| blob | 605dd16c7115dd28baf72944cd06822120425bdd |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2013 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com)
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
22 /* High-level class interface. */
40 /* The number of nested classes being processed. If we are not in the
41 scope of any class, this is zero. */
45 /* In order to deal with nested classes, we keep a stack of classes.
46 The topmost entry is the innermost class, and is the entry at index
47 CURRENT_CLASS_DEPTH */
50 /* The name of the class. */
51 tree name;
53 /* The _TYPE node for the class. */
54 tree type;
56 /* The access specifier pending for new declarations in the scope of
57 this class. */
58 tree access;
60 /* If were defining TYPE, the names used in this class. */
61 splay_tree names_used;
63 /* Nonzero if this class is no longer open, because of a call to
64 push_to_top_level. */
69 {
70 /* The base for which we're building initializers. */
71 tree binfo;
72 /* The type of the most-derived type. */
73 tree derived;
74 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
75 unless ctor_vtbl_p is true. */
76 tree rtti_binfo;
77 /* The negative-index vtable initializers built up so far. These
78 are in order from least negative index to most negative index. */
80 /* The binfo for the virtual base for which we're building
81 vcall offset initializers. */
82 tree vbase;
83 /* The functions in vbase for which we have already provided vcall
84 offsets. */
86 /* The vtable index of the next vcall or vbase offset. */
87 tree index;
88 /* Nonzero if we are building the initializer for the primary
89 vtable. */
91 /* Nonzero if we are building the initializer for a construction
92 vtable. */
94 /* True when adding vcall offset entries to the vtable. False when
95 merely computing the indices. */
99 /* The type of a function passed to walk_subobject_offsets. */
102 /* The stack itself. This is a dynamically resized array. The
103 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
107 /* The size of the largest empty class seen in this translation unit. */
110 /* An array of all local classes present in this translation unit, in
111 declaration order. */
193 tree *);
203 splay_tree_key k2);
212 /* Variables shared between class.c and call.c. */
222 /* Convert to or from a base subobject. EXPR is an expression of type
223 `A' or `A*', an expression of type `B' or `B*' is returned. To
224 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
225 the B base instance within A. To convert base A to derived B, CODE
226 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
227 In this latter case, A must not be a morally virtual base of B.
228 NONNULL is true if EXPR is known to be non-NULL (this is only
229 needed when EXPR is of pointer type). CV qualifiers are preserved
230 from EXPR. */
232 tree
234 tree expr,
235 tree binfo,
237 tsubst_flags_t complain)
238 {
241 tree probe;
242 tree offset;
243 tree target_type;
245 tree ptr_target_type;
255 {
261 }
269 {
270 /* This can happen when adjust_result_of_qualified_name_lookup can't
271 find a unique base binfo in a call to a member function. We
272 couldn't give the diagnostic then since we might have been calling
273 a static member function, so we do it now. */
275 {
279 }
281 }
288 /* Nothing to do. */
292 {
298 }
301 /* This must happen before the call to save_expr. */
303 else
309 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
310 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
311 expression returned matches the input. */
312 target_type = cp_build_qualified_type
316 /* Do we need to look in the vtable for the real offset? */
319 /* Don't bother with the calculations inside sizeof; they'll ICE if the
320 source type is incomplete and the pointer value doesn't matter. In a
321 template (even in fold_non_dependent_expr), we don't have vtables set
322 up properly yet, and the value doesn't matter there either; we're just
323 interested in the result of overload resolution. */
326 {
331 }
333 /* If we're in an NSDMI, we don't have the full constructor context yet
334 that we need for converting to a virtual base, so just build a stub
335 CONVERT_EXPR and expand it later in bot_replace. */
338 {
344 }
346 /* Do we need to check for a null pointer? */
348 {
349 /* If we know the conversion will not actually change the value
350 of EXPR, then we can avoid testing the expression for NULL.
351 We have to avoid generating a COMPONENT_REF for a base class
352 field, because other parts of the compiler know that such
353 expressions are always non-NULL. */
357 }
359 /* Protect against multiple evaluation if necessary. */
363 /* Now that we've saved expr, build the real null test. */
365 {
369 }
371 /* If this is a simple base reference, express it as a COMPONENT_REF. */
373 /* We don't build base fields for empty bases, and they aren't very
374 interesting to the optimizers anyway. */
376 {
383 }
386 {
387 /* Going via virtual base V_BINFO. We need the static offset
388 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
389 V_BINFO. That offset is an entry in D_BINFO's vtable. */
390 tree v_offset;
393 {
394 /* In a base member initializer, we cannot rely on the
395 vtable being set up. We have to indirect via the
396 vtt_parm. */
397 tree t;
403 }
404 else
406 complain),
412 v_offset);
424 /* Negative fixed_type_p means this is a constructor or destructor;
425 virtual base layout is fixed in in-charge [cd]tors, but not in
426 base [cd]tors. */
430 v_offset,
433 else
435 }
443 {
448 }
449 else
455 out:
461 }
463 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
464 Perform a derived-to-base conversion by recursively building up a
465 sequence of COMPONENT_REFs to the appropriate base fields. */
467 static tree
469 {
472 tree field;
475 {
476 tree temp;
480 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
481 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
482 an lvalue in the front end; only _DECLs and _REFs are lvalues
483 in the back end. */
489 }
491 /* Recurse. */
496 /* Is this the base field created by build_base_field? */
500 /* If we're looking for a field in the most-derived class,
501 also check the field offset; we can have two base fields
502 of the same type if one is an indirect virtual base and one
503 is a direct non-virtual base. */
507 {
508 /* We don't use build_class_member_access_expr here, as that
509 has unnecessary checks, and more importantly results in
510 recursive calls to dfs_walk_once. */
518 /* Mark the expression const or volatile, as appropriate.
519 Even though we've dealt with the type above, we still have
520 to mark the expression itself. */
527 }
529 /* Didn't find the base field?!? */
531 }
533 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
534 type is a class type or a pointer to a class type. In the former
535 case, TYPE is also a class type; in the latter it is another
536 pointer type. If CHECK_ACCESS is true, an error message is emitted
537 if TYPE is inaccessible. If OBJECT has pointer type, the value is
538 assumed to be non-NULL. */
540 tree
542 tsubst_flags_t complain)
543 {
544 tree binfo;
545 tree object_type;
548 {
551 }
552 else
561 }
563 /* EXPR is an expression with unqualified class type. BASE is a base
564 binfo of that class type. Returns EXPR, converted to the BASE
565 type. This function assumes that EXPR is the most derived class;
566 therefore virtual bases can be found at their static offsets. */
568 tree
570 {
571 tree expr_type;
575 {
576 /* If this is a non-empty base, use a COMPONENT_REF. */
580 /* We use fold_build2 and fold_convert below to simplify the trees
581 provided to the optimizers. It is not safe to call these functions
582 when processing a template because they do not handle C++-specific
583 trees. */
591 }
594 }
596 \f
597 tree
599 {
605 /* First, convert to the requested type. */
610 /* Second, the requested type may not be the owner of its own vptr.
611 If not, convert to the base class that owns it. We cannot use
612 convert_to_base here, because VCONTEXT may appear more than once
613 in the inheritance hierarchy of TYPE, and thus direct conversion
614 between the types may be ambiguous. Following the path back up
615 one step at a time via primary bases avoids the problem. */
619 {
622 }
625 }
627 /* Given an object INSTANCE, return an expression which yields the
628 vtable element corresponding to INDEX. There are many special
629 cases for INSTANCE which we take care of here, mainly to avoid
630 creating extra tree nodes when we don't have to. */
632 static tree
634 {
635 tree aref;
638 /* Try to figure out what a reference refers to, and
639 access its virtual function table directly. */
647 {
652 }
661 }
663 tree
665 {
669 }
671 /* Given a stable object pointer INSTANCE_PTR, return an expression which
672 yields a function pointer corresponding to vtable element INDEX. */
674 tree
676 {
677 tree aref;
680 tf_warning_or_error),
681 idx);
683 /* When using function descriptors, the address of the
684 vtable entry is treated as a function pointer. */
689 /* Remember this as a method reference, for later devirtualization. */
693 }
695 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
696 for the given TYPE. */
698 static tree
700 {
702 }
704 /* DECL is an entity associated with TYPE, like a virtual table or an
705 implicitly generated constructor. Determine whether or not DECL
706 should have external or internal linkage at the object file
707 level. This routine does not deal with COMDAT linkage and other
708 similar complexities; it simply sets TREE_PUBLIC if it possible for
709 entities in other translation units to contain copies of DECL, in
710 the abstract. */
712 void
714 {
717 }
719 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
720 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
721 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
723 static tree
725 {
726 tree decl;
729 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
730 now to avoid confusion in mangle_decl. */
739 /* At one time the vtable info was grabbed 2 words at a time. This
740 fails on sparc unless you have 8-byte alignment. (tiemann) */
744 /* The vtable has not been defined -- yet. */
748 /* Mark the VAR_DECL node representing the vtable itself as a
749 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
750 is rather important that such things be ignored because any
751 effort to actually generate DWARF for them will run into
752 trouble when/if we encounter code like:
754 #pragma interface
755 struct S { virtual void member (); };
757 because the artificial declaration of the vtable itself (as
758 manufactured by the g++ front end) will say that the vtable is
759 a static member of `S' but only *after* the debug output for
760 the definition of `S' has already been output. This causes
761 grief because the DWARF entry for the definition of the vtable
762 will try to refer back to an earlier *declaration* of the
763 vtable as a static member of `S' and there won't be one. We
764 might be able to arrange to have the "vtable static member"
765 attached to the member list for `S' before the debug info for
766 `S' get written (which would solve the problem) but that would
767 require more intrusive changes to the g++ front end. */
771 }
773 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
774 or even complete. If this does not exist, create it. If COMPLETE is
775 nonzero, then complete the definition of it -- that will render it
776 impossible to actually build the vtable, but is useful to get at those
777 which are known to exist in the runtime. */
779 tree
781 {
782 tree decl;
791 {
794 }
797 }
799 /* Build the primary virtual function table for TYPE. If BINFO is
800 non-NULL, build the vtable starting with the initial approximation
801 that it is the same as the one which is the head of the association
802 list. Returns a nonzero value if a new vtable is actually
803 created. */
805 static int
807 {
808 tree decl;
809 tree virtuals;
814 {
816 /* We have already created a vtable for this base, so there's
817 no need to do it again. */
824 }
825 else
826 {
829 }
832 {
835 }
837 /* Initialize the association list for this type, based
838 on our first approximation. */
843 }
845 /* Give BINFO a new virtual function table which is initialized
846 with a skeleton-copy of its original initialization. The only
847 entry that changes is the `delta' entry, so we can really
848 share a lot of structure.
850 FOR_TYPE is the most derived type which caused this table to
851 be needed.
853 Returns nonzero if we haven't met BINFO before.
855 The order in which vtables are built (by calling this function) for
856 an object must remain the same, otherwise a binary incompatibility
857 can result. */
859 static int
861 {
863 /* We already created a vtable for this base. There's no need to
864 do it again. */
867 /* Remember that we've created a vtable for this BINFO, so that we
868 don't try to do so again. */
871 /* Make fresh virtual list, so we can smash it later. */
874 /* Secondary vtables are laid out as part of the same structure as
875 the primary vtable. */
878 }
880 /* Create a new vtable for BINFO which is the hierarchy dominated by
881 T. Return nonzero if we actually created a new vtable. */
883 static int
885 {
887 /* In this case, it is *type*'s vtable we are modifying. We start
888 with the approximation that its vtable is that of the
889 immediate base class. */
891 else
892 /* This is our very own copy of `basetype' to play with. Later,
893 we will fill in all the virtual functions that override the
894 virtual functions in these base classes which are not defined
895 by the current type. */
897 }
899 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
900 (which is in the hierarchy dominated by T) list FNDECL as its
901 BV_FN. DELTA is the required constant adjustment from the `this'
902 pointer where the vtable entry appears to the `this' required when
903 the function is actually called. */
905 static void
907 tree binfo,
908 tree fndecl,
909 tree delta,
911 {
912 tree v;
918 {
919 /* We need a new vtable for BINFO. */
921 {
922 /* If we really did make a new vtable, we also made a copy
923 of the BINFO_VIRTUALS list. Now, we have to find the
924 corresponding entry in that list. */
929 }
934 }
935 }
937 \f
938 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
939 the USING_DECL naming METHOD. Returns true if the method could be
940 added to the method vec. */
942 bool
944 {
946 tree overload;
952 tree current_fns;
953 tree fns;
966 {
967 /* Make a new method vector. We start with 8 entries. We must
968 allocate at least two (for constructors and destructors), and
969 we're going to end up with an assignment operator at some
970 point as well. */
972 /* Create slots for constructors and destructors. */
976 }
978 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
981 /* Constructors and destructors go in special slots. */
985 {
989 {
995 type);
996 }
997 }
998 else
999 {
1000 tree m;
1003 /* See if we already have an entry with this name. */
1007 {
1010 {
1015 }
1019 {
1022 }
1027 }
1028 }
1031 /* Check to see if we've already got this method. */
1033 {
1035 tree fn_type;
1036 tree method_type;
1037 tree parms1;
1038 tree parms2;
1043 /* [over.load] Member function declarations with the
1044 same name and the same parameter types cannot be
1045 overloaded if any of them is a static member
1046 function declaration.
1048 [namespace.udecl] When a using-declaration brings names
1049 from a base class into a derived class scope, member
1050 functions in the derived class override and/or hide member
1051 functions with the same name and parameter types in a base
1052 class (rather than conflicting). */
1058 /* Compare the quals on the 'this' parm. Don't compare
1059 the whole types, as used functions are treated as
1060 coming from the using class in overload resolution. */
1069 /* For templates, the return type and template parameters
1070 must be identical. */
1087 {
1088 /* For function versions, their parms and types match
1089 but they are not duplicates. Record function versions
1090 as and when they are found. extern "C" functions are
1091 not treated as versions. */
1097 {
1098 /* Mark functions as versions if necessary. Modify the mangled
1099 decl name if necessary. */
1101 {
1105 }
1107 {
1111 }
1114 }
1116 {
1118 {
1125 }
1126 /* Otherwise defer to the other function. */
1128 }
1130 {
1132 /* Defer to the local function. */
1134 }
1135 else
1136 {
1139 }
1141 /* We don't call duplicate_decls here to merge the
1142 declarations because that will confuse things if the
1143 methods have inline definitions. In particular, we
1144 will crash while processing the definitions. */
1146 }
1147 }
1149 /* A class should never have more than one destructor. */
1153 /* Add the new binding. */
1155 {
1158 }
1159 else
1168 {
1171 /* We only expect to add few methods in the COMPLETE_P case, so
1172 just make room for one more method in that case. */
1175 else
1181 else
1183 }
1184 else
1185 /* Replace the current slot. */
1188 }
1190 /* Subroutines of finish_struct. */
1192 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1193 legit, otherwise return 0. */
1195 static int
1197 {
1198 tree elem;
1207 {
1209 {
1213 else
1216 }
1217 else
1218 {
1219 /* They're changing the access to the same thing they changed
1220 it to before. That's OK. */
1221 ;
1222 }
1223 }
1224 else
1225 {
1227 tf_warning_or_error);
1230 }
1232 }
1234 /* Process the USING_DECL, which is a member of T. */
1236 static void
1238 {
1241 tree access
1246 tree old_value;
1251 tf_warning_or_error);
1253 {
1259 else
1261 }
1269 ;
1271 {
1273 /* It's OK to use functions from a base when there are functions with
1275 else
1276 {
1281 }
1282 }
1284 {
1288 }
1290 /* Make type T see field decl FDECL with access ACCESS. */
1293 {
1296 }
1297 else
1299 }
1300 \f
1301 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1302 types with abi tags, add the corresponding identifiers to the VEC in
1303 *DATA and set IDENTIFIER_MARKED. */
1305 struct abi_tag_data
1306 {
1307 tree t;
1308 tree subob;
1309 };
1311 static tree
1313 {
1318 {
1322 {
1326 {
1328 {
1333 }
1334 else
1335 {
1342 }
1343 }
1344 }
1345 }
1347 }
1349 /* Check that class T has all the abi tags that subobject SUBOB has, or
1350 warn if not. */
1352 static void
1354 {
1357 {
1360 {
1364 }
1365 }
1373 {
1376 {
1380 }
1381 }
1382 }
1384 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1385 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1386 properties of the bases. */
1388 static void
1392 {
1396 tree base_binfo;
1397 tree binfo;
1407 {
1416 /* If any base class is non-literal, so is the derived class. */
1420 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1421 here because the case of virtual functions but non-virtual
1422 dtor is handled in finish_struct_1. */
1427 /* If the base class doesn't have copy constructors or
1428 assignment operators that take const references, then the
1429 derived class cannot have such a member automatically
1430 generated. */
1439 /* A virtual base does not effect nearly emptiness. */
1440 ;
1442 {
1444 /* And if there is more than one nearly empty base, then the
1445 derived class is not nearly empty either. */
1447 else
1448 /* Remember we've seen one. */
1450 }
1452 /* If the base class is not empty or nearly empty, then this
1453 class cannot be nearly empty. */
1456 /* A lot of properties from the bases also apply to the derived
1457 class. */
1475 /* A standard-layout class is a class that:
1476 ...
1477 * has no non-standard-layout base classes, */
1480 {
1481 tree basefield;
1482 /* ...has no base classes of the same type as the first non-static
1483 data member... */
1485 && (same_type_ignoring_top_level_qualifiers_p
1488 else
1489 /* ...either has no non-static data members in the most-derived
1490 class and at most one base class with non-static data
1491 members, or has no base classes with non-static data
1492 members */
1496 {
1499 else
1502 }
1503 }
1505 /* Don't bother collecting tm attributes if transactional memory
1506 support is not enabled. */
1508 {
1512 }
1515 }
1517 /* If one of the base classes had TM attributes, and the current class
1518 doesn't define its own, then the current class inherits one. */
1520 {
1523 }
1524 }
1526 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1527 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1528 that have had a nearly-empty virtual primary base stolen by some
1529 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1530 T. */
1532 static void
1534 {
1538 tree base_binfo;
1540 /* Determine the primary bases of our bases. */
1543 {
1546 /* See if we're the non-virtual primary of our inheritance
1547 chain. */
1549 {
1556 /* We are the primary binfo. */
1558 }
1559 /* Determine if we have a virtual primary base, and mark it so.
1560 */
1562 {
1566 /* Someone already claimed this base. */
1568 else
1569 {
1570 tree delta;
1575 /* A virtual binfo might have been copied from within
1576 another hierarchy. As we're about to use it as a
1577 primary base, make sure the offsets match. */
1585 }
1586 }
1587 }
1589 /* First look for a dynamic direct non-virtual base. */
1591 {
1595 {
1598 }
1599 }
1601 /* A "nearly-empty" virtual base class can be the primary base
1602 class, if no non-virtual polymorphic base can be found. Look for
1603 a nearly-empty virtual dynamic base that is not already a primary
1604 base of something in the hierarchy. If there is no such base,
1605 just pick the first nearly-empty virtual base. */
1611 {
1613 {
1614 /* Found one that is not primary. */
1617 }
1619 /* Remember the first candidate. */
1621 }
1623 found:
1624 /* If we've got a primary base, use it. */
1626 {
1631 /* We are stealing a primary base. */
1635 {
1636 tree delta;
1639 /* A virtual binfo might have been copied from within
1640 another hierarchy. As we're about to use it as a primary
1641 base, make sure the offsets match. */
1646 }
1653 }
1654 }
1656 /* Update the variant types of T. */
1658 void
1660 {
1661 tree variants;
1667 variants;
1669 {
1670 /* These fields are in the _TYPE part of the node, not in
1671 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1681 /* Copy whatever these are holding today. */
1685 }
1686 }
1688 /* Early variant fixups: we apply attributes at the beginning of the class
1689 definition, and we need to fix up any variants that have already been
1690 made via elaborated-type-specifier so that check_qualified_type works. */
1692 void
1694 {
1695 tree variants;
1701 variants;
1703 {
1704 /* These are the two fields that check_qualified_type looks at and
1705 are affected by attributes. */
1708 }
1709 }
1710 \f
1711 /* Set memoizing fields and bits of T (and its variants) for later
1712 use. */
1714 static void
1716 {
1717 /* Fix up variants (if any). */
1721 /* For a class w/o baseclasses, 'finish_struct' has set
1722 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1723 Similarly for a class whose base classes do not have vtables.
1724 When neither of these is true, we might have removed abstract
1725 virtuals (by providing a definition), added some (by declaring
1726 new ones), or redeclared ones from a base class. We need to
1727 recalculate what's really an abstract virtual at this point (by
1728 looking in the vtables). */
1731 /* If this type has a copy constructor or a destructor, force its
1732 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1733 nonzero. This will cause it to be passed by invisible reference
1734 and prevent it from being returned in a register. */
1737 {
1738 tree variants;
1741 {
1744 }
1745 }
1746 }
1748 /* Issue warnings about T having private constructors, but no friends,
1749 and so forth.
1751 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1752 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1753 non-private static member functions. */
1755 static void
1757 {
1760 tree fn;
1763 /* If the class has friends, those entities might create and
1764 access instances, so we should not warn. */
1767 /* We will have warned when the template was declared; there's
1768 no need to warn on every instantiation. */
1770 /* There's no reason to even consider warning about this
1771 class. */
1774 /* We only issue one warning, if more than one applies, because
1775 otherwise, on code like:
1777 class A {
1778 // Oops - forgot `public:'
1779 A();
1780 A(const A&);
1781 ~A();
1782 };
1784 we warn several times about essentially the same problem. */
1786 /* Check to see if all (non-constructor, non-destructor) member
1787 functions are private. (Since there are no friends or
1788 non-private statics, we can't ever call any of the private member
1789 functions.) */
1791 /* We're not interested in compiler-generated methods; they don't
1792 provide any way to call private members. */
1794 {
1796 {
1798 /* A non-private static member function is just like a
1799 friend; it can create and invoke private member
1800 functions, and be accessed without a class
1801 instance. */
1805 /* Keep searching for a static member function. */
1806 }
1809 }
1812 {
1813 /* There are no non-private methods, and there's at least one
1814 private member function that isn't a constructor or
1815 destructor. (If all the private members are
1816 constructors/destructors we want to use the code below that
1817 issues error messages specifically referring to
1818 constructors/destructors.) */
1824 {
1827 }
1829 {
1833 }
1834 }
1836 /* Even if some of the member functions are non-private, the class
1837 won't be useful for much if all the constructors or destructors
1838 are private: such an object can never be created or destroyed. */
1841 {
1844 t);
1846 }
1848 /* Warn about classes that have private constructors and no friends. */
1850 /* Implicitly generated constructors are always public. */
1853 {
1856 /* If a non-template class does not define a copy
1857 constructor, one is defined for it, enabling it to avoid
1858 this warning. For a template class, this does not
1859 happen, and so we would normally get a warning on:
1861 template <class T> class C { private: C(); };
1863 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1864 complete non-template or fully instantiated classes have this
1865 flag set. */
1868 else
1870 {
1872 /* Ideally, we wouldn't count copy constructors (or, in
1873 fact, any constructor that takes an argument of the
1874 class type as a parameter) because such things cannot
1875 be used to construct an instance of the class unless
1876 you already have one. But, for now at least, we're
1877 more generous. */
1879 {
1882 }
1883 }
1886 {
1889 t);
1891 }
1892 }
1893 }
1896 gt_pointer_operator new_value;
1900 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1902 static int
1904 {
1917 }
1919 /* This routine compares two fields like method_name_cmp but using the
1920 pointer operator in resort_field_decl_data. */
1922 static int
1924 {
1933 {
1940 }
1942 }
1944 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1946 void
1949 gt_pointer_operator new_value,
1951 {
1955 tree fn;
1957 /* The type conversion ops have to live at the front of the vec, so we
1958 can't sort them. */
1966 {
1970 resort_method_name_cmp);
1971 }
1972 }
1974 /* Warn about duplicate methods in fn_fields.
1976 Sort methods that are not special (i.e., constructors, destructors,
1977 and type conversion operators) so that we can find them faster in
1978 search. */
1980 static void
1982 {
1983 tree fn_fields;
1993 /* Clear DECL_IN_AGGR_P for all functions. */
1998 /* Issue warnings about private constructors and such. If there are
1999 no methods, then some public defaults are generated. */
2002 /* The type conversion ops have to live at the front of the vec, so we
2003 can't sort them. */
2012 }
2014 /* Make BINFO's vtable have N entries, including RTTI entries,
2015 vbase and vcall offsets, etc. Set its type and call the back end
2016 to lay it out. */
2018 static void
2020 {
2021 tree atype;
2022 tree vtable;
2027 /* We may have to grow the vtable. */
2030 {
2034 }
2035 }
2037 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2038 have the same signature. */
2040 int
2042 {
2043 /* One destructor overrides another if they are the same kind of
2044 destructor. */
2048 /* But a non-destructor never overrides a destructor, nor vice
2049 versa, nor do different kinds of destructors override
2050 one-another. For example, a complete object destructor does not
2051 override a deleting destructor. */
2060 {
2068 }
2070 }
2072 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2073 subobject. */
2075 static bool
2077 {
2078 tree probe;
2081 {
2085 /* If we meet a virtual base, we can't follow the inheritance
2086 any more. See if the complete type of DERIVED contains
2087 such a virtual base. */
2090 }
2092 }
2095 /* The function for which we are trying to find a final overrider. */
2096 tree fn;
2097 /* The base class in which the function was declared. */
2098 tree declaring_base;
2099 /* The candidate overriders. */
2100 tree candidates;
2101 /* Path to most derived. */
2105 /* Add the overrider along the current path to FFOD->CANDIDATES.
2106 Returns true if an overrider was found; false otherwise. */
2108 static bool
2112 {
2113 tree method;
2115 /* If BINFO is not the most derived type, try a more derived class.
2116 A definition there will overrider a definition here. */
2118 {
2119 depth--;
2123 }
2127 {
2130 /* Remove any candidates overridden by this new function. */
2132 {
2133 /* If *CANDIDATE overrides METHOD, then METHOD
2134 cannot override anything else on the list. */
2137 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2140 else
2142 }
2144 /* Add the new function. */
2147 }
2150 }
2152 /* Called from find_final_overrider via dfs_walk. */
2154 static tree
2156 {
2164 }
2166 static tree
2168 {
2173 }
2175 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2176 FN and whose TREE_VALUE is the binfo for the base where the
2177 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2178 DERIVED) is the base object in which FN is declared. */
2180 static tree
2182 {
2183 find_final_overrider_data ffod;
2185 /* Getting this right is a little tricky. This is valid:
2187 struct S { virtual void f (); };
2188 struct T { virtual void f (); };
2189 struct U : public S, public T { };
2191 even though calling `f' in `U' is ambiguous. But,
2193 struct R { virtual void f(); };
2194 struct S : virtual public R { virtual void f (); };
2195 struct T : virtual public R { virtual void f (); };
2196 struct U : public S, public T { };
2198 is not -- there's no way to decide whether to put `S::f' or
2199 `T::f' in the vtable for `R'.
2201 The solution is to look at all paths to BINFO. If we find
2202 different overriders along any two, then there is a problem. */
2206 /* Determine the depth of the hierarchy. */
2217 /* If there was no winner, issue an error message. */
2222 }
2224 /* Return the index of the vcall offset for FN when TYPE is used as a
2225 virtual base. */
2227 static tree
2229 {
2231 tree_pair_p p;
2239 /* There should always be an appropriate index. */
2241 }
2243 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2244 dominated by T. FN is the old function; VIRTUALS points to the
2245 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2246 of that entry in the list. */
2248 static void
2251 {
2252 tree b;
2253 tree overrider;
2254 tree delta;
2255 tree virtual_base;
2256 tree first_defn;
2262 /* Find the nearest primary base (possibly binfo itself) which defines
2263 this function; this is the class the caller will convert to when
2264 calling FN through BINFO. */
2266 {
2271 /* The nearest definition is from a lost primary. */
2274 }
2277 /* Find the final overrider. */
2280 {
2283 }
2286 /* Check for adjusting covariant return types. */
2294 /* If the overrider is invalid, don't even try. */
2296 {
2297 /* If FN is a covariant thunk, we must figure out the adjustment
2298 to the final base FN was converting to. As OVERRIDER_TARGET might
2299 also be converting to the return type of FN, we have to
2300 combine the two conversions here. */
2307 {
2311 }
2312 else
2316 /* Find the equivalent binfo within the return type of the
2317 overriding function. We will want the vbase offset from
2318 there. */
2320 over_return);
2323 {
2324 /* There was no existing virtual thunk (which takes
2325 precedence). So find the binfo of the base function's
2326 return type within the overriding function's return type.
2327 We cannot call lookup base here, because we're inside a
2328 dfs_walk, and will therefore clobber the BINFO_MARKED
2329 flags. Fortunately we know the covariancy is valid (it
2330 has already been checked), so we can just iterate along
2331 the binfos, which have been chained in inheritance graph
2332 order. Of course it is lame that we have to repeat the
2333 search here anyway -- we should really be caching pieces
2334 of the vtable and avoiding this repeated work. */
2337 /* Find the base binfo within the overriding function's
2338 return type. We will always find a thunk_binfo, except
2339 when the covariancy is invalid (which we will have
2340 already diagnosed). */
2343 thunk_binfo;
2349 /* See if virtual inheritance is involved. */
2351 virtual_offset;
2358 {
2362 {
2363 /* We convert via virtual base. Adjust the fixed
2364 offset to be from there. */
2365 offset =
2369 }
2371 /* There was an existing fixed offset, this must be
2372 from the base just converted to, and the base the
2373 FN was thunking to. */
2375 else
2377 }
2378 }
2381 /* Replace the overriding function with a covariant thunk. We
2382 will emit the overriding function in its own slot as
2383 well. */
2386 }
2387 else
2391 /* If we need a covariant thunk, then we may need to adjust first_defn.
2392 The ABI specifies that the thunks emitted with a function are
2393 determined by which bases the function overrides, so we need to be
2394 sure that we're using a thunk for some overridden base; even if we
2395 know that the necessary this adjustment is zero, there may not be an
2396 appropriate zero-this-adjusment thunk for us to use since thunks for
2397 overriding virtual bases always use the vcall offset.
2399 Furthermore, just choosing any base that overrides this function isn't
2400 quite right, as this slot won't be used for calls through a type that
2401 puts a covariant thunk here. Calling the function through such a type
2402 will use a different slot, and that slot is the one that determines
2403 the thunk emitted for that base.
2405 So, keep looking until we find the base that we're really overriding
2406 in this slot: the nearest primary base that doesn't use a covariant
2407 thunk in this slot. */
2409 {
2411 /* We already know that the overrider needs a covariant thunk. */
2414 {
2421 }
2423 }
2425 /* Assume that we will produce a thunk that convert all the way to
2426 the final overrider, and not to an intermediate virtual base. */
2429 /* See if we can convert to an intermediate virtual base first, and then
2430 use the vcall offset located there to finish the conversion. */
2432 {
2433 /* If we find the final overrider, then we can stop
2434 walking. */
2439 /* If we find a virtual base, and we haven't yet found the
2440 overrider, then there is a virtual base between the
2441 declaring base (first_defn) and the final overrider. */
2443 {
2446 }
2447 }
2449 /* Compute the constant adjustment to the `this' pointer. The
2450 `this' pointer, when this function is called, will point at BINFO
2451 (or one of its primary bases, which are at the same offset). */
2453 /* The `this' pointer needs to be adjusted from the declaration to
2454 the nearest virtual base. */
2459 /* If the nearest definition is in a lost primary, we don't need an
2460 entry in our vtable. Except possibly in a constructor vtable,
2461 if we happen to get our primary back. In that case, the offset
2462 will be zero, as it will be a primary base. */
2464 else
2465 /* The `this' pointer needs to be adjusted from pointing to
2466 BINFO to pointing at the base where the final overrider
2467 appears. */
2478 else
2482 }
2484 /* Called from modify_all_vtables via dfs_walk. */
2486 static tree
2488 {
2490 tree virtuals;
2491 tree old_virtuals;
2495 /* A base without a vtable needs no modification, and its bases
2496 are uninteresting. */
2501 /* Don't do the primary vtable, if it's new. */
2505 /* There's no need to modify the vtable for a non-virtual primary
2506 base; we're not going to use that vtable anyhow. We do still
2507 need to do this for virtual primary bases, as they could become
2508 non-primary in a construction vtable. */
2513 /* Now, go through each of the virtual functions in the virtual
2514 function table for BINFO. Find the final overrider, and update
2515 the BINFO_VIRTUALS list appropriately. */
2518 virtuals;
2522 binfo,
2527 }
2529 /* Update all of the primary and secondary vtables for T. Create new
2530 vtables as required, and initialize their RTTI information. Each
2531 of the functions in VIRTUALS is declared in T and may override a
2532 virtual function from a base class; find and modify the appropriate
2533 entries to point to the overriding functions. Returns a list, in
2534 declaration order, of the virtual functions that are declared in T,
2535 but do not appear in the primary base class vtable, and which
2536 should therefore be appended to the end of the vtable for T. */
2538 static tree
2540 {
2544 /* Update all of the vtables. */
2547 /* Add virtual functions not already in our primary vtable. These
2548 will be both those introduced by this class, and those overridden
2549 from secondary bases. It does not include virtuals merely
2550 inherited from secondary bases. */
2552 {
2557 {
2558 /* We don't need to adjust the `this' pointer when
2559 calling this function. */
2563 /* This is a function not already in our vtable. Keep it. */
2565 }
2566 else
2567 /* We've already got an entry for this function. Skip it. */
2569 }
2572 }
2574 /* Get the base virtual function declarations in T that have the
2575 indicated NAME. */
2577 static tree
2579 {
2580 tree methods;
2585 /* Find virtual functions in T with the indicated NAME. */
2589 methods;
2591 {
2597 }
2603 {
2606 base_fndecls);
2607 }
2610 }
2612 /* If this declaration supersedes the declaration of
2613 a method declared virtual in the base class, then
2614 mark this field as being virtual as well. */
2616 void
2618 {
2621 /* In [temp.mem] we have:
2623 A specialization of a member function template does not
2624 override a virtual function from a base class. */
2631 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2632 the error_mark_node so that we know it is an overriding
2633 function. */
2634 {
2637 }
2640 {
2646 }
2651 }
2653 /* Warn about hidden virtual functions that are not overridden in t.
2654 We know that constructors and destructors don't apply. */
2656 static void
2658 {
2660 tree fns;
2663 /* We go through each separately named virtual function. */
2667 {
2668 tree fn;
2669 tree name;
2670 tree fndecl;
2671 tree base_fndecls;
2672 tree base_binfo;
2673 tree binfo;
2676 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2677 have the same name. Figure out what name that is. */
2679 /* There are no possibly hidden functions yet. */
2681 /* Iterate through all of the base classes looking for possibly
2682 hidden functions. */
2685 {
2688 base_fndecls);
2689 }
2691 /* If there are no functions to hide, continue. */
2695 /* Remove any overridden functions. */
2697 {
2700 {
2704 /* If the method from the base class has the same
2705 signature as the method from the derived class, it
2706 has been overridden. */
2709 else
2711 }
2712 }
2714 /* Now give a warning for all base functions without overriders,
2715 as they are hidden. */
2717 {
2718 /* Here we know it is a hider, and no overrider exists. */
2722 }
2723 }
2724 }
2726 /* Check for things that are invalid. There are probably plenty of other
2727 things we should check for also. */
2729 static void
2731 {
2732 tree field;
2735 {
2743 {
2747 {
2748 /* We're generally only interested in entities the user
2749 declared, but we also find nested classes by noticing
2750 the TYPE_DECL that we create implicitly. You're
2751 allowed to put one anonymous union inside another,
2752 though, so we explicitly tolerate that. We use
2753 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2754 we also allow unnamed types used for defining fields. */
2761 {
2765 else
2769 }
2772 {
2775 else
2777 }
2779 {
2782 else
2784 }
2788 }
2789 }
2790 }
2791 }
2793 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2794 will be used later during class template instantiation.
2795 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2796 a non-static member data (FIELD_DECL), a member function
2797 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2798 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2799 When FRIEND_P is nonzero, T is either a friend class
2800 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2801 (FUNCTION_DECL, TEMPLATE_DECL). */
2803 void
2805 {
2806 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2811 }
2813 /* This function is called from declare_virt_assop_and_dtor via
2814 dfs_walk_all.
2816 DATA is a type that direcly or indirectly inherits the base
2817 represented by BINFO. If BINFO contains a virtual assignment [copy
2818 assignment or move assigment] operator or a virtual constructor,
2819 declare that function in DATA if it hasn't been already declared. */
2821 static tree
2823 {
2831 /* A base without a vtable needs no modification, and its bases
2832 are uninteresting. */
2836 /* If this is a primary base, then we have already looked at the
2837 virtual functions of its vtable. */
2841 {
2845 {
2850 }
2854 }
2857 }
2859 /* If the class type T has a direct or indirect base that contains a
2860 virtual assignment operator or a virtual destructor, declare that
2861 function in T if it hasn't been already declared. */
2863 static void
2865 {
2873 dfs_declare_virt_assop_and_dtor,
2875 }
2877 /* Declare the inheriting constructor for class T inherited from base
2878 constructor CTOR with the parameter array PARMS of size NPARMS. */
2880 static void
2882 {
2883 /* We don't declare an inheriting ctor that would be a default,
2884 copy or move ctor for derived or base. */
2889 {
2893 }
2901 {
2904 }
2905 }
2907 /* Declare all the inheriting constructors for class T inherited from base
2908 constructor CTOR. */
2910 static void
2912 {
2918 {
2922 }
2925 {
2929 }
2930 }
2932 /* Create default constructors, assignment operators, and so forth for
2933 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2934 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2935 the class cannot have a default constructor, copy constructor
2936 taking a const reference argument, or an assignment operator taking
2937 a const reference, respectively. */
2939 static void
2943 {
2951 /* Destructor. */
2953 {
2954 /* In general, we create destructors lazily. */
2959 /* But if this is a Java class, any non-trivial destructor is
2960 invalid, even if compiler-generated. Therefore, if the
2961 destructor is non-trivial we create it now. */
2963 }
2965 /* [class.ctor]
2967 If there is no user-declared constructor for a class, a default
2968 constructor is implicitly declared. */
2970 {
2975 /* This might force the declaration. */
2977 }
2979 /* [class.ctor]
2981 If a class definition does not explicitly declare a copy
2982 constructor, one is declared implicitly. */
2984 {
2990 }
2992 /* If there is no assignment operator, one will be created if and
2993 when it is needed. For now, just record whether or not the type
2994 of the parameter to the assignment operator will be a const or
2995 non-const reference. */
2997 {
3003 }
3005 /* We can't be lazy about declaring functions that might override
3006 a virtual function from a base class. */
3010 {
3014 {
3015 /* declare, then remove the decl */
3017 ctor_identifier);
3025 }
3026 else
3028 }
3029 }
3031 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3032 count the number of fields in TYPE, including anonymous union
3033 members. */
3035 static int
3037 {
3038 tree x;
3041 {
3044 else
3046 }
3048 }
3050 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3051 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3052 elts, starting at offset IDX. */
3054 static int
3056 {
3057 tree x;
3059 {
3062 else
3064 }
3066 }
3068 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3069 starting at offset IDX. */
3071 static int
3075 {
3076 tree values;
3080 }
3082 /* FIELD is a bit-field. We are finishing the processing for its
3083 enclosing type. Issue any appropriate messages and set appropriate
3084 flags. Returns false if an error has been diagnosed. */
3086 static bool
3088 {
3090 tree w;
3092 /* Extract the declared width of the bitfield, which has been
3093 temporarily stashed in DECL_INITIAL. */
3096 /* Remove the bit-field width indicator so that the rest of the
3097 compiler does not treat that value as an initializer. */
3100 /* Detect invalid bit-field type. */
3102 {
3105 }
3106 else
3107 {
3109 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3112 /* detect invalid field size. */
3118 {
3121 }
3123 {
3126 }
3128 {
3131 }
3140 }
3143 {
3147 }
3148 else
3149 {
3150 /* Non-bit-fields are aligned for their type. */
3154 }
3155 }
3157 /* FIELD is a non bit-field. We are finishing the processing for its
3158 enclosing type T. Issue any appropriate messages and set appropriate
3159 flags. */
3161 static void
3163 tree t,
3167 {
3170 /* In C++98 an anonymous union cannot contain any fields which would change
3171 the settings of CANT_HAVE_CONST_CTOR and friends. */
3173 ;
3174 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3175 structs. So, we recurse through their fields here. */
3177 {
3178 tree fields;
3184 }
3185 /* Check members with class type for constructors, destructors,
3186 etc. */
3188 {
3189 /* Never let anything with uninheritable virtuals
3190 make it through without complaint. */
3194 {
3199 field);
3204 field);
3206 {
3210 }
3211 }
3212 else
3213 {
3226 }
3235 }
3240 {
3241 /* `build_class_init_list' does not recognize
3242 non-FIELD_DECLs. */
3246 }
3247 }
3249 /* Check the data members (both static and non-static), class-scoped
3250 typedefs, etc., appearing in the declaration of T. Issue
3251 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3252 declaration order) of access declarations; each TREE_VALUE in this
3253 list is a USING_DECL.
3255 In addition, set the following flags:
3257 EMPTY_P
3258 The class is empty, i.e., contains no non-static data members.
3260 CANT_HAVE_CONST_CTOR_P
3261 This class cannot have an implicitly generated copy constructor
3262 taking a const reference.
3264 CANT_HAVE_CONST_ASN_REF
3265 This class cannot have an implicitly generated assignment
3266 operator taking a const reference.
3268 All of these flags should be initialized before calling this
3269 function.
3271 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3272 fields can be added by adding to this chain. */
3274 static void
3278 {
3286 /* Assume there are no access declarations. */
3288 /* Assume this class has no pointer members. */
3290 /* Assume none of the members of this class have default
3291 initializations. */
3295 {
3303 {
3304 /* Save the access declarations for our caller. */
3307 }
3313 /* If we've gotten this far, it's a data member, possibly static,
3314 or an enumerator. */
3318 /* When this goes into scope, it will be a non-local reference. */
3322 {
3323 /* [class.union]
3325 If a union contains a static data member, or a member of
3326 reference type, the program is ill-formed. */
3328 {
3331 }
3333 {
3338 }
3339 }
3341 /* Perform error checking that did not get done in
3342 grokdeclarator. */
3344 {
3348 }
3350 {
3354 }
3362 /* Now it can only be a FIELD_DECL. */
3367 /* If at least one non-static data member is non-literal, the whole
3368 class becomes non-literal. Note: if the type is incomplete we
3369 will complain later on. */
3373 /* A standard-layout class is a class that:
3374 ...
3375 has the same access control (Clause 11) for all non-static data members,
3376 ... */
3383 /* If this is of reference type, check if it needs an init. */
3385 {
3391 /* ARM $12.6.2: [A member initializer list] (or, for an
3392 aggregate, initialization by a brace-enclosed list) is the
3393 only way to initialize nonstatic const and reference
3394 members. */
3397 }
3402 {
3404 {
3405 warning
3408 x);
3410 }
3414 }
3417 /* We don't treat zero-width bitfields as making a class
3418 non-empty. */
3419 ;
3420 else
3421 {
3422 /* The class is non-empty. */
3424 /* The class is not even nearly empty. */
3426 /* If one of the data members contains an empty class,
3427 so does T. */
3431 }
3433 /* This is used by -Weffc++ (see below). Warn only for pointers
3434 to members which might hold dynamic memory. So do not warn
3435 for pointers to functions or pointers to members. */
3441 {
3446 }
3452 /* DR 148 now allows pointers to members (which are POD themselves),
3453 to be allowed in POD structs. */
3462 /* We set DECL_C_BIT_FIELD in grokbitfield.
3463 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3466 cant_have_const_ctor_p,
3467 no_const_asn_ref_p,
3470 /* Now that we've removed bit-field widths from DECL_INITIAL,
3471 anything left in DECL_INITIAL is an NSDMI that makes the class
3472 non-aggregate. */
3476 /* If any field is const, the structure type is pseudo-const. */
3478 {
3483 /* ARM $12.6.2: [A member initializer list] (or, for an
3484 aggregate, initialization by a brace-enclosed list) is the
3485 only way to initialize nonstatic const and reference
3486 members. */
3489 }
3490 /* A field that is pseudo-const makes the structure likewise. */
3492 {
3497 }
3499 /* Core issue 80: A nonstatic data member is required to have a
3500 different name from the class iff the class has a
3501 user-declared constructor. */
3505 }
3507 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3508 it should also define a copy constructor and an assignment operator to
3509 implement the correct copy semantic (deep vs shallow, etc.). As it is
3510 not feasible to check whether the constructors do allocate dynamic memory
3511 and store it within members, we approximate the warning like this:
3513 -- Warn only if there are members which are pointers
3514 -- Warn only if there is a non-trivial constructor (otherwise,
3515 there cannot be memory allocated).
3516 -- Warn only if there is a non-trivial destructor. We assume that the
3517 user at least implemented the cleanup correctly, and a destructor
3518 is needed to free dynamic memory.
3520 This seems enough for practical purposes. */
3522 && has_pointers
3526 {
3530 {
3535 }
3539 }
3541 /* Non-static data member initializers make the default constructor
3542 non-trivial. */
3544 {
3547 }
3549 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3553 /* Check anonymous struct/anonymous union fields. */
3556 /* We've built up the list of access declarations in reverse order.
3557 Fix that now. */
3559 }
3561 /* If TYPE is an empty class type, records its OFFSET in the table of
3562 OFFSETS. */
3564 static int
3566 {
3567 splay_tree_node n;
3572 /* Record the location of this empty object in OFFSETS. */
3580 type,
3584 }
3586 /* Returns nonzero if TYPE is an empty class type and there is
3587 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3589 static int
3591 {
3592 splay_tree_node n;
3593 tree t;
3598 /* Record the location of this empty object in OFFSETS. */
3608 }
3610 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3611 F for every subobject, passing it the type, offset, and table of
3612 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3613 be traversed.
3615 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3616 than MAX_OFFSET will not be walked.
3618 If F returns a nonzero value, the traversal ceases, and that value
3619 is returned. Otherwise, returns zero. */
3621 static int
3623 subobject_offset_fn f,
3624 tree offset,
3625 splay_tree offsets,
3626 tree max_offset,
3628 {
3632 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3633 stop. */
3641 {
3645 }
3648 {
3649 tree field;
3650 tree binfo;
3653 /* Avoid recursing into objects that are not interesting. */
3657 /* Record the location of TYPE. */
3662 /* Iterate through the direct base classes of TYPE. */
3666 {
3667 tree binfo_offset;
3680 offset,
3682 else
3683 {
3684 tree orig_binfo;
3685 /* We cannot rely on BINFO_OFFSET being set for the base
3686 class yet, but the offsets for direct non-virtual
3687 bases can be calculated by going back to the TYPE. */
3690 offset,
3692 }
3695 f,
3696 binfo_offset,
3697 offsets,
3698 max_offset,
3703 }
3706 {
3710 /* Iterate through the virtual base classes of TYPE. In G++
3711 3.2, we included virtual bases in the direct base class
3712 loop above, which results in incorrect results; the
3713 correct offsets for virtual bases are only known when
3714 working with the most derived type. */
3718 {
3720 f,
3722 offset,
3724 offsets,
3725 max_offset,
3729 }
3730 else
3731 {
3732 /* We still have to walk the primary base, if it is
3733 virtual. (If it is non-virtual, then it was walked
3734 above.) */
3740 {
3741 r = (walk_subobject_offsets
3746 }
3747 }
3748 }
3750 /* Iterate through the fields of TYPE. */
3753 {
3754 tree field_offset;
3758 else
3759 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3763 f,
3765 offset,
3766 field_offset),
3767 offsets,
3768 max_offset,
3772 }
3773 }
3775 {
3778 tree index;
3780 /* Avoid recursing into objects that are not interesting. */
3785 /* Step through each of the elements in the array. */
3787 /* G++ 3.2 had an off-by-one error here. */
3792 {
3794 f,
3795 offset,
3796 offsets,
3797 max_offset,
3803 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3804 there's no point in iterating through the remaining
3805 elements of the array. */
3808 }
3809 }
3812 }
3814 /* Record all of the empty subobjects of TYPE (either a type or a
3815 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3816 is being placed at OFFSET; otherwise, it is a base class that is
3817 being placed at OFFSET. */
3819 static void
3821 tree offset,
3822 splay_tree offsets,
3824 {
3825 tree max_offset;
3826 /* If recording subobjects for a non-static data member or a
3827 non-empty base class , we do not need to record offsets beyond
3828 the size of the biggest empty class. Additional data members
3829 will go at the end of the class. Additional base classes will go
3830 either at offset zero (if empty, in which case they cannot
3831 overlap with offsets past the size of the biggest empty class) or
3832 at the end of the class.
3834 However, if we are placing an empty base class, then we must record
3835 all offsets, as either the empty class is at offset zero (where
3836 other empty classes might later be placed) or at the end of the
3837 class (where other objects might then be placed, so other empty
3838 subobjects might later overlap). */
3842 else
3846 }
3848 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3849 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3850 virtual bases of TYPE are examined. */
3852 static int
3854 tree offset,
3855 splay_tree offsets,
3857 {
3858 splay_tree_node max_node;
3860 /* Get the node in OFFSETS that indicates the maximum offset where
3861 an empty subobject is located. */
3863 /* If there aren't any empty subobjects, then there's no point in
3864 performing this check. */
3870 vbases_p);
3871 }
3873 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3874 non-static data member of the type indicated by RLI. BINFO is the
3875 binfo corresponding to the base subobject, OFFSETS maps offsets to
3876 types already located at those offsets. This function determines
3877 the position of the DECL. */
3879 static void
3881 tree decl,
3882 tree binfo,
3883 splay_tree offsets)
3884 {
3887 tree type;
3890 {
3891 /* For the purposes of determining layout conflicts, we want to
3892 use the class type of BINFO; TREE_TYPE (DECL) will be the
3893 CLASSTYPE_AS_BASE version, which does not contain entries for
3894 zero-sized bases. */
3897 }
3898 else
3899 {
3902 }
3904 /* Try to place the field. It may take more than one try if we have
3905 a hard time placing the field without putting two objects of the
3906 same type at the same address. */
3908 {
3911 /* Place this field. */
3915 /* We have to check to see whether or not there is already
3916 something of the same type at the offset we're about to use.
3917 For example, consider:
3919 struct S {};
3920 struct T : public S { int i; };
3921 struct U : public S, public T {};
3923 Here, we put S at offset zero in U. Then, we can't put T at
3924 offset zero -- its S component would be at the same address
3925 as the S we already allocated. So, we have to skip ahead.
3926 Since all data members, including those whose type is an
3927 empty class, have nonzero size, any overlap can happen only
3928 with a direct or indirect base-class -- it can't happen with
3929 a data member. */
3930 /* In a union, overlap is permitted; all members are placed at
3931 offset zero. */
3934 /* G++ 3.2 did not check for overlaps when placing a non-empty
3935 virtual base. */
3940 {
3941 /* Strip off the size allocated to this field. That puts us
3942 at the first place we could have put the field with
3943 proper alignment. */
3946 /* Bump up by the alignment required for the type. */
3947 rli->bitpos
3953 }
3954 else
3955 /* There was no conflict. We're done laying out this field. */
3957 }
3959 /* Now that we know where it will be placed, update its
3960 BINFO_OFFSET. */
3962 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3963 this point because their BINFO_OFFSET is copied from another
3964 hierarchy. Therefore, we may not need to add the entire
3965 OFFSET. */
3971 }
3973 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3975 static int
3977 tree offset,
3979 {
3981 }
3983 /* Layout the empty base BINFO. EOC indicates the byte currently just
3984 past the end of the class, and should be correctly aligned for a
3985 class of the type indicated by BINFO; OFFSETS gives the offsets of
3986 the empty bases allocated so far. T is the most derived
3987 type. Return nonzero iff we added it at the end. */
3989 static bool
3992 {
3993 tree alignment;
3997 /* This routine should only be used for empty classes. */
4002 {
4004 propagate_binfo_offsets
4007 else
4009 "offset of empty base %qT may not be ABI-compliant and may"
4012 }
4014 /* This is an empty base class. We first try to put it at offset
4015 zero. */
4018 offsets,
4020 {
4021 /* That didn't work. Now, we move forward from the next
4022 available spot in the class. */
4026 {
4029 offsets,
4031 /* We finally found a spot where there's no overlap. */
4034 /* There's overlap here, too. Bump along to the next spot. */
4036 }
4037 }
4040 {
4045 }
4048 }
4050 /* Layout the base given by BINFO in the class indicated by RLI.
4051 *BASE_ALIGN is a running maximum of the alignments of
4052 any base class. OFFSETS gives the location of empty base
4053 subobjects. T is the most derived type. Return nonzero if the new
4054 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4055 *NEXT_FIELD, unless BINFO is for an empty base class.
4057 Returns the location at which the next field should be inserted. */
4062 {
4067 /* This error is now reported in xref_tag, thus giving better
4068 location information. */
4071 /* Place the base class. */
4073 {
4074 tree decl;
4076 /* The containing class is non-empty because it has a non-empty
4077 base class. */
4080 /* Create the FIELD_DECL. */
4087 {
4095 /* Try to place the field. It may take more than one try if we
4096 have a hard time placing the field without putting two
4097 objects of the same type at the same address. */
4099 /* Add the new FIELD_DECL to the list of fields for T. */
4103 }
4104 }
4105 else
4106 {
4107 tree eoc;
4110 /* On some platforms (ARM), even empty classes will not be
4111 byte-aligned. */
4116 /* A nearly-empty class "has no proper base class that is empty,
4117 not morally virtual, and at an offset other than zero." */
4119 {
4122 /* The check above (used in G++ 3.2) is insufficient because
4123 an empty class placed at offset zero might itself have an
4124 empty base at a nonzero offset. */
4126 empty_base_at_nonzero_offset_p,
4127 size_zero_node,
4131 {
4134 else
4136 "class %qT will be considered nearly empty in a "
4138 }
4139 }
4141 /* We do not create a FIELD_DECL for empty base classes because
4142 it might overlap some other field. We want to be able to
4143 create CONSTRUCTORs for the class by iterating over the
4144 FIELD_DECLs, and the back end does not handle overlapping
4145 FIELD_DECLs. */
4147 /* An empty virtual base causes a class to be non-empty
4148 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4149 here because that was already done when the virtual table
4150 pointer was created. */
4151 }
4153 /* Record the offsets of BINFO and its base subobjects. */
4156 offsets,
4160 }
4162 /* Layout all of the non-virtual base classes. Record empty
4163 subobjects in OFFSETS. T is the most derived type. Return nonzero
4164 if the type cannot be nearly empty. The fields created
4165 corresponding to the base classes will be inserted at
4166 *NEXT_FIELD. */
4168 static void
4171 {
4172 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4173 subobjects. */
4178 /* The primary base class is always allocated first. */
4183 /* Now allocate the rest of the bases. */
4185 {
4186 tree base_binfo;
4190 /* The primary base was already allocated above, so we don't
4191 need to allocate it again here. */
4195 /* Virtual bases are added at the end (a primary virtual base
4196 will have already been added). */
4202 }
4203 }
4205 /* Go through the TYPE_METHODS of T issuing any appropriate
4206 diagnostics, figuring out which methods override which other
4207 methods, and so forth. */
4209 static void
4211 {
4212 tree x;
4215 {
4219 /* The name of the field is the original field name
4220 Save this in auxiliary field for later overloading. */
4222 {
4226 }
4227 /* All user-provided destructors are non-trivial.
4228 Constructors and assignment ops are handled in
4229 grok_special_member_properties. */
4232 }
4233 }
4235 /* FN is a constructor or destructor. Clone the declaration to create
4236 a specialized in-charge or not-in-charge version, as indicated by
4237 NAME. */
4239 static tree
4241 {
4242 tree parms;
4243 tree clone;
4245 /* Copy the function. */
4247 /* Reset the function name. */
4250 /* Remember where this function came from. */
4252 /* Make it easy to find the CLONE given the FN. */
4256 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4258 {
4265 }
4268 /* There's no pending inline data for this function. */
4272 /* The base-class destructor is not virtual. */
4274 {
4278 }
4280 /* If there was an in-charge parameter, drop it from the function
4281 type. */
4283 {
4284 tree basetype;
4285 tree parmtypes;
4286 tree exceptions;
4291 /* Skip the `this' parameter. */
4293 /* Skip the in-charge parameter. */
4295 /* And the VTT parm, in a complete [cd]tor. */
4299 /* If this is subobject constructor or destructor, add the vtt
4300 parameter. */
4304 parmtypes);
4307 exceptions);
4311 }
4313 /* Copy the function parameters. */
4315 /* Remove the in-charge parameter. */
4317 {
4321 }
4322 /* And the VTT parm, in a complete [cd]tor. */
4324 {
4327 else
4328 {
4332 }
4333 }
4336 {
4339 }
4341 /* Create the RTL for this function. */
4349 }
4351 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4352 not invoke this function directly.
4354 For a non-thunk function, returns the address of the slot for storing
4355 the function it is a clone of. Otherwise returns NULL_TREE.
4357 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4358 cloned_function is unset. This is to support the separate
4359 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4360 on a template makes sense, but not the former. */
4362 tree *
4364 {
4372 {
4373 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4376 else
4377 #endif
4379 }
4384 else
4386 }
4388 /* Produce declarations for all appropriate clones of FN. If
4389 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4390 CLASTYPE_METHOD_VEC as well. */
4392 void
4394 {
4395 tree clone;
4397 /* Avoid inappropriate cloning. */
4403 {
4404 /* For each constructor, we need two variants: an in-charge version
4405 and a not-in-charge version. */
4412 }
4413 else
4414 {
4417 /* For each destructor, we need three variants: an in-charge
4418 version, a not-in-charge version, and an in-charge deleting
4419 version. We clone the deleting version first because that
4420 means it will go second on the TYPE_METHODS list -- and that
4421 corresponds to the correct layout order in the virtual
4422 function table.
4424 For a non-virtual destructor, we do not build a deleting
4425 destructor. */
4427 {
4431 }
4438 }
4440 /* Note that this is an abstract function that is never emitted. */
4442 }
4444 /* DECL is an in charge constructor, which is being defined. This will
4445 have had an in class declaration, from whence clones were
4446 declared. An out-of-class definition can specify additional default
4447 arguments. As it is the clones that are involved in overload
4448 resolution, we must propagate the information from the DECL to its
4449 clones. */
4451 void
4453 {
4454 tree clone;
4458 {
4465 /* Skip the 'this' parameter. */
4481 {
4486 {
4487 /* A default parameter has been added. Adjust the
4488 clone's parameters. */
4492 tree type;
4497 {
4500 clone_parms);
4502 }
4505 clone_parms);
4514 }
4515 }
4517 }
4518 }
4520 /* For each of the constructors and destructors in T, create an
4521 in-charge and not-in-charge variant. */
4523 static void
4525 {
4526 tree fns;
4528 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4529 out now. */
4537 }
4539 /* Deduce noexcept for a destructor DTOR. */
4541 void
4543 {
4545 {
4552 }
4553 }
4555 /* For each destructor in T, deduce noexcept:
4557 12.4/3: A declaration of a destructor that does not have an
4558 exception-specification is implicitly considered to have the
4559 same exception-specification as an implicit declaration (15.4). */
4561 static void
4563 {
4564 tree fns;
4566 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4567 out now. */
4573 }
4575 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4576 of TYPE for virtual functions which FNDECL overrides. Return a
4577 mask of the tm attributes found therein. */
4579 static int
4581 {
4583 tree base_binfo;
4587 {
4597 else
4599 }
4602 }
4604 /* Subroutine of set_method_tm_attributes. Handle the checks and
4605 inheritance for one virtual method FNDECL. */
4607 static void
4609 {
4610 tree tm_attr;
4615 /* If FNDECL doesn't actually override anything (i.e. T is the
4616 class that first declares FNDECL virtual), then we're done. */
4623 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4624 tm_pure must match exactly, otherwise no weakening of
4625 tm_safe > tm_callable > nothing. */
4626 /* ??? The tm_pure attribute didn't make the transition to the
4627 multivendor language spec. */
4629 {
4631 {
4634 }
4635 }
4636 /* If the overridden function is tm_pure, then FNDECL must be. */
4639 /* Look for base class combinations that cannot be satisfied. */
4641 {
4647 }
4648 /* If FNDECL did not declare an attribute, then inherit the most
4649 restrictive one. */
4651 {
4653 }
4654 /* Otherwise validate that we're not weaker than a function
4655 that is being overridden. */
4656 else
4657 {
4661 }
4664 err_override:
4668 }
4670 /* For each of the methods in T, propagate a class-level tm attribute. */
4672 static void
4674 {
4677 /* Don't bother collecting tm attributes if transactional memory
4678 support is not enabled. */
4682 /* Process virtual methods first, as they inherit directly from the
4683 base virtual function and also require validation of new attributes. */
4685 {
4686 tree vchain;
4689 {
4694 }
4695 }
4697 /* If the class doesn't have an attribute, nothing more to do. */
4702 /* Any method that does not yet have a tm attribute inherits
4703 the one from the class. */
4705 {
4708 }
4709 }
4711 /* Returns true iff class T has a user-defined constructor other than
4712 the default constructor. */
4714 bool
4716 {
4717 tree fns;
4723 {
4730 }
4733 }
4735 /* Returns the defaulted constructor if T has one. Otherwise, returns
4736 NULL_TREE. */
4738 tree
4740 {
4747 {
4751 {
4757 }
4758 }
4761 }
4763 /* Returns true iff FN is a user-provided function, i.e. user-declared
4764 and not defaulted at its first declaration; or explicit, private,
4765 protected, or non-const. */
4767 bool
4769 {
4772 else
4775 }
4777 /* Returns true iff class T has a user-provided constructor. */
4779 bool
4781 {
4782 tree fns;
4790 /* This can happen in error cases; avoid crashing. */
4799 }
4801 /* Returns true iff class T has a user-provided default constructor. */
4803 bool
4805 {
4806 tree fns;
4812 {
4818 }
4821 }
4823 /* If default-initialization leaves part of TYPE uninitialized, returns
4824 a DECL for the field or TYPE itself (DR 253). */
4826 tree
4828 {
4839 {
4843 }
4848 {
4852 }
4855 }
4857 /* Returns true iff for class T, a trivial synthesized default constructor
4858 would be constexpr. */
4860 bool
4862 {
4863 /* A defaulted trivial default constructor is constexpr
4864 if there is nothing to initialize. */
4867 }
4869 /* Returns true iff class T has a constexpr default constructor. */
4871 bool
4873 {
4874 tree fns;
4877 {
4878 /* The caller should have stripped an enclosing array. */
4881 }
4883 {
4886 /* Non-trivial, we need to check subobject constructors. */
4888 }
4891 }
4893 /* Returns true iff class TYPE has a virtual destructor. */
4895 bool
4897 {
4898 tree dtor;
4906 }
4908 /* Returns true iff class T has a move constructor. */
4910 bool
4912 {
4913 tree fns;
4916 {
4919 }
4929 }
4931 /* Returns true iff class T has a move assignment operator. */
4933 bool
4935 {
4936 tree fns;
4939 {
4942 }
4950 }
4952 /* Returns true iff class T has a move constructor that was explicitly
4953 declared in the class body. Note that this is different from
4954 "user-provided", which doesn't include functions that are defaulted in
4955 the class. */
4957 bool
4959 {
4960 tree fns;
4969 {
4973 }
4976 }
4978 /* Returns true iff class T has a move assignment operator that was
4979 explicitly declared in the class body. */
4981 bool
4983 {
4984 tree fns;
4991 {
4995 }
4998 }
5000 /* Nonzero if we need to build up a constructor call when initializing an
5001 object of this class, either because it has a user-provided constructor
5002 or because it doesn't have a default constructor (so we need to give an
5003 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5004 what you care about is whether or not an object can be produced by a
5005 constructor (e.g. so we don't set TREE_READONLY on const variables of
5006 such type); use this function when what you care about is whether or not
5007 to try to call a constructor to create an object. The latter case is
5008 the former plus some cases of constructors that cannot be called. */
5010 bool
5012 {
5013 tree inner;
5019 }
5021 /* Remove all zero-width bit-fields from T. */
5023 static void
5025 {
5030 {
5033 /* We should not be confused by the fact that grokbitfield
5034 temporarily sets the width of the bit field into
5035 DECL_INITIAL (*fieldsp).
5036 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5037 to that width. */
5040 else
5042 }
5043 }
5045 /* Returns TRUE iff we need a cookie when dynamically allocating an
5046 array whose elements have the indicated class TYPE. */
5048 static bool
5050 {
5051 tree fns;
5056 /* If there's a non-trivial destructor, we need a cookie. In order
5057 to iterate through the array calling the destructor for each
5058 element, we'll have to know how many elements there are. */
5062 /* If the usual deallocation function is a two-argument whose second
5063 argument is of type `size_t', then we have to pass the size of
5064 the array to the deallocation function, so we will need to store
5065 a cookie. */
5069 /* If there are no `operator []' members, or the lookup is
5070 ambiguous, then we don't need a cookie. */
5073 /* Loop through all of the functions. */
5075 {
5076 tree fn;
5077 tree second_parm;
5079 /* Select the current function. */
5081 /* See if this function is a one-argument delete function. If
5082 it is, then it will be the usual deallocation function. */
5086 /* Do not consider this function if its second argument is an
5087 ellipsis. */
5090 /* Otherwise, if we have a two-argument function and the second
5091 argument is `size_t', it will be the usual deallocation
5092 function -- unless there is one-argument function, too. */
5096 }
5099 }
5101 /* Finish computing the `literal type' property of class type T.
5103 At this point, we have already processed base classes and
5104 non-static data members. We need to check whether the copy
5105 constructor is trivial, the destructor is trivial, and there
5106 is a trivial default constructor or at least one constexpr
5107 constructor other than the copy constructor. */
5109 static void
5111 {
5112 tree fn;
5128 {
5131 {
5135 }
5136 }
5137 }
5139 /* T is a non-literal type used in a context which requires a constant
5140 expression. Explain why it isn't literal. */
5142 void
5144 {
5154 /* Already explained. */
5163 {
5165 "default constructor, and has no constexpr constructor that "
5169 {
5170 /* Note that we can't simply call locate_ctor because when the
5171 constructor is deleted it just returns NULL_TREE. */
5172 tree fns;
5174 {
5181 {
5184 else
5187 }
5188 }
5189 }
5190 }
5191 else
5192 {
5196 {
5199 {
5204 }
5205 }
5207 {
5208 tree ftype;
5213 {
5218 }
5219 }
5220 }
5221 }
5223 /* Check the validity of the bases and members declared in T. Add any
5224 implicitly-generated functions (like copy-constructors and
5225 assignment operators). Compute various flag bits (like
5226 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5227 level: i.e., independently of the ABI in use. */
5229 static void
5231 {
5232 /* Nonzero if the implicitly generated copy constructor should take
5233 a non-const reference argument. */
5235 /* Nonzero if the implicitly generated assignment operator
5236 should take a non-const reference argument. */
5238 tree access_decls;
5241 tree fn;
5243 /* By default, we use const reference arguments and generate default
5244 constructors. */
5248 /* Deduce noexcept on destructors. */
5252 /* Check all the base-classes. */
5256 /* Check all the method declarations. */
5259 /* Save the initial values of these flags which only indicate whether
5260 or not the class has user-provided functions. As we analyze the
5261 bases and members we can set these flags for other reasons. */
5265 /* Check all the data member declarations. We cannot call
5266 check_field_decls until we have called check_bases check_methods,
5267 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5268 being set appropriately. */
5273 /* A nearly-empty class has to be vptr-containing; a nearly empty
5274 class contains just a vptr. */
5278 /* Do some bookkeeping that will guide the generation of implicitly
5279 declared member functions. */
5282 /* We need to call a constructor for this class if it has a
5283 user-provided constructor, or if the default constructor is going
5284 to initialize the vptr. (This is not an if-and-only-if;
5285 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5286 themselves need constructing.) */
5289 /* [dcl.init.aggr]
5291 An aggregate is an array or a class with no user-provided
5292 constructors ... and no virtual functions.
5294 Again, other conditions for being an aggregate are checked
5295 elsewhere. */
5298 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5299 retain the old definition internally for ABI reasons. */
5308 /* If the class has no user-declared constructor, but does have
5309 non-static const or reference data members that can never be
5310 initialized, issue a warning. */
5312 /* Classes with user-declared constructors are presumed to
5313 initialize these members. */
5315 /* Aggregates can be initialized with brace-enclosed
5316 initializers. */
5318 {
5319 tree field;
5322 {
5323 tree type;
5338 }
5339 }
5341 /* Synthesize any needed methods. */
5343 cant_have_const_ctor,
5344 no_const_asn_ref);
5346 /* Check defaulted declarations here so we have cant_have_const_ctor
5347 and don't need to worry about clones. */
5350 {
5353 {
5354 bool imp_const_p
5360 /* If the function is defaulted outside the class, we just
5361 give the synthesis error. */
5364 }
5366 }
5369 {
5370 /* "The closure type associated with a lambda-expression has a deleted
5371 default constructor and a deleted copy assignment operator." */
5377 /* "This class type is not an aggregate." */
5379 }
5381 /* Compute the 'literal type' property before we
5382 do anything with non-static member functions. */
5385 /* Create the in-charge and not-in-charge variants of constructors
5386 and destructors. */
5389 /* Process the using-declarations. */
5393 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5396 /* Figure out whether or not we will need a cookie when dynamically
5397 allocating an array of this type. */
5400 }
5402 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5403 accordingly. If a new vfield was created (because T doesn't have a
5404 primary base class), then the newly created field is returned. It
5405 is not added to the TYPE_FIELDS list; it is the caller's
5406 responsibility to do that. Accumulate declared virtual functions
5407 on VIRTUALS_P. */
5409 static tree
5411 {
5412 tree fn;
5414 /* Collect the virtual functions declared in T. */
5418 {
5427 }
5429 /* If we couldn't find an appropriate base class, create a new field
5430 here. Even if there weren't any new virtual functions, we might need a
5431 new virtual function table if we're supposed to include vptrs in
5432 all classes that need them. */
5434 {
5435 /* We build this decl with vtbl_ptr_type_node, which is a
5436 `vtable_entry_type*'. It might seem more precise to use
5437 `vtable_entry_type (*)[N]' where N is the number of virtual
5438 functions. However, that would require the vtable pointer in
5439 base classes to have a different type than the vtable pointer
5440 in derived classes. We could make that happen, but that
5441 still wouldn't solve all the problems. In particular, the
5442 type-based alias analysis code would decide that assignments
5443 to the base class vtable pointer can't alias assignments to
5444 the derived class vtable pointer, since they have different
5445 types. Thus, in a derived class destructor, where the base
5446 class constructor was inlined, we could generate bad code for
5447 setting up the vtable pointer.
5449 Therefore, we use one type for all vtable pointers. We still
5450 use a type-correct type; it's just doesn't indicate the array
5451 bounds. That's better than using `void*' or some such; it's
5452 cleaner, and it let's the alias analysis code know that these
5453 stores cannot alias stores to void*! */
5454 tree field;
5467 /* This class is non-empty. */
5471 }
5474 }
5476 /* Add OFFSET to all base types of BINFO which is a base in the
5477 hierarchy dominated by T.
5479 OFFSET, which is a type offset, is number of bytes. */
5481 static void
5483 {
5485 tree primary_binfo;
5486 tree base_binfo;
5488 /* Update BINFO's offset. */
5493 offset));
5495 /* Find the primary base class. */
5501 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5502 downwards. */
5504 {
5505 /* Don't do the primary base twice. */
5513 }
5514 }
5516 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5517 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5518 empty subobjects of T. */
5520 static void
5522 {
5523 tree vbase;
5532 {
5533 /* In G++ 3.2, we incorrectly rounded the size before laying out
5534 the virtual bases. */
5536 #ifdef STRUCTURE_SIZE_BOUNDARY
5537 /* Packed structures don't need to have minimum size. */
5540 #endif
5544 }
5546 /* Find the last field. The artificial fields created for virtual
5547 bases will go after the last extant field to date. */
5552 /* Go through the virtual bases, allocating space for each virtual
5553 base that is not already a primary base class. These are
5554 allocated in inheritance graph order. */
5556 {
5561 {
5564 /* This virtual base is not a primary base of any class in the
5565 hierarchy, so we have to add space for it. */
5569 /* If the first virtual base might have been placed at a
5570 lower address, had we started from CLASSTYPE_SIZE, rather
5571 than TYPE_SIZE, issue a warning. There can be both false
5572 positives and false negatives from this warning in rare
5573 cases; to deal with all the possibilities would probably
5574 require performing both layout algorithms and comparing
5575 the results which is not particularly tractable. */
5577 && first_vbase
5578 && (tree_int_cst_lt
5583 bitsize_unit_node),
5586 "offset of virtual base %qT is not ABI-compliant and "
5588 basetype);
5591 }
5592 }
5593 }
5595 /* Returns the offset of the byte just past the end of the base class
5596 BINFO. */
5598 static tree
5600 {
5601 tree size;
5606 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5607 allocate some space for it. It cannot have virtual bases, so
5608 TYPE_SIZE_UNIT is fine. */
5610 else
5614 }
5616 /* Returns the offset of the byte just past the end of the base class
5617 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5618 only non-virtual bases are included. */
5620 static tree
5622 {
5625 tree binfo;
5626 tree base_binfo;
5627 tree offset;
5632 {
5642 }
5644 /* G++ 3.2 did not check indirect virtual bases. */
5648 {
5652 }
5655 }
5657 /* Warn about bases of T that are inaccessible because they are
5658 ambiguous. For example:
5660 struct S {};
5661 struct T : public S {};
5662 struct U : public S, public T {};
5664 Here, `(S*) new U' is not allowed because there are two `S'
5665 subobjects of U. */
5667 static void
5669 {
5672 tree basetype;
5673 tree binfo;
5674 tree base_binfo;
5676 /* If there are no repeated bases, nothing can be ambiguous. */
5680 /* Check direct bases. */
5683 {
5689 }
5691 /* Check for ambiguous virtual bases. */
5695 {
5701 }
5702 }
5704 /* Compare two INTEGER_CSTs K1 and K2. */
5706 static int
5708 {
5710 }
5712 /* Increase the size indicated in RLI to account for empty classes
5713 that are "off the end" of the class. */
5715 static void
5717 {
5718 tree eoc;
5719 tree rli_size;
5721 /* It might be the case that we grew the class to allocate a
5722 zero-sized base class. That won't be reflected in RLI, yet,
5723 because we are willing to overlay multiple bases at the same
5724 offset. However, now we need to make sure that RLI is big enough
5725 to reflect the entire class. */
5731 {
5733 /* In version 1 of the ABI, the size of a class that ends with
5734 a bitfield was not rounded up to a whole multiple of a
5735 byte. Because rli_size_unit_so_far returns only the number
5736 of fully allocated bytes, any extra bits were not included
5737 in the size. */
5739 else
5740 /* The size should have been rounded to a whole byte. */
5743 rli->bitpos
5752 }
5753 }
5755 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5756 BINFO_OFFSETs for all of the base-classes. Position the vtable
5757 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5759 static void
5761 {
5762 tree non_static_data_members;
5763 tree field;
5764 tree vptr;
5765 record_layout_info rli;
5766 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5767 types that appear at that offset. */
5768 splay_tree empty_base_offsets;
5769 /* True if the last field layed out was a bit-field. */
5771 /* The location at which the next field should be inserted. */
5773 /* T, as a base class. */
5774 tree base_t;
5776 /* Keep track of the first non-static data member. */
5779 /* Start laying out the record. */
5782 /* Mark all the primary bases in the hierarchy. */
5785 /* Create a pointer to our virtual function table. */
5788 /* The vptr is always the first thing in the class. */
5790 {
5795 }
5796 else
5799 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5804 /* Layout the non-static data members. */
5806 {
5807 tree type;
5808 tree padding;
5810 /* We still pass things that aren't non-static data members to
5811 the back end, in case it wants to do something with them. */
5813 {
5815 /* If the static data member has incomplete type, keep track
5816 of it so that it can be completed later. (The handling
5817 of pending statics in finish_record_layout is
5818 insufficient; consider:
5820 struct S1;
5821 struct S2 { static S1 s1; };
5823 At this point, finish_record_layout will be called, but
5824 S1 is still incomplete.) */
5826 {
5828 /* The visibility of static data members is determined
5829 at their point of declaration, not their point of
5830 definition. */
5832 }
5834 }
5842 /* If this field is a bit-field whose width is greater than its
5843 type, then there are some special rules for allocating
5844 it. */
5847 {
5849 tree integer_type;
5851 /* We must allocate the bits as if suitably aligned for the
5852 longest integer type that fits in this many bits. type
5853 of the field. Then, we are supposed to use the left over
5854 bits as additional padding. */
5863 /* ITK now indicates a type that is too large for the
5864 field. We have to back up by one to find the largest
5865 type that fits. */
5866 do
5867 {
5872 /* Figure out how much additional padding is required. GCC
5873 3.2 always created a padding field, even if it had zero
5874 width. */
5877 {
5879 /* In a union, the padding field must have the full width
5880 of the bit-field; all fields start at offset zero. */
5882 else
5883 {
5886 "ABI-compliant and may change in a future "
5888 t);
5891 }
5892 }
5893 #ifdef PCC_BITFIELD_TYPE_MATTERS
5894 /* An unnamed bitfield does not normally affect the
5895 alignment of the containing class on a target where
5896 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5897 make any exceptions for unnamed bitfields when the
5898 bitfields are longer than their types. Therefore, we
5899 temporarily give the field a name. */
5901 {
5904 }
5905 #endif
5910 empty_base_offsets);
5913 /* Now that layout has been performed, set the size of the
5914 field to the size of its declared type; the rest of the
5915 field is effectively invisible. */
5917 /* We must also reset the DECL_MODE of the field. */
5922 /* Versions of G++ before G++ 3.4 did not reset the
5923 DECL_MODE. */
5925 "the offset of %qD may not be ABI-compliant and may "
5927 }
5928 else
5930 empty_base_offsets);
5932 /* Remember the location of any empty classes in FIELD. */
5936 empty_base_offsets,
5939 /* If a bit-field does not immediately follow another bit-field,
5940 and yet it starts in the middle of a byte, we have failed to
5941 comply with the ABI. */
5944 /* The TREE_NO_WARNING flag gets set by Objective-C when
5945 laying out an Objective-C class. The ObjC ABI differs
5946 from the C++ ABI, and so we do not want a warning
5947 here. */
5949 && !last_field_was_bitfield
5952 bitsize_unit_node)))
5956 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5957 offset of the field. */
5964 "classes to be placed at different locations in a "
5967 /* The middle end uses the type of expressions to determine the
5968 possible range of expression values. In order to optimize
5969 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5970 must be made aware of the width of "i", via its type.
5972 Because C++ does not have integer types of arbitrary width,
5973 we must (for the purposes of the front end) convert from the
5974 type assigned here to the declared type of the bitfield
5975 whenever a bitfield expression is used as an rvalue.
5976 Similarly, when assigning a value to a bitfield, the value
5977 must be converted to the type given the bitfield here. */
5979 {
5984 {
5991 }
5992 }
5994 /* If we needed additional padding after this field, add it
5995 now. */
5997 {
5998 tree padding_field;
6001 FIELD_DECL,
6002 NULL_TREE,
6003 char_type_node);
6010 NULL_TREE,
6011 empty_base_offsets);
6012 }
6015 }
6018 {
6019 /* Make sure that we are on a byte boundary so that the size of
6020 the class without virtual bases will always be a round number
6021 of bytes. */
6024 }
6026 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6027 padding. */
6031 /* Delete all zero-width bit-fields from the list of fields. Now
6032 that the type is laid out they are no longer important. */
6035 /* Create the version of T used for virtual bases. We do not use
6036 make_class_type for this version; this is an artificial type. For
6037 a POD type, we just reuse T. */
6039 {
6042 /* Set the size and alignment for the new type. In G++ 3.2, all
6043 empty classes were considered to have size zero when used as
6044 base classes. */
6046 {
6051 "layout of classes derived from empty class %qT "
6053 t);
6054 }
6055 else
6056 {
6057 tree eoc;
6059 /* If the ABI version is not at least two, and the last
6060 field was a bit-field, RLI may not be on a byte
6061 boundary. In particular, rli_size_unit_so_far might
6062 indicate the last complete byte, while rli_size_so_far
6063 indicates the total number of bits used. Therefore,
6064 rli_size_so_far, rather than rli_size_unit_so_far, is
6065 used to compute TYPE_SIZE_UNIT. */
6073 eoc);
6080 }
6084 /* Copy the fields from T. */
6088 {
6090 FIELD_DECL,
6100 }
6102 /* Record the base version of the type. */
6105 }
6106 else
6109 /* Every empty class contains an empty class. */
6113 /* Set the TYPE_DECL for this type to contain the right
6114 value for DECL_OFFSET, so that we can use it as part
6115 of a COMPONENT_REF for multiple inheritance. */
6118 /* Now fix up any virtual base class types that we left lying
6119 around. We must get these done before we try to lay out the
6120 virtual function table. As a side-effect, this will remove the
6121 base subobject fields. */
6124 /* Make sure that empty classes are reflected in RLI at this
6125 point. */
6128 /* Make sure not to create any structures with zero size. */
6134 /* If this is a non-POD, declaring it packed makes a difference to how it
6135 can be used as a field; don't let finalize_record_size undo it. */
6139 /* Let the back end lay out the type. */
6142 /* Warn about bases that can't be talked about due to ambiguity. */
6145 /* Now that we're done with layout, give the base fields the real types. */
6150 /* Clean up. */
6157 }
6159 /* Determine the "key method" for the class type indicated by TYPE,
6160 and set CLASSTYPE_KEY_METHOD accordingly. */
6162 void
6164 {
6165 tree method;
6168 || processing_template_decl
6173 /* The key method is the first non-pure virtual function that is not
6174 inline at the point of class definition. On some targets the
6175 key function may not be inline; those targets should not call
6176 this function until the end of the translation unit. */
6182 {
6185 }
6188 }
6191 /* Allocate and return an instance of struct sorted_fields_type with
6192 N fields. */
6196 {
6203 }
6206 /* Perform processing required when the definition of T (a class type)
6207 is complete. */
6209 void
6211 {
6212 tree x;
6213 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6217 {
6222 }
6224 /* If this type was previously laid out as a forward reference,
6225 make sure we lay it out again. */
6229 /* Make assumptions about the class; we'll reset the flags if
6230 necessary. */
6236 /* Do end-of-class semantic processing: checking the validity of the
6237 bases and members and add implicitly generated methods. */
6240 /* Find the key method. */
6242 {
6243 /* The Itanium C++ ABI permits the key method to be chosen when
6244 the class is defined -- even though the key method so
6245 selected may later turn out to be an inline function. On
6246 some systems (such as ARM Symbian OS) the key method cannot
6247 be determined until the end of the translation unit. On such
6248 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6249 will cause the class to be added to KEYED_CLASSES. Then, in
6250 finish_file we will determine the key method. */
6254 /* If a polymorphic class has no key method, we may emit the vtable
6255 in every translation unit where the class definition appears. */
6258 }
6260 /* Layout the class itself. */
6263 /* We use the base type for trivial assignments, and hence it
6264 needs a mode. */
6269 /* If necessary, create the primary vtable for this class. */
6271 {
6272 /* We must enter these virtuals into the table. */
6276 /* Here we know enough to change the type of our virtual
6277 function table, but we will wait until later this function. */
6280 /* If we're warning about ABI tags, check the types of the new
6281 virtual functions. */
6285 }
6288 {
6290 tree fn;
6297 /* Add entries for virtual functions introduced by this class. */
6301 /* Set DECL_VINDEX for all functions declared in this class. */
6303 fn;
6305 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6307 {
6311 /* A thunk. We should never be calling this entry directly
6312 from this vtable -- we'd use the entry for the non
6313 thunk base function. */
6317 }
6318 }
6323 /* Complete the rtl for any static member objects of the type we're
6324 working on. */
6331 /* Done with FIELDS...now decide whether to sort these for
6332 faster lookups later.
6334 We use a small number because most searches fail (succeeding
6335 ultimately as the search bores through the inheritance
6336 hierarchy), and we want this failure to occur quickly. */
6340 /* Complain if one of the field types requires lower visibility. */
6343 /* Make the rtl for any new vtables we have created, and unmark
6344 the base types we marked. */
6347 /* Build the VTT for T. */
6350 /* This warning does not make sense for Java classes, since they
6351 cannot have destructors. */
6353 {
6354 tree dtor;
6358 if it were virtual, we would have created it by now. */
6359 !dtor
6368 "%q#T has virtual functions and accessible"
6370 }
6377 /* Class layout, assignment of virtual table slots, etc., is now
6378 complete. Give the back end a chance to tweak the visibility of
6379 the class or perform any other required target modifications. */
6386 /* Finish debugging output for this type. */
6390 {
6393 {
6396 }
6398 {
6401 else
6402 {
6405 }
6407 }
6409 {
6411 "the type of the first field has a different ABI from the "
6414 }
6415 }
6416 }
6418 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6419 equal to THRESHOLD or greater than THRESHOLD. */
6421 static void
6423 {
6426 {
6431 }
6432 }
6434 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6436 void
6438 {
6441 {
6443 int n_fields
6454 }
6455 }
6457 /* When T was built up, the member declarations were added in reverse
6458 order. Rearrange them to declaration order. */
6460 void
6462 {
6463 tree next;
6464 tree prev;
6465 tree x;
6467 /* The following lists are all in reverse order. Put them in
6468 declaration order now. */
6472 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6473 reverse order, so we can't just use nreverse. */
6478 {
6482 }
6484 {
6488 }
6489 }
6491 tree
6493 {
6496 /* Now that we've got all the field declarations, reverse everything
6497 as necessary. */
6502 /* Nadger the current location so that diagnostics point to the start of
6503 the struct, not the end. */
6507 {
6508 tree x;
6514 /* We need to emit an error message if this type was used as a parameter
6515 and it is an abstract type, even if it is a template. We construct
6516 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6517 account and we call complete_vars with this type, which will check
6518 the PARM_DECLS. Note that while the type is being defined,
6519 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6520 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6526 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6527 an enclosing scope is a template class, so that this function be
6528 found by lookup_fnfields_1 when the using declaration is not
6529 instantiated yet. */
6532 {
6537 }
6539 /* Remember current #pragma pack value. */
6542 /* Fix up any variants we've already built. */
6544 {
6549 }
6550 }
6551 else
6560 else
6564 /* Lambdas are defined by the LAMBDA_EXPR. */
6569 }
6570 \f
6571 /* Hash table to avoid endless recursion when handling references. */
6574 /* Return the dynamic type of INSTANCE, if known.
6575 Used to determine whether the virtual function table is needed
6576 or not.
6578 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6579 of our knowledge of its type. *NONNULL should be initialized
6580 before this function is called. */
6582 static tree
6584 {
6585 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6588 {
6592 else
6596 /* This is a call to a constructor, hence it's never zero. */
6598 {
6602 }
6606 /* This is a call to a constructor, hence it's never zero. */
6608 {
6612 }
6621 /* Propagate nonnull. */
6626 CASE_CONVERT:
6632 {
6633 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6634 with a real object -- given &p->f, p can still be null. */
6636 /* ??? Probably should check DECL_WEAK here. */
6639 }
6643 /* If this component is really a base class reference, then the field
6644 itself isn't definitive. */
6653 {
6657 }
6658 /* fall through... */
6663 {
6667 }
6669 {
6673 /* if we're in a ctor or dtor, we know our type. If
6674 current_class_ptr is set but we aren't in a function, we're in
6675 an NSDMI (and therefore a constructor). */
6680 {
6684 }
6685 }
6687 {
6688 /* We only need one hash table because it is always left empty. */
6692 /* Reference variables should be references to objects. */
6696 /* Enter the INSTANCE in a table to prevent recursion; a
6697 variable's initializer may refer to the variable
6698 itself. */
6703 {
6704 tree type;
6713 }
6714 }
6719 }
6720 #undef RECUR
6721 }
6723 /* Return nonzero if the dynamic type of INSTANCE is known, and
6724 equivalent to the static type. We also handle the case where
6725 INSTANCE is really a pointer. Return negative if this is a
6726 ctor/dtor. There the dynamic type is known, but this might not be
6727 the most derived base of the original object, and hence virtual
6728 bases may not be layed out according to this type.
6730 Used to determine whether the virtual function table is needed
6731 or not.
6733 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6734 of our knowledge of its type. *NONNULL should be initialized
6735 before this function is called. */
6737 int
6739 {
6742 tree fixed;
6744 /* processing_template_decl can be false in a template if we're in
6745 fold_non_dependent_expr, but we still want to suppress this check. */
6747 {
6748 /* In a template we only care about the type of the result. */
6752 }
6762 }
6764 \f
6765 void
6767 {
6770 current_class_stack
6778 }
6780 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6782 static void
6784 {
6785 tree type;
6787 /* We are re-entering the same class we just left, so we don't
6788 have to search the whole inheritance matrix to find all the
6789 decls to bind again. Instead, we install the cached
6790 class_shadowed list and walk through it binding names. */
6793 /* Restore IDENTIFIER_TYPE_VALUE. */
6795 type;
6798 }
6800 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6801 appropriate for TYPE.
6803 So that we may avoid calls to lookup_name, we cache the _TYPE
6804 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6806 For multiple inheritance, we perform a two-pass depth-first search
6807 of the type lattice. */
6809 void
6811 {
6812 class_stack_node_t csn;
6816 /* Make sure there is enough room for the new entry on the stack. */
6818 {
6820 current_class_stack
6822 current_class_stack_size);
6823 }
6825 /* Insert a new entry on the class stack. */
6832 current_class_depth++;
6834 /* Now set up the new type. */
6840 /* By default, things in classes are private, while things in
6841 structures or unions are public. */
6843 ? access_private_node
6849 {
6850 /* Forcibly remove any old class remnants. */
6852 }
6858 else
6860 }
6862 /* When we exit a toplevel class scope, we save its binding level so
6863 that we can restore it quickly. Here, we've entered some other
6864 class, so we must invalidate our cache. */
6866 void
6868 {
6870 }
6872 /* Get out of the current class scope. If we were in a class scope
6873 previously, that is the one popped to. */
6875 void
6877 {
6880 current_class_depth--;
6886 }
6888 /* Mark the top of the class stack as hidden. */
6890 void
6892 {
6895 }
6897 /* Mark the top of the class stack as un-hidden. */
6899 void
6901 {
6904 }
6906 /* Returns 1 if the class type currently being defined is either T or
6907 a nested type of T. */
6909 bool
6911 {
6919 /* We start looking from 1 because entry 0 is from global scope,
6920 and has no type. */
6922 {
6923 tree c;
6926 else
6927 {
6931 }
6936 }
6938 }
6940 /* If either current_class_type or one of its enclosing classes are derived
6941 from T, return the appropriate type. Used to determine how we found
6942 something via unqualified lookup. */
6944 tree
6946 {
6949 /* The bases of a dependent type are unknown. */
6960 {
6965 }
6968 }
6970 /* Returns the innermost class type which is not a lambda closure type. */
6972 tree
6974 {
6977 /* We start looking from 1 because entry 0 is from global scope,
6978 and has no type. */
6980 {
6981 tree c;
6984 else
6985 {
6989 }
6994 }
6996 }
6998 /* When entering a class scope, all enclosing class scopes' names with
6999 static meaning (static variables, static functions, types and
7000 enumerators) have to be visible. This recursive function calls
7001 pushclass for all enclosing class contexts until global or a local
7002 scope is reached. TYPE is the enclosed class. */
7004 void
7006 {
7007 /* A namespace might be passed in error cases, like A::B:C. */
7015 }
7017 /* Undoes a push_nested_class call. */
7019 void
7021 {
7027 }
7029 /* Returns the number of extern "LANG" blocks we are nested within. */
7031 int
7033 {
7035 }
7037 /* Set global variables CURRENT_LANG_NAME to appropriate value
7038 so that behavior of name-mangling machinery is correct. */
7040 void
7042 {
7046 {
7048 }
7050 {
7052 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7053 (See record_builtin_java_type in decl.c.) However, that causes
7054 incorrect debug entries if these types are actually used.
7055 So we re-enable debug output after extern "Java". */
7064 }
7066 {
7068 }
7069 else
7071 }
7073 /* Get out of the current language scope. */
7075 void
7077 {
7079 }
7080 \f
7081 /* Type instantiation routines. */
7083 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7084 matches the TARGET_TYPE. If there is no satisfactory match, return
7085 error_mark_node, and issue an error & warning messages under
7086 control of FLAGS. Permit pointers to member function if FLAGS
7087 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7088 a template-id, and EXPLICIT_TARGS are the explicitly provided
7089 template arguments.
7091 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7092 is the base path used to reference those member functions. If
7093 the address is resolved to a member function, access checks will be
7094 performed and errors issued if appropriate. */
7096 static tree
7098 tree overload,
7099 tsubst_flags_t flags,
7101 tree explicit_targs,
7102 tree access_path)
7103 {
7104 /* Here's what the standard says:
7106 [over.over]
7108 If the name is a function template, template argument deduction
7109 is done, and if the argument deduction succeeds, the deduced
7110 arguments are used to generate a single template function, which
7111 is added to the set of overloaded functions considered.
7113 Non-member functions and static member functions match targets of
7114 type "pointer-to-function" or "reference-to-function." Nonstatic
7115 member functions match targets of type "pointer-to-member
7116 function;" the function type of the pointer to member is used to
7117 select the member function from the set of overloaded member
7118 functions. If a nonstatic member function is selected, the
7119 reference to the overloaded function name is required to have the
7120 form of a pointer to member as described in 5.3.1.
7122 If more than one function is selected, any template functions in
7123 the set are eliminated if the set also contains a non-template
7124 function, and any given template function is eliminated if the
7125 set contains a second template function that is more specialized
7126 than the first according to the partial ordering rules 14.5.5.2.
7127 After such eliminations, if any, there shall remain exactly one
7128 selected function. */
7131 /* We store the matches in a TREE_LIST rooted here. The functions
7132 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7133 interoperability with most_specialized_instantiation. */
7135 tree fn;
7136 tree target_fn_type;
7138 /* By the time we get here, we should be seeing only real
7139 pointer-to-member types, not the internal POINTER_TYPE to
7140 METHOD_TYPE representation. */
7146 /* Check that the TARGET_TYPE is reasonable. */
7150 /* This is OK, too. */
7153 /* This is OK, too. This comes from a conversion to reference
7154 type. */
7156 else
7157 {
7163 }
7165 /* Non-member functions and static member functions match targets of type
7166 "pointer-to-function" or "reference-to-function." Nonstatic member
7167 functions match targets of type "pointer-to-member-function;" the
7168 function type of the pointer to member is used to select the member
7169 function from the set of overloaded member functions.
7171 So figure out the FUNCTION_TYPE that we want to match against. */
7174 /* If we can find a non-template function that matches, we can just
7175 use it. There's no point in generating template instantiations
7176 if we're just going to throw them out anyhow. But, of course, we
7177 can only do this when we don't *need* a template function. */
7179 {
7180 tree fns;
7183 {
7187 /* We're not looking for templates just yet. */
7192 /* We're looking for a non-static member, and this isn't
7193 one, or vice versa. */
7196 /* Ignore functions which haven't been explicitly
7197 declared. */
7201 /* See if there's a match. */
7204 }
7205 }
7207 /* Now, if we've already got a match (or matches), there's no need
7208 to proceed to the template functions. But, if we don't have a
7209 match we need to look at them, too. */
7211 {
7212 tree target_arg_types;
7213 tree target_ret_type;
7214 tree fns;
7217 tree arg;
7231 {
7233 tree instantiation;
7234 tree targs;
7237 /* We're only looking for templates. */
7242 /* We're not looking for a non-static member, and this is
7243 one, or vice versa. */
7246 /* Try to do argument deduction. */
7253 /* Instantiation failed. */
7256 /* See if there's a match. */
7259 }
7261 /* Now, remove all but the most specialized of the matches. */
7263 {
7268 NULL_TREE,
7269 NULL_TREE);
7270 }
7271 }
7273 /* Now we should have exactly one function in MATCHES. */
7275 {
7276 /* There were *no* matches. */
7278 {
7281 target_type);
7284 }
7286 }
7288 {
7289 /* There were too many matches. First check if they're all
7290 the same function. */
7295 /* For multi-versioned functions, more than one match is just fine and
7296 decls_match will return false as they are different. */
7304 {
7306 {
7309 target_type);
7311 /* Since print_candidates expects the functions in the
7312 TREE_VALUE slot, we flip them here. */
7317 }
7320 }
7321 }
7323 /* Good, exactly one match. Now, convert it to the correct type. */
7328 {
7336 {
7339 }
7340 }
7342 /* If a pointer to a function that is multi-versioned is requested, the
7343 pointer to the dispatcher function is returned instead. This works
7344 well because indirectly calling the function will dispatch the right
7345 function version at run-time. */
7347 {
7351 /* Mark all the versions corresponding to the dispatcher as used. */
7354 }
7356 /* If we're doing overload resolution purely for the purpose of
7357 determining conversion sequences, we should not consider the
7358 function used. If this conversion sequence is selected, the
7359 function will be marked as used at this point. */
7361 {
7362 /* Make =delete work with SFINAE. */
7367 }
7369 /* We could not check access to member functions when this
7370 expression was originally created since we did not know at that
7371 time to which function the expression referred. */
7373 {
7376 }
7380 else
7381 {
7382 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7383 will mark the function as addressed, but here we must do it
7384 explicitly. */
7388 }
7389 }
7391 /* This function will instantiate the type of the expression given in
7392 RHS to match the type of LHSTYPE. If errors exist, then return
7393 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7394 we complain on errors. If we are not complaining, never modify rhs,
7395 as overload resolution wants to try many possible instantiations, in
7396 the hope that at least one will work.
7398 For non-recursive calls, LHSTYPE should be a function, pointer to
7399 function, or a pointer to member function. */
7401 tree
7403 {
7410 {
7414 }
7417 {
7423 /* Microsoft allows `A::f' to be resolved to a
7424 pointer-to-member. */
7425 ;
7426 else
7427 {
7432 }
7433 }
7436 {
7439 }
7441 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7442 deduce any type information. */
7444 {
7448 }
7450 /* There only a few kinds of expressions that may have a type
7451 dependent on overload resolution. */
7457 /* This should really only be used when attempting to distinguish
7458 what sort of a pointer to function we have. For now, any
7459 arithmetic operation which is not supported on pointers
7460 is rejected as an error. */
7463 {
7465 {
7471 /* Do not lose object's side effects. */
7475 }
7482 /* This can happen if we are forming a pointer-to-member for a
7483 member template. */
7486 /* Fall through. */
7489 {
7493 return
7497 }
7501 return
7505 access_path);
7508 {
7513 }
7520 }
7522 }
7523 \f
7524 /* Return the name of the virtual function pointer field
7525 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7526 this may have to look back through base types to find the
7527 ultimate field name. (For single inheritance, these could
7528 all be the same name. Who knows for multiple inheritance). */
7530 static tree
7532 {
7539 {
7545 }
7553 }
7555 void
7557 {
7564 {
7569 }
7570 }
7572 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7573 according to [class]:
7574 The class-name is also inserted
7575 into the scope of the class itself. For purposes of access checking,
7576 the inserted class name is treated as if it were a public member name. */
7578 void
7580 {
7583 tree saved_cas;
7598 }
7600 /* Returns 1 if TYPE contains only padding bytes. */
7602 int
7604 {
7611 /* In G++ 3.2, whether or not a class was empty was determined by
7612 looking at its size. */
7615 else
7617 }
7619 /* Returns true if TYPE contains an empty class. */
7621 static bool
7623 {
7627 {
7628 tree field;
7629 tree binfo;
7630 tree base_binfo;
7642 }
7646 }
7648 /* Returns true if TYPE contains no actual data, just various
7649 possible combinations of empty classes and possibly a vptr. */
7651 bool
7653 {
7655 {
7656 tree field;
7657 tree binfo;
7658 tree base_binfo;
7661 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7662 out, but we'd like to be able to check this before then. */
7676 }
7680 }
7682 /* Note that NAME was looked up while the current class was being
7683 defined and that the result of that lookup was DECL. */
7685 void
7687 {
7688 splay_tree names_used;
7690 /* If we're not defining a class, there's nothing to do. */
7696 /* If there's already a binding for this NAME, then we don't have
7697 anything to worry about. */
7710 }
7712 /* Note that NAME was declared (as DECL) in the current class. Check
7713 to see that the declaration is valid. */
7715 void
7717 {
7718 splay_tree names_used;
7719 splay_tree_node n;
7721 /* Look to see if we ever used this name. */
7722 names_used
7726 /* The C language allows members to be declared with a type of the same
7727 name, and the C++ standard says this diagnostic is not required. So
7728 allow it in extern "C" blocks unless predantic is specified.
7729 Allow it in all cases if -ms-extensions is specified. */
7735 {
7736 /* [basic.scope.class]
7738 A name N used in a class S shall refer to the same declaration
7739 in its context and when re-evaluated in the completed scope of
7740 S. */
7744 }
7745 }
7747 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7748 Secondary vtables are merged with primary vtables; this function
7749 will return the VAR_DECL for the primary vtable. */
7751 tree
7753 {
7754 tree decl;
7758 {
7761 }
7765 }
7768 /* Returns the binfo for the primary base of BINFO. If the resulting
7769 BINFO is a virtual base, and it is inherited elsewhere in the
7770 hierarchy, then the returned binfo might not be the primary base of
7771 BINFO in the complete object. Check BINFO_PRIMARY_P or
7772 BINFO_LOST_PRIMARY_P to be sure. */
7774 static tree
7776 {
7777 tree primary_base;
7784 }
7786 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7788 static int
7790 {
7794 }
7796 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7797 INDENT should be zero when called from the top level; it is
7798 incremented recursively. IGO indicates the next expected BINFO in
7799 inheritance graph ordering. */
7801 static tree
7804 tree binfo,
7805 tree igo,
7807 {
7809 tree base_binfo;
7817 {
7820 }
7835 {
7839 TFF_PLAIN_IDENTIFIER),
7841 }
7843 {
7846 }
7851 {
7855 {
7859 TFF_PLAIN_IDENTIFIER));
7860 }
7862 {
7866 TFF_PLAIN_IDENTIFIER));
7867 }
7869 {
7873 TFF_PLAIN_IDENTIFIER));
7874 }
7876 {
7880 TFF_PLAIN_IDENTIFIER));
7881 }
7885 }
7891 }
7893 /* Dump the BINFO hierarchy for T. */
7895 static void
7897 {
7909 }
7911 /* Debug interface to hierarchy dumping. */
7913 void
7915 {
7917 }
7919 static void
7921 {
7926 {
7929 }
7930 }
7932 static void
7934 {
7935 tree value;
7937 HOST_WIDE_INT elt;
7945 TFF_PLAIN_IDENTIFIER));
7952 }
7954 static void
7956 {
7964 {
7971 {
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 }