| blob | 04f9df5a23a5af179199d2a6136cdb9f2031b6c2 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011,
4 2012
5 Free Software Foundation, Inc.
6 Contributed by Michael Tiemann (tiemann@cygnus.com)
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
25 /* High-level class interface. */
43 /* The number of nested classes being processed. If we are not in the
44 scope of any class, this is zero. */
48 /* In order to deal with nested classes, we keep a stack of classes.
49 The topmost entry is the innermost class, and is the entry at index
50 CURRENT_CLASS_DEPTH */
53 /* The name of the class. */
54 tree name;
56 /* The _TYPE node for the class. */
57 tree type;
59 /* The access specifier pending for new declarations in the scope of
60 this class. */
61 tree access;
63 /* If were defining TYPE, the names used in this class. */
64 splay_tree names_used;
66 /* Nonzero if this class is no longer open, because of a call to
67 push_to_top_level. */
72 {
73 /* The base for which we're building initializers. */
74 tree binfo;
75 /* The type of the most-derived type. */
76 tree derived;
77 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
78 unless ctor_vtbl_p is true. */
79 tree rtti_binfo;
80 /* The negative-index vtable initializers built up so far. These
81 are in order from least negative index to most negative index. */
83 /* The binfo for the virtual base for which we're building
84 vcall offset initializers. */
85 tree vbase;
86 /* The functions in vbase for which we have already provided vcall
87 offsets. */
89 /* The vtable index of the next vcall or vbase offset. */
90 tree index;
91 /* Nonzero if we are building the initializer for the primary
92 vtable. */
94 /* Nonzero if we are building the initializer for a construction
95 vtable. */
97 /* True when adding vcall offset entries to the vtable. False when
98 merely computing the indices. */
102 /* The type of a function passed to walk_subobject_offsets. */
105 /* The stack itself. This is a dynamically resized array. The
106 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
110 /* The size of the largest empty class seen in this translation unit. */
113 /* An array of all local classes present in this translation unit, in
114 declaration order. */
196 tree *);
206 splay_tree_key k2);
215 /* Variables shared between class.c and call.c. */
225 /* Convert to or from a base subobject. EXPR is an expression of type
226 `A' or `A*', an expression of type `B' or `B*' is returned. To
227 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
228 the B base instance within A. To convert base A to derived B, CODE
229 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
230 In this latter case, A must not be a morally virtual base of B.
231 NONNULL is true if EXPR is known to be non-NULL (this is only
232 needed when EXPR is of pointer type). CV qualifiers are preserved
233 from EXPR. */
235 tree
237 tree expr,
238 tree binfo,
240 tsubst_flags_t complain)
241 {
244 tree probe;
245 tree offset;
246 tree target_type;
248 tree ptr_target_type;
258 {
264 }
272 {
273 /* This can happen when adjust_result_of_qualified_name_lookup can't
274 find a unique base binfo in a call to a member function. We
275 couldn't give the diagnostic then since we might have been calling
276 a static member function, so we do it now. */
278 {
282 }
284 }
291 /* Nothing to do. */
295 {
301 }
304 /* This must happen before the call to save_expr. */
306 else
312 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
313 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
314 expression returned matches the input. */
315 target_type = cp_build_qualified_type
319 /* Do we need to look in the vtable for the real offset? */
322 /* Don't bother with the calculations inside sizeof; they'll ICE if the
323 source type is incomplete and the pointer value doesn't matter. In a
324 template (even in fold_non_dependent_expr), we don't have vtables set
325 up properly yet, and the value doesn't matter there either; we're just
326 interested in the result of overload resolution. */
329 {
334 }
336 /* If we're in an NSDMI, we don't have the full constructor context yet
337 that we need for converting to a virtual base, so just build a stub
338 CONVERT_EXPR and expand it later in bot_replace. */
341 {
347 }
349 /* Do we need to check for a null pointer? */
351 {
352 /* If we know the conversion will not actually change the value
353 of EXPR, then we can avoid testing the expression for NULL.
354 We have to avoid generating a COMPONENT_REF for a base class
355 field, because other parts of the compiler know that such
356 expressions are always non-NULL. */
360 }
362 /* Protect against multiple evaluation if necessary. */
366 /* Now that we've saved expr, build the real null test. */
368 {
372 }
374 /* If this is a simple base reference, express it as a COMPONENT_REF. */
376 /* We don't build base fields for empty bases, and they aren't very
377 interesting to the optimizers anyway. */
379 {
386 }
389 {
390 /* Going via virtual base V_BINFO. We need the static offset
391 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
392 V_BINFO. That offset is an entry in D_BINFO's vtable. */
393 tree v_offset;
396 {
397 /* In a base member initializer, we cannot rely on the
398 vtable being set up. We have to indirect via the
399 vtt_parm. */
400 tree t;
406 }
407 else
409 complain),
415 v_offset);
427 /* Negative fixed_type_p means this is a constructor or destructor;
428 virtual base layout is fixed in in-charge [cd]tors, but not in
429 base [cd]tors. */
433 v_offset,
436 else
438 }
446 {
451 }
452 else
458 out:
464 }
466 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
467 Perform a derived-to-base conversion by recursively building up a
468 sequence of COMPONENT_REFs to the appropriate base fields. */
470 static tree
472 {
475 tree field;
478 {
479 tree temp;
483 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
484 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
485 an lvalue in the front end; only _DECLs and _REFs are lvalues
486 in the back end. */
492 }
494 /* Recurse. */
499 /* Is this the base field created by build_base_field? */
503 /* If we're looking for a field in the most-derived class,
504 also check the field offset; we can have two base fields
505 of the same type if one is an indirect virtual base and one
506 is a direct non-virtual base. */
510 {
511 /* We don't use build_class_member_access_expr here, as that
512 has unnecessary checks, and more importantly results in
513 recursive calls to dfs_walk_once. */
521 /* Mark the expression const or volatile, as appropriate.
522 Even though we've dealt with the type above, we still have
523 to mark the expression itself. */
530 }
532 /* Didn't find the base field?!? */
534 }
536 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
537 type is a class type or a pointer to a class type. In the former
538 case, TYPE is also a class type; in the latter it is another
539 pointer type. If CHECK_ACCESS is true, an error message is emitted
540 if TYPE is inaccessible. If OBJECT has pointer type, the value is
541 assumed to be non-NULL. */
543 tree
545 tsubst_flags_t complain)
546 {
547 tree binfo;
548 tree object_type;
551 {
554 }
555 else
564 }
566 /* EXPR is an expression with unqualified class type. BASE is a base
567 binfo of that class type. Returns EXPR, converted to the BASE
568 type. This function assumes that EXPR is the most derived class;
569 therefore virtual bases can be found at their static offsets. */
571 tree
573 {
574 tree expr_type;
578 {
579 /* If this is a non-empty base, use a COMPONENT_REF. */
583 /* We use fold_build2 and fold_convert below to simplify the trees
584 provided to the optimizers. It is not safe to call these functions
585 when processing a template because they do not handle C++-specific
586 trees. */
594 }
597 }
599 \f
600 tree
602 {
608 /* First, convert to the requested type. */
613 /* Second, the requested type may not be the owner of its own vptr.
614 If not, convert to the base class that owns it. We cannot use
615 convert_to_base here, because VCONTEXT may appear more than once
616 in the inheritance hierarchy of TYPE, and thus direct conversion
617 between the types may be ambiguous. Following the path back up
618 one step at a time via primary bases avoids the problem. */
622 {
625 }
628 }
630 /* Given an object INSTANCE, return an expression which yields the
631 vtable element corresponding to INDEX. There are many special
632 cases for INSTANCE which we take care of here, mainly to avoid
633 creating extra tree nodes when we don't have to. */
635 static tree
637 {
638 tree aref;
641 /* Try to figure out what a reference refers to, and
642 access its virtual function table directly. */
650 {
655 }
664 }
666 tree
668 {
672 }
674 /* Given a stable object pointer INSTANCE_PTR, return an expression which
675 yields a function pointer corresponding to vtable element INDEX. */
677 tree
679 {
680 tree aref;
683 tf_warning_or_error),
684 idx);
686 /* When using function descriptors, the address of the
687 vtable entry is treated as a function pointer. */
692 /* Remember this as a method reference, for later devirtualization. */
696 }
698 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
699 for the given TYPE. */
701 static tree
703 {
705 }
707 /* DECL is an entity associated with TYPE, like a virtual table or an
708 implicitly generated constructor. Determine whether or not DECL
709 should have external or internal linkage at the object file
710 level. This routine does not deal with COMDAT linkage and other
711 similar complexities; it simply sets TREE_PUBLIC if it possible for
712 entities in other translation units to contain copies of DECL, in
713 the abstract. */
715 void
717 {
720 }
722 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
723 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
724 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
726 static tree
728 {
729 tree decl;
732 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
733 now to avoid confusion in mangle_decl. */
742 /* At one time the vtable info was grabbed 2 words at a time. This
743 fails on sparc unless you have 8-byte alignment. (tiemann) */
747 /* The vtable has not been defined -- yet. */
751 /* Mark the VAR_DECL node representing the vtable itself as a
752 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
753 is rather important that such things be ignored because any
754 effort to actually generate DWARF for them will run into
755 trouble when/if we encounter code like:
757 #pragma interface
758 struct S { virtual void member (); };
760 because the artificial declaration of the vtable itself (as
761 manufactured by the g++ front end) will say that the vtable is
762 a static member of `S' but only *after* the debug output for
763 the definition of `S' has already been output. This causes
764 grief because the DWARF entry for the definition of the vtable
765 will try to refer back to an earlier *declaration* of the
766 vtable as a static member of `S' and there won't be one. We
767 might be able to arrange to have the "vtable static member"
768 attached to the member list for `S' before the debug info for
769 `S' get written (which would solve the problem) but that would
770 require more intrusive changes to the g++ front end. */
774 }
776 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
777 or even complete. If this does not exist, create it. If COMPLETE is
778 nonzero, then complete the definition of it -- that will render it
779 impossible to actually build the vtable, but is useful to get at those
780 which are known to exist in the runtime. */
782 tree
784 {
785 tree decl;
794 {
797 }
800 }
802 /* Build the primary virtual function table for TYPE. If BINFO is
803 non-NULL, build the vtable starting with the initial approximation
804 that it is the same as the one which is the head of the association
805 list. Returns a nonzero value if a new vtable is actually
806 created. */
808 static int
810 {
811 tree decl;
812 tree virtuals;
817 {
819 /* We have already created a vtable for this base, so there's
820 no need to do it again. */
827 }
828 else
829 {
832 }
835 {
838 }
840 /* Initialize the association list for this type, based
841 on our first approximation. */
846 }
848 /* Give BINFO a new virtual function table which is initialized
849 with a skeleton-copy of its original initialization. The only
850 entry that changes is the `delta' entry, so we can really
851 share a lot of structure.
853 FOR_TYPE is the most derived type which caused this table to
854 be needed.
856 Returns nonzero if we haven't met BINFO before.
858 The order in which vtables are built (by calling this function) for
859 an object must remain the same, otherwise a binary incompatibility
860 can result. */
862 static int
864 {
866 /* We already created a vtable for this base. There's no need to
867 do it again. */
870 /* Remember that we've created a vtable for this BINFO, so that we
871 don't try to do so again. */
874 /* Make fresh virtual list, so we can smash it later. */
877 /* Secondary vtables are laid out as part of the same structure as
878 the primary vtable. */
881 }
883 /* Create a new vtable for BINFO which is the hierarchy dominated by
884 T. Return nonzero if we actually created a new vtable. */
886 static int
888 {
890 /* In this case, it is *type*'s vtable we are modifying. We start
891 with the approximation that its vtable is that of the
892 immediate base class. */
894 else
895 /* This is our very own copy of `basetype' to play with. Later,
896 we will fill in all the virtual functions that override the
897 virtual functions in these base classes which are not defined
898 by the current type. */
900 }
902 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
903 (which is in the hierarchy dominated by T) list FNDECL as its
904 BV_FN. DELTA is the required constant adjustment from the `this'
905 pointer where the vtable entry appears to the `this' required when
906 the function is actually called. */
908 static void
910 tree binfo,
911 tree fndecl,
912 tree delta,
914 {
915 tree v;
921 {
922 /* We need a new vtable for BINFO. */
924 {
925 /* If we really did make a new vtable, we also made a copy
926 of the BINFO_VIRTUALS list. Now, we have to find the
927 corresponding entry in that list. */
932 }
937 }
938 }
940 \f
941 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
942 the USING_DECL naming METHOD. Returns true if the method could be
943 added to the method vec. */
945 bool
947 {
949 tree overload;
955 tree current_fns;
956 tree fns;
969 {
970 /* Make a new method vector. We start with 8 entries. We must
971 allocate at least two (for constructors and destructors), and
972 we're going to end up with an assignment operator at some
973 point as well. */
975 /* Create slots for constructors and destructors. */
979 }
981 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
984 /* Constructors and destructors go in special slots. */
988 {
992 {
998 type);
999 }
1000 }
1001 else
1002 {
1003 tree m;
1006 /* See if we already have an entry with this name. */
1010 {
1013 {
1018 }
1022 {
1025 }
1030 }
1031 }
1034 /* Check to see if we've already got this method. */
1036 {
1038 tree fn_type;
1039 tree method_type;
1040 tree parms1;
1041 tree parms2;
1046 /* [over.load] Member function declarations with the
1047 same name and the same parameter types cannot be
1048 overloaded if any of them is a static member
1049 function declaration.
1051 [namespace.udecl] When a using-declaration brings names
1052 from a base class into a derived class scope, member
1053 functions in the derived class override and/or hide member
1054 functions with the same name and parameter types in a base
1055 class (rather than conflicting). */
1061 /* Compare the quals on the 'this' parm. Don't compare
1062 the whole types, as used functions are treated as
1063 coming from the using class in overload resolution. */
1072 /* For templates, the return type and template parameters
1073 must be identical. */
1090 {
1091 /* For function versions, their parms and types match
1092 but they are not duplicates. Record function versions
1093 as and when they are found. extern "C" functions are
1094 not treated as versions. */
1102 {
1103 /* Mark functions as versions if necessary. Modify the mangled
1104 decl name if necessary. */
1106 {
1110 }
1112 {
1116 }
1119 }
1121 {
1123 {
1130 }
1131 /* Otherwise defer to the other function. */
1133 }
1135 {
1137 /* Defer to the local function. */
1139 }
1140 else
1141 {
1144 }
1146 /* We don't call duplicate_decls here to merge the
1147 declarations because that will confuse things if the
1148 methods have inline definitions. In particular, we
1149 will crash while processing the definitions. */
1151 }
1152 }
1154 /* A class should never have more than one destructor. */
1158 /* Add the new binding. */
1160 {
1163 }
1164 else
1173 {
1176 /* We only expect to add few methods in the COMPLETE_P case, so
1177 just make room for one more method in that case. */
1180 else
1186 else
1188 }
1189 else
1190 /* Replace the current slot. */
1193 }
1195 /* Subroutines of finish_struct. */
1197 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1198 legit, otherwise return 0. */
1200 static int
1202 {
1203 tree elem;
1212 {
1214 {
1218 else
1221 }
1222 else
1223 {
1224 /* They're changing the access to the same thing they changed
1225 it to before. That's OK. */
1226 ;
1227 }
1228 }
1229 else
1230 {
1232 tf_warning_or_error);
1235 }
1237 }
1239 /* Process the USING_DECL, which is a member of T. */
1241 static void
1243 {
1246 tree access
1251 tree old_value;
1256 tf_warning_or_error);
1258 {
1264 else
1266 }
1274 ;
1276 {
1278 /* It's OK to use functions from a base when there are functions with
1280 else
1281 {
1286 }
1287 }
1289 {
1293 }
1295 /* Make type T see field decl FDECL with access ACCESS. */
1298 {
1301 }
1302 else
1304 }
1305 \f
1306 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1307 types with abi tags, add the corresponding identifiers to the VEC in
1308 *DATA and set IDENTIFIER_MARKED. */
1310 struct abi_tag_data
1311 {
1312 tree t;
1313 tree subob;
1314 };
1316 static tree
1318 {
1323 {
1327 {
1331 {
1333 {
1338 }
1339 else
1340 {
1347 }
1348 }
1349 }
1350 }
1352 }
1354 /* Check that class T has all the abi tags that subobject SUBOB has, or
1355 warn if not. */
1357 static void
1359 {
1362 {
1365 {
1369 }
1370 }
1378 {
1381 {
1385 }
1386 }
1387 }
1389 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1390 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1391 properties of the bases. */
1393 static void
1397 {
1401 tree base_binfo;
1402 tree binfo;
1412 {
1421 /* If any base class is non-literal, so is the derived class. */
1425 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1426 here because the case of virtual functions but non-virtual
1427 dtor is handled in finish_struct_1. */
1432 /* If the base class doesn't have copy constructors or
1433 assignment operators that take const references, then the
1434 derived class cannot have such a member automatically
1435 generated. */
1444 /* A virtual base does not effect nearly emptiness. */
1445 ;
1447 {
1449 /* And if there is more than one nearly empty base, then the
1450 derived class is not nearly empty either. */
1452 else
1453 /* Remember we've seen one. */
1455 }
1457 /* If the base class is not empty or nearly empty, then this
1458 class cannot be nearly empty. */
1461 /* A lot of properties from the bases also apply to the derived
1462 class. */
1480 /* A standard-layout class is a class that:
1481 ...
1482 * has no non-standard-layout base classes, */
1485 {
1486 tree basefield;
1487 /* ...has no base classes of the same type as the first non-static
1488 data member... */
1490 && (same_type_ignoring_top_level_qualifiers_p
1493 else
1494 /* ...either has no non-static data members in the most-derived
1495 class and at most one base class with non-static data
1496 members, or has no base classes with non-static data
1497 members */
1501 {
1504 else
1507 }
1508 }
1510 /* Don't bother collecting tm attributes if transactional memory
1511 support is not enabled. */
1513 {
1517 }
1520 }
1522 /* If one of the base classes had TM attributes, and the current class
1523 doesn't define its own, then the current class inherits one. */
1525 {
1528 }
1529 }
1531 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1532 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1533 that have had a nearly-empty virtual primary base stolen by some
1534 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1535 T. */
1537 static void
1539 {
1543 tree base_binfo;
1545 /* Determine the primary bases of our bases. */
1548 {
1551 /* See if we're the non-virtual primary of our inheritance
1552 chain. */
1554 {
1561 /* We are the primary binfo. */
1563 }
1564 /* Determine if we have a virtual primary base, and mark it so.
1565 */
1567 {
1571 /* Someone already claimed this base. */
1573 else
1574 {
1575 tree delta;
1580 /* A virtual binfo might have been copied from within
1581 another hierarchy. As we're about to use it as a
1582 primary base, make sure the offsets match. */
1590 }
1591 }
1592 }
1594 /* First look for a dynamic direct non-virtual base. */
1596 {
1600 {
1603 }
1604 }
1606 /* A "nearly-empty" virtual base class can be the primary base
1607 class, if no non-virtual polymorphic base can be found. Look for
1608 a nearly-empty virtual dynamic base that is not already a primary
1609 base of something in the hierarchy. If there is no such base,
1610 just pick the first nearly-empty virtual base. */
1616 {
1618 {
1619 /* Found one that is not primary. */
1622 }
1624 /* Remember the first candidate. */
1626 }
1628 found:
1629 /* If we've got a primary base, use it. */
1631 {
1636 /* We are stealing a primary base. */
1640 {
1641 tree delta;
1644 /* A virtual binfo might have been copied from within
1645 another hierarchy. As we're about to use it as a primary
1646 base, make sure the offsets match. */
1651 }
1658 }
1659 }
1661 /* Update the variant types of T. */
1663 void
1665 {
1666 tree variants;
1672 variants;
1674 {
1675 /* These fields are in the _TYPE part of the node, not in
1676 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1686 /* Copy whatever these are holding today. */
1690 }
1691 }
1693 /* Early variant fixups: we apply attributes at the beginning of the class
1694 definition, and we need to fix up any variants that have already been
1695 made via elaborated-type-specifier so that check_qualified_type works. */
1697 void
1699 {
1700 tree variants;
1706 variants;
1708 {
1709 /* These are the two fields that check_qualified_type looks at and
1710 are affected by attributes. */
1713 }
1714 }
1715 \f
1716 /* Set memoizing fields and bits of T (and its variants) for later
1717 use. */
1719 static void
1721 {
1722 /* Fix up variants (if any). */
1726 /* For a class w/o baseclasses, 'finish_struct' has set
1727 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1728 Similarly for a class whose base classes do not have vtables.
1729 When neither of these is true, we might have removed abstract
1730 virtuals (by providing a definition), added some (by declaring
1731 new ones), or redeclared ones from a base class. We need to
1732 recalculate what's really an abstract virtual at this point (by
1733 looking in the vtables). */
1736 /* If this type has a copy constructor or a destructor, force its
1737 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1738 nonzero. This will cause it to be passed by invisible reference
1739 and prevent it from being returned in a register. */
1742 {
1743 tree variants;
1746 {
1749 }
1750 }
1751 }
1753 /* Issue warnings about T having private constructors, but no friends,
1754 and so forth.
1756 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1757 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1758 non-private static member functions. */
1760 static void
1762 {
1765 tree fn;
1768 /* If the class has friends, those entities might create and
1769 access instances, so we should not warn. */
1772 /* We will have warned when the template was declared; there's
1773 no need to warn on every instantiation. */
1775 /* There's no reason to even consider warning about this
1776 class. */
1779 /* We only issue one warning, if more than one applies, because
1780 otherwise, on code like:
1782 class A {
1783 // Oops - forgot `public:'
1784 A();
1785 A(const A&);
1786 ~A();
1787 };
1789 we warn several times about essentially the same problem. */
1791 /* Check to see if all (non-constructor, non-destructor) member
1792 functions are private. (Since there are no friends or
1793 non-private statics, we can't ever call any of the private member
1794 functions.) */
1796 /* We're not interested in compiler-generated methods; they don't
1797 provide any way to call private members. */
1799 {
1801 {
1803 /* A non-private static member function is just like a
1804 friend; it can create and invoke private member
1805 functions, and be accessed without a class
1806 instance. */
1810 /* Keep searching for a static member function. */
1811 }
1814 }
1817 {
1818 /* There are no non-private methods, and there's at least one
1819 private member function that isn't a constructor or
1820 destructor. (If all the private members are
1821 constructors/destructors we want to use the code below that
1822 issues error messages specifically referring to
1823 constructors/destructors.) */
1829 {
1832 }
1834 {
1838 }
1839 }
1841 /* Even if some of the member functions are non-private, the class
1842 won't be useful for much if all the constructors or destructors
1843 are private: such an object can never be created or destroyed. */
1846 {
1849 t);
1851 }
1853 /* Warn about classes that have private constructors and no friends. */
1855 /* Implicitly generated constructors are always public. */
1858 {
1861 /* If a non-template class does not define a copy
1862 constructor, one is defined for it, enabling it to avoid
1863 this warning. For a template class, this does not
1864 happen, and so we would normally get a warning on:
1866 template <class T> class C { private: C(); };
1868 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1869 complete non-template or fully instantiated classes have this
1870 flag set. */
1873 else
1875 {
1877 /* Ideally, we wouldn't count copy constructors (or, in
1878 fact, any constructor that takes an argument of the
1879 class type as a parameter) because such things cannot
1880 be used to construct an instance of the class unless
1881 you already have one. But, for now at least, we're
1882 more generous. */
1884 {
1887 }
1888 }
1891 {
1894 t);
1896 }
1897 }
1898 }
1901 gt_pointer_operator new_value;
1905 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1907 static int
1909 {
1922 }
1924 /* This routine compares two fields like method_name_cmp but using the
1925 pointer operator in resort_field_decl_data. */
1927 static int
1929 {
1938 {
1945 }
1947 }
1949 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1951 void
1954 gt_pointer_operator new_value,
1956 {
1960 tree fn;
1962 /* The type conversion ops have to live at the front of the vec, so we
1963 can't sort them. */
1971 {
1975 resort_method_name_cmp);
1976 }
1977 }
1979 /* Warn about duplicate methods in fn_fields.
1981 Sort methods that are not special (i.e., constructors, destructors,
1982 and type conversion operators) so that we can find them faster in
1983 search. */
1985 static void
1987 {
1988 tree fn_fields;
1998 /* Clear DECL_IN_AGGR_P for all functions. */
2003 /* Issue warnings about private constructors and such. If there are
2004 no methods, then some public defaults are generated. */
2007 /* The type conversion ops have to live at the front of the vec, so we
2008 can't sort them. */
2017 }
2019 /* Make BINFO's vtable have N entries, including RTTI entries,
2020 vbase and vcall offsets, etc. Set its type and call the back end
2021 to lay it out. */
2023 static void
2025 {
2026 tree atype;
2027 tree vtable;
2032 /* We may have to grow the vtable. */
2035 {
2039 }
2040 }
2042 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2043 have the same signature. */
2045 int
2047 {
2048 /* One destructor overrides another if they are the same kind of
2049 destructor. */
2053 /* But a non-destructor never overrides a destructor, nor vice
2054 versa, nor do different kinds of destructors override
2055 one-another. For example, a complete object destructor does not
2056 override a deleting destructor. */
2065 {
2073 }
2075 }
2077 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2078 subobject. */
2080 static bool
2082 {
2083 tree probe;
2086 {
2090 /* If we meet a virtual base, we can't follow the inheritance
2091 any more. See if the complete type of DERIVED contains
2092 such a virtual base. */
2095 }
2097 }
2100 /* The function for which we are trying to find a final overrider. */
2101 tree fn;
2102 /* The base class in which the function was declared. */
2103 tree declaring_base;
2104 /* The candidate overriders. */
2105 tree candidates;
2106 /* Path to most derived. */
2110 /* Add the overrider along the current path to FFOD->CANDIDATES.
2111 Returns true if an overrider was found; false otherwise. */
2113 static bool
2117 {
2118 tree method;
2120 /* If BINFO is not the most derived type, try a more derived class.
2121 A definition there will overrider a definition here. */
2123 {
2124 depth--;
2128 }
2132 {
2135 /* Remove any candidates overridden by this new function. */
2137 {
2138 /* If *CANDIDATE overrides METHOD, then METHOD
2139 cannot override anything else on the list. */
2142 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2145 else
2147 }
2149 /* Add the new function. */
2152 }
2155 }
2157 /* Called from find_final_overrider via dfs_walk. */
2159 static tree
2161 {
2169 }
2171 static tree
2173 {
2178 }
2180 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2181 FN and whose TREE_VALUE is the binfo for the base where the
2182 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2183 DERIVED) is the base object in which FN is declared. */
2185 static tree
2187 {
2188 find_final_overrider_data ffod;
2190 /* Getting this right is a little tricky. This is valid:
2192 struct S { virtual void f (); };
2193 struct T { virtual void f (); };
2194 struct U : public S, public T { };
2196 even though calling `f' in `U' is ambiguous. But,
2198 struct R { virtual void f(); };
2199 struct S : virtual public R { virtual void f (); };
2200 struct T : virtual public R { virtual void f (); };
2201 struct U : public S, public T { };
2203 is not -- there's no way to decide whether to put `S::f' or
2204 `T::f' in the vtable for `R'.
2206 The solution is to look at all paths to BINFO. If we find
2207 different overriders along any two, then there is a problem. */
2211 /* Determine the depth of the hierarchy. */
2222 /* If there was no winner, issue an error message. */
2227 }
2229 /* Return the index of the vcall offset for FN when TYPE is used as a
2230 virtual base. */
2232 static tree
2234 {
2236 tree_pair_p p;
2244 /* There should always be an appropriate index. */
2246 }
2248 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2249 dominated by T. FN is the old function; VIRTUALS points to the
2250 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2251 of that entry in the list. */
2253 static void
2256 {
2257 tree b;
2258 tree overrider;
2259 tree delta;
2260 tree virtual_base;
2261 tree first_defn;
2267 /* Find the nearest primary base (possibly binfo itself) which defines
2268 this function; this is the class the caller will convert to when
2269 calling FN through BINFO. */
2271 {
2276 /* The nearest definition is from a lost primary. */
2279 }
2282 /* Find the final overrider. */
2285 {
2288 }
2291 /* Check for adjusting covariant return types. */
2299 /* If the overrider is invalid, don't even try. */
2301 {
2302 /* If FN is a covariant thunk, we must figure out the adjustment
2303 to the final base FN was converting to. As OVERRIDER_TARGET might
2304 also be converting to the return type of FN, we have to
2305 combine the two conversions here. */
2312 {
2316 }
2317 else
2321 /* Find the equivalent binfo within the return type of the
2322 overriding function. We will want the vbase offset from
2323 there. */
2325 over_return);
2328 {
2329 /* There was no existing virtual thunk (which takes
2330 precedence). So find the binfo of the base function's
2331 return type within the overriding function's return type.
2332 We cannot call lookup base here, because we're inside a
2333 dfs_walk, and will therefore clobber the BINFO_MARKED
2334 flags. Fortunately we know the covariancy is valid (it
2335 has already been checked), so we can just iterate along
2336 the binfos, which have been chained in inheritance graph
2337 order. Of course it is lame that we have to repeat the
2338 search here anyway -- we should really be caching pieces
2339 of the vtable and avoiding this repeated work. */
2342 /* Find the base binfo within the overriding function's
2343 return type. We will always find a thunk_binfo, except
2344 when the covariancy is invalid (which we will have
2345 already diagnosed). */
2348 thunk_binfo;
2354 /* See if virtual inheritance is involved. */
2356 virtual_offset;
2363 {
2367 {
2368 /* We convert via virtual base. Adjust the fixed
2369 offset to be from there. */
2370 offset =
2374 }
2376 /* There was an existing fixed offset, this must be
2377 from the base just converted to, and the base the
2378 FN was thunking to. */
2380 else
2382 }
2383 }
2386 /* Replace the overriding function with a covariant thunk. We
2387 will emit the overriding function in its own slot as
2388 well. */
2391 }
2392 else
2396 /* If we need a covariant thunk, then we may need to adjust first_defn.
2397 The ABI specifies that the thunks emitted with a function are
2398 determined by which bases the function overrides, so we need to be
2399 sure that we're using a thunk for some overridden base; even if we
2400 know that the necessary this adjustment is zero, there may not be an
2401 appropriate zero-this-adjusment thunk for us to use since thunks for
2402 overriding virtual bases always use the vcall offset.
2404 Furthermore, just choosing any base that overrides this function isn't
2405 quite right, as this slot won't be used for calls through a type that
2406 puts a covariant thunk here. Calling the function through such a type
2407 will use a different slot, and that slot is the one that determines
2408 the thunk emitted for that base.
2410 So, keep looking until we find the base that we're really overriding
2411 in this slot: the nearest primary base that doesn't use a covariant
2412 thunk in this slot. */
2414 {
2416 /* We already know that the overrider needs a covariant thunk. */
2419 {
2426 }
2428 }
2430 /* Assume that we will produce a thunk that convert all the way to
2431 the final overrider, and not to an intermediate virtual base. */
2434 /* See if we can convert to an intermediate virtual base first, and then
2435 use the vcall offset located there to finish the conversion. */
2437 {
2438 /* If we find the final overrider, then we can stop
2439 walking. */
2444 /* If we find a virtual base, and we haven't yet found the
2445 overrider, then there is a virtual base between the
2446 declaring base (first_defn) and the final overrider. */
2448 {
2451 }
2452 }
2454 /* Compute the constant adjustment to the `this' pointer. The
2455 `this' pointer, when this function is called, will point at BINFO
2456 (or one of its primary bases, which are at the same offset). */
2458 /* The `this' pointer needs to be adjusted from the declaration to
2459 the nearest virtual base. */
2464 /* If the nearest definition is in a lost primary, we don't need an
2465 entry in our vtable. Except possibly in a constructor vtable,
2466 if we happen to get our primary back. In that case, the offset
2467 will be zero, as it will be a primary base. */
2469 else
2470 /* The `this' pointer needs to be adjusted from pointing to
2471 BINFO to pointing at the base where the final overrider
2472 appears. */
2483 else
2487 }
2489 /* Called from modify_all_vtables via dfs_walk. */
2491 static tree
2493 {
2495 tree virtuals;
2496 tree old_virtuals;
2500 /* A base without a vtable needs no modification, and its bases
2501 are uninteresting. */
2506 /* Don't do the primary vtable, if it's new. */
2510 /* There's no need to modify the vtable for a non-virtual primary
2511 base; we're not going to use that vtable anyhow. We do still
2512 need to do this for virtual primary bases, as they could become
2513 non-primary in a construction vtable. */
2518 /* Now, go through each of the virtual functions in the virtual
2519 function table for BINFO. Find the final overrider, and update
2520 the BINFO_VIRTUALS list appropriately. */
2523 virtuals;
2527 binfo,
2532 }
2534 /* Update all of the primary and secondary vtables for T. Create new
2535 vtables as required, and initialize their RTTI information. Each
2536 of the functions in VIRTUALS is declared in T and may override a
2537 virtual function from a base class; find and modify the appropriate
2538 entries to point to the overriding functions. Returns a list, in
2539 declaration order, of the virtual functions that are declared in T,
2540 but do not appear in the primary base class vtable, and which
2541 should therefore be appended to the end of the vtable for T. */
2543 static tree
2545 {
2549 /* Update all of the vtables. */
2552 /* Add virtual functions not already in our primary vtable. These
2553 will be both those introduced by this class, and those overridden
2554 from secondary bases. It does not include virtuals merely
2555 inherited from secondary bases. */
2557 {
2562 {
2563 /* We don't need to adjust the `this' pointer when
2564 calling this function. */
2568 /* This is a function not already in our vtable. Keep it. */
2570 }
2571 else
2572 /* We've already got an entry for this function. Skip it. */
2574 }
2577 }
2579 /* Get the base virtual function declarations in T that have the
2580 indicated NAME. */
2582 static tree
2584 {
2585 tree methods;
2590 /* Find virtual functions in T with the indicated NAME. */
2594 methods;
2596 {
2602 }
2608 {
2611 base_fndecls);
2612 }
2615 }
2617 /* If this declaration supersedes the declaration of
2618 a method declared virtual in the base class, then
2619 mark this field as being virtual as well. */
2621 void
2623 {
2626 /* In [temp.mem] we have:
2628 A specialization of a member function template does not
2629 override a virtual function from a base class. */
2636 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2637 the error_mark_node so that we know it is an overriding
2638 function. */
2639 {
2642 }
2645 {
2651 }
2656 }
2658 /* Warn about hidden virtual functions that are not overridden in t.
2659 We know that constructors and destructors don't apply. */
2661 static void
2663 {
2665 tree fns;
2668 /* We go through each separately named virtual function. */
2672 {
2673 tree fn;
2674 tree name;
2675 tree fndecl;
2676 tree base_fndecls;
2677 tree base_binfo;
2678 tree binfo;
2681 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2682 have the same name. Figure out what name that is. */
2684 /* There are no possibly hidden functions yet. */
2686 /* Iterate through all of the base classes looking for possibly
2687 hidden functions. */
2690 {
2693 base_fndecls);
2694 }
2696 /* If there are no functions to hide, continue. */
2700 /* Remove any overridden functions. */
2702 {
2705 {
2709 /* If the method from the base class has the same
2710 signature as the method from the derived class, it
2711 has been overridden. */
2714 else
2716 }
2717 }
2719 /* Now give a warning for all base functions without overriders,
2720 as they are hidden. */
2722 {
2723 /* Here we know it is a hider, and no overrider exists. */
2727 }
2728 }
2729 }
2731 /* Check for things that are invalid. There are probably plenty of other
2732 things we should check for also. */
2734 static void
2736 {
2737 tree field;
2740 {
2748 {
2752 {
2753 /* We're generally only interested in entities the user
2754 declared, but we also find nested classes by noticing
2755 the TYPE_DECL that we create implicitly. You're
2756 allowed to put one anonymous union inside another,
2757 though, so we explicitly tolerate that. We use
2758 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2759 we also allow unnamed types used for defining fields. */
2766 {
2770 else
2774 }
2777 {
2780 else
2782 }
2784 {
2787 else
2789 }
2793 }
2794 }
2795 }
2796 }
2798 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2799 will be used later during class template instantiation.
2800 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2801 a non-static member data (FIELD_DECL), a member function
2802 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2803 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2804 When FRIEND_P is nonzero, T is either a friend class
2805 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2806 (FUNCTION_DECL, TEMPLATE_DECL). */
2808 void
2810 {
2811 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2816 }
2818 /* This function is called from declare_virt_assop_and_dtor via
2819 dfs_walk_all.
2821 DATA is a type that direcly or indirectly inherits the base
2822 represented by BINFO. If BINFO contains a virtual assignment [copy
2823 assignment or move assigment] operator or a virtual constructor,
2824 declare that function in DATA if it hasn't been already declared. */
2826 static tree
2828 {
2836 /* A base without a vtable needs no modification, and its bases
2837 are uninteresting. */
2841 /* If this is a primary base, then we have already looked at the
2842 virtual functions of its vtable. */
2846 {
2850 {
2855 }
2859 }
2862 }
2864 /* If the class type T has a direct or indirect base that contains a
2865 virtual assignment operator or a virtual destructor, declare that
2866 function in T if it hasn't been already declared. */
2868 static void
2870 {
2878 dfs_declare_virt_assop_and_dtor,
2880 }
2882 /* Declare the inheriting constructor for class T inherited from base
2883 constructor CTOR with the parameter array PARMS of size NPARMS. */
2885 static void
2887 {
2888 /* We don't declare an inheriting ctor that would be a default,
2889 copy or move ctor. */
2902 {
2905 }
2906 }
2908 /* Declare all the inheriting constructors for class T inherited from base
2909 constructor CTOR. */
2911 static void
2913 {
2919 {
2923 }
2926 {
2930 }
2931 }
2933 /* Create default constructors, assignment operators, and so forth for
2934 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2935 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2936 the class cannot have a default constructor, copy constructor
2937 taking a const reference argument, or an assignment operator taking
2938 a const reference, respectively. */
2940 static void
2944 {
2952 /* Destructor. */
2954 {
2955 /* In general, we create destructors lazily. */
2960 /* But if this is a Java class, any non-trivial destructor is
2961 invalid, even if compiler-generated. Therefore, if the
2962 destructor is non-trivial we create it now. */
2964 }
2966 /* [class.ctor]
2968 If there is no user-declared constructor for a class, a default
2969 constructor is implicitly declared. */
2971 {
2976 /* This might force the declaration. */
2978 }
2980 /* [class.ctor]
2982 If a class definition does not explicitly declare a copy
2983 constructor, one is declared implicitly. */
2985 {
2991 }
2993 /* If there is no assignment operator, one will be created if and
2994 when it is needed. For now, just record whether or not the type
2995 of the parameter to the assignment operator will be a const or
2996 non-const reference. */
2998 {
3004 }
3006 /* We can't be lazy about declaring functions that might override
3007 a virtual function from a base class. */
3011 {
3015 {
3016 /* declare, then remove the decl */
3018 ctor_identifier);
3026 }
3027 else
3029 }
3030 }
3032 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3033 count the number of fields in TYPE, including anonymous union
3034 members. */
3036 static int
3038 {
3039 tree x;
3042 {
3045 else
3047 }
3049 }
3051 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3052 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3053 elts, starting at offset IDX. */
3055 static int
3057 {
3058 tree x;
3060 {
3063 else
3065 }
3067 }
3069 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3070 starting at offset IDX. */
3072 static int
3076 {
3077 tree values;
3081 }
3083 /* FIELD is a bit-field. We are finishing the processing for its
3084 enclosing type. Issue any appropriate messages and set appropriate
3085 flags. Returns false if an error has been diagnosed. */
3087 static bool
3089 {
3091 tree w;
3093 /* Extract the declared width of the bitfield, which has been
3094 temporarily stashed in DECL_INITIAL. */
3097 /* Remove the bit-field width indicator so that the rest of the
3098 compiler does not treat that value as an initializer. */
3101 /* Detect invalid bit-field type. */
3103 {
3106 }
3107 else
3108 {
3110 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3113 /* detect invalid field size. */
3119 {
3122 }
3124 {
3127 }
3129 {
3132 }
3141 }
3144 {
3148 }
3149 else
3150 {
3151 /* Non-bit-fields are aligned for their type. */
3155 }
3156 }
3158 /* FIELD is a non bit-field. We are finishing the processing for its
3159 enclosing type T. Issue any appropriate messages and set appropriate
3160 flags. */
3162 static void
3164 tree t,
3168 {
3171 /* In C++98 an anonymous union cannot contain any fields which would change
3172 the settings of CANT_HAVE_CONST_CTOR and friends. */
3174 ;
3175 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3176 structs. So, we recurse through their fields here. */
3178 {
3179 tree fields;
3185 }
3186 /* Check members with class type for constructors, destructors,
3187 etc. */
3189 {
3190 /* Never let anything with uninheritable virtuals
3191 make it through without complaint. */
3195 {
3200 field);
3205 field);
3207 {
3211 }
3212 }
3213 else
3214 {
3227 }
3236 }
3241 {
3242 /* `build_class_init_list' does not recognize
3243 non-FIELD_DECLs. */
3247 }
3248 }
3250 /* Check the data members (both static and non-static), class-scoped
3251 typedefs, etc., appearing in the declaration of T. Issue
3252 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3253 declaration order) of access declarations; each TREE_VALUE in this
3254 list is a USING_DECL.
3256 In addition, set the following flags:
3258 EMPTY_P
3259 The class is empty, i.e., contains no non-static data members.
3261 CANT_HAVE_CONST_CTOR_P
3262 This class cannot have an implicitly generated copy constructor
3263 taking a const reference.
3265 CANT_HAVE_CONST_ASN_REF
3266 This class cannot have an implicitly generated assignment
3267 operator taking a const reference.
3269 All of these flags should be initialized before calling this
3270 function.
3272 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3273 fields can be added by adding to this chain. */
3275 static void
3279 {
3287 /* Assume there are no access declarations. */
3289 /* Assume this class has no pointer members. */
3291 /* Assume none of the members of this class have default
3292 initializations. */
3296 {
3304 {
3305 /* Save the access declarations for our caller. */
3308 }
3314 /* If we've gotten this far, it's a data member, possibly static,
3315 or an enumerator. */
3319 /* When this goes into scope, it will be a non-local reference. */
3323 {
3324 /* [class.union]
3326 If a union contains a static data member, or a member of
3327 reference type, the program is ill-formed. */
3329 {
3332 }
3334 {
3339 }
3340 }
3342 /* Perform error checking that did not get done in
3343 grokdeclarator. */
3345 {
3349 }
3351 {
3355 }
3363 /* Now it can only be a FIELD_DECL. */
3368 /* If at least one non-static data member is non-literal, the whole
3369 class becomes non-literal. Note: if the type is incomplete we
3370 will complain later on. */
3374 /* A standard-layout class is a class that:
3375 ...
3376 has the same access control (Clause 11) for all non-static data members,
3377 ... */
3384 /* If this is of reference type, check if it needs an init. */
3386 {
3392 /* ARM $12.6.2: [A member initializer list] (or, for an
3393 aggregate, initialization by a brace-enclosed list) is the
3394 only way to initialize nonstatic const and reference
3395 members. */
3398 }
3403 {
3405 {
3406 warning
3409 x);
3411 }
3415 }
3418 /* We don't treat zero-width bitfields as making a class
3419 non-empty. */
3420 ;
3421 else
3422 {
3423 /* The class is non-empty. */
3425 /* The class is not even nearly empty. */
3427 /* If one of the data members contains an empty class,
3428 so does T. */
3432 }
3434 /* This is used by -Weffc++ (see below). Warn only for pointers
3435 to members which might hold dynamic memory. So do not warn
3436 for pointers to functions or pointers to members. */
3442 {
3447 }
3453 /* DR 148 now allows pointers to members (which are POD themselves),
3454 to be allowed in POD structs. */
3463 /* We set DECL_C_BIT_FIELD in grokbitfield.
3464 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3467 cant_have_const_ctor_p,
3468 no_const_asn_ref_p,
3471 /* Now that we've removed bit-field widths from DECL_INITIAL,
3472 anything left in DECL_INITIAL is an NSDMI that makes the class
3473 non-aggregate. */
3477 /* If any field is const, the structure type is pseudo-const. */
3479 {
3484 /* ARM $12.6.2: [A member initializer list] (or, for an
3485 aggregate, initialization by a brace-enclosed list) is the
3486 only way to initialize nonstatic const and reference
3487 members. */
3490 }
3491 /* A field that is pseudo-const makes the structure likewise. */
3493 {
3498 }
3500 /* Core issue 80: A nonstatic data member is required to have a
3501 different name from the class iff the class has a
3502 user-declared constructor. */
3506 }
3508 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3509 it should also define a copy constructor and an assignment operator to
3510 implement the correct copy semantic (deep vs shallow, etc.). As it is
3511 not feasible to check whether the constructors do allocate dynamic memory
3512 and store it within members, we approximate the warning like this:
3514 -- Warn only if there are members which are pointers
3515 -- Warn only if there is a non-trivial constructor (otherwise,
3516 there cannot be memory allocated).
3517 -- Warn only if there is a non-trivial destructor. We assume that the
3518 user at least implemented the cleanup correctly, and a destructor
3519 is needed to free dynamic memory.
3521 This seems enough for practical purposes. */
3523 && has_pointers
3527 {
3531 {
3536 }
3540 }
3542 /* Non-static data member initializers make the default constructor
3543 non-trivial. */
3545 {
3548 }
3550 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3554 /* Check anonymous struct/anonymous union fields. */
3557 /* We've built up the list of access declarations in reverse order.
3558 Fix that now. */
3560 }
3562 /* If TYPE is an empty class type, records its OFFSET in the table of
3563 OFFSETS. */
3565 static int
3567 {
3568 splay_tree_node n;
3573 /* Record the location of this empty object in OFFSETS. */
3581 type,
3585 }
3587 /* Returns nonzero if TYPE is an empty class type and there is
3588 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3590 static int
3592 {
3593 splay_tree_node n;
3594 tree t;
3599 /* Record the location of this empty object in OFFSETS. */
3609 }
3611 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3612 F for every subobject, passing it the type, offset, and table of
3613 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3614 be traversed.
3616 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3617 than MAX_OFFSET will not be walked.
3619 If F returns a nonzero value, the traversal ceases, and that value
3620 is returned. Otherwise, returns zero. */
3622 static int
3624 subobject_offset_fn f,
3625 tree offset,
3626 splay_tree offsets,
3627 tree max_offset,
3629 {
3633 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3634 stop. */
3642 {
3646 }
3649 {
3650 tree field;
3651 tree binfo;
3654 /* Avoid recursing into objects that are not interesting. */
3658 /* Record the location of TYPE. */
3663 /* Iterate through the direct base classes of TYPE. */
3667 {
3668 tree binfo_offset;
3681 offset,
3683 else
3684 {
3685 tree orig_binfo;
3686 /* We cannot rely on BINFO_OFFSET being set for the base
3687 class yet, but the offsets for direct non-virtual
3688 bases can be calculated by going back to the TYPE. */
3691 offset,
3693 }
3696 f,
3697 binfo_offset,
3698 offsets,
3699 max_offset,
3704 }
3707 {
3711 /* Iterate through the virtual base classes of TYPE. In G++
3712 3.2, we included virtual bases in the direct base class
3713 loop above, which results in incorrect results; the
3714 correct offsets for virtual bases are only known when
3715 working with the most derived type. */
3719 {
3721 f,
3723 offset,
3725 offsets,
3726 max_offset,
3730 }
3731 else
3732 {
3733 /* We still have to walk the primary base, if it is
3734 virtual. (If it is non-virtual, then it was walked
3735 above.) */
3741 {
3742 r = (walk_subobject_offsets
3747 }
3748 }
3749 }
3751 /* Iterate through the fields of TYPE. */
3754 {
3755 tree field_offset;
3759 else
3760 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3764 f,
3766 offset,
3767 field_offset),
3768 offsets,
3769 max_offset,
3773 }
3774 }
3776 {
3779 tree index;
3781 /* Avoid recursing into objects that are not interesting. */
3786 /* Step through each of the elements in the array. */
3788 /* G++ 3.2 had an off-by-one error here. */
3793 {
3795 f,
3796 offset,
3797 offsets,
3798 max_offset,
3804 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3805 there's no point in iterating through the remaining
3806 elements of the array. */
3809 }
3810 }
3813 }
3815 /* Record all of the empty subobjects of TYPE (either a type or a
3816 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3817 is being placed at OFFSET; otherwise, it is a base class that is
3818 being placed at OFFSET. */
3820 static void
3822 tree offset,
3823 splay_tree offsets,
3825 {
3826 tree max_offset;
3827 /* If recording subobjects for a non-static data member or a
3828 non-empty base class , we do not need to record offsets beyond
3829 the size of the biggest empty class. Additional data members
3830 will go at the end of the class. Additional base classes will go
3831 either at offset zero (if empty, in which case they cannot
3832 overlap with offsets past the size of the biggest empty class) or
3833 at the end of the class.
3835 However, if we are placing an empty base class, then we must record
3836 all offsets, as either the empty class is at offset zero (where
3837 other empty classes might later be placed) or at the end of the
3838 class (where other objects might then be placed, so other empty
3839 subobjects might later overlap). */
3843 else
3847 }
3849 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3850 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3851 virtual bases of TYPE are examined. */
3853 static int
3855 tree offset,
3856 splay_tree offsets,
3858 {
3859 splay_tree_node max_node;
3861 /* Get the node in OFFSETS that indicates the maximum offset where
3862 an empty subobject is located. */
3864 /* If there aren't any empty subobjects, then there's no point in
3865 performing this check. */
3871 vbases_p);
3872 }
3874 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3875 non-static data member of the type indicated by RLI. BINFO is the
3876 binfo corresponding to the base subobject, OFFSETS maps offsets to
3877 types already located at those offsets. This function determines
3878 the position of the DECL. */
3880 static void
3882 tree decl,
3883 tree binfo,
3884 splay_tree offsets)
3885 {
3888 tree type;
3891 {
3892 /* For the purposes of determining layout conflicts, we want to
3893 use the class type of BINFO; TREE_TYPE (DECL) will be the
3894 CLASSTYPE_AS_BASE version, which does not contain entries for
3895 zero-sized bases. */
3898 }
3899 else
3900 {
3903 }
3905 /* Try to place the field. It may take more than one try if we have
3906 a hard time placing the field without putting two objects of the
3907 same type at the same address. */
3909 {
3912 /* Place this field. */
3916 /* We have to check to see whether or not there is already
3917 something of the same type at the offset we're about to use.
3918 For example, consider:
3920 struct S {};
3921 struct T : public S { int i; };
3922 struct U : public S, public T {};
3924 Here, we put S at offset zero in U. Then, we can't put T at
3925 offset zero -- its S component would be at the same address
3926 as the S we already allocated. So, we have to skip ahead.
3927 Since all data members, including those whose type is an
3928 empty class, have nonzero size, any overlap can happen only
3929 with a direct or indirect base-class -- it can't happen with
3930 a data member. */
3931 /* In a union, overlap is permitted; all members are placed at
3932 offset zero. */
3935 /* G++ 3.2 did not check for overlaps when placing a non-empty
3936 virtual base. */
3941 {
3942 /* Strip off the size allocated to this field. That puts us
3943 at the first place we could have put the field with
3944 proper alignment. */
3947 /* Bump up by the alignment required for the type. */
3948 rli->bitpos
3954 }
3955 else
3956 /* There was no conflict. We're done laying out this field. */
3958 }
3960 /* Now that we know where it will be placed, update its
3961 BINFO_OFFSET. */
3963 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3964 this point because their BINFO_OFFSET is copied from another
3965 hierarchy. Therefore, we may not need to add the entire
3966 OFFSET. */
3972 }
3974 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3976 static int
3978 tree offset,
3980 {
3982 }
3984 /* Layout the empty base BINFO. EOC indicates the byte currently just
3985 past the end of the class, and should be correctly aligned for a
3986 class of the type indicated by BINFO; OFFSETS gives the offsets of
3987 the empty bases allocated so far. T is the most derived
3988 type. Return nonzero iff we added it at the end. */
3990 static bool
3993 {
3994 tree alignment;
3998 /* This routine should only be used for empty classes. */
4003 {
4005 propagate_binfo_offsets
4008 else
4010 "offset of empty base %qT may not be ABI-compliant and may"
4013 }
4015 /* This is an empty base class. We first try to put it at offset
4016 zero. */
4019 offsets,
4021 {
4022 /* That didn't work. Now, we move forward from the next
4023 available spot in the class. */
4027 {
4030 offsets,
4032 /* We finally found a spot where there's no overlap. */
4035 /* There's overlap here, too. Bump along to the next spot. */
4037 }
4038 }
4041 {
4046 }
4049 }
4051 /* Layout the base given by BINFO in the class indicated by RLI.
4052 *BASE_ALIGN is a running maximum of the alignments of
4053 any base class. OFFSETS gives the location of empty base
4054 subobjects. T is the most derived type. Return nonzero if the new
4055 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4056 *NEXT_FIELD, unless BINFO is for an empty base class.
4058 Returns the location at which the next field should be inserted. */
4063 {
4068 /* This error is now reported in xref_tag, thus giving better
4069 location information. */
4072 /* Place the base class. */
4074 {
4075 tree decl;
4077 /* The containing class is non-empty because it has a non-empty
4078 base class. */
4081 /* Create the FIELD_DECL. */
4088 {
4096 /* Try to place the field. It may take more than one try if we
4097 have a hard time placing the field without putting two
4098 objects of the same type at the same address. */
4100 /* Add the new FIELD_DECL to the list of fields for T. */
4104 }
4105 }
4106 else
4107 {
4108 tree eoc;
4111 /* On some platforms (ARM), even empty classes will not be
4112 byte-aligned. */
4117 /* A nearly-empty class "has no proper base class that is empty,
4118 not morally virtual, and at an offset other than zero." */
4120 {
4123 /* The check above (used in G++ 3.2) is insufficient because
4124 an empty class placed at offset zero might itself have an
4125 empty base at a nonzero offset. */
4127 empty_base_at_nonzero_offset_p,
4128 size_zero_node,
4132 {
4135 else
4137 "class %qT will be considered nearly empty in a "
4139 }
4140 }
4142 /* We do not create a FIELD_DECL for empty base classes because
4143 it might overlap some other field. We want to be able to
4144 create CONSTRUCTORs for the class by iterating over the
4145 FIELD_DECLs, and the back end does not handle overlapping
4146 FIELD_DECLs. */
4148 /* An empty virtual base causes a class to be non-empty
4149 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4150 here because that was already done when the virtual table
4151 pointer was created. */
4152 }
4154 /* Record the offsets of BINFO and its base subobjects. */
4157 offsets,
4161 }
4163 /* Layout all of the non-virtual base classes. Record empty
4164 subobjects in OFFSETS. T is the most derived type. Return nonzero
4165 if the type cannot be nearly empty. The fields created
4166 corresponding to the base classes will be inserted at
4167 *NEXT_FIELD. */
4169 static void
4172 {
4173 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4174 subobjects. */
4179 /* The primary base class is always allocated first. */
4184 /* Now allocate the rest of the bases. */
4186 {
4187 tree base_binfo;
4191 /* The primary base was already allocated above, so we don't
4192 need to allocate it again here. */
4196 /* Virtual bases are added at the end (a primary virtual base
4197 will have already been added). */
4203 }
4204 }
4206 /* Go through the TYPE_METHODS of T issuing any appropriate
4207 diagnostics, figuring out which methods override which other
4208 methods, and so forth. */
4210 static void
4212 {
4213 tree x;
4216 {
4220 /* The name of the field is the original field name
4221 Save this in auxiliary field for later overloading. */
4223 {
4227 }
4228 /* All user-provided destructors are non-trivial.
4229 Constructors and assignment ops are handled in
4230 grok_special_member_properties. */
4233 }
4234 }
4236 /* FN is a constructor or destructor. Clone the declaration to create
4237 a specialized in-charge or not-in-charge version, as indicated by
4238 NAME. */
4240 static tree
4242 {
4243 tree parms;
4244 tree clone;
4246 /* Copy the function. */
4248 /* Reset the function name. */
4251 /* Remember where this function came from. */
4253 /* Make it easy to find the CLONE given the FN. */
4257 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4259 {
4266 }
4269 /* There's no pending inline data for this function. */
4273 /* The base-class destructor is not virtual. */
4275 {
4279 }
4281 /* If there was an in-charge parameter, drop it from the function
4282 type. */
4284 {
4285 tree basetype;
4286 tree parmtypes;
4287 tree exceptions;
4292 /* Skip the `this' parameter. */
4294 /* Skip the in-charge parameter. */
4296 /* And the VTT parm, in a complete [cd]tor. */
4300 /* If this is subobject constructor or destructor, add the vtt
4301 parameter. */
4305 parmtypes);
4308 exceptions);
4312 }
4314 /* Copy the function parameters. */
4316 /* Remove the in-charge parameter. */
4318 {
4322 }
4323 /* And the VTT parm, in a complete [cd]tor. */
4325 {
4328 else
4329 {
4333 }
4334 }
4337 {
4340 }
4342 /* Create the RTL for this function. */
4350 }
4352 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4353 not invoke this function directly.
4355 For a non-thunk function, returns the address of the slot for storing
4356 the function it is a clone of. Otherwise returns NULL_TREE.
4358 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4359 cloned_function is unset. This is to support the separate
4360 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4361 on a template makes sense, but not the former. */
4363 tree *
4365 {
4373 {
4374 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4377 else
4378 #endif
4380 }
4385 else
4387 }
4389 /* Produce declarations for all appropriate clones of FN. If
4390 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4391 CLASTYPE_METHOD_VEC as well. */
4393 void
4395 {
4396 tree clone;
4398 /* Avoid inappropriate cloning. */
4404 {
4405 /* For each constructor, we need two variants: an in-charge version
4406 and a not-in-charge version. */
4413 }
4414 else
4415 {
4418 /* For each destructor, we need three variants: an in-charge
4419 version, a not-in-charge version, and an in-charge deleting
4420 version. We clone the deleting version first because that
4421 means it will go second on the TYPE_METHODS list -- and that
4422 corresponds to the correct layout order in the virtual
4423 function table.
4425 For a non-virtual destructor, we do not build a deleting
4426 destructor. */
4428 {
4432 }
4439 }
4441 /* Note that this is an abstract function that is never emitted. */
4443 }
4445 /* DECL is an in charge constructor, which is being defined. This will
4446 have had an in class declaration, from whence clones were
4447 declared. An out-of-class definition can specify additional default
4448 arguments. As it is the clones that are involved in overload
4449 resolution, we must propagate the information from the DECL to its
4450 clones. */
4452 void
4454 {
4455 tree clone;
4459 {
4466 /* Skip the 'this' parameter. */
4482 {
4487 {
4488 /* A default parameter has been added. Adjust the
4489 clone's parameters. */
4493 tree type;
4498 {
4501 clone_parms);
4503 }
4506 clone_parms);
4515 }
4516 }
4518 }
4519 }
4521 /* For each of the constructors and destructors in T, create an
4522 in-charge and not-in-charge variant. */
4524 static void
4526 {
4527 tree fns;
4529 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4530 out now. */
4538 }
4540 /* Deduce noexcept for a destructor DTOR. */
4542 void
4544 {
4546 {
4553 }
4554 }
4556 /* For each destructor in T, deduce noexcept:
4558 12.4/3: A declaration of a destructor that does not have an
4559 exception-specification is implicitly considered to have the
4560 same exception-specification as an implicit declaration (15.4). */
4562 static void
4564 {
4565 tree fns;
4567 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4568 out now. */
4574 }
4576 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4577 of TYPE for virtual functions which FNDECL overrides. Return a
4578 mask of the tm attributes found therein. */
4580 static int
4582 {
4584 tree base_binfo;
4588 {
4598 else
4600 }
4603 }
4605 /* Subroutine of set_method_tm_attributes. Handle the checks and
4606 inheritance for one virtual method FNDECL. */
4608 static void
4610 {
4611 tree tm_attr;
4616 /* If FNDECL doesn't actually override anything (i.e. T is the
4617 class that first declares FNDECL virtual), then we're done. */
4624 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4625 tm_pure must match exactly, otherwise no weakening of
4626 tm_safe > tm_callable > nothing. */
4627 /* ??? The tm_pure attribute didn't make the transition to the
4628 multivendor language spec. */
4630 {
4632 {
4635 }
4636 }
4637 /* If the overridden function is tm_pure, then FNDECL must be. */
4640 /* Look for base class combinations that cannot be satisfied. */
4642 {
4648 }
4649 /* If FNDECL did not declare an attribute, then inherit the most
4650 restrictive one. */
4652 {
4654 }
4655 /* Otherwise validate that we're not weaker than a function
4656 that is being overridden. */
4657 else
4658 {
4662 }
4665 err_override:
4669 }
4671 /* For each of the methods in T, propagate a class-level tm attribute. */
4673 static void
4675 {
4678 /* Don't bother collecting tm attributes if transactional memory
4679 support is not enabled. */
4683 /* Process virtual methods first, as they inherit directly from the
4684 base virtual function and also require validation of new attributes. */
4686 {
4687 tree vchain;
4690 {
4695 }
4696 }
4698 /* If the class doesn't have an attribute, nothing more to do. */
4703 /* Any method that does not yet have a tm attribute inherits
4704 the one from the class. */
4706 {
4709 }
4710 }
4712 /* Returns true iff class T has a user-defined constructor other than
4713 the default constructor. */
4715 bool
4717 {
4718 tree fns;
4724 {
4731 }
4734 }
4736 /* Returns the defaulted constructor if T has one. Otherwise, returns
4737 NULL_TREE. */
4739 tree
4741 {
4748 {
4752 {
4758 }
4759 }
4762 }
4764 /* Returns true iff FN is a user-provided function, i.e. user-declared
4765 and not defaulted at its first declaration; or explicit, private,
4766 protected, or non-const. */
4768 bool
4770 {
4773 else
4776 }
4778 /* Returns true iff class T has a user-provided constructor. */
4780 bool
4782 {
4783 tree fns;
4791 /* This can happen in error cases; avoid crashing. */
4800 }
4802 /* Returns true iff class T has a user-provided default constructor. */
4804 bool
4806 {
4807 tree fns;
4813 {
4819 }
4822 }
4824 /* If default-initialization leaves part of TYPE uninitialized, returns
4825 a DECL for the field or TYPE itself (DR 253). */
4827 tree
4829 {
4840 {
4844 }
4849 {
4853 }
4856 }
4858 /* Returns true iff for class T, a trivial synthesized default constructor
4859 would be constexpr. */
4861 bool
4863 {
4864 /* A defaulted trivial default constructor is constexpr
4865 if there is nothing to initialize. */
4868 }
4870 /* Returns true iff class T has a constexpr default constructor. */
4872 bool
4874 {
4875 tree fns;
4878 {
4879 /* The caller should have stripped an enclosing array. */
4882 }
4884 {
4887 /* Non-trivial, we need to check subobject constructors. */
4889 }
4892 }
4894 /* Returns true iff class TYPE has a virtual destructor. */
4896 bool
4898 {
4899 tree dtor;
4907 }
4909 /* Returns true iff class T has a move constructor. */
4911 bool
4913 {
4914 tree fns;
4917 {
4920 }
4930 }
4932 /* Returns true iff class T has a move assignment operator. */
4934 bool
4936 {
4937 tree fns;
4940 {
4943 }
4951 }
4953 /* Returns true iff class T has a move constructor that was explicitly
4954 declared in the class body. Note that this is different from
4955 "user-provided", which doesn't include functions that are defaulted in
4956 the class. */
4958 bool
4960 {
4961 tree fns;
4970 {
4974 }
4977 }
4979 /* Returns true iff class T has a move assignment operator that was
4980 explicitly declared in the class body. */
4982 bool
4984 {
4985 tree fns;
4992 {
4996 }
4999 }
5001 /* Nonzero if we need to build up a constructor call when initializing an
5002 object of this class, either because it has a user-provided constructor
5003 or because it doesn't have a default constructor (so we need to give an
5004 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5005 what you care about is whether or not an object can be produced by a
5006 constructor (e.g. so we don't set TREE_READONLY on const variables of
5007 such type); use this function when what you care about is whether or not
5008 to try to call a constructor to create an object. The latter case is
5009 the former plus some cases of constructors that cannot be called. */
5011 bool
5013 {
5014 tree inner;
5020 }
5022 /* Remove all zero-width bit-fields from T. */
5024 static void
5026 {
5031 {
5034 /* We should not be confused by the fact that grokbitfield
5035 temporarily sets the width of the bit field into
5036 DECL_INITIAL (*fieldsp).
5037 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5038 to that width. */
5041 else
5043 }
5044 }
5046 /* Returns TRUE iff we need a cookie when dynamically allocating an
5047 array whose elements have the indicated class TYPE. */
5049 static bool
5051 {
5052 tree fns;
5057 /* If there's a non-trivial destructor, we need a cookie. In order
5058 to iterate through the array calling the destructor for each
5059 element, we'll have to know how many elements there are. */
5063 /* If the usual deallocation function is a two-argument whose second
5064 argument is of type `size_t', then we have to pass the size of
5065 the array to the deallocation function, so we will need to store
5066 a cookie. */
5070 /* If there are no `operator []' members, or the lookup is
5071 ambiguous, then we don't need a cookie. */
5074 /* Loop through all of the functions. */
5076 {
5077 tree fn;
5078 tree second_parm;
5080 /* Select the current function. */
5082 /* See if this function is a one-argument delete function. If
5083 it is, then it will be the usual deallocation function. */
5087 /* Do not consider this function if its second argument is an
5088 ellipsis. */
5091 /* Otherwise, if we have a two-argument function and the second
5092 argument is `size_t', it will be the usual deallocation
5093 function -- unless there is one-argument function, too. */
5097 }
5100 }
5102 /* Finish computing the `literal type' property of class type T.
5104 At this point, we have already processed base classes and
5105 non-static data members. We need to check whether the copy
5106 constructor is trivial, the destructor is trivial, and there
5107 is a trivial default constructor or at least one constexpr
5108 constructor other than the copy constructor. */
5110 static void
5112 {
5113 tree fn;
5129 {
5132 {
5136 }
5137 }
5138 }
5140 /* T is a non-literal type used in a context which requires a constant
5141 expression. Explain why it isn't literal. */
5143 void
5145 {
5155 /* Already explained. */
5164 {
5166 "default constructor, and has no constexpr constructor that "
5170 {
5171 /* Note that we can't simply call locate_ctor because when the
5172 constructor is deleted it just returns NULL_TREE. */
5173 tree fns;
5175 {
5182 {
5185 else
5188 }
5189 }
5190 }
5191 }
5192 else
5193 {
5197 {
5200 {
5205 }
5206 }
5208 {
5209 tree ftype;
5214 {
5219 }
5220 }
5221 }
5222 }
5224 /* Check the validity of the bases and members declared in T. Add any
5225 implicitly-generated functions (like copy-constructors and
5226 assignment operators). Compute various flag bits (like
5227 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5228 level: i.e., independently of the ABI in use. */
5230 static void
5232 {
5233 /* Nonzero if the implicitly generated copy constructor should take
5234 a non-const reference argument. */
5236 /* Nonzero if the implicitly generated assignment operator
5237 should take a non-const reference argument. */
5239 tree access_decls;
5242 tree fn;
5244 /* By default, we use const reference arguments and generate default
5245 constructors. */
5249 /* Deduce noexcept on destructors. */
5253 /* Check all the base-classes. */
5257 /* Check all the method declarations. */
5260 /* Save the initial values of these flags which only indicate whether
5261 or not the class has user-provided functions. As we analyze the
5262 bases and members we can set these flags for other reasons. */
5266 /* Check all the data member declarations. We cannot call
5267 check_field_decls until we have called check_bases check_methods,
5268 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5269 being set appropriately. */
5274 /* A nearly-empty class has to be vptr-containing; a nearly empty
5275 class contains just a vptr. */
5279 /* Do some bookkeeping that will guide the generation of implicitly
5280 declared member functions. */
5283 /* We need to call a constructor for this class if it has a
5284 user-provided constructor, or if the default constructor is going
5285 to initialize the vptr. (This is not an if-and-only-if;
5286 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5287 themselves need constructing.) */
5290 /* [dcl.init.aggr]
5292 An aggregate is an array or a class with no user-provided
5293 constructors ... and no virtual functions.
5295 Again, other conditions for being an aggregate are checked
5296 elsewhere. */
5299 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5300 retain the old definition internally for ABI reasons. */
5309 /* If the class has no user-declared constructor, but does have
5310 non-static const or reference data members that can never be
5311 initialized, issue a warning. */
5313 /* Classes with user-declared constructors are presumed to
5314 initialize these members. */
5316 /* Aggregates can be initialized with brace-enclosed
5317 initializers. */
5319 {
5320 tree field;
5323 {
5324 tree type;
5339 }
5340 }
5342 /* Synthesize any needed methods. */
5344 cant_have_const_ctor,
5345 no_const_asn_ref);
5347 /* Check defaulted declarations here so we have cant_have_const_ctor
5348 and don't need to worry about clones. */
5351 {
5354 {
5355 bool imp_const_p
5361 /* If the function is defaulted outside the class, we just
5362 give the synthesis error. */
5365 }
5367 }
5370 {
5371 /* "The closure type associated with a lambda-expression has a deleted
5372 default constructor and a deleted copy assignment operator." */
5378 /* "This class type is not an aggregate." */
5380 }
5382 /* Compute the 'literal type' property before we
5383 do anything with non-static member functions. */
5386 /* Create the in-charge and not-in-charge variants of constructors
5387 and destructors. */
5390 /* Process the using-declarations. */
5394 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5397 /* Figure out whether or not we will need a cookie when dynamically
5398 allocating an array of this type. */
5401 }
5403 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5404 accordingly. If a new vfield was created (because T doesn't have a
5405 primary base class), then the newly created field is returned. It
5406 is not added to the TYPE_FIELDS list; it is the caller's
5407 responsibility to do that. Accumulate declared virtual functions
5408 on VIRTUALS_P. */
5410 static tree
5412 {
5413 tree fn;
5415 /* Collect the virtual functions declared in T. */
5419 {
5428 }
5430 /* If we couldn't find an appropriate base class, create a new field
5431 here. Even if there weren't any new virtual functions, we might need a
5432 new virtual function table if we're supposed to include vptrs in
5433 all classes that need them. */
5435 {
5436 /* We build this decl with vtbl_ptr_type_node, which is a
5437 `vtable_entry_type*'. It might seem more precise to use
5438 `vtable_entry_type (*)[N]' where N is the number of virtual
5439 functions. However, that would require the vtable pointer in
5440 base classes to have a different type than the vtable pointer
5441 in derived classes. We could make that happen, but that
5442 still wouldn't solve all the problems. In particular, the
5443 type-based alias analysis code would decide that assignments
5444 to the base class vtable pointer can't alias assignments to
5445 the derived class vtable pointer, since they have different
5446 types. Thus, in a derived class destructor, where the base
5447 class constructor was inlined, we could generate bad code for
5448 setting up the vtable pointer.
5450 Therefore, we use one type for all vtable pointers. We still
5451 use a type-correct type; it's just doesn't indicate the array
5452 bounds. That's better than using `void*' or some such; it's
5453 cleaner, and it let's the alias analysis code know that these
5454 stores cannot alias stores to void*! */
5455 tree field;
5468 /* This class is non-empty. */
5472 }
5475 }
5477 /* Add OFFSET to all base types of BINFO which is a base in the
5478 hierarchy dominated by T.
5480 OFFSET, which is a type offset, is number of bytes. */
5482 static void
5484 {
5486 tree primary_binfo;
5487 tree base_binfo;
5489 /* Update BINFO's offset. */
5494 offset));
5496 /* Find the primary base class. */
5502 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5503 downwards. */
5505 {
5506 /* Don't do the primary base twice. */
5514 }
5515 }
5517 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5518 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5519 empty subobjects of T. */
5521 static void
5523 {
5524 tree vbase;
5533 {
5534 /* In G++ 3.2, we incorrectly rounded the size before laying out
5535 the virtual bases. */
5537 #ifdef STRUCTURE_SIZE_BOUNDARY
5538 /* Packed structures don't need to have minimum size. */
5541 #endif
5545 }
5547 /* Find the last field. The artificial fields created for virtual
5548 bases will go after the last extant field to date. */
5553 /* Go through the virtual bases, allocating space for each virtual
5554 base that is not already a primary base class. These are
5555 allocated in inheritance graph order. */
5557 {
5562 {
5565 /* This virtual base is not a primary base of any class in the
5566 hierarchy, so we have to add space for it. */
5570 /* If the first virtual base might have been placed at a
5571 lower address, had we started from CLASSTYPE_SIZE, rather
5572 than TYPE_SIZE, issue a warning. There can be both false
5573 positives and false negatives from this warning in rare
5574 cases; to deal with all the possibilities would probably
5575 require performing both layout algorithms and comparing
5576 the results which is not particularly tractable. */
5578 && first_vbase
5579 && (tree_int_cst_lt
5584 bitsize_unit_node),
5587 "offset of virtual base %qT is not ABI-compliant and "
5589 basetype);
5592 }
5593 }
5594 }
5596 /* Returns the offset of the byte just past the end of the base class
5597 BINFO. */
5599 static tree
5601 {
5602 tree size;
5607 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5608 allocate some space for it. It cannot have virtual bases, so
5609 TYPE_SIZE_UNIT is fine. */
5611 else
5615 }
5617 /* Returns the offset of the byte just past the end of the base class
5618 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5619 only non-virtual bases are included. */
5621 static tree
5623 {
5626 tree binfo;
5627 tree base_binfo;
5628 tree offset;
5633 {
5643 }
5645 /* G++ 3.2 did not check indirect virtual bases. */
5649 {
5653 }
5656 }
5658 /* Warn about bases of T that are inaccessible because they are
5659 ambiguous. For example:
5661 struct S {};
5662 struct T : public S {};
5663 struct U : public S, public T {};
5665 Here, `(S*) new U' is not allowed because there are two `S'
5666 subobjects of U. */
5668 static void
5670 {
5673 tree basetype;
5674 tree binfo;
5675 tree base_binfo;
5677 /* If there are no repeated bases, nothing can be ambiguous. */
5681 /* Check direct bases. */
5684 {
5690 }
5692 /* Check for ambiguous virtual bases. */
5696 {
5702 }
5703 }
5705 /* Compare two INTEGER_CSTs K1 and K2. */
5707 static int
5709 {
5711 }
5713 /* Increase the size indicated in RLI to account for empty classes
5714 that are "off the end" of the class. */
5716 static void
5718 {
5719 tree eoc;
5720 tree rli_size;
5722 /* It might be the case that we grew the class to allocate a
5723 zero-sized base class. That won't be reflected in RLI, yet,
5724 because we are willing to overlay multiple bases at the same
5725 offset. However, now we need to make sure that RLI is big enough
5726 to reflect the entire class. */
5732 {
5734 /* In version 1 of the ABI, the size of a class that ends with
5735 a bitfield was not rounded up to a whole multiple of a
5736 byte. Because rli_size_unit_so_far returns only the number
5737 of fully allocated bytes, any extra bits were not included
5738 in the size. */
5740 else
5741 /* The size should have been rounded to a whole byte. */
5744 rli->bitpos
5753 }
5754 }
5756 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5757 BINFO_OFFSETs for all of the base-classes. Position the vtable
5758 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5760 static void
5762 {
5763 tree non_static_data_members;
5764 tree field;
5765 tree vptr;
5766 record_layout_info rli;
5767 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5768 types that appear at that offset. */
5769 splay_tree empty_base_offsets;
5770 /* True if the last field layed out was a bit-field. */
5772 /* The location at which the next field should be inserted. */
5774 /* T, as a base class. */
5775 tree base_t;
5777 /* Keep track of the first non-static data member. */
5780 /* Start laying out the record. */
5783 /* Mark all the primary bases in the hierarchy. */
5786 /* Create a pointer to our virtual function table. */
5789 /* The vptr is always the first thing in the class. */
5791 {
5796 }
5797 else
5800 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5805 /* Layout the non-static data members. */
5807 {
5808 tree type;
5809 tree padding;
5811 /* We still pass things that aren't non-static data members to
5812 the back end, in case it wants to do something with them. */
5814 {
5816 /* If the static data member has incomplete type, keep track
5817 of it so that it can be completed later. (The handling
5818 of pending statics in finish_record_layout is
5819 insufficient; consider:
5821 struct S1;
5822 struct S2 { static S1 s1; };
5824 At this point, finish_record_layout will be called, but
5825 S1 is still incomplete.) */
5827 {
5829 /* The visibility of static data members is determined
5830 at their point of declaration, not their point of
5831 definition. */
5833 }
5835 }
5843 /* If this field is a bit-field whose width is greater than its
5844 type, then there are some special rules for allocating
5845 it. */
5848 {
5850 tree integer_type;
5852 /* We must allocate the bits as if suitably aligned for the
5853 longest integer type that fits in this many bits. type
5854 of the field. Then, we are supposed to use the left over
5855 bits as additional padding. */
5864 /* ITK now indicates a type that is too large for the
5865 field. We have to back up by one to find the largest
5866 type that fits. */
5867 do
5868 {
5873 /* Figure out how much additional padding is required. GCC
5874 3.2 always created a padding field, even if it had zero
5875 width. */
5878 {
5880 /* In a union, the padding field must have the full width
5881 of the bit-field; all fields start at offset zero. */
5883 else
5884 {
5887 "ABI-compliant and may change in a future "
5889 t);
5892 }
5893 }
5894 #ifdef PCC_BITFIELD_TYPE_MATTERS
5895 /* An unnamed bitfield does not normally affect the
5896 alignment of the containing class on a target where
5897 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5898 make any exceptions for unnamed bitfields when the
5899 bitfields are longer than their types. Therefore, we
5900 temporarily give the field a name. */
5902 {
5905 }
5906 #endif
5911 empty_base_offsets);
5914 /* Now that layout has been performed, set the size of the
5915 field to the size of its declared type; the rest of the
5916 field is effectively invisible. */
5918 /* We must also reset the DECL_MODE of the field. */
5923 /* Versions of G++ before G++ 3.4 did not reset the
5924 DECL_MODE. */
5926 "the offset of %qD may not be ABI-compliant and may "
5928 }
5929 else
5931 empty_base_offsets);
5933 /* Remember the location of any empty classes in FIELD. */
5937 empty_base_offsets,
5940 /* If a bit-field does not immediately follow another bit-field,
5941 and yet it starts in the middle of a byte, we have failed to
5942 comply with the ABI. */
5945 /* The TREE_NO_WARNING flag gets set by Objective-C when
5946 laying out an Objective-C class. The ObjC ABI differs
5947 from the C++ ABI, and so we do not want a warning
5948 here. */
5950 && !last_field_was_bitfield
5953 bitsize_unit_node)))
5957 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5958 offset of the field. */
5965 "classes to be placed at different locations in a "
5968 /* The middle end uses the type of expressions to determine the
5969 possible range of expression values. In order to optimize
5970 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5971 must be made aware of the width of "i", via its type.
5973 Because C++ does not have integer types of arbitrary width,
5974 we must (for the purposes of the front end) convert from the
5975 type assigned here to the declared type of the bitfield
5976 whenever a bitfield expression is used as an rvalue.
5977 Similarly, when assigning a value to a bitfield, the value
5978 must be converted to the type given the bitfield here. */
5980 {
5985 {
5992 }
5993 }
5995 /* If we needed additional padding after this field, add it
5996 now. */
5998 {
5999 tree padding_field;
6002 FIELD_DECL,
6003 NULL_TREE,
6004 char_type_node);
6011 NULL_TREE,
6012 empty_base_offsets);
6013 }
6016 }
6019 {
6020 /* Make sure that we are on a byte boundary so that the size of
6021 the class without virtual bases will always be a round number
6022 of bytes. */
6025 }
6027 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6028 padding. */
6032 /* Delete all zero-width bit-fields from the list of fields. Now
6033 that the type is laid out they are no longer important. */
6036 /* Create the version of T used for virtual bases. We do not use
6037 make_class_type for this version; this is an artificial type. For
6038 a POD type, we just reuse T. */
6040 {
6043 /* Set the size and alignment for the new type. In G++ 3.2, all
6044 empty classes were considered to have size zero when used as
6045 base classes. */
6047 {
6052 "layout of classes derived from empty class %qT "
6054 t);
6055 }
6056 else
6057 {
6058 tree eoc;
6060 /* If the ABI version is not at least two, and the last
6061 field was a bit-field, RLI may not be on a byte
6062 boundary. In particular, rli_size_unit_so_far might
6063 indicate the last complete byte, while rli_size_so_far
6064 indicates the total number of bits used. Therefore,
6065 rli_size_so_far, rather than rli_size_unit_so_far, is
6066 used to compute TYPE_SIZE_UNIT. */
6074 eoc);
6081 }
6085 /* Copy the fields from T. */
6089 {
6091 FIELD_DECL,
6101 }
6103 /* Record the base version of the type. */
6106 }
6107 else
6110 /* Every empty class contains an empty class. */
6114 /* Set the TYPE_DECL for this type to contain the right
6115 value for DECL_OFFSET, so that we can use it as part
6116 of a COMPONENT_REF for multiple inheritance. */
6119 /* Now fix up any virtual base class types that we left lying
6120 around. We must get these done before we try to lay out the
6121 virtual function table. As a side-effect, this will remove the
6122 base subobject fields. */
6125 /* Make sure that empty classes are reflected in RLI at this
6126 point. */
6129 /* Make sure not to create any structures with zero size. */
6135 /* If this is a non-POD, declaring it packed makes a difference to how it
6136 can be used as a field; don't let finalize_record_size undo it. */
6140 /* Let the back end lay out the type. */
6143 /* Warn about bases that can't be talked about due to ambiguity. */
6146 /* Now that we're done with layout, give the base fields the real types. */
6151 /* Clean up. */
6158 }
6160 /* Determine the "key method" for the class type indicated by TYPE,
6161 and set CLASSTYPE_KEY_METHOD accordingly. */
6163 void
6165 {
6166 tree method;
6169 || processing_template_decl
6174 /* The key method is the first non-pure virtual function that is not
6175 inline at the point of class definition. On some targets the
6176 key function may not be inline; those targets should not call
6177 this function until the end of the translation unit. */
6183 {
6186 }
6189 }
6192 /* Allocate and return an instance of struct sorted_fields_type with
6193 N fields. */
6197 {
6204 }
6207 /* Perform processing required when the definition of T (a class type)
6208 is complete. */
6210 void
6212 {
6213 tree x;
6214 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6218 {
6223 }
6225 /* If this type was previously laid out as a forward reference,
6226 make sure we lay it out again. */
6230 /* Make assumptions about the class; we'll reset the flags if
6231 necessary. */
6237 /* Do end-of-class semantic processing: checking the validity of the
6238 bases and members and add implicitly generated methods. */
6241 /* Find the key method. */
6243 {
6244 /* The Itanium C++ ABI permits the key method to be chosen when
6245 the class is defined -- even though the key method so
6246 selected may later turn out to be an inline function. On
6247 some systems (such as ARM Symbian OS) the key method cannot
6248 be determined until the end of the translation unit. On such
6249 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6250 will cause the class to be added to KEYED_CLASSES. Then, in
6251 finish_file we will determine the key method. */
6255 /* If a polymorphic class has no key method, we may emit the vtable
6256 in every translation unit where the class definition appears. */
6259 }
6261 /* Layout the class itself. */
6264 /* We use the base type for trivial assignments, and hence it
6265 needs a mode. */
6270 /* If necessary, create the primary vtable for this class. */
6272 {
6273 /* We must enter these virtuals into the table. */
6277 /* Here we know enough to change the type of our virtual
6278 function table, but we will wait until later this function. */
6281 /* If we're warning about ABI tags, check the types of the new
6282 virtual functions. */
6286 }
6289 {
6291 tree fn;
6298 /* Add entries for virtual functions introduced by this class. */
6302 /* Set DECL_VINDEX for all functions declared in this class. */
6304 fn;
6306 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6308 {
6312 /* A thunk. We should never be calling this entry directly
6313 from this vtable -- we'd use the entry for the non
6314 thunk base function. */
6318 }
6319 }
6324 /* Complete the rtl for any static member objects of the type we're
6325 working on. */
6332 /* Done with FIELDS...now decide whether to sort these for
6333 faster lookups later.
6335 We use a small number because most searches fail (succeeding
6336 ultimately as the search bores through the inheritance
6337 hierarchy), and we want this failure to occur quickly. */
6341 /* Complain if one of the field types requires lower visibility. */
6344 /* Make the rtl for any new vtables we have created, and unmark
6345 the base types we marked. */
6348 /* Build the VTT for T. */
6351 /* This warning does not make sense for Java classes, since they
6352 cannot have destructors. */
6354 {
6355 tree dtor;
6359 if it were virtual, we would have created it by now. */
6360 !dtor
6369 "%q#T has virtual functions and accessible"
6371 }
6378 /* Class layout, assignment of virtual table slots, etc., is now
6379 complete. Give the back end a chance to tweak the visibility of
6380 the class or perform any other required target modifications. */
6387 /* Finish debugging output for this type. */
6391 {
6394 {
6397 }
6399 {
6402 else
6403 {
6406 }
6408 }
6410 {
6412 "the type of the first field has a different ABI from the "
6415 }
6416 }
6417 }
6419 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6420 equal to THRESHOLD or greater than THRESHOLD. */
6422 static void
6424 {
6427 {
6432 }
6433 }
6435 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6437 void
6439 {
6442 {
6444 int n_fields
6455 }
6456 }
6458 /* When T was built up, the member declarations were added in reverse
6459 order. Rearrange them to declaration order. */
6461 void
6463 {
6464 tree next;
6465 tree prev;
6466 tree x;
6468 /* The following lists are all in reverse order. Put them in
6469 declaration order now. */
6473 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6474 reverse order, so we can't just use nreverse. */
6479 {
6483 }
6485 {
6489 }
6490 }
6492 tree
6494 {
6497 /* Now that we've got all the field declarations, reverse everything
6498 as necessary. */
6503 /* Nadger the current location so that diagnostics point to the start of
6504 the struct, not the end. */
6508 {
6509 tree x;
6515 /* We need to emit an error message if this type was used as a parameter
6516 and it is an abstract type, even if it is a template. We construct
6517 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6518 account and we call complete_vars with this type, which will check
6519 the PARM_DECLS. Note that while the type is being defined,
6520 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6521 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6527 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6528 an enclosing scope is a template class, so that this function be
6529 found by lookup_fnfields_1 when the using declaration is not
6530 instantiated yet. */
6533 {
6538 }
6540 /* Remember current #pragma pack value. */
6543 /* Fix up any variants we've already built. */
6545 {
6550 }
6551 }
6552 else
6561 else
6565 /* Lambdas are defined by the LAMBDA_EXPR. */
6570 }
6571 \f
6572 /* Hash table to avoid endless recursion when handling references. */
6575 /* Return the dynamic type of INSTANCE, if known.
6576 Used to determine whether the virtual function table is needed
6577 or not.
6579 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6580 of our knowledge of its type. *NONNULL should be initialized
6581 before this function is called. */
6583 static tree
6585 {
6586 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6589 {
6593 else
6597 /* This is a call to a constructor, hence it's never zero. */
6599 {
6603 }
6607 /* This is a call to a constructor, hence it's never zero. */
6609 {
6613 }
6622 /* Propagate nonnull. */
6627 CASE_CONVERT:
6633 {
6634 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6635 with a real object -- given &p->f, p can still be null. */
6637 /* ??? Probably should check DECL_WEAK here. */
6640 }
6644 /* If this component is really a base class reference, then the field
6645 itself isn't definitive. */
6654 {
6658 }
6659 /* fall through... */
6664 {
6668 }
6670 {
6674 /* if we're in a ctor or dtor, we know our type. If
6675 current_class_ptr is set but we aren't in a function, we're in
6676 an NSDMI (and therefore a constructor). */
6681 {
6685 }
6686 }
6688 {
6689 /* We only need one hash table because it is always left empty. */
6693 /* Reference variables should be references to objects. */
6697 /* Enter the INSTANCE in a table to prevent recursion; a
6698 variable's initializer may refer to the variable
6699 itself. */
6704 {
6705 tree type;
6714 }
6715 }
6720 }
6721 #undef RECUR
6722 }
6724 /* Return nonzero if the dynamic type of INSTANCE is known, and
6725 equivalent to the static type. We also handle the case where
6726 INSTANCE is really a pointer. Return negative if this is a
6727 ctor/dtor. There the dynamic type is known, but this might not be
6728 the most derived base of the original object, and hence virtual
6729 bases may not be layed out according to this type.
6731 Used to determine whether the virtual function table is needed
6732 or not.
6734 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6735 of our knowledge of its type. *NONNULL should be initialized
6736 before this function is called. */
6738 int
6740 {
6743 tree fixed;
6745 /* processing_template_decl can be false in a template if we're in
6746 fold_non_dependent_expr, but we still want to suppress this check. */
6748 {
6749 /* In a template we only care about the type of the result. */
6753 }
6763 }
6765 \f
6766 void
6768 {
6771 current_class_stack
6779 }
6781 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6783 static void
6785 {
6786 tree type;
6788 /* We are re-entering the same class we just left, so we don't
6789 have to search the whole inheritance matrix to find all the
6790 decls to bind again. Instead, we install the cached
6791 class_shadowed list and walk through it binding names. */
6794 /* Restore IDENTIFIER_TYPE_VALUE. */
6796 type;
6799 }
6801 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6802 appropriate for TYPE.
6804 So that we may avoid calls to lookup_name, we cache the _TYPE
6805 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6807 For multiple inheritance, we perform a two-pass depth-first search
6808 of the type lattice. */
6810 void
6812 {
6813 class_stack_node_t csn;
6817 /* Make sure there is enough room for the new entry on the stack. */
6819 {
6821 current_class_stack
6823 current_class_stack_size);
6824 }
6826 /* Insert a new entry on the class stack. */
6833 current_class_depth++;
6835 /* Now set up the new type. */
6841 /* By default, things in classes are private, while things in
6842 structures or unions are public. */
6844 ? access_private_node
6850 {
6851 /* Forcibly remove any old class remnants. */
6853 }
6859 else
6861 }
6863 /* When we exit a toplevel class scope, we save its binding level so
6864 that we can restore it quickly. Here, we've entered some other
6865 class, so we must invalidate our cache. */
6867 void
6869 {
6871 }
6873 /* Get out of the current class scope. If we were in a class scope
6874 previously, that is the one popped to. */
6876 void
6878 {
6881 current_class_depth--;
6887 }
6889 /* Mark the top of the class stack as hidden. */
6891 void
6893 {
6896 }
6898 /* Mark the top of the class stack as un-hidden. */
6900 void
6902 {
6905 }
6907 /* Returns 1 if the class type currently being defined is either T or
6908 a nested type of T. */
6910 bool
6912 {
6920 /* We start looking from 1 because entry 0 is from global scope,
6921 and has no type. */
6923 {
6924 tree c;
6927 else
6928 {
6932 }
6937 }
6939 }
6941 /* If either current_class_type or one of its enclosing classes are derived
6942 from T, return the appropriate type. Used to determine how we found
6943 something via unqualified lookup. */
6945 tree
6947 {
6950 /* The bases of a dependent type are unknown. */
6961 {
6966 }
6969 }
6971 /* Returns the innermost class type which is not a lambda closure type. */
6973 tree
6975 {
6978 /* We start looking from 1 because entry 0 is from global scope,
6979 and has no type. */
6981 {
6982 tree c;
6985 else
6986 {
6990 }
6995 }
6997 }
6999 /* When entering a class scope, all enclosing class scopes' names with
7000 static meaning (static variables, static functions, types and
7001 enumerators) have to be visible. This recursive function calls
7002 pushclass for all enclosing class contexts until global or a local
7003 scope is reached. TYPE is the enclosed class. */
7005 void
7007 {
7008 /* A namespace might be passed in error cases, like A::B:C. */
7016 }
7018 /* Undoes a push_nested_class call. */
7020 void
7022 {
7028 }
7030 /* Returns the number of extern "LANG" blocks we are nested within. */
7032 int
7034 {
7036 }
7038 /* Set global variables CURRENT_LANG_NAME to appropriate value
7039 so that behavior of name-mangling machinery is correct. */
7041 void
7043 {
7047 {
7049 }
7051 {
7053 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7054 (See record_builtin_java_type in decl.c.) However, that causes
7055 incorrect debug entries if these types are actually used.
7056 So we re-enable debug output after extern "Java". */
7065 }
7067 {
7069 }
7070 else
7072 }
7074 /* Get out of the current language scope. */
7076 void
7078 {
7080 }
7081 \f
7082 /* Type instantiation routines. */
7084 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7085 matches the TARGET_TYPE. If there is no satisfactory match, return
7086 error_mark_node, and issue an error & warning messages under
7087 control of FLAGS. Permit pointers to member function if FLAGS
7088 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7089 a template-id, and EXPLICIT_TARGS are the explicitly provided
7090 template arguments.
7092 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7093 is the base path used to reference those member functions. If
7094 the address is resolved to a member function, access checks will be
7095 performed and errors issued if appropriate. */
7097 static tree
7099 tree overload,
7100 tsubst_flags_t flags,
7102 tree explicit_targs,
7103 tree access_path)
7104 {
7105 /* Here's what the standard says:
7107 [over.over]
7109 If the name is a function template, template argument deduction
7110 is done, and if the argument deduction succeeds, the deduced
7111 arguments are used to generate a single template function, which
7112 is added to the set of overloaded functions considered.
7114 Non-member functions and static member functions match targets of
7115 type "pointer-to-function" or "reference-to-function." Nonstatic
7116 member functions match targets of type "pointer-to-member
7117 function;" the function type of the pointer to member is used to
7118 select the member function from the set of overloaded member
7119 functions. If a nonstatic member function is selected, the
7120 reference to the overloaded function name is required to have the
7121 form of a pointer to member as described in 5.3.1.
7123 If more than one function is selected, any template functions in
7124 the set are eliminated if the set also contains a non-template
7125 function, and any given template function is eliminated if the
7126 set contains a second template function that is more specialized
7127 than the first according to the partial ordering rules 14.5.5.2.
7128 After such eliminations, if any, there shall remain exactly one
7129 selected function. */
7132 /* We store the matches in a TREE_LIST rooted here. The functions
7133 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7134 interoperability with most_specialized_instantiation. */
7136 tree fn;
7137 tree target_fn_type;
7139 /* By the time we get here, we should be seeing only real
7140 pointer-to-member types, not the internal POINTER_TYPE to
7141 METHOD_TYPE representation. */
7147 /* Check that the TARGET_TYPE is reasonable. */
7151 /* This is OK, too. */
7154 /* This is OK, too. This comes from a conversion to reference
7155 type. */
7157 else
7158 {
7164 }
7166 /* Non-member functions and static member functions match targets of type
7167 "pointer-to-function" or "reference-to-function." Nonstatic member
7168 functions match targets of type "pointer-to-member-function;" the
7169 function type of the pointer to member is used to select the member
7170 function from the set of overloaded member functions.
7172 So figure out the FUNCTION_TYPE that we want to match against. */
7175 /* If we can find a non-template function that matches, we can just
7176 use it. There's no point in generating template instantiations
7177 if we're just going to throw them out anyhow. But, of course, we
7178 can only do this when we don't *need* a template function. */
7180 {
7181 tree fns;
7184 {
7188 /* We're not looking for templates just yet. */
7193 /* We're looking for a non-static member, and this isn't
7194 one, or vice versa. */
7197 /* Ignore functions which haven't been explicitly
7198 declared. */
7202 /* See if there's a match. */
7205 }
7206 }
7208 /* Now, if we've already got a match (or matches), there's no need
7209 to proceed to the template functions. But, if we don't have a
7210 match we need to look at them, too. */
7212 {
7213 tree target_arg_types;
7214 tree target_ret_type;
7215 tree fns;
7218 tree arg;
7232 {
7234 tree instantiation;
7235 tree targs;
7238 /* We're only looking for templates. */
7243 /* We're not looking for a non-static member, and this is
7244 one, or vice versa. */
7247 /* Try to do argument deduction. */
7254 /* Instantiation failed. */
7257 /* See if there's a match. */
7260 }
7262 /* Now, remove all but the most specialized of the matches. */
7264 {
7269 NULL_TREE,
7270 NULL_TREE);
7271 }
7272 }
7274 /* Now we should have exactly one function in MATCHES. */
7276 {
7277 /* There were *no* matches. */
7279 {
7282 target_type);
7285 }
7287 }
7289 {
7290 /* There were too many matches. First check if they're all
7291 the same function. */
7296 /* For multi-versioned functions, more than one match is just fine and
7297 decls_match will return false as they are different. */
7305 {
7307 {
7310 target_type);
7312 /* Since print_candidates expects the functions in the
7313 TREE_VALUE slot, we flip them here. */
7318 }
7321 }
7322 }
7324 /* Good, exactly one match. Now, convert it to the correct type. */
7329 {
7337 {
7340 }
7341 }
7343 /* If a pointer to a function that is multi-versioned is requested, the
7344 pointer to the dispatcher function is returned instead. This works
7345 well because indirectly calling the function will dispatch the right
7346 function version at run-time. */
7348 {
7352 /* Mark all the versions corresponding to the dispatcher as used. */
7355 }
7357 /* If we're doing overload resolution purely for the purpose of
7358 determining conversion sequences, we should not consider the
7359 function used. If this conversion sequence is selected, the
7360 function will be marked as used at this point. */
7362 {
7363 /* Make =delete work with SFINAE. */
7368 }
7370 /* We could not check access to member functions when this
7371 expression was originally created since we did not know at that
7372 time to which function the expression referred. */
7374 {
7377 }
7381 else
7382 {
7383 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7384 will mark the function as addressed, but here we must do it
7385 explicitly. */
7389 }
7390 }
7392 /* This function will instantiate the type of the expression given in
7393 RHS to match the type of LHSTYPE. If errors exist, then return
7394 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7395 we complain on errors. If we are not complaining, never modify rhs,
7396 as overload resolution wants to try many possible instantiations, in
7397 the hope that at least one will work.
7399 For non-recursive calls, LHSTYPE should be a function, pointer to
7400 function, or a pointer to member function. */
7402 tree
7404 {
7411 {
7415 }
7418 {
7424 /* Microsoft allows `A::f' to be resolved to a
7425 pointer-to-member. */
7426 ;
7427 else
7428 {
7433 }
7434 }
7437 {
7440 }
7442 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7443 deduce any type information. */
7445 {
7449 }
7451 /* There only a few kinds of expressions that may have a type
7452 dependent on overload resolution. */
7458 /* This should really only be used when attempting to distinguish
7459 what sort of a pointer to function we have. For now, any
7460 arithmetic operation which is not supported on pointers
7461 is rejected as an error. */
7464 {
7466 {
7472 /* Do not lose object's side effects. */
7476 }
7483 /* This can happen if we are forming a pointer-to-member for a
7484 member template. */
7487 /* Fall through. */
7490 {
7494 return
7498 }
7502 return
7506 access_path);
7509 {
7514 }
7521 }
7523 }
7524 \f
7525 /* Return the name of the virtual function pointer field
7526 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7527 this may have to look back through base types to find the
7528 ultimate field name. (For single inheritance, these could
7529 all be the same name. Who knows for multiple inheritance). */
7531 static tree
7533 {
7540 {
7546 }
7554 }
7556 void
7558 {
7565 {
7570 }
7571 }
7573 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7574 according to [class]:
7575 The class-name is also inserted
7576 into the scope of the class itself. For purposes of access checking,
7577 the inserted class name is treated as if it were a public member name. */
7579 void
7581 {
7584 tree saved_cas;
7599 }
7601 /* Returns 1 if TYPE contains only padding bytes. */
7603 int
7605 {
7612 /* In G++ 3.2, whether or not a class was empty was determined by
7613 looking at its size. */
7616 else
7618 }
7620 /* Returns true if TYPE contains an empty class. */
7622 static bool
7624 {
7628 {
7629 tree field;
7630 tree binfo;
7631 tree base_binfo;
7643 }
7647 }
7649 /* Returns true if TYPE contains no actual data, just various
7650 possible combinations of empty classes and possibly a vptr. */
7652 bool
7654 {
7656 {
7657 tree field;
7658 tree binfo;
7659 tree base_binfo;
7662 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7663 out, but we'd like to be able to check this before then. */
7677 }
7681 }
7683 /* Note that NAME was looked up while the current class was being
7684 defined and that the result of that lookup was DECL. */
7686 void
7688 {
7689 splay_tree names_used;
7691 /* If we're not defining a class, there's nothing to do. */
7697 /* If there's already a binding for this NAME, then we don't have
7698 anything to worry about. */
7711 }
7713 /* Note that NAME was declared (as DECL) in the current class. Check
7714 to see that the declaration is valid. */
7716 void
7718 {
7719 splay_tree names_used;
7720 splay_tree_node n;
7722 /* Look to see if we ever used this name. */
7723 names_used
7727 /* The C language allows members to be declared with a type of the same
7728 name, and the C++ standard says this diagnostic is not required. So
7729 allow it in extern "C" blocks unless predantic is specified.
7730 Allow it in all cases if -ms-extensions is specified. */
7736 {
7737 /* [basic.scope.class]
7739 A name N used in a class S shall refer to the same declaration
7740 in its context and when re-evaluated in the completed scope of
7741 S. */
7745 }
7746 }
7748 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7749 Secondary vtables are merged with primary vtables; this function
7750 will return the VAR_DECL for the primary vtable. */
7752 tree
7754 {
7755 tree decl;
7759 {
7762 }
7766 }
7769 /* Returns the binfo for the primary base of BINFO. If the resulting
7770 BINFO is a virtual base, and it is inherited elsewhere in the
7771 hierarchy, then the returned binfo might not be the primary base of
7772 BINFO in the complete object. Check BINFO_PRIMARY_P or
7773 BINFO_LOST_PRIMARY_P to be sure. */
7775 static tree
7777 {
7778 tree primary_base;
7785 }
7787 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7789 static int
7791 {
7795 }
7797 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7798 INDENT should be zero when called from the top level; it is
7799 incremented recursively. IGO indicates the next expected BINFO in
7800 inheritance graph ordering. */
7802 static tree
7805 tree binfo,
7806 tree igo,
7808 {
7810 tree base_binfo;
7818 {
7821 }
7836 {
7840 TFF_PLAIN_IDENTIFIER),
7842 }
7844 {
7847 }
7852 {
7856 {
7860 TFF_PLAIN_IDENTIFIER));
7861 }
7863 {
7867 TFF_PLAIN_IDENTIFIER));
7868 }
7870 {
7874 TFF_PLAIN_IDENTIFIER));
7875 }
7877 {
7881 TFF_PLAIN_IDENTIFIER));
7882 }
7886 }
7892 }
7894 /* Dump the BINFO hierarchy for T. */
7896 static void
7898 {
7910 }
7912 /* Debug interface to hierarchy dumping. */
7914 void
7916 {
7918 }
7920 static void
7922 {
7927 {
7930 }
7931 }
7933 static void
7935 {
7936 tree value;
7938 HOST_WIDE_INT elt;
7946 TFF_PLAIN_IDENTIFIER));
7953 }
7955 static void
7957 {
7965 {
7972 {
7976 }
7980 }
7983 }
7985 static void
7987 {
7995 {
8000 }
8003 }
8005 /* Dump a function or thunk and its thunkees. */
8007 static void
8009 {
8012 tree thunks;
8020 {
8030 else
8036 }
8040 }
8042 /* Dump the thunks for FN. */
8044 void
8046 {
8048 }
8050 /* Virtual function table initialization. */
8052 /* Create all the necessary vtables for T and its base classes. */
8054 static void
8056 {
8057 tree vbase;
8061 /* We lay out the primary and secondary vtables in one contiguous
8062 vtable. The primary vtable is first, followed by the non-virtual
8063 secondary vtables in inheritance graph order. */
8067 /* Then come the virtual bases, also in inheritance graph order. */
8069 {
8073 }
8077 }
8079 /* Initialize the vtable for BINFO with the INITS. */
8081 static void
8083 {
8084 tree decl;
8090 }
8092 /* Build the VTT (virtual table table) for T.
8093 A class requires a VTT if it has virtual bases.
8095 This holds
8096 1 - primary virtual pointer for complete object T
8097 2 - secondary VTTs for each direct non-virtual base of T which requires a
8098 VTT
8099 3 - secondary virtual pointers for each direct or indirect base of T which
8100 has virtual bases or is reachable via a virtual path from T.
8101 4 - secondary VTTs for each direct or indirect virtual base of T.
8103 Secondary VTTs look like complete object VTTs without part 4. */
8105 static void
8107 {
8108 tree type;
8109 tree vtt;
8110 tree index;
8113 /* Build up the initializers for the VTT. */
8118 /* If we didn't need a VTT, we're done. */
8122 /* Figure out the type of the VTT. */
8126 /* Now, build the VTT object itself. */
8129 /* Add the VTT to the vtables list. */
8134 }
8136 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8137 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8138 and CHAIN the vtable pointer for this binfo after construction is
8139 complete. VALUE can also be another BINFO, in which case we recurse. */
8141 static tree
8143 {
8144 tree vt;
8147 {
8153 else
8155 }
8158 }
8160 /* Data for secondary VTT initialization. */
8162 {
8163 /* Is this the primary VTT? */
8166 /* Current index into the VTT. */
8167 tree index;
8169 /* Vector of initializers built up. */
8172 /* The type being constructed by this secondary VTT. */
8173 tree type_being_constructed;
8176 /* Recursively build the VTT-initializer for BINFO (which is in the
8177 hierarchy dominated by T). INITS points to the end of the initializer
8178 list to date. INDEX is the VTT index where the next element will be
8179 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8180 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8181 for virtual bases of T. When it is not so, we build the constructor
8182 vtables for the BINFO-in-T variant. */
8184 static void
8187 {
8189 tree b;
8190 tree init;
8191 secondary_vptr_vtt_init_data data;
8194 /* We only need VTTs for subobjects with virtual bases. */
8198 /* We need to use a construction vtable if this is not the primary
8199 VTT. */
8201 {
8204 /* Record the offset in the VTT where this sub-VTT can be found. */
8206 }
8208 /* Add the address of the primary vtable for the complete object. */
8212 {
8215 }
8218 /* Recursively add the secondary VTTs for non-virtual bases. */
8223 /* Add secondary virtual pointers for all subobjects of BINFO with
8224 either virtual bases or reachable along a virtual path, except
8225 subobjects that are non-virtual primary bases. */
8235 /* data.inits might have grown as we added secondary virtual pointers.
8236 Make sure our caller knows about the new vector. */
8240 /* Add the secondary VTTs for virtual bases in inheritance graph
8241 order. */
8243 {
8248 }
8249 else
8250 /* Remove the ctor vtables we created. */
8252 }
8254 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8255 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8257 static tree
8259 {
8262 /* We don't care about bases that don't have vtables. */
8266 /* We're only interested in proper subobjects of the type being
8267 constructed. */
8271 /* We're only interested in bases with virtual bases or reachable
8272 via a virtual path from the type being constructed. */
8277 /* We're not interested in non-virtual primary bases. */
8281 /* Record the index where this secondary vptr can be found. */
8283 {
8288 {
8289 /* It's a primary virtual base, and this is not a
8290 construction vtable. Find the base this is primary of in
8291 the inheritance graph, and use that base's vtable
8292 now. */
8295 }
8296 }
8298 /* Add the initializer for the secondary vptr itself. */
8301 /* Advance the vtt index. */
8306 }
8308 /* Called from build_vtt_inits via dfs_walk. After building
8309 constructor vtables and generating the sub-vtt from them, we need
8310 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8311 binfo of the base whose sub vtt was generated. */
8313 static tree
8315 {
8319 /* If this class has no vtable, none of its bases do. */
8323 /* This might be a primary base, so have no vtable in this
8324 hierarchy. */
8327 /* If we scribbled the construction vtable vptr into BINFO, clear it
8328 out now. */
8334 }
8336 /* Build the construction vtable group for BINFO which is in the
8337 hierarchy dominated by T. */
8339 static void
8341 {
8342 tree type;
8343 tree vtbl;
8344 tree id;
8345 tree vbase;
8348 /* See if we've already created this construction vtable group. */
8354 /* Build a version of VTBL (with the wrong type) for use in
8355 constructing the addresses of secondary vtables in the
8356 construction vtable group. */
8364 /* Add the vtables for each of our virtual bases using the vbase in T
8365 binfo. */
8367 vbase;
8369 {
8370 tree b;
8377 }
8379 /* Figure out the type of the construction vtable. */
8386 /* Initialize the construction vtable. */
8390 }
8392 /* Add the vtbl initializers for BINFO (and its bases other than
8393 non-virtual primaries) to the list of INITS. BINFO is in the
8394 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8395 the constructor the vtbl inits should be accumulated for. (If this
8396 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8397 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8398 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8399 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8400 but are not necessarily the same in terms of layout. */
8402 static void
8404 tree orig_binfo,
8405 tree rtti_binfo,
8406 tree vtbl,
8407 tree t,
8409 {
8411 tree base_binfo;
8416 /* If it doesn't have a vptr, we don't do anything. */
8420 /* If we're building a construction vtable, we're not interested in
8421 subobjects that don't require construction vtables. */
8427 /* Build the initializers for the BINFO-in-T vtable. */
8430 /* Walk the BINFO and its bases. We walk in preorder so that as we
8431 initialize each vtable we can figure out at what offset the
8432 secondary vtable lies from the primary vtable. We can't use
8433 dfs_walk here because we need to iterate through bases of BINFO
8434 and RTTI_BINFO simultaneously. */
8436 {
8437 /* Skip virtual bases. */
8443 inits);
8444 }
8445 }
8447 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8448 BINFO vtable to L. */
8450 static void
8452 tree orig_binfo,
8453 tree rtti_binfo,
8454 tree orig_vtbl,
8455 tree t,
8457 {
8464 {
8465 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8466 primary virtual base. If it is not the same primary in
8467 the hierarchy of T, we'll need to generate a ctor vtable
8468 for it, to place at its location in T. If it is the same
8469 primary, we still need a VTT entry for the vtable, but it
8470 should point to the ctor vtable for the base it is a
8471 primary for within the sub-hierarchy of RTTI_BINFO.
8473 There are three possible cases:
8475 1) We are in the same place.
8476 2) We are a primary base within a lost primary virtual base of
8477 RTTI_BINFO.
8478 3) We are primary to something not a base of RTTI_BINFO. */
8480 tree b;
8483 /* First, look through the bases we are primary to for RTTI_BINFO
8484 or a virtual base. */
8487 {
8492 }
8493 /* If we run out of primary links, keep looking down our
8494 inheritance chain; we might be an indirect primary. */
8498 found:
8500 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8501 base B and it is a base of RTTI_BINFO, this is case 2. In
8502 either case, we share our vtable with LAST, i.e. the
8503 derived-most base within B of which we are a primary. */
8506 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8507 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8508 binfo_ctor_vtable after everything's been set up. */
8511 /* Otherwise, this is case 3 and we get our own. */
8512 }
8519 {
8520 tree index;
8523 /* Add the initializer for this vtable. */
8527 /* Figure out the position to which the VPTR should point. */
8533 }
8536 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8537 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8538 straighten this out. */
8541 /* Throw away any unneeded intializers. */
8543 else
8544 /* For an ordinary vtable, set BINFO_VTABLE. */
8546 }
8550 /* Construct the initializer for BINFO's virtual function table. BINFO
8551 is part of the hierarchy dominated by T. If we're building a
8552 construction vtable, the ORIG_BINFO is the binfo we should use to
8553 find the actual function pointers to put in the vtable - but they
8554 can be overridden on the path to most-derived in the graph that
8555 ORIG_BINFO belongs. Otherwise,
8556 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8557 BINFO that should be indicated by the RTTI information in the
8558 vtable; it will be a base class of T, rather than T itself, if we
8559 are building a construction vtable.
8561 The value returned is a TREE_LIST suitable for wrapping in a
8562 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8563 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8564 number of non-function entries in the vtable.
8566 It might seem that this function should never be called with a
8567 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8568 base is always subsumed by a derived class vtable. However, when
8569 we are building construction vtables, we do build vtables for
8570 primary bases; we need these while the primary base is being
8571 constructed. */
8573 static void
8575 tree orig_binfo,
8576 tree t,
8577 tree rtti_binfo,
8580 {
8581 tree v;
8582 vtbl_init_data vid;
8584 tree vbinfo;
8588 /* Initialize VID. */
8596 /* The first vbase or vcall offset is at index -3 in the vtable. */
8599 /* Add entries to the vtable for RTTI. */
8602 /* Create an array for keeping track of the functions we've
8603 processed. When we see multiple functions with the same
8604 signature, we share the vcall offsets. */
8606 /* Add the vcall and vbase offset entries. */
8609 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8610 build_vbase_offset_vtbl_entries. */
8615 /* If the target requires padding between data entries, add that now. */
8617 {
8622 /* Move data entries into their new positions and add padding
8623 after the new positions. Iterate backwards so we don't
8624 overwrite entries that we would need to process later. */
8627 ix--)
8628 {
8636 {
8640 null_pointer_node);
8641 }
8642 }
8643 }
8648 /* The initializers for virtual functions were built up in reverse
8649 order. Straighten them out and add them to the running list in one
8650 step. */
8659 /* Go through all the ordinary virtual functions, building up
8660 initializers. */
8662 {
8663 tree delta;
8664 tree vcall_index;
8671 {
8675 {
8678 }
8680 }
8682 /* If the only definition of this function signature along our
8683 primary base chain is from a lost primary, this vtable slot will
8684 never be used, so just zero it out. This is important to avoid
8685 requiring extra thunks which cannot be generated with the function.
8687 We first check this in update_vtable_entry_for_fn, so we handle
8688 restored primary bases properly; we also need to do it here so we
8689 zero out unused slots in ctor vtables, rather than filling them
8690 with erroneous values (though harmless, apart from relocation
8691 costs). */
8696 {
8697 /* Pull the offset for `this', and the function to call, out of
8698 the list. */
8705 /* You can't call an abstract virtual function; it's abstract.
8706 So, we replace these functions with __pure_virtual. */
8708 {
8711 {
8713 abort_fndecl_addr
8717 }
8718 }
8719 /* Likewise for deleted virtuals. */
8721 {
8726 NULL_TREE);
8730 }
8731 else
8732 {
8734 {
8738 }
8739 /* Take the address of the function, considering it to be of an
8740 appropriate generic type. */
8744 }
8745 }
8747 /* And add it to the chain of initializers. */
8749 {
8754 else
8756 {
8762 }
8763 }
8764 else
8766 }
8767 }
8769 /* Adds to vid->inits the initializers for the vbase and vcall
8770 offsets in BINFO, which is in the hierarchy dominated by T. */
8772 static void
8774 {
8775 tree b;
8777 /* If this is a derived class, we must first create entries
8778 corresponding to the primary base class. */
8783 /* Add the vbase entries for this base. */
8785 /* Add the vcall entries for this base. */
8787 }
8789 /* Returns the initializers for the vbase offset entries in the vtable
8790 for BINFO (which is part of the class hierarchy dominated by T), in
8791 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8792 where the next vbase offset will go. */
8794 static void
8796 {
8797 tree vbase;
8798 tree t;
8799 tree non_primary_binfo;
8801 /* If there are no virtual baseclasses, then there is nothing to
8802 do. */
8808 /* We might be a primary base class. Go up the inheritance hierarchy
8809 until we find the most derived class of which we are a primary base:
8810 it is the offset of that which we need to use. */
8813 {
8814 tree b;
8816 /* If we have reached a virtual base, then it must be a primary
8817 base (possibly multi-level) of vid->binfo, or we wouldn't
8818 have called build_vcall_and_vbase_vtbl_entries for it. But it
8819 might be a lost primary, so just skip down to vid->binfo. */
8821 {
8824 }
8830 }
8832 /* Go through the virtual bases, adding the offsets. */
8834 vbase;
8836 {
8837 tree b;
8838 tree delta;
8843 /* Find the instance of this virtual base in the complete
8844 object. */
8847 /* If we've already got an offset for this virtual base, we
8848 don't need another one. */
8853 /* Figure out where we can find this vbase offset. */
8862 /* The vbase offset had better be the same. */
8865 /* The next vbase will come at a more negative offset. */
8869 /* The initializer is the delta from BINFO to this virtual base.
8870 The vbase offsets go in reverse inheritance-graph order, and
8871 we are walking in inheritance graph order so these end up in
8872 the right order. */
8879 }
8880 }
8882 /* Adds the initializers for the vcall offset entries in the vtable
8883 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8884 to VID->INITS. */
8886 static void
8888 {
8889 /* We only need these entries if this base is a virtual base. We
8890 compute the indices -- but do not add to the vtable -- when
8891 building the main vtable for a class. */
8894 /* If BINFO is RTTI_BINFO, then (since BINFO does not
8895 correspond to VID->DERIVED), we are building a primary
8896 construction virtual table. Since this is a primary
8897 virtual table, we do not need the vcall offsets for
8898 BINFO. */
8900 {
8901 /* We need a vcall offset for each of the virtual functions in this
8902 vtable. For example:
8904 class A { virtual void f (); };
8905 class B1 : virtual public A { virtual void f (); };
8906 class B2 : virtual public A { virtual void f (); };
8907 class C: public B1, public B2 { virtual void f (); };
8909 A C object has a primary base of B1, which has a primary base of A. A
8910 C also has a secondary base of B2, which no longer has a primary base
8911 of A. So the B2-in-C construction vtable needs a secondary vtable for
8912 A, which will adjust the A* to a B2* to call f. We have no way of
8913 knowing what (or even whether) this offset will be when we define B2,
8914 so we store this "vcall offset" in the A sub-vtable and look it up in
8915 a "virtual thunk" for B2::f.
8917 We need entries for all the functions in our primary vtable and
8918 in our non-virtual bases' secondary vtables. */
8920 /* If we are just computing the vcall indices -- but do not need
8921 the actual entries -- not that. */
8924 /* Now, walk through the non-virtual bases, adding vcall offsets. */
8926 }
8927 }
8929 /* Build vcall offsets, starting with those for BINFO. */
8931 static void
8933 {
8935 tree primary_binfo;
8936 tree base_binfo;
8938 /* Don't walk into virtual bases -- except, of course, for the
8939 virtual base for which we are building vcall offsets. Any
8940 primary virtual base will have already had its offsets generated
8941 through the recursion in build_vcall_and_vbase_vtbl_entries. */
8945 /* If BINFO has a primary base, process it first. */
8950 /* Add BINFO itself to the list. */
8953 /* Scan the non-primary bases of BINFO. */
8957 }
8959 /* Called from build_vcall_offset_vtbl_entries_r. */
8961 static void
8963 {
8964 /* Make entries for the rest of the virtuals. */
8966 {
8967 tree orig_fn;
8969 /* The ABI requires that the methods be processed in declaration
8970 order. G++ 3.2 used the order in the vtable. */
8972 orig_fn;
8976 }
8977 else
8978 {
8979 tree derived_virtuals;
8980 tree base_virtuals;
8981 tree orig_virtuals;
8982 /* If BINFO is a primary base, the most derived class which has
8983 BINFO as a primary base; otherwise, just BINFO. */
8984 tree non_primary_binfo;
8986 /* We might be a primary base class. Go up the inheritance hierarchy
8987 until we find the most derived class of which we are a primary base:
8988 it is the BINFO_VIRTUALS there that we need to consider. */
8991 {
8992 tree b;
8994 /* If we have reached a virtual base, then it must be vid->vbase,
8995 because we ignore other virtual bases in
8996 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
8997 base (possibly multi-level) of vid->binfo, or we wouldn't
8998 have called build_vcall_and_vbase_vtbl_entries for it. But it
8999 might be a lost primary, so just skip down to vid->binfo. */
9001 {
9005 }
9011 }
9014 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9015 where rtti_binfo is the most derived type. */
9016 non_primary_binfo
9022 base_virtuals;
9026 {
9027 tree orig_fn;
9029 /* Find the declaration that originally caused this function to
9030 be present in BINFO_TYPE (binfo). */
9033 /* When processing BINFO, we only want to generate vcall slots for
9034 function slots introduced in BINFO. So don't try to generate
9035 one if the function isn't even defined in BINFO. */
9040 }
9041 }
9042 }
9044 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9046 static void
9048 {
9050 tree vcall_offset;
9051 tree derived_entry;
9053 /* If there is already an entry for a function with the same
9054 signature as FN, then we do not need a second vcall offset.
9055 Check the list of functions already present in the derived
9056 class vtable. */
9058 {
9060 /* We only use one vcall offset for virtual destructors,
9061 even though there are two virtual table entries. */
9065 }
9067 /* If we are building these vcall offsets as part of building
9068 the vtable for the most derived class, remember the vcall
9069 offset. */
9071 {
9074 }
9076 /* The next vcall offset will be found at a more negative
9077 offset. */
9081 /* Keep track of this function. */
9085 {
9086 tree base;
9087 tree fn;
9089 /* Find the overriding function. */
9093 else
9094 {
9097 /* The vbase we're working on is a primary base of
9098 vid->binfo. But it might be a lost primary, so its
9099 BINFO_OFFSET might be wrong, so we just use the
9100 BINFO_OFFSET from vid->binfo. */
9106 vcall_offset);
9107 }
9108 /* Add the initializer to the vtable. */
9110 }
9111 }
9113 /* Return vtbl initializers for the RTTI entries corresponding to the
9114 BINFO's vtable. The RTTI entries should indicate the object given
9115 by VID->rtti_binfo. */
9117 static void
9119 {
9120 tree b;
9121 tree t;
9122 tree offset;
9123 tree decl;
9124 tree init;
9128 /* To find the complete object, we will first convert to our most
9129 primary base, and then add the offset in the vtbl to that value. */
9133 {
9134 tree primary_base;
9140 }
9144 /* The second entry is the address of the typeinfo object. */
9147 else
9150 /* Convert the declaration to a type that can be stored in the
9151 vtable. */
9155 /* Add the offset-to-top entry. It comes earlier in the vtable than
9156 the typeinfo entry. Convert the offset to look like a
9157 function pointer, so that we can put it in the vtable. */
9160 }
9162 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9163 accessibility. */
9165 bool
9167 {
9170 }
9172 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9174 bool
9176 {
9180 }