| blob | c83c8adfab278dfc81543745f54b79c8dad7bcc7 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2014 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com)
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
22 /* High-level class interface. */
55 /* The number of nested classes being processed. If we are not in the
56 scope of any class, this is zero. */
60 /* In order to deal with nested classes, we keep a stack of classes.
61 The topmost entry is the innermost class, and is the entry at index
62 CURRENT_CLASS_DEPTH */
65 /* The name of the class. */
66 tree name;
68 /* The _TYPE node for the class. */
69 tree type;
71 /* The access specifier pending for new declarations in the scope of
72 this class. */
73 tree access;
75 /* If were defining TYPE, the names used in this class. */
76 splay_tree names_used;
78 /* Nonzero if this class is no longer open, because of a call to
79 push_to_top_level. */
84 {
85 /* The base for which we're building initializers. */
86 tree binfo;
87 /* The type of the most-derived type. */
88 tree derived;
89 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
90 unless ctor_vtbl_p is true. */
91 tree rtti_binfo;
92 /* The negative-index vtable initializers built up so far. These
93 are in order from least negative index to most negative index. */
95 /* The binfo for the virtual base for which we're building
96 vcall offset initializers. */
97 tree vbase;
98 /* The functions in vbase for which we have already provided vcall
99 offsets. */
101 /* The vtable index of the next vcall or vbase offset. */
102 tree index;
103 /* Nonzero if we are building the initializer for the primary
104 vtable. */
106 /* Nonzero if we are building the initializer for a construction
107 vtable. */
109 /* True when adding vcall offset entries to the vtable. False when
110 merely computing the indices. */
114 /* The type of a function passed to walk_subobject_offsets. */
117 /* The stack itself. This is a dynamically resized array. The
118 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
122 /* The size of the largest empty class seen in this translation unit. */
125 /* An array of all local classes present in this translation unit, in
126 declaration order. */
209 tree *);
219 splay_tree_key k2);
227 /* Variables shared between class.c and call.c. */
237 /* Convert to or from a base subobject. EXPR is an expression of type
238 `A' or `A*', an expression of type `B' or `B*' is returned. To
239 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
240 the B base instance within A. To convert base A to derived B, CODE
241 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
242 In this latter case, A must not be a morally virtual base of B.
243 NONNULL is true if EXPR is known to be non-NULL (this is only
244 needed when EXPR is of pointer type). CV qualifiers are preserved
245 from EXPR. */
247 tree
249 tree expr,
250 tree binfo,
252 tsubst_flags_t complain)
253 {
256 tree probe;
257 tree offset;
258 tree target_type;
260 tree ptr_target_type;
271 {
277 }
285 {
286 /* This can happen when adjust_result_of_qualified_name_lookup can't
287 find a unique base binfo in a call to a member function. We
288 couldn't give the diagnostic then since we might have been calling
289 a static member function, so we do it now. */
291 {
295 }
297 }
304 /* Nothing to do. */
308 {
310 {
312 {
315 "pointer to derived class %qT because the base is "
317 else
321 }
322 else
323 {
329 else
333 }
334 }
336 }
339 {
341 /* This must happen before the call to save_expr. */
343 }
344 else
350 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
351 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
352 expression returned matches the input. */
353 target_type = cp_build_qualified_type
357 /* Do we need to look in the vtable for the real offset? */
360 /* Don't bother with the calculations inside sizeof; they'll ICE if the
361 source type is incomplete and the pointer value doesn't matter. In a
362 template (even in instantiate_non_dependent_expr), we don't have vtables
363 set up properly yet, and the value doesn't matter there either; we're
364 just interested in the result of overload resolution. */
367 {
370 }
372 /* If we're in an NSDMI, we don't have the full constructor context yet
373 that we need for converting to a virtual base, so just build a stub
374 CONVERT_EXPR and expand it later in bot_replace. */
377 {
381 }
383 /* Do we need to check for a null pointer? */
385 {
386 /* If we know the conversion will not actually change the value
387 of EXPR, then we can avoid testing the expression for NULL.
388 We have to avoid generating a COMPONENT_REF for a base class
389 field, because other parts of the compiler know that such
390 expressions are always non-NULL. */
394 }
396 /* Protect against multiple evaluation if necessary. */
400 /* Now that we've saved expr, build the real null test. */
402 {
406 }
408 /* If this is a simple base reference, express it as a COMPONENT_REF. */
410 /* We don't build base fields for empty bases, and they aren't very
411 interesting to the optimizers anyway. */
413 {
422 }
425 {
426 /* Going via virtual base V_BINFO. We need the static offset
427 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
428 V_BINFO. That offset is an entry in D_BINFO's vtable. */
429 tree v_offset;
432 {
433 /* In a base member initializer, we cannot rely on the
434 vtable being set up. We have to indirect via the
435 vtt_parm. */
436 tree t;
442 }
443 else
445 complain),
454 v_offset);
466 /* Negative fixed_type_p means this is a constructor or destructor;
467 virtual base layout is fixed in in-charge [cd]tors, but not in
468 base [cd]tors. */
472 v_offset,
475 else
477 }
485 {
490 }
491 else
494 indout:
496 {
500 }
502 out:
508 }
510 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
511 Perform a derived-to-base conversion by recursively building up a
512 sequence of COMPONENT_REFs to the appropriate base fields. */
514 static tree
516 {
519 tree field;
522 {
523 tree temp;
527 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
528 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
529 an lvalue in the front end; only _DECLs and _REFs are lvalues
530 in the back end. */
536 }
538 /* Recurse. */
543 /* Is this the base field created by build_base_field? */
547 /* If we're looking for a field in the most-derived class,
548 also check the field offset; we can have two base fields
549 of the same type if one is an indirect virtual base and one
550 is a direct non-virtual base. */
554 {
555 /* We don't use build_class_member_access_expr here, as that
556 has unnecessary checks, and more importantly results in
557 recursive calls to dfs_walk_once. */
565 /* Mark the expression const or volatile, as appropriate.
566 Even though we've dealt with the type above, we still have
567 to mark the expression itself. */
574 }
576 /* Didn't find the base field?!? */
578 }
580 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
581 type is a class type or a pointer to a class type. In the former
582 case, TYPE is also a class type; in the latter it is another
583 pointer type. If CHECK_ACCESS is true, an error message is emitted
584 if TYPE is inaccessible. If OBJECT has pointer type, the value is
585 assumed to be non-NULL. */
587 tree
589 tsubst_flags_t complain)
590 {
591 tree binfo;
592 tree object_type;
595 {
598 }
599 else
608 }
610 /* EXPR is an expression with unqualified class type. BASE is a base
611 binfo of that class type. Returns EXPR, converted to the BASE
612 type. This function assumes that EXPR is the most derived class;
613 therefore virtual bases can be found at their static offsets. */
615 tree
617 {
618 tree expr_type;
622 {
623 /* If this is a non-empty base, use a COMPONENT_REF. */
627 /* We use fold_build2 and fold_convert below to simplify the trees
628 provided to the optimizers. It is not safe to call these functions
629 when processing a template because they do not handle C++-specific
630 trees. */
638 }
641 }
643 \f
644 tree
646 {
650 /* Can happen in case of duplicate base types (c++/59082). */
654 /* First, convert to the requested type. */
659 /* Second, the requested type may not be the owner of its own vptr.
660 If not, convert to the base class that owns it. We cannot use
661 convert_to_base here, because VCONTEXT may appear more than once
662 in the inheritance hierarchy of TYPE, and thus direct conversion
663 between the types may be ambiguous. Following the path back up
664 one step at a time via primary bases avoids the problem. */
668 {
671 }
674 }
676 /* Given an object INSTANCE, return an expression which yields the
677 vtable element corresponding to INDEX. There are many special
678 cases for INSTANCE which we take care of here, mainly to avoid
679 creating extra tree nodes when we don't have to. */
681 static tree
683 {
684 tree aref;
687 /* Try to figure out what a reference refers to, and
688 access its virtual function table directly. */
696 {
701 }
710 }
712 tree
714 {
718 }
720 /* Given a stable object pointer INSTANCE_PTR, return an expression which
721 yields a function pointer corresponding to vtable element INDEX. */
723 tree
725 {
726 tree aref;
729 tf_warning_or_error),
730 idx);
732 /* When using function descriptors, the address of the
733 vtable entry is treated as a function pointer. */
738 /* Remember this as a method reference, for later devirtualization. */
742 }
744 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
745 for the given TYPE. */
747 static tree
749 {
751 }
753 /* DECL is an entity associated with TYPE, like a virtual table or an
754 implicitly generated constructor. Determine whether or not DECL
755 should have external or internal linkage at the object file
756 level. This routine does not deal with COMDAT linkage and other
757 similar complexities; it simply sets TREE_PUBLIC if it possible for
758 entities in other translation units to contain copies of DECL, in
759 the abstract. */
761 void
763 {
766 }
768 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
769 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
770 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
772 static tree
774 {
775 tree decl;
778 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
779 now to avoid confusion in mangle_decl. */
790 /* The vtable has not been defined -- yet. */
794 /* Mark the VAR_DECL node representing the vtable itself as a
795 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
796 is rather important that such things be ignored because any
797 effort to actually generate DWARF for them will run into
798 trouble when/if we encounter code like:
800 #pragma interface
801 struct S { virtual void member (); };
803 because the artificial declaration of the vtable itself (as
804 manufactured by the g++ front end) will say that the vtable is
805 a static member of `S' but only *after* the debug output for
806 the definition of `S' has already been output. This causes
807 grief because the DWARF entry for the definition of the vtable
808 will try to refer back to an earlier *declaration* of the
809 vtable as a static member of `S' and there won't be one. We
810 might be able to arrange to have the "vtable static member"
811 attached to the member list for `S' before the debug info for
812 `S' get written (which would solve the problem) but that would
813 require more intrusive changes to the g++ front end. */
817 }
819 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
820 or even complete. If this does not exist, create it. If COMPLETE is
821 nonzero, then complete the definition of it -- that will render it
822 impossible to actually build the vtable, but is useful to get at those
823 which are known to exist in the runtime. */
825 tree
827 {
828 tree decl;
837 {
840 }
843 }
845 /* Build the primary virtual function table for TYPE. If BINFO is
846 non-NULL, build the vtable starting with the initial approximation
847 that it is the same as the one which is the head of the association
848 list. Returns a nonzero value if a new vtable is actually
849 created. */
851 static int
853 {
854 tree decl;
855 tree virtuals;
860 {
862 /* We have already created a vtable for this base, so there's
863 no need to do it again. */
870 }
871 else
872 {
875 }
878 {
881 }
883 /* Initialize the association list for this type, based
884 on our first approximation. */
889 }
891 /* Give BINFO a new virtual function table which is initialized
892 with a skeleton-copy of its original initialization. The only
893 entry that changes is the `delta' entry, so we can really
894 share a lot of structure.
896 FOR_TYPE is the most derived type which caused this table to
897 be needed.
899 Returns nonzero if we haven't met BINFO before.
901 The order in which vtables are built (by calling this function) for
902 an object must remain the same, otherwise a binary incompatibility
903 can result. */
905 static int
907 {
909 /* We already created a vtable for this base. There's no need to
910 do it again. */
913 /* Remember that we've created a vtable for this BINFO, so that we
914 don't try to do so again. */
917 /* Make fresh virtual list, so we can smash it later. */
920 /* Secondary vtables are laid out as part of the same structure as
921 the primary vtable. */
924 }
926 /* Create a new vtable for BINFO which is the hierarchy dominated by
927 T. Return nonzero if we actually created a new vtable. */
929 static int
931 {
933 /* In this case, it is *type*'s vtable we are modifying. We start
934 with the approximation that its vtable is that of the
935 immediate base class. */
937 else
938 /* This is our very own copy of `basetype' to play with. Later,
939 we will fill in all the virtual functions that override the
940 virtual functions in these base classes which are not defined
941 by the current type. */
943 }
945 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
946 (which is in the hierarchy dominated by T) list FNDECL as its
947 BV_FN. DELTA is the required constant adjustment from the `this'
948 pointer where the vtable entry appears to the `this' required when
949 the function is actually called. */
951 static void
953 tree binfo,
954 tree fndecl,
955 tree delta,
957 {
958 tree v;
964 {
965 /* We need a new vtable for BINFO. */
967 {
968 /* If we really did make a new vtable, we also made a copy
969 of the BINFO_VIRTUALS list. Now, we have to find the
970 corresponding entry in that list. */
975 }
980 }
981 }
983 \f
984 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
985 the USING_DECL naming METHOD. Returns true if the method could be
986 added to the method vec. */
988 bool
990 {
992 tree overload;
998 tree current_fns;
999 tree fns;
1012 {
1013 /* Make a new method vector. We start with 8 entries. We must
1014 allocate at least two (for constructors and destructors), and
1015 we're going to end up with an assignment operator at some
1016 point as well. */
1018 /* Create slots for constructors and destructors. */
1022 }
1024 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1027 /* Constructors and destructors go in special slots. */
1031 {
1035 {
1041 type);
1042 }
1043 }
1044 else
1045 {
1046 tree m;
1049 /* See if we already have an entry with this name. */
1053 {
1056 {
1061 }
1065 {
1068 }
1073 }
1074 }
1077 /* Check to see if we've already got this method. */
1079 {
1081 tree fn_type;
1082 tree method_type;
1083 tree parms1;
1084 tree parms2;
1089 /* [over.load] Member function declarations with the
1090 same name and the same parameter types cannot be
1091 overloaded if any of them is a static member
1092 function declaration.
1094 [over.load] Member function declarations with the same name and
1095 the same parameter-type-list as well as member function template
1096 declarations with the same name, the same parameter-type-list, and
1097 the same template parameter lists cannot be overloaded if any of
1098 them, but not all, have a ref-qualifier.
1100 [namespace.udecl] When a using-declaration brings names
1101 from a base class into a derived class scope, member
1102 functions in the derived class override and/or hide member
1103 functions with the same name and parameter types in a base
1104 class (rather than conflicting). */
1110 /* Compare the quals on the 'this' parm. Don't compare
1111 the whole types, as used functions are treated as
1112 coming from the using class in overload resolution. */
1115 /* Either both or neither need to be ref-qualified for
1116 differing quals to allow overloading. */
1123 /* For templates, the return type and template parameters
1124 must be identical. */
1141 {
1142 /* For function versions, their parms and types match
1143 but they are not duplicates. Record function versions
1144 as and when they are found. extern "C" functions are
1145 not treated as versions. */
1151 {
1152 /* Mark functions as versions if necessary. Modify the mangled
1153 decl name if necessary. */
1155 {
1159 }
1161 {
1165 }
1168 }
1170 {
1172 {
1179 }
1180 /* Otherwise defer to the other function. */
1182 }
1184 {
1186 /* Defer to the local function. */
1188 }
1189 else
1190 {
1193 }
1195 /* We don't call duplicate_decls here to merge the
1196 declarations because that will confuse things if the
1197 methods have inline definitions. In particular, we
1198 will crash while processing the definitions. */
1200 }
1201 }
1203 /* A class should never have more than one destructor. */
1207 /* Add the new binding. */
1209 {
1212 }
1213 else
1222 {
1225 /* We only expect to add few methods in the COMPLETE_P case, so
1226 just make room for one more method in that case. */
1229 else
1235 else
1237 }
1238 else
1239 /* Replace the current slot. */
1242 }
1244 /* Subroutines of finish_struct. */
1246 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1247 legit, otherwise return 0. */
1249 static int
1251 {
1252 tree elem;
1261 {
1263 {
1267 else
1270 }
1271 else
1272 {
1273 /* They're changing the access to the same thing they changed
1274 it to before. That's OK. */
1275 ;
1276 }
1277 }
1278 else
1279 {
1281 tf_warning_or_error);
1284 }
1286 }
1288 /* Process the USING_DECL, which is a member of T. */
1290 static void
1292 {
1295 tree access
1300 tree old_value;
1305 tf_warning_or_error);
1307 {
1313 else
1315 }
1323 ;
1325 {
1327 /* It's OK to use functions from a base when there are functions with
1329 else
1330 {
1335 }
1336 }
1338 {
1342 }
1344 /* Make type T see field decl FDECL with access ACCESS. */
1347 {
1350 }
1351 else
1353 }
1354 \f
1355 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1356 types with abi tags, add the corresponding identifiers to the VEC in
1357 *DATA and set IDENTIFIER_MARKED. */
1359 struct abi_tag_data
1360 {
1361 tree t;
1362 tree subob;
1363 // error_mark_node to get diagnostics; otherwise collect missing tags here
1364 tree tags;
1365 };
1367 static tree
1369 {
1373 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1374 anyway, but let's make sure of it. */
1378 {
1382 {
1386 {
1388 {
1389 /* We're collecting tags from template arguments. */
1395 /* Don't inherit this tag multiple times. */
1397 }
1399 /* Otherwise we're diagnosing missing tags. */
1401 {
1406 }
1407 else
1408 {
1412 {
1416 }
1417 }
1418 }
1419 }
1420 }
1422 }
1424 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1425 complete) template arguments. */
1427 static void
1429 {
1432 {
1435 {
1439 }
1440 }
1441 }
1443 /* Check that class T has all the abi tags that subobject SUBOB has, or
1444 warn if not. */
1446 static void
1448 {
1457 }
1459 void
1461 {
1471 {
1474 {
1478 }
1479 }
1481 // If we found some tags on our template arguments, add them to our
1482 // abi_tag attribute.
1484 {
1488 else
1492 }
1495 }
1497 /* Return true, iff class T has a non-virtual destructor that is
1498 accessible from outside the class heirarchy (i.e. is public, or
1499 there's a suitable friend. */
1501 static bool
1503 {
1506 /* An implicitly declared destructor is always public. And,
1507 if it were virtual, we would have created it by now. */
1522 }
1524 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1525 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1526 properties of the bases. */
1528 static void
1532 {
1536 tree base_binfo;
1537 tree binfo;
1547 {
1556 /* If any base class is non-literal, so is the derived class. */
1560 /* If the base class doesn't have copy constructors or
1561 assignment operators that take const references, then the
1562 derived class cannot have such a member automatically
1563 generated. */
1572 /* A virtual base does not effect nearly emptiness. */
1573 ;
1575 {
1577 /* And if there is more than one nearly empty base, then the
1578 derived class is not nearly empty either. */
1580 else
1581 /* Remember we've seen one. */
1583 }
1585 /* If the base class is not empty or nearly empty, then this
1586 class cannot be nearly empty. */
1589 /* A lot of properties from the bases also apply to the derived
1590 class. */
1607 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1610 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1614 /* A standard-layout class is a class that:
1615 ...
1616 * has no non-standard-layout base classes, */
1619 {
1620 tree basefield;
1621 /* ...has no base classes of the same type as the first non-static
1622 data member... */
1624 && (same_type_ignoring_top_level_qualifiers_p
1627 else
1628 /* ...either has no non-static data members in the most-derived
1629 class and at most one base class with non-static data
1630 members, or has no base classes with non-static data
1631 members */
1635 {
1638 else
1641 }
1642 }
1644 /* Don't bother collecting tm attributes if transactional memory
1645 support is not enabled. */
1647 {
1651 }
1654 }
1656 /* If one of the base classes had TM attributes, and the current class
1657 doesn't define its own, then the current class inherits one. */
1659 {
1662 }
1663 }
1665 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1666 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1667 that have had a nearly-empty virtual primary base stolen by some
1668 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1669 T. */
1671 static void
1673 {
1677 tree base_binfo;
1679 /* Determine the primary bases of our bases. */
1682 {
1685 /* See if we're the non-virtual primary of our inheritance
1686 chain. */
1688 {
1695 /* We are the primary binfo. */
1697 }
1698 /* Determine if we have a virtual primary base, and mark it so.
1699 */
1701 {
1705 /* Someone already claimed this base. */
1707 else
1708 {
1709 tree delta;
1714 /* A virtual binfo might have been copied from within
1715 another hierarchy. As we're about to use it as a
1716 primary base, make sure the offsets match. */
1724 }
1725 }
1726 }
1728 /* First look for a dynamic direct non-virtual base. */
1730 {
1734 {
1737 }
1738 }
1740 /* A "nearly-empty" virtual base class can be the primary base
1741 class, if no non-virtual polymorphic base can be found. Look for
1742 a nearly-empty virtual dynamic base that is not already a primary
1743 base of something in the hierarchy. If there is no such base,
1744 just pick the first nearly-empty virtual base. */
1750 {
1752 {
1753 /* Found one that is not primary. */
1756 }
1758 /* Remember the first candidate. */
1760 }
1762 found:
1763 /* If we've got a primary base, use it. */
1765 {
1770 /* We are stealing a primary base. */
1774 {
1775 tree delta;
1778 /* A virtual binfo might have been copied from within
1779 another hierarchy. As we're about to use it as a primary
1780 base, make sure the offsets match. */
1785 }
1792 }
1793 }
1795 /* Update the variant types of T. */
1797 void
1799 {
1800 tree variants;
1806 variants;
1808 {
1809 /* These fields are in the _TYPE part of the node, not in
1810 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1820 /* Copy whatever these are holding today. */
1824 }
1825 }
1827 /* Early variant fixups: we apply attributes at the beginning of the class
1828 definition, and we need to fix up any variants that have already been
1829 made via elaborated-type-specifier so that check_qualified_type works. */
1831 void
1833 {
1834 tree variants;
1840 variants;
1842 {
1843 /* These are the two fields that check_qualified_type looks at and
1844 are affected by attributes. */
1847 }
1848 }
1849 \f
1850 /* Set memoizing fields and bits of T (and its variants) for later
1851 use. */
1853 static void
1855 {
1856 /* Fix up variants (if any). */
1860 /* For a class w/o baseclasses, 'finish_struct' has set
1861 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1862 Similarly for a class whose base classes do not have vtables.
1863 When neither of these is true, we might have removed abstract
1864 virtuals (by providing a definition), added some (by declaring
1865 new ones), or redeclared ones from a base class. We need to
1866 recalculate what's really an abstract virtual at this point (by
1867 looking in the vtables). */
1870 /* If this type has a copy constructor or a destructor, force its
1871 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1872 nonzero. This will cause it to be passed by invisible reference
1873 and prevent it from being returned in a register. */
1876 {
1877 tree variants;
1880 {
1883 }
1884 }
1885 }
1887 /* Issue warnings about T having private constructors, but no friends,
1888 and so forth.
1890 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1891 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1892 non-private static member functions. */
1894 static void
1896 {
1899 tree fn;
1902 /* If the class has friends, those entities might create and
1903 access instances, so we should not warn. */
1906 /* We will have warned when the template was declared; there's
1907 no need to warn on every instantiation. */
1909 /* There's no reason to even consider warning about this
1910 class. */
1913 /* We only issue one warning, if more than one applies, because
1914 otherwise, on code like:
1916 class A {
1917 // Oops - forgot `public:'
1918 A();
1919 A(const A&);
1920 ~A();
1921 };
1923 we warn several times about essentially the same problem. */
1925 /* Check to see if all (non-constructor, non-destructor) member
1926 functions are private. (Since there are no friends or
1927 non-private statics, we can't ever call any of the private member
1928 functions.) */
1930 /* We're not interested in compiler-generated methods; they don't
1931 provide any way to call private members. */
1933 {
1935 {
1937 /* A non-private static member function is just like a
1938 friend; it can create and invoke private member
1939 functions, and be accessed without a class
1940 instance. */
1944 /* Keep searching for a static member function. */
1945 }
1948 }
1951 {
1952 /* There are no non-private methods, and there's at least one
1953 private member function that isn't a constructor or
1954 destructor. (If all the private members are
1955 constructors/destructors we want to use the code below that
1956 issues error messages specifically referring to
1957 constructors/destructors.) */
1963 {
1966 }
1968 {
1972 }
1973 }
1975 /* Even if some of the member functions are non-private, the class
1976 won't be useful for much if all the constructors or destructors
1977 are private: such an object can never be created or destroyed. */
1980 {
1983 t);
1985 }
1987 /* Warn about classes that have private constructors and no friends. */
1989 /* Implicitly generated constructors are always public. */
1992 {
1995 /* If a non-template class does not define a copy
1996 constructor, one is defined for it, enabling it to avoid
1997 this warning. For a template class, this does not
1998 happen, and so we would normally get a warning on:
2000 template <class T> class C { private: C(); };
2002 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2003 complete non-template or fully instantiated classes have this
2004 flag set. */
2007 else
2009 {
2011 /* Ideally, we wouldn't count copy constructors (or, in
2012 fact, any constructor that takes an argument of the
2013 class type as a parameter) because such things cannot
2014 be used to construct an instance of the class unless
2015 you already have one. But, for now at least, we're
2016 more generous. */
2018 {
2021 }
2022 }
2025 {
2028 t);
2030 }
2031 }
2032 }
2035 gt_pointer_operator new_value;
2039 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2041 static int
2043 {
2056 }
2058 /* This routine compares two fields like method_name_cmp but using the
2059 pointer operator in resort_field_decl_data. */
2061 static int
2063 {
2072 {
2079 }
2081 }
2083 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2085 void
2088 gt_pointer_operator new_value,
2090 {
2094 tree fn;
2096 /* The type conversion ops have to live at the front of the vec, so we
2097 can't sort them. */
2105 {
2109 resort_method_name_cmp);
2110 }
2111 }
2113 /* Warn about duplicate methods in fn_fields.
2115 Sort methods that are not special (i.e., constructors, destructors,
2116 and type conversion operators) so that we can find them faster in
2117 search. */
2119 static void
2121 {
2122 tree fn_fields;
2132 /* Clear DECL_IN_AGGR_P for all functions. */
2137 /* Issue warnings about private constructors and such. If there are
2138 no methods, then some public defaults are generated. */
2141 /* The type conversion ops have to live at the front of the vec, so we
2142 can't sort them. */
2151 }
2153 /* Make BINFO's vtable have N entries, including RTTI entries,
2154 vbase and vcall offsets, etc. Set its type and call the back end
2155 to lay it out. */
2157 static void
2159 {
2160 tree atype;
2161 tree vtable;
2166 /* We may have to grow the vtable. */
2169 {
2173 }
2174 }
2176 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2177 have the same signature. */
2179 int
2181 {
2182 /* One destructor overrides another if they are the same kind of
2183 destructor. */
2187 /* But a non-destructor never overrides a destructor, nor vice
2188 versa, nor do different kinds of destructors override
2189 one-another. For example, a complete object destructor does not
2190 override a deleting destructor. */
2199 {
2207 }
2209 }
2211 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2212 subobject. */
2214 static bool
2216 {
2217 tree probe;
2220 {
2224 /* If we meet a virtual base, we can't follow the inheritance
2225 any more. See if the complete type of DERIVED contains
2226 such a virtual base. */
2229 }
2231 }
2234 /* The function for which we are trying to find a final overrider. */
2235 tree fn;
2236 /* The base class in which the function was declared. */
2237 tree declaring_base;
2238 /* The candidate overriders. */
2239 tree candidates;
2240 /* Path to most derived. */
2244 /* Add the overrider along the current path to FFOD->CANDIDATES.
2245 Returns true if an overrider was found; false otherwise. */
2247 static bool
2251 {
2252 tree method;
2254 /* If BINFO is not the most derived type, try a more derived class.
2255 A definition there will overrider a definition here. */
2257 {
2258 depth--;
2262 }
2266 {
2269 /* Remove any candidates overridden by this new function. */
2271 {
2272 /* If *CANDIDATE overrides METHOD, then METHOD
2273 cannot override anything else on the list. */
2276 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2279 else
2281 }
2283 /* Add the new function. */
2286 }
2289 }
2291 /* Called from find_final_overrider via dfs_walk. */
2293 static tree
2295 {
2303 }
2305 static tree
2307 {
2312 }
2314 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2315 FN and whose TREE_VALUE is the binfo for the base where the
2316 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2317 DERIVED) is the base object in which FN is declared. */
2319 static tree
2321 {
2322 find_final_overrider_data ffod;
2324 /* Getting this right is a little tricky. This is valid:
2326 struct S { virtual void f (); };
2327 struct T { virtual void f (); };
2328 struct U : public S, public T { };
2330 even though calling `f' in `U' is ambiguous. But,
2332 struct R { virtual void f(); };
2333 struct S : virtual public R { virtual void f (); };
2334 struct T : virtual public R { virtual void f (); };
2335 struct U : public S, public T { };
2337 is not -- there's no way to decide whether to put `S::f' or
2338 `T::f' in the vtable for `R'.
2340 The solution is to look at all paths to BINFO. If we find
2341 different overriders along any two, then there is a problem. */
2345 /* Determine the depth of the hierarchy. */
2356 /* If there was no winner, issue an error message. */
2361 }
2363 /* Return the index of the vcall offset for FN when TYPE is used as a
2364 virtual base. */
2366 static tree
2368 {
2370 tree_pair_p p;
2378 /* There should always be an appropriate index. */
2380 }
2382 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2383 dominated by T. FN is the old function; VIRTUALS points to the
2384 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2385 of that entry in the list. */
2387 static void
2390 {
2391 tree b;
2392 tree overrider;
2393 tree delta;
2394 tree virtual_base;
2395 tree first_defn;
2401 /* Find the nearest primary base (possibly binfo itself) which defines
2402 this function; this is the class the caller will convert to when
2403 calling FN through BINFO. */
2405 {
2410 /* The nearest definition is from a lost primary. */
2413 }
2416 /* Find the final overrider. */
2419 {
2422 }
2425 /* Check for adjusting covariant return types. */
2433 /* If the overrider is invalid, don't even try. */
2435 {
2436 /* If FN is a covariant thunk, we must figure out the adjustment
2437 to the final base FN was converting to. As OVERRIDER_TARGET might
2438 also be converting to the return type of FN, we have to
2439 combine the two conversions here. */
2446 {
2450 }
2451 else
2455 /* Find the equivalent binfo within the return type of the
2456 overriding function. We will want the vbase offset from
2457 there. */
2459 over_return);
2462 {
2463 /* There was no existing virtual thunk (which takes
2464 precedence). So find the binfo of the base function's
2465 return type within the overriding function's return type.
2466 We cannot call lookup base here, because we're inside a
2467 dfs_walk, and will therefore clobber the BINFO_MARKED
2468 flags. Fortunately we know the covariancy is valid (it
2469 has already been checked), so we can just iterate along
2470 the binfos, which have been chained in inheritance graph
2471 order. Of course it is lame that we have to repeat the
2472 search here anyway -- we should really be caching pieces
2473 of the vtable and avoiding this repeated work. */
2476 /* Find the base binfo within the overriding function's
2477 return type. We will always find a thunk_binfo, except
2478 when the covariancy is invalid (which we will have
2479 already diagnosed). */
2482 thunk_binfo;
2488 /* See if virtual inheritance is involved. */
2490 virtual_offset;
2497 {
2501 {
2502 /* We convert via virtual base. Adjust the fixed
2503 offset to be from there. */
2504 offset =
2508 }
2510 /* There was an existing fixed offset, this must be
2511 from the base just converted to, and the base the
2512 FN was thunking to. */
2514 else
2516 }
2517 }
2520 /* Replace the overriding function with a covariant thunk. We
2521 will emit the overriding function in its own slot as
2522 well. */
2525 }
2526 else
2530 /* If we need a covariant thunk, then we may need to adjust first_defn.
2531 The ABI specifies that the thunks emitted with a function are
2532 determined by which bases the function overrides, so we need to be
2533 sure that we're using a thunk for some overridden base; even if we
2534 know that the necessary this adjustment is zero, there may not be an
2535 appropriate zero-this-adjusment thunk for us to use since thunks for
2536 overriding virtual bases always use the vcall offset.
2538 Furthermore, just choosing any base that overrides this function isn't
2539 quite right, as this slot won't be used for calls through a type that
2540 puts a covariant thunk here. Calling the function through such a type
2541 will use a different slot, and that slot is the one that determines
2542 the thunk emitted for that base.
2544 So, keep looking until we find the base that we're really overriding
2545 in this slot: the nearest primary base that doesn't use a covariant
2546 thunk in this slot. */
2548 {
2550 /* We already know that the overrider needs a covariant thunk. */
2553 {
2560 }
2562 }
2564 /* Assume that we will produce a thunk that convert all the way to
2565 the final overrider, and not to an intermediate virtual base. */
2568 /* See if we can convert to an intermediate virtual base first, and then
2569 use the vcall offset located there to finish the conversion. */
2571 {
2572 /* If we find the final overrider, then we can stop
2573 walking. */
2578 /* If we find a virtual base, and we haven't yet found the
2579 overrider, then there is a virtual base between the
2580 declaring base (first_defn) and the final overrider. */
2582 {
2585 }
2586 }
2588 /* Compute the constant adjustment to the `this' pointer. The
2589 `this' pointer, when this function is called, will point at BINFO
2590 (or one of its primary bases, which are at the same offset). */
2592 /* The `this' pointer needs to be adjusted from the declaration to
2593 the nearest virtual base. */
2598 /* If the nearest definition is in a lost primary, we don't need an
2599 entry in our vtable. Except possibly in a constructor vtable,
2600 if we happen to get our primary back. In that case, the offset
2601 will be zero, as it will be a primary base. */
2603 else
2604 /* The `this' pointer needs to be adjusted from pointing to
2605 BINFO to pointing at the base where the final overrider
2606 appears. */
2617 else
2621 }
2623 /* Called from modify_all_vtables via dfs_walk. */
2625 static tree
2627 {
2629 tree virtuals;
2630 tree old_virtuals;
2634 /* A base without a vtable needs no modification, and its bases
2635 are uninteresting. */
2640 /* Don't do the primary vtable, if it's new. */
2644 /* There's no need to modify the vtable for a non-virtual primary
2645 base; we're not going to use that vtable anyhow. We do still
2646 need to do this for virtual primary bases, as they could become
2647 non-primary in a construction vtable. */
2652 /* Now, go through each of the virtual functions in the virtual
2653 function table for BINFO. Find the final overrider, and update
2654 the BINFO_VIRTUALS list appropriately. */
2657 virtuals;
2661 binfo,
2666 }
2668 /* Update all of the primary and secondary vtables for T. Create new
2669 vtables as required, and initialize their RTTI information. Each
2670 of the functions in VIRTUALS is declared in T and may override a
2671 virtual function from a base class; find and modify the appropriate
2672 entries to point to the overriding functions. Returns a list, in
2673 declaration order, of the virtual functions that are declared in T,
2674 but do not appear in the primary base class vtable, and which
2675 should therefore be appended to the end of the vtable for T. */
2677 static tree
2679 {
2683 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2687 /* Update all of the vtables. */
2690 /* Add virtual functions not already in our primary vtable. These
2691 will be both those introduced by this class, and those overridden
2692 from secondary bases. It does not include virtuals merely
2693 inherited from secondary bases. */
2695 {
2700 {
2701 /* We don't need to adjust the `this' pointer when
2702 calling this function. */
2706 /* This is a function not already in our vtable. Keep it. */
2708 }
2709 else
2710 /* We've already got an entry for this function. Skip it. */
2712 }
2715 }
2717 /* Get the base virtual function declarations in T that have the
2718 indicated NAME. */
2720 static tree
2722 {
2723 tree methods;
2728 /* Find virtual functions in T with the indicated NAME. */
2732 methods;
2734 {
2740 }
2746 {
2749 base_fndecls);
2750 }
2753 }
2755 /* If this declaration supersedes the declaration of
2756 a method declared virtual in the base class, then
2757 mark this field as being virtual as well. */
2759 void
2761 {
2764 /* In [temp.mem] we have:
2766 A specialization of a member function template does not
2767 override a virtual function from a base class. */
2774 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2775 the error_mark_node so that we know it is an overriding
2776 function. */
2777 {
2780 }
2783 {
2789 }
2794 }
2796 /* Warn about hidden virtual functions that are not overridden in t.
2797 We know that constructors and destructors don't apply. */
2799 static void
2801 {
2803 tree fns;
2806 /* We go through each separately named virtual function. */
2810 {
2811 tree fn;
2812 tree name;
2813 tree fndecl;
2814 tree base_fndecls;
2815 tree base_binfo;
2816 tree binfo;
2819 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2820 have the same name. Figure out what name that is. */
2822 /* There are no possibly hidden functions yet. */
2824 /* Iterate through all of the base classes looking for possibly
2825 hidden functions. */
2828 {
2831 base_fndecls);
2832 }
2834 /* If there are no functions to hide, continue. */
2838 /* Remove any overridden functions. */
2840 {
2844 {
2848 /* If the method from the base class has the same
2849 signature as the method from the derived class, it
2850 has been overridden. */
2853 else
2855 }
2856 }
2858 /* Now give a warning for all base functions without overriders,
2859 as they are hidden. */
2861 {
2862 /* Here we know it is a hider, and no overrider exists. */
2866 }
2867 }
2868 }
2870 /* Recursive helper for finish_struct_anon. */
2872 static void
2874 {
2878 {
2879 /* We're generally only interested in entities the user
2880 declared, but we also find nested classes by noticing
2881 the TYPE_DECL that we create implicitly. You're
2882 allowed to put one anonymous union inside another,
2883 though, so we explicitly tolerate that. We use
2884 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2885 we also allow unnamed types used for defining fields. */
2892 {
2893 /* We already complained about static data members in
2894 finish_static_data_member_decl. */
2896 {
2899 "%q+#D invalid; an anonymous union can "
2901 else
2903 "%q+#D invalid; an anonymous struct can "
2905 }
2907 }
2910 {
2912 {
2916 else
2919 }
2921 {
2925 else
2928 }
2929 }
2934 /* Recurse into the anonymous aggregates to handle correctly
2935 access control (c++/24926):
2937 class A {
2938 union {
2939 union {
2940 int i;
2941 };
2942 };
2943 };
2945 int j=A().i; */
2949 }
2950 }
2952 /* Check for things that are invalid. There are probably plenty of other
2953 things we should check for also. */
2955 static void
2957 {
2959 {
2968 }
2969 }
2971 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2972 will be used later during class template instantiation.
2973 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2974 a non-static member data (FIELD_DECL), a member function
2975 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2976 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2977 When FRIEND_P is nonzero, T is either a friend class
2978 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2979 (FUNCTION_DECL, TEMPLATE_DECL). */
2981 void
2983 {
2984 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2989 }
2991 /* This function is called from declare_virt_assop_and_dtor via
2992 dfs_walk_all.
2994 DATA is a type that direcly or indirectly inherits the base
2995 represented by BINFO. If BINFO contains a virtual assignment [copy
2996 assignment or move assigment] operator or a virtual constructor,
2997 declare that function in DATA if it hasn't been already declared. */
2999 static tree
3001 {
3009 /* A base without a vtable needs no modification, and its bases
3010 are uninteresting. */
3014 /* If this is a primary base, then we have already looked at the
3015 virtual functions of its vtable. */
3019 {
3023 {
3028 }
3032 }
3035 }
3037 /* If the class type T has a direct or indirect base that contains a
3038 virtual assignment operator or a virtual destructor, declare that
3039 function in T if it hasn't been already declared. */
3041 static void
3043 {
3051 dfs_declare_virt_assop_and_dtor,
3053 }
3055 /* Declare the inheriting constructor for class T inherited from base
3056 constructor CTOR with the parameter array PARMS of size NPARMS. */
3058 static void
3060 {
3061 /* We don't declare an inheriting ctor that would be a default,
3062 copy or move ctor for derived or base. */
3067 {
3071 }
3079 {
3082 }
3083 }
3085 /* Declare all the inheriting constructors for class T inherited from base
3086 constructor CTOR. */
3088 static void
3090 {
3096 {
3100 }
3103 {
3107 }
3108 }
3110 /* Create default constructors, assignment operators, and so forth for
3111 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3112 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3113 the class cannot have a default constructor, copy constructor
3114 taking a const reference argument, or an assignment operator taking
3115 a const reference, respectively. */
3117 static void
3121 {
3129 /* Destructor. */
3131 {
3132 /* In general, we create destructors lazily. */
3137 /* But if this is a Java class, any non-trivial destructor is
3138 invalid, even if compiler-generated. Therefore, if the
3139 destructor is non-trivial we create it now. */
3141 }
3143 /* [class.ctor]
3145 If there is no user-declared constructor for a class, a default
3146 constructor is implicitly declared. */
3148 {
3153 /* This might force the declaration. */
3155 }
3157 /* [class.ctor]
3159 If a class definition does not explicitly declare a copy
3160 constructor, one is declared implicitly. */
3162 {
3168 }
3170 /* If there is no assignment operator, one will be created if and
3171 when it is needed. For now, just record whether or not the type
3172 of the parameter to the assignment operator will be a const or
3173 non-const reference. */
3175 {
3181 }
3183 /* We can't be lazy about declaring functions that might override
3184 a virtual function from a base class. */
3188 {
3192 {
3193 /* declare, then remove the decl */
3202 }
3203 else
3205 }
3206 }
3208 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3209 count the number of fields in TYPE, including anonymous union
3210 members. */
3212 static int
3214 {
3215 tree x;
3218 {
3221 else
3223 }
3225 }
3227 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3228 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3229 elts, starting at offset IDX. */
3231 static int
3233 {
3234 tree x;
3236 {
3239 else
3241 }
3243 }
3245 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3246 starting at offset IDX. */
3248 static int
3252 {
3253 tree values;
3257 }
3259 /* FIELD is a bit-field. We are finishing the processing for its
3260 enclosing type. Issue any appropriate messages and set appropriate
3261 flags. Returns false if an error has been diagnosed. */
3263 static bool
3265 {
3267 tree w;
3269 /* Extract the declared width of the bitfield, which has been
3270 temporarily stashed in DECL_INITIAL. */
3273 /* Remove the bit-field width indicator so that the rest of the
3274 compiler does not treat that value as an initializer. */
3277 /* Detect invalid bit-field type. */
3279 {
3282 }
3283 else
3284 {
3286 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3289 /* detect invalid field size. */
3295 {
3298 }
3300 {
3303 }
3305 {
3308 }
3320 }
3323 {
3327 }
3328 else
3329 {
3330 /* Non-bit-fields are aligned for their type. */
3334 }
3335 }
3337 /* FIELD is a non bit-field. We are finishing the processing for its
3338 enclosing type T. Issue any appropriate messages and set appropriate
3339 flags. */
3341 static void
3343 tree t,
3347 {
3350 /* In C++98 an anonymous union cannot contain any fields which would change
3351 the settings of CANT_HAVE_CONST_CTOR and friends. */
3353 ;
3354 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3355 structs. So, we recurse through their fields here. */
3357 {
3358 tree fields;
3364 }
3365 /* Check members with class type for constructors, destructors,
3366 etc. */
3368 {
3369 /* Never let anything with uninheritable virtuals
3370 make it through without complaint. */
3374 {
3379 field);
3384 field);
3386 {
3390 }
3391 }
3392 else
3393 {
3406 }
3415 }
3420 {
3421 /* `build_class_init_list' does not recognize
3422 non-FIELD_DECLs. */
3426 }
3427 }
3429 /* Check the data members (both static and non-static), class-scoped
3430 typedefs, etc., appearing in the declaration of T. Issue
3431 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3432 declaration order) of access declarations; each TREE_VALUE in this
3433 list is a USING_DECL.
3435 In addition, set the following flags:
3437 EMPTY_P
3438 The class is empty, i.e., contains no non-static data members.
3440 CANT_HAVE_CONST_CTOR_P
3441 This class cannot have an implicitly generated copy constructor
3442 taking a const reference.
3444 CANT_HAVE_CONST_ASN_REF
3445 This class cannot have an implicitly generated assignment
3446 operator taking a const reference.
3448 All of these flags should be initialized before calling this
3449 function.
3451 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3452 fields can be added by adding to this chain. */
3454 static void
3458 {
3466 /* Assume there are no access declarations. */
3468 /* Assume this class has no pointer members. */
3470 /* Assume none of the members of this class have default
3471 initializations. */
3475 {
3483 {
3484 /* Save the access declarations for our caller. */
3487 }
3493 /* If we've gotten this far, it's a data member, possibly static,
3494 or an enumerator. */
3498 /* When this goes into scope, it will be a non-local reference. */
3503 {
3504 /* [class.union] (C++98)
3506 If a union contains a static data member, or a member of
3507 reference type, the program is ill-formed.
3509 In C++11 this limitation doesn't exist anymore. */
3511 {
3515 }
3517 {
3521 }
3522 }
3524 /* Perform error checking that did not get done in
3525 grokdeclarator. */
3527 {
3531 }
3533 {
3537 }
3545 /* Now it can only be a FIELD_DECL. */
3550 /* If at least one non-static data member is non-literal, the whole
3551 class becomes non-literal. Per Core/1453, volatile non-static
3552 data members and base classes are also not allowed.
3553 Note: if the type is incomplete we will complain later on. */
3558 /* A standard-layout class is a class that:
3559 ...
3560 has the same access control (Clause 11) for all non-static data members,
3561 ... */
3568 /* If this is of reference type, check if it needs an init. */
3570 {
3576 /* ARM $12.6.2: [A member initializer list] (or, for an
3577 aggregate, initialization by a brace-enclosed list) is the
3578 only way to initialize nonstatic const and reference
3579 members. */
3582 }
3587 {
3589 {
3590 warning
3593 x);
3595 }
3599 }
3602 /* We don't treat zero-width bitfields as making a class
3603 non-empty. */
3604 ;
3605 else
3606 {
3607 /* The class is non-empty. */
3609 /* The class is not even nearly empty. */
3611 /* If one of the data members contains an empty class,
3612 so does T. */
3616 }
3618 /* This is used by -Weffc++ (see below). Warn only for pointers
3619 to members which might hold dynamic memory. So do not warn
3620 for pointers to functions or pointers to members. */
3626 {
3631 }
3637 {
3639 {
3643 }
3645 {
3649 }
3650 }
3653 /* DR 148 now allows pointers to members (which are POD themselves),
3654 to be allowed in POD structs. */
3663 /* We set DECL_C_BIT_FIELD in grokbitfield.
3664 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3667 cant_have_const_ctor_p,
3668 no_const_asn_ref_p,
3671 /* Now that we've removed bit-field widths from DECL_INITIAL,
3672 anything left in DECL_INITIAL is an NSDMI that makes the class
3673 non-aggregate in C++11. */
3677 /* If any field is const, the structure type is pseudo-const. */
3679 {
3684 /* ARM $12.6.2: [A member initializer list] (or, for an
3685 aggregate, initialization by a brace-enclosed list) is the
3686 only way to initialize nonstatic const and reference
3687 members. */
3690 }
3691 /* A field that is pseudo-const makes the structure likewise. */
3693 {
3698 }
3700 /* Core issue 80: A nonstatic data member is required to have a
3701 different name from the class iff the class has a
3702 user-declared constructor. */
3706 }
3708 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3709 it should also define a copy constructor and an assignment operator to
3710 implement the correct copy semantic (deep vs shallow, etc.). As it is
3711 not feasible to check whether the constructors do allocate dynamic memory
3712 and store it within members, we approximate the warning like this:
3714 -- Warn only if there are members which are pointers
3715 -- Warn only if there is a non-trivial constructor (otherwise,
3716 there cannot be memory allocated).
3717 -- Warn only if there is a non-trivial destructor. We assume that the
3718 user at least implemented the cleanup correctly, and a destructor
3719 is needed to free dynamic memory.
3721 This seems enough for practical purposes. */
3723 && has_pointers
3727 {
3731 {
3736 }
3740 }
3742 /* Non-static data member initializers make the default constructor
3743 non-trivial. */
3745 {
3748 }
3750 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3754 /* Check anonymous struct/anonymous union fields. */
3757 /* We've built up the list of access declarations in reverse order.
3758 Fix that now. */
3760 }
3762 /* If TYPE is an empty class type, records its OFFSET in the table of
3763 OFFSETS. */
3765 static int
3767 {
3768 splay_tree_node n;
3773 /* Record the location of this empty object in OFFSETS. */
3781 type,
3785 }
3787 /* Returns nonzero if TYPE is an empty class type and there is
3788 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3790 static int
3792 {
3793 splay_tree_node n;
3794 tree t;
3799 /* Record the location of this empty object in OFFSETS. */
3809 }
3811 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3812 F for every subobject, passing it the type, offset, and table of
3813 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3814 be traversed.
3816 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3817 than MAX_OFFSET will not be walked.
3819 If F returns a nonzero value, the traversal ceases, and that value
3820 is returned. Otherwise, returns zero. */
3822 static int
3824 subobject_offset_fn f,
3825 tree offset,
3826 splay_tree offsets,
3827 tree max_offset,
3829 {
3833 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3834 stop. */
3842 {
3845 }
3848 {
3849 tree field;
3850 tree binfo;
3853 /* Avoid recursing into objects that are not interesting. */
3857 /* Record the location of TYPE. */
3862 /* Iterate through the direct base classes of TYPE. */
3866 {
3867 tree binfo_offset;
3872 tree orig_binfo;
3873 /* We cannot rely on BINFO_OFFSET being set for the base
3874 class yet, but the offsets for direct non-virtual
3875 bases can be calculated by going back to the TYPE. */
3878 offset,
3882 f,
3883 binfo_offset,
3884 offsets,
3885 max_offset,
3889 }
3892 {
3896 /* Iterate through the virtual base classes of TYPE. In G++
3897 3.2, we included virtual bases in the direct base class
3898 loop above, which results in incorrect results; the
3899 correct offsets for virtual bases are only known when
3900 working with the most derived type. */
3904 {
3906 f,
3908 offset,
3910 offsets,
3911 max_offset,
3915 }
3916 else
3917 {
3918 /* We still have to walk the primary base, if it is
3919 virtual. (If it is non-virtual, then it was walked
3920 above.) */
3926 {
3927 r = (walk_subobject_offsets
3932 }
3933 }
3934 }
3936 /* Iterate through the fields of TYPE. */
3941 {
3942 tree field_offset;
3947 f,
3949 offset,
3950 field_offset),
3951 offsets,
3952 max_offset,
3956 }
3957 }
3959 {
3962 tree index;
3964 /* Avoid recursing into objects that are not interesting. */
3969 /* Step through each of the elements in the array. */
3973 {
3975 f,
3976 offset,
3977 offsets,
3978 max_offset,
3984 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3985 there's no point in iterating through the remaining
3986 elements of the array. */
3989 }
3990 }
3993 }
3995 /* Record all of the empty subobjects of TYPE (either a type or a
3996 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3997 is being placed at OFFSET; otherwise, it is a base class that is
3998 being placed at OFFSET. */
4000 static void
4002 tree offset,
4003 splay_tree offsets,
4005 {
4006 tree max_offset;
4007 /* If recording subobjects for a non-static data member or a
4008 non-empty base class , we do not need to record offsets beyond
4009 the size of the biggest empty class. Additional data members
4010 will go at the end of the class. Additional base classes will go
4011 either at offset zero (if empty, in which case they cannot
4012 overlap with offsets past the size of the biggest empty class) or
4013 at the end of the class.
4015 However, if we are placing an empty base class, then we must record
4016 all offsets, as either the empty class is at offset zero (where
4017 other empty classes might later be placed) or at the end of the
4018 class (where other objects might then be placed, so other empty
4019 subobjects might later overlap). */
4023 else
4027 }
4029 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4030 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4031 virtual bases of TYPE are examined. */
4033 static int
4035 tree offset,
4036 splay_tree offsets,
4038 {
4039 splay_tree_node max_node;
4041 /* Get the node in OFFSETS that indicates the maximum offset where
4042 an empty subobject is located. */
4044 /* If there aren't any empty subobjects, then there's no point in
4045 performing this check. */
4051 vbases_p);
4052 }
4054 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4055 non-static data member of the type indicated by RLI. BINFO is the
4056 binfo corresponding to the base subobject, OFFSETS maps offsets to
4057 types already located at those offsets. This function determines
4058 the position of the DECL. */
4060 static void
4062 tree decl,
4063 tree binfo,
4064 splay_tree offsets)
4065 {
4068 tree type;
4071 {
4072 /* For the purposes of determining layout conflicts, we want to
4073 use the class type of BINFO; TREE_TYPE (DECL) will be the
4074 CLASSTYPE_AS_BASE version, which does not contain entries for
4075 zero-sized bases. */
4078 }
4079 else
4080 {
4083 }
4085 /* Try to place the field. It may take more than one try if we have
4086 a hard time placing the field without putting two objects of the
4087 same type at the same address. */
4089 {
4092 /* Place this field. */
4096 /* We have to check to see whether or not there is already
4097 something of the same type at the offset we're about to use.
4098 For example, consider:
4100 struct S {};
4101 struct T : public S { int i; };
4102 struct U : public S, public T {};
4104 Here, we put S at offset zero in U. Then, we can't put T at
4105 offset zero -- its S component would be at the same address
4106 as the S we already allocated. So, we have to skip ahead.
4107 Since all data members, including those whose type is an
4108 empty class, have nonzero size, any overlap can happen only
4109 with a direct or indirect base-class -- it can't happen with
4110 a data member. */
4111 /* In a union, overlap is permitted; all members are placed at
4112 offset zero. */
4117 {
4118 /* Strip off the size allocated to this field. That puts us
4119 at the first place we could have put the field with
4120 proper alignment. */
4123 /* Bump up by the alignment required for the type. */
4124 rli->bitpos
4130 }
4131 else
4132 /* There was no conflict. We're done laying out this field. */
4134 }
4136 /* Now that we know where it will be placed, update its
4137 BINFO_OFFSET. */
4139 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4140 this point because their BINFO_OFFSET is copied from another
4141 hierarchy. Therefore, we may not need to add the entire
4142 OFFSET. */
4148 }
4150 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4152 static int
4154 tree offset,
4156 {
4158 }
4160 /* Layout the empty base BINFO. EOC indicates the byte currently just
4161 past the end of the class, and should be correctly aligned for a
4162 class of the type indicated by BINFO; OFFSETS gives the offsets of
4163 the empty bases allocated so far. T is the most derived
4164 type. Return nonzero iff we added it at the end. */
4166 static bool
4169 {
4170 tree alignment;
4174 /* This routine should only be used for empty classes. */
4179 propagate_binfo_offsets
4183 /* This is an empty base class. We first try to put it at offset
4184 zero. */
4187 offsets,
4189 {
4190 /* That didn't work. Now, we move forward from the next
4191 available spot in the class. */
4195 {
4198 offsets,
4200 /* We finally found a spot where there's no overlap. */
4203 /* There's overlap here, too. Bump along to the next spot. */
4205 }
4206 }
4209 {
4214 }
4217 }
4219 /* Layout the base given by BINFO in the class indicated by RLI.
4220 *BASE_ALIGN is a running maximum of the alignments of
4221 any base class. OFFSETS gives the location of empty base
4222 subobjects. T is the most derived type. Return nonzero if the new
4223 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4224 *NEXT_FIELD, unless BINFO is for an empty base class.
4226 Returns the location at which the next field should be inserted. */
4231 {
4236 /* This error is now reported in xref_tag, thus giving better
4237 location information. */
4240 /* Place the base class. */
4242 {
4243 tree decl;
4245 /* The containing class is non-empty because it has a non-empty
4246 base class. */
4249 /* Create the FIELD_DECL. */
4256 {
4264 /* Try to place the field. It may take more than one try if we
4265 have a hard time placing the field without putting two
4266 objects of the same type at the same address. */
4268 /* Add the new FIELD_DECL to the list of fields for T. */
4272 }
4273 }
4274 else
4275 {
4276 tree eoc;
4279 /* On some platforms (ARM), even empty classes will not be
4280 byte-aligned. */
4285 /* A nearly-empty class "has no proper base class that is empty,
4286 not morally virtual, and at an offset other than zero." */
4288 {
4291 /* The check above (used in G++ 3.2) is insufficient because
4292 an empty class placed at offset zero might itself have an
4293 empty base at a nonzero offset. */
4295 empty_base_at_nonzero_offset_p,
4296 size_zero_node,
4301 }
4303 /* We do not create a FIELD_DECL for empty base classes because
4304 it might overlap some other field. We want to be able to
4305 create CONSTRUCTORs for the class by iterating over the
4306 FIELD_DECLs, and the back end does not handle overlapping
4307 FIELD_DECLs. */
4309 /* An empty virtual base causes a class to be non-empty
4310 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4311 here because that was already done when the virtual table
4312 pointer was created. */
4313 }
4315 /* Record the offsets of BINFO and its base subobjects. */
4318 offsets,
4322 }
4324 /* Layout all of the non-virtual base classes. Record empty
4325 subobjects in OFFSETS. T is the most derived type. Return nonzero
4326 if the type cannot be nearly empty. The fields created
4327 corresponding to the base classes will be inserted at
4328 *NEXT_FIELD. */
4330 static void
4333 {
4334 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4335 subobjects. */
4340 /* The primary base class is always allocated first. */
4345 /* Now allocate the rest of the bases. */
4347 {
4348 tree base_binfo;
4352 /* The primary base was already allocated above, so we don't
4353 need to allocate it again here. */
4357 /* Virtual bases are added at the end (a primary virtual base
4358 will have already been added). */
4364 }
4365 }
4367 /* Go through the TYPE_METHODS of T issuing any appropriate
4368 diagnostics, figuring out which methods override which other
4369 methods, and so forth. */
4371 static void
4373 {
4374 tree x;
4377 {
4381 /* The name of the field is the original field name
4382 Save this in auxiliary field for later overloading. */
4384 {
4388 }
4389 /* All user-provided destructors are non-trivial.
4390 Constructors and assignment ops are handled in
4391 grok_special_member_properties. */
4394 }
4395 }
4397 /* FN is a constructor or destructor. Clone the declaration to create
4398 a specialized in-charge or not-in-charge version, as indicated by
4399 NAME. */
4401 static tree
4403 {
4404 tree parms;
4405 tree clone;
4407 /* Copy the function. */
4409 /* Reset the function name. */
4411 /* Remember where this function came from. */
4413 /* Make it easy to find the CLONE given the FN. */
4417 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4419 {
4426 }
4430 /* There's no pending inline data for this function. */
4434 /* The base-class destructor is not virtual. */
4436 {
4440 }
4442 /* If there was an in-charge parameter, drop it from the function
4443 type. */
4445 {
4446 tree basetype;
4447 tree parmtypes;
4448 tree exceptions;
4453 /* Skip the `this' parameter. */
4455 /* Skip the in-charge parameter. */
4457 /* And the VTT parm, in a complete [cd]tor. */
4461 /* If this is subobject constructor or destructor, add the vtt
4462 parameter. */
4466 parmtypes);
4469 exceptions);
4473 }
4475 /* Copy the function parameters. */
4477 /* Remove the in-charge parameter. */
4479 {
4483 }
4484 /* And the VTT parm, in a complete [cd]tor. */
4486 {
4489 else
4490 {
4494 }
4495 }
4498 {
4501 }
4503 /* Create the RTL for this function. */
4511 }
4513 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4514 not invoke this function directly.
4516 For a non-thunk function, returns the address of the slot for storing
4517 the function it is a clone of. Otherwise returns NULL_TREE.
4519 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4520 cloned_function is unset. This is to support the separate
4521 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4522 on a template makes sense, but not the former. */
4524 tree *
4526 {
4534 {
4535 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4538 else
4539 #endif
4541 }
4546 else
4548 }
4550 /* Produce declarations for all appropriate clones of FN. If
4551 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4552 CLASTYPE_METHOD_VEC as well. */
4554 void
4556 {
4557 tree clone;
4559 /* Avoid inappropriate cloning. */
4565 {
4566 /* For each constructor, we need two variants: an in-charge version
4567 and a not-in-charge version. */
4574 }
4575 else
4576 {
4579 /* For each destructor, we need three variants: an in-charge
4580 version, a not-in-charge version, and an in-charge deleting
4581 version. We clone the deleting version first because that
4582 means it will go second on the TYPE_METHODS list -- and that
4583 corresponds to the correct layout order in the virtual
4584 function table.
4586 For a non-virtual destructor, we do not build a deleting
4587 destructor. */
4589 {
4593 }
4600 }
4602 /* Note that this is an abstract function that is never emitted. */
4604 }
4606 /* DECL is an in charge constructor, which is being defined. This will
4607 have had an in class declaration, from whence clones were
4608 declared. An out-of-class definition can specify additional default
4609 arguments. As it is the clones that are involved in overload
4610 resolution, we must propagate the information from the DECL to its
4611 clones. */
4613 void
4615 {
4616 tree clone;
4620 {
4627 /* Skip the 'this' parameter. */
4643 {
4648 {
4649 /* A default parameter has been added. Adjust the
4650 clone's parameters. */
4654 tree type;
4659 {
4662 clone_parms);
4664 }
4667 clone_parms);
4676 }
4677 }
4679 }
4680 }
4682 /* For each of the constructors and destructors in T, create an
4683 in-charge and not-in-charge variant. */
4685 static void
4687 {
4688 tree fns;
4690 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4691 out now. */
4699 }
4701 /* Deduce noexcept for a destructor DTOR. */
4703 void
4705 {
4707 {
4710 }
4711 }
4713 /* For each destructor in T, deduce noexcept:
4715 12.4/3: A declaration of a destructor that does not have an
4716 exception-specification is implicitly considered to have the
4717 same exception-specification as an implicit declaration (15.4). */
4719 static void
4721 {
4722 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4723 out now. */
4729 }
4731 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4732 of TYPE for virtual functions which FNDECL overrides. Return a
4733 mask of the tm attributes found therein. */
4735 static int
4737 {
4739 tree base_binfo;
4743 {
4753 else
4755 }
4758 }
4760 /* Subroutine of set_method_tm_attributes. Handle the checks and
4761 inheritance for one virtual method FNDECL. */
4763 static void
4765 {
4766 tree tm_attr;
4771 /* If FNDECL doesn't actually override anything (i.e. T is the
4772 class that first declares FNDECL virtual), then we're done. */
4779 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4780 tm_pure must match exactly, otherwise no weakening of
4781 tm_safe > tm_callable > nothing. */
4782 /* ??? The tm_pure attribute didn't make the transition to the
4783 multivendor language spec. */
4785 {
4787 {
4790 }
4791 }
4792 /* If the overridden function is tm_pure, then FNDECL must be. */
4795 /* Look for base class combinations that cannot be satisfied. */
4797 {
4803 }
4804 /* If FNDECL did not declare an attribute, then inherit the most
4805 restrictive one. */
4807 {
4809 }
4810 /* Otherwise validate that we're not weaker than a function
4811 that is being overridden. */
4812 else
4813 {
4817 }
4820 err_override:
4824 }
4826 /* For each of the methods in T, propagate a class-level tm attribute. */
4828 static void
4830 {
4833 /* Don't bother collecting tm attributes if transactional memory
4834 support is not enabled. */
4838 /* Process virtual methods first, as they inherit directly from the
4839 base virtual function and also require validation of new attributes. */
4841 {
4842 tree vchain;
4845 {
4850 }
4851 }
4853 /* If the class doesn't have an attribute, nothing more to do. */
4858 /* Any method that does not yet have a tm attribute inherits
4859 the one from the class. */
4861 {
4864 }
4865 }
4867 /* Returns true iff class T has a user-defined constructor other than
4868 the default constructor. */
4870 bool
4872 {
4873 tree fns;
4879 {
4886 }
4889 }
4891 /* Returns the defaulted constructor if T has one. Otherwise, returns
4892 NULL_TREE. */
4894 tree
4896 {
4903 {
4907 {
4913 }
4914 }
4917 }
4919 /* Returns true iff FN is a user-provided function, i.e. user-declared
4920 and not defaulted at its first declaration; or explicit, private,
4921 protected, or non-const. */
4923 bool
4925 {
4928 else
4932 }
4934 /* Returns true iff class T has a user-provided constructor. */
4936 bool
4938 {
4939 tree fns;
4947 /* This can happen in error cases; avoid crashing. */
4956 }
4958 /* Returns true iff class T has a non-user-provided (i.e. implicitly
4959 declared or explicitly defaulted in the class body) default
4960 constructor. */
4962 bool
4964 {
4965 tree fns;
4973 {
4979 }
4982 }
4984 /* TYPE is being used as a virtual base, and has a non-trivial move
4985 assignment. Return true if this is due to there being a user-provided
4986 move assignment in TYPE or one of its subobjects; if there isn't, then
4987 multiple move assignment can't cause any harm. */
4989 bool
4991 {
4992 /* Does the type itself have a user-provided move assignment operator? */
4996 {
5000 }
5002 /* Do any of its bases? */
5004 tree base_binfo;
5009 /* Or non-static data members? */
5011 {
5016 }
5018 /* Seems not. */
5020 }
5022 /* If default-initialization leaves part of TYPE uninitialized, returns
5023 a DECL for the field or TYPE itself (DR 253). */
5025 tree
5027 {
5038 {
5042 }
5047 {
5051 }
5054 }
5056 /* Returns true iff for class T, a trivial synthesized default constructor
5057 would be constexpr. */
5059 bool
5061 {
5062 /* A defaulted trivial default constructor is constexpr
5063 if there is nothing to initialize. */
5066 }
5068 /* Returns true iff class T has a constexpr default constructor. */
5070 bool
5072 {
5073 tree fns;
5076 {
5077 /* The caller should have stripped an enclosing array. */
5080 }
5082 {
5085 /* Non-trivial, we need to check subobject constructors. */
5087 }
5090 }
5092 /* Returns true iff class TYPE has a virtual destructor. */
5094 bool
5096 {
5097 tree dtor;
5105 }
5107 /* Returns true iff class T has a move constructor. */
5109 bool
5111 {
5112 tree fns;
5115 {
5118 }
5128 }
5130 /* Returns true iff class T has a move assignment operator. */
5132 bool
5134 {
5135 tree fns;
5138 {
5141 }
5149 }
5151 /* Returns true iff class T has a move constructor that was explicitly
5152 declared in the class body. Note that this is different from
5153 "user-provided", which doesn't include functions that are defaulted in
5154 the class. */
5156 bool
5158 {
5159 tree fns;
5168 {
5172 }
5175 }
5177 /* Returns true iff class T has a move assignment operator that was
5178 explicitly declared in the class body. */
5180 bool
5182 {
5183 tree fns;
5190 {
5194 }
5197 }
5199 /* Nonzero if we need to build up a constructor call when initializing an
5200 object of this class, either because it has a user-declared constructor
5201 or because it doesn't have a default constructor (so we need to give an
5202 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5203 what you care about is whether or not an object can be produced by a
5204 constructor (e.g. so we don't set TREE_READONLY on const variables of
5205 such type); use this function when what you care about is whether or not
5206 to try to call a constructor to create an object. The latter case is
5207 the former plus some cases of constructors that cannot be called. */
5209 bool
5211 {
5212 tree inner;
5222 /* A user-declared constructor might be private, and a constructor might
5223 be trivial but deleted. */
5226 {
5231 }
5233 }
5235 /* Like type_build_ctor_call, but for destructors. */
5237 bool
5239 {
5240 tree inner;
5249 /* A user-declared destructor might be private, and a destructor might
5250 be trivial but deleted. */
5253 {
5258 }
5260 }
5262 /* Remove all zero-width bit-fields from T. */
5264 static void
5266 {
5271 {
5274 /* We should not be confused by the fact that grokbitfield
5275 temporarily sets the width of the bit field into
5276 DECL_INITIAL (*fieldsp).
5277 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5278 to that width. */
5281 else
5283 }
5284 }
5286 /* Returns TRUE iff we need a cookie when dynamically allocating an
5287 array whose elements have the indicated class TYPE. */
5289 static bool
5291 {
5292 tree fns;
5297 /* If there's a non-trivial destructor, we need a cookie. In order
5298 to iterate through the array calling the destructor for each
5299 element, we'll have to know how many elements there are. */
5303 /* If the usual deallocation function is a two-argument whose second
5304 argument is of type `size_t', then we have to pass the size of
5305 the array to the deallocation function, so we will need to store
5306 a cookie. */
5310 /* If there are no `operator []' members, or the lookup is
5311 ambiguous, then we don't need a cookie. */
5314 /* Loop through all of the functions. */
5316 {
5317 tree fn;
5318 tree second_parm;
5320 /* Select the current function. */
5322 /* See if this function is a one-argument delete function. If
5323 it is, then it will be the usual deallocation function. */
5327 /* Do not consider this function if its second argument is an
5328 ellipsis. */
5331 /* Otherwise, if we have a two-argument function and the second
5332 argument is `size_t', it will be the usual deallocation
5333 function -- unless there is one-argument function, too. */
5337 }
5340 }
5342 /* Finish computing the `literal type' property of class type T.
5344 At this point, we have already processed base classes and
5345 non-static data members. We need to check whether the copy
5346 constructor is trivial, the destructor is trivial, and there
5347 is a trivial default constructor or at least one constexpr
5348 constructor other than the copy constructor. */
5350 static void
5352 {
5353 tree fn;
5369 {
5372 {
5376 }
5377 }
5378 }
5380 /* T is a non-literal type used in a context which requires a constant
5381 expression. Explain why it isn't literal. */
5383 void
5385 {
5395 /* Already explained. */
5404 {
5406 "default constructor, and has no constexpr constructor that "
5409 {
5410 /* Note that we can't simply call locate_ctor because when the
5411 constructor is deleted it just returns NULL_TREE. */
5412 tree fns;
5414 {
5421 {
5424 else
5427 }
5428 }
5429 }
5430 }
5431 else
5432 {
5436 {
5439 {
5444 }
5445 }
5447 {
5448 tree ftype;
5453 {
5458 }
5462 }
5463 }
5464 }
5466 /* Check the validity of the bases and members declared in T. Add any
5467 implicitly-generated functions (like copy-constructors and
5468 assignment operators). Compute various flag bits (like
5469 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5470 level: i.e., independently of the ABI in use. */
5472 static void
5474 {
5475 /* Nonzero if the implicitly generated copy constructor should take
5476 a non-const reference argument. */
5478 /* Nonzero if the implicitly generated assignment operator
5479 should take a non-const reference argument. */
5481 tree access_decls;
5484 tree fn;
5486 /* By default, we use const reference arguments and generate default
5487 constructors. */
5491 /* Check all the base-classes. */
5495 /* Deduce noexcept on destructors. This needs to happen after we've set
5496 triviality flags appropriately for our bases. */
5500 /* Check all the method declarations. */
5503 /* Save the initial values of these flags which only indicate whether
5504 or not the class has user-provided functions. As we analyze the
5505 bases and members we can set these flags for other reasons. */
5509 /* Check all the data member declarations. We cannot call
5510 check_field_decls until we have called check_bases check_methods,
5511 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5512 being set appropriately. */
5517 /* A nearly-empty class has to be vptr-containing; a nearly empty
5518 class contains just a vptr. */
5522 /* Do some bookkeeping that will guide the generation of implicitly
5523 declared member functions. */
5526 /* We need to call a constructor for this class if it has a
5527 user-provided constructor, or if the default constructor is going
5528 to initialize the vptr. (This is not an if-and-only-if;
5529 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5530 themselves need constructing.) */
5533 /* [dcl.init.aggr]
5535 An aggregate is an array or a class with no user-provided
5536 constructors ... and no virtual functions.
5538 Again, other conditions for being an aggregate are checked
5539 elsewhere. */
5542 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5543 retain the old definition internally for ABI reasons. */
5552 /* If the only explicitly declared default constructor is user-provided,
5553 set TYPE_HAS_COMPLEX_DFLT. */
5559 /* Warn if a public base of a polymorphic type has an accessible
5560 non-virtual destructor. It is only now that we know the class is
5561 polymorphic. Although a polymorphic base will have a already
5562 been diagnosed during its definition, we warn on use too. */
5564 {
5567 tree base_binfo;
5571 {
5579 basetype);
5580 }
5581 }
5583 /* If the class has no user-declared constructor, but does have
5584 non-static const or reference data members that can never be
5585 initialized, issue a warning. */
5587 /* Classes with user-declared constructors are presumed to
5588 initialize these members. */
5590 /* Aggregates can be initialized with brace-enclosed
5591 initializers. */
5593 {
5594 tree field;
5597 {
5598 tree type;
5613 }
5614 }
5616 /* Synthesize any needed methods. */
5618 cant_have_const_ctor,
5619 no_const_asn_ref);
5621 /* Check defaulted declarations here so we have cant_have_const_ctor
5622 and don't need to worry about clones. */
5625 {
5628 {
5629 bool imp_const_p
5635 /* If the function is defaulted outside the class, we just
5636 give the synthesis error. */
5639 }
5641 }
5644 {
5645 /* "This class type is not an aggregate." */
5647 }
5649 /* Compute the 'literal type' property before we
5650 do anything with non-static member functions. */
5653 /* Create the in-charge and not-in-charge variants of constructors
5654 and destructors. */
5657 /* Process the using-declarations. */
5661 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5664 /* Figure out whether or not we will need a cookie when dynamically
5665 allocating an array of this type. */
5668 }
5670 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5671 accordingly. If a new vfield was created (because T doesn't have a
5672 primary base class), then the newly created field is returned. It
5673 is not added to the TYPE_FIELDS list; it is the caller's
5674 responsibility to do that. Accumulate declared virtual functions
5675 on VIRTUALS_P. */
5677 static tree
5679 {
5680 tree fn;
5682 /* Collect the virtual functions declared in T. */
5687 {
5696 }
5698 /* If we couldn't find an appropriate base class, create a new field
5699 here. Even if there weren't any new virtual functions, we might need a
5700 new virtual function table if we're supposed to include vptrs in
5701 all classes that need them. */
5703 {
5704 /* We build this decl with vtbl_ptr_type_node, which is a
5705 `vtable_entry_type*'. It might seem more precise to use
5706 `vtable_entry_type (*)[N]' where N is the number of virtual
5707 functions. However, that would require the vtable pointer in
5708 base classes to have a different type than the vtable pointer
5709 in derived classes. We could make that happen, but that
5710 still wouldn't solve all the problems. In particular, the
5711 type-based alias analysis code would decide that assignments
5712 to the base class vtable pointer can't alias assignments to
5713 the derived class vtable pointer, since they have different
5714 types. Thus, in a derived class destructor, where the base
5715 class constructor was inlined, we could generate bad code for
5716 setting up the vtable pointer.
5718 Therefore, we use one type for all vtable pointers. We still
5719 use a type-correct type; it's just doesn't indicate the array
5720 bounds. That's better than using `void*' or some such; it's
5721 cleaner, and it let's the alias analysis code know that these
5722 stores cannot alias stores to void*! */
5723 tree field;
5736 /* This class is non-empty. */
5740 }
5743 }
5745 /* Add OFFSET to all base types of BINFO which is a base in the
5746 hierarchy dominated by T.
5748 OFFSET, which is a type offset, is number of bytes. */
5750 static void
5752 {
5754 tree primary_binfo;
5755 tree base_binfo;
5757 /* Update BINFO's offset. */
5762 offset));
5764 /* Find the primary base class. */
5770 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5771 downwards. */
5773 {
5774 /* Don't do the primary base twice. */
5782 }
5783 }
5785 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5786 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5787 empty subobjects of T. */
5789 static void
5791 {
5792 tree vbase;
5799 /* Find the last field. The artificial fields created for virtual
5800 bases will go after the last extant field to date. */
5805 /* Go through the virtual bases, allocating space for each virtual
5806 base that is not already a primary base class. These are
5807 allocated in inheritance graph order. */
5809 {
5814 {
5815 /* This virtual base is not a primary base of any class in the
5816 hierarchy, so we have to add space for it. */
5819 }
5820 }
5821 }
5823 /* Returns the offset of the byte just past the end of the base class
5824 BINFO. */
5826 static tree
5828 {
5829 tree size;
5834 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5835 allocate some space for it. It cannot have virtual bases, so
5836 TYPE_SIZE_UNIT is fine. */
5838 else
5842 }
5844 /* Returns the offset of the byte just past the end of the base class
5845 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5846 only non-virtual bases are included. */
5848 static tree
5850 {
5853 tree binfo;
5854 tree base_binfo;
5855 tree offset;
5860 {
5870 }
5875 {
5879 }
5882 }
5884 /* Warn about bases of T that are inaccessible because they are
5885 ambiguous. For example:
5887 struct S {};
5888 struct T : public S {};
5889 struct U : public S, public T {};
5891 Here, `(S*) new U' is not allowed because there are two `S'
5892 subobjects of U. */
5894 static void
5896 {
5899 tree basetype;
5900 tree binfo;
5901 tree base_binfo;
5903 /* If there are no repeated bases, nothing can be ambiguous. */
5907 /* Check direct bases. */
5910 {
5916 }
5918 /* Check for ambiguous virtual bases. */
5922 {
5928 }
5929 }
5931 /* Compare two INTEGER_CSTs K1 and K2. */
5933 static int
5935 {
5937 }
5939 /* Increase the size indicated in RLI to account for empty classes
5940 that are "off the end" of the class. */
5942 static void
5944 {
5945 tree eoc;
5946 tree rli_size;
5948 /* It might be the case that we grew the class to allocate a
5949 zero-sized base class. That won't be reflected in RLI, yet,
5950 because we are willing to overlay multiple bases at the same
5951 offset. However, now we need to make sure that RLI is big enough
5952 to reflect the entire class. */
5958 {
5959 /* The size should have been rounded to a whole byte. */
5962 rli->bitpos
5971 }
5972 }
5974 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5975 BINFO_OFFSETs for all of the base-classes. Position the vtable
5976 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5978 static void
5980 {
5981 tree non_static_data_members;
5982 tree field;
5983 tree vptr;
5984 record_layout_info rli;
5985 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5986 types that appear at that offset. */
5987 splay_tree empty_base_offsets;
5988 /* True if the last field laid out was a bit-field. */
5990 /* The location at which the next field should be inserted. */
5992 /* T, as a base class. */
5993 tree base_t;
5995 /* Keep track of the first non-static data member. */
5998 /* Start laying out the record. */
6001 /* Mark all the primary bases in the hierarchy. */
6004 /* Create a pointer to our virtual function table. */
6007 /* The vptr is always the first thing in the class. */
6009 {
6014 }
6015 else
6018 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6023 /* Layout the non-static data members. */
6025 {
6026 tree type;
6027 tree padding;
6029 /* We still pass things that aren't non-static data members to
6030 the back end, in case it wants to do something with them. */
6032 {
6034 /* If the static data member has incomplete type, keep track
6035 of it so that it can be completed later. (The handling
6036 of pending statics in finish_record_layout is
6037 insufficient; consider:
6039 struct S1;
6040 struct S2 { static S1 s1; };
6042 At this point, finish_record_layout will be called, but
6043 S1 is still incomplete.) */
6045 {
6047 /* The visibility of static data members is determined
6048 at their point of declaration, not their point of
6049 definition. */
6051 }
6053 }
6061 /* If this field is a bit-field whose width is greater than its
6062 type, then there are some special rules for allocating
6063 it. */
6066 {
6068 tree integer_type;
6070 /* We must allocate the bits as if suitably aligned for the
6071 longest integer type that fits in this many bits. type
6072 of the field. Then, we are supposed to use the left over
6073 bits as additional padding. */
6082 /* ITK now indicates a type that is too large for the
6083 field. We have to back up by one to find the largest
6084 type that fits. */
6085 do
6086 {
6091 /* Figure out how much additional padding is required. */
6093 {
6095 /* In a union, the padding field must have the full width
6096 of the bit-field; all fields start at offset zero. */
6098 else
6101 }
6102 #ifdef PCC_BITFIELD_TYPE_MATTERS
6103 /* An unnamed bitfield does not normally affect the
6104 alignment of the containing class on a target where
6105 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6106 make any exceptions for unnamed bitfields when the
6107 bitfields are longer than their types. Therefore, we
6108 temporarily give the field a name. */
6110 {
6113 }
6114 #endif
6119 empty_base_offsets);
6122 /* Now that layout has been performed, set the size of the
6123 field to the size of its declared type; the rest of the
6124 field is effectively invisible. */
6126 /* We must also reset the DECL_MODE of the field. */
6128 }
6129 else
6131 empty_base_offsets);
6133 /* Remember the location of any empty classes in FIELD. */
6136 empty_base_offsets,
6139 /* If a bit-field does not immediately follow another bit-field,
6140 and yet it starts in the middle of a byte, we have failed to
6141 comply with the ABI. */
6144 /* The TREE_NO_WARNING flag gets set by Objective-C when
6145 laying out an Objective-C class. The ObjC ABI differs
6146 from the C++ ABI, and so we do not want a warning
6147 here. */
6149 && !last_field_was_bitfield
6152 bitsize_unit_node)))
6156 /* The middle end uses the type of expressions to determine the
6157 possible range of expression values. In order to optimize
6158 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6159 must be made aware of the width of "i", via its type.
6161 Because C++ does not have integer types of arbitrary width,
6162 we must (for the purposes of the front end) convert from the
6163 type assigned here to the declared type of the bitfield
6164 whenever a bitfield expression is used as an rvalue.
6165 Similarly, when assigning a value to a bitfield, the value
6166 must be converted to the type given the bitfield here. */
6168 {
6173 {
6180 }
6181 }
6183 /* If we needed additional padding after this field, add it
6184 now. */
6186 {
6187 tree padding_field;
6190 FIELD_DECL,
6191 NULL_TREE,
6192 char_type_node);
6199 NULL_TREE,
6200 empty_base_offsets);
6201 }
6204 }
6207 {
6208 /* Make sure that we are on a byte boundary so that the size of
6209 the class without virtual bases will always be a round number
6210 of bytes. */
6213 }
6215 /* Delete all zero-width bit-fields from the list of fields. Now
6216 that the type is laid out they are no longer important. */
6219 /* Create the version of T used for virtual bases. We do not use
6220 make_class_type for this version; this is an artificial type. For
6221 a POD type, we just reuse T. */
6223 {
6226 /* Set the size and alignment for the new type. */
6227 tree eoc;
6229 /* If the ABI version is not at least two, and the last
6230 field was a bit-field, RLI may not be on a byte
6231 boundary. In particular, rli_size_unit_so_far might
6232 indicate the last complete byte, while rli_size_so_far
6233 indicates the total number of bits used. Therefore,
6234 rli_size_so_far, rather than rli_size_unit_so_far, is
6235 used to compute TYPE_SIZE_UNIT. */
6243 eoc);
6253 /* Copy the fields from T. */
6257 {
6259 FIELD_DECL,
6269 }
6271 /* Record the base version of the type. */
6274 }
6275 else
6278 /* Every empty class contains an empty class. */
6282 /* Set the TYPE_DECL for this type to contain the right
6283 value for DECL_OFFSET, so that we can use it as part
6284 of a COMPONENT_REF for multiple inheritance. */
6287 /* Now fix up any virtual base class types that we left lying
6288 around. We must get these done before we try to lay out the
6289 virtual function table. As a side-effect, this will remove the
6290 base subobject fields. */
6293 /* Make sure that empty classes are reflected in RLI at this
6294 point. */
6297 /* Make sure not to create any structures with zero size. */
6303 /* If this is a non-POD, declaring it packed makes a difference to how it
6304 can be used as a field; don't let finalize_record_size undo it. */
6308 /* Let the back end lay out the type. */
6317 /* Warn about bases that can't be talked about due to ambiguity. */
6320 /* Now that we're done with layout, give the base fields the real types. */
6325 /* Clean up. */
6332 }
6334 /* Determine the "key method" for the class type indicated by TYPE,
6335 and set CLASSTYPE_KEY_METHOD accordingly. */
6337 void
6339 {
6340 tree method;
6343 || processing_template_decl
6348 /* The key method is the first non-pure virtual function that is not
6349 inline at the point of class definition. On some targets the
6350 key function may not be inline; those targets should not call
6351 this function until the end of the translation unit. */
6358 {
6361 }
6364 }
6367 /* Allocate and return an instance of struct sorted_fields_type with
6368 N fields. */
6372 {
6379 }
6382 /* Perform processing required when the definition of T (a class type)
6383 is complete. */
6385 void
6387 {
6388 tree x;
6389 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6393 {
6398 }
6400 /* If this type was previously laid out as a forward reference,
6401 make sure we lay it out again. */
6405 /* Make assumptions about the class; we'll reset the flags if
6406 necessary. */
6412 /* Do end-of-class semantic processing: checking the validity of the
6413 bases and members and add implicitly generated methods. */
6416 /* Find the key method. */
6418 {
6419 /* The Itanium C++ ABI permits the key method to be chosen when
6420 the class is defined -- even though the key method so
6421 selected may later turn out to be an inline function. On
6422 some systems (such as ARM Symbian OS) the key method cannot
6423 be determined until the end of the translation unit. On such
6424 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6425 will cause the class to be added to KEYED_CLASSES. Then, in
6426 finish_file we will determine the key method. */
6430 /* If a polymorphic class has no key method, we may emit the vtable
6431 in every translation unit where the class definition appears. If
6432 we're devirtualizing, we can look into the vtable even if we
6433 aren't emitting it. */
6436 }
6438 /* Layout the class itself. */
6441 /* We use the base type for trivial assignments, and hence it
6442 needs a mode. */
6447 /* If necessary, create the primary vtable for this class. */
6449 {
6450 /* We must enter these virtuals into the table. */
6454 /* Here we know enough to change the type of our virtual
6455 function table, but we will wait until later this function. */
6458 /* If we're warning about ABI tags, check the types of the new
6459 virtual functions. */
6463 }
6466 {
6468 tree fn;
6475 /* Add entries for virtual functions introduced by this class. */
6479 /* Set DECL_VINDEX for all functions declared in this class. */
6481 fn;
6483 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6485 {
6489 /* A thunk. We should never be calling this entry directly
6490 from this vtable -- we'd use the entry for the non
6491 thunk base function. */
6495 }
6496 }
6501 /* Complete the rtl for any static member objects of the type we're
6502 working on. */
6509 /* Done with FIELDS...now decide whether to sort these for
6510 faster lookups later.
6512 We use a small number because most searches fail (succeeding
6513 ultimately as the search bores through the inheritance
6514 hierarchy), and we want this failure to occur quickly. */
6518 /* Complain if one of the field types requires lower visibility. */
6521 /* Make the rtl for any new vtables we have created, and unmark
6522 the base types we marked. */
6525 /* Build the VTT for T. */
6528 /* This warning does not make sense for Java classes, since they
6529 cannot have destructors. */
6534 "%q#T has virtual functions and accessible"
6542 /* Class layout, assignment of virtual table slots, etc., is now
6543 complete. Give the back end a chance to tweak the visibility of
6544 the class or perform any other required target modifications. */
6554 /* Finish debugging output for this type. */
6558 {
6561 {
6564 }
6566 {
6569 else
6570 {
6573 }
6575 }
6577 {
6579 "the type of the first field has a different ABI from the "
6582 }
6583 }
6584 }
6586 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6587 equal to THRESHOLD or greater than THRESHOLD. */
6589 static void
6591 {
6594 {
6599 }
6600 }
6602 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6604 void
6606 {
6609 {
6611 int n_fields
6622 }
6623 }
6625 /* When T was built up, the member declarations were added in reverse
6626 order. Rearrange them to declaration order. */
6628 void
6630 {
6631 tree next;
6632 tree prev;
6633 tree x;
6635 /* The following lists are all in reverse order. Put them in
6636 declaration order now. */
6640 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6641 reverse order, so we can't just use nreverse. */
6646 {
6650 }
6652 {
6656 }
6657 }
6659 tree
6661 {
6664 /* Now that we've got all the field declarations, reverse everything
6665 as necessary. */
6670 /* Nadger the current location so that diagnostics point to the start of
6671 the struct, not the end. */
6675 {
6676 tree x;
6682 /* We need to emit an error message if this type was used as a parameter
6683 and it is an abstract type, even if it is a template. We construct
6684 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6685 account and we call complete_vars with this type, which will check
6686 the PARM_DECLS. Note that while the type is being defined,
6687 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6688 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6694 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6695 an enclosing scope is a template class, so that this function be
6696 found by lookup_fnfields_1 when the using declaration is not
6697 instantiated yet. */
6700 {
6705 }
6707 /* Remember current #pragma pack value. */
6710 /* Fix up any variants we've already built. */
6712 {
6717 }
6718 }
6719 else
6723 {
6724 /* People keep complaining that the compiler crashes on an invalid
6725 definition of initializer_list, so I guess we should explicitly
6726 reject it. What the compiler internals care about is that it's a
6727 template and has a pointer field followed by an integer field. */
6730 {
6733 {
6737 }
6738 }
6742 }
6750 else
6754 /* Lambdas are defined by the LAMBDA_EXPR. */
6759 }
6760 \f
6761 /* Hash table to avoid endless recursion when handling references. */
6764 /* Return the dynamic type of INSTANCE, if known.
6765 Used to determine whether the virtual function table is needed
6766 or not.
6768 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6769 of our knowledge of its type. *NONNULL should be initialized
6770 before this function is called. */
6772 static tree
6774 {
6775 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6778 {
6782 else
6786 /* This is a call to a constructor, hence it's never zero. */
6788 {
6792 }
6796 /* This is a call to a constructor, hence it's never zero. */
6798 {
6802 }
6811 /* Propagate nonnull. */
6816 CASE_CONVERT:
6822 {
6823 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6824 with a real object -- given &p->f, p can still be null. */
6826 /* ??? Probably should check DECL_WEAK here. */
6829 }
6833 /* If this component is really a base class reference, then the field
6834 itself isn't definitive. */
6843 {
6847 }
6848 /* fall through... */
6853 {
6857 }
6859 {
6863 /* if we're in a ctor or dtor, we know our type. If
6864 current_class_ptr is set but we aren't in a function, we're in
6865 an NSDMI (and therefore a constructor). */
6870 {
6874 }
6875 }
6877 {
6878 /* We only need one hash table because it is always left empty. */
6880 fixed_type_or_null_ref_ht
6883 /* Reference variables should be references to objects. */
6887 /* Enter the INSTANCE in a table to prevent recursion; a
6888 variable's initializer may refer to the variable
6889 itself. */
6894 {
6895 tree type;
6904 }
6905 }
6910 }
6911 #undef RECUR
6912 }
6914 /* Return nonzero if the dynamic type of INSTANCE is known, and
6915 equivalent to the static type. We also handle the case where
6916 INSTANCE is really a pointer. Return negative if this is a
6917 ctor/dtor. There the dynamic type is known, but this might not be
6918 the most derived base of the original object, and hence virtual
6919 bases may not be laid out according to this type.
6921 Used to determine whether the virtual function table is needed
6922 or not.
6924 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6925 of our knowledge of its type. *NONNULL should be initialized
6926 before this function is called. */
6928 int
6930 {
6933 tree fixed;
6935 /* processing_template_decl can be false in a template if we're in
6936 instantiate_non_dependent_expr, but we still want to suppress
6937 this check. */
6939 {
6940 /* In a template we only care about the type of the result. */
6944 }
6954 }
6956 \f
6957 void
6959 {
6962 current_class_stack
6970 }
6972 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6974 static void
6976 {
6977 tree type;
6979 /* We are re-entering the same class we just left, so we don't
6980 have to search the whole inheritance matrix to find all the
6981 decls to bind again. Instead, we install the cached
6982 class_shadowed list and walk through it binding names. */
6985 /* Restore IDENTIFIER_TYPE_VALUE. */
6987 type;
6990 }
6992 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6993 appropriate for TYPE.
6995 So that we may avoid calls to lookup_name, we cache the _TYPE
6996 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6998 For multiple inheritance, we perform a two-pass depth-first search
6999 of the type lattice. */
7001 void
7003 {
7004 class_stack_node_t csn;
7008 /* Make sure there is enough room for the new entry on the stack. */
7010 {
7012 current_class_stack
7014 current_class_stack_size);
7015 }
7017 /* Insert a new entry on the class stack. */
7024 current_class_depth++;
7026 /* Now set up the new type. */
7032 /* By default, things in classes are private, while things in
7033 structures or unions are public. */
7035 ? access_private_node
7041 {
7042 /* Forcibly remove any old class remnants. */
7044 }
7050 else
7052 }
7054 /* When we exit a toplevel class scope, we save its binding level so
7055 that we can restore it quickly. Here, we've entered some other
7056 class, so we must invalidate our cache. */
7058 void
7060 {
7062 }
7064 /* Get out of the current class scope. If we were in a class scope
7065 previously, that is the one popped to. */
7067 void
7069 {
7072 current_class_depth--;
7078 }
7080 /* Mark the top of the class stack as hidden. */
7082 void
7084 {
7087 }
7089 /* Mark the top of the class stack as un-hidden. */
7091 void
7093 {
7096 }
7098 /* Returns 1 if the class type currently being defined is either T or
7099 a nested type of T. */
7101 bool
7103 {
7111 /* We start looking from 1 because entry 0 is from global scope,
7112 and has no type. */
7114 {
7115 tree c;
7118 else
7119 {
7123 }
7128 }
7130 }
7132 /* If either current_class_type or one of its enclosing classes are derived
7133 from T, return the appropriate type. Used to determine how we found
7134 something via unqualified lookup. */
7136 tree
7138 {
7141 /* The bases of a dependent type are unknown. */
7152 {
7157 }
7160 }
7162 /* Return the outermost enclosing class type that is still open, or
7163 NULL_TREE. */
7165 tree
7167 {
7174 {
7181 }
7183 }
7185 /* Returns the innermost class type which is not a lambda closure type. */
7187 tree
7189 {
7192 /* We start looking from 1 because entry 0 is from global scope,
7193 and has no type. */
7195 {
7196 tree c;
7199 else
7200 {
7204 }
7209 }
7211 }
7213 /* When entering a class scope, all enclosing class scopes' names with
7214 static meaning (static variables, static functions, types and
7215 enumerators) have to be visible. This recursive function calls
7216 pushclass for all enclosing class contexts until global or a local
7217 scope is reached. TYPE is the enclosed class. */
7219 void
7221 {
7222 /* A namespace might be passed in error cases, like A::B:C. */
7230 }
7232 /* Undoes a push_nested_class call. */
7234 void
7236 {
7242 }
7244 /* Returns the number of extern "LANG" blocks we are nested within. */
7246 int
7248 {
7250 }
7252 /* Set global variables CURRENT_LANG_NAME to appropriate value
7253 so that behavior of name-mangling machinery is correct. */
7255 void
7257 {
7261 {
7263 }
7265 {
7267 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7268 (See record_builtin_java_type in decl.c.) However, that causes
7269 incorrect debug entries if these types are actually used.
7270 So we re-enable debug output after extern "Java". */
7279 }
7281 {
7283 }
7284 else
7286 }
7288 /* Get out of the current language scope. */
7290 void
7292 {
7294 }
7295 \f
7296 /* Type instantiation routines. */
7298 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7299 matches the TARGET_TYPE. If there is no satisfactory match, return
7300 error_mark_node, and issue an error & warning messages under
7301 control of FLAGS. Permit pointers to member function if FLAGS
7302 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7303 a template-id, and EXPLICIT_TARGS are the explicitly provided
7304 template arguments.
7306 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7307 is the base path used to reference those member functions. If
7308 the address is resolved to a member function, access checks will be
7309 performed and errors issued if appropriate. */
7311 static tree
7313 tree overload,
7314 tsubst_flags_t flags,
7316 tree explicit_targs,
7317 tree access_path)
7318 {
7319 /* Here's what the standard says:
7321 [over.over]
7323 If the name is a function template, template argument deduction
7324 is done, and if the argument deduction succeeds, the deduced
7325 arguments are used to generate a single template function, which
7326 is added to the set of overloaded functions considered.
7328 Non-member functions and static member functions match targets of
7329 type "pointer-to-function" or "reference-to-function." Nonstatic
7330 member functions match targets of type "pointer-to-member
7331 function;" the function type of the pointer to member is used to
7332 select the member function from the set of overloaded member
7333 functions. If a nonstatic member function is selected, the
7334 reference to the overloaded function name is required to have the
7335 form of a pointer to member as described in 5.3.1.
7337 If more than one function is selected, any template functions in
7338 the set are eliminated if the set also contains a non-template
7339 function, and any given template function is eliminated if the
7340 set contains a second template function that is more specialized
7341 than the first according to the partial ordering rules 14.5.5.2.
7342 After such eliminations, if any, there shall remain exactly one
7343 selected function. */
7346 /* We store the matches in a TREE_LIST rooted here. The functions
7347 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7348 interoperability with most_specialized_instantiation. */
7350 tree fn;
7351 tree target_fn_type;
7353 /* By the time we get here, we should be seeing only real
7354 pointer-to-member types, not the internal POINTER_TYPE to
7355 METHOD_TYPE representation. */
7361 /* Check that the TARGET_TYPE is reasonable. */
7366 /* This is OK, too. */
7369 /* This is OK, too. This comes from a conversion to reference
7370 type. */
7372 else
7373 {
7379 }
7381 /* Non-member functions and static member functions match targets of type
7382 "pointer-to-function" or "reference-to-function." Nonstatic member
7383 functions match targets of type "pointer-to-member-function;" the
7384 function type of the pointer to member is used to select the member
7385 function from the set of overloaded member functions.
7387 So figure out the FUNCTION_TYPE that we want to match against. */
7390 /* If we can find a non-template function that matches, we can just
7391 use it. There's no point in generating template instantiations
7392 if we're just going to throw them out anyhow. But, of course, we
7393 can only do this when we don't *need* a template function. */
7395 {
7396 tree fns;
7399 {
7403 /* We're not looking for templates just yet. */
7408 /* We're looking for a non-static member, and this isn't
7409 one, or vice versa. */
7412 /* Ignore functions which haven't been explicitly
7413 declared. */
7417 /* See if there's a match. */
7420 }
7421 }
7423 /* Now, if we've already got a match (or matches), there's no need
7424 to proceed to the template functions. But, if we don't have a
7425 match we need to look at them, too. */
7427 {
7428 tree target_arg_types;
7429 tree target_ret_type;
7430 tree fns;
7433 tree arg;
7447 {
7449 tree instantiation;
7450 tree targs;
7453 /* We're only looking for templates. */
7458 /* We're not looking for a non-static member, and this is
7459 one, or vice versa. */
7464 /* If the template has a deduced return type, don't expose it to
7465 template argument deduction. */
7469 /* Try to do argument deduction. */
7476 /* Instantiation failed. */
7479 /* And now force instantiation to do return type deduction. */
7481 {
7487 }
7489 /* See if there's a match. */
7492 }
7494 /* Now, remove all but the most specialized of the matches. */
7496 {
7501 NULL_TREE,
7502 NULL_TREE);
7503 }
7504 }
7506 /* Now we should have exactly one function in MATCHES. */
7508 {
7509 /* There were *no* matches. */
7511 {
7514 target_type);
7517 }
7519 }
7521 {
7522 /* There were too many matches. First check if they're all
7523 the same function. */
7528 /* For multi-versioned functions, more than one match is just fine and
7529 decls_match will return false as they are different. */
7537 {
7539 {
7542 target_type);
7544 /* Since print_candidates expects the functions in the
7545 TREE_VALUE slot, we flip them here. */
7550 }
7553 }
7554 }
7556 /* Good, exactly one match. Now, convert it to the correct type. */
7561 {
7569 {
7572 }
7573 }
7575 /* If a pointer to a function that is multi-versioned is requested, the
7576 pointer to the dispatcher function is returned instead. This works
7577 well because indirectly calling the function will dispatch the right
7578 function version at run-time. */
7580 {
7584 /* Mark all the versions corresponding to the dispatcher as used. */
7587 }
7589 /* If we're doing overload resolution purely for the purpose of
7590 determining conversion sequences, we should not consider the
7591 function used. If this conversion sequence is selected, the
7592 function will be marked as used at this point. */
7594 {
7595 /* Make =delete work with SFINAE. */
7600 }
7602 /* We could not check access to member functions when this
7603 expression was originally created since we did not know at that
7604 time to which function the expression referred. */
7606 {
7609 }
7613 else
7614 {
7615 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7616 will mark the function as addressed, but here we must do it
7617 explicitly. */
7621 }
7622 }
7624 /* This function will instantiate the type of the expression given in
7625 RHS to match the type of LHSTYPE. If errors exist, then return
7626 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7627 we complain on errors. If we are not complaining, never modify rhs,
7628 as overload resolution wants to try many possible instantiations, in
7629 the hope that at least one will work.
7631 For non-recursive calls, LHSTYPE should be a function, pointer to
7632 function, or a pointer to member function. */
7634 tree
7636 {
7643 {
7647 }
7650 {
7657 /* Microsoft allows `A::f' to be resolved to a
7658 pointer-to-member. */
7659 ;
7660 else
7661 {
7666 }
7667 }
7670 {
7673 }
7675 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7676 deduce any type information. */
7678 {
7682 }
7684 /* There only a few kinds of expressions that may have a type
7685 dependent on overload resolution. */
7691 /* This should really only be used when attempting to distinguish
7692 what sort of a pointer to function we have. For now, any
7693 arithmetic operation which is not supported on pointers
7694 is rejected as an error. */
7697 {
7699 {
7705 /* Do not lose object's side effects. */
7709 }
7716 /* This can happen if we are forming a pointer-to-member for a
7717 member template. */
7720 /* Fall through. */
7723 {
7727 return
7731 }
7735 return
7739 access_path);
7742 {
7747 }
7754 }
7756 }
7757 \f
7758 /* Return the name of the virtual function pointer field
7759 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7760 this may have to look back through base types to find the
7761 ultimate field name. (For single inheritance, these could
7762 all be the same name. Who knows for multiple inheritance). */
7764 static tree
7766 {
7773 {
7779 }
7787 }
7789 void
7791 {
7798 {
7803 }
7804 }
7806 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7807 according to [class]:
7808 The class-name is also inserted
7809 into the scope of the class itself. For purposes of access checking,
7810 the inserted class name is treated as if it were a public member name. */
7812 void
7814 {
7817 tree saved_cas;
7832 }
7834 /* Returns 1 if TYPE contains only padding bytes. */
7836 int
7838 {
7846 }
7848 /* Returns true if TYPE contains no actual data, just various
7849 possible combinations of empty classes and possibly a vptr. */
7851 bool
7853 {
7855 {
7856 tree field;
7857 tree binfo;
7858 tree base_binfo;
7861 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7862 out, but we'd like to be able to check this before then. */
7876 }
7880 }
7882 /* Note that NAME was looked up while the current class was being
7883 defined and that the result of that lookup was DECL. */
7885 void
7887 {
7888 splay_tree names_used;
7890 /* If we're not defining a class, there's nothing to do. */
7896 /* If there's already a binding for this NAME, then we don't have
7897 anything to worry about. */
7910 }
7912 /* Note that NAME was declared (as DECL) in the current class. Check
7913 to see that the declaration is valid. */
7915 void
7917 {
7918 splay_tree names_used;
7919 splay_tree_node n;
7921 /* Look to see if we ever used this name. */
7922 names_used
7926 /* The C language allows members to be declared with a type of the same
7927 name, and the C++ standard says this diagnostic is not required. So
7928 allow it in extern "C" blocks unless predantic is specified.
7929 Allow it in all cases if -ms-extensions is specified. */
7935 {
7936 /* [basic.scope.class]
7938 A name N used in a class S shall refer to the same declaration
7939 in its context and when re-evaluated in the completed scope of
7940 S. */
7944 }
7945 }
7947 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7948 Secondary vtables are merged with primary vtables; this function
7949 will return the VAR_DECL for the primary vtable. */
7951 tree
7953 {
7954 tree decl;
7958 {
7961 }
7965 }
7968 /* Returns the binfo for the primary base of BINFO. If the resulting
7969 BINFO is a virtual base, and it is inherited elsewhere in the
7970 hierarchy, then the returned binfo might not be the primary base of
7971 BINFO in the complete object. Check BINFO_PRIMARY_P or
7972 BINFO_LOST_PRIMARY_P to be sure. */
7974 static tree
7976 {
7977 tree primary_base;
7984 }
7986 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7988 static int
7990 {
7994 }
7996 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7997 INDENT should be zero when called from the top level; it is
7998 incremented recursively. IGO indicates the next expected BINFO in
7999 inheritance graph ordering. */
8001 static tree
8004 tree binfo,
8005 tree igo,
8007 {
8009 tree base_binfo;
8017 {
8020 }
8035 {
8039 TFF_PLAIN_IDENTIFIER),
8041 }
8043 {
8046 }
8051 {
8055 {
8059 TFF_PLAIN_IDENTIFIER));
8060 }
8062 {
8066 TFF_PLAIN_IDENTIFIER));
8067 }
8069 {
8073 TFF_PLAIN_IDENTIFIER));
8074 }
8076 {
8080 TFF_PLAIN_IDENTIFIER));
8081 }
8085 }
8091 }
8093 /* Dump the BINFO hierarchy for T. */
8095 static void
8097 {
8109 }
8111 /* Debug interface to hierarchy dumping. */
8113 void
8115 {
8117 }
8119 static void
8121 {
8126 {
8128 }
8129 }
8131 static void
8133 {
8134 tree value;
8136 HOST_WIDE_INT elt;
8144 TFF_PLAIN_IDENTIFIER));
8151 }
8153 static void
8155 {
8163 {
8170 {
8175 }
8179 }
8180 }
8182 static void
8184 {
8192 {
8197 }
8198 }
8200 /* Dump a function or thunk and its thunkees. */
8202 static void
8204 {
8207 tree thunks;
8215 {
8225 else
8231 }
8235 }
8237 /* Dump the thunks for FN. */
8239 void
8241 {
8243 }
8245 /* Virtual function table initialization. */
8247 /* Create all the necessary vtables for T and its base classes. */
8249 static void
8251 {
8252 tree vbase;
8256 /* We lay out the primary and secondary vtables in one contiguous
8257 vtable. The primary vtable is first, followed by the non-virtual
8258 secondary vtables in inheritance graph order. */
8262 /* Then come the virtual bases, also in inheritance graph order. */
8264 {
8268 }
8272 }
8274 /* Initialize the vtable for BINFO with the INITS. */
8276 static void
8278 {
8279 tree decl;
8285 }
8287 /* Build the VTT (virtual table table) for T.
8288 A class requires a VTT if it has virtual bases.
8290 This holds
8291 1 - primary virtual pointer for complete object T
8292 2 - secondary VTTs for each direct non-virtual base of T which requires a
8293 VTT
8294 3 - secondary virtual pointers for each direct or indirect base of T which
8295 has virtual bases or is reachable via a virtual path from T.
8296 4 - secondary VTTs for each direct or indirect virtual base of T.
8298 Secondary VTTs look like complete object VTTs without part 4. */
8300 static void
8302 {
8303 tree type;
8304 tree vtt;
8305 tree index;
8308 /* Build up the initializers for the VTT. */
8313 /* If we didn't need a VTT, we're done. */
8317 /* Figure out the type of the VTT. */
8321 /* Now, build the VTT object itself. */
8324 /* Add the VTT to the vtables list. */
8329 }
8331 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8332 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8333 and CHAIN the vtable pointer for this binfo after construction is
8334 complete. VALUE can also be another BINFO, in which case we recurse. */
8336 static tree
8338 {
8339 tree vt;
8342 {
8348 else
8350 }
8353 }
8355 /* Data for secondary VTT initialization. */
8357 {
8358 /* Is this the primary VTT? */
8361 /* Current index into the VTT. */
8362 tree index;
8364 /* Vector of initializers built up. */
8367 /* The type being constructed by this secondary VTT. */
8368 tree type_being_constructed;
8371 /* Recursively build the VTT-initializer for BINFO (which is in the
8372 hierarchy dominated by T). INITS points to the end of the initializer
8373 list to date. INDEX is the VTT index where the next element will be
8374 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8375 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8376 for virtual bases of T. When it is not so, we build the constructor
8377 vtables for the BINFO-in-T variant. */
8379 static void
8382 {
8384 tree b;
8385 tree init;
8386 secondary_vptr_vtt_init_data data;
8389 /* We only need VTTs for subobjects with virtual bases. */
8393 /* We need to use a construction vtable if this is not the primary
8394 VTT. */
8396 {
8399 /* Record the offset in the VTT where this sub-VTT can be found. */
8401 }
8403 /* Add the address of the primary vtable for the complete object. */
8407 {
8410 }
8413 /* Recursively add the secondary VTTs for non-virtual bases. */
8418 /* Add secondary virtual pointers for all subobjects of BINFO with
8419 either virtual bases or reachable along a virtual path, except
8420 subobjects that are non-virtual primary bases. */
8430 /* data.inits might have grown as we added secondary virtual pointers.
8431 Make sure our caller knows about the new vector. */
8435 /* Add the secondary VTTs for virtual bases in inheritance graph
8436 order. */
8438 {
8443 }
8444 else
8445 /* Remove the ctor vtables we created. */
8447 }
8449 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8450 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8452 static tree
8454 {
8457 /* We don't care about bases that don't have vtables. */
8461 /* We're only interested in proper subobjects of the type being
8462 constructed. */
8466 /* We're only interested in bases with virtual bases or reachable
8467 via a virtual path from the type being constructed. */
8472 /* We're not interested in non-virtual primary bases. */
8476 /* Record the index where this secondary vptr can be found. */
8478 {
8483 {
8484 /* It's a primary virtual base, and this is not a
8485 construction vtable. Find the base this is primary of in
8486 the inheritance graph, and use that base's vtable
8487 now. */
8490 }
8491 }
8493 /* Add the initializer for the secondary vptr itself. */
8496 /* Advance the vtt index. */
8501 }
8503 /* Called from build_vtt_inits via dfs_walk. After building
8504 constructor vtables and generating the sub-vtt from them, we need
8505 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8506 binfo of the base whose sub vtt was generated. */
8508 static tree
8510 {
8514 /* If this class has no vtable, none of its bases do. */
8518 /* This might be a primary base, so have no vtable in this
8519 hierarchy. */
8522 /* If we scribbled the construction vtable vptr into BINFO, clear it
8523 out now. */
8529 }
8531 /* Build the construction vtable group for BINFO which is in the
8532 hierarchy dominated by T. */
8534 static void
8536 {
8537 tree type;
8538 tree vtbl;
8539 tree id;
8540 tree vbase;
8543 /* See if we've already created this construction vtable group. */
8549 /* Build a version of VTBL (with the wrong type) for use in
8550 constructing the addresses of secondary vtables in the
8551 construction vtable group. */
8554 /* Don't export construction vtables from shared libraries. Even on
8555 targets that don't support hidden visibility, this tells
8556 can_refer_decl_in_current_unit_p not to assume that it's safe to
8557 access from a different compilation unit (bz 54314). */
8565 /* Add the vtables for each of our virtual bases using the vbase in T
8566 binfo. */
8568 vbase;
8570 {
8571 tree b;
8578 }
8580 /* Figure out the type of the construction vtable. */
8587 /* Initialize the construction vtable. */
8591 }
8593 /* Add the vtbl initializers for BINFO (and its bases other than
8594 non-virtual primaries) to the list of INITS. BINFO is in the
8595 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8596 the constructor the vtbl inits should be accumulated for. (If this
8597 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8598 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8599 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8600 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8601 but are not necessarily the same in terms of layout. */
8603 static void
8605 tree orig_binfo,
8606 tree rtti_binfo,
8607 tree vtbl,
8608 tree t,
8610 {
8612 tree base_binfo;
8617 /* If it doesn't have a vptr, we don't do anything. */
8621 /* If we're building a construction vtable, we're not interested in
8622 subobjects that don't require construction vtables. */
8628 /* Build the initializers for the BINFO-in-T vtable. */
8631 /* Walk the BINFO and its bases. We walk in preorder so that as we
8632 initialize each vtable we can figure out at what offset the
8633 secondary vtable lies from the primary vtable. We can't use
8634 dfs_walk here because we need to iterate through bases of BINFO
8635 and RTTI_BINFO simultaneously. */
8637 {
8638 /* Skip virtual bases. */
8644 inits);
8645 }
8646 }
8648 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8649 BINFO vtable to L. */
8651 static void
8653 tree orig_binfo,
8654 tree rtti_binfo,
8655 tree orig_vtbl,
8656 tree t,
8658 {
8665 {
8666 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8667 primary virtual base. If it is not the same primary in
8668 the hierarchy of T, we'll need to generate a ctor vtable
8669 for it, to place at its location in T. If it is the same
8670 primary, we still need a VTT entry for the vtable, but it
8671 should point to the ctor vtable for the base it is a
8672 primary for within the sub-hierarchy of RTTI_BINFO.
8674 There are three possible cases:
8676 1) We are in the same place.
8677 2) We are a primary base within a lost primary virtual base of
8678 RTTI_BINFO.
8679 3) We are primary to something not a base of RTTI_BINFO. */
8681 tree b;
8684 /* First, look through the bases we are primary to for RTTI_BINFO
8685 or a virtual base. */
8688 {
8693 }
8694 /* If we run out of primary links, keep looking down our
8695 inheritance chain; we might be an indirect primary. */
8699 found:
8701 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8702 base B and it is a base of RTTI_BINFO, this is case 2. In
8703 either case, we share our vtable with LAST, i.e. the
8704 derived-most base within B of which we are a primary. */
8707 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8708 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8709 binfo_ctor_vtable after everything's been set up. */
8712 /* Otherwise, this is case 3 and we get our own. */
8713 }
8720 {
8721 tree index;
8724 /* Add the initializer for this vtable. */
8728 /* Figure out the position to which the VPTR should point. */
8734 }
8737 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8738 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8739 straighten this out. */
8742 /* Throw away any unneeded intializers. */
8744 else
8745 /* For an ordinary vtable, set BINFO_VTABLE. */
8747 }
8751 /* Construct the initializer for BINFO's virtual function table. BINFO
8752 is part of the hierarchy dominated by T. If we're building a
8753 construction vtable, the ORIG_BINFO is the binfo we should use to
8754 find the actual function pointers to put in the vtable - but they
8755 can be overridden on the path to most-derived in the graph that
8756 ORIG_BINFO belongs. Otherwise,
8757 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8758 BINFO that should be indicated by the RTTI information in the
8759 vtable; it will be a base class of T, rather than T itself, if we
8760 are building a construction vtable.
8762 The value returned is a TREE_LIST suitable for wrapping in a
8763 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8764 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8765 number of non-function entries in the vtable.
8767 It might seem that this function should never be called with a
8768 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8769 base is always subsumed by a derived class vtable. However, when
8770 we are building construction vtables, we do build vtables for
8771 primary bases; we need these while the primary base is being
8772 constructed. */
8774 static void
8776 tree orig_binfo,
8777 tree t,
8778 tree rtti_binfo,
8781 {
8782 tree v;
8783 vtbl_init_data vid;
8785 tree vbinfo;
8789 /* Initialize VID. */
8797 /* The first vbase or vcall offset is at index -3 in the vtable. */
8800 /* Add entries to the vtable for RTTI. */
8803 /* Create an array for keeping track of the functions we've
8804 processed. When we see multiple functions with the same
8805 signature, we share the vcall offsets. */
8807 /* Add the vcall and vbase offset entries. */
8810 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8811 build_vbase_offset_vtbl_entries. */
8816 /* If the target requires padding between data entries, add that now. */
8818 {
8823 /* Move data entries into their new positions and add padding
8824 after the new positions. Iterate backwards so we don't
8825 overwrite entries that we would need to process later. */
8828 ix--)
8829 {
8837 {
8841 null_pointer_node);
8842 }
8843 }
8844 }
8849 /* The initializers for virtual functions were built up in reverse
8850 order. Straighten them out and add them to the running list in one
8851 step. */
8860 /* Go through all the ordinary virtual functions, building up
8861 initializers. */
8863 {
8864 tree delta;
8865 tree vcall_index;
8872 {
8876 {
8879 }
8881 }
8883 /* If the only definition of this function signature along our
8884 primary base chain is from a lost primary, this vtable slot will
8885 never be used, so just zero it out. This is important to avoid
8886 requiring extra thunks which cannot be generated with the function.
8888 We first check this in update_vtable_entry_for_fn, so we handle
8889 restored primary bases properly; we also need to do it here so we
8890 zero out unused slots in ctor vtables, rather than filling them
8891 with erroneous values (though harmless, apart from relocation
8892 costs). */
8897 {
8898 /* Pull the offset for `this', and the function to call, out of
8899 the list. */
8906 /* You can't call an abstract virtual function; it's abstract.
8907 So, we replace these functions with __pure_virtual. */
8909 {
8912 {
8914 abort_fndecl_addr
8918 }
8919 }
8920 /* Likewise for deleted virtuals. */
8922 {
8931 }
8932 else
8933 {
8935 {
8939 }
8940 /* Take the address of the function, considering it to be of an
8941 appropriate generic type. */
8945 /* Don't refer to a virtual destructor from a constructor
8946 vtable or a vtable for an abstract class, since destroying
8947 an object under construction is undefined behavior and we
8948 don't want it to be considered a candidate for speculative
8949 devirtualization. But do create the thunk for ABI
8950 compliance. */
8955 }
8956 }
8958 /* And add it to the chain of initializers. */
8960 {
8965 else
8967 {
8973 }
8974 }
8975 else
8977 }
8978 }
8980 /* Adds to vid->inits the initializers for the vbase and vcall
8981 offsets in BINFO, which is in the hierarchy dominated by T. */
8983 static void
8985 {
8986 tree b;
8988 /* If this is a derived class, we must first create entries
8989 corresponding to the primary base class. */
8994 /* Add the vbase entries for this base. */
8996 /* Add the vcall entries for this base. */
8998 }
9000 /* Returns the initializers for the vbase offset entries in the vtable
9001 for BINFO (which is part of the class hierarchy dominated by T), in
9002 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9003 where the next vbase offset will go. */
9005 static void
9007 {
9008 tree vbase;
9009 tree t;
9010 tree non_primary_binfo;
9012 /* If there are no virtual baseclasses, then there is nothing to
9013 do. */
9019 /* We might be a primary base class. Go up the inheritance hierarchy
9020 until we find the most derived class of which we are a primary base:
9021 it is the offset of that which we need to use. */
9024 {
9025 tree b;
9027 /* If we have reached a virtual base, then it must be a primary
9028 base (possibly multi-level) of vid->binfo, or we wouldn't
9029 have called build_vcall_and_vbase_vtbl_entries for it. But it
9030 might be a lost primary, so just skip down to vid->binfo. */
9032 {
9035 }
9041 }
9043 /* Go through the virtual bases, adding the offsets. */
9045 vbase;
9047 {
9048 tree b;
9049 tree delta;
9054 /* Find the instance of this virtual base in the complete
9055 object. */
9058 /* If we've already got an offset for this virtual base, we
9059 don't need another one. */
9064 /* Figure out where we can find this vbase offset. */
9073 /* The vbase offset had better be the same. */
9076 /* The next vbase will come at a more negative offset. */
9080 /* The initializer is the delta from BINFO to this virtual base.
9081 The vbase offsets go in reverse inheritance-graph order, and
9082 we are walking in inheritance graph order so these end up in
9083 the right order. */
9090 }
9091 }
9093 /* Adds the initializers for the vcall offset entries in the vtable
9094 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9095 to VID->INITS. */
9097 static void
9099 {
9100 /* We only need these entries if this base is a virtual base. We
9101 compute the indices -- but do not add to the vtable -- when
9102 building the main vtable for a class. */
9105 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9106 correspond to VID->DERIVED), we are building a primary
9107 construction virtual table. Since this is a primary
9108 virtual table, we do not need the vcall offsets for
9109 BINFO. */
9111 {
9112 /* We need a vcall offset for each of the virtual functions in this
9113 vtable. For example:
9115 class A { virtual void f (); };
9116 class B1 : virtual public A { virtual void f (); };
9117 class B2 : virtual public A { virtual void f (); };
9118 class C: public B1, public B2 { virtual void f (); };
9120 A C object has a primary base of B1, which has a primary base of A. A
9121 C also has a secondary base of B2, which no longer has a primary base
9122 of A. So the B2-in-C construction vtable needs a secondary vtable for
9123 A, which will adjust the A* to a B2* to call f. We have no way of
9124 knowing what (or even whether) this offset will be when we define B2,
9125 so we store this "vcall offset" in the A sub-vtable and look it up in
9126 a "virtual thunk" for B2::f.
9128 We need entries for all the functions in our primary vtable and
9129 in our non-virtual bases' secondary vtables. */
9131 /* If we are just computing the vcall indices -- but do not need
9132 the actual entries -- not that. */
9135 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9137 }
9138 }
9140 /* Build vcall offsets, starting with those for BINFO. */
9142 static void
9144 {
9146 tree primary_binfo;
9147 tree base_binfo;
9149 /* Don't walk into virtual bases -- except, of course, for the
9150 virtual base for which we are building vcall offsets. Any
9151 primary virtual base will have already had its offsets generated
9152 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9156 /* If BINFO has a primary base, process it first. */
9161 /* Add BINFO itself to the list. */
9164 /* Scan the non-primary bases of BINFO. */
9168 }
9170 /* Called from build_vcall_offset_vtbl_entries_r. */
9172 static void
9174 {
9175 /* Make entries for the rest of the virtuals. */
9176 tree orig_fn;
9178 /* The ABI requires that the methods be processed in declaration
9179 order. */
9181 orig_fn;
9185 }
9187 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9189 static void
9191 {
9193 tree vcall_offset;
9194 tree derived_entry;
9196 /* If there is already an entry for a function with the same
9197 signature as FN, then we do not need a second vcall offset.
9198 Check the list of functions already present in the derived
9199 class vtable. */
9201 {
9203 /* We only use one vcall offset for virtual destructors,
9204 even though there are two virtual table entries. */
9208 }
9210 /* If we are building these vcall offsets as part of building
9211 the vtable for the most derived class, remember the vcall
9212 offset. */
9214 {
9217 }
9219 /* The next vcall offset will be found at a more negative
9220 offset. */
9224 /* Keep track of this function. */
9228 {
9229 tree base;
9230 tree fn;
9232 /* Find the overriding function. */
9236 else
9237 {
9240 /* The vbase we're working on is a primary base of
9241 vid->binfo. But it might be a lost primary, so its
9242 BINFO_OFFSET might be wrong, so we just use the
9243 BINFO_OFFSET from vid->binfo. */
9249 vcall_offset);
9250 }
9251 /* Add the initializer to the vtable. */
9253 }
9254 }
9256 /* Return vtbl initializers for the RTTI entries corresponding to the
9257 BINFO's vtable. The RTTI entries should indicate the object given
9258 by VID->rtti_binfo. */
9260 static void
9262 {
9263 tree b;
9264 tree t;
9265 tree offset;
9266 tree decl;
9267 tree init;
9271 /* To find the complete object, we will first convert to our most
9272 primary base, and then add the offset in the vtbl to that value. */
9276 {
9277 tree primary_base;
9283 }
9287 /* The second entry is the address of the typeinfo object. */
9290 else
9293 /* Convert the declaration to a type that can be stored in the
9294 vtable. */
9298 /* Add the offset-to-top entry. It comes earlier in the vtable than
9299 the typeinfo entry. Convert the offset to look like a
9300 function pointer, so that we can put it in the vtable. */
9303 }
9305 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9306 accessibility. */
9308 bool
9310 {
9313 }
9315 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9317 bool
9319 {
9323 }
9325 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9326 class between them, if any. */
9328 tree
9330 {
9342 {
9345 }
9349 }