returns the innermost class type which is not a lambda closure type. */
7133 tree
7135 {
7138 /* We start looking from 1 because entry 0 is from global scope,
7139 and has no type. */
7141 {
7142 tree c;
7145 else
7146 {
7150 }
7155 }
7157 }
7159 /* When entering a class scope, all enclosing class scopes' names with
7160 static meaning (static variables, static functions, types and
7161 enumerators) have to be visible. This recursive function calls
7162 pushclass for all enclosing class contexts until global or a local
7163 scope is reached. TYPE is the enclosed class. */
7165 void
7167 {
7168 /* A namespace might be passed in error cases, like A::B:C. */
7176 }
7178 /* Undoes a push_nested_class call. */
7180 void
7182 {
7188 }
7190 /* Returns the number of extern "LANG" blocks we are nested within. */
7192 int
7194 {
7196 }
7198 /* Set global variables CURRENT_LANG_NAME to appropriate value
7199 so that behavior of name-mangling machinery is correct. */
7201 void
7203 {
7207 {
7209 }
7211 {
7213 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7214 (See record_builtin_java_type in decl.c.) However, that causes
7215 incorrect debug entries if these types are actually used.
7216 So we re-enable debug output after extern "Java". */
7225 }
7227 {
7229 }
7230 else
7232 }
7234 /* Get out of the current language scope. */
7236 void
7238 {
7240 }
7241 \f
7242 /* Type instantiation routines. */
7244 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7245 matches the TARGET_TYPE. If there is no satisfactory match, return
7246 error_mark_node, and issue an error & warning messages under
7247 control of FLAGS. Permit pointers to member function if FLAGS
7248 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7249 a template-id, and EXPLICIT_TARGS are the explicitly provided
7250 template arguments.
7252 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7253 is the base path used to reference those member functions. If
7254 the address is resolved to a member function, access checks will be
7255 performed and errors issued if appropriate. */
7257 static tree
7259 tree overload,
7260 tsubst_flags_t flags,
7262 tree explicit_targs,
7263 tree access_path)
7264 {
7265 /* Here's what the standard says:
7267 [over.over]
7269 If the name is a function template, template argument deduction
7270 is done, and if the argument deduction succeeds, the deduced
7271 arguments are used to generate a single template function, which
7272 is added to the set of overloaded functions considered.
7274 Non-member functions and static member functions match targets of
7275 type "pointer-to-function" or "reference-to-function." Nonstatic
7276 member functions match targets of type "pointer-to-member
7277 function;" the function type of the pointer to member is used to
7278 select the member function from the set of overloaded member
7279 functions. If a nonstatic member function is selected, the
7280 reference to the overloaded function name is required to have the
7281 form of a pointer to member as described in 5.3.1.
7283 If more than one function is selected, any template functions in
7284 the set are eliminated if the set also contains a non-template
7285 function, and any given template function is eliminated if the
7286 set contains a second template function that is more specialized
7287 than the first according to the partial ordering rules 14.5.5.2.
7288 After such eliminations, if any, there shall remain exactly one
7289 selected function. */
7292 /* We store the matches in a TREE_LIST rooted here. The functions
7293 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7294 interoperability with most_specialized_instantiation. */
7296 tree fn;
7297 tree target_fn_type;
7299 /* By the time we get here, we should be seeing only real
7300 pointer-to-member types, not the internal POINTER_TYPE to
7301 METHOD_TYPE representation. */
7307 /* Check that the TARGET_TYPE is reasonable. */
7312 /* This is OK, too. */
7315 /* This is OK, too. This comes from a conversion to reference
7316 type. */
7318 else
7319 {
7325 }
7327 /* Non-member functions and static member functions match targets of type
7328 "pointer-to-function" or "reference-to-function." Nonstatic member
7329 functions match targets of type "pointer-to-member-function;" the
7330 function type of the pointer to member is used to select the member
7331 function from the set of overloaded member functions.
7333 So figure out the FUNCTION_TYPE that we want to match against. */
7336 /* If we can find a non-template function that matches, we can just
7337 use it. There's no point in generating template instantiations
7338 if we're just going to throw them out anyhow. But, of course, we
7339 can only do this when we don't *need* a template function. */
7341 {
7342 tree fns;
7345 {
7349 /* We're not looking for templates just yet. */
7354 /* We're looking for a non-static member, and this isn't
7355 one, or vice versa. */
7358 /* Ignore functions which haven't been explicitly
7359 declared. */
7363 /* See if there's a match. */
7366 }
7367 }
7369 /* Now, if we've already got a match (or matches), there's no need
7370 to proceed to the template functions. But, if we don't have a
7371 match we need to look at them, too. */
7373 {
7374 tree target_arg_types;
7375 tree target_ret_type;
7376 tree fns;
7379 tree arg;
7393 {
7395 tree instantiation;
7396 tree targs;
7399 /* We're only looking for templates. */
7404 /* We're not looking for a non-static member, and this is
7405 one, or vice versa. */
7410 /* If the template has a deduced return type, don't expose it to
7411 template argument deduction. */
7415 /* Try to do argument deduction. */
7422 /* Instantiation failed. */
7425 /* And now force instantiation to do return type deduction. */
7427 {
7433 }
7435 /* See if there's a match. */
7440 }
7442 /* Now, remove all but the most specialized of the matches. */
7444 {
7449 NULL_TREE,
7450 NULL_TREE);
7451 }
7452 }
7454 /* Now we should have exactly one function in MATCHES. */
7456 {
7457 /* There were *no* matches. */
7459 {
7462 target_type);
7465 }
7467 }
7469 {
7470 /* There were too many matches. First check if they're all
7471 the same function. */
7476 /* For multi-versioned functions, more than one match is just fine and
7477 decls_match will return false as they are different. */
7485 {
7487 {
7490 target_type);
7492 /* Since print_candidates expects the functions in the
7493 TREE_VALUE slot, we flip them here. */
7498 }
7501 }
7502 }
7504 /* Good, exactly one match. Now, convert it to the correct type. */
7509 {
7517 {
7520 }
7521 }
7523 /* If a pointer to a function that is multi-versioned is requested, the
7524 pointer to the dispatcher function is returned instead. This works
7525 well because indirectly calling the function will dispatch the right
7526 function version at run-time. */
7528 {
7532 /* Mark all the versions corresponding to the dispatcher as used. */
7535 }
7537 /* If we're doing overload resolution purely for the purpose of
7538 determining conversion sequences, we should not consider the
7539 function used. If this conversion sequence is selected, the
7540 function will be marked as used at this point. */
7542 {
7543 /* Make =delete work with SFINAE. */
7548 }
7550 /* We could not check access to member functions when this
7551 expression was originally created since we did not know at that
7552 time to which function the expression referred. */
7554 {
7557 }
7561 else
7562 {
7563 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7564 will mark the function as addressed, but here we must do it
7565 explicitly. */
7569 }
7570 }
7572 /* This function will instantiate the type of the expression given in
7573 RHS to match the type of LHSTYPE. If errors exist, then return
7574 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7575 we complain on errors. If we are not complaining, never modify rhs,
7576 as overload resolution wants to try many possible instantiations, in
7577 the hope that at least one will work.
7579 For non-recursive calls, LHSTYPE should be a function, pointer to
7580 function, or a pointer to member function. */
7582 tree
7584 {
7591 {
7595 }
7598 {
7605 /* Microsoft allows `A::f' to be resolved to a
7606 pointer-to-member. */
7607 ;
7608 else
7609 {
7614 }
7615 }
7618 {
7621 }
7623 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7624 deduce any type information. */
7626 {
7630 }
7632 /* There only a few kinds of expressions that may have a type
7633 dependent on overload resolution. */
7639 /* This should really only be used when attempting to distinguish
7640 what sort of a pointer to function we have. For now, any
7641 arithmetic operation which is not supported on pointers
7642 is rejected as an error. */
7645 {
7647 {
7653 /* Do not lose object's side effects. */
7657 }
7664 /* This can happen if we are forming a pointer-to-member for a
7665 member template. */
7668 /* Fall through. */
7671 {
7675 return
7679 }
7683 return
7687 access_path);
7690 {
7695 }
7702 }
7704 }
7705 \f
7706 /* Return the name of the virtual function pointer field
7707 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7708 this may have to look back through base types to find the
7709 ultimate field name. (For single inheritance, these could
7710 all be the same name. Who knows for multiple inheritance). */
7712 static tree
7714 {
7721 {
7727 }
7735 }
7737 void
7739 {
7746 {
7751 }
7752 }
7754 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7755 according to [class]:
7756 The class-name is also inserted
7757 into the scope of the class itself. For purposes of access checking,
7758 the inserted class name is treated as if it were a public member name. */
7760 void
7762 {
7765 tree saved_cas;
7780 }
7782 /* Returns 1 if TYPE contains only padding bytes. */
7784 int
7786 {
7793 /* In G++ 3.2, whether or not a class was empty was determined by
7794 looking at its size. */
7797 else
7799 }
7801 /* Returns true if TYPE contains an empty class. */
7803 static bool
7805 {
7809 {
7810 tree field;
7811 tree binfo;
7812 tree base_binfo;
7824 }
7828 }
7830 /* Returns true if TYPE contains no actual data, just various
7831 possible combinations of empty classes and possibly a vptr. */
7833 bool
7835 {
7837 {
7838 tree field;
7839 tree binfo;
7840 tree base_binfo;
7843 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7844 out, but we'd like to be able to check this before then. */
7858 }
7862 }
7864 /* Note that NAME was looked up while the current class was being
7865 defined and that the result of that lookup was DECL. */
7867 void
7869 {
7870 splay_tree names_used;
7872 /* If we're not defining a class, there's nothing to do. */
7878 /* If there's already a binding for this NAME, then we don't have
7879 anything to worry about. */
7892 }
7894 /* Note that NAME was declared (as DECL) in the current class. Check
7895 to see that the declaration is valid. */
7897 void
7899 {
7900 splay_tree names_used;
7901 splay_tree_node n;
7903 /* Look to see if we ever used this name. */
7904 names_used
7908 /* The C language allows members to be declared with a type of the same
7909 name, and the C++ standard says this diagnostic is not required. So
7910 allow it in extern "C" blocks unless predantic is specified.
7911 Allow it in all cases if -ms-extensions is specified. */
7917 {
7918 /* [basic.scope.class]
7920 A name N used in a class S shall refer to the same declaration
7921 in its context and when re-evaluated in the completed scope of
7922 S. */
7926 }
7927 }
7929 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7930 Secondary vtables are merged with primary vtables; this function
7931 will return the VAR_DECL for the primary vtable. */
7933 tree
7935 {
7936 tree decl;
7940 {
7943 }
7947 }
7950 /* Returns the binfo for the primary base of BINFO. If the resulting
7951 BINFO is a virtual base, and it is inherited elsewhere in the
7952 hierarchy, then the returned binfo might not be the primary base of
7953 BINFO in the complete object. Check BINFO_PRIMARY_P or
7954 BINFO_LOST_PRIMARY_P to be sure. */
7956 static tree
7958 {
7959 tree primary_base;
7966 }
7968 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7970 static int
7972 {
7976 }
7978 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7979 INDENT should be zero when called from the top level; it is
7980 incremented recursively. IGO indicates the next expected BINFO in
7981 inheritance graph ordering. */
7983 static tree
7986 tree binfo,
7987 tree igo,
7989 {
7991 tree base_binfo;
7999 {
8002 }
8017 {
8021 TFF_PLAIN_IDENTIFIER),
8023 }
8025 {
8028 }
8033 {
8037 {
8041 TFF_PLAIN_IDENTIFIER));
8042 }
8044 {
8048 TFF_PLAIN_IDENTIFIER));
8049 }
8051 {
8055 TFF_PLAIN_IDENTIFIER));
8056 }
8058 {
8062 TFF_PLAIN_IDENTIFIER));
8063 }
8067 }
8073 }
8075 /* Dump the BINFO hierarchy for T. */
8077 static void
8079 {
8091 }
8093 /* Debug interface to hierarchy dumping. */
8095 void
8097 {
8099 }
8101 static void
8103 {
8108 {
8111 }
8112 }
8114 static void
8116 {
8117 tree value;
8119 HOST_WIDE_INT elt;
8127 TFF_PLAIN_IDENTIFIER));
8134 }
8136 static void
8138 {
8146 {
8153 {
8158 }
8162 }
8165 }
8167 static void
8169 {
8177 {
8182 }
8185 }
8187 /* Dump a function or thunk and its thunkees. */
8189 static void
8191 {
8194 tree thunks;
8202 {
8212 else
8218 }
8222 }
8224 /* Dump the thunks for FN. */
8226 void
8228 {
8230 }
8232 /* Virtual function table initialization. */
8234 /* Create all the necessary vtables for T and its base classes. */
8236 static void
8238 {
8239 tree vbase;
8243 /* We lay out the primary and secondary vtables in one contiguous
8244 vtable. The primary vtable is first, followed by the non-virtual
8245 secondary vtables in inheritance graph order. */
8249 /* Then come the virtual bases, also in inheritance graph order. */
8251 {
8255 }
8259 }
8261 /* Initialize the vtable for BINFO with the INITS. */
8263 static void
8265 {
8266 tree decl;
8272 }
8274 /* Build the VTT (virtual table table) for T.
8275 A class requires a VTT if it has virtual bases.
8277 This holds
8278 1 - primary virtual pointer for complete object T
8279 2 - secondary VTTs for each direct non-virtual base of T which requires a
8280 VTT
8281 3 - secondary virtual pointers for each direct or indirect base of T which
8282 has virtual bases or is reachable via a virtual path from T.
8283 4 - secondary VTTs for each direct or indirect virtual base of T.
8285 Secondary VTTs look like complete object VTTs without part 4. */
8287 static void
8289 {
8290 tree type;
8291 tree vtt;
8292 tree index;
8295 /* Build up the initializers for the VTT. */
8300 /* If we didn't need a VTT, we're done. */
8304 /* Figure out the type of the VTT. */
8308 /* Now, build the VTT object itself. */
8311 /* Add the VTT to the vtables list. */
8316 }
8318 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8319 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8320 and CHAIN the vtable pointer for this binfo after construction is
8321 complete. VALUE can also be another BINFO, in which case we recurse. */
8323 static tree
8325 {
8326 tree vt;
8329 {
8335 else
8337 }
8340 }
8342 /* Data for secondary VTT initialization. */
8344 {
8345 /* Is this the primary VTT? */
8348 /* Current index into the VTT. */
8349 tree index;
8351 /* Vector of initializers built up. */
8354 /* The type being constructed by this secondary VTT. */
8355 tree type_being_constructed;
8358 /* Recursively build the VTT-initializer for BINFO (which is in the
8359 hierarchy dominated by T). INITS points to the end of the initializer
8360 list to date. INDEX is the VTT index where the next element will be
8361 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8362 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8363 for virtual bases of T. When it is not so, we build the constructor
8364 vtables for the BINFO-in-T variant. */
8366 static void
8369 {
8371 tree b;
8372 tree init;
8373 secondary_vptr_vtt_init_data data;
8376 /* We only need VTTs for subobjects with virtual bases. */
8380 /* We need to use a construction vtable if this is not the primary
8381 VTT. */
8383 {
8386 /* Record the offset in the VTT where this sub-VTT can be found. */
8388 }
8390 /* Add the address of the primary vtable for the complete object. */
8394 {
8397 }
8400 /* Recursively add the secondary VTTs for non-virtual bases. */
8405 /* Add secondary virtual pointers for all subobjects of BINFO with
8406 either virtual bases or reachable along a virtual path, except
8407 subobjects that are non-virtual primary bases. */
8417 /* data.inits might have grown as we added secondary virtual pointers.
8418 Make sure our caller knows about the new vector. */
8422 /* Add the secondary VTTs for virtual bases in inheritance graph
8423 order. */
8425 {
8430 }
8431 else
8432 /* Remove the ctor vtables we created. */
8434 }
8436 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8437 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8439 static tree
8441 {
8444 /* We don't care about bases that don't have vtables. */
8448 /* We're only interested in proper subobjects of the type being
8449 constructed. */
8453 /* We're only interested in bases with virtual bases or reachable
8454 via a virtual path from the type being constructed. */
8459 /* We're not interested in non-virtual primary bases. */
8463 /* Record the index where this secondary vptr can be found. */
8465 {
8470 {
8471 /* It's a primary virtual base, and this is not a
8472 construction vtable. Find the base this is primary of in
8473 the inheritance graph, and use that base's vtable
8474 now. */
8477 }
8478 }
8480 /* Add the initializer for the secondary vptr itself. */
8483 /* Advance the vtt index. */
8488 }
8490 /* Called from build_vtt_inits via dfs_walk. After building
8491 constructor vtables and generating the sub-vtt from them, we need
8492 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8493 binfo of the base whose sub vtt was generated. */
8495 static tree
8497 {
8501 /* If this class has no vtable, none of its bases do. */
8505 /* This might be a primary base, so have no vtable in this
8506 hierarchy. */
8509 /* If we scribbled the construction vtable vptr into BINFO, clear it
8510 out now. */
8516 }
8518 /* Build the construction vtable group for BINFO which is in the
8519 hierarchy dominated by T. */
8521 static void
8523 {
8524 tree type;
8525 tree vtbl;
8526 tree id;
8527 tree vbase;
8530 /* See if we've already created this construction vtable group. */
8536 /* Build a version of VTBL (with the wrong type) for use in
8537 constructing the addresses of secondary vtables in the
8538 construction vtable group. */
8541 /* Don't export construction vtables from shared libraries. Even on
8542 targets that don't support hidden visibility, this tells
8543 can_refer_decl_in_current_unit_p not to assume that it's safe to
8544 access from a different compilation unit (bz 54314). */
8552 /* Add the vtables for each of our virtual bases using the vbase in T
8553 binfo. */
8555 vbase;
8557 {
8558 tree b;
8565 }
8567 /* Figure out the type of the construction vtable. */
8574 /* Initialize the construction vtable. */
8578 }
8580 /* Add the vtbl initializers for BINFO (and its bases other than
8581 non-virtual primaries) to the list of INITS. BINFO is in the
8582 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8583 the constructor the vtbl inits should be accumulated for. (If this
8584 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8585 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8586 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8587 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8588 but are not necessarily the same in terms of layout. */
8590 static void
8592 tree orig_binfo,
8593 tree rtti_binfo,
8594 tree vtbl,
8595 tree t,
8597 {
8599 tree base_binfo;
8604 /* If it doesn't have a vptr, we don't do anything. */
8608 /* If we're building a construction vtable, we're not interested in
8609 subobjects that don't require construction vtables. */
8615 /* Build the initializers for the BINFO-in-T vtable. */
8618 /* Walk the BINFO and its bases. We walk in preorder so that as we
8619 initialize each vtable we can figure out at what offset the
8620 secondary vtable lies from the primary vtable. We can't use
8621 dfs_walk here because we need to iterate through bases of BINFO
8622 and RTTI_BINFO simultaneously. */
8624 {
8625 /* Skip virtual bases. */
8631 inits);
8632 }
8633 }
8635 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8636 BINFO vtable to L. */
8638 static void
8640 tree orig_binfo,
8641 tree rtti_binfo,
8642 tree orig_vtbl,
8643 tree t,
8645 {
8652 {
8653 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8654 primary virtual base. If it is not the same primary in
8655 the hierarchy of T, we'll need to generate a ctor vtable
8656 for it, to place at its location in T. If it is the same
8657 primary, we still need a VTT entry for the vtable, but it
8658 should point to the ctor vtable for the base it is a
8659 primary for within the sub-hierarchy of RTTI_BINFO.
8661 There are three possible cases:
8663 1) We are in the same place.
8664 2) We are a primary base within a lost primary virtual base of
8665 RTTI_BINFO.
8666 3) We are primary to something not a base of RTTI_BINFO. */
8668 tree b;
8671 /* First, look through the bases we are primary to for RTTI_BINFO
8672 or a virtual base. */
8675 {
8680 }
8681 /* If we run out of primary links, keep looking down our
8682 inheritance chain; we might be an indirect primary. */
8686 found:
8688 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8689 base B and it is a base of RTTI_BINFO, this is case 2. In
8690 either case, we share our vtable with LAST, i.e. the
8691 derived-most base within B of which we are a primary. */
8694 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8695 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8696 binfo_ctor_vtable after everything's been set up. */
8699 /* Otherwise, this is case 3 and we get our own. */
8700 }
8707 {
8708 tree index;
8711 /* Add the initializer for this vtable. */
8715 /* Figure out the position to which the VPTR should point. */
8721 }
8724 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8725 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8726 straighten this out. */
8729 /* Throw away any unneeded intializers. */
8731 else
8732 /* For an ordinary vtable, set BINFO_VTABLE. */
8734 }
8738 /* Construct the initializer for BINFO's virtual function table. BINFO
8739 is part of the hierarchy dominated by T. If we're building a
8740 construction vtable, the ORIG_BINFO is the binfo we should use to
8741 find the actual function pointers to put in the vtable - but they
8742 can be overridden on the path to most-derived in the graph that
8743 ORIG_BINFO belongs. Otherwise,
8744 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8745 BINFO that should be indicated by the RTTI information in the
8746 vtable; it will be a base class of T, rather than T itself, if we
8747 are building a construction vtable.
8749 The value returned is a TREE_LIST suitable for wrapping in a
8750 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8751 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8752 number of non-function entries in the vtable.
8754 It might seem that this function should never be called with a
8755 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8756 base is always subsumed by a derived class vtable. However, when
8757 we are building construction vtables, we do build vtables for
8758 primary bases; we need these while the primary base is being
8759 constructed. */
8761 static void
8763 tree orig_binfo,
8764 tree t,
8765 tree rtti_binfo,
8768 {
8769 tree v;
8770 vtbl_init_data vid;
8772 tree vbinfo;
8776 /* Initialize VID. */
8784 /* The first vbase or vcall offset is at index -3 in the vtable. */
8787 /* Add entries to the vtable for RTTI. */
8790 /* Create an array for keeping track of the functions we've
8791 processed. When we see multiple functions with the same
8792 signature, we share the vcall offsets. */
8794 /* Add the vcall and vbase offset entries. */
8797 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8798 build_vbase_offset_vtbl_entries. */
8803 /* If the target requires padding between data entries, add that now. */
8805 {
8810 /* Move data entries into their new positions and add padding
8811 after the new positions. Iterate backwards so we don't
8812 overwrite entries that we would need to process later. */
8815 ix--)
8816 {
8824 {
8828 null_pointer_node);
8829 }
8830 }
8831 }
8836 /* The initializers for virtual functions were built up in reverse
8837 order. Straighten them out and add them to the running list in one
8838 step. */
8847 /* Go through all the ordinary virtual functions, building up
8848 initializers. */
8850 {
8851 tree delta;
8852 tree vcall_index;
8859 {
8863 {
8866 }
8868 }
8870 /* If the only definition of this function signature along our
8871 primary base chain is from a lost primary, this vtable slot will
8872 never be used, so just zero it out. This is important to avoid
8873 requiring extra thunks which cannot be generated with the function.
8875 We first check this in update_vtable_entry_for_fn, so we handle
8876 restored primary bases properly; we also need to do it here so we
8877 zero out unused slots in ctor vtables, rather than filling them
8878 with erroneous values (though harmless, apart from relocation
8879 costs). */
8884 {
8885 /* Pull the offset for `this', and the function to call, out of
8886 the list. */
8893 /* You can't call an abstract virtual function; it's abstract.
8894 So, we replace these functions with __pure_virtual. */
8896 {
8899 {
8901 abort_fndecl_addr
8905 }
8906 }
8907 /* Likewise for deleted virtuals. */
8909 {
8918 }
8919 else
8920 {
8922 {
8926 }
8927 /* Take the address of the function, considering it to be of an
8928 appropriate generic type. */
8932 }
8933 }
8935 /* And add it to the chain of initializers. */
8937 {
8942 else
8944 {
8950 }
8951 }
8952 else
8954 }
8955 }
8957 /* Adds to vid->inits the initializers for the vbase and vcall
8958 offsets in BINFO, which is in the hierarchy dominated by T. */
8960 static void
8962 {
8963 tree b;
8965 /* If this is a derived class, we must first create entries
8966 corresponding to the primary base class. */
8971 /* Add the vbase entries for this base. */
8973 /* Add the vcall entries for this base. */
8975 }
8977 /* Returns the initializers for the vbase offset entries in the vtable
8978 for BINFO (which is part of the class hierarchy dominated by T), in
8979 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8980 where the next vbase offset will go. */
8982 static void
8984 {
8985 tree vbase;
8986 tree t;
8987 tree non_primary_binfo;
8989 /* If there are no virtual baseclasses, then there is nothing to
8990 do. */
8996 /* We might be a primary base class. Go up the inheritance hierarchy
8997 until we find the most derived class of which we are a primary base:
8998 it is the offset of that which we need to use. */
9001 {
9002 tree b;
9004 /* If we have reached a virtual base, then it must be a primary
9005 base (possibly multi-level) of vid->binfo, or we wouldn't
9006 have called build_vcall_and_vbase_vtbl_entries for it. But it
9007 might be a lost primary, so just skip down to vid->binfo. */
9009 {
9012 }
9018 }
9020 /* Go through the virtual bases, adding the offsets. */
9022 vbase;
9024 {
9025 tree b;
9026 tree delta;
9031 /* Find the instance of this virtual base in the complete
9032 object. */
9035 /* If we've already got an offset for this virtual base, we
9036 don't need another one. */
9041 /* Figure out where we can find this vbase offset. */
9050 /* The vbase offset had better be the same. */
9053 /* The next vbase will come at a more negative offset. */
9057 /* The initializer is the delta from BINFO to this virtual base.
9058 The vbase offsets go in reverse inheritance-graph order, and
9059 we are walking in inheritance graph order so these end up in
9060 the right order. */
9067 }
9068 }
9070 /* Adds the initializers for the vcall offset entries in the vtable
9071 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9072 to VID->INITS. */
9074 static void
9076 {
9077 /* We only need these entries if this base is a virtual base. We
9078 compute the indices -- but do not add to the vtable -- when
9079 building the main vtable for a class. */
9082 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9083 correspond to VID->DERIVED), we are building a primary
9084 construction virtual table. Since this is a primary
9085 virtual table, we do not need the vcall offsets for
9086 BINFO. */
9088 {
9089 /* We need a vcall offset for each of the virtual functions in this
9090 vtable. For example:
9092 class A { virtual void f (); };
9093 class B1 : virtual public A { virtual void f (); };
9094 class B2 : virtual public A { virtual void f (); };
9095 class C: public B1, public B2 { virtual void f (); };
9097 A C object has a primary base of B1, which has a primary base of A. A
9098 C also has a secondary base of B2, which no longer has a primary base
9099 of A. So the B2-in-C construction vtable needs a secondary vtable for
9100 A, which will adjust the A* to a B2* to call f. We have no way of
9101 knowing what (or even whether) this offset will be when we define B2,
9102 so we store this "vcall offset" in the A sub-vtable and look it up in
9103 a "virtual thunk" for B2::f.
9105 We need entries for all the functions in our primary vtable and
9106 in our non-virtual bases' secondary vtables. */
9108 /* If we are just computing the vcall indices -- but do not need
9109 the actual entries -- not that. */
9112 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9114 }
9115 }
9117 /* Build vcall offsets, starting with those for BINFO. */
9119 static void
9121 {
9123 tree primary_binfo;
9124 tree base_binfo;
9126 /* Don't walk into virtual bases -- except, of course, for the
9127 virtual base for which we are building vcall offsets. Any
9128 primary virtual base will have already had its offsets generated
9129 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9133 /* If BINFO has a primary base, process it first. */
9138 /* Add BINFO itself to the list. */
9141 /* Scan the non-primary bases of BINFO. */
9145 }
9147 /* Called from build_vcall_offset_vtbl_entries_r. */
9149 static void
9151 {
9152 /* Make entries for the rest of the virtuals. */
9154 {
9155 tree orig_fn;
9157 /* The ABI requires that the methods be processed in declaration
9158 order. G++ 3.2 used the order in the vtable. */
9160 orig_fn;
9164 }
9165 else
9166 {
9167 tree derived_virtuals;
9168 tree base_virtuals;
9169 tree orig_virtuals;
9170 /* If BINFO is a primary base, the most derived class which has
9171 BINFO as a primary base; otherwise, just BINFO. */
9172 tree non_primary_binfo;
9174 /* We might be a primary base class. Go up the inheritance hierarchy
9175 until we find the most derived class of which we are a primary base:
9176 it is the BINFO_VIRTUALS there that we need to consider. */
9179 {
9180 tree b;
9182 /* If we have reached a virtual base, then it must be vid->vbase,
9183 because we ignore other virtual bases in
9184 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9185 base (possibly multi-level) of vid->binfo, or we wouldn't
9186 have called build_vcall_and_vbase_vtbl_entries for it. But it
9187 might be a lost primary, so just skip down to vid->binfo. */
9189 {
9193 }
9199 }
9202 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9203 where rtti_binfo is the most derived type. */
9204 non_primary_binfo
9210 base_virtuals;
9214 {
9215 tree orig_fn;
9217 /* Find the declaration that originally caused this function to
9218 be present in BINFO_TYPE (binfo). */
9221 /* When processing BINFO, we only want to generate vcall slots for
9222 function slots introduced in BINFO. So don't try to generate
9223 one if the function isn't even defined in BINFO. */
9228 }
9229 }
9230 }
9232 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9234 static void
9236 {
9238 tree vcall_offset;
9239 tree derived_entry;
9241 /* If there is already an entry for a function with the same
9242 signature as FN, then we do not need a second vcall offset.
9243 Check the list of functions already present in the derived
9244 class vtable. */
9246 {
9248 /* We only use one vcall offset for virtual destructors,
9249 even though there are two virtual table entries. */
9253 }
9255 /* If we are building these vcall offsets as part of building
9256 the vtable for the most derived class, remember the vcall
9257 offset. */
9259 {
9262 }
9264 /* The next vcall offset will be found at a more negative
9265 offset. */
9269 /* Keep track of this function. */
9273 {
9274 tree base;
9275 tree fn;
9277 /* Find the overriding function. */
9281 else
9282 {
9285 /* The vbase we're working on is a primary base of
9286 vid->binfo. But it might be a lost primary, so its
9287 BINFO_OFFSET might be wrong, so we just use the
9288 BINFO_OFFSET from vid->binfo. */
9294 vcall_offset);
9295 }
9296 /* Add the initializer to the vtable. */
9298 }
9299 }
9301 /* Return vtbl initializers for the RTTI entries corresponding to the
9302 BINFO's vtable. The RTTI entries should indicate the object given
9303 by VID->rtti_binfo. */
9305 static void
9307 {
9308 tree b;
9309 tree t;
9310 tree offset;
9311 tree decl;
9312 tree init;
9316 /* To find the complete object, we will first convert to our most
9317 primary base, and then add the offset in the vtbl to that value. */
9321 {
9322 tree primary_base;
9328 }
9332 /* The second entry is the address of the typeinfo object. */
9335 else
9338 /* Convert the declaration to a type that can be stored in the
9339 vtable. */
9343 /* Add the offset-to-top entry. It comes earlier in the vtable than
9344 the typeinfo entry. Convert the offset to look like a
9345 function pointer, so that we can put it in the vtable. */
9348 }
9350 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9351 accessibility. */
9353 bool
9355 {
9358 }
9360 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9362 bool
9364 {
9368 }
9370 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9371 class between them, if any. */
9373 tree
9375 {
9387 {
9390 }
9394 }