| blob | 18ce2f86e0a47b4f7af20bbc52e61e06a1eff3a2 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2013 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. */
42 /* The number of nested classes being processed. If we are not in the
43 scope of any class, this is zero. */
47 /* In order to deal with nested classes, we keep a stack of classes.
48 The topmost entry is the innermost class, and is the entry at index
49 CURRENT_CLASS_DEPTH */
52 /* The name of the class. */
53 tree name;
55 /* The _TYPE node for the class. */
56 tree type;
58 /* The access specifier pending for new declarations in the scope of
59 this class. */
60 tree access;
62 /* If were defining TYPE, the names used in this class. */
63 splay_tree names_used;
65 /* Nonzero if this class is no longer open, because of a call to
66 push_to_top_level. */
71 {
72 /* The base for which we're building initializers. */
73 tree binfo;
74 /* The type of the most-derived type. */
75 tree derived;
76 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
77 unless ctor_vtbl_p is true. */
78 tree rtti_binfo;
79 /* The negative-index vtable initializers built up so far. These
80 are in order from least negative index to most negative index. */
82 /* The binfo for the virtual base for which we're building
83 vcall offset initializers. */
84 tree vbase;
85 /* The functions in vbase for which we have already provided vcall
86 offsets. */
88 /* The vtable index of the next vcall or vbase offset. */
89 tree index;
90 /* Nonzero if we are building the initializer for the primary
91 vtable. */
93 /* Nonzero if we are building the initializer for a construction
94 vtable. */
96 /* True when adding vcall offset entries to the vtable. False when
97 merely computing the indices. */
101 /* The type of a function passed to walk_subobject_offsets. */
104 /* The stack itself. This is a dynamically resized array. The
105 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
109 /* The size of the largest empty class seen in this translation unit. */
112 /* An array of all local classes present in this translation unit, in
113 declaration order. */
195 tree *);
205 splay_tree_key k2);
214 /* Variables shared between class.c and call.c. */
224 /* Convert to or from a base subobject. EXPR is an expression of type
225 `A' or `A*', an expression of type `B' or `B*' is returned. To
226 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
227 the B base instance within A. To convert base A to derived B, CODE
228 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
229 In this latter case, A must not be a morally virtual base of B.
230 NONNULL is true if EXPR is known to be non-NULL (this is only
231 needed when EXPR is of pointer type). CV qualifiers are preserved
232 from EXPR. */
234 tree
236 tree expr,
237 tree binfo,
239 tsubst_flags_t complain)
240 {
243 tree probe;
244 tree offset;
245 tree target_type;
247 tree ptr_target_type;
257 {
263 }
271 {
272 /* This can happen when adjust_result_of_qualified_name_lookup can't
273 find a unique base binfo in a call to a member function. We
274 couldn't give the diagnostic then since we might have been calling
275 a static member function, so we do it now. */
277 {
281 }
283 }
290 /* Nothing to do. */
294 {
296 {
298 {
301 "pointer to derived class %qT because the base is "
303 else
307 }
308 else
309 {
315 else
319 }
320 }
322 }
325 /* This must happen before the call to save_expr. */
327 else
333 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
334 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
335 expression returned matches the input. */
336 target_type = cp_build_qualified_type
340 /* Do we need to look in the vtable for the real offset? */
343 /* Don't bother with the calculations inside sizeof; they'll ICE if the
344 source type is incomplete and the pointer value doesn't matter. In a
345 template (even in fold_non_dependent_expr), we don't have vtables set
346 up properly yet, and the value doesn't matter there either; we're just
347 interested in the result of overload resolution. */
350 {
355 }
357 /* If we're in an NSDMI, we don't have the full constructor context yet
358 that we need for converting to a virtual base, so just build a stub
359 CONVERT_EXPR and expand it later in bot_replace. */
362 {
368 }
370 /* Do we need to check for a null pointer? */
372 {
373 /* If we know the conversion will not actually change the value
374 of EXPR, then we can avoid testing the expression for NULL.
375 We have to avoid generating a COMPONENT_REF for a base class
376 field, because other parts of the compiler know that such
377 expressions are always non-NULL. */
381 }
383 /* Protect against multiple evaluation if necessary. */
387 /* Now that we've saved expr, build the real null test. */
389 {
393 }
395 /* If this is a simple base reference, express it as a COMPONENT_REF. */
397 /* We don't build base fields for empty bases, and they aren't very
398 interesting to the optimizers anyway. */
400 {
407 }
410 {
411 /* Going via virtual base V_BINFO. We need the static offset
412 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
413 V_BINFO. That offset is an entry in D_BINFO's vtable. */
414 tree v_offset;
417 {
418 /* In a base member initializer, we cannot rely on the
419 vtable being set up. We have to indirect via the
420 vtt_parm. */
421 tree t;
427 }
428 else
430 complain),
436 v_offset);
448 /* Negative fixed_type_p means this is a constructor or destructor;
449 virtual base layout is fixed in in-charge [cd]tors, but not in
450 base [cd]tors. */
454 v_offset,
457 else
459 }
467 {
472 }
473 else
479 out:
485 }
487 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
488 Perform a derived-to-base conversion by recursively building up a
489 sequence of COMPONENT_REFs to the appropriate base fields. */
491 static tree
493 {
496 tree field;
499 {
500 tree temp;
504 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
505 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
506 an lvalue in the front end; only _DECLs and _REFs are lvalues
507 in the back end. */
513 }
515 /* Recurse. */
520 /* Is this the base field created by build_base_field? */
524 /* If we're looking for a field in the most-derived class,
525 also check the field offset; we can have two base fields
526 of the same type if one is an indirect virtual base and one
527 is a direct non-virtual base. */
531 {
532 /* We don't use build_class_member_access_expr here, as that
533 has unnecessary checks, and more importantly results in
534 recursive calls to dfs_walk_once. */
542 /* Mark the expression const or volatile, as appropriate.
543 Even though we've dealt with the type above, we still have
544 to mark the expression itself. */
551 }
553 /* Didn't find the base field?!? */
555 }
557 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
558 type is a class type or a pointer to a class type. In the former
559 case, TYPE is also a class type; in the latter it is another
560 pointer type. If CHECK_ACCESS is true, an error message is emitted
561 if TYPE is inaccessible. If OBJECT has pointer type, the value is
562 assumed to be non-NULL. */
564 tree
566 tsubst_flags_t complain)
567 {
568 tree binfo;
569 tree object_type;
572 {
575 }
576 else
585 }
587 /* EXPR is an expression with unqualified class type. BASE is a base
588 binfo of that class type. Returns EXPR, converted to the BASE
589 type. This function assumes that EXPR is the most derived class;
590 therefore virtual bases can be found at their static offsets. */
592 tree
594 {
595 tree expr_type;
599 {
600 /* If this is a non-empty base, use a COMPONENT_REF. */
604 /* We use fold_build2 and fold_convert below to simplify the trees
605 provided to the optimizers. It is not safe to call these functions
606 when processing a template because they do not handle C++-specific
607 trees. */
615 }
618 }
620 \f
621 tree
623 {
629 /* First, convert to the requested type. */
634 /* Second, the requested type may not be the owner of its own vptr.
635 If not, convert to the base class that owns it. We cannot use
636 convert_to_base here, because VCONTEXT may appear more than once
637 in the inheritance hierarchy of TYPE, and thus direct conversion
638 between the types may be ambiguous. Following the path back up
639 one step at a time via primary bases avoids the problem. */
643 {
646 }
649 }
651 /* Given an object INSTANCE, return an expression which yields the
652 vtable element corresponding to INDEX. There are many special
653 cases for INSTANCE which we take care of here, mainly to avoid
654 creating extra tree nodes when we don't have to. */
656 static tree
658 {
659 tree aref;
662 /* Try to figure out what a reference refers to, and
663 access its virtual function table directly. */
671 {
676 }
685 }
687 tree
689 {
693 }
695 /* Given a stable object pointer INSTANCE_PTR, return an expression which
696 yields a function pointer corresponding to vtable element INDEX. */
698 tree
700 {
701 tree aref;
704 tf_warning_or_error),
705 idx);
707 /* When using function descriptors, the address of the
708 vtable entry is treated as a function pointer. */
713 /* Remember this as a method reference, for later devirtualization. */
717 }
719 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
720 for the given TYPE. */
722 static tree
724 {
726 }
728 /* DECL is an entity associated with TYPE, like a virtual table or an
729 implicitly generated constructor. Determine whether or not DECL
730 should have external or internal linkage at the object file
731 level. This routine does not deal with COMDAT linkage and other
732 similar complexities; it simply sets TREE_PUBLIC if it possible for
733 entities in other translation units to contain copies of DECL, in
734 the abstract. */
736 void
738 {
741 }
743 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
744 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
745 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
747 static tree
749 {
750 tree decl;
753 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
754 now to avoid confusion in mangle_decl. */
763 /* At one time the vtable info was grabbed 2 words at a time. This
764 fails on sparc unless you have 8-byte alignment. (tiemann) */
768 /* The vtable has not been defined -- yet. */
772 /* Mark the VAR_DECL node representing the vtable itself as a
773 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
774 is rather important that such things be ignored because any
775 effort to actually generate DWARF for them will run into
776 trouble when/if we encounter code like:
778 #pragma interface
779 struct S { virtual void member (); };
781 because the artificial declaration of the vtable itself (as
782 manufactured by the g++ front end) will say that the vtable is
783 a static member of `S' but only *after* the debug output for
784 the definition of `S' has already been output. This causes
785 grief because the DWARF entry for the definition of the vtable
786 will try to refer back to an earlier *declaration* of the
787 vtable as a static member of `S' and there won't be one. We
788 might be able to arrange to have the "vtable static member"
789 attached to the member list for `S' before the debug info for
790 `S' get written (which would solve the problem) but that would
791 require more intrusive changes to the g++ front end. */
795 }
797 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
798 or even complete. If this does not exist, create it. If COMPLETE is
799 nonzero, then complete the definition of it -- that will render it
800 impossible to actually build the vtable, but is useful to get at those
801 which are known to exist in the runtime. */
803 tree
805 {
806 tree decl;
815 {
818 }
821 }
823 /* Build the primary virtual function table for TYPE. If BINFO is
824 non-NULL, build the vtable starting with the initial approximation
825 that it is the same as the one which is the head of the association
826 list. Returns a nonzero value if a new vtable is actually
827 created. */
829 static int
831 {
832 tree decl;
833 tree virtuals;
838 {
840 /* We have already created a vtable for this base, so there's
841 no need to do it again. */
848 }
849 else
850 {
853 }
856 {
859 }
861 /* Initialize the association list for this type, based
862 on our first approximation. */
867 }
869 /* Give BINFO a new virtual function table which is initialized
870 with a skeleton-copy of its original initialization. The only
871 entry that changes is the `delta' entry, so we can really
872 share a lot of structure.
874 FOR_TYPE is the most derived type which caused this table to
875 be needed.
877 Returns nonzero if we haven't met BINFO before.
879 The order in which vtables are built (by calling this function) for
880 an object must remain the same, otherwise a binary incompatibility
881 can result. */
883 static int
885 {
887 /* We already created a vtable for this base. There's no need to
888 do it again. */
891 /* Remember that we've created a vtable for this BINFO, so that we
892 don't try to do so again. */
895 /* Make fresh virtual list, so we can smash it later. */
898 /* Secondary vtables are laid out as part of the same structure as
899 the primary vtable. */
902 }
904 /* Create a new vtable for BINFO which is the hierarchy dominated by
905 T. Return nonzero if we actually created a new vtable. */
907 static int
909 {
911 /* In this case, it is *type*'s vtable we are modifying. We start
912 with the approximation that its vtable is that of the
913 immediate base class. */
915 else
916 /* This is our very own copy of `basetype' to play with. Later,
917 we will fill in all the virtual functions that override the
918 virtual functions in these base classes which are not defined
919 by the current type. */
921 }
923 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
924 (which is in the hierarchy dominated by T) list FNDECL as its
925 BV_FN. DELTA is the required constant adjustment from the `this'
926 pointer where the vtable entry appears to the `this' required when
927 the function is actually called. */
929 static void
931 tree binfo,
932 tree fndecl,
933 tree delta,
935 {
936 tree v;
942 {
943 /* We need a new vtable for BINFO. */
945 {
946 /* If we really did make a new vtable, we also made a copy
947 of the BINFO_VIRTUALS list. Now, we have to find the
948 corresponding entry in that list. */
953 }
958 }
959 }
961 // Returns the template associated with the member FN or
962 // NULL if the declaration is neither a template nor temploid.
965 {
971 }
973 // Returns true if NEWDECL and OLDDECL are member functions with with
974 // different constraints. If NEWDECL and OLDDECL are non-template members
975 // or specializations of non-template members, the overloads are
976 // differentiated by the template constraints.
977 //
978 // Note that the types of the functions are assumed to be equivalent.
981 {
985 // If neither is a template or temploid, then they cannot
986 // be constrained declarations.
989 else
991 }
993 \f
994 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
995 the USING_DECL naming METHOD. Returns true if the method could be
996 added to the method vec. */
998 bool
1000 {
1002 tree overload;
1008 tree current_fns;
1009 tree fns;
1022 {
1023 /* Make a new method vector. We start with 8 entries. We must
1024 allocate at least two (for constructors and destructors), and
1025 we're going to end up with an assignment operator at some
1026 point as well. */
1028 /* Create slots for constructors and destructors. */
1032 }
1034 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1037 /* Constructors and destructors go in special slots. */
1041 {
1045 {
1051 type);
1052 }
1053 }
1054 else
1055 {
1056 tree m;
1059 /* See if we already have an entry with this name. */
1063 {
1066 {
1071 }
1075 {
1078 }
1083 }
1084 }
1087 /* Check to see if we've already got this method. */
1089 {
1091 tree fn_type;
1092 tree method_type;
1093 tree parms1;
1094 tree parms2;
1099 /* [over.load] Member function declarations with the
1100 same name and the same parameter types cannot be
1101 overloaded if any of them is a static member
1102 function declaration.
1104 [over.load] Member function declarations with the same name and
1105 the same parameter-type-list as well as member function template
1106 declarations with the same name, the same parameter-type-list, and
1107 the same template parameter lists cannot be overloaded if any of
1108 them, but not all, have a ref-qualifier.
1110 [namespace.udecl] When a using-declaration brings names
1111 from a base class into a derived class scope, member
1112 functions in the derived class override and/or hide member
1113 functions with the same name and parameter types in a base
1114 class (rather than conflicting). */
1120 /* Compare the quals on the 'this' parm. Don't compare
1121 the whole types, as used functions are treated as
1122 coming from the using class in overload resolution. */
1125 /* Either both or neither need to be ref-qualified for
1126 differing quals to allow overloading. */
1133 /* For templates, the return type and template parameters
1134 must be identical. */
1151 {
1152 /* For function versions, their parms and types match
1153 but they are not duplicates. Record function versions
1154 as and when they are found. extern "C" functions are
1155 not treated as versions. */
1161 {
1162 /* Mark functions as versions if necessary. Modify the mangled
1163 decl name if necessary. */
1165 {
1169 }
1171 {
1175 }
1178 }
1180 {
1182 {
1189 }
1190 /* Otherwise defer to the other function. */
1192 }
1194 {
1196 /* Defer to the local function. */
1198 }
1201 else
1202 {
1205 }
1207 /* We don't call duplicate_decls here to merge the
1208 declarations because that will confuse things if the
1209 methods have inline definitions. In particular, we
1210 will crash while processing the definitions. */
1212 }
1213 }
1215 /* A class should never have more than one destructor. */
1219 /* Add the new binding. */
1221 {
1224 }
1225 else
1234 {
1237 /* We only expect to add few methods in the COMPLETE_P case, so
1238 just make room for one more method in that case. */
1241 else
1247 else
1249 }
1250 else
1251 /* Replace the current slot. */
1254 }
1256 /* Subroutines of finish_struct. */
1258 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1259 legit, otherwise return 0. */
1261 static int
1263 {
1264 tree elem;
1273 {
1275 {
1279 else
1282 }
1283 else
1284 {
1285 /* They're changing the access to the same thing they changed
1286 it to before. That's OK. */
1287 ;
1288 }
1289 }
1290 else
1291 {
1293 tf_warning_or_error);
1296 }
1298 }
1300 /* Process the USING_DECL, which is a member of T. */
1302 static void
1304 {
1307 tree access
1312 tree old_value;
1317 tf_warning_or_error);
1319 {
1325 else
1327 }
1335 ;
1337 {
1339 /* It's OK to use functions from a base when there are functions with
1341 else
1342 {
1347 }
1348 }
1350 {
1354 }
1356 /* Make type T see field decl FDECL with access ACCESS. */
1359 {
1362 }
1363 else
1365 }
1366 \f
1367 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1368 types with abi tags, add the corresponding identifiers to the VEC in
1369 *DATA and set IDENTIFIER_MARKED. */
1371 struct abi_tag_data
1372 {
1373 tree t;
1374 tree subob;
1375 };
1377 static tree
1379 {
1384 {
1388 {
1392 {
1394 {
1399 }
1400 else
1401 {
1408 }
1409 }
1410 }
1411 }
1413 }
1415 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1416 complete) template arguments. */
1418 static void
1420 {
1423 {
1426 {
1430 }
1431 }
1433 /* Also mark ABI tags from template arguments. */
1435 {
1438 {
1441 {
1445 }
1446 }
1447 }
1448 }
1450 /* Check that class T has all the abi tags that subobject SUBOB has, or
1451 warn if not. */
1453 static void
1455 {
1464 }
1466 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1467 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1468 properties of the bases. */
1470 static void
1474 {
1478 tree base_binfo;
1479 tree binfo;
1489 {
1498 /* If any base class is non-literal, so is the derived class. */
1502 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1503 here because the case of virtual functions but non-virtual
1504 dtor is handled in finish_struct_1. */
1509 /* If the base class doesn't have copy constructors or
1510 assignment operators that take const references, then the
1511 derived class cannot have such a member automatically
1512 generated. */
1521 /* A virtual base does not effect nearly emptiness. */
1522 ;
1524 {
1526 /* And if there is more than one nearly empty base, then the
1527 derived class is not nearly empty either. */
1529 else
1530 /* Remember we've seen one. */
1532 }
1534 /* If the base class is not empty or nearly empty, then this
1535 class cannot be nearly empty. */
1538 /* A lot of properties from the bases also apply to the derived
1539 class. */
1556 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1559 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1563 /* A standard-layout class is a class that:
1564 ...
1565 * has no non-standard-layout base classes, */
1568 {
1569 tree basefield;
1570 /* ...has no base classes of the same type as the first non-static
1571 data member... */
1573 && (same_type_ignoring_top_level_qualifiers_p
1576 else
1577 /* ...either has no non-static data members in the most-derived
1578 class and at most one base class with non-static data
1579 members, or has no base classes with non-static data
1580 members */
1584 {
1587 else
1590 }
1591 }
1593 /* Don't bother collecting tm attributes if transactional memory
1594 support is not enabled. */
1596 {
1600 }
1603 }
1605 /* If one of the base classes had TM attributes, and the current class
1606 doesn't define its own, then the current class inherits one. */
1608 {
1611 }
1612 }
1614 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1615 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1616 that have had a nearly-empty virtual primary base stolen by some
1617 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1618 T. */
1620 static void
1622 {
1626 tree base_binfo;
1628 /* Determine the primary bases of our bases. */
1631 {
1634 /* See if we're the non-virtual primary of our inheritance
1635 chain. */
1637 {
1644 /* We are the primary binfo. */
1646 }
1647 /* Determine if we have a virtual primary base, and mark it so.
1648 */
1650 {
1654 /* Someone already claimed this base. */
1656 else
1657 {
1658 tree delta;
1663 /* A virtual binfo might have been copied from within
1664 another hierarchy. As we're about to use it as a
1665 primary base, make sure the offsets match. */
1673 }
1674 }
1675 }
1677 /* First look for a dynamic direct non-virtual base. */
1679 {
1683 {
1686 }
1687 }
1689 /* A "nearly-empty" virtual base class can be the primary base
1690 class, if no non-virtual polymorphic base can be found. Look for
1691 a nearly-empty virtual dynamic base that is not already a primary
1692 base of something in the hierarchy. If there is no such base,
1693 just pick the first nearly-empty virtual base. */
1699 {
1701 {
1702 /* Found one that is not primary. */
1705 }
1707 /* Remember the first candidate. */
1709 }
1711 found:
1712 /* If we've got a primary base, use it. */
1714 {
1719 /* We are stealing a primary base. */
1723 {
1724 tree delta;
1727 /* A virtual binfo might have been copied from within
1728 another hierarchy. As we're about to use it as a primary
1729 base, make sure the offsets match. */
1734 }
1741 }
1742 }
1744 /* Update the variant types of T. */
1746 void
1748 {
1749 tree variants;
1755 variants;
1757 {
1758 /* These fields are in the _TYPE part of the node, not in
1759 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1769 /* Copy whatever these are holding today. */
1773 }
1774 }
1776 /* Early variant fixups: we apply attributes at the beginning of the class
1777 definition, and we need to fix up any variants that have already been
1778 made via elaborated-type-specifier so that check_qualified_type works. */
1780 void
1782 {
1783 tree variants;
1789 variants;
1791 {
1792 /* These are the two fields that check_qualified_type looks at and
1793 are affected by attributes. */
1796 }
1797 }
1798 \f
1799 /* Set memoizing fields and bits of T (and its variants) for later
1800 use. */
1802 static void
1804 {
1805 /* Fix up variants (if any). */
1809 /* For a class w/o baseclasses, 'finish_struct' has set
1810 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1811 Similarly for a class whose base classes do not have vtables.
1812 When neither of these is true, we might have removed abstract
1813 virtuals (by providing a definition), added some (by declaring
1814 new ones), or redeclared ones from a base class. We need to
1815 recalculate what's really an abstract virtual at this point (by
1816 looking in the vtables). */
1819 /* If this type has a copy constructor or a destructor, force its
1820 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1821 nonzero. This will cause it to be passed by invisible reference
1822 and prevent it from being returned in a register. */
1825 {
1826 tree variants;
1829 {
1832 }
1833 }
1834 }
1836 /* Issue warnings about T having private constructors, but no friends,
1837 and so forth.
1839 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1840 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1841 non-private static member functions. */
1843 static void
1845 {
1848 tree fn;
1851 /* If the class has friends, those entities might create and
1852 access instances, so we should not warn. */
1855 /* We will have warned when the template was declared; there's
1856 no need to warn on every instantiation. */
1858 /* There's no reason to even consider warning about this
1859 class. */
1862 /* We only issue one warning, if more than one applies, because
1863 otherwise, on code like:
1865 class A {
1866 // Oops - forgot `public:'
1867 A();
1868 A(const A&);
1869 ~A();
1870 };
1872 we warn several times about essentially the same problem. */
1874 /* Check to see if all (non-constructor, non-destructor) member
1875 functions are private. (Since there are no friends or
1876 non-private statics, we can't ever call any of the private member
1877 functions.) */
1879 /* We're not interested in compiler-generated methods; they don't
1880 provide any way to call private members. */
1882 {
1884 {
1886 /* A non-private static member function is just like a
1887 friend; it can create and invoke private member
1888 functions, and be accessed without a class
1889 instance. */
1893 /* Keep searching for a static member function. */
1894 }
1897 }
1900 {
1901 /* There are no non-private methods, and there's at least one
1902 private member function that isn't a constructor or
1903 destructor. (If all the private members are
1904 constructors/destructors we want to use the code below that
1905 issues error messages specifically referring to
1906 constructors/destructors.) */
1912 {
1915 }
1917 {
1921 }
1922 }
1924 /* Even if some of the member functions are non-private, the class
1925 won't be useful for much if all the constructors or destructors
1926 are private: such an object can never be created or destroyed. */
1929 {
1932 t);
1934 }
1936 /* Warn about classes that have private constructors and no friends. */
1938 /* Implicitly generated constructors are always public. */
1941 {
1944 /* If a non-template class does not define a copy
1945 constructor, one is defined for it, enabling it to avoid
1946 this warning. For a template class, this does not
1947 happen, and so we would normally get a warning on:
1949 template <class T> class C { private: C(); };
1951 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1952 complete non-template or fully instantiated classes have this
1953 flag set. */
1956 else
1958 {
1960 /* Ideally, we wouldn't count copy constructors (or, in
1961 fact, any constructor that takes an argument of the
1962 class type as a parameter) because such things cannot
1963 be used to construct an instance of the class unless
1964 you already have one. But, for now at least, we're
1965 more generous. */
1967 {
1970 }
1971 }
1974 {
1977 t);
1979 }
1980 }
1981 }
1984 gt_pointer_operator new_value;
1988 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1990 static int
1992 {
2005 }
2007 /* This routine compares two fields like method_name_cmp but using the
2008 pointer operator in resort_field_decl_data. */
2010 static int
2012 {
2021 {
2028 }
2030 }
2032 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2034 void
2037 gt_pointer_operator new_value,
2039 {
2043 tree fn;
2045 /* The type conversion ops have to live at the front of the vec, so we
2046 can't sort them. */
2054 {
2058 resort_method_name_cmp);
2059 }
2060 }
2062 /* Warn about duplicate methods in fn_fields.
2064 Sort methods that are not special (i.e., constructors, destructors,
2065 and type conversion operators) so that we can find them faster in
2066 search. */
2068 static void
2070 {
2071 tree fn_fields;
2081 /* Clear DECL_IN_AGGR_P for all functions. */
2086 /* Issue warnings about private constructors and such. If there are
2087 no methods, then some public defaults are generated. */
2090 /* The type conversion ops have to live at the front of the vec, so we
2091 can't sort them. */
2100 }
2102 /* Make BINFO's vtable have N entries, including RTTI entries,
2103 vbase and vcall offsets, etc. Set its type and call the back end
2104 to lay it out. */
2106 static void
2108 {
2109 tree atype;
2110 tree vtable;
2115 /* We may have to grow the vtable. */
2118 {
2122 }
2123 }
2125 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2126 have the same signature. */
2128 int
2130 {
2131 /* One destructor overrides another if they are the same kind of
2132 destructor. */
2136 /* But a non-destructor never overrides a destructor, nor vice
2137 versa, nor do different kinds of destructors override
2138 one-another. For example, a complete object destructor does not
2139 override a deleting destructor. */
2148 {
2156 }
2158 }
2160 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2161 subobject. */
2163 static bool
2165 {
2166 tree probe;
2169 {
2173 /* If we meet a virtual base, we can't follow the inheritance
2174 any more. See if the complete type of DERIVED contains
2175 such a virtual base. */
2178 }
2180 }
2183 /* The function for which we are trying to find a final overrider. */
2184 tree fn;
2185 /* The base class in which the function was declared. */
2186 tree declaring_base;
2187 /* The candidate overriders. */
2188 tree candidates;
2189 /* Path to most derived. */
2193 /* Add the overrider along the current path to FFOD->CANDIDATES.
2194 Returns true if an overrider was found; false otherwise. */
2196 static bool
2200 {
2201 tree method;
2203 /* If BINFO is not the most derived type, try a more derived class.
2204 A definition there will overrider a definition here. */
2206 {
2207 depth--;
2211 }
2215 {
2218 /* Remove any candidates overridden by this new function. */
2220 {
2221 /* If *CANDIDATE overrides METHOD, then METHOD
2222 cannot override anything else on the list. */
2225 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2228 else
2230 }
2232 /* Add the new function. */
2235 }
2238 }
2240 /* Called from find_final_overrider via dfs_walk. */
2242 static tree
2244 {
2252 }
2254 static tree
2256 {
2261 }
2263 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2264 FN and whose TREE_VALUE is the binfo for the base where the
2265 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2266 DERIVED) is the base object in which FN is declared. */
2268 static tree
2270 {
2271 find_final_overrider_data ffod;
2273 /* Getting this right is a little tricky. This is valid:
2275 struct S { virtual void f (); };
2276 struct T { virtual void f (); };
2277 struct U : public S, public T { };
2279 even though calling `f' in `U' is ambiguous. But,
2281 struct R { virtual void f(); };
2282 struct S : virtual public R { virtual void f (); };
2283 struct T : virtual public R { virtual void f (); };
2284 struct U : public S, public T { };
2286 is not -- there's no way to decide whether to put `S::f' or
2287 `T::f' in the vtable for `R'.
2289 The solution is to look at all paths to BINFO. If we find
2290 different overriders along any two, then there is a problem. */
2294 /* Determine the depth of the hierarchy. */
2305 /* If there was no winner, issue an error message. */
2310 }
2312 /* Return the index of the vcall offset for FN when TYPE is used as a
2313 virtual base. */
2315 static tree
2317 {
2319 tree_pair_p p;
2327 /* There should always be an appropriate index. */
2329 }
2331 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2332 dominated by T. FN is the old function; VIRTUALS points to the
2333 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2334 of that entry in the list. */
2336 static void
2339 {
2340 tree b;
2341 tree overrider;
2342 tree delta;
2343 tree virtual_base;
2344 tree first_defn;
2350 /* Find the nearest primary base (possibly binfo itself) which defines
2351 this function; this is the class the caller will convert to when
2352 calling FN through BINFO. */
2354 {
2359 /* The nearest definition is from a lost primary. */
2362 }
2365 /* Find the final overrider. */
2368 {
2371 }
2374 /* Check for adjusting covariant return types. */
2382 /* If the overrider is invalid, don't even try. */
2384 {
2385 /* If FN is a covariant thunk, we must figure out the adjustment
2386 to the final base FN was converting to. As OVERRIDER_TARGET might
2387 also be converting to the return type of FN, we have to
2388 combine the two conversions here. */
2395 {
2399 }
2400 else
2404 /* Find the equivalent binfo within the return type of the
2405 overriding function. We will want the vbase offset from
2406 there. */
2408 over_return);
2411 {
2412 /* There was no existing virtual thunk (which takes
2413 precedence). So find the binfo of the base function's
2414 return type within the overriding function's return type.
2415 We cannot call lookup base here, because we're inside a
2416 dfs_walk, and will therefore clobber the BINFO_MARKED
2417 flags. Fortunately we know the covariancy is valid (it
2418 has already been checked), so we can just iterate along
2419 the binfos, which have been chained in inheritance graph
2420 order. Of course it is lame that we have to repeat the
2421 search here anyway -- we should really be caching pieces
2422 of the vtable and avoiding this repeated work. */
2425 /* Find the base binfo within the overriding function's
2426 return type. We will always find a thunk_binfo, except
2427 when the covariancy is invalid (which we will have
2428 already diagnosed). */
2431 thunk_binfo;
2437 /* See if virtual inheritance is involved. */
2439 virtual_offset;
2446 {
2450 {
2451 /* We convert via virtual base. Adjust the fixed
2452 offset to be from there. */
2453 offset =
2457 }
2459 /* There was an existing fixed offset, this must be
2460 from the base just converted to, and the base the
2461 FN was thunking to. */
2463 else
2465 }
2466 }
2469 /* Replace the overriding function with a covariant thunk. We
2470 will emit the overriding function in its own slot as
2471 well. */
2474 }
2475 else
2479 /* If we need a covariant thunk, then we may need to adjust first_defn.
2480 The ABI specifies that the thunks emitted with a function are
2481 determined by which bases the function overrides, so we need to be
2482 sure that we're using a thunk for some overridden base; even if we
2483 know that the necessary this adjustment is zero, there may not be an
2484 appropriate zero-this-adjusment thunk for us to use since thunks for
2485 overriding virtual bases always use the vcall offset.
2487 Furthermore, just choosing any base that overrides this function isn't
2488 quite right, as this slot won't be used for calls through a type that
2489 puts a covariant thunk here. Calling the function through such a type
2490 will use a different slot, and that slot is the one that determines
2491 the thunk emitted for that base.
2493 So, keep looking until we find the base that we're really overriding
2494 in this slot: the nearest primary base that doesn't use a covariant
2495 thunk in this slot. */
2497 {
2499 /* We already know that the overrider needs a covariant thunk. */
2502 {
2509 }
2511 }
2513 /* Assume that we will produce a thunk that convert all the way to
2514 the final overrider, and not to an intermediate virtual base. */
2517 /* See if we can convert to an intermediate virtual base first, and then
2518 use the vcall offset located there to finish the conversion. */
2520 {
2521 /* If we find the final overrider, then we can stop
2522 walking. */
2527 /* If we find a virtual base, and we haven't yet found the
2528 overrider, then there is a virtual base between the
2529 declaring base (first_defn) and the final overrider. */
2531 {
2534 }
2535 }
2537 /* Compute the constant adjustment to the `this' pointer. The
2538 `this' pointer, when this function is called, will point at BINFO
2539 (or one of its primary bases, which are at the same offset). */
2541 /* The `this' pointer needs to be adjusted from the declaration to
2542 the nearest virtual base. */
2547 /* If the nearest definition is in a lost primary, we don't need an
2548 entry in our vtable. Except possibly in a constructor vtable,
2549 if we happen to get our primary back. In that case, the offset
2550 will be zero, as it will be a primary base. */
2552 else
2553 /* The `this' pointer needs to be adjusted from pointing to
2554 BINFO to pointing at the base where the final overrider
2555 appears. */
2566 else
2570 }
2572 /* Called from modify_all_vtables via dfs_walk. */
2574 static tree
2576 {
2578 tree virtuals;
2579 tree old_virtuals;
2583 /* A base without a vtable needs no modification, and its bases
2584 are uninteresting. */
2589 /* Don't do the primary vtable, if it's new. */
2593 /* There's no need to modify the vtable for a non-virtual primary
2594 base; we're not going to use that vtable anyhow. We do still
2595 need to do this for virtual primary bases, as they could become
2596 non-primary in a construction vtable. */
2601 /* Now, go through each of the virtual functions in the virtual
2602 function table for BINFO. Find the final overrider, and update
2603 the BINFO_VIRTUALS list appropriately. */
2606 virtuals;
2610 binfo,
2615 }
2617 /* Update all of the primary and secondary vtables for T. Create new
2618 vtables as required, and initialize their RTTI information. Each
2619 of the functions in VIRTUALS is declared in T and may override a
2620 virtual function from a base class; find and modify the appropriate
2621 entries to point to the overriding functions. Returns a list, in
2622 declaration order, of the virtual functions that are declared in T,
2623 but do not appear in the primary base class vtable, and which
2624 should therefore be appended to the end of the vtable for T. */
2626 static tree
2628 {
2632 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2636 /* Update all of the vtables. */
2639 /* Add virtual functions not already in our primary vtable. These
2640 will be both those introduced by this class, and those overridden
2641 from secondary bases. It does not include virtuals merely
2642 inherited from secondary bases. */
2644 {
2649 {
2650 /* We don't need to adjust the `this' pointer when
2651 calling this function. */
2655 /* This is a function not already in our vtable. Keep it. */
2657 }
2658 else
2659 /* We've already got an entry for this function. Skip it. */
2661 }
2664 }
2666 /* Get the base virtual function declarations in T that have the
2667 indicated NAME. */
2669 static tree
2671 {
2672 tree methods;
2677 /* Find virtual functions in T with the indicated NAME. */
2681 methods;
2683 {
2689 }
2695 {
2698 base_fndecls);
2699 }
2702 }
2704 /* If this declaration supersedes the declaration of
2705 a method declared virtual in the base class, then
2706 mark this field as being virtual as well. */
2708 void
2710 {
2713 /* In [temp.mem] we have:
2715 A specialization of a member function template does not
2716 override a virtual function from a base class. */
2723 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2724 the error_mark_node so that we know it is an overriding
2725 function. */
2726 {
2729 }
2732 {
2738 }
2743 }
2745 /* Warn about hidden virtual functions that are not overridden in t.
2746 We know that constructors and destructors don't apply. */
2748 static void
2750 {
2752 tree fns;
2755 /* We go through each separately named virtual function. */
2759 {
2760 tree fn;
2761 tree name;
2762 tree fndecl;
2763 tree base_fndecls;
2764 tree base_binfo;
2765 tree binfo;
2768 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2769 have the same name. Figure out what name that is. */
2771 /* There are no possibly hidden functions yet. */
2773 /* Iterate through all of the base classes looking for possibly
2774 hidden functions. */
2777 {
2780 base_fndecls);
2781 }
2783 /* If there are no functions to hide, continue. */
2787 /* Remove any overridden functions. */
2789 {
2792 {
2796 /* If the method from the base class has the same
2797 signature as the method from the derived class, it
2798 has been overridden. */
2801 else
2803 }
2804 }
2806 /* Now give a warning for all base functions without overriders,
2807 as they are hidden. */
2809 {
2810 /* Here we know it is a hider, and no overrider exists. */
2814 }
2815 }
2816 }
2818 /* Recursive helper for finish_struct_anon. */
2820 static void
2822 {
2826 {
2827 /* We're generally only interested in entities the user
2828 declared, but we also find nested classes by noticing
2829 the TYPE_DECL that we create implicitly. You're
2830 allowed to put one anonymous union inside another,
2831 though, so we explicitly tolerate that. We use
2832 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2833 we also allow unnamed types used for defining fields. */
2840 {
2842 {
2845 "%q+#D invalid; an anonymous union can "
2847 else
2849 "%q+#D invalid; an anonymous struct can "
2851 }
2853 }
2856 {
2858 {
2862 else
2865 }
2867 {
2871 else
2874 }
2875 }
2880 /* Recurse into the anonymous aggregates to handle correctly
2881 access control (c++/24926):
2883 class A {
2884 union {
2885 union {
2886 int i;
2887 };
2888 };
2889 };
2891 int j=A().i; */
2895 }
2896 }
2898 /* Check for things that are invalid. There are probably plenty of other
2899 things we should check for also. */
2901 static void
2903 {
2905 {
2914 }
2915 }
2917 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2918 will be used later during class template instantiation.
2919 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2920 a non-static member data (FIELD_DECL), a member function
2921 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2922 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2923 When FRIEND_P is nonzero, T is either a friend class
2924 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2925 (FUNCTION_DECL, TEMPLATE_DECL). */
2927 void
2929 {
2930 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2935 }
2937 /* This function is called from declare_virt_assop_and_dtor via
2938 dfs_walk_all.
2940 DATA is a type that direcly or indirectly inherits the base
2941 represented by BINFO. If BINFO contains a virtual assignment [copy
2942 assignment or move assigment] operator or a virtual constructor,
2943 declare that function in DATA if it hasn't been already declared. */
2945 static tree
2947 {
2955 /* A base without a vtable needs no modification, and its bases
2956 are uninteresting. */
2960 /* If this is a primary base, then we have already looked at the
2961 virtual functions of its vtable. */
2965 {
2969 {
2974 }
2978 }
2981 }
2983 /* If the class type T has a direct or indirect base that contains a
2984 virtual assignment operator or a virtual destructor, declare that
2985 function in T if it hasn't been already declared. */
2987 static void
2989 {
2997 dfs_declare_virt_assop_and_dtor,
2999 }
3001 /* Declare the inheriting constructor for class T inherited from base
3002 constructor CTOR with the parameter array PARMS of size NPARMS. */
3004 static void
3006 {
3007 /* We don't declare an inheriting ctor that would be a default,
3008 copy or move ctor for derived or base. */
3013 {
3017 }
3025 {
3028 }
3029 }
3031 /* Declare all the inheriting constructors for class T inherited from base
3032 constructor CTOR. */
3034 static void
3036 {
3042 {
3046 }
3049 {
3053 }
3054 }
3056 /* Create default constructors, assignment operators, and so forth for
3057 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3058 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3059 the class cannot have a default constructor, copy constructor
3060 taking a const reference argument, or an assignment operator taking
3061 a const reference, respectively. */
3063 static void
3067 {
3075 /* Destructor. */
3077 {
3078 /* In general, we create destructors lazily. */
3083 /* But if this is a Java class, any non-trivial destructor is
3084 invalid, even if compiler-generated. Therefore, if the
3085 destructor is non-trivial we create it now. */
3087 }
3089 /* [class.ctor]
3091 If there is no user-declared constructor for a class, a default
3092 constructor is implicitly declared. */
3094 {
3099 /* This might force the declaration. */
3101 }
3103 /* [class.ctor]
3105 If a class definition does not explicitly declare a copy
3106 constructor, one is declared implicitly. */
3108 {
3114 }
3116 /* If there is no assignment operator, one will be created if and
3117 when it is needed. For now, just record whether or not the type
3118 of the parameter to the assignment operator will be a const or
3119 non-const reference. */
3121 {
3127 }
3129 /* We can't be lazy about declaring functions that might override
3130 a virtual function from a base class. */
3134 {
3138 {
3139 /* declare, then remove the decl */
3148 }
3149 else
3151 }
3152 }
3154 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3155 count the number of fields in TYPE, including anonymous union
3156 members. */
3158 static int
3160 {
3161 tree x;
3164 {
3167 else
3169 }
3171 }
3173 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3174 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3175 elts, starting at offset IDX. */
3177 static int
3179 {
3180 tree x;
3182 {
3185 else
3187 }
3189 }
3191 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3192 starting at offset IDX. */
3194 static int
3198 {
3199 tree values;
3203 }
3205 /* FIELD is a bit-field. We are finishing the processing for its
3206 enclosing type. Issue any appropriate messages and set appropriate
3207 flags. Returns false if an error has been diagnosed. */
3209 static bool
3211 {
3213 tree w;
3215 /* Extract the declared width of the bitfield, which has been
3216 temporarily stashed in DECL_INITIAL. */
3219 /* Remove the bit-field width indicator so that the rest of the
3220 compiler does not treat that value as an initializer. */
3223 /* Detect invalid bit-field type. */
3225 {
3228 }
3229 else
3230 {
3232 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3235 /* detect invalid field size. */
3241 {
3244 }
3246 {
3249 }
3251 {
3254 }
3266 }
3269 {
3273 }
3274 else
3275 {
3276 /* Non-bit-fields are aligned for their type. */
3280 }
3281 }
3283 /* FIELD is a non bit-field. We are finishing the processing for its
3284 enclosing type T. Issue any appropriate messages and set appropriate
3285 flags. */
3287 static void
3289 tree t,
3293 {
3296 /* In C++98 an anonymous union cannot contain any fields which would change
3297 the settings of CANT_HAVE_CONST_CTOR and friends. */
3299 ;
3300 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3301 structs. So, we recurse through their fields here. */
3303 {
3304 tree fields;
3310 }
3311 /* Check members with class type for constructors, destructors,
3312 etc. */
3314 {
3315 /* Never let anything with uninheritable virtuals
3316 make it through without complaint. */
3320 {
3325 field);
3330 field);
3332 {
3336 }
3337 }
3338 else
3339 {
3352 }
3361 }
3366 {
3367 /* `build_class_init_list' does not recognize
3368 non-FIELD_DECLs. */
3372 }
3373 }
3375 /* Check the data members (both static and non-static), class-scoped
3376 typedefs, etc., appearing in the declaration of T. Issue
3377 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3378 declaration order) of access declarations; each TREE_VALUE in this
3379 list is a USING_DECL.
3381 In addition, set the following flags:
3383 EMPTY_P
3384 The class is empty, i.e., contains no non-static data members.
3386 CANT_HAVE_CONST_CTOR_P
3387 This class cannot have an implicitly generated copy constructor
3388 taking a const reference.
3390 CANT_HAVE_CONST_ASN_REF
3391 This class cannot have an implicitly generated assignment
3392 operator taking a const reference.
3394 All of these flags should be initialized before calling this
3395 function.
3397 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3398 fields can be added by adding to this chain. */
3400 static void
3404 {
3412 /* Assume there are no access declarations. */
3414 /* Assume this class has no pointer members. */
3416 /* Assume none of the members of this class have default
3417 initializations. */
3421 {
3429 {
3430 /* Save the access declarations for our caller. */
3433 }
3439 /* If we've gotten this far, it's a data member, possibly static,
3440 or an enumerator. */
3444 /* When this goes into scope, it will be a non-local reference. */
3448 {
3449 /* [class.union]
3451 If a union contains a static data member, or a member of
3452 reference type, the program is ill-formed. */
3454 {
3457 }
3459 {
3464 }
3465 }
3467 /* Perform error checking that did not get done in
3468 grokdeclarator. */
3470 {
3474 }
3476 {
3480 }
3488 /* Now it can only be a FIELD_DECL. */
3493 /* If at least one non-static data member is non-literal, the whole
3494 class becomes non-literal. Note: if the type is incomplete we
3495 will complain later on. */
3499 /* A standard-layout class is a class that:
3500 ...
3501 has the same access control (Clause 11) for all non-static data members,
3502 ... */
3509 /* If this is of reference type, check if it needs an init. */
3511 {
3517 /* ARM $12.6.2: [A member initializer list] (or, for an
3518 aggregate, initialization by a brace-enclosed list) is the
3519 only way to initialize nonstatic const and reference
3520 members. */
3523 }
3528 {
3530 {
3531 warning
3534 x);
3536 }
3540 }
3543 /* We don't treat zero-width bitfields as making a class
3544 non-empty. */
3545 ;
3546 else
3547 {
3548 /* The class is non-empty. */
3550 /* The class is not even nearly empty. */
3552 /* If one of the data members contains an empty class,
3553 so does T. */
3557 }
3559 /* This is used by -Weffc++ (see below). Warn only for pointers
3560 to members which might hold dynamic memory. So do not warn
3561 for pointers to functions or pointers to members. */
3567 {
3572 }
3578 {
3580 {
3584 }
3586 {
3590 }
3591 }
3594 /* DR 148 now allows pointers to members (which are POD themselves),
3595 to be allowed in POD structs. */
3604 /* We set DECL_C_BIT_FIELD in grokbitfield.
3605 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3608 cant_have_const_ctor_p,
3609 no_const_asn_ref_p,
3612 /* Now that we've removed bit-field widths from DECL_INITIAL,
3613 anything left in DECL_INITIAL is an NSDMI that makes the class
3614 non-aggregate. */
3618 /* If any field is const, the structure type is pseudo-const. */
3620 {
3625 /* ARM $12.6.2: [A member initializer list] (or, for an
3626 aggregate, initialization by a brace-enclosed list) is the
3627 only way to initialize nonstatic const and reference
3628 members. */
3631 }
3632 /* A field that is pseudo-const makes the structure likewise. */
3634 {
3639 }
3641 /* Core issue 80: A nonstatic data member is required to have a
3642 different name from the class iff the class has a
3643 user-declared constructor. */
3647 }
3649 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3650 it should also define a copy constructor and an assignment operator to
3651 implement the correct copy semantic (deep vs shallow, etc.). As it is
3652 not feasible to check whether the constructors do allocate dynamic memory
3653 and store it within members, we approximate the warning like this:
3655 -- Warn only if there are members which are pointers
3656 -- Warn only if there is a non-trivial constructor (otherwise,
3657 there cannot be memory allocated).
3658 -- Warn only if there is a non-trivial destructor. We assume that the
3659 user at least implemented the cleanup correctly, and a destructor
3660 is needed to free dynamic memory.
3662 This seems enough for practical purposes. */
3664 && has_pointers
3668 {
3672 {
3677 }
3681 }
3683 /* Non-static data member initializers make the default constructor
3684 non-trivial. */
3686 {
3689 }
3691 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3695 /* Check anonymous struct/anonymous union fields. */
3698 /* We've built up the list of access declarations in reverse order.
3699 Fix that now. */
3701 }
3703 /* If TYPE is an empty class type, records its OFFSET in the table of
3704 OFFSETS. */
3706 static int
3708 {
3709 splay_tree_node n;
3714 /* Record the location of this empty object in OFFSETS. */
3722 type,
3726 }
3728 /* Returns nonzero if TYPE is an empty class type and there is
3729 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3731 static int
3733 {
3734 splay_tree_node n;
3735 tree t;
3740 /* Record the location of this empty object in OFFSETS. */
3750 }
3752 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3753 F for every subobject, passing it the type, offset, and table of
3754 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3755 be traversed.
3757 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3758 than MAX_OFFSET will not be walked.
3760 If F returns a nonzero value, the traversal ceases, and that value
3761 is returned. Otherwise, returns zero. */
3763 static int
3765 subobject_offset_fn f,
3766 tree offset,
3767 splay_tree offsets,
3768 tree max_offset,
3770 {
3774 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3775 stop. */
3783 {
3787 }
3790 {
3791 tree field;
3792 tree binfo;
3795 /* Avoid recursing into objects that are not interesting. */
3799 /* Record the location of TYPE. */
3804 /* Iterate through the direct base classes of TYPE. */
3808 {
3809 tree binfo_offset;
3822 offset,
3824 else
3825 {
3826 tree orig_binfo;
3827 /* We cannot rely on BINFO_OFFSET being set for the base
3828 class yet, but the offsets for direct non-virtual
3829 bases can be calculated by going back to the TYPE. */
3832 offset,
3834 }
3837 f,
3838 binfo_offset,
3839 offsets,
3840 max_offset,
3845 }
3848 {
3852 /* Iterate through the virtual base classes of TYPE. In G++
3853 3.2, we included virtual bases in the direct base class
3854 loop above, which results in incorrect results; the
3855 correct offsets for virtual bases are only known when
3856 working with the most derived type. */
3860 {
3862 f,
3864 offset,
3866 offsets,
3867 max_offset,
3871 }
3872 else
3873 {
3874 /* We still have to walk the primary base, if it is
3875 virtual. (If it is non-virtual, then it was walked
3876 above.) */
3882 {
3883 r = (walk_subobject_offsets
3888 }
3889 }
3890 }
3892 /* Iterate through the fields of TYPE. */
3897 {
3898 tree field_offset;
3902 else
3903 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3907 f,
3909 offset,
3910 field_offset),
3911 offsets,
3912 max_offset,
3916 }
3917 }
3919 {
3922 tree index;
3924 /* Avoid recursing into objects that are not interesting. */
3929 /* Step through each of the elements in the array. */
3931 /* G++ 3.2 had an off-by-one error here. */
3936 {
3938 f,
3939 offset,
3940 offsets,
3941 max_offset,
3947 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3948 there's no point in iterating through the remaining
3949 elements of the array. */
3952 }
3953 }
3956 }
3958 /* Record all of the empty subobjects of TYPE (either a type or a
3959 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3960 is being placed at OFFSET; otherwise, it is a base class that is
3961 being placed at OFFSET. */
3963 static void
3965 tree offset,
3966 splay_tree offsets,
3968 {
3969 tree max_offset;
3970 /* If recording subobjects for a non-static data member or a
3971 non-empty base class , we do not need to record offsets beyond
3972 the size of the biggest empty class. Additional data members
3973 will go at the end of the class. Additional base classes will go
3974 either at offset zero (if empty, in which case they cannot
3975 overlap with offsets past the size of the biggest empty class) or
3976 at the end of the class.
3978 However, if we are placing an empty base class, then we must record
3979 all offsets, as either the empty class is at offset zero (where
3980 other empty classes might later be placed) or at the end of the
3981 class (where other objects might then be placed, so other empty
3982 subobjects might later overlap). */
3986 else
3990 }
3992 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3993 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3994 virtual bases of TYPE are examined. */
3996 static int
3998 tree offset,
3999 splay_tree offsets,
4001 {
4002 splay_tree_node max_node;
4004 /* Get the node in OFFSETS that indicates the maximum offset where
4005 an empty subobject is located. */
4007 /* If there aren't any empty subobjects, then there's no point in
4008 performing this check. */
4014 vbases_p);
4015 }
4017 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4018 non-static data member of the type indicated by RLI. BINFO is the
4019 binfo corresponding to the base subobject, OFFSETS maps offsets to
4020 types already located at those offsets. This function determines
4021 the position of the DECL. */
4023 static void
4025 tree decl,
4026 tree binfo,
4027 splay_tree offsets)
4028 {
4031 tree type;
4034 {
4035 /* For the purposes of determining layout conflicts, we want to
4036 use the class type of BINFO; TREE_TYPE (DECL) will be the
4037 CLASSTYPE_AS_BASE version, which does not contain entries for
4038 zero-sized bases. */
4041 }
4042 else
4043 {
4046 }
4048 /* Try to place the field. It may take more than one try if we have
4049 a hard time placing the field without putting two objects of the
4050 same type at the same address. */
4052 {
4055 /* Place this field. */
4059 /* We have to check to see whether or not there is already
4060 something of the same type at the offset we're about to use.
4061 For example, consider:
4063 struct S {};
4064 struct T : public S { int i; };
4065 struct U : public S, public T {};
4067 Here, we put S at offset zero in U. Then, we can't put T at
4068 offset zero -- its S component would be at the same address
4069 as the S we already allocated. So, we have to skip ahead.
4070 Since all data members, including those whose type is an
4071 empty class, have nonzero size, any overlap can happen only
4072 with a direct or indirect base-class -- it can't happen with
4073 a data member. */
4074 /* In a union, overlap is permitted; all members are placed at
4075 offset zero. */
4078 /* G++ 3.2 did not check for overlaps when placing a non-empty
4079 virtual base. */
4084 {
4085 /* Strip off the size allocated to this field. That puts us
4086 at the first place we could have put the field with
4087 proper alignment. */
4090 /* Bump up by the alignment required for the type. */
4091 rli->bitpos
4097 }
4098 else
4099 /* There was no conflict. We're done laying out this field. */
4101 }
4103 /* Now that we know where it will be placed, update its
4104 BINFO_OFFSET. */
4106 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4107 this point because their BINFO_OFFSET is copied from another
4108 hierarchy. Therefore, we may not need to add the entire
4109 OFFSET. */
4115 }
4117 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4119 static int
4121 tree offset,
4123 {
4125 }
4127 /* Layout the empty base BINFO. EOC indicates the byte currently just
4128 past the end of the class, and should be correctly aligned for a
4129 class of the type indicated by BINFO; OFFSETS gives the offsets of
4130 the empty bases allocated so far. T is the most derived
4131 type. Return nonzero iff we added it at the end. */
4133 static bool
4136 {
4137 tree alignment;
4141 /* This routine should only be used for empty classes. */
4146 {
4148 propagate_binfo_offsets
4151 else
4153 "offset of empty base %qT may not be ABI-compliant and may"
4156 }
4158 /* This is an empty base class. We first try to put it at offset
4159 zero. */
4162 offsets,
4164 {
4165 /* That didn't work. Now, we move forward from the next
4166 available spot in the class. */
4170 {
4173 offsets,
4175 /* We finally found a spot where there's no overlap. */
4178 /* There's overlap here, too. Bump along to the next spot. */
4180 }
4181 }
4184 {
4189 }
4192 }
4194 /* Layout the base given by BINFO in the class indicated by RLI.
4195 *BASE_ALIGN is a running maximum of the alignments of
4196 any base class. OFFSETS gives the location of empty base
4197 subobjects. T is the most derived type. Return nonzero if the new
4198 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4199 *NEXT_FIELD, unless BINFO is for an empty base class.
4201 Returns the location at which the next field should be inserted. */
4206 {
4211 /* This error is now reported in xref_tag, thus giving better
4212 location information. */
4215 /* Place the base class. */
4217 {
4218 tree decl;
4220 /* The containing class is non-empty because it has a non-empty
4221 base class. */
4224 /* Create the FIELD_DECL. */
4231 {
4239 /* Try to place the field. It may take more than one try if we
4240 have a hard time placing the field without putting two
4241 objects of the same type at the same address. */
4243 /* Add the new FIELD_DECL to the list of fields for T. */
4247 }
4248 }
4249 else
4250 {
4251 tree eoc;
4254 /* On some platforms (ARM), even empty classes will not be
4255 byte-aligned. */
4260 /* A nearly-empty class "has no proper base class that is empty,
4261 not morally virtual, and at an offset other than zero." */
4263 {
4266 /* The check above (used in G++ 3.2) is insufficient because
4267 an empty class placed at offset zero might itself have an
4268 empty base at a nonzero offset. */
4270 empty_base_at_nonzero_offset_p,
4271 size_zero_node,
4275 {
4278 else
4280 "class %qT will be considered nearly empty in a "
4282 }
4283 }
4285 /* We do not create a FIELD_DECL for empty base classes because
4286 it might overlap some other field. We want to be able to
4287 create CONSTRUCTORs for the class by iterating over the
4288 FIELD_DECLs, and the back end does not handle overlapping
4289 FIELD_DECLs. */
4291 /* An empty virtual base causes a class to be non-empty
4292 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4293 here because that was already done when the virtual table
4294 pointer was created. */
4295 }
4297 /* Record the offsets of BINFO and its base subobjects. */
4300 offsets,
4304 }
4306 /* Layout all of the non-virtual base classes. Record empty
4307 subobjects in OFFSETS. T is the most derived type. Return nonzero
4308 if the type cannot be nearly empty. The fields created
4309 corresponding to the base classes will be inserted at
4310 *NEXT_FIELD. */
4312 static void
4315 {
4316 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4317 subobjects. */
4322 /* The primary base class is always allocated first. */
4327 /* Now allocate the rest of the bases. */
4329 {
4330 tree base_binfo;
4334 /* The primary base was already allocated above, so we don't
4335 need to allocate it again here. */
4339 /* Virtual bases are added at the end (a primary virtual base
4340 will have already been added). */
4346 }
4347 }
4349 /* Go through the TYPE_METHODS of T issuing any appropriate
4350 diagnostics, figuring out which methods override which other
4351 methods, and so forth. */
4353 static void
4355 {
4356 tree x;
4359 {
4363 /* The name of the field is the original field name
4364 Save this in auxiliary field for later overloading. */
4366 {
4370 }
4371 /* All user-provided destructors are non-trivial.
4372 Constructors and assignment ops are handled in
4373 grok_special_member_properties. */
4376 }
4377 }
4379 /* FN is a constructor or destructor. Clone the declaration to create
4380 a specialized in-charge or not-in-charge version, as indicated by
4381 NAME. */
4383 static tree
4385 {
4386 tree parms;
4387 tree clone;
4389 /* Copy the function. */
4391 /* Reset the function name. */
4394 /* Remember where this function came from. */
4396 /* Make it easy to find the CLONE given the FN. */
4400 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4402 {
4409 }
4412 /* There's no pending inline data for this function. */
4416 /* The base-class destructor is not virtual. */
4418 {
4422 }
4424 /* If there was an in-charge parameter, drop it from the function
4425 type. */
4427 {
4428 tree basetype;
4429 tree parmtypes;
4430 tree exceptions;
4435 /* Skip the `this' parameter. */
4437 /* Skip the in-charge parameter. */
4439 /* And the VTT parm, in a complete [cd]tor. */
4443 /* If this is subobject constructor or destructor, add the vtt
4444 parameter. */
4448 parmtypes);
4451 exceptions);
4455 }
4457 /* Copy the function parameters. */
4459 /* Remove the in-charge parameter. */
4461 {
4465 }
4466 /* And the VTT parm, in a complete [cd]tor. */
4468 {
4471 else
4472 {
4476 }
4477 }
4480 {
4483 }
4485 /* Create the RTL for this function. */
4493 }
4495 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4496 not invoke this function directly.
4498 For a non-thunk function, returns the address of the slot for storing
4499 the function it is a clone of. Otherwise returns NULL_TREE.
4501 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4502 cloned_function is unset. This is to support the separate
4503 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4504 on a template makes sense, but not the former. */
4506 tree *
4508 {
4516 {
4517 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4520 else
4521 #endif
4523 }
4528 else
4530 }
4532 /* Produce declarations for all appropriate clones of FN. If
4533 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4534 CLASTYPE_METHOD_VEC as well. */
4536 void
4538 {
4539 tree clone;
4541 /* Avoid inappropriate cloning. */
4547 {
4548 /* For each constructor, we need two variants: an in-charge version
4549 and a not-in-charge version. */
4556 }
4557 else
4558 {
4561 /* For each destructor, we need three variants: an in-charge
4562 version, a not-in-charge version, and an in-charge deleting
4563 version. We clone the deleting version first because that
4564 means it will go second on the TYPE_METHODS list -- and that
4565 corresponds to the correct layout order in the virtual
4566 function table.
4568 For a non-virtual destructor, we do not build a deleting
4569 destructor. */
4571 {
4575 }
4582 }
4584 /* Note that this is an abstract function that is never emitted. */
4586 }
4588 /* DECL is an in charge constructor, which is being defined. This will
4589 have had an in class declaration, from whence clones were
4590 declared. An out-of-class definition can specify additional default
4591 arguments. As it is the clones that are involved in overload
4592 resolution, we must propagate the information from the DECL to its
4593 clones. */
4595 void
4597 {
4598 tree clone;
4602 {
4609 /* Skip the 'this' parameter. */
4625 {
4630 {
4631 /* A default parameter has been added. Adjust the
4632 clone's parameters. */
4636 tree type;
4641 {
4644 clone_parms);
4646 }
4649 clone_parms);
4658 }
4659 }
4661 }
4662 }
4664 /* For each of the constructors and destructors in T, create an
4665 in-charge and not-in-charge variant. */
4667 static void
4669 {
4670 tree fns;
4672 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4673 out now. */
4681 }
4683 /* Deduce noexcept for a destructor DTOR. */
4685 void
4687 {
4689 {
4696 }
4697 }
4699 /* For each destructor in T, deduce noexcept:
4701 12.4/3: A declaration of a destructor that does not have an
4702 exception-specification is implicitly considered to have the
4703 same exception-specification as an implicit declaration (15.4). */
4705 static void
4707 {
4708 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4709 out now. */
4715 }
4717 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4718 of TYPE for virtual functions which FNDECL overrides. Return a
4719 mask of the tm attributes found therein. */
4721 static int
4723 {
4725 tree base_binfo;
4729 {
4739 else
4741 }
4744 }
4746 /* Subroutine of set_method_tm_attributes. Handle the checks and
4747 inheritance for one virtual method FNDECL. */
4749 static void
4751 {
4752 tree tm_attr;
4757 /* If FNDECL doesn't actually override anything (i.e. T is the
4758 class that first declares FNDECL virtual), then we're done. */
4765 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4766 tm_pure must match exactly, otherwise no weakening of
4767 tm_safe > tm_callable > nothing. */
4768 /* ??? The tm_pure attribute didn't make the transition to the
4769 multivendor language spec. */
4771 {
4773 {
4776 }
4777 }
4778 /* If the overridden function is tm_pure, then FNDECL must be. */
4781 /* Look for base class combinations that cannot be satisfied. */
4783 {
4789 }
4790 /* If FNDECL did not declare an attribute, then inherit the most
4791 restrictive one. */
4793 {
4795 }
4796 /* Otherwise validate that we're not weaker than a function
4797 that is being overridden. */
4798 else
4799 {
4803 }
4806 err_override:
4810 }
4812 /* For each of the methods in T, propagate a class-level tm attribute. */
4814 static void
4816 {
4819 /* Don't bother collecting tm attributes if transactional memory
4820 support is not enabled. */
4824 /* Process virtual methods first, as they inherit directly from the
4825 base virtual function and also require validation of new attributes. */
4827 {
4828 tree vchain;
4831 {
4836 }
4837 }
4839 /* If the class doesn't have an attribute, nothing more to do. */
4844 /* Any method that does not yet have a tm attribute inherits
4845 the one from the class. */
4847 {
4850 }
4851 }
4853 /* Returns true iff class T has a user-defined constructor other than
4854 the default constructor. */
4856 bool
4858 {
4859 tree fns;
4865 {
4872 }
4875 }
4877 /* Returns the defaulted constructor if T has one. Otherwise, returns
4878 NULL_TREE. */
4880 tree
4882 {
4889 {
4893 {
4899 }
4900 }
4903 }
4905 /* Returns true iff FN is a user-provided function, i.e. user-declared
4906 and not defaulted at its first declaration; or explicit, private,
4907 protected, or non-const. */
4909 bool
4911 {
4914 else
4918 }
4920 /* Returns true iff class T has a user-provided constructor. */
4922 bool
4924 {
4925 tree fns;
4933 /* This can happen in error cases; avoid crashing. */
4942 }
4944 /* Returns true iff class T has a user-provided default constructor. */
4946 bool
4948 {
4949 tree fns;
4955 {
4961 }
4964 }
4966 /* TYPE is being used as a virtual base, and has a non-trivial move
4967 assignment. Return true if this is due to there being a user-provided
4968 move assignment in TYPE or one of its subobjects; if there isn't, then
4969 multiple move assignment can't cause any harm. */
4971 bool
4973 {
4974 /* Does the type itself have a user-provided move assignment operator? */
4978 {
4982 }
4984 /* Do any of its bases? */
4986 tree base_binfo;
4991 /* Or non-static data members? */
4993 {
4998 }
5000 /* Seems not. */
5002 }
5004 /* If default-initialization leaves part of TYPE uninitialized, returns
5005 a DECL for the field or TYPE itself (DR 253). */
5007 tree
5009 {
5020 {
5024 }
5029 {
5033 }
5036 }
5038 /* Returns true iff for class T, a trivial synthesized default constructor
5039 would be constexpr. */
5041 bool
5043 {
5044 /* A defaulted trivial default constructor is constexpr
5045 if there is nothing to initialize. */
5048 }
5050 /* Returns true iff class T has a constexpr default constructor. */
5052 bool
5054 {
5055 tree fns;
5058 {
5059 /* The caller should have stripped an enclosing array. */
5062 }
5064 {
5067 /* Non-trivial, we need to check subobject constructors. */
5069 }
5072 }
5074 /* Returns true iff class TYPE has a virtual destructor. */
5076 bool
5078 {
5079 tree dtor;
5087 }
5089 /* Returns true iff class T has a move constructor. */
5091 bool
5093 {
5094 tree fns;
5097 {
5100 }
5110 }
5112 /* Returns true iff class T has a move assignment operator. */
5114 bool
5116 {
5117 tree fns;
5120 {
5123 }
5131 }
5133 /* Returns true iff class T has a move constructor that was explicitly
5134 declared in the class body. Note that this is different from
5135 "user-provided", which doesn't include functions that are defaulted in
5136 the class. */
5138 bool
5140 {
5141 tree fns;
5150 {
5154 }
5157 }
5159 /* Returns true iff class T has a move assignment operator that was
5160 explicitly declared in the class body. */
5162 bool
5164 {
5165 tree fns;
5172 {
5176 }
5179 }
5181 /* Nonzero if we need to build up a constructor call when initializing an
5182 object of this class, either because it has a user-declared constructor
5183 or because it doesn't have a default constructor (so we need to give an
5184 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5185 what you care about is whether or not an object can be produced by a
5186 constructor (e.g. so we don't set TREE_READONLY on const variables of
5187 such type); use this function when what you care about is whether or not
5188 to try to call a constructor to create an object. The latter case is
5189 the former plus some cases of constructors that cannot be called. */
5191 bool
5193 {
5194 tree inner;
5204 /* A user-declared constructor might be private, and a constructor might
5205 be trivial but deleted. */
5208 {
5213 }
5215 }
5217 /* Like type_build_ctor_call, but for destructors. */
5219 bool
5221 {
5222 tree inner;
5231 /* A user-declared destructor might be private, and a destructor might
5232 be trivial but deleted. */
5235 {
5240 }
5242 }
5244 /* Remove all zero-width bit-fields from T. */
5246 static void
5248 {
5253 {
5256 /* We should not be confused by the fact that grokbitfield
5257 temporarily sets the width of the bit field into
5258 DECL_INITIAL (*fieldsp).
5259 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5260 to that width. */
5263 else
5265 }
5266 }
5268 /* Returns TRUE iff we need a cookie when dynamically allocating an
5269 array whose elements have the indicated class TYPE. */
5271 static bool
5273 {
5274 tree fns;
5279 /* If there's a non-trivial destructor, we need a cookie. In order
5280 to iterate through the array calling the destructor for each
5281 element, we'll have to know how many elements there are. */
5285 /* If the usual deallocation function is a two-argument whose second
5286 argument is of type `size_t', then we have to pass the size of
5287 the array to the deallocation function, so we will need to store
5288 a cookie. */
5292 /* If there are no `operator []' members, or the lookup is
5293 ambiguous, then we don't need a cookie. */
5296 /* Loop through all of the functions. */
5298 {
5299 tree fn;
5300 tree second_parm;
5302 /* Select the current function. */
5304 /* See if this function is a one-argument delete function. If
5305 it is, then it will be the usual deallocation function. */
5309 /* Do not consider this function if its second argument is an
5310 ellipsis. */
5313 /* Otherwise, if we have a two-argument function and the second
5314 argument is `size_t', it will be the usual deallocation
5315 function -- unless there is one-argument function, too. */
5319 }
5322 }
5324 /* Finish computing the `literal type' property of class type T.
5326 At this point, we have already processed base classes and
5327 non-static data members. We need to check whether the copy
5328 constructor is trivial, the destructor is trivial, and there
5329 is a trivial default constructor or at least one constexpr
5330 constructor other than the copy constructor. */
5332 static void
5334 {
5335 tree fn;
5351 {
5354 {
5358 }
5359 }
5360 }
5362 /* T is a non-literal type used in a context which requires a constant
5363 expression. Explain why it isn't literal. */
5365 void
5367 {
5377 /* Already explained. */
5386 {
5388 "default constructor, and has no constexpr constructor that "
5392 {
5393 /* Note that we can't simply call locate_ctor because when the
5394 constructor is deleted it just returns NULL_TREE. */
5395 tree fns;
5397 {
5404 {
5407 else
5410 }
5411 }
5412 }
5413 }
5414 else
5415 {
5419 {
5422 {
5427 }
5428 }
5430 {
5431 tree ftype;
5436 {
5441 }
5442 }
5443 }
5444 }
5446 /* Check the validity of the bases and members declared in T. Add any
5447 implicitly-generated functions (like copy-constructors and
5448 assignment operators). Compute various flag bits (like
5449 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5450 level: i.e., independently of the ABI in use. */
5452 static void
5454 {
5455 /* Nonzero if the implicitly generated copy constructor should take
5456 a non-const reference argument. */
5458 /* Nonzero if the implicitly generated assignment operator
5459 should take a non-const reference argument. */
5461 tree access_decls;
5464 tree fn;
5466 /* By default, we use const reference arguments and generate default
5467 constructors. */
5471 /* Check all the base-classes. */
5475 /* Deduce noexcept on destructors. This needs to happen after we've set
5476 triviality flags appropriately for our bases. */
5480 /* Check all the method declarations. */
5483 /* Save the initial values of these flags which only indicate whether
5484 or not the class has user-provided functions. As we analyze the
5485 bases and members we can set these flags for other reasons. */
5489 /* Check all the data member declarations. We cannot call
5490 check_field_decls until we have called check_bases check_methods,
5491 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5492 being set appropriately. */
5497 /* A nearly-empty class has to be vptr-containing; a nearly empty
5498 class contains just a vptr. */
5502 /* Do some bookkeeping that will guide the generation of implicitly
5503 declared member functions. */
5506 /* We need to call a constructor for this class if it has a
5507 user-provided constructor, or if the default constructor is going
5508 to initialize the vptr. (This is not an if-and-only-if;
5509 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5510 themselves need constructing.) */
5513 /* [dcl.init.aggr]
5515 An aggregate is an array or a class with no user-provided
5516 constructors ... and no virtual functions.
5518 Again, other conditions for being an aggregate are checked
5519 elsewhere. */
5522 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5523 retain the old definition internally for ABI reasons. */
5532 /* If the class has no user-declared constructor, but does have
5533 non-static const or reference data members that can never be
5534 initialized, issue a warning. */
5536 /* Classes with user-declared constructors are presumed to
5537 initialize these members. */
5539 /* Aggregates can be initialized with brace-enclosed
5540 initializers. */
5542 {
5543 tree field;
5546 {
5547 tree type;
5562 }
5563 }
5565 /* Synthesize any needed methods. */
5567 cant_have_const_ctor,
5568 no_const_asn_ref);
5570 /* Check defaulted declarations here so we have cant_have_const_ctor
5571 and don't need to worry about clones. */
5574 {
5577 {
5578 bool imp_const_p
5584 /* If the function is defaulted outside the class, we just
5585 give the synthesis error. */
5588 }
5590 }
5593 {
5594 /* "The closure type associated with a lambda-expression has a deleted
5595 default constructor and a deleted copy assignment operator." */
5601 /* "This class type is not an aggregate." */
5603 }
5605 /* Compute the 'literal type' property before we
5606 do anything with non-static member functions. */
5609 /* Create the in-charge and not-in-charge variants of constructors
5610 and destructors. */
5613 /* Process the using-declarations. */
5617 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5620 /* Figure out whether or not we will need a cookie when dynamically
5621 allocating an array of this type. */
5624 }
5626 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5627 accordingly. If a new vfield was created (because T doesn't have a
5628 primary base class), then the newly created field is returned. It
5629 is not added to the TYPE_FIELDS list; it is the caller's
5630 responsibility to do that. Accumulate declared virtual functions
5631 on VIRTUALS_P. */
5633 static tree
5635 {
5636 tree fn;
5638 /* Collect the virtual functions declared in T. */
5642 {
5651 }
5653 /* If we couldn't find an appropriate base class, create a new field
5654 here. Even if there weren't any new virtual functions, we might need a
5655 new virtual function table if we're supposed to include vptrs in
5656 all classes that need them. */
5658 {
5659 /* We build this decl with vtbl_ptr_type_node, which is a
5660 `vtable_entry_type*'. It might seem more precise to use
5661 `vtable_entry_type (*)[N]' where N is the number of virtual
5662 functions. However, that would require the vtable pointer in
5663 base classes to have a different type than the vtable pointer
5664 in derived classes. We could make that happen, but that
5665 still wouldn't solve all the problems. In particular, the
5666 type-based alias analysis code would decide that assignments
5667 to the base class vtable pointer can't alias assignments to
5668 the derived class vtable pointer, since they have different
5669 types. Thus, in a derived class destructor, where the base
5670 class constructor was inlined, we could generate bad code for
5671 setting up the vtable pointer.
5673 Therefore, we use one type for all vtable pointers. We still
5674 use a type-correct type; it's just doesn't indicate the array
5675 bounds. That's better than using `void*' or some such; it's
5676 cleaner, and it let's the alias analysis code know that these
5677 stores cannot alias stores to void*! */
5678 tree field;
5691 /* This class is non-empty. */
5695 }
5698 }
5700 /* Add OFFSET to all base types of BINFO which is a base in the
5701 hierarchy dominated by T.
5703 OFFSET, which is a type offset, is number of bytes. */
5705 static void
5707 {
5709 tree primary_binfo;
5710 tree base_binfo;
5712 /* Update BINFO's offset. */
5717 offset));
5719 /* Find the primary base class. */
5725 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5726 downwards. */
5728 {
5729 /* Don't do the primary base twice. */
5737 }
5738 }
5740 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5741 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5742 empty subobjects of T. */
5744 static void
5746 {
5747 tree vbase;
5756 {
5757 /* In G++ 3.2, we incorrectly rounded the size before laying out
5758 the virtual bases. */
5760 #ifdef STRUCTURE_SIZE_BOUNDARY
5761 /* Packed structures don't need to have minimum size. */
5764 #endif
5768 }
5770 /* Find the last field. The artificial fields created for virtual
5771 bases will go after the last extant field to date. */
5776 /* Go through the virtual bases, allocating space for each virtual
5777 base that is not already a primary base class. These are
5778 allocated in inheritance graph order. */
5780 {
5785 {
5788 /* This virtual base is not a primary base of any class in the
5789 hierarchy, so we have to add space for it. */
5793 /* If the first virtual base might have been placed at a
5794 lower address, had we started from CLASSTYPE_SIZE, rather
5795 than TYPE_SIZE, issue a warning. There can be both false
5796 positives and false negatives from this warning in rare
5797 cases; to deal with all the possibilities would probably
5798 require performing both layout algorithms and comparing
5799 the results which is not particularly tractable. */
5801 && first_vbase
5802 && (tree_int_cst_lt
5807 bitsize_unit_node),
5810 "offset of virtual base %qT is not ABI-compliant and "
5812 basetype);
5815 }
5816 }
5817 }
5819 /* Returns the offset of the byte just past the end of the base class
5820 BINFO. */
5822 static tree
5824 {
5825 tree size;
5830 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5831 allocate some space for it. It cannot have virtual bases, so
5832 TYPE_SIZE_UNIT is fine. */
5834 else
5838 }
5840 /* Returns the offset of the byte just past the end of the base class
5841 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5842 only non-virtual bases are included. */
5844 static tree
5846 {
5849 tree binfo;
5850 tree base_binfo;
5851 tree offset;
5856 {
5866 }
5868 /* G++ 3.2 did not check indirect virtual bases. */
5872 {
5876 }
5879 }
5881 /* Warn about bases of T that are inaccessible because they are
5882 ambiguous. For example:
5884 struct S {};
5885 struct T : public S {};
5886 struct U : public S, public T {};
5888 Here, `(S*) new U' is not allowed because there are two `S'
5889 subobjects of U. */
5891 static void
5893 {
5896 tree basetype;
5897 tree binfo;
5898 tree base_binfo;
5900 /* If there are no repeated bases, nothing can be ambiguous. */
5904 /* Check direct bases. */
5907 {
5913 }
5915 /* Check for ambiguous virtual bases. */
5919 {
5925 }
5926 }
5928 /* Compare two INTEGER_CSTs K1 and K2. */
5930 static int
5932 {
5934 }
5936 /* Increase the size indicated in RLI to account for empty classes
5937 that are "off the end" of the class. */
5939 static void
5941 {
5942 tree eoc;
5943 tree rli_size;
5945 /* It might be the case that we grew the class to allocate a
5946 zero-sized base class. That won't be reflected in RLI, yet,
5947 because we are willing to overlay multiple bases at the same
5948 offset. However, now we need to make sure that RLI is big enough
5949 to reflect the entire class. */
5955 {
5957 /* In version 1 of the ABI, the size of a class that ends with
5958 a bitfield was not rounded up to a whole multiple of a
5959 byte. Because rli_size_unit_so_far returns only the number
5960 of fully allocated bytes, any extra bits were not included
5961 in the size. */
5963 else
5964 /* The size should have been rounded to a whole byte. */
5967 rli->bitpos
5976 }
5977 }
5979 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5980 BINFO_OFFSETs for all of the base-classes. Position the vtable
5981 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5983 static void
5985 {
5986 tree non_static_data_members;
5987 tree field;
5988 tree vptr;
5989 record_layout_info rli;
5990 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5991 types that appear at that offset. */
5992 splay_tree empty_base_offsets;
5993 /* True if the last field laid out was a bit-field. */
5995 /* The location at which the next field should be inserted. */
5997 /* T, as a base class. */
5998 tree base_t;
6000 /* Keep track of the first non-static data member. */
6003 /* Start laying out the record. */
6006 /* Mark all the primary bases in the hierarchy. */
6009 /* Create a pointer to our virtual function table. */
6012 /* The vptr is always the first thing in the class. */
6014 {
6019 }
6020 else
6023 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6028 /* Layout the non-static data members. */
6030 {
6031 tree type;
6032 tree padding;
6034 /* We still pass things that aren't non-static data members to
6035 the back end, in case it wants to do something with them. */
6037 {
6039 /* If the static data member has incomplete type, keep track
6040 of it so that it can be completed later. (The handling
6041 of pending statics in finish_record_layout is
6042 insufficient; consider:
6044 struct S1;
6045 struct S2 { static S1 s1; };
6047 At this point, finish_record_layout will be called, but
6048 S1 is still incomplete.) */
6050 {
6052 /* The visibility of static data members is determined
6053 at their point of declaration, not their point of
6054 definition. */
6056 }
6058 }
6066 /* If this field is a bit-field whose width is greater than its
6067 type, then there are some special rules for allocating
6068 it. */
6071 {
6073 tree integer_type;
6075 /* We must allocate the bits as if suitably aligned for the
6076 longest integer type that fits in this many bits. type
6077 of the field. Then, we are supposed to use the left over
6078 bits as additional padding. */
6087 /* ITK now indicates a type that is too large for the
6088 field. We have to back up by one to find the largest
6089 type that fits. */
6090 do
6091 {
6096 /* Figure out how much additional padding is required. GCC
6097 3.2 always created a padding field, even if it had zero
6098 width. */
6101 {
6103 /* In a union, the padding field must have the full width
6104 of the bit-field; all fields start at offset zero. */
6106 else
6107 {
6110 "ABI-compliant and may change in a future "
6112 t);
6115 }
6116 }
6117 #ifdef PCC_BITFIELD_TYPE_MATTERS
6118 /* An unnamed bitfield does not normally affect the
6119 alignment of the containing class on a target where
6120 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6121 make any exceptions for unnamed bitfields when the
6122 bitfields are longer than their types. Therefore, we
6123 temporarily give the field a name. */
6125 {
6128 }
6129 #endif
6134 empty_base_offsets);
6137 /* Now that layout has been performed, set the size of the
6138 field to the size of its declared type; the rest of the
6139 field is effectively invisible. */
6141 /* We must also reset the DECL_MODE of the field. */
6146 /* Versions of G++ before G++ 3.4 did not reset the
6147 DECL_MODE. */
6149 "the offset of %qD may not be ABI-compliant and may "
6151 }
6152 else
6154 empty_base_offsets);
6156 /* Remember the location of any empty classes in FIELD. */
6160 empty_base_offsets,
6163 /* If a bit-field does not immediately follow another bit-field,
6164 and yet it starts in the middle of a byte, we have failed to
6165 comply with the ABI. */
6168 /* The TREE_NO_WARNING flag gets set by Objective-C when
6169 laying out an Objective-C class. The ObjC ABI differs
6170 from the C++ ABI, and so we do not want a warning
6171 here. */
6173 && !last_field_was_bitfield
6176 bitsize_unit_node)))
6180 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
6181 offset of the field. */
6188 "classes to be placed at different locations in a "
6191 /* The middle end uses the type of expressions to determine the
6192 possible range of expression values. In order to optimize
6193 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6194 must be made aware of the width of "i", via its type.
6196 Because C++ does not have integer types of arbitrary width,
6197 we must (for the purposes of the front end) convert from the
6198 type assigned here to the declared type of the bitfield
6199 whenever a bitfield expression is used as an rvalue.
6200 Similarly, when assigning a value to a bitfield, the value
6201 must be converted to the type given the bitfield here. */
6203 {
6208 {
6215 }
6216 }
6218 /* If we needed additional padding after this field, add it
6219 now. */
6221 {
6222 tree padding_field;
6225 FIELD_DECL,
6226 NULL_TREE,
6227 char_type_node);
6234 NULL_TREE,
6235 empty_base_offsets);
6236 }
6239 }
6242 {
6243 /* Make sure that we are on a byte boundary so that the size of
6244 the class without virtual bases will always be a round number
6245 of bytes. */
6248 }
6250 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6251 padding. */
6255 /* Delete all zero-width bit-fields from the list of fields. Now
6256 that the type is laid out they are no longer important. */
6259 /* Create the version of T used for virtual bases. We do not use
6260 make_class_type for this version; this is an artificial type. For
6261 a POD type, we just reuse T. */
6263 {
6266 /* Set the size and alignment for the new type. In G++ 3.2, all
6267 empty classes were considered to have size zero when used as
6268 base classes. */
6270 {
6275 "layout of classes derived from empty class %qT "
6277 t);
6278 }
6279 else
6280 {
6281 tree eoc;
6283 /* If the ABI version is not at least two, and the last
6284 field was a bit-field, RLI may not be on a byte
6285 boundary. In particular, rli_size_unit_so_far might
6286 indicate the last complete byte, while rli_size_so_far
6287 indicates the total number of bits used. Therefore,
6288 rli_size_so_far, rather than rli_size_unit_so_far, is
6289 used to compute TYPE_SIZE_UNIT. */
6297 eoc);
6304 }
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. */
6412 {
6415 }
6418 }
6421 /* Allocate and return an instance of struct sorted_fields_type with
6422 N fields. */
6426 {
6433 }
6436 /* Perform processing required when the definition of T (a class type)
6437 is complete. */
6439 void
6441 {
6442 tree x;
6443 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6447 {
6452 }
6454 /* If this type was previously laid out as a forward reference,
6455 make sure we lay it out again. */
6459 /* Make assumptions about the class; we'll reset the flags if
6460 necessary. */
6466 /* Do end-of-class semantic processing: checking the validity of the
6467 bases and members and add implicitly generated methods. */
6470 /* Find the key method. */
6472 {
6473 /* The Itanium C++ ABI permits the key method to be chosen when
6474 the class is defined -- even though the key method so
6475 selected may later turn out to be an inline function. On
6476 some systems (such as ARM Symbian OS) the key method cannot
6477 be determined until the end of the translation unit. On such
6478 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6479 will cause the class to be added to KEYED_CLASSES. Then, in
6480 finish_file we will determine the key method. */
6484 /* If a polymorphic class has no key method, we may emit the vtable
6485 in every translation unit where the class definition appears. */
6488 }
6490 /* Layout the class itself. */
6493 /* We use the base type for trivial assignments, and hence it
6494 needs a mode. */
6499 /* If necessary, create the primary vtable for this class. */
6501 {
6502 /* We must enter these virtuals into the table. */
6506 /* Here we know enough to change the type of our virtual
6507 function table, but we will wait until later this function. */
6510 /* If we're warning about ABI tags, check the types of the new
6511 virtual functions. */
6515 }
6518 {
6520 tree fn;
6527 /* Add entries for virtual functions introduced by this class. */
6531 /* Set DECL_VINDEX for all functions declared in this class. */
6533 fn;
6535 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6537 {
6541 /* A thunk. We should never be calling this entry directly
6542 from this vtable -- we'd use the entry for the non
6543 thunk base function. */
6547 }
6548 }
6553 /* Complete the rtl for any static member objects of the type we're
6554 working on. */
6561 /* Done with FIELDS...now decide whether to sort these for
6562 faster lookups later.
6564 We use a small number because most searches fail (succeeding
6565 ultimately as the search bores through the inheritance
6566 hierarchy), and we want this failure to occur quickly. */
6570 /* Complain if one of the field types requires lower visibility. */
6573 /* Make the rtl for any new vtables we have created, and unmark
6574 the base types we marked. */
6577 /* Build the VTT for T. */
6580 /* This warning does not make sense for Java classes, since they
6581 cannot have destructors. */
6583 {
6584 tree dtor;
6588 if it were virtual, we would have created it by now. */
6589 !dtor
6598 "%q#T has virtual functions and accessible"
6600 }
6607 /* Class layout, assignment of virtual table slots, etc., is now
6608 complete. Give the back end a chance to tweak the visibility of
6609 the class or perform any other required target modifications. */
6619 /* Finish debugging output for this type. */
6623 {
6626 {
6629 }
6631 {
6634 else
6635 {
6638 }
6640 }
6642 {
6644 "the type of the first field has a different ABI from the "
6647 }
6648 }
6649 }
6651 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6652 equal to THRESHOLD or greater than THRESHOLD. */
6654 static void
6656 {
6659 {
6664 }
6665 }
6667 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6669 void
6671 {
6674 {
6676 int n_fields
6687 }
6688 }
6690 /* When T was built up, the member declarations were added in reverse
6691 order. Rearrange them to declaration order. */
6693 void
6695 {
6696 tree next;
6697 tree prev;
6698 tree x;
6700 /* The following lists are all in reverse order. Put them in
6701 declaration order now. */
6705 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6706 reverse order, so we can't just use nreverse. */
6711 {
6715 }
6717 {
6721 }
6722 }
6724 tree
6726 {
6729 /* Now that we've got all the field declarations, reverse everything
6730 as necessary. */
6735 /* Nadger the current location so that diagnostics point to the start of
6736 the struct, not the end. */
6740 {
6741 tree x;
6747 /* We need to emit an error message if this type was used as a parameter
6748 and it is an abstract type, even if it is a template. We construct
6749 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6750 account and we call complete_vars with this type, which will check
6751 the PARM_DECLS. Note that while the type is being defined,
6752 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6753 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6759 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6760 an enclosing scope is a template class, so that this function be
6761 found by lookup_fnfields_1 when the using declaration is not
6762 instantiated yet. */
6765 {
6770 }
6772 /* Remember current #pragma pack value. */
6775 /* Fix up any variants we've already built. */
6777 {
6782 }
6783 }
6784 else
6793 else
6797 /* Lambdas are defined by the LAMBDA_EXPR. */
6802 }
6803 \f
6804 /* Hash table to avoid endless recursion when handling references. */
6807 /* Return the dynamic type of INSTANCE, if known.
6808 Used to determine whether the virtual function table is needed
6809 or not.
6811 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6812 of our knowledge of its type. *NONNULL should be initialized
6813 before this function is called. */
6815 static tree
6817 {
6818 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6821 {
6825 else
6829 /* This is a call to a constructor, hence it's never zero. */
6831 {
6835 }
6839 /* This is a call to a constructor, hence it's never zero. */
6841 {
6845 }
6854 /* Propagate nonnull. */
6859 CASE_CONVERT:
6865 {
6866 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6867 with a real object -- given &p->f, p can still be null. */
6869 /* ??? Probably should check DECL_WEAK here. */
6872 }
6876 /* If this component is really a base class reference, then the field
6877 itself isn't definitive. */
6886 {
6890 }
6891 /* fall through... */
6896 {
6900 }
6902 {
6906 /* if we're in a ctor or dtor, we know our type. If
6907 current_class_ptr is set but we aren't in a function, we're in
6908 an NSDMI (and therefore a constructor). */
6913 {
6917 }
6918 }
6920 {
6921 /* We only need one hash table because it is always left empty. */
6925 /* Reference variables should be references to objects. */
6929 /* Enter the INSTANCE in a table to prevent recursion; a
6930 variable's initializer may refer to the variable
6931 itself. */
6936 {
6937 tree type;
6946 }
6947 }
6952 }
6953 #undef RECUR
6954 }
6956 /* Return nonzero if the dynamic type of INSTANCE is known, and
6957 equivalent to the static type. We also handle the case where
6958 INSTANCE is really a pointer. Return negative if this is a
6959 ctor/dtor. There the dynamic type is known, but this might not be
6960 the most derived base of the original object, and hence virtual
6961 bases may not be laid out according to this type.
6963 Used to determine whether the virtual function table is needed
6964 or not.
6966 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6967 of our knowledge of its type. *NONNULL should be initialized
6968 before this function is called. */
6970 int
6972 {
6975 tree fixed;
6977 /* processing_template_decl can be false in a template if we're in
6978 fold_non_dependent_expr, but we still want to suppress this check. */
6980 {
6981 /* In a template we only care about the type of the result. */
6985 }
6995 }
6997 \f
6998 void
7000 {
7003 current_class_stack
7011 }
7013 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7015 static void
7017 {
7018 tree type;
7020 /* We are re-entering the same class we just left, so we don't
7021 have to search the whole inheritance matrix to find all the
7022 decls to bind again. Instead, we install the cached
7023 class_shadowed list and walk through it binding names. */
7026 /* Restore IDENTIFIER_TYPE_VALUE. */
7028 type;
7031 }
7033 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7034 appropriate for TYPE.
7036 So that we may avoid calls to lookup_name, we cache the _TYPE
7037 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7039 For multiple inheritance, we perform a two-pass depth-first search
7040 of the type lattice. */
7042 void
7044 {
7045 class_stack_node_t csn;
7049 /* Make sure there is enough room for the new entry on the stack. */
7051 {
7053 current_class_stack
7055 current_class_stack_size);
7056 }
7058 /* Insert a new entry on the class stack. */
7065 current_class_depth++;
7067 /* Now set up the new type. */
7073 /* By default, things in classes are private, while things in
7074 structures or unions are public. */
7076 ? access_private_node
7082 {
7083 /* Forcibly remove any old class remnants. */
7085 }
7091 else
7093 }
7095 /* When we exit a toplevel class scope, we save its binding level so
7096 that we can restore it quickly. Here, we've entered some other
7097 class, so we must invalidate our cache. */
7099 void
7101 {
7103 }
7105 /* Get out of the current class scope. If we were in a class scope
7106 previously, that is the one popped to. */
7108 void
7110 {
7113 current_class_depth--;
7119 }
7121 /* Mark the top of the class stack as hidden. */
7123 void
7125 {
7128 }
7130 /* Mark the top of the class stack as un-hidden. */
7132 void
7134 {
7137 }
7139 /* Returns 1 if the class type currently being defined is either T or
7140 a nested type of T. */
7142 bool
7144 {
7152 /* We start looking from 1 because entry 0 is from global scope,
7153 and has no type. */
7155 {
7156 tree c;
7159 else
7160 {
7164 }
7169 }
7171 }
7173 /* If either current_class_type or one of its enclosing classes are derived
7174 from T, return the appropriate type. Used to determine how we found
7175 something via unqualified lookup. */
7177 tree
7179 {
7182 /* The bases of a dependent type are unknown. */
7193 {
7198 }
7201 }
7203 /* Returns the innermost class type which is not a lambda closure type. */
7205 tree
7207 {
7210 /* We start looking from 1 because entry 0 is from global scope,
7211 and has no type. */
7213 {
7214 tree c;
7217 else
7218 {
7222 }
7227 }
7229 }
7231 /* When entering a class scope, all enclosing class scopes' names with
7232 static meaning (static variables, static functions, types and
7233 enumerators) have to be visible. This recursive function calls
7234 pushclass for all enclosing class contexts until global or a local
7235 scope is reached. TYPE is the enclosed class. */
7237 void
7239 {
7240 /* A namespace might be passed in error cases, like A::B:C. */
7248 }
7250 /* Undoes a push_nested_class call. */
7252 void
7254 {
7260 }
7262 /* Returns the number of extern "LANG" blocks we are nested within. */
7264 int
7266 {
7268 }
7270 /* Set global variables CURRENT_LANG_NAME to appropriate value
7271 so that behavior of name-mangling machinery is correct. */
7273 void
7275 {
7279 {
7281 }
7283 {
7285 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7286 (See record_builtin_java_type in decl.c.) However, that causes
7287 incorrect debug entries if these types are actually used.
7288 So we re-enable debug output after extern "Java". */
7297 }
7299 {
7301 }
7302 else
7304 }
7306 /* Get out of the current language scope. */
7308 void
7310 {
7312 }
7313 \f
7314 /* Type instantiation routines. */
7316 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7317 matches the TARGET_TYPE. If there is no satisfactory match, return
7318 error_mark_node, and issue an error & warning messages under
7319 control of FLAGS. Permit pointers to member function if FLAGS
7320 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7321 a template-id, and EXPLICIT_TARGS are the explicitly provided
7322 template arguments.
7324 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7325 is the base path used to reference those member functions. If
7326 the address is resolved to a member function, access checks will be
7327 performed and errors issued if appropriate. */
7329 static tree
7331 tree overload,
7332 tsubst_flags_t flags,
7334 tree explicit_targs,
7335 tree access_path)
7336 {
7337 /* Here's what the standard says:
7339 [over.over]
7341 If the name is a function template, template argument deduction
7342 is done, and if the argument deduction succeeds, the deduced
7343 arguments are used to generate a single template function, which
7344 is added to the set of overloaded functions considered.
7346 Non-member functions and static member functions match targets of
7347 type "pointer-to-function" or "reference-to-function." Nonstatic
7348 member functions match targets of type "pointer-to-member
7349 function;" the function type of the pointer to member is used to
7350 select the member function from the set of overloaded member
7351 functions. If a nonstatic member function is selected, the
7352 reference to the overloaded function name is required to have the
7353 form of a pointer to member as described in 5.3.1.
7355 If more than one function is selected, any template functions in
7356 the set are eliminated if the set also contains a non-template
7357 function, and any given template function is eliminated if the
7358 set contains a second template function that is more specialized
7359 than the first according to the partial ordering rules 14.5.5.2.
7360 After such eliminations, if any, there shall remain exactly one
7361 selected function. */
7364 /* We store the matches in a TREE_LIST rooted here. The functions
7365 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7366 interoperability with most_specialized_instantiation. */
7368 tree fn;
7369 tree target_fn_type;
7371 /* By the time we get here, we should be seeing only real
7372 pointer-to-member types, not the internal POINTER_TYPE to
7373 METHOD_TYPE representation. */
7379 /* Check that the TARGET_TYPE is reasonable. */
7384 /* This is OK, too. */
7387 /* This is OK, too. This comes from a conversion to reference
7388 type. */
7390 else
7391 {
7397 }
7399 /* Non-member functions and static member functions match targets of type
7400 "pointer-to-function" or "reference-to-function." Nonstatic member
7401 functions match targets of type "pointer-to-member-function;" the
7402 function type of the pointer to member is used to select the member
7403 function from the set of overloaded member functions.
7405 So figure out the FUNCTION_TYPE that we want to match against. */
7408 /* If we can find a non-template function that matches, we can just
7409 use it. There's no point in generating template instantiations
7410 if we're just going to throw them out anyhow. But, of course, we
7411 can only do this when we don't *need* a template function. */
7413 {
7414 tree fns;
7417 {
7421 /* We're not looking for templates just yet. */
7426 /* We're looking for a non-static member, and this isn't
7427 one, or vice versa. */
7430 /* Ignore functions which haven't been explicitly
7431 declared. */
7435 /* See if there's a match. */
7438 }
7439 }
7441 /* Now, if we've already got a match (or matches), there's no need
7442 to proceed to the template functions. But, if we don't have a
7443 match we need to look at them, too. */
7445 {
7446 tree target_arg_types;
7447 tree target_ret_type;
7448 tree fns;
7451 tree arg;
7465 {
7467 tree instantiation;
7468 tree targs;
7471 /* We're only looking for templates. */
7476 /* We're not looking for a non-static member, and this is
7477 one, or vice versa. */
7482 /* If the template has a deduced return type, don't expose it to
7483 template argument deduction. */
7487 /* Try to do argument deduction. */
7494 /* Instantiation failed. */
7497 /* And now force instantiation to do return type deduction. */
7499 {
7505 }
7507 /* See if there's a match. */
7512 }
7514 /* Now, remove all but the most specialized of the matches. */
7516 {
7521 NULL_TREE,
7522 NULL_TREE);
7523 }
7524 }
7526 /* Now we should have exactly one function in MATCHES. */
7528 {
7529 /* There were *no* matches. */
7531 {
7534 target_type);
7537 }
7539 }
7541 {
7542 /* There were too many matches. First check if they're all
7543 the same function. */
7548 /* For multi-versioned functions, more than one match is just fine and
7549 decls_match will return false as they are different. */
7557 {
7559 {
7562 target_type);
7564 /* Since print_candidates expects the functions in the
7565 TREE_VALUE slot, we flip them here. */
7570 }
7573 }
7574 }
7576 /* Good, exactly one match. Now, convert it to the correct type. */
7581 {
7589 {
7592 }
7593 }
7595 /* If a pointer to a function that is multi-versioned is requested, the
7596 pointer to the dispatcher function is returned instead. This works
7597 well because indirectly calling the function will dispatch the right
7598 function version at run-time. */
7600 {
7604 /* Mark all the versions corresponding to the dispatcher as used. */
7607 }
7609 /* If we're doing overload resolution purely for the purpose of
7610 determining conversion sequences, we should not consider the
7611 function used. If this conversion sequence is selected, the
7612 function will be marked as used at this point. */
7614 {
7615 /* Make =delete work with SFINAE. */
7620 }
7622 /* We could not check access to member functions when this
7623 expression was originally created since we did not know at that
7624 time to which function the expression referred. */
7626 {
7629 }
7633 else
7634 {
7635 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7636 will mark the function as addressed, but here we must do it
7637 explicitly. */
7641 }
7642 }
7644 /* This function will instantiate the type of the expression given in
7645 RHS to match the type of LHSTYPE. If errors exist, then return
7646 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7647 we complain on errors. If we are not complaining, never modify rhs,
7648 as overload resolution wants to try many possible instantiations, in
7649 the hope that at least one will work.
7651 For non-recursive calls, LHSTYPE should be a function, pointer to
7652 function, or a pointer to member function. */
7654 tree
7656 {
7663 {
7667 }
7670 {
7677 /* Microsoft allows `A::f' to be resolved to a
7678 pointer-to-member. */
7679 ;
7680 else
7681 {
7686 }
7687 }
7690 {
7693 }
7695 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7696 deduce any type information. */
7698 {
7702 }
7704 /* There only a few kinds of expressions that may have a type
7705 dependent on overload resolution. */
7711 /* This should really only be used when attempting to distinguish
7712 what sort of a pointer to function we have. For now, any
7713 arithmetic operation which is not supported on pointers
7714 is rejected as an error. */
7717 {
7719 {
7725 /* Do not lose object's side effects. */
7729 }
7736 /* This can happen if we are forming a pointer-to-member for a
7737 member template. */
7740 /* Fall through. */
7743 {
7747 return
7751 }
7755 return
7759 access_path);
7762 {
7767 }
7774 }
7776 }
7777 \f
7778 /* Return the name of the virtual function pointer field
7779 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7780 this may have to look back through base types to find the
7781 ultimate field name. (For single inheritance, these could
7782 all be the same name. Who knows for multiple inheritance). */
7784 static tree
7786 {
7793 {
7799 }
7807 }
7809 void
7811 {
7818 {
7823 }
7824 }
7826 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7827 according to [class]:
7828 The class-name is also inserted
7829 into the scope of the class itself. For purposes of access checking,
7830 the inserted class name is treated as if it were a public member name. */
7832 void
7834 {
7837 tree saved_cas;
7852 }
7854 /* Returns 1 if TYPE contains only padding bytes. */
7856 int
7858 {
7865 /* In G++ 3.2, whether or not a class was empty was determined by
7866 looking at its size. */
7869 else
7871 }
7873 /* Returns true if TYPE contains an empty class. */
7875 static bool
7877 {
7881 {
7882 tree field;
7883 tree binfo;
7884 tree base_binfo;
7896 }
7900 }
7902 /* Returns true if TYPE contains no actual data, just various
7903 possible combinations of empty classes and possibly a vptr. */
7905 bool
7907 {
7909 {
7910 tree field;
7911 tree binfo;
7912 tree base_binfo;
7915 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7916 out, but we'd like to be able to check this before then. */
7930 }
7934 }
7936 /* Note that NAME was looked up while the current class was being
7937 defined and that the result of that lookup was DECL. */
7939 void
7941 {
7942 splay_tree names_used;
7944 /* If we're not defining a class, there's nothing to do. */
7950 /* If there's already a binding for this NAME, then we don't have
7951 anything to worry about. */
7964 }
7966 /* Note that NAME was declared (as DECL) in the current class. Check
7967 to see that the declaration is valid. */
7969 void
7971 {
7972 splay_tree names_used;
7973 splay_tree_node n;
7975 /* Look to see if we ever used this name. */
7976 names_used
7980 /* The C language allows members to be declared with a type of the same
7981 name, and the C++ standard says this diagnostic is not required. So
7982 allow it in extern "C" blocks unless predantic is specified.
7983 Allow it in all cases if -ms-extensions is specified. */
7989 {
7990 /* [basic.scope.class]
7992 A name N used in a class S shall refer to the same declaration
7993 in its context and when re-evaluated in the completed scope of
7994 S. */
7998 }
7999 }
8001 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8002 Secondary vtables are merged with primary vtables; this function
8003 will return the VAR_DECL for the primary vtable. */
8005 tree
8007 {
8008 tree decl;
8012 {
8015 }
8019 }
8022 /* Returns the binfo for the primary base of BINFO. If the resulting
8023 BINFO is a virtual base, and it is inherited elsewhere in the
8024 hierarchy, then the returned binfo might not be the primary base of
8025 BINFO in the complete object. Check BINFO_PRIMARY_P or
8026 BINFO_LOST_PRIMARY_P to be sure. */
8028 static tree
8030 {
8031 tree primary_base;
8038 }
8040 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8042 static int
8044 {
8048 }
8050 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8051 INDENT should be zero when called from the top level; it is
8052 incremented recursively. IGO indicates the next expected BINFO in
8053 inheritance graph ordering. */
8055 static tree
8058 tree binfo,
8059 tree igo,
8061 {
8063 tree base_binfo;
8071 {
8074 }
8089 {
8093 TFF_PLAIN_IDENTIFIER),
8095 }
8097 {
8100 }
8105 {
8109 {
8113 TFF_PLAIN_IDENTIFIER));
8114 }
8116 {
8120 TFF_PLAIN_IDENTIFIER));
8121 }
8123 {
8127 TFF_PLAIN_IDENTIFIER));
8128 }
8130 {
8134 TFF_PLAIN_IDENTIFIER));
8135 }
8139 }
8145 }
8147 /* Dump the BINFO hierarchy for T. */
8149 static void
8151 {
8163 }
8165 /* Debug interface to hierarchy dumping. */
8167 void
8169 {
8171 }
8173 static void
8175 {
8180 {
8183 }
8184 }
8186 static void
8188 {
8189 tree value;
8191 HOST_WIDE_INT elt;
8199 TFF_PLAIN_IDENTIFIER));
8206 }
8208 static void
8210 {
8218 {
8225 {
8230 }
8234 }
8237 }
8239 static void
8241 {
8249 {
8254 }
8257 }
8259 /* Dump a function or thunk and its thunkees. */
8261 static void
8263 {
8266 tree thunks;
8274 {
8284 else
8290 }
8294 }
8296 /* Dump the thunks for FN. */
8298 void
8300 {
8302 }
8304 /* Virtual function table initialization. */
8306 /* Create all the necessary vtables for T and its base classes. */
8308 static void
8310 {
8311 tree vbase;
8315 /* We lay out the primary and secondary vtables in one contiguous
8316 vtable. The primary vtable is first, followed by the non-virtual
8317 secondary vtables in inheritance graph order. */
8321 /* Then come the virtual bases, also in inheritance graph order. */
8323 {
8327 }
8331 }
8333 /* Initialize the vtable for BINFO with the INITS. */
8335 static void
8337 {
8338 tree decl;
8344 }
8346 /* Build the VTT (virtual table table) for T.
8347 A class requires a VTT if it has virtual bases.
8349 This holds
8350 1 - primary virtual pointer for complete object T
8351 2 - secondary VTTs for each direct non-virtual base of T which requires a
8352 VTT
8353 3 - secondary virtual pointers for each direct or indirect base of T which
8354 has virtual bases or is reachable via a virtual path from T.
8355 4 - secondary VTTs for each direct or indirect virtual base of T.
8357 Secondary VTTs look like complete object VTTs without part 4. */
8359 static void
8361 {
8362 tree type;
8363 tree vtt;
8364 tree index;
8367 /* Build up the initializers for the VTT. */
8372 /* If we didn't need a VTT, we're done. */
8376 /* Figure out the type of the VTT. */
8380 /* Now, build the VTT object itself. */
8383 /* Add the VTT to the vtables list. */
8388 }
8390 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8391 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8392 and CHAIN the vtable pointer for this binfo after construction is
8393 complete. VALUE can also be another BINFO, in which case we recurse. */
8395 static tree
8397 {
8398 tree vt;
8401 {
8407 else
8409 }
8412 }
8414 /* Data for secondary VTT initialization. */
8416 {
8417 /* Is this the primary VTT? */
8420 /* Current index into the VTT. */
8421 tree index;
8423 /* Vector of initializers built up. */
8426 /* The type being constructed by this secondary VTT. */
8427 tree type_being_constructed;
8430 /* Recursively build the VTT-initializer for BINFO (which is in the
8431 hierarchy dominated by T). INITS points to the end of the initializer
8432 list to date. INDEX is the VTT index where the next element will be
8433 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8434 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8435 for virtual bases of T. When it is not so, we build the constructor
8436 vtables for the BINFO-in-T variant. */
8438 static void
8441 {
8443 tree b;
8444 tree init;
8445 secondary_vptr_vtt_init_data data;
8448 /* We only need VTTs for subobjects with virtual bases. */
8452 /* We need to use a construction vtable if this is not the primary
8453 VTT. */
8455 {
8458 /* Record the offset in the VTT where this sub-VTT can be found. */
8460 }
8462 /* Add the address of the primary vtable for the complete object. */
8466 {
8469 }
8472 /* Recursively add the secondary VTTs for non-virtual bases. */
8477 /* Add secondary virtual pointers for all subobjects of BINFO with
8478 either virtual bases or reachable along a virtual path, except
8479 subobjects that are non-virtual primary bases. */
8489 /* data.inits might have grown as we added secondary virtual pointers.
8490 Make sure our caller knows about the new vector. */
8494 /* Add the secondary VTTs for virtual bases in inheritance graph
8495 order. */
8497 {
8502 }
8503 else
8504 /* Remove the ctor vtables we created. */
8506 }
8508 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8509 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8511 static tree
8513 {
8516 /* We don't care about bases that don't have vtables. */
8520 /* We're only interested in proper subobjects of the type being
8521 constructed. */
8525 /* We're only interested in bases with virtual bases or reachable
8526 via a virtual path from the type being constructed. */
8531 /* We're not interested in non-virtual primary bases. */
8535 /* Record the index where this secondary vptr can be found. */
8537 {
8542 {
8543 /* It's a primary virtual base, and this is not a
8544 construction vtable. Find the base this is primary of in
8545 the inheritance graph, and use that base's vtable
8546 now. */
8549 }
8550 }
8552 /* Add the initializer for the secondary vptr itself. */
8555 /* Advance the vtt index. */
8560 }
8562 /* Called from build_vtt_inits via dfs_walk. After building
8563 constructor vtables and generating the sub-vtt from them, we need
8564 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8565 binfo of the base whose sub vtt was generated. */
8567 static tree
8569 {
8573 /* If this class has no vtable, none of its bases do. */
8577 /* This might be a primary base, so have no vtable in this
8578 hierarchy. */
8581 /* If we scribbled the construction vtable vptr into BINFO, clear it
8582 out now. */
8588 }
8590 /* Build the construction vtable group for BINFO which is in the
8591 hierarchy dominated by T. */
8593 static void
8595 {
8596 tree type;
8597 tree vtbl;
8598 tree id;
8599 tree vbase;
8602 /* See if we've already created this construction vtable group. */
8608 /* Build a version of VTBL (with the wrong type) for use in
8609 constructing the addresses of secondary vtables in the
8610 construction vtable group. */
8613 /* Don't export construction vtables from shared libraries. Even on
8614 targets that don't support hidden visibility, this tells
8615 can_refer_decl_in_current_unit_p not to assume that it's safe to
8616 access from a different compilation unit (bz 54314). */
8624 /* Add the vtables for each of our virtual bases using the vbase in T
8625 binfo. */
8627 vbase;
8629 {
8630 tree b;
8637 }
8639 /* Figure out the type of the construction vtable. */
8646 /* Initialize the construction vtable. */
8650 }
8652 /* Add the vtbl initializers for BINFO (and its bases other than
8653 non-virtual primaries) to the list of INITS. BINFO is in the
8654 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8655 the constructor the vtbl inits should be accumulated for. (If this
8656 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8657 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8658 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8659 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8660 but are not necessarily the same in terms of layout. */
8662 static void
8664 tree orig_binfo,
8665 tree rtti_binfo,
8666 tree vtbl,
8667 tree t,
8669 {
8671 tree base_binfo;
8676 /* If it doesn't have a vptr, we don't do anything. */
8680 /* If we're building a construction vtable, we're not interested in
8681 subobjects that don't require construction vtables. */
8687 /* Build the initializers for the BINFO-in-T vtable. */
8690 /* Walk the BINFO and its bases. We walk in preorder so that as we
8691 initialize each vtable we can figure out at what offset the
8692 secondary vtable lies from the primary vtable. We can't use
8693 dfs_walk here because we need to iterate through bases of BINFO
8694 and RTTI_BINFO simultaneously. */
8696 {
8697 /* Skip virtual bases. */
8703 inits);
8704 }
8705 }
8707 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8708 BINFO vtable to L. */
8710 static void
8712 tree orig_binfo,
8713 tree rtti_binfo,
8714 tree orig_vtbl,
8715 tree t,
8717 {
8724 {
8725 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8726 primary virtual base. If it is not the same primary in
8727 the hierarchy of T, we'll need to generate a ctor vtable
8728 for it, to place at its location in T. If it is the same
8729 primary, we still need a VTT entry for the vtable, but it
8730 should point to the ctor vtable for the base it is a
8731 primary for within the sub-hierarchy of RTTI_BINFO.
8733 There are three possible cases:
8735 1) We are in the same place.
8736 2) We are a primary base within a lost primary virtual base of
8737 RTTI_BINFO.
8738 3) We are primary to something not a base of RTTI_BINFO. */
8740 tree b;
8743 /* First, look through the bases we are primary to for RTTI_BINFO
8744 or a virtual base. */
8747 {
8752 }
8753 /* If we run out of primary links, keep looking down our
8754 inheritance chain; we might be an indirect primary. */
8758 found:
8760 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8761 base B and it is a base of RTTI_BINFO, this is case 2. In
8762 either case, we share our vtable with LAST, i.e. the
8763 derived-most base within B of which we are a primary. */
8766 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8767 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8768 binfo_ctor_vtable after everything's been set up. */
8771 /* Otherwise, this is case 3 and we get our own. */
8772 }
8779 {
8780 tree index;
8783 /* Add the initializer for this vtable. */
8787 /* Figure out the position to which the VPTR should point. */
8793 }
8796 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8797 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8798 straighten this out. */
8801 /* Throw away any unneeded intializers. */
8803 else
8804 /* For an ordinary vtable, set BINFO_VTABLE. */
8806 }
8810 /* Construct the initializer for BINFO's virtual function table. BINFO
8811 is part of the hierarchy dominated by T. If we're building a
8812 construction vtable, the ORIG_BINFO is the binfo we should use to
8813 find the actual function pointers to put in the vtable - but they
8814 can be overridden on the path to most-derived in the graph that
8815 ORIG_BINFO belongs. Otherwise,
8816 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8817 BINFO that should be indicated by the RTTI information in the
8818 vtable; it will be a base class of T, rather than T itself, if we
8819 are building a construction vtable.
8821 The value returned is a TREE_LIST suitable for wrapping in a
8822 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8823 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8824 number of non-function entries in the vtable.
8826 It might seem that this function should never be called with a
8827 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8828 base is always subsumed by a derived class vtable. However, when
8829 we are building construction vtables, we do build vtables for
8830 primary bases; we need these while the primary base is being
8831 constructed. */
8833 static void
8835 tree orig_binfo,
8836 tree t,
8837 tree rtti_binfo,
8840 {
8841 tree v;
8842 vtbl_init_data vid;
8844 tree vbinfo;
8848 /* Initialize VID. */
8856 /* The first vbase or vcall offset is at index -3 in the vtable. */
8859 /* Add entries to the vtable for RTTI. */
8862 /* Create an array for keeping track of the functions we've
8863 processed. When we see multiple functions with the same
8864 signature, we share the vcall offsets. */
8866 /* Add the vcall and vbase offset entries. */
8869 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8870 build_vbase_offset_vtbl_entries. */
8875 /* If the target requires padding between data entries, add that now. */
8877 {
8882 /* Move data entries into their new positions and add padding
8883 after the new positions. Iterate backwards so we don't
8884 overwrite entries that we would need to process later. */
8887 ix--)
8888 {
8896 {
8900 null_pointer_node);
8901 }
8902 }
8903 }
8908 /* The initializers for virtual functions were built up in reverse
8909 order. Straighten them out and add them to the running list in one
8910 step. */
8919 /* Go through all the ordinary virtual functions, building up
8920 initializers. */
8922 {
8923 tree delta;
8924 tree vcall_index;
8931 {
8935 {
8938 }
8940 }
8942 /* If the only definition of this function signature along our
8943 primary base chain is from a lost primary, this vtable slot will
8944 never be used, so just zero it out. This is important to avoid
8945 requiring extra thunks which cannot be generated with the function.
8947 We first check this in update_vtable_entry_for_fn, so we handle
8948 restored primary bases properly; we also need to do it here so we
8949 zero out unused slots in ctor vtables, rather than filling them
8950 with erroneous values (though harmless, apart from relocation
8951 costs). */
8956 {
8957 /* Pull the offset for `this', and the function to call, out of
8958 the list. */
8965 /* You can't call an abstract virtual function; it's abstract.
8966 So, we replace these functions with __pure_virtual. */
8968 {
8971 {
8973 abort_fndecl_addr
8977 }
8978 }
8979 /* Likewise for deleted virtuals. */
8981 {
8990 }
8991 else
8992 {
8994 {
8998 }
8999 /* Take the address of the function, considering it to be of an
9000 appropriate generic type. */
9004 }
9005 }
9007 /* And add it to the chain of initializers. */
9009 {
9014 else
9016 {
9022 }
9023 }
9024 else
9026 }
9027 }
9029 /* Adds to vid->inits the initializers for the vbase and vcall
9030 offsets in BINFO, which is in the hierarchy dominated by T. */
9032 static void
9034 {
9035 tree b;
9037 /* If this is a derived class, we must first create entries
9038 corresponding to the primary base class. */
9043 /* Add the vbase entries for this base. */
9045 /* Add the vcall entries for this base. */
9047 }
9049 /* Returns the initializers for the vbase offset entries in the vtable
9050 for BINFO (which is part of the class hierarchy dominated by T), in
9051 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9052 where the next vbase offset will go. */
9054 static void
9056 {
9057 tree vbase;
9058 tree t;
9059 tree non_primary_binfo;
9061 /* If there are no virtual baseclasses, then there is nothing to
9062 do. */
9068 /* We might be a primary base class. Go up the inheritance hierarchy
9069 until we find the most derived class of which we are a primary base:
9070 it is the offset of that which we need to use. */
9073 {
9074 tree b;
9076 /* If we have reached a virtual base, then it must be a primary
9077 base (possibly multi-level) of vid->binfo, or we wouldn't
9078 have called build_vcall_and_vbase_vtbl_entries for it. But it
9079 might be a lost primary, so just skip down to vid->binfo. */
9081 {
9084 }
9090 }
9092 /* Go through the virtual bases, adding the offsets. */
9094 vbase;
9096 {
9097 tree b;
9098 tree delta;
9103 /* Find the instance of this virtual base in the complete
9104 object. */
9107 /* If we've already got an offset for this virtual base, we
9108 don't need another one. */
9113 /* Figure out where we can find this vbase offset. */
9122 /* The vbase offset had better be the same. */
9125 /* The next vbase will come at a more negative offset. */
9129 /* The initializer is the delta from BINFO to this virtual base.
9130 The vbase offsets go in reverse inheritance-graph order, and
9131 we are walking in inheritance graph order so these end up in
9132 the right order. */
9139 }
9140 }
9142 /* Adds the initializers for the vcall offset entries in the vtable
9143 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9144 to VID->INITS. */
9146 static void
9148 {
9149 /* We only need these entries if this base is a virtual base. We
9150 compute the indices -- but do not add to the vtable -- when
9151 building the main vtable for a class. */
9154 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9155 correspond to VID->DERIVED), we are building a primary
9156 construction virtual table. Since this is a primary
9157 virtual table, we do not need the vcall offsets for
9158 BINFO. */
9160 {
9161 /* We need a vcall offset for each of the virtual functions in this
9162 vtable. For example:
9164 class A { virtual void f (); };
9165 class B1 : virtual public A { virtual void f (); };
9166 class B2 : virtual public A { virtual void f (); };
9167 class C: public B1, public B2 { virtual void f (); };
9169 A C object has a primary base of B1, which has a primary base of A. A
9170 C also has a secondary base of B2, which no longer has a primary base
9171 of A. So the B2-in-C construction vtable needs a secondary vtable for
9172 A, which will adjust the A* to a B2* to call f. We have no way of
9173 knowing what (or even whether) this offset will be when we define B2,
9174 so we store this "vcall offset" in the A sub-vtable and look it up in
9175 a "virtual thunk" for B2::f.
9177 We need entries for all the functions in our primary vtable and
9178 in our non-virtual bases' secondary vtables. */
9180 /* If we are just computing the vcall indices -- but do not need
9181 the actual entries -- not that. */
9184 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9186 }
9187 }
9189 /* Build vcall offsets, starting with those for BINFO. */
9191 static void
9193 {
9195 tree primary_binfo;
9196 tree base_binfo;
9198 /* Don't walk into virtual bases -- except, of course, for the
9199 virtual base for which we are building vcall offsets. Any
9200 primary virtual base will have already had its offsets generated
9201 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9205 /* If BINFO has a primary base, process it first. */
9210 /* Add BINFO itself to the list. */
9213 /* Scan the non-primary bases of BINFO. */
9217 }
9219 /* Called from build_vcall_offset_vtbl_entries_r. */
9221 static void
9223 {
9224 /* Make entries for the rest of the virtuals. */
9226 {
9227 tree orig_fn;
9229 /* The ABI requires that the methods be processed in declaration
9230 order. G++ 3.2 used the order in the vtable. */
9232 orig_fn;
9236 }
9237 else
9238 {
9239 tree derived_virtuals;
9240 tree base_virtuals;
9241 tree orig_virtuals;
9242 /* If BINFO is a primary base, the most derived class which has
9243 BINFO as a primary base; otherwise, just BINFO. */
9244 tree non_primary_binfo;
9246 /* We might be a primary base class. Go up the inheritance hierarchy
9247 until we find the most derived class of which we are a primary base:
9248 it is the BINFO_VIRTUALS there that we need to consider. */
9251 {
9252 tree b;
9254 /* If we have reached a virtual base, then it must be vid->vbase,
9255 because we ignore other virtual bases in
9256 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9257 base (possibly multi-level) of vid->binfo, or we wouldn't
9258 have called build_vcall_and_vbase_vtbl_entries for it. But it
9259 might be a lost primary, so just skip down to vid->binfo. */
9261 {
9265 }
9271 }
9274 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9275 where rtti_binfo is the most derived type. */
9276 non_primary_binfo
9282 base_virtuals;
9286 {
9287 tree orig_fn;
9289 /* Find the declaration that originally caused this function to
9290 be present in BINFO_TYPE (binfo). */
9293 /* When processing BINFO, we only want to generate vcall slots for
9294 function slots introduced in BINFO. So don't try to generate
9295 one if the function isn't even defined in BINFO. */
9300 }
9301 }
9302 }
9304 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9306 static void
9308 {
9310 tree vcall_offset;
9311 tree derived_entry;
9313 /* If there is already an entry for a function with the same
9314 signature as FN, then we do not need a second vcall offset.
9315 Check the list of functions already present in the derived
9316 class vtable. */
9318 {
9320 /* We only use one vcall offset for virtual destructors,
9321 even though there are two virtual table entries. */
9325 }
9327 /* If we are building these vcall offsets as part of building
9328 the vtable for the most derived class, remember the vcall
9329 offset. */
9331 {
9334 }
9336 /* The next vcall offset will be found at a more negative
9337 offset. */
9341 /* Keep track of this function. */
9345 {
9346 tree base;
9347 tree fn;
9349 /* Find the overriding function. */
9353 else
9354 {
9357 /* The vbase we're working on is a primary base of
9358 vid->binfo. But it might be a lost primary, so its
9359 BINFO_OFFSET might be wrong, so we just use the
9360 BINFO_OFFSET from vid->binfo. */
9366 vcall_offset);
9367 }
9368 /* Add the initializer to the vtable. */
9370 }
9371 }
9373 /* Return vtbl initializers for the RTTI entries corresponding to the
9374 BINFO's vtable. The RTTI entries should indicate the object given
9375 by VID->rtti_binfo. */
9377 static void
9379 {
9380 tree b;
9381 tree t;
9382 tree offset;
9383 tree decl;
9384 tree init;
9388 /* To find the complete object, we will first convert to our most
9389 primary base, and then add the offset in the vtbl to that value. */
9393 {
9394 tree primary_base;
9400 }
9404 /* The second entry is the address of the typeinfo object. */
9407 else
9410 /* Convert the declaration to a type that can be stored in the
9411 vtable. */
9415 /* Add the offset-to-top entry. It comes earlier in the vtable than
9416 the typeinfo entry. Convert the offset to look like a
9417 function pointer, so that we can put it in the vtable. */
9420 }
9422 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9423 accessibility. */
9425 bool
9427 {
9430 }
9432 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9434 bool
9436 {
9440 }
9442 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9443 class between them, if any. */
9445 tree
9447 {
9459 {
9462 }
9466 }