| blob | b48f29a16abd8770d7aae83959dd7bc7abd23932 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2015 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. */
61 /* The number of nested classes being processed. If we are not in the
62 scope of any class, this is zero. */
66 /* In order to deal with nested classes, we keep a stack of classes.
67 The topmost entry is the innermost class, and is the entry at index
68 CURRENT_CLASS_DEPTH */
71 /* The name of the class. */
72 tree name;
74 /* The _TYPE node for the class. */
75 tree type;
77 /* The access specifier pending for new declarations in the scope of
78 this class. */
79 tree access;
81 /* If were defining TYPE, the names used in this class. */
82 splay_tree names_used;
84 /* Nonzero if this class is no longer open, because of a call to
85 push_to_top_level. */
90 {
91 /* The base for which we're building initializers. */
92 tree binfo;
93 /* The type of the most-derived type. */
94 tree derived;
95 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
96 unless ctor_vtbl_p is true. */
97 tree rtti_binfo;
98 /* The negative-index vtable initializers built up so far. These
99 are in order from least negative index to most negative index. */
101 /* The binfo for the virtual base for which we're building
102 vcall offset initializers. */
103 tree vbase;
104 /* The functions in vbase for which we have already provided vcall
105 offsets. */
107 /* The vtable index of the next vcall or vbase offset. */
108 tree index;
109 /* Nonzero if we are building the initializer for the primary
110 vtable. */
112 /* Nonzero if we are building the initializer for a construction
113 vtable. */
115 /* True when adding vcall offset entries to the vtable. False when
116 merely computing the indices. */
120 /* The type of a function passed to walk_subobject_offsets. */
123 /* The stack itself. This is a dynamically resized array. The
124 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
128 /* The size of the largest empty class seen in this translation unit. */
131 /* An array of all local classes present in this translation unit, in
132 declaration order. */
215 tree *);
225 splay_tree_key k2);
233 /* Variables shared between class.c and call.c. */
243 /* Convert to or from a base subobject. EXPR is an expression of type
244 `A' or `A*', an expression of type `B' or `B*' is returned. To
245 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
246 the B base instance within A. To convert base A to derived B, CODE
247 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
248 In this latter case, A must not be a morally virtual base of B.
249 NONNULL is true if EXPR is known to be non-NULL (this is only
250 needed when EXPR is of pointer type). CV qualifiers are preserved
251 from EXPR. */
253 tree
255 tree expr,
256 tree binfo,
258 tsubst_flags_t complain)
259 {
262 tree probe;
263 tree offset;
264 tree target_type;
266 tree ptr_target_type;
277 {
283 }
291 {
292 /* This can happen when adjust_result_of_qualified_name_lookup can't
293 find a unique base binfo in a call to a member function. We
294 couldn't give the diagnostic then since we might have been calling
295 a static member function, so we do it now. */
297 {
301 }
303 }
310 /* Nothing to do. */
314 {
316 {
318 {
321 "pointer to derived class %qT because the base is "
323 else
327 }
328 else
329 {
335 else
339 }
340 }
342 }
345 {
347 /* This must happen before the call to save_expr. */
349 }
350 else
356 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
357 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
358 expression returned matches the input. */
359 target_type = cp_build_qualified_type
363 /* Do we need to look in the vtable for the real offset? */
366 /* Don't bother with the calculations inside sizeof; they'll ICE if the
367 source type is incomplete and the pointer value doesn't matter. In a
368 template (even in instantiate_non_dependent_expr), we don't have vtables
369 set up properly yet, and the value doesn't matter there either; we're
370 just interested in the result of overload resolution. */
373 {
376 }
378 /* If we're in an NSDMI, we don't have the full constructor context yet
379 that we need for converting to a virtual base, so just build a stub
380 CONVERT_EXPR and expand it later in bot_replace. */
383 {
387 }
389 /* Do we need to check for a null pointer? */
391 {
392 /* If we know the conversion will not actually change the value
393 of EXPR, then we can avoid testing the expression for NULL.
394 We have to avoid generating a COMPONENT_REF for a base class
395 field, because other parts of the compiler know that such
396 expressions are always non-NULL. */
400 }
402 /* Protect against multiple evaluation if necessary. */
406 /* Now that we've saved expr, build the real null test. */
408 {
412 }
414 /* If this is a simple base reference, express it as a COMPONENT_REF. */
416 /* We don't build base fields for empty bases, and they aren't very
417 interesting to the optimizers anyway. */
419 {
428 }
431 {
432 /* Going via virtual base V_BINFO. We need the static offset
433 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
434 V_BINFO. That offset is an entry in D_BINFO's vtable. */
435 tree v_offset;
438 {
439 /* In a base member initializer, we cannot rely on the
440 vtable being set up. We have to indirect via the
441 vtt_parm. */
442 tree t;
448 }
449 else
450 {
453 {
458 }
460 complain),
462 }
470 v_offset);
482 /* Negative fixed_type_p means this is a constructor or destructor;
483 virtual base layout is fixed in in-charge [cd]tors, but not in
484 base [cd]tors. */
488 v_offset,
491 else
493 }
501 {
506 }
507 else
510 indout:
512 {
516 }
518 out:
524 }
526 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
527 Perform a derived-to-base conversion by recursively building up a
528 sequence of COMPONENT_REFs to the appropriate base fields. */
530 static tree
532 {
535 tree field;
538 {
539 tree temp;
543 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
544 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
545 an lvalue in the front end; only _DECLs and _REFs are lvalues
546 in the back end. */
552 }
554 /* Recurse. */
559 /* Is this the base field created by build_base_field? */
563 /* If we're looking for a field in the most-derived class,
564 also check the field offset; we can have two base fields
565 of the same type if one is an indirect virtual base and one
566 is a direct non-virtual base. */
570 {
571 /* We don't use build_class_member_access_expr here, as that
572 has unnecessary checks, and more importantly results in
573 recursive calls to dfs_walk_once. */
581 /* Mark the expression const or volatile, as appropriate.
582 Even though we've dealt with the type above, we still have
583 to mark the expression itself. */
590 }
592 /* Didn't find the base field?!? */
594 }
596 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
597 type is a class type or a pointer to a class type. In the former
598 case, TYPE is also a class type; in the latter it is another
599 pointer type. If CHECK_ACCESS is true, an error message is emitted
600 if TYPE is inaccessible. If OBJECT has pointer type, the value is
601 assumed to be non-NULL. */
603 tree
605 tsubst_flags_t complain)
606 {
607 tree binfo;
608 tree object_type;
611 {
614 }
615 else
624 }
626 /* EXPR is an expression with unqualified class type. BASE is a base
627 binfo of that class type. Returns EXPR, converted to the BASE
628 type. This function assumes that EXPR is the most derived class;
629 therefore virtual bases can be found at their static offsets. */
631 tree
633 {
634 tree expr_type;
638 {
639 /* If this is a non-empty base, use a COMPONENT_REF. */
643 /* We use fold_build2 and fold_convert below to simplify the trees
644 provided to the optimizers. It is not safe to call these functions
645 when processing a template because they do not handle C++-specific
646 trees. */
654 }
657 }
659 \f
660 tree
662 {
666 /* Can happen in case of duplicate base types (c++/59082). */
670 /* First, convert to the requested type. */
675 /* Second, the requested type may not be the owner of its own vptr.
676 If not, convert to the base class that owns it. We cannot use
677 convert_to_base here, because VCONTEXT may appear more than once
678 in the inheritance hierarchy of TYPE, and thus direct conversion
679 between the types may be ambiguous. Following the path back up
680 one step at a time via primary bases avoids the problem. */
684 {
687 }
690 }
692 /* Given an object INSTANCE, return an expression which yields the
693 vtable element corresponding to INDEX. There are many special
694 cases for INSTANCE which we take care of here, mainly to avoid
695 creating extra tree nodes when we don't have to. */
697 static tree
699 {
700 tree aref;
703 /* Try to figure out what a reference refers to, and
704 access its virtual function table directly. */
712 {
717 }
726 }
728 tree
730 {
734 }
736 /* Given a stable object pointer INSTANCE_PTR, return an expression which
737 yields a function pointer corresponding to vtable element INDEX. */
739 tree
741 {
742 tree aref;
745 tf_warning_or_error),
746 idx);
748 /* When using function descriptors, the address of the
749 vtable entry is treated as a function pointer. */
754 /* Remember this as a method reference, for later devirtualization. */
758 }
760 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
761 for the given TYPE. */
763 static tree
765 {
767 }
769 /* DECL is an entity associated with TYPE, like a virtual table or an
770 implicitly generated constructor. Determine whether or not DECL
771 should have external or internal linkage at the object file
772 level. This routine does not deal with COMDAT linkage and other
773 similar complexities; it simply sets TREE_PUBLIC if it possible for
774 entities in other translation units to contain copies of DECL, in
775 the abstract. */
777 void
779 {
782 }
784 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
785 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
786 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
788 static tree
790 {
791 tree decl;
794 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
795 now to avoid confusion in mangle_decl. */
806 /* The vtable has not been defined -- yet. */
810 /* Mark the VAR_DECL node representing the vtable itself as a
811 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
812 is rather important that such things be ignored because any
813 effort to actually generate DWARF for them will run into
814 trouble when/if we encounter code like:
816 #pragma interface
817 struct S { virtual void member (); };
819 because the artificial declaration of the vtable itself (as
820 manufactured by the g++ front end) will say that the vtable is
821 a static member of `S' but only *after* the debug output for
822 the definition of `S' has already been output. This causes
823 grief because the DWARF entry for the definition of the vtable
824 will try to refer back to an earlier *declaration* of the
825 vtable as a static member of `S' and there won't be one. We
826 might be able to arrange to have the "vtable static member"
827 attached to the member list for `S' before the debug info for
828 `S' get written (which would solve the problem) but that would
829 require more intrusive changes to the g++ front end. */
833 }
835 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
836 or even complete. If this does not exist, create it. If COMPLETE is
837 nonzero, then complete the definition of it -- that will render it
838 impossible to actually build the vtable, but is useful to get at those
839 which are known to exist in the runtime. */
841 tree
843 {
844 tree decl;
853 {
856 }
859 }
861 /* Build the primary virtual function table for TYPE. If BINFO is
862 non-NULL, build the vtable starting with the initial approximation
863 that it is the same as the one which is the head of the association
864 list. Returns a nonzero value if a new vtable is actually
865 created. */
867 static int
869 {
870 tree decl;
871 tree virtuals;
876 {
878 /* We have already created a vtable for this base, so there's
879 no need to do it again. */
886 }
887 else
888 {
891 }
894 {
897 }
899 /* Initialize the association list for this type, based
900 on our first approximation. */
905 }
907 /* Give BINFO a new virtual function table which is initialized
908 with a skeleton-copy of its original initialization. The only
909 entry that changes is the `delta' entry, so we can really
910 share a lot of structure.
912 FOR_TYPE is the most derived type which caused this table to
913 be needed.
915 Returns nonzero if we haven't met BINFO before.
917 The order in which vtables are built (by calling this function) for
918 an object must remain the same, otherwise a binary incompatibility
919 can result. */
921 static int
923 {
925 /* We already created a vtable for this base. There's no need to
926 do it again. */
929 /* Remember that we've created a vtable for this BINFO, so that we
930 don't try to do so again. */
933 /* Make fresh virtual list, so we can smash it later. */
936 /* Secondary vtables are laid out as part of the same structure as
937 the primary vtable. */
940 }
942 /* Create a new vtable for BINFO which is the hierarchy dominated by
943 T. Return nonzero if we actually created a new vtable. */
945 static int
947 {
949 /* In this case, it is *type*'s vtable we are modifying. We start
950 with the approximation that its vtable is that of the
951 immediate base class. */
953 else
954 /* This is our very own copy of `basetype' to play with. Later,
955 we will fill in all the virtual functions that override the
956 virtual functions in these base classes which are not defined
957 by the current type. */
959 }
961 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
962 (which is in the hierarchy dominated by T) list FNDECL as its
963 BV_FN. DELTA is the required constant adjustment from the `this'
964 pointer where the vtable entry appears to the `this' required when
965 the function is actually called. */
967 static void
969 tree binfo,
970 tree fndecl,
971 tree delta,
973 {
974 tree v;
980 {
981 /* We need a new vtable for BINFO. */
983 {
984 /* If we really did make a new vtable, we also made a copy
985 of the BINFO_VIRTUALS list. Now, we have to find the
986 corresponding entry in that list. */
991 }
996 }
997 }
999 \f
1000 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
1001 the USING_DECL naming METHOD. Returns true if the method could be
1002 added to the method vec. */
1004 bool
1006 {
1008 tree overload;
1014 tree current_fns;
1015 tree fns;
1028 {
1029 /* Make a new method vector. We start with 8 entries. We must
1030 allocate at least two (for constructors and destructors), and
1031 we're going to end up with an assignment operator at some
1032 point as well. */
1034 /* Create slots for constructors and destructors. */
1038 }
1040 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1043 /* Constructors and destructors go in special slots. */
1047 {
1051 {
1057 type);
1058 }
1059 }
1060 else
1061 {
1062 tree m;
1065 /* See if we already have an entry with this name. */
1069 {
1072 {
1077 }
1081 {
1084 }
1089 }
1090 }
1093 /* Check to see if we've already got this method. */
1095 {
1097 tree fn_type;
1098 tree method_type;
1099 tree parms1;
1100 tree parms2;
1105 /* [over.load] Member function declarations with the
1106 same name and the same parameter types cannot be
1107 overloaded if any of them is a static member
1108 function declaration.
1110 [over.load] Member function declarations with the same name and
1111 the same parameter-type-list as well as member function template
1112 declarations with the same name, the same parameter-type-list, and
1113 the same template parameter lists cannot be overloaded if any of
1114 them, but not all, have a ref-qualifier.
1116 [namespace.udecl] When a using-declaration brings names
1117 from a base class into a derived class scope, member
1118 functions in the derived class override and/or hide member
1119 functions with the same name and parameter types in a base
1120 class (rather than conflicting). */
1126 /* Compare the quals on the 'this' parm. Don't compare
1127 the whole types, as used functions are treated as
1128 coming from the using class in overload resolution. */
1131 /* Either both or neither need to be ref-qualified for
1132 differing quals to allow overloading. */
1139 /* For templates, the return type and template parameters
1140 must be identical. */
1157 {
1158 /* For function versions, their parms and types match
1159 but they are not duplicates. Record function versions
1160 as and when they are found. extern "C" functions are
1161 not treated as versions. */
1167 {
1168 /* Mark functions as versions if necessary. Modify the mangled
1169 decl name if necessary. */
1171 {
1175 }
1177 {
1181 }
1184 }
1186 {
1188 {
1195 }
1196 /* Otherwise defer to the other function. */
1198 }
1200 {
1202 /* Defer to the local function. */
1204 }
1205 else
1206 {
1209 }
1211 /* We don't call duplicate_decls here to merge the
1212 declarations because that will confuse things if the
1213 methods have inline definitions. In particular, we
1214 will crash while processing the definitions. */
1216 }
1217 }
1219 /* A class should never have more than one destructor. */
1223 /* Add the new binding. */
1225 {
1228 }
1229 else
1238 {
1241 /* We only expect to add few methods in the COMPLETE_P case, so
1242 just make room for one more method in that case. */
1245 else
1251 else
1253 }
1254 else
1255 /* Replace the current slot. */
1258 }
1260 /* Subroutines of finish_struct. */
1262 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1263 legit, otherwise return 0. */
1265 static int
1267 {
1268 tree elem;
1277 {
1279 {
1283 else
1286 }
1287 else
1288 {
1289 /* They're changing the access to the same thing they changed
1290 it to before. That's OK. */
1291 ;
1292 }
1293 }
1294 else
1295 {
1297 tf_warning_or_error);
1300 }
1302 }
1304 /* Process the USING_DECL, which is a member of T. */
1306 static void
1308 {
1311 tree access
1316 tree old_value;
1321 tf_warning_or_error);
1323 {
1329 else
1331 }
1339 ;
1341 {
1343 /* It's OK to use functions from a base when there are functions with
1345 else
1346 {
1351 }
1352 }
1354 {
1358 }
1360 /* Make type T see field decl FDECL with access ACCESS. */
1363 {
1366 }
1367 else
1369 }
1370 \f
1371 /* Data structure for find_abi_tags_r, below. */
1373 struct abi_tag_data
1374 {
1378 };
1380 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1381 in the context of P. TAG can be either an identifier (the DECL_NAME of
1382 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1384 static void
1386 {
1388 {
1390 {
1391 /* We're collecting tags from template arguments or from
1392 the type of a variable or function return type. */
1395 /* Don't inherit this tag multiple times. */
1399 {
1400 /* Tags inherited from type template arguments are only used
1401 to avoid warnings. */
1404 }
1405 /* For functions and variables we want to warn, too. */
1406 }
1408 /* Otherwise we're diagnosing missing tags. */
1410 {
1415 }
1417 {
1421 }
1423 {
1428 }
1429 else
1430 {
1434 {
1438 }
1439 }
1440 }
1441 }
1443 /* Find all the ABI tags in the attribute list ATTR and either call
1444 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1446 static void
1448 {
1455 {
1460 else
1462 }
1463 }
1465 /* Find all the ABI tags on T and its enclosing scopes and either call
1466 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1468 static void
1470 {
1472 {
1473 tree attr;
1475 {
1478 }
1479 else
1480 {
1483 }
1485 }
1486 }
1488 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1489 types with ABI tags, add the corresponding identifiers to the VEC in
1490 *DATA and set IDENTIFIER_MARKED. */
1492 static tree
1494 {
1498 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1499 anyway, but let's make sure of it. */
1507 }
1509 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1510 IDENTIFIER_MARKED on its ABI tags. */
1512 static tree
1514 {
1518 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1519 anyway, but let's make sure of it. */
1527 }
1529 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1530 scopes. */
1532 static void
1534 {
1537 {
1540 {
1541 /* Template arguments are part of the signature. */
1544 {
1547 }
1548 }
1550 /* A function's parameter types are part of the signature, so
1551 we don't need to inherit any tags that are also in them. */
1556 }
1557 }
1559 /* Check that T has all the ABI tags that subobject SUBOB has, or
1560 warn if not. If T is a (variable or function) declaration, also
1561 add any missing tags. */
1563 static void
1565 {
1573 /* No need to worry about things local to this TU. */
1586 {
1590 else
1594 }
1597 }
1599 /* Check that DECL has all the ABI tags that are used in parts of its type
1600 that are not reflected in its mangled name. */
1602 void
1604 {
1610 }
1612 void
1614 {
1624 {
1627 {
1631 }
1632 }
1634 // If we found some tags on our template arguments, add them to our
1635 // abi_tag attribute.
1637 {
1641 else
1645 }
1648 }
1650 /* Return true, iff class T has a non-virtual destructor that is
1651 accessible from outside the class heirarchy (i.e. is public, or
1652 there's a suitable friend. */
1654 static bool
1656 {
1659 /* An implicitly declared destructor is always public. And,
1660 if it were virtual, we would have created it by now. */
1675 }
1677 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1678 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1679 properties of the bases. */
1681 static void
1685 {
1689 tree base_binfo;
1690 tree binfo;
1700 {
1709 /* If any base class is non-literal, so is the derived class. */
1713 /* If the base class doesn't have copy constructors or
1714 assignment operators that take const references, then the
1715 derived class cannot have such a member automatically
1716 generated. */
1725 /* A virtual base does not effect nearly emptiness. */
1726 ;
1728 {
1730 /* And if there is more than one nearly empty base, then the
1731 derived class is not nearly empty either. */
1733 else
1734 /* Remember we've seen one. */
1736 }
1738 /* If the base class is not empty or nearly empty, then this
1739 class cannot be nearly empty. */
1742 /* A lot of properties from the bases also apply to the derived
1743 class. */
1760 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1763 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1767 /* A standard-layout class is a class that:
1768 ...
1769 * has no non-standard-layout base classes, */
1772 {
1773 tree basefield;
1774 /* ...has no base classes of the same type as the first non-static
1775 data member... */
1777 && (same_type_ignoring_top_level_qualifiers_p
1780 else
1781 /* ...either has no non-static data members in the most-derived
1782 class and at most one base class with non-static data
1783 members, or has no base classes with non-static data
1784 members */
1788 {
1791 else
1794 }
1795 }
1797 /* Don't bother collecting tm attributes if transactional memory
1798 support is not enabled. */
1800 {
1804 }
1807 }
1809 /* If one of the base classes had TM attributes, and the current class
1810 doesn't define its own, then the current class inherits one. */
1812 {
1815 }
1816 }
1818 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1819 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1820 that have had a nearly-empty virtual primary base stolen by some
1821 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1822 T. */
1824 static void
1826 {
1830 tree base_binfo;
1832 /* Determine the primary bases of our bases. */
1835 {
1838 /* See if we're the non-virtual primary of our inheritance
1839 chain. */
1841 {
1848 /* We are the primary binfo. */
1850 }
1851 /* Determine if we have a virtual primary base, and mark it so.
1852 */
1854 {
1858 /* Someone already claimed this base. */
1860 else
1861 {
1862 tree delta;
1867 /* A virtual binfo might have been copied from within
1868 another hierarchy. As we're about to use it as a
1869 primary base, make sure the offsets match. */
1877 }
1878 }
1879 }
1881 /* First look for a dynamic direct non-virtual base. */
1883 {
1887 {
1890 }
1891 }
1893 /* A "nearly-empty" virtual base class can be the primary base
1894 class, if no non-virtual polymorphic base can be found. Look for
1895 a nearly-empty virtual dynamic base that is not already a primary
1896 base of something in the hierarchy. If there is no such base,
1897 just pick the first nearly-empty virtual base. */
1903 {
1905 {
1906 /* Found one that is not primary. */
1909 }
1911 /* Remember the first candidate. */
1913 }
1915 found:
1916 /* If we've got a primary base, use it. */
1918 {
1923 /* We are stealing a primary base. */
1927 {
1928 tree delta;
1931 /* A virtual binfo might have been copied from within
1932 another hierarchy. As we're about to use it as a primary
1933 base, make sure the offsets match. */
1938 }
1945 }
1946 }
1948 /* Update the variant types of T. */
1950 void
1952 {
1953 tree variants;
1959 variants;
1961 {
1962 /* These fields are in the _TYPE part of the node, not in
1963 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1973 /* Copy whatever these are holding today. */
1977 }
1978 }
1980 /* Early variant fixups: we apply attributes at the beginning of the class
1981 definition, and we need to fix up any variants that have already been
1982 made via elaborated-type-specifier so that check_qualified_type works. */
1984 void
1986 {
1987 tree variants;
1997 variants;
1999 {
2000 /* These are the two fields that check_qualified_type looks at and
2001 are affected by attributes. */
2006 else
2009 }
2010 }
2011 \f
2012 /* Set memoizing fields and bits of T (and its variants) for later
2013 use. */
2015 static void
2017 {
2018 /* Fix up variants (if any). */
2022 /* For a class w/o baseclasses, 'finish_struct' has set
2023 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2024 Similarly for a class whose base classes do not have vtables.
2025 When neither of these is true, we might have removed abstract
2026 virtuals (by providing a definition), added some (by declaring
2027 new ones), or redeclared ones from a base class. We need to
2028 recalculate what's really an abstract virtual at this point (by
2029 looking in the vtables). */
2032 /* If this type has a copy constructor or a destructor, force its
2033 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2034 nonzero. This will cause it to be passed by invisible reference
2035 and prevent it from being returned in a register. */
2038 {
2039 tree variants;
2042 {
2045 }
2046 }
2047 }
2049 /* Issue warnings about T having private constructors, but no friends,
2050 and so forth.
2052 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2053 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2054 non-private static member functions. */
2056 static void
2058 {
2061 tree fn;
2064 /* If the class has friends, those entities might create and
2065 access instances, so we should not warn. */
2068 /* We will have warned when the template was declared; there's
2069 no need to warn on every instantiation. */
2071 /* There's no reason to even consider warning about this
2072 class. */
2075 /* We only issue one warning, if more than one applies, because
2076 otherwise, on code like:
2078 class A {
2079 // Oops - forgot `public:'
2080 A();
2081 A(const A&);
2082 ~A();
2083 };
2085 we warn several times about essentially the same problem. */
2087 /* Check to see if all (non-constructor, non-destructor) member
2088 functions are private. (Since there are no friends or
2089 non-private statics, we can't ever call any of the private member
2090 functions.) */
2092 /* We're not interested in compiler-generated methods; they don't
2093 provide any way to call private members. */
2095 {
2097 {
2099 /* A non-private static member function is just like a
2100 friend; it can create and invoke private member
2101 functions, and be accessed without a class
2102 instance. */
2106 /* Keep searching for a static member function. */
2107 }
2110 }
2113 {
2114 /* There are no non-private methods, and there's at least one
2115 private member function that isn't a constructor or
2116 destructor. (If all the private members are
2117 constructors/destructors we want to use the code below that
2118 issues error messages specifically referring to
2119 constructors/destructors.) */
2125 {
2128 }
2130 {
2134 }
2135 }
2137 /* Even if some of the member functions are non-private, the class
2138 won't be useful for much if all the constructors or destructors
2139 are private: such an object can never be created or destroyed. */
2142 {
2145 t);
2147 }
2149 /* Warn about classes that have private constructors and no friends. */
2151 /* Implicitly generated constructors are always public. */
2154 {
2157 /* If a non-template class does not define a copy
2158 constructor, one is defined for it, enabling it to avoid
2159 this warning. For a template class, this does not
2160 happen, and so we would normally get a warning on:
2162 template <class T> class C { private: C(); };
2164 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2165 complete non-template or fully instantiated classes have this
2166 flag set. */
2169 else
2171 {
2173 /* Ideally, we wouldn't count copy constructors (or, in
2174 fact, any constructor that takes an argument of the
2175 class type as a parameter) because such things cannot
2176 be used to construct an instance of the class unless
2177 you already have one. But, for now at least, we're
2178 more generous. */
2180 {
2183 }
2184 }
2187 {
2190 t);
2192 }
2193 }
2194 }
2197 gt_pointer_operator new_value;
2201 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2203 static int
2205 {
2218 }
2220 /* This routine compares two fields like method_name_cmp but using the
2221 pointer operator in resort_field_decl_data. */
2223 static int
2225 {
2234 {
2241 }
2243 }
2245 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2247 void
2250 gt_pointer_operator new_value,
2252 {
2256 tree fn;
2258 /* The type conversion ops have to live at the front of the vec, so we
2259 can't sort them. */
2267 {
2271 resort_method_name_cmp);
2272 }
2273 }
2275 /* Warn about duplicate methods in fn_fields.
2277 Sort methods that are not special (i.e., constructors, destructors,
2278 and type conversion operators) so that we can find them faster in
2279 search. */
2281 static void
2283 {
2284 tree fn_fields;
2294 /* Clear DECL_IN_AGGR_P for all functions. */
2299 /* Issue warnings about private constructors and such. If there are
2300 no methods, then some public defaults are generated. */
2303 /* The type conversion ops have to live at the front of the vec, so we
2304 can't sort them. */
2313 }
2315 /* Make BINFO's vtable have N entries, including RTTI entries,
2316 vbase and vcall offsets, etc. Set its type and call the back end
2317 to lay it out. */
2319 static void
2321 {
2322 tree atype;
2323 tree vtable;
2328 /* We may have to grow the vtable. */
2331 {
2335 }
2336 }
2338 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2339 have the same signature. */
2341 int
2343 {
2344 /* One destructor overrides another if they are the same kind of
2345 destructor. */
2349 /* But a non-destructor never overrides a destructor, nor vice
2350 versa, nor do different kinds of destructors override
2351 one-another. For example, a complete object destructor does not
2352 override a deleting destructor. */
2361 {
2369 }
2371 }
2373 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2374 subobject. */
2376 static bool
2378 {
2379 tree probe;
2382 {
2386 /* If we meet a virtual base, we can't follow the inheritance
2387 any more. See if the complete type of DERIVED contains
2388 such a virtual base. */
2391 }
2393 }
2396 /* The function for which we are trying to find a final overrider. */
2397 tree fn;
2398 /* The base class in which the function was declared. */
2399 tree declaring_base;
2400 /* The candidate overriders. */
2401 tree candidates;
2402 /* Path to most derived. */
2406 /* Add the overrider along the current path to FFOD->CANDIDATES.
2407 Returns true if an overrider was found; false otherwise. */
2409 static bool
2413 {
2414 tree method;
2416 /* If BINFO is not the most derived type, try a more derived class.
2417 A definition there will overrider a definition here. */
2419 {
2420 depth--;
2424 }
2428 {
2431 /* Remove any candidates overridden by this new function. */
2433 {
2434 /* If *CANDIDATE overrides METHOD, then METHOD
2435 cannot override anything else on the list. */
2438 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2441 else
2443 }
2445 /* Add the new function. */
2448 }
2451 }
2453 /* Called from find_final_overrider via dfs_walk. */
2455 static tree
2457 {
2465 }
2467 static tree
2469 {
2474 }
2476 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2477 FN and whose TREE_VALUE is the binfo for the base where the
2478 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2479 DERIVED) is the base object in which FN is declared. */
2481 static tree
2483 {
2484 find_final_overrider_data ffod;
2486 /* Getting this right is a little tricky. This is valid:
2488 struct S { virtual void f (); };
2489 struct T { virtual void f (); };
2490 struct U : public S, public T { };
2492 even though calling `f' in `U' is ambiguous. But,
2494 struct R { virtual void f(); };
2495 struct S : virtual public R { virtual void f (); };
2496 struct T : virtual public R { virtual void f (); };
2497 struct U : public S, public T { };
2499 is not -- there's no way to decide whether to put `S::f' or
2500 `T::f' in the vtable for `R'.
2502 The solution is to look at all paths to BINFO. If we find
2503 different overriders along any two, then there is a problem. */
2507 /* Determine the depth of the hierarchy. */
2518 /* If there was no winner, issue an error message. */
2523 }
2525 /* Return the index of the vcall offset for FN when TYPE is used as a
2526 virtual base. */
2528 static tree
2530 {
2532 tree_pair_p p;
2540 /* There should always be an appropriate index. */
2542 }
2544 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2545 dominated by T. FN is the old function; VIRTUALS points to the
2546 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2547 of that entry in the list. */
2549 static void
2552 {
2553 tree b;
2554 tree overrider;
2555 tree delta;
2556 tree virtual_base;
2557 tree first_defn;
2563 /* Find the nearest primary base (possibly binfo itself) which defines
2564 this function; this is the class the caller will convert to when
2565 calling FN through BINFO. */
2567 {
2572 /* The nearest definition is from a lost primary. */
2575 }
2578 /* Find the final overrider. */
2581 {
2584 }
2587 /* Check for adjusting covariant return types. */
2595 /* If the overrider is invalid, don't even try. */
2597 {
2598 /* If FN is a covariant thunk, we must figure out the adjustment
2599 to the final base FN was converting to. As OVERRIDER_TARGET might
2600 also be converting to the return type of FN, we have to
2601 combine the two conversions here. */
2608 {
2612 }
2613 else
2617 /* Find the equivalent binfo within the return type of the
2618 overriding function. We will want the vbase offset from
2619 there. */
2621 over_return);
2624 {
2625 /* There was no existing virtual thunk (which takes
2626 precedence). So find the binfo of the base function's
2627 return type within the overriding function's return type.
2628 We cannot call lookup base here, because we're inside a
2629 dfs_walk, and will therefore clobber the BINFO_MARKED
2630 flags. Fortunately we know the covariancy is valid (it
2631 has already been checked), so we can just iterate along
2632 the binfos, which have been chained in inheritance graph
2633 order. Of course it is lame that we have to repeat the
2634 search here anyway -- we should really be caching pieces
2635 of the vtable and avoiding this repeated work. */
2638 /* Find the base binfo within the overriding function's
2639 return type. We will always find a thunk_binfo, except
2640 when the covariancy is invalid (which we will have
2641 already diagnosed). */
2644 thunk_binfo;
2650 /* See if virtual inheritance is involved. */
2652 virtual_offset;
2659 {
2663 {
2664 /* We convert via virtual base. Adjust the fixed
2665 offset to be from there. */
2666 offset =
2670 }
2672 /* There was an existing fixed offset, this must be
2673 from the base just converted to, and the base the
2674 FN was thunking to. */
2676 else
2678 }
2679 }
2682 /* Replace the overriding function with a covariant thunk. We
2683 will emit the overriding function in its own slot as
2684 well. */
2687 }
2688 else
2692 /* If we need a covariant thunk, then we may need to adjust first_defn.
2693 The ABI specifies that the thunks emitted with a function are
2694 determined by which bases the function overrides, so we need to be
2695 sure that we're using a thunk for some overridden base; even if we
2696 know that the necessary this adjustment is zero, there may not be an
2697 appropriate zero-this-adjusment thunk for us to use since thunks for
2698 overriding virtual bases always use the vcall offset.
2700 Furthermore, just choosing any base that overrides this function isn't
2701 quite right, as this slot won't be used for calls through a type that
2702 puts a covariant thunk here. Calling the function through such a type
2703 will use a different slot, and that slot is the one that determines
2704 the thunk emitted for that base.
2706 So, keep looking until we find the base that we're really overriding
2707 in this slot: the nearest primary base that doesn't use a covariant
2708 thunk in this slot. */
2710 {
2712 /* We already know that the overrider needs a covariant thunk. */
2715 {
2722 }
2724 }
2726 /* Assume that we will produce a thunk that convert all the way to
2727 the final overrider, and not to an intermediate virtual base. */
2730 /* See if we can convert to an intermediate virtual base first, and then
2731 use the vcall offset located there to finish the conversion. */
2733 {
2734 /* If we find the final overrider, then we can stop
2735 walking. */
2740 /* If we find a virtual base, and we haven't yet found the
2741 overrider, then there is a virtual base between the
2742 declaring base (first_defn) and the final overrider. */
2744 {
2747 }
2748 }
2750 /* Compute the constant adjustment to the `this' pointer. The
2751 `this' pointer, when this function is called, will point at BINFO
2752 (or one of its primary bases, which are at the same offset). */
2754 /* The `this' pointer needs to be adjusted from the declaration to
2755 the nearest virtual base. */
2760 /* If the nearest definition is in a lost primary, we don't need an
2761 entry in our vtable. Except possibly in a constructor vtable,
2762 if we happen to get our primary back. In that case, the offset
2763 will be zero, as it will be a primary base. */
2765 else
2766 /* The `this' pointer needs to be adjusted from pointing to
2767 BINFO to pointing at the base where the final overrider
2768 appears. */
2779 else
2783 }
2785 /* Called from modify_all_vtables via dfs_walk. */
2787 static tree
2789 {
2791 tree virtuals;
2792 tree old_virtuals;
2796 /* A base without a vtable needs no modification, and its bases
2797 are uninteresting. */
2802 /* Don't do the primary vtable, if it's new. */
2806 /* There's no need to modify the vtable for a non-virtual primary
2807 base; we're not going to use that vtable anyhow. We do still
2808 need to do this for virtual primary bases, as they could become
2809 non-primary in a construction vtable. */
2814 /* Now, go through each of the virtual functions in the virtual
2815 function table for BINFO. Find the final overrider, and update
2816 the BINFO_VIRTUALS list appropriately. */
2819 virtuals;
2823 binfo,
2828 }
2830 /* Update all of the primary and secondary vtables for T. Create new
2831 vtables as required, and initialize their RTTI information. Each
2832 of the functions in VIRTUALS is declared in T and may override a
2833 virtual function from a base class; find and modify the appropriate
2834 entries to point to the overriding functions. Returns a list, in
2835 declaration order, of the virtual functions that are declared in T,
2836 but do not appear in the primary base class vtable, and which
2837 should therefore be appended to the end of the vtable for T. */
2839 static tree
2841 {
2845 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2849 /* Update all of the vtables. */
2852 /* Add virtual functions not already in our primary vtable. These
2853 will be both those introduced by this class, and those overridden
2854 from secondary bases. It does not include virtuals merely
2855 inherited from secondary bases. */
2857 {
2862 {
2863 /* We don't need to adjust the `this' pointer when
2864 calling this function. */
2868 /* This is a function not already in our vtable. Keep it. */
2870 }
2871 else
2872 /* We've already got an entry for this function. Skip it. */
2874 }
2877 }
2879 /* Get the base virtual function declarations in T that have the
2880 indicated NAME. */
2882 static void
2884 {
2885 tree methods;
2889 /* Find virtual functions in T with the indicated NAME. */
2894 methods;
2896 {
2901 {
2904 }
2905 }
2911 {
2914 }
2915 }
2917 /* If this declaration supersedes the declaration of
2918 a method declared virtual in the base class, then
2919 mark this field as being virtual as well. */
2921 void
2923 {
2926 /* In [temp.mem] we have:
2928 A specialization of a member function template does not
2929 override a virtual function from a base class. */
2936 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2937 the error_mark_node so that we know it is an overriding
2938 function. */
2939 {
2946 }
2949 {
2955 }
2960 }
2962 /* Warn about hidden virtual functions that are not overridden in t.
2963 We know that constructors and destructors don't apply. */
2965 static void
2967 {
2969 tree fns;
2972 /* We go through each separately named virtual function. */
2976 {
2977 tree fn;
2978 tree name;
2979 tree fndecl;
2980 tree base_binfo;
2981 tree binfo;
2984 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2985 have the same name. Figure out what name that is. */
2987 /* There are no possibly hidden functions yet. */
2989 /* Iterate through all of the base classes looking for possibly
2990 hidden functions. */
2993 {
2996 }
2998 /* If there are no functions to hide, continue. */
3002 /* Remove any overridden functions. */
3004 {
3008 {
3009 /* If the method from the base class has the same
3010 signature as the method from the derived class, it
3011 has been overridden. */
3016 }
3017 }
3019 /* Now give a warning for all base functions without overriders,
3020 as they are hidden. */
3022 tree base_fndecl;
3025 {
3026 /* Here we know it is a hider, and no overrider exists. */
3029 }
3030 }
3031 }
3033 /* Recursive helper for finish_struct_anon. */
3035 static void
3037 {
3041 {
3042 /* We're generally only interested in entities the user
3043 declared, but we also find nested classes by noticing
3044 the TYPE_DECL that we create implicitly. You're
3045 allowed to put one anonymous union inside another,
3046 though, so we explicitly tolerate that. We use
3047 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
3048 we also allow unnamed types used for defining fields. */
3055 {
3056 /* We already complained about static data members in
3057 finish_static_data_member_decl. */
3059 {
3062 "%q+#D invalid; an anonymous union can "
3064 else
3066 "%q+#D invalid; an anonymous struct can "
3068 }
3070 }
3073 {
3075 {
3079 else
3082 }
3084 {
3088 else
3091 }
3092 }
3097 /* Recurse into the anonymous aggregates to handle correctly
3098 access control (c++/24926):
3100 class A {
3101 union {
3102 union {
3103 int i;
3104 };
3105 };
3106 };
3108 int j=A().i; */
3112 }
3113 }
3115 /* Check for things that are invalid. There are probably plenty of other
3116 things we should check for also. */
3118 static void
3120 {
3122 {
3131 }
3132 }
3134 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3135 will be used later during class template instantiation.
3136 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3137 a non-static member data (FIELD_DECL), a member function
3138 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3139 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3140 When FRIEND_P is nonzero, T is either a friend class
3141 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3142 (FUNCTION_DECL, TEMPLATE_DECL). */
3144 void
3146 {
3147 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3152 }
3154 /* This function is called from declare_virt_assop_and_dtor via
3155 dfs_walk_all.
3157 DATA is a type that direcly or indirectly inherits the base
3158 represented by BINFO. If BINFO contains a virtual assignment [copy
3159 assignment or move assigment] operator or a virtual constructor,
3160 declare that function in DATA if it hasn't been already declared. */
3162 static tree
3164 {
3172 /* A base without a vtable needs no modification, and its bases
3173 are uninteresting. */
3177 /* If this is a primary base, then we have already looked at the
3178 virtual functions of its vtable. */
3182 {
3186 {
3191 }
3195 }
3198 }
3200 /* If the class type T has a direct or indirect base that contains a
3201 virtual assignment operator or a virtual destructor, declare that
3202 function in T if it hasn't been already declared. */
3204 static void
3206 {
3214 dfs_declare_virt_assop_and_dtor,
3216 }
3218 /* Declare the inheriting constructor for class T inherited from base
3219 constructor CTOR with the parameter array PARMS of size NPARMS. */
3221 static void
3223 {
3224 /* We don't declare an inheriting ctor that would be a default,
3225 copy or move ctor for derived or base. */
3230 {
3234 }
3242 {
3245 }
3246 }
3248 /* Declare all the inheriting constructors for class T inherited from base
3249 constructor CTOR. */
3251 static void
3253 {
3259 {
3263 }
3266 {
3270 }
3271 }
3273 /* Create default constructors, assignment operators, and so forth for
3274 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3275 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3276 the class cannot have a default constructor, copy constructor
3277 taking a const reference argument, or an assignment operator taking
3278 a const reference, respectively. */
3280 static void
3284 {
3292 /* Destructor. */
3294 {
3295 /* In general, we create destructors lazily. */
3300 /* But if this is a Java class, any non-trivial destructor is
3301 invalid, even if compiler-generated. Therefore, if the
3302 destructor is non-trivial we create it now. */
3304 }
3306 /* [class.ctor]
3308 If there is no user-declared constructor for a class, a default
3309 constructor is implicitly declared. */
3311 {
3316 /* This might force the declaration. */
3318 }
3320 /* [class.ctor]
3322 If a class definition does not explicitly declare a copy
3323 constructor, one is declared implicitly. */
3325 {
3331 }
3333 /* If there is no assignment operator, one will be created if and
3334 when it is needed. For now, just record whether or not the type
3335 of the parameter to the assignment operator will be a const or
3336 non-const reference. */
3338 {
3344 }
3346 /* We can't be lazy about declaring functions that might override
3347 a virtual function from a base class. */
3351 {
3355 {
3356 /* declare, then remove the decl */
3365 }
3366 else
3368 }
3369 }
3371 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3372 count the number of fields in TYPE, including anonymous union
3373 members. */
3375 static int
3377 {
3378 tree x;
3381 {
3384 else
3386 }
3388 }
3390 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3391 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3392 elts, starting at offset IDX. */
3394 static int
3396 {
3397 tree x;
3399 {
3402 else
3404 }
3406 }
3408 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3409 starting at offset IDX. */
3411 static int
3415 {
3416 tree values;
3420 }
3422 /* FIELD is a bit-field. We are finishing the processing for its
3423 enclosing type. Issue any appropriate messages and set appropriate
3424 flags. Returns false if an error has been diagnosed. */
3426 static bool
3428 {
3430 tree w;
3432 /* Extract the declared width of the bitfield, which has been
3433 temporarily stashed in DECL_INITIAL. */
3436 /* Remove the bit-field width indicator so that the rest of the
3437 compiler does not treat that value as an initializer. */
3440 /* Detect invalid bit-field type. */
3442 {
3445 }
3446 else
3447 {
3449 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3452 /* detect invalid field size. */
3458 {
3461 }
3463 {
3466 }
3468 {
3471 }
3483 }
3486 {
3490 }
3491 else
3492 {
3493 /* Non-bit-fields are aligned for their type. */
3497 }
3498 }
3500 /* FIELD is a non bit-field. We are finishing the processing for its
3501 enclosing type T. Issue any appropriate messages and set appropriate
3502 flags. */
3504 static void
3506 tree t,
3510 {
3513 /* In C++98 an anonymous union cannot contain any fields which would change
3514 the settings of CANT_HAVE_CONST_CTOR and friends. */
3516 ;
3517 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3518 structs. So, we recurse through their fields here. */
3520 {
3521 tree fields;
3527 }
3528 /* Check members with class type for constructors, destructors,
3529 etc. */
3531 {
3532 /* Never let anything with uninheritable virtuals
3533 make it through without complaint. */
3537 {
3542 field);
3547 field);
3549 {
3553 }
3554 }
3555 else
3556 {
3569 }
3578 }
3583 {
3584 /* `build_class_init_list' does not recognize
3585 non-FIELD_DECLs. */
3589 }
3590 }
3592 /* Check the data members (both static and non-static), class-scoped
3593 typedefs, etc., appearing in the declaration of T. Issue
3594 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3595 declaration order) of access declarations; each TREE_VALUE in this
3596 list is a USING_DECL.
3598 In addition, set the following flags:
3600 EMPTY_P
3601 The class is empty, i.e., contains no non-static data members.
3603 CANT_HAVE_CONST_CTOR_P
3604 This class cannot have an implicitly generated copy constructor
3605 taking a const reference.
3607 CANT_HAVE_CONST_ASN_REF
3608 This class cannot have an implicitly generated assignment
3609 operator taking a const reference.
3611 All of these flags should be initialized before calling this
3612 function.
3614 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3615 fields can be added by adding to this chain. */
3617 static void
3621 {
3629 /* Assume there are no access declarations. */
3631 /* Assume this class has no pointer members. */
3633 /* Assume none of the members of this class have default
3634 initializations. */
3638 {
3646 {
3647 /* Save the access declarations for our caller. */
3650 }
3656 /* If we've gotten this far, it's a data member, possibly static,
3657 or an enumerator. */
3661 /* When this goes into scope, it will be a non-local reference. */
3666 {
3667 /* [class.union] (C++98)
3669 If a union contains a static data member, or a member of
3670 reference type, the program is ill-formed.
3672 In C++11 this limitation doesn't exist anymore. */
3674 {
3678 }
3680 {
3684 }
3685 }
3687 /* Perform error checking that did not get done in
3688 grokdeclarator. */
3690 {
3694 }
3696 {
3700 }
3708 /* Now it can only be a FIELD_DECL. */
3713 /* If at least one non-static data member is non-literal, the whole
3714 class becomes non-literal. Per Core/1453, volatile non-static
3715 data members and base classes are also not allowed.
3716 Note: if the type is incomplete we will complain later on. */
3721 /* A standard-layout class is a class that:
3722 ...
3723 has the same access control (Clause 11) for all non-static data members,
3724 ... */
3731 /* If this is of reference type, check if it needs an init. */
3733 {
3739 {
3740 /* ARM $12.6.2: [A member initializer list] (or, for an
3741 aggregate, initialization by a brace-enclosed list) is the
3742 only way to initialize nonstatic const and reference
3743 members. */
3746 }
3747 }
3752 {
3754 {
3755 warning
3758 x);
3760 }
3764 }
3767 /* We don't treat zero-width bitfields as making a class
3768 non-empty. */
3769 ;
3770 else
3771 {
3772 /* The class is non-empty. */
3774 /* The class is not even nearly empty. */
3776 /* If one of the data members contains an empty class,
3777 so does T. */
3781 }
3783 /* This is used by -Weffc++ (see below). Warn only for pointers
3784 to members which might hold dynamic memory. So do not warn
3785 for pointers to functions or pointers to members. */
3791 {
3796 }
3802 {
3804 {
3808 }
3810 {
3814 }
3815 }
3818 /* DR 148 now allows pointers to members (which are POD themselves),
3819 to be allowed in POD structs. */
3828 /* We set DECL_C_BIT_FIELD in grokbitfield.
3829 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3832 cant_have_const_ctor_p,
3833 no_const_asn_ref_p,
3836 /* Now that we've removed bit-field widths from DECL_INITIAL,
3837 anything left in DECL_INITIAL is an NSDMI that makes the class
3838 non-aggregate in C++11. */
3842 /* If any field is const, the structure type is pseudo-const. */
3844 {
3849 {
3850 /* ARM $12.6.2: [A member initializer list] (or, for an
3851 aggregate, initialization by a brace-enclosed list) is the
3852 only way to initialize nonstatic const and reference
3853 members. */
3856 }
3857 }
3858 /* A field that is pseudo-const makes the structure likewise. */
3860 {
3865 }
3867 /* Core issue 80: A nonstatic data member is required to have a
3868 different name from the class iff the class has a
3869 user-declared constructor. */
3873 }
3875 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3876 it should also define a copy constructor and an assignment operator to
3877 implement the correct copy semantic (deep vs shallow, etc.). As it is
3878 not feasible to check whether the constructors do allocate dynamic memory
3879 and store it within members, we approximate the warning like this:
3881 -- Warn only if there are members which are pointers
3882 -- Warn only if there is a non-trivial constructor (otherwise,
3883 there cannot be memory allocated).
3884 -- Warn only if there is a non-trivial destructor. We assume that the
3885 user at least implemented the cleanup correctly, and a destructor
3886 is needed to free dynamic memory.
3888 This seems enough for practical purposes. */
3890 && has_pointers
3894 {
3898 {
3903 }
3907 }
3909 /* Non-static data member initializers make the default constructor
3910 non-trivial. */
3912 {
3915 }
3917 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3921 /* Check anonymous struct/anonymous union fields. */
3924 /* We've built up the list of access declarations in reverse order.
3925 Fix that now. */
3927 }
3929 /* If TYPE is an empty class type, records its OFFSET in the table of
3930 OFFSETS. */
3932 static int
3934 {
3935 splay_tree_node n;
3940 /* Record the location of this empty object in OFFSETS. */
3948 type,
3952 }
3954 /* Returns nonzero if TYPE is an empty class type and there is
3955 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3957 static int
3959 {
3960 splay_tree_node n;
3961 tree t;
3966 /* Record the location of this empty object in OFFSETS. */
3976 }
3978 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3979 F for every subobject, passing it the type, offset, and table of
3980 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3981 be traversed.
3983 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3984 than MAX_OFFSET will not be walked.
3986 If F returns a nonzero value, the traversal ceases, and that value
3987 is returned. Otherwise, returns zero. */
3989 static int
3991 subobject_offset_fn f,
3992 tree offset,
3993 splay_tree offsets,
3994 tree max_offset,
3996 {
4000 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
4001 stop. */
4009 {
4012 }
4015 {
4016 tree field;
4017 tree binfo;
4020 /* Avoid recursing into objects that are not interesting. */
4024 /* Record the location of TYPE. */
4029 /* Iterate through the direct base classes of TYPE. */
4033 {
4034 tree binfo_offset;
4039 tree orig_binfo;
4040 /* We cannot rely on BINFO_OFFSET being set for the base
4041 class yet, but the offsets for direct non-virtual
4042 bases can be calculated by going back to the TYPE. */
4045 offset,
4049 f,
4050 binfo_offset,
4051 offsets,
4052 max_offset,
4056 }
4059 {
4063 /* Iterate through the virtual base classes of TYPE. In G++
4064 3.2, we included virtual bases in the direct base class
4065 loop above, which results in incorrect results; the
4066 correct offsets for virtual bases are only known when
4067 working with the most derived type. */
4071 {
4073 f,
4075 offset,
4077 offsets,
4078 max_offset,
4082 }
4083 else
4084 {
4085 /* We still have to walk the primary base, if it is
4086 virtual. (If it is non-virtual, then it was walked
4087 above.) */
4093 {
4094 r = (walk_subobject_offsets
4099 }
4100 }
4101 }
4103 /* Iterate through the fields of TYPE. */
4108 {
4109 tree field_offset;
4114 f,
4116 offset,
4117 field_offset),
4118 offsets,
4119 max_offset,
4123 }
4124 }
4126 {
4129 tree index;
4131 /* Avoid recursing into objects that are not interesting. */
4136 /* Step through each of the elements in the array. */
4140 {
4142 f,
4143 offset,
4144 offsets,
4145 max_offset,
4151 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4152 there's no point in iterating through the remaining
4153 elements of the array. */
4156 }
4157 }
4160 }
4162 /* Record all of the empty subobjects of TYPE (either a type or a
4163 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4164 is being placed at OFFSET; otherwise, it is a base class that is
4165 being placed at OFFSET. */
4167 static void
4169 tree offset,
4170 splay_tree offsets,
4172 {
4173 tree max_offset;
4174 /* If recording subobjects for a non-static data member or a
4175 non-empty base class , we do not need to record offsets beyond
4176 the size of the biggest empty class. Additional data members
4177 will go at the end of the class. Additional base classes will go
4178 either at offset zero (if empty, in which case they cannot
4179 overlap with offsets past the size of the biggest empty class) or
4180 at the end of the class.
4182 However, if we are placing an empty base class, then we must record
4183 all offsets, as either the empty class is at offset zero (where
4184 other empty classes might later be placed) or at the end of the
4185 class (where other objects might then be placed, so other empty
4186 subobjects might later overlap). */
4190 else
4194 }
4196 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4197 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4198 virtual bases of TYPE are examined. */
4200 static int
4202 tree offset,
4203 splay_tree offsets,
4205 {
4206 splay_tree_node max_node;
4208 /* Get the node in OFFSETS that indicates the maximum offset where
4209 an empty subobject is located. */
4211 /* If there aren't any empty subobjects, then there's no point in
4212 performing this check. */
4218 vbases_p);
4219 }
4221 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4222 non-static data member of the type indicated by RLI. BINFO is the
4223 binfo corresponding to the base subobject, OFFSETS maps offsets to
4224 types already located at those offsets. This function determines
4225 the position of the DECL. */
4227 static void
4229 tree decl,
4230 tree binfo,
4231 splay_tree offsets)
4232 {
4235 tree type;
4238 {
4239 /* For the purposes of determining layout conflicts, we want to
4240 use the class type of BINFO; TREE_TYPE (DECL) will be the
4241 CLASSTYPE_AS_BASE version, which does not contain entries for
4242 zero-sized bases. */
4245 }
4246 else
4247 {
4250 }
4252 /* Try to place the field. It may take more than one try if we have
4253 a hard time placing the field without putting two objects of the
4254 same type at the same address. */
4256 {
4259 /* Place this field. */
4263 /* We have to check to see whether or not there is already
4264 something of the same type at the offset we're about to use.
4265 For example, consider:
4267 struct S {};
4268 struct T : public S { int i; };
4269 struct U : public S, public T {};
4271 Here, we put S at offset zero in U. Then, we can't put T at
4272 offset zero -- its S component would be at the same address
4273 as the S we already allocated. So, we have to skip ahead.
4274 Since all data members, including those whose type is an
4275 empty class, have nonzero size, any overlap can happen only
4276 with a direct or indirect base-class -- it can't happen with
4277 a data member. */
4278 /* In a union, overlap is permitted; all members are placed at
4279 offset zero. */
4284 {
4285 /* Strip off the size allocated to this field. That puts us
4286 at the first place we could have put the field with
4287 proper alignment. */
4290 /* Bump up by the alignment required for the type. */
4291 rli->bitpos
4297 }
4298 else
4299 /* There was no conflict. We're done laying out this field. */
4301 }
4303 /* Now that we know where it will be placed, update its
4304 BINFO_OFFSET. */
4306 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4307 this point because their BINFO_OFFSET is copied from another
4308 hierarchy. Therefore, we may not need to add the entire
4309 OFFSET. */
4315 }
4317 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4319 static int
4321 tree offset,
4323 {
4325 }
4327 /* Layout the empty base BINFO. EOC indicates the byte currently just
4328 past the end of the class, and should be correctly aligned for a
4329 class of the type indicated by BINFO; OFFSETS gives the offsets of
4330 the empty bases allocated so far. T is the most derived
4331 type. Return nonzero iff we added it at the end. */
4333 static bool
4336 {
4337 tree alignment;
4341 /* This routine should only be used for empty classes. */
4346 propagate_binfo_offsets
4350 /* This is an empty base class. We first try to put it at offset
4351 zero. */
4354 offsets,
4356 {
4357 /* That didn't work. Now, we move forward from the next
4358 available spot in the class. */
4362 {
4365 offsets,
4367 /* We finally found a spot where there's no overlap. */
4370 /* There's overlap here, too. Bump along to the next spot. */
4372 }
4373 }
4376 {
4381 }
4384 }
4386 /* Layout the base given by BINFO in the class indicated by RLI.
4387 *BASE_ALIGN is a running maximum of the alignments of
4388 any base class. OFFSETS gives the location of empty base
4389 subobjects. T is the most derived type. Return nonzero if the new
4390 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4391 *NEXT_FIELD, unless BINFO is for an empty base class.
4393 Returns the location at which the next field should be inserted. */
4398 {
4403 /* This error is now reported in xref_tag, thus giving better
4404 location information. */
4407 /* Place the base class. */
4409 {
4410 tree decl;
4412 /* The containing class is non-empty because it has a non-empty
4413 base class. */
4416 /* Create the FIELD_DECL. */
4423 {
4431 /* Try to place the field. It may take more than one try if we
4432 have a hard time placing the field without putting two
4433 objects of the same type at the same address. */
4435 /* Add the new FIELD_DECL to the list of fields for T. */
4439 }
4440 }
4441 else
4442 {
4443 tree eoc;
4446 /* On some platforms (ARM), even empty classes will not be
4447 byte-aligned. */
4452 /* A nearly-empty class "has no proper base class that is empty,
4453 not morally virtual, and at an offset other than zero." */
4455 {
4458 /* The check above (used in G++ 3.2) is insufficient because
4459 an empty class placed at offset zero might itself have an
4460 empty base at a nonzero offset. */
4462 empty_base_at_nonzero_offset_p,
4463 size_zero_node,
4468 }
4470 /* We do not create a FIELD_DECL for empty base classes because
4471 it might overlap some other field. We want to be able to
4472 create CONSTRUCTORs for the class by iterating over the
4473 FIELD_DECLs, and the back end does not handle overlapping
4474 FIELD_DECLs. */
4476 /* An empty virtual base causes a class to be non-empty
4477 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4478 here because that was already done when the virtual table
4479 pointer was created. */
4480 }
4482 /* Record the offsets of BINFO and its base subobjects. */
4485 offsets,
4489 }
4491 /* Layout all of the non-virtual base classes. Record empty
4492 subobjects in OFFSETS. T is the most derived type. Return nonzero
4493 if the type cannot be nearly empty. The fields created
4494 corresponding to the base classes will be inserted at
4495 *NEXT_FIELD. */
4497 static void
4500 {
4501 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4502 subobjects. */
4507 /* The primary base class is always allocated first. */
4512 /* Now allocate the rest of the bases. */
4514 {
4515 tree base_binfo;
4519 /* The primary base was already allocated above, so we don't
4520 need to allocate it again here. */
4524 /* Virtual bases are added at the end (a primary virtual base
4525 will have already been added). */
4531 }
4532 }
4534 /* Go through the TYPE_METHODS of T issuing any appropriate
4535 diagnostics, figuring out which methods override which other
4536 methods, and so forth. */
4538 static void
4540 {
4541 tree x;
4544 {
4548 /* The name of the field is the original field name
4549 Save this in auxiliary field for later overloading. */
4551 {
4555 }
4556 /* All user-provided destructors are non-trivial.
4557 Constructors and assignment ops are handled in
4558 grok_special_member_properties. */
4561 }
4562 }
4564 /* FN is a constructor or destructor. Clone the declaration to create
4565 a specialized in-charge or not-in-charge version, as indicated by
4566 NAME. */
4568 static tree
4570 {
4571 tree parms;
4572 tree clone;
4574 /* Copy the function. */
4576 /* Reset the function name. */
4578 /* Remember where this function came from. */
4580 /* Make it easy to find the CLONE given the FN. */
4584 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4586 {
4593 }
4597 /* There's no pending inline data for this function. */
4601 /* The base-class destructor is not virtual. */
4603 {
4607 }
4609 /* If there was an in-charge parameter, drop it from the function
4610 type. */
4612 {
4613 tree basetype;
4614 tree parmtypes;
4615 tree exceptions;
4620 /* Skip the `this' parameter. */
4622 /* Skip the in-charge parameter. */
4624 /* And the VTT parm, in a complete [cd]tor. */
4628 /* If this is subobject constructor or destructor, add the vtt
4629 parameter. */
4633 parmtypes);
4636 exceptions);
4640 }
4642 /* Copy the function parameters. */
4644 /* Remove the in-charge parameter. */
4646 {
4650 }
4651 /* And the VTT parm, in a complete [cd]tor. */
4653 {
4656 else
4657 {
4661 }
4662 }
4665 {
4668 }
4670 /* Create the RTL for this function. */
4678 }
4680 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4681 not invoke this function directly.
4683 For a non-thunk function, returns the address of the slot for storing
4684 the function it is a clone of. Otherwise returns NULL_TREE.
4686 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4687 cloned_function is unset. This is to support the separate
4688 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4689 on a template makes sense, but not the former. */
4691 tree *
4693 {
4701 {
4702 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4705 else
4706 #endif
4708 }
4713 else
4715 }
4717 /* Produce declarations for all appropriate clones of FN. If
4718 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4719 CLASTYPE_METHOD_VEC as well. */
4721 void
4723 {
4724 tree clone;
4726 /* Avoid inappropriate cloning. */
4732 {
4733 /* For each constructor, we need two variants: an in-charge version
4734 and a not-in-charge version. */
4741 }
4742 else
4743 {
4746 /* For each destructor, we need three variants: an in-charge
4747 version, a not-in-charge version, and an in-charge deleting
4748 version. We clone the deleting version first because that
4749 means it will go second on the TYPE_METHODS list -- and that
4750 corresponds to the correct layout order in the virtual
4751 function table.
4753 For a non-virtual destructor, we do not build a deleting
4754 destructor. */
4756 {
4760 }
4767 }
4769 /* Note that this is an abstract function that is never emitted. */
4771 }
4773 /* DECL is an in charge constructor, which is being defined. This will
4774 have had an in class declaration, from whence clones were
4775 declared. An out-of-class definition can specify additional default
4776 arguments. As it is the clones that are involved in overload
4777 resolution, we must propagate the information from the DECL to its
4778 clones. */
4780 void
4782 {
4783 tree clone;
4787 {
4794 /* Skip the 'this' parameter. */
4810 {
4815 {
4816 /* A default parameter has been added. Adjust the
4817 clone's parameters. */
4821 tree type;
4826 {
4829 clone_parms);
4831 }
4834 clone_parms);
4843 }
4844 }
4846 }
4847 }
4849 /* For each of the constructors and destructors in T, create an
4850 in-charge and not-in-charge variant. */
4852 static void
4854 {
4855 tree fns;
4857 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4858 out now. */
4866 }
4868 /* Deduce noexcept for a destructor DTOR. */
4870 void
4872 {
4874 {
4877 }
4878 }
4880 /* For each destructor in T, deduce noexcept:
4882 12.4/3: A declaration of a destructor that does not have an
4883 exception-specification is implicitly considered to have the
4884 same exception-specification as an implicit declaration (15.4). */
4886 static void
4888 {
4889 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4890 out now. */
4896 }
4898 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4899 of TYPE for virtual functions which FNDECL overrides. Return a
4900 mask of the tm attributes found therein. */
4902 static int
4904 {
4906 tree base_binfo;
4910 {
4920 else
4922 }
4925 }
4927 /* Subroutine of set_method_tm_attributes. Handle the checks and
4928 inheritance for one virtual method FNDECL. */
4930 static void
4932 {
4933 tree tm_attr;
4938 /* If FNDECL doesn't actually override anything (i.e. T is the
4939 class that first declares FNDECL virtual), then we're done. */
4946 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4947 tm_pure must match exactly, otherwise no weakening of
4948 tm_safe > tm_callable > nothing. */
4949 /* ??? The tm_pure attribute didn't make the transition to the
4950 multivendor language spec. */
4952 {
4954 {
4957 }
4958 }
4959 /* If the overridden function is tm_pure, then FNDECL must be. */
4962 /* Look for base class combinations that cannot be satisfied. */
4964 {
4970 }
4971 /* If FNDECL did not declare an attribute, then inherit the most
4972 restrictive one. */
4974 {
4976 }
4977 /* Otherwise validate that we're not weaker than a function
4978 that is being overridden. */
4979 else
4980 {
4984 }
4987 err_override:
4991 }
4993 /* For each of the methods in T, propagate a class-level tm attribute. */
4995 static void
4997 {
5000 /* Don't bother collecting tm attributes if transactional memory
5001 support is not enabled. */
5005 /* Process virtual methods first, as they inherit directly from the
5006 base virtual function and also require validation of new attributes. */
5008 {
5009 tree vchain;
5012 {
5017 }
5018 }
5020 /* If the class doesn't have an attribute, nothing more to do. */
5025 /* Any method that does not yet have a tm attribute inherits
5026 the one from the class. */
5028 {
5031 }
5032 }
5034 /* Returns true iff class T has a user-defined constructor other than
5035 the default constructor. */
5037 bool
5039 {
5040 tree fns;
5046 {
5053 }
5056 }
5058 /* Returns the defaulted constructor if T has one. Otherwise, returns
5059 NULL_TREE. */
5061 tree
5063 {
5070 {
5074 {
5080 }
5081 }
5084 }
5086 /* Returns true iff FN is a user-provided function, i.e. user-declared
5087 and not defaulted at its first declaration; or explicit, private,
5088 protected, or non-const. */
5090 bool
5092 {
5095 else
5099 }
5101 /* Returns true iff class T has a user-provided constructor. */
5103 bool
5105 {
5106 tree fns;
5114 /* This can happen in error cases; avoid crashing. */
5123 }
5125 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5126 declared or explicitly defaulted in the class body) default
5127 constructor. */
5129 bool
5131 {
5132 tree fns;
5140 {
5146 }
5149 }
5151 /* TYPE is being used as a virtual base, and has a non-trivial move
5152 assignment. Return true if this is due to there being a user-provided
5153 move assignment in TYPE or one of its subobjects; if there isn't, then
5154 multiple move assignment can't cause any harm. */
5156 bool
5158 {
5159 /* Does the type itself have a user-provided move assignment operator? */
5163 {
5167 }
5169 /* Do any of its bases? */
5171 tree base_binfo;
5176 /* Or non-static data members? */
5178 {
5183 }
5185 /* Seems not. */
5187 }
5189 /* If default-initialization leaves part of TYPE uninitialized, returns
5190 a DECL for the field or TYPE itself (DR 253). */
5192 tree
5194 {
5205 {
5209 }
5214 {
5218 }
5221 }
5223 /* Returns true iff for class T, a trivial synthesized default constructor
5224 would be constexpr. */
5226 bool
5228 {
5229 /* A defaulted trivial default constructor is constexpr
5230 if there is nothing to initialize. */
5233 }
5235 /* Returns true iff class T has a constexpr default constructor. */
5237 bool
5239 {
5240 tree fns;
5243 {
5244 /* The caller should have stripped an enclosing array. */
5247 }
5249 {
5252 /* Non-trivial, we need to check subobject constructors. */
5254 }
5257 }
5259 /* Returns true iff class TYPE has a virtual destructor. */
5261 bool
5263 {
5264 tree dtor;
5272 }
5274 /* Returns true iff class T has a move constructor. */
5276 bool
5278 {
5279 tree fns;
5282 {
5285 }
5295 }
5297 /* Returns true iff class T has a move assignment operator. */
5299 bool
5301 {
5302 tree fns;
5305 {
5308 }
5316 }
5318 /* Returns true iff class T has a move constructor that was explicitly
5319 declared in the class body. Note that this is different from
5320 "user-provided", which doesn't include functions that are defaulted in
5321 the class. */
5323 bool
5325 {
5326 tree fns;
5335 {
5339 }
5342 }
5344 /* Returns true iff class T has a move assignment operator that was
5345 explicitly declared in the class body. */
5347 bool
5349 {
5350 tree fns;
5357 {
5361 }
5364 }
5366 /* Nonzero if we need to build up a constructor call when initializing an
5367 object of this class, either because it has a user-declared constructor
5368 or because it doesn't have a default constructor (so we need to give an
5369 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5370 what you care about is whether or not an object can be produced by a
5371 constructor (e.g. so we don't set TREE_READONLY on const variables of
5372 such type); use this function when what you care about is whether or not
5373 to try to call a constructor to create an object. The latter case is
5374 the former plus some cases of constructors that cannot be called. */
5376 bool
5378 {
5379 tree inner;
5389 /* A user-declared constructor might be private, and a constructor might
5390 be trivial but deleted. */
5393 {
5398 }
5400 }
5402 /* Like type_build_ctor_call, but for destructors. */
5404 bool
5406 {
5407 tree inner;
5416 /* A user-declared destructor might be private, and a destructor might
5417 be trivial but deleted. */
5420 {
5425 }
5427 }
5429 /* Remove all zero-width bit-fields from T. */
5431 static void
5433 {
5438 {
5441 /* We should not be confused by the fact that grokbitfield
5442 temporarily sets the width of the bit field into
5443 DECL_INITIAL (*fieldsp).
5444 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5445 to that width. */
5449 else
5451 }
5452 }
5454 /* Returns TRUE iff we need a cookie when dynamically allocating an
5455 array whose elements have the indicated class TYPE. */
5457 static bool
5459 {
5460 tree fns;
5465 /* If there's a non-trivial destructor, we need a cookie. In order
5466 to iterate through the array calling the destructor for each
5467 element, we'll have to know how many elements there are. */
5471 /* If the usual deallocation function is a two-argument whose second
5472 argument is of type `size_t', then we have to pass the size of
5473 the array to the deallocation function, so we will need to store
5474 a cookie. */
5478 /* If there are no `operator []' members, or the lookup is
5479 ambiguous, then we don't need a cookie. */
5482 /* Loop through all of the functions. */
5484 {
5485 tree fn;
5486 tree second_parm;
5488 /* Select the current function. */
5490 /* See if this function is a one-argument delete function. If
5491 it is, then it will be the usual deallocation function. */
5495 /* Do not consider this function if its second argument is an
5496 ellipsis. */
5499 /* Otherwise, if we have a two-argument function and the second
5500 argument is `size_t', it will be the usual deallocation
5501 function -- unless there is one-argument function, too. */
5505 }
5508 }
5510 /* Finish computing the `literal type' property of class type T.
5512 At this point, we have already processed base classes and
5513 non-static data members. We need to check whether the copy
5514 constructor is trivial, the destructor is trivial, and there
5515 is a trivial default constructor or at least one constexpr
5516 constructor other than the copy constructor. */
5518 static void
5520 {
5521 tree fn;
5537 {
5540 {
5544 }
5545 }
5546 }
5548 /* T is a non-literal type used in a context which requires a constant
5549 expression. Explain why it isn't literal. */
5551 void
5553 {
5563 /* Already explained. */
5572 {
5574 "default constructor, and has no constexpr constructor that "
5577 {
5578 /* Note that we can't simply call locate_ctor because when the
5579 constructor is deleted it just returns NULL_TREE. */
5580 tree fns;
5582 {
5589 {
5592 else
5595 }
5596 }
5597 }
5598 }
5599 else
5600 {
5604 {
5607 {
5612 }
5613 }
5615 {
5616 tree ftype;
5621 {
5626 }
5630 }
5631 }
5632 }
5634 /* Check the validity of the bases and members declared in T. Add any
5635 implicitly-generated functions (like copy-constructors and
5636 assignment operators). Compute various flag bits (like
5637 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5638 level: i.e., independently of the ABI in use. */
5640 static void
5642 {
5643 /* Nonzero if the implicitly generated copy constructor should take
5644 a non-const reference argument. */
5646 /* Nonzero if the implicitly generated assignment operator
5647 should take a non-const reference argument. */
5649 tree access_decls;
5652 tree fn;
5654 /* By default, we use const reference arguments and generate default
5655 constructors. */
5659 /* Check all the base-classes. */
5663 /* Deduce noexcept on destructors. This needs to happen after we've set
5664 triviality flags appropriately for our bases. */
5668 /* Check all the method declarations. */
5671 /* Save the initial values of these flags which only indicate whether
5672 or not the class has user-provided functions. As we analyze the
5673 bases and members we can set these flags for other reasons. */
5677 /* Check all the data member declarations. We cannot call
5678 check_field_decls until we have called check_bases check_methods,
5679 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5680 being set appropriately. */
5685 /* A nearly-empty class has to be vptr-containing; a nearly empty
5686 class contains just a vptr. */
5690 /* Do some bookkeeping that will guide the generation of implicitly
5691 declared member functions. */
5694 /* We need to call a constructor for this class if it has a
5695 user-provided constructor, or if the default constructor is going
5696 to initialize the vptr. (This is not an if-and-only-if;
5697 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5698 themselves need constructing.) */
5701 /* [dcl.init.aggr]
5703 An aggregate is an array or a class with no user-provided
5704 constructors ... and no virtual functions.
5706 Again, other conditions for being an aggregate are checked
5707 elsewhere. */
5710 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5711 retain the old definition internally for ABI reasons. */
5720 /* If the only explicitly declared default constructor is user-provided,
5721 set TYPE_HAS_COMPLEX_DFLT. */
5727 /* Warn if a public base of a polymorphic type has an accessible
5728 non-virtual destructor. It is only now that we know the class is
5729 polymorphic. Although a polymorphic base will have a already
5730 been diagnosed during its definition, we warn on use too. */
5732 {
5735 tree base_binfo;
5739 {
5747 basetype);
5748 }
5749 }
5751 /* If the class has no user-declared constructor, but does have
5752 non-static const or reference data members that can never be
5753 initialized, issue a warning. */
5755 /* Classes with user-declared constructors are presumed to
5756 initialize these members. */
5758 /* Aggregates can be initialized with brace-enclosed
5759 initializers. */
5761 {
5762 tree field;
5765 {
5766 tree type;
5781 }
5782 }
5784 /* Synthesize any needed methods. */
5786 cant_have_const_ctor,
5787 no_const_asn_ref);
5789 /* Check defaulted declarations here so we have cant_have_const_ctor
5790 and don't need to worry about clones. */
5793 {
5796 {
5797 bool imp_const_p
5803 /* If the function is defaulted outside the class, we just
5804 give the synthesis error. */
5807 }
5809 }
5812 {
5813 /* "This class type is not an aggregate." */
5815 }
5817 /* Compute the 'literal type' property before we
5818 do anything with non-static member functions. */
5821 /* Create the in-charge and not-in-charge variants of constructors
5822 and destructors. */
5825 /* Process the using-declarations. */
5829 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5832 /* Figure out whether or not we will need a cookie when dynamically
5833 allocating an array of this type. */
5836 }
5838 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5839 accordingly. If a new vfield was created (because T doesn't have a
5840 primary base class), then the newly created field is returned. It
5841 is not added to the TYPE_FIELDS list; it is the caller's
5842 responsibility to do that. Accumulate declared virtual functions
5843 on VIRTUALS_P. */
5845 static tree
5847 {
5848 tree fn;
5850 /* Collect the virtual functions declared in T. */
5855 {
5864 }
5866 /* If we couldn't find an appropriate base class, create a new field
5867 here. Even if there weren't any new virtual functions, we might need a
5868 new virtual function table if we're supposed to include vptrs in
5869 all classes that need them. */
5871 {
5872 /* We build this decl with vtbl_ptr_type_node, which is a
5873 `vtable_entry_type*'. It might seem more precise to use
5874 `vtable_entry_type (*)[N]' where N is the number of virtual
5875 functions. However, that would require the vtable pointer in
5876 base classes to have a different type than the vtable pointer
5877 in derived classes. We could make that happen, but that
5878 still wouldn't solve all the problems. In particular, the
5879 type-based alias analysis code would decide that assignments
5880 to the base class vtable pointer can't alias assignments to
5881 the derived class vtable pointer, since they have different
5882 types. Thus, in a derived class destructor, where the base
5883 class constructor was inlined, we could generate bad code for
5884 setting up the vtable pointer.
5886 Therefore, we use one type for all vtable pointers. We still
5887 use a type-correct type; it's just doesn't indicate the array
5888 bounds. That's better than using `void*' or some such; it's
5889 cleaner, and it let's the alias analysis code know that these
5890 stores cannot alias stores to void*! */
5891 tree field;
5904 /* This class is non-empty. */
5908 }
5911 }
5913 /* Add OFFSET to all base types of BINFO which is a base in the
5914 hierarchy dominated by T.
5916 OFFSET, which is a type offset, is number of bytes. */
5918 static void
5920 {
5922 tree primary_binfo;
5923 tree base_binfo;
5925 /* Update BINFO's offset. */
5930 offset));
5932 /* Find the primary base class. */
5938 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5939 downwards. */
5941 {
5942 /* Don't do the primary base twice. */
5950 }
5951 }
5953 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5954 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5955 empty subobjects of T. */
5957 static void
5959 {
5960 tree vbase;
5967 /* Find the last field. The artificial fields created for virtual
5968 bases will go after the last extant field to date. */
5973 /* Go through the virtual bases, allocating space for each virtual
5974 base that is not already a primary base class. These are
5975 allocated in inheritance graph order. */
5977 {
5982 {
5983 /* This virtual base is not a primary base of any class in the
5984 hierarchy, so we have to add space for it. */
5987 }
5988 }
5989 }
5991 /* Returns the offset of the byte just past the end of the base class
5992 BINFO. */
5994 static tree
5996 {
5997 tree size;
6002 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6003 allocate some space for it. It cannot have virtual bases, so
6004 TYPE_SIZE_UNIT is fine. */
6006 else
6010 }
6012 /* Returns the offset of the byte just past the end of the base class
6013 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
6014 only non-virtual bases are included. */
6016 static tree
6018 {
6021 tree binfo;
6022 tree base_binfo;
6023 tree offset;
6028 {
6038 }
6043 {
6047 }
6050 }
6052 /* Warn about bases of T that are inaccessible because they are
6053 ambiguous. For example:
6055 struct S {};
6056 struct T : public S {};
6057 struct U : public S, public T {};
6059 Here, `(S*) new U' is not allowed because there are two `S'
6060 subobjects of U. */
6062 static void
6064 {
6067 tree basetype;
6068 tree binfo;
6069 tree base_binfo;
6071 /* If there are no repeated bases, nothing can be ambiguous. */
6075 /* Check direct bases. */
6078 {
6084 }
6086 /* Check for ambiguous virtual bases. */
6090 {
6096 }
6097 }
6099 /* Compare two INTEGER_CSTs K1 and K2. */
6101 static int
6103 {
6105 }
6107 /* Increase the size indicated in RLI to account for empty classes
6108 that are "off the end" of the class. */
6110 static void
6112 {
6113 tree eoc;
6114 tree rli_size;
6116 /* It might be the case that we grew the class to allocate a
6117 zero-sized base class. That won't be reflected in RLI, yet,
6118 because we are willing to overlay multiple bases at the same
6119 offset. However, now we need to make sure that RLI is big enough
6120 to reflect the entire class. */
6126 {
6127 /* The size should have been rounded to a whole byte. */
6130 rli->bitpos
6139 }
6140 }
6142 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6143 BINFO_OFFSETs for all of the base-classes. Position the vtable
6144 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6146 static void
6148 {
6149 tree non_static_data_members;
6150 tree field;
6151 tree vptr;
6152 record_layout_info rli;
6153 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6154 types that appear at that offset. */
6155 splay_tree empty_base_offsets;
6156 /* True if the last field laid out was a bit-field. */
6158 /* The location at which the next field should be inserted. */
6160 /* T, as a base class. */
6161 tree base_t;
6163 /* Keep track of the first non-static data member. */
6166 /* Start laying out the record. */
6169 /* Mark all the primary bases in the hierarchy. */
6172 /* Create a pointer to our virtual function table. */
6175 /* The vptr is always the first thing in the class. */
6177 {
6182 }
6183 else
6186 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6191 /* Layout the non-static data members. */
6193 {
6194 tree type;
6195 tree padding;
6197 /* We still pass things that aren't non-static data members to
6198 the back end, in case it wants to do something with them. */
6200 {
6202 /* If the static data member has incomplete type, keep track
6203 of it so that it can be completed later. (The handling
6204 of pending statics in finish_record_layout is
6205 insufficient; consider:
6207 struct S1;
6208 struct S2 { static S1 s1; };
6210 At this point, finish_record_layout will be called, but
6211 S1 is still incomplete.) */
6213 {
6215 /* The visibility of static data members is determined
6216 at their point of declaration, not their point of
6217 definition. */
6219 }
6221 }
6229 /* If this field is a bit-field whose width is greater than its
6230 type, then there are some special rules for allocating
6231 it. */
6234 {
6236 tree integer_type;
6238 /* We must allocate the bits as if suitably aligned for the
6239 longest integer type that fits in this many bits. type
6240 of the field. Then, we are supposed to use the left over
6241 bits as additional padding. */
6250 /* ITK now indicates a type that is too large for the
6251 field. We have to back up by one to find the largest
6252 type that fits. */
6253 do
6254 {
6259 /* Figure out how much additional padding is required. */
6261 {
6263 /* In a union, the padding field must have the full width
6264 of the bit-field; all fields start at offset zero. */
6266 else
6269 }
6271 /* An unnamed bitfield does not normally affect the
6272 alignment of the containing class on a target where
6273 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6274 make any exceptions for unnamed bitfields when the
6275 bitfields are longer than their types. Therefore, we
6276 temporarily give the field a name. */
6278 {
6281 }
6287 empty_base_offsets);
6290 /* Now that layout has been performed, set the size of the
6291 field to the size of its declared type; the rest of the
6292 field is effectively invisible. */
6294 /* We must also reset the DECL_MODE of the field. */
6296 }
6297 else
6299 empty_base_offsets);
6301 /* Remember the location of any empty classes in FIELD. */
6304 empty_base_offsets,
6307 /* If a bit-field does not immediately follow another bit-field,
6308 and yet it starts in the middle of a byte, we have failed to
6309 comply with the ABI. */
6312 /* The TREE_NO_WARNING flag gets set by Objective-C when
6313 laying out an Objective-C class. The ObjC ABI differs
6314 from the C++ ABI, and so we do not want a warning
6315 here. */
6317 && !last_field_was_bitfield
6320 bitsize_unit_node)))
6324 /* The middle end uses the type of expressions to determine the
6325 possible range of expression values. In order to optimize
6326 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6327 must be made aware of the width of "i", via its type.
6329 Because C++ does not have integer types of arbitrary width,
6330 we must (for the purposes of the front end) convert from the
6331 type assigned here to the declared type of the bitfield
6332 whenever a bitfield expression is used as an rvalue.
6333 Similarly, when assigning a value to a bitfield, the value
6334 must be converted to the type given the bitfield here. */
6336 {
6341 {
6348 }
6349 }
6351 /* If we needed additional padding after this field, add it
6352 now. */
6354 {
6355 tree padding_field;
6358 FIELD_DECL,
6359 NULL_TREE,
6360 char_type_node);
6367 NULL_TREE,
6368 empty_base_offsets);
6369 }
6372 }
6375 {
6376 /* Make sure that we are on a byte boundary so that the size of
6377 the class without virtual bases will always be a round number
6378 of bytes. */
6381 }
6383 /* Delete all zero-width bit-fields from the list of fields. Now
6384 that the type is laid out they are no longer important. */
6387 /* Create the version of T used for virtual bases. We do not use
6388 make_class_type for this version; this is an artificial type. For
6389 a POD type, we just reuse T. */
6391 {
6394 /* Set the size and alignment for the new type. */
6395 tree eoc;
6397 /* If the ABI version is not at least two, and the last
6398 field was a bit-field, RLI may not be on a byte
6399 boundary. In particular, rli_size_unit_so_far might
6400 indicate the last complete byte, while rli_size_so_far
6401 indicates the total number of bits used. Therefore,
6402 rli_size_so_far, rather than rli_size_unit_so_far, is
6403 used to compute TYPE_SIZE_UNIT. */
6411 eoc);
6421 /* Copy the fields from T. */
6425 {
6427 FIELD_DECL,
6437 }
6439 /* Record the base version of the type. */
6442 }
6443 else
6446 /* Every empty class contains an empty class. */
6450 /* Set the TYPE_DECL for this type to contain the right
6451 value for DECL_OFFSET, so that we can use it as part
6452 of a COMPONENT_REF for multiple inheritance. */
6455 /* Now fix up any virtual base class types that we left lying
6456 around. We must get these done before we try to lay out the
6457 virtual function table. As a side-effect, this will remove the
6458 base subobject fields. */
6461 /* Make sure that empty classes are reflected in RLI at this
6462 point. */
6465 /* Make sure not to create any structures with zero size. */
6471 /* If this is a non-POD, declaring it packed makes a difference to how it
6472 can be used as a field; don't let finalize_record_size undo it. */
6476 /* Let the back end lay out the type. */
6485 /* Warn about bases that can't be talked about due to ambiguity. */
6488 /* Now that we're done with layout, give the base fields the real types. */
6493 /* Clean up. */
6500 }
6502 /* Determine the "key method" for the class type indicated by TYPE,
6503 and set CLASSTYPE_KEY_METHOD accordingly. */
6505 void
6507 {
6508 tree method;
6511 || processing_template_decl
6516 /* The key method is the first non-pure virtual function that is not
6517 inline at the point of class definition. On some targets the
6518 key function may not be inline; those targets should not call
6519 this function until the end of the translation unit. */
6526 {
6529 }
6532 }
6535 /* Allocate and return an instance of struct sorted_fields_type with
6536 N fields. */
6540 {
6547 }
6550 /* Perform processing required when the definition of T (a class type)
6551 is complete. */
6553 void
6555 {
6556 tree x;
6557 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6561 {
6566 }
6568 /* If this type was previously laid out as a forward reference,
6569 make sure we lay it out again. */
6573 /* Make assumptions about the class; we'll reset the flags if
6574 necessary. */
6580 /* Do end-of-class semantic processing: checking the validity of the
6581 bases and members and add implicitly generated methods. */
6584 /* Find the key method. */
6586 {
6587 /* The Itanium C++ ABI permits the key method to be chosen when
6588 the class is defined -- even though the key method so
6589 selected may later turn out to be an inline function. On
6590 some systems (such as ARM Symbian OS) the key method cannot
6591 be determined until the end of the translation unit. On such
6592 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6593 will cause the class to be added to KEYED_CLASSES. Then, in
6594 finish_file we will determine the key method. */
6598 /* If a polymorphic class has no key method, we may emit the vtable
6599 in every translation unit where the class definition appears. If
6600 we're devirtualizing, we can look into the vtable even if we
6601 aren't emitting it. */
6604 }
6606 /* Layout the class itself. */
6609 /* We use the base type for trivial assignments, and hence it
6610 needs a mode. */
6615 /* If necessary, create the primary vtable for this class. */
6617 {
6618 /* We must enter these virtuals into the table. */
6622 /* Here we know enough to change the type of our virtual
6623 function table, but we will wait until later this function. */
6626 /* If we're warning about ABI tags, check the types of the new
6627 virtual functions. */
6631 }
6634 {
6636 tree fn;
6643 /* Add entries for virtual functions introduced by this class. */
6647 /* Set DECL_VINDEX for all functions declared in this class. */
6649 fn;
6651 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6653 {
6657 /* A thunk. We should never be calling this entry directly
6658 from this vtable -- we'd use the entry for the non
6659 thunk base function. */
6663 }
6664 }
6669 /* Complete the rtl for any static member objects of the type we're
6670 working on. */
6679 {
6681 do
6685 {
6692 }
6693 }
6695 /* Done with FIELDS...now decide whether to sort these for
6696 faster lookups later.
6698 We use a small number because most searches fail (succeeding
6699 ultimately as the search bores through the inheritance
6700 hierarchy), and we want this failure to occur quickly. */
6704 /* Complain if one of the field types requires lower visibility. */
6707 /* Make the rtl for any new vtables we have created, and unmark
6708 the base types we marked. */
6711 /* Build the VTT for T. */
6714 /* This warning does not make sense for Java classes, since they
6715 cannot have destructors. */
6720 "%q#T has virtual functions and accessible"
6728 /* Class layout, assignment of virtual table slots, etc., is now
6729 complete. Give the back end a chance to tweak the visibility of
6730 the class or perform any other required target modifications. */
6740 /* Finish debugging output for this type. */
6744 {
6747 {
6750 }
6752 {
6755 else
6756 {
6759 }
6761 }
6763 {
6765 "the type of the first field has a different ABI from the "
6768 }
6769 }
6770 }
6772 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6773 equal to THRESHOLD or greater than THRESHOLD. */
6775 static void
6777 {
6780 {
6785 }
6786 }
6788 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6790 void
6792 {
6795 {
6797 int n_fields
6808 }
6809 }
6811 /* When T was built up, the member declarations were added in reverse
6812 order. Rearrange them to declaration order. */
6814 void
6816 {
6817 tree next;
6818 tree prev;
6819 tree x;
6821 /* The following lists are all in reverse order. Put them in
6822 declaration order now. */
6826 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6827 reverse order, so we can't just use nreverse. */
6832 {
6836 }
6838 {
6842 }
6843 }
6845 tree
6847 {
6850 /* Now that we've got all the field declarations, reverse everything
6851 as necessary. */
6856 /* Nadger the current location so that diagnostics point to the start of
6857 the struct, not the end. */
6861 {
6862 tree x;
6868 /* We need to emit an error message if this type was used as a parameter
6869 and it is an abstract type, even if it is a template. We construct
6870 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6871 account and we call complete_vars with this type, which will check
6872 the PARM_DECLS. Note that while the type is being defined,
6873 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6874 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6880 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6881 an enclosing scope is a template class, so that this function be
6882 found by lookup_fnfields_1 when the using declaration is not
6883 instantiated yet. */
6886 {
6891 }
6893 /* Remember current #pragma pack value. */
6896 /* Fix up any variants we've already built. */
6898 {
6903 }
6904 }
6905 else
6909 {
6910 /* People keep complaining that the compiler crashes on an invalid
6911 definition of initializer_list, so I guess we should explicitly
6912 reject it. What the compiler internals care about is that it's a
6913 template and has a pointer field followed by an integer field. */
6916 {
6919 {
6923 }
6924 }
6927 "definition of std::initializer_list does not match "
6929 }
6937 else
6941 /* Lambdas are defined by the LAMBDA_EXPR. */
6946 }
6947 \f
6948 /* Hash table to avoid endless recursion when handling references. */
6951 /* Return the dynamic type of INSTANCE, if known.
6952 Used to determine whether the virtual function table is needed
6953 or not.
6955 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6956 of our knowledge of its type. *NONNULL should be initialized
6957 before this function is called. */
6959 static tree
6961 {
6962 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6965 {
6969 else
6973 /* This is a call to a constructor, hence it's never zero. */
6975 {
6979 }
6983 /* This is a call to a constructor, hence it's never zero. */
6985 {
6989 }
6998 /* Propagate nonnull. */
7003 CASE_CONVERT:
7009 {
7010 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7011 with a real object -- given &p->f, p can still be null. */
7013 /* ??? Probably should check DECL_WEAK here. */
7016 }
7020 /* If this component is really a base class reference, then the field
7021 itself isn't definitive. */
7030 {
7034 }
7035 /* fall through... */
7040 {
7044 }
7046 {
7050 /* if we're in a ctor or dtor, we know our type. If
7051 current_class_ptr is set but we aren't in a function, we're in
7052 an NSDMI (and therefore a constructor). */
7057 {
7061 }
7062 }
7064 {
7065 /* We only need one hash table because it is always left empty. */
7067 fixed_type_or_null_ref_ht
7070 /* Reference variables should be references to objects. */
7074 /* Enter the INSTANCE in a table to prevent recursion; a
7075 variable's initializer may refer to the variable
7076 itself. */
7081 {
7082 tree type;
7091 }
7092 }
7097 }
7098 #undef RECUR
7099 }
7101 /* Return nonzero if the dynamic type of INSTANCE is known, and
7102 equivalent to the static type. We also handle the case where
7103 INSTANCE is really a pointer. Return negative if this is a
7104 ctor/dtor. There the dynamic type is known, but this might not be
7105 the most derived base of the original object, and hence virtual
7106 bases may not be laid out according to this type.
7108 Used to determine whether the virtual function table is needed
7109 or not.
7111 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7112 of our knowledge of its type. *NONNULL should be initialized
7113 before this function is called. */
7115 int
7117 {
7120 tree fixed;
7122 /* processing_template_decl can be false in a template if we're in
7123 instantiate_non_dependent_expr, but we still want to suppress
7124 this check. */
7126 {
7127 /* In a template we only care about the type of the result. */
7131 }
7141 }
7143 \f
7144 void
7146 {
7149 current_class_stack
7157 }
7159 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7161 static void
7163 {
7164 tree type;
7166 /* We are re-entering the same class we just left, so we don't
7167 have to search the whole inheritance matrix to find all the
7168 decls to bind again. Instead, we install the cached
7169 class_shadowed list and walk through it binding names. */
7172 /* Restore IDENTIFIER_TYPE_VALUE. */
7174 type;
7177 }
7179 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7180 appropriate for TYPE.
7182 So that we may avoid calls to lookup_name, we cache the _TYPE
7183 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7185 For multiple inheritance, we perform a two-pass depth-first search
7186 of the type lattice. */
7188 void
7190 {
7191 class_stack_node_t csn;
7195 /* Make sure there is enough room for the new entry on the stack. */
7197 {
7199 current_class_stack
7201 current_class_stack_size);
7202 }
7204 /* Insert a new entry on the class stack. */
7211 current_class_depth++;
7213 /* Now set up the new type. */
7219 /* By default, things in classes are private, while things in
7220 structures or unions are public. */
7222 ? access_private_node
7228 {
7229 /* Forcibly remove any old class remnants. */
7231 }
7237 else
7239 }
7241 /* When we exit a toplevel class scope, we save its binding level so
7242 that we can restore it quickly. Here, we've entered some other
7243 class, so we must invalidate our cache. */
7245 void
7247 {
7249 }
7251 /* Get out of the current class scope. If we were in a class scope
7252 previously, that is the one popped to. */
7254 void
7256 {
7259 current_class_depth--;
7265 }
7267 /* Mark the top of the class stack as hidden. */
7269 void
7271 {
7274 }
7276 /* Mark the top of the class stack as un-hidden. */
7278 void
7280 {
7283 }
7285 /* Returns 1 if the class type currently being defined is either T or
7286 a nested type of T. */
7288 bool
7290 {
7298 /* We start looking from 1 because entry 0 is from global scope,
7299 and has no type. */
7301 {
7302 tree c;
7305 else
7306 {
7310 }
7315 }
7317 }
7319 /* If either current_class_type or one of its enclosing classes are derived
7320 from T, return the appropriate type. Used to determine how we found
7321 something via unqualified lookup. */
7323 tree
7325 {
7328 /* The bases of a dependent type are unknown. */
7339 {
7344 }
7347 }
7349 /* Return the outermost enclosing class type that is still open, or
7350 NULL_TREE. */
7352 tree
7354 {
7361 {
7368 }
7370 }
7372 /* Returns the innermost class type which is not a lambda closure type. */
7374 tree
7376 {
7379 /* We start looking from 1 because entry 0 is from global scope,
7380 and has no type. */
7382 {
7383 tree c;
7386 else
7387 {
7391 }
7396 }
7398 }
7400 /* When entering a class scope, all enclosing class scopes' names with
7401 static meaning (static variables, static functions, types and
7402 enumerators) have to be visible. This recursive function calls
7403 pushclass for all enclosing class contexts until global or a local
7404 scope is reached. TYPE is the enclosed class. */
7406 void
7408 {
7409 /* A namespace might be passed in error cases, like A::B:C. */
7417 }
7419 /* Undoes a push_nested_class call. */
7421 void
7423 {
7429 }
7431 /* Returns the number of extern "LANG" blocks we are nested within. */
7433 int
7435 {
7437 }
7439 /* Set global variables CURRENT_LANG_NAME to appropriate value
7440 so that behavior of name-mangling machinery is correct. */
7442 void
7444 {
7448 {
7450 }
7452 {
7454 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7455 (See record_builtin_java_type in decl.c.) However, that causes
7456 incorrect debug entries if these types are actually used.
7457 So we re-enable debug output after extern "Java". */
7466 }
7468 {
7470 }
7471 else
7473 }
7475 /* Get out of the current language scope. */
7477 void
7479 {
7481 }
7482 \f
7483 /* Type instantiation routines. */
7485 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7486 matches the TARGET_TYPE. If there is no satisfactory match, return
7487 error_mark_node, and issue an error & warning messages under
7488 control of FLAGS. Permit pointers to member function if FLAGS
7489 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7490 a template-id, and EXPLICIT_TARGS are the explicitly provided
7491 template arguments.
7493 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7494 is the base path used to reference those member functions. If
7495 the address is resolved to a member function, access checks will be
7496 performed and errors issued if appropriate. */
7498 static tree
7500 tree overload,
7501 tsubst_flags_t complain,
7503 tree explicit_targs,
7504 tree access_path)
7505 {
7506 /* Here's what the standard says:
7508 [over.over]
7510 If the name is a function template, template argument deduction
7511 is done, and if the argument deduction succeeds, the deduced
7512 arguments are used to generate a single template function, which
7513 is added to the set of overloaded functions considered.
7515 Non-member functions and static member functions match targets of
7516 type "pointer-to-function" or "reference-to-function." Nonstatic
7517 member functions match targets of type "pointer-to-member
7518 function;" the function type of the pointer to member is used to
7519 select the member function from the set of overloaded member
7520 functions. If a nonstatic member function is selected, the
7521 reference to the overloaded function name is required to have the
7522 form of a pointer to member as described in 5.3.1.
7524 If more than one function is selected, any template functions in
7525 the set are eliminated if the set also contains a non-template
7526 function, and any given template function is eliminated if the
7527 set contains a second template function that is more specialized
7528 than the first according to the partial ordering rules 14.5.5.2.
7529 After such eliminations, if any, there shall remain exactly one
7530 selected function. */
7533 /* We store the matches in a TREE_LIST rooted here. The functions
7534 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7535 interoperability with most_specialized_instantiation. */
7537 tree fn;
7538 tree target_fn_type;
7540 /* By the time we get here, we should be seeing only real
7541 pointer-to-member types, not the internal POINTER_TYPE to
7542 METHOD_TYPE representation. */
7548 /* Check that the TARGET_TYPE is reasonable. */
7553 /* This is OK, too. */
7556 /* This is OK, too. This comes from a conversion to reference
7557 type. */
7559 else
7560 {
7566 }
7568 /* Non-member functions and static member functions match targets of type
7569 "pointer-to-function" or "reference-to-function." Nonstatic member
7570 functions match targets of type "pointer-to-member-function;" the
7571 function type of the pointer to member is used to select the member
7572 function from the set of overloaded member functions.
7574 So figure out the FUNCTION_TYPE that we want to match against. */
7577 /* If we can find a non-template function that matches, we can just
7578 use it. There's no point in generating template instantiations
7579 if we're just going to throw them out anyhow. But, of course, we
7580 can only do this when we don't *need* a template function. */
7582 {
7583 tree fns;
7586 {
7590 /* We're not looking for templates just yet. */
7595 /* We're looking for a non-static member, and this isn't
7596 one, or vice versa. */
7599 /* Ignore functions which haven't been explicitly
7600 declared. */
7604 /* See if there's a match. */
7607 }
7608 }
7610 /* Now, if we've already got a match (or matches), there's no need
7611 to proceed to the template functions. But, if we don't have a
7612 match we need to look at them, too. */
7614 {
7615 tree target_arg_types;
7616 tree target_ret_type;
7617 tree fns;
7620 tree arg;
7634 {
7636 tree instantiation;
7637 tree targs;
7640 /* We're only looking for templates. */
7645 /* We're not looking for a non-static member, and this is
7646 one, or vice versa. */
7651 /* If the template has a deduced return type, don't expose it to
7652 template argument deduction. */
7656 /* Try to do argument deduction. */
7663 /* Instantiation failed. */
7666 /* And now force instantiation to do return type deduction. */
7668 {
7674 }
7676 /* See if there's a match. */
7679 }
7681 /* Now, remove all but the most specialized of the matches. */
7683 {
7688 NULL_TREE,
7689 NULL_TREE);
7690 }
7691 }
7693 /* Now we should have exactly one function in MATCHES. */
7695 {
7696 /* There were *no* matches. */
7698 {
7701 target_type);
7704 }
7706 }
7708 {
7709 /* There were too many matches. First check if they're all
7710 the same function. */
7715 /* For multi-versioned functions, more than one match is just fine and
7716 decls_match will return false as they are different. */
7724 {
7726 {
7729 target_type);
7731 /* Since print_candidates expects the functions in the
7732 TREE_VALUE slot, we flip them here. */
7737 }
7740 }
7741 }
7743 /* Good, exactly one match. Now, convert it to the correct type. */
7748 {
7756 {
7759 }
7760 }
7762 /* If a pointer to a function that is multi-versioned is requested, the
7763 pointer to the dispatcher function is returned instead. This works
7764 well because indirectly calling the function will dispatch the right
7765 function version at run-time. */
7767 {
7771 /* Mark all the versions corresponding to the dispatcher as used. */
7774 }
7776 /* If we're doing overload resolution purely for the purpose of
7777 determining conversion sequences, we should not consider the
7778 function used. If this conversion sequence is selected, the
7779 function will be marked as used at this point. */
7781 {
7782 /* Make =delete work with SFINAE. */
7787 }
7789 /* We could not check access to member functions when this
7790 expression was originally created since we did not know at that
7791 time to which function the expression referred. */
7793 {
7796 }
7800 else
7801 {
7802 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7803 will mark the function as addressed, but here we must do it
7804 explicitly. */
7808 }
7809 }
7811 /* This function will instantiate the type of the expression given in
7812 RHS to match the type of LHSTYPE. If errors exist, then return
7813 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
7814 we complain on errors. If we are not complaining, never modify rhs,
7815 as overload resolution wants to try many possible instantiations, in
7816 the hope that at least one will work.
7818 For non-recursive calls, LHSTYPE should be a function, pointer to
7819 function, or a pointer to member function. */
7821 tree
7823 {
7830 {
7834 }
7837 {
7844 /* Microsoft allows `A::f' to be resolved to a
7845 pointer-to-member. */
7846 ;
7847 else
7848 {
7853 }
7854 }
7857 {
7860 }
7862 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7863 deduce any type information. */
7865 {
7869 }
7871 /* There only a few kinds of expressions that may have a type
7872 dependent on overload resolution. */
7878 /* This should really only be used when attempting to distinguish
7879 what sort of a pointer to function we have. For now, any
7880 arithmetic operation which is not supported on pointers
7881 is rejected as an error. */
7884 {
7886 {
7892 /* Do not lose object's side effects. */
7896 }
7903 /* This can happen if we are forming a pointer-to-member for a
7904 member template. */
7907 /* Fall through. */
7910 {
7914 return
7918 }
7922 return
7926 access_path);
7929 {
7934 }
7941 }
7943 }
7944 \f
7945 /* Return the name of the virtual function pointer field
7946 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7947 this may have to look back through base types to find the
7948 ultimate field name. (For single inheritance, these could
7949 all be the same name. Who knows for multiple inheritance). */
7951 static tree
7953 {
7960 {
7966 }
7974 }
7976 void
7978 {
7985 {
7990 }
7991 }
7993 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7994 according to [class]:
7995 The class-name is also inserted
7996 into the scope of the class itself. For purposes of access checking,
7997 the inserted class name is treated as if it were a public member name. */
7999 void
8001 {
8004 tree saved_cas;
8019 }
8021 /* Returns 1 if TYPE contains only padding bytes. */
8023 int
8025 {
8033 }
8035 /* Returns true if TYPE contains no actual data, just various
8036 possible combinations of empty classes and possibly a vptr. */
8038 bool
8040 {
8042 {
8043 tree field;
8044 tree binfo;
8045 tree base_binfo;
8048 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8049 out, but we'd like to be able to check this before then. */
8063 }
8067 }
8069 /* Note that NAME was looked up while the current class was being
8070 defined and that the result of that lookup was DECL. */
8072 void
8074 {
8075 splay_tree names_used;
8077 /* If we're not defining a class, there's nothing to do. */
8083 /* If there's already a binding for this NAME, then we don't have
8084 anything to worry about. */
8097 }
8099 /* Note that NAME was declared (as DECL) in the current class. Check
8100 to see that the declaration is valid. */
8102 void
8104 {
8105 splay_tree names_used;
8106 splay_tree_node n;
8108 /* Look to see if we ever used this name. */
8109 names_used
8113 /* The C language allows members to be declared with a type of the same
8114 name, and the C++ standard says this diagnostic is not required. So
8115 allow it in extern "C" blocks unless predantic is specified.
8116 Allow it in all cases if -ms-extensions is specified. */
8122 {
8123 /* [basic.scope.class]
8125 A name N used in a class S shall refer to the same declaration
8126 in its context and when re-evaluated in the completed scope of
8127 S. */
8131 }
8132 }
8134 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8135 Secondary vtables are merged with primary vtables; this function
8136 will return the VAR_DECL for the primary vtable. */
8138 tree
8140 {
8141 tree decl;
8145 {
8148 }
8152 }
8155 /* Returns the binfo for the primary base of BINFO. If the resulting
8156 BINFO is a virtual base, and it is inherited elsewhere in the
8157 hierarchy, then the returned binfo might not be the primary base of
8158 BINFO in the complete object. Check BINFO_PRIMARY_P or
8159 BINFO_LOST_PRIMARY_P to be sure. */
8161 static tree
8163 {
8164 tree primary_base;
8171 }
8173 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8175 static int
8177 {
8181 }
8183 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8184 INDENT should be zero when called from the top level; it is
8185 incremented recursively. IGO indicates the next expected BINFO in
8186 inheritance graph ordering. */
8188 static tree
8191 tree binfo,
8192 tree igo,
8194 {
8196 tree base_binfo;
8204 {
8207 }
8222 {
8226 TFF_PLAIN_IDENTIFIER),
8228 }
8230 {
8233 }
8238 {
8242 {
8246 TFF_PLAIN_IDENTIFIER));
8247 }
8249 {
8253 TFF_PLAIN_IDENTIFIER));
8254 }
8256 {
8260 TFF_PLAIN_IDENTIFIER));
8261 }
8263 {
8267 TFF_PLAIN_IDENTIFIER));
8268 }
8272 }
8278 }
8280 /* Dump the BINFO hierarchy for T. */
8282 static void
8284 {
8296 }
8298 /* Debug interface to hierarchy dumping. */
8300 void
8302 {
8304 }
8306 static void
8308 {
8313 {
8315 }
8316 }
8318 static void
8320 {
8321 tree value;
8323 HOST_WIDE_INT elt;
8331 TFF_PLAIN_IDENTIFIER));
8338 }
8340 static void
8342 {
8350 {
8357 {
8362 }
8366 }
8367 }
8369 static void
8371 {
8379 {
8384 }
8385 }
8387 /* Dump a function or thunk and its thunkees. */
8389 static void
8391 {
8394 tree thunks;
8402 {
8412 else
8418 }
8422 }
8424 /* Dump the thunks for FN. */
8426 void
8428 {
8430 }
8432 /* Virtual function table initialization. */
8434 /* Create all the necessary vtables for T and its base classes. */
8436 static void
8438 {
8439 tree vbase;
8443 /* We lay out the primary and secondary vtables in one contiguous
8444 vtable. The primary vtable is first, followed by the non-virtual
8445 secondary vtables in inheritance graph order. */
8449 /* Then come the virtual bases, also in inheritance graph order. */
8451 {
8455 }
8459 }
8461 /* Initialize the vtable for BINFO with the INITS. */
8463 static void
8465 {
8466 tree decl;
8472 }
8474 /* Build the VTT (virtual table table) for T.
8475 A class requires a VTT if it has virtual bases.
8477 This holds
8478 1 - primary virtual pointer for complete object T
8479 2 - secondary VTTs for each direct non-virtual base of T which requires a
8480 VTT
8481 3 - secondary virtual pointers for each direct or indirect base of T which
8482 has virtual bases or is reachable via a virtual path from T.
8483 4 - secondary VTTs for each direct or indirect virtual base of T.
8485 Secondary VTTs look like complete object VTTs without part 4. */
8487 static void
8489 {
8490 tree type;
8491 tree vtt;
8492 tree index;
8495 /* Build up the initializers for the VTT. */
8500 /* If we didn't need a VTT, we're done. */
8504 /* Figure out the type of the VTT. */
8508 /* Now, build the VTT object itself. */
8511 /* Add the VTT to the vtables list. */
8516 }
8518 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8519 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8520 and CHAIN the vtable pointer for this binfo after construction is
8521 complete. VALUE can also be another BINFO, in which case we recurse. */
8523 static tree
8525 {
8526 tree vt;
8529 {
8535 else
8537 }
8540 }
8542 /* Data for secondary VTT initialization. */
8544 {
8545 /* Is this the primary VTT? */
8548 /* Current index into the VTT. */
8549 tree index;
8551 /* Vector of initializers built up. */
8554 /* The type being constructed by this secondary VTT. */
8555 tree type_being_constructed;
8558 /* Recursively build the VTT-initializer for BINFO (which is in the
8559 hierarchy dominated by T). INITS points to the end of the initializer
8560 list to date. INDEX is the VTT index where the next element will be
8561 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8562 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8563 for virtual bases of T. When it is not so, we build the constructor
8564 vtables for the BINFO-in-T variant. */
8566 static void
8569 {
8571 tree b;
8572 tree init;
8573 secondary_vptr_vtt_init_data data;
8576 /* We only need VTTs for subobjects with virtual bases. */
8580 /* We need to use a construction vtable if this is not the primary
8581 VTT. */
8583 {
8586 /* Record the offset in the VTT where this sub-VTT can be found. */
8588 }
8590 /* Add the address of the primary vtable for the complete object. */
8594 {
8597 }
8600 /* Recursively add the secondary VTTs for non-virtual bases. */
8605 /* Add secondary virtual pointers for all subobjects of BINFO with
8606 either virtual bases or reachable along a virtual path, except
8607 subobjects that are non-virtual primary bases. */
8617 /* data.inits might have grown as we added secondary virtual pointers.
8618 Make sure our caller knows about the new vector. */
8622 /* Add the secondary VTTs for virtual bases in inheritance graph
8623 order. */
8625 {
8630 }
8631 else
8632 /* Remove the ctor vtables we created. */
8634 }
8636 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8637 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8639 static tree
8641 {
8644 /* We don't care about bases that don't have vtables. */
8648 /* We're only interested in proper subobjects of the type being
8649 constructed. */
8653 /* We're only interested in bases with virtual bases or reachable
8654 via a virtual path from the type being constructed. */
8659 /* We're not interested in non-virtual primary bases. */
8663 /* Record the index where this secondary vptr can be found. */
8665 {
8670 {
8671 /* It's a primary virtual base, and this is not a
8672 construction vtable. Find the base this is primary of in
8673 the inheritance graph, and use that base's vtable
8674 now. */
8677 }
8678 }
8680 /* Add the initializer for the secondary vptr itself. */
8683 /* Advance the vtt index. */
8688 }
8690 /* Called from build_vtt_inits via dfs_walk. After building
8691 constructor vtables and generating the sub-vtt from them, we need
8692 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8693 binfo of the base whose sub vtt was generated. */
8695 static tree
8697 {
8701 /* If this class has no vtable, none of its bases do. */
8705 /* This might be a primary base, so have no vtable in this
8706 hierarchy. */
8709 /* If we scribbled the construction vtable vptr into BINFO, clear it
8710 out now. */
8716 }
8718 /* Build the construction vtable group for BINFO which is in the
8719 hierarchy dominated by T. */
8721 static void
8723 {
8724 tree type;
8725 tree vtbl;
8726 tree id;
8727 tree vbase;
8730 /* See if we've already created this construction vtable group. */
8736 /* Build a version of VTBL (with the wrong type) for use in
8737 constructing the addresses of secondary vtables in the
8738 construction vtable group. */
8741 /* Don't export construction vtables from shared libraries. Even on
8742 targets that don't support hidden visibility, this tells
8743 can_refer_decl_in_current_unit_p not to assume that it's safe to
8744 access from a different compilation unit (bz 54314). */
8752 /* Add the vtables for each of our virtual bases using the vbase in T
8753 binfo. */
8755 vbase;
8757 {
8758 tree b;
8765 }
8767 /* Figure out the type of the construction vtable. */
8774 /* Initialize the construction vtable. */
8778 }
8780 /* Add the vtbl initializers for BINFO (and its bases other than
8781 non-virtual primaries) to the list of INITS. BINFO is in the
8782 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8783 the constructor the vtbl inits should be accumulated for. (If this
8784 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8785 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8786 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8787 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8788 but are not necessarily the same in terms of layout. */
8790 static void
8792 tree orig_binfo,
8793 tree rtti_binfo,
8794 tree vtbl,
8795 tree t,
8797 {
8799 tree base_binfo;
8804 /* If it doesn't have a vptr, we don't do anything. */
8808 /* If we're building a construction vtable, we're not interested in
8809 subobjects that don't require construction vtables. */
8815 /* Build the initializers for the BINFO-in-T vtable. */
8818 /* Walk the BINFO and its bases. We walk in preorder so that as we
8819 initialize each vtable we can figure out at what offset the
8820 secondary vtable lies from the primary vtable. We can't use
8821 dfs_walk here because we need to iterate through bases of BINFO
8822 and RTTI_BINFO simultaneously. */
8824 {
8825 /* Skip virtual bases. */
8831 inits);
8832 }
8833 }
8835 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8836 BINFO vtable to L. */
8838 static void
8840 tree orig_binfo,
8841 tree rtti_binfo,
8842 tree orig_vtbl,
8843 tree t,
8845 {
8852 {
8853 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8854 primary virtual base. If it is not the same primary in
8855 the hierarchy of T, we'll need to generate a ctor vtable
8856 for it, to place at its location in T. If it is the same
8857 primary, we still need a VTT entry for the vtable, but it
8858 should point to the ctor vtable for the base it is a
8859 primary for within the sub-hierarchy of RTTI_BINFO.
8861 There are three possible cases:
8863 1) We are in the same place.
8864 2) We are a primary base within a lost primary virtual base of
8865 RTTI_BINFO.
8866 3) We are primary to something not a base of RTTI_BINFO. */
8868 tree b;
8871 /* First, look through the bases we are primary to for RTTI_BINFO
8872 or a virtual base. */
8875 {
8880 }
8881 /* If we run out of primary links, keep looking down our
8882 inheritance chain; we might be an indirect primary. */
8886 found:
8888 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8889 base B and it is a base of RTTI_BINFO, this is case 2. In
8890 either case, we share our vtable with LAST, i.e. the
8891 derived-most base within B of which we are a primary. */
8894 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8895 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8896 binfo_ctor_vtable after everything's been set up. */
8899 /* Otherwise, this is case 3 and we get our own. */
8900 }
8907 {
8908 tree index;
8911 /* Add the initializer for this vtable. */
8915 /* Figure out the position to which the VPTR should point. */
8921 }
8924 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8925 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8926 straighten this out. */
8929 /* Throw away any unneeded intializers. */
8931 else
8932 /* For an ordinary vtable, set BINFO_VTABLE. */
8934 }
8938 /* Construct the initializer for BINFO's virtual function table. BINFO
8939 is part of the hierarchy dominated by T. If we're building a
8940 construction vtable, the ORIG_BINFO is the binfo we should use to
8941 find the actual function pointers to put in the vtable - but they
8942 can be overridden on the path to most-derived in the graph that
8943 ORIG_BINFO belongs. Otherwise,
8944 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8945 BINFO that should be indicated by the RTTI information in the
8946 vtable; it will be a base class of T, rather than T itself, if we
8947 are building a construction vtable.
8949 The value returned is a TREE_LIST suitable for wrapping in a
8950 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8951 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8952 number of non-function entries in the vtable.
8954 It might seem that this function should never be called with a
8955 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8956 base is always subsumed by a derived class vtable. However, when
8957 we are building construction vtables, we do build vtables for
8958 primary bases; we need these while the primary base is being
8959 constructed. */
8961 static void
8963 tree orig_binfo,
8964 tree t,
8965 tree rtti_binfo,
8968 {
8969 tree v;
8970 vtbl_init_data vid;
8972 tree vbinfo;
8976 /* Initialize VID. */
8984 /* The first vbase or vcall offset is at index -3 in the vtable. */
8987 /* Add entries to the vtable for RTTI. */
8990 /* Create an array for keeping track of the functions we've
8991 processed. When we see multiple functions with the same
8992 signature, we share the vcall offsets. */
8994 /* Add the vcall and vbase offset entries. */
8997 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8998 build_vbase_offset_vtbl_entries. */
9003 /* If the target requires padding between data entries, add that now. */
9005 {
9010 /* Move data entries into their new positions and add padding
9011 after the new positions. Iterate backwards so we don't
9012 overwrite entries that we would need to process later. */
9015 ix--)
9016 {
9024 {
9028 null_pointer_node);
9029 }
9030 }
9031 }
9036 /* The initializers for virtual functions were built up in reverse
9037 order. Straighten them out and add them to the running list in one
9038 step. */
9047 /* Go through all the ordinary virtual functions, building up
9048 initializers. */
9050 {
9051 tree delta;
9052 tree vcall_index;
9059 {
9063 {
9066 }
9068 }
9070 /* If the only definition of this function signature along our
9071 primary base chain is from a lost primary, this vtable slot will
9072 never be used, so just zero it out. This is important to avoid
9073 requiring extra thunks which cannot be generated with the function.
9075 We first check this in update_vtable_entry_for_fn, so we handle
9076 restored primary bases properly; we also need to do it here so we
9077 zero out unused slots in ctor vtables, rather than filling them
9078 with erroneous values (though harmless, apart from relocation
9079 costs). */
9084 {
9085 /* Pull the offset for `this', and the function to call, out of
9086 the list. */
9093 /* You can't call an abstract virtual function; it's abstract.
9094 So, we replace these functions with __pure_virtual. */
9096 {
9099 {
9101 abort_fndecl_addr
9105 }
9106 }
9107 /* Likewise for deleted virtuals. */
9109 {
9118 }
9119 else
9120 {
9122 {
9126 }
9127 /* Take the address of the function, considering it to be of an
9128 appropriate generic type. */
9132 /* Don't refer to a virtual destructor from a constructor
9133 vtable or a vtable for an abstract class, since destroying
9134 an object under construction is undefined behavior and we
9135 don't want it to be considered a candidate for speculative
9136 devirtualization. But do create the thunk for ABI
9137 compliance. */
9142 }
9143 }
9145 /* And add it to the chain of initializers. */
9147 {
9152 else
9154 {
9160 }
9161 }
9162 else
9164 }
9165 }
9167 /* Adds to vid->inits the initializers for the vbase and vcall
9168 offsets in BINFO, which is in the hierarchy dominated by T. */
9170 static void
9172 {
9173 tree b;
9175 /* If this is a derived class, we must first create entries
9176 corresponding to the primary base class. */
9181 /* Add the vbase entries for this base. */
9183 /* Add the vcall entries for this base. */
9185 }
9187 /* Returns the initializers for the vbase offset entries in the vtable
9188 for BINFO (which is part of the class hierarchy dominated by T), in
9189 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9190 where the next vbase offset will go. */
9192 static void
9194 {
9195 tree vbase;
9196 tree t;
9197 tree non_primary_binfo;
9199 /* If there are no virtual baseclasses, then there is nothing to
9200 do. */
9206 /* We might be a primary base class. Go up the inheritance hierarchy
9207 until we find the most derived class of which we are a primary base:
9208 it is the offset of that which we need to use. */
9211 {
9212 tree b;
9214 /* If we have reached a virtual base, then it must be a primary
9215 base (possibly multi-level) of vid->binfo, or we wouldn't
9216 have called build_vcall_and_vbase_vtbl_entries for it. But it
9217 might be a lost primary, so just skip down to vid->binfo. */
9219 {
9222 }
9228 }
9230 /* Go through the virtual bases, adding the offsets. */
9232 vbase;
9234 {
9235 tree b;
9236 tree delta;
9241 /* Find the instance of this virtual base in the complete
9242 object. */
9245 /* If we've already got an offset for this virtual base, we
9246 don't need another one. */
9251 /* Figure out where we can find this vbase offset. */
9260 /* The vbase offset had better be the same. */
9263 /* The next vbase will come at a more negative offset. */
9267 /* The initializer is the delta from BINFO to this virtual base.
9268 The vbase offsets go in reverse inheritance-graph order, and
9269 we are walking in inheritance graph order so these end up in
9270 the right order. */
9277 }
9278 }
9280 /* Adds the initializers for the vcall offset entries in the vtable
9281 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9282 to VID->INITS. */
9284 static void
9286 {
9287 /* We only need these entries if this base is a virtual base. We
9288 compute the indices -- but do not add to the vtable -- when
9289 building the main vtable for a class. */
9292 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9293 correspond to VID->DERIVED), we are building a primary
9294 construction virtual table. Since this is a primary
9295 virtual table, we do not need the vcall offsets for
9296 BINFO. */
9298 {
9299 /* We need a vcall offset for each of the virtual functions in this
9300 vtable. For example:
9302 class A { virtual void f (); };
9303 class B1 : virtual public A { virtual void f (); };
9304 class B2 : virtual public A { virtual void f (); };
9305 class C: public B1, public B2 { virtual void f (); };
9307 A C object has a primary base of B1, which has a primary base of A. A
9308 C also has a secondary base of B2, which no longer has a primary base
9309 of A. So the B2-in-C construction vtable needs a secondary vtable for
9310 A, which will adjust the A* to a B2* to call f. We have no way of
9311 knowing what (or even whether) this offset will be when we define B2,
9312 so we store this "vcall offset" in the A sub-vtable and look it up in
9313 a "virtual thunk" for B2::f.
9315 We need entries for all the functions in our primary vtable and
9316 in our non-virtual bases' secondary vtables. */
9318 /* If we are just computing the vcall indices -- but do not need
9319 the actual entries -- not that. */
9322 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9324 }
9325 }
9327 /* Build vcall offsets, starting with those for BINFO. */
9329 static void
9331 {
9333 tree primary_binfo;
9334 tree base_binfo;
9336 /* Don't walk into virtual bases -- except, of course, for the
9337 virtual base for which we are building vcall offsets. Any
9338 primary virtual base will have already had its offsets generated
9339 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9343 /* If BINFO has a primary base, process it first. */
9348 /* Add BINFO itself to the list. */
9351 /* Scan the non-primary bases of BINFO. */
9355 }
9357 /* Called from build_vcall_offset_vtbl_entries_r. */
9359 static void
9361 {
9362 /* Make entries for the rest of the virtuals. */
9363 tree orig_fn;
9365 /* The ABI requires that the methods be processed in declaration
9366 order. */
9368 orig_fn;
9372 }
9374 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9376 static void
9378 {
9380 tree vcall_offset;
9381 tree derived_entry;
9383 /* If there is already an entry for a function with the same
9384 signature as FN, then we do not need a second vcall offset.
9385 Check the list of functions already present in the derived
9386 class vtable. */
9388 {
9390 /* We only use one vcall offset for virtual destructors,
9391 even though there are two virtual table entries. */
9395 }
9397 /* If we are building these vcall offsets as part of building
9398 the vtable for the most derived class, remember the vcall
9399 offset. */
9401 {
9404 }
9406 /* The next vcall offset will be found at a more negative
9407 offset. */
9411 /* Keep track of this function. */
9415 {
9416 tree base;
9417 tree fn;
9419 /* Find the overriding function. */
9423 else
9424 {
9427 /* The vbase we're working on is a primary base of
9428 vid->binfo. But it might be a lost primary, so its
9429 BINFO_OFFSET might be wrong, so we just use the
9430 BINFO_OFFSET from vid->binfo. */
9436 vcall_offset);
9437 }
9438 /* Add the initializer to the vtable. */
9440 }
9441 }
9443 /* Return vtbl initializers for the RTTI entries corresponding to the
9444 BINFO's vtable. The RTTI entries should indicate the object given
9445 by VID->rtti_binfo. */
9447 static void
9449 {
9450 tree b;
9451 tree t;
9452 tree offset;
9453 tree decl;
9454 tree init;
9458 /* To find the complete object, we will first convert to our most
9459 primary base, and then add the offset in the vtbl to that value. */
9463 {
9464 tree primary_base;
9470 }
9474 /* The second entry is the address of the typeinfo object. */
9477 else
9480 /* Convert the declaration to a type that can be stored in the
9481 vtable. */
9485 /* Add the offset-to-top entry. It comes earlier in the vtable than
9486 the typeinfo entry. Convert the offset to look like a
9487 function pointer, so that we can put it in the vtable. */
9490 }
9492 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9493 accessibility. */
9495 bool
9497 {
9500 }
9502 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9504 bool
9506 {
9510 }
9512 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9513 class between them, if any. */
9515 tree
9517 {
9529 {
9532 }
9536 }