| blob | a478de8056376268f2c44beee008ce7aad3b6af5 |
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 }
2810 }
2812 /* Create default constructors, assignment operators, and so forth for
2813 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2814 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2815 the class cannot have a default constructor, copy constructor
2816 taking a const reference argument, or an assignment operator taking
2817 a const reference, respectively. */
2819 static void
2823 {
2831 /* Destructor. */
2833 {
2834 /* In general, we create destructors lazily. */
2839 /* But if this is a Java class, any non-trivial destructor is
2840 invalid, even if compiler-generated. Therefore, if the
2841 destructor is non-trivial we create it now. */
2843 }
2845 /* [class.ctor]
2847 If there is no user-declared constructor for a class, a default
2848 constructor is implicitly declared. */
2850 {
2855 /* This might force the declaration. */
2857 }
2859 /* [class.ctor]
2861 If a class definition does not explicitly declare a copy
2862 constructor, one is declared implicitly. */
2864 {
2870 }
2872 /* If there is no assignment operator, one will be created if and
2873 when it is needed. For now, just record whether or not the type
2874 of the parameter to the assignment operator will be a const or
2875 non-const reference. */
2877 {
2883 }
2885 /* We can't be lazy about declaring functions that might override
2886 a virtual function from a base class. */
2890 {
2894 {
2895 /* declare, then remove the decl */
2904 }
2905 else
2907 }
2908 }
2910 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
2911 count the number of fields in TYPE, including anonymous union
2912 members. */
2914 static int
2916 {
2917 tree x;
2920 {
2923 else
2925 }
2927 }
2929 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
2930 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
2931 elts, starting at offset IDX. */
2933 static int
2935 {
2936 tree x;
2938 {
2941 else
2943 }
2945 }
2947 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
2948 starting at offset IDX. */
2950 static int
2954 {
2955 tree values;
2959 }
2961 /* FIELD is a bit-field. We are finishing the processing for its
2962 enclosing type. Issue any appropriate messages and set appropriate
2963 flags. Returns false if an error has been diagnosed. */
2965 static bool
2967 {
2969 tree w;
2971 /* Extract the declared width of the bitfield, which has been
2972 temporarily stashed in DECL_INITIAL. */
2975 /* Remove the bit-field width indicator so that the rest of the
2976 compiler does not treat that value as an initializer. */
2979 /* Detect invalid bit-field type. */
2981 {
2984 }
2985 else
2986 {
2988 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2991 /* detect invalid field size. */
2997 {
3000 }
3002 {
3005 }
3007 {
3010 }
3019 }
3022 {
3026 }
3027 else
3028 {
3029 /* Non-bit-fields are aligned for their type. */
3033 }
3034 }
3036 /* FIELD is a non bit-field. We are finishing the processing for its
3037 enclosing type T. Issue any appropriate messages and set appropriate
3038 flags. */
3040 static void
3042 tree t,
3046 {
3049 /* In C++98 an anonymous union cannot contain any fields which would change
3050 the settings of CANT_HAVE_CONST_CTOR and friends. */
3052 ;
3053 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3054 structs. So, we recurse through their fields here. */
3056 {
3057 tree fields;
3063 }
3064 /* Check members with class type for constructors, destructors,
3065 etc. */
3067 {
3068 /* Never let anything with uninheritable virtuals
3069 make it through without complaint. */
3073 {
3078 field);
3083 field);
3085 {
3089 }
3090 }
3091 else
3092 {
3105 }
3114 }
3116 {
3117 /* `build_class_init_list' does not recognize
3118 non-FIELD_DECLs. */
3122 }
3123 }
3125 /* Check the data members (both static and non-static), class-scoped
3126 typedefs, etc., appearing in the declaration of T. Issue
3127 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3128 declaration order) of access declarations; each TREE_VALUE in this
3129 list is a USING_DECL.
3131 In addition, set the following flags:
3133 EMPTY_P
3134 The class is empty, i.e., contains no non-static data members.
3136 CANT_HAVE_CONST_CTOR_P
3137 This class cannot have an implicitly generated copy constructor
3138 taking a const reference.
3140 CANT_HAVE_CONST_ASN_REF
3141 This class cannot have an implicitly generated assignment
3142 operator taking a const reference.
3144 All of these flags should be initialized before calling this
3145 function.
3147 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3148 fields can be added by adding to this chain. */
3150 static void
3154 {
3162 /* Assume there are no access declarations. */
3164 /* Assume this class has no pointer members. */
3166 /* Assume none of the members of this class have default
3167 initializations. */
3171 {
3179 {
3180 /* Save the access declarations for our caller. */
3183 }
3189 /* If we've gotten this far, it's a data member, possibly static,
3190 or an enumerator. */
3194 /* When this goes into scope, it will be a non-local reference. */
3198 {
3199 /* [class.union]
3201 If a union contains a static data member, or a member of
3202 reference type, the program is ill-formed. */
3204 {
3207 }
3209 {
3214 }
3215 }
3217 /* Perform error checking that did not get done in
3218 grokdeclarator. */
3220 {
3224 }
3226 {
3230 }
3238 /* Now it can only be a FIELD_DECL. */
3243 /* If at least one non-static data member is non-literal, the whole
3244 class becomes non-literal. Note: if the type is incomplete we
3245 will complain later on. */
3249 /* A standard-layout class is a class that:
3250 ...
3251 has the same access control (Clause 11) for all non-static data members,
3252 ... */
3259 /* If this is of reference type, check if it needs an init. */
3261 {
3267 /* ARM $12.6.2: [A member initializer list] (or, for an
3268 aggregate, initialization by a brace-enclosed list) is the
3269 only way to initialize nonstatic const and reference
3270 members. */
3273 }
3278 {
3280 {
3281 warning
3284 x);
3286 }
3290 }
3293 /* We don't treat zero-width bitfields as making a class
3294 non-empty. */
3295 ;
3296 else
3297 {
3298 /* The class is non-empty. */
3300 /* The class is not even nearly empty. */
3302 /* If one of the data members contains an empty class,
3303 so does T. */
3307 }
3309 /* This is used by -Weffc++ (see below). Warn only for pointers
3310 to members which might hold dynamic memory. So do not warn
3311 for pointers to functions or pointers to members. */
3317 {
3322 }
3328 /* DR 148 now allows pointers to members (which are POD themselves),
3329 to be allowed in POD structs. */
3338 /* We set DECL_C_BIT_FIELD in grokbitfield.
3339 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3342 cant_have_const_ctor_p,
3343 no_const_asn_ref_p,
3346 /* Now that we've removed bit-field widths from DECL_INITIAL,
3347 anything left in DECL_INITIAL is an NSDMI that makes the class
3348 non-aggregate. */
3352 /* If any field is const, the structure type is pseudo-const. */
3354 {
3359 /* ARM $12.6.2: [A member initializer list] (or, for an
3360 aggregate, initialization by a brace-enclosed list) is the
3361 only way to initialize nonstatic const and reference
3362 members. */
3365 }
3366 /* A field that is pseudo-const makes the structure likewise. */
3368 {
3373 }
3375 /* Core issue 80: A nonstatic data member is required to have a
3376 different name from the class iff the class has a
3377 user-declared constructor. */
3381 }
3383 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3384 it should also define a copy constructor and an assignment operator to
3385 implement the correct copy semantic (deep vs shallow, etc.). As it is
3386 not feasible to check whether the constructors do allocate dynamic memory
3387 and store it within members, we approximate the warning like this:
3389 -- Warn only if there are members which are pointers
3390 -- Warn only if there is a non-trivial constructor (otherwise,
3391 there cannot be memory allocated).
3392 -- Warn only if there is a non-trivial destructor. We assume that the
3393 user at least implemented the cleanup correctly, and a destructor
3394 is needed to free dynamic memory.
3396 This seems enough for practical purposes. */
3398 && has_pointers
3402 {
3406 {
3411 }
3415 }
3417 /* Non-static data member initializers make the default constructor
3418 non-trivial. */
3420 {
3423 }
3425 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3429 /* Check anonymous struct/anonymous union fields. */
3432 /* We've built up the list of access declarations in reverse order.
3433 Fix that now. */
3435 }
3437 /* If TYPE is an empty class type, records its OFFSET in the table of
3438 OFFSETS. */
3440 static int
3442 {
3443 splay_tree_node n;
3448 /* Record the location of this empty object in OFFSETS. */
3456 type,
3460 }
3462 /* Returns nonzero if TYPE is an empty class type and there is
3463 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3465 static int
3467 {
3468 splay_tree_node n;
3469 tree t;
3474 /* Record the location of this empty object in OFFSETS. */
3484 }
3486 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3487 F for every subobject, passing it the type, offset, and table of
3488 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3489 be traversed.
3491 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3492 than MAX_OFFSET will not be walked.
3494 If F returns a nonzero value, the traversal ceases, and that value
3495 is returned. Otherwise, returns zero. */
3497 static int
3499 subobject_offset_fn f,
3500 tree offset,
3501 splay_tree offsets,
3502 tree max_offset,
3504 {
3508 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3509 stop. */
3517 {
3521 }
3524 {
3525 tree field;
3526 tree binfo;
3529 /* Avoid recursing into objects that are not interesting. */
3533 /* Record the location of TYPE. */
3538 /* Iterate through the direct base classes of TYPE. */
3542 {
3543 tree binfo_offset;
3556 offset,
3558 else
3559 {
3560 tree orig_binfo;
3561 /* We cannot rely on BINFO_OFFSET being set for the base
3562 class yet, but the offsets for direct non-virtual
3563 bases can be calculated by going back to the TYPE. */
3566 offset,
3568 }
3571 f,
3572 binfo_offset,
3573 offsets,
3574 max_offset,
3579 }
3582 {
3586 /* Iterate through the virtual base classes of TYPE. In G++
3587 3.2, we included virtual bases in the direct base class
3588 loop above, which results in incorrect results; the
3589 correct offsets for virtual bases are only known when
3590 working with the most derived type. */
3594 {
3596 f,
3598 offset,
3600 offsets,
3601 max_offset,
3605 }
3606 else
3607 {
3608 /* We still have to walk the primary base, if it is
3609 virtual. (If it is non-virtual, then it was walked
3610 above.) */
3616 {
3617 r = (walk_subobject_offsets
3622 }
3623 }
3624 }
3626 /* Iterate through the fields of TYPE. */
3629 {
3630 tree field_offset;
3634 else
3635 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3639 f,
3641 offset,
3642 field_offset),
3643 offsets,
3644 max_offset,
3648 }
3649 }
3651 {
3654 tree index;
3656 /* Avoid recursing into objects that are not interesting. */
3661 /* Step through each of the elements in the array. */
3663 /* G++ 3.2 had an off-by-one error here. */
3668 {
3670 f,
3671 offset,
3672 offsets,
3673 max_offset,
3679 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3680 there's no point in iterating through the remaining
3681 elements of the array. */
3684 }
3685 }
3688 }
3690 /* Record all of the empty subobjects of TYPE (either a type or a
3691 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3692 is being placed at OFFSET; otherwise, it is a base class that is
3693 being placed at OFFSET. */
3695 static void
3697 tree offset,
3698 splay_tree offsets,
3700 {
3701 tree max_offset;
3702 /* If recording subobjects for a non-static data member or a
3703 non-empty base class , we do not need to record offsets beyond
3704 the size of the biggest empty class. Additional data members
3705 will go at the end of the class. Additional base classes will go
3706 either at offset zero (if empty, in which case they cannot
3707 overlap with offsets past the size of the biggest empty class) or
3708 at the end of the class.
3710 However, if we are placing an empty base class, then we must record
3711 all offsets, as either the empty class is at offset zero (where
3712 other empty classes might later be placed) or at the end of the
3713 class (where other objects might then be placed, so other empty
3714 subobjects might later overlap). */
3718 else
3722 }
3724 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3725 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3726 virtual bases of TYPE are examined. */
3728 static int
3730 tree offset,
3731 splay_tree offsets,
3733 {
3734 splay_tree_node max_node;
3736 /* Get the node in OFFSETS that indicates the maximum offset where
3737 an empty subobject is located. */
3739 /* If there aren't any empty subobjects, then there's no point in
3740 performing this check. */
3746 vbases_p);
3747 }
3749 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3750 non-static data member of the type indicated by RLI. BINFO is the
3751 binfo corresponding to the base subobject, OFFSETS maps offsets to
3752 types already located at those offsets. This function determines
3753 the position of the DECL. */
3755 static void
3757 tree decl,
3758 tree binfo,
3759 splay_tree offsets)
3760 {
3763 tree type;
3766 {
3767 /* For the purposes of determining layout conflicts, we want to
3768 use the class type of BINFO; TREE_TYPE (DECL) will be the
3769 CLASSTYPE_AS_BASE version, which does not contain entries for
3770 zero-sized bases. */
3773 }
3774 else
3775 {
3778 }
3780 /* Try to place the field. It may take more than one try if we have
3781 a hard time placing the field without putting two objects of the
3782 same type at the same address. */
3784 {
3787 /* Place this field. */
3791 /* We have to check to see whether or not there is already
3792 something of the same type at the offset we're about to use.
3793 For example, consider:
3795 struct S {};
3796 struct T : public S { int i; };
3797 struct U : public S, public T {};
3799 Here, we put S at offset zero in U. Then, we can't put T at
3800 offset zero -- its S component would be at the same address
3801 as the S we already allocated. So, we have to skip ahead.
3802 Since all data members, including those whose type is an
3803 empty class, have nonzero size, any overlap can happen only
3804 with a direct or indirect base-class -- it can't happen with
3805 a data member. */
3806 /* In a union, overlap is permitted; all members are placed at
3807 offset zero. */
3810 /* G++ 3.2 did not check for overlaps when placing a non-empty
3811 virtual base. */
3816 {
3817 /* Strip off the size allocated to this field. That puts us
3818 at the first place we could have put the field with
3819 proper alignment. */
3822 /* Bump up by the alignment required for the type. */
3823 rli->bitpos
3829 }
3830 else
3831 /* There was no conflict. We're done laying out this field. */
3833 }
3835 /* Now that we know where it will be placed, update its
3836 BINFO_OFFSET. */
3838 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3839 this point because their BINFO_OFFSET is copied from another
3840 hierarchy. Therefore, we may not need to add the entire
3841 OFFSET. */
3847 }
3849 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3851 static int
3853 tree offset,
3855 {
3857 }
3859 /* Layout the empty base BINFO. EOC indicates the byte currently just
3860 past the end of the class, and should be correctly aligned for a
3861 class of the type indicated by BINFO; OFFSETS gives the offsets of
3862 the empty bases allocated so far. T is the most derived
3863 type. Return nonzero iff we added it at the end. */
3865 static bool
3868 {
3869 tree alignment;
3873 /* This routine should only be used for empty classes. */
3878 {
3880 propagate_binfo_offsets
3883 else
3885 "offset of empty base %qT may not be ABI-compliant and may"
3888 }
3890 /* This is an empty base class. We first try to put it at offset
3891 zero. */
3894 offsets,
3896 {
3897 /* That didn't work. Now, we move forward from the next
3898 available spot in the class. */
3902 {
3905 offsets,
3907 /* We finally found a spot where there's no overlap. */
3910 /* There's overlap here, too. Bump along to the next spot. */
3912 }
3913 }
3916 {
3921 }
3924 }
3926 /* Layout the base given by BINFO in the class indicated by RLI.
3927 *BASE_ALIGN is a running maximum of the alignments of
3928 any base class. OFFSETS gives the location of empty base
3929 subobjects. T is the most derived type. Return nonzero if the new
3930 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3931 *NEXT_FIELD, unless BINFO is for an empty base class.
3933 Returns the location at which the next field should be inserted. */
3938 {
3943 /* This error is now reported in xref_tag, thus giving better
3944 location information. */
3947 /* Place the base class. */
3949 {
3950 tree decl;
3952 /* The containing class is non-empty because it has a non-empty
3953 base class. */
3956 /* Create the FIELD_DECL. */
3963 {
3971 /* Try to place the field. It may take more than one try if we
3972 have a hard time placing the field without putting two
3973 objects of the same type at the same address. */
3975 /* Add the new FIELD_DECL to the list of fields for T. */
3979 }
3980 }
3981 else
3982 {
3983 tree eoc;
3986 /* On some platforms (ARM), even empty classes will not be
3987 byte-aligned. */
3992 /* A nearly-empty class "has no proper base class that is empty,
3993 not morally virtual, and at an offset other than zero." */
3995 {
3998 /* The check above (used in G++ 3.2) is insufficient because
3999 an empty class placed at offset zero might itself have an
4000 empty base at a nonzero offset. */
4002 empty_base_at_nonzero_offset_p,
4003 size_zero_node,
4007 {
4010 else
4012 "class %qT will be considered nearly empty in a "
4014 }
4015 }
4017 /* We do not create a FIELD_DECL for empty base classes because
4018 it might overlap some other field. We want to be able to
4019 create CONSTRUCTORs for the class by iterating over the
4020 FIELD_DECLs, and the back end does not handle overlapping
4021 FIELD_DECLs. */
4023 /* An empty virtual base causes a class to be non-empty
4024 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4025 here because that was already done when the virtual table
4026 pointer was created. */
4027 }
4029 /* Record the offsets of BINFO and its base subobjects. */
4032 offsets,
4036 }
4038 /* Layout all of the non-virtual base classes. Record empty
4039 subobjects in OFFSETS. T is the most derived type. Return nonzero
4040 if the type cannot be nearly empty. The fields created
4041 corresponding to the base classes will be inserted at
4042 *NEXT_FIELD. */
4044 static void
4047 {
4048 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4049 subobjects. */
4054 /* The primary base class is always allocated first. */
4059 /* Now allocate the rest of the bases. */
4061 {
4062 tree base_binfo;
4066 /* The primary base was already allocated above, so we don't
4067 need to allocate it again here. */
4071 /* Virtual bases are added at the end (a primary virtual base
4072 will have already been added). */
4078 }
4079 }
4081 /* Go through the TYPE_METHODS of T issuing any appropriate
4082 diagnostics, figuring out which methods override which other
4083 methods, and so forth. */
4085 static void
4087 {
4088 tree x;
4091 {
4095 /* The name of the field is the original field name
4096 Save this in auxiliary field for later overloading. */
4098 {
4102 }
4103 /* All user-provided destructors are non-trivial.
4104 Constructors and assignment ops are handled in
4105 grok_special_member_properties. */
4108 }
4109 }
4111 /* FN is a constructor or destructor. Clone the declaration to create
4112 a specialized in-charge or not-in-charge version, as indicated by
4113 NAME. */
4115 static tree
4117 {
4118 tree parms;
4119 tree clone;
4121 /* Copy the function. */
4123 /* Reset the function name. */
4126 /* Remember where this function came from. */
4128 /* Make it easy to find the CLONE given the FN. */
4132 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4134 {
4141 }
4144 /* There's no pending inline data for this function. */
4148 /* The base-class destructor is not virtual. */
4150 {
4154 }
4156 /* If there was an in-charge parameter, drop it from the function
4157 type. */
4159 {
4160 tree basetype;
4161 tree parmtypes;
4162 tree exceptions;
4167 /* Skip the `this' parameter. */
4169 /* Skip the in-charge parameter. */
4171 /* And the VTT parm, in a complete [cd]tor. */
4175 /* If this is subobject constructor or destructor, add the vtt
4176 parameter. */
4180 parmtypes);
4183 exceptions);
4187 }
4189 /* Copy the function parameters. */
4191 /* Remove the in-charge parameter. */
4193 {
4197 }
4198 /* And the VTT parm, in a complete [cd]tor. */
4200 {
4203 else
4204 {
4208 }
4209 }
4212 {
4215 }
4217 /* Create the RTL for this function. */
4225 }
4227 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4228 not invoke this function directly.
4230 For a non-thunk function, returns the address of the slot for storing
4231 the function it is a clone of. Otherwise returns NULL_TREE.
4233 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4234 cloned_function is unset. This is to support the separate
4235 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4236 on a template makes sense, but not the former. */
4238 tree *
4240 {
4248 {
4249 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4252 else
4253 #endif
4255 }
4260 else
4262 }
4264 /* Produce declarations for all appropriate clones of FN. If
4265 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4266 CLASTYPE_METHOD_VEC as well. */
4268 void
4270 {
4271 tree clone;
4273 /* Avoid inappropriate cloning. */
4279 {
4280 /* For each constructor, we need two variants: an in-charge version
4281 and a not-in-charge version. */
4288 }
4289 else
4290 {
4293 /* For each destructor, we need three variants: an in-charge
4294 version, a not-in-charge version, and an in-charge deleting
4295 version. We clone the deleting version first because that
4296 means it will go second on the TYPE_METHODS list -- and that
4297 corresponds to the correct layout order in the virtual
4298 function table.
4300 For a non-virtual destructor, we do not build a deleting
4301 destructor. */
4303 {
4307 }
4314 }
4316 /* Note that this is an abstract function that is never emitted. */
4318 }
4320 /* DECL is an in charge constructor, which is being defined. This will
4321 have had an in class declaration, from whence clones were
4322 declared. An out-of-class definition can specify additional default
4323 arguments. As it is the clones that are involved in overload
4324 resolution, we must propagate the information from the DECL to its
4325 clones. */
4327 void
4329 {
4330 tree clone;
4334 {
4341 /* Skip the 'this' parameter. */
4357 {
4362 {
4363 /* A default parameter has been added. Adjust the
4364 clone's parameters. */
4368 tree type;
4373 {
4376 clone_parms);
4378 }
4381 clone_parms);
4390 }
4391 }
4393 }
4394 }
4396 /* For each of the constructors and destructors in T, create an
4397 in-charge and not-in-charge variant. */
4399 static void
4401 {
4402 tree fns;
4404 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4405 out now. */
4413 }
4415 /* Deduce noexcept for a destructor DTOR. */
4417 void
4419 {
4421 {
4428 }
4429 }
4431 /* For each destructor in T, deduce noexcept:
4433 12.4/3: A declaration of a destructor that does not have an
4434 exception-specification is implicitly considered to have the
4435 same exception-specification as an implicit declaration (15.4). */
4437 static void
4439 {
4440 tree fns;
4442 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4443 out now. */
4449 }
4451 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4452 of TYPE for virtual functions which FNDECL overrides. Return a
4453 mask of the tm attributes found therein. */
4455 static int
4457 {
4459 tree base_binfo;
4463 {
4473 else
4475 }
4478 }
4480 /* Subroutine of set_method_tm_attributes. Handle the checks and
4481 inheritance for one virtual method FNDECL. */
4483 static void
4485 {
4486 tree tm_attr;
4491 /* If FNDECL doesn't actually override anything (i.e. T is the
4492 class that first declares FNDECL virtual), then we're done. */
4499 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4500 tm_pure must match exactly, otherwise no weakening of
4501 tm_safe > tm_callable > nothing. */
4502 /* ??? The tm_pure attribute didn't make the transition to the
4503 multivendor language spec. */
4505 {
4507 {
4510 }
4511 }
4512 /* If the overridden function is tm_pure, then FNDECL must be. */
4515 /* Look for base class combinations that cannot be satisfied. */
4517 {
4523 }
4524 /* If FNDECL did not declare an attribute, then inherit the most
4525 restrictive one. */
4527 {
4529 }
4530 /* Otherwise validate that we're not weaker than a function
4531 that is being overridden. */
4532 else
4533 {
4537 }
4540 err_override:
4544 }
4546 /* For each of the methods in T, propagate a class-level tm attribute. */
4548 static void
4550 {
4553 /* Don't bother collecting tm attributes if transactional memory
4554 support is not enabled. */
4558 /* Process virtual methods first, as they inherit directly from the
4559 base virtual function and also require validation of new attributes. */
4561 {
4562 tree vchain;
4565 {
4570 }
4571 }
4573 /* If the class doesn't have an attribute, nothing more to do. */
4578 /* Any method that does not yet have a tm attribute inherits
4579 the one from the class. */
4581 {
4584 }
4585 }
4587 /* Returns true iff class T has a user-defined constructor other than
4588 the default constructor. */
4590 bool
4592 {
4593 tree fns;
4599 {
4606 }
4609 }
4611 /* Returns the defaulted constructor if T has one. Otherwise, returns
4612 NULL_TREE. */
4614 tree
4616 {
4623 {
4627 {
4633 }
4634 }
4637 }
4639 /* Returns true iff FN is a user-provided function, i.e. user-declared
4640 and not defaulted at its first declaration; or explicit, private,
4641 protected, or non-const. */
4643 bool
4645 {
4648 else
4651 }
4653 /* Returns true iff class T has a user-provided constructor. */
4655 bool
4657 {
4658 tree fns;
4666 /* This can happen in error cases; avoid crashing. */
4675 }
4677 /* Returns true iff class T has a user-provided default constructor. */
4679 bool
4681 {
4682 tree fns;
4688 {
4694 }
4697 }
4699 /* If default-initialization leaves part of TYPE uninitialized, returns
4700 a DECL for the field or TYPE itself (DR 253). */
4702 tree
4704 {
4715 {
4719 }
4724 {
4728 }
4731 }
4733 /* Returns true iff for class T, a trivial synthesized default constructor
4734 would be constexpr. */
4736 bool
4738 {
4739 /* A defaulted trivial default constructor is constexpr
4740 if there is nothing to initialize. */
4743 }
4745 /* Returns true iff class T has a constexpr default constructor. */
4747 bool
4749 {
4750 tree fns;
4753 {
4754 /* The caller should have stripped an enclosing array. */
4757 }
4759 {
4762 /* Non-trivial, we need to check subobject constructors. */
4764 }
4767 }
4769 /* Returns true iff class TYPE has a virtual destructor. */
4771 bool
4773 {
4774 tree dtor;
4782 }
4784 /* Returns true iff class T has a move constructor. */
4786 bool
4788 {
4789 tree fns;
4792 {
4795 }
4805 }
4807 /* Returns true iff class T has a move assignment operator. */
4809 bool
4811 {
4812 tree fns;
4815 {
4818 }
4826 }
4828 /* Returns true iff class T has a move constructor that was explicitly
4829 declared in the class body. Note that this is different from
4830 "user-provided", which doesn't include functions that are defaulted in
4831 the class. */
4833 bool
4835 {
4836 tree fns;
4845 {
4849 }
4852 }
4854 /* Returns true iff class T has a move assignment operator that was
4855 explicitly declared in the class body. */
4857 bool
4859 {
4860 tree fns;
4867 {
4871 }
4874 }
4876 /* Nonzero if we need to build up a constructor call when initializing an
4877 object of this class, either because it has a user-provided constructor
4878 or because it doesn't have a default constructor (so we need to give an
4879 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
4880 what you care about is whether or not an object can be produced by a
4881 constructor (e.g. so we don't set TREE_READONLY on const variables of
4882 such type); use this function when what you care about is whether or not
4883 to try to call a constructor to create an object. The latter case is
4884 the former plus some cases of constructors that cannot be called. */
4886 bool
4888 {
4889 tree inner;
4895 }
4897 /* Remove all zero-width bit-fields from T. */
4899 static void
4901 {
4906 {
4909 /* We should not be confused by the fact that grokbitfield
4910 temporarily sets the width of the bit field into
4911 DECL_INITIAL (*fieldsp).
4912 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
4913 to that width. */
4916 else
4918 }
4919 }
4921 /* Returns TRUE iff we need a cookie when dynamically allocating an
4922 array whose elements have the indicated class TYPE. */
4924 static bool
4926 {
4927 tree fns;
4932 /* If there's a non-trivial destructor, we need a cookie. In order
4933 to iterate through the array calling the destructor for each
4934 element, we'll have to know how many elements there are. */
4938 /* If the usual deallocation function is a two-argument whose second
4939 argument is of type `size_t', then we have to pass the size of
4940 the array to the deallocation function, so we will need to store
4941 a cookie. */
4945 /* If there are no `operator []' members, or the lookup is
4946 ambiguous, then we don't need a cookie. */
4949 /* Loop through all of the functions. */
4951 {
4952 tree fn;
4953 tree second_parm;
4955 /* Select the current function. */
4957 /* See if this function is a one-argument delete function. If
4958 it is, then it will be the usual deallocation function. */
4962 /* Do not consider this function if its second argument is an
4963 ellipsis. */
4966 /* Otherwise, if we have a two-argument function and the second
4967 argument is `size_t', it will be the usual deallocation
4968 function -- unless there is one-argument function, too. */
4972 }
4975 }
4977 /* Finish computing the `literal type' property of class type T.
4979 At this point, we have already processed base classes and
4980 non-static data members. We need to check whether the copy
4981 constructor is trivial, the destructor is trivial, and there
4982 is a trivial default constructor or at least one constexpr
4983 constructor other than the copy constructor. */
4985 static void
4987 {
4988 tree fn;
5004 {
5007 {
5011 }
5012 }
5013 }
5015 /* T is a non-literal type used in a context which requires a constant
5016 expression. Explain why it isn't literal. */
5018 void
5020 {
5030 /* Already explained. */
5039 {
5041 "default constructor, and has no constexpr constructor that "
5045 {
5046 /* Note that we can't simply call locate_ctor because when the
5047 constructor is deleted it just returns NULL_TREE. */
5048 tree fns;
5050 {
5057 {
5060 else
5063 }
5064 }
5065 }
5066 }
5067 else
5068 {
5072 {
5075 {
5080 }
5081 }
5083 {
5084 tree ftype;
5089 {
5094 }
5095 }
5096 }
5097 }
5099 /* Check the validity of the bases and members declared in T. Add any
5100 implicitly-generated functions (like copy-constructors and
5101 assignment operators). Compute various flag bits (like
5102 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5103 level: i.e., independently of the ABI in use. */
5105 static void
5107 {
5108 /* Nonzero if the implicitly generated copy constructor should take
5109 a non-const reference argument. */
5111 /* Nonzero if the implicitly generated assignment operator
5112 should take a non-const reference argument. */
5114 tree access_decls;
5117 tree fn;
5119 /* By default, we use const reference arguments and generate default
5120 constructors. */
5124 /* Deduce noexcept on destructors. */
5128 /* Check all the base-classes. */
5132 /* Check all the method declarations. */
5135 /* Save the initial values of these flags which only indicate whether
5136 or not the class has user-provided functions. As we analyze the
5137 bases and members we can set these flags for other reasons. */
5141 /* Check all the data member declarations. We cannot call
5142 check_field_decls until we have called check_bases check_methods,
5143 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5144 being set appropriately. */
5149 /* A nearly-empty class has to be vptr-containing; a nearly empty
5150 class contains just a vptr. */
5154 /* Do some bookkeeping that will guide the generation of implicitly
5155 declared member functions. */
5158 /* We need to call a constructor for this class if it has a
5159 user-provided constructor, or if the default constructor is going
5160 to initialize the vptr. (This is not an if-and-only-if;
5161 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5162 themselves need constructing.) */
5165 /* [dcl.init.aggr]
5167 An aggregate is an array or a class with no user-provided
5168 constructors ... and no virtual functions.
5170 Again, other conditions for being an aggregate are checked
5171 elsewhere. */
5174 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5175 retain the old definition internally for ABI reasons. */
5184 /* If the class has no user-declared constructor, but does have
5185 non-static const or reference data members that can never be
5186 initialized, issue a warning. */
5188 /* Classes with user-declared constructors are presumed to
5189 initialize these members. */
5191 /* Aggregates can be initialized with brace-enclosed
5192 initializers. */
5194 {
5195 tree field;
5198 {
5199 tree type;
5214 }
5215 }
5217 /* Synthesize any needed methods. */
5219 cant_have_const_ctor,
5220 no_const_asn_ref);
5222 /* Check defaulted declarations here so we have cant_have_const_ctor
5223 and don't need to worry about clones. */
5226 {
5229 {
5230 bool imp_const_p
5236 /* If the function is defaulted outside the class, we just
5237 give the synthesis error. */
5240 }
5242 }
5245 {
5246 /* "The closure type associated with a lambda-expression has a deleted
5247 default constructor and a deleted copy assignment operator." */
5253 /* "This class type is not an aggregate." */
5255 }
5257 /* Compute the 'literal type' property before we
5258 do anything with non-static member functions. */
5261 /* Create the in-charge and not-in-charge variants of constructors
5262 and destructors. */
5265 /* Process the using-declarations. */
5269 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5272 /* Figure out whether or not we will need a cookie when dynamically
5273 allocating an array of this type. */
5276 }
5278 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5279 accordingly. If a new vfield was created (because T doesn't have a
5280 primary base class), then the newly created field is returned. It
5281 is not added to the TYPE_FIELDS list; it is the caller's
5282 responsibility to do that. Accumulate declared virtual functions
5283 on VIRTUALS_P. */
5285 static tree
5287 {
5288 tree fn;
5290 /* Collect the virtual functions declared in T. */
5294 {
5303 }
5305 /* If we couldn't find an appropriate base class, create a new field
5306 here. Even if there weren't any new virtual functions, we might need a
5307 new virtual function table if we're supposed to include vptrs in
5308 all classes that need them. */
5310 {
5311 /* We build this decl with vtbl_ptr_type_node, which is a
5312 `vtable_entry_type*'. It might seem more precise to use
5313 `vtable_entry_type (*)[N]' where N is the number of virtual
5314 functions. However, that would require the vtable pointer in
5315 base classes to have a different type than the vtable pointer
5316 in derived classes. We could make that happen, but that
5317 still wouldn't solve all the problems. In particular, the
5318 type-based alias analysis code would decide that assignments
5319 to the base class vtable pointer can't alias assignments to
5320 the derived class vtable pointer, since they have different
5321 types. Thus, in a derived class destructor, where the base
5322 class constructor was inlined, we could generate bad code for
5323 setting up the vtable pointer.
5325 Therefore, we use one type for all vtable pointers. We still
5326 use a type-correct type; it's just doesn't indicate the array
5327 bounds. That's better than using `void*' or some such; it's
5328 cleaner, and it let's the alias analysis code know that these
5329 stores cannot alias stores to void*! */
5330 tree field;
5343 /* This class is non-empty. */
5347 }
5350 }
5352 /* Add OFFSET to all base types of BINFO which is a base in the
5353 hierarchy dominated by T.
5355 OFFSET, which is a type offset, is number of bytes. */
5357 static void
5359 {
5361 tree primary_binfo;
5362 tree base_binfo;
5364 /* Update BINFO's offset. */
5369 offset));
5371 /* Find the primary base class. */
5377 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5378 downwards. */
5380 {
5381 /* Don't do the primary base twice. */
5389 }
5390 }
5392 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5393 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5394 empty subobjects of T. */
5396 static void
5398 {
5399 tree vbase;
5408 {
5409 /* In G++ 3.2, we incorrectly rounded the size before laying out
5410 the virtual bases. */
5412 #ifdef STRUCTURE_SIZE_BOUNDARY
5413 /* Packed structures don't need to have minimum size. */
5416 #endif
5420 }
5422 /* Find the last field. The artificial fields created for virtual
5423 bases will go after the last extant field to date. */
5428 /* Go through the virtual bases, allocating space for each virtual
5429 base that is not already a primary base class. These are
5430 allocated in inheritance graph order. */
5432 {
5437 {
5440 /* This virtual base is not a primary base of any class in the
5441 hierarchy, so we have to add space for it. */
5445 /* If the first virtual base might have been placed at a
5446 lower address, had we started from CLASSTYPE_SIZE, rather
5447 than TYPE_SIZE, issue a warning. There can be both false
5448 positives and false negatives from this warning in rare
5449 cases; to deal with all the possibilities would probably
5450 require performing both layout algorithms and comparing
5451 the results which is not particularly tractable. */
5453 && first_vbase
5454 && (tree_int_cst_lt
5459 bitsize_unit_node),
5462 "offset of virtual base %qT is not ABI-compliant and "
5464 basetype);
5467 }
5468 }
5469 }
5471 /* Returns the offset of the byte just past the end of the base class
5472 BINFO. */
5474 static tree
5476 {
5477 tree size;
5482 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5483 allocate some space for it. It cannot have virtual bases, so
5484 TYPE_SIZE_UNIT is fine. */
5486 else
5490 }
5492 /* Returns the offset of the byte just past the end of the base class
5493 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5494 only non-virtual bases are included. */
5496 static tree
5498 {
5501 tree binfo;
5502 tree base_binfo;
5503 tree offset;
5508 {
5518 }
5520 /* G++ 3.2 did not check indirect virtual bases. */
5524 {
5528 }
5531 }
5533 /* Warn about bases of T that are inaccessible because they are
5534 ambiguous. For example:
5536 struct S {};
5537 struct T : public S {};
5538 struct U : public S, public T {};
5540 Here, `(S*) new U' is not allowed because there are two `S'
5541 subobjects of U. */
5543 static void
5545 {
5548 tree basetype;
5549 tree binfo;
5550 tree base_binfo;
5552 /* If there are no repeated bases, nothing can be ambiguous. */
5556 /* Check direct bases. */
5559 {
5565 }
5567 /* Check for ambiguous virtual bases. */
5571 {
5577 }
5578 }
5580 /* Compare two INTEGER_CSTs K1 and K2. */
5582 static int
5584 {
5586 }
5588 /* Increase the size indicated in RLI to account for empty classes
5589 that are "off the end" of the class. */
5591 static void
5593 {
5594 tree eoc;
5595 tree rli_size;
5597 /* It might be the case that we grew the class to allocate a
5598 zero-sized base class. That won't be reflected in RLI, yet,
5599 because we are willing to overlay multiple bases at the same
5600 offset. However, now we need to make sure that RLI is big enough
5601 to reflect the entire class. */
5607 {
5609 /* In version 1 of the ABI, the size of a class that ends with
5610 a bitfield was not rounded up to a whole multiple of a
5611 byte. Because rli_size_unit_so_far returns only the number
5612 of fully allocated bytes, any extra bits were not included
5613 in the size. */
5615 else
5616 /* The size should have been rounded to a whole byte. */
5619 rli->bitpos
5628 }
5629 }
5631 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5632 BINFO_OFFSETs for all of the base-classes. Position the vtable
5633 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5635 static void
5637 {
5638 tree non_static_data_members;
5639 tree field;
5640 tree vptr;
5641 record_layout_info rli;
5642 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5643 types that appear at that offset. */
5644 splay_tree empty_base_offsets;
5645 /* True if the last field layed out was a bit-field. */
5647 /* The location at which the next field should be inserted. */
5649 /* T, as a base class. */
5650 tree base_t;
5652 /* Keep track of the first non-static data member. */
5655 /* Start laying out the record. */
5658 /* Mark all the primary bases in the hierarchy. */
5661 /* Create a pointer to our virtual function table. */
5664 /* The vptr is always the first thing in the class. */
5666 {
5671 }
5672 else
5675 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5680 /* Layout the non-static data members. */
5682 {
5683 tree type;
5684 tree padding;
5686 /* We still pass things that aren't non-static data members to
5687 the back end, in case it wants to do something with them. */
5689 {
5691 /* If the static data member has incomplete type, keep track
5692 of it so that it can be completed later. (The handling
5693 of pending statics in finish_record_layout is
5694 insufficient; consider:
5696 struct S1;
5697 struct S2 { static S1 s1; };
5699 At this point, finish_record_layout will be called, but
5700 S1 is still incomplete.) */
5702 {
5704 /* The visibility of static data members is determined
5705 at their point of declaration, not their point of
5706 definition. */
5708 }
5710 }
5718 /* If this field is a bit-field whose width is greater than its
5719 type, then there are some special rules for allocating
5720 it. */
5723 {
5725 tree integer_type;
5727 /* We must allocate the bits as if suitably aligned for the
5728 longest integer type that fits in this many bits. type
5729 of the field. Then, we are supposed to use the left over
5730 bits as additional padding. */
5739 /* ITK now indicates a type that is too large for the
5740 field. We have to back up by one to find the largest
5741 type that fits. */
5742 do
5743 {
5748 /* Figure out how much additional padding is required. GCC
5749 3.2 always created a padding field, even if it had zero
5750 width. */
5753 {
5755 /* In a union, the padding field must have the full width
5756 of the bit-field; all fields start at offset zero. */
5758 else
5759 {
5762 "ABI-compliant and may change in a future "
5764 t);
5767 }
5768 }
5769 #ifdef PCC_BITFIELD_TYPE_MATTERS
5770 /* An unnamed bitfield does not normally affect the
5771 alignment of the containing class on a target where
5772 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5773 make any exceptions for unnamed bitfields when the
5774 bitfields are longer than their types. Therefore, we
5775 temporarily give the field a name. */
5777 {
5780 }
5781 #endif
5786 empty_base_offsets);
5789 /* Now that layout has been performed, set the size of the
5790 field to the size of its declared type; the rest of the
5791 field is effectively invisible. */
5793 /* We must also reset the DECL_MODE of the field. */
5798 /* Versions of G++ before G++ 3.4 did not reset the
5799 DECL_MODE. */
5801 "the offset of %qD may not be ABI-compliant and may "
5803 }
5804 else
5806 empty_base_offsets);
5808 /* Remember the location of any empty classes in FIELD. */
5812 empty_base_offsets,
5815 /* If a bit-field does not immediately follow another bit-field,
5816 and yet it starts in the middle of a byte, we have failed to
5817 comply with the ABI. */
5820 /* The TREE_NO_WARNING flag gets set by Objective-C when
5821 laying out an Objective-C class. The ObjC ABI differs
5822 from the C++ ABI, and so we do not want a warning
5823 here. */
5825 && !last_field_was_bitfield
5828 bitsize_unit_node)))
5832 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5833 offset of the field. */
5840 "classes to be placed at different locations in a "
5843 /* The middle end uses the type of expressions to determine the
5844 possible range of expression values. In order to optimize
5845 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5846 must be made aware of the width of "i", via its type.
5848 Because C++ does not have integer types of arbitrary width,
5849 we must (for the purposes of the front end) convert from the
5850 type assigned here to the declared type of the bitfield
5851 whenever a bitfield expression is used as an rvalue.
5852 Similarly, when assigning a value to a bitfield, the value
5853 must be converted to the type given the bitfield here. */
5855 {
5860 {
5867 }
5868 }
5870 /* If we needed additional padding after this field, add it
5871 now. */
5873 {
5874 tree padding_field;
5877 FIELD_DECL,
5878 NULL_TREE,
5879 char_type_node);
5886 NULL_TREE,
5887 empty_base_offsets);
5888 }
5891 }
5894 {
5895 /* Make sure that we are on a byte boundary so that the size of
5896 the class without virtual bases will always be a round number
5897 of bytes. */
5900 }
5902 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
5903 padding. */
5907 /* Delete all zero-width bit-fields from the list of fields. Now
5908 that the type is laid out they are no longer important. */
5911 /* Create the version of T used for virtual bases. We do not use
5912 make_class_type for this version; this is an artificial type. For
5913 a POD type, we just reuse T. */
5915 {
5918 /* Set the size and alignment for the new type. In G++ 3.2, all
5919 empty classes were considered to have size zero when used as
5920 base classes. */
5922 {
5927 "layout of classes derived from empty class %qT "
5929 t);
5930 }
5931 else
5932 {
5933 tree eoc;
5935 /* If the ABI version is not at least two, and the last
5936 field was a bit-field, RLI may not be on a byte
5937 boundary. In particular, rli_size_unit_so_far might
5938 indicate the last complete byte, while rli_size_so_far
5939 indicates the total number of bits used. Therefore,
5940 rli_size_so_far, rather than rli_size_unit_so_far, is
5941 used to compute TYPE_SIZE_UNIT. */
5949 eoc);
5956 }
5960 /* Copy the fields from T. */
5964 {
5966 FIELD_DECL,
5976 }
5978 /* Record the base version of the type. */
5981 }
5982 else
5985 /* Every empty class contains an empty class. */
5989 /* Set the TYPE_DECL for this type to contain the right
5990 value for DECL_OFFSET, so that we can use it as part
5991 of a COMPONENT_REF for multiple inheritance. */
5994 /* Now fix up any virtual base class types that we left lying
5995 around. We must get these done before we try to lay out the
5996 virtual function table. As a side-effect, this will remove the
5997 base subobject fields. */
6000 /* Make sure that empty classes are reflected in RLI at this
6001 point. */
6004 /* Make sure not to create any structures with zero size. */
6010 /* If this is a non-POD, declaring it packed makes a difference to how it
6011 can be used as a field; don't let finalize_record_size undo it. */
6015 /* Let the back end lay out the type. */
6018 /* Warn about bases that can't be talked about due to ambiguity. */
6021 /* Now that we're done with layout, give the base fields the real types. */
6026 /* Clean up. */
6033 }
6035 /* Determine the "key method" for the class type indicated by TYPE,
6036 and set CLASSTYPE_KEY_METHOD accordingly. */
6038 void
6040 {
6041 tree method;
6044 || processing_template_decl
6049 /* The key method is the first non-pure virtual function that is not
6050 inline at the point of class definition. On some targets the
6051 key function may not be inline; those targets should not call
6052 this function until the end of the translation unit. */
6058 {
6061 }
6064 }
6067 /* Allocate and return an instance of struct sorted_fields_type with
6068 N fields. */
6072 {
6079 }
6082 /* Perform processing required when the definition of T (a class type)
6083 is complete. */
6085 void
6087 {
6088 tree x;
6089 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6093 {
6098 }
6100 /* If this type was previously laid out as a forward reference,
6101 make sure we lay it out again. */
6105 /* Make assumptions about the class; we'll reset the flags if
6106 necessary. */
6112 /* Do end-of-class semantic processing: checking the validity of the
6113 bases and members and add implicitly generated methods. */
6116 /* Find the key method. */
6118 {
6119 /* The Itanium C++ ABI permits the key method to be chosen when
6120 the class is defined -- even though the key method so
6121 selected may later turn out to be an inline function. On
6122 some systems (such as ARM Symbian OS) the key method cannot
6123 be determined until the end of the translation unit. On such
6124 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6125 will cause the class to be added to KEYED_CLASSES. Then, in
6126 finish_file we will determine the key method. */
6130 /* If a polymorphic class has no key method, we may emit the vtable
6131 in every translation unit where the class definition appears. */
6134 }
6136 /* Layout the class itself. */
6139 /* We use the base type for trivial assignments, and hence it
6140 needs a mode. */
6145 /* If necessary, create the primary vtable for this class. */
6147 {
6148 /* We must enter these virtuals into the table. */
6152 /* Here we know enough to change the type of our virtual
6153 function table, but we will wait until later this function. */
6155 }
6158 {
6160 tree fn;
6167 /* Add entries for virtual functions introduced by this class. */
6171 /* Set DECL_VINDEX for all functions declared in this class. */
6173 fn;
6175 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6177 {
6181 /* A thunk. We should never be calling this entry directly
6182 from this vtable -- we'd use the entry for the non
6183 thunk base function. */
6187 }
6188 }
6193 /* Complete the rtl for any static member objects of the type we're
6194 working on. */
6201 /* Done with FIELDS...now decide whether to sort these for
6202 faster lookups later.
6204 We use a small number because most searches fail (succeeding
6205 ultimately as the search bores through the inheritance
6206 hierarchy), and we want this failure to occur quickly. */
6210 /* Complain if one of the field types requires lower visibility. */
6213 /* Make the rtl for any new vtables we have created, and unmark
6214 the base types we marked. */
6217 /* Build the VTT for T. */
6220 /* This warning does not make sense for Java classes, since they
6221 cannot have destructors. */
6223 {
6224 tree dtor;
6228 if it were virtual, we would have created it by now. */
6229 !dtor
6238 "%q#T has virtual functions and accessible"
6240 }
6247 /* Class layout, assignment of virtual table slots, etc., is now
6248 complete. Give the back end a chance to tweak the visibility of
6249 the class or perform any other required target modifications. */
6256 /* Finish debugging output for this type. */
6260 {
6263 {
6266 }
6268 {
6271 else
6272 {
6275 }
6277 }
6278 }
6279 }
6281 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6282 equal to THRESHOLD or greater than THRESHOLD. */
6284 static void
6286 {
6289 {
6294 }
6295 }
6297 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6299 void
6301 {
6304 {
6306 int n_fields
6317 }
6318 }
6320 /* When T was built up, the member declarations were added in reverse
6321 order. Rearrange them to declaration order. */
6323 void
6325 {
6326 tree next;
6327 tree prev;
6328 tree x;
6330 /* The following lists are all in reverse order. Put them in
6331 declaration order now. */
6335 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6336 reverse order, so we can't just use nreverse. */
6341 {
6345 }
6347 {
6351 }
6352 }
6354 tree
6356 {
6359 /* Now that we've got all the field declarations, reverse everything
6360 as necessary. */
6365 /* Nadger the current location so that diagnostics point to the start of
6366 the struct, not the end. */
6370 {
6371 tree x;
6377 /* We need to emit an error message if this type was used as a parameter
6378 and it is an abstract type, even if it is a template. We construct
6379 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6380 account and we call complete_vars with this type, which will check
6381 the PARM_DECLS. Note that while the type is being defined,
6382 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6383 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6389 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6390 an enclosing scope is a template class, so that this function be
6391 found by lookup_fnfields_1 when the using declaration is not
6392 instantiated yet. */
6395 {
6400 }
6402 /* Remember current #pragma pack value. */
6405 /* Fix up any variants we've already built. */
6407 {
6412 }
6413 }
6414 else
6423 else
6427 /* Lambdas are defined by the LAMBDA_EXPR. */
6432 }
6433 \f
6434 /* Return the dynamic type of INSTANCE, if known.
6435 Used to determine whether the virtual function table is needed
6436 or not.
6438 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6439 of our knowledge of its type. *NONNULL should be initialized
6440 before this function is called. */
6442 static tree
6444 {
6445 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6448 {
6452 else
6456 /* This is a call to a constructor, hence it's never zero. */
6458 {
6462 }
6466 /* This is a call to a constructor, hence it's never zero. */
6468 {
6472 }
6481 /* Propagate nonnull. */
6486 CASE_CONVERT:
6492 {
6493 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6494 with a real object -- given &p->f, p can still be null. */
6496 /* ??? Probably should check DECL_WEAK here. */
6499 }
6503 /* If this component is really a base class reference, then the field
6504 itself isn't definitive. */
6513 {
6517 }
6518 /* fall through... */
6523 {
6527 }
6529 {
6533 /* if we're in a ctor or dtor, we know our type. If
6534 current_class_ptr is set but we aren't in a function, we're in
6535 an NSDMI (and therefore a constructor). */
6540 {
6544 }
6545 }
6547 {
6548 /* We only need one hash table because it is always left empty. */
6553 /* Reference variables should be references to objects. */
6557 /* Enter the INSTANCE in a table to prevent recursion; a
6558 variable's initializer may refer to the variable
6559 itself. */
6564 {
6565 tree type;
6574 }
6575 }
6580 }
6581 #undef RECUR
6582 }
6584 /* Return nonzero if the dynamic type of INSTANCE is known, and
6585 equivalent to the static type. We also handle the case where
6586 INSTANCE is really a pointer. Return negative if this is a
6587 ctor/dtor. There the dynamic type is known, but this might not be
6588 the most derived base of the original object, and hence virtual
6589 bases may not be layed out according to this type.
6591 Used to determine whether the virtual function table is needed
6592 or not.
6594 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6595 of our knowledge of its type. *NONNULL should be initialized
6596 before this function is called. */
6598 int
6600 {
6603 tree fixed;
6605 /* processing_template_decl can be false in a template if we're in
6606 fold_non_dependent_expr, but we still want to suppress this check. */
6608 {
6609 /* In a template we only care about the type of the result. */
6613 }
6623 }
6625 \f
6626 void
6628 {
6631 current_class_stack
6639 }
6641 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6643 static void
6645 {
6646 tree type;
6648 /* We are re-entering the same class we just left, so we don't
6649 have to search the whole inheritance matrix to find all the
6650 decls to bind again. Instead, we install the cached
6651 class_shadowed list and walk through it binding names. */
6654 /* Restore IDENTIFIER_TYPE_VALUE. */
6656 type;
6659 }
6661 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6662 appropriate for TYPE.
6664 So that we may avoid calls to lookup_name, we cache the _TYPE
6665 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6667 For multiple inheritance, we perform a two-pass depth-first search
6668 of the type lattice. */
6670 void
6672 {
6673 class_stack_node_t csn;
6677 /* Make sure there is enough room for the new entry on the stack. */
6679 {
6681 current_class_stack
6683 current_class_stack_size);
6684 }
6686 /* Insert a new entry on the class stack. */
6693 current_class_depth++;
6695 /* Now set up the new type. */
6701 /* By default, things in classes are private, while things in
6702 structures or unions are public. */
6704 ? access_private_node
6710 {
6711 /* Forcibly remove any old class remnants. */
6713 }
6719 else
6721 }
6723 /* When we exit a toplevel class scope, we save its binding level so
6724 that we can restore it quickly. Here, we've entered some other
6725 class, so we must invalidate our cache. */
6727 void
6729 {
6731 }
6733 /* Get out of the current class scope. If we were in a class scope
6734 previously, that is the one popped to. */
6736 void
6738 {
6741 current_class_depth--;
6747 }
6749 /* Mark the top of the class stack as hidden. */
6751 void
6753 {
6756 }
6758 /* Mark the top of the class stack as un-hidden. */
6760 void
6762 {
6765 }
6767 /* Returns 1 if the class type currently being defined is either T or
6768 a nested type of T. */
6770 bool
6772 {
6780 /* We start looking from 1 because entry 0 is from global scope,
6781 and has no type. */
6783 {
6784 tree c;
6787 else
6788 {
6792 }
6797 }
6799 }
6801 /* If either current_class_type or one of its enclosing classes are derived
6802 from T, return the appropriate type. Used to determine how we found
6803 something via unqualified lookup. */
6805 tree
6807 {
6810 /* The bases of a dependent type are unknown. */
6821 {
6826 }
6829 }
6831 /* Returns the innermost class type which is not a lambda closure type. */
6833 tree
6835 {
6838 /* We start looking from 1 because entry 0 is from global scope,
6839 and has no type. */
6841 {
6842 tree c;
6845 else
6846 {
6850 }
6855 }
6857 }
6859 /* When entering a class scope, all enclosing class scopes' names with
6860 static meaning (static variables, static functions, types and
6861 enumerators) have to be visible. This recursive function calls
6862 pushclass for all enclosing class contexts until global or a local
6863 scope is reached. TYPE is the enclosed class. */
6865 void
6867 {
6868 /* A namespace might be passed in error cases, like A::B:C. */
6876 }
6878 /* Undoes a push_nested_class call. */
6880 void
6882 {
6888 }
6890 /* Returns the number of extern "LANG" blocks we are nested within. */
6892 int
6894 {
6896 }
6898 /* Set global variables CURRENT_LANG_NAME to appropriate value
6899 so that behavior of name-mangling machinery is correct. */
6901 void
6903 {
6907 {
6909 }
6911 {
6913 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
6914 (See record_builtin_java_type in decl.c.) However, that causes
6915 incorrect debug entries if these types are actually used.
6916 So we re-enable debug output after extern "Java". */
6925 }
6927 {
6929 }
6930 else
6932 }
6934 /* Get out of the current language scope. */
6936 void
6938 {
6940 }
6941 \f
6942 /* Type instantiation routines. */
6944 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
6945 matches the TARGET_TYPE. If there is no satisfactory match, return
6946 error_mark_node, and issue an error & warning messages under
6947 control of FLAGS. Permit pointers to member function if FLAGS
6948 permits. If TEMPLATE_ONLY, the name of the overloaded function was
6949 a template-id, and EXPLICIT_TARGS are the explicitly provided
6950 template arguments.
6952 If OVERLOAD is for one or more member functions, then ACCESS_PATH
6953 is the base path used to reference those member functions. If
6954 the address is resolved to a member function, access checks will be
6955 performed and errors issued if appropriate. */
6957 static tree
6959 tree overload,
6960 tsubst_flags_t flags,
6962 tree explicit_targs,
6963 tree access_path)
6964 {
6965 /* Here's what the standard says:
6967 [over.over]
6969 If the name is a function template, template argument deduction
6970 is done, and if the argument deduction succeeds, the deduced
6971 arguments are used to generate a single template function, which
6972 is added to the set of overloaded functions considered.
6974 Non-member functions and static member functions match targets of
6975 type "pointer-to-function" or "reference-to-function." Nonstatic
6976 member functions match targets of type "pointer-to-member
6977 function;" the function type of the pointer to member is used to
6978 select the member function from the set of overloaded member
6979 functions. If a nonstatic member function is selected, the
6980 reference to the overloaded function name is required to have the
6981 form of a pointer to member as described in 5.3.1.
6983 If more than one function is selected, any template functions in
6984 the set are eliminated if the set also contains a non-template
6985 function, and any given template function is eliminated if the
6986 set contains a second template function that is more specialized
6987 than the first according to the partial ordering rules 14.5.5.2.
6988 After such eliminations, if any, there shall remain exactly one
6989 selected function. */
6992 /* We store the matches in a TREE_LIST rooted here. The functions
6993 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
6994 interoperability with most_specialized_instantiation. */
6996 tree fn;
6997 tree target_fn_type;
6999 /* By the time we get here, we should be seeing only real
7000 pointer-to-member types, not the internal POINTER_TYPE to
7001 METHOD_TYPE representation. */
7007 /* Check that the TARGET_TYPE is reasonable. */
7011 /* This is OK, too. */
7014 /* This is OK, too. This comes from a conversion to reference
7015 type. */
7017 else
7018 {
7024 }
7026 /* Non-member functions and static member functions match targets of type
7027 "pointer-to-function" or "reference-to-function." Nonstatic member
7028 functions match targets of type "pointer-to-member-function;" the
7029 function type of the pointer to member is used to select the member
7030 function from the set of overloaded member functions.
7032 So figure out the FUNCTION_TYPE that we want to match against. */
7035 /* If we can find a non-template function that matches, we can just
7036 use it. There's no point in generating template instantiations
7037 if we're just going to throw them out anyhow. But, of course, we
7038 can only do this when we don't *need* a template function. */
7040 {
7041 tree fns;
7044 {
7048 /* We're not looking for templates just yet. */
7053 /* We're looking for a non-static member, and this isn't
7054 one, or vice versa. */
7057 /* Ignore functions which haven't been explicitly
7058 declared. */
7062 /* See if there's a match. */
7065 }
7066 }
7068 /* Now, if we've already got a match (or matches), there's no need
7069 to proceed to the template functions. But, if we don't have a
7070 match we need to look at them, too. */
7072 {
7073 tree target_arg_types;
7074 tree target_ret_type;
7075 tree fns;
7078 tree arg;
7092 {
7094 tree instantiation;
7095 tree targs;
7098 /* We're only looking for templates. */
7103 /* We're not looking for a non-static member, and this is
7104 one, or vice versa. */
7107 /* Try to do argument deduction. */
7114 /* Instantiation failed. */
7117 /* See if there's a match. */
7120 }
7122 /* Now, remove all but the most specialized of the matches. */
7124 {
7129 NULL_TREE,
7130 NULL_TREE);
7131 }
7132 }
7134 /* Now we should have exactly one function in MATCHES. */
7136 {
7137 /* There were *no* matches. */
7139 {
7142 target_type);
7145 }
7147 }
7149 {
7150 /* There were too many matches. First check if they're all
7151 the same function. */
7152 tree match;
7160 {
7162 {
7165 target_type);
7167 /* Since print_candidates expects the functions in the
7168 TREE_VALUE slot, we flip them here. */
7173 }
7176 }
7177 }
7179 /* Good, exactly one match. Now, convert it to the correct type. */
7184 {
7192 {
7195 }
7196 }
7198 /* If we're doing overload resolution purely for the purpose of
7199 determining conversion sequences, we should not consider the
7200 function used. If this conversion sequence is selected, the
7201 function will be marked as used at this point. */
7203 {
7204 /* Make =delete work with SFINAE. */
7209 }
7211 /* We could not check access to member functions when this
7212 expression was originally created since we did not know at that
7213 time to which function the expression referred. */
7215 {
7218 }
7222 else
7223 {
7224 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7225 will mark the function as addressed, but here we must do it
7226 explicitly. */
7230 }
7231 }
7233 /* This function will instantiate the type of the expression given in
7234 RHS to match the type of LHSTYPE. If errors exist, then return
7235 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7236 we complain on errors. If we are not complaining, never modify rhs,
7237 as overload resolution wants to try many possible instantiations, in
7238 the hope that at least one will work.
7240 For non-recursive calls, LHSTYPE should be a function, pointer to
7241 function, or a pointer to member function. */
7243 tree
7245 {
7252 {
7256 }
7259 {
7265 /* Microsoft allows `A::f' to be resolved to a
7266 pointer-to-member. */
7267 ;
7268 else
7269 {
7274 }
7275 }
7278 {
7281 }
7283 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7284 deduce any type information. */
7286 {
7290 }
7292 /* There only a few kinds of expressions that may have a type
7293 dependent on overload resolution. */
7299 /* This should really only be used when attempting to distinguish
7300 what sort of a pointer to function we have. For now, any
7301 arithmetic operation which is not supported on pointers
7302 is rejected as an error. */
7305 {
7307 {
7313 /* Do not lose object's side effects. */
7317 }
7324 /* This can happen if we are forming a pointer-to-member for a
7325 member template. */
7328 /* Fall through. */
7331 {
7335 return
7339 }
7343 return
7347 access_path);
7350 {
7355 }
7362 }
7364 }
7365 \f
7366 /* Return the name of the virtual function pointer field
7367 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7368 this may have to look back through base types to find the
7369 ultimate field name. (For single inheritance, these could
7370 all be the same name. Who knows for multiple inheritance). */
7372 static tree
7374 {
7381 {
7387 }
7395 }
7397 void
7399 {
7406 {
7411 }
7412 }
7414 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7415 according to [class]:
7416 The class-name is also inserted
7417 into the scope of the class itself. For purposes of access checking,
7418 the inserted class name is treated as if it were a public member name. */
7420 void
7422 {
7425 tree saved_cas;
7440 }
7442 /* Returns 1 if TYPE contains only padding bytes. */
7444 int
7446 {
7453 /* In G++ 3.2, whether or not a class was empty was determined by
7454 looking at its size. */
7457 else
7459 }
7461 /* Returns true if TYPE contains an empty class. */
7463 static bool
7465 {
7469 {
7470 tree field;
7471 tree binfo;
7472 tree base_binfo;
7484 }
7488 }
7490 /* Returns true if TYPE contains no actual data, just various
7491 possible combinations of empty classes and possibly a vptr. */
7493 bool
7495 {
7497 {
7498 tree field;
7499 tree binfo;
7500 tree base_binfo;
7503 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7504 out, but we'd like to be able to check this before then. */
7518 }
7522 }
7524 /* Note that NAME was looked up while the current class was being
7525 defined and that the result of that lookup was DECL. */
7527 void
7529 {
7530 splay_tree names_used;
7532 /* If we're not defining a class, there's nothing to do. */
7538 /* If there's already a binding for this NAME, then we don't have
7539 anything to worry about. */
7552 }
7554 /* Note that NAME was declared (as DECL) in the current class. Check
7555 to see that the declaration is valid. */
7557 void
7559 {
7560 splay_tree names_used;
7561 splay_tree_node n;
7563 /* Look to see if we ever used this name. */
7564 names_used
7568 /* The C language allows members to be declared with a type of the same
7569 name, and the C++ standard says this diagnostic is not required. So
7570 allow it in extern "C" blocks unless predantic is specified.
7571 Allow it in all cases if -ms-extensions is specified. */
7577 {
7578 /* [basic.scope.class]
7580 A name N used in a class S shall refer to the same declaration
7581 in its context and when re-evaluated in the completed scope of
7582 S. */
7586 }
7587 }
7589 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7590 Secondary vtables are merged with primary vtables; this function
7591 will return the VAR_DECL for the primary vtable. */
7593 tree
7595 {
7596 tree decl;
7600 {
7603 }
7607 }
7610 /* Returns the binfo for the primary base of BINFO. If the resulting
7611 BINFO is a virtual base, and it is inherited elsewhere in the
7612 hierarchy, then the returned binfo might not be the primary base of
7613 BINFO in the complete object. Check BINFO_PRIMARY_P or
7614 BINFO_LOST_PRIMARY_P to be sure. */
7616 static tree
7618 {
7619 tree primary_base;
7626 }
7628 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7630 static int
7632 {
7636 }
7638 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7639 INDENT should be zero when called from the top level; it is
7640 incremented recursively. IGO indicates the next expected BINFO in
7641 inheritance graph ordering. */
7643 static tree
7646 tree binfo,
7647 tree igo,
7649 {
7651 tree base_binfo;
7659 {
7662 }
7677 {
7681 TFF_PLAIN_IDENTIFIER),
7683 }
7685 {
7688 }
7693 {
7697 {
7701 TFF_PLAIN_IDENTIFIER));
7702 }
7704 {
7708 TFF_PLAIN_IDENTIFIER));
7709 }
7711 {
7715 TFF_PLAIN_IDENTIFIER));
7716 }
7718 {
7722 TFF_PLAIN_IDENTIFIER));
7723 }
7727 }
7733 }
7735 /* Dump the BINFO hierarchy for T. */
7737 static void
7739 {
7751 }
7753 /* Debug interface to hierarchy dumping. */
7755 void
7757 {
7759 }
7761 static void
7763 {
7768 {
7771 }
7772 }
7774 static void
7776 {
7777 tree value;
7779 HOST_WIDE_INT elt;
7787 TFF_PLAIN_IDENTIFIER));
7794 }
7796 static void
7798 {
7806 {
7813 {
7817 }
7821 }
7824 }
7826 static void
7828 {
7836 {
7841 }
7844 }
7846 /* Dump a function or thunk and its thunkees. */
7848 static void
7850 {
7853 tree thunks;
7861 {
7871 else
7877 }
7881 }
7883 /* Dump the thunks for FN. */
7885 void
7887 {
7889 }
7891 /* Virtual function table initialization. */
7893 /* Create all the necessary vtables for T and its base classes. */
7895 static void
7897 {
7898 tree vbase;
7902 /* We lay out the primary and secondary vtables in one contiguous
7903 vtable. The primary vtable is first, followed by the non-virtual
7904 secondary vtables in inheritance graph order. */
7908 /* Then come the virtual bases, also in inheritance graph order. */
7910 {
7914 }
7918 }
7920 /* Initialize the vtable for BINFO with the INITS. */
7922 static void
7924 {
7925 tree decl;
7931 }
7933 /* Build the VTT (virtual table table) for T.
7934 A class requires a VTT if it has virtual bases.
7936 This holds
7937 1 - primary virtual pointer for complete object T
7938 2 - secondary VTTs for each direct non-virtual base of T which requires a
7939 VTT
7940 3 - secondary virtual pointers for each direct or indirect base of T which
7941 has virtual bases or is reachable via a virtual path from T.
7942 4 - secondary VTTs for each direct or indirect virtual base of T.
7944 Secondary VTTs look like complete object VTTs without part 4. */
7946 static void
7948 {
7949 tree type;
7950 tree vtt;
7951 tree index;
7954 /* Build up the initializers for the VTT. */
7959 /* If we didn't need a VTT, we're done. */
7963 /* Figure out the type of the VTT. */
7967 /* Now, build the VTT object itself. */
7970 /* Add the VTT to the vtables list. */
7975 }
7977 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7978 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7979 and CHAIN the vtable pointer for this binfo after construction is
7980 complete. VALUE can also be another BINFO, in which case we recurse. */
7982 static tree
7984 {
7985 tree vt;
7988 {
7994 else
7996 }
7999 }
8001 /* Data for secondary VTT initialization. */
8003 {
8004 /* Is this the primary VTT? */
8007 /* Current index into the VTT. */
8008 tree index;
8010 /* Vector of initializers built up. */
8013 /* The type being constructed by this secondary VTT. */
8014 tree type_being_constructed;
8017 /* Recursively build the VTT-initializer for BINFO (which is in the
8018 hierarchy dominated by T). INITS points to the end of the initializer
8019 list to date. INDEX is the VTT index where the next element will be
8020 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8021 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8022 for virtual bases of T. When it is not so, we build the constructor
8023 vtables for the BINFO-in-T variant. */
8025 static void
8027 {
8029 tree b;
8030 tree init;
8031 secondary_vptr_vtt_init_data data;
8034 /* We only need VTTs for subobjects with virtual bases. */
8038 /* We need to use a construction vtable if this is not the primary
8039 VTT. */
8041 {
8044 /* Record the offset in the VTT where this sub-VTT can be found. */
8046 }
8048 /* Add the address of the primary vtable for the complete object. */
8052 {
8055 }
8058 /* Recursively add the secondary VTTs for non-virtual bases. */
8063 /* Add secondary virtual pointers for all subobjects of BINFO with
8064 either virtual bases or reachable along a virtual path, except
8065 subobjects that are non-virtual primary bases. */
8075 /* data.inits might have grown as we added secondary virtual pointers.
8076 Make sure our caller knows about the new vector. */
8080 /* Add the secondary VTTs for virtual bases in inheritance graph
8081 order. */
8083 {
8088 }
8089 else
8090 /* Remove the ctor vtables we created. */
8092 }
8094 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8095 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8097 static tree
8099 {
8102 /* We don't care about bases that don't have vtables. */
8106 /* We're only interested in proper subobjects of the type being
8107 constructed. */
8111 /* We're only interested in bases with virtual bases or reachable
8112 via a virtual path from the type being constructed. */
8117 /* We're not interested in non-virtual primary bases. */
8121 /* Record the index where this secondary vptr can be found. */
8123 {
8128 {
8129 /* It's a primary virtual base, and this is not a
8130 construction vtable. Find the base this is primary of in
8131 the inheritance graph, and use that base's vtable
8132 now. */
8135 }
8136 }
8138 /* Add the initializer for the secondary vptr itself. */
8141 /* Advance the vtt index. */
8146 }
8148 /* Called from build_vtt_inits via dfs_walk. After building
8149 constructor vtables and generating the sub-vtt from them, we need
8150 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8151 binfo of the base whose sub vtt was generated. */
8153 static tree
8155 {
8159 /* If this class has no vtable, none of its bases do. */
8163 /* This might be a primary base, so have no vtable in this
8164 hierarchy. */
8167 /* If we scribbled the construction vtable vptr into BINFO, clear it
8168 out now. */
8174 }
8176 /* Build the construction vtable group for BINFO which is in the
8177 hierarchy dominated by T. */
8179 static void
8181 {
8182 tree type;
8183 tree vtbl;
8184 tree id;
8185 tree vbase;
8188 /* See if we've already created this construction vtable group. */
8194 /* Build a version of VTBL (with the wrong type) for use in
8195 constructing the addresses of secondary vtables in the
8196 construction vtable group. */
8204 /* Add the vtables for each of our virtual bases using the vbase in T
8205 binfo. */
8207 vbase;
8209 {
8210 tree b;
8217 }
8219 /* Figure out the type of the construction vtable. */
8227 /* Initialize the construction vtable. */
8231 }
8233 /* Add the vtbl initializers for BINFO (and its bases other than
8234 non-virtual primaries) to the list of INITS. BINFO is in the
8235 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8236 the constructor the vtbl inits should be accumulated for. (If this
8237 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8238 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8239 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8240 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8241 but are not necessarily the same in terms of layout. */
8243 static void
8245 tree orig_binfo,
8246 tree rtti_binfo,
8247 tree vtbl,
8248 tree t,
8250 {
8252 tree base_binfo;
8257 /* If it doesn't have a vptr, we don't do anything. */
8261 /* If we're building a construction vtable, we're not interested in
8262 subobjects that don't require construction vtables. */
8268 /* Build the initializers for the BINFO-in-T vtable. */
8271 /* Walk the BINFO and its bases. We walk in preorder so that as we
8272 initialize each vtable we can figure out at what offset the
8273 secondary vtable lies from the primary vtable. We can't use
8274 dfs_walk here because we need to iterate through bases of BINFO
8275 and RTTI_BINFO simultaneously. */
8277 {
8278 /* Skip virtual bases. */
8284 inits);
8285 }
8286 }
8288 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8289 BINFO vtable to L. */
8291 static void
8293 tree orig_binfo,
8294 tree rtti_binfo,
8295 tree orig_vtbl,
8296 tree t,
8298 {
8305 {
8306 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8307 primary virtual base. If it is not the same primary in
8308 the hierarchy of T, we'll need to generate a ctor vtable
8309 for it, to place at its location in T. If it is the same
8310 primary, we still need a VTT entry for the vtable, but it
8311 should point to the ctor vtable for the base it is a
8312 primary for within the sub-hierarchy of RTTI_BINFO.
8314 There are three possible cases:
8316 1) We are in the same place.
8317 2) We are a primary base within a lost primary virtual base of
8318 RTTI_BINFO.
8319 3) We are primary to something not a base of RTTI_BINFO. */
8321 tree b;
8324 /* First, look through the bases we are primary to for RTTI_BINFO
8325 or a virtual base. */
8328 {
8333 }
8334 /* If we run out of primary links, keep looking down our
8335 inheritance chain; we might be an indirect primary. */
8339 found:
8341 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8342 base B and it is a base of RTTI_BINFO, this is case 2. In
8343 either case, we share our vtable with LAST, i.e. the
8344 derived-most base within B of which we are a primary. */
8347 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8348 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8349 binfo_ctor_vtable after everything's been set up. */
8352 /* Otherwise, this is case 3 and we get our own. */
8353 }
8360 {
8361 tree index;
8364 /* Add the initializer for this vtable. */
8368 /* Figure out the position to which the VPTR should point. */
8374 }
8377 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8378 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8379 straighten this out. */
8382 /* Throw away any unneeded intializers. */
8384 else
8385 /* For an ordinary vtable, set BINFO_VTABLE. */
8387 }
8391 /* Construct the initializer for BINFO's virtual function table. BINFO
8392 is part of the hierarchy dominated by T. If we're building a
8393 construction vtable, the ORIG_BINFO is the binfo we should use to
8394 find the actual function pointers to put in the vtable - but they
8395 can be overridden on the path to most-derived in the graph that
8396 ORIG_BINFO belongs. Otherwise,
8397 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8398 BINFO that should be indicated by the RTTI information in the
8399 vtable; it will be a base class of T, rather than T itself, if we
8400 are building a construction vtable.
8402 The value returned is a TREE_LIST suitable for wrapping in a
8403 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8404 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8405 number of non-function entries in the vtable.
8407 It might seem that this function should never be called with a
8408 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8409 base is always subsumed by a derived class vtable. However, when
8410 we are building construction vtables, we do build vtables for
8411 primary bases; we need these while the primary base is being
8412 constructed. */
8414 static void
8416 tree orig_binfo,
8417 tree t,
8418 tree rtti_binfo,
8421 {
8422 tree v;
8423 vtbl_init_data vid;
8425 tree vbinfo;
8429 /* Initialize VID. */
8437 /* The first vbase or vcall offset is at index -3 in the vtable. */
8440 /* Add entries to the vtable for RTTI. */
8443 /* Create an array for keeping track of the functions we've
8444 processed. When we see multiple functions with the same
8445 signature, we share the vcall offsets. */
8447 /* Add the vcall and vbase offset entries. */
8450 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8451 build_vbase_offset_vtbl_entries. */
8456 /* If the target requires padding between data entries, add that now. */
8458 {
8464 /* Move data entries into their new positions and add padding
8465 after the new positions. Iterate backwards so we don't
8466 overwrite entries that we would need to process later. */
8469 ix--)
8470 {
8478 {
8483 null_pointer_node);
8484 }
8485 }
8486 }
8491 /* The initializers for virtual functions were built up in reverse
8492 order. Straighten them out and add them to the running list in one
8493 step. */
8503 /* Go through all the ordinary virtual functions, building up
8504 initializers. */
8506 {
8507 tree delta;
8508 tree vcall_index;
8515 {
8519 {
8522 }
8524 }
8526 /* If the only definition of this function signature along our
8527 primary base chain is from a lost primary, this vtable slot will
8528 never be used, so just zero it out. This is important to avoid
8529 requiring extra thunks which cannot be generated with the function.
8531 We first check this in update_vtable_entry_for_fn, so we handle
8532 restored primary bases properly; we also need to do it here so we
8533 zero out unused slots in ctor vtables, rather than filling them
8534 with erroneous values (though harmless, apart from relocation
8535 costs). */
8540 {
8541 /* Pull the offset for `this', and the function to call, out of
8542 the list. */
8549 /* You can't call an abstract virtual function; it's abstract.
8550 So, we replace these functions with __pure_virtual. */
8552 {
8555 {
8557 abort_fndecl_addr
8561 }
8562 }
8563 /* Likewise for deleted virtuals. */
8565 {
8570 NULL_TREE);
8574 }
8575 else
8576 {
8578 {
8582 }
8583 /* Take the address of the function, considering it to be of an
8584 appropriate generic type. */
8588 }
8589 }
8591 /* And add it to the chain of initializers. */
8593 {
8598 else
8600 {
8606 }
8607 }
8608 else
8610 }
8611 }
8613 /* Adds to vid->inits the initializers for the vbase and vcall
8614 offsets in BINFO, which is in the hierarchy dominated by T. */
8616 static void
8618 {
8619 tree b;
8621 /* If this is a derived class, we must first create entries
8622 corresponding to the primary base class. */
8627 /* Add the vbase entries for this base. */
8629 /* Add the vcall entries for this base. */
8631 }
8633 /* Returns the initializers for the vbase offset entries in the vtable
8634 for BINFO (which is part of the class hierarchy dominated by T), in
8635 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8636 where the next vbase offset will go. */
8638 static void
8640 {
8641 tree vbase;
8642 tree t;
8643 tree non_primary_binfo;
8645 /* If there are no virtual baseclasses, then there is nothing to
8646 do. */
8652 /* We might be a primary base class. Go up the inheritance hierarchy
8653 until we find the most derived class of which we are a primary base:
8654 it is the offset of that which we need to use. */
8657 {
8658 tree b;
8660 /* If we have reached a virtual base, then it must be a primary
8661 base (possibly multi-level) of vid->binfo, or we wouldn't
8662 have called build_vcall_and_vbase_vtbl_entries for it. But it
8663 might be a lost primary, so just skip down to vid->binfo. */
8665 {
8668 }
8674 }
8676 /* Go through the virtual bases, adding the offsets. */
8678 vbase;
8680 {
8681 tree b;
8682 tree delta;
8687 /* Find the instance of this virtual base in the complete
8688 object. */
8691 /* If we've already got an offset for this virtual base, we
8692 don't need another one. */
8697 /* Figure out where we can find this vbase offset. */
8706 /* The vbase offset had better be the same. */
8709 /* The next vbase will come at a more negative offset. */
8713 /* The initializer is the delta from BINFO to this virtual base.
8714 The vbase offsets go in reverse inheritance-graph order, and
8715 we are walking in inheritance graph order so these end up in
8716 the right order. */
8723 }
8724 }
8726 /* Adds the initializers for the vcall offset entries in the vtable
8727 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8728 to VID->INITS. */
8730 static void
8732 {
8733 /* We only need these entries if this base is a virtual base. We
8734 compute the indices -- but do not add to the vtable -- when
8735 building the main vtable for a class. */
8738 /* If BINFO is RTTI_BINFO, then (since BINFO does not
8739 correspond to VID->DERIVED), we are building a primary
8740 construction virtual table. Since this is a primary
8741 virtual table, we do not need the vcall offsets for
8742 BINFO. */
8744 {
8745 /* We need a vcall offset for each of the virtual functions in this
8746 vtable. For example:
8748 class A { virtual void f (); };
8749 class B1 : virtual public A { virtual void f (); };
8750 class B2 : virtual public A { virtual void f (); };
8751 class C: public B1, public B2 { virtual void f (); };
8753 A C object has a primary base of B1, which has a primary base of A. A
8754 C also has a secondary base of B2, which no longer has a primary base
8755 of A. So the B2-in-C construction vtable needs a secondary vtable for
8756 A, which will adjust the A* to a B2* to call f. We have no way of
8757 knowing what (or even whether) this offset will be when we define B2,
8758 so we store this "vcall offset" in the A sub-vtable and look it up in
8759 a "virtual thunk" for B2::f.
8761 We need entries for all the functions in our primary vtable and
8762 in our non-virtual bases' secondary vtables. */
8764 /* If we are just computing the vcall indices -- but do not need
8765 the actual entries -- not that. */
8768 /* Now, walk through the non-virtual bases, adding vcall offsets. */
8770 }
8771 }
8773 /* Build vcall offsets, starting with those for BINFO. */
8775 static void
8777 {
8779 tree primary_binfo;
8780 tree base_binfo;
8782 /* Don't walk into virtual bases -- except, of course, for the
8783 virtual base for which we are building vcall offsets. Any
8784 primary virtual base will have already had its offsets generated
8785 through the recursion in build_vcall_and_vbase_vtbl_entries. */
8789 /* If BINFO has a primary base, process it first. */
8794 /* Add BINFO itself to the list. */
8797 /* Scan the non-primary bases of BINFO. */
8801 }
8803 /* Called from build_vcall_offset_vtbl_entries_r. */
8805 static void
8807 {
8808 /* Make entries for the rest of the virtuals. */
8810 {
8811 tree orig_fn;
8813 /* The ABI requires that the methods be processed in declaration
8814 order. G++ 3.2 used the order in the vtable. */
8816 orig_fn;
8820 }
8821 else
8822 {
8823 tree derived_virtuals;
8824 tree base_virtuals;
8825 tree orig_virtuals;
8826 /* If BINFO is a primary base, the most derived class which has
8827 BINFO as a primary base; otherwise, just BINFO. */
8828 tree non_primary_binfo;
8830 /* We might be a primary base class. Go up the inheritance hierarchy
8831 until we find the most derived class of which we are a primary base:
8832 it is the BINFO_VIRTUALS there that we need to consider. */
8835 {
8836 tree b;
8838 /* If we have reached a virtual base, then it must be vid->vbase,
8839 because we ignore other virtual bases in
8840 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
8841 base (possibly multi-level) of vid->binfo, or we wouldn't
8842 have called build_vcall_and_vbase_vtbl_entries for it. But it
8843 might be a lost primary, so just skip down to vid->binfo. */
8845 {
8849 }
8855 }
8858 /* For a ctor vtable we need the equivalent binfo within the hierarchy
8859 where rtti_binfo is the most derived type. */
8860 non_primary_binfo
8866 base_virtuals;
8870 {
8871 tree orig_fn;
8873 /* Find the declaration that originally caused this function to
8874 be present in BINFO_TYPE (binfo). */
8877 /* When processing BINFO, we only want to generate vcall slots for
8878 function slots introduced in BINFO. So don't try to generate
8879 one if the function isn't even defined in BINFO. */
8884 }
8885 }
8886 }
8888 /* Add a vcall offset entry for ORIG_FN to the vtable. */
8890 static void
8892 {
8894 tree vcall_offset;
8895 tree derived_entry;
8897 /* If there is already an entry for a function with the same
8898 signature as FN, then we do not need a second vcall offset.
8899 Check the list of functions already present in the derived
8900 class vtable. */
8902 {
8904 /* We only use one vcall offset for virtual destructors,
8905 even though there are two virtual table entries. */
8909 }
8911 /* If we are building these vcall offsets as part of building
8912 the vtable for the most derived class, remember the vcall
8913 offset. */
8915 {
8918 elt);
8919 }
8921 /* The next vcall offset will be found at a more negative
8922 offset. */
8926 /* Keep track of this function. */
8930 {
8931 tree base;
8932 tree fn;
8934 /* Find the overriding function. */
8938 else
8939 {
8942 /* The vbase we're working on is a primary base of
8943 vid->binfo. But it might be a lost primary, so its
8944 BINFO_OFFSET might be wrong, so we just use the
8945 BINFO_OFFSET from vid->binfo. */
8951 vcall_offset);
8952 }
8953 /* Add the initializer to the vtable. */
8955 }
8956 }
8958 /* Return vtbl initializers for the RTTI entries corresponding to the
8959 BINFO's vtable. The RTTI entries should indicate the object given
8960 by VID->rtti_binfo. */
8962 static void
8964 {
8965 tree b;
8966 tree t;
8967 tree offset;
8968 tree decl;
8969 tree init;
8973 /* To find the complete object, we will first convert to our most
8974 primary base, and then add the offset in the vtbl to that value. */
8978 {
8979 tree primary_base;
8985 }
8989 /* The second entry is the address of the typeinfo object. */
8992 else
8995 /* Convert the declaration to a type that can be stored in the
8996 vtable. */
9000 /* Add the offset-to-top entry. It comes earlier in the vtable than
9001 the typeinfo entry. Convert the offset to look like a
9002 function pointer, so that we can put it in the vtable. */
9005 }
9007 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9008 accessibility. */
9010 bool
9012 {
9015 }
9017 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9019 bool
9021 {
9025 }