| blob | 8612163711cf3e0708c702eb4f4c7a1e851c38b6 |
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 {
1387 tree id;
1391 else
1392 {
1395 }
1398 {
1403 {
1404 /* We're collecting tags from template arguments. */
1408 /* Don't inherit this tag multiple times. */
1410 }
1412 /* Otherwise we're diagnosing missing tags. */
1414 {
1419 }
1420 else
1421 {
1425 {
1429 }
1430 }
1431 }
1432 }
1434 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1435 types with abi tags, add the corresponding identifiers to the VEC in
1436 *DATA and set IDENTIFIER_MARKED. */
1438 static tree
1440 {
1444 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1445 anyway, but let's make sure of it. */
1457 {
1460 {
1463 }
1464 }
1466 }
1468 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1469 complete) template arguments. */
1471 static void
1473 {
1482 {
1485 {
1489 }
1490 }
1491 }
1493 /* Check that class T has all the abi tags that subobject SUBOB has, or
1494 warn if not. */
1496 static void
1498 {
1507 }
1509 void
1511 {
1521 {
1524 {
1528 }
1529 }
1531 // If we found some tags on our template arguments, add them to our
1532 // abi_tag attribute.
1534 {
1538 else
1542 }
1545 }
1547 /* Return true, iff class T has a non-virtual destructor that is
1548 accessible from outside the class heirarchy (i.e. is public, or
1549 there's a suitable friend. */
1551 static bool
1553 {
1556 /* An implicitly declared destructor is always public. And,
1557 if it were virtual, we would have created it by now. */
1572 }
1574 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1575 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1576 properties of the bases. */
1578 static void
1582 {
1586 tree base_binfo;
1587 tree binfo;
1597 {
1606 /* If any base class is non-literal, so is the derived class. */
1610 /* If the base class doesn't have copy constructors or
1611 assignment operators that take const references, then the
1612 derived class cannot have such a member automatically
1613 generated. */
1622 /* A virtual base does not effect nearly emptiness. */
1623 ;
1625 {
1627 /* And if there is more than one nearly empty base, then the
1628 derived class is not nearly empty either. */
1630 else
1631 /* Remember we've seen one. */
1633 }
1635 /* If the base class is not empty or nearly empty, then this
1636 class cannot be nearly empty. */
1639 /* A lot of properties from the bases also apply to the derived
1640 class. */
1657 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1660 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1664 /* A standard-layout class is a class that:
1665 ...
1666 * has no non-standard-layout base classes, */
1669 {
1670 tree basefield;
1671 /* ...has no base classes of the same type as the first non-static
1672 data member... */
1674 && (same_type_ignoring_top_level_qualifiers_p
1677 else
1678 /* ...either has no non-static data members in the most-derived
1679 class and at most one base class with non-static data
1680 members, or has no base classes with non-static data
1681 members */
1685 {
1688 else
1691 }
1692 }
1694 /* Don't bother collecting tm attributes if transactional memory
1695 support is not enabled. */
1697 {
1701 }
1704 }
1706 /* If one of the base classes had TM attributes, and the current class
1707 doesn't define its own, then the current class inherits one. */
1709 {
1712 }
1713 }
1715 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1716 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1717 that have had a nearly-empty virtual primary base stolen by some
1718 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1719 T. */
1721 static void
1723 {
1727 tree base_binfo;
1729 /* Determine the primary bases of our bases. */
1732 {
1735 /* See if we're the non-virtual primary of our inheritance
1736 chain. */
1738 {
1745 /* We are the primary binfo. */
1747 }
1748 /* Determine if we have a virtual primary base, and mark it so.
1749 */
1751 {
1755 /* Someone already claimed this base. */
1757 else
1758 {
1759 tree delta;
1764 /* A virtual binfo might have been copied from within
1765 another hierarchy. As we're about to use it as a
1766 primary base, make sure the offsets match. */
1774 }
1775 }
1776 }
1778 /* First look for a dynamic direct non-virtual base. */
1780 {
1784 {
1787 }
1788 }
1790 /* A "nearly-empty" virtual base class can be the primary base
1791 class, if no non-virtual polymorphic base can be found. Look for
1792 a nearly-empty virtual dynamic base that is not already a primary
1793 base of something in the hierarchy. If there is no such base,
1794 just pick the first nearly-empty virtual base. */
1800 {
1802 {
1803 /* Found one that is not primary. */
1806 }
1808 /* Remember the first candidate. */
1810 }
1812 found:
1813 /* If we've got a primary base, use it. */
1815 {
1820 /* We are stealing a primary base. */
1824 {
1825 tree delta;
1828 /* A virtual binfo might have been copied from within
1829 another hierarchy. As we're about to use it as a primary
1830 base, make sure the offsets match. */
1835 }
1842 }
1843 }
1845 /* Update the variant types of T. */
1847 void
1849 {
1850 tree variants;
1856 variants;
1858 {
1859 /* These fields are in the _TYPE part of the node, not in
1860 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1870 /* Copy whatever these are holding today. */
1874 }
1875 }
1877 /* Early variant fixups: we apply attributes at the beginning of the class
1878 definition, and we need to fix up any variants that have already been
1879 made via elaborated-type-specifier so that check_qualified_type works. */
1881 void
1883 {
1884 tree variants;
1890 variants;
1892 {
1893 /* These are the two fields that check_qualified_type looks at and
1894 are affected by attributes. */
1897 }
1898 }
1899 \f
1900 /* Set memoizing fields and bits of T (and its variants) for later
1901 use. */
1903 static void
1905 {
1906 /* Fix up variants (if any). */
1910 /* For a class w/o baseclasses, 'finish_struct' has set
1911 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1912 Similarly for a class whose base classes do not have vtables.
1913 When neither of these is true, we might have removed abstract
1914 virtuals (by providing a definition), added some (by declaring
1915 new ones), or redeclared ones from a base class. We need to
1916 recalculate what's really an abstract virtual at this point (by
1917 looking in the vtables). */
1920 /* If this type has a copy constructor or a destructor, force its
1921 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1922 nonzero. This will cause it to be passed by invisible reference
1923 and prevent it from being returned in a register. */
1926 {
1927 tree variants;
1930 {
1933 }
1934 }
1935 }
1937 /* Issue warnings about T having private constructors, but no friends,
1938 and so forth.
1940 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1941 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1942 non-private static member functions. */
1944 static void
1946 {
1949 tree fn;
1952 /* If the class has friends, those entities might create and
1953 access instances, so we should not warn. */
1956 /* We will have warned when the template was declared; there's
1957 no need to warn on every instantiation. */
1959 /* There's no reason to even consider warning about this
1960 class. */
1963 /* We only issue one warning, if more than one applies, because
1964 otherwise, on code like:
1966 class A {
1967 // Oops - forgot `public:'
1968 A();
1969 A(const A&);
1970 ~A();
1971 };
1973 we warn several times about essentially the same problem. */
1975 /* Check to see if all (non-constructor, non-destructor) member
1976 functions are private. (Since there are no friends or
1977 non-private statics, we can't ever call any of the private member
1978 functions.) */
1980 /* We're not interested in compiler-generated methods; they don't
1981 provide any way to call private members. */
1983 {
1985 {
1987 /* A non-private static member function is just like a
1988 friend; it can create and invoke private member
1989 functions, and be accessed without a class
1990 instance. */
1994 /* Keep searching for a static member function. */
1995 }
1998 }
2001 {
2002 /* There are no non-private methods, and there's at least one
2003 private member function that isn't a constructor or
2004 destructor. (If all the private members are
2005 constructors/destructors we want to use the code below that
2006 issues error messages specifically referring to
2007 constructors/destructors.) */
2013 {
2016 }
2018 {
2022 }
2023 }
2025 /* Even if some of the member functions are non-private, the class
2026 won't be useful for much if all the constructors or destructors
2027 are private: such an object can never be created or destroyed. */
2030 {
2033 t);
2035 }
2037 /* Warn about classes that have private constructors and no friends. */
2039 /* Implicitly generated constructors are always public. */
2042 {
2045 /* If a non-template class does not define a copy
2046 constructor, one is defined for it, enabling it to avoid
2047 this warning. For a template class, this does not
2048 happen, and so we would normally get a warning on:
2050 template <class T> class C { private: C(); };
2052 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2053 complete non-template or fully instantiated classes have this
2054 flag set. */
2057 else
2059 {
2061 /* Ideally, we wouldn't count copy constructors (or, in
2062 fact, any constructor that takes an argument of the
2063 class type as a parameter) because such things cannot
2064 be used to construct an instance of the class unless
2065 you already have one. But, for now at least, we're
2066 more generous. */
2068 {
2071 }
2072 }
2075 {
2078 t);
2080 }
2081 }
2082 }
2085 gt_pointer_operator new_value;
2089 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2091 static int
2093 {
2106 }
2108 /* This routine compares two fields like method_name_cmp but using the
2109 pointer operator in resort_field_decl_data. */
2111 static int
2113 {
2122 {
2129 }
2131 }
2133 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2135 void
2138 gt_pointer_operator new_value,
2140 {
2144 tree fn;
2146 /* The type conversion ops have to live at the front of the vec, so we
2147 can't sort them. */
2155 {
2159 resort_method_name_cmp);
2160 }
2161 }
2163 /* Warn about duplicate methods in fn_fields.
2165 Sort methods that are not special (i.e., constructors, destructors,
2166 and type conversion operators) so that we can find them faster in
2167 search. */
2169 static void
2171 {
2172 tree fn_fields;
2182 /* Clear DECL_IN_AGGR_P for all functions. */
2187 /* Issue warnings about private constructors and such. If there are
2188 no methods, then some public defaults are generated. */
2191 /* The type conversion ops have to live at the front of the vec, so we
2192 can't sort them. */
2201 }
2203 /* Make BINFO's vtable have N entries, including RTTI entries,
2204 vbase and vcall offsets, etc. Set its type and call the back end
2205 to lay it out. */
2207 static void
2209 {
2210 tree atype;
2211 tree vtable;
2216 /* We may have to grow the vtable. */
2219 {
2223 }
2224 }
2226 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2227 have the same signature. */
2229 int
2231 {
2232 /* One destructor overrides another if they are the same kind of
2233 destructor. */
2237 /* But a non-destructor never overrides a destructor, nor vice
2238 versa, nor do different kinds of destructors override
2239 one-another. For example, a complete object destructor does not
2240 override a deleting destructor. */
2249 {
2257 }
2259 }
2261 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2262 subobject. */
2264 static bool
2266 {
2267 tree probe;
2270 {
2274 /* If we meet a virtual base, we can't follow the inheritance
2275 any more. See if the complete type of DERIVED contains
2276 such a virtual base. */
2279 }
2281 }
2284 /* The function for which we are trying to find a final overrider. */
2285 tree fn;
2286 /* The base class in which the function was declared. */
2287 tree declaring_base;
2288 /* The candidate overriders. */
2289 tree candidates;
2290 /* Path to most derived. */
2294 /* Add the overrider along the current path to FFOD->CANDIDATES.
2295 Returns true if an overrider was found; false otherwise. */
2297 static bool
2301 {
2302 tree method;
2304 /* If BINFO is not the most derived type, try a more derived class.
2305 A definition there will overrider a definition here. */
2307 {
2308 depth--;
2312 }
2316 {
2319 /* Remove any candidates overridden by this new function. */
2321 {
2322 /* If *CANDIDATE overrides METHOD, then METHOD
2323 cannot override anything else on the list. */
2326 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2329 else
2331 }
2333 /* Add the new function. */
2336 }
2339 }
2341 /* Called from find_final_overrider via dfs_walk. */
2343 static tree
2345 {
2353 }
2355 static tree
2357 {
2362 }
2364 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2365 FN and whose TREE_VALUE is the binfo for the base where the
2366 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2367 DERIVED) is the base object in which FN is declared. */
2369 static tree
2371 {
2372 find_final_overrider_data ffod;
2374 /* Getting this right is a little tricky. This is valid:
2376 struct S { virtual void f (); };
2377 struct T { virtual void f (); };
2378 struct U : public S, public T { };
2380 even though calling `f' in `U' is ambiguous. But,
2382 struct R { virtual void f(); };
2383 struct S : virtual public R { virtual void f (); };
2384 struct T : virtual public R { virtual void f (); };
2385 struct U : public S, public T { };
2387 is not -- there's no way to decide whether to put `S::f' or
2388 `T::f' in the vtable for `R'.
2390 The solution is to look at all paths to BINFO. If we find
2391 different overriders along any two, then there is a problem. */
2395 /* Determine the depth of the hierarchy. */
2406 /* If there was no winner, issue an error message. */
2411 }
2413 /* Return the index of the vcall offset for FN when TYPE is used as a
2414 virtual base. */
2416 static tree
2418 {
2420 tree_pair_p p;
2428 /* There should always be an appropriate index. */
2430 }
2432 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2433 dominated by T. FN is the old function; VIRTUALS points to the
2434 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2435 of that entry in the list. */
2437 static void
2440 {
2441 tree b;
2442 tree overrider;
2443 tree delta;
2444 tree virtual_base;
2445 tree first_defn;
2451 /* Find the nearest primary base (possibly binfo itself) which defines
2452 this function; this is the class the caller will convert to when
2453 calling FN through BINFO. */
2455 {
2460 /* The nearest definition is from a lost primary. */
2463 }
2466 /* Find the final overrider. */
2469 {
2472 }
2475 /* Check for adjusting covariant return types. */
2483 /* If the overrider is invalid, don't even try. */
2485 {
2486 /* If FN is a covariant thunk, we must figure out the adjustment
2487 to the final base FN was converting to. As OVERRIDER_TARGET might
2488 also be converting to the return type of FN, we have to
2489 combine the two conversions here. */
2496 {
2500 }
2501 else
2505 /* Find the equivalent binfo within the return type of the
2506 overriding function. We will want the vbase offset from
2507 there. */
2509 over_return);
2512 {
2513 /* There was no existing virtual thunk (which takes
2514 precedence). So find the binfo of the base function's
2515 return type within the overriding function's return type.
2516 We cannot call lookup base here, because we're inside a
2517 dfs_walk, and will therefore clobber the BINFO_MARKED
2518 flags. Fortunately we know the covariancy is valid (it
2519 has already been checked), so we can just iterate along
2520 the binfos, which have been chained in inheritance graph
2521 order. Of course it is lame that we have to repeat the
2522 search here anyway -- we should really be caching pieces
2523 of the vtable and avoiding this repeated work. */
2526 /* Find the base binfo within the overriding function's
2527 return type. We will always find a thunk_binfo, except
2528 when the covariancy is invalid (which we will have
2529 already diagnosed). */
2532 thunk_binfo;
2538 /* See if virtual inheritance is involved. */
2540 virtual_offset;
2547 {
2551 {
2552 /* We convert via virtual base. Adjust the fixed
2553 offset to be from there. */
2554 offset =
2558 }
2560 /* There was an existing fixed offset, this must be
2561 from the base just converted to, and the base the
2562 FN was thunking to. */
2564 else
2566 }
2567 }
2570 /* Replace the overriding function with a covariant thunk. We
2571 will emit the overriding function in its own slot as
2572 well. */
2575 }
2576 else
2580 /* If we need a covariant thunk, then we may need to adjust first_defn.
2581 The ABI specifies that the thunks emitted with a function are
2582 determined by which bases the function overrides, so we need to be
2583 sure that we're using a thunk for some overridden base; even if we
2584 know that the necessary this adjustment is zero, there may not be an
2585 appropriate zero-this-adjusment thunk for us to use since thunks for
2586 overriding virtual bases always use the vcall offset.
2588 Furthermore, just choosing any base that overrides this function isn't
2589 quite right, as this slot won't be used for calls through a type that
2590 puts a covariant thunk here. Calling the function through such a type
2591 will use a different slot, and that slot is the one that determines
2592 the thunk emitted for that base.
2594 So, keep looking until we find the base that we're really overriding
2595 in this slot: the nearest primary base that doesn't use a covariant
2596 thunk in this slot. */
2598 {
2600 /* We already know that the overrider needs a covariant thunk. */
2603 {
2610 }
2612 }
2614 /* Assume that we will produce a thunk that convert all the way to
2615 the final overrider, and not to an intermediate virtual base. */
2618 /* See if we can convert to an intermediate virtual base first, and then
2619 use the vcall offset located there to finish the conversion. */
2621 {
2622 /* If we find the final overrider, then we can stop
2623 walking. */
2628 /* If we find a virtual base, and we haven't yet found the
2629 overrider, then there is a virtual base between the
2630 declaring base (first_defn) and the final overrider. */
2632 {
2635 }
2636 }
2638 /* Compute the constant adjustment to the `this' pointer. The
2639 `this' pointer, when this function is called, will point at BINFO
2640 (or one of its primary bases, which are at the same offset). */
2642 /* The `this' pointer needs to be adjusted from the declaration to
2643 the nearest virtual base. */
2648 /* If the nearest definition is in a lost primary, we don't need an
2649 entry in our vtable. Except possibly in a constructor vtable,
2650 if we happen to get our primary back. In that case, the offset
2651 will be zero, as it will be a primary base. */
2653 else
2654 /* The `this' pointer needs to be adjusted from pointing to
2655 BINFO to pointing at the base where the final overrider
2656 appears. */
2667 else
2671 }
2673 /* Called from modify_all_vtables via dfs_walk. */
2675 static tree
2677 {
2679 tree virtuals;
2680 tree old_virtuals;
2684 /* A base without a vtable needs no modification, and its bases
2685 are uninteresting. */
2690 /* Don't do the primary vtable, if it's new. */
2694 /* There's no need to modify the vtable for a non-virtual primary
2695 base; we're not going to use that vtable anyhow. We do still
2696 need to do this for virtual primary bases, as they could become
2697 non-primary in a construction vtable. */
2702 /* Now, go through each of the virtual functions in the virtual
2703 function table for BINFO. Find the final overrider, and update
2704 the BINFO_VIRTUALS list appropriately. */
2707 virtuals;
2711 binfo,
2716 }
2718 /* Update all of the primary and secondary vtables for T. Create new
2719 vtables as required, and initialize their RTTI information. Each
2720 of the functions in VIRTUALS is declared in T and may override a
2721 virtual function from a base class; find and modify the appropriate
2722 entries to point to the overriding functions. Returns a list, in
2723 declaration order, of the virtual functions that are declared in T,
2724 but do not appear in the primary base class vtable, and which
2725 should therefore be appended to the end of the vtable for T. */
2727 static tree
2729 {
2733 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2737 /* Update all of the vtables. */
2740 /* Add virtual functions not already in our primary vtable. These
2741 will be both those introduced by this class, and those overridden
2742 from secondary bases. It does not include virtuals merely
2743 inherited from secondary bases. */
2745 {
2750 {
2751 /* We don't need to adjust the `this' pointer when
2752 calling this function. */
2756 /* This is a function not already in our vtable. Keep it. */
2758 }
2759 else
2760 /* We've already got an entry for this function. Skip it. */
2762 }
2765 }
2767 /* Get the base virtual function declarations in T that have the
2768 indicated NAME. */
2770 static void
2772 {
2773 tree methods;
2777 /* Find virtual functions in T with the indicated NAME. */
2782 methods;
2784 {
2789 {
2792 }
2793 }
2799 {
2802 }
2803 }
2805 /* If this declaration supersedes the declaration of
2806 a method declared virtual in the base class, then
2807 mark this field as being virtual as well. */
2809 void
2811 {
2814 /* In [temp.mem] we have:
2816 A specialization of a member function template does not
2817 override a virtual function from a base class. */
2824 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2825 the error_mark_node so that we know it is an overriding
2826 function. */
2827 {
2834 }
2837 {
2843 }
2848 }
2850 /* Warn about hidden virtual functions that are not overridden in t.
2851 We know that constructors and destructors don't apply. */
2853 static void
2855 {
2857 tree fns;
2860 /* We go through each separately named virtual function. */
2864 {
2865 tree fn;
2866 tree name;
2867 tree fndecl;
2868 tree base_binfo;
2869 tree binfo;
2872 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2873 have the same name. Figure out what name that is. */
2875 /* There are no possibly hidden functions yet. */
2877 /* Iterate through all of the base classes looking for possibly
2878 hidden functions. */
2881 {
2884 }
2886 /* If there are no functions to hide, continue. */
2890 /* Remove any overridden functions. */
2892 {
2896 {
2897 /* If the method from the base class has the same
2898 signature as the method from the derived class, it
2899 has been overridden. */
2904 }
2905 }
2907 /* Now give a warning for all base functions without overriders,
2908 as they are hidden. */
2910 tree base_fndecl;
2913 {
2914 /* Here we know it is a hider, and no overrider exists. */
2917 }
2918 }
2919 }
2921 /* Recursive helper for finish_struct_anon. */
2923 static void
2925 {
2929 {
2930 /* We're generally only interested in entities the user
2931 declared, but we also find nested classes by noticing
2932 the TYPE_DECL that we create implicitly. You're
2933 allowed to put one anonymous union inside another,
2934 though, so we explicitly tolerate that. We use
2935 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2936 we also allow unnamed types used for defining fields. */
2943 {
2944 /* We already complained about static data members in
2945 finish_static_data_member_decl. */
2947 {
2950 "%q+#D invalid; an anonymous union can "
2952 else
2954 "%q+#D invalid; an anonymous struct can "
2956 }
2958 }
2961 {
2963 {
2967 else
2970 }
2972 {
2976 else
2979 }
2980 }
2985 /* Recurse into the anonymous aggregates to handle correctly
2986 access control (c++/24926):
2988 class A {
2989 union {
2990 union {
2991 int i;
2992 };
2993 };
2994 };
2996 int j=A().i; */
3000 }
3001 }
3003 /* Check for things that are invalid. There are probably plenty of other
3004 things we should check for also. */
3006 static void
3008 {
3010 {
3019 }
3020 }
3022 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3023 will be used later during class template instantiation.
3024 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3025 a non-static member data (FIELD_DECL), a member function
3026 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3027 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3028 When FRIEND_P is nonzero, T is either a friend class
3029 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3030 (FUNCTION_DECL, TEMPLATE_DECL). */
3032 void
3034 {
3035 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3040 }
3042 /* This function is called from declare_virt_assop_and_dtor via
3043 dfs_walk_all.
3045 DATA is a type that direcly or indirectly inherits the base
3046 represented by BINFO. If BINFO contains a virtual assignment [copy
3047 assignment or move assigment] operator or a virtual constructor,
3048 declare that function in DATA if it hasn't been already declared. */
3050 static tree
3052 {
3060 /* A base without a vtable needs no modification, and its bases
3061 are uninteresting. */
3065 /* If this is a primary base, then we have already looked at the
3066 virtual functions of its vtable. */
3070 {
3074 {
3079 }
3083 }
3086 }
3088 /* If the class type T has a direct or indirect base that contains a
3089 virtual assignment operator or a virtual destructor, declare that
3090 function in T if it hasn't been already declared. */
3092 static void
3094 {
3102 dfs_declare_virt_assop_and_dtor,
3104 }
3106 /* Declare the inheriting constructor for class T inherited from base
3107 constructor CTOR with the parameter array PARMS of size NPARMS. */
3109 static void
3111 {
3112 /* We don't declare an inheriting ctor that would be a default,
3113 copy or move ctor for derived or base. */
3118 {
3122 }
3130 {
3133 }
3134 }
3136 /* Declare all the inheriting constructors for class T inherited from base
3137 constructor CTOR. */
3139 static void
3141 {
3147 {
3151 }
3154 {
3158 }
3159 }
3161 /* Create default constructors, assignment operators, and so forth for
3162 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3163 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3164 the class cannot have a default constructor, copy constructor
3165 taking a const reference argument, or an assignment operator taking
3166 a const reference, respectively. */
3168 static void
3172 {
3180 /* Destructor. */
3182 {
3183 /* In general, we create destructors lazily. */
3188 /* But if this is a Java class, any non-trivial destructor is
3189 invalid, even if compiler-generated. Therefore, if the
3190 destructor is non-trivial we create it now. */
3192 }
3194 /* [class.ctor]
3196 If there is no user-declared constructor for a class, a default
3197 constructor is implicitly declared. */
3199 {
3204 /* This might force the declaration. */
3206 }
3208 /* [class.ctor]
3210 If a class definition does not explicitly declare a copy
3211 constructor, one is declared implicitly. */
3213 {
3219 }
3221 /* If there is no assignment operator, one will be created if and
3222 when it is needed. For now, just record whether or not the type
3223 of the parameter to the assignment operator will be a const or
3224 non-const reference. */
3226 {
3232 }
3234 /* We can't be lazy about declaring functions that might override
3235 a virtual function from a base class. */
3239 {
3243 {
3244 /* declare, then remove the decl */
3253 }
3254 else
3256 }
3257 }
3259 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3260 count the number of fields in TYPE, including anonymous union
3261 members. */
3263 static int
3265 {
3266 tree x;
3269 {
3272 else
3274 }
3276 }
3278 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3279 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3280 elts, starting at offset IDX. */
3282 static int
3284 {
3285 tree x;
3287 {
3290 else
3292 }
3294 }
3296 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3297 starting at offset IDX. */
3299 static int
3303 {
3304 tree values;
3308 }
3310 /* FIELD is a bit-field. We are finishing the processing for its
3311 enclosing type. Issue any appropriate messages and set appropriate
3312 flags. Returns false if an error has been diagnosed. */
3314 static bool
3316 {
3318 tree w;
3320 /* Extract the declared width of the bitfield, which has been
3321 temporarily stashed in DECL_INITIAL. */
3324 /* Remove the bit-field width indicator so that the rest of the
3325 compiler does not treat that value as an initializer. */
3328 /* Detect invalid bit-field type. */
3330 {
3333 }
3334 else
3335 {
3337 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3340 /* detect invalid field size. */
3346 {
3349 }
3351 {
3354 }
3356 {
3359 }
3371 }
3374 {
3378 }
3379 else
3380 {
3381 /* Non-bit-fields are aligned for their type. */
3385 }
3386 }
3388 /* FIELD is a non bit-field. We are finishing the processing for its
3389 enclosing type T. Issue any appropriate messages and set appropriate
3390 flags. */
3392 static void
3394 tree t,
3398 {
3401 /* In C++98 an anonymous union cannot contain any fields which would change
3402 the settings of CANT_HAVE_CONST_CTOR and friends. */
3404 ;
3405 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3406 structs. So, we recurse through their fields here. */
3408 {
3409 tree fields;
3415 }
3416 /* Check members with class type for constructors, destructors,
3417 etc. */
3419 {
3420 /* Never let anything with uninheritable virtuals
3421 make it through without complaint. */
3425 {
3430 field);
3435 field);
3437 {
3441 }
3442 }
3443 else
3444 {
3457 }
3466 }
3471 {
3472 /* `build_class_init_list' does not recognize
3473 non-FIELD_DECLs. */
3477 }
3478 }
3480 /* Check the data members (both static and non-static), class-scoped
3481 typedefs, etc., appearing in the declaration of T. Issue
3482 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3483 declaration order) of access declarations; each TREE_VALUE in this
3484 list is a USING_DECL.
3486 In addition, set the following flags:
3488 EMPTY_P
3489 The class is empty, i.e., contains no non-static data members.
3491 CANT_HAVE_CONST_CTOR_P
3492 This class cannot have an implicitly generated copy constructor
3493 taking a const reference.
3495 CANT_HAVE_CONST_ASN_REF
3496 This class cannot have an implicitly generated assignment
3497 operator taking a const reference.
3499 All of these flags should be initialized before calling this
3500 function.
3502 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3503 fields can be added by adding to this chain. */
3505 static void
3509 {
3517 /* Assume there are no access declarations. */
3519 /* Assume this class has no pointer members. */
3521 /* Assume none of the members of this class have default
3522 initializations. */
3526 {
3534 {
3535 /* Save the access declarations for our caller. */
3538 }
3544 /* If we've gotten this far, it's a data member, possibly static,
3545 or an enumerator. */
3549 /* When this goes into scope, it will be a non-local reference. */
3554 {
3555 /* [class.union] (C++98)
3557 If a union contains a static data member, or a member of
3558 reference type, the program is ill-formed.
3560 In C++11 this limitation doesn't exist anymore. */
3562 {
3566 }
3568 {
3572 }
3573 }
3575 /* Perform error checking that did not get done in
3576 grokdeclarator. */
3578 {
3582 }
3584 {
3588 }
3596 /* Now it can only be a FIELD_DECL. */
3601 /* If at least one non-static data member is non-literal, the whole
3602 class becomes non-literal. Per Core/1453, volatile non-static
3603 data members and base classes are also not allowed.
3604 Note: if the type is incomplete we will complain later on. */
3609 /* A standard-layout class is a class that:
3610 ...
3611 has the same access control (Clause 11) for all non-static data members,
3612 ... */
3619 /* If this is of reference type, check if it needs an init. */
3621 {
3627 {
3628 /* ARM $12.6.2: [A member initializer list] (or, for an
3629 aggregate, initialization by a brace-enclosed list) is the
3630 only way to initialize nonstatic const and reference
3631 members. */
3634 }
3635 }
3640 {
3642 {
3643 warning
3646 x);
3648 }
3652 }
3655 /* We don't treat zero-width bitfields as making a class
3656 non-empty. */
3657 ;
3658 else
3659 {
3660 /* The class is non-empty. */
3662 /* The class is not even nearly empty. */
3664 /* If one of the data members contains an empty class,
3665 so does T. */
3669 }
3671 /* This is used by -Weffc++ (see below). Warn only for pointers
3672 to members which might hold dynamic memory. So do not warn
3673 for pointers to functions or pointers to members. */
3679 {
3684 }
3690 {
3692 {
3696 }
3698 {
3702 }
3703 }
3706 /* DR 148 now allows pointers to members (which are POD themselves),
3707 to be allowed in POD structs. */
3716 /* We set DECL_C_BIT_FIELD in grokbitfield.
3717 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3720 cant_have_const_ctor_p,
3721 no_const_asn_ref_p,
3724 /* Now that we've removed bit-field widths from DECL_INITIAL,
3725 anything left in DECL_INITIAL is an NSDMI that makes the class
3726 non-aggregate in C++11. */
3730 /* If any field is const, the structure type is pseudo-const. */
3732 {
3737 {
3738 /* ARM $12.6.2: [A member initializer list] (or, for an
3739 aggregate, initialization by a brace-enclosed list) is the
3740 only way to initialize nonstatic const and reference
3741 members. */
3744 }
3745 }
3746 /* A field that is pseudo-const makes the structure likewise. */
3748 {
3753 }
3755 /* Core issue 80: A nonstatic data member is required to have a
3756 different name from the class iff the class has a
3757 user-declared constructor. */
3761 }
3763 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3764 it should also define a copy constructor and an assignment operator to
3765 implement the correct copy semantic (deep vs shallow, etc.). As it is
3766 not feasible to check whether the constructors do allocate dynamic memory
3767 and store it within members, we approximate the warning like this:
3769 -- Warn only if there are members which are pointers
3770 -- Warn only if there is a non-trivial constructor (otherwise,
3771 there cannot be memory allocated).
3772 -- Warn only if there is a non-trivial destructor. We assume that the
3773 user at least implemented the cleanup correctly, and a destructor
3774 is needed to free dynamic memory.
3776 This seems enough for practical purposes. */
3778 && has_pointers
3782 {
3786 {
3791 }
3795 }
3797 /* Non-static data member initializers make the default constructor
3798 non-trivial. */
3800 {
3803 }
3805 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3809 /* Check anonymous struct/anonymous union fields. */
3812 /* We've built up the list of access declarations in reverse order.
3813 Fix that now. */
3815 }
3817 /* If TYPE is an empty class type, records its OFFSET in the table of
3818 OFFSETS. */
3820 static int
3822 {
3823 splay_tree_node n;
3828 /* Record the location of this empty object in OFFSETS. */
3836 type,
3840 }
3842 /* Returns nonzero if TYPE is an empty class type and there is
3843 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3845 static int
3847 {
3848 splay_tree_node n;
3849 tree t;
3854 /* Record the location of this empty object in OFFSETS. */
3864 }
3866 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3867 F for every subobject, passing it the type, offset, and table of
3868 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3869 be traversed.
3871 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3872 than MAX_OFFSET will not be walked.
3874 If F returns a nonzero value, the traversal ceases, and that value
3875 is returned. Otherwise, returns zero. */
3877 static int
3879 subobject_offset_fn f,
3880 tree offset,
3881 splay_tree offsets,
3882 tree max_offset,
3884 {
3888 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3889 stop. */
3897 {
3900 }
3903 {
3904 tree field;
3905 tree binfo;
3908 /* Avoid recursing into objects that are not interesting. */
3912 /* Record the location of TYPE. */
3917 /* Iterate through the direct base classes of TYPE. */
3921 {
3922 tree binfo_offset;
3927 tree orig_binfo;
3928 /* We cannot rely on BINFO_OFFSET being set for the base
3929 class yet, but the offsets for direct non-virtual
3930 bases can be calculated by going back to the TYPE. */
3933 offset,
3937 f,
3938 binfo_offset,
3939 offsets,
3940 max_offset,
3944 }
3947 {
3951 /* Iterate through the virtual base classes of TYPE. In G++
3952 3.2, we included virtual bases in the direct base class
3953 loop above, which results in incorrect results; the
3954 correct offsets for virtual bases are only known when
3955 working with the most derived type. */
3959 {
3961 f,
3963 offset,
3965 offsets,
3966 max_offset,
3970 }
3971 else
3972 {
3973 /* We still have to walk the primary base, if it is
3974 virtual. (If it is non-virtual, then it was walked
3975 above.) */
3981 {
3982 r = (walk_subobject_offsets
3987 }
3988 }
3989 }
3991 /* Iterate through the fields of TYPE. */
3996 {
3997 tree field_offset;
4002 f,
4004 offset,
4005 field_offset),
4006 offsets,
4007 max_offset,
4011 }
4012 }
4014 {
4017 tree index;
4019 /* Avoid recursing into objects that are not interesting. */
4024 /* Step through each of the elements in the array. */
4028 {
4030 f,
4031 offset,
4032 offsets,
4033 max_offset,
4039 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4040 there's no point in iterating through the remaining
4041 elements of the array. */
4044 }
4045 }
4048 }
4050 /* Record all of the empty subobjects of TYPE (either a type or a
4051 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4052 is being placed at OFFSET; otherwise, it is a base class that is
4053 being placed at OFFSET. */
4055 static void
4057 tree offset,
4058 splay_tree offsets,
4060 {
4061 tree max_offset;
4062 /* If recording subobjects for a non-static data member or a
4063 non-empty base class , we do not need to record offsets beyond
4064 the size of the biggest empty class. Additional data members
4065 will go at the end of the class. Additional base classes will go
4066 either at offset zero (if empty, in which case they cannot
4067 overlap with offsets past the size of the biggest empty class) or
4068 at the end of the class.
4070 However, if we are placing an empty base class, then we must record
4071 all offsets, as either the empty class is at offset zero (where
4072 other empty classes might later be placed) or at the end of the
4073 class (where other objects might then be placed, so other empty
4074 subobjects might later overlap). */
4078 else
4082 }
4084 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4085 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4086 virtual bases of TYPE are examined. */
4088 static int
4090 tree offset,
4091 splay_tree offsets,
4093 {
4094 splay_tree_node max_node;
4096 /* Get the node in OFFSETS that indicates the maximum offset where
4097 an empty subobject is located. */
4099 /* If there aren't any empty subobjects, then there's no point in
4100 performing this check. */
4106 vbases_p);
4107 }
4109 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4110 non-static data member of the type indicated by RLI. BINFO is the
4111 binfo corresponding to the base subobject, OFFSETS maps offsets to
4112 types already located at those offsets. This function determines
4113 the position of the DECL. */
4115 static void
4117 tree decl,
4118 tree binfo,
4119 splay_tree offsets)
4120 {
4123 tree type;
4126 {
4127 /* For the purposes of determining layout conflicts, we want to
4128 use the class type of BINFO; TREE_TYPE (DECL) will be the
4129 CLASSTYPE_AS_BASE version, which does not contain entries for
4130 zero-sized bases. */
4133 }
4134 else
4135 {
4138 }
4140 /* Try to place the field. It may take more than one try if we have
4141 a hard time placing the field without putting two objects of the
4142 same type at the same address. */
4144 {
4147 /* Place this field. */
4151 /* We have to check to see whether or not there is already
4152 something of the same type at the offset we're about to use.
4153 For example, consider:
4155 struct S {};
4156 struct T : public S { int i; };
4157 struct U : public S, public T {};
4159 Here, we put S at offset zero in U. Then, we can't put T at
4160 offset zero -- its S component would be at the same address
4161 as the S we already allocated. So, we have to skip ahead.
4162 Since all data members, including those whose type is an
4163 empty class, have nonzero size, any overlap can happen only
4164 with a direct or indirect base-class -- it can't happen with
4165 a data member. */
4166 /* In a union, overlap is permitted; all members are placed at
4167 offset zero. */
4172 {
4173 /* Strip off the size allocated to this field. That puts us
4174 at the first place we could have put the field with
4175 proper alignment. */
4178 /* Bump up by the alignment required for the type. */
4179 rli->bitpos
4185 }
4186 else
4187 /* There was no conflict. We're done laying out this field. */
4189 }
4191 /* Now that we know where it will be placed, update its
4192 BINFO_OFFSET. */
4194 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4195 this point because their BINFO_OFFSET is copied from another
4196 hierarchy. Therefore, we may not need to add the entire
4197 OFFSET. */
4203 }
4205 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4207 static int
4209 tree offset,
4211 {
4213 }
4215 /* Layout the empty base BINFO. EOC indicates the byte currently just
4216 past the end of the class, and should be correctly aligned for a
4217 class of the type indicated by BINFO; OFFSETS gives the offsets of
4218 the empty bases allocated so far. T is the most derived
4219 type. Return nonzero iff we added it at the end. */
4221 static bool
4224 {
4225 tree alignment;
4229 /* This routine should only be used for empty classes. */
4234 propagate_binfo_offsets
4238 /* This is an empty base class. We first try to put it at offset
4239 zero. */
4242 offsets,
4244 {
4245 /* That didn't work. Now, we move forward from the next
4246 available spot in the class. */
4250 {
4253 offsets,
4255 /* We finally found a spot where there's no overlap. */
4258 /* There's overlap here, too. Bump along to the next spot. */
4260 }
4261 }
4264 {
4269 }
4272 }
4274 /* Layout the base given by BINFO in the class indicated by RLI.
4275 *BASE_ALIGN is a running maximum of the alignments of
4276 any base class. OFFSETS gives the location of empty base
4277 subobjects. T is the most derived type. Return nonzero if the new
4278 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4279 *NEXT_FIELD, unless BINFO is for an empty base class.
4281 Returns the location at which the next field should be inserted. */
4286 {
4291 /* This error is now reported in xref_tag, thus giving better
4292 location information. */
4295 /* Place the base class. */
4297 {
4298 tree decl;
4300 /* The containing class is non-empty because it has a non-empty
4301 base class. */
4304 /* Create the FIELD_DECL. */
4311 {
4319 /* Try to place the field. It may take more than one try if we
4320 have a hard time placing the field without putting two
4321 objects of the same type at the same address. */
4323 /* Add the new FIELD_DECL to the list of fields for T. */
4327 }
4328 }
4329 else
4330 {
4331 tree eoc;
4334 /* On some platforms (ARM), even empty classes will not be
4335 byte-aligned. */
4340 /* A nearly-empty class "has no proper base class that is empty,
4341 not morally virtual, and at an offset other than zero." */
4343 {
4346 /* The check above (used in G++ 3.2) is insufficient because
4347 an empty class placed at offset zero might itself have an
4348 empty base at a nonzero offset. */
4350 empty_base_at_nonzero_offset_p,
4351 size_zero_node,
4356 }
4358 /* We do not create a FIELD_DECL for empty base classes because
4359 it might overlap some other field. We want to be able to
4360 create CONSTRUCTORs for the class by iterating over the
4361 FIELD_DECLs, and the back end does not handle overlapping
4362 FIELD_DECLs. */
4364 /* An empty virtual base causes a class to be non-empty
4365 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4366 here because that was already done when the virtual table
4367 pointer was created. */
4368 }
4370 /* Record the offsets of BINFO and its base subobjects. */
4373 offsets,
4377 }
4379 /* Layout all of the non-virtual base classes. Record empty
4380 subobjects in OFFSETS. T is the most derived type. Return nonzero
4381 if the type cannot be nearly empty. The fields created
4382 corresponding to the base classes will be inserted at
4383 *NEXT_FIELD. */
4385 static void
4388 {
4389 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4390 subobjects. */
4395 /* The primary base class is always allocated first. */
4400 /* Now allocate the rest of the bases. */
4402 {
4403 tree base_binfo;
4407 /* The primary base was already allocated above, so we don't
4408 need to allocate it again here. */
4412 /* Virtual bases are added at the end (a primary virtual base
4413 will have already been added). */
4419 }
4420 }
4422 /* Go through the TYPE_METHODS of T issuing any appropriate
4423 diagnostics, figuring out which methods override which other
4424 methods, and so forth. */
4426 static void
4428 {
4429 tree x;
4432 {
4436 /* The name of the field is the original field name
4437 Save this in auxiliary field for later overloading. */
4439 {
4443 }
4444 /* All user-provided destructors are non-trivial.
4445 Constructors and assignment ops are handled in
4446 grok_special_member_properties. */
4449 }
4450 }
4452 /* FN is a constructor or destructor. Clone the declaration to create
4453 a specialized in-charge or not-in-charge version, as indicated by
4454 NAME. */
4456 static tree
4458 {
4459 tree parms;
4460 tree clone;
4462 /* Copy the function. */
4464 /* Reset the function name. */
4466 /* Remember where this function came from. */
4468 /* Make it easy to find the CLONE given the FN. */
4472 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4474 {
4481 }
4485 /* There's no pending inline data for this function. */
4489 /* The base-class destructor is not virtual. */
4491 {
4495 }
4497 /* If there was an in-charge parameter, drop it from the function
4498 type. */
4500 {
4501 tree basetype;
4502 tree parmtypes;
4503 tree exceptions;
4508 /* Skip the `this' parameter. */
4510 /* Skip the in-charge parameter. */
4512 /* And the VTT parm, in a complete [cd]tor. */
4516 /* If this is subobject constructor or destructor, add the vtt
4517 parameter. */
4521 parmtypes);
4524 exceptions);
4528 }
4530 /* Copy the function parameters. */
4532 /* Remove the in-charge parameter. */
4534 {
4538 }
4539 /* And the VTT parm, in a complete [cd]tor. */
4541 {
4544 else
4545 {
4549 }
4550 }
4553 {
4556 }
4558 /* Create the RTL for this function. */
4566 }
4568 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4569 not invoke this function directly.
4571 For a non-thunk function, returns the address of the slot for storing
4572 the function it is a clone of. Otherwise returns NULL_TREE.
4574 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4575 cloned_function is unset. This is to support the separate
4576 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4577 on a template makes sense, but not the former. */
4579 tree *
4581 {
4589 {
4590 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4593 else
4594 #endif
4596 }
4601 else
4603 }
4605 /* Produce declarations for all appropriate clones of FN. If
4606 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4607 CLASTYPE_METHOD_VEC as well. */
4609 void
4611 {
4612 tree clone;
4614 /* Avoid inappropriate cloning. */
4620 {
4621 /* For each constructor, we need two variants: an in-charge version
4622 and a not-in-charge version. */
4629 }
4630 else
4631 {
4634 /* For each destructor, we need three variants: an in-charge
4635 version, a not-in-charge version, and an in-charge deleting
4636 version. We clone the deleting version first because that
4637 means it will go second on the TYPE_METHODS list -- and that
4638 corresponds to the correct layout order in the virtual
4639 function table.
4641 For a non-virtual destructor, we do not build a deleting
4642 destructor. */
4644 {
4648 }
4655 }
4657 /* Note that this is an abstract function that is never emitted. */
4659 }
4661 /* DECL is an in charge constructor, which is being defined. This will
4662 have had an in class declaration, from whence clones were
4663 declared. An out-of-class definition can specify additional default
4664 arguments. As it is the clones that are involved in overload
4665 resolution, we must propagate the information from the DECL to its
4666 clones. */
4668 void
4670 {
4671 tree clone;
4675 {
4682 /* Skip the 'this' parameter. */
4698 {
4703 {
4704 /* A default parameter has been added. Adjust the
4705 clone's parameters. */
4709 tree type;
4714 {
4717 clone_parms);
4719 }
4722 clone_parms);
4731 }
4732 }
4734 }
4735 }
4737 /* For each of the constructors and destructors in T, create an
4738 in-charge and not-in-charge variant. */
4740 static void
4742 {
4743 tree fns;
4745 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4746 out now. */
4754 }
4756 /* Deduce noexcept for a destructor DTOR. */
4758 void
4760 {
4762 {
4765 }
4766 }
4768 /* For each destructor in T, deduce noexcept:
4770 12.4/3: A declaration of a destructor that does not have an
4771 exception-specification is implicitly considered to have the
4772 same exception-specification as an implicit declaration (15.4). */
4774 static void
4776 {
4777 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4778 out now. */
4784 }
4786 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4787 of TYPE for virtual functions which FNDECL overrides. Return a
4788 mask of the tm attributes found therein. */
4790 static int
4792 {
4794 tree base_binfo;
4798 {
4808 else
4810 }
4813 }
4815 /* Subroutine of set_method_tm_attributes. Handle the checks and
4816 inheritance for one virtual method FNDECL. */
4818 static void
4820 {
4821 tree tm_attr;
4826 /* If FNDECL doesn't actually override anything (i.e. T is the
4827 class that first declares FNDECL virtual), then we're done. */
4834 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4835 tm_pure must match exactly, otherwise no weakening of
4836 tm_safe > tm_callable > nothing. */
4837 /* ??? The tm_pure attribute didn't make the transition to the
4838 multivendor language spec. */
4840 {
4842 {
4845 }
4846 }
4847 /* If the overridden function is tm_pure, then FNDECL must be. */
4850 /* Look for base class combinations that cannot be satisfied. */
4852 {
4858 }
4859 /* If FNDECL did not declare an attribute, then inherit the most
4860 restrictive one. */
4862 {
4864 }
4865 /* Otherwise validate that we're not weaker than a function
4866 that is being overridden. */
4867 else
4868 {
4872 }
4875 err_override:
4879 }
4881 /* For each of the methods in T, propagate a class-level tm attribute. */
4883 static void
4885 {
4888 /* Don't bother collecting tm attributes if transactional memory
4889 support is not enabled. */
4893 /* Process virtual methods first, as they inherit directly from the
4894 base virtual function and also require validation of new attributes. */
4896 {
4897 tree vchain;
4900 {
4905 }
4906 }
4908 /* If the class doesn't have an attribute, nothing more to do. */
4913 /* Any method that does not yet have a tm attribute inherits
4914 the one from the class. */
4916 {
4919 }
4920 }
4922 /* Returns true iff class T has a user-defined constructor other than
4923 the default constructor. */
4925 bool
4927 {
4928 tree fns;
4934 {
4941 }
4944 }
4946 /* Returns the defaulted constructor if T has one. Otherwise, returns
4947 NULL_TREE. */
4949 tree
4951 {
4958 {
4962 {
4968 }
4969 }
4972 }
4974 /* Returns true iff FN is a user-provided function, i.e. user-declared
4975 and not defaulted at its first declaration; or explicit, private,
4976 protected, or non-const. */
4978 bool
4980 {
4983 else
4987 }
4989 /* Returns true iff class T has a user-provided constructor. */
4991 bool
4993 {
4994 tree fns;
5002 /* This can happen in error cases; avoid crashing. */
5011 }
5013 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5014 declared or explicitly defaulted in the class body) default
5015 constructor. */
5017 bool
5019 {
5020 tree fns;
5028 {
5034 }
5037 }
5039 /* TYPE is being used as a virtual base, and has a non-trivial move
5040 assignment. Return true if this is due to there being a user-provided
5041 move assignment in TYPE or one of its subobjects; if there isn't, then
5042 multiple move assignment can't cause any harm. */
5044 bool
5046 {
5047 /* Does the type itself have a user-provided move assignment operator? */
5051 {
5055 }
5057 /* Do any of its bases? */
5059 tree base_binfo;
5064 /* Or non-static data members? */
5066 {
5071 }
5073 /* Seems not. */
5075 }
5077 /* If default-initialization leaves part of TYPE uninitialized, returns
5078 a DECL for the field or TYPE itself (DR 253). */
5080 tree
5082 {
5093 {
5097 }
5102 {
5106 }
5109 }
5111 /* Returns true iff for class T, a trivial synthesized default constructor
5112 would be constexpr. */
5114 bool
5116 {
5117 /* A defaulted trivial default constructor is constexpr
5118 if there is nothing to initialize. */
5121 }
5123 /* Returns true iff class T has a constexpr default constructor. */
5125 bool
5127 {
5128 tree fns;
5131 {
5132 /* The caller should have stripped an enclosing array. */
5135 }
5137 {
5140 /* Non-trivial, we need to check subobject constructors. */
5142 }
5145 }
5147 /* Returns true iff class TYPE has a virtual destructor. */
5149 bool
5151 {
5152 tree dtor;
5160 }
5162 /* Returns true iff class T has a move constructor. */
5164 bool
5166 {
5167 tree fns;
5170 {
5173 }
5183 }
5185 /* Returns true iff class T has a move assignment operator. */
5187 bool
5189 {
5190 tree fns;
5193 {
5196 }
5204 }
5206 /* Returns true iff class T has a move constructor that was explicitly
5207 declared in the class body. Note that this is different from
5208 "user-provided", which doesn't include functions that are defaulted in
5209 the class. */
5211 bool
5213 {
5214 tree fns;
5223 {
5227 }
5230 }
5232 /* Returns true iff class T has a move assignment operator that was
5233 explicitly declared in the class body. */
5235 bool
5237 {
5238 tree fns;
5245 {
5249 }
5252 }
5254 /* Nonzero if we need to build up a constructor call when initializing an
5255 object of this class, either because it has a user-declared constructor
5256 or because it doesn't have a default constructor (so we need to give an
5257 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5258 what you care about is whether or not an object can be produced by a
5259 constructor (e.g. so we don't set TREE_READONLY on const variables of
5260 such type); use this function when what you care about is whether or not
5261 to try to call a constructor to create an object. The latter case is
5262 the former plus some cases of constructors that cannot be called. */
5264 bool
5266 {
5267 tree inner;
5277 /* A user-declared constructor might be private, and a constructor might
5278 be trivial but deleted. */
5281 {
5286 }
5288 }
5290 /* Like type_build_ctor_call, but for destructors. */
5292 bool
5294 {
5295 tree inner;
5304 /* A user-declared destructor might be private, and a destructor might
5305 be trivial but deleted. */
5308 {
5313 }
5315 }
5317 /* Remove all zero-width bit-fields from T. */
5319 static void
5321 {
5326 {
5329 /* We should not be confused by the fact that grokbitfield
5330 temporarily sets the width of the bit field into
5331 DECL_INITIAL (*fieldsp).
5332 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5333 to that width. */
5336 else
5338 }
5339 }
5341 /* Returns TRUE iff we need a cookie when dynamically allocating an
5342 array whose elements have the indicated class TYPE. */
5344 static bool
5346 {
5347 tree fns;
5352 /* If there's a non-trivial destructor, we need a cookie. In order
5353 to iterate through the array calling the destructor for each
5354 element, we'll have to know how many elements there are. */
5358 /* If the usual deallocation function is a two-argument whose second
5359 argument is of type `size_t', then we have to pass the size of
5360 the array to the deallocation function, so we will need to store
5361 a cookie. */
5365 /* If there are no `operator []' members, or the lookup is
5366 ambiguous, then we don't need a cookie. */
5369 /* Loop through all of the functions. */
5371 {
5372 tree fn;
5373 tree second_parm;
5375 /* Select the current function. */
5377 /* See if this function is a one-argument delete function. If
5378 it is, then it will be the usual deallocation function. */
5382 /* Do not consider this function if its second argument is an
5383 ellipsis. */
5386 /* Otherwise, if we have a two-argument function and the second
5387 argument is `size_t', it will be the usual deallocation
5388 function -- unless there is one-argument function, too. */
5392 }
5395 }
5397 /* Finish computing the `literal type' property of class type T.
5399 At this point, we have already processed base classes and
5400 non-static data members. We need to check whether the copy
5401 constructor is trivial, the destructor is trivial, and there
5402 is a trivial default constructor or at least one constexpr
5403 constructor other than the copy constructor. */
5405 static void
5407 {
5408 tree fn;
5424 {
5427 {
5431 }
5432 }
5433 }
5435 /* T is a non-literal type used in a context which requires a constant
5436 expression. Explain why it isn't literal. */
5438 void
5440 {
5450 /* Already explained. */
5459 {
5461 "default constructor, and has no constexpr constructor that "
5464 {
5465 /* Note that we can't simply call locate_ctor because when the
5466 constructor is deleted it just returns NULL_TREE. */
5467 tree fns;
5469 {
5476 {
5479 else
5482 }
5483 }
5484 }
5485 }
5486 else
5487 {
5491 {
5494 {
5499 }
5500 }
5502 {
5503 tree ftype;
5508 {
5513 }
5517 }
5518 }
5519 }
5521 /* Check the validity of the bases and members declared in T. Add any
5522 implicitly-generated functions (like copy-constructors and
5523 assignment operators). Compute various flag bits (like
5524 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5525 level: i.e., independently of the ABI in use. */
5527 static void
5529 {
5530 /* Nonzero if the implicitly generated copy constructor should take
5531 a non-const reference argument. */
5533 /* Nonzero if the implicitly generated assignment operator
5534 should take a non-const reference argument. */
5536 tree access_decls;
5539 tree fn;
5541 /* By default, we use const reference arguments and generate default
5542 constructors. */
5546 /* Check all the base-classes. */
5550 /* Deduce noexcept on destructors. This needs to happen after we've set
5551 triviality flags appropriately for our bases. */
5555 /* Check all the method declarations. */
5558 /* Save the initial values of these flags which only indicate whether
5559 or not the class has user-provided functions. As we analyze the
5560 bases and members we can set these flags for other reasons. */
5564 /* Check all the data member declarations. We cannot call
5565 check_field_decls until we have called check_bases check_methods,
5566 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5567 being set appropriately. */
5572 /* A nearly-empty class has to be vptr-containing; a nearly empty
5573 class contains just a vptr. */
5577 /* Do some bookkeeping that will guide the generation of implicitly
5578 declared member functions. */
5581 /* We need to call a constructor for this class if it has a
5582 user-provided constructor, or if the default constructor is going
5583 to initialize the vptr. (This is not an if-and-only-if;
5584 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5585 themselves need constructing.) */
5588 /* [dcl.init.aggr]
5590 An aggregate is an array or a class with no user-provided
5591 constructors ... and no virtual functions.
5593 Again, other conditions for being an aggregate are checked
5594 elsewhere. */
5597 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5598 retain the old definition internally for ABI reasons. */
5607 /* If the only explicitly declared default constructor is user-provided,
5608 set TYPE_HAS_COMPLEX_DFLT. */
5614 /* Warn if a public base of a polymorphic type has an accessible
5615 non-virtual destructor. It is only now that we know the class is
5616 polymorphic. Although a polymorphic base will have a already
5617 been diagnosed during its definition, we warn on use too. */
5619 {
5622 tree base_binfo;
5626 {
5634 basetype);
5635 }
5636 }
5638 /* If the class has no user-declared constructor, but does have
5639 non-static const or reference data members that can never be
5640 initialized, issue a warning. */
5642 /* Classes with user-declared constructors are presumed to
5643 initialize these members. */
5645 /* Aggregates can be initialized with brace-enclosed
5646 initializers. */
5648 {
5649 tree field;
5652 {
5653 tree type;
5668 }
5669 }
5671 /* Synthesize any needed methods. */
5673 cant_have_const_ctor,
5674 no_const_asn_ref);
5676 /* Check defaulted declarations here so we have cant_have_const_ctor
5677 and don't need to worry about clones. */
5680 {
5683 {
5684 bool imp_const_p
5690 /* If the function is defaulted outside the class, we just
5691 give the synthesis error. */
5694 }
5696 }
5699 {
5700 /* "This class type is not an aggregate." */
5702 }
5704 /* Compute the 'literal type' property before we
5705 do anything with non-static member functions. */
5708 /* Create the in-charge and not-in-charge variants of constructors
5709 and destructors. */
5712 /* Process the using-declarations. */
5716 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5719 /* Figure out whether or not we will need a cookie when dynamically
5720 allocating an array of this type. */
5723 }
5725 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5726 accordingly. If a new vfield was created (because T doesn't have a
5727 primary base class), then the newly created field is returned. It
5728 is not added to the TYPE_FIELDS list; it is the caller's
5729 responsibility to do that. Accumulate declared virtual functions
5730 on VIRTUALS_P. */
5732 static tree
5734 {
5735 tree fn;
5737 /* Collect the virtual functions declared in T. */
5742 {
5751 }
5753 /* If we couldn't find an appropriate base class, create a new field
5754 here. Even if there weren't any new virtual functions, we might need a
5755 new virtual function table if we're supposed to include vptrs in
5756 all classes that need them. */
5758 {
5759 /* We build this decl with vtbl_ptr_type_node, which is a
5760 `vtable_entry_type*'. It might seem more precise to use
5761 `vtable_entry_type (*)[N]' where N is the number of virtual
5762 functions. However, that would require the vtable pointer in
5763 base classes to have a different type than the vtable pointer
5764 in derived classes. We could make that happen, but that
5765 still wouldn't solve all the problems. In particular, the
5766 type-based alias analysis code would decide that assignments
5767 to the base class vtable pointer can't alias assignments to
5768 the derived class vtable pointer, since they have different
5769 types. Thus, in a derived class destructor, where the base
5770 class constructor was inlined, we could generate bad code for
5771 setting up the vtable pointer.
5773 Therefore, we use one type for all vtable pointers. We still
5774 use a type-correct type; it's just doesn't indicate the array
5775 bounds. That's better than using `void*' or some such; it's
5776 cleaner, and it let's the alias analysis code know that these
5777 stores cannot alias stores to void*! */
5778 tree field;
5791 /* This class is non-empty. */
5795 }
5798 }
5800 /* Add OFFSET to all base types of BINFO which is a base in the
5801 hierarchy dominated by T.
5803 OFFSET, which is a type offset, is number of bytes. */
5805 static void
5807 {
5809 tree primary_binfo;
5810 tree base_binfo;
5812 /* Update BINFO's offset. */
5817 offset));
5819 /* Find the primary base class. */
5825 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5826 downwards. */
5828 {
5829 /* Don't do the primary base twice. */
5837 }
5838 }
5840 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5841 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5842 empty subobjects of T. */
5844 static void
5846 {
5847 tree vbase;
5854 /* Find the last field. The artificial fields created for virtual
5855 bases will go after the last extant field to date. */
5860 /* Go through the virtual bases, allocating space for each virtual
5861 base that is not already a primary base class. These are
5862 allocated in inheritance graph order. */
5864 {
5869 {
5870 /* This virtual base is not a primary base of any class in the
5871 hierarchy, so we have to add space for it. */
5874 }
5875 }
5876 }
5878 /* Returns the offset of the byte just past the end of the base class
5879 BINFO. */
5881 static tree
5883 {
5884 tree size;
5889 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5890 allocate some space for it. It cannot have virtual bases, so
5891 TYPE_SIZE_UNIT is fine. */
5893 else
5897 }
5899 /* Returns the offset of the byte just past the end of the base class
5900 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5901 only non-virtual bases are included. */
5903 static tree
5905 {
5908 tree binfo;
5909 tree base_binfo;
5910 tree offset;
5915 {
5925 }
5930 {
5934 }
5937 }
5939 /* Warn about bases of T that are inaccessible because they are
5940 ambiguous. For example:
5942 struct S {};
5943 struct T : public S {};
5944 struct U : public S, public T {};
5946 Here, `(S*) new U' is not allowed because there are two `S'
5947 subobjects of U. */
5949 static void
5951 {
5954 tree basetype;
5955 tree binfo;
5956 tree base_binfo;
5958 /* If there are no repeated bases, nothing can be ambiguous. */
5962 /* Check direct bases. */
5965 {
5971 }
5973 /* Check for ambiguous virtual bases. */
5977 {
5983 }
5984 }
5986 /* Compare two INTEGER_CSTs K1 and K2. */
5988 static int
5990 {
5992 }
5994 /* Increase the size indicated in RLI to account for empty classes
5995 that are "off the end" of the class. */
5997 static void
5999 {
6000 tree eoc;
6001 tree rli_size;
6003 /* It might be the case that we grew the class to allocate a
6004 zero-sized base class. That won't be reflected in RLI, yet,
6005 because we are willing to overlay multiple bases at the same
6006 offset. However, now we need to make sure that RLI is big enough
6007 to reflect the entire class. */
6013 {
6014 /* The size should have been rounded to a whole byte. */
6017 rli->bitpos
6026 }
6027 }
6029 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6030 BINFO_OFFSETs for all of the base-classes. Position the vtable
6031 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6033 static void
6035 {
6036 tree non_static_data_members;
6037 tree field;
6038 tree vptr;
6039 record_layout_info rli;
6040 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6041 types that appear at that offset. */
6042 splay_tree empty_base_offsets;
6043 /* True if the last field laid out was a bit-field. */
6045 /* The location at which the next field should be inserted. */
6047 /* T, as a base class. */
6048 tree base_t;
6050 /* Keep track of the first non-static data member. */
6053 /* Start laying out the record. */
6056 /* Mark all the primary bases in the hierarchy. */
6059 /* Create a pointer to our virtual function table. */
6062 /* The vptr is always the first thing in the class. */
6064 {
6069 }
6070 else
6073 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6078 /* Layout the non-static data members. */
6080 {
6081 tree type;
6082 tree padding;
6084 /* We still pass things that aren't non-static data members to
6085 the back end, in case it wants to do something with them. */
6087 {
6089 /* If the static data member has incomplete type, keep track
6090 of it so that it can be completed later. (The handling
6091 of pending statics in finish_record_layout is
6092 insufficient; consider:
6094 struct S1;
6095 struct S2 { static S1 s1; };
6097 At this point, finish_record_layout will be called, but
6098 S1 is still incomplete.) */
6100 {
6102 /* The visibility of static data members is determined
6103 at their point of declaration, not their point of
6104 definition. */
6106 }
6108 }
6116 /* If this field is a bit-field whose width is greater than its
6117 type, then there are some special rules for allocating
6118 it. */
6121 {
6123 tree integer_type;
6125 /* We must allocate the bits as if suitably aligned for the
6126 longest integer type that fits in this many bits. type
6127 of the field. Then, we are supposed to use the left over
6128 bits as additional padding. */
6137 /* ITK now indicates a type that is too large for the
6138 field. We have to back up by one to find the largest
6139 type that fits. */
6140 do
6141 {
6146 /* Figure out how much additional padding is required. */
6148 {
6150 /* In a union, the padding field must have the full width
6151 of the bit-field; all fields start at offset zero. */
6153 else
6156 }
6157 #ifdef PCC_BITFIELD_TYPE_MATTERS
6158 /* An unnamed bitfield does not normally affect the
6159 alignment of the containing class on a target where
6160 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6161 make any exceptions for unnamed bitfields when the
6162 bitfields are longer than their types. Therefore, we
6163 temporarily give the field a name. */
6165 {
6168 }
6169 #endif
6174 empty_base_offsets);
6177 /* Now that layout has been performed, set the size of the
6178 field to the size of its declared type; the rest of the
6179 field is effectively invisible. */
6181 /* We must also reset the DECL_MODE of the field. */
6183 }
6184 else
6186 empty_base_offsets);
6188 /* Remember the location of any empty classes in FIELD. */
6191 empty_base_offsets,
6194 /* If a bit-field does not immediately follow another bit-field,
6195 and yet it starts in the middle of a byte, we have failed to
6196 comply with the ABI. */
6199 /* The TREE_NO_WARNING flag gets set by Objective-C when
6200 laying out an Objective-C class. The ObjC ABI differs
6201 from the C++ ABI, and so we do not want a warning
6202 here. */
6204 && !last_field_was_bitfield
6207 bitsize_unit_node)))
6211 /* The middle end uses the type of expressions to determine the
6212 possible range of expression values. In order to optimize
6213 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6214 must be made aware of the width of "i", via its type.
6216 Because C++ does not have integer types of arbitrary width,
6217 we must (for the purposes of the front end) convert from the
6218 type assigned here to the declared type of the bitfield
6219 whenever a bitfield expression is used as an rvalue.
6220 Similarly, when assigning a value to a bitfield, the value
6221 must be converted to the type given the bitfield here. */
6223 {
6228 {
6235 }
6236 }
6238 /* If we needed additional padding after this field, add it
6239 now. */
6241 {
6242 tree padding_field;
6245 FIELD_DECL,
6246 NULL_TREE,
6247 char_type_node);
6254 NULL_TREE,
6255 empty_base_offsets);
6256 }
6259 }
6262 {
6263 /* Make sure that we are on a byte boundary so that the size of
6264 the class without virtual bases will always be a round number
6265 of bytes. */
6268 }
6270 /* Delete all zero-width bit-fields from the list of fields. Now
6271 that the type is laid out they are no longer important. */
6274 /* Create the version of T used for virtual bases. We do not use
6275 make_class_type for this version; this is an artificial type. For
6276 a POD type, we just reuse T. */
6278 {
6281 /* Set the size and alignment for the new type. */
6282 tree eoc;
6284 /* If the ABI version is not at least two, and the last
6285 field was a bit-field, RLI may not be on a byte
6286 boundary. In particular, rli_size_unit_so_far might
6287 indicate the last complete byte, while rli_size_so_far
6288 indicates the total number of bits used. Therefore,
6289 rli_size_so_far, rather than rli_size_unit_so_far, is
6290 used to compute TYPE_SIZE_UNIT. */
6298 eoc);
6308 /* Copy the fields from T. */
6312 {
6314 FIELD_DECL,
6324 }
6326 /* Record the base version of the type. */
6329 }
6330 else
6333 /* Every empty class contains an empty class. */
6337 /* Set the TYPE_DECL for this type to contain the right
6338 value for DECL_OFFSET, so that we can use it as part
6339 of a COMPONENT_REF for multiple inheritance. */
6342 /* Now fix up any virtual base class types that we left lying
6343 around. We must get these done before we try to lay out the
6344 virtual function table. As a side-effect, this will remove the
6345 base subobject fields. */
6348 /* Make sure that empty classes are reflected in RLI at this
6349 point. */
6352 /* Make sure not to create any structures with zero size. */
6358 /* If this is a non-POD, declaring it packed makes a difference to how it
6359 can be used as a field; don't let finalize_record_size undo it. */
6363 /* Let the back end lay out the type. */
6372 /* Warn about bases that can't be talked about due to ambiguity. */
6375 /* Now that we're done with layout, give the base fields the real types. */
6380 /* Clean up. */
6387 }
6389 /* Determine the "key method" for the class type indicated by TYPE,
6390 and set CLASSTYPE_KEY_METHOD accordingly. */
6392 void
6394 {
6395 tree method;
6398 || processing_template_decl
6403 /* The key method is the first non-pure virtual function that is not
6404 inline at the point of class definition. On some targets the
6405 key function may not be inline; those targets should not call
6406 this function until the end of the translation unit. */
6413 {
6416 }
6419 }
6422 /* Allocate and return an instance of struct sorted_fields_type with
6423 N fields. */
6427 {
6434 }
6437 /* Perform processing required when the definition of T (a class type)
6438 is complete. */
6440 void
6442 {
6443 tree x;
6444 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6448 {
6453 }
6455 /* If this type was previously laid out as a forward reference,
6456 make sure we lay it out again. */
6460 /* Make assumptions about the class; we'll reset the flags if
6461 necessary. */
6467 /* Do end-of-class semantic processing: checking the validity of the
6468 bases and members and add implicitly generated methods. */
6471 /* Find the key method. */
6473 {
6474 /* The Itanium C++ ABI permits the key method to be chosen when
6475 the class is defined -- even though the key method so
6476 selected may later turn out to be an inline function. On
6477 some systems (such as ARM Symbian OS) the key method cannot
6478 be determined until the end of the translation unit. On such
6479 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6480 will cause the class to be added to KEYED_CLASSES. Then, in
6481 finish_file we will determine the key method. */
6485 /* If a polymorphic class has no key method, we may emit the vtable
6486 in every translation unit where the class definition appears. If
6487 we're devirtualizing, we can look into the vtable even if we
6488 aren't emitting it. */
6491 }
6493 /* Layout the class itself. */
6496 /* We use the base type for trivial assignments, and hence it
6497 needs a mode. */
6502 /* If necessary, create the primary vtable for this class. */
6504 {
6505 /* We must enter these virtuals into the table. */
6509 /* Here we know enough to change the type of our virtual
6510 function table, but we will wait until later this function. */
6513 /* If we're warning about ABI tags, check the types of the new
6514 virtual functions. */
6518 }
6521 {
6523 tree fn;
6530 /* Add entries for virtual functions introduced by this class. */
6534 /* Set DECL_VINDEX for all functions declared in this class. */
6536 fn;
6538 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6540 {
6544 /* A thunk. We should never be calling this entry directly
6545 from this vtable -- we'd use the entry for the non
6546 thunk base function. */
6550 }
6551 }
6556 /* Complete the rtl for any static member objects of the type we're
6557 working on. */
6564 /* Done with FIELDS...now decide whether to sort these for
6565 faster lookups later.
6567 We use a small number because most searches fail (succeeding
6568 ultimately as the search bores through the inheritance
6569 hierarchy), and we want this failure to occur quickly. */
6573 /* Complain if one of the field types requires lower visibility. */
6576 /* Make the rtl for any new vtables we have created, and unmark
6577 the base types we marked. */
6580 /* Build the VTT for T. */
6583 /* This warning does not make sense for Java classes, since they
6584 cannot have destructors. */
6589 "%q#T has virtual functions and accessible"
6597 /* Class layout, assignment of virtual table slots, etc., is now
6598 complete. Give the back end a chance to tweak the visibility of
6599 the class or perform any other required target modifications. */
6609 /* Finish debugging output for this type. */
6613 {
6616 {
6619 }
6621 {
6624 else
6625 {
6628 }
6630 }
6632 {
6634 "the type of the first field has a different ABI from the "
6637 }
6638 }
6639 }
6641 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6642 equal to THRESHOLD or greater than THRESHOLD. */
6644 static void
6646 {
6649 {
6654 }
6655 }
6657 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6659 void
6661 {
6664 {
6666 int n_fields
6677 }
6678 }
6680 /* When T was built up, the member declarations were added in reverse
6681 order. Rearrange them to declaration order. */
6683 void
6685 {
6686 tree next;
6687 tree prev;
6688 tree x;
6690 /* The following lists are all in reverse order. Put them in
6691 declaration order now. */
6695 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6696 reverse order, so we can't just use nreverse. */
6701 {
6705 }
6707 {
6711 }
6712 }
6714 tree
6716 {
6719 /* Now that we've got all the field declarations, reverse everything
6720 as necessary. */
6725 /* Nadger the current location so that diagnostics point to the start of
6726 the struct, not the end. */
6730 {
6731 tree x;
6737 /* We need to emit an error message if this type was used as a parameter
6738 and it is an abstract type, even if it is a template. We construct
6739 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6740 account and we call complete_vars with this type, which will check
6741 the PARM_DECLS. Note that while the type is being defined,
6742 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6743 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6749 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6750 an enclosing scope is a template class, so that this function be
6751 found by lookup_fnfields_1 when the using declaration is not
6752 instantiated yet. */
6755 {
6760 }
6762 /* Remember current #pragma pack value. */
6765 /* Fix up any variants we've already built. */
6767 {
6772 }
6773 }
6774 else
6778 {
6779 /* People keep complaining that the compiler crashes on an invalid
6780 definition of initializer_list, so I guess we should explicitly
6781 reject it. What the compiler internals care about is that it's a
6782 template and has a pointer field followed by an integer field. */
6785 {
6788 {
6792 }
6793 }
6796 "definition of std::initializer_list does not match "
6798 }
6806 else
6810 /* Lambdas are defined by the LAMBDA_EXPR. */
6815 }
6816 \f
6817 /* Hash table to avoid endless recursion when handling references. */
6820 /* Return the dynamic type of INSTANCE, if known.
6821 Used to determine whether the virtual function table is needed
6822 or not.
6824 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6825 of our knowledge of its type. *NONNULL should be initialized
6826 before this function is called. */
6828 static tree
6830 {
6831 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6834 {
6838 else
6842 /* This is a call to a constructor, hence it's never zero. */
6844 {
6848 }
6852 /* This is a call to a constructor, hence it's never zero. */
6854 {
6858 }
6867 /* Propagate nonnull. */
6872 CASE_CONVERT:
6878 {
6879 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6880 with a real object -- given &p->f, p can still be null. */
6882 /* ??? Probably should check DECL_WEAK here. */
6885 }
6889 /* If this component is really a base class reference, then the field
6890 itself isn't definitive. */
6899 {
6903 }
6904 /* fall through... */
6909 {
6913 }
6915 {
6919 /* if we're in a ctor or dtor, we know our type. If
6920 current_class_ptr is set but we aren't in a function, we're in
6921 an NSDMI (and therefore a constructor). */
6926 {
6930 }
6931 }
6933 {
6934 /* We only need one hash table because it is always left empty. */
6936 fixed_type_or_null_ref_ht
6939 /* Reference variables should be references to objects. */
6943 /* Enter the INSTANCE in a table to prevent recursion; a
6944 variable's initializer may refer to the variable
6945 itself. */
6950 {
6951 tree type;
6960 }
6961 }
6966 }
6967 #undef RECUR
6968 }
6970 /* Return nonzero if the dynamic type of INSTANCE is known, and
6971 equivalent to the static type. We also handle the case where
6972 INSTANCE is really a pointer. Return negative if this is a
6973 ctor/dtor. There the dynamic type is known, but this might not be
6974 the most derived base of the original object, and hence virtual
6975 bases may not be laid out according to this type.
6977 Used to determine whether the virtual function table is needed
6978 or not.
6980 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6981 of our knowledge of its type. *NONNULL should be initialized
6982 before this function is called. */
6984 int
6986 {
6989 tree fixed;
6991 /* processing_template_decl can be false in a template if we're in
6992 instantiate_non_dependent_expr, but we still want to suppress
6993 this check. */
6995 {
6996 /* In a template we only care about the type of the result. */
7000 }
7010 }
7012 \f
7013 void
7015 {
7018 current_class_stack
7026 }
7028 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7030 static void
7032 {
7033 tree type;
7035 /* We are re-entering the same class we just left, so we don't
7036 have to search the whole inheritance matrix to find all the
7037 decls to bind again. Instead, we install the cached
7038 class_shadowed list and walk through it binding names. */
7041 /* Restore IDENTIFIER_TYPE_VALUE. */
7043 type;
7046 }
7048 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7049 appropriate for TYPE.
7051 So that we may avoid calls to lookup_name, we cache the _TYPE
7052 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7054 For multiple inheritance, we perform a two-pass depth-first search
7055 of the type lattice. */
7057 void
7059 {
7060 class_stack_node_t csn;
7064 /* Make sure there is enough room for the new entry on the stack. */
7066 {
7068 current_class_stack
7070 current_class_stack_size);
7071 }
7073 /* Insert a new entry on the class stack. */
7080 current_class_depth++;
7082 /* Now set up the new type. */
7088 /* By default, things in classes are private, while things in
7089 structures or unions are public. */
7091 ? access_private_node
7097 {
7098 /* Forcibly remove any old class remnants. */
7100 }
7106 else
7108 }
7110 /* When we exit a toplevel class scope, we save its binding level so
7111 that we can restore it quickly. Here, we've entered some other
7112 class, so we must invalidate our cache. */
7114 void
7116 {
7118 }
7120 /* Get out of the current class scope. If we were in a class scope
7121 previously, that is the one popped to. */
7123 void
7125 {
7128 current_class_depth--;
7134 }
7136 /* Mark the top of the class stack as hidden. */
7138 void
7140 {
7143 }
7145 /* Mark the top of the class stack as un-hidden. */
7147 void
7149 {
7152 }
7154 /* Returns 1 if the class type currently being defined is either T or
7155 a nested type of T. */
7157 bool
7159 {
7167 /* We start looking from 1 because entry 0 is from global scope,
7168 and has no type. */
7170 {
7171 tree c;
7174 else
7175 {
7179 }
7184 }
7186 }
7188 /* If either current_class_type or one of its enclosing classes are derived
7189 from T, return the appropriate type. Used to determine how we found
7190 something via unqualified lookup. */
7192 tree
7194 {
7197 /* The bases of a dependent type are unknown. */
7208 {
7213 }
7216 }
7218 /* Return the outermost enclosing class type that is still open, or
7219 NULL_TREE. */
7221 tree
7223 {
7230 {
7237 }
7239 }
7241 /* Returns the innermost class type which is not a lambda closure type. */
7243 tree
7245 {
7248 /* We start looking from 1 because entry 0 is from global scope,
7249 and has no type. */
7251 {
7252 tree c;
7255 else
7256 {
7260 }
7265 }
7267 }
7269 /* When entering a class scope, all enclosing class scopes' names with
7270 static meaning (static variables, static functions, types and
7271 enumerators) have to be visible. This recursive function calls
7272 pushclass for all enclosing class contexts until global or a local
7273 scope is reached. TYPE is the enclosed class. */
7275 void
7277 {
7278 /* A namespace might be passed in error cases, like A::B:C. */
7286 }
7288 /* Undoes a push_nested_class call. */
7290 void
7292 {
7298 }
7300 /* Returns the number of extern "LANG" blocks we are nested within. */
7302 int
7304 {
7306 }
7308 /* Set global variables CURRENT_LANG_NAME to appropriate value
7309 so that behavior of name-mangling machinery is correct. */
7311 void
7313 {
7317 {
7319 }
7321 {
7323 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7324 (See record_builtin_java_type in decl.c.) However, that causes
7325 incorrect debug entries if these types are actually used.
7326 So we re-enable debug output after extern "Java". */
7335 }
7337 {
7339 }
7340 else
7342 }
7344 /* Get out of the current language scope. */
7346 void
7348 {
7350 }
7351 \f
7352 /* Type instantiation routines. */
7354 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7355 matches the TARGET_TYPE. If there is no satisfactory match, return
7356 error_mark_node, and issue an error & warning messages under
7357 control of FLAGS. Permit pointers to member function if FLAGS
7358 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7359 a template-id, and EXPLICIT_TARGS are the explicitly provided
7360 template arguments.
7362 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7363 is the base path used to reference those member functions. If
7364 the address is resolved to a member function, access checks will be
7365 performed and errors issued if appropriate. */
7367 static tree
7369 tree overload,
7370 tsubst_flags_t flags,
7372 tree explicit_targs,
7373 tree access_path)
7374 {
7375 /* Here's what the standard says:
7377 [over.over]
7379 If the name is a function template, template argument deduction
7380 is done, and if the argument deduction succeeds, the deduced
7381 arguments are used to generate a single template function, which
7382 is added to the set of overloaded functions considered.
7384 Non-member functions and static member functions match targets of
7385 type "pointer-to-function" or "reference-to-function." Nonstatic
7386 member functions match targets of type "pointer-to-member
7387 function;" the function type of the pointer to member is used to
7388 select the member function from the set of overloaded member
7389 functions. If a nonstatic member function is selected, the
7390 reference to the overloaded function name is required to have the
7391 form of a pointer to member as described in 5.3.1.
7393 If more than one function is selected, any template functions in
7394 the set are eliminated if the set also contains a non-template
7395 function, and any given template function is eliminated if the
7396 set contains a second template function that is more specialized
7397 than the first according to the partial ordering rules 14.5.5.2.
7398 After such eliminations, if any, there shall remain exactly one
7399 selected function. */
7402 /* We store the matches in a TREE_LIST rooted here. The functions
7403 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7404 interoperability with most_specialized_instantiation. */
7406 tree fn;
7407 tree target_fn_type;
7409 /* By the time we get here, we should be seeing only real
7410 pointer-to-member types, not the internal POINTER_TYPE to
7411 METHOD_TYPE representation. */
7417 /* Check that the TARGET_TYPE is reasonable. */
7422 /* This is OK, too. */
7425 /* This is OK, too. This comes from a conversion to reference
7426 type. */
7428 else
7429 {
7435 }
7437 /* Non-member functions and static member functions match targets of type
7438 "pointer-to-function" or "reference-to-function." Nonstatic member
7439 functions match targets of type "pointer-to-member-function;" the
7440 function type of the pointer to member is used to select the member
7441 function from the set of overloaded member functions.
7443 So figure out the FUNCTION_TYPE that we want to match against. */
7446 /* If we can find a non-template function that matches, we can just
7447 use it. There's no point in generating template instantiations
7448 if we're just going to throw them out anyhow. But, of course, we
7449 can only do this when we don't *need* a template function. */
7451 {
7452 tree fns;
7455 {
7459 /* We're not looking for templates just yet. */
7464 /* We're looking for a non-static member, and this isn't
7465 one, or vice versa. */
7468 /* Ignore functions which haven't been explicitly
7469 declared. */
7473 /* See if there's a match. */
7476 }
7477 }
7479 /* Now, if we've already got a match (or matches), there's no need
7480 to proceed to the template functions. But, if we don't have a
7481 match we need to look at them, too. */
7483 {
7484 tree target_arg_types;
7485 tree target_ret_type;
7486 tree fns;
7489 tree arg;
7503 {
7505 tree instantiation;
7506 tree targs;
7509 /* We're only looking for templates. */
7514 /* We're not looking for a non-static member, and this is
7515 one, or vice versa. */
7520 /* If the template has a deduced return type, don't expose it to
7521 template argument deduction. */
7525 /* Try to do argument deduction. */
7532 /* Instantiation failed. */
7535 /* And now force instantiation to do return type deduction. */
7537 {
7543 }
7545 /* See if there's a match. */
7548 }
7550 /* Now, remove all but the most specialized of the matches. */
7552 {
7557 NULL_TREE,
7558 NULL_TREE);
7559 }
7560 }
7562 /* Now we should have exactly one function in MATCHES. */
7564 {
7565 /* There were *no* matches. */
7567 {
7570 target_type);
7573 }
7575 }
7577 {
7578 /* There were too many matches. First check if they're all
7579 the same function. */
7584 /* For multi-versioned functions, more than one match is just fine and
7585 decls_match will return false as they are different. */
7593 {
7595 {
7598 target_type);
7600 /* Since print_candidates expects the functions in the
7601 TREE_VALUE slot, we flip them here. */
7606 }
7609 }
7610 }
7612 /* Good, exactly one match. Now, convert it to the correct type. */
7617 {
7625 {
7628 }
7629 }
7631 /* If a pointer to a function that is multi-versioned is requested, the
7632 pointer to the dispatcher function is returned instead. This works
7633 well because indirectly calling the function will dispatch the right
7634 function version at run-time. */
7636 {
7640 /* Mark all the versions corresponding to the dispatcher as used. */
7643 }
7645 /* If we're doing overload resolution purely for the purpose of
7646 determining conversion sequences, we should not consider the
7647 function used. If this conversion sequence is selected, the
7648 function will be marked as used at this point. */
7650 {
7651 /* Make =delete work with SFINAE. */
7656 }
7658 /* We could not check access to member functions when this
7659 expression was originally created since we did not know at that
7660 time to which function the expression referred. */
7662 {
7665 }
7669 else
7670 {
7671 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7672 will mark the function as addressed, but here we must do it
7673 explicitly. */
7677 }
7678 }
7680 /* This function will instantiate the type of the expression given in
7681 RHS to match the type of LHSTYPE. If errors exist, then return
7682 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7683 we complain on errors. If we are not complaining, never modify rhs,
7684 as overload resolution wants to try many possible instantiations, in
7685 the hope that at least one will work.
7687 For non-recursive calls, LHSTYPE should be a function, pointer to
7688 function, or a pointer to member function. */
7690 tree
7692 {
7699 {
7703 }
7706 {
7713 /* Microsoft allows `A::f' to be resolved to a
7714 pointer-to-member. */
7715 ;
7716 else
7717 {
7722 }
7723 }
7726 {
7729 }
7731 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7732 deduce any type information. */
7734 {
7738 }
7740 /* There only a few kinds of expressions that may have a type
7741 dependent on overload resolution. */
7747 /* This should really only be used when attempting to distinguish
7748 what sort of a pointer to function we have. For now, any
7749 arithmetic operation which is not supported on pointers
7750 is rejected as an error. */
7753 {
7755 {
7761 /* Do not lose object's side effects. */
7765 }
7772 /* This can happen if we are forming a pointer-to-member for a
7773 member template. */
7776 /* Fall through. */
7779 {
7783 return
7787 }
7791 return
7795 access_path);
7798 {
7803 }
7810 }
7812 }
7813 \f
7814 /* Return the name of the virtual function pointer field
7815 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7816 this may have to look back through base types to find the
7817 ultimate field name. (For single inheritance, these could
7818 all be the same name. Who knows for multiple inheritance). */
7820 static tree
7822 {
7829 {
7835 }
7843 }
7845 void
7847 {
7854 {
7859 }
7860 }
7862 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7863 according to [class]:
7864 The class-name is also inserted
7865 into the scope of the class itself. For purposes of access checking,
7866 the inserted class name is treated as if it were a public member name. */
7868 void
7870 {
7873 tree saved_cas;
7888 }
7890 /* Returns 1 if TYPE contains only padding bytes. */
7892 int
7894 {
7902 }
7904 /* Returns true if TYPE contains no actual data, just various
7905 possible combinations of empty classes and possibly a vptr. */
7907 bool
7909 {
7911 {
7912 tree field;
7913 tree binfo;
7914 tree base_binfo;
7917 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7918 out, but we'd like to be able to check this before then. */
7932 }
7936 }
7938 /* Note that NAME was looked up while the current class was being
7939 defined and that the result of that lookup was DECL. */
7941 void
7943 {
7944 splay_tree names_used;
7946 /* If we're not defining a class, there's nothing to do. */
7952 /* If there's already a binding for this NAME, then we don't have
7953 anything to worry about. */
7966 }
7968 /* Note that NAME was declared (as DECL) in the current class. Check
7969 to see that the declaration is valid. */
7971 void
7973 {
7974 splay_tree names_used;
7975 splay_tree_node n;
7977 /* Look to see if we ever used this name. */
7978 names_used
7982 /* The C language allows members to be declared with a type of the same
7983 name, and the C++ standard says this diagnostic is not required. So
7984 allow it in extern "C" blocks unless predantic is specified.
7985 Allow it in all cases if -ms-extensions is specified. */
7991 {
7992 /* [basic.scope.class]
7994 A name N used in a class S shall refer to the same declaration
7995 in its context and when re-evaluated in the completed scope of
7996 S. */
8000 }
8001 }
8003 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8004 Secondary vtables are merged with primary vtables; this function
8005 will return the VAR_DECL for the primary vtable. */
8007 tree
8009 {
8010 tree decl;
8014 {
8017 }
8021 }
8024 /* Returns the binfo for the primary base of BINFO. If the resulting
8025 BINFO is a virtual base, and it is inherited elsewhere in the
8026 hierarchy, then the returned binfo might not be the primary base of
8027 BINFO in the complete object. Check BINFO_PRIMARY_P or
8028 BINFO_LOST_PRIMARY_P to be sure. */
8030 static tree
8032 {
8033 tree primary_base;
8040 }
8042 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8044 static int
8046 {
8050 }
8052 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8053 INDENT should be zero when called from the top level; it is
8054 incremented recursively. IGO indicates the next expected BINFO in
8055 inheritance graph ordering. */
8057 static tree
8060 tree binfo,
8061 tree igo,
8063 {
8065 tree base_binfo;
8073 {
8076 }
8091 {
8095 TFF_PLAIN_IDENTIFIER),
8097 }
8099 {
8102 }
8107 {
8111 {
8115 TFF_PLAIN_IDENTIFIER));
8116 }
8118 {
8122 TFF_PLAIN_IDENTIFIER));
8123 }
8125 {
8129 TFF_PLAIN_IDENTIFIER));
8130 }
8132 {
8136 TFF_PLAIN_IDENTIFIER));
8137 }
8141 }
8147 }
8149 /* Dump the BINFO hierarchy for T. */
8151 static void
8153 {
8165 }
8167 /* Debug interface to hierarchy dumping. */
8169 void
8171 {
8173 }
8175 static void
8177 {
8182 {
8184 }
8185 }
8187 static void
8189 {
8190 tree value;
8192 HOST_WIDE_INT elt;
8200 TFF_PLAIN_IDENTIFIER));
8207 }
8209 static void
8211 {
8219 {
8226 {
8231 }
8235 }
8236 }
8238 static void
8240 {
8248 {
8253 }
8254 }
8256 /* Dump a function or thunk and its thunkees. */
8258 static void
8260 {
8263 tree thunks;
8271 {
8281 else
8287 }
8291 }
8293 /* Dump the thunks for FN. */
8295 void
8297 {
8299 }
8301 /* Virtual function table initialization. */
8303 /* Create all the necessary vtables for T and its base classes. */
8305 static void
8307 {
8308 tree vbase;
8312 /* We lay out the primary and secondary vtables in one contiguous
8313 vtable. The primary vtable is first, followed by the non-virtual
8314 secondary vtables in inheritance graph order. */
8318 /* Then come the virtual bases, also in inheritance graph order. */
8320 {
8324 }
8328 }
8330 /* Initialize the vtable for BINFO with the INITS. */
8332 static void
8334 {
8335 tree decl;
8341 }
8343 /* Build the VTT (virtual table table) for T.
8344 A class requires a VTT if it has virtual bases.
8346 This holds
8347 1 - primary virtual pointer for complete object T
8348 2 - secondary VTTs for each direct non-virtual base of T which requires a
8349 VTT
8350 3 - secondary virtual pointers for each direct or indirect base of T which
8351 has virtual bases or is reachable via a virtual path from T.
8352 4 - secondary VTTs for each direct or indirect virtual base of T.
8354 Secondary VTTs look like complete object VTTs without part 4. */
8356 static void
8358 {
8359 tree type;
8360 tree vtt;
8361 tree index;
8364 /* Build up the initializers for the VTT. */
8369 /* If we didn't need a VTT, we're done. */
8373 /* Figure out the type of the VTT. */
8377 /* Now, build the VTT object itself. */
8380 /* Add the VTT to the vtables list. */
8385 }
8387 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8388 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8389 and CHAIN the vtable pointer for this binfo after construction is
8390 complete. VALUE can also be another BINFO, in which case we recurse. */
8392 static tree
8394 {
8395 tree vt;
8398 {
8404 else
8406 }
8409 }
8411 /* Data for secondary VTT initialization. */
8413 {
8414 /* Is this the primary VTT? */
8417 /* Current index into the VTT. */
8418 tree index;
8420 /* Vector of initializers built up. */
8423 /* The type being constructed by this secondary VTT. */
8424 tree type_being_constructed;
8427 /* Recursively build the VTT-initializer for BINFO (which is in the
8428 hierarchy dominated by T). INITS points to the end of the initializer
8429 list to date. INDEX is the VTT index where the next element will be
8430 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8431 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8432 for virtual bases of T. When it is not so, we build the constructor
8433 vtables for the BINFO-in-T variant. */
8435 static void
8438 {
8440 tree b;
8441 tree init;
8442 secondary_vptr_vtt_init_data data;
8445 /* We only need VTTs for subobjects with virtual bases. */
8449 /* We need to use a construction vtable if this is not the primary
8450 VTT. */
8452 {
8455 /* Record the offset in the VTT where this sub-VTT can be found. */
8457 }
8459 /* Add the address of the primary vtable for the complete object. */
8463 {
8466 }
8469 /* Recursively add the secondary VTTs for non-virtual bases. */
8474 /* Add secondary virtual pointers for all subobjects of BINFO with
8475 either virtual bases or reachable along a virtual path, except
8476 subobjects that are non-virtual primary bases. */
8486 /* data.inits might have grown as we added secondary virtual pointers.
8487 Make sure our caller knows about the new vector. */
8491 /* Add the secondary VTTs for virtual bases in inheritance graph
8492 order. */
8494 {
8499 }
8500 else
8501 /* Remove the ctor vtables we created. */
8503 }
8505 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8506 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8508 static tree
8510 {
8513 /* We don't care about bases that don't have vtables. */
8517 /* We're only interested in proper subobjects of the type being
8518 constructed. */
8522 /* We're only interested in bases with virtual bases or reachable
8523 via a virtual path from the type being constructed. */
8528 /* We're not interested in non-virtual primary bases. */
8532 /* Record the index where this secondary vptr can be found. */
8534 {
8539 {
8540 /* It's a primary virtual base, and this is not a
8541 construction vtable. Find the base this is primary of in
8542 the inheritance graph, and use that base's vtable
8543 now. */
8546 }
8547 }
8549 /* Add the initializer for the secondary vptr itself. */
8552 /* Advance the vtt index. */
8557 }
8559 /* Called from build_vtt_inits via dfs_walk. After building
8560 constructor vtables and generating the sub-vtt from them, we need
8561 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8562 binfo of the base whose sub vtt was generated. */
8564 static tree
8566 {
8570 /* If this class has no vtable, none of its bases do. */
8574 /* This might be a primary base, so have no vtable in this
8575 hierarchy. */
8578 /* If we scribbled the construction vtable vptr into BINFO, clear it
8579 out now. */
8585 }
8587 /* Build the construction vtable group for BINFO which is in the
8588 hierarchy dominated by T. */
8590 static void
8592 {
8593 tree type;
8594 tree vtbl;
8595 tree id;
8596 tree vbase;
8599 /* See if we've already created this construction vtable group. */
8605 /* Build a version of VTBL (with the wrong type) for use in
8606 constructing the addresses of secondary vtables in the
8607 construction vtable group. */
8610 /* Don't export construction vtables from shared libraries. Even on
8611 targets that don't support hidden visibility, this tells
8612 can_refer_decl_in_current_unit_p not to assume that it's safe to
8613 access from a different compilation unit (bz 54314). */
8621 /* Add the vtables for each of our virtual bases using the vbase in T
8622 binfo. */
8624 vbase;
8626 {
8627 tree b;
8634 }
8636 /* Figure out the type of the construction vtable. */
8643 /* Initialize the construction vtable. */
8647 }
8649 /* Add the vtbl initializers for BINFO (and its bases other than
8650 non-virtual primaries) to the list of INITS. BINFO is in the
8651 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8652 the constructor the vtbl inits should be accumulated for. (If this
8653 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8654 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8655 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8656 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8657 but are not necessarily the same in terms of layout. */
8659 static void
8661 tree orig_binfo,
8662 tree rtti_binfo,
8663 tree vtbl,
8664 tree t,
8666 {
8668 tree base_binfo;
8673 /* If it doesn't have a vptr, we don't do anything. */
8677 /* If we're building a construction vtable, we're not interested in
8678 subobjects that don't require construction vtables. */
8684 /* Build the initializers for the BINFO-in-T vtable. */
8687 /* Walk the BINFO and its bases. We walk in preorder so that as we
8688 initialize each vtable we can figure out at what offset the
8689 secondary vtable lies from the primary vtable. We can't use
8690 dfs_walk here because we need to iterate through bases of BINFO
8691 and RTTI_BINFO simultaneously. */
8693 {
8694 /* Skip virtual bases. */
8700 inits);
8701 }
8702 }
8704 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8705 BINFO vtable to L. */
8707 static void
8709 tree orig_binfo,
8710 tree rtti_binfo,
8711 tree orig_vtbl,
8712 tree t,
8714 {
8721 {
8722 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8723 primary virtual base. If it is not the same primary in
8724 the hierarchy of T, we'll need to generate a ctor vtable
8725 for it, to place at its location in T. If it is the same
8726 primary, we still need a VTT entry for the vtable, but it
8727 should point to the ctor vtable for the base it is a
8728 primary for within the sub-hierarchy of RTTI_BINFO.
8730 There are three possible cases:
8732 1) We are in the same place.
8733 2) We are a primary base within a lost primary virtual base of
8734 RTTI_BINFO.
8735 3) We are primary to something not a base of RTTI_BINFO. */
8737 tree b;
8740 /* First, look through the bases we are primary to for RTTI_BINFO
8741 or a virtual base. */
8744 {
8749 }
8750 /* If we run out of primary links, keep looking down our
8751 inheritance chain; we might be an indirect primary. */
8755 found:
8757 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8758 base B and it is a base of RTTI_BINFO, this is case 2. In
8759 either case, we share our vtable with LAST, i.e. the
8760 derived-most base within B of which we are a primary. */
8763 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8764 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8765 binfo_ctor_vtable after everything's been set up. */
8768 /* Otherwise, this is case 3 and we get our own. */
8769 }
8776 {
8777 tree index;
8780 /* Add the initializer for this vtable. */
8784 /* Figure out the position to which the VPTR should point. */
8790 }
8793 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8794 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8795 straighten this out. */
8798 /* Throw away any unneeded intializers. */
8800 else
8801 /* For an ordinary vtable, set BINFO_VTABLE. */
8803 }
8807 /* Construct the initializer for BINFO's virtual function table. BINFO
8808 is part of the hierarchy dominated by T. If we're building a
8809 construction vtable, the ORIG_BINFO is the binfo we should use to
8810 find the actual function pointers to put in the vtable - but they
8811 can be overridden on the path to most-derived in the graph that
8812 ORIG_BINFO belongs. Otherwise,
8813 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8814 BINFO that should be indicated by the RTTI information in the
8815 vtable; it will be a base class of T, rather than T itself, if we
8816 are building a construction vtable.
8818 The value returned is a TREE_LIST suitable for wrapping in a
8819 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8820 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8821 number of non-function entries in the vtable.
8823 It might seem that this function should never be called with a
8824 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8825 base is always subsumed by a derived class vtable. However, when
8826 we are building construction vtables, we do build vtables for
8827 primary bases; we need these while the primary base is being
8828 constructed. */
8830 static void
8832 tree orig_binfo,
8833 tree t,
8834 tree rtti_binfo,
8837 {
8838 tree v;
8839 vtbl_init_data vid;
8841 tree vbinfo;
8845 /* Initialize VID. */
8853 /* The first vbase or vcall offset is at index -3 in the vtable. */
8856 /* Add entries to the vtable for RTTI. */
8859 /* Create an array for keeping track of the functions we've
8860 processed. When we see multiple functions with the same
8861 signature, we share the vcall offsets. */
8863 /* Add the vcall and vbase offset entries. */
8866 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8867 build_vbase_offset_vtbl_entries. */
8872 /* If the target requires padding between data entries, add that now. */
8874 {
8879 /* Move data entries into their new positions and add padding
8880 after the new positions. Iterate backwards so we don't
8881 overwrite entries that we would need to process later. */
8884 ix--)
8885 {
8893 {
8897 null_pointer_node);
8898 }
8899 }
8900 }
8905 /* The initializers for virtual functions were built up in reverse
8906 order. Straighten them out and add them to the running list in one
8907 step. */
8916 /* Go through all the ordinary virtual functions, building up
8917 initializers. */
8919 {
8920 tree delta;
8921 tree vcall_index;
8928 {
8932 {
8935 }
8937 }
8939 /* If the only definition of this function signature along our
8940 primary base chain is from a lost primary, this vtable slot will
8941 never be used, so just zero it out. This is important to avoid
8942 requiring extra thunks which cannot be generated with the function.
8944 We first check this in update_vtable_entry_for_fn, so we handle
8945 restored primary bases properly; we also need to do it here so we
8946 zero out unused slots in ctor vtables, rather than filling them
8947 with erroneous values (though harmless, apart from relocation
8948 costs). */
8953 {
8954 /* Pull the offset for `this', and the function to call, out of
8955 the list. */
8962 /* You can't call an abstract virtual function; it's abstract.
8963 So, we replace these functions with __pure_virtual. */
8965 {
8968 {
8970 abort_fndecl_addr
8974 }
8975 }
8976 /* Likewise for deleted virtuals. */
8978 {
8987 }
8988 else
8989 {
8991 {
8995 }
8996 /* Take the address of the function, considering it to be of an
8997 appropriate generic type. */
9001 /* Don't refer to a virtual destructor from a constructor
9002 vtable or a vtable for an abstract class, since destroying
9003 an object under construction is undefined behavior and we
9004 don't want it to be considered a candidate for speculative
9005 devirtualization. But do create the thunk for ABI
9006 compliance. */
9011 }
9012 }
9014 /* And add it to the chain of initializers. */
9016 {
9021 else
9023 {
9029 }
9030 }
9031 else
9033 }
9034 }
9036 /* Adds to vid->inits the initializers for the vbase and vcall
9037 offsets in BINFO, which is in the hierarchy dominated by T. */
9039 static void
9041 {
9042 tree b;
9044 /* If this is a derived class, we must first create entries
9045 corresponding to the primary base class. */
9050 /* Add the vbase entries for this base. */
9052 /* Add the vcall entries for this base. */
9054 }
9056 /* Returns the initializers for the vbase offset entries in the vtable
9057 for BINFO (which is part of the class hierarchy dominated by T), in
9058 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9059 where the next vbase offset will go. */
9061 static void
9063 {
9064 tree vbase;
9065 tree t;
9066 tree non_primary_binfo;
9068 /* If there are no virtual baseclasses, then there is nothing to
9069 do. */
9075 /* We might be a primary base class. Go up the inheritance hierarchy
9076 until we find the most derived class of which we are a primary base:
9077 it is the offset of that which we need to use. */
9080 {
9081 tree b;
9083 /* If we have reached a virtual base, then it must be a primary
9084 base (possibly multi-level) of vid->binfo, or we wouldn't
9085 have called build_vcall_and_vbase_vtbl_entries for it. But it
9086 might be a lost primary, so just skip down to vid->binfo. */
9088 {
9091 }
9097 }
9099 /* Go through the virtual bases, adding the offsets. */
9101 vbase;
9103 {
9104 tree b;
9105 tree delta;
9110 /* Find the instance of this virtual base in the complete
9111 object. */
9114 /* If we've already got an offset for this virtual base, we
9115 don't need another one. */
9120 /* Figure out where we can find this vbase offset. */
9129 /* The vbase offset had better be the same. */
9132 /* The next vbase will come at a more negative offset. */
9136 /* The initializer is the delta from BINFO to this virtual base.
9137 The vbase offsets go in reverse inheritance-graph order, and
9138 we are walking in inheritance graph order so these end up in
9139 the right order. */
9146 }
9147 }
9149 /* Adds the initializers for the vcall offset entries in the vtable
9150 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9151 to VID->INITS. */
9153 static void
9155 {
9156 /* We only need these entries if this base is a virtual base. We
9157 compute the indices -- but do not add to the vtable -- when
9158 building the main vtable for a class. */
9161 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9162 correspond to VID->DERIVED), we are building a primary
9163 construction virtual table. Since this is a primary
9164 virtual table, we do not need the vcall offsets for
9165 BINFO. */
9167 {
9168 /* We need a vcall offset for each of the virtual functions in this
9169 vtable. For example:
9171 class A { virtual void f (); };
9172 class B1 : virtual public A { virtual void f (); };
9173 class B2 : virtual public A { virtual void f (); };
9174 class C: public B1, public B2 { virtual void f (); };
9176 A C object has a primary base of B1, which has a primary base of A. A
9177 C also has a secondary base of B2, which no longer has a primary base
9178 of A. So the B2-in-C construction vtable needs a secondary vtable for
9179 A, which will adjust the A* to a B2* to call f. We have no way of
9180 knowing what (or even whether) this offset will be when we define B2,
9181 so we store this "vcall offset" in the A sub-vtable and look it up in
9182 a "virtual thunk" for B2::f.
9184 We need entries for all the functions in our primary vtable and
9185 in our non-virtual bases' secondary vtables. */
9187 /* If we are just computing the vcall indices -- but do not need
9188 the actual entries -- not that. */
9191 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9193 }
9194 }
9196 /* Build vcall offsets, starting with those for BINFO. */
9198 static void
9200 {
9202 tree primary_binfo;
9203 tree base_binfo;
9205 /* Don't walk into virtual bases -- except, of course, for the
9206 virtual base for which we are building vcall offsets. Any
9207 primary virtual base will have already had its offsets generated
9208 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9212 /* If BINFO has a primary base, process it first. */
9217 /* Add BINFO itself to the list. */
9220 /* Scan the non-primary bases of BINFO. */
9224 }
9226 /* Called from build_vcall_offset_vtbl_entries_r. */
9228 static void
9230 {
9231 /* Make entries for the rest of the virtuals. */
9232 tree orig_fn;
9234 /* The ABI requires that the methods be processed in declaration
9235 order. */
9237 orig_fn;
9241 }
9243 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9245 static void
9247 {
9249 tree vcall_offset;
9250 tree derived_entry;
9252 /* If there is already an entry for a function with the same
9253 signature as FN, then we do not need a second vcall offset.
9254 Check the list of functions already present in the derived
9255 class vtable. */
9257 {
9259 /* We only use one vcall offset for virtual destructors,
9260 even though there are two virtual table entries. */
9264 }
9266 /* If we are building these vcall offsets as part of building
9267 the vtable for the most derived class, remember the vcall
9268 offset. */
9270 {
9273 }
9275 /* The next vcall offset will be found at a more negative
9276 offset. */
9280 /* Keep track of this function. */
9284 {
9285 tree base;
9286 tree fn;
9288 /* Find the overriding function. */
9292 else
9293 {
9296 /* The vbase we're working on is a primary base of
9297 vid->binfo. But it might be a lost primary, so its
9298 BINFO_OFFSET might be wrong, so we just use the
9299 BINFO_OFFSET from vid->binfo. */
9305 vcall_offset);
9306 }
9307 /* Add the initializer to the vtable. */
9309 }
9310 }
9312 /* Return vtbl initializers for the RTTI entries corresponding to the
9313 BINFO's vtable. The RTTI entries should indicate the object given
9314 by VID->rtti_binfo. */
9316 static void
9318 {
9319 tree b;
9320 tree t;
9321 tree offset;
9322 tree decl;
9323 tree init;
9327 /* To find the complete object, we will first convert to our most
9328 primary base, and then add the offset in the vtbl to that value. */
9332 {
9333 tree primary_base;
9339 }
9343 /* The second entry is the address of the typeinfo object. */
9346 else
9349 /* Convert the declaration to a type that can be stored in the
9350 vtable. */
9354 /* Add the offset-to-top entry. It comes earlier in the vtable than
9355 the typeinfo entry. Convert the offset to look like a
9356 function pointer, so that we can put it in the vtable. */
9359 }
9361 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9362 accessibility. */
9364 bool
9366 {
9369 }
9371 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9373 bool
9375 {
9379 }
9381 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9382 class between them, if any. */
9384 tree
9386 {
9398 {
9401 }
9405 }