| blob | 3e1b44a4c1ec4371b5caaf1975ed6718a91d8ab2 |
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. */
205 splay_tree_key k2);
214 /* Variables shared between class.c and call.c. */
224 /* Convert to or from a base subobject. EXPR is an expression of type
225 `A' or `A*', an expression of type `B' or `B*' is returned. To
226 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
227 the B base instance within A. To convert base A to derived B, CODE
228 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
229 In this latter case, A must not be a morally virtual base of B.
230 NONNULL is true if EXPR is known to be non-NULL (this is only
231 needed when EXPR is of pointer type). CV qualifiers are preserved
232 from EXPR. */
234 tree
236 tree expr,
237 tree binfo,
239 tsubst_flags_t complain)
240 {
243 tree probe;
244 tree offset;
245 tree target_type;
247 tree ptr_target_type;
257 {
263 }
271 {
272 /* This can happen when adjust_result_of_qualified_name_lookup can't
273 find a unique base binfo in a call to a member function. We
274 couldn't give the diagnostic then since we might have been calling
275 a static member function, so we do it now. */
277 {
281 }
283 }
290 /* Nothing to do. */
294 {
300 }
303 /* This must happen before the call to save_expr. */
305 else
311 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
312 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
313 expression returned matches the input. */
314 target_type = cp_build_qualified_type
318 /* Do we need to look in the vtable for the real offset? */
321 /* Don't bother with the calculations inside sizeof; they'll ICE if the
322 source type is incomplete and the pointer value doesn't matter. In a
323 template (even in fold_non_dependent_expr), we don't have vtables set
324 up properly yet, and the value doesn't matter there either; we're just
325 interested in the result of overload resolution. */
328 {
333 }
335 /* If we're in an NSDMI, we don't have the full constructor context yet
336 that we need for converting to a virtual base, so just build a stub
337 CONVERT_EXPR and expand it later in bot_replace. */
340 {
346 }
348 /* Do we need to check for a null pointer? */
350 {
351 /* If we know the conversion will not actually change the value
352 of EXPR, then we can avoid testing the expression for NULL.
353 We have to avoid generating a COMPONENT_REF for a base class
354 field, because other parts of the compiler know that such
355 expressions are always non-NULL. */
359 }
361 /* Protect against multiple evaluation if necessary. */
365 /* Now that we've saved expr, build the real null test. */
367 {
371 }
373 /* If this is a simple base reference, express it as a COMPONENT_REF. */
375 /* We don't build base fields for empty bases, and they aren't very
376 interesting to the optimizers anyway. */
378 {
385 }
388 {
389 /* Going via virtual base V_BINFO. We need the static offset
390 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
391 V_BINFO. That offset is an entry in D_BINFO's vtable. */
392 tree v_offset;
395 {
396 /* In a base member initializer, we cannot rely on the
397 vtable being set up. We have to indirect via the
398 vtt_parm. */
399 tree t;
405 }
406 else
408 complain),
414 v_offset);
426 /* Negative fixed_type_p means this is a constructor or destructor;
427 virtual base layout is fixed in in-charge [cd]tors, but not in
428 base [cd]tors. */
432 v_offset,
435 else
437 }
445 {
450 }
451 else
457 out:
463 }
465 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
466 Perform a derived-to-base conversion by recursively building up a
467 sequence of COMPONENT_REFs to the appropriate base fields. */
469 static tree
471 {
474 tree field;
477 {
478 tree temp;
482 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
483 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
484 an lvalue in the front end; only _DECLs and _REFs are lvalues
485 in the back end. */
491 }
493 /* Recurse. */
498 /* Is this the base field created by build_base_field? */
502 /* If we're looking for a field in the most-derived class,
503 also check the field offset; we can have two base fields
504 of the same type if one is an indirect virtual base and one
505 is a direct non-virtual base. */
509 {
510 /* We don't use build_class_member_access_expr here, as that
511 has unnecessary checks, and more importantly results in
512 recursive calls to dfs_walk_once. */
520 /* Mark the expression const or volatile, as appropriate.
521 Even though we've dealt with the type above, we still have
522 to mark the expression itself. */
529 }
531 /* Didn't find the base field?!? */
533 }
535 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
536 type is a class type or a pointer to a class type. In the former
537 case, TYPE is also a class type; in the latter it is another
538 pointer type. If CHECK_ACCESS is true, an error message is emitted
539 if TYPE is inaccessible. If OBJECT has pointer type, the value is
540 assumed to be non-NULL. */
542 tree
544 tsubst_flags_t complain)
545 {
546 tree binfo;
547 tree object_type;
550 {
553 }
554 else
563 }
565 /* EXPR is an expression with unqualified class type. BASE is a base
566 binfo of that class type. Returns EXPR, converted to the BASE
567 type. This function assumes that EXPR is the most derived class;
568 therefore virtual bases can be found at their static offsets. */
570 tree
572 {
573 tree expr_type;
577 {
578 /* If this is a non-empty base, use a COMPONENT_REF. */
582 /* We use fold_build2 and fold_convert below to simplify the trees
583 provided to the optimizers. It is not safe to call these functions
584 when processing a template because they do not handle C++-specific
585 trees. */
593 }
596 }
598 \f
599 tree
601 {
607 /* First, convert to the requested type. */
612 /* Second, the requested type may not be the owner of its own vptr.
613 If not, convert to the base class that owns it. We cannot use
614 convert_to_base here, because VCONTEXT may appear more than once
615 in the inheritance hierarchy of TYPE, and thus direct conversion
616 between the types may be ambiguous. Following the path back up
617 one step at a time via primary bases avoids the problem. */
621 {
624 }
627 }
629 /* Given an object INSTANCE, return an expression which yields the
630 vtable element corresponding to INDEX. There are many special
631 cases for INSTANCE which we take care of here, mainly to avoid
632 creating extra tree nodes when we don't have to. */
634 static tree
636 {
637 tree aref;
640 /* Try to figure out what a reference refers to, and
641 access its virtual function table directly. */
649 {
654 }
663 }
665 tree
667 {
671 }
673 /* Given a stable object pointer INSTANCE_PTR, return an expression which
674 yields a function pointer corresponding to vtable element INDEX. */
676 tree
678 {
679 tree aref;
682 tf_warning_or_error),
683 idx);
685 /* When using function descriptors, the address of the
686 vtable entry is treated as a function pointer. */
691 /* Remember this as a method reference, for later devirtualization. */
695 }
697 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
698 for the given TYPE. */
700 static tree
702 {
704 }
706 /* DECL is an entity associated with TYPE, like a virtual table or an
707 implicitly generated constructor. Determine whether or not DECL
708 should have external or internal linkage at the object file
709 level. This routine does not deal with COMDAT linkage and other
710 similar complexities; it simply sets TREE_PUBLIC if it possible for
711 entities in other translation units to contain copies of DECL, in
712 the abstract. */
714 void
716 {
719 }
721 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
722 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
723 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
725 static tree
727 {
728 tree decl;
731 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
732 now to avoid confusion in mangle_decl. */
741 /* At one time the vtable info was grabbed 2 words at a time. This
742 fails on sparc unless you have 8-byte alignment. (tiemann) */
746 /* The vtable has not been defined -- yet. */
750 /* Mark the VAR_DECL node representing the vtable itself as a
751 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
752 is rather important that such things be ignored because any
753 effort to actually generate DWARF for them will run into
754 trouble when/if we encounter code like:
756 #pragma interface
757 struct S { virtual void member (); };
759 because the artificial declaration of the vtable itself (as
760 manufactured by the g++ front end) will say that the vtable is
761 a static member of `S' but only *after* the debug output for
762 the definition of `S' has already been output. This causes
763 grief because the DWARF entry for the definition of the vtable
764 will try to refer back to an earlier *declaration* of the
765 vtable as a static member of `S' and there won't be one. We
766 might be able to arrange to have the "vtable static member"
767 attached to the member list for `S' before the debug info for
768 `S' get written (which would solve the problem) but that would
769 require more intrusive changes to the g++ front end. */
773 }
775 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
776 or even complete. If this does not exist, create it. If COMPLETE is
777 nonzero, then complete the definition of it -- that will render it
778 impossible to actually build the vtable, but is useful to get at those
779 which are known to exist in the runtime. */
781 tree
783 {
784 tree decl;
793 {
796 }
799 }
801 /* Build the primary virtual function table for TYPE. If BINFO is
802 non-NULL, build the vtable starting with the initial approximation
803 that it is the same as the one which is the head of the association
804 list. Returns a nonzero value if a new vtable is actually
805 created. */
807 static int
809 {
810 tree decl;
811 tree virtuals;
816 {
818 /* We have already created a vtable for this base, so there's
819 no need to do it again. */
826 }
827 else
828 {
831 }
834 {
837 }
839 /* Initialize the association list for this type, based
840 on our first approximation. */
845 }
847 /* Give BINFO a new virtual function table which is initialized
848 with a skeleton-copy of its original initialization. The only
849 entry that changes is the `delta' entry, so we can really
850 share a lot of structure.
852 FOR_TYPE is the most derived type which caused this table to
853 be needed.
855 Returns nonzero if we haven't met BINFO before.
857 The order in which vtables are built (by calling this function) for
858 an object must remain the same, otherwise a binary incompatibility
859 can result. */
861 static int
863 {
865 /* We already created a vtable for this base. There's no need to
866 do it again. */
869 /* Remember that we've created a vtable for this BINFO, so that we
870 don't try to do so again. */
873 /* Make fresh virtual list, so we can smash it later. */
876 /* Secondary vtables are laid out as part of the same structure as
877 the primary vtable. */
880 }
882 /* Create a new vtable for BINFO which is the hierarchy dominated by
883 T. Return nonzero if we actually created a new vtable. */
885 static int
887 {
889 /* In this case, it is *type*'s vtable we are modifying. We start
890 with the approximation that its vtable is that of the
891 immediate base class. */
893 else
894 /* This is our very own copy of `basetype' to play with. Later,
895 we will fill in all the virtual functions that override the
896 virtual functions in these base classes which are not defined
897 by the current type. */
899 }
901 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
902 (which is in the hierarchy dominated by T) list FNDECL as its
903 BV_FN. DELTA is the required constant adjustment from the `this'
904 pointer where the vtable entry appears to the `this' required when
905 the function is actually called. */
907 static void
909 tree binfo,
910 tree fndecl,
911 tree delta,
913 {
914 tree v;
920 {
921 /* We need a new vtable for BINFO. */
923 {
924 /* If we really did make a new vtable, we also made a copy
925 of the BINFO_VIRTUALS list. Now, we have to find the
926 corresponding entry in that list. */
931 }
936 }
937 }
939 \f
940 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
941 the USING_DECL naming METHOD. Returns true if the method could be
942 added to the method vec. */
944 bool
946 {
948 tree overload;
954 tree current_fns;
955 tree fns;
968 {
969 /* Make a new method vector. We start with 8 entries. We must
970 allocate at least two (for constructors and destructors), and
971 we're going to end up with an assignment operator at some
972 point as well. */
974 /* Create slots for constructors and destructors. */
978 }
980 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
983 /* Constructors and destructors go in special slots. */
987 {
991 {
997 type);
998 }
999 }
1000 else
1001 {
1002 tree m;
1005 /* See if we already have an entry with this name. */
1009 {
1012 {
1017 }
1021 {
1024 }
1029 }
1030 }
1033 /* Check to see if we've already got this method. */
1035 {
1037 tree fn_type;
1038 tree method_type;
1039 tree parms1;
1040 tree parms2;
1045 /* [over.load] Member function declarations with the
1046 same name and the same parameter types cannot be
1047 overloaded if any of them is a static member
1048 function declaration.
1050 [namespace.udecl] When a using-declaration brings names
1051 from a base class into a derived class scope, member
1052 functions in the derived class override and/or hide member
1053 functions with the same name and parameter types in a base
1054 class (rather than conflicting). */
1060 /* Compare the quals on the 'this' parm. Don't compare
1061 the whole types, as used functions are treated as
1062 coming from the using class in overload resolution. */
1071 /* For templates, the return type and template parameters
1072 must be identical. */
1089 {
1091 {
1093 {
1100 }
1101 /* Otherwise defer to the other function. */
1103 }
1105 {
1107 /* Defer to the local function. */
1109 }
1110 else
1111 {
1114 }
1116 /* We don't call duplicate_decls here to merge the
1117 declarations because that will confuse things if the
1118 methods have inline definitions. In particular, we
1119 will crash while processing the definitions. */
1121 }
1122 }
1124 /* A class should never have more than one destructor. */
1128 /* Add the new binding. */
1130 {
1133 }
1134 else
1143 {
1146 /* We only expect to add few methods in the COMPLETE_P case, so
1147 just make room for one more method in that case. */
1150 else
1156 else
1158 }
1159 else
1160 /* Replace the current slot. */
1163 }
1165 /* Subroutines of finish_struct. */
1167 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1168 legit, otherwise return 0. */
1170 static int
1172 {
1173 tree elem;
1182 {
1184 {
1188 else
1191 }
1192 else
1193 {
1194 /* They're changing the access to the same thing they changed
1195 it to before. That's OK. */
1196 ;
1197 }
1198 }
1199 else
1200 {
1202 tf_warning_or_error);
1205 }
1207 }
1209 /* Process the USING_DECL, which is a member of T. */
1211 static void
1213 {
1216 tree access
1221 tree old_value;
1226 tf_warning_or_error);
1228 {
1234 else
1236 }
1244 ;
1246 {
1248 /* It's OK to use functions from a base when there are functions with
1250 else
1251 {
1256 }
1257 }
1259 {
1263 }
1265 /* Make type T see field decl FDECL with access ACCESS. */
1268 {
1271 }
1272 else
1274 }
1275 \f
1276 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1277 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1278 properties of the bases. */
1280 static void
1284 {
1288 tree base_binfo;
1289 tree binfo;
1299 {
1308 /* If any base class is non-literal, so is the derived class. */
1312 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1313 here because the case of virtual functions but non-virtual
1314 dtor is handled in finish_struct_1. */
1319 /* If the base class doesn't have copy constructors or
1320 assignment operators that take const references, then the
1321 derived class cannot have such a member automatically
1322 generated. */
1331 /* A virtual base does not effect nearly emptiness. */
1332 ;
1334 {
1336 /* And if there is more than one nearly empty base, then the
1337 derived class is not nearly empty either. */
1339 else
1340 /* Remember we've seen one. */
1342 }
1344 /* If the base class is not empty or nearly empty, then this
1345 class cannot be nearly empty. */
1348 /* A lot of properties from the bases also apply to the derived
1349 class. */
1367 /* A standard-layout class is a class that:
1368 ...
1369 * has no non-standard-layout base classes, */
1372 {
1373 tree basefield;
1374 /* ...has no base classes of the same type as the first non-static
1375 data member... */
1377 && (same_type_ignoring_top_level_qualifiers_p
1380 else
1381 /* ...either has no non-static data members in the most-derived
1382 class and at most one base class with non-static data
1383 members, or has no base classes with non-static data
1384 members */
1388 {
1391 else
1394 }
1395 }
1397 /* Don't bother collecting tm attributes if transactional memory
1398 support is not enabled. */
1400 {
1404 }
1405 }
1407 /* If one of the base classes had TM attributes, and the current class
1408 doesn't define its own, then the current class inherits one. */
1410 {
1413 }
1414 }
1416 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1417 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1418 that have had a nearly-empty virtual primary base stolen by some
1419 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1420 T. */
1422 static void
1424 {
1428 tree base_binfo;
1430 /* Determine the primary bases of our bases. */
1433 {
1436 /* See if we're the non-virtual primary of our inheritance
1437 chain. */
1439 {
1446 /* We are the primary binfo. */
1448 }
1449 /* Determine if we have a virtual primary base, and mark it so.
1450 */
1452 {
1456 /* Someone already claimed this base. */
1458 else
1459 {
1460 tree delta;
1465 /* A virtual binfo might have been copied from within
1466 another hierarchy. As we're about to use it as a
1467 primary base, make sure the offsets match. */
1475 }
1476 }
1477 }
1479 /* First look for a dynamic direct non-virtual base. */
1481 {
1485 {
1488 }
1489 }
1491 /* A "nearly-empty" virtual base class can be the primary base
1492 class, if no non-virtual polymorphic base can be found. Look for
1493 a nearly-empty virtual dynamic base that is not already a primary
1494 base of something in the hierarchy. If there is no such base,
1495 just pick the first nearly-empty virtual base. */
1501 {
1503 {
1504 /* Found one that is not primary. */
1507 }
1509 /* Remember the first candidate. */
1511 }
1513 found:
1514 /* If we've got a primary base, use it. */
1516 {
1521 /* We are stealing a primary base. */
1525 {
1526 tree delta;
1529 /* A virtual binfo might have been copied from within
1530 another hierarchy. As we're about to use it as a primary
1531 base, make sure the offsets match. */
1536 }
1543 }
1544 }
1546 /* Update the variant types of T. */
1548 void
1550 {
1551 tree variants;
1557 variants;
1559 {
1560 /* These fields are in the _TYPE part of the node, not in
1561 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1571 /* Copy whatever these are holding today. */
1575 }
1576 }
1578 /* Early variant fixups: we apply attributes at the beginning of the class
1579 definition, and we need to fix up any variants that have already been
1580 made via elaborated-type-specifier so that check_qualified_type works. */
1582 void
1584 {
1585 tree variants;
1591 variants;
1593 {
1594 /* These are the two fields that check_qualified_type looks at and
1595 are affected by attributes. */
1598 }
1599 }
1600 \f
1601 /* Set memoizing fields and bits of T (and its variants) for later
1602 use. */
1604 static void
1606 {
1607 /* Fix up variants (if any). */
1611 /* For a class w/o baseclasses, 'finish_struct' has set
1612 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1613 Similarly for a class whose base classes do not have vtables.
1614 When neither of these is true, we might have removed abstract
1615 virtuals (by providing a definition), added some (by declaring
1616 new ones), or redeclared ones from a base class. We need to
1617 recalculate what's really an abstract virtual at this point (by
1618 looking in the vtables). */
1621 /* If this type has a copy constructor or a destructor, force its
1622 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1623 nonzero. This will cause it to be passed by invisible reference
1624 and prevent it from being returned in a register. */
1627 {
1628 tree variants;
1631 {
1634 }
1635 }
1636 }
1638 /* Issue warnings about T having private constructors, but no friends,
1639 and so forth.
1641 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1642 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1643 non-private static member functions. */
1645 static void
1647 {
1650 tree fn;
1653 /* If the class has friends, those entities might create and
1654 access instances, so we should not warn. */
1657 /* We will have warned when the template was declared; there's
1658 no need to warn on every instantiation. */
1660 /* There's no reason to even consider warning about this
1661 class. */
1664 /* We only issue one warning, if more than one applies, because
1665 otherwise, on code like:
1667 class A {
1668 // Oops - forgot `public:'
1669 A();
1670 A(const A&);
1671 ~A();
1672 };
1674 we warn several times about essentially the same problem. */
1676 /* Check to see if all (non-constructor, non-destructor) member
1677 functions are private. (Since there are no friends or
1678 non-private statics, we can't ever call any of the private member
1679 functions.) */
1681 /* We're not interested in compiler-generated methods; they don't
1682 provide any way to call private members. */
1684 {
1686 {
1688 /* A non-private static member function is just like a
1689 friend; it can create and invoke private member
1690 functions, and be accessed without a class
1691 instance. */
1695 /* Keep searching for a static member function. */
1696 }
1699 }
1702 {
1703 /* There are no non-private methods, and there's at least one
1704 private member function that isn't a constructor or
1705 destructor. (If all the private members are
1706 constructors/destructors we want to use the code below that
1707 issues error messages specifically referring to
1708 constructors/destructors.) */
1714 {
1717 }
1719 {
1723 }
1724 }
1726 /* Even if some of the member functions are non-private, the class
1727 won't be useful for much if all the constructors or destructors
1728 are private: such an object can never be created or destroyed. */
1731 {
1734 t);
1736 }
1738 /* Warn about classes that have private constructors and no friends. */
1740 /* Implicitly generated constructors are always public. */
1743 {
1746 /* If a non-template class does not define a copy
1747 constructor, one is defined for it, enabling it to avoid
1748 this warning. For a template class, this does not
1749 happen, and so we would normally get a warning on:
1751 template <class T> class C { private: C(); };
1753 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1754 complete non-template or fully instantiated classes have this
1755 flag set. */
1758 else
1760 {
1762 /* Ideally, we wouldn't count copy constructors (or, in
1763 fact, any constructor that takes an argument of the
1764 class type as a parameter) because such things cannot
1765 be used to construct an instance of the class unless
1766 you already have one. But, for now at least, we're
1767 more generous. */
1769 {
1772 }
1773 }
1776 {
1779 t);
1781 }
1782 }
1783 }
1786 gt_pointer_operator new_value;
1790 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1792 static int
1794 {
1807 }
1809 /* This routine compares two fields like method_name_cmp but using the
1810 pointer operator in resort_field_decl_data. */
1812 static int
1814 {
1823 {
1830 }
1832 }
1834 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1836 void
1839 gt_pointer_operator new_value,
1841 {
1845 tree fn;
1847 /* The type conversion ops have to live at the front of the vec, so we
1848 can't sort them. */
1856 {
1860 resort_method_name_cmp);
1861 }
1862 }
1864 /* Warn about duplicate methods in fn_fields.
1866 Sort methods that are not special (i.e., constructors, destructors,
1867 and type conversion operators) so that we can find them faster in
1868 search. */
1870 static void
1872 {
1873 tree fn_fields;
1883 /* Clear DECL_IN_AGGR_P for all functions. */
1888 /* Issue warnings about private constructors and such. If there are
1889 no methods, then some public defaults are generated. */
1892 /* The type conversion ops have to live at the front of the vec, so we
1893 can't sort them. */
1902 }
1904 /* Make BINFO's vtable have N entries, including RTTI entries,
1905 vbase and vcall offsets, etc. Set its type and call the back end
1906 to lay it out. */
1908 static void
1910 {
1911 tree atype;
1912 tree vtable;
1917 /* We may have to grow the vtable. */
1920 {
1924 }
1925 }
1927 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1928 have the same signature. */
1930 int
1932 {
1933 /* One destructor overrides another if they are the same kind of
1934 destructor. */
1938 /* But a non-destructor never overrides a destructor, nor vice
1939 versa, nor do different kinds of destructors override
1940 one-another. For example, a complete object destructor does not
1941 override a deleting destructor. */
1950 {
1958 }
1960 }
1962 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1963 subobject. */
1965 static bool
1967 {
1968 tree probe;
1971 {
1975 /* If we meet a virtual base, we can't follow the inheritance
1976 any more. See if the complete type of DERIVED contains
1977 such a virtual base. */
1980 }
1982 }
1985 /* The function for which we are trying to find a final overrider. */
1986 tree fn;
1987 /* The base class in which the function was declared. */
1988 tree declaring_base;
1989 /* The candidate overriders. */
1990 tree candidates;
1991 /* Path to most derived. */
1995 /* Add the overrider along the current path to FFOD->CANDIDATES.
1996 Returns true if an overrider was found; false otherwise. */
1998 static bool
2002 {
2003 tree method;
2005 /* If BINFO is not the most derived type, try a more derived class.
2006 A definition there will overrider a definition here. */
2008 {
2009 depth--;
2013 }
2017 {
2020 /* Remove any candidates overridden by this new function. */
2022 {
2023 /* If *CANDIDATE overrides METHOD, then METHOD
2024 cannot override anything else on the list. */
2027 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2030 else
2032 }
2034 /* Add the new function. */
2037 }
2040 }
2042 /* Called from find_final_overrider via dfs_walk. */
2044 static tree
2046 {
2054 }
2056 static tree
2058 {
2063 }
2065 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2066 FN and whose TREE_VALUE is the binfo for the base where the
2067 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2068 DERIVED) is the base object in which FN is declared. */
2070 static tree
2072 {
2073 find_final_overrider_data ffod;
2075 /* Getting this right is a little tricky. This is valid:
2077 struct S { virtual void f (); };
2078 struct T { virtual void f (); };
2079 struct U : public S, public T { };
2081 even though calling `f' in `U' is ambiguous. But,
2083 struct R { virtual void f(); };
2084 struct S : virtual public R { virtual void f (); };
2085 struct T : virtual public R { virtual void f (); };
2086 struct U : public S, public T { };
2088 is not -- there's no way to decide whether to put `S::f' or
2089 `T::f' in the vtable for `R'.
2091 The solution is to look at all paths to BINFO. If we find
2092 different overriders along any two, then there is a problem. */
2096 /* Determine the depth of the hierarchy. */
2107 /* If there was no winner, issue an error message. */
2112 }
2114 /* Return the index of the vcall offset for FN when TYPE is used as a
2115 virtual base. */
2117 static tree
2119 {
2121 tree_pair_p p;
2129 /* There should always be an appropriate index. */
2131 }
2133 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2134 dominated by T. FN is the old function; VIRTUALS points to the
2135 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2136 of that entry in the list. */
2138 static void
2141 {
2142 tree b;
2143 tree overrider;
2144 tree delta;
2145 tree virtual_base;
2146 tree first_defn;
2152 /* Find the nearest primary base (possibly binfo itself) which defines
2153 this function; this is the class the caller will convert to when
2154 calling FN through BINFO. */
2156 {
2161 /* The nearest definition is from a lost primary. */
2164 }
2167 /* Find the final overrider. */
2170 {
2173 }
2176 /* Check for adjusting covariant return types. */
2184 /* If the overrider is invalid, don't even try. */
2186 {
2187 /* If FN is a covariant thunk, we must figure out the adjustment
2188 to the final base FN was converting to. As OVERRIDER_TARGET might
2189 also be converting to the return type of FN, we have to
2190 combine the two conversions here. */
2197 {
2201 }
2202 else
2206 /* Find the equivalent binfo within the return type of the
2207 overriding function. We will want the vbase offset from
2208 there. */
2210 over_return);
2213 {
2214 /* There was no existing virtual thunk (which takes
2215 precedence). So find the binfo of the base function's
2216 return type within the overriding function's return type.
2217 We cannot call lookup base here, because we're inside a
2218 dfs_walk, and will therefore clobber the BINFO_MARKED
2219 flags. Fortunately we know the covariancy is valid (it
2220 has already been checked), so we can just iterate along
2221 the binfos, which have been chained in inheritance graph
2222 order. Of course it is lame that we have to repeat the
2223 search here anyway -- we should really be caching pieces
2224 of the vtable and avoiding this repeated work. */
2227 /* Find the base binfo within the overriding function's
2228 return type. We will always find a thunk_binfo, except
2229 when the covariancy is invalid (which we will have
2230 already diagnosed). */
2233 thunk_binfo;
2239 /* See if virtual inheritance is involved. */
2241 virtual_offset;
2248 {
2252 {
2253 /* We convert via virtual base. Adjust the fixed
2254 offset to be from there. */
2255 offset =
2259 }
2261 /* There was an existing fixed offset, this must be
2262 from the base just converted to, and the base the
2263 FN was thunking to. */
2265 else
2267 }
2268 }
2271 /* Replace the overriding function with a covariant thunk. We
2272 will emit the overriding function in its own slot as
2273 well. */
2276 }
2277 else
2281 /* If we need a covariant thunk, then we may need to adjust first_defn.
2282 The ABI specifies that the thunks emitted with a function are
2283 determined by which bases the function overrides, so we need to be
2284 sure that we're using a thunk for some overridden base; even if we
2285 know that the necessary this adjustment is zero, there may not be an
2286 appropriate zero-this-adjusment thunk for us to use since thunks for
2287 overriding virtual bases always use the vcall offset.
2289 Furthermore, just choosing any base that overrides this function isn't
2290 quite right, as this slot won't be used for calls through a type that
2291 puts a covariant thunk here. Calling the function through such a type
2292 will use a different slot, and that slot is the one that determines
2293 the thunk emitted for that base.
2295 So, keep looking until we find the base that we're really overriding
2296 in this slot: the nearest primary base that doesn't use a covariant
2297 thunk in this slot. */
2299 {
2301 /* We already know that the overrider needs a covariant thunk. */
2304 {
2311 }
2313 }
2315 /* Assume that we will produce a thunk that convert all the way to
2316 the final overrider, and not to an intermediate virtual base. */
2319 /* See if we can convert to an intermediate virtual base first, and then
2320 use the vcall offset located there to finish the conversion. */
2322 {
2323 /* If we find the final overrider, then we can stop
2324 walking. */
2329 /* If we find a virtual base, and we haven't yet found the
2330 overrider, then there is a virtual base between the
2331 declaring base (first_defn) and the final overrider. */
2333 {
2336 }
2337 }
2339 /* Compute the constant adjustment to the `this' pointer. The
2340 `this' pointer, when this function is called, will point at BINFO
2341 (or one of its primary bases, which are at the same offset). */
2343 /* The `this' pointer needs to be adjusted from the declaration to
2344 the nearest virtual base. */
2349 /* If the nearest definition is in a lost primary, we don't need an
2350 entry in our vtable. Except possibly in a constructor vtable,
2351 if we happen to get our primary back. In that case, the offset
2352 will be zero, as it will be a primary base. */
2354 else
2355 /* The `this' pointer needs to be adjusted from pointing to
2356 BINFO to pointing at the base where the final overrider
2357 appears. */
2368 else
2372 }
2374 /* Called from modify_all_vtables via dfs_walk. */
2376 static tree
2378 {
2380 tree virtuals;
2381 tree old_virtuals;
2385 /* A base without a vtable needs no modification, and its bases
2386 are uninteresting. */
2391 /* Don't do the primary vtable, if it's new. */
2395 /* There's no need to modify the vtable for a non-virtual primary
2396 base; we're not going to use that vtable anyhow. We do still
2397 need to do this for virtual primary bases, as they could become
2398 non-primary in a construction vtable. */
2403 /* Now, go through each of the virtual functions in the virtual
2404 function table for BINFO. Find the final overrider, and update
2405 the BINFO_VIRTUALS list appropriately. */
2408 virtuals;
2412 binfo,
2417 }
2419 /* Update all of the primary and secondary vtables for T. Create new
2420 vtables as required, and initialize their RTTI information. Each
2421 of the functions in VIRTUALS is declared in T and may override a
2422 virtual function from a base class; find and modify the appropriate
2423 entries to point to the overriding functions. Returns a list, in
2424 declaration order, of the virtual functions that are declared in T,
2425 but do not appear in the primary base class vtable, and which
2426 should therefore be appended to the end of the vtable for T. */
2428 static tree
2430 {
2434 /* Update all of the vtables. */
2437 /* Add virtual functions not already in our primary vtable. These
2438 will be both those introduced by this class, and those overridden
2439 from secondary bases. It does not include virtuals merely
2440 inherited from secondary bases. */
2442 {
2447 {
2448 /* We don't need to adjust the `this' pointer when
2449 calling this function. */
2453 /* This is a function not already in our vtable. Keep it. */
2455 }
2456 else
2457 /* We've already got an entry for this function. Skip it. */
2459 }
2462 }
2464 /* Get the base virtual function declarations in T that have the
2465 indicated NAME. */
2467 static tree
2469 {
2470 tree methods;
2475 /* Find virtual functions in T with the indicated NAME. */
2479 methods;
2481 {
2487 }
2493 {
2496 base_fndecls);
2497 }
2500 }
2502 /* If this declaration supersedes the declaration of
2503 a method declared virtual in the base class, then
2504 mark this field as being virtual as well. */
2506 void
2508 {
2511 /* In [temp.mem] we have:
2513 A specialization of a member function template does not
2514 override a virtual function from a base class. */
2521 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2522 the error_mark_node so that we know it is an overriding
2523 function. */
2524 {
2527 }
2530 {
2536 }
2541 }
2543 /* Warn about hidden virtual functions that are not overridden in t.
2544 We know that constructors and destructors don't apply. */
2546 static void
2548 {
2550 tree fns;
2553 /* We go through each separately named virtual function. */
2557 {
2558 tree fn;
2559 tree name;
2560 tree fndecl;
2561 tree base_fndecls;
2562 tree base_binfo;
2563 tree binfo;
2566 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2567 have the same name. Figure out what name that is. */
2569 /* There are no possibly hidden functions yet. */
2571 /* Iterate through all of the base classes looking for possibly
2572 hidden functions. */
2575 {
2578 base_fndecls);
2579 }
2581 /* If there are no functions to hide, continue. */
2585 /* Remove any overridden functions. */
2587 {
2590 {
2594 /* If the method from the base class has the same
2595 signature as the method from the derived class, it
2596 has been overridden. */
2599 else
2601 }
2602 }
2604 /* Now give a warning for all base functions without overriders,
2605 as they are hidden. */
2607 {
2608 /* Here we know it is a hider, and no overrider exists. */
2612 }
2613 }
2614 }
2616 /* Check for things that are invalid. There are probably plenty of other
2617 things we should check for also. */
2619 static void
2621 {
2622 tree field;
2625 {
2633 {
2637 {
2638 /* We're generally only interested in entities the user
2639 declared, but we also find nested classes by noticing
2640 the TYPE_DECL that we create implicitly. You're
2641 allowed to put one anonymous union inside another,
2642 though, so we explicitly tolerate that. We use
2643 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2644 we also allow unnamed types used for defining fields. */
2651 {
2655 else
2659 }
2662 {
2665 else
2667 }
2669 {
2672 else
2674 }
2678 }
2679 }
2680 }
2681 }
2683 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2684 will be used later during class template instantiation.
2685 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2686 a non-static member data (FIELD_DECL), a member function
2687 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2688 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2689 When FRIEND_P is nonzero, T is either a friend class
2690 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2691 (FUNCTION_DECL, TEMPLATE_DECL). */
2693 void
2695 {
2696 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2701 }
2703 /* This function is called from declare_virt_assop_and_dtor via
2704 dfs_walk_all.
2706 DATA is a type that direcly or indirectly inherits the base
2707 represented by BINFO. If BINFO contains a virtual assignment [copy
2708 assignment or move assigment] operator or a virtual constructor,
2709 declare that function in DATA if it hasn't been already declared. */
2711 static tree
2713 {
2721 /* A base without a vtable needs no modification, and its bases
2722 are uninteresting. */
2726 /* If this is a primary base, then we have already looked at the
2727 virtual functions of its vtable. */
2731 {
2735 {
2740 }
2744 }
2747 }
2749 /* If the class type T has a direct or indirect base that contains a
2750 virtual assignment operator or a virtual destructor, declare that
2751 function in T if it hasn't been already declared. */
2753 static void
2755 {
2763 dfs_declare_virt_assop_and_dtor,
2765 }
2767 /* Declare the inheriting constructor for class T inherited from base
2768 constructor CTOR with the parameter array PARMS of size NPARMS. */
2770 static void
2772 {
2773 /* We don't declare an inheriting ctor that would be a default,
2774 copy or move ctor. */
2787 {
2790 }
2791 }
2793 /* Declare all the inheriting constructors for class T inherited from base
2794 constructor CTOR. */
2796 static void
2798 {
2804 {
2808 }
2811 {
2815 }
2816 }
2818 /* Create default constructors, assignment operators, and so forth for
2819 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2820 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2821 the class cannot have a default constructor, copy constructor
2822 taking a const reference argument, or an assignment operator taking
2823 a const reference, respectively. */
2825 static void
2829 {
2837 /* Destructor. */
2839 {
2840 /* In general, we create destructors lazily. */
2845 /* But if this is a Java class, any non-trivial destructor is
2846 invalid, even if compiler-generated. Therefore, if the
2847 destructor is non-trivial we create it now. */
2849 }
2851 /* [class.ctor]
2853 If there is no user-declared constructor for a class, a default
2854 constructor is implicitly declared. */
2856 {
2861 /* This might force the declaration. */
2863 }
2865 /* [class.ctor]
2867 If a class definition does not explicitly declare a copy
2868 constructor, one is declared implicitly. */
2870 {
2876 }
2878 /* If there is no assignment operator, one will be created if and
2879 when it is needed. For now, just record whether or not the type
2880 of the parameter to the assignment operator will be a const or
2881 non-const reference. */
2883 {
2889 }
2891 /* We can't be lazy about declaring functions that might override
2892 a virtual function from a base class. */
2896 {
2900 {
2901 /* declare, then remove the decl */
2910 }
2911 else
2913 }
2914 }
2916 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
2917 count the number of fields in TYPE, including anonymous union
2918 members. */
2920 static int
2922 {
2923 tree x;
2926 {
2929 else
2931 }
2933 }
2935 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
2936 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
2937 elts, starting at offset IDX. */
2939 static int
2941 {
2942 tree x;
2944 {
2947 else
2949 }
2951 }
2953 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
2954 starting at offset IDX. */
2956 static int
2960 {
2961 tree values;
2965 }
2967 /* FIELD is a bit-field. We are finishing the processing for its
2968 enclosing type. Issue any appropriate messages and set appropriate
2969 flags. Returns false if an error has been diagnosed. */
2971 static bool
2973 {
2975 tree w;
2977 /* Extract the declared width of the bitfield, which has been
2978 temporarily stashed in DECL_INITIAL. */
2981 /* Remove the bit-field width indicator so that the rest of the
2982 compiler does not treat that value as an initializer. */
2985 /* Detect invalid bit-field type. */
2987 {
2990 }
2991 else
2992 {
2994 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2997 /* detect invalid field size. */
3003 {
3006 }
3008 {
3011 }
3013 {
3016 }
3025 }
3028 {
3032 }
3033 else
3034 {
3035 /* Non-bit-fields are aligned for their type. */
3039 }
3040 }
3042 /* FIELD is a non bit-field. We are finishing the processing for its
3043 enclosing type T. Issue any appropriate messages and set appropriate
3044 flags. */
3046 static void
3048 tree t,
3052 {
3055 /* In C++98 an anonymous union cannot contain any fields which would change
3056 the settings of CANT_HAVE_CONST_CTOR and friends. */
3058 ;
3059 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3060 structs. So, we recurse through their fields here. */
3062 {
3063 tree fields;
3069 }
3070 /* Check members with class type for constructors, destructors,
3071 etc. */
3073 {
3074 /* Never let anything with uninheritable virtuals
3075 make it through without complaint. */
3079 {
3084 field);
3089 field);
3091 {
3095 }
3096 }
3097 else
3098 {
3111 }
3120 }
3122 {
3123 /* `build_class_init_list' does not recognize
3124 non-FIELD_DECLs. */
3128 }
3129 }
3131 /* Check the data members (both static and non-static), class-scoped
3132 typedefs, etc., appearing in the declaration of T. Issue
3133 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3134 declaration order) of access declarations; each TREE_VALUE in this
3135 list is a USING_DECL.
3137 In addition, set the following flags:
3139 EMPTY_P
3140 The class is empty, i.e., contains no non-static data members.
3142 CANT_HAVE_CONST_CTOR_P
3143 This class cannot have an implicitly generated copy constructor
3144 taking a const reference.
3146 CANT_HAVE_CONST_ASN_REF
3147 This class cannot have an implicitly generated assignment
3148 operator taking a const reference.
3150 All of these flags should be initialized before calling this
3151 function.
3153 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3154 fields can be added by adding to this chain. */
3156 static void
3160 {
3168 /* Assume there are no access declarations. */
3170 /* Assume this class has no pointer members. */
3172 /* Assume none of the members of this class have default
3173 initializations. */
3177 {
3185 {
3186 /* Save the access declarations for our caller. */
3189 }
3195 /* If we've gotten this far, it's a data member, possibly static,
3196 or an enumerator. */
3200 /* When this goes into scope, it will be a non-local reference. */
3204 {
3205 /* [class.union]
3207 If a union contains a static data member, or a member of
3208 reference type, the program is ill-formed. */
3210 {
3213 }
3215 {
3220 }
3221 }
3223 /* Perform error checking that did not get done in
3224 grokdeclarator. */
3226 {
3230 }
3232 {
3236 }
3244 /* Now it can only be a FIELD_DECL. */
3249 /* If at least one non-static data member is non-literal, the whole
3250 class becomes non-literal. Note: if the type is incomplete we
3251 will complain later on. */
3255 /* A standard-layout class is a class that:
3256 ...
3257 has the same access control (Clause 11) for all non-static data members,
3258 ... */
3265 /* If this is of reference type, check if it needs an init. */
3267 {
3273 /* ARM $12.6.2: [A member initializer list] (or, for an
3274 aggregate, initialization by a brace-enclosed list) is the
3275 only way to initialize nonstatic const and reference
3276 members. */
3279 }
3284 {
3286 {
3287 warning
3290 x);
3292 }
3296 }
3299 /* We don't treat zero-width bitfields as making a class
3300 non-empty. */
3301 ;
3302 else
3303 {
3304 /* The class is non-empty. */
3306 /* The class is not even nearly empty. */
3308 /* If one of the data members contains an empty class,
3309 so does T. */
3313 }
3315 /* This is used by -Weffc++ (see below). Warn only for pointers
3316 to members which might hold dynamic memory. So do not warn
3317 for pointers to functions or pointers to members. */
3323 {
3328 }
3334 /* DR 148 now allows pointers to members (which are POD themselves),
3335 to be allowed in POD structs. */
3344 /* We set DECL_C_BIT_FIELD in grokbitfield.
3345 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3348 cant_have_const_ctor_p,
3349 no_const_asn_ref_p,
3352 /* Now that we've removed bit-field widths from DECL_INITIAL,
3353 anything left in DECL_INITIAL is an NSDMI that makes the class
3354 non-aggregate. */
3358 /* If any field is const, the structure type is pseudo-const. */
3360 {
3365 /* ARM $12.6.2: [A member initializer list] (or, for an
3366 aggregate, initialization by a brace-enclosed list) is the
3367 only way to initialize nonstatic const and reference
3368 members. */
3371 }
3372 /* A field that is pseudo-const makes the structure likewise. */
3374 {
3379 }
3381 /* Core issue 80: A nonstatic data member is required to have a
3382 different name from the class iff the class has a
3383 user-declared constructor. */
3387 }
3389 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3390 it should also define a copy constructor and an assignment operator to
3391 implement the correct copy semantic (deep vs shallow, etc.). As it is
3392 not feasible to check whether the constructors do allocate dynamic memory
3393 and store it within members, we approximate the warning like this:
3395 -- Warn only if there are members which are pointers
3396 -- Warn only if there is a non-trivial constructor (otherwise,
3397 there cannot be memory allocated).
3398 -- Warn only if there is a non-trivial destructor. We assume that the
3399 user at least implemented the cleanup correctly, and a destructor
3400 is needed to free dynamic memory.
3402 This seems enough for practical purposes. */
3404 && has_pointers
3408 {
3412 {
3417 }
3421 }
3423 /* Non-static data member initializers make the default constructor
3424 non-trivial. */
3426 {
3429 }
3431 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3435 /* Check anonymous struct/anonymous union fields. */
3438 /* We've built up the list of access declarations in reverse order.
3439 Fix that now. */
3441 }
3443 /* If TYPE is an empty class type, records its OFFSET in the table of
3444 OFFSETS. */
3446 static int
3448 {
3449 splay_tree_node n;
3454 /* Record the location of this empty object in OFFSETS. */
3462 type,
3466 }
3468 /* Returns nonzero if TYPE is an empty class type and there is
3469 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3471 static int
3473 {
3474 splay_tree_node n;
3475 tree t;
3480 /* Record the location of this empty object in OFFSETS. */
3490 }
3492 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3493 F for every subobject, passing it the type, offset, and table of
3494 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3495 be traversed.
3497 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3498 than MAX_OFFSET will not be walked.
3500 If F returns a nonzero value, the traversal ceases, and that value
3501 is returned. Otherwise, returns zero. */
3503 static int
3505 subobject_offset_fn f,
3506 tree offset,
3507 splay_tree offsets,
3508 tree max_offset,
3510 {
3514 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3515 stop. */
3523 {
3527 }
3530 {
3531 tree field;
3532 tree binfo;
3535 /* Avoid recursing into objects that are not interesting. */
3539 /* Record the location of TYPE. */
3544 /* Iterate through the direct base classes of TYPE. */
3548 {
3549 tree binfo_offset;
3562 offset,
3564 else
3565 {
3566 tree orig_binfo;
3567 /* We cannot rely on BINFO_OFFSET being set for the base
3568 class yet, but the offsets for direct non-virtual
3569 bases can be calculated by going back to the TYPE. */
3572 offset,
3574 }
3577 f,
3578 binfo_offset,
3579 offsets,
3580 max_offset,
3585 }
3588 {
3592 /* Iterate through the virtual base classes of TYPE. In G++
3593 3.2, we included virtual bases in the direct base class
3594 loop above, which results in incorrect results; the
3595 correct offsets for virtual bases are only known when
3596 working with the most derived type. */
3600 {
3602 f,
3604 offset,
3606 offsets,
3607 max_offset,
3611 }
3612 else
3613 {
3614 /* We still have to walk the primary base, if it is
3615 virtual. (If it is non-virtual, then it was walked
3616 above.) */
3622 {
3623 r = (walk_subobject_offsets
3628 }
3629 }
3630 }
3632 /* Iterate through the fields of TYPE. */
3635 {
3636 tree field_offset;
3640 else
3641 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3645 f,
3647 offset,
3648 field_offset),
3649 offsets,
3650 max_offset,
3654 }
3655 }
3657 {
3660 tree index;
3662 /* Avoid recursing into objects that are not interesting. */
3667 /* Step through each of the elements in the array. */
3669 /* G++ 3.2 had an off-by-one error here. */
3674 {
3676 f,
3677 offset,
3678 offsets,
3679 max_offset,
3685 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3686 there's no point in iterating through the remaining
3687 elements of the array. */
3690 }
3691 }
3694 }
3696 /* Record all of the empty subobjects of TYPE (either a type or a
3697 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3698 is being placed at OFFSET; otherwise, it is a base class that is
3699 being placed at OFFSET. */
3701 static void
3703 tree offset,
3704 splay_tree offsets,
3706 {
3707 tree max_offset;
3708 /* If recording subobjects for a non-static data member or a
3709 non-empty base class , we do not need to record offsets beyond
3710 the size of the biggest empty class. Additional data members
3711 will go at the end of the class. Additional base classes will go
3712 either at offset zero (if empty, in which case they cannot
3713 overlap with offsets past the size of the biggest empty class) or
3714 at the end of the class.
3716 However, if we are placing an empty base class, then we must record
3717 all offsets, as either the empty class is at offset zero (where
3718 other empty classes might later be placed) or at the end of the
3719 class (where other objects might then be placed, so other empty
3720 subobjects might later overlap). */
3724 else
3728 }
3730 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3731 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3732 virtual bases of TYPE are examined. */
3734 static int
3736 tree offset,
3737 splay_tree offsets,
3739 {
3740 splay_tree_node max_node;
3742 /* Get the node in OFFSETS that indicates the maximum offset where
3743 an empty subobject is located. */
3745 /* If there aren't any empty subobjects, then there's no point in
3746 performing this check. */
3752 vbases_p);
3753 }
3755 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3756 non-static data member of the type indicated by RLI. BINFO is the
3757 binfo corresponding to the base subobject, OFFSETS maps offsets to
3758 types already located at those offsets. This function determines
3759 the position of the DECL. */
3761 static void
3763 tree decl,
3764 tree binfo,
3765 splay_tree offsets)
3766 {
3769 tree type;
3772 {
3773 /* For the purposes of determining layout conflicts, we want to
3774 use the class type of BINFO; TREE_TYPE (DECL) will be the
3775 CLASSTYPE_AS_BASE version, which does not contain entries for
3776 zero-sized bases. */
3779 }
3780 else
3781 {
3784 }
3786 /* Try to place the field. It may take more than one try if we have
3787 a hard time placing the field without putting two objects of the
3788 same type at the same address. */
3790 {
3793 /* Place this field. */
3797 /* We have to check to see whether or not there is already
3798 something of the same type at the offset we're about to use.
3799 For example, consider:
3801 struct S {};
3802 struct T : public S { int i; };
3803 struct U : public S, public T {};
3805 Here, we put S at offset zero in U. Then, we can't put T at
3806 offset zero -- its S component would be at the same address
3807 as the S we already allocated. So, we have to skip ahead.
3808 Since all data members, including those whose type is an
3809 empty class, have nonzero size, any overlap can happen only
3810 with a direct or indirect base-class -- it can't happen with
3811 a data member. */
3812 /* In a union, overlap is permitted; all members are placed at
3813 offset zero. */
3816 /* G++ 3.2 did not check for overlaps when placing a non-empty
3817 virtual base. */
3822 {
3823 /* Strip off the size allocated to this field. That puts us
3824 at the first place we could have put the field with
3825 proper alignment. */
3828 /* Bump up by the alignment required for the type. */
3829 rli->bitpos
3835 }
3836 else
3837 /* There was no conflict. We're done laying out this field. */
3839 }
3841 /* Now that we know where it will be placed, update its
3842 BINFO_OFFSET. */
3844 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3845 this point because their BINFO_OFFSET is copied from another
3846 hierarchy. Therefore, we may not need to add the entire
3847 OFFSET. */
3853 }
3855 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3857 static int
3859 tree offset,
3861 {
3863 }
3865 /* Layout the empty base BINFO. EOC indicates the byte currently just
3866 past the end of the class, and should be correctly aligned for a
3867 class of the type indicated by BINFO; OFFSETS gives the offsets of
3868 the empty bases allocated so far. T is the most derived
3869 type. Return nonzero iff we added it at the end. */
3871 static bool
3874 {
3875 tree alignment;
3879 /* This routine should only be used for empty classes. */
3884 {
3886 propagate_binfo_offsets
3889 else
3891 "offset of empty base %qT may not be ABI-compliant and may"
3894 }
3896 /* This is an empty base class. We first try to put it at offset
3897 zero. */
3900 offsets,
3902 {
3903 /* That didn't work. Now, we move forward from the next
3904 available spot in the class. */
3908 {
3911 offsets,
3913 /* We finally found a spot where there's no overlap. */
3916 /* There's overlap here, too. Bump along to the next spot. */
3918 }
3919 }
3922 {
3927 }
3930 }
3932 /* Layout the base given by BINFO in the class indicated by RLI.
3933 *BASE_ALIGN is a running maximum of the alignments of
3934 any base class. OFFSETS gives the location of empty base
3935 subobjects. T is the most derived type. Return nonzero if the new
3936 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3937 *NEXT_FIELD, unless BINFO is for an empty base class.
3939 Returns the location at which the next field should be inserted. */
3944 {
3949 /* This error is now reported in xref_tag, thus giving better
3950 location information. */
3953 /* Place the base class. */
3955 {
3956 tree decl;
3958 /* The containing class is non-empty because it has a non-empty
3959 base class. */
3962 /* Create the FIELD_DECL. */
3969 {
3977 /* Try to place the field. It may take more than one try if we
3978 have a hard time placing the field without putting two
3979 objects of the same type at the same address. */
3981 /* Add the new FIELD_DECL to the list of fields for T. */
3985 }
3986 }
3987 else
3988 {
3989 tree eoc;
3992 /* On some platforms (ARM), even empty classes will not be
3993 byte-aligned. */
3998 /* A nearly-empty class "has no proper base class that is empty,
3999 not morally virtual, and at an offset other than zero." */
4001 {
4004 /* The check above (used in G++ 3.2) is insufficient because
4005 an empty class placed at offset zero might itself have an
4006 empty base at a nonzero offset. */
4008 empty_base_at_nonzero_offset_p,
4009 size_zero_node,
4013 {
4016 else
4018 "class %qT will be considered nearly empty in a "
4020 }
4021 }
4023 /* We do not create a FIELD_DECL for empty base classes because
4024 it might overlap some other field. We want to be able to
4025 create CONSTRUCTORs for the class by iterating over the
4026 FIELD_DECLs, and the back end does not handle overlapping
4027 FIELD_DECLs. */
4029 /* An empty virtual base causes a class to be non-empty
4030 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4031 here because that was already done when the virtual table
4032 pointer was created. */
4033 }
4035 /* Record the offsets of BINFO and its base subobjects. */
4038 offsets,
4042 }
4044 /* Layout all of the non-virtual base classes. Record empty
4045 subobjects in OFFSETS. T is the most derived type. Return nonzero
4046 if the type cannot be nearly empty. The fields created
4047 corresponding to the base classes will be inserted at
4048 *NEXT_FIELD. */
4050 static void
4053 {
4054 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4055 subobjects. */
4060 /* The primary base class is always allocated first. */
4065 /* Now allocate the rest of the bases. */
4067 {
4068 tree base_binfo;
4072 /* The primary base was already allocated above, so we don't
4073 need to allocate it again here. */
4077 /* Virtual bases are added at the end (a primary virtual base
4078 will have already been added). */
4084 }
4085 }
4087 /* Go through the TYPE_METHODS of T issuing any appropriate
4088 diagnostics, figuring out which methods override which other
4089 methods, and so forth. */
4091 static void
4093 {
4094 tree x;
4097 {
4101 /* The name of the field is the original field name
4102 Save this in auxiliary field for later overloading. */
4104 {
4108 }
4109 /* All user-provided destructors are non-trivial.
4110 Constructors and assignment ops are handled in
4111 grok_special_member_properties. */
4114 }
4115 }
4117 /* FN is a constructor or destructor. Clone the declaration to create
4118 a specialized in-charge or not-in-charge version, as indicated by
4119 NAME. */
4121 static tree
4123 {
4124 tree parms;
4125 tree clone;
4127 /* Copy the function. */
4129 /* Reset the function name. */
4132 /* Remember where this function came from. */
4134 /* Make it easy to find the CLONE given the FN. */
4138 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4140 {
4147 }
4150 /* There's no pending inline data for this function. */
4154 /* The base-class destructor is not virtual. */
4156 {
4160 }
4162 /* If there was an in-charge parameter, drop it from the function
4163 type. */
4165 {
4166 tree basetype;
4167 tree parmtypes;
4168 tree exceptions;
4173 /* Skip the `this' parameter. */
4175 /* Skip the in-charge parameter. */
4177 /* And the VTT parm, in a complete [cd]tor. */
4181 /* If this is subobject constructor or destructor, add the vtt
4182 parameter. */
4186 parmtypes);
4189 exceptions);
4193 }
4195 /* Copy the function parameters. */
4197 /* Remove the in-charge parameter. */
4199 {
4203 }
4204 /* And the VTT parm, in a complete [cd]tor. */
4206 {
4209 else
4210 {
4214 }
4215 }
4218 {
4221 }
4223 /* Create the RTL for this function. */
4231 }
4233 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4234 not invoke this function directly.
4236 For a non-thunk function, returns the address of the slot for storing
4237 the function it is a clone of. Otherwise returns NULL_TREE.
4239 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4240 cloned_function is unset. This is to support the separate
4241 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4242 on a template makes sense, but not the former. */
4244 tree *
4246 {
4254 {
4255 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4258 else
4259 #endif
4261 }
4266 else
4268 }
4270 /* Produce declarations for all appropriate clones of FN. If
4271 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4272 CLASTYPE_METHOD_VEC as well. */
4274 void
4276 {
4277 tree clone;
4279 /* Avoid inappropriate cloning. */
4285 {
4286 /* For each constructor, we need two variants: an in-charge version
4287 and a not-in-charge version. */
4294 }
4295 else
4296 {
4299 /* For each destructor, we need three variants: an in-charge
4300 version, a not-in-charge version, and an in-charge deleting
4301 version. We clone the deleting version first because that
4302 means it will go second on the TYPE_METHODS list -- and that
4303 corresponds to the correct layout order in the virtual
4304 function table.
4306 For a non-virtual destructor, we do not build a deleting
4307 destructor. */
4309 {
4313 }
4320 }
4322 /* Note that this is an abstract function that is never emitted. */
4324 }
4326 /* DECL is an in charge constructor, which is being defined. This will
4327 have had an in class declaration, from whence clones were
4328 declared. An out-of-class definition can specify additional default
4329 arguments. As it is the clones that are involved in overload
4330 resolution, we must propagate the information from the DECL to its
4331 clones. */
4333 void
4335 {
4336 tree clone;
4340 {
4347 /* Skip the 'this' parameter. */
4363 {
4368 {
4369 /* A default parameter has been added. Adjust the
4370 clone's parameters. */
4374 tree type;
4379 {
4382 clone_parms);
4384 }
4387 clone_parms);
4396 }
4397 }
4399 }
4400 }
4402 /* For each of the constructors and destructors in T, create an
4403 in-charge and not-in-charge variant. */
4405 static void
4407 {
4408 tree fns;
4410 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4411 out now. */
4419 }
4421 /* Deduce noexcept for a destructor DTOR. */
4423 void
4425 {
4427 {
4434 }
4435 }
4437 /* For each destructor in T, deduce noexcept:
4439 12.4/3: A declaration of a destructor that does not have an
4440 exception-specification is implicitly considered to have the
4441 same exception-specification as an implicit declaration (15.4). */
4443 static void
4445 {
4446 tree fns;
4448 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4449 out now. */
4455 }
4457 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4458 of TYPE for virtual functions which FNDECL overrides. Return a
4459 mask of the tm attributes found therein. */
4461 static int
4463 {
4465 tree base_binfo;
4469 {
4479 else
4481 }
4484 }
4486 /* Subroutine of set_method_tm_attributes. Handle the checks and
4487 inheritance for one virtual method FNDECL. */
4489 static void
4491 {
4492 tree tm_attr;
4497 /* If FNDECL doesn't actually override anything (i.e. T is the
4498 class that first declares FNDECL virtual), then we're done. */
4505 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4506 tm_pure must match exactly, otherwise no weakening of
4507 tm_safe > tm_callable > nothing. */
4508 /* ??? The tm_pure attribute didn't make the transition to the
4509 multivendor language spec. */
4511 {
4513 {
4516 }
4517 }
4518 /* If the overridden function is tm_pure, then FNDECL must be. */
4521 /* Look for base class combinations that cannot be satisfied. */
4523 {
4529 }
4530 /* If FNDECL did not declare an attribute, then inherit the most
4531 restrictive one. */
4533 {
4535 }
4536 /* Otherwise validate that we're not weaker than a function
4537 that is being overridden. */
4538 else
4539 {
4543 }
4546 err_override:
4550 }
4552 /* For each of the methods in T, propagate a class-level tm attribute. */
4554 static void
4556 {
4559 /* Don't bother collecting tm attributes if transactional memory
4560 support is not enabled. */
4564 /* Process virtual methods first, as they inherit directly from the
4565 base virtual function and also require validation of new attributes. */
4567 {
4568 tree vchain;
4571 {
4576 }
4577 }
4579 /* If the class doesn't have an attribute, nothing more to do. */
4584 /* Any method that does not yet have a tm attribute inherits
4585 the one from the class. */
4587 {
4590 }
4591 }
4593 /* Returns true iff class T has a user-defined constructor other than
4594 the default constructor. */
4596 bool
4598 {
4599 tree fns;
4605 {
4612 }
4615 }
4617 /* Returns the defaulted constructor if T has one. Otherwise, returns
4618 NULL_TREE. */
4620 tree
4622 {
4629 {
4633 {
4639 }
4640 }
4643 }
4645 /* Returns true iff FN is a user-provided function, i.e. user-declared
4646 and not defaulted at its first declaration; or explicit, private,
4647 protected, or non-const. */
4649 bool
4651 {
4654 else
4657 }
4659 /* Returns true iff class T has a user-provided constructor. */
4661 bool
4663 {
4664 tree fns;
4672 /* This can happen in error cases; avoid crashing. */
4681 }
4683 /* Returns true iff class T has a user-provided default constructor. */
4685 bool
4687 {
4688 tree fns;
4694 {
4700 }
4703 }
4705 /* If default-initialization leaves part of TYPE uninitialized, returns
4706 a DECL for the field or TYPE itself (DR 253). */
4708 tree
4710 {
4721 {
4725 }
4730 {
4734 }
4737 }
4739 /* Returns true iff for class T, a trivial synthesized default constructor
4740 would be constexpr. */
4742 bool
4744 {
4745 /* A defaulted trivial default constructor is constexpr
4746 if there is nothing to initialize. */
4749 }
4751 /* Returns true iff class T has a constexpr default constructor. */
4753 bool
4755 {
4756 tree fns;
4759 {
4760 /* The caller should have stripped an enclosing array. */
4763 }
4765 {
4768 /* Non-trivial, we need to check subobject constructors. */
4770 }
4773 }
4775 /* Returns true iff class TYPE has a virtual destructor. */
4777 bool
4779 {
4780 tree dtor;
4788 }
4790 /* Returns true iff class T has a move constructor. */
4792 bool
4794 {
4795 tree fns;
4798 {
4801 }
4811 }
4813 /* Returns true iff class T has a move assignment operator. */
4815 bool
4817 {
4818 tree fns;
4821 {
4824 }
4832 }
4834 /* Returns true iff class T has a move constructor that was explicitly
4835 declared in the class body. Note that this is different from
4836 "user-provided", which doesn't include functions that are defaulted in
4837 the class. */
4839 bool
4841 {
4842 tree fns;
4851 {
4855 }
4858 }
4860 /* Returns true iff class T has a move assignment operator that was
4861 explicitly declared in the class body. */
4863 bool
4865 {
4866 tree fns;
4873 {
4877 }
4880 }
4882 /* Nonzero if we need to build up a constructor call when initializing an
4883 object of this class, either because it has a user-provided constructor
4884 or because it doesn't have a default constructor (so we need to give an
4885 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
4886 what you care about is whether or not an object can be produced by a
4887 constructor (e.g. so we don't set TREE_READONLY on const variables of
4888 such type); use this function when what you care about is whether or not
4889 to try to call a constructor to create an object. The latter case is
4890 the former plus some cases of constructors that cannot be called. */
4892 bool
4894 {
4895 tree inner;
4901 }
4903 /* Remove all zero-width bit-fields from T. */
4905 static void
4907 {
4912 {
4915 /* We should not be confused by the fact that grokbitfield
4916 temporarily sets the width of the bit field into
4917 DECL_INITIAL (*fieldsp).
4918 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
4919 to that width. */
4922 else
4924 }
4925 }
4927 /* Returns TRUE iff we need a cookie when dynamically allocating an
4928 array whose elements have the indicated class TYPE. */
4930 static bool
4932 {
4933 tree fns;
4938 /* If there's a non-trivial destructor, we need a cookie. In order
4939 to iterate through the array calling the destructor for each
4940 element, we'll have to know how many elements there are. */
4944 /* If the usual deallocation function is a two-argument whose second
4945 argument is of type `size_t', then we have to pass the size of
4946 the array to the deallocation function, so we will need to store
4947 a cookie. */
4951 /* If there are no `operator []' members, or the lookup is
4952 ambiguous, then we don't need a cookie. */
4955 /* Loop through all of the functions. */
4957 {
4958 tree fn;
4959 tree second_parm;
4961 /* Select the current function. */
4963 /* See if this function is a one-argument delete function. If
4964 it is, then it will be the usual deallocation function. */
4968 /* Do not consider this function if its second argument is an
4969 ellipsis. */
4972 /* Otherwise, if we have a two-argument function and the second
4973 argument is `size_t', it will be the usual deallocation
4974 function -- unless there is one-argument function, too. */
4978 }
4981 }
4983 /* Finish computing the `literal type' property of class type T.
4985 At this point, we have already processed base classes and
4986 non-static data members. We need to check whether the copy
4987 constructor is trivial, the destructor is trivial, and there
4988 is a trivial default constructor or at least one constexpr
4989 constructor other than the copy constructor. */
4991 static void
4993 {
4994 tree fn;
5010 {
5013 {
5017 }
5018 }
5019 }
5021 /* T is a non-literal type used in a context which requires a constant
5022 expression. Explain why it isn't literal. */
5024 void
5026 {
5036 /* Already explained. */
5045 {
5047 "default constructor, and has no constexpr constructor that "
5051 {
5052 /* Note that we can't simply call locate_ctor because when the
5053 constructor is deleted it just returns NULL_TREE. */
5054 tree fns;
5056 {
5063 {
5066 else
5069 }
5070 }
5071 }
5072 }
5073 else
5074 {
5078 {
5081 {
5086 }
5087 }
5089 {
5090 tree ftype;
5095 {
5100 }
5101 }
5102 }
5103 }
5105 /* Check the validity of the bases and members declared in T. Add any
5106 implicitly-generated functions (like copy-constructors and
5107 assignment operators). Compute various flag bits (like
5108 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5109 level: i.e., independently of the ABI in use. */
5111 static void
5113 {
5114 /* Nonzero if the implicitly generated copy constructor should take
5115 a non-const reference argument. */
5117 /* Nonzero if the implicitly generated assignment operator
5118 should take a non-const reference argument. */
5120 tree access_decls;
5123 tree fn;
5125 /* By default, we use const reference arguments and generate default
5126 constructors. */
5130 /* Deduce noexcept on destructors. */
5134 /* Check all the base-classes. */
5138 /* Check all the method declarations. */
5141 /* Save the initial values of these flags which only indicate whether
5142 or not the class has user-provided functions. As we analyze the
5143 bases and members we can set these flags for other reasons. */
5147 /* Check all the data member declarations. We cannot call
5148 check_field_decls until we have called check_bases check_methods,
5149 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5150 being set appropriately. */
5155 /* A nearly-empty class has to be vptr-containing; a nearly empty
5156 class contains just a vptr. */
5160 /* Do some bookkeeping that will guide the generation of implicitly
5161 declared member functions. */
5164 /* We need to call a constructor for this class if it has a
5165 user-provided constructor, or if the default constructor is going
5166 to initialize the vptr. (This is not an if-and-only-if;
5167 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5168 themselves need constructing.) */
5171 /* [dcl.init.aggr]
5173 An aggregate is an array or a class with no user-provided
5174 constructors ... and no virtual functions.
5176 Again, other conditions for being an aggregate are checked
5177 elsewhere. */
5180 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5181 retain the old definition internally for ABI reasons. */
5190 /* If the class has no user-declared constructor, but does have
5191 non-static const or reference data members that can never be
5192 initialized, issue a warning. */
5194 /* Classes with user-declared constructors are presumed to
5195 initialize these members. */
5197 /* Aggregates can be initialized with brace-enclosed
5198 initializers. */
5200 {
5201 tree field;
5204 {
5205 tree type;
5220 }
5221 }
5223 /* Synthesize any needed methods. */
5225 cant_have_const_ctor,
5226 no_const_asn_ref);
5228 /* Check defaulted declarations here so we have cant_have_const_ctor
5229 and don't need to worry about clones. */
5232 {
5235 {
5236 bool imp_const_p
5242 /* If the function is defaulted outside the class, we just
5243 give the synthesis error. */
5246 }
5248 }
5251 {
5252 /* "The closure type associated with a lambda-expression has a deleted
5253 default constructor and a deleted copy assignment operator." */
5259 /* "This class type is not an aggregate." */
5261 }
5263 /* Compute the 'literal type' property before we
5264 do anything with non-static member functions. */
5267 /* Create the in-charge and not-in-charge variants of constructors
5268 and destructors. */
5271 /* Process the using-declarations. */
5275 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5278 /* Figure out whether or not we will need a cookie when dynamically
5279 allocating an array of this type. */
5282 }
5284 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5285 accordingly. If a new vfield was created (because T doesn't have a
5286 primary base class), then the newly created field is returned. It
5287 is not added to the TYPE_FIELDS list; it is the caller's
5288 responsibility to do that. Accumulate declared virtual functions
5289 on VIRTUALS_P. */
5291 static tree
5293 {
5294 tree fn;
5296 /* Collect the virtual functions declared in T. */
5300 {
5309 }
5311 /* If we couldn't find an appropriate base class, create a new field
5312 here. Even if there weren't any new virtual functions, we might need a
5313 new virtual function table if we're supposed to include vptrs in
5314 all classes that need them. */
5316 {
5317 /* We build this decl with vtbl_ptr_type_node, which is a
5318 `vtable_entry_type*'. It might seem more precise to use
5319 `vtable_entry_type (*)[N]' where N is the number of virtual
5320 functions. However, that would require the vtable pointer in
5321 base classes to have a different type than the vtable pointer
5322 in derived classes. We could make that happen, but that
5323 still wouldn't solve all the problems. In particular, the
5324 type-based alias analysis code would decide that assignments
5325 to the base class vtable pointer can't alias assignments to
5326 the derived class vtable pointer, since they have different
5327 types. Thus, in a derived class destructor, where the base
5328 class constructor was inlined, we could generate bad code for
5329 setting up the vtable pointer.
5331 Therefore, we use one type for all vtable pointers. We still
5332 use a type-correct type; it's just doesn't indicate the array
5333 bounds. That's better than using `void*' or some such; it's
5334 cleaner, and it let's the alias analysis code know that these
5335 stores cannot alias stores to void*! */
5336 tree field;
5349 /* This class is non-empty. */
5353 }
5356 }
5358 /* Add OFFSET to all base types of BINFO which is a base in the
5359 hierarchy dominated by T.
5361 OFFSET, which is a type offset, is number of bytes. */
5363 static void
5365 {
5367 tree primary_binfo;
5368 tree base_binfo;
5370 /* Update BINFO's offset. */
5375 offset));
5377 /* Find the primary base class. */
5383 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5384 downwards. */
5386 {
5387 /* Don't do the primary base twice. */
5395 }
5396 }
5398 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5399 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5400 empty subobjects of T. */
5402 static void
5404 {
5405 tree vbase;
5414 {
5415 /* In G++ 3.2, we incorrectly rounded the size before laying out
5416 the virtual bases. */
5418 #ifdef STRUCTURE_SIZE_BOUNDARY
5419 /* Packed structures don't need to have minimum size. */
5422 #endif
5426 }
5428 /* Find the last field. The artificial fields created for virtual
5429 bases will go after the last extant field to date. */
5434 /* Go through the virtual bases, allocating space for each virtual
5435 base that is not already a primary base class. These are
5436 allocated in inheritance graph order. */
5438 {
5443 {
5446 /* This virtual base is not a primary base of any class in the
5447 hierarchy, so we have to add space for it. */
5451 /* If the first virtual base might have been placed at a
5452 lower address, had we started from CLASSTYPE_SIZE, rather
5453 than TYPE_SIZE, issue a warning. There can be both false
5454 positives and false negatives from this warning in rare
5455 cases; to deal with all the possibilities would probably
5456 require performing both layout algorithms and comparing
5457 the results which is not particularly tractable. */
5459 && first_vbase
5460 && (tree_int_cst_lt
5465 bitsize_unit_node),
5468 "offset of virtual base %qT is not ABI-compliant and "
5470 basetype);
5473 }
5474 }
5475 }
5477 /* Returns the offset of the byte just past the end of the base class
5478 BINFO. */
5480 static tree
5482 {
5483 tree size;
5488 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5489 allocate some space for it. It cannot have virtual bases, so
5490 TYPE_SIZE_UNIT is fine. */
5492 else
5496 }
5498 /* Returns the offset of the byte just past the end of the base class
5499 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5500 only non-virtual bases are included. */
5502 static tree
5504 {
5507 tree binfo;
5508 tree base_binfo;
5509 tree offset;
5514 {
5524 }
5526 /* G++ 3.2 did not check indirect virtual bases. */
5530 {
5534 }
5537 }
5539 /* Warn about bases of T that are inaccessible because they are
5540 ambiguous. For example:
5542 struct S {};
5543 struct T : public S {};
5544 struct U : public S, public T {};
5546 Here, `(S*) new U' is not allowed because there are two `S'
5547 subobjects of U. */
5549 static void
5551 {
5554 tree basetype;
5555 tree binfo;
5556 tree base_binfo;
5558 /* If there are no repeated bases, nothing can be ambiguous. */
5562 /* Check direct bases. */
5565 {
5571 }
5573 /* Check for ambiguous virtual bases. */
5577 {
5583 }
5584 }
5586 /* Compare two INTEGER_CSTs K1 and K2. */
5588 static int
5590 {
5592 }
5594 /* Increase the size indicated in RLI to account for empty classes
5595 that are "off the end" of the class. */
5597 static void
5599 {
5600 tree eoc;
5601 tree rli_size;
5603 /* It might be the case that we grew the class to allocate a
5604 zero-sized base class. That won't be reflected in RLI, yet,
5605 because we are willing to overlay multiple bases at the same
5606 offset. However, now we need to make sure that RLI is big enough
5607 to reflect the entire class. */
5613 {
5615 /* In version 1 of the ABI, the size of a class that ends with
5616 a bitfield was not rounded up to a whole multiple of a
5617 byte. Because rli_size_unit_so_far returns only the number
5618 of fully allocated bytes, any extra bits were not included
5619 in the size. */
5621 else
5622 /* The size should have been rounded to a whole byte. */
5625 rli->bitpos
5634 }
5635 }
5637 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5638 BINFO_OFFSETs for all of the base-classes. Position the vtable
5639 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5641 static void
5643 {
5644 tree non_static_data_members;
5645 tree field;
5646 tree vptr;
5647 record_layout_info rli;
5648 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5649 types that appear at that offset. */
5650 splay_tree empty_base_offsets;
5651 /* True if the last field layed out was a bit-field. */
5653 /* The location at which the next field should be inserted. */
5655 /* T, as a base class. */
5656 tree base_t;
5658 /* Keep track of the first non-static data member. */
5661 /* Start laying out the record. */
5664 /* Mark all the primary bases in the hierarchy. */
5667 /* Create a pointer to our virtual function table. */
5670 /* The vptr is always the first thing in the class. */
5672 {
5677 }
5678 else
5681 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5686 /* Layout the non-static data members. */
5688 {
5689 tree type;
5690 tree padding;
5692 /* We still pass things that aren't non-static data members to
5693 the back end, in case it wants to do something with them. */
5695 {
5697 /* If the static data member has incomplete type, keep track
5698 of it so that it can be completed later. (The handling
5699 of pending statics in finish_record_layout is
5700 insufficient; consider:
5702 struct S1;
5703 struct S2 { static S1 s1; };
5705 At this point, finish_record_layout will be called, but
5706 S1 is still incomplete.) */
5708 {
5710 /* The visibility of static data members is determined
5711 at their point of declaration, not their point of
5712 definition. */
5714 }
5716 }
5724 /* If this field is a bit-field whose width is greater than its
5725 type, then there are some special rules for allocating
5726 it. */
5729 {
5731 tree integer_type;
5733 /* We must allocate the bits as if suitably aligned for the
5734 longest integer type that fits in this many bits. type
5735 of the field. Then, we are supposed to use the left over
5736 bits as additional padding. */
5745 /* ITK now indicates a type that is too large for the
5746 field. We have to back up by one to find the largest
5747 type that fits. */
5748 do
5749 {
5754 /* Figure out how much additional padding is required. GCC
5755 3.2 always created a padding field, even if it had zero
5756 width. */
5759 {
5761 /* In a union, the padding field must have the full width
5762 of the bit-field; all fields start at offset zero. */
5764 else
5765 {
5768 "ABI-compliant and may change in a future "
5770 t);
5773 }
5774 }
5775 #ifdef PCC_BITFIELD_TYPE_MATTERS
5776 /* An unnamed bitfield does not normally affect the
5777 alignment of the containing class on a target where
5778 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5779 make any exceptions for unnamed bitfields when the
5780 bitfields are longer than their types. Therefore, we
5781 temporarily give the field a name. */
5783 {
5786 }
5787 #endif
5792 empty_base_offsets);
5795 /* Now that layout has been performed, set the size of the
5796 field to the size of its declared type; the rest of the
5797 field is effectively invisible. */
5799 /* We must also reset the DECL_MODE of the field. */
5804 /* Versions of G++ before G++ 3.4 did not reset the
5805 DECL_MODE. */
5807 "the offset of %qD may not be ABI-compliant and may "
5809 }
5810 else
5812 empty_base_offsets);
5814 /* Remember the location of any empty classes in FIELD. */
5818 empty_base_offsets,
5821 /* If a bit-field does not immediately follow another bit-field,
5822 and yet it starts in the middle of a byte, we have failed to
5823 comply with the ABI. */
5826 /* The TREE_NO_WARNING flag gets set by Objective-C when
5827 laying out an Objective-C class. The ObjC ABI differs
5828 from the C++ ABI, and so we do not want a warning
5829 here. */
5831 && !last_field_was_bitfield
5834 bitsize_unit_node)))
5838 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5839 offset of the field. */
5846 "classes to be placed at different locations in a "
5849 /* The middle end uses the type of expressions to determine the
5850 possible range of expression values. In order to optimize
5851 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5852 must be made aware of the width of "i", via its type.
5854 Because C++ does not have integer types of arbitrary width,
5855 we must (for the purposes of the front end) convert from the
5856 type assigned here to the declared type of the bitfield
5857 whenever a bitfield expression is used as an rvalue.
5858 Similarly, when assigning a value to a bitfield, the value
5859 must be converted to the type given the bitfield here. */
5861 {
5866 {
5873 }
5874 }
5876 /* If we needed additional padding after this field, add it
5877 now. */
5879 {
5880 tree padding_field;
5883 FIELD_DECL,
5884 NULL_TREE,
5885 char_type_node);
5892 NULL_TREE,
5893 empty_base_offsets);
5894 }
5897 }
5900 {
5901 /* Make sure that we are on a byte boundary so that the size of
5902 the class without virtual bases will always be a round number
5903 of bytes. */
5906 }
5908 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
5909 padding. */
5913 /* Delete all zero-width bit-fields from the list of fields. Now
5914 that the type is laid out they are no longer important. */
5917 /* Create the version of T used for virtual bases. We do not use
5918 make_class_type for this version; this is an artificial type. For
5919 a POD type, we just reuse T. */
5921 {
5924 /* Set the size and alignment for the new type. In G++ 3.2, all
5925 empty classes were considered to have size zero when used as
5926 base classes. */
5928 {
5933 "layout of classes derived from empty class %qT "
5935 t);
5936 }
5937 else
5938 {
5939 tree eoc;
5941 /* If the ABI version is not at least two, and the last
5942 field was a bit-field, RLI may not be on a byte
5943 boundary. In particular, rli_size_unit_so_far might
5944 indicate the last complete byte, while rli_size_so_far
5945 indicates the total number of bits used. Therefore,
5946 rli_size_so_far, rather than rli_size_unit_so_far, is
5947 used to compute TYPE_SIZE_UNIT. */
5955 eoc);
5962 }
5966 /* Copy the fields from T. */
5970 {
5972 FIELD_DECL,
5982 }
5984 /* Record the base version of the type. */
5987 }
5988 else
5991 /* Every empty class contains an empty class. */
5995 /* Set the TYPE_DECL for this type to contain the right
5996 value for DECL_OFFSET, so that we can use it as part
5997 of a COMPONENT_REF for multiple inheritance. */
6000 /* Now fix up any virtual base class types that we left lying
6001 around. We must get these done before we try to lay out the
6002 virtual function table. As a side-effect, this will remove the
6003 base subobject fields. */
6006 /* Make sure that empty classes are reflected in RLI at this
6007 point. */
6010 /* Make sure not to create any structures with zero size. */
6016 /* If this is a non-POD, declaring it packed makes a difference to how it
6017 can be used as a field; don't let finalize_record_size undo it. */
6021 /* Let the back end lay out the type. */
6024 /* Warn about bases that can't be talked about due to ambiguity. */
6027 /* Now that we're done with layout, give the base fields the real types. */
6032 /* Clean up. */
6039 }
6041 /* Determine the "key method" for the class type indicated by TYPE,
6042 and set CLASSTYPE_KEY_METHOD accordingly. */
6044 void
6046 {
6047 tree method;
6050 || processing_template_decl
6055 /* The key method is the first non-pure virtual function that is not
6056 inline at the point of class definition. On some targets the
6057 key function may not be inline; those targets should not call
6058 this function until the end of the translation unit. */
6064 {
6067 }
6070 }
6073 /* Allocate and return an instance of struct sorted_fields_type with
6074 N fields. */
6078 {
6085 }
6088 /* Perform processing required when the definition of T (a class type)
6089 is complete. */
6091 void
6093 {
6094 tree x;
6095 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6099 {
6104 }
6106 /* If this type was previously laid out as a forward reference,
6107 make sure we lay it out again. */
6111 /* Make assumptions about the class; we'll reset the flags if
6112 necessary. */
6118 /* Do end-of-class semantic processing: checking the validity of the
6119 bases and members and add implicitly generated methods. */
6122 /* Find the key method. */
6124 {
6125 /* The Itanium C++ ABI permits the key method to be chosen when
6126 the class is defined -- even though the key method so
6127 selected may later turn out to be an inline function. On
6128 some systems (such as ARM Symbian OS) the key method cannot
6129 be determined until the end of the translation unit. On such
6130 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6131 will cause the class to be added to KEYED_CLASSES. Then, in
6132 finish_file we will determine the key method. */
6136 /* If a polymorphic class has no key method, we may emit the vtable
6137 in every translation unit where the class definition appears. */
6140 }
6142 /* Layout the class itself. */
6145 /* We use the base type for trivial assignments, and hence it
6146 needs a mode. */
6151 /* If necessary, create the primary vtable for this class. */
6153 {
6154 /* We must enter these virtuals into the table. */
6158 /* Here we know enough to change the type of our virtual
6159 function table, but we will wait until later this function. */
6161 }
6164 {
6166 tree fn;
6173 /* Add entries for virtual functions introduced by this class. */
6177 /* Set DECL_VINDEX for all functions declared in this class. */
6179 fn;
6181 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6183 {
6187 /* A thunk. We should never be calling this entry directly
6188 from this vtable -- we'd use the entry for the non
6189 thunk base function. */
6193 }
6194 }
6199 /* Complete the rtl for any static member objects of the type we're
6200 working on. */
6207 /* Done with FIELDS...now decide whether to sort these for
6208 faster lookups later.
6210 We use a small number because most searches fail (succeeding
6211 ultimately as the search bores through the inheritance
6212 hierarchy), and we want this failure to occur quickly. */
6216 /* Complain if one of the field types requires lower visibility. */
6219 /* Make the rtl for any new vtables we have created, and unmark
6220 the base types we marked. */
6223 /* Build the VTT for T. */
6226 /* This warning does not make sense for Java classes, since they
6227 cannot have destructors. */
6229 {
6230 tree dtor;
6234 if it were virtual, we would have created it by now. */
6235 !dtor
6244 "%q#T has virtual functions and accessible"
6246 }
6253 /* Class layout, assignment of virtual table slots, etc., is now
6254 complete. Give the back end a chance to tweak the visibility of
6255 the class or perform any other required target modifications. */
6262 /* Finish debugging output for this type. */
6266 {
6269 {
6272 }
6274 {
6277 else
6278 {
6281 }
6283 }
6284 }
6285 }
6287 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6288 equal to THRESHOLD or greater than THRESHOLD. */
6290 static void
6292 {
6295 {
6300 }
6301 }
6303 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6305 void
6307 {
6310 {
6312 int n_fields
6323 }
6324 }
6326 /* When T was built up, the member declarations were added in reverse
6327 order. Rearrange them to declaration order. */
6329 void
6331 {
6332 tree next;
6333 tree prev;
6334 tree x;
6336 /* The following lists are all in reverse order. Put them in
6337 declaration order now. */
6341 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6342 reverse order, so we can't just use nreverse. */
6347 {
6351 }
6353 {
6357 }
6358 }
6360 tree
6362 {
6365 /* Now that we've got all the field declarations, reverse everything
6366 as necessary. */
6371 /* Nadger the current location so that diagnostics point to the start of
6372 the struct, not the end. */
6376 {
6377 tree x;
6383 /* We need to emit an error message if this type was used as a parameter
6384 and it is an abstract type, even if it is a template. We construct
6385 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6386 account and we call complete_vars with this type, which will check
6387 the PARM_DECLS. Note that while the type is being defined,
6388 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6389 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6395 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6396 an enclosing scope is a template class, so that this function be
6397 found by lookup_fnfields_1 when the using declaration is not
6398 instantiated yet. */
6401 {
6406 }
6408 /* Remember current #pragma pack value. */
6411 /* Fix up any variants we've already built. */
6413 {
6418 }
6419 }
6420 else
6429 else
6433 /* Lambdas are defined by the LAMBDA_EXPR. */
6438 }
6439 \f
6440 /* Return the dynamic type of INSTANCE, if known.
6441 Used to determine whether the virtual function table is needed
6442 or not.
6444 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6445 of our knowledge of its type. *NONNULL should be initialized
6446 before this function is called. */
6448 static tree
6450 {
6451 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6454 {
6458 else
6462 /* This is a call to a constructor, hence it's never zero. */
6464 {
6468 }
6472 /* This is a call to a constructor, hence it's never zero. */
6474 {
6478 }
6487 /* Propagate nonnull. */
6492 CASE_CONVERT:
6498 {
6499 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6500 with a real object -- given &p->f, p can still be null. */
6502 /* ??? Probably should check DECL_WEAK here. */
6505 }
6509 /* If this component is really a base class reference, then the field
6510 itself isn't definitive. */
6519 {
6523 }
6524 /* fall through... */
6529 {
6533 }
6535 {
6539 /* if we're in a ctor or dtor, we know our type. If
6540 current_class_ptr is set but we aren't in a function, we're in
6541 an NSDMI (and therefore a constructor). */
6546 {
6550 }
6551 }
6553 {
6554 /* We only need one hash table because it is always left empty. */
6559 /* Reference variables should be references to objects. */
6563 /* Enter the INSTANCE in a table to prevent recursion; a
6564 variable's initializer may refer to the variable
6565 itself. */
6570 {
6571 tree type;
6580 }
6581 }
6586 }
6587 #undef RECUR
6588 }
6590 /* Return nonzero if the dynamic type of INSTANCE is known, and
6591 equivalent to the static type. We also handle the case where
6592 INSTANCE is really a pointer. Return negative if this is a
6593 ctor/dtor. There the dynamic type is known, but this might not be
6594 the most derived base of the original object, and hence virtual
6595 bases may not be layed out according to this type.
6597 Used to determine whether the virtual function table is needed
6598 or not.
6600 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6601 of our knowledge of its type. *NONNULL should be initialized
6602 before this function is called. */
6604 int
6606 {
6609 tree fixed;
6611 /* processing_template_decl can be false in a template if we're in
6612 fold_non_dependent_expr, but we still want to suppress this check. */
6614 {
6615 /* In a template we only care about the type of the result. */
6619 }
6629 }
6631 \f
6632 void
6634 {
6637 current_class_stack
6645 }
6647 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6649 static void
6651 {
6652 tree type;
6654 /* We are re-entering the same class we just left, so we don't
6655 have to search the whole inheritance matrix to find all the
6656 decls to bind again. Instead, we install the cached
6657 class_shadowed list and walk through it binding names. */
6660 /* Restore IDENTIFIER_TYPE_VALUE. */
6662 type;
6665 }
6667 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6668 appropriate for TYPE.
6670 So that we may avoid calls to lookup_name, we cache the _TYPE
6671 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6673 For multiple inheritance, we perform a two-pass depth-first search
6674 of the type lattice. */
6676 void
6678 {
6679 class_stack_node_t csn;
6683 /* Make sure there is enough room for the new entry on the stack. */
6685 {
6687 current_class_stack
6689 current_class_stack_size);
6690 }
6692 /* Insert a new entry on the class stack. */
6699 current_class_depth++;
6701 /* Now set up the new type. */
6707 /* By default, things in classes are private, while things in
6708 structures or unions are public. */
6710 ? access_private_node
6716 {
6717 /* Forcibly remove any old class remnants. */
6719 }
6725 else
6727 }
6729 /* When we exit a toplevel class scope, we save its binding level so
6730 that we can restore it quickly. Here, we've entered some other
6731 class, so we must invalidate our cache. */
6733 void
6735 {
6737 }
6739 /* Get out of the current class scope. If we were in a class scope
6740 previously, that is the one popped to. */
6742 void
6744 {
6747 current_class_depth--;
6753 }
6755 /* Mark the top of the class stack as hidden. */
6757 void
6759 {
6762 }
6764 /* Mark the top of the class stack as un-hidden. */
6766 void
6768 {
6771 }
6773 /* Returns 1 if the class type currently being defined is either T or
6774 a nested type of T. */
6776 bool
6778 {
6786 /* We start looking from 1 because entry 0 is from global scope,
6787 and has no type. */
6789 {
6790 tree c;
6793 else
6794 {
6798 }
6803 }
6805 }
6807 /* If either current_class_type or one of its enclosing classes are derived
6808 from T, return the appropriate type. Used to determine how we found
6809 something via unqualified lookup. */
6811 tree
6813 {
6816 /* The bases of a dependent type are unknown. */
6827 {
6832 }
6835 }
6837 /* Returns the innermost class type which is not a lambda closure type. */
6839 tree
6841 {
6844 /* We start looking from 1 because entry 0 is from global scope,
6845 and has no type. */
6847 {
6848 tree c;
6851 else
6852 {
6856 }
6861 }
6863 }
6865 /* When entering a class scope, all enclosing class scopes' names with
6866 static meaning (static variables, static functions, types and
6867 enumerators) have to be visible. This recursive function calls
6868 pushclass for all enclosing class contexts until global or a local
6869 scope is reached. TYPE is the enclosed class. */
6871 void
6873 {
6874 /* A namespace might be passed in error cases, like A::B:C. */
6882 }
6884 /* Undoes a push_nested_class call. */
6886 void
6888 {
6894 }
6896 /* Returns the number of extern "LANG" blocks we are nested within. */
6898 int
6900 {
6902 }
6904 /* Set global variables CURRENT_LANG_NAME to appropriate value
6905 so that behavior of name-mangling machinery is correct. */
6907 void
6909 {
6913 {
6915 }
6917 {
6919 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
6920 (See record_builtin_java_type in decl.c.) However, that causes
6921 incorrect debug entries if these types are actually used.
6922 So we re-enable debug output after extern "Java". */
6931 }
6933 {
6935 }
6936 else
6938 }
6940 /* Get out of the current language scope. */
6942 void
6944 {
6946 }
6947 \f
6948 /* Type instantiation routines. */
6950 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
6951 matches the TARGET_TYPE. If there is no satisfactory match, return
6952 error_mark_node, and issue an error & warning messages under
6953 control of FLAGS. Permit pointers to member function if FLAGS
6954 permits. If TEMPLATE_ONLY, the name of the overloaded function was
6955 a template-id, and EXPLICIT_TARGS are the explicitly provided
6956 template arguments.
6958 If OVERLOAD is for one or more member functions, then ACCESS_PATH
6959 is the base path used to reference those member functions. If
6960 the address is resolved to a member function, access checks will be
6961 performed and errors issued if appropriate. */
6963 static tree
6965 tree overload,
6966 tsubst_flags_t flags,
6968 tree explicit_targs,
6969 tree access_path)
6970 {
6971 /* Here's what the standard says:
6973 [over.over]
6975 If the name is a function template, template argument deduction
6976 is done, and if the argument deduction succeeds, the deduced
6977 arguments are used to generate a single template function, which
6978 is added to the set of overloaded functions considered.
6980 Non-member functions and static member functions match targets of
6981 type "pointer-to-function" or "reference-to-function." Nonstatic
6982 member functions match targets of type "pointer-to-member
6983 function;" the function type of the pointer to member is used to
6984 select the member function from the set of overloaded member
6985 functions. If a nonstatic member function is selected, the
6986 reference to the overloaded function name is required to have the
6987 form of a pointer to member as described in 5.3.1.
6989 If more than one function is selected, any template functions in
6990 the set are eliminated if the set also contains a non-template
6991 function, and any given template function is eliminated if the
6992 set contains a second template function that is more specialized
6993 than the first according to the partial ordering rules 14.5.5.2.
6994 After such eliminations, if any, there shall remain exactly one
6995 selected function. */
6998 /* We store the matches in a TREE_LIST rooted here. The functions
6999 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7000 interoperability with most_specialized_instantiation. */
7002 tree fn;
7003 tree target_fn_type;
7005 /* By the time we get here, we should be seeing only real
7006 pointer-to-member types, not the internal POINTER_TYPE to
7007 METHOD_TYPE representation. */
7013 /* Check that the TARGET_TYPE is reasonable. */
7017 /* This is OK, too. */
7020 /* This is OK, too. This comes from a conversion to reference
7021 type. */
7023 else
7024 {
7030 }
7032 /* Non-member functions and static member functions match targets of type
7033 "pointer-to-function" or "reference-to-function." Nonstatic member
7034 functions match targets of type "pointer-to-member-function;" the
7035 function type of the pointer to member is used to select the member
7036 function from the set of overloaded member functions.
7038 So figure out the FUNCTION_TYPE that we want to match against. */
7041 /* If we can find a non-template function that matches, we can just
7042 use it. There's no point in generating template instantiations
7043 if we're just going to throw them out anyhow. But, of course, we
7044 can only do this when we don't *need* a template function. */
7046 {
7047 tree fns;
7050 {
7054 /* We're not looking for templates just yet. */
7059 /* We're looking for a non-static member, and this isn't
7060 one, or vice versa. */
7063 /* Ignore functions which haven't been explicitly
7064 declared. */
7068 /* See if there's a match. */
7071 }
7072 }
7074 /* Now, if we've already got a match (or matches), there's no need
7075 to proceed to the template functions. But, if we don't have a
7076 match we need to look at them, too. */
7078 {
7079 tree target_arg_types;
7080 tree target_ret_type;
7081 tree fns;
7084 tree arg;
7098 {
7100 tree instantiation;
7101 tree targs;
7104 /* We're only looking for templates. */
7109 /* We're not looking for a non-static member, and this is
7110 one, or vice versa. */
7113 /* Try to do argument deduction. */
7120 /* Instantiation failed. */
7123 /* See if there's a match. */
7126 }
7128 /* Now, remove all but the most specialized of the matches. */
7130 {
7135 NULL_TREE,
7136 NULL_TREE);
7137 }
7138 }
7140 /* Now we should have exactly one function in MATCHES. */
7142 {
7143 /* There were *no* matches. */
7145 {
7148 target_type);
7151 }
7153 }
7155 {
7156 /* There were too many matches. First check if they're all
7157 the same function. */
7158 tree match;
7166 {
7168 {
7171 target_type);
7173 /* Since print_candidates expects the functions in the
7174 TREE_VALUE slot, we flip them here. */
7179 }
7182 }
7183 }
7185 /* Good, exactly one match. Now, convert it to the correct type. */
7190 {
7198 {
7201 }
7202 }
7204 /* If we're doing overload resolution purely for the purpose of
7205 determining conversion sequences, we should not consider the
7206 function used. If this conversion sequence is selected, the
7207 function will be marked as used at this point. */
7209 {
7210 /* Make =delete work with SFINAE. */
7215 }
7217 /* We could not check access to member functions when this
7218 expression was originally created since we did not know at that
7219 time to which function the expression referred. */
7221 {
7224 }
7228 else
7229 {
7230 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7231 will mark the function as addressed, but here we must do it
7232 explicitly. */
7236 }
7237 }
7239 /* This function will instantiate the type of the expression given in
7240 RHS to match the type of LHSTYPE. If errors exist, then return
7241 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7242 we complain on errors. If we are not complaining, never modify rhs,
7243 as overload resolution wants to try many possible instantiations, in
7244 the hope that at least one will work.
7246 For non-recursive calls, LHSTYPE should be a function, pointer to
7247 function, or a pointer to member function. */
7249 tree
7251 {
7258 {
7262 }
7265 {
7271 /* Microsoft allows `A::f' to be resolved to a
7272 pointer-to-member. */
7273 ;
7274 else
7275 {
7280 }
7281 }
7284 {
7287 }
7289 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7290 deduce any type information. */
7292 {
7296 }
7298 /* There only a few kinds of expressions that may have a type
7299 dependent on overload resolution. */
7305 /* This should really only be used when attempting to distinguish
7306 what sort of a pointer to function we have. For now, any
7307 arithmetic operation which is not supported on pointers
7308 is rejected as an error. */
7311 {
7313 {
7319 /* Do not lose object's side effects. */
7323 }
7330 /* This can happen if we are forming a pointer-to-member for a
7331 member template. */
7334 /* Fall through. */
7337 {
7341 return
7345 }
7349 return
7353 access_path);
7356 {
7361 }
7368 }
7370 }
7371 \f
7372 /* Return the name of the virtual function pointer field
7373 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7374 this may have to look back through base types to find the
7375 ultimate field name. (For single inheritance, these could
7376 all be the same name. Who knows for multiple inheritance). */
7378 static tree
7380 {
7387 {
7393 }
7401 }
7403 void
7405 {
7412 {
7417 }
7418 }
7420 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7421 according to [class]:
7422 The class-name is also inserted
7423 into the scope of the class itself. For purposes of access checking,
7424 the inserted class name is treated as if it were a public member name. */
7426 void
7428 {
7431 tree saved_cas;
7446 }
7448 /* Returns 1 if TYPE contains only padding bytes. */
7450 int
7452 {
7459 /* In G++ 3.2, whether or not a class was empty was determined by
7460 looking at its size. */
7463 else
7465 }
7467 /* Returns true if TYPE contains an empty class. */
7469 static bool
7471 {
7475 {
7476 tree field;
7477 tree binfo;
7478 tree base_binfo;
7490 }
7494 }
7496 /* Returns true if TYPE contains no actual data, just various
7497 possible combinations of empty classes and possibly a vptr. */
7499 bool
7501 {
7503 {
7504 tree field;
7505 tree binfo;
7506 tree base_binfo;
7509 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7510 out, but we'd like to be able to check this before then. */
7524 }
7528 }
7530 /* Note that NAME was looked up while the current class was being
7531 defined and that the result of that lookup was DECL. */
7533 void
7535 {
7536 splay_tree names_used;
7538 /* If we're not defining a class, there's nothing to do. */
7544 /* If there's already a binding for this NAME, then we don't have
7545 anything to worry about. */
7558 }
7560 /* Note that NAME was declared (as DECL) in the current class. Check
7561 to see that the declaration is valid. */
7563 void
7565 {
7566 splay_tree names_used;
7567 splay_tree_node n;
7569 /* Look to see if we ever used this name. */
7570 names_used
7574 /* The C language allows members to be declared with a type of the same
7575 name, and the C++ standard says this diagnostic is not required. So
7576 allow it in extern "C" blocks unless predantic is specified.
7577 Allow it in all cases if -ms-extensions is specified. */
7583 {
7584 /* [basic.scope.class]
7586 A name N used in a class S shall refer to the same declaration
7587 in its context and when re-evaluated in the completed scope of
7588 S. */
7592 }
7593 }
7595 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7596 Secondary vtables are merged with primary vtables; this function
7597 will return the VAR_DECL for the primary vtable. */
7599 tree
7601 {
7602 tree decl;
7606 {
7609 }
7613 }
7616 /* Returns the binfo for the primary base of BINFO. If the resulting
7617 BINFO is a virtual base, and it is inherited elsewhere in the
7618 hierarchy, then the returned binfo might not be the primary base of
7619 BINFO in the complete object. Check BINFO_PRIMARY_P or
7620 BINFO_LOST_PRIMARY_P to be sure. */
7622 static tree
7624 {
7625 tree primary_base;
7632 }
7634 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7636 static int
7638 {
7642 }
7644 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7645 INDENT should be zero when called from the top level; it is
7646 incremented recursively. IGO indicates the next expected BINFO in
7647 inheritance graph ordering. */
7649 static tree
7652 tree binfo,
7653 tree igo,
7655 {
7657 tree base_binfo;
7665 {
7668 }
7683 {
7687 TFF_PLAIN_IDENTIFIER),
7689 }
7691 {
7694 }
7699 {
7703 {
7707 TFF_PLAIN_IDENTIFIER));
7708 }
7710 {
7714 TFF_PLAIN_IDENTIFIER));
7715 }
7717 {
7721 TFF_PLAIN_IDENTIFIER));
7722 }
7724 {
7728 TFF_PLAIN_IDENTIFIER));
7729 }
7733 }
7739 }
7741 /* Dump the BINFO hierarchy for T. */
7743 static void
7745 {
7757 }
7759 /* Debug interface to hierarchy dumping. */
7761 void
7763 {
7765 }
7767 static void
7769 {
7774 {
7777 }
7778 }
7780 static void
7782 {
7783 tree value;
7785 HOST_WIDE_INT elt;
7793 TFF_PLAIN_IDENTIFIER));
7800 }
7802 static void
7804 {
7812 {
7819 {
7823 }
7827 }
7830 }
7832 static void
7834 {
7842 {
7847 }
7850 }
7852 /* Dump a function or thunk and its thunkees. */
7854 static void
7856 {
7859 tree thunks;
7867 {
7877 else
7883 }
7887 }
7889 /* Dump the thunks for FN. */
7891 void
7893 {
7895 }
7897 /* Virtual function table initialization. */
7899 /* Create all the necessary vtables for T and its base classes. */
7901 static void
7903 {
7904 tree vbase;
7908 /* We lay out the primary and secondary vtables in one contiguous
7909 vtable. The primary vtable is first, followed by the non-virtual
7910 secondary vtables in inheritance graph order. */
7914 /* Then come the virtual bases, also in inheritance graph order. */
7916 {
7920 }
7924 }
7926 /* Initialize the vtable for BINFO with the INITS. */
7928 static void
7930 {
7931 tree decl;
7937 }
7939 /* Build the VTT (virtual table table) for T.
7940 A class requires a VTT if it has virtual bases.
7942 This holds
7943 1 - primary virtual pointer for complete object T
7944 2 - secondary VTTs for each direct non-virtual base of T which requires a
7945 VTT
7946 3 - secondary virtual pointers for each direct or indirect base of T which
7947 has virtual bases or is reachable via a virtual path from T.
7948 4 - secondary VTTs for each direct or indirect virtual base of T.
7950 Secondary VTTs look like complete object VTTs without part 4. */
7952 static void
7954 {
7955 tree type;
7956 tree vtt;
7957 tree index;
7960 /* Build up the initializers for the VTT. */
7965 /* If we didn't need a VTT, we're done. */
7969 /* Figure out the type of the VTT. */
7973 /* Now, build the VTT object itself. */
7976 /* Add the VTT to the vtables list. */
7981 }
7983 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7984 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7985 and CHAIN the vtable pointer for this binfo after construction is
7986 complete. VALUE can also be another BINFO, in which case we recurse. */
7988 static tree
7990 {
7991 tree vt;
7994 {
8000 else
8002 }
8005 }
8007 /* Data for secondary VTT initialization. */
8009 {
8010 /* Is this the primary VTT? */
8013 /* Current index into the VTT. */
8014 tree index;
8016 /* Vector of initializers built up. */
8019 /* The type being constructed by this secondary VTT. */
8020 tree type_being_constructed;
8023 /* Recursively build the VTT-initializer for BINFO (which is in the
8024 hierarchy dominated by T). INITS points to the end of the initializer
8025 list to date. INDEX is the VTT index where the next element will be
8026 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8027 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8028 for virtual bases of T. When it is not so, we build the constructor
8029 vtables for the BINFO-in-T variant. */
8031 static void
8033 {
8035 tree b;
8036 tree init;
8037 secondary_vptr_vtt_init_data data;
8040 /* We only need VTTs for subobjects with virtual bases. */
8044 /* We need to use a construction vtable if this is not the primary
8045 VTT. */
8047 {
8050 /* Record the offset in the VTT where this sub-VTT can be found. */
8052 }
8054 /* Add the address of the primary vtable for the complete object. */
8058 {
8061 }
8064 /* Recursively add the secondary VTTs for non-virtual bases. */
8069 /* Add secondary virtual pointers for all subobjects of BINFO with
8070 either virtual bases or reachable along a virtual path, except
8071 subobjects that are non-virtual primary bases. */
8081 /* data.inits might have grown as we added secondary virtual pointers.
8082 Make sure our caller knows about the new vector. */
8086 /* Add the secondary VTTs for virtual bases in inheritance graph
8087 order. */
8089 {
8094 }
8095 else
8096 /* Remove the ctor vtables we created. */
8098 }
8100 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8101 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8103 static tree
8105 {
8108 /* We don't care about bases that don't have vtables. */
8112 /* We're only interested in proper subobjects of the type being
8113 constructed. */
8117 /* We're only interested in bases with virtual bases or reachable
8118 via a virtual path from the type being constructed. */
8123 /* We're not interested in non-virtual primary bases. */
8127 /* Record the index where this secondary vptr can be found. */
8129 {
8134 {
8135 /* It's a primary virtual base, and this is not a
8136 construction vtable. Find the base this is primary of in
8137 the inheritance graph, and use that base's vtable
8138 now. */
8141 }
8142 }
8144 /* Add the initializer for the secondary vptr itself. */
8147 /* Advance the vtt index. */
8152 }
8154 /* Called from build_vtt_inits via dfs_walk. After building
8155 constructor vtables and generating the sub-vtt from them, we need
8156 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8157 binfo of the base whose sub vtt was generated. */
8159 static tree
8161 {
8165 /* If this class has no vtable, none of its bases do. */
8169 /* This might be a primary base, so have no vtable in this
8170 hierarchy. */
8173 /* If we scribbled the construction vtable vptr into BINFO, clear it
8174 out now. */
8180 }
8182 /* Build the construction vtable group for BINFO which is in the
8183 hierarchy dominated by T. */
8185 static void
8187 {
8188 tree type;
8189 tree vtbl;
8190 tree id;
8191 tree vbase;
8194 /* See if we've already created this construction vtable group. */
8200 /* Build a version of VTBL (with the wrong type) for use in
8201 constructing the addresses of secondary vtables in the
8202 construction vtable group. */
8210 /* Add the vtables for each of our virtual bases using the vbase in T
8211 binfo. */
8213 vbase;
8215 {
8216 tree b;
8223 }
8225 /* Figure out the type of the construction vtable. */
8233 /* Initialize the construction vtable. */
8237 }
8239 /* Add the vtbl initializers for BINFO (and its bases other than
8240 non-virtual primaries) to the list of INITS. BINFO is in the
8241 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8242 the constructor the vtbl inits should be accumulated for. (If this
8243 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8244 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8245 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8246 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8247 but are not necessarily the same in terms of layout. */
8249 static void
8251 tree orig_binfo,
8252 tree rtti_binfo,
8253 tree vtbl,
8254 tree t,
8256 {
8258 tree base_binfo;
8263 /* If it doesn't have a vptr, we don't do anything. */
8267 /* If we're building a construction vtable, we're not interested in
8268 subobjects that don't require construction vtables. */
8274 /* Build the initializers for the BINFO-in-T vtable. */
8277 /* Walk the BINFO and its bases. We walk in preorder so that as we
8278 initialize each vtable we can figure out at what offset the
8279 secondary vtable lies from the primary vtable. We can't use
8280 dfs_walk here because we need to iterate through bases of BINFO
8281 and RTTI_BINFO simultaneously. */
8283 {
8284 /* Skip virtual bases. */
8290 inits);
8291 }
8292 }
8294 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8295 BINFO vtable to L. */
8297 static void
8299 tree orig_binfo,
8300 tree rtti_binfo,
8301 tree orig_vtbl,
8302 tree t,
8304 {
8311 {
8312 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8313 primary virtual base. If it is not the same primary in
8314 the hierarchy of T, we'll need to generate a ctor vtable
8315 for it, to place at its location in T. If it is the same
8316 primary, we still need a VTT entry for the vtable, but it
8317 should point to the ctor vtable for the base it is a
8318 primary for within the sub-hierarchy of RTTI_BINFO.
8320 There are three possible cases:
8322 1) We are in the same place.
8323 2) We are a primary base within a lost primary virtual base of
8324 RTTI_BINFO.
8325 3) We are primary to something not a base of RTTI_BINFO. */
8327 tree b;
8330 /* First, look through the bases we are primary to for RTTI_BINFO
8331 or a virtual base. */
8334 {
8339 }
8340 /* If we run out of primary links, keep looking down our
8341 inheritance chain; we might be an indirect primary. */
8345 found:
8347 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8348 base B and it is a base of RTTI_BINFO, this is case 2. In
8349 either case, we share our vtable with LAST, i.e. the
8350 derived-most base within B of which we are a primary. */
8353 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8354 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8355 binfo_ctor_vtable after everything's been set up. */
8358 /* Otherwise, this is case 3 and we get our own. */
8359 }
8366 {
8367 tree index;
8370 /* Add the initializer for this vtable. */
8374 /* Figure out the position to which the VPTR should point. */
8380 }
8383 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8384 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8385 straighten this out. */
8388 /* Throw away any unneeded intializers. */
8390 else
8391 /* For an ordinary vtable, set BINFO_VTABLE. */
8393 }
8397 /* Construct the initializer for BINFO's virtual function table. BINFO
8398 is part of the hierarchy dominated by T. If we're building a
8399 construction vtable, the ORIG_BINFO is the binfo we should use to
8400 find the actual function pointers to put in the vtable - but they
8401 can be overridden on the path to most-derived in the graph that
8402 ORIG_BINFO belongs. Otherwise,
8403 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8404 BINFO that should be indicated by the RTTI information in the
8405 vtable; it will be a base class of T, rather than T itself, if we
8406 are building a construction vtable.
8408 The value returned is a TREE_LIST suitable for wrapping in a
8409 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8410 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8411 number of non-function entries in the vtable.
8413 It might seem that this function should never be called with a
8414 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8415 base is always subsumed by a derived class vtable. However, when
8416 we are building construction vtables, we do build vtables for
8417 primary bases; we need these while the primary base is being
8418 constructed. */
8420 static void
8422 tree orig_binfo,
8423 tree t,
8424 tree rtti_binfo,
8427 {
8428 tree v;
8429 vtbl_init_data vid;
8431 tree vbinfo;
8435 /* Initialize VID. */
8443 /* The first vbase or vcall offset is at index -3 in the vtable. */
8446 /* Add entries to the vtable for RTTI. */
8449 /* Create an array for keeping track of the functions we've
8450 processed. When we see multiple functions with the same
8451 signature, we share the vcall offsets. */
8453 /* Add the vcall and vbase offset entries. */
8456 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8457 build_vbase_offset_vtbl_entries. */
8462 /* If the target requires padding between data entries, add that now. */
8464 {
8470 /* Move data entries into their new positions and add padding
8471 after the new positions. Iterate backwards so we don't
8472 overwrite entries that we would need to process later. */
8475 ix--)
8476 {
8484 {
8489 null_pointer_node);
8490 }
8491 }
8492 }
8497 /* The initializers for virtual functions were built up in reverse
8498 order. Straighten them out and add them to the running list in one
8499 step. */
8509 /* Go through all the ordinary virtual functions, building up
8510 initializers. */
8512 {
8513 tree delta;
8514 tree vcall_index;
8521 {
8525 {
8528 }
8530 }
8532 /* If the only definition of this function signature along our
8533 primary base chain is from a lost primary, this vtable slot will
8534 never be used, so just zero it out. This is important to avoid
8535 requiring extra thunks which cannot be generated with the function.
8537 We first check this in update_vtable_entry_for_fn, so we handle
8538 restored primary bases properly; we also need to do it here so we
8539 zero out unused slots in ctor vtables, rather than filling them
8540 with erroneous values (though harmless, apart from relocation
8541 costs). */
8546 {
8547 /* Pull the offset for `this', and the function to call, out of
8548 the list. */
8555 /* You can't call an abstract virtual function; it's abstract.
8556 So, we replace these functions with __pure_virtual. */
8558 {
8561 {
8563 abort_fndecl_addr
8567 }
8568 }
8569 /* Likewise for deleted virtuals. */
8571 {
8576 NULL_TREE);
8580 }
8581 else
8582 {
8584 {
8588 }
8589 /* Take the address of the function, considering it to be of an
8590 appropriate generic type. */
8594 }
8595 }
8597 /* And add it to the chain of initializers. */
8599 {
8604 else
8606 {
8612 }
8613 }
8614 else
8616 }
8617 }
8619 /* Adds to vid->inits the initializers for the vbase and vcall
8620 offsets in BINFO, which is in the hierarchy dominated by T. */
8622 static void
8624 {
8625 tree b;
8627 /* If this is a derived class, we must first create entries
8628 corresponding to the primary base class. */
8633 /* Add the vbase entries for this base. */
8635 /* Add the vcall entries for this base. */
8637 }
8639 /* Returns the initializers for the vbase offset entries in the vtable
8640 for BINFO (which is part of the class hierarchy dominated by T), in
8641 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8642 where the next vbase offset will go. */
8644 static void
8646 {
8647 tree vbase;
8648 tree t;
8649 tree non_primary_binfo;
8651 /* If there are no virtual baseclasses, then there is nothing to
8652 do. */
8658 /* We might be a primary base class. Go up the inheritance hierarchy
8659 until we find the most derived class of which we are a primary base:
8660 it is the offset of that which we need to use. */
8663 {
8664 tree b;
8666 /* If we have reached a virtual base, then it must be a primary
8667 base (possibly multi-level) of vid->binfo, or we wouldn't
8668 have called build_vcall_and_vbase_vtbl_entries for it. But it
8669 might be a lost primary, so just skip down to vid->binfo. */
8671 {
8674 }
8680 }
8682 /* Go through the virtual bases, adding the offsets. */
8684 vbase;
8686 {
8687 tree b;
8688 tree delta;
8693 /* Find the instance of this virtual base in the complete
8694 object. */
8697 /* If we've already got an offset for this virtual base, we
8698 don't need another one. */
8703 /* Figure out where we can find this vbase offset. */
8712 /* The vbase offset had better be the same. */
8715 /* The next vbase will come at a more negative offset. */
8719 /* The initializer is the delta from BINFO to this virtual base.
8720 The vbase offsets go in reverse inheritance-graph order, and
8721 we are walking in inheritance graph order so these end up in
8722 the right order. */
8729 }
8730 }
8732 /* Adds the initializers for the vcall offset entries in the vtable
8733 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8734 to VID->INITS. */
8736 static void
8738 {
8739 /* We only need these entries if this base is a virtual base. We
8740 compute the indices -- but do not add to the vtable -- when
8741 building the main vtable for a class. */
8744 /* If BINFO is RTTI_BINFO, then (since BINFO does not
8745 correspond to VID->DERIVED), we are building a primary
8746 construction virtual table. Since this is a primary
8747 virtual table, we do not need the vcall offsets for
8748 BINFO. */
8750 {
8751 /* We need a vcall offset for each of the virtual functions in this
8752 vtable. For example:
8754 class A { virtual void f (); };
8755 class B1 : virtual public A { virtual void f (); };
8756 class B2 : virtual public A { virtual void f (); };
8757 class C: public B1, public B2 { virtual void f (); };
8759 A C object has a primary base of B1, which has a primary base of A. A
8760 C also has a secondary base of B2, which no longer has a primary base
8761 of A. So the B2-in-C construction vtable needs a secondary vtable for
8762 A, which will adjust the A* to a B2* to call f. We have no way of
8763 knowing what (or even whether) this offset will be when we define B2,
8764 so we store this "vcall offset" in the A sub-vtable and look it up in
8765 a "virtual thunk" for B2::f.
8767 We need entries for all the functions in our primary vtable and
8768 in our non-virtual bases' secondary vtables. */
8770 /* If we are just computing the vcall indices -- but do not need
8771 the actual entries -- not that. */
8774 /* Now, walk through the non-virtual bases, adding vcall offsets. */
8776 }
8777 }
8779 /* Build vcall offsets, starting with those for BINFO. */
8781 static void
8783 {
8785 tree primary_binfo;
8786 tree base_binfo;
8788 /* Don't walk into virtual bases -- except, of course, for the
8789 virtual base for which we are building vcall offsets. Any
8790 primary virtual base will have already had its offsets generated
8791 through the recursion in build_vcall_and_vbase_vtbl_entries. */
8795 /* If BINFO has a primary base, process it first. */
8800 /* Add BINFO itself to the list. */
8803 /* Scan the non-primary bases of BINFO. */
8807 }
8809 /* Called from build_vcall_offset_vtbl_entries_r. */
8811 static void
8813 {
8814 /* Make entries for the rest of the virtuals. */
8816 {
8817 tree orig_fn;
8819 /* The ABI requires that the methods be processed in declaration
8820 order. G++ 3.2 used the order in the vtable. */
8822 orig_fn;
8826 }
8827 else
8828 {
8829 tree derived_virtuals;
8830 tree base_virtuals;
8831 tree orig_virtuals;
8832 /* If BINFO is a primary base, the most derived class which has
8833 BINFO as a primary base; otherwise, just BINFO. */
8834 tree non_primary_binfo;
8836 /* We might be a primary base class. Go up the inheritance hierarchy
8837 until we find the most derived class of which we are a primary base:
8838 it is the BINFO_VIRTUALS there that we need to consider. */
8841 {
8842 tree b;
8844 /* If we have reached a virtual base, then it must be vid->vbase,
8845 because we ignore other virtual bases in
8846 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
8847 base (possibly multi-level) of vid->binfo, or we wouldn't
8848 have called build_vcall_and_vbase_vtbl_entries for it. But it
8849 might be a lost primary, so just skip down to vid->binfo. */
8851 {
8855 }
8861 }
8864 /* For a ctor vtable we need the equivalent binfo within the hierarchy
8865 where rtti_binfo is the most derived type. */
8866 non_primary_binfo
8872 base_virtuals;
8876 {
8877 tree orig_fn;
8879 /* Find the declaration that originally caused this function to
8880 be present in BINFO_TYPE (binfo). */
8883 /* When processing BINFO, we only want to generate vcall slots for
8884 function slots introduced in BINFO. So don't try to generate
8885 one if the function isn't even defined in BINFO. */
8890 }
8891 }
8892 }
8894 /* Add a vcall offset entry for ORIG_FN to the vtable. */
8896 static void
8898 {
8900 tree vcall_offset;
8901 tree derived_entry;
8903 /* If there is already an entry for a function with the same
8904 signature as FN, then we do not need a second vcall offset.
8905 Check the list of functions already present in the derived
8906 class vtable. */
8908 {
8910 /* We only use one vcall offset for virtual destructors,
8911 even though there are two virtual table entries. */
8915 }
8917 /* If we are building these vcall offsets as part of building
8918 the vtable for the most derived class, remember the vcall
8919 offset. */
8921 {
8924 elt);
8925 }
8927 /* The next vcall offset will be found at a more negative
8928 offset. */
8932 /* Keep track of this function. */
8936 {
8937 tree base;
8938 tree fn;
8940 /* Find the overriding function. */
8944 else
8945 {
8948 /* The vbase we're working on is a primary base of
8949 vid->binfo. But it might be a lost primary, so its
8950 BINFO_OFFSET might be wrong, so we just use the
8951 BINFO_OFFSET from vid->binfo. */
8957 vcall_offset);
8958 }
8959 /* Add the initializer to the vtable. */
8961 }
8962 }
8964 /* Return vtbl initializers for the RTTI entries corresponding to the
8965 BINFO's vtable. The RTTI entries should indicate the object given
8966 by VID->rtti_binfo. */
8968 static void
8970 {
8971 tree b;
8972 tree t;
8973 tree offset;
8974 tree decl;
8975 tree init;
8979 /* To find the complete object, we will first convert to our most
8980 primary base, and then add the offset in the vtbl to that value. */
8984 {
8985 tree primary_base;
8991 }
8995 /* The second entry is the address of the typeinfo object. */
8998 else
9001 /* Convert the declaration to a type that can be stored in the
9002 vtable. */
9006 /* Add the offset-to-top entry. It comes earlier in the vtable than
9007 the typeinfo entry. Convert the offset to look like a
9008 function pointer, so that we can put it in the vtable. */
9011 }
9013 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9014 accessibility. */
9016 bool
9018 {
9021 }
9023 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9025 bool
9027 {
9031 }