| blob | 07bbc69806cd4b13850055c6dd8e4f6cd1694018 |
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 /* Data structure for find_abi_tags_r, below. */
1357 struct abi_tag_data
1358 {
1362 };
1364 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1365 in the context of P. TAG can be either an identifier (the DECL_NAME of
1366 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1368 static void
1370 {
1371 tree id;
1375 else
1376 {
1379 }
1382 {
1387 {
1388 /* We're collecting tags from template arguments. */
1392 /* Don't inherit this tag multiple times. */
1394 }
1396 /* Otherwise we're diagnosing missing tags. */
1398 {
1403 }
1404 else
1405 {
1409 {
1413 }
1414 }
1415 }
1416 }
1418 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1419 types with abi tags, add the corresponding identifiers to the VEC in
1420 *DATA and set IDENTIFIER_MARKED. */
1422 static tree
1424 {
1428 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1429 anyway, but let's make sure of it. */
1441 {
1444 {
1447 }
1448 }
1450 }
1452 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1453 complete) template arguments. */
1455 static void
1457 {
1466 {
1469 {
1473 }
1474 }
1475 }
1477 /* Check that class T has all the abi tags that subobject SUBOB has, or
1478 warn if not. */
1480 static void
1482 {
1491 }
1493 void
1495 {
1505 {
1508 {
1512 }
1513 }
1515 // If we found some tags on our template arguments, add them to our
1516 // abi_tag attribute.
1518 {
1522 else
1526 }
1529 }
1531 /* Return true, iff class T has a non-virtual destructor that is
1532 accessible from outside the class heirarchy (i.e. is public, or
1533 there's a suitable friend. */
1535 static bool
1537 {
1540 /* An implicitly declared destructor is always public. And,
1541 if it were virtual, we would have created it by now. */
1556 }
1558 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1559 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1560 properties of the bases. */
1562 static void
1566 {
1570 tree base_binfo;
1571 tree binfo;
1581 {
1590 /* If any base class is non-literal, so is the derived class. */
1594 /* If the base class doesn't have copy constructors or
1595 assignment operators that take const references, then the
1596 derived class cannot have such a member automatically
1597 generated. */
1606 /* A virtual base does not effect nearly emptiness. */
1607 ;
1609 {
1611 /* And if there is more than one nearly empty base, then the
1612 derived class is not nearly empty either. */
1614 else
1615 /* Remember we've seen one. */
1617 }
1619 /* If the base class is not empty or nearly empty, then this
1620 class cannot be nearly empty. */
1623 /* A lot of properties from the bases also apply to the derived
1624 class. */
1641 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1644 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1648 /* A standard-layout class is a class that:
1649 ...
1650 * has no non-standard-layout base classes, */
1653 {
1654 tree basefield;
1655 /* ...has no base classes of the same type as the first non-static
1656 data member... */
1658 && (same_type_ignoring_top_level_qualifiers_p
1661 else
1662 /* ...either has no non-static data members in the most-derived
1663 class and at most one base class with non-static data
1664 members, or has no base classes with non-static data
1665 members */
1669 {
1672 else
1675 }
1676 }
1678 /* Don't bother collecting tm attributes if transactional memory
1679 support is not enabled. */
1681 {
1685 }
1688 }
1690 /* If one of the base classes had TM attributes, and the current class
1691 doesn't define its own, then the current class inherits one. */
1693 {
1696 }
1697 }
1699 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1700 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1701 that have had a nearly-empty virtual primary base stolen by some
1702 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1703 T. */
1705 static void
1707 {
1711 tree base_binfo;
1713 /* Determine the primary bases of our bases. */
1716 {
1719 /* See if we're the non-virtual primary of our inheritance
1720 chain. */
1722 {
1729 /* We are the primary binfo. */
1731 }
1732 /* Determine if we have a virtual primary base, and mark it so.
1733 */
1735 {
1739 /* Someone already claimed this base. */
1741 else
1742 {
1743 tree delta;
1748 /* A virtual binfo might have been copied from within
1749 another hierarchy. As we're about to use it as a
1750 primary base, make sure the offsets match. */
1758 }
1759 }
1760 }
1762 /* First look for a dynamic direct non-virtual base. */
1764 {
1768 {
1771 }
1772 }
1774 /* A "nearly-empty" virtual base class can be the primary base
1775 class, if no non-virtual polymorphic base can be found. Look for
1776 a nearly-empty virtual dynamic base that is not already a primary
1777 base of something in the hierarchy. If there is no such base,
1778 just pick the first nearly-empty virtual base. */
1784 {
1786 {
1787 /* Found one that is not primary. */
1790 }
1792 /* Remember the first candidate. */
1794 }
1796 found:
1797 /* If we've got a primary base, use it. */
1799 {
1804 /* We are stealing a primary base. */
1808 {
1809 tree delta;
1812 /* A virtual binfo might have been copied from within
1813 another hierarchy. As we're about to use it as a primary
1814 base, make sure the offsets match. */
1819 }
1826 }
1827 }
1829 /* Update the variant types of T. */
1831 void
1833 {
1834 tree variants;
1840 variants;
1842 {
1843 /* These fields are in the _TYPE part of the node, not in
1844 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1854 /* Copy whatever these are holding today. */
1858 }
1859 }
1861 /* Early variant fixups: we apply attributes at the beginning of the class
1862 definition, and we need to fix up any variants that have already been
1863 made via elaborated-type-specifier so that check_qualified_type works. */
1865 void
1867 {
1868 tree variants;
1874 variants;
1876 {
1877 /* These are the two fields that check_qualified_type looks at and
1878 are affected by attributes. */
1881 }
1882 }
1883 \f
1884 /* Set memoizing fields and bits of T (and its variants) for later
1885 use. */
1887 static void
1889 {
1890 /* Fix up variants (if any). */
1894 /* For a class w/o baseclasses, 'finish_struct' has set
1895 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1896 Similarly for a class whose base classes do not have vtables.
1897 When neither of these is true, we might have removed abstract
1898 virtuals (by providing a definition), added some (by declaring
1899 new ones), or redeclared ones from a base class. We need to
1900 recalculate what's really an abstract virtual at this point (by
1901 looking in the vtables). */
1904 /* If this type has a copy constructor or a destructor, force its
1905 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1906 nonzero. This will cause it to be passed by invisible reference
1907 and prevent it from being returned in a register. */
1910 {
1911 tree variants;
1914 {
1917 }
1918 }
1919 }
1921 /* Issue warnings about T having private constructors, but no friends,
1922 and so forth.
1924 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1925 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1926 non-private static member functions. */
1928 static void
1930 {
1933 tree fn;
1936 /* If the class has friends, those entities might create and
1937 access instances, so we should not warn. */
1940 /* We will have warned when the template was declared; there's
1941 no need to warn on every instantiation. */
1943 /* There's no reason to even consider warning about this
1944 class. */
1947 /* We only issue one warning, if more than one applies, because
1948 otherwise, on code like:
1950 class A {
1951 // Oops - forgot `public:'
1952 A();
1953 A(const A&);
1954 ~A();
1955 };
1957 we warn several times about essentially the same problem. */
1959 /* Check to see if all (non-constructor, non-destructor) member
1960 functions are private. (Since there are no friends or
1961 non-private statics, we can't ever call any of the private member
1962 functions.) */
1964 /* We're not interested in compiler-generated methods; they don't
1965 provide any way to call private members. */
1967 {
1969 {
1971 /* A non-private static member function is just like a
1972 friend; it can create and invoke private member
1973 functions, and be accessed without a class
1974 instance. */
1978 /* Keep searching for a static member function. */
1979 }
1982 }
1985 {
1986 /* There are no non-private methods, and there's at least one
1987 private member function that isn't a constructor or
1988 destructor. (If all the private members are
1989 constructors/destructors we want to use the code below that
1990 issues error messages specifically referring to
1991 constructors/destructors.) */
1997 {
2000 }
2002 {
2006 }
2007 }
2009 /* Even if some of the member functions are non-private, the class
2010 won't be useful for much if all the constructors or destructors
2011 are private: such an object can never be created or destroyed. */
2014 {
2017 t);
2019 }
2021 /* Warn about classes that have private constructors and no friends. */
2023 /* Implicitly generated constructors are always public. */
2026 {
2029 /* If a non-template class does not define a copy
2030 constructor, one is defined for it, enabling it to avoid
2031 this warning. For a template class, this does not
2032 happen, and so we would normally get a warning on:
2034 template <class T> class C { private: C(); };
2036 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2037 complete non-template or fully instantiated classes have this
2038 flag set. */
2041 else
2043 {
2045 /* Ideally, we wouldn't count copy constructors (or, in
2046 fact, any constructor that takes an argument of the
2047 class type as a parameter) because such things cannot
2048 be used to construct an instance of the class unless
2049 you already have one. But, for now at least, we're
2050 more generous. */
2052 {
2055 }
2056 }
2059 {
2062 t);
2064 }
2065 }
2066 }
2069 gt_pointer_operator new_value;
2073 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2075 static int
2077 {
2090 }
2092 /* This routine compares two fields like method_name_cmp but using the
2093 pointer operator in resort_field_decl_data. */
2095 static int
2097 {
2106 {
2113 }
2115 }
2117 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2119 void
2122 gt_pointer_operator new_value,
2124 {
2128 tree fn;
2130 /* The type conversion ops have to live at the front of the vec, so we
2131 can't sort them. */
2139 {
2143 resort_method_name_cmp);
2144 }
2145 }
2147 /* Warn about duplicate methods in fn_fields.
2149 Sort methods that are not special (i.e., constructors, destructors,
2150 and type conversion operators) so that we can find them faster in
2151 search. */
2153 static void
2155 {
2156 tree fn_fields;
2166 /* Clear DECL_IN_AGGR_P for all functions. */
2171 /* Issue warnings about private constructors and such. If there are
2172 no methods, then some public defaults are generated. */
2175 /* The type conversion ops have to live at the front of the vec, so we
2176 can't sort them. */
2185 }
2187 /* Make BINFO's vtable have N entries, including RTTI entries,
2188 vbase and vcall offsets, etc. Set its type and call the back end
2189 to lay it out. */
2191 static void
2193 {
2194 tree atype;
2195 tree vtable;
2200 /* We may have to grow the vtable. */
2203 {
2207 }
2208 }
2210 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2211 have the same signature. */
2213 int
2215 {
2216 /* One destructor overrides another if they are the same kind of
2217 destructor. */
2221 /* But a non-destructor never overrides a destructor, nor vice
2222 versa, nor do different kinds of destructors override
2223 one-another. For example, a complete object destructor does not
2224 override a deleting destructor. */
2233 {
2241 }
2243 }
2245 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2246 subobject. */
2248 static bool
2250 {
2251 tree probe;
2254 {
2258 /* If we meet a virtual base, we can't follow the inheritance
2259 any more. See if the complete type of DERIVED contains
2260 such a virtual base. */
2263 }
2265 }
2268 /* The function for which we are trying to find a final overrider. */
2269 tree fn;
2270 /* The base class in which the function was declared. */
2271 tree declaring_base;
2272 /* The candidate overriders. */
2273 tree candidates;
2274 /* Path to most derived. */
2278 /* Add the overrider along the current path to FFOD->CANDIDATES.
2279 Returns true if an overrider was found; false otherwise. */
2281 static bool
2285 {
2286 tree method;
2288 /* If BINFO is not the most derived type, try a more derived class.
2289 A definition there will overrider a definition here. */
2291 {
2292 depth--;
2296 }
2300 {
2303 /* Remove any candidates overridden by this new function. */
2305 {
2306 /* If *CANDIDATE overrides METHOD, then METHOD
2307 cannot override anything else on the list. */
2310 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2313 else
2315 }
2317 /* Add the new function. */
2320 }
2323 }
2325 /* Called from find_final_overrider via dfs_walk. */
2327 static tree
2329 {
2337 }
2339 static tree
2341 {
2346 }
2348 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2349 FN and whose TREE_VALUE is the binfo for the base where the
2350 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2351 DERIVED) is the base object in which FN is declared. */
2353 static tree
2355 {
2356 find_final_overrider_data ffod;
2358 /* Getting this right is a little tricky. This is valid:
2360 struct S { virtual void f (); };
2361 struct T { virtual void f (); };
2362 struct U : public S, public T { };
2364 even though calling `f' in `U' is ambiguous. But,
2366 struct R { virtual void f(); };
2367 struct S : virtual public R { virtual void f (); };
2368 struct T : virtual public R { virtual void f (); };
2369 struct U : public S, public T { };
2371 is not -- there's no way to decide whether to put `S::f' or
2372 `T::f' in the vtable for `R'.
2374 The solution is to look at all paths to BINFO. If we find
2375 different overriders along any two, then there is a problem. */
2379 /* Determine the depth of the hierarchy. */
2390 /* If there was no winner, issue an error message. */
2395 }
2397 /* Return the index of the vcall offset for FN when TYPE is used as a
2398 virtual base. */
2400 static tree
2402 {
2404 tree_pair_p p;
2412 /* There should always be an appropriate index. */
2414 }
2416 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2417 dominated by T. FN is the old function; VIRTUALS points to the
2418 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2419 of that entry in the list. */
2421 static void
2424 {
2425 tree b;
2426 tree overrider;
2427 tree delta;
2428 tree virtual_base;
2429 tree first_defn;
2435 /* Find the nearest primary base (possibly binfo itself) which defines
2436 this function; this is the class the caller will convert to when
2437 calling FN through BINFO. */
2439 {
2444 /* The nearest definition is from a lost primary. */
2447 }
2450 /* Find the final overrider. */
2453 {
2456 }
2459 /* Check for adjusting covariant return types. */
2467 /* If the overrider is invalid, don't even try. */
2469 {
2470 /* If FN is a covariant thunk, we must figure out the adjustment
2471 to the final base FN was converting to. As OVERRIDER_TARGET might
2472 also be converting to the return type of FN, we have to
2473 combine the two conversions here. */
2480 {
2484 }
2485 else
2489 /* Find the equivalent binfo within the return type of the
2490 overriding function. We will want the vbase offset from
2491 there. */
2493 over_return);
2496 {
2497 /* There was no existing virtual thunk (which takes
2498 precedence). So find the binfo of the base function's
2499 return type within the overriding function's return type.
2500 We cannot call lookup base here, because we're inside a
2501 dfs_walk, and will therefore clobber the BINFO_MARKED
2502 flags. Fortunately we know the covariancy is valid (it
2503 has already been checked), so we can just iterate along
2504 the binfos, which have been chained in inheritance graph
2505 order. Of course it is lame that we have to repeat the
2506 search here anyway -- we should really be caching pieces
2507 of the vtable and avoiding this repeated work. */
2510 /* Find the base binfo within the overriding function's
2511 return type. We will always find a thunk_binfo, except
2512 when the covariancy is invalid (which we will have
2513 already diagnosed). */
2516 thunk_binfo;
2522 /* See if virtual inheritance is involved. */
2524 virtual_offset;
2531 {
2535 {
2536 /* We convert via virtual base. Adjust the fixed
2537 offset to be from there. */
2538 offset =
2542 }
2544 /* There was an existing fixed offset, this must be
2545 from the base just converted to, and the base the
2546 FN was thunking to. */
2548 else
2550 }
2551 }
2554 /* Replace the overriding function with a covariant thunk. We
2555 will emit the overriding function in its own slot as
2556 well. */
2559 }
2560 else
2564 /* If we need a covariant thunk, then we may need to adjust first_defn.
2565 The ABI specifies that the thunks emitted with a function are
2566 determined by which bases the function overrides, so we need to be
2567 sure that we're using a thunk for some overridden base; even if we
2568 know that the necessary this adjustment is zero, there may not be an
2569 appropriate zero-this-adjusment thunk for us to use since thunks for
2570 overriding virtual bases always use the vcall offset.
2572 Furthermore, just choosing any base that overrides this function isn't
2573 quite right, as this slot won't be used for calls through a type that
2574 puts a covariant thunk here. Calling the function through such a type
2575 will use a different slot, and that slot is the one that determines
2576 the thunk emitted for that base.
2578 So, keep looking until we find the base that we're really overriding
2579 in this slot: the nearest primary base that doesn't use a covariant
2580 thunk in this slot. */
2582 {
2584 /* We already know that the overrider needs a covariant thunk. */
2587 {
2594 }
2596 }
2598 /* Assume that we will produce a thunk that convert all the way to
2599 the final overrider, and not to an intermediate virtual base. */
2602 /* See if we can convert to an intermediate virtual base first, and then
2603 use the vcall offset located there to finish the conversion. */
2605 {
2606 /* If we find the final overrider, then we can stop
2607 walking. */
2612 /* If we find a virtual base, and we haven't yet found the
2613 overrider, then there is a virtual base between the
2614 declaring base (first_defn) and the final overrider. */
2616 {
2619 }
2620 }
2622 /* Compute the constant adjustment to the `this' pointer. The
2623 `this' pointer, when this function is called, will point at BINFO
2624 (or one of its primary bases, which are at the same offset). */
2626 /* The `this' pointer needs to be adjusted from the declaration to
2627 the nearest virtual base. */
2632 /* If the nearest definition is in a lost primary, we don't need an
2633 entry in our vtable. Except possibly in a constructor vtable,
2634 if we happen to get our primary back. In that case, the offset
2635 will be zero, as it will be a primary base. */
2637 else
2638 /* The `this' pointer needs to be adjusted from pointing to
2639 BINFO to pointing at the base where the final overrider
2640 appears. */
2651 else
2655 }
2657 /* Called from modify_all_vtables via dfs_walk. */
2659 static tree
2661 {
2663 tree virtuals;
2664 tree old_virtuals;
2668 /* A base without a vtable needs no modification, and its bases
2669 are uninteresting. */
2674 /* Don't do the primary vtable, if it's new. */
2678 /* There's no need to modify the vtable for a non-virtual primary
2679 base; we're not going to use that vtable anyhow. We do still
2680 need to do this for virtual primary bases, as they could become
2681 non-primary in a construction vtable. */
2686 /* Now, go through each of the virtual functions in the virtual
2687 function table for BINFO. Find the final overrider, and update
2688 the BINFO_VIRTUALS list appropriately. */
2691 virtuals;
2695 binfo,
2700 }
2702 /* Update all of the primary and secondary vtables for T. Create new
2703 vtables as required, and initialize their RTTI information. Each
2704 of the functions in VIRTUALS is declared in T and may override a
2705 virtual function from a base class; find and modify the appropriate
2706 entries to point to the overriding functions. Returns a list, in
2707 declaration order, of the virtual functions that are declared in T,
2708 but do not appear in the primary base class vtable, and which
2709 should therefore be appended to the end of the vtable for T. */
2711 static tree
2713 {
2717 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2721 /* Update all of the vtables. */
2724 /* Add virtual functions not already in our primary vtable. These
2725 will be both those introduced by this class, and those overridden
2726 from secondary bases. It does not include virtuals merely
2727 inherited from secondary bases. */
2729 {
2734 {
2735 /* We don't need to adjust the `this' pointer when
2736 calling this function. */
2740 /* This is a function not already in our vtable. Keep it. */
2742 }
2743 else
2744 /* We've already got an entry for this function. Skip it. */
2746 }
2749 }
2751 /* Get the base virtual function declarations in T that have the
2752 indicated NAME. */
2754 static tree
2756 {
2757 tree methods;
2762 /* Find virtual functions in T with the indicated NAME. */
2766 methods;
2768 {
2774 }
2780 {
2783 base_fndecls);
2784 }
2787 }
2789 /* If this declaration supersedes the declaration of
2790 a method declared virtual in the base class, then
2791 mark this field as being virtual as well. */
2793 void
2795 {
2798 /* In [temp.mem] we have:
2800 A specialization of a member function template does not
2801 override a virtual function from a base class. */
2808 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2809 the error_mark_node so that we know it is an overriding
2810 function. */
2811 {
2814 }
2817 {
2823 }
2828 }
2830 /* Warn about hidden virtual functions that are not overridden in t.
2831 We know that constructors and destructors don't apply. */
2833 static void
2835 {
2837 tree fns;
2840 /* We go through each separately named virtual function. */
2844 {
2845 tree fn;
2846 tree name;
2847 tree fndecl;
2848 tree base_fndecls;
2849 tree base_binfo;
2850 tree binfo;
2853 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2854 have the same name. Figure out what name that is. */
2856 /* There are no possibly hidden functions yet. */
2858 /* Iterate through all of the base classes looking for possibly
2859 hidden functions. */
2862 {
2865 base_fndecls);
2866 }
2868 /* If there are no functions to hide, continue. */
2872 /* Remove any overridden functions. */
2874 {
2878 {
2882 /* If the method from the base class has the same
2883 signature as the method from the derived class, it
2884 has been overridden. */
2887 else
2889 }
2890 }
2892 /* Now give a warning for all base functions without overriders,
2893 as they are hidden. */
2895 {
2896 /* Here we know it is a hider, and no overrider exists. */
2900 }
2901 }
2902 }
2904 /* Recursive helper for finish_struct_anon. */
2906 static void
2908 {
2912 {
2913 /* We're generally only interested in entities the user
2914 declared, but we also find nested classes by noticing
2915 the TYPE_DECL that we create implicitly. You're
2916 allowed to put one anonymous union inside another,
2917 though, so we explicitly tolerate that. We use
2918 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2919 we also allow unnamed types used for defining fields. */
2926 {
2927 /* We already complained about static data members in
2928 finish_static_data_member_decl. */
2930 {
2933 "%q+#D invalid; an anonymous union can "
2935 else
2937 "%q+#D invalid; an anonymous struct can "
2939 }
2941 }
2944 {
2946 {
2950 else
2953 }
2955 {
2959 else
2962 }
2963 }
2968 /* Recurse into the anonymous aggregates to handle correctly
2969 access control (c++/24926):
2971 class A {
2972 union {
2973 union {
2974 int i;
2975 };
2976 };
2977 };
2979 int j=A().i; */
2983 }
2984 }
2986 /* Check for things that are invalid. There are probably plenty of other
2987 things we should check for also. */
2989 static void
2991 {
2993 {
3002 }
3003 }
3005 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3006 will be used later during class template instantiation.
3007 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3008 a non-static member data (FIELD_DECL), a member function
3009 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3010 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3011 When FRIEND_P is nonzero, T is either a friend class
3012 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3013 (FUNCTION_DECL, TEMPLATE_DECL). */
3015 void
3017 {
3018 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3023 }
3025 /* This function is called from declare_virt_assop_and_dtor via
3026 dfs_walk_all.
3028 DATA is a type that direcly or indirectly inherits the base
3029 represented by BINFO. If BINFO contains a virtual assignment [copy
3030 assignment or move assigment] operator or a virtual constructor,
3031 declare that function in DATA if it hasn't been already declared. */
3033 static tree
3035 {
3043 /* A base without a vtable needs no modification, and its bases
3044 are uninteresting. */
3048 /* If this is a primary base, then we have already looked at the
3049 virtual functions of its vtable. */
3053 {
3057 {
3062 }
3066 }
3069 }
3071 /* If the class type T has a direct or indirect base that contains a
3072 virtual assignment operator or a virtual destructor, declare that
3073 function in T if it hasn't been already declared. */
3075 static void
3077 {
3085 dfs_declare_virt_assop_and_dtor,
3087 }
3089 /* Declare the inheriting constructor for class T inherited from base
3090 constructor CTOR with the parameter array PARMS of size NPARMS. */
3092 static void
3094 {
3095 /* We don't declare an inheriting ctor that would be a default,
3096 copy or move ctor for derived or base. */
3101 {
3105 }
3113 {
3116 }
3117 }
3119 /* Declare all the inheriting constructors for class T inherited from base
3120 constructor CTOR. */
3122 static void
3124 {
3130 {
3134 }
3137 {
3141 }
3142 }
3144 /* Create default constructors, assignment operators, and so forth for
3145 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3146 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3147 the class cannot have a default constructor, copy constructor
3148 taking a const reference argument, or an assignment operator taking
3149 a const reference, respectively. */
3151 static void
3155 {
3163 /* Destructor. */
3165 {
3166 /* In general, we create destructors lazily. */
3171 /* But if this is a Java class, any non-trivial destructor is
3172 invalid, even if compiler-generated. Therefore, if the
3173 destructor is non-trivial we create it now. */
3175 }
3177 /* [class.ctor]
3179 If there is no user-declared constructor for a class, a default
3180 constructor is implicitly declared. */
3182 {
3187 /* This might force the declaration. */
3189 }
3191 /* [class.ctor]
3193 If a class definition does not explicitly declare a copy
3194 constructor, one is declared implicitly. */
3196 {
3202 }
3204 /* If there is no assignment operator, one will be created if and
3205 when it is needed. For now, just record whether or not the type
3206 of the parameter to the assignment operator will be a const or
3207 non-const reference. */
3209 {
3215 }
3217 /* We can't be lazy about declaring functions that might override
3218 a virtual function from a base class. */
3222 {
3226 {
3227 /* declare, then remove the decl */
3236 }
3237 else
3239 }
3240 }
3242 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3243 count the number of fields in TYPE, including anonymous union
3244 members. */
3246 static int
3248 {
3249 tree x;
3252 {
3255 else
3257 }
3259 }
3261 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3262 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3263 elts, starting at offset IDX. */
3265 static int
3267 {
3268 tree x;
3270 {
3273 else
3275 }
3277 }
3279 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3280 starting at offset IDX. */
3282 static int
3286 {
3287 tree values;
3291 }
3293 /* FIELD is a bit-field. We are finishing the processing for its
3294 enclosing type. Issue any appropriate messages and set appropriate
3295 flags. Returns false if an error has been diagnosed. */
3297 static bool
3299 {
3301 tree w;
3303 /* Extract the declared width of the bitfield, which has been
3304 temporarily stashed in DECL_INITIAL. */
3307 /* Remove the bit-field width indicator so that the rest of the
3308 compiler does not treat that value as an initializer. */
3311 /* Detect invalid bit-field type. */
3313 {
3316 }
3317 else
3318 {
3320 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3323 /* detect invalid field size. */
3329 {
3332 }
3334 {
3337 }
3339 {
3342 }
3354 }
3357 {
3361 }
3362 else
3363 {
3364 /* Non-bit-fields are aligned for their type. */
3368 }
3369 }
3371 /* FIELD is a non bit-field. We are finishing the processing for its
3372 enclosing type T. Issue any appropriate messages and set appropriate
3373 flags. */
3375 static void
3377 tree t,
3381 {
3384 /* In C++98 an anonymous union cannot contain any fields which would change
3385 the settings of CANT_HAVE_CONST_CTOR and friends. */
3387 ;
3388 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3389 structs. So, we recurse through their fields here. */
3391 {
3392 tree fields;
3398 }
3399 /* Check members with class type for constructors, destructors,
3400 etc. */
3402 {
3403 /* Never let anything with uninheritable virtuals
3404 make it through without complaint. */
3408 {
3413 field);
3418 field);
3420 {
3424 }
3425 }
3426 else
3427 {
3440 }
3449 }
3454 {
3455 /* `build_class_init_list' does not recognize
3456 non-FIELD_DECLs. */
3460 }
3461 }
3463 /* Check the data members (both static and non-static), class-scoped
3464 typedefs, etc., appearing in the declaration of T. Issue
3465 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3466 declaration order) of access declarations; each TREE_VALUE in this
3467 list is a USING_DECL.
3469 In addition, set the following flags:
3471 EMPTY_P
3472 The class is empty, i.e., contains no non-static data members.
3474 CANT_HAVE_CONST_CTOR_P
3475 This class cannot have an implicitly generated copy constructor
3476 taking a const reference.
3478 CANT_HAVE_CONST_ASN_REF
3479 This class cannot have an implicitly generated assignment
3480 operator taking a const reference.
3482 All of these flags should be initialized before calling this
3483 function.
3485 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3486 fields can be added by adding to this chain. */
3488 static void
3492 {
3500 /* Assume there are no access declarations. */
3502 /* Assume this class has no pointer members. */
3504 /* Assume none of the members of this class have default
3505 initializations. */
3509 {
3517 {
3518 /* Save the access declarations for our caller. */
3521 }
3527 /* If we've gotten this far, it's a data member, possibly static,
3528 or an enumerator. */
3532 /* When this goes into scope, it will be a non-local reference. */
3537 {
3538 /* [class.union] (C++98)
3540 If a union contains a static data member, or a member of
3541 reference type, the program is ill-formed.
3543 In C++11 this limitation doesn't exist anymore. */
3545 {
3549 }
3551 {
3555 }
3556 }
3558 /* Perform error checking that did not get done in
3559 grokdeclarator. */
3561 {
3565 }
3567 {
3571 }
3579 /* Now it can only be a FIELD_DECL. */
3584 /* If at least one non-static data member is non-literal, the whole
3585 class becomes non-literal. Per Core/1453, volatile non-static
3586 data members and base classes are also not allowed.
3587 Note: if the type is incomplete we will complain later on. */
3592 /* A standard-layout class is a class that:
3593 ...
3594 has the same access control (Clause 11) for all non-static data members,
3595 ... */
3602 /* If this is of reference type, check if it needs an init. */
3604 {
3610 /* ARM $12.6.2: [A member initializer list] (or, for an
3611 aggregate, initialization by a brace-enclosed list) is the
3612 only way to initialize nonstatic const and reference
3613 members. */
3616 }
3621 {
3623 {
3624 warning
3627 x);
3629 }
3633 }
3636 /* We don't treat zero-width bitfields as making a class
3637 non-empty. */
3638 ;
3639 else
3640 {
3641 /* The class is non-empty. */
3643 /* The class is not even nearly empty. */
3645 /* If one of the data members contains an empty class,
3646 so does T. */
3650 }
3652 /* This is used by -Weffc++ (see below). Warn only for pointers
3653 to members which might hold dynamic memory. So do not warn
3654 for pointers to functions or pointers to members. */
3660 {
3665 }
3671 {
3673 {
3677 }
3679 {
3683 }
3684 }
3687 /* DR 148 now allows pointers to members (which are POD themselves),
3688 to be allowed in POD structs. */
3697 /* We set DECL_C_BIT_FIELD in grokbitfield.
3698 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3701 cant_have_const_ctor_p,
3702 no_const_asn_ref_p,
3705 /* Now that we've removed bit-field widths from DECL_INITIAL,
3706 anything left in DECL_INITIAL is an NSDMI that makes the class
3707 non-aggregate in C++11. */
3711 /* If any field is const, the structure type is pseudo-const. */
3713 {
3718 /* ARM $12.6.2: [A member initializer list] (or, for an
3719 aggregate, initialization by a brace-enclosed list) is the
3720 only way to initialize nonstatic const and reference
3721 members. */
3724 }
3725 /* A field that is pseudo-const makes the structure likewise. */
3727 {
3732 }
3734 /* Core issue 80: A nonstatic data member is required to have a
3735 different name from the class iff the class has a
3736 user-declared constructor. */
3740 }
3742 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3743 it should also define a copy constructor and an assignment operator to
3744 implement the correct copy semantic (deep vs shallow, etc.). As it is
3745 not feasible to check whether the constructors do allocate dynamic memory
3746 and store it within members, we approximate the warning like this:
3748 -- Warn only if there are members which are pointers
3749 -- Warn only if there is a non-trivial constructor (otherwise,
3750 there cannot be memory allocated).
3751 -- Warn only if there is a non-trivial destructor. We assume that the
3752 user at least implemented the cleanup correctly, and a destructor
3753 is needed to free dynamic memory.
3755 This seems enough for practical purposes. */
3757 && has_pointers
3761 {
3765 {
3770 }
3774 }
3776 /* Non-static data member initializers make the default constructor
3777 non-trivial. */
3779 {
3782 }
3784 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3788 /* Check anonymous struct/anonymous union fields. */
3791 /* We've built up the list of access declarations in reverse order.
3792 Fix that now. */
3794 }
3796 /* If TYPE is an empty class type, records its OFFSET in the table of
3797 OFFSETS. */
3799 static int
3801 {
3802 splay_tree_node n;
3807 /* Record the location of this empty object in OFFSETS. */
3815 type,
3819 }
3821 /* Returns nonzero if TYPE is an empty class type and there is
3822 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3824 static int
3826 {
3827 splay_tree_node n;
3828 tree t;
3833 /* Record the location of this empty object in OFFSETS. */
3843 }
3845 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3846 F for every subobject, passing it the type, offset, and table of
3847 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3848 be traversed.
3850 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3851 than MAX_OFFSET will not be walked.
3853 If F returns a nonzero value, the traversal ceases, and that value
3854 is returned. Otherwise, returns zero. */
3856 static int
3858 subobject_offset_fn f,
3859 tree offset,
3860 splay_tree offsets,
3861 tree max_offset,
3863 {
3867 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3868 stop. */
3876 {
3879 }
3882 {
3883 tree field;
3884 tree binfo;
3887 /* Avoid recursing into objects that are not interesting. */
3891 /* Record the location of TYPE. */
3896 /* Iterate through the direct base classes of TYPE. */
3900 {
3901 tree binfo_offset;
3906 tree orig_binfo;
3907 /* We cannot rely on BINFO_OFFSET being set for the base
3908 class yet, but the offsets for direct non-virtual
3909 bases can be calculated by going back to the TYPE. */
3912 offset,
3916 f,
3917 binfo_offset,
3918 offsets,
3919 max_offset,
3923 }
3926 {
3930 /* Iterate through the virtual base classes of TYPE. In G++
3931 3.2, we included virtual bases in the direct base class
3932 loop above, which results in incorrect results; the
3933 correct offsets for virtual bases are only known when
3934 working with the most derived type. */
3938 {
3940 f,
3942 offset,
3944 offsets,
3945 max_offset,
3949 }
3950 else
3951 {
3952 /* We still have to walk the primary base, if it is
3953 virtual. (If it is non-virtual, then it was walked
3954 above.) */
3960 {
3961 r = (walk_subobject_offsets
3966 }
3967 }
3968 }
3970 /* Iterate through the fields of TYPE. */
3975 {
3976 tree field_offset;
3981 f,
3983 offset,
3984 field_offset),
3985 offsets,
3986 max_offset,
3990 }
3991 }
3993 {
3996 tree index;
3998 /* Avoid recursing into objects that are not interesting. */
4003 /* Step through each of the elements in the array. */
4007 {
4009 f,
4010 offset,
4011 offsets,
4012 max_offset,
4018 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4019 there's no point in iterating through the remaining
4020 elements of the array. */
4023 }
4024 }
4027 }
4029 /* Record all of the empty subobjects of TYPE (either a type or a
4030 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4031 is being placed at OFFSET; otherwise, it is a base class that is
4032 being placed at OFFSET. */
4034 static void
4036 tree offset,
4037 splay_tree offsets,
4039 {
4040 tree max_offset;
4041 /* If recording subobjects for a non-static data member or a
4042 non-empty base class , we do not need to record offsets beyond
4043 the size of the biggest empty class. Additional data members
4044 will go at the end of the class. Additional base classes will go
4045 either at offset zero (if empty, in which case they cannot
4046 overlap with offsets past the size of the biggest empty class) or
4047 at the end of the class.
4049 However, if we are placing an empty base class, then we must record
4050 all offsets, as either the empty class is at offset zero (where
4051 other empty classes might later be placed) or at the end of the
4052 class (where other objects might then be placed, so other empty
4053 subobjects might later overlap). */
4057 else
4061 }
4063 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4064 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4065 virtual bases of TYPE are examined. */
4067 static int
4069 tree offset,
4070 splay_tree offsets,
4072 {
4073 splay_tree_node max_node;
4075 /* Get the node in OFFSETS that indicates the maximum offset where
4076 an empty subobject is located. */
4078 /* If there aren't any empty subobjects, then there's no point in
4079 performing this check. */
4085 vbases_p);
4086 }
4088 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4089 non-static data member of the type indicated by RLI. BINFO is the
4090 binfo corresponding to the base subobject, OFFSETS maps offsets to
4091 types already located at those offsets. This function determines
4092 the position of the DECL. */
4094 static void
4096 tree decl,
4097 tree binfo,
4098 splay_tree offsets)
4099 {
4102 tree type;
4105 {
4106 /* For the purposes of determining layout conflicts, we want to
4107 use the class type of BINFO; TREE_TYPE (DECL) will be the
4108 CLASSTYPE_AS_BASE version, which does not contain entries for
4109 zero-sized bases. */
4112 }
4113 else
4114 {
4117 }
4119 /* Try to place the field. It may take more than one try if we have
4120 a hard time placing the field without putting two objects of the
4121 same type at the same address. */
4123 {
4126 /* Place this field. */
4130 /* We have to check to see whether or not there is already
4131 something of the same type at the offset we're about to use.
4132 For example, consider:
4134 struct S {};
4135 struct T : public S { int i; };
4136 struct U : public S, public T {};
4138 Here, we put S at offset zero in U. Then, we can't put T at
4139 offset zero -- its S component would be at the same address
4140 as the S we already allocated. So, we have to skip ahead.
4141 Since all data members, including those whose type is an
4142 empty class, have nonzero size, any overlap can happen only
4143 with a direct or indirect base-class -- it can't happen with
4144 a data member. */
4145 /* In a union, overlap is permitted; all members are placed at
4146 offset zero. */
4151 {
4152 /* Strip off the size allocated to this field. That puts us
4153 at the first place we could have put the field with
4154 proper alignment. */
4157 /* Bump up by the alignment required for the type. */
4158 rli->bitpos
4164 }
4165 else
4166 /* There was no conflict. We're done laying out this field. */
4168 }
4170 /* Now that we know where it will be placed, update its
4171 BINFO_OFFSET. */
4173 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4174 this point because their BINFO_OFFSET is copied from another
4175 hierarchy. Therefore, we may not need to add the entire
4176 OFFSET. */
4182 }
4184 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4186 static int
4188 tree offset,
4190 {
4192 }
4194 /* Layout the empty base BINFO. EOC indicates the byte currently just
4195 past the end of the class, and should be correctly aligned for a
4196 class of the type indicated by BINFO; OFFSETS gives the offsets of
4197 the empty bases allocated so far. T is the most derived
4198 type. Return nonzero iff we added it at the end. */
4200 static bool
4203 {
4204 tree alignment;
4208 /* This routine should only be used for empty classes. */
4213 propagate_binfo_offsets
4217 /* This is an empty base class. We first try to put it at offset
4218 zero. */
4221 offsets,
4223 {
4224 /* That didn't work. Now, we move forward from the next
4225 available spot in the class. */
4229 {
4232 offsets,
4234 /* We finally found a spot where there's no overlap. */
4237 /* There's overlap here, too. Bump along to the next spot. */
4239 }
4240 }
4243 {
4248 }
4251 }
4253 /* Layout the base given by BINFO in the class indicated by RLI.
4254 *BASE_ALIGN is a running maximum of the alignments of
4255 any base class. OFFSETS gives the location of empty base
4256 subobjects. T is the most derived type. Return nonzero if the new
4257 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4258 *NEXT_FIELD, unless BINFO is for an empty base class.
4260 Returns the location at which the next field should be inserted. */
4265 {
4270 /* This error is now reported in xref_tag, thus giving better
4271 location information. */
4274 /* Place the base class. */
4276 {
4277 tree decl;
4279 /* The containing class is non-empty because it has a non-empty
4280 base class. */
4283 /* Create the FIELD_DECL. */
4290 {
4298 /* Try to place the field. It may take more than one try if we
4299 have a hard time placing the field without putting two
4300 objects of the same type at the same address. */
4302 /* Add the new FIELD_DECL to the list of fields for T. */
4306 }
4307 }
4308 else
4309 {
4310 tree eoc;
4313 /* On some platforms (ARM), even empty classes will not be
4314 byte-aligned. */
4319 /* A nearly-empty class "has no proper base class that is empty,
4320 not morally virtual, and at an offset other than zero." */
4322 {
4325 /* The check above (used in G++ 3.2) is insufficient because
4326 an empty class placed at offset zero might itself have an
4327 empty base at a nonzero offset. */
4329 empty_base_at_nonzero_offset_p,
4330 size_zero_node,
4335 }
4337 /* We do not create a FIELD_DECL for empty base classes because
4338 it might overlap some other field. We want to be able to
4339 create CONSTRUCTORs for the class by iterating over the
4340 FIELD_DECLs, and the back end does not handle overlapping
4341 FIELD_DECLs. */
4343 /* An empty virtual base causes a class to be non-empty
4344 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4345 here because that was already done when the virtual table
4346 pointer was created. */
4347 }
4349 /* Record the offsets of BINFO and its base subobjects. */
4352 offsets,
4356 }
4358 /* Layout all of the non-virtual base classes. Record empty
4359 subobjects in OFFSETS. T is the most derived type. Return nonzero
4360 if the type cannot be nearly empty. The fields created
4361 corresponding to the base classes will be inserted at
4362 *NEXT_FIELD. */
4364 static void
4367 {
4368 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4369 subobjects. */
4374 /* The primary base class is always allocated first. */
4379 /* Now allocate the rest of the bases. */
4381 {
4382 tree base_binfo;
4386 /* The primary base was already allocated above, so we don't
4387 need to allocate it again here. */
4391 /* Virtual bases are added at the end (a primary virtual base
4392 will have already been added). */
4398 }
4399 }
4401 /* Go through the TYPE_METHODS of T issuing any appropriate
4402 diagnostics, figuring out which methods override which other
4403 methods, and so forth. */
4405 static void
4407 {
4408 tree x;
4411 {
4415 /* The name of the field is the original field name
4416 Save this in auxiliary field for later overloading. */
4418 {
4422 }
4423 /* All user-provided destructors are non-trivial.
4424 Constructors and assignment ops are handled in
4425 grok_special_member_properties. */
4428 }
4429 }
4431 /* FN is a constructor or destructor. Clone the declaration to create
4432 a specialized in-charge or not-in-charge version, as indicated by
4433 NAME. */
4435 static tree
4437 {
4438 tree parms;
4439 tree clone;
4441 /* Copy the function. */
4443 /* Reset the function name. */
4445 /* Remember where this function came from. */
4447 /* Make it easy to find the CLONE given the FN. */
4451 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4453 {
4460 }
4464 /* There's no pending inline data for this function. */
4468 /* The base-class destructor is not virtual. */
4470 {
4474 }
4476 /* If there was an in-charge parameter, drop it from the function
4477 type. */
4479 {
4480 tree basetype;
4481 tree parmtypes;
4482 tree exceptions;
4487 /* Skip the `this' parameter. */
4489 /* Skip the in-charge parameter. */
4491 /* And the VTT parm, in a complete [cd]tor. */
4495 /* If this is subobject constructor or destructor, add the vtt
4496 parameter. */
4500 parmtypes);
4503 exceptions);
4507 }
4509 /* Copy the function parameters. */
4511 /* Remove the in-charge parameter. */
4513 {
4517 }
4518 /* And the VTT parm, in a complete [cd]tor. */
4520 {
4523 else
4524 {
4528 }
4529 }
4532 {
4535 }
4537 /* Create the RTL for this function. */
4545 }
4547 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4548 not invoke this function directly.
4550 For a non-thunk function, returns the address of the slot for storing
4551 the function it is a clone of. Otherwise returns NULL_TREE.
4553 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4554 cloned_function is unset. This is to support the separate
4555 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4556 on a template makes sense, but not the former. */
4558 tree *
4560 {
4568 {
4569 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4572 else
4573 #endif
4575 }
4580 else
4582 }
4584 /* Produce declarations for all appropriate clones of FN. If
4585 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4586 CLASTYPE_METHOD_VEC as well. */
4588 void
4590 {
4591 tree clone;
4593 /* Avoid inappropriate cloning. */
4599 {
4600 /* For each constructor, we need two variants: an in-charge version
4601 and a not-in-charge version. */
4608 }
4609 else
4610 {
4613 /* For each destructor, we need three variants: an in-charge
4614 version, a not-in-charge version, and an in-charge deleting
4615 version. We clone the deleting version first because that
4616 means it will go second on the TYPE_METHODS list -- and that
4617 corresponds to the correct layout order in the virtual
4618 function table.
4620 For a non-virtual destructor, we do not build a deleting
4621 destructor. */
4623 {
4627 }
4634 }
4636 /* Note that this is an abstract function that is never emitted. */
4638 }
4640 /* DECL is an in charge constructor, which is being defined. This will
4641 have had an in class declaration, from whence clones were
4642 declared. An out-of-class definition can specify additional default
4643 arguments. As it is the clones that are involved in overload
4644 resolution, we must propagate the information from the DECL to its
4645 clones. */
4647 void
4649 {
4650 tree clone;
4654 {
4661 /* Skip the 'this' parameter. */
4677 {
4682 {
4683 /* A default parameter has been added. Adjust the
4684 clone's parameters. */
4688 tree type;
4693 {
4696 clone_parms);
4698 }
4701 clone_parms);
4710 }
4711 }
4713 }
4714 }
4716 /* For each of the constructors and destructors in T, create an
4717 in-charge and not-in-charge variant. */
4719 static void
4721 {
4722 tree fns;
4724 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4725 out now. */
4733 }
4735 /* Deduce noexcept for a destructor DTOR. */
4737 void
4739 {
4741 {
4744 }
4745 }
4747 /* For each destructor in T, deduce noexcept:
4749 12.4/3: A declaration of a destructor that does not have an
4750 exception-specification is implicitly considered to have the
4751 same exception-specification as an implicit declaration (15.4). */
4753 static void
4755 {
4756 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4757 out now. */
4763 }
4765 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4766 of TYPE for virtual functions which FNDECL overrides. Return a
4767 mask of the tm attributes found therein. */
4769 static int
4771 {
4773 tree base_binfo;
4777 {
4787 else
4789 }
4792 }
4794 /* Subroutine of set_method_tm_attributes. Handle the checks and
4795 inheritance for one virtual method FNDECL. */
4797 static void
4799 {
4800 tree tm_attr;
4805 /* If FNDECL doesn't actually override anything (i.e. T is the
4806 class that first declares FNDECL virtual), then we're done. */
4813 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4814 tm_pure must match exactly, otherwise no weakening of
4815 tm_safe > tm_callable > nothing. */
4816 /* ??? The tm_pure attribute didn't make the transition to the
4817 multivendor language spec. */
4819 {
4821 {
4824 }
4825 }
4826 /* If the overridden function is tm_pure, then FNDECL must be. */
4829 /* Look for base class combinations that cannot be satisfied. */
4831 {
4837 }
4838 /* If FNDECL did not declare an attribute, then inherit the most
4839 restrictive one. */
4841 {
4843 }
4844 /* Otherwise validate that we're not weaker than a function
4845 that is being overridden. */
4846 else
4847 {
4851 }
4854 err_override:
4858 }
4860 /* For each of the methods in T, propagate a class-level tm attribute. */
4862 static void
4864 {
4867 /* Don't bother collecting tm attributes if transactional memory
4868 support is not enabled. */
4872 /* Process virtual methods first, as they inherit directly from the
4873 base virtual function and also require validation of new attributes. */
4875 {
4876 tree vchain;
4879 {
4884 }
4885 }
4887 /* If the class doesn't have an attribute, nothing more to do. */
4892 /* Any method that does not yet have a tm attribute inherits
4893 the one from the class. */
4895 {
4898 }
4899 }
4901 /* Returns true iff class T has a user-defined constructor other than
4902 the default constructor. */
4904 bool
4906 {
4907 tree fns;
4913 {
4920 }
4923 }
4925 /* Returns the defaulted constructor if T has one. Otherwise, returns
4926 NULL_TREE. */
4928 tree
4930 {
4937 {
4941 {
4947 }
4948 }
4951 }
4953 /* Returns true iff FN is a user-provided function, i.e. user-declared
4954 and not defaulted at its first declaration; or explicit, private,
4955 protected, or non-const. */
4957 bool
4959 {
4962 else
4966 }
4968 /* Returns true iff class T has a user-provided constructor. */
4970 bool
4972 {
4973 tree fns;
4981 /* This can happen in error cases; avoid crashing. */
4990 }
4992 /* Returns true iff class T has a non-user-provided (i.e. implicitly
4993 declared or explicitly defaulted in the class body) default
4994 constructor. */
4996 bool
4998 {
4999 tree fns;
5007 {
5013 }
5016 }
5018 /* TYPE is being used as a virtual base, and has a non-trivial move
5019 assignment. Return true if this is due to there being a user-provided
5020 move assignment in TYPE or one of its subobjects; if there isn't, then
5021 multiple move assignment can't cause any harm. */
5023 bool
5025 {
5026 /* Does the type itself have a user-provided move assignment operator? */
5030 {
5034 }
5036 /* Do any of its bases? */
5038 tree base_binfo;
5043 /* Or non-static data members? */
5045 {
5050 }
5052 /* Seems not. */
5054 }
5056 /* If default-initialization leaves part of TYPE uninitialized, returns
5057 a DECL for the field or TYPE itself (DR 253). */
5059 tree
5061 {
5072 {
5076 }
5081 {
5085 }
5088 }
5090 /* Returns true iff for class T, a trivial synthesized default constructor
5091 would be constexpr. */
5093 bool
5095 {
5096 /* A defaulted trivial default constructor is constexpr
5097 if there is nothing to initialize. */
5100 }
5102 /* Returns true iff class T has a constexpr default constructor. */
5104 bool
5106 {
5107 tree fns;
5110 {
5111 /* The caller should have stripped an enclosing array. */
5114 }
5116 {
5119 /* Non-trivial, we need to check subobject constructors. */
5121 }
5124 }
5126 /* Returns true iff class TYPE has a virtual destructor. */
5128 bool
5130 {
5131 tree dtor;
5139 }
5141 /* Returns true iff class T has a move constructor. */
5143 bool
5145 {
5146 tree fns;
5149 {
5152 }
5162 }
5164 /* Returns true iff class T has a move assignment operator. */
5166 bool
5168 {
5169 tree fns;
5172 {
5175 }
5183 }
5185 /* Returns true iff class T has a move constructor that was explicitly
5186 declared in the class body. Note that this is different from
5187 "user-provided", which doesn't include functions that are defaulted in
5188 the class. */
5190 bool
5192 {
5193 tree fns;
5202 {
5206 }
5209 }
5211 /* Returns true iff class T has a move assignment operator that was
5212 explicitly declared in the class body. */
5214 bool
5216 {
5217 tree fns;
5224 {
5228 }
5231 }
5233 /* Nonzero if we need to build up a constructor call when initializing an
5234 object of this class, either because it has a user-declared constructor
5235 or because it doesn't have a default constructor (so we need to give an
5236 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5237 what you care about is whether or not an object can be produced by a
5238 constructor (e.g. so we don't set TREE_READONLY on const variables of
5239 such type); use this function when what you care about is whether or not
5240 to try to call a constructor to create an object. The latter case is
5241 the former plus some cases of constructors that cannot be called. */
5243 bool
5245 {
5246 tree inner;
5256 /* A user-declared constructor might be private, and a constructor might
5257 be trivial but deleted. */
5260 {
5265 }
5267 }
5269 /* Like type_build_ctor_call, but for destructors. */
5271 bool
5273 {
5274 tree inner;
5283 /* A user-declared destructor might be private, and a destructor might
5284 be trivial but deleted. */
5287 {
5292 }
5294 }
5296 /* Remove all zero-width bit-fields from T. */
5298 static void
5300 {
5305 {
5308 /* We should not be confused by the fact that grokbitfield
5309 temporarily sets the width of the bit field into
5310 DECL_INITIAL (*fieldsp).
5311 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5312 to that width. */
5315 else
5317 }
5318 }
5320 /* Returns TRUE iff we need a cookie when dynamically allocating an
5321 array whose elements have the indicated class TYPE. */
5323 static bool
5325 {
5326 tree fns;
5331 /* If there's a non-trivial destructor, we need a cookie. In order
5332 to iterate through the array calling the destructor for each
5333 element, we'll have to know how many elements there are. */
5337 /* If the usual deallocation function is a two-argument whose second
5338 argument is of type `size_t', then we have to pass the size of
5339 the array to the deallocation function, so we will need to store
5340 a cookie. */
5344 /* If there are no `operator []' members, or the lookup is
5345 ambiguous, then we don't need a cookie. */
5348 /* Loop through all of the functions. */
5350 {
5351 tree fn;
5352 tree second_parm;
5354 /* Select the current function. */
5356 /* See if this function is a one-argument delete function. If
5357 it is, then it will be the usual deallocation function. */
5361 /* Do not consider this function if its second argument is an
5362 ellipsis. */
5365 /* Otherwise, if we have a two-argument function and the second
5366 argument is `size_t', it will be the usual deallocation
5367 function -- unless there is one-argument function, too. */
5371 }
5374 }
5376 /* Finish computing the `literal type' property of class type T.
5378 At this point, we have already processed base classes and
5379 non-static data members. We need to check whether the copy
5380 constructor is trivial, the destructor is trivial, and there
5381 is a trivial default constructor or at least one constexpr
5382 constructor other than the copy constructor. */
5384 static void
5386 {
5387 tree fn;
5403 {
5406 {
5410 }
5411 }
5412 }
5414 /* T is a non-literal type used in a context which requires a constant
5415 expression. Explain why it isn't literal. */
5417 void
5419 {
5429 /* Already explained. */
5438 {
5440 "default constructor, and has no constexpr constructor that "
5443 {
5444 /* Note that we can't simply call locate_ctor because when the
5445 constructor is deleted it just returns NULL_TREE. */
5446 tree fns;
5448 {
5455 {
5458 else
5461 }
5462 }
5463 }
5464 }
5465 else
5466 {
5470 {
5473 {
5478 }
5479 }
5481 {
5482 tree ftype;
5487 {
5492 }
5496 }
5497 }
5498 }
5500 /* Check the validity of the bases and members declared in T. Add any
5501 implicitly-generated functions (like copy-constructors and
5502 assignment operators). Compute various flag bits (like
5503 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5504 level: i.e., independently of the ABI in use. */
5506 static void
5508 {
5509 /* Nonzero if the implicitly generated copy constructor should take
5510 a non-const reference argument. */
5512 /* Nonzero if the implicitly generated assignment operator
5513 should take a non-const reference argument. */
5515 tree access_decls;
5518 tree fn;
5520 /* By default, we use const reference arguments and generate default
5521 constructors. */
5525 /* Check all the base-classes. */
5529 /* Deduce noexcept on destructors. This needs to happen after we've set
5530 triviality flags appropriately for our bases. */
5534 /* Check all the method declarations. */
5537 /* Save the initial values of these flags which only indicate whether
5538 or not the class has user-provided functions. As we analyze the
5539 bases and members we can set these flags for other reasons. */
5543 /* Check all the data member declarations. We cannot call
5544 check_field_decls until we have called check_bases check_methods,
5545 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5546 being set appropriately. */
5551 /* A nearly-empty class has to be vptr-containing; a nearly empty
5552 class contains just a vptr. */
5556 /* Do some bookkeeping that will guide the generation of implicitly
5557 declared member functions. */
5560 /* We need to call a constructor for this class if it has a
5561 user-provided constructor, or if the default constructor is going
5562 to initialize the vptr. (This is not an if-and-only-if;
5563 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5564 themselves need constructing.) */
5567 /* [dcl.init.aggr]
5569 An aggregate is an array or a class with no user-provided
5570 constructors ... and no virtual functions.
5572 Again, other conditions for being an aggregate are checked
5573 elsewhere. */
5576 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5577 retain the old definition internally for ABI reasons. */
5586 /* If the only explicitly declared default constructor is user-provided,
5587 set TYPE_HAS_COMPLEX_DFLT. */
5593 /* Warn if a public base of a polymorphic type has an accessible
5594 non-virtual destructor. It is only now that we know the class is
5595 polymorphic. Although a polymorphic base will have a already
5596 been diagnosed during its definition, we warn on use too. */
5598 {
5601 tree base_binfo;
5605 {
5613 basetype);
5614 }
5615 }
5617 /* If the class has no user-declared constructor, but does have
5618 non-static const or reference data members that can never be
5619 initialized, issue a warning. */
5621 /* Classes with user-declared constructors are presumed to
5622 initialize these members. */
5624 /* Aggregates can be initialized with brace-enclosed
5625 initializers. */
5627 {
5628 tree field;
5631 {
5632 tree type;
5647 }
5648 }
5650 /* Synthesize any needed methods. */
5652 cant_have_const_ctor,
5653 no_const_asn_ref);
5655 /* Check defaulted declarations here so we have cant_have_const_ctor
5656 and don't need to worry about clones. */
5659 {
5662 {
5663 bool imp_const_p
5669 /* If the function is defaulted outside the class, we just
5670 give the synthesis error. */
5673 }
5675 }
5678 {
5679 /* "This class type is not an aggregate." */
5681 }
5683 /* Compute the 'literal type' property before we
5684 do anything with non-static member functions. */
5687 /* Create the in-charge and not-in-charge variants of constructors
5688 and destructors. */
5691 /* Process the using-declarations. */
5695 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5698 /* Figure out whether or not we will need a cookie when dynamically
5699 allocating an array of this type. */
5702 }
5704 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5705 accordingly. If a new vfield was created (because T doesn't have a
5706 primary base class), then the newly created field is returned. It
5707 is not added to the TYPE_FIELDS list; it is the caller's
5708 responsibility to do that. Accumulate declared virtual functions
5709 on VIRTUALS_P. */
5711 static tree
5713 {
5714 tree fn;
5716 /* Collect the virtual functions declared in T. */
5721 {
5730 }
5732 /* If we couldn't find an appropriate base class, create a new field
5733 here. Even if there weren't any new virtual functions, we might need a
5734 new virtual function table if we're supposed to include vptrs in
5735 all classes that need them. */
5737 {
5738 /* We build this decl with vtbl_ptr_type_node, which is a
5739 `vtable_entry_type*'. It might seem more precise to use
5740 `vtable_entry_type (*)[N]' where N is the number of virtual
5741 functions. However, that would require the vtable pointer in
5742 base classes to have a different type than the vtable pointer
5743 in derived classes. We could make that happen, but that
5744 still wouldn't solve all the problems. In particular, the
5745 type-based alias analysis code would decide that assignments
5746 to the base class vtable pointer can't alias assignments to
5747 the derived class vtable pointer, since they have different
5748 types. Thus, in a derived class destructor, where the base
5749 class constructor was inlined, we could generate bad code for
5750 setting up the vtable pointer.
5752 Therefore, we use one type for all vtable pointers. We still
5753 use a type-correct type; it's just doesn't indicate the array
5754 bounds. That's better than using `void*' or some such; it's
5755 cleaner, and it let's the alias analysis code know that these
5756 stores cannot alias stores to void*! */
5757 tree field;
5770 /* This class is non-empty. */
5774 }
5777 }
5779 /* Add OFFSET to all base types of BINFO which is a base in the
5780 hierarchy dominated by T.
5782 OFFSET, which is a type offset, is number of bytes. */
5784 static void
5786 {
5788 tree primary_binfo;
5789 tree base_binfo;
5791 /* Update BINFO's offset. */
5796 offset));
5798 /* Find the primary base class. */
5804 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5805 downwards. */
5807 {
5808 /* Don't do the primary base twice. */
5816 }
5817 }
5819 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5820 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5821 empty subobjects of T. */
5823 static void
5825 {
5826 tree vbase;
5833 /* Find the last field. The artificial fields created for virtual
5834 bases will go after the last extant field to date. */
5839 /* Go through the virtual bases, allocating space for each virtual
5840 base that is not already a primary base class. These are
5841 allocated in inheritance graph order. */
5843 {
5848 {
5849 /* This virtual base is not a primary base of any class in the
5850 hierarchy, so we have to add space for it. */
5853 }
5854 }
5855 }
5857 /* Returns the offset of the byte just past the end of the base class
5858 BINFO. */
5860 static tree
5862 {
5863 tree size;
5868 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5869 allocate some space for it. It cannot have virtual bases, so
5870 TYPE_SIZE_UNIT is fine. */
5872 else
5876 }
5878 /* Returns the offset of the byte just past the end of the base class
5879 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5880 only non-virtual bases are included. */
5882 static tree
5884 {
5887 tree binfo;
5888 tree base_binfo;
5889 tree offset;
5894 {
5904 }
5909 {
5913 }
5916 }
5918 /* Warn about bases of T that are inaccessible because they are
5919 ambiguous. For example:
5921 struct S {};
5922 struct T : public S {};
5923 struct U : public S, public T {};
5925 Here, `(S*) new U' is not allowed because there are two `S'
5926 subobjects of U. */
5928 static void
5930 {
5933 tree basetype;
5934 tree binfo;
5935 tree base_binfo;
5937 /* If there are no repeated bases, nothing can be ambiguous. */
5941 /* Check direct bases. */
5944 {
5950 }
5952 /* Check for ambiguous virtual bases. */
5956 {
5962 }
5963 }
5965 /* Compare two INTEGER_CSTs K1 and K2. */
5967 static int
5969 {
5971 }
5973 /* Increase the size indicated in RLI to account for empty classes
5974 that are "off the end" of the class. */
5976 static void
5978 {
5979 tree eoc;
5980 tree rli_size;
5982 /* It might be the case that we grew the class to allocate a
5983 zero-sized base class. That won't be reflected in RLI, yet,
5984 because we are willing to overlay multiple bases at the same
5985 offset. However, now we need to make sure that RLI is big enough
5986 to reflect the entire class. */
5992 {
5993 /* The size should have been rounded to a whole byte. */
5996 rli->bitpos
6005 }
6006 }
6008 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6009 BINFO_OFFSETs for all of the base-classes. Position the vtable
6010 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6012 static void
6014 {
6015 tree non_static_data_members;
6016 tree field;
6017 tree vptr;
6018 record_layout_info rli;
6019 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6020 types that appear at that offset. */
6021 splay_tree empty_base_offsets;
6022 /* True if the last field laid out was a bit-field. */
6024 /* The location at which the next field should be inserted. */
6026 /* T, as a base class. */
6027 tree base_t;
6029 /* Keep track of the first non-static data member. */
6032 /* Start laying out the record. */
6035 /* Mark all the primary bases in the hierarchy. */
6038 /* Create a pointer to our virtual function table. */
6041 /* The vptr is always the first thing in the class. */
6043 {
6048 }
6049 else
6052 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6057 /* Layout the non-static data members. */
6059 {
6060 tree type;
6061 tree padding;
6063 /* We still pass things that aren't non-static data members to
6064 the back end, in case it wants to do something with them. */
6066 {
6068 /* If the static data member has incomplete type, keep track
6069 of it so that it can be completed later. (The handling
6070 of pending statics in finish_record_layout is
6071 insufficient; consider:
6073 struct S1;
6074 struct S2 { static S1 s1; };
6076 At this point, finish_record_layout will be called, but
6077 S1 is still incomplete.) */
6079 {
6081 /* The visibility of static data members is determined
6082 at their point of declaration, not their point of
6083 definition. */
6085 }
6087 }
6095 /* If this field is a bit-field whose width is greater than its
6096 type, then there are some special rules for allocating
6097 it. */
6100 {
6102 tree integer_type;
6104 /* We must allocate the bits as if suitably aligned for the
6105 longest integer type that fits in this many bits. type
6106 of the field. Then, we are supposed to use the left over
6107 bits as additional padding. */
6116 /* ITK now indicates a type that is too large for the
6117 field. We have to back up by one to find the largest
6118 type that fits. */
6119 do
6120 {
6125 /* Figure out how much additional padding is required. */
6127 {
6129 /* In a union, the padding field must have the full width
6130 of the bit-field; all fields start at offset zero. */
6132 else
6135 }
6136 #ifdef PCC_BITFIELD_TYPE_MATTERS
6137 /* An unnamed bitfield does not normally affect the
6138 alignment of the containing class on a target where
6139 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6140 make any exceptions for unnamed bitfields when the
6141 bitfields are longer than their types. Therefore, we
6142 temporarily give the field a name. */
6144 {
6147 }
6148 #endif
6153 empty_base_offsets);
6156 /* Now that layout has been performed, set the size of the
6157 field to the size of its declared type; the rest of the
6158 field is effectively invisible. */
6160 /* We must also reset the DECL_MODE of the field. */
6162 }
6163 else
6165 empty_base_offsets);
6167 /* Remember the location of any empty classes in FIELD. */
6170 empty_base_offsets,
6173 /* If a bit-field does not immediately follow another bit-field,
6174 and yet it starts in the middle of a byte, we have failed to
6175 comply with the ABI. */
6178 /* The TREE_NO_WARNING flag gets set by Objective-C when
6179 laying out an Objective-C class. The ObjC ABI differs
6180 from the C++ ABI, and so we do not want a warning
6181 here. */
6183 && !last_field_was_bitfield
6186 bitsize_unit_node)))
6190 /* The middle end uses the type of expressions to determine the
6191 possible range of expression values. In order to optimize
6192 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6193 must be made aware of the width of "i", via its type.
6195 Because C++ does not have integer types of arbitrary width,
6196 we must (for the purposes of the front end) convert from the
6197 type assigned here to the declared type of the bitfield
6198 whenever a bitfield expression is used as an rvalue.
6199 Similarly, when assigning a value to a bitfield, the value
6200 must be converted to the type given the bitfield here. */
6202 {
6207 {
6214 }
6215 }
6217 /* If we needed additional padding after this field, add it
6218 now. */
6220 {
6221 tree padding_field;
6224 FIELD_DECL,
6225 NULL_TREE,
6226 char_type_node);
6233 NULL_TREE,
6234 empty_base_offsets);
6235 }
6238 }
6241 {
6242 /* Make sure that we are on a byte boundary so that the size of
6243 the class without virtual bases will always be a round number
6244 of bytes. */
6247 }
6249 /* Delete all zero-width bit-fields from the list of fields. Now
6250 that the type is laid out they are no longer important. */
6253 /* Create the version of T used for virtual bases. We do not use
6254 make_class_type for this version; this is an artificial type. For
6255 a POD type, we just reuse T. */
6257 {
6260 /* Set the size and alignment for the new type. */
6261 tree eoc;
6263 /* If the ABI version is not at least two, and the last
6264 field was a bit-field, RLI may not be on a byte
6265 boundary. In particular, rli_size_unit_so_far might
6266 indicate the last complete byte, while rli_size_so_far
6267 indicates the total number of bits used. Therefore,
6268 rli_size_so_far, rather than rli_size_unit_so_far, is
6269 used to compute TYPE_SIZE_UNIT. */
6277 eoc);
6287 /* Copy the fields from T. */
6291 {
6293 FIELD_DECL,
6303 }
6305 /* Record the base version of the type. */
6308 }
6309 else
6312 /* Every empty class contains an empty class. */
6316 /* Set the TYPE_DECL for this type to contain the right
6317 value for DECL_OFFSET, so that we can use it as part
6318 of a COMPONENT_REF for multiple inheritance. */
6321 /* Now fix up any virtual base class types that we left lying
6322 around. We must get these done before we try to lay out the
6323 virtual function table. As a side-effect, this will remove the
6324 base subobject fields. */
6327 /* Make sure that empty classes are reflected in RLI at this
6328 point. */
6331 /* Make sure not to create any structures with zero size. */
6337 /* If this is a non-POD, declaring it packed makes a difference to how it
6338 can be used as a field; don't let finalize_record_size undo it. */
6342 /* Let the back end lay out the type. */
6351 /* Warn about bases that can't be talked about due to ambiguity. */
6354 /* Now that we're done with layout, give the base fields the real types. */
6359 /* Clean up. */
6366 }
6368 /* Determine the "key method" for the class type indicated by TYPE,
6369 and set CLASSTYPE_KEY_METHOD accordingly. */
6371 void
6373 {
6374 tree method;
6377 || processing_template_decl
6382 /* The key method is the first non-pure virtual function that is not
6383 inline at the point of class definition. On some targets the
6384 key function may not be inline; those targets should not call
6385 this function until the end of the translation unit. */
6392 {
6395 }
6398 }
6401 /* Allocate and return an instance of struct sorted_fields_type with
6402 N fields. */
6406 {
6413 }
6416 /* Perform processing required when the definition of T (a class type)
6417 is complete. */
6419 void
6421 {
6422 tree x;
6423 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6427 {
6432 }
6434 /* If this type was previously laid out as a forward reference,
6435 make sure we lay it out again. */
6439 /* Make assumptions about the class; we'll reset the flags if
6440 necessary. */
6446 /* Do end-of-class semantic processing: checking the validity of the
6447 bases and members and add implicitly generated methods. */
6450 /* Find the key method. */
6452 {
6453 /* The Itanium C++ ABI permits the key method to be chosen when
6454 the class is defined -- even though the key method so
6455 selected may later turn out to be an inline function. On
6456 some systems (such as ARM Symbian OS) the key method cannot
6457 be determined until the end of the translation unit. On such
6458 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6459 will cause the class to be added to KEYED_CLASSES. Then, in
6460 finish_file we will determine the key method. */
6464 /* If a polymorphic class has no key method, we may emit the vtable
6465 in every translation unit where the class definition appears. If
6466 we're devirtualizing, we can look into the vtable even if we
6467 aren't emitting it. */
6470 }
6472 /* Layout the class itself. */
6475 /* We use the base type for trivial assignments, and hence it
6476 needs a mode. */
6481 /* If necessary, create the primary vtable for this class. */
6483 {
6484 /* We must enter these virtuals into the table. */
6488 /* Here we know enough to change the type of our virtual
6489 function table, but we will wait until later this function. */
6492 /* If we're warning about ABI tags, check the types of the new
6493 virtual functions. */
6497 }
6500 {
6502 tree fn;
6509 /* Add entries for virtual functions introduced by this class. */
6513 /* Set DECL_VINDEX for all functions declared in this class. */
6515 fn;
6517 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6519 {
6523 /* A thunk. We should never be calling this entry directly
6524 from this vtable -- we'd use the entry for the non
6525 thunk base function. */
6529 }
6530 }
6535 /* Complete the rtl for any static member objects of the type we're
6536 working on. */
6543 /* Done with FIELDS...now decide whether to sort these for
6544 faster lookups later.
6546 We use a small number because most searches fail (succeeding
6547 ultimately as the search bores through the inheritance
6548 hierarchy), and we want this failure to occur quickly. */
6552 /* Complain if one of the field types requires lower visibility. */
6555 /* Make the rtl for any new vtables we have created, and unmark
6556 the base types we marked. */
6559 /* Build the VTT for T. */
6562 /* This warning does not make sense for Java classes, since they
6563 cannot have destructors. */
6568 "%q#T has virtual functions and accessible"
6576 /* Class layout, assignment of virtual table slots, etc., is now
6577 complete. Give the back end a chance to tweak the visibility of
6578 the class or perform any other required target modifications. */
6588 /* Finish debugging output for this type. */
6592 {
6595 {
6598 }
6600 {
6603 else
6604 {
6607 }
6609 }
6611 {
6613 "the type of the first field has a different ABI from the "
6616 }
6617 }
6618 }
6620 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6621 equal to THRESHOLD or greater than THRESHOLD. */
6623 static void
6625 {
6628 {
6633 }
6634 }
6636 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6638 void
6640 {
6643 {
6645 int n_fields
6656 }
6657 }
6659 /* When T was built up, the member declarations were added in reverse
6660 order. Rearrange them to declaration order. */
6662 void
6664 {
6665 tree next;
6666 tree prev;
6667 tree x;
6669 /* The following lists are all in reverse order. Put them in
6670 declaration order now. */
6674 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6675 reverse order, so we can't just use nreverse. */
6680 {
6684 }
6686 {
6690 }
6691 }
6693 tree
6695 {
6698 /* Now that we've got all the field declarations, reverse everything
6699 as necessary. */
6704 /* Nadger the current location so that diagnostics point to the start of
6705 the struct, not the end. */
6709 {
6710 tree x;
6716 /* We need to emit an error message if this type was used as a parameter
6717 and it is an abstract type, even if it is a template. We construct
6718 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6719 account and we call complete_vars with this type, which will check
6720 the PARM_DECLS. Note that while the type is being defined,
6721 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6722 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6728 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6729 an enclosing scope is a template class, so that this function be
6730 found by lookup_fnfields_1 when the using declaration is not
6731 instantiated yet. */
6734 {
6739 }
6741 /* Remember current #pragma pack value. */
6744 /* Fix up any variants we've already built. */
6746 {
6751 }
6752 }
6753 else
6757 {
6758 /* People keep complaining that the compiler crashes on an invalid
6759 definition of initializer_list, so I guess we should explicitly
6760 reject it. What the compiler internals care about is that it's a
6761 template and has a pointer field followed by an integer field. */
6764 {
6767 {
6771 }
6772 }
6776 }
6784 else
6788 /* Lambdas are defined by the LAMBDA_EXPR. */
6793 }
6794 \f
6795 /* Hash table to avoid endless recursion when handling references. */
6798 /* Return the dynamic type of INSTANCE, if known.
6799 Used to determine whether the virtual function table is needed
6800 or not.
6802 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6803 of our knowledge of its type. *NONNULL should be initialized
6804 before this function is called. */
6806 static tree
6808 {
6809 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6812 {
6816 else
6820 /* This is a call to a constructor, hence it's never zero. */
6822 {
6826 }
6830 /* This is a call to a constructor, hence it's never zero. */
6832 {
6836 }
6845 /* Propagate nonnull. */
6850 CASE_CONVERT:
6856 {
6857 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6858 with a real object -- given &p->f, p can still be null. */
6860 /* ??? Probably should check DECL_WEAK here. */
6863 }
6867 /* If this component is really a base class reference, then the field
6868 itself isn't definitive. */
6877 {
6881 }
6882 /* fall through... */
6887 {
6891 }
6893 {
6897 /* if we're in a ctor or dtor, we know our type. If
6898 current_class_ptr is set but we aren't in a function, we're in
6899 an NSDMI (and therefore a constructor). */
6904 {
6908 }
6909 }
6911 {
6912 /* We only need one hash table because it is always left empty. */
6914 fixed_type_or_null_ref_ht
6917 /* Reference variables should be references to objects. */
6921 /* Enter the INSTANCE in a table to prevent recursion; a
6922 variable's initializer may refer to the variable
6923 itself. */
6928 {
6929 tree type;
6938 }
6939 }
6944 }
6945 #undef RECUR
6946 }
6948 /* Return nonzero if the dynamic type of INSTANCE is known, and
6949 equivalent to the static type. We also handle the case where
6950 INSTANCE is really a pointer. Return negative if this is a
6951 ctor/dtor. There the dynamic type is known, but this might not be
6952 the most derived base of the original object, and hence virtual
6953 bases may not be laid out according to this type.
6955 Used to determine whether the virtual function table is needed
6956 or not.
6958 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6959 of our knowledge of its type. *NONNULL should be initialized
6960 before this function is called. */
6962 int
6964 {
6967 tree fixed;
6969 /* processing_template_decl can be false in a template if we're in
6970 instantiate_non_dependent_expr, but we still want to suppress
6971 this check. */
6973 {
6974 /* In a template we only care about the type of the result. */
6978 }
6988 }
6990 \f
6991 void
6993 {
6996 current_class_stack
7004 }
7006 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7008 static void
7010 {
7011 tree type;
7013 /* We are re-entering the same class we just left, so we don't
7014 have to search the whole inheritance matrix to find all the
7015 decls to bind again. Instead, we install the cached
7016 class_shadowed list and walk through it binding names. */
7019 /* Restore IDENTIFIER_TYPE_VALUE. */
7021 type;
7024 }
7026 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7027 appropriate for TYPE.
7029 So that we may avoid calls to lookup_name, we cache the _TYPE
7030 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7032 For multiple inheritance, we perform a two-pass depth-first search
7033 of the type lattice. */
7035 void
7037 {
7038 class_stack_node_t csn;
7042 /* Make sure there is enough room for the new entry on the stack. */
7044 {
7046 current_class_stack
7048 current_class_stack_size);
7049 }
7051 /* Insert a new entry on the class stack. */
7058 current_class_depth++;
7060 /* Now set up the new type. */
7066 /* By default, things in classes are private, while things in
7067 structures or unions are public. */
7069 ? access_private_node
7075 {
7076 /* Forcibly remove any old class remnants. */
7078 }
7084 else
7086 }
7088 /* When we exit a toplevel class scope, we save its binding level so
7089 that we can restore it quickly. Here, we've entered some other
7090 class, so we must invalidate our cache. */
7092 void
7094 {
7096 }
7098 /* Get out of the current class scope. If we were in a class scope
7099 previously, that is the one popped to. */
7101 void
7103 {
7106 current_class_depth--;
7112 }
7114 /* Mark the top of the class stack as hidden. */
7116 void
7118 {
7121 }
7123 /* Mark the top of the class stack as un-hidden. */
7125 void
7127 {
7130 }
7132 /* Returns 1 if the class type currently being defined is either T or
7133 a nested type of T. */
7135 bool
7137 {
7145 /* We start looking from 1 because entry 0 is from global scope,
7146 and has no type. */
7148 {
7149 tree c;
7152 else
7153 {
7157 }
7162 }
7164 }
7166 /* If either current_class_type or one of its enclosing classes are derived
7167 from T, return the appropriate type. Used to determine how we found
7168 something via unqualified lookup. */
7170 tree
7172 {
7175 /* The bases of a dependent type are unknown. */
7186 {
7191 }
7194 }
7196 /* Return the outermost enclosing class type that is still open, or
7197 NULL_TREE. */
7199 tree
7201 {
7208 {
7215 }
7217 }
7219 /* Returns the innermost class type which is not a lambda closure type. */
7221 tree
7223 {
7226 /* We start looking from 1 because entry 0 is from global scope,
7227 and has no type. */
7229 {
7230 tree c;
7233 else
7234 {
7238 }
7243 }
7245 }
7247 /* When entering a class scope, all enclosing class scopes' names with
7248 static meaning (static variables, static functions, types and
7249 enumerators) have to be visible. This recursive function calls
7250 pushclass for all enclosing class contexts until global or a local
7251 scope is reached. TYPE is the enclosed class. */
7253 void
7255 {
7256 /* A namespace might be passed in error cases, like A::B:C. */
7264 }
7266 /* Undoes a push_nested_class call. */
7268 void
7270 {
7276 }
7278 /* Returns the number of extern "LANG" blocks we are nested within. */
7280 int
7282 {
7284 }
7286 /* Set global variables CURRENT_LANG_NAME to appropriate value
7287 so that behavior of name-mangling machinery is correct. */
7289 void
7291 {
7295 {
7297 }
7299 {
7301 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7302 (See record_builtin_java_type in decl.c.) However, that causes
7303 incorrect debug entries if these types are actually used.
7304 So we re-enable debug output after extern "Java". */
7313 }
7315 {
7317 }
7318 else
7320 }
7322 /* Get out of the current language scope. */
7324 void
7326 {
7328 }
7329 \f
7330 /* Type instantiation routines. */
7332 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7333 matches the TARGET_TYPE. If there is no satisfactory match, return
7334 error_mark_node, and issue an error & warning messages under
7335 control of FLAGS. Permit pointers to member function if FLAGS
7336 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7337 a template-id, and EXPLICIT_TARGS are the explicitly provided
7338 template arguments.
7340 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7341 is the base path used to reference those member functions. If
7342 the address is resolved to a member function, access checks will be
7343 performed and errors issued if appropriate. */
7345 static tree
7347 tree overload,
7348 tsubst_flags_t flags,
7350 tree explicit_targs,
7351 tree access_path)
7352 {
7353 /* Here's what the standard says:
7355 [over.over]
7357 If the name is a function template, template argument deduction
7358 is done, and if the argument deduction succeeds, the deduced
7359 arguments are used to generate a single template function, which
7360 is added to the set of overloaded functions considered.
7362 Non-member functions and static member functions match targets of
7363 type "pointer-to-function" or "reference-to-function." Nonstatic
7364 member functions match targets of type "pointer-to-member
7365 function;" the function type of the pointer to member is used to
7366 select the member function from the set of overloaded member
7367 functions. If a nonstatic member function is selected, the
7368 reference to the overloaded function name is required to have the
7369 form of a pointer to member as described in 5.3.1.
7371 If more than one function is selected, any template functions in
7372 the set are eliminated if the set also contains a non-template
7373 function, and any given template function is eliminated if the
7374 set contains a second template function that is more specialized
7375 than the first according to the partial ordering rules 14.5.5.2.
7376 After such eliminations, if any, there shall remain exactly one
7377 selected function. */
7380 /* We store the matches in a TREE_LIST rooted here. The functions
7381 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7382 interoperability with most_specialized_instantiation. */
7384 tree fn;
7385 tree target_fn_type;
7387 /* By the time we get here, we should be seeing only real
7388 pointer-to-member types, not the internal POINTER_TYPE to
7389 METHOD_TYPE representation. */
7395 /* Check that the TARGET_TYPE is reasonable. */
7400 /* This is OK, too. */
7403 /* This is OK, too. This comes from a conversion to reference
7404 type. */
7406 else
7407 {
7413 }
7415 /* Non-member functions and static member functions match targets of type
7416 "pointer-to-function" or "reference-to-function." Nonstatic member
7417 functions match targets of type "pointer-to-member-function;" the
7418 function type of the pointer to member is used to select the member
7419 function from the set of overloaded member functions.
7421 So figure out the FUNCTION_TYPE that we want to match against. */
7424 /* If we can find a non-template function that matches, we can just
7425 use it. There's no point in generating template instantiations
7426 if we're just going to throw them out anyhow. But, of course, we
7427 can only do this when we don't *need* a template function. */
7429 {
7430 tree fns;
7433 {
7437 /* We're not looking for templates just yet. */
7442 /* We're looking for a non-static member, and this isn't
7443 one, or vice versa. */
7446 /* Ignore functions which haven't been explicitly
7447 declared. */
7451 /* See if there's a match. */
7454 }
7455 }
7457 /* Now, if we've already got a match (or matches), there's no need
7458 to proceed to the template functions. But, if we don't have a
7459 match we need to look at them, too. */
7461 {
7462 tree target_arg_types;
7463 tree target_ret_type;
7464 tree fns;
7467 tree arg;
7481 {
7483 tree instantiation;
7484 tree targs;
7487 /* We're only looking for templates. */
7492 /* We're not looking for a non-static member, and this is
7493 one, or vice versa. */
7498 /* If the template has a deduced return type, don't expose it to
7499 template argument deduction. */
7503 /* Try to do argument deduction. */
7510 /* Instantiation failed. */
7513 /* And now force instantiation to do return type deduction. */
7515 {
7521 }
7523 /* See if there's a match. */
7526 }
7528 /* Now, remove all but the most specialized of the matches. */
7530 {
7535 NULL_TREE,
7536 NULL_TREE);
7537 }
7538 }
7540 /* Now we should have exactly one function in MATCHES. */
7542 {
7543 /* There were *no* matches. */
7545 {
7548 target_type);
7551 }
7553 }
7555 {
7556 /* There were too many matches. First check if they're all
7557 the same function. */
7562 /* For multi-versioned functions, more than one match is just fine and
7563 decls_match will return false as they are different. */
7571 {
7573 {
7576 target_type);
7578 /* Since print_candidates expects the functions in the
7579 TREE_VALUE slot, we flip them here. */
7584 }
7587 }
7588 }
7590 /* Good, exactly one match. Now, convert it to the correct type. */
7595 {
7603 {
7606 }
7607 }
7609 /* If a pointer to a function that is multi-versioned is requested, the
7610 pointer to the dispatcher function is returned instead. This works
7611 well because indirectly calling the function will dispatch the right
7612 function version at run-time. */
7614 {
7618 /* Mark all the versions corresponding to the dispatcher as used. */
7621 }
7623 /* If we're doing overload resolution purely for the purpose of
7624 determining conversion sequences, we should not consider the
7625 function used. If this conversion sequence is selected, the
7626 function will be marked as used at this point. */
7628 {
7629 /* Make =delete work with SFINAE. */
7634 }
7636 /* We could not check access to member functions when this
7637 expression was originally created since we did not know at that
7638 time to which function the expression referred. */
7640 {
7643 }
7647 else
7648 {
7649 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7650 will mark the function as addressed, but here we must do it
7651 explicitly. */
7655 }
7656 }
7658 /* This function will instantiate the type of the expression given in
7659 RHS to match the type of LHSTYPE. If errors exist, then return
7660 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7661 we complain on errors. If we are not complaining, never modify rhs,
7662 as overload resolution wants to try many possible instantiations, in
7663 the hope that at least one will work.
7665 For non-recursive calls, LHSTYPE should be a function, pointer to
7666 function, or a pointer to member function. */
7668 tree
7670 {
7677 {
7681 }
7684 {
7691 /* Microsoft allows `A::f' to be resolved to a
7692 pointer-to-member. */
7693 ;
7694 else
7695 {
7700 }
7701 }
7704 {
7707 }
7709 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7710 deduce any type information. */
7712 {
7716 }
7718 /* There only a few kinds of expressions that may have a type
7719 dependent on overload resolution. */
7725 /* This should really only be used when attempting to distinguish
7726 what sort of a pointer to function we have. For now, any
7727 arithmetic operation which is not supported on pointers
7728 is rejected as an error. */
7731 {
7733 {
7739 /* Do not lose object's side effects. */
7743 }
7750 /* This can happen if we are forming a pointer-to-member for a
7751 member template. */
7754 /* Fall through. */
7757 {
7761 return
7765 }
7769 return
7773 access_path);
7776 {
7781 }
7788 }
7790 }
7791 \f
7792 /* Return the name of the virtual function pointer field
7793 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7794 this may have to look back through base types to find the
7795 ultimate field name. (For single inheritance, these could
7796 all be the same name. Who knows for multiple inheritance). */
7798 static tree
7800 {
7807 {
7813 }
7821 }
7823 void
7825 {
7832 {
7837 }
7838 }
7840 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7841 according to [class]:
7842 The class-name is also inserted
7843 into the scope of the class itself. For purposes of access checking,
7844 the inserted class name is treated as if it were a public member name. */
7846 void
7848 {
7851 tree saved_cas;
7866 }
7868 /* Returns 1 if TYPE contains only padding bytes. */
7870 int
7872 {
7880 }
7882 /* Returns true if TYPE contains no actual data, just various
7883 possible combinations of empty classes and possibly a vptr. */
7885 bool
7887 {
7889 {
7890 tree field;
7891 tree binfo;
7892 tree base_binfo;
7895 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7896 out, but we'd like to be able to check this before then. */
7910 }
7914 }
7916 /* Note that NAME was looked up while the current class was being
7917 defined and that the result of that lookup was DECL. */
7919 void
7921 {
7922 splay_tree names_used;
7924 /* If we're not defining a class, there's nothing to do. */
7930 /* If there's already a binding for this NAME, then we don't have
7931 anything to worry about. */
7944 }
7946 /* Note that NAME was declared (as DECL) in the current class. Check
7947 to see that the declaration is valid. */
7949 void
7951 {
7952 splay_tree names_used;
7953 splay_tree_node n;
7955 /* Look to see if we ever used this name. */
7956 names_used
7960 /* The C language allows members to be declared with a type of the same
7961 name, and the C++ standard says this diagnostic is not required. So
7962 allow it in extern "C" blocks unless predantic is specified.
7963 Allow it in all cases if -ms-extensions is specified. */
7969 {
7970 /* [basic.scope.class]
7972 A name N used in a class S shall refer to the same declaration
7973 in its context and when re-evaluated in the completed scope of
7974 S. */
7978 }
7979 }
7981 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7982 Secondary vtables are merged with primary vtables; this function
7983 will return the VAR_DECL for the primary vtable. */
7985 tree
7987 {
7988 tree decl;
7992 {
7995 }
7999 }
8002 /* Returns the binfo for the primary base of BINFO. If the resulting
8003 BINFO is a virtual base, and it is inherited elsewhere in the
8004 hierarchy, then the returned binfo might not be the primary base of
8005 BINFO in the complete object. Check BINFO_PRIMARY_P or
8006 BINFO_LOST_PRIMARY_P to be sure. */
8008 static tree
8010 {
8011 tree primary_base;
8018 }
8020 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8022 static int
8024 {
8028 }
8030 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8031 INDENT should be zero when called from the top level; it is
8032 incremented recursively. IGO indicates the next expected BINFO in
8033 inheritance graph ordering. */
8035 static tree
8038 tree binfo,
8039 tree igo,
8041 {
8043 tree base_binfo;
8051 {
8054 }
8069 {
8073 TFF_PLAIN_IDENTIFIER),
8075 }
8077 {
8080 }
8085 {
8089 {
8093 TFF_PLAIN_IDENTIFIER));
8094 }
8096 {
8100 TFF_PLAIN_IDENTIFIER));
8101 }
8103 {
8107 TFF_PLAIN_IDENTIFIER));
8108 }
8110 {
8114 TFF_PLAIN_IDENTIFIER));
8115 }
8119 }
8125 }
8127 /* Dump the BINFO hierarchy for T. */
8129 static void
8131 {
8143 }
8145 /* Debug interface to hierarchy dumping. */
8147 void
8149 {
8151 }
8153 static void
8155 {
8160 {
8162 }
8163 }
8165 static void
8167 {
8168 tree value;
8170 HOST_WIDE_INT elt;
8178 TFF_PLAIN_IDENTIFIER));
8185 }
8187 static void
8189 {
8197 {
8204 {
8209 }
8213 }
8214 }
8216 static void
8218 {
8226 {
8231 }
8232 }
8234 /* Dump a function or thunk and its thunkees. */
8236 static void
8238 {
8241 tree thunks;
8249 {
8259 else
8265 }
8269 }
8271 /* Dump the thunks for FN. */
8273 void
8275 {
8277 }
8279 /* Virtual function table initialization. */
8281 /* Create all the necessary vtables for T and its base classes. */
8283 static void
8285 {
8286 tree vbase;
8290 /* We lay out the primary and secondary vtables in one contiguous
8291 vtable. The primary vtable is first, followed by the non-virtual
8292 secondary vtables in inheritance graph order. */
8296 /* Then come the virtual bases, also in inheritance graph order. */
8298 {
8302 }
8306 }
8308 /* Initialize the vtable for BINFO with the INITS. */
8310 static void
8312 {
8313 tree decl;
8319 }
8321 /* Build the VTT (virtual table table) for T.
8322 A class requires a VTT if it has virtual bases.
8324 This holds
8325 1 - primary virtual pointer for complete object T
8326 2 - secondary VTTs for each direct non-virtual base of T which requires a
8327 VTT
8328 3 - secondary virtual pointers for each direct or indirect base of T which
8329 has virtual bases or is reachable via a virtual path from T.
8330 4 - secondary VTTs for each direct or indirect virtual base of T.
8332 Secondary VTTs look like complete object VTTs without part 4. */
8334 static void
8336 {
8337 tree type;
8338 tree vtt;
8339 tree index;
8342 /* Build up the initializers for the VTT. */
8347 /* If we didn't need a VTT, we're done. */
8351 /* Figure out the type of the VTT. */
8355 /* Now, build the VTT object itself. */
8358 /* Add the VTT to the vtables list. */
8363 }
8365 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8366 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8367 and CHAIN the vtable pointer for this binfo after construction is
8368 complete. VALUE can also be another BINFO, in which case we recurse. */
8370 static tree
8372 {
8373 tree vt;
8376 {
8382 else
8384 }
8387 }
8389 /* Data for secondary VTT initialization. */
8391 {
8392 /* Is this the primary VTT? */
8395 /* Current index into the VTT. */
8396 tree index;
8398 /* Vector of initializers built up. */
8401 /* The type being constructed by this secondary VTT. */
8402 tree type_being_constructed;
8405 /* Recursively build the VTT-initializer for BINFO (which is in the
8406 hierarchy dominated by T). INITS points to the end of the initializer
8407 list to date. INDEX is the VTT index where the next element will be
8408 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8409 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8410 for virtual bases of T. When it is not so, we build the constructor
8411 vtables for the BINFO-in-T variant. */
8413 static void
8416 {
8418 tree b;
8419 tree init;
8420 secondary_vptr_vtt_init_data data;
8423 /* We only need VTTs for subobjects with virtual bases. */
8427 /* We need to use a construction vtable if this is not the primary
8428 VTT. */
8430 {
8433 /* Record the offset in the VTT where this sub-VTT can be found. */
8435 }
8437 /* Add the address of the primary vtable for the complete object. */
8441 {
8444 }
8447 /* Recursively add the secondary VTTs for non-virtual bases. */
8452 /* Add secondary virtual pointers for all subobjects of BINFO with
8453 either virtual bases or reachable along a virtual path, except
8454 subobjects that are non-virtual primary bases. */
8464 /* data.inits might have grown as we added secondary virtual pointers.
8465 Make sure our caller knows about the new vector. */
8469 /* Add the secondary VTTs for virtual bases in inheritance graph
8470 order. */
8472 {
8477 }
8478 else
8479 /* Remove the ctor vtables we created. */
8481 }
8483 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8484 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8486 static tree
8488 {
8491 /* We don't care about bases that don't have vtables. */
8495 /* We're only interested in proper subobjects of the type being
8496 constructed. */
8500 /* We're only interested in bases with virtual bases or reachable
8501 via a virtual path from the type being constructed. */
8506 /* We're not interested in non-virtual primary bases. */
8510 /* Record the index where this secondary vptr can be found. */
8512 {
8517 {
8518 /* It's a primary virtual base, and this is not a
8519 construction vtable. Find the base this is primary of in
8520 the inheritance graph, and use that base's vtable
8521 now. */
8524 }
8525 }
8527 /* Add the initializer for the secondary vptr itself. */
8530 /* Advance the vtt index. */
8535 }
8537 /* Called from build_vtt_inits via dfs_walk. After building
8538 constructor vtables and generating the sub-vtt from them, we need
8539 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8540 binfo of the base whose sub vtt was generated. */
8542 static tree
8544 {
8548 /* If this class has no vtable, none of its bases do. */
8552 /* This might be a primary base, so have no vtable in this
8553 hierarchy. */
8556 /* If we scribbled the construction vtable vptr into BINFO, clear it
8557 out now. */
8563 }
8565 /* Build the construction vtable group for BINFO which is in the
8566 hierarchy dominated by T. */
8568 static void
8570 {
8571 tree type;
8572 tree vtbl;
8573 tree id;
8574 tree vbase;
8577 /* See if we've already created this construction vtable group. */
8583 /* Build a version of VTBL (with the wrong type) for use in
8584 constructing the addresses of secondary vtables in the
8585 construction vtable group. */
8588 /* Don't export construction vtables from shared libraries. Even on
8589 targets that don't support hidden visibility, this tells
8590 can_refer_decl_in_current_unit_p not to assume that it's safe to
8591 access from a different compilation unit (bz 54314). */
8599 /* Add the vtables for each of our virtual bases using the vbase in T
8600 binfo. */
8602 vbase;
8604 {
8605 tree b;
8612 }
8614 /* Figure out the type of the construction vtable. */
8621 /* Initialize the construction vtable. */
8625 }
8627 /* Add the vtbl initializers for BINFO (and its bases other than
8628 non-virtual primaries) to the list of INITS. BINFO is in the
8629 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8630 the constructor the vtbl inits should be accumulated for. (If this
8631 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8632 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8633 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8634 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8635 but are not necessarily the same in terms of layout. */
8637 static void
8639 tree orig_binfo,
8640 tree rtti_binfo,
8641 tree vtbl,
8642 tree t,
8644 {
8646 tree base_binfo;
8651 /* If it doesn't have a vptr, we don't do anything. */
8655 /* If we're building a construction vtable, we're not interested in
8656 subobjects that don't require construction vtables. */
8662 /* Build the initializers for the BINFO-in-T vtable. */
8665 /* Walk the BINFO and its bases. We walk in preorder so that as we
8666 initialize each vtable we can figure out at what offset the
8667 secondary vtable lies from the primary vtable. We can't use
8668 dfs_walk here because we need to iterate through bases of BINFO
8669 and RTTI_BINFO simultaneously. */
8671 {
8672 /* Skip virtual bases. */
8678 inits);
8679 }
8680 }
8682 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8683 BINFO vtable to L. */
8685 static void
8687 tree orig_binfo,
8688 tree rtti_binfo,
8689 tree orig_vtbl,
8690 tree t,
8692 {
8699 {
8700 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8701 primary virtual base. If it is not the same primary in
8702 the hierarchy of T, we'll need to generate a ctor vtable
8703 for it, to place at its location in T. If it is the same
8704 primary, we still need a VTT entry for the vtable, but it
8705 should point to the ctor vtable for the base it is a
8706 primary for within the sub-hierarchy of RTTI_BINFO.
8708 There are three possible cases:
8710 1) We are in the same place.
8711 2) We are a primary base within a lost primary virtual base of
8712 RTTI_BINFO.
8713 3) We are primary to something not a base of RTTI_BINFO. */
8715 tree b;
8718 /* First, look through the bases we are primary to for RTTI_BINFO
8719 or a virtual base. */
8722 {
8727 }
8728 /* If we run out of primary links, keep looking down our
8729 inheritance chain; we might be an indirect primary. */
8733 found:
8735 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8736 base B and it is a base of RTTI_BINFO, this is case 2. In
8737 either case, we share our vtable with LAST, i.e. the
8738 derived-most base within B of which we are a primary. */
8741 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8742 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8743 binfo_ctor_vtable after everything's been set up. */
8746 /* Otherwise, this is case 3 and we get our own. */
8747 }
8754 {
8755 tree index;
8758 /* Add the initializer for this vtable. */
8762 /* Figure out the position to which the VPTR should point. */
8768 }
8771 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8772 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8773 straighten this out. */
8776 /* Throw away any unneeded intializers. */
8778 else
8779 /* For an ordinary vtable, set BINFO_VTABLE. */
8781 }
8785 /* Construct the initializer for BINFO's virtual function table. BINFO
8786 is part of the hierarchy dominated by T. If we're building a
8787 construction vtable, the ORIG_BINFO is the binfo we should use to
8788 find the actual function pointers to put in the vtable - but they
8789 can be overridden on the path to most-derived in the graph that
8790 ORIG_BINFO belongs. Otherwise,
8791 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8792 BINFO that should be indicated by the RTTI information in the
8793 vtable; it will be a base class of T, rather than T itself, if we
8794 are building a construction vtable.
8796 The value returned is a TREE_LIST suitable for wrapping in a
8797 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8798 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8799 number of non-function entries in the vtable.
8801 It might seem that this function should never be called with a
8802 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8803 base is always subsumed by a derived class vtable. However, when
8804 we are building construction vtables, we do build vtables for
8805 primary bases; we need these while the primary base is being
8806 constructed. */
8808 static void
8810 tree orig_binfo,
8811 tree t,
8812 tree rtti_binfo,
8815 {
8816 tree v;
8817 vtbl_init_data vid;
8819 tree vbinfo;
8823 /* Initialize VID. */
8831 /* The first vbase or vcall offset is at index -3 in the vtable. */
8834 /* Add entries to the vtable for RTTI. */
8837 /* Create an array for keeping track of the functions we've
8838 processed. When we see multiple functions with the same
8839 signature, we share the vcall offsets. */
8841 /* Add the vcall and vbase offset entries. */
8844 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8845 build_vbase_offset_vtbl_entries. */
8850 /* If the target requires padding between data entries, add that now. */
8852 {
8857 /* Move data entries into their new positions and add padding
8858 after the new positions. Iterate backwards so we don't
8859 overwrite entries that we would need to process later. */
8862 ix--)
8863 {
8871 {
8875 null_pointer_node);
8876 }
8877 }
8878 }
8883 /* The initializers for virtual functions were built up in reverse
8884 order. Straighten them out and add them to the running list in one
8885 step. */
8894 /* Go through all the ordinary virtual functions, building up
8895 initializers. */
8897 {
8898 tree delta;
8899 tree vcall_index;
8906 {
8910 {
8913 }
8915 }
8917 /* If the only definition of this function signature along our
8918 primary base chain is from a lost primary, this vtable slot will
8919 never be used, so just zero it out. This is important to avoid
8920 requiring extra thunks which cannot be generated with the function.
8922 We first check this in update_vtable_entry_for_fn, so we handle
8923 restored primary bases properly; we also need to do it here so we
8924 zero out unused slots in ctor vtables, rather than filling them
8925 with erroneous values (though harmless, apart from relocation
8926 costs). */
8931 {
8932 /* Pull the offset for `this', and the function to call, out of
8933 the list. */
8940 /* You can't call an abstract virtual function; it's abstract.
8941 So, we replace these functions with __pure_virtual. */
8943 {
8946 {
8948 abort_fndecl_addr
8952 }
8953 }
8954 /* Likewise for deleted virtuals. */
8956 {
8965 }
8966 else
8967 {
8969 {
8973 }
8974 /* Take the address of the function, considering it to be of an
8975 appropriate generic type. */
8979 /* Don't refer to a virtual destructor from a constructor
8980 vtable or a vtable for an abstract class, since destroying
8981 an object under construction is undefined behavior and we
8982 don't want it to be considered a candidate for speculative
8983 devirtualization. But do create the thunk for ABI
8984 compliance. */
8989 }
8990 }
8992 /* And add it to the chain of initializers. */
8994 {
8999 else
9001 {
9007 }
9008 }
9009 else
9011 }
9012 }
9014 /* Adds to vid->inits the initializers for the vbase and vcall
9015 offsets in BINFO, which is in the hierarchy dominated by T. */
9017 static void
9019 {
9020 tree b;
9022 /* If this is a derived class, we must first create entries
9023 corresponding to the primary base class. */
9028 /* Add the vbase entries for this base. */
9030 /* Add the vcall entries for this base. */
9032 }
9034 /* Returns the initializers for the vbase offset entries in the vtable
9035 for BINFO (which is part of the class hierarchy dominated by T), in
9036 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9037 where the next vbase offset will go. */
9039 static void
9041 {
9042 tree vbase;
9043 tree t;
9044 tree non_primary_binfo;
9046 /* If there are no virtual baseclasses, then there is nothing to
9047 do. */
9053 /* We might be a primary base class. Go up the inheritance hierarchy
9054 until we find the most derived class of which we are a primary base:
9055 it is the offset of that which we need to use. */
9058 {
9059 tree b;
9061 /* If we have reached a virtual base, then it must be a primary
9062 base (possibly multi-level) of vid->binfo, or we wouldn't
9063 have called build_vcall_and_vbase_vtbl_entries for it. But it
9064 might be a lost primary, so just skip down to vid->binfo. */
9066 {
9069 }
9075 }
9077 /* Go through the virtual bases, adding the offsets. */
9079 vbase;
9081 {
9082 tree b;
9083 tree delta;
9088 /* Find the instance of this virtual base in the complete
9089 object. */
9092 /* If we've already got an offset for this virtual base, we
9093 don't need another one. */
9098 /* Figure out where we can find this vbase offset. */
9107 /* The vbase offset had better be the same. */
9110 /* The next vbase will come at a more negative offset. */
9114 /* The initializer is the delta from BINFO to this virtual base.
9115 The vbase offsets go in reverse inheritance-graph order, and
9116 we are walking in inheritance graph order so these end up in
9117 the right order. */
9124 }
9125 }
9127 /* Adds the initializers for the vcall offset entries in the vtable
9128 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9129 to VID->INITS. */
9131 static void
9133 {
9134 /* We only need these entries if this base is a virtual base. We
9135 compute the indices -- but do not add to the vtable -- when
9136 building the main vtable for a class. */
9139 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9140 correspond to VID->DERIVED), we are building a primary
9141 construction virtual table. Since this is a primary
9142 virtual table, we do not need the vcall offsets for
9143 BINFO. */
9145 {
9146 /* We need a vcall offset for each of the virtual functions in this
9147 vtable. For example:
9149 class A { virtual void f (); };
9150 class B1 : virtual public A { virtual void f (); };
9151 class B2 : virtual public A { virtual void f (); };
9152 class C: public B1, public B2 { virtual void f (); };
9154 A C object has a primary base of B1, which has a primary base of A. A
9155 C also has a secondary base of B2, which no longer has a primary base
9156 of A. So the B2-in-C construction vtable needs a secondary vtable for
9157 A, which will adjust the A* to a B2* to call f. We have no way of
9158 knowing what (or even whether) this offset will be when we define B2,
9159 so we store this "vcall offset" in the A sub-vtable and look it up in
9160 a "virtual thunk" for B2::f.
9162 We need entries for all the functions in our primary vtable and
9163 in our non-virtual bases' secondary vtables. */
9165 /* If we are just computing the vcall indices -- but do not need
9166 the actual entries -- not that. */
9169 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9171 }
9172 }
9174 /* Build vcall offsets, starting with those for BINFO. */
9176 static void
9178 {
9180 tree primary_binfo;
9181 tree base_binfo;
9183 /* Don't walk into virtual bases -- except, of course, for the
9184 virtual base for which we are building vcall offsets. Any
9185 primary virtual base will have already had its offsets generated
9186 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9190 /* If BINFO has a primary base, process it first. */
9195 /* Add BINFO itself to the list. */
9198 /* Scan the non-primary bases of BINFO. */
9202 }
9204 /* Called from build_vcall_offset_vtbl_entries_r. */
9206 static void
9208 {
9209 /* Make entries for the rest of the virtuals. */
9210 tree orig_fn;
9212 /* The ABI requires that the methods be processed in declaration
9213 order. */
9215 orig_fn;
9219 }
9221 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9223 static void
9225 {
9227 tree vcall_offset;
9228 tree derived_entry;
9230 /* If there is already an entry for a function with the same
9231 signature as FN, then we do not need a second vcall offset.
9232 Check the list of functions already present in the derived
9233 class vtable. */
9235 {
9237 /* We only use one vcall offset for virtual destructors,
9238 even though there are two virtual table entries. */
9242 }
9244 /* If we are building these vcall offsets as part of building
9245 the vtable for the most derived class, remember the vcall
9246 offset. */
9248 {
9251 }
9253 /* The next vcall offset will be found at a more negative
9254 offset. */
9258 /* Keep track of this function. */
9262 {
9263 tree base;
9264 tree fn;
9266 /* Find the overriding function. */
9270 else
9271 {
9274 /* The vbase we're working on is a primary base of
9275 vid->binfo. But it might be a lost primary, so its
9276 BINFO_OFFSET might be wrong, so we just use the
9277 BINFO_OFFSET from vid->binfo. */
9283 vcall_offset);
9284 }
9285 /* Add the initializer to the vtable. */
9287 }
9288 }
9290 /* Return vtbl initializers for the RTTI entries corresponding to the
9291 BINFO's vtable. The RTTI entries should indicate the object given
9292 by VID->rtti_binfo. */
9294 static void
9296 {
9297 tree b;
9298 tree t;
9299 tree offset;
9300 tree decl;
9301 tree init;
9305 /* To find the complete object, we will first convert to our most
9306 primary base, and then add the offset in the vtbl to that value. */
9310 {
9311 tree primary_base;
9317 }
9321 /* The second entry is the address of the typeinfo object. */
9324 else
9327 /* Convert the declaration to a type that can be stored in the
9328 vtable. */
9332 /* Add the offset-to-top entry. It comes earlier in the vtable than
9333 the typeinfo entry. Convert the offset to look like a
9334 function pointer, so that we can put it in the vtable. */
9337 }
9339 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9340 accessibility. */
9342 bool
9344 {
9347 }
9349 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9351 bool
9353 {
9357 }
9359 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9360 class between them, if any. */
9362 tree
9364 {
9376 {
9379 }
9383 }