| blob | 0aecabb380e6cda713abff0d226fb1bf308e73ee |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011,
4 2012
5 Free Software Foundation, Inc.
6 Contributed by Michael Tiemann (tiemann@cygnus.com)
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
25 /* High-level class interface. */
43 /* The number of nested classes being processed. If we are not in the
44 scope of any class, this is zero. */
48 /* In order to deal with nested classes, we keep a stack of classes.
49 The topmost entry is the innermost class, and is the entry at index
50 CURRENT_CLASS_DEPTH */
53 /* The name of the class. */
54 tree name;
56 /* The _TYPE node for the class. */
57 tree type;
59 /* The access specifier pending for new declarations in the scope of
60 this class. */
61 tree access;
63 /* If were defining TYPE, the names used in this class. */
64 splay_tree names_used;
66 /* Nonzero if this class is no longer open, because of a call to
67 push_to_top_level. */
72 {
73 /* The base for which we're building initializers. */
74 tree binfo;
75 /* The type of the most-derived type. */
76 tree derived;
77 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
78 unless ctor_vtbl_p is true. */
79 tree rtti_binfo;
80 /* The negative-index vtable initializers built up so far. These
81 are in order from least negative index to most negative index. */
83 /* The binfo for the virtual base for which we're building
84 vcall offset initializers. */
85 tree vbase;
86 /* The functions in vbase for which we have already provided vcall
87 offsets. */
89 /* The vtable index of the next vcall or vbase offset. */
90 tree index;
91 /* Nonzero if we are building the initializer for the primary
92 vtable. */
94 /* Nonzero if we are building the initializer for a construction
95 vtable. */
97 /* True when adding vcall offset entries to the vtable. False when
98 merely computing the indices. */
102 /* The type of a function passed to walk_subobject_offsets. */
105 /* The stack itself. This is a dynamically resized array. The
106 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
110 /* The size of the largest empty class seen in this translation unit. */
113 /* An array of all local classes present in this translation unit, in
114 declaration order. */
196 tree *);
206 splay_tree_key k2);
215 /* Variables shared between class.c and call.c. */
225 /* Convert to or from a base subobject. EXPR is an expression of type
226 `A' or `A*', an expression of type `B' or `B*' is returned. To
227 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
228 the B base instance within A. To convert base A to derived B, CODE
229 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
230 In this latter case, A must not be a morally virtual base of B.
231 NONNULL is true if EXPR is known to be non-NULL (this is only
232 needed when EXPR is of pointer type). CV qualifiers are preserved
233 from EXPR. */
235 tree
237 tree expr,
238 tree binfo,
240 tsubst_flags_t complain)
241 {
244 tree probe;
245 tree offset;
246 tree target_type;
248 tree ptr_target_type;
258 {
264 }
272 {
273 /* This can happen when adjust_result_of_qualified_name_lookup can't
274 find a unique base binfo in a call to a member function. We
275 couldn't give the diagnostic then since we might have been calling
276 a static member function, so we do it now. */
278 {
282 }
284 }
291 /* Nothing to do. */
295 {
301 }
304 /* This must happen before the call to save_expr. */
306 else
312 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
313 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
314 expression returned matches the input. */
315 target_type = cp_build_qualified_type
319 /* Do we need to look in the vtable for the real offset? */
322 /* Don't bother with the calculations inside sizeof; they'll ICE if the
323 source type is incomplete and the pointer value doesn't matter. In a
324 template (even in fold_non_dependent_expr), we don't have vtables set
325 up properly yet, and the value doesn't matter there either; we're just
326 interested in the result of overload resolution. */
329 {
334 }
336 /* If we're in an NSDMI, we don't have the full constructor context yet
337 that we need for converting to a virtual base, so just build a stub
338 CONVERT_EXPR and expand it later in bot_replace. */
341 {
347 }
349 /* Do we need to check for a null pointer? */
351 {
352 /* If we know the conversion will not actually change the value
353 of EXPR, then we can avoid testing the expression for NULL.
354 We have to avoid generating a COMPONENT_REF for a base class
355 field, because other parts of the compiler know that such
356 expressions are always non-NULL. */
360 }
362 /* Protect against multiple evaluation if necessary. */
366 /* Now that we've saved expr, build the real null test. */
368 {
372 }
374 /* If this is a simple base reference, express it as a COMPONENT_REF. */
376 /* We don't build base fields for empty bases, and they aren't very
377 interesting to the optimizers anyway. */
379 {
386 }
389 {
390 /* Going via virtual base V_BINFO. We need the static offset
391 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
392 V_BINFO. That offset is an entry in D_BINFO's vtable. */
393 tree v_offset;
396 {
397 /* In a base member initializer, we cannot rely on the
398 vtable being set up. We have to indirect via the
399 vtt_parm. */
400 tree t;
406 }
407 else
409 complain),
415 v_offset);
427 /* Negative fixed_type_p means this is a constructor or destructor;
428 virtual base layout is fixed in in-charge [cd]tors, but not in
429 base [cd]tors. */
433 v_offset,
436 else
438 }
446 {
451 }
452 else
458 out:
464 }
466 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
467 Perform a derived-to-base conversion by recursively building up a
468 sequence of COMPONENT_REFs to the appropriate base fields. */
470 static tree
472 {
475 tree field;
478 {
479 tree temp;
483 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
484 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
485 an lvalue in the front end; only _DECLs and _REFs are lvalues
486 in the back end. */
492 }
494 /* Recurse. */
499 /* Is this the base field created by build_base_field? */
503 /* If we're looking for a field in the most-derived class,
504 also check the field offset; we can have two base fields
505 of the same type if one is an indirect virtual base and one
506 is a direct non-virtual base. */
510 {
511 /* We don't use build_class_member_access_expr here, as that
512 has unnecessary checks, and more importantly results in
513 recursive calls to dfs_walk_once. */
521 /* Mark the expression const or volatile, as appropriate.
522 Even though we've dealt with the type above, we still have
523 to mark the expression itself. */
530 }
532 /* Didn't find the base field?!? */
534 }
536 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
537 type is a class type or a pointer to a class type. In the former
538 case, TYPE is also a class type; in the latter it is another
539 pointer type. If CHECK_ACCESS is true, an error message is emitted
540 if TYPE is inaccessible. If OBJECT has pointer type, the value is
541 assumed to be non-NULL. */
543 tree
545 tsubst_flags_t complain)
546 {
547 tree binfo;
548 tree object_type;
551 {
554 }
555 else
564 }
566 /* EXPR is an expression with unqualified class type. BASE is a base
567 binfo of that class type. Returns EXPR, converted to the BASE
568 type. This function assumes that EXPR is the most derived class;
569 therefore virtual bases can be found at their static offsets. */
571 tree
573 {
574 tree expr_type;
578 {
579 /* If this is a non-empty base, use a COMPONENT_REF. */
583 /* We use fold_build2 and fold_convert below to simplify the trees
584 provided to the optimizers. It is not safe to call these functions
585 when processing a template because they do not handle C++-specific
586 trees. */
594 }
597 }
599 \f
600 tree
602 {
608 /* First, convert to the requested type. */
613 /* Second, the requested type may not be the owner of its own vptr.
614 If not, convert to the base class that owns it. We cannot use
615 convert_to_base here, because VCONTEXT may appear more than once
616 in the inheritance hierarchy of TYPE, and thus direct conversion
617 between the types may be ambiguous. Following the path back up
618 one step at a time via primary bases avoids the problem. */
622 {
625 }
628 }
630 /* Given an object INSTANCE, return an expression which yields the
631 vtable element corresponding to INDEX. There are many special
632 cases for INSTANCE which we take care of here, mainly to avoid
633 creating extra tree nodes when we don't have to. */
635 static tree
637 {
638 tree aref;
641 /* Try to figure out what a reference refers to, and
642 access its virtual function table directly. */
650 {
655 }
664 }
666 tree
668 {
672 }
674 /* Given a stable object pointer INSTANCE_PTR, return an expression which
675 yields a function pointer corresponding to vtable element INDEX. */
677 tree
679 {
680 tree aref;
683 tf_warning_or_error),
684 idx);
686 /* When using function descriptors, the address of the
687 vtable entry is treated as a function pointer. */
692 /* Remember this as a method reference, for later devirtualization. */
696 }
698 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
699 for the given TYPE. */
701 static tree
703 {
705 }
707 /* DECL is an entity associated with TYPE, like a virtual table or an
708 implicitly generated constructor. Determine whether or not DECL
709 should have external or internal linkage at the object file
710 level. This routine does not deal with COMDAT linkage and other
711 similar complexities; it simply sets TREE_PUBLIC if it possible for
712 entities in other translation units to contain copies of DECL, in
713 the abstract. */
715 void
717 {
720 }
722 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
723 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
724 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
726 static tree
728 {
729 tree decl;
732 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
733 now to avoid confusion in mangle_decl. */
742 /* At one time the vtable info was grabbed 2 words at a time. This
743 fails on sparc unless you have 8-byte alignment. (tiemann) */
747 /* The vtable has not been defined -- yet. */
751 /* Mark the VAR_DECL node representing the vtable itself as a
752 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
753 is rather important that such things be ignored because any
754 effort to actually generate DWARF for them will run into
755 trouble when/if we encounter code like:
757 #pragma interface
758 struct S { virtual void member (); };
760 because the artificial declaration of the vtable itself (as
761 manufactured by the g++ front end) will say that the vtable is
762 a static member of `S' but only *after* the debug output for
763 the definition of `S' has already been output. This causes
764 grief because the DWARF entry for the definition of the vtable
765 will try to refer back to an earlier *declaration* of the
766 vtable as a static member of `S' and there won't be one. We
767 might be able to arrange to have the "vtable static member"
768 attached to the member list for `S' before the debug info for
769 `S' get written (which would solve the problem) but that would
770 require more intrusive changes to the g++ front end. */
774 }
776 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
777 or even complete. If this does not exist, create it. If COMPLETE is
778 nonzero, then complete the definition of it -- that will render it
779 impossible to actually build the vtable, but is useful to get at those
780 which are known to exist in the runtime. */
782 tree
784 {
785 tree decl;
794 {
797 }
800 }
802 /* Build the primary virtual function table for TYPE. If BINFO is
803 non-NULL, build the vtable starting with the initial approximation
804 that it is the same as the one which is the head of the association
805 list. Returns a nonzero value if a new vtable is actually
806 created. */
808 static int
810 {
811 tree decl;
812 tree virtuals;
817 {
819 /* We have already created a vtable for this base, so there's
820 no need to do it again. */
827 }
828 else
829 {
832 }
835 {
838 }
840 /* Initialize the association list for this type, based
841 on our first approximation. */
846 }
848 /* Give BINFO a new virtual function table which is initialized
849 with a skeleton-copy of its original initialization. The only
850 entry that changes is the `delta' entry, so we can really
851 share a lot of structure.
853 FOR_TYPE is the most derived type which caused this table to
854 be needed.
856 Returns nonzero if we haven't met BINFO before.
858 The order in which vtables are built (by calling this function) for
859 an object must remain the same, otherwise a binary incompatibility
860 can result. */
862 static int
864 {
866 /* We already created a vtable for this base. There's no need to
867 do it again. */
870 /* Remember that we've created a vtable for this BINFO, so that we
871 don't try to do so again. */
874 /* Make fresh virtual list, so we can smash it later. */
877 /* Secondary vtables are laid out as part of the same structure as
878 the primary vtable. */
881 }
883 /* Create a new vtable for BINFO which is the hierarchy dominated by
884 T. Return nonzero if we actually created a new vtable. */
886 static int
888 {
890 /* In this case, it is *type*'s vtable we are modifying. We start
891 with the approximation that its vtable is that of the
892 immediate base class. */
894 else
895 /* This is our very own copy of `basetype' to play with. Later,
896 we will fill in all the virtual functions that override the
897 virtual functions in these base classes which are not defined
898 by the current type. */
900 }
902 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
903 (which is in the hierarchy dominated by T) list FNDECL as its
904 BV_FN. DELTA is the required constant adjustment from the `this'
905 pointer where the vtable entry appears to the `this' required when
906 the function is actually called. */
908 static void
910 tree binfo,
911 tree fndecl,
912 tree delta,
914 {
915 tree v;
921 {
922 /* We need a new vtable for BINFO. */
924 {
925 /* If we really did make a new vtable, we also made a copy
926 of the BINFO_VIRTUALS list. Now, we have to find the
927 corresponding entry in that list. */
932 }
937 }
938 }
940 \f
941 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
942 the USING_DECL naming METHOD. Returns true if the method could be
943 added to the method vec. */
945 bool
947 {
949 tree overload;
955 tree current_fns;
956 tree fns;
969 {
970 /* Make a new method vector. We start with 8 entries. We must
971 allocate at least two (for constructors and destructors), and
972 we're going to end up with an assignment operator at some
973 point as well. */
975 /* Create slots for constructors and destructors. */
979 }
981 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
984 /* Constructors and destructors go in special slots. */
988 {
992 {
998 type);
999 }
1000 }
1001 else
1002 {
1003 tree m;
1006 /* See if we already have an entry with this name. */
1010 {
1013 {
1018 }
1022 {
1025 }
1030 }
1031 }
1034 /* Check to see if we've already got this method. */
1036 {
1038 tree fn_type;
1039 tree method_type;
1040 tree parms1;
1041 tree parms2;
1046 /* [over.load] Member function declarations with the
1047 same name and the same parameter types cannot be
1048 overloaded if any of them is a static member
1049 function declaration.
1051 [namespace.udecl] When a using-declaration brings names
1052 from a base class into a derived class scope, member
1053 functions in the derived class override and/or hide member
1054 functions with the same name and parameter types in a base
1055 class (rather than conflicting). */
1061 /* Compare the quals on the 'this' parm. Don't compare
1062 the whole types, as used functions are treated as
1063 coming from the using class in overload resolution. */
1072 /* For templates, the return type and template parameters
1073 must be identical. */
1090 {
1091 /* For function versions, their parms and types match
1092 but they are not duplicates. Record function versions
1093 as and when they are found. extern "C" functions are
1094 not treated as versions. */
1100 {
1101 /* Mark functions as versions if necessary. Modify the mangled
1102 decl name if necessary. */
1104 {
1108 }
1110 {
1114 }
1117 }
1119 {
1121 {
1128 }
1129 /* Otherwise defer to the other function. */
1131 }
1133 {
1135 /* Defer to the local function. */
1137 }
1138 else
1139 {
1142 }
1144 /* We don't call duplicate_decls here to merge the
1145 declarations because that will confuse things if the
1146 methods have inline definitions. In particular, we
1147 will crash while processing the definitions. */
1149 }
1150 }
1152 /* A class should never have more than one destructor. */
1156 /* Add the new binding. */
1158 {
1161 }
1162 else
1171 {
1174 /* We only expect to add few methods in the COMPLETE_P case, so
1175 just make room for one more method in that case. */
1178 else
1184 else
1186 }
1187 else
1188 /* Replace the current slot. */
1191 }
1193 /* Subroutines of finish_struct. */
1195 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1196 legit, otherwise return 0. */
1198 static int
1200 {
1201 tree elem;
1210 {
1212 {
1216 else
1219 }
1220 else
1221 {
1222 /* They're changing the access to the same thing they changed
1223 it to before. That's OK. */
1224 ;
1225 }
1226 }
1227 else
1228 {
1230 tf_warning_or_error);
1233 }
1235 }
1237 /* Process the USING_DECL, which is a member of T. */
1239 static void
1241 {
1244 tree access
1249 tree old_value;
1254 tf_warning_or_error);
1256 {
1262 else
1264 }
1272 ;
1274 {
1276 /* It's OK to use functions from a base when there are functions with
1278 else
1279 {
1284 }
1285 }
1287 {
1291 }
1293 /* Make type T see field decl FDECL with access ACCESS. */
1296 {
1299 }
1300 else
1302 }
1303 \f
1304 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1305 types with abi tags, add the corresponding identifiers to the VEC in
1306 *DATA and set IDENTIFIER_MARKED. */
1308 struct abi_tag_data
1309 {
1310 tree t;
1311 tree subob;
1312 };
1314 static tree
1316 {
1321 {
1325 {
1329 {
1331 {
1336 }
1337 else
1338 {
1345 }
1346 }
1347 }
1348 }
1350 }
1352 /* Check that class T has all the abi tags that subobject SUBOB has, or
1353 warn if not. */
1355 static void
1357 {
1360 {
1363 {
1367 }
1368 }
1376 {
1379 {
1383 }
1384 }
1385 }
1387 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1388 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1389 properties of the bases. */
1391 static void
1395 {
1399 tree base_binfo;
1400 tree binfo;
1410 {
1419 /* If any base class is non-literal, so is the derived class. */
1423 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1424 here because the case of virtual functions but non-virtual
1425 dtor is handled in finish_struct_1. */
1430 /* If the base class doesn't have copy constructors or
1431 assignment operators that take const references, then the
1432 derived class cannot have such a member automatically
1433 generated. */
1442 /* A virtual base does not effect nearly emptiness. */
1443 ;
1445 {
1447 /* And if there is more than one nearly empty base, then the
1448 derived class is not nearly empty either. */
1450 else
1451 /* Remember we've seen one. */
1453 }
1455 /* If the base class is not empty or nearly empty, then this
1456 class cannot be nearly empty. */
1459 /* A lot of properties from the bases also apply to the derived
1460 class. */
1478 /* A standard-layout class is a class that:
1479 ...
1480 * has no non-standard-layout base classes, */
1483 {
1484 tree basefield;
1485 /* ...has no base classes of the same type as the first non-static
1486 data member... */
1488 && (same_type_ignoring_top_level_qualifiers_p
1491 else
1492 /* ...either has no non-static data members in the most-derived
1493 class and at most one base class with non-static data
1494 members, or has no base classes with non-static data
1495 members */
1499 {
1502 else
1505 }
1506 }
1508 /* Don't bother collecting tm attributes if transactional memory
1509 support is not enabled. */
1511 {
1515 }
1518 }
1520 /* If one of the base classes had TM attributes, and the current class
1521 doesn't define its own, then the current class inherits one. */
1523 {
1526 }
1527 }
1529 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1530 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1531 that have had a nearly-empty virtual primary base stolen by some
1532 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1533 T. */
1535 static void
1537 {
1541 tree base_binfo;
1543 /* Determine the primary bases of our bases. */
1546 {
1549 /* See if we're the non-virtual primary of our inheritance
1550 chain. */
1552 {
1559 /* We are the primary binfo. */
1561 }
1562 /* Determine if we have a virtual primary base, and mark it so.
1563 */
1565 {
1569 /* Someone already claimed this base. */
1571 else
1572 {
1573 tree delta;
1578 /* A virtual binfo might have been copied from within
1579 another hierarchy. As we're about to use it as a
1580 primary base, make sure the offsets match. */
1588 }
1589 }
1590 }
1592 /* First look for a dynamic direct non-virtual base. */
1594 {
1598 {
1601 }
1602 }
1604 /* A "nearly-empty" virtual base class can be the primary base
1605 class, if no non-virtual polymorphic base can be found. Look for
1606 a nearly-empty virtual dynamic base that is not already a primary
1607 base of something in the hierarchy. If there is no such base,
1608 just pick the first nearly-empty virtual base. */
1614 {
1616 {
1617 /* Found one that is not primary. */
1620 }
1622 /* Remember the first candidate. */
1624 }
1626 found:
1627 /* If we've got a primary base, use it. */
1629 {
1634 /* We are stealing a primary base. */
1638 {
1639 tree delta;
1642 /* A virtual binfo might have been copied from within
1643 another hierarchy. As we're about to use it as a primary
1644 base, make sure the offsets match. */
1649 }
1656 }
1657 }
1659 /* Update the variant types of T. */
1661 void
1663 {
1664 tree variants;
1670 variants;
1672 {
1673 /* These fields are in the _TYPE part of the node, not in
1674 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1684 /* Copy whatever these are holding today. */
1688 }
1689 }
1691 /* Early variant fixups: we apply attributes at the beginning of the class
1692 definition, and we need to fix up any variants that have already been
1693 made via elaborated-type-specifier so that check_qualified_type works. */
1695 void
1697 {
1698 tree variants;
1704 variants;
1706 {
1707 /* These are the two fields that check_qualified_type looks at and
1708 are affected by attributes. */
1711 }
1712 }
1713 \f
1714 /* Set memoizing fields and bits of T (and its variants) for later
1715 use. */
1717 static void
1719 {
1720 /* Fix up variants (if any). */
1724 /* For a class w/o baseclasses, 'finish_struct' has set
1725 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1726 Similarly for a class whose base classes do not have vtables.
1727 When neither of these is true, we might have removed abstract
1728 virtuals (by providing a definition), added some (by declaring
1729 new ones), or redeclared ones from a base class. We need to
1730 recalculate what's really an abstract virtual at this point (by
1731 looking in the vtables). */
1734 /* If this type has a copy constructor or a destructor, force its
1735 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1736 nonzero. This will cause it to be passed by invisible reference
1737 and prevent it from being returned in a register. */
1740 {
1741 tree variants;
1744 {
1747 }
1748 }
1749 }
1751 /* Issue warnings about T having private constructors, but no friends,
1752 and so forth.
1754 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1755 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1756 non-private static member functions. */
1758 static void
1760 {
1763 tree fn;
1766 /* If the class has friends, those entities might create and
1767 access instances, so we should not warn. */
1770 /* We will have warned when the template was declared; there's
1771 no need to warn on every instantiation. */
1773 /* There's no reason to even consider warning about this
1774 class. */
1777 /* We only issue one warning, if more than one applies, because
1778 otherwise, on code like:
1780 class A {
1781 // Oops - forgot `public:'
1782 A();
1783 A(const A&);
1784 ~A();
1785 };
1787 we warn several times about essentially the same problem. */
1789 /* Check to see if all (non-constructor, non-destructor) member
1790 functions are private. (Since there are no friends or
1791 non-private statics, we can't ever call any of the private member
1792 functions.) */
1794 /* We're not interested in compiler-generated methods; they don't
1795 provide any way to call private members. */
1797 {
1799 {
1801 /* A non-private static member function is just like a
1802 friend; it can create and invoke private member
1803 functions, and be accessed without a class
1804 instance. */
1808 /* Keep searching for a static member function. */
1809 }
1812 }
1815 {
1816 /* There are no non-private methods, and there's at least one
1817 private member function that isn't a constructor or
1818 destructor. (If all the private members are
1819 constructors/destructors we want to use the code below that
1820 issues error messages specifically referring to
1821 constructors/destructors.) */
1827 {
1830 }
1832 {
1836 }
1837 }
1839 /* Even if some of the member functions are non-private, the class
1840 won't be useful for much if all the constructors or destructors
1841 are private: such an object can never be created or destroyed. */
1844 {
1847 t);
1849 }
1851 /* Warn about classes that have private constructors and no friends. */
1853 /* Implicitly generated constructors are always public. */
1856 {
1859 /* If a non-template class does not define a copy
1860 constructor, one is defined for it, enabling it to avoid
1861 this warning. For a template class, this does not
1862 happen, and so we would normally get a warning on:
1864 template <class T> class C { private: C(); };
1866 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1867 complete non-template or fully instantiated classes have this
1868 flag set. */
1871 else
1873 {
1875 /* Ideally, we wouldn't count copy constructors (or, in
1876 fact, any constructor that takes an argument of the
1877 class type as a parameter) because such things cannot
1878 be used to construct an instance of the class unless
1879 you already have one. But, for now at least, we're
1880 more generous. */
1882 {
1885 }
1886 }
1889 {
1892 t);
1894 }
1895 }
1896 }
1899 gt_pointer_operator new_value;
1903 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1905 static int
1907 {
1920 }
1922 /* This routine compares two fields like method_name_cmp but using the
1923 pointer operator in resort_field_decl_data. */
1925 static int
1927 {
1936 {
1943 }
1945 }
1947 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1949 void
1952 gt_pointer_operator new_value,
1954 {
1958 tree fn;
1960 /* The type conversion ops have to live at the front of the vec, so we
1961 can't sort them. */
1969 {
1973 resort_method_name_cmp);
1974 }
1975 }
1977 /* Warn about duplicate methods in fn_fields.
1979 Sort methods that are not special (i.e., constructors, destructors,
1980 and type conversion operators) so that we can find them faster in
1981 search. */
1983 static void
1985 {
1986 tree fn_fields;
1996 /* Clear DECL_IN_AGGR_P for all functions. */
2001 /* Issue warnings about private constructors and such. If there are
2002 no methods, then some public defaults are generated. */
2005 /* The type conversion ops have to live at the front of the vec, so we
2006 can't sort them. */
2015 }
2017 /* Make BINFO's vtable have N entries, including RTTI entries,
2018 vbase and vcall offsets, etc. Set its type and call the back end
2019 to lay it out. */
2021 static void
2023 {
2024 tree atype;
2025 tree vtable;
2030 /* We may have to grow the vtable. */
2033 {
2037 }
2038 }
2040 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2041 have the same signature. */
2043 int
2045 {
2046 /* One destructor overrides another if they are the same kind of
2047 destructor. */
2051 /* But a non-destructor never overrides a destructor, nor vice
2052 versa, nor do different kinds of destructors override
2053 one-another. For example, a complete object destructor does not
2054 override a deleting destructor. */
2063 {
2071 }
2073 }
2075 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2076 subobject. */
2078 static bool
2080 {
2081 tree probe;
2084 {
2088 /* If we meet a virtual base, we can't follow the inheritance
2089 any more. See if the complete type of DERIVED contains
2090 such a virtual base. */
2093 }
2095 }
2098 /* The function for which we are trying to find a final overrider. */
2099 tree fn;
2100 /* The base class in which the function was declared. */
2101 tree declaring_base;
2102 /* The candidate overriders. */
2103 tree candidates;
2104 /* Path to most derived. */
2108 /* Add the overrider along the current path to FFOD->CANDIDATES.
2109 Returns true if an overrider was found; false otherwise. */
2111 static bool
2115 {
2116 tree method;
2118 /* If BINFO is not the most derived type, try a more derived class.
2119 A definition there will overrider a definition here. */
2121 {
2122 depth--;
2126 }
2130 {
2133 /* Remove any candidates overridden by this new function. */
2135 {
2136 /* If *CANDIDATE overrides METHOD, then METHOD
2137 cannot override anything else on the list. */
2140 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2143 else
2145 }
2147 /* Add the new function. */
2150 }
2153 }
2155 /* Called from find_final_overrider via dfs_walk. */
2157 static tree
2159 {
2167 }
2169 static tree
2171 {
2176 }
2178 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2179 FN and whose TREE_VALUE is the binfo for the base where the
2180 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2181 DERIVED) is the base object in which FN is declared. */
2183 static tree
2185 {
2186 find_final_overrider_data ffod;
2188 /* Getting this right is a little tricky. This is valid:
2190 struct S { virtual void f (); };
2191 struct T { virtual void f (); };
2192 struct U : public S, public T { };
2194 even though calling `f' in `U' is ambiguous. But,
2196 struct R { virtual void f(); };
2197 struct S : virtual public R { virtual void f (); };
2198 struct T : virtual public R { virtual void f (); };
2199 struct U : public S, public T { };
2201 is not -- there's no way to decide whether to put `S::f' or
2202 `T::f' in the vtable for `R'.
2204 The solution is to look at all paths to BINFO. If we find
2205 different overriders along any two, then there is a problem. */
2209 /* Determine the depth of the hierarchy. */
2220 /* If there was no winner, issue an error message. */
2225 }
2227 /* Return the index of the vcall offset for FN when TYPE is used as a
2228 virtual base. */
2230 static tree
2232 {
2234 tree_pair_p p;
2242 /* There should always be an appropriate index. */
2244 }
2246 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2247 dominated by T. FN is the old function; VIRTUALS points to the
2248 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2249 of that entry in the list. */
2251 static void
2254 {
2255 tree b;
2256 tree overrider;
2257 tree delta;
2258 tree virtual_base;
2259 tree first_defn;
2265 /* Find the nearest primary base (possibly binfo itself) which defines
2266 this function; this is the class the caller will convert to when
2267 calling FN through BINFO. */
2269 {
2274 /* The nearest definition is from a lost primary. */
2277 }
2280 /* Find the final overrider. */
2283 {
2286 }
2289 /* Check for adjusting covariant return types. */
2297 /* If the overrider is invalid, don't even try. */
2299 {
2300 /* If FN is a covariant thunk, we must figure out the adjustment
2301 to the final base FN was converting to. As OVERRIDER_TARGET might
2302 also be converting to the return type of FN, we have to
2303 combine the two conversions here. */
2310 {
2314 }
2315 else
2319 /* Find the equivalent binfo within the return type of the
2320 overriding function. We will want the vbase offset from
2321 there. */
2323 over_return);
2326 {
2327 /* There was no existing virtual thunk (which takes
2328 precedence). So find the binfo of the base function's
2329 return type within the overriding function's return type.
2330 We cannot call lookup base here, because we're inside a
2331 dfs_walk, and will therefore clobber the BINFO_MARKED
2332 flags. Fortunately we know the covariancy is valid (it
2333 has already been checked), so we can just iterate along
2334 the binfos, which have been chained in inheritance graph
2335 order. Of course it is lame that we have to repeat the
2336 search here anyway -- we should really be caching pieces
2337 of the vtable and avoiding this repeated work. */
2340 /* Find the base binfo within the overriding function's
2341 return type. We will always find a thunk_binfo, except
2342 when the covariancy is invalid (which we will have
2343 already diagnosed). */
2346 thunk_binfo;
2352 /* See if virtual inheritance is involved. */
2354 virtual_offset;
2361 {
2365 {
2366 /* We convert via virtual base. Adjust the fixed
2367 offset to be from there. */
2368 offset =
2372 }
2374 /* There was an existing fixed offset, this must be
2375 from the base just converted to, and the base the
2376 FN was thunking to. */
2378 else
2380 }
2381 }
2384 /* Replace the overriding function with a covariant thunk. We
2385 will emit the overriding function in its own slot as
2386 well. */
2389 }
2390 else
2394 /* If we need a covariant thunk, then we may need to adjust first_defn.
2395 The ABI specifies that the thunks emitted with a function are
2396 determined by which bases the function overrides, so we need to be
2397 sure that we're using a thunk for some overridden base; even if we
2398 know that the necessary this adjustment is zero, there may not be an
2399 appropriate zero-this-adjusment thunk for us to use since thunks for
2400 overriding virtual bases always use the vcall offset.
2402 Furthermore, just choosing any base that overrides this function isn't
2403 quite right, as this slot won't be used for calls through a type that
2404 puts a covariant thunk here. Calling the function through such a type
2405 will use a different slot, and that slot is the one that determines
2406 the thunk emitted for that base.
2408 So, keep looking until we find the base that we're really overriding
2409 in this slot: the nearest primary base that doesn't use a covariant
2410 thunk in this slot. */
2412 {
2414 /* We already know that the overrider needs a covariant thunk. */
2417 {
2424 }
2426 }
2428 /* Assume that we will produce a thunk that convert all the way to
2429 the final overrider, and not to an intermediate virtual base. */
2432 /* See if we can convert to an intermediate virtual base first, and then
2433 use the vcall offset located there to finish the conversion. */
2435 {
2436 /* If we find the final overrider, then we can stop
2437 walking. */
2442 /* If we find a virtual base, and we haven't yet found the
2443 overrider, then there is a virtual base between the
2444 declaring base (first_defn) and the final overrider. */
2446 {
2449 }
2450 }
2452 /* Compute the constant adjustment to the `this' pointer. The
2453 `this' pointer, when this function is called, will point at BINFO
2454 (or one of its primary bases, which are at the same offset). */
2456 /* The `this' pointer needs to be adjusted from the declaration to
2457 the nearest virtual base. */
2462 /* If the nearest definition is in a lost primary, we don't need an
2463 entry in our vtable. Except possibly in a constructor vtable,
2464 if we happen to get our primary back. In that case, the offset
2465 will be zero, as it will be a primary base. */
2467 else
2468 /* The `this' pointer needs to be adjusted from pointing to
2469 BINFO to pointing at the base where the final overrider
2470 appears. */
2481 else
2485 }
2487 /* Called from modify_all_vtables via dfs_walk. */
2489 static tree
2491 {
2493 tree virtuals;
2494 tree old_virtuals;
2498 /* A base without a vtable needs no modification, and its bases
2499 are uninteresting. */
2504 /* Don't do the primary vtable, if it's new. */
2508 /* There's no need to modify the vtable for a non-virtual primary
2509 base; we're not going to use that vtable anyhow. We do still
2510 need to do this for virtual primary bases, as they could become
2511 non-primary in a construction vtable. */
2516 /* Now, go through each of the virtual functions in the virtual
2517 function table for BINFO. Find the final overrider, and update
2518 the BINFO_VIRTUALS list appropriately. */
2521 virtuals;
2525 binfo,
2530 }
2532 /* Update all of the primary and secondary vtables for T. Create new
2533 vtables as required, and initialize their RTTI information. Each
2534 of the functions in VIRTUALS is declared in T and may override a
2535 virtual function from a base class; find and modify the appropriate
2536 entries to point to the overriding functions. Returns a list, in
2537 declaration order, of the virtual functions that are declared in T,
2538 but do not appear in the primary base class vtable, and which
2539 should therefore be appended to the end of the vtable for T. */
2541 static tree
2543 {
2547 /* Update all of the vtables. */
2550 /* Add virtual functions not already in our primary vtable. These
2551 will be both those introduced by this class, and those overridden
2552 from secondary bases. It does not include virtuals merely
2553 inherited from secondary bases. */
2555 {
2560 {
2561 /* We don't need to adjust the `this' pointer when
2562 calling this function. */
2566 /* This is a function not already in our vtable. Keep it. */
2568 }
2569 else
2570 /* We've already got an entry for this function. Skip it. */
2572 }
2575 }
2577 /* Get the base virtual function declarations in T that have the
2578 indicated NAME. */
2580 static tree
2582 {
2583 tree methods;
2588 /* Find virtual functions in T with the indicated NAME. */
2592 methods;
2594 {
2600 }
2606 {
2609 base_fndecls);
2610 }
2613 }
2615 /* If this declaration supersedes the declaration of
2616 a method declared virtual in the base class, then
2617 mark this field as being virtual as well. */
2619 void
2621 {
2624 /* In [temp.mem] we have:
2626 A specialization of a member function template does not
2627 override a virtual function from a base class. */
2634 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2635 the error_mark_node so that we know it is an overriding
2636 function. */
2637 {
2640 }
2643 {
2649 }
2654 }
2656 /* Warn about hidden virtual functions that are not overridden in t.
2657 We know that constructors and destructors don't apply. */
2659 static void
2661 {
2663 tree fns;
2666 /* We go through each separately named virtual function. */
2670 {
2671 tree fn;
2672 tree name;
2673 tree fndecl;
2674 tree base_fndecls;
2675 tree base_binfo;
2676 tree binfo;
2679 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2680 have the same name. Figure out what name that is. */
2682 /* There are no possibly hidden functions yet. */
2684 /* Iterate through all of the base classes looking for possibly
2685 hidden functions. */
2688 {
2691 base_fndecls);
2692 }
2694 /* If there are no functions to hide, continue. */
2698 /* Remove any overridden functions. */
2700 {
2703 {
2707 /* If the method from the base class has the same
2708 signature as the method from the derived class, it
2709 has been overridden. */
2712 else
2714 }
2715 }
2717 /* Now give a warning for all base functions without overriders,
2718 as they are hidden. */
2720 {
2721 /* Here we know it is a hider, and no overrider exists. */
2725 }
2726 }
2727 }
2729 /* Check for things that are invalid. There are probably plenty of other
2730 things we should check for also. */
2732 static void
2734 {
2735 tree field;
2738 {
2746 {
2750 {
2751 /* We're generally only interested in entities the user
2752 declared, but we also find nested classes by noticing
2753 the TYPE_DECL that we create implicitly. You're
2754 allowed to put one anonymous union inside another,
2755 though, so we explicitly tolerate that. We use
2756 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2757 we also allow unnamed types used for defining fields. */
2764 {
2768 else
2772 }
2775 {
2778 else
2780 }
2782 {
2785 else
2787 }
2791 }
2792 }
2793 }
2794 }
2796 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2797 will be used later during class template instantiation.
2798 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2799 a non-static member data (FIELD_DECL), a member function
2800 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2801 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2802 When FRIEND_P is nonzero, T is either a friend class
2803 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2804 (FUNCTION_DECL, TEMPLATE_DECL). */
2806 void
2808 {
2809 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2814 }
2816 /* This function is called from declare_virt_assop_and_dtor via
2817 dfs_walk_all.
2819 DATA is a type that direcly or indirectly inherits the base
2820 represented by BINFO. If BINFO contains a virtual assignment [copy
2821 assignment or move assigment] operator or a virtual constructor,
2822 declare that function in DATA if it hasn't been already declared. */
2824 static tree
2826 {
2834 /* A base without a vtable needs no modification, and its bases
2835 are uninteresting. */
2839 /* If this is a primary base, then we have already looked at the
2840 virtual functions of its vtable. */
2844 {
2848 {
2853 }
2857 }
2860 }
2862 /* If the class type T has a direct or indirect base that contains a
2863 virtual assignment operator or a virtual destructor, declare that
2864 function in T if it hasn't been already declared. */
2866 static void
2868 {
2876 dfs_declare_virt_assop_and_dtor,
2878 }
2880 /* Declare the inheriting constructor for class T inherited from base
2881 constructor CTOR with the parameter array PARMS of size NPARMS. */
2883 static void
2885 {
2886 /* We don't declare an inheriting ctor that would be a default,
2887 copy or move ctor for derived or base. */
2892 {
2896 }
2904 {
2907 }
2908 }
2910 /* Declare all the inheriting constructors for class T inherited from base
2911 constructor CTOR. */
2913 static void
2915 {
2921 {
2925 }
2928 {
2932 }
2933 }
2935 /* Create default constructors, assignment operators, and so forth for
2936 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2937 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2938 the class cannot have a default constructor, copy constructor
2939 taking a const reference argument, or an assignment operator taking
2940 a const reference, respectively. */
2942 static void
2946 {
2954 /* Destructor. */
2956 {
2957 /* In general, we create destructors lazily. */
2962 /* But if this is a Java class, any non-trivial destructor is
2963 invalid, even if compiler-generated. Therefore, if the
2964 destructor is non-trivial we create it now. */
2966 }
2968 /* [class.ctor]
2970 If there is no user-declared constructor for a class, a default
2971 constructor is implicitly declared. */
2973 {
2978 /* This might force the declaration. */
2980 }
2982 /* [class.ctor]
2984 If a class definition does not explicitly declare a copy
2985 constructor, one is declared implicitly. */
2987 {
2993 }
2995 /* If there is no assignment operator, one will be created if and
2996 when it is needed. For now, just record whether or not the type
2997 of the parameter to the assignment operator will be a const or
2998 non-const reference. */
3000 {
3006 }
3008 /* We can't be lazy about declaring functions that might override
3009 a virtual function from a base class. */
3013 {
3017 {
3018 /* declare, then remove the decl */
3020 ctor_identifier);
3028 }
3029 else
3031 }
3032 }
3034 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3035 count the number of fields in TYPE, including anonymous union
3036 members. */
3038 static int
3040 {
3041 tree x;
3044 {
3047 else
3049 }
3051 }
3053 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3054 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3055 elts, starting at offset IDX. */
3057 static int
3059 {
3060 tree x;
3062 {
3065 else
3067 }
3069 }
3071 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3072 starting at offset IDX. */
3074 static int
3078 {
3079 tree values;
3083 }
3085 /* FIELD is a bit-field. We are finishing the processing for its
3086 enclosing type. Issue any appropriate messages and set appropriate
3087 flags. Returns false if an error has been diagnosed. */
3089 static bool
3091 {
3093 tree w;
3095 /* Extract the declared width of the bitfield, which has been
3096 temporarily stashed in DECL_INITIAL. */
3099 /* Remove the bit-field width indicator so that the rest of the
3100 compiler does not treat that value as an initializer. */
3103 /* Detect invalid bit-field type. */
3105 {
3108 }
3109 else
3110 {
3112 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3115 /* detect invalid field size. */
3121 {
3124 }
3126 {
3129 }
3131 {
3134 }
3143 }
3146 {
3150 }
3151 else
3152 {
3153 /* Non-bit-fields are aligned for their type. */
3157 }
3158 }
3160 /* FIELD is a non bit-field. We are finishing the processing for its
3161 enclosing type T. Issue any appropriate messages and set appropriate
3162 flags. */
3164 static void
3166 tree t,
3170 {
3173 /* In C++98 an anonymous union cannot contain any fields which would change
3174 the settings of CANT_HAVE_CONST_CTOR and friends. */
3176 ;
3177 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3178 structs. So, we recurse through their fields here. */
3180 {
3181 tree fields;
3187 }
3188 /* Check members with class type for constructors, destructors,
3189 etc. */
3191 {
3192 /* Never let anything with uninheritable virtuals
3193 make it through without complaint. */
3197 {
3202 field);
3207 field);
3209 {
3213 }
3214 }
3215 else
3216 {
3229 }
3238 }
3243 {
3244 /* `build_class_init_list' does not recognize
3245 non-FIELD_DECLs. */
3249 }
3250 }
3252 /* Check the data members (both static and non-static), class-scoped
3253 typedefs, etc., appearing in the declaration of T. Issue
3254 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3255 declaration order) of access declarations; each TREE_VALUE in this
3256 list is a USING_DECL.
3258 In addition, set the following flags:
3260 EMPTY_P
3261 The class is empty, i.e., contains no non-static data members.
3263 CANT_HAVE_CONST_CTOR_P
3264 This class cannot have an implicitly generated copy constructor
3265 taking a const reference.
3267 CANT_HAVE_CONST_ASN_REF
3268 This class cannot have an implicitly generated assignment
3269 operator taking a const reference.
3271 All of these flags should be initialized before calling this
3272 function.
3274 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3275 fields can be added by adding to this chain. */
3277 static void
3281 {
3289 /* Assume there are no access declarations. */
3291 /* Assume this class has no pointer members. */
3293 /* Assume none of the members of this class have default
3294 initializations. */
3298 {
3306 {
3307 /* Save the access declarations for our caller. */
3310 }
3316 /* If we've gotten this far, it's a data member, possibly static,
3317 or an enumerator. */
3321 /* When this goes into scope, it will be a non-local reference. */
3325 {
3326 /* [class.union]
3328 If a union contains a static data member, or a member of
3329 reference type, the program is ill-formed. */
3331 {
3334 }
3336 {
3341 }
3342 }
3344 /* Perform error checking that did not get done in
3345 grokdeclarator. */
3347 {
3351 }
3353 {
3357 }
3365 /* Now it can only be a FIELD_DECL. */
3370 /* If at least one non-static data member is non-literal, the whole
3371 class becomes non-literal. Note: if the type is incomplete we
3372 will complain later on. */
3376 /* A standard-layout class is a class that:
3377 ...
3378 has the same access control (Clause 11) for all non-static data members,
3379 ... */
3386 /* If this is of reference type, check if it needs an init. */
3388 {
3394 /* ARM $12.6.2: [A member initializer list] (or, for an
3395 aggregate, initialization by a brace-enclosed list) is the
3396 only way to initialize nonstatic const and reference
3397 members. */
3400 }
3405 {
3407 {
3408 warning
3411 x);
3413 }
3417 }
3420 /* We don't treat zero-width bitfields as making a class
3421 non-empty. */
3422 ;
3423 else
3424 {
3425 /* The class is non-empty. */
3427 /* The class is not even nearly empty. */
3429 /* If one of the data members contains an empty class,
3430 so does T. */
3434 }
3436 /* This is used by -Weffc++ (see below). Warn only for pointers
3437 to members which might hold dynamic memory. So do not warn
3438 for pointers to functions or pointers to members. */
3444 {
3449 }
3455 /* DR 148 now allows pointers to members (which are POD themselves),
3456 to be allowed in POD structs. */
3465 /* We set DECL_C_BIT_FIELD in grokbitfield.
3466 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3469 cant_have_const_ctor_p,
3470 no_const_asn_ref_p,
3473 /* Now that we've removed bit-field widths from DECL_INITIAL,
3474 anything left in DECL_INITIAL is an NSDMI that makes the class
3475 non-aggregate. */
3479 /* If any field is const, the structure type is pseudo-const. */
3481 {
3486 /* ARM $12.6.2: [A member initializer list] (or, for an
3487 aggregate, initialization by a brace-enclosed list) is the
3488 only way to initialize nonstatic const and reference
3489 members. */
3492 }
3493 /* A field that is pseudo-const makes the structure likewise. */
3495 {
3500 }
3502 /* Core issue 80: A nonstatic data member is required to have a
3503 different name from the class iff the class has a
3504 user-declared constructor. */
3508 }
3510 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3511 it should also define a copy constructor and an assignment operator to
3512 implement the correct copy semantic (deep vs shallow, etc.). As it is
3513 not feasible to check whether the constructors do allocate dynamic memory
3514 and store it within members, we approximate the warning like this:
3516 -- Warn only if there are members which are pointers
3517 -- Warn only if there is a non-trivial constructor (otherwise,
3518 there cannot be memory allocated).
3519 -- Warn only if there is a non-trivial destructor. We assume that the
3520 user at least implemented the cleanup correctly, and a destructor
3521 is needed to free dynamic memory.
3523 This seems enough for practical purposes. */
3525 && has_pointers
3529 {
3533 {
3538 }
3542 }
3544 /* Non-static data member initializers make the default constructor
3545 non-trivial. */
3547 {
3550 }
3552 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3556 /* Check anonymous struct/anonymous union fields. */
3559 /* We've built up the list of access declarations in reverse order.
3560 Fix that now. */
3562 }
3564 /* If TYPE is an empty class type, records its OFFSET in the table of
3565 OFFSETS. */
3567 static int
3569 {
3570 splay_tree_node n;
3575 /* Record the location of this empty object in OFFSETS. */
3583 type,
3587 }
3589 /* Returns nonzero if TYPE is an empty class type and there is
3590 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3592 static int
3594 {
3595 splay_tree_node n;
3596 tree t;
3601 /* Record the location of this empty object in OFFSETS. */
3611 }
3613 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3614 F for every subobject, passing it the type, offset, and table of
3615 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3616 be traversed.
3618 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3619 than MAX_OFFSET will not be walked.
3621 If F returns a nonzero value, the traversal ceases, and that value
3622 is returned. Otherwise, returns zero. */
3624 static int
3626 subobject_offset_fn f,
3627 tree offset,
3628 splay_tree offsets,
3629 tree max_offset,
3631 {
3635 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3636 stop. */
3644 {
3648 }
3651 {
3652 tree field;
3653 tree binfo;
3656 /* Avoid recursing into objects that are not interesting. */
3660 /* Record the location of TYPE. */
3665 /* Iterate through the direct base classes of TYPE. */
3669 {
3670 tree binfo_offset;
3683 offset,
3685 else
3686 {
3687 tree orig_binfo;
3688 /* We cannot rely on BINFO_OFFSET being set for the base
3689 class yet, but the offsets for direct non-virtual
3690 bases can be calculated by going back to the TYPE. */
3693 offset,
3695 }
3698 f,
3699 binfo_offset,
3700 offsets,
3701 max_offset,
3706 }
3709 {
3713 /* Iterate through the virtual base classes of TYPE. In G++
3714 3.2, we included virtual bases in the direct base class
3715 loop above, which results in incorrect results; the
3716 correct offsets for virtual bases are only known when
3717 working with the most derived type. */
3721 {
3723 f,
3725 offset,
3727 offsets,
3728 max_offset,
3732 }
3733 else
3734 {
3735 /* We still have to walk the primary base, if it is
3736 virtual. (If it is non-virtual, then it was walked
3737 above.) */
3743 {
3744 r = (walk_subobject_offsets
3749 }
3750 }
3751 }
3753 /* Iterate through the fields of TYPE. */
3756 {
3757 tree field_offset;
3761 else
3762 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3766 f,
3768 offset,
3769 field_offset),
3770 offsets,
3771 max_offset,
3775 }
3776 }
3778 {
3781 tree index;
3783 /* Avoid recursing into objects that are not interesting. */
3788 /* Step through each of the elements in the array. */
3790 /* G++ 3.2 had an off-by-one error here. */
3795 {
3797 f,
3798 offset,
3799 offsets,
3800 max_offset,
3806 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3807 there's no point in iterating through the remaining
3808 elements of the array. */
3811 }
3812 }
3815 }
3817 /* Record all of the empty subobjects of TYPE (either a type or a
3818 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3819 is being placed at OFFSET; otherwise, it is a base class that is
3820 being placed at OFFSET. */
3822 static void
3824 tree offset,
3825 splay_tree offsets,
3827 {
3828 tree max_offset;
3829 /* If recording subobjects for a non-static data member or a
3830 non-empty base class , we do not need to record offsets beyond
3831 the size of the biggest empty class. Additional data members
3832 will go at the end of the class. Additional base classes will go
3833 either at offset zero (if empty, in which case they cannot
3834 overlap with offsets past the size of the biggest empty class) or
3835 at the end of the class.
3837 However, if we are placing an empty base class, then we must record
3838 all offsets, as either the empty class is at offset zero (where
3839 other empty classes might later be placed) or at the end of the
3840 class (where other objects might then be placed, so other empty
3841 subobjects might later overlap). */
3845 else
3849 }
3851 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3852 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3853 virtual bases of TYPE are examined. */
3855 static int
3857 tree offset,
3858 splay_tree offsets,
3860 {
3861 splay_tree_node max_node;
3863 /* Get the node in OFFSETS that indicates the maximum offset where
3864 an empty subobject is located. */
3866 /* If there aren't any empty subobjects, then there's no point in
3867 performing this check. */
3873 vbases_p);
3874 }
3876 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3877 non-static data member of the type indicated by RLI. BINFO is the
3878 binfo corresponding to the base subobject, OFFSETS maps offsets to
3879 types already located at those offsets. This function determines
3880 the position of the DECL. */
3882 static void
3884 tree decl,
3885 tree binfo,
3886 splay_tree offsets)
3887 {
3890 tree type;
3893 {
3894 /* For the purposes of determining layout conflicts, we want to
3895 use the class type of BINFO; TREE_TYPE (DECL) will be the
3896 CLASSTYPE_AS_BASE version, which does not contain entries for
3897 zero-sized bases. */
3900 }
3901 else
3902 {
3905 }
3907 /* Try to place the field. It may take more than one try if we have
3908 a hard time placing the field without putting two objects of the
3909 same type at the same address. */
3911 {
3914 /* Place this field. */
3918 /* We have to check to see whether or not there is already
3919 something of the same type at the offset we're about to use.
3920 For example, consider:
3922 struct S {};
3923 struct T : public S { int i; };
3924 struct U : public S, public T {};
3926 Here, we put S at offset zero in U. Then, we can't put T at
3927 offset zero -- its S component would be at the same address
3928 as the S we already allocated. So, we have to skip ahead.
3929 Since all data members, including those whose type is an
3930 empty class, have nonzero size, any overlap can happen only
3931 with a direct or indirect base-class -- it can't happen with
3932 a data member. */
3933 /* In a union, overlap is permitted; all members are placed at
3934 offset zero. */
3937 /* G++ 3.2 did not check for overlaps when placing a non-empty
3938 virtual base. */
3943 {
3944 /* Strip off the size allocated to this field. That puts us
3945 at the first place we could have put the field with
3946 proper alignment. */
3949 /* Bump up by the alignment required for the type. */
3950 rli->bitpos
3956 }
3957 else
3958 /* There was no conflict. We're done laying out this field. */
3960 }
3962 /* Now that we know where it will be placed, update its
3963 BINFO_OFFSET. */
3965 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3966 this point because their BINFO_OFFSET is copied from another
3967 hierarchy. Therefore, we may not need to add the entire
3968 OFFSET. */
3974 }
3976 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3978 static int
3980 tree offset,
3982 {
3984 }
3986 /* Layout the empty base BINFO. EOC indicates the byte currently just
3987 past the end of the class, and should be correctly aligned for a
3988 class of the type indicated by BINFO; OFFSETS gives the offsets of
3989 the empty bases allocated so far. T is the most derived
3990 type. Return nonzero iff we added it at the end. */
3992 static bool
3995 {
3996 tree alignment;
4000 /* This routine should only be used for empty classes. */
4005 {
4007 propagate_binfo_offsets
4010 else
4012 "offset of empty base %qT may not be ABI-compliant and may"
4015 }
4017 /* This is an empty base class. We first try to put it at offset
4018 zero. */
4021 offsets,
4023 {
4024 /* That didn't work. Now, we move forward from the next
4025 available spot in the class. */
4029 {
4032 offsets,
4034 /* We finally found a spot where there's no overlap. */
4037 /* There's overlap here, too. Bump along to the next spot. */
4039 }
4040 }
4043 {
4048 }
4051 }
4053 /* Layout the base given by BINFO in the class indicated by RLI.
4054 *BASE_ALIGN is a running maximum of the alignments of
4055 any base class. OFFSETS gives the location of empty base
4056 subobjects. T is the most derived type. Return nonzero if the new
4057 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4058 *NEXT_FIELD, unless BINFO is for an empty base class.
4060 Returns the location at which the next field should be inserted. */
4065 {
4070 /* This error is now reported in xref_tag, thus giving better
4071 location information. */
4074 /* Place the base class. */
4076 {
4077 tree decl;
4079 /* The containing class is non-empty because it has a non-empty
4080 base class. */
4083 /* Create the FIELD_DECL. */
4090 {
4098 /* Try to place the field. It may take more than one try if we
4099 have a hard time placing the field without putting two
4100 objects of the same type at the same address. */
4102 /* Add the new FIELD_DECL to the list of fields for T. */
4106 }
4107 }
4108 else
4109 {
4110 tree eoc;
4113 /* On some platforms (ARM), even empty classes will not be
4114 byte-aligned. */
4119 /* A nearly-empty class "has no proper base class that is empty,
4120 not morally virtual, and at an offset other than zero." */
4122 {
4125 /* The check above (used in G++ 3.2) is insufficient because
4126 an empty class placed at offset zero might itself have an
4127 empty base at a nonzero offset. */
4129 empty_base_at_nonzero_offset_p,
4130 size_zero_node,
4134 {
4137 else
4139 "class %qT will be considered nearly empty in a "
4141 }
4142 }
4144 /* We do not create a FIELD_DECL for empty base classes because
4145 it might overlap some other field. We want to be able to
4146 create CONSTRUCTORs for the class by iterating over the
4147 FIELD_DECLs, and the back end does not handle overlapping
4148 FIELD_DECLs. */
4150 /* An empty virtual base causes a class to be non-empty
4151 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4152 here because that was already done when the virtual table
4153 pointer was created. */
4154 }
4156 /* Record the offsets of BINFO and its base subobjects. */
4159 offsets,
4163 }
4165 /* Layout all of the non-virtual base classes. Record empty
4166 subobjects in OFFSETS. T is the most derived type. Return nonzero
4167 if the type cannot be nearly empty. The fields created
4168 corresponding to the base classes will be inserted at
4169 *NEXT_FIELD. */
4171 static void
4174 {
4175 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4176 subobjects. */
4181 /* The primary base class is always allocated first. */
4186 /* Now allocate the rest of the bases. */
4188 {
4189 tree base_binfo;
4193 /* The primary base was already allocated above, so we don't
4194 need to allocate it again here. */
4198 /* Virtual bases are added at the end (a primary virtual base
4199 will have already been added). */
4205 }
4206 }
4208 /* Go through the TYPE_METHODS of T issuing any appropriate
4209 diagnostics, figuring out which methods override which other
4210 methods, and so forth. */
4212 static void
4214 {
4215 tree x;
4218 {
4222 /* The name of the field is the original field name
4223 Save this in auxiliary field for later overloading. */
4225 {
4229 }
4230 /* All user-provided destructors are non-trivial.
4231 Constructors and assignment ops are handled in
4232 grok_special_member_properties. */
4235 }
4236 }
4238 /* FN is a constructor or destructor. Clone the declaration to create
4239 a specialized in-charge or not-in-charge version, as indicated by
4240 NAME. */
4242 static tree
4244 {
4245 tree parms;
4246 tree clone;
4248 /* Copy the function. */
4250 /* Reset the function name. */
4253 /* Remember where this function came from. */
4255 /* Make it easy to find the CLONE given the FN. */
4259 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4261 {
4268 }
4271 /* There's no pending inline data for this function. */
4275 /* The base-class destructor is not virtual. */
4277 {
4281 }
4283 /* If there was an in-charge parameter, drop it from the function
4284 type. */
4286 {
4287 tree basetype;
4288 tree parmtypes;
4289 tree exceptions;
4294 /* Skip the `this' parameter. */
4296 /* Skip the in-charge parameter. */
4298 /* And the VTT parm, in a complete [cd]tor. */
4302 /* If this is subobject constructor or destructor, add the vtt
4303 parameter. */
4307 parmtypes);
4310 exceptions);
4314 }
4316 /* Copy the function parameters. */
4318 /* Remove the in-charge parameter. */
4320 {
4324 }
4325 /* And the VTT parm, in a complete [cd]tor. */
4327 {
4330 else
4331 {
4335 }
4336 }
4339 {
4342 }
4344 /* Create the RTL for this function. */
4352 }
4354 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4355 not invoke this function directly.
4357 For a non-thunk function, returns the address of the slot for storing
4358 the function it is a clone of. Otherwise returns NULL_TREE.
4360 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4361 cloned_function is unset. This is to support the separate
4362 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4363 on a template makes sense, but not the former. */
4365 tree *
4367 {
4375 {
4376 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4379 else
4380 #endif
4382 }
4387 else
4389 }
4391 /* Produce declarations for all appropriate clones of FN. If
4392 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4393 CLASTYPE_METHOD_VEC as well. */
4395 void
4397 {
4398 tree clone;
4400 /* Avoid inappropriate cloning. */
4406 {
4407 /* For each constructor, we need two variants: an in-charge version
4408 and a not-in-charge version. */
4415 }
4416 else
4417 {
4420 /* For each destructor, we need three variants: an in-charge
4421 version, a not-in-charge version, and an in-charge deleting
4422 version. We clone the deleting version first because that
4423 means it will go second on the TYPE_METHODS list -- and that
4424 corresponds to the correct layout order in the virtual
4425 function table.
4427 For a non-virtual destructor, we do not build a deleting
4428 destructor. */
4430 {
4434 }
4441 }
4443 /* Note that this is an abstract function that is never emitted. */
4445 }
4447 /* DECL is an in charge constructor, which is being defined. This will
4448 have had an in class declaration, from whence clones were
4449 declared. An out-of-class definition can specify additional default
4450 arguments. As it is the clones that are involved in overload
4451 resolution, we must propagate the information from the DECL to its
4452 clones. */
4454 void
4456 {
4457 tree clone;
4461 {
4468 /* Skip the 'this' parameter. */
4484 {
4489 {
4490 /* A default parameter has been added. Adjust the
4491 clone's parameters. */
4495 tree type;
4500 {
4503 clone_parms);
4505 }
4508 clone_parms);
4517 }
4518 }
4520 }
4521 }
4523 /* For each of the constructors and destructors in T, create an
4524 in-charge and not-in-charge variant. */
4526 static void
4528 {
4529 tree fns;
4531 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4532 out now. */
4540 }
4542 /* Deduce noexcept for a destructor DTOR. */
4544 void
4546 {
4548 {
4555 }
4556 }
4558 /* For each destructor in T, deduce noexcept:
4560 12.4/3: A declaration of a destructor that does not have an
4561 exception-specification is implicitly considered to have the
4562 same exception-specification as an implicit declaration (15.4). */
4564 static void
4566 {
4567 tree fns;
4569 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4570 out now. */
4576 }
4578 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4579 of TYPE for virtual functions which FNDECL overrides. Return a
4580 mask of the tm attributes found therein. */
4582 static int
4584 {
4586 tree base_binfo;
4590 {
4600 else
4602 }
4605 }
4607 /* Subroutine of set_method_tm_attributes. Handle the checks and
4608 inheritance for one virtual method FNDECL. */
4610 static void
4612 {
4613 tree tm_attr;
4618 /* If FNDECL doesn't actually override anything (i.e. T is the
4619 class that first declares FNDECL virtual), then we're done. */
4626 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4627 tm_pure must match exactly, otherwise no weakening of
4628 tm_safe > tm_callable > nothing. */
4629 /* ??? The tm_pure attribute didn't make the transition to the
4630 multivendor language spec. */
4632 {
4634 {
4637 }
4638 }
4639 /* If the overridden function is tm_pure, then FNDECL must be. */
4642 /* Look for base class combinations that cannot be satisfied. */
4644 {
4650 }
4651 /* If FNDECL did not declare an attribute, then inherit the most
4652 restrictive one. */
4654 {
4656 }
4657 /* Otherwise validate that we're not weaker than a function
4658 that is being overridden. */
4659 else
4660 {
4664 }
4667 err_override:
4671 }
4673 /* For each of the methods in T, propagate a class-level tm attribute. */
4675 static void
4677 {
4680 /* Don't bother collecting tm attributes if transactional memory
4681 support is not enabled. */
4685 /* Process virtual methods first, as they inherit directly from the
4686 base virtual function and also require validation of new attributes. */
4688 {
4689 tree vchain;
4692 {
4697 }
4698 }
4700 /* If the class doesn't have an attribute, nothing more to do. */
4705 /* Any method that does not yet have a tm attribute inherits
4706 the one from the class. */
4708 {
4711 }
4712 }
4714 /* Returns true iff class T has a user-defined constructor other than
4715 the default constructor. */
4717 bool
4719 {
4720 tree fns;
4726 {
4733 }
4736 }
4738 /* Returns the defaulted constructor if T has one. Otherwise, returns
4739 NULL_TREE. */
4741 tree
4743 {
4750 {
4754 {
4760 }
4761 }
4764 }
4766 /* Returns true iff FN is a user-provided function, i.e. user-declared
4767 and not defaulted at its first declaration; or explicit, private,
4768 protected, or non-const. */
4770 bool
4772 {
4775 else
4778 }
4780 /* Returns true iff class T has a user-provided constructor. */
4782 bool
4784 {
4785 tree fns;
4793 /* This can happen in error cases; avoid crashing. */
4802 }
4804 /* Returns true iff class T has a user-provided default constructor. */
4806 bool
4808 {
4809 tree fns;
4815 {
4821 }
4824 }
4826 /* If default-initialization leaves part of TYPE uninitialized, returns
4827 a DECL for the field or TYPE itself (DR 253). */
4829 tree
4831 {
4842 {
4846 }
4851 {
4855 }
4858 }
4860 /* Returns true iff for class T, a trivial synthesized default constructor
4861 would be constexpr. */
4863 bool
4865 {
4866 /* A defaulted trivial default constructor is constexpr
4867 if there is nothing to initialize. */
4870 }
4872 /* Returns true iff class T has a constexpr default constructor. */
4874 bool
4876 {
4877 tree fns;
4880 {
4881 /* The caller should have stripped an enclosing array. */
4884 }
4886 {
4889 /* Non-trivial, we need to check subobject constructors. */
4891 }
4894 }
4896 /* Returns true iff class TYPE has a virtual destructor. */
4898 bool
4900 {
4901 tree dtor;
4909 }
4911 /* Returns true iff class T has a move constructor. */
4913 bool
4915 {
4916 tree fns;
4919 {
4922 }
4932 }
4934 /* Returns true iff class T has a move assignment operator. */
4936 bool
4938 {
4939 tree fns;
4942 {
4945 }
4953 }
4955 /* Returns true iff class T has a move constructor that was explicitly
4956 declared in the class body. Note that this is different from
4957 "user-provided", which doesn't include functions that are defaulted in
4958 the class. */
4960 bool
4962 {
4963 tree fns;
4972 {
4976 }
4979 }
4981 /* Returns true iff class T has a move assignment operator that was
4982 explicitly declared in the class body. */
4984 bool
4986 {
4987 tree fns;
4994 {
4998 }
5001 }
5003 /* Nonzero if we need to build up a constructor call when initializing an
5004 object of this class, either because it has a user-provided constructor
5005 or because it doesn't have a default constructor (so we need to give an
5006 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5007 what you care about is whether or not an object can be produced by a
5008 constructor (e.g. so we don't set TREE_READONLY on const variables of
5009 such type); use this function when what you care about is whether or not
5010 to try to call a constructor to create an object. The latter case is
5011 the former plus some cases of constructors that cannot be called. */
5013 bool
5015 {
5016 tree inner;
5022 }
5024 /* Remove all zero-width bit-fields from T. */
5026 static void
5028 {
5033 {
5036 /* We should not be confused by the fact that grokbitfield
5037 temporarily sets the width of the bit field into
5038 DECL_INITIAL (*fieldsp).
5039 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5040 to that width. */
5043 else
5045 }
5046 }
5048 /* Returns TRUE iff we need a cookie when dynamically allocating an
5049 array whose elements have the indicated class TYPE. */
5051 static bool
5053 {
5054 tree fns;
5059 /* If there's a non-trivial destructor, we need a cookie. In order
5060 to iterate through the array calling the destructor for each
5061 element, we'll have to know how many elements there are. */
5065 /* If the usual deallocation function is a two-argument whose second
5066 argument is of type `size_t', then we have to pass the size of
5067 the array to the deallocation function, so we will need to store
5068 a cookie. */
5072 /* If there are no `operator []' members, or the lookup is
5073 ambiguous, then we don't need a cookie. */
5076 /* Loop through all of the functions. */
5078 {
5079 tree fn;
5080 tree second_parm;
5082 /* Select the current function. */
5084 /* See if this function is a one-argument delete function. If
5085 it is, then it will be the usual deallocation function. */
5089 /* Do not consider this function if its second argument is an
5090 ellipsis. */
5093 /* Otherwise, if we have a two-argument function and the second
5094 argument is `size_t', it will be the usual deallocation
5095 function -- unless there is one-argument function, too. */
5099 }
5102 }
5104 /* Finish computing the `literal type' property of class type T.
5106 At this point, we have already processed base classes and
5107 non-static data members. We need to check whether the copy
5108 constructor is trivial, the destructor is trivial, and there
5109 is a trivial default constructor or at least one constexpr
5110 constructor other than the copy constructor. */
5112 static void
5114 {
5115 tree fn;
5131 {
5134 {
5138 }
5139 }
5140 }
5142 /* T is a non-literal type used in a context which requires a constant
5143 expression. Explain why it isn't literal. */
5145 void
5147 {
5157 /* Already explained. */
5166 {
5168 "default constructor, and has no constexpr constructor that "
5172 {
5173 /* Note that we can't simply call locate_ctor because when the
5174 constructor is deleted it just returns NULL_TREE. */
5175 tree fns;
5177 {
5184 {
5187 else
5190 }
5191 }
5192 }
5193 }
5194 else
5195 {
5199 {
5202 {
5207 }
5208 }
5210 {
5211 tree ftype;
5216 {
5221 }
5222 }
5223 }
5224 }
5226 /* Check the validity of the bases and members declared in T. Add any
5227 implicitly-generated functions (like copy-constructors and
5228 assignment operators). Compute various flag bits (like
5229 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5230 level: i.e., independently of the ABI in use. */
5232 static void
5234 {
5235 /* Nonzero if the implicitly generated copy constructor should take
5236 a non-const reference argument. */
5238 /* Nonzero if the implicitly generated assignment operator
5239 should take a non-const reference argument. */
5241 tree access_decls;
5244 tree fn;
5246 /* By default, we use const reference arguments and generate default
5247 constructors. */
5251 /* Deduce noexcept on destructors. */
5255 /* Check all the base-classes. */
5259 /* Check all the method declarations. */
5262 /* Save the initial values of these flags which only indicate whether
5263 or not the class has user-provided functions. As we analyze the
5264 bases and members we can set these flags for other reasons. */
5268 /* Check all the data member declarations. We cannot call
5269 check_field_decls until we have called check_bases check_methods,
5270 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5271 being set appropriately. */
5276 /* A nearly-empty class has to be vptr-containing; a nearly empty
5277 class contains just a vptr. */
5281 /* Do some bookkeeping that will guide the generation of implicitly
5282 declared member functions. */
5285 /* We need to call a constructor for this class if it has a
5286 user-provided constructor, or if the default constructor is going
5287 to initialize the vptr. (This is not an if-and-only-if;
5288 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5289 themselves need constructing.) */
5292 /* [dcl.init.aggr]
5294 An aggregate is an array or a class with no user-provided
5295 constructors ... and no virtual functions.
5297 Again, other conditions for being an aggregate are checked
5298 elsewhere. */
5301 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5302 retain the old definition internally for ABI reasons. */
5311 /* If the class has no user-declared constructor, but does have
5312 non-static const or reference data members that can never be
5313 initialized, issue a warning. */
5315 /* Classes with user-declared constructors are presumed to
5316 initialize these members. */
5318 /* Aggregates can be initialized with brace-enclosed
5319 initializers. */
5321 {
5322 tree field;
5325 {
5326 tree type;
5341 }
5342 }
5344 /* Synthesize any needed methods. */
5346 cant_have_const_ctor,
5347 no_const_asn_ref);
5349 /* Check defaulted declarations here so we have cant_have_const_ctor
5350 and don't need to worry about clones. */
5353 {
5356 {
5357 bool imp_const_p
5363 /* If the function is defaulted outside the class, we just
5364 give the synthesis error. */
5367 }
5369 }
5372 {
5373 /* "The closure type associated with a lambda-expression has a deleted
5374 default constructor and a deleted copy assignment operator." */
5380 /* "This class type is not an aggregate." */
5382 }
5384 /* Compute the 'literal type' property before we
5385 do anything with non-static member functions. */
5388 /* Create the in-charge and not-in-charge variants of constructors
5389 and destructors. */
5392 /* Process the using-declarations. */
5396 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5399 /* Figure out whether or not we will need a cookie when dynamically
5400 allocating an array of this type. */
5403 }
5405 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5406 accordingly. If a new vfield was created (because T doesn't have a
5407 primary base class), then the newly created field is returned. It
5408 is not added to the TYPE_FIELDS list; it is the caller's
5409 responsibility to do that. Accumulate declared virtual functions
5410 on VIRTUALS_P. */
5412 static tree
5414 {
5415 tree fn;
5417 /* Collect the virtual functions declared in T. */
5421 {
5430 }
5432 /* If we couldn't find an appropriate base class, create a new field
5433 here. Even if there weren't any new virtual functions, we might need a
5434 new virtual function table if we're supposed to include vptrs in
5435 all classes that need them. */
5437 {
5438 /* We build this decl with vtbl_ptr_type_node, which is a
5439 `vtable_entry_type*'. It might seem more precise to use
5440 `vtable_entry_type (*)[N]' where N is the number of virtual
5441 functions. However, that would require the vtable pointer in
5442 base classes to have a different type than the vtable pointer
5443 in derived classes. We could make that happen, but that
5444 still wouldn't solve all the problems. In particular, the
5445 type-based alias analysis code would decide that assignments
5446 to the base class vtable pointer can't alias assignments to
5447 the derived class vtable pointer, since they have different
5448 types. Thus, in a derived class destructor, where the base
5449 class constructor was inlined, we could generate bad code for
5450 setting up the vtable pointer.
5452 Therefore, we use one type for all vtable pointers. We still
5453 use a type-correct type; it's just doesn't indicate the array
5454 bounds. That's better than using `void*' or some such; it's
5455 cleaner, and it let's the alias analysis code know that these
5456 stores cannot alias stores to void*! */
5457 tree field;
5470 /* This class is non-empty. */
5474 }
5477 }
5479 /* Add OFFSET to all base types of BINFO which is a base in the
5480 hierarchy dominated by T.
5482 OFFSET, which is a type offset, is number of bytes. */
5484 static void
5486 {
5488 tree primary_binfo;
5489 tree base_binfo;
5491 /* Update BINFO's offset. */
5496 offset));
5498 /* Find the primary base class. */
5504 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5505 downwards. */
5507 {
5508 /* Don't do the primary base twice. */
5516 }
5517 }
5519 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5520 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5521 empty subobjects of T. */
5523 static void
5525 {
5526 tree vbase;
5535 {
5536 /* In G++ 3.2, we incorrectly rounded the size before laying out
5537 the virtual bases. */
5539 #ifdef STRUCTURE_SIZE_BOUNDARY
5540 /* Packed structures don't need to have minimum size. */
5543 #endif
5547 }
5549 /* Find the last field. The artificial fields created for virtual
5550 bases will go after the last extant field to date. */
5555 /* Go through the virtual bases, allocating space for each virtual
5556 base that is not already a primary base class. These are
5557 allocated in inheritance graph order. */
5559 {
5564 {
5567 /* This virtual base is not a primary base of any class in the
5568 hierarchy, so we have to add space for it. */
5572 /* If the first virtual base might have been placed at a
5573 lower address, had we started from CLASSTYPE_SIZE, rather
5574 than TYPE_SIZE, issue a warning. There can be both false
5575 positives and false negatives from this warning in rare
5576 cases; to deal with all the possibilities would probably
5577 require performing both layout algorithms and comparing
5578 the results which is not particularly tractable. */
5580 && first_vbase
5581 && (tree_int_cst_lt
5586 bitsize_unit_node),
5589 "offset of virtual base %qT is not ABI-compliant and "
5591 basetype);
5594 }
5595 }
5596 }
5598 /* Returns the offset of the byte just past the end of the base class
5599 BINFO. */
5601 static tree
5603 {
5604 tree size;
5609 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5610 allocate some space for it. It cannot have virtual bases, so
5611 TYPE_SIZE_UNIT is fine. */
5613 else
5617 }
5619 /* Returns the offset of the byte just past the end of the base class
5620 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5621 only non-virtual bases are included. */
5623 static tree
5625 {
5628 tree binfo;
5629 tree base_binfo;
5630 tree offset;
5635 {
5645 }
5647 /* G++ 3.2 did not check indirect virtual bases. */
5651 {
5655 }
5658 }
5660 /* Warn about bases of T that are inaccessible because they are
5661 ambiguous. For example:
5663 struct S {};
5664 struct T : public S {};
5665 struct U : public S, public T {};
5667 Here, `(S*) new U' is not allowed because there are two `S'
5668 subobjects of U. */
5670 static void
5672 {
5675 tree basetype;
5676 tree binfo;
5677 tree base_binfo;
5679 /* If there are no repeated bases, nothing can be ambiguous. */
5683 /* Check direct bases. */
5686 {
5692 }
5694 /* Check for ambiguous virtual bases. */
5698 {
5704 }
5705 }
5707 /* Compare two INTEGER_CSTs K1 and K2. */
5709 static int
5711 {
5713 }
5715 /* Increase the size indicated in RLI to account for empty classes
5716 that are "off the end" of the class. */
5718 static void
5720 {
5721 tree eoc;
5722 tree rli_size;
5724 /* It might be the case that we grew the class to allocate a
5725 zero-sized base class. That won't be reflected in RLI, yet,
5726 because we are willing to overlay multiple bases at the same
5727 offset. However, now we need to make sure that RLI is big enough
5728 to reflect the entire class. */
5734 {
5736 /* In version 1 of the ABI, the size of a class that ends with
5737 a bitfield was not rounded up to a whole multiple of a
5738 byte. Because rli_size_unit_so_far returns only the number
5739 of fully allocated bytes, any extra bits were not included
5740 in the size. */
5742 else
5743 /* The size should have been rounded to a whole byte. */
5746 rli->bitpos
5755 }
5756 }
5758 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5759 BINFO_OFFSETs for all of the base-classes. Position the vtable
5760 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5762 static void
5764 {
5765 tree non_static_data_members;
5766 tree field;
5767 tree vptr;
5768 record_layout_info rli;
5769 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5770 types that appear at that offset. */
5771 splay_tree empty_base_offsets;
5772 /* True if the last field layed out was a bit-field. */
5774 /* The location at which the next field should be inserted. */
5776 /* T, as a base class. */
5777 tree base_t;
5779 /* Keep track of the first non-static data member. */
5782 /* Start laying out the record. */
5785 /* Mark all the primary bases in the hierarchy. */
5788 /* Create a pointer to our virtual function table. */
5791 /* The vptr is always the first thing in the class. */
5793 {
5798 }
5799 else
5802 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5807 /* Layout the non-static data members. */
5809 {
5810 tree type;
5811 tree padding;
5813 /* We still pass things that aren't non-static data members to
5814 the back end, in case it wants to do something with them. */
5816 {
5818 /* If the static data member has incomplete type, keep track
5819 of it so that it can be completed later. (The handling
5820 of pending statics in finish_record_layout is
5821 insufficient; consider:
5823 struct S1;
5824 struct S2 { static S1 s1; };
5826 At this point, finish_record_layout will be called, but
5827 S1 is still incomplete.) */
5829 {
5831 /* The visibility of static data members is determined
5832 at their point of declaration, not their point of
5833 definition. */
5835 }
5837 }
5845 /* If this field is a bit-field whose width is greater than its
5846 type, then there are some special rules for allocating
5847 it. */
5850 {
5852 tree integer_type;
5854 /* We must allocate the bits as if suitably aligned for the
5855 longest integer type that fits in this many bits. type
5856 of the field. Then, we are supposed to use the left over
5857 bits as additional padding. */
5866 /* ITK now indicates a type that is too large for the
5867 field. We have to back up by one to find the largest
5868 type that fits. */
5869 do
5870 {
5875 /* Figure out how much additional padding is required. GCC
5876 3.2 always created a padding field, even if it had zero
5877 width. */
5880 {
5882 /* In a union, the padding field must have the full width
5883 of the bit-field; all fields start at offset zero. */
5885 else
5886 {
5889 "ABI-compliant and may change in a future "
5891 t);
5894 }
5895 }
5896 #ifdef PCC_BITFIELD_TYPE_MATTERS
5897 /* An unnamed bitfield does not normally affect the
5898 alignment of the containing class on a target where
5899 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5900 make any exceptions for unnamed bitfields when the
5901 bitfields are longer than their types. Therefore, we
5902 temporarily give the field a name. */
5904 {
5907 }
5908 #endif
5913 empty_base_offsets);
5916 /* Now that layout has been performed, set the size of the
5917 field to the size of its declared type; the rest of the
5918 field is effectively invisible. */
5920 /* We must also reset the DECL_MODE of the field. */
5925 /* Versions of G++ before G++ 3.4 did not reset the
5926 DECL_MODE. */
5928 "the offset of %qD may not be ABI-compliant and may "
5930 }
5931 else
5933 empty_base_offsets);
5935 /* Remember the location of any empty classes in FIELD. */
5939 empty_base_offsets,
5942 /* If a bit-field does not immediately follow another bit-field,
5943 and yet it starts in the middle of a byte, we have failed to
5944 comply with the ABI. */
5947 /* The TREE_NO_WARNING flag gets set by Objective-C when
5948 laying out an Objective-C class. The ObjC ABI differs
5949 from the C++ ABI, and so we do not want a warning
5950 here. */
5952 && !last_field_was_bitfield
5955 bitsize_unit_node)))
5959 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5960 offset of the field. */
5967 "classes to be placed at different locations in a "
5970 /* The middle end uses the type of expressions to determine the
5971 possible range of expression values. In order to optimize
5972 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5973 must be made aware of the width of "i", via its type.
5975 Because C++ does not have integer types of arbitrary width,
5976 we must (for the purposes of the front end) convert from the
5977 type assigned here to the declared type of the bitfield
5978 whenever a bitfield expression is used as an rvalue.
5979 Similarly, when assigning a value to a bitfield, the value
5980 must be converted to the type given the bitfield here. */
5982 {
5987 {
5994 }
5995 }
5997 /* If we needed additional padding after this field, add it
5998 now. */
6000 {
6001 tree padding_field;
6004 FIELD_DECL,
6005 NULL_TREE,
6006 char_type_node);
6013 NULL_TREE,
6014 empty_base_offsets);
6015 }
6018 }
6021 {
6022 /* Make sure that we are on a byte boundary so that the size of
6023 the class without virtual bases will always be a round number
6024 of bytes. */
6027 }
6029 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6030 padding. */
6034 /* Delete all zero-width bit-fields from the list of fields. Now
6035 that the type is laid out they are no longer important. */
6038 /* Create the version of T used for virtual bases. We do not use
6039 make_class_type for this version; this is an artificial type. For
6040 a POD type, we just reuse T. */
6042 {
6045 /* Set the size and alignment for the new type. In G++ 3.2, all
6046 empty classes were considered to have size zero when used as
6047 base classes. */
6049 {
6054 "layout of classes derived from empty class %qT "
6056 t);
6057 }
6058 else
6059 {
6060 tree eoc;
6062 /* If the ABI version is not at least two, and the last
6063 field was a bit-field, RLI may not be on a byte
6064 boundary. In particular, rli_size_unit_so_far might
6065 indicate the last complete byte, while rli_size_so_far
6066 indicates the total number of bits used. Therefore,
6067 rli_size_so_far, rather than rli_size_unit_so_far, is
6068 used to compute TYPE_SIZE_UNIT. */
6076 eoc);
6083 }
6087 /* Copy the fields from T. */
6091 {
6093 FIELD_DECL,
6103 }
6105 /* Record the base version of the type. */
6108 }
6109 else
6112 /* Every empty class contains an empty class. */
6116 /* Set the TYPE_DECL for this type to contain the right
6117 value for DECL_OFFSET, so that we can use it as part
6118 of a COMPONENT_REF for multiple inheritance. */
6121 /* Now fix up any virtual base class types that we left lying
6122 around. We must get these done before we try to lay out the
6123 virtual function table. As a side-effect, this will remove the
6124 base subobject fields. */
6127 /* Make sure that empty classes are reflected in RLI at this
6128 point. */
6131 /* Make sure not to create any structures with zero size. */
6137 /* If this is a non-POD, declaring it packed makes a difference to how it
6138 can be used as a field; don't let finalize_record_size undo it. */
6142 /* Let the back end lay out the type. */
6145 /* Warn about bases that can't be talked about due to ambiguity. */
6148 /* Now that we're done with layout, give the base fields the real types. */
6153 /* Clean up. */
6160 }
6162 /* Determine the "key method" for the class type indicated by TYPE,
6163 and set CLASSTYPE_KEY_METHOD accordingly. */
6165 void
6167 {
6168 tree method;
6171 || processing_template_decl
6176 /* The key method is the first non-pure virtual function that is not
6177 inline at the point of class definition. On some targets the
6178 key function may not be inline; those targets should not call
6179 this function until the end of the translation unit. */
6185 {
6188 }
6191 }
6194 /* Allocate and return an instance of struct sorted_fields_type with
6195 N fields. */
6199 {
6206 }
6209 /* Perform processing required when the definition of T (a class type)
6210 is complete. */
6212 void
6214 {
6215 tree x;
6216 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6220 {
6225 }
6227 /* If this type was previously laid out as a forward reference,
6228 make sure we lay it out again. */
6232 /* Make assumptions about the class; we'll reset the flags if
6233 necessary. */
6239 /* Do end-of-class semantic processing: checking the validity of the
6240 bases and members and add implicitly generated methods. */
6243 /* Find the key method. */
6245 {
6246 /* The Itanium C++ ABI permits the key method to be chosen when
6247 the class is defined -- even though the key method so
6248 selected may later turn out to be an inline function. On
6249 some systems (such as ARM Symbian OS) the key method cannot
6250 be determined until the end of the translation unit. On such
6251 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6252 will cause the class to be added to KEYED_CLASSES. Then, in
6253 finish_file we will determine the key method. */
6257 /* If a polymorphic class has no key method, we may emit the vtable
6258 in every translation unit where the class definition appears. */
6261 }
6263 /* Layout the class itself. */
6266 /* We use the base type for trivial assignments, and hence it
6267 needs a mode. */
6272 /* If necessary, create the primary vtable for this class. */
6274 {
6275 /* We must enter these virtuals into the table. */
6279 /* Here we know enough to change the type of our virtual
6280 function table, but we will wait until later this function. */
6283 /* If we're warning about ABI tags, check the types of the new
6284 virtual functions. */
6288 }
6291 {
6293 tree fn;
6300 /* Add entries for virtual functions introduced by this class. */
6304 /* Set DECL_VINDEX for all functions declared in this class. */
6306 fn;
6308 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6310 {
6314 /* A thunk. We should never be calling this entry directly
6315 from this vtable -- we'd use the entry for the non
6316 thunk base function. */
6320 }
6321 }
6326 /* Complete the rtl for any static member objects of the type we're
6327 working on. */
6334 /* Done with FIELDS...now decide whether to sort these for
6335 faster lookups later.
6337 We use a small number because most searches fail (succeeding
6338 ultimately as the search bores through the inheritance
6339 hierarchy), and we want this failure to occur quickly. */
6343 /* Complain if one of the field types requires lower visibility. */
6346 /* Make the rtl for any new vtables we have created, and unmark
6347 the base types we marked. */
6350 /* Build the VTT for T. */
6353 /* This warning does not make sense for Java classes, since they
6354 cannot have destructors. */
6356 {
6357 tree dtor;
6361 if it were virtual, we would have created it by now. */
6362 !dtor
6371 "%q#T has virtual functions and accessible"
6373 }
6380 /* Class layout, assignment of virtual table slots, etc., is now
6381 complete. Give the back end a chance to tweak the visibility of
6382 the class or perform any other required target modifications. */
6389 /* Finish debugging output for this type. */
6393 {
6396 {
6399 }
6401 {
6404 else
6405 {
6408 }
6410 }
6412 {
6414 "the type of the first field has a different ABI from the "
6417 }
6418 }
6419 }
6421 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6422 equal to THRESHOLD or greater than THRESHOLD. */
6424 static void
6426 {
6429 {
6434 }
6435 }
6437 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6439 void
6441 {
6444 {
6446 int n_fields
6457 }
6458 }
6460 /* When T was built up, the member declarations were added in reverse
6461 order. Rearrange them to declaration order. */
6463 void
6465 {
6466 tree next;
6467 tree prev;
6468 tree x;
6470 /* The following lists are all in reverse order. Put them in
6471 declaration order now. */
6475 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6476 reverse order, so we can't just use nreverse. */
6481 {
6485 }
6487 {
6491 }
6492 }
6494 tree
6496 {
6499 /* Now that we've got all the field declarations, reverse everything
6500 as necessary. */
6505 /* Nadger the current location so that diagnostics point to the start of
6506 the struct, not the end. */
6510 {
6511 tree x;
6517 /* We need to emit an error message if this type was used as a parameter
6518 and it is an abstract type, even if it is a template. We construct
6519 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6520 account and we call complete_vars with this type, which will check
6521 the PARM_DECLS. Note that while the type is being defined,
6522 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6523 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6529 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6530 an enclosing scope is a template class, so that this function be
6531 found by lookup_fnfields_1 when the using declaration is not
6532 instantiated yet. */
6535 {
6540 }
6542 /* Remember current #pragma pack value. */
6545 /* Fix up any variants we've already built. */
6547 {
6552 }
6553 }
6554 else
6563 else
6567 /* Lambdas are defined by the LAMBDA_EXPR. */
6572 }
6573 \f
6574 /* Hash table to avoid endless recursion when handling references. */
6577 /* Return the dynamic type of INSTANCE, if known.
6578 Used to determine whether the virtual function table is needed
6579 or not.
6581 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6582 of our knowledge of its type. *NONNULL should be initialized
6583 before this function is called. */
6585 static tree
6587 {
6588 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6591 {
6595 else
6599 /* This is a call to a constructor, hence it's never zero. */
6601 {
6605 }
6609 /* This is a call to a constructor, hence it's never zero. */
6611 {
6615 }
6624 /* Propagate nonnull. */
6629 CASE_CONVERT:
6635 {
6636 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6637 with a real object -- given &p->f, p can still be null. */
6639 /* ??? Probably should check DECL_WEAK here. */
6642 }
6646 /* If this component is really a base class reference, then the field
6647 itself isn't definitive. */
6656 {
6660 }
6661 /* fall through... */
6666 {
6670 }
6672 {
6676 /* if we're in a ctor or dtor, we know our type. If
6677 current_class_ptr is set but we aren't in a function, we're in
6678 an NSDMI (and therefore a constructor). */
6683 {
6687 }
6688 }
6690 {
6691 /* We only need one hash table because it is always left empty. */
6695 /* Reference variables should be references to objects. */
6699 /* Enter the INSTANCE in a table to prevent recursion; a
6700 variable's initializer may refer to the variable
6701 itself. */
6706 {
6707 tree type;
6716 }
6717 }
6722 }
6723 #undef RECUR
6724 }
6726 /* Return nonzero if the dynamic type of INSTANCE is known, and
6727 equivalent to the static type. We also handle the case where
6728 INSTANCE is really a pointer. Return negative if this is a
6729 ctor/dtor. There the dynamic type is known, but this might not be
6730 the most derived base of the original object, and hence virtual
6731 bases may not be layed out according to this type.
6733 Used to determine whether the virtual function table is needed
6734 or not.
6736 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6737 of our knowledge of its type. *NONNULL should be initialized
6738 before this function is called. */
6740 int
6742 {
6745 tree fixed;
6747 /* processing_template_decl can be false in a template if we're in
6748 fold_non_dependent_expr, but we still want to suppress this check. */
6750 {
6751 /* In a template we only care about the type of the result. */
6755 }
6765 }
6767 \f
6768 void
6770 {
6773 current_class_stack
6781 }
6783 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6785 static void
6787 {
6788 tree type;
6790 /* We are re-entering the same class we just left, so we don't
6791 have to search the whole inheritance matrix to find all the
6792 decls to bind again. Instead, we install the cached
6793 class_shadowed list and walk through it binding names. */
6796 /* Restore IDENTIFIER_TYPE_VALUE. */
6798 type;
6801 }
6803 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6804 appropriate for TYPE.
6806 So that we may avoid calls to lookup_name, we cache the _TYPE
6807 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6809 For multiple inheritance, we perform a two-pass depth-first search
6810 of the type lattice. */
6812 void
6814 {
6815 class_stack_node_t csn;
6819 /* Make sure there is enough room for the new entry on the stack. */
6821 {
6823 current_class_stack
6825 current_class_stack_size);
6826 }
6828 /* Insert a new entry on the class stack. */
6835 current_class_depth++;
6837 /* Now set up the new type. */
6843 /* By default, things in classes are private, while things in
6844 structures or unions are public. */
6846 ? access_private_node
6852 {
6853 /* Forcibly remove any old class remnants. */
6855 }
6861 else
6863 }
6865 /* When we exit a toplevel class scope, we save its binding level so
6866 that we can restore it quickly. Here, we've entered some other
6867 class, so we must invalidate our cache. */
6869 void
6871 {
6873 }
6875 /* Get out of the current class scope. If we were in a class scope
6876 previously, that is the one popped to. */
6878 void
6880 {
6883 current_class_depth--;
6889 }
6891 /* Mark the top of the class stack as hidden. */
6893 void
6895 {
6898 }
6900 /* Mark the top of the class stack as un-hidden. */
6902 void
6904 {
6907 }
6909 /* Returns 1 if the class type currently being defined is either T or
6910 a nested type of T. */
6912 bool
6914 {
6922 /* We start looking from 1 because entry 0 is from global scope,
6923 and has no type. */
6925 {
6926 tree c;
6929 else
6930 {
6934 }
6939 }
6941 }
6943 /* If either current_class_type or one of its enclosing classes are derived
6944 from T, return the appropriate type. Used to determine how we found
6945 something via unqualified lookup. */
6947 tree
6949 {
6952 /* The bases of a dependent type are unknown. */
6963 {
6968 }
6971 }
6973 /* Returns the innermost class type which is not a lambda closure type. */
6975 tree
6977 {
6980 /* We start looking from 1 because entry 0 is from global scope,
6981 and has no type. */
6983 {
6984 tree c;
6987 else
6988 {
6992 }
6997 }
6999 }
7001 /* When entering a class scope, all enclosing class scopes' names with
7002 static meaning (static variables, static functions, types and
7003 enumerators) have to be visible. This recursive function calls
7004 pushclass for all enclosing class contexts until global or a local
7005 scope is reached. TYPE is the enclosed class. */
7007 void
7009 {
7010 /* A namespace might be passed in error cases, like A::B:C. */
7018 }
7020 /* Undoes a push_nested_class call. */
7022 void
7024 {
7030 }
7032 /* Returns the number of extern "LANG" blocks we are nested within. */
7034 int
7036 {
7038 }
7040 /* Set global variables CURRENT_LANG_NAME to appropriate value
7041 so that behavior of name-mangling machinery is correct. */
7043 void
7045 {
7049 {
7051 }
7053 {
7055 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7056 (See record_builtin_java_type in decl.c.) However, that causes
7057 incorrect debug entries if these types are actually used.
7058 So we re-enable debug output after extern "Java". */
7067 }
7069 {
7071 }
7072 else
7074 }
7076 /* Get out of the current language scope. */
7078 void
7080 {
7082 }
7083 \f
7084 /* Type instantiation routines. */
7086 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7087 matches the TARGET_TYPE. If there is no satisfactory match, return
7088 error_mark_node, and issue an error & warning messages under
7089 control of FLAGS. Permit pointers to member function if FLAGS
7090 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7091 a template-id, and EXPLICIT_TARGS are the explicitly provided
7092 template arguments.
7094 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7095 is the base path used to reference those member functions. If
7096 the address is resolved to a member function, access checks will be
7097 performed and errors issued if appropriate. */
7099 static tree
7101 tree overload,
7102 tsubst_flags_t flags,
7104 tree explicit_targs,
7105 tree access_path)
7106 {
7107 /* Here's what the standard says:
7109 [over.over]
7111 If the name is a function template, template argument deduction
7112 is done, and if the argument deduction succeeds, the deduced
7113 arguments are used to generate a single template function, which
7114 is added to the set of overloaded functions considered.
7116 Non-member functions and static member functions match targets of
7117 type "pointer-to-function" or "reference-to-function." Nonstatic
7118 member functions match targets of type "pointer-to-member
7119 function;" the function type of the pointer to member is used to
7120 select the member function from the set of overloaded member
7121 functions. If a nonstatic member function is selected, the
7122 reference to the overloaded function name is required to have the
7123 form of a pointer to member as described in 5.3.1.
7125 If more than one function is selected, any template functions in
7126 the set are eliminated if the set also contains a non-template
7127 function, and any given template function is eliminated if the
7128 set contains a second template function that is more specialized
7129 than the first according to the partial ordering rules 14.5.5.2.
7130 After such eliminations, if any, there shall remain exactly one
7131 selected function. */
7134 /* We store the matches in a TREE_LIST rooted here. The functions
7135 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7136 interoperability with most_specialized_instantiation. */
7138 tree fn;
7139 tree target_fn_type;
7141 /* By the time we get here, we should be seeing only real
7142 pointer-to-member types, not the internal POINTER_TYPE to
7143 METHOD_TYPE representation. */
7149 /* Check that the TARGET_TYPE is reasonable. */
7153 /* This is OK, too. */
7156 /* This is OK, too. This comes from a conversion to reference
7157 type. */
7159 else
7160 {
7166 }
7168 /* Non-member functions and static member functions match targets of type
7169 "pointer-to-function" or "reference-to-function." Nonstatic member
7170 functions match targets of type "pointer-to-member-function;" the
7171 function type of the pointer to member is used to select the member
7172 function from the set of overloaded member functions.
7174 So figure out the FUNCTION_TYPE that we want to match against. */
7177 /* If we can find a non-template function that matches, we can just
7178 use it. There's no point in generating template instantiations
7179 if we're just going to throw them out anyhow. But, of course, we
7180 can only do this when we don't *need* a template function. */
7182 {
7183 tree fns;
7186 {
7190 /* We're not looking for templates just yet. */
7195 /* We're looking for a non-static member, and this isn't
7196 one, or vice versa. */
7199 /* Ignore functions which haven't been explicitly
7200 declared. */
7204 /* See if there's a match. */
7207 }
7208 }
7210 /* Now, if we've already got a match (or matches), there's no need
7211 to proceed to the template functions. But, if we don't have a
7212 match we need to look at them, too. */
7214 {
7215 tree target_arg_types;
7216 tree target_ret_type;
7217 tree fns;
7220 tree arg;
7234 {
7236 tree instantiation;
7237 tree targs;
7240 /* We're only looking for templates. */
7245 /* We're not looking for a non-static member, and this is
7246 one, or vice versa. */
7249 /* Try to do argument deduction. */
7256 /* Instantiation failed. */
7259 /* See if there's a match. */
7262 }
7264 /* Now, remove all but the most specialized of the matches. */
7266 {
7271 NULL_TREE,
7272 NULL_TREE);
7273 }
7274 }
7276 /* Now we should have exactly one function in MATCHES. */
7278 {
7279 /* There were *no* matches. */
7281 {
7284 target_type);
7287 }
7289 }
7291 {
7292 /* There were too many matches. First check if they're all
7293 the same function. */
7298 /* For multi-versioned functions, more than one match is just fine and
7299 decls_match will return false as they are different. */
7307 {
7309 {
7312 target_type);
7314 /* Since print_candidates expects the functions in the
7315 TREE_VALUE slot, we flip them here. */
7320 }
7323 }
7324 }
7326 /* Good, exactly one match. Now, convert it to the correct type. */
7331 {
7339 {
7342 }
7343 }
7345 /* If a pointer to a function that is multi-versioned is requested, the
7346 pointer to the dispatcher function is returned instead. This works
7347 well because indirectly calling the function will dispatch the right
7348 function version at run-time. */
7350 {
7354 /* Mark all the versions corresponding to the dispatcher as used. */
7357 }
7359 /* If we're doing overload resolution purely for the purpose of
7360 determining conversion sequences, we should not consider the
7361 function used. If this conversion sequence is selected, the
7362 function will be marked as used at this point. */
7364 {
7365 /* Make =delete work with SFINAE. */
7370 }
7372 /* We could not check access to member functions when this
7373 expression was originally created since we did not know at that
7374 time to which function the expression referred. */
7376 {
7379 }
7383 else
7384 {
7385 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7386 will mark the function as addressed, but here we must do it
7387 explicitly. */
7391 }
7392 }
7394 /* This function will instantiate the type of the expression given in
7395 RHS to match the type of LHSTYPE. If errors exist, then return
7396 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7397 we complain on errors. If we are not complaining, never modify rhs,
7398 as overload resolution wants to try many possible instantiations, in
7399 the hope that at least one will work.
7401 For non-recursive calls, LHSTYPE should be a function, pointer to
7402 function, or a pointer to member function. */
7404 tree
7406 {
7413 {
7417 }
7420 {
7426 /* Microsoft allows `A::f' to be resolved to a
7427 pointer-to-member. */
7428 ;
7429 else
7430 {
7435 }
7436 }
7439 {
7442 }
7444 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7445 deduce any type information. */
7447 {
7451 }
7453 /* There only a few kinds of expressions that may have a type
7454 dependent on overload resolution. */
7460 /* This should really only be used when attempting to distinguish
7461 what sort of a pointer to function we have. For now, any
7462 arithmetic operation which is not supported on pointers
7463 is rejected as an error. */
7466 {
7468 {
7474 /* Do not lose object's side effects. */
7478 }
7485 /* This can happen if we are forming a pointer-to-member for a
7486 member template. */
7489 /* Fall through. */
7492 {
7496 return
7500 }
7504 return
7508 access_path);
7511 {
7516 }
7523 }
7525 }
7526 \f
7527 /* Return the name of the virtual function pointer field
7528 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7529 this may have to look back through base types to find the
7530 ultimate field name. (For single inheritance, these could
7531 all be the same name. Who knows for multiple inheritance). */
7533 static tree
7535 {
7542 {
7548 }
7556 }
7558 void
7560 {
7567 {
7572 }
7573 }
7575 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7576 according to [class]:
7577 The class-name is also inserted
7578 into the scope of the class itself. For purposes of access checking,
7579 the inserted class name is treated as if it were a public member name. */
7581 void
7583 {
7586 tree saved_cas;
7601 }
7603 /* Returns 1 if TYPE contains only padding bytes. */
7605 int
7607 {
7614 /* In G++ 3.2, whether or not a class was empty was determined by
7615 looking at its size. */
7618 else
7620 }
7622 /* Returns true if TYPE contains an empty class. */
7624 static bool
7626 {
7630 {
7631 tree field;
7632 tree binfo;
7633 tree base_binfo;
7645 }
7649 }
7651 /* Returns true if TYPE contains no actual data, just various
7652 possible combinations of empty classes and possibly a vptr. */
7654 bool
7656 {
7658 {
7659 tree field;
7660 tree binfo;
7661 tree base_binfo;
7664 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7665 out, but we'd like to be able to check this before then. */
7679 }
7683 }
7685 /* Note that NAME was looked up while the current class was being
7686 defined and that the result of that lookup was DECL. */
7688 void
7690 {
7691 splay_tree names_used;
7693 /* If we're not defining a class, there's nothing to do. */
7699 /* If there's already a binding for this NAME, then we don't have
7700 anything to worry about. */
7713 }
7715 /* Note that NAME was declared (as DECL) in the current class. Check
7716 to see that the declaration is valid. */
7718 void
7720 {
7721 splay_tree names_used;
7722 splay_tree_node n;
7724 /* Look to see if we ever used this name. */
7725 names_used
7729 /* The C language allows members to be declared with a type of the same
7730 name, and the C++ standard says this diagnostic is not required. So
7731 allow it in extern "C" blocks unless predantic is specified.
7732 Allow it in all cases if -ms-extensions is specified. */
7738 {
7739 /* [basic.scope.class]
7741 A name N used in a class S shall refer to the same declaration
7742 in its context and when re-evaluated in the completed scope of
7743 S. */
7747 }
7748 }
7750 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7751 Secondary vtables are merged with primary vtables; this function
7752 will return the VAR_DECL for the primary vtable. */
7754 tree
7756 {
7757 tree decl;
7761 {
7764 }
7768 }
7771 /* Returns the binfo for the primary base of BINFO. If the resulting
7772 BINFO is a virtual base, and it is inherited elsewhere in the
7773 hierarchy, then the returned binfo might not be the primary base of
7774 BINFO in the complete object. Check BINFO_PRIMARY_P or
7775 BINFO_LOST_PRIMARY_P to be sure. */
7777 static tree
7779 {
7780 tree primary_base;
7787 }
7789 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7791 static int
7793 {
7797 }
7799 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7800 INDENT should be zero when called from the top level; it is
7801 incremented recursively. IGO indicates the next expected BINFO in
7802 inheritance graph ordering. */
7804 static tree
7807 tree binfo,
7808 tree igo,
7810 {
7812 tree base_binfo;
7820 {
7823 }
7838 {
7842 TFF_PLAIN_IDENTIFIER),
7844 }
7846 {
7849 }
7854 {
7858 {
7862 TFF_PLAIN_IDENTIFIER));
7863 }
7865 {
7869 TFF_PLAIN_IDENTIFIER));
7870 }
7872 {
7876 TFF_PLAIN_IDENTIFIER));
7877 }
7879 {
7883 TFF_PLAIN_IDENTIFIER));
7884 }
7888 }
7894 }
7896 /* Dump the BINFO hierarchy for T. */
7898 static void
7900 {
7912 }
7914 /* Debug interface to hierarchy dumping. */
7916 void
7918 {
7920 }
7922 static void
7924 {
7929 {
7932 }
7933 }
7935 static void
7937 {
7938 tree value;
7940 HOST_WIDE_INT elt;
7948 TFF_PLAIN_IDENTIFIER));
7955 }
7957 static void
7959 {
7967 {
7974 {
7979 }
7983 }
7986 }
7988 static void
7990 {
7998 {
8003 }
8006 }
8008 /* Dump a function or thunk and its thunkees. */
8010 static void
8012 {
8015 tree thunks;
8023 {
8033 else
8039 }
8043 }
8045 /* Dump the thunks for FN. */
8047 void
8049 {
8051 }
8053 /* Virtual function table initialization. */
8055 /* Create all the necessary vtables for T and its base classes. */
8057 static void
8059 {
8060 tree vbase;
8064 /* We lay out the primary and secondary vtables in one contiguous
8065 vtable. The primary vtable is first, followed by the non-virtual
8066 secondary vtables in inheritance graph order. */
8070 /* Then come the virtual bases, also in inheritance graph order. */
8072 {
8076 }
8080 }
8082 /* Initialize the vtable for BINFO with the INITS. */
8084 static void
8086 {
8087 tree decl;
8093 }
8095 /* Build the VTT (virtual table table) for T.
8096 A class requires a VTT if it has virtual bases.
8098 This holds
8099 1 - primary virtual pointer for complete object T
8100 2 - secondary VTTs for each direct non-virtual base of T which requires a
8101 VTT
8102 3 - secondary virtual pointers for each direct or indirect base of T which
8103 has virtual bases or is reachable via a virtual path from T.
8104 4 - secondary VTTs for each direct or indirect virtual base of T.
8106 Secondary VTTs look like complete object VTTs without part 4. */
8108 static void
8110 {
8111 tree type;
8112 tree vtt;
8113 tree index;
8116 /* Build up the initializers for the VTT. */
8121 /* If we didn't need a VTT, we're done. */
8125 /* Figure out the type of the VTT. */
8129 /* Now, build the VTT object itself. */
8132 /* Add the VTT to the vtables list. */
8137 }
8139 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8140 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8141 and CHAIN the vtable pointer for this binfo after construction is
8142 complete. VALUE can also be another BINFO, in which case we recurse. */
8144 static tree
8146 {
8147 tree vt;
8150 {
8156 else
8158 }
8161 }
8163 /* Data for secondary VTT initialization. */
8165 {
8166 /* Is this the primary VTT? */
8169 /* Current index into the VTT. */
8170 tree index;
8172 /* Vector of initializers built up. */
8175 /* The type being constructed by this secondary VTT. */
8176 tree type_being_constructed;
8179 /* Recursively build the VTT-initializer for BINFO (which is in the
8180 hierarchy dominated by T). INITS points to the end of the initializer
8181 list to date. INDEX is the VTT index where the next element will be
8182 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8183 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8184 for virtual bases of T. When it is not so, we build the constructor
8185 vtables for the BINFO-in-T variant. */
8187 static void
8190 {
8192 tree b;
8193 tree init;
8194 secondary_vptr_vtt_init_data data;
8197 /* We only need VTTs for subobjects with virtual bases. */
8201 /* We need to use a construction vtable if this is not the primary
8202 VTT. */
8204 {
8207 /* Record the offset in the VTT where this sub-VTT can be found. */
8209 }
8211 /* Add the address of the primary vtable for the complete object. */
8215 {
8218 }
8221 /* Recursively add the secondary VTTs for non-virtual bases. */
8226 /* Add secondary virtual pointers for all subobjects of BINFO with
8227 either virtual bases or reachable along a virtual path, except
8228 subobjects that are non-virtual primary bases. */
8238 /* data.inits might have grown as we added secondary virtual pointers.
8239 Make sure our caller knows about the new vector. */
8243 /* Add the secondary VTTs for virtual bases in inheritance graph
8244 order. */
8246 {
8251 }
8252 else
8253 /* Remove the ctor vtables we created. */
8255 }
8257 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8258 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8260 static tree
8262 {
8265 /* We don't care about bases that don't have vtables. */
8269 /* We're only interested in proper subobjects of the type being
8270 constructed. */
8274 /* We're only interested in bases with virtual bases or reachable
8275 via a virtual path from the type being constructed. */
8280 /* We're not interested in non-virtual primary bases. */
8284 /* Record the index where this secondary vptr can be found. */
8286 {
8291 {
8292 /* It's a primary virtual base, and this is not a
8293 construction vtable. Find the base this is primary of in
8294 the inheritance graph, and use that base's vtable
8295 now. */
8298 }
8299 }
8301 /* Add the initializer for the secondary vptr itself. */
8304 /* Advance the vtt index. */
8309 }
8311 /* Called from build_vtt_inits via dfs_walk. After building
8312 constructor vtables and generating the sub-vtt from them, we need
8313 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8314 binfo of the base whose sub vtt was generated. */
8316 static tree
8318 {
8322 /* If this class has no vtable, none of its bases do. */
8326 /* This might be a primary base, so have no vtable in this
8327 hierarchy. */
8330 /* If we scribbled the construction vtable vptr into BINFO, clear it
8331 out now. */
8337 }
8339 /* Build the construction vtable group for BINFO which is in the
8340 hierarchy dominated by T. */
8342 static void
8344 {
8345 tree type;
8346 tree vtbl;
8347 tree id;
8348 tree vbase;
8351 /* See if we've already created this construction vtable group. */
8357 /* Build a version of VTBL (with the wrong type) for use in
8358 constructing the addresses of secondary vtables in the
8359 construction vtable group. */
8367 /* Add the vtables for each of our virtual bases using the vbase in T
8368 binfo. */
8370 vbase;
8372 {
8373 tree b;
8380 }
8382 /* Figure out the type of the construction vtable. */
8389 /* Initialize the construction vtable. */
8393 }
8395 /* Add the vtbl initializers for BINFO (and its bases other than
8396 non-virtual primaries) to the list of INITS. BINFO is in the
8397 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8398 the constructor the vtbl inits should be accumulated for. (If this
8399 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8400 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8401 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8402 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8403 but are not necessarily the same in terms of layout. */
8405 static void
8407 tree orig_binfo,
8408 tree rtti_binfo,
8409 tree vtbl,
8410 tree t,
8412 {
8414 tree base_binfo;
8419 /* If it doesn't have a vptr, we don't do anything. */
8423 /* If we're building a construction vtable, we're not interested in
8424 subobjects that don't require construction vtables. */
8430 /* Build the initializers for the BINFO-in-T vtable. */
8433 /* Walk the BINFO and its bases. We walk in preorder so that as we
8434 initialize each vtable we can figure out at what offset the
8435 secondary vtable lies from the primary vtable. We can't use
8436 dfs_walk here because we need to iterate through bases of BINFO
8437 and RTTI_BINFO simultaneously. */
8439 {
8440 /* Skip virtual bases. */
8446 inits);
8447 }
8448 }
8450 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8451 BINFO vtable to L. */
8453 static void
8455 tree orig_binfo,
8456 tree rtti_binfo,
8457 tree orig_vtbl,
8458 tree t,
8460 {
8467 {
8468 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8469 primary virtual base. If it is not the same primary in
8470 the hierarchy of T, we'll need to generate a ctor vtable
8471 for it, to place at its location in T. If it is the same
8472 primary, we still need a VTT entry for the vtable, but it
8473 should point to the ctor vtable for the base it is a
8474 primary for within the sub-hierarchy of RTTI_BINFO.
8476 There are three possible cases:
8478 1) We are in the same place.
8479 2) We are a primary base within a lost primary virtual base of
8480 RTTI_BINFO.
8481 3) We are primary to something not a base of RTTI_BINFO. */
8483 tree b;
8486 /* First, look through the bases we are primary to for RTTI_BINFO
8487 or a virtual base. */
8490 {
8495 }
8496 /* If we run out of primary links, keep looking down our
8497 inheritance chain; we might be an indirect primary. */
8501 found:
8503 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8504 base B and it is a base of RTTI_BINFO, this is case 2. In
8505 either case, we share our vtable with LAST, i.e. the
8506 derived-most base within B of which we are a primary. */
8509 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8510 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8511 binfo_ctor_vtable after everything's been set up. */
8514 /* Otherwise, this is case 3 and we get our own. */
8515 }
8522 {
8523 tree index;
8526 /* Add the initializer for this vtable. */
8530 /* Figure out the position to which the VPTR should point. */
8536 }
8539 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8540 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8541 straighten this out. */
8544 /* Throw away any unneeded intializers. */
8546 else
8547 /* For an ordinary vtable, set BINFO_VTABLE. */
8549 }
8553 /* Construct the initializer for BINFO's virtual function table. BINFO
8554 is part of the hierarchy dominated by T. If we're building a
8555 construction vtable, the ORIG_BINFO is the binfo we should use to
8556 find the actual function pointers to put in the vtable - but they
8557 can be overridden on the path to most-derived in the graph that
8558 ORIG_BINFO belongs. Otherwise,
8559 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8560 BINFO that should be indicated by the RTTI information in the
8561 vtable; it will be a base class of T, rather than T itself, if we
8562 are building a construction vtable.
8564 The value returned is a TREE_LIST suitable for wrapping in a
8565 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8566 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8567 number of non-function entries in the vtable.
8569 It might seem that this function should never be called with a
8570 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8571 base is always subsumed by a derived class vtable. However, when
8572 we are building construction vtables, we do build vtables for
8573 primary bases; we need these while the primary base is being
8574 constructed. */
8576 static void
8578 tree orig_binfo,
8579 tree t,
8580 tree rtti_binfo,
8583 {
8584 tree v;
8585 vtbl_init_data vid;
8587 tree vbinfo;
8591 /* Initialize VID. */
8599 /* The first vbase or vcall offset is at index -3 in the vtable. */
8602 /* Add entries to the vtable for RTTI. */
8605 /* Create an array for keeping track of the functions we've
8606 processed. When we see multiple functions with the same
8607 signature, we share the vcall offsets. */
8609 /* Add the vcall and vbase offset entries. */
8612 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8613 build_vbase_offset_vtbl_entries. */
8618 /* If the target requires padding between data entries, add that now. */
8620 {
8625 /* Move data entries into their new positions and add padding
8626 after the new positions. Iterate backwards so we don't
8627 overwrite entries that we would need to process later. */
8630 ix--)
8631 {
8639 {
8643 null_pointer_node);
8644 }
8645 }
8646 }
8651 /* The initializers for virtual functions were built up in reverse
8652 order. Straighten them out and add them to the running list in one
8653 step. */
8662 /* Go through all the ordinary virtual functions, building up
8663 initializers. */
8665 {
8666 tree delta;
8667 tree vcall_index;
8674 {
8678 {
8681 }
8683 }
8685 /* If the only definition of this function signature along our
8686 primary base chain is from a lost primary, this vtable slot will
8687 never be used, so just zero it out. This is important to avoid
8688 requiring extra thunks which cannot be generated with the function.
8690 We first check this in update_vtable_entry_for_fn, so we handle
8691 restored primary bases properly; we also need to do it here so we
8692 zero out unused slots in ctor vtables, rather than filling them
8693 with erroneous values (though harmless, apart from relocation
8694 costs). */
8699 {
8700 /* Pull the offset for `this', and the function to call, out of
8701 the list. */
8708 /* You can't call an abstract virtual function; it's abstract.
8709 So, we replace these functions with __pure_virtual. */
8711 {
8714 {
8716 abort_fndecl_addr
8720 }
8721 }
8722 /* Likewise for deleted virtuals. */
8724 {
8729 NULL_TREE);
8733 }
8734 else
8735 {
8737 {
8741 }
8742 /* Take the address of the function, considering it to be of an
8743 appropriate generic type. */
8747 }
8748 }
8750 /* And add it to the chain of initializers. */
8752 {
8757 else
8759 {
8765 }
8766 }
8767 else
8769 }
8770 }
8772 /* Adds to vid->inits the initializers for the vbase and vcall
8773 offsets in BINFO, which is in the hierarchy dominated by T. */
8775 static void
8777 {
8778 tree b;
8780 /* If this is a derived class, we must first create entries
8781 corresponding to the primary base class. */
8786 /* Add the vbase entries for this base. */
8788 /* Add the vcall entries for this base. */
8790 }
8792 /* Returns the initializers for the vbase offset entries in the vtable
8793 for BINFO (which is part of the class hierarchy dominated by T), in
8794 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8795 where the next vbase offset will go. */
8797 static void
8799 {
8800 tree vbase;
8801 tree t;
8802 tree non_primary_binfo;
8804 /* If there are no virtual baseclasses, then there is nothing to
8805 do. */
8811 /* We might be a primary base class. Go up the inheritance hierarchy
8812 until we find the most derived class of which we are a primary base:
8813 it is the offset of that which we need to use. */
8816 {
8817 tree b;
8819 /* If we have reached a virtual base, then it must be a primary
8820 base (possibly multi-level) of vid->binfo, or we wouldn't
8821 have called build_vcall_and_vbase_vtbl_entries for it. But it
8822 might be a lost primary, so just skip down to vid->binfo. */
8824 {
8827 }
8833 }
8835 /* Go through the virtual bases, adding the offsets. */
8837 vbase;
8839 {
8840 tree b;
8841 tree delta;
8846 /* Find the instance of this virtual base in the complete
8847 object. */
8850 /* If we've already got an offset for this virtual base, we
8851 don't need another one. */
8856 /* Figure out where we can find this vbase offset. */
8865 /* The vbase offset had better be the same. */
8868 /* The next vbase will come at a more negative offset. */
8872 /* The initializer is the delta from BINFO to this virtual base.
8873 The vbase offsets go in reverse inheritance-graph order, and
8874 we are walking in inheritance graph order so these end up in
8875 the right order. */
8882 }
8883 }
8885 /* Adds the initializers for the vcall offset entries in the vtable
8886 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8887 to VID->INITS. */
8889 static void
8891 {
8892 /* We only need these entries if this base is a virtual base. We
8893 compute the indices -- but do not add to the vtable -- when
8894 building the main vtable for a class. */
8897 /* If BINFO is RTTI_BINFO, then (since BINFO does not
8898 correspond to VID->DERIVED), we are building a primary
8899 construction virtual table. Since this is a primary
8900 virtual table, we do not need the vcall offsets for
8901 BINFO. */
8903 {
8904 /* We need a vcall offset for each of the virtual functions in this
8905 vtable. For example:
8907 class A { virtual void f (); };
8908 class B1 : virtual public A { virtual void f (); };
8909 class B2 : virtual public A { virtual void f (); };
8910 class C: public B1, public B2 { virtual void f (); };
8912 A C object has a primary base of B1, which has a primary base of A. A
8913 C also has a secondary base of B2, which no longer has a primary base
8914 of A. So the B2-in-C construction vtable needs a secondary vtable for
8915 A, which will adjust the A* to a B2* to call f. We have no way of
8916 knowing what (or even whether) this offset will be when we define B2,
8917 so we store this "vcall offset" in the A sub-vtable and look it up in
8918 a "virtual thunk" for B2::f.
8920 We need entries for all the functions in our primary vtable and
8921 in our non-virtual bases' secondary vtables. */
8923 /* If we are just computing the vcall indices -- but do not need
8924 the actual entries -- not that. */
8927 /* Now, walk through the non-virtual bases, adding vcall offsets. */
8929 }
8930 }
8932 /* Build vcall offsets, starting with those for BINFO. */
8934 static void
8936 {
8938 tree primary_binfo;
8939 tree base_binfo;
8941 /* Don't walk into virtual bases -- except, of course, for the
8942 virtual base for which we are building vcall offsets. Any
8943 primary virtual base will have already had its offsets generated
8944 through the recursion in build_vcall_and_vbase_vtbl_entries. */
8948 /* If BINFO has a primary base, process it first. */
8953 /* Add BINFO itself to the list. */
8956 /* Scan the non-primary bases of BINFO. */
8960 }
8962 /* Called from build_vcall_offset_vtbl_entries_r. */
8964 static void
8966 {
8967 /* Make entries for the rest of the virtuals. */
8969 {
8970 tree orig_fn;
8972 /* The ABI requires that the methods be processed in declaration
8973 order. G++ 3.2 used the order in the vtable. */
8975 orig_fn;
8979 }
8980 else
8981 {
8982 tree derived_virtuals;
8983 tree base_virtuals;
8984 tree orig_virtuals;
8985 /* If BINFO is a primary base, the most derived class which has
8986 BINFO as a primary base; otherwise, just BINFO. */
8987 tree non_primary_binfo;
8989 /* We might be a primary base class. Go up the inheritance hierarchy
8990 until we find the most derived class of which we are a primary base:
8991 it is the BINFO_VIRTUALS there that we need to consider. */
8994 {
8995 tree b;
8997 /* If we have reached a virtual base, then it must be vid->vbase,
8998 because we ignore other virtual bases in
8999 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9000 base (possibly multi-level) of vid->binfo, or we wouldn't
9001 have called build_vcall_and_vbase_vtbl_entries for it. But it
9002 might be a lost primary, so just skip down to vid->binfo. */
9004 {
9008 }
9014 }
9017 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9018 where rtti_binfo is the most derived type. */
9019 non_primary_binfo
9025 base_virtuals;
9029 {
9030 tree orig_fn;
9032 /* Find the declaration that originally caused this function to
9033 be present in BINFO_TYPE (binfo). */
9036 /* When processing BINFO, we only want to generate vcall slots for
9037 function slots introduced in BINFO. So don't try to generate
9038 one if the function isn't even defined in BINFO. */
9043 }
9044 }
9045 }
9047 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9049 static void
9051 {
9053 tree vcall_offset;
9054 tree derived_entry;
9056 /* If there is already an entry for a function with the same
9057 signature as FN, then we do not need a second vcall offset.
9058 Check the list of functions already present in the derived
9059 class vtable. */
9061 {
9063 /* We only use one vcall offset for virtual destructors,
9064 even though there are two virtual table entries. */
9068 }
9070 /* If we are building these vcall offsets as part of building
9071 the vtable for the most derived class, remember the vcall
9072 offset. */
9074 {
9077 }
9079 /* The next vcall offset will be found at a more negative
9080 offset. */
9084 /* Keep track of this function. */
9088 {
9089 tree base;
9090 tree fn;
9092 /* Find the overriding function. */
9096 else
9097 {
9100 /* The vbase we're working on is a primary base of
9101 vid->binfo. But it might be a lost primary, so its
9102 BINFO_OFFSET might be wrong, so we just use the
9103 BINFO_OFFSET from vid->binfo. */
9109 vcall_offset);
9110 }
9111 /* Add the initializer to the vtable. */
9113 }
9114 }
9116 /* Return vtbl initializers for the RTTI entries corresponding to the
9117 BINFO's vtable. The RTTI entries should indicate the object given
9118 by VID->rtti_binfo. */
9120 static void
9122 {
9123 tree b;
9124 tree t;
9125 tree offset;
9126 tree decl;
9127 tree init;
9131 /* To find the complete object, we will first convert to our most
9132 primary base, and then add the offset in the vtbl to that value. */
9136 {
9137 tree primary_base;
9143 }
9147 /* The second entry is the address of the typeinfo object. */
9150 else
9153 /* Convert the declaration to a type that can be stored in the
9154 vtable. */
9158 /* Add the offset-to-top entry. It comes earlier in the vtable than
9159 the typeinfo entry. Convert the offset to look like a
9160 function pointer, so that we can put it in the vtable. */
9163 }
9165 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9166 accessibility. */
9168 bool
9170 {
9173 }
9175 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9177 bool
9179 {
9183 }