| blob | 508570bdb04ccb0a862bcb7d59cbc1d789010a02 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2017 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. */
41 /* Id for dumping the class hierarchy. */
44 /* The number of nested classes being processed. If we are not in the
45 scope of any class, this is zero. */
49 /* In order to deal with nested classes, we keep a stack of classes.
50 The topmost entry is the innermost class, and is the entry at index
51 CURRENT_CLASS_DEPTH */
54 /* The name of the class. */
55 tree name;
57 /* The _TYPE node for the class. */
58 tree type;
60 /* The access specifier pending for new declarations in the scope of
61 this class. */
62 tree access;
64 /* If were defining TYPE, the names used in this class. */
65 splay_tree names_used;
67 /* Nonzero if this class is no longer open, because of a call to
68 push_to_top_level. */
72 struct vtbl_init_data
73 {
74 /* The base for which we're building initializers. */
75 tree binfo;
76 /* The type of the most-derived type. */
77 tree derived;
78 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
79 unless ctor_vtbl_p is true. */
80 tree rtti_binfo;
81 /* The negative-index vtable initializers built up so far. These
82 are in order from least negative index to most negative index. */
84 /* The binfo for the virtual base for which we're building
85 vcall offset initializers. */
86 tree vbase;
87 /* The functions in vbase for which we have already provided vcall
88 offsets. */
90 /* The vtable index of the next vcall or vbase offset. */
91 tree index;
92 /* Nonzero if we are building the initializer for the primary
93 vtable. */
95 /* Nonzero if we are building the initializer for a construction
96 vtable. */
98 /* True when adding vcall offset entries to the vtable. False when
99 merely computing the indices. */
101 };
103 /* The type of a function passed to walk_subobject_offsets. */
106 /* The stack itself. This is a dynamically resized array. The
107 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
111 /* The size of the largest empty class seen in this translation unit. */
114 /* An array of all local classes present in this translation unit, in
115 declaration order. */
154 /* Used by find_flexarrays and related functions. */
205 tree *);
215 splay_tree_key k2);
224 /* Variables shared between class.c and call.c. */
234 /* Return a COND_EXPR that executes TRUE_STMT if this execution of the
235 'structor is in charge of 'structing virtual bases, or FALSE_STMT
236 otherwise. */
238 tree
240 {
250 }
252 /* Convert to or from a base subobject. EXPR is an expression of type
253 `A' or `A*', an expression of type `B' or `B*' is returned. To
254 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
255 the B base instance within A. To convert base A to derived B, CODE
256 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
257 In this latter case, A must not be a morally virtual base of B.
258 NONNULL is true if EXPR is known to be non-NULL (this is only
259 needed when EXPR is of pointer type). CV qualifiers are preserved
260 from EXPR. */
262 tree
264 tree expr,
265 tree binfo,
267 tsubst_flags_t complain)
268 {
271 tree probe;
272 tree offset;
273 tree target_type;
275 tree ptr_target_type;
286 {
292 }
300 {
301 /* This can happen when adjust_result_of_qualified_name_lookup can't
302 find a unique base binfo in a call to a member function. We
303 couldn't give the diagnostic then since we might have been calling
304 a static member function, so we do it now. In other cases, eg.
305 during error recovery (c++/71979), we may not have a base at all. */
307 {
311 }
313 }
320 /* Nothing to do. */
324 {
326 {
328 {
331 "pointer to derived class %qT because the base is "
333 else
337 }
338 else
339 {
345 else
349 }
350 }
352 }
355 {
357 /* This must happen before the call to save_expr. */
359 }
360 else
366 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
367 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
368 expression returned matches the input. */
369 target_type = cp_build_qualified_type
373 /* Do we need to look in the vtable for the real offset? */
376 /* Don't bother with the calculations inside sizeof; they'll ICE if the
377 source type is incomplete and the pointer value doesn't matter. In a
378 template (even in instantiate_non_dependent_expr), we don't have vtables
379 set up properly yet, and the value doesn't matter there either; we're
380 just interested in the result of overload resolution. */
382 || processing_template_decl
384 {
387 }
389 /* If we're in an NSDMI, we don't have the full constructor context yet
390 that we need for converting to a virtual base, so just build a stub
391 CONVERT_EXPR and expand it later in bot_replace. */
394 {
398 }
400 /* Do we need to check for a null pointer? */
402 {
403 /* If we know the conversion will not actually change the value
404 of EXPR, then we can avoid testing the expression for NULL.
405 We have to avoid generating a COMPONENT_REF for a base class
406 field, because other parts of the compiler know that such
407 expressions are always non-NULL. */
411 }
413 /* Protect against multiple evaluation if necessary. */
417 /* Now that we've saved expr, build the real null test. */
419 {
423 /* This is a compiler generated comparison, don't emit
424 e.g. -Wnonnull-compare warning for it. */
426 }
428 /* If this is a simple base reference, express it as a COMPONENT_REF. */
430 /* We don't build base fields for empty bases, and they aren't very
431 interesting to the optimizers anyway. */
433 {
442 }
445 {
446 /* Going via virtual base V_BINFO. We need the static offset
447 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
448 V_BINFO. That offset is an entry in D_BINFO's vtable. */
449 tree v_offset;
452 {
453 /* In a base member initializer, we cannot rely on the
454 vtable being set up. We have to indirect via the
455 vtt_parm. */
456 tree t;
462 }
463 else
464 {
468 {
473 }
475 complain),
477 }
485 v_offset);
497 /* Negative fixed_type_p means this is a constructor or destructor;
498 virtual base layout is fixed in in-charge [cd]tors, but not in
499 base [cd]tors. */
500 offset = build_if_in_charge
502 v_offset);
503 else
505 }
513 {
518 }
519 else
522 indout:
524 {
528 }
530 out:
536 }
538 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
539 Perform a derived-to-base conversion by recursively building up a
540 sequence of COMPONENT_REFs to the appropriate base fields. */
542 static tree
544 {
547 tree field;
550 {
551 tree temp;
555 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
556 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
557 an lvalue in the front end; only _DECLs and _REFs are lvalues
558 in the back end. */
564 }
566 /* Recurse. */
571 /* Is this the base field created by build_base_field? */
575 /* If we're looking for a field in the most-derived class,
576 also check the field offset; we can have two base fields
577 of the same type if one is an indirect virtual base and one
578 is a direct non-virtual base. */
582 {
583 /* We don't use build_class_member_access_expr here, as that
584 has unnecessary checks, and more importantly results in
585 recursive calls to dfs_walk_once. */
591 /* Mark the expression const or volatile, as appropriate.
592 Even though we've dealt with the type above, we still have
593 to mark the expression itself. */
600 }
602 /* Didn't find the base field?!? */
604 }
606 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
607 type is a class type or a pointer to a class type. In the former
608 case, TYPE is also a class type; in the latter it is another
609 pointer type. If CHECK_ACCESS is true, an error message is emitted
610 if TYPE is inaccessible. If OBJECT has pointer type, the value is
611 assumed to be non-NULL. */
613 tree
615 tsubst_flags_t complain)
616 {
617 tree binfo;
618 tree object_type;
621 {
624 }
625 else
634 }
636 /* EXPR is an expression with unqualified class type. BASE is a base
637 binfo of that class type. Returns EXPR, converted to the BASE
638 type. This function assumes that EXPR is the most derived class;
639 therefore virtual bases can be found at their static offsets. */
641 tree
643 {
644 tree expr_type;
648 {
649 /* If this is a non-empty base, use a COMPONENT_REF. */
653 /* We use fold_build2 and fold_convert below to simplify the trees
654 provided to the optimizers. It is not safe to call these functions
655 when processing a template because they do not handle C++-specific
656 trees. */
664 }
667 }
669 \f
670 tree
672 {
676 /* Can happen in case of duplicate base types (c++/59082). */
680 /* First, convert to the requested type. */
685 /* Second, the requested type may not be the owner of its own vptr.
686 If not, convert to the base class that owns it. We cannot use
687 convert_to_base here, because VCONTEXT may appear more than once
688 in the inheritance hierarchy of TYPE, and thus direct conversion
689 between the types may be ambiguous. Following the path back up
690 one step at a time via primary bases avoids the problem. */
694 {
697 }
700 }
702 /* Given an object INSTANCE, return an expression which yields the
703 vtable element corresponding to INDEX. There are many special
704 cases for INSTANCE which we take care of here, mainly to avoid
705 creating extra tree nodes when we don't have to. */
707 static tree
709 {
710 tree aref;
713 /* Try to figure out what a reference refers to, and
714 access its virtual function table directly. */
722 {
727 }
736 }
738 tree
740 {
744 }
746 /* Given a stable object pointer INSTANCE_PTR, return an expression which
747 yields a function pointer corresponding to vtable element INDEX. */
749 tree
751 {
752 tree aref;
755 tf_warning_or_error),
756 idx);
758 /* When using function descriptors, the address of the
759 vtable entry is treated as a function pointer. */
764 /* Remember this as a method reference, for later devirtualization. */
768 }
770 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
771 for the given TYPE. */
773 static tree
775 {
777 }
779 /* DECL is an entity associated with TYPE, like a virtual table or an
780 implicitly generated constructor. Determine whether or not DECL
781 should have external or internal linkage at the object file
782 level. This routine does not deal with COMDAT linkage and other
783 similar complexities; it simply sets TREE_PUBLIC if it possible for
784 entities in other translation units to contain copies of DECL, in
785 the abstract. */
787 void
789 {
792 }
794 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
795 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
796 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
798 static tree
800 {
801 tree decl;
804 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
805 now to avoid confusion in mangle_decl. */
816 /* The vtable has not been defined -- yet. */
820 /* Mark the VAR_DECL node representing the vtable itself as a
821 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
822 is rather important that such things be ignored because any
823 effort to actually generate DWARF for them will run into
824 trouble when/if we encounter code like:
826 #pragma interface
827 struct S { virtual void member (); };
829 because the artificial declaration of the vtable itself (as
830 manufactured by the g++ front end) will say that the vtable is
831 a static member of `S' but only *after* the debug output for
832 the definition of `S' has already been output. This causes
833 grief because the DWARF entry for the definition of the vtable
834 will try to refer back to an earlier *declaration* of the
835 vtable as a static member of `S' and there won't be one. We
836 might be able to arrange to have the "vtable static member"
837 attached to the member list for `S' before the debug info for
838 `S' get written (which would solve the problem) but that would
839 require more intrusive changes to the g++ front end. */
843 }
845 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
846 or even complete. If this does not exist, create it. If COMPLETE is
847 nonzero, then complete the definition of it -- that will render it
848 impossible to actually build the vtable, but is useful to get at those
849 which are known to exist in the runtime. */
851 tree
853 {
854 tree decl;
863 {
866 }
869 }
871 /* Build the primary virtual function table for TYPE. If BINFO is
872 non-NULL, build the vtable starting with the initial approximation
873 that it is the same as the one which is the head of the association
874 list. Returns a nonzero value if a new vtable is actually
875 created. */
877 static int
879 {
880 tree decl;
881 tree virtuals;
886 {
888 /* We have already created a vtable for this base, so there's
889 no need to do it again. */
896 }
897 else
898 {
901 }
904 {
907 }
909 /* Initialize the association list for this type, based
910 on our first approximation. */
915 }
917 /* Give BINFO a new virtual function table which is initialized
918 with a skeleton-copy of its original initialization. The only
919 entry that changes is the `delta' entry, so we can really
920 share a lot of structure.
922 FOR_TYPE is the most derived type which caused this table to
923 be needed.
925 Returns nonzero if we haven't met BINFO before.
927 The order in which vtables are built (by calling this function) for
928 an object must remain the same, otherwise a binary incompatibility
929 can result. */
931 static int
933 {
935 /* We already created a vtable for this base. There's no need to
936 do it again. */
939 /* Remember that we've created a vtable for this BINFO, so that we
940 don't try to do so again. */
943 /* Make fresh virtual list, so we can smash it later. */
946 /* Secondary vtables are laid out as part of the same structure as
947 the primary vtable. */
950 }
952 /* Create a new vtable for BINFO which is the hierarchy dominated by
953 T. Return nonzero if we actually created a new vtable. */
955 static int
957 {
959 /* In this case, it is *type*'s vtable we are modifying. We start
960 with the approximation that its vtable is that of the
961 immediate base class. */
963 else
964 /* This is our very own copy of `basetype' to play with. Later,
965 we will fill in all the virtual functions that override the
966 virtual functions in these base classes which are not defined
967 by the current type. */
969 }
971 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
972 (which is in the hierarchy dominated by T) list FNDECL as its
973 BV_FN. DELTA is the required constant adjustment from the `this'
974 pointer where the vtable entry appears to the `this' required when
975 the function is actually called. */
977 static void
979 tree binfo,
980 tree fndecl,
981 tree delta,
983 {
984 tree v;
990 {
991 /* We need a new vtable for BINFO. */
993 {
994 /* If we really did make a new vtable, we also made a copy
995 of the BINFO_VIRTUALS list. Now, we have to find the
996 corresponding entry in that list. */
1001 }
1006 }
1007 }
1009 \f
1010 /* Add method METHOD to class TYPE. If VIA_USING indicates whether
1011 METHOD is being injected via a using_decl. Returns true if the
1012 method could be added to the method vec. */
1014 bool
1016 {
1023 tree current_fns;
1036 {
1037 /* Make a new method vector. We start with 8 entries. We must
1038 allocate at least two (for constructors and destructors), and
1039 we're going to end up with an assignment operator at some
1040 point as well. */
1043 }
1045 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1048 tree m;
1051 /* See if we already have an entry with this name. */
1055 {
1058 {
1063 }
1067 {
1070 }
1075 }
1078 /* Check to see if we've already got this method. */
1080 {
1082 tree fn_type;
1083 tree method_type;
1084 tree parms1;
1085 tree parms2;
1090 /* Two using-declarations can coexist, we'll complain about ambiguity in
1091 overload resolution. */
1093 /* Except handle inherited constructors specially. */
1097 /* [over.load] Member function declarations with the
1098 same name and the same parameter types cannot be
1099 overloaded if any of them is a static member
1100 function declaration.
1102 [over.load] Member function declarations with the same name and
1103 the same parameter-type-list as well as member function template
1104 declarations with the same name, the same parameter-type-list, and
1105 the same template parameter lists cannot be overloaded if any of
1106 them, but not all, have a ref-qualifier.
1108 [namespace.udecl] When a using-declaration brings names
1109 from a base class into a derived class scope, member
1110 functions in the derived class override and/or hide member
1111 functions with the same name and parameter types in a base
1112 class (rather than conflicting). */
1118 /* Compare the quals on the 'this' parm. Don't compare
1119 the whole types, as used functions are treated as
1120 coming from the using class in overload resolution. */
1123 /* Either both or neither need to be ref-qualified for
1124 differing quals to allow overloading. */
1131 /* For templates, the return type and template parameters
1132 must be identical. */
1145 /* Bring back parameters omitted from an inherited ctor. */
1156 {
1157 /* For function versions, their parms and types match
1158 but they are not duplicates. Record function versions
1159 as and when they are found. extern "C" functions are
1160 not treated as versions. */
1166 {
1167 /* Mark functions as versions if necessary. Modify the mangled
1168 decl name if necessary. */
1170 {
1174 }
1176 {
1180 }
1183 }
1186 {
1188 {
1192 {
1194 {
1195 /* Inheriting the same constructor along different
1196 paths, combine them. */
1197 SET_DECL_INHERITED_CTOR
1200 /* And discard the new one. */
1202 }
1203 else
1204 /* Inherited ctors can coexist until overload
1205 resolution. */
1207 }
1213 basef);
1214 }
1215 /* Otherwise defer to the other function. */
1217 }
1220 /* Defer to the local function. */
1224 {
1225 /* Remove the inherited constructor. */
1228 }
1229 else
1230 {
1236 }
1237 }
1238 }
1240 /* A class should never have more than one destructor. */
1252 {
1255 /* We only expect to add few methods in the COMPLETE_P case, so
1256 just make room for one more method in that case. */
1259 else
1265 else
1267 }
1268 else
1269 /* Replace the current slot. */
1272 }
1274 /* Subroutines of finish_struct. */
1276 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1277 legit, otherwise return 0. */
1279 static int
1281 {
1282 tree elem;
1290 {
1292 {
1296 else
1299 }
1300 else
1301 {
1302 /* They're changing the access to the same thing they changed
1303 it to before. That's OK. */
1304 ;
1305 }
1306 }
1307 else
1308 {
1310 tf_warning_or_error);
1313 }
1315 }
1317 /* Return the access node for DECL's access in its enclosing class. */
1319 tree
1321 {
1325 }
1327 /* Process the USING_DECL, which is a member of T. */
1329 static void
1331 {
1336 tree old_value;
1341 tf_warning_or_error);
1343 {
1348 else
1350 }
1358 ;
1360 {
1362 /* It's OK to use functions from a base when there are functions with
1364 else
1365 {
1372 }
1373 }
1375 {
1382 }
1384 /* Make type T see field decl FDECL with access ACCESS. */
1387 {
1390 }
1391 else
1393 }
1394 \f
1395 /* Data structure for find_abi_tags_r, below. */
1397 struct abi_tag_data
1398 {
1402 };
1404 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1405 in the context of P. TAG can be either an identifier (the DECL_NAME of
1406 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1408 static void
1410 {
1412 {
1414 {
1415 /* We're collecting tags from template arguments or from
1416 the type of a variable or function return type. */
1419 /* Don't inherit this tag multiple times. */
1423 {
1424 /* Tags inherited from type template arguments are only used
1425 to avoid warnings. */
1428 }
1429 /* For functions and variables we want to warn, too. */
1430 }
1432 /* Otherwise we're diagnosing missing tags. */
1434 {
1439 }
1441 {
1445 }
1447 {
1452 }
1453 else
1454 {
1458 {
1462 }
1463 }
1464 }
1465 }
1467 /* Find all the ABI tags in the attribute list ATTR and either call
1468 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1470 static void
1472 {
1479 {
1484 else
1486 }
1487 }
1489 /* Find all the ABI tags on T and its enclosing scopes and either call
1490 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1492 static void
1494 {
1496 {
1497 tree attr;
1499 {
1502 }
1503 else
1504 {
1507 }
1509 }
1510 }
1512 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1513 types with ABI tags, add the corresponding identifiers to the VEC in
1514 *DATA and set IDENTIFIER_MARKED. */
1516 static tree
1518 {
1522 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1523 anyway, but let's make sure of it. */
1531 }
1533 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1534 IDENTIFIER_MARKED on its ABI tags. */
1536 static tree
1538 {
1542 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1543 anyway, but let's make sure of it. */
1551 }
1553 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1554 scopes. */
1556 static void
1558 {
1561 {
1564 {
1565 /* Template arguments are part of the signature. */
1568 {
1571 }
1572 }
1574 /* A function's parameter types are part of the signature, so
1575 we don't need to inherit any tags that are also in them. */
1580 }
1581 }
1583 /* Check that T has all the ABI tags that subobject SUBOB has, or
1584 warn if not. If T is a (variable or function) declaration, also
1585 return any missing tags, and add them to T if JUST_CHECKING is false. */
1587 static tree
1589 {
1597 /* No need to worry about things local to this TU. */
1613 {
1616 }
1617 else
1618 {
1622 else
1626 }
1631 }
1633 /* Check that DECL has all the ABI tags that are used in parts of its type
1634 that are not reflected in its mangled name. */
1636 void
1638 {
1645 }
1647 /* Return any ABI tags that are used in parts of the type of DECL
1648 that are not reflected in its mangled name. This function is only
1649 used in backward-compatible mangling for ABI <11. */
1651 tree
1653 {
1657 /* Don't check DECL_CONV_FN_P here like we do in check_abi_tags, so
1658 that we can use this function for setting need_abi_warning
1659 regardless of the current flag_abi_version. */
1662 else
1664 }
1666 void
1668 {
1678 {
1681 {
1685 }
1686 }
1688 // If we found some tags on our template arguments, add them to our
1689 // abi_tag attribute.
1691 {
1695 else
1699 }
1702 }
1704 /* Return true, iff class T has a non-virtual destructor that is
1705 accessible from outside the class heirarchy (i.e. is public, or
1706 there's a suitable friend. */
1708 static bool
1710 {
1713 /* An implicitly declared destructor is always public. And,
1714 if it were virtual, we would have created it by now. */
1729 }
1731 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1732 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1733 properties of the bases. */
1735 static void
1739 {
1743 tree base_binfo;
1744 tree binfo;
1754 {
1763 /* If any base class is non-literal, so is the derived class. */
1767 /* If the base class doesn't have copy constructors or
1768 assignment operators that take const references, then the
1769 derived class cannot have such a member automatically
1770 generated. */
1779 /* A virtual base does not effect nearly emptiness. */
1780 ;
1782 {
1784 /* And if there is more than one nearly empty base, then the
1785 derived class is not nearly empty either. */
1787 else
1788 /* Remember we've seen one. */
1790 }
1792 /* If the base class is not empty or nearly empty, then this
1793 class cannot be nearly empty. */
1796 /* A lot of properties from the bases also apply to the derived
1797 class. */
1814 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1817 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1823 /* A standard-layout class is a class that:
1824 ...
1825 * has no non-standard-layout base classes, */
1828 {
1829 tree basefield;
1830 /* ...has no base classes of the same type as the first non-static
1831 data member... */
1833 && (same_type_ignoring_top_level_qualifiers_p
1836 else
1837 /* ...either has no non-static data members in the most-derived
1838 class and at most one base class with non-static data
1839 members, or has no base classes with non-static data
1840 members */
1846 {
1849 else
1852 }
1853 }
1855 /* Don't bother collecting tm attributes if transactional memory
1856 support is not enabled. */
1858 {
1862 }
1865 }
1867 /* If one of the base classes had TM attributes, and the current class
1868 doesn't define its own, then the current class inherits one. */
1870 {
1873 }
1874 }
1876 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1877 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1878 that have had a nearly-empty virtual primary base stolen by some
1879 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1880 T. */
1882 static void
1884 {
1888 tree base_binfo;
1890 /* Determine the primary bases of our bases. */
1893 {
1896 /* See if we're the non-virtual primary of our inheritance
1897 chain. */
1899 {
1906 /* We are the primary binfo. */
1908 }
1909 /* Determine if we have a virtual primary base, and mark it so.
1910 */
1912 {
1916 /* Someone already claimed this base. */
1918 else
1919 {
1920 tree delta;
1925 /* A virtual binfo might have been copied from within
1926 another hierarchy. As we're about to use it as a
1927 primary base, make sure the offsets match. */
1935 }
1936 }
1937 }
1939 /* First look for a dynamic direct non-virtual base. */
1941 {
1945 {
1948 }
1949 }
1951 /* A "nearly-empty" virtual base class can be the primary base
1952 class, if no non-virtual polymorphic base can be found. Look for
1953 a nearly-empty virtual dynamic base that is not already a primary
1954 base of something in the hierarchy. If there is no such base,
1955 just pick the first nearly-empty virtual base. */
1961 {
1963 {
1964 /* Found one that is not primary. */
1967 }
1969 /* Remember the first candidate. */
1971 }
1973 found:
1974 /* If we've got a primary base, use it. */
1976 {
1981 /* We are stealing a primary base. */
1985 {
1986 tree delta;
1989 /* A virtual binfo might have been copied from within
1990 another hierarchy. As we're about to use it as a primary
1991 base, make sure the offsets match. */
1996 }
2003 }
2004 }
2006 /* Update the variant types of T. */
2008 void
2010 {
2011 tree variants;
2017 variants;
2019 {
2020 /* These fields are in the _TYPE part of the node, not in
2021 the TYPE_LANG_SPECIFIC component, so they are not shared. */
2031 /* Copy whatever these are holding today. */
2034 }
2035 }
2037 /* KLASS is a class that we're applying may_alias to after the body is
2038 parsed. Fixup any POINTER_TO and REFERENCE_TO types. The
2039 canonical type(s) will be implicitly updated. */
2041 static void
2043 {
2052 }
2054 /* Early variant fixups: we apply attributes at the beginning of the class
2055 definition, and we need to fix up any variants that have already been
2056 made via elaborated-type-specifier so that check_qualified_type works. */
2058 void
2060 {
2061 tree variants;
2075 variants;
2077 {
2078 /* These are the two fields that check_qualified_type looks at and
2079 are affected by attributes. */
2084 else
2089 }
2090 }
2091 \f
2092 /* Set memoizing fields and bits of T (and its variants) for later
2093 use. */
2095 static void
2097 {
2098 /* Fix up variants (if any). */
2102 /* For a class w/o baseclasses, 'finish_struct' has set
2103 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2104 Similarly for a class whose base classes do not have vtables.
2105 When neither of these is true, we might have removed abstract
2106 virtuals (by providing a definition), added some (by declaring
2107 new ones), or redeclared ones from a base class. We need to
2108 recalculate what's really an abstract virtual at this point (by
2109 looking in the vtables). */
2112 /* If this type has a copy constructor or a destructor, force its
2113 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2114 nonzero. This will cause it to be passed by invisible reference
2115 and prevent it from being returned in a register. */
2118 {
2119 tree variants;
2122 {
2125 }
2126 }
2127 }
2129 /* Issue warnings about T having private constructors, but no friends,
2130 and so forth.
2132 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2133 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2134 non-private static member functions. */
2136 static void
2138 {
2143 /* If the class has friends, those entities might create and
2144 access instances, so we should not warn. */
2147 /* We will have warned when the template was declared; there's
2148 no need to warn on every instantiation. */
2150 /* There's no reason to even consider warning about this
2151 class. */
2154 /* We only issue one warning, if more than one applies, because
2155 otherwise, on code like:
2157 class A {
2158 // Oops - forgot `public:'
2159 A();
2160 A(const A&);
2161 ~A();
2162 };
2164 we warn several times about essentially the same problem. */
2166 /* Check to see if all (non-constructor, non-destructor) member
2167 functions are private. (Since there are no friends or
2168 non-private statics, we can't ever call any of the private member
2169 functions.) */
2174 /* We're not interested in compiler-generated methods; they don't
2177 {
2179 /* A non-private static member function is just like a
2180 friend; it can create and invoke private member
2181 functions, and be accessed without a class
2182 instance. */
2186 /* Keep searching for a static member function. */
2187 }
2192 {
2193 /* There are no non-private methods, and there's at least one
2194 private member function that isn't a constructor or
2195 destructor. (If all the private members are
2196 constructors/destructors we want to use the code below that
2197 issues error messages specifically referring to
2198 constructors/destructors.) */
2204 {
2207 }
2209 {
2213 }
2214 }
2216 /* Even if some of the member functions are non-private, the class
2217 won't be useful for much if all the constructors or destructors
2218 are private: such an object can never be created or destroyed. */
2221 {
2224 t);
2226 }
2228 /* Warn about classes that have private constructors and no friends. */
2230 /* Implicitly generated constructors are always public. */
2232 {
2236 /* If a non-template class does not define a copy
2237 constructor, one is defined for it, enabling it to avoid
2238 this warning. For a template class, this does not
2239 happen, and so we would normally get a warning on:
2241 template <class T> class C { private: C(); };
2243 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2244 complete non-template or fully instantiated classes have this
2245 flag set. */
2248 else
2254 /* Ideally, we wouldn't count any constructor that takes
2255 an argument of the class type as a parameter, because
2256 such things cannot be used to construct an instance of
2257 the class unless you already have one. */
2259 else
2263 {
2266 t);
2272 }
2273 }
2274 }
2277 gt_pointer_operator new_value;
2281 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2283 static int
2285 {
2298 }
2300 /* This routine compares two fields like method_name_cmp but using the
2301 pointer operator in resort_field_decl_data. */
2303 static int
2305 {
2314 {
2321 }
2323 }
2325 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2327 void
2330 gt_pointer_operator new_value,
2332 {
2334 {
2338 /* The type conversion ops have to live at the front of the vec, so we
2339 can't sort them. */
2346 {
2350 resort_method_name_cmp);
2351 }
2352 }
2353 }
2355 /* Warn about duplicate methods in fn_fields.
2357 Sort methods that are not special (i.e., constructors, destructors,
2358 and type conversion operators) so that we can find them faster in
2359 search. */
2361 static void
2363 {
2373 /* Clear DECL_IN_AGGR_P for all functions. */
2378 /* Issue warnings about private constructors and such. If there are
2379 no methods, then some public defaults are generated. */
2382 /* The type conversion ops have to live at the front of the vec, so we
2383 can't sort them. */
2384 tree fn_fields;
2393 }
2395 /* Make BINFO's vtable have N entries, including RTTI entries,
2396 vbase and vcall offsets, etc. Set its type and call the back end
2397 to lay it out. */
2399 static void
2401 {
2402 tree atype;
2403 tree vtable;
2408 /* We may have to grow the vtable. */
2411 {
2415 }
2416 }
2418 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2419 have the same signature. */
2421 int
2423 {
2424 /* One destructor overrides another if they are the same kind of
2425 destructor. */
2429 /* But a non-destructor never overrides a destructor, nor vice
2430 versa, nor do different kinds of destructors override
2431 one-another. For example, a complete object destructor does not
2432 override a deleting destructor. */
2441 {
2449 }
2451 }
2453 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2454 subobject. */
2456 static bool
2458 {
2459 tree probe;
2462 {
2466 /* If we meet a virtual base, we can't follow the inheritance
2467 any more. See if the complete type of DERIVED contains
2468 such a virtual base. */
2471 }
2473 }
2476 /* The function for which we are trying to find a final overrider. */
2477 tree fn;
2478 /* The base class in which the function was declared. */
2479 tree declaring_base;
2480 /* The candidate overriders. */
2481 tree candidates;
2482 /* Path to most derived. */
2484 };
2486 /* Add the overrider along the current path to FFOD->CANDIDATES.
2487 Returns true if an overrider was found; false otherwise. */
2489 static bool
2493 {
2494 tree method;
2496 /* If BINFO is not the most derived type, try a more derived class.
2497 A definition there will overrider a definition here. */
2499 {
2500 depth--;
2504 }
2508 {
2511 /* Remove any candidates overridden by this new function. */
2513 {
2514 /* If *CANDIDATE overrides METHOD, then METHOD
2515 cannot override anything else on the list. */
2518 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2521 else
2523 }
2525 /* Add the new function. */
2528 }
2531 }
2533 /* Called from find_final_overrider via dfs_walk. */
2535 static tree
2537 {
2545 }
2547 static tree
2549 {
2554 }
2556 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2557 FN and whose TREE_VALUE is the binfo for the base where the
2558 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2559 DERIVED) is the base object in which FN is declared. */
2561 static tree
2563 {
2564 find_final_overrider_data ffod;
2566 /* Getting this right is a little tricky. This is valid:
2568 struct S { virtual void f (); };
2569 struct T { virtual void f (); };
2570 struct U : public S, public T { };
2572 even though calling `f' in `U' is ambiguous. But,
2574 struct R { virtual void f(); };
2575 struct S : virtual public R { virtual void f (); };
2576 struct T : virtual public R { virtual void f (); };
2577 struct U : public S, public T { };
2579 is not -- there's no way to decide whether to put `S::f' or
2580 `T::f' in the vtable for `R'.
2582 The solution is to look at all paths to BINFO. If we find
2583 different overriders along any two, then there is a problem. */
2587 /* Determine the depth of the hierarchy. */
2598 /* If there was no winner, issue an error message. */
2603 }
2605 /* Return the index of the vcall offset for FN when TYPE is used as a
2606 virtual base. */
2608 static tree
2610 {
2612 tree_pair_p p;
2620 /* There should always be an appropriate index. */
2622 }
2624 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2625 dominated by T. FN is the old function; VIRTUALS points to the
2626 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2627 of that entry in the list. */
2629 static void
2632 {
2633 tree b;
2634 tree overrider;
2635 tree delta;
2636 tree virtual_base;
2637 tree first_defn;
2643 /* Find the nearest primary base (possibly binfo itself) which defines
2644 this function; this is the class the caller will convert to when
2645 calling FN through BINFO. */
2647 {
2652 /* The nearest definition is from a lost primary. */
2655 }
2658 /* Find the final overrider. */
2661 {
2664 }
2667 /* Check for adjusting covariant return types. */
2675 /* If the overrider is invalid, don't even try. */
2677 {
2678 /* If FN is a covariant thunk, we must figure out the adjustment
2679 to the final base FN was converting to. As OVERRIDER_TARGET might
2680 also be converting to the return type of FN, we have to
2681 combine the two conversions here. */
2688 {
2692 }
2693 else
2697 /* Find the equivalent binfo within the return type of the
2698 overriding function. We will want the vbase offset from
2699 there. */
2701 over_return);
2704 {
2705 /* There was no existing virtual thunk (which takes
2706 precedence). So find the binfo of the base function's
2707 return type within the overriding function's return type.
2708 Fortunately we know the covariancy is valid (it
2709 has already been checked), so we can just iterate along
2710 the binfos, which have been chained in inheritance graph
2711 order. Of course it is lame that we have to repeat the
2712 search here anyway -- we should really be caching pieces
2713 of the vtable and avoiding this repeated work. */
2716 /* Find the base binfo within the overriding function's
2717 return type. We will always find a thunk_binfo, except
2718 when the covariancy is invalid (which we will have
2719 already diagnosed). */
2722 thunk_binfo;
2728 /* See if virtual inheritance is involved. */
2730 virtual_offset;
2737 {
2741 {
2742 /* We convert via virtual base. Adjust the fixed
2743 offset to be from there. */
2744 offset =
2748 }
2750 /* There was an existing fixed offset, this must be
2751 from the base just converted to, and the base the
2752 FN was thunking to. */
2754 else
2756 }
2757 }
2760 /* Replace the overriding function with a covariant thunk. We
2761 will emit the overriding function in its own slot as
2762 well. */
2765 }
2766 else
2770 /* If we need a covariant thunk, then we may need to adjust first_defn.
2771 The ABI specifies that the thunks emitted with a function are
2772 determined by which bases the function overrides, so we need to be
2773 sure that we're using a thunk for some overridden base; even if we
2774 know that the necessary this adjustment is zero, there may not be an
2775 appropriate zero-this-adjustment thunk for us to use since thunks for
2776 overriding virtual bases always use the vcall offset.
2778 Furthermore, just choosing any base that overrides this function isn't
2779 quite right, as this slot won't be used for calls through a type that
2780 puts a covariant thunk here. Calling the function through such a type
2781 will use a different slot, and that slot is the one that determines
2782 the thunk emitted for that base.
2784 So, keep looking until we find the base that we're really overriding
2785 in this slot: the nearest primary base that doesn't use a covariant
2786 thunk in this slot. */
2788 {
2790 /* We already know that the overrider needs a covariant thunk. */
2793 {
2800 }
2802 }
2804 /* Assume that we will produce a thunk that convert all the way to
2805 the final overrider, and not to an intermediate virtual base. */
2808 /* See if we can convert to an intermediate virtual base first, and then
2809 use the vcall offset located there to finish the conversion. */
2811 {
2812 /* If we find the final overrider, then we can stop
2813 walking. */
2818 /* If we find a virtual base, and we haven't yet found the
2819 overrider, then there is a virtual base between the
2820 declaring base (first_defn) and the final overrider. */
2822 {
2825 }
2826 }
2828 /* Compute the constant adjustment to the `this' pointer. The
2829 `this' pointer, when this function is called, will point at BINFO
2830 (or one of its primary bases, which are at the same offset). */
2832 /* The `this' pointer needs to be adjusted from the declaration to
2833 the nearest virtual base. */
2838 /* If the nearest definition is in a lost primary, we don't need an
2839 entry in our vtable. Except possibly in a constructor vtable,
2840 if we happen to get our primary back. In that case, the offset
2841 will be zero, as it will be a primary base. */
2843 else
2844 /* The `this' pointer needs to be adjusted from pointing to
2845 BINFO to pointing at the base where the final overrider
2846 appears. */
2857 else
2861 }
2863 /* Called from modify_all_vtables via dfs_walk. */
2865 static tree
2867 {
2869 tree virtuals;
2870 tree old_virtuals;
2874 /* A base without a vtable needs no modification, and its bases
2875 are uninteresting. */
2880 /* Don't do the primary vtable, if it's new. */
2884 /* There's no need to modify the vtable for a non-virtual primary
2885 base; we're not going to use that vtable anyhow. We do still
2886 need to do this for virtual primary bases, as they could become
2887 non-primary in a construction vtable. */
2892 /* Now, go through each of the virtual functions in the virtual
2893 function table for BINFO. Find the final overrider, and update
2894 the BINFO_VIRTUALS list appropriately. */
2897 virtuals;
2901 binfo,
2906 }
2908 /* Update all of the primary and secondary vtables for T. Create new
2909 vtables as required, and initialize their RTTI information. Each
2910 of the functions in VIRTUALS is declared in T and may override a
2911 virtual function from a base class; find and modify the appropriate
2912 entries to point to the overriding functions. Returns a list, in
2913 declaration order, of the virtual functions that are declared in T,
2914 but do not appear in the primary base class vtable, and which
2915 should therefore be appended to the end of the vtable for T. */
2917 static tree
2919 {
2923 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2927 /* Update all of the vtables. */
2930 /* Add virtual functions not already in our primary vtable. These
2931 will be both those introduced by this class, and those overridden
2932 from secondary bases. It does not include virtuals merely
2933 inherited from secondary bases. */
2935 {
2940 {
2941 /* We don't need to adjust the `this' pointer when
2942 calling this function. */
2946 /* This is a function not already in our vtable. Keep it. */
2948 }
2949 else
2950 /* We've already got an entry for this function. Skip it. */
2952 }
2955 }
2957 /* Get the base virtual function declarations in T that have the
2958 indicated NAME. */
2960 static void
2962 {
2965 /* Find virtual functions in T with the indicated NAME. */
2967 {
2971 {
2974 }
2975 }
2982 {
2985 }
2986 }
2988 /* If this declaration supersedes the declaration of
2989 a method declared virtual in the base class, then
2990 mark this field as being virtual as well. */
2992 void
2994 {
2997 /* In [temp.mem] we have:
2999 A specialization of a member function template does not
3000 override a virtual function from a base class. */
3007 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
3008 the error_mark_node so that we know it is an overriding
3009 function. */
3010 {
3017 }
3020 {
3026 }
3031 }
3033 /* Warn about hidden virtual functions that are not overridden in t.
3034 We know that constructors and destructors don't apply. */
3036 static void
3038 {
3040 tree fns;
3043 /* We go through each separately named virtual function. */
3047 {
3048 tree fndecl;
3049 tree base_binfo;
3050 tree binfo;
3053 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
3054 have the same name. Figure out what name that is. */
3056 /* There are no possibly hidden functions yet. */
3058 /* Iterate through all of the base classes looking for possibly
3059 hidden functions. */
3062 {
3065 }
3067 /* If there are no functions to hide, continue. */
3071 /* Remove any overridden functions. */
3073 {
3077 {
3078 /* If the method from the base class has the same
3079 signature as the method from the derived class, it
3080 has been overridden. */
3085 }
3086 }
3088 /* Now give a warning for all base functions without overriders,
3089 as they are hidden. */
3091 tree base_fndecl;
3094 {
3095 /* Here we know it is a hider, and no overrider exists. */
3097 OPT_Woverloaded_virtual,
3101 }
3102 }
3103 }
3105 /* Recursive helper for finish_struct_anon. */
3107 static void
3109 {
3113 {
3114 /* We're generally only interested in entities the user
3115 declared, but we also find nested classes by noticing
3116 the TYPE_DECL that we create implicitly. You're
3117 allowed to put one anonymous union inside another,
3118 though, so we explicitly tolerate that. We use
3119 TYPE_UNNAMED_P rather than ANON_AGGR_TYPE_P so that
3120 we also allow unnamed types used for defining fields. */
3127 {
3128 /* We already complained about static data members in
3129 finish_static_data_member_decl. */
3131 {
3134 "%q#D invalid; an anonymous union can "
3136 else
3138 "%q#D invalid; an anonymous struct can "
3140 }
3142 }
3145 {
3147 {
3151 else
3154 }
3156 {
3160 else
3163 }
3164 }
3169 /* Recurse into the anonymous aggregates to handle correctly
3170 access control (c++/24926):
3172 class A {
3173 union {
3174 union {
3175 int i;
3176 };
3177 };
3178 };
3180 int j=A().i; */
3184 }
3185 }
3187 /* Check for things that are invalid. There are probably plenty of other
3188 things we should check for also. */
3190 static void
3192 {
3194 {
3203 }
3204 }
3206 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3207 will be used later during class template instantiation.
3208 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3209 a non-static member data (FIELD_DECL), a member function
3210 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3211 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3212 When FRIEND_P is nonzero, T is either a friend class
3213 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3214 (FUNCTION_DECL, TEMPLATE_DECL). */
3216 void
3218 {
3219 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3224 }
3226 /* This function is called from declare_virt_assop_and_dtor via
3227 dfs_walk_all.
3229 DATA is a type that direcly or indirectly inherits the base
3230 represented by BINFO. If BINFO contains a virtual assignment [copy
3231 assignment or move assigment] operator or a virtual constructor,
3232 declare that function in DATA if it hasn't been already declared. */
3234 static tree
3236 {
3244 /* A base without a vtable needs no modification, and its bases
3245 are uninteresting. */
3249 /* If this is a primary base, then we have already looked at the
3250 virtual functions of its vtable. */
3254 {
3258 {
3263 }
3267 }
3270 }
3272 /* If the class type T has a direct or indirect base that contains a
3273 virtual assignment operator or a virtual destructor, declare that
3274 function in T if it hasn't been already declared. */
3276 static void
3278 {
3286 dfs_declare_virt_assop_and_dtor,
3288 }
3290 /* Declare the inheriting constructor for class T inherited from base
3291 constructor CTOR with the parameter array PARMS of size NPARMS. */
3293 static void
3295 {
3298 /* We don't declare an inheriting ctor that would be a default,
3299 copy or move ctor for derived or base. */
3304 {
3308 }
3317 {
3320 }
3321 }
3323 /* Declare all the inheriting constructors for class T inherited from base
3324 constructor CTOR. */
3326 static void
3328 {
3332 {
3338 }
3343 {
3347 }
3350 {
3354 }
3355 }
3357 /* Create default constructors, assignment operators, and so forth for
3358 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3359 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3360 the class cannot have a default constructor, copy constructor
3361 taking a const reference argument, or an assignment operator taking
3362 a const reference, respectively. */
3364 static void
3368 {
3369 /* Destructor. */
3371 /* In general, we create destructors lazily. */
3380 /* [class.ctor]
3382 If there is no user-declared constructor for a class, a default
3383 constructor is implicitly declared. */
3385 {
3390 /* Don't force the declaration to get a hard answer; if the
3391 definition would have made the class non-literal, it will still be
3392 non-literal because of the base or member in question, and that
3393 gives a better diagnostic. */
3395 }
3397 /* [class.ctor]
3399 If a class definition does not explicitly declare a copy
3400 constructor, one is declared implicitly. */
3402 {
3408 }
3410 /* If there is no assignment operator, one will be created if and
3411 when it is needed. For now, just record whether or not the type
3412 of the parameter to the assignment operator will be a const or
3413 non-const reference. */
3415 {
3421 }
3423 /* We can't be lazy about declaring functions that might override
3424 a virtual function from a base class. */
3428 {
3432 {
3433 /* declare, then remove the decl */
3441 }
3442 else
3444 }
3445 }
3447 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3448 count the number of fields in TYPE, including anonymous union
3449 members. */
3451 static int
3453 {
3454 tree x;
3457 {
3462 else
3464 }
3466 }
3468 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3469 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3470 elts, starting at offset IDX. */
3472 static int
3474 {
3475 tree x;
3477 {
3482 else
3484 }
3486 }
3488 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3489 starting at offset IDX. */
3491 static int
3495 {
3496 tree values;
3500 }
3502 /* FIELD is a bit-field. We are finishing the processing for its
3503 enclosing type. Issue any appropriate messages and set appropriate
3504 flags. Returns false if an error has been diagnosed. */
3506 static bool
3508 {
3510 tree w;
3512 /* Extract the declared width of the bitfield, which has been
3513 temporarily stashed in DECL_INITIAL. */
3516 /* Remove the bit-field width indicator so that the rest of the
3517 compiler does not treat that value as an initializer. */
3520 /* Detect invalid bit-field type. */
3522 {
3525 }
3526 else
3527 {
3529 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3532 /* detect invalid field size. */
3538 {
3541 }
3543 {
3546 }
3548 {
3551 }
3566 }
3569 {
3573 }
3574 else
3575 {
3576 /* Non-bit-fields are aligned for their type. */
3580 }
3581 }
3583 /* FIELD is a non bit-field. We are finishing the processing for its
3584 enclosing type T. Issue any appropriate messages and set appropriate
3585 flags. */
3587 static bool
3589 tree t,
3592 {
3596 /* In C++98 an anonymous union cannot contain any fields which would change
3597 the settings of CANT_HAVE_CONST_CTOR and friends. */
3599 ;
3600 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3601 structs. So, we recurse through their fields here. */
3603 {
3608 cant_have_const_ctor,
3609 no_const_asn_ref);
3610 }
3611 /* Check members with class type for constructors, destructors,
3612 etc. */
3614 {
3615 /* Never let anything with uninheritable virtuals
3616 make it through without complaint. */
3620 {
3625 field);
3630 field);
3632 {
3636 }
3637 }
3638 else
3639 {
3652 }
3661 }
3666 /* `build_class_init_list' does not recognize
3667 non-FIELD_DECLs. */
3671 }
3673 /* Check the data members (both static and non-static), class-scoped
3674 typedefs, etc., appearing in the declaration of T. Issue
3675 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3676 declaration order) of access declarations; each TREE_VALUE in this
3677 list is a USING_DECL.
3679 In addition, set the following flags:
3681 EMPTY_P
3682 The class is empty, i.e., contains no non-static data members.
3684 CANT_HAVE_CONST_CTOR_P
3685 This class cannot have an implicitly generated copy constructor
3686 taking a const reference.
3688 CANT_HAVE_CONST_ASN_REF
3689 This class cannot have an implicitly generated assignment
3690 operator taking a const reference.
3692 All of these flags should be initialized before calling this
3693 function.
3695 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3696 fields can be added by adding to this chain. */
3698 static void
3702 {
3710 /* Assume there are no access declarations. */
3712 /* Assume this class has no pointer members. */
3714 /* Assume none of the members of this class have default
3715 initializations. */
3719 {
3727 {
3728 /* Save the access declarations for our caller. */
3731 }
3738 /* FIXME: We should fold in the checking from check_methods. */
3741 /* If we've gotten this far, it's a data member, possibly static,
3742 or an enumerator. */
3746 /* When this goes into scope, it will be a non-local reference. */
3750 {
3751 /* [class.union] (C++98)
3753 If a union contains a static data member, or a member of
3754 reference type, the program is ill-formed.
3756 In C++11 [class.union] says:
3757 If a union contains a non-static data member of reference type
3758 the program is ill-formed. */
3760 {
3764 }
3767 {
3771 }
3772 }
3774 /* Perform error checking that did not get done in
3775 grokdeclarator. */
3777 {
3781 }
3783 {
3787 }
3795 /* Now it can only be a FIELD_DECL. */
3800 /* If at least one non-static data member is non-literal, the whole
3801 class becomes non-literal. Per Core/1453, volatile non-static
3802 data members and base classes are also not allowed.
3803 Note: if the type is incomplete we will complain later on. */
3808 /* A standard-layout class is a class that:
3809 ...
3810 has the same access control (Clause 11) for all non-static data members,
3811 ... */
3818 /* If this is of reference type, check if it needs an init. */
3820 {
3826 {
3827 /* ARM $12.6.2: [A member initializer list] (or, for an
3828 aggregate, initialization by a brace-enclosed list) is the
3829 only way to initialize nonstatic const and reference
3830 members. */
3833 }
3834 }
3839 {
3841 {
3842 warning_at
3845 x);
3847 }
3851 }
3854 /* We don't treat zero-width bitfields as making a class
3855 non-empty. */
3856 ;
3857 else
3858 {
3859 /* The class is non-empty. */
3861 /* The class is not even nearly empty. */
3863 /* If one of the data members contains an empty class,
3864 so does T. */
3868 }
3870 /* This is used by -Weffc++ (see below). Warn only for pointers
3871 to members which might hold dynamic memory. So do not warn
3872 for pointers to functions or pointers to members. */
3878 {
3883 }
3889 {
3891 {
3895 }
3897 {
3901 }
3902 }
3905 /* DR 148 now allows pointers to members (which are POD themselves),
3906 to be allowed in POD structs. */
3915 /* We set DECL_C_BIT_FIELD in grokbitfield.
3916 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3919 cant_have_const_ctor_p,
3920 no_const_asn_ref_p))
3921 {
3926 }
3928 /* Now that we've removed bit-field widths from DECL_INITIAL,
3929 anything left in DECL_INITIAL is an NSDMI that makes the class
3930 non-aggregate in C++11. */
3934 /* If any field is const, the structure type is pseudo-const. */
3936 {
3941 {
3942 /* ARM $12.6.2: [A member initializer list] (or, for an
3943 aggregate, initialization by a brace-enclosed list) is the
3944 only way to initialize nonstatic const and reference
3945 members. */
3948 }
3949 }
3950 /* A field that is pseudo-const makes the structure likewise. */
3952 {
3957 }
3959 /* Core issue 80: A nonstatic data member is required to have a
3960 different name from the class iff the class has a
3961 user-declared constructor. */
3966 }
3968 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3969 it should also define a copy constructor and an assignment operator to
3970 implement the correct copy semantic (deep vs shallow, etc.). As it is
3971 not feasible to check whether the constructors do allocate dynamic memory
3972 and store it within members, we approximate the warning like this:
3974 -- Warn only if there are members which are pointers
3975 -- Warn only if there is a non-trivial constructor (otherwise,
3976 there cannot be memory allocated).
3977 -- Warn only if there is a non-trivial destructor. We assume that the
3978 user at least implemented the cleanup correctly, and a destructor
3979 is needed to free dynamic memory.
3981 This seems enough for practical purposes. */
3983 && has_pointers
3987 {
3991 {
3996 }
4000 }
4002 /* Non-static data member initializers make the default constructor
4003 non-trivial. */
4005 {
4008 }
4010 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
4014 /* Check anonymous struct/anonymous union fields. */
4017 /* We've built up the list of access declarations in reverse order.
4018 Fix that now. */
4020 }
4022 /* If TYPE is an empty class type, records its OFFSET in the table of
4023 OFFSETS. */
4025 static int
4027 {
4028 splay_tree_node n;
4033 /* Record the location of this empty object in OFFSETS. */
4041 type,
4045 }
4047 /* Returns nonzero if TYPE is an empty class type and there is
4048 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
4050 static int
4052 {
4053 splay_tree_node n;
4054 tree t;
4059 /* Record the location of this empty object in OFFSETS. */
4069 }
4071 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
4072 F for every subobject, passing it the type, offset, and table of
4073 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
4074 be traversed.
4076 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
4077 than MAX_OFFSET will not be walked.
4079 If F returns a nonzero value, the traversal ceases, and that value
4080 is returned. Otherwise, returns zero. */
4082 static int
4084 subobject_offset_fn f,
4085 tree offset,
4086 splay_tree offsets,
4087 tree max_offset,
4089 {
4093 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
4094 stop. */
4102 {
4105 }
4108 {
4109 tree field;
4110 tree binfo;
4113 /* Avoid recursing into objects that are not interesting. */
4117 /* Record the location of TYPE. */
4122 /* Iterate through the direct base classes of TYPE. */
4126 {
4127 tree binfo_offset;
4132 tree orig_binfo;
4133 /* We cannot rely on BINFO_OFFSET being set for the base
4134 class yet, but the offsets for direct non-virtual
4135 bases can be calculated by going back to the TYPE. */
4138 offset,
4142 f,
4143 binfo_offset,
4144 offsets,
4145 max_offset,
4149 }
4152 {
4156 /* Iterate through the virtual base classes of TYPE. In G++
4157 3.2, we included virtual bases in the direct base class
4158 loop above, which results in incorrect results; the
4159 correct offsets for virtual bases are only known when
4160 working with the most derived type. */
4164 {
4166 f,
4168 offset,
4170 offsets,
4171 max_offset,
4175 }
4176 else
4177 {
4178 /* We still have to walk the primary base, if it is
4179 virtual. (If it is non-virtual, then it was walked
4180 above.) */
4186 {
4187 r = (walk_subobject_offsets
4192 }
4193 }
4194 }
4196 /* Iterate through the fields of TYPE. */
4201 {
4202 tree field_offset;
4207 f,
4209 offset,
4210 field_offset),
4211 offsets,
4212 max_offset,
4216 }
4217 }
4219 {
4222 tree index;
4224 /* Avoid recursing into objects that are not interesting. */
4227 || !domain
4231 /* Step through each of the elements in the array. */
4235 {
4237 f,
4238 offset,
4239 offsets,
4240 max_offset,
4246 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4247 there's no point in iterating through the remaining
4248 elements of the array. */
4251 }
4252 }
4255 }
4257 /* Record all of the empty subobjects of TYPE (either a type or a
4258 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4259 is being placed at OFFSET; otherwise, it is a base class that is
4260 being placed at OFFSET. */
4262 static void
4264 tree offset,
4265 splay_tree offsets,
4267 {
4268 tree max_offset;
4269 /* If recording subobjects for a non-static data member or a
4270 non-empty base class , we do not need to record offsets beyond
4271 the size of the biggest empty class. Additional data members
4272 will go at the end of the class. Additional base classes will go
4273 either at offset zero (if empty, in which case they cannot
4274 overlap with offsets past the size of the biggest empty class) or
4275 at the end of the class.
4277 However, if we are placing an empty base class, then we must record
4278 all offsets, as either the empty class is at offset zero (where
4279 other empty classes might later be placed) or at the end of the
4280 class (where other objects might then be placed, so other empty
4281 subobjects might later overlap). */
4285 else
4289 }
4291 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4292 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4293 virtual bases of TYPE are examined. */
4295 static int
4297 tree offset,
4298 splay_tree offsets,
4300 {
4301 splay_tree_node max_node;
4303 /* Get the node in OFFSETS that indicates the maximum offset where
4304 an empty subobject is located. */
4306 /* If there aren't any empty subobjects, then there's no point in
4307 performing this check. */
4313 vbases_p);
4314 }
4316 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4317 non-static data member of the type indicated by RLI. BINFO is the
4318 binfo corresponding to the base subobject, OFFSETS maps offsets to
4319 types already located at those offsets. This function determines
4320 the position of the DECL. */
4322 static void
4324 tree decl,
4325 tree binfo,
4326 splay_tree offsets)
4327 {
4330 tree type;
4333 {
4334 /* For the purposes of determining layout conflicts, we want to
4335 use the class type of BINFO; TREE_TYPE (DECL) will be the
4336 CLASSTYPE_AS_BASE version, which does not contain entries for
4337 zero-sized bases. */
4340 }
4341 else
4342 {
4345 }
4347 /* Try to place the field. It may take more than one try if we have
4348 a hard time placing the field without putting two objects of the
4349 same type at the same address. */
4351 {
4354 /* Place this field. */
4358 /* We have to check to see whether or not there is already
4359 something of the same type at the offset we're about to use.
4360 For example, consider:
4362 struct S {};
4363 struct T : public S { int i; };
4364 struct U : public S, public T {};
4366 Here, we put S at offset zero in U. Then, we can't put T at
4367 offset zero -- its S component would be at the same address
4368 as the S we already allocated. So, we have to skip ahead.
4369 Since all data members, including those whose type is an
4370 empty class, have nonzero size, any overlap can happen only
4371 with a direct or indirect base-class -- it can't happen with
4372 a data member. */
4373 /* In a union, overlap is permitted; all members are placed at
4374 offset zero. */
4379 {
4380 /* Strip off the size allocated to this field. That puts us
4381 at the first place we could have put the field with
4382 proper alignment. */
4385 /* Bump up by the alignment required for the type. */
4386 rli->bitpos
4392 }
4395 {
4396 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4397 the offset wasn't aligned like a pointer when we started to
4398 layout this field, that affects its position. */
4401 {
4404 "alignment of %qD increased in -fabi-version=9 "
4406 else
4409 }
4411 }
4412 else
4413 /* There was no conflict. We're done laying out this field. */
4415 }
4417 /* Now that we know where it will be placed, update its
4418 BINFO_OFFSET. */
4420 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4421 this point because their BINFO_OFFSET is copied from another
4422 hierarchy. Therefore, we may not need to add the entire
4423 OFFSET. */
4429 }
4431 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4433 static int
4435 tree offset,
4437 {
4439 }
4441 /* Layout the empty base BINFO. EOC indicates the byte currently just
4442 past the end of the class, and should be correctly aligned for a
4443 class of the type indicated by BINFO; OFFSETS gives the offsets of
4444 the empty bases allocated so far. T is the most derived
4445 type. Return nonzero iff we added it at the end. */
4447 static bool
4450 {
4451 tree alignment;
4455 /* This routine should only be used for empty classes. */
4460 propagate_binfo_offsets
4464 /* This is an empty base class. We first try to put it at offset
4465 zero. */
4468 offsets,
4470 {
4471 /* That didn't work. Now, we move forward from the next
4472 available spot in the class. */
4476 {
4479 offsets,
4481 /* We finally found a spot where there's no overlap. */
4484 /* There's overlap here, too. Bump along to the next spot. */
4486 }
4487 }
4490 {
4495 }
4498 }
4500 /* Build the FIELD_DECL for BASETYPE as a base of T, add it to the chain of
4501 fields at NEXT_FIELD, and return it. */
4503 static tree
4505 {
4506 /* Create the FIELD_DECL. */
4520 /* Add the new FIELD_DECL to the list of fields for T. */
4526 }
4528 /* Layout the base given by BINFO in the class indicated by RLI.
4529 *BASE_ALIGN is a running maximum of the alignments of
4530 any base class. OFFSETS gives the location of empty base
4531 subobjects. T is the most derived type. Return nonzero if the new
4532 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4533 *NEXT_FIELD, unless BINFO is for an empty base class.
4535 Returns the location at which the next field should be inserted. */
4540 {
4545 /* This error is now reported in xref_tag, thus giving better
4546 location information. */
4549 /* Place the base class. */
4551 {
4552 tree decl;
4554 /* The containing class is non-empty because it has a non-empty
4555 base class. */
4558 /* Create the FIELD_DECL. */
4561 /* Try to place the field. It may take more than one try if we
4562 have a hard time placing the field without putting two
4563 objects of the same type at the same address. */
4565 }
4566 else
4567 {
4568 tree eoc;
4571 /* On some platforms (ARM), even empty classes will not be
4572 byte-aligned. */
4577 /* A nearly-empty class "has no proper base class that is empty,
4578 not morally virtual, and at an offset other than zero." */
4580 {
4583 /* The check above (used in G++ 3.2) is insufficient because
4584 an empty class placed at offset zero might itself have an
4585 empty base at a nonzero offset. */
4587 empty_base_at_nonzero_offset_p,
4588 size_zero_node,
4593 }
4595 /* We used to not create a FIELD_DECL for empty base classes because of
4596 back end issues with overlapping FIELD_DECLs, but that doesn't seem to
4597 be a problem anymore. We need them to handle initialization of C++17
4598 aggregate bases. */
4600 {
4605 }
4607 /* An empty virtual base causes a class to be non-empty
4608 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4609 here because that was already done when the virtual table
4610 pointer was created. */
4611 }
4613 /* Record the offsets of BINFO and its base subobjects. */
4616 offsets,
4620 }
4622 /* Layout all of the non-virtual base classes. Record empty
4623 subobjects in OFFSETS. T is the most derived type. Return nonzero
4624 if the type cannot be nearly empty. The fields created
4625 corresponding to the base classes will be inserted at
4626 *NEXT_FIELD. */
4628 static void
4631 {
4632 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4633 subobjects. */
4638 /* The primary base class is always allocated first. */
4643 /* Now allocate the rest of the bases. */
4645 {
4646 tree base_binfo;
4650 /* The primary base was already allocated above, so we don't
4651 need to allocate it again here. */
4655 /* Virtual bases are added at the end (a primary virtual base
4656 will have already been added). */
4662 }
4663 }
4665 /* Go through the TYPE_FIELDS of T issuing any appropriate
4666 diagnostics, figuring out which methods override which other
4667 methods, and so forth. */
4669 static void
4671 {
4674 {
4680 /* The name of the field is the original field name
4681 Save this in auxiliary field for later overloading. */
4683 {
4687 }
4689 /* All user-provided destructors are non-trivial.
4690 Constructors and assignment ops are handled in
4691 grok_special_member_properties. */
4698 "%<transaction_safe_dynamic%> may only be specified for "
4700 }
4701 }
4703 /* FN is a constructor or destructor. Clone the declaration to create
4704 a specialized in-charge or not-in-charge version, as indicated by
4705 NAME. */
4707 static tree
4709 {
4710 tree parms;
4711 tree clone;
4713 /* Copy the function. */
4715 /* Reset the function name. */
4717 /* Remember where this function came from. */
4719 /* Make it easy to find the CLONE given the FN. */
4723 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4725 {
4732 }
4733 else
4734 {
4735 // Clone constraints.
4739 }
4744 /* There's no pending inline data for this function. */
4748 /* The base-class destructor is not virtual. */
4750 {
4754 }
4760 /* If there was an in-charge parameter, drop it from the function
4761 type. */
4763 {
4764 tree basetype;
4765 tree parmtypes;
4766 tree exceptions;
4771 /* Skip the `this' parameter. */
4773 /* Skip the in-charge parameter. */
4775 /* And the VTT parm, in a complete [cd]tor. */
4780 {
4781 /* If we're omitting inherited parms, that just leaves the VTT. */
4784 }
4788 parmtypes);
4791 exceptions);
4795 }
4797 /* Copy the function parameters. */
4799 /* Remove the in-charge parameter. */
4801 {
4805 }
4806 /* And the VTT parm, in a complete [cd]tor. */
4808 {
4811 else
4812 {
4816 }
4817 }
4819 /* A base constructor inheriting from a virtual base doesn't get the
4820 arguments. */
4825 {
4828 }
4830 /* Create the RTL for this function. */
4835 }
4837 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4838 not invoke this function directly.
4840 For a non-thunk function, returns the address of the slot for storing
4841 the function it is a clone of. Otherwise returns NULL_TREE.
4843 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4844 cloned_function is unset. This is to support the separate
4845 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4846 on a template makes sense, but not the former. */
4848 tree *
4850 {
4858 {
4859 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4862 else
4863 #endif
4865 }
4870 else
4872 }
4874 /* Produce declarations for all appropriate clones of FN. If
4875 UPDATE_METHODS is true, the clones are added to the
4876 CLASSTYPE_METHOD_VEC. */
4878 void
4880 {
4881 tree clone;
4883 /* Avoid inappropriate cloning. */
4889 {
4890 /* For each constructor, we need two variants: an in-charge version
4891 and a not-in-charge version. */
4898 }
4899 else
4900 {
4903 /* For each destructor, we need three variants: an in-charge
4904 version, a not-in-charge version, and an in-charge deleting
4905 version. We clone the deleting version first because that
4906 means it will go second on the TYPE_FIELDS list -- and that
4907 corresponds to the correct layout order in the virtual
4908 function table.
4910 For a non-virtual destructor, we do not build a deleting
4911 destructor. */
4913 {
4917 }
4924 }
4926 /* Note that this is an abstract function that is never emitted. */
4928 }
4930 /* DECL is an in charge constructor, which is being defined. This will
4931 have had an in class declaration, from whence clones were
4932 declared. An out-of-class definition can specify additional default
4933 arguments. As it is the clones that are involved in overload
4934 resolution, we must propagate the information from the DECL to its
4935 clones. */
4937 void
4939 {
4940 tree clone;
4944 {
4951 /* Skip the 'this' parameter. */
4967 {
4969 {
4973 }
4979 {
4980 /* A default parameter has been added. Adjust the
4981 clone's parameters. */
4985 tree type;
4990 {
4993 clone_parms);
4995 }
4998 clone_parms);
5007 }
5008 }
5010 }
5011 }
5013 /* For each of the constructors and destructors in T, create an
5014 in-charge and not-in-charge variant. */
5016 static void
5018 {
5019 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
5020 out now. */
5024 /* While constructors can be via a using declaration, at this point
5025 we no longer need to know that. */
5031 }
5033 /* Deduce noexcept for a destructor DTOR. */
5035 void
5037 {
5040 noexcept_deferred_spec);
5041 }
5043 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
5044 of TYPE for virtual functions which FNDECL overrides. Return a
5045 mask of the tm attributes found therein. */
5047 static int
5049 {
5051 tree base_binfo;
5055 {
5063 {
5067 else
5070 }
5071 else
5073 }
5076 }
5078 /* Subroutine of set_method_tm_attributes. Handle the checks and
5079 inheritance for one virtual method FNDECL. */
5081 static void
5083 {
5084 tree tm_attr;
5089 /* If FNDECL doesn't actually override anything (i.e. T is the
5090 class that first declares FNDECL virtual), then we're done. */
5097 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
5098 tm_pure must match exactly, otherwise no weakening of
5099 tm_safe > tm_callable > nothing. */
5100 /* ??? The tm_pure attribute didn't make the transition to the
5101 multivendor language spec. */
5103 {
5105 {
5108 }
5109 }
5110 /* If the overridden function is tm_pure, then FNDECL must be. */
5113 /* Look for base class combinations that cannot be satisfied. */
5115 {
5121 }
5122 /* If FNDECL did not declare an attribute, then inherit the most
5123 restrictive one. */
5125 {
5127 }
5128 /* Otherwise validate that we're not weaker than a function
5129 that is being overridden. */
5130 else
5131 {
5135 }
5138 err_override:
5142 }
5144 /* For each of the methods in T, propagate a class-level tm attribute. */
5146 static void
5148 {
5151 /* Don't bother collecting tm attributes if transactional memory
5152 support is not enabled. */
5156 /* Process virtual methods first, as they inherit directly from the
5157 base virtual function and also require validation of new attributes. */
5159 {
5160 tree vchain;
5163 {
5168 }
5169 }
5171 /* If the class doesn't have an attribute, nothing more to do. */
5176 /* Any method that does not yet have a tm attribute inherits
5177 the one from the class. */
5182 }
5184 /* Returns true if FN is a default constructor. */
5186 bool
5188 {
5191 }
5193 /* Returns true iff class T has a user-defined constructor that can be called
5194 with more than zero arguments. */
5196 bool
5198 {
5203 {
5210 }
5213 }
5215 /* Returns the defaulted constructor if T has one. Otherwise, returns
5216 NULL_TREE. */
5218 tree
5220 {
5225 {
5231 }
5234 }
5236 /* Returns true iff FN is a user-provided function, i.e. user-declared
5237 and not defaulted at its first declaration. */
5239 bool
5241 {
5244 else
5248 }
5250 /* Returns true iff class T has a user-provided constructor. */
5252 bool
5254 {
5261 /* This can happen in error cases; avoid crashing. */
5270 }
5272 /* Returns true iff class T has a user-provided or explicit constructor. */
5274 bool
5276 {
5283 /* This can happen in error cases; avoid crashing. */
5288 {
5292 }
5295 }
5297 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5298 declared or explicitly defaulted in the class body) default
5299 constructor. */
5301 bool
5303 {
5310 {
5316 }
5319 }
5321 /* TYPE is being used as a virtual base, and has a non-trivial move
5322 assignment. Return true if this is due to there being a user-provided
5323 move assignment in TYPE or one of its subobjects; if there isn't, then
5324 multiple move assignment can't cause any harm. */
5326 bool
5328 {
5329 /* Does the type itself have a user-provided move assignment operator? */
5333 {
5337 }
5339 /* Do any of its bases? */
5341 tree base_binfo;
5346 /* Or non-static data members? */
5348 {
5353 }
5355 /* Seems not. */
5357 }
5359 /* If default-initialization leaves part of TYPE uninitialized, returns
5360 a DECL for the field or TYPE itself (DR 253). */
5362 tree
5364 {
5375 {
5379 }
5384 {
5388 }
5391 }
5393 /* Returns true iff for class T, a trivial synthesized default constructor
5394 would be constexpr. */
5396 bool
5398 {
5399 /* A defaulted trivial default constructor is constexpr
5400 if there is nothing to initialize. */
5403 }
5405 /* Returns true iff class T has a constexpr default constructor. */
5407 bool
5409 {
5410 tree fns;
5413 {
5414 /* The caller should have stripped an enclosing array. */
5417 }
5419 {
5422 /* Non-trivial, we need to check subobject constructors. */
5424 }
5427 }
5429 /* Returns true iff class T has a constexpr default constructor or has an
5430 implicitly declared default constructor that we can't tell if it's constexpr
5431 without forcing a lazy declaration (which might cause undesired
5432 instantiations). */
5434 bool
5436 {
5439 /* Assume it's constexpr. */
5442 }
5444 /* Returns true iff class TYPE has a virtual destructor. */
5446 bool
5448 {
5449 tree dtor;
5457 }
5459 /* Returns true iff T, a class, has a move-assignment or
5460 move-constructor. Does not lazily declare either.
5461 If USER_P is false, any move function will do. If it is true, the
5462 move function must be user-declared.
5464 Note that user-declared here is different from "user-provided",
5465 which doesn't include functions that are defaulted in the
5466 class. */
5468 bool
5470 {
5492 }
5494 /* Nonzero if we need to build up a constructor call when initializing an
5495 object of this class, either because it has a user-declared constructor
5496 or because it doesn't have a default constructor (so we need to give an
5497 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5498 what you care about is whether or not an object can be produced by a
5499 constructor (e.g. so we don't set TREE_READONLY on const variables of
5500 such type); use this function when what you care about is whether or not
5501 to try to call a constructor to create an object. The latter case is
5502 the former plus some cases of constructors that cannot be called. */
5504 bool
5506 {
5507 tree inner;
5517 /* A user-declared constructor might be private, and a constructor might
5518 be trivial but deleted. */
5522 {
5527 }
5529 }
5531 /* Like type_build_ctor_call, but for destructors. */
5533 bool
5535 {
5536 tree inner;
5545 /* A user-declared destructor might be private, and a destructor might
5546 be trivial but deleted. */
5550 {
5555 }
5557 }
5559 /* Remove all zero-width bit-fields from T. */
5561 static void
5563 {
5568 {
5571 /* We should not be confused by the fact that grokbitfield
5572 temporarily sets the width of the bit field into
5573 DECL_INITIAL (*fieldsp).
5574 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5575 to that width. */
5579 else
5581 }
5582 }
5584 /* Returns TRUE iff we need a cookie when dynamically allocating an
5585 array whose elements have the indicated class TYPE. */
5587 static bool
5589 {
5590 tree fns;
5595 /* If there's a non-trivial destructor, we need a cookie. In order
5596 to iterate through the array calling the destructor for each
5597 element, we'll have to know how many elements there are. */
5601 /* If the usual deallocation function is a two-argument whose second
5602 argument is of type `size_t', then we have to pass the size of
5603 the array to the deallocation function, so we will need to store
5604 a cookie. */
5608 /* If there are no `operator []' members, or the lookup is
5609 ambiguous, then we don't need a cookie. */
5612 /* Loop through all of the functions. */
5614 {
5617 /* See if this function is a one-argument delete function. If
5618 it is, then it will be the usual deallocation function. */
5622 /* Do not consider this function if its second argument is an
5623 ellipsis. */
5626 /* Otherwise, if we have a two-argument function and the second
5627 argument is `size_t', it will be the usual deallocation
5628 function -- unless there is one-argument function, too. */
5632 }
5635 }
5637 /* Finish computing the `literal type' property of class type T.
5639 At this point, we have already processed base classes and
5640 non-static data members. We need to check whether the copy
5641 constructor is trivial, the destructor is trivial, and there
5642 is a trivial default constructor or at least one constexpr
5643 constructor other than the copy constructor. */
5645 static void
5647 {
5648 tree fn;
5660 /* C++14 DR 1684 removed this restriction. */
5668 {
5672 "enclosing class of constexpr non-static member "
5675 }
5676 }
5678 /* T is a non-literal type used in a context which requires a constant
5679 expression. Explain why it isn't literal. */
5681 void
5683 {
5693 /* Already explained. */
5706 {
5708 "default constructor, and has no constexpr constructor that "
5711 /* Note that we can't simply call locate_ctor because when the
5712 constructor is deleted it just returns NULL_TREE. */
5714 {
5721 {
5724 else
5727 }
5728 }
5729 }
5730 else
5731 {
5735 {
5738 {
5743 }
5744 }
5746 {
5747 tree ftype;
5752 {
5755 field);
5758 }
5762 }
5763 }
5764 }
5766 /* Check the validity of the bases and members declared in T. Add any
5767 implicitly-generated functions (like copy-constructors and
5768 assignment operators). Compute various flag bits (like
5769 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5770 level: i.e., independently of the ABI in use. */
5772 static void
5774 {
5775 /* Nonzero if the implicitly generated copy constructor should take
5776 a non-const reference argument. */
5778 /* Nonzero if the implicitly generated assignment operator
5779 should take a non-const reference argument. */
5781 tree access_decls;
5784 tree fn;
5786 /* By default, we use const reference arguments and generate default
5787 constructors. */
5791 /* Check all the base-classes and set FMEM members to point to arrays
5792 of potential interest. */
5795 /* Deduce noexcept on destructor. This needs to happen after we've set
5796 triviality flags appropriately for our bases. */
5801 /* Check all the method declarations. */
5804 /* Save the initial values of these flags which only indicate whether
5805 or not the class has user-provided functions. As we analyze the
5806 bases and members we can set these flags for other reasons. */
5810 /* Check all the data member declarations. We cannot call
5811 check_field_decls until we have called check_bases check_methods,
5812 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5813 being set appropriately. */
5818 /* A nearly-empty class has to be vptr-containing; a nearly empty
5819 class contains just a vptr. */
5823 /* Do some bookkeeping that will guide the generation of implicitly
5824 declared member functions. */
5827 /* We need to call a constructor for this class if it has a
5828 user-provided constructor, or if the default constructor is going
5829 to initialize the vptr. (This is not an if-and-only-if;
5830 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5831 themselves need constructing.) */
5834 /* [dcl.init.aggr]
5836 An aggregate is an array or a class with no user-provided
5837 constructors ... and no virtual functions.
5839 Again, other conditions for being an aggregate are checked
5840 elsewhere. */
5844 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5845 retain the old definition internally for ABI reasons. */
5854 /* If the only explicitly declared default constructor is user-provided,
5855 set TYPE_HAS_COMPLEX_DFLT. */
5861 /* Warn if a public base of a polymorphic type has an accessible
5862 non-virtual destructor. It is only now that we know the class is
5863 polymorphic. Although a polymorphic base will have a already
5864 been diagnosed during its definition, we warn on use too. */
5866 {
5869 tree base_binfo;
5873 {
5881 basetype);
5882 }
5883 }
5885 /* If the class has no user-declared constructor, but does have
5886 non-static const or reference data members that can never be
5887 initialized, issue a warning. */
5889 /* Classes with user-declared constructors are presumed to
5890 initialize these members. */
5892 /* Aggregates can be initialized with brace-enclosed
5893 initializers. */
5895 {
5896 tree field;
5899 {
5900 tree type;
5917 }
5918 }
5920 /* Synthesize any needed methods. */
5922 cant_have_const_ctor,
5923 no_const_asn_ref);
5925 /* Check defaulted declarations here so we have cant_have_const_ctor
5926 and don't need to worry about clones. */
5931 {
5934 {
5935 bool imp_const_p
5941 /* If the function is defaulted outside the class, we just
5942 give the synthesis error. */
5945 }
5947 }
5950 {
5951 /* "This class type is not an aggregate." */
5953 }
5955 /* Compute the 'literal type' property before we
5956 do anything with non-static member functions. */
5959 /* Create the in-charge and not-in-charge variants of constructors
5960 and destructors. */
5963 /* Process the using-declarations. */
5967 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5970 /* Figure out whether or not we will need a cookie when dynamically
5971 allocating an array of this type. */
5974 }
5976 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5977 accordingly. If a new vfield was created (because T doesn't have a
5978 primary base class), then the newly created field is returned. It
5979 is not added to the TYPE_FIELDS list; it is the caller's
5980 responsibility to do that. Accumulate declared virtual functions
5981 on VIRTUALS_P. */
5983 static tree
5985 {
5986 tree fn;
5988 /* Collect the virtual functions declared in T. */
5993 {
6002 }
6004 /* If we couldn't find an appropriate base class, create a new field
6005 here. Even if there weren't any new virtual functions, we might need a
6006 new virtual function table if we're supposed to include vptrs in
6007 all classes that need them. */
6009 {
6010 /* We build this decl with vtbl_ptr_type_node, which is a
6011 `vtable_entry_type*'. It might seem more precise to use
6012 `vtable_entry_type (*)[N]' where N is the number of virtual
6013 functions. However, that would require the vtable pointer in
6014 base classes to have a different type than the vtable pointer
6015 in derived classes. We could make that happen, but that
6016 still wouldn't solve all the problems. In particular, the
6017 type-based alias analysis code would decide that assignments
6018 to the base class vtable pointer can't alias assignments to
6019 the derived class vtable pointer, since they have different
6020 types. Thus, in a derived class destructor, where the base
6021 class constructor was inlined, we could generate bad code for
6022 setting up the vtable pointer.
6024 Therefore, we use one type for all vtable pointers. We still
6025 use a type-correct type; it's just doesn't indicate the array
6026 bounds. That's better than using `void*' or some such; it's
6027 cleaner, and it let's the alias analysis code know that these
6028 stores cannot alias stores to void*! */
6029 tree field;
6042 /* This class is non-empty. */
6046 }
6049 }
6051 /* Add OFFSET to all base types of BINFO which is a base in the
6052 hierarchy dominated by T.
6054 OFFSET, which is a type offset, is number of bytes. */
6056 static void
6058 {
6060 tree primary_binfo;
6061 tree base_binfo;
6063 /* Update BINFO's offset. */
6068 offset));
6070 /* Find the primary base class. */
6076 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
6077 downwards. */
6079 {
6080 /* Don't do the primary base twice. */
6088 }
6089 }
6091 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
6092 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
6093 empty subobjects of T. */
6095 static void
6097 {
6098 tree vbase;
6105 /* Find the last field. The artificial fields created for virtual
6106 bases will go after the last extant field to date. */
6111 /* Go through the virtual bases, allocating space for each virtual
6112 base that is not already a primary base class. These are
6113 allocated in inheritance graph order. */
6115 {
6120 {
6121 /* This virtual base is not a primary base of any class in the
6122 hierarchy, so we have to add space for it. */
6125 }
6126 }
6127 }
6129 /* Returns the offset of the byte just past the end of the base class
6130 BINFO. */
6132 static tree
6134 {
6135 tree size;
6140 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6141 allocate some space for it. It cannot have virtual bases, so
6142 TYPE_SIZE_UNIT is fine. */
6144 else
6148 }
6150 /* Returns the offset of the byte just past the end of the base class
6151 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
6152 only non-virtual bases are included. */
6154 static tree
6156 {
6159 tree binfo;
6160 tree base_binfo;
6161 tree offset;
6166 {
6176 }
6181 {
6185 }
6188 }
6190 /* Warn about bases of T that are inaccessible because they are
6191 ambiguous. For example:
6193 struct S {};
6194 struct T : public S {};
6195 struct U : public S, public T {};
6197 Here, `(S*) new U' is not allowed because there are two `S'
6198 subobjects of U. */
6200 static void
6202 {
6205 tree basetype;
6206 tree binfo;
6207 tree base_binfo;
6209 /* If there are no repeated bases, nothing can be ambiguous. */
6213 /* Check direct bases. */
6216 {
6222 }
6224 /* Check for ambiguous virtual bases. */
6228 {
6234 }
6235 }
6237 /* Compare two INTEGER_CSTs K1 and K2. */
6239 static int
6241 {
6243 }
6245 /* Increase the size indicated in RLI to account for empty classes
6246 that are "off the end" of the class. */
6248 static void
6250 {
6251 tree eoc;
6252 tree rli_size;
6254 /* It might be the case that we grew the class to allocate a
6255 zero-sized base class. That won't be reflected in RLI, yet,
6256 because we are willing to overlay multiple bases at the same
6257 offset. However, now we need to make sure that RLI is big enough
6258 to reflect the entire class. */
6263 {
6264 /* The size should have been rounded to a whole byte. */
6267 rli->bitpos
6276 }
6277 }
6279 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6280 BINFO_OFFSETs for all of the base-classes. Position the vtable
6281 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6283 static void
6285 {
6286 tree non_static_data_members;
6287 tree field;
6288 tree vptr;
6289 record_layout_info rli;
6290 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6291 types that appear at that offset. */
6292 splay_tree empty_base_offsets;
6293 /* True if the last field laid out was a bit-field. */
6295 /* The location at which the next field should be inserted. */
6297 /* T, as a base class. */
6298 tree base_t;
6300 /* Keep track of the first non-static data member. */
6303 /* Start laying out the record. */
6306 /* Mark all the primary bases in the hierarchy. */
6309 /* Create a pointer to our virtual function table. */
6312 /* The vptr is always the first thing in the class. */
6314 {
6319 }
6320 else
6323 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6328 /* Layout the non-static data members. */
6330 {
6331 tree type;
6332 tree padding;
6334 /* We still pass things that aren't non-static data members to
6335 the back end, in case it wants to do something with them. */
6337 {
6339 /* If the static data member has incomplete type, keep track
6340 of it so that it can be completed later. (The handling
6341 of pending statics in finish_record_layout is
6342 insufficient; consider:
6344 struct S1;
6345 struct S2 { static S1 s1; };
6347 At this point, finish_record_layout will be called, but
6348 S1 is still incomplete.) */
6350 {
6352 /* The visibility of static data members is determined
6353 at their point of declaration, not their point of
6354 definition. */
6356 }
6358 }
6366 /* If this field is a bit-field whose width is greater than its
6367 type, then there are some special rules for allocating
6368 it. */
6371 {
6373 /* We must allocate the bits as if suitably aligned for the
6374 longest integer type that fits in this many bits. Then,
6375 we are supposed to use the left over bits as additional
6376 padding. */
6378 /* Do not pick a type bigger than MAX_FIXED_MODE_SIZE. */
6386 {
6388 /* Too big, so our current guess is what we want. */
6390 /* Not bigger than limit, ok */
6392 }
6394 /* Figure out how much additional padding is required. */
6396 /* In a union, the padding field must have the full width
6397 of the bit-field; all fields start at offset zero. */
6399 else
6406 /* An unnamed bitfield does not normally affect the
6407 alignment of the containing class on a target where
6408 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6409 make any exceptions for unnamed bitfields when the
6410 bitfields are longer than their types. Therefore, we
6411 temporarily give the field a name. */
6413 {
6416 }
6422 empty_base_offsets);
6425 /* Now that layout has been performed, set the size of the
6426 field to the size of its declared type; the rest of the
6427 field is effectively invisible. */
6429 /* We must also reset the DECL_MODE of the field. */
6431 }
6432 else
6434 empty_base_offsets);
6436 /* Remember the location of any empty classes in FIELD. */
6439 empty_base_offsets,
6442 /* If a bit-field does not immediately follow another bit-field,
6443 and yet it starts in the middle of a byte, we have failed to
6444 comply with the ABI. */
6447 /* The TREE_NO_WARNING flag gets set by Objective-C when
6448 laying out an Objective-C class. The ObjC ABI differs
6449 from the C++ ABI, and so we do not want a warning
6450 here. */
6452 && !last_field_was_bitfield
6455 bitsize_unit_node)))
6457 "offset of %qD is not ABI-compliant and may "
6460 /* The middle end uses the type of expressions to determine the
6461 possible range of expression values. In order to optimize
6462 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6463 must be made aware of the width of "i", via its type.
6465 Because C++ does not have integer types of arbitrary width,
6466 we must (for the purposes of the front end) convert from the
6467 type assigned here to the declared type of the bitfield
6468 whenever a bitfield expression is used as an rvalue.
6469 Similarly, when assigning a value to a bitfield, the value
6470 must be converted to the type given the bitfield here. */
6472 {
6477 {
6484 }
6485 }
6487 /* If we needed additional padding after this field, add it
6488 now. */
6490 {
6491 tree padding_field;
6494 FIELD_DECL,
6495 NULL_TREE,
6496 char_type_node);
6503 NULL_TREE,
6504 empty_base_offsets);
6505 }
6508 }
6511 {
6512 /* Make sure that we are on a byte boundary so that the size of
6513 the class without virtual bases will always be a round number
6514 of bytes. */
6517 }
6519 /* Delete all zero-width bit-fields from the list of fields. Now
6520 that the type is laid out they are no longer important. */
6523 /* Create the version of T used for virtual bases. We do not use
6524 make_class_type for this version; this is an artificial type. For
6525 a POD type, we just reuse T. */
6527 {
6530 /* Set the size and alignment for the new type. */
6531 tree eoc;
6533 /* If the ABI version is not at least two, and the last
6534 field was a bit-field, RLI may not be on a byte
6535 boundary. In particular, rli_size_unit_so_far might
6536 indicate the last complete byte, while rli_size_so_far
6537 indicates the total number of bits used. Therefore,
6538 rli_size_so_far, rather than rli_size_unit_so_far, is
6539 used to compute TYPE_SIZE_UNIT. */
6547 eoc);
6557 /* Copy the fields from T. */
6561 {
6565 }
6568 /* Record the base version of the type. */
6571 }
6572 else
6575 /* Every empty class contains an empty class. */
6579 /* Set the TYPE_DECL for this type to contain the right
6580 value for DECL_OFFSET, so that we can use it as part
6581 of a COMPONENT_REF for multiple inheritance. */
6584 /* Now fix up any virtual base class types that we left lying
6585 around. We must get these done before we try to lay out the
6586 virtual function table. As a side-effect, this will remove the
6587 base subobject fields. */
6590 /* Make sure that empty classes are reflected in RLI at this
6591 point. */
6594 /* Make sure not to create any structures with zero size. */
6600 /* If this is a non-POD, declaring it packed makes a difference to how it
6601 can be used as a field; don't let finalize_record_size undo it. */
6605 /* Let the back end lay out the type. */
6614 /* Warn about bases that can't be talked about due to ambiguity. */
6617 /* Now that we're done with layout, give the base fields the real types. */
6622 /* Clean up. */
6629 }
6631 /* Determine the "key method" for the class type indicated by TYPE,
6632 and set CLASSTYPE_KEY_METHOD accordingly. */
6634 void
6636 {
6637 tree method;
6644 /* The key method is the first non-pure virtual function that is not
6645 inline at the point of class definition. On some targets the
6646 key function may not be inline; those targets should not call
6647 this function until the end of the translation unit. */
6653 {
6656 }
6659 }
6662 /* Allocate and return an instance of struct sorted_fields_type with
6663 N fields. */
6667 {
6674 }
6676 /* Helper of find_flexarrays. Return true when FLD refers to a non-static
6677 class data member of non-zero size, otherwise false. */
6681 {
6689 {
6693 }
6696 }
6698 /* Used by find_flexarrays and related functions. */
6700 struct flexmems_t
6701 {
6702 /* The first flexible array member or non-zero array member found
6703 in the order of layout. */
6704 tree array;
6705 /* First non-static non-empty data member in the class or its bases. */
6706 tree first;
6707 /* The first non-static non-empty data member following either
6708 the flexible array member, if found, or the zero-length array member
6709 otherwise. AFTER[1] refers to the first such data member of a union
6710 of which the struct containing the flexible array member or zero-length
6711 array is a member, or NULL when no such union exists. This element is
6712 only used during searching, not for diagnosing problems. AFTER[0]
6713 refers to the first such data member that is not a member of such
6714 a union. */
6717 /* Refers to a struct (not union) in which the struct of which the flexible
6718 array is member is defined. Used to diagnose strictly (according to C)
6719 invalid uses of the latter structs. */
6720 tree enclosing;
6721 };
6723 /* Find either the first flexible array member or the first zero-length
6724 array, in that order of preference, among members of class T (but not
6725 its base classes), and set members of FMEM accordingly.
6726 BASE_P is true if T is a base class of another class.
6727 PUN is set to the outermost union in which the flexible array member
6728 (or zero-length array) is defined if one such union exists, otherwise
6729 to NULL.
6730 Similarly, PSTR is set to a data member of the outermost struct of
6731 which the flexible array is a member if one such struct exists,
6732 otherwise to NULL. */
6734 static void
6738 {
6739 /* Set the "pointer" to the outermost enclosing union if not set
6740 yet and maintain it for the remainder of the recursion. */
6745 {
6749 /* Is FLD a typedef for an anonymous struct? */
6751 /* FIXME: Note that typedefs (as well as arrays) need to be fully
6752 handled elsewhere so that errors like the following are detected
6753 as well:
6754 typedef struct { int i, a[], j; } S; // bug c++/72753
6755 S s [2]; // bug c++/68489
6756 */
6761 {
6762 /* Check the nested unnamed type referenced via a typedef
6763 independently of FMEM (since it's not a data member of
6764 the enclosing class). */
6767 }
6769 /* Skip anything that's GCC-generated or not a (non-static) data
6770 member. */
6774 /* Type of the member. */
6779 /* Determine the type of the array element or object referenced
6780 by the member so that it can be checked for flexible array
6781 members if it hasn't been yet. */
6789 {
6791 {
6792 /* Once the member after the flexible array has been found
6793 we're done. */
6796 }
6799 {
6800 /* Descend into the non-static member struct or union and try
6801 to find a flexible array member or zero-length array among
6802 its members. This is only necessary for anonymous types
6803 and types in whose context the current type T has not been
6804 defined (the latter must not be checked again because they
6805 are already in the process of being checked by one of the
6806 recursive calls). */
6811 /* If this member isn't anonymous and a prior non-flexible array
6812 member has been seen in one of the enclosing structs, clear
6813 the FIRST member since it doesn't contribute to the flexible
6814 array struct's members. */
6825 {
6826 /* Restore the FIRST member reset above if no flexible
6827 array member has been found in this member's struct. */
6829 }
6831 /* If the member struct contains the first flexible array
6832 member, or if this member is a base class, continue to
6833 the next member and avoid setting the FMEM->NEXT pointer
6834 to point to it. */
6837 }
6838 }
6841 {
6842 /* Remember the first non-static data member. */
6846 /* Remember the first non-static data member after the flexible
6847 array member, if one has been found, or the zero-length array
6848 if it has been found. */
6851 }
6853 /* Skip non-arrays. */
6857 /* Determine the upper bound of the array if it has one. */
6859 {
6861 {
6862 /* Make a record of the zero-length array if either one
6863 such field or a flexible array member has been seen to
6864 handle the pathological and unlikely case of multiple
6865 such members. */
6868 }
6870 {
6871 /* Remember the first zero-length array unless a flexible array
6872 member has already been seen. */
6875 }
6876 }
6877 else
6878 {
6879 /* Flexible array members have no upper bound. */
6881 {
6882 /* Replace the zero-length array if it's been stored and
6883 reset the after pointer. */
6885 {
6889 }
6890 }
6891 else
6892 {
6895 }
6896 }
6897 }
6898 }
6900 /* Diagnose a strictly (by the C standard) invalid use of a struct with
6901 a flexible array member (or the zero-length array extension). */
6903 static void
6905 {
6917 }
6919 /* Issue diagnostics for invalid flexible array members or zero-length
6920 arrays that are not the last elements of the containing class or its
6921 base classes or that are its sole members. */
6923 static void
6925 {
6930 {
6933 }
6935 /* Has a diagnostic been issued? */
6941 {
6948 {
6952 {
6955 }
6956 }
6957 }
6958 else
6959 {
6966 {
6972 /* In the unlikely event that the member following the flexible
6973 array member is declared in a different class, or the member
6974 overlaps another member of a common union, point to it.
6975 Otherwise it should be obvious. */
6979 {
6984 }
6985 }
6986 }
6990 }
6993 /* Recursively check to make sure that any flexible array or zero-length
6994 array members of class T or its bases are valid (i.e., not the sole
6995 non-static data member of T and, if one exists, that it is the last
6996 non-static data member of T and its base classes. FMEM is expected
6997 to be initially null and is used internally by recursive calls to
6998 the function. Issue the appropriate diagnostics for the array member
6999 that fails the checks. */
7001 static void
7004 {
7005 /* Initialize the result of a search for flexible array and zero-length
7006 array members. Avoid doing any work if the most interesting FMEM data
7007 have already been populated. */
7016 /* Recursively check the primary base class first. */
7018 {
7021 }
7023 /* Recursively check the base classes. */
7026 {
7029 /* The primary base class was already checked above. */
7033 /* Virtual base classes are at the end. */
7037 /* Check the base class. */
7039 }
7042 {
7043 /* Check virtual base classes only once per derived class.
7044 I.e., this check is not performed recursively for base
7045 classes. */
7047 tree base_binfo;
7051 {
7052 /* Check the virtual base class. */
7056 }
7057 }
7059 /* Is the type unnamed (and therefore a member of it potentially
7060 an anonymous struct or union)? */
7063 /* Search the members of the current (possibly derived) class, skipping
7064 unnamed structs and unions since those could be anonymous. */
7069 {
7070 /* Issue diagnostics for invalid flexible and zero-length array
7071 members found in base classes or among the members of the current
7072 class. Ignore anonymous structs and unions whose members are
7073 considered to be members of the enclosing class and thus will
7074 be diagnosed when checking it. */
7076 }
7077 }
7079 /* Perform processing required when the definition of T (a class type)
7080 is complete. Diagnose invalid definitions of flexible array members
7081 and zero-size arrays. */
7083 void
7085 {
7086 tree x;
7087 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
7091 {
7096 }
7098 /* If this type was previously laid out as a forward reference,
7099 make sure we lay it out again. */
7103 /* Make assumptions about the class; we'll reset the flags if
7104 necessary. */
7110 /* Do end-of-class semantic processing: checking the validity of the
7111 bases and members and add implicitly generated methods. */
7114 /* Find the key method. */
7116 {
7117 /* The Itanium C++ ABI permits the key method to be chosen when
7118 the class is defined -- even though the key method so
7119 selected may later turn out to be an inline function. On
7120 some systems (such as ARM Symbian OS) the key method cannot
7121 be determined until the end of the translation unit. On such
7122 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
7123 will cause the class to be added to KEYED_CLASSES. Then, in
7124 finish_file we will determine the key method. */
7128 /* If a polymorphic class has no key method, we may emit the vtable
7129 in every translation unit where the class definition appears. If
7130 we're devirtualizing, we can look into the vtable even if we
7131 aren't emitting it. */
7134 }
7136 /* Layout the class itself. */
7139 /* We use the base type for trivial assignments, and hence it
7140 needs a mode. */
7143 /* With the layout complete, check for flexible array members and
7144 zero-length arrays that might overlap other members in the final
7145 layout. */
7150 /* If necessary, create the primary vtable for this class. */
7152 {
7153 /* We must enter these virtuals into the table. */
7157 /* Here we know enough to change the type of our virtual
7158 function table, but we will wait until later this function. */
7161 /* If we're warning about ABI tags, check the types of the new
7162 virtual functions. */
7166 }
7169 {
7171 tree fn;
7178 /* Add entries for virtual functions introduced by this class. */
7182 /* Set DECL_VINDEX for all functions declared in this class. */
7184 fn;
7186 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
7188 {
7192 /* A thunk. We should never be calling this entry directly
7193 from this vtable -- we'd use the entry for the non
7194 thunk base function. */
7198 }
7199 }
7206 /* Complete the rtl for any static member objects of the type we're
7207 working on. */
7214 /* Done with FIELDS...now decide whether to sort these for
7215 faster lookups later.
7217 We use a small number because most searches fail (succeeding
7218 ultimately as the search bores through the inheritance
7219 hierarchy), and we want this failure to occur quickly. */
7223 /* Complain if one of the field types requires lower visibility. */
7226 /* Make the rtl for any new vtables we have created, and unmark
7227 the base types we marked. */
7230 /* Build the VTT for T. */
7237 "%q#T has virtual functions and accessible"
7245 /* Class layout, assignment of virtual table slots, etc., is now
7246 complete. Give the back end a chance to tweak the visibility of
7247 the class or perform any other required target modifications. */
7257 /* Finish debugging output for this type. */
7261 {
7264 {
7267 }
7269 {
7272 else
7273 {
7276 }
7278 }
7280 {
7282 "the type of the first field has a different ABI from the "
7285 }
7286 }
7287 }
7289 /* Insert FIELDS into T for the sorted case if the FIELDS count is
7290 equal to THRESHOLD or greater than THRESHOLD. */
7292 static void
7294 {
7297 {
7302 }
7303 }
7305 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
7307 void
7309 {
7312 {
7314 int n_fields
7325 }
7326 }
7328 /* When T was built up, the member declarations were added in reverse
7329 order. Rearrange them to declaration order. */
7331 void
7333 {
7334 tree next;
7335 tree prev;
7336 tree x;
7338 /* The following lists are all in reverse order. Put them in
7339 declaration order now. */
7342 /* For the TYPE_FIELDS, only the non TYPE_DECLs are in reverse
7343 order, so we can't just use nreverse. Due to stat_hack
7344 chicanery in finish_member_declarations. */
7349 {
7353 }
7356 {
7360 }
7361 }
7363 tree
7365 {
7368 /* Now that we've got all the field declarations, reverse everything
7369 as necessary. */
7375 /* Nadger the current location so that diagnostics point to the start of
7376 the struct, not the end. */
7380 {
7381 tree x;
7387 /* We need to emit an error message if this type was used as a parameter
7388 and it is an abstract type, even if it is a template. We construct
7389 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
7390 account and we call complete_vars with this type, which will check
7391 the PARM_DECLS. Note that while the type is being defined,
7392 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
7393 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
7399 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
7400 an enclosing scope is a template class, so that this function be
7401 found by lookup_fnfields_1 when the using declaration is not
7402 instantiated yet. */
7405 {
7410 }
7412 /* Remember current #pragma pack value. */
7415 /* Fix up any variants we've already built. */
7417 {
7421 }
7422 }
7423 else
7427 {
7428 /* People keep complaining that the compiler crashes on an invalid
7429 definition of initializer_list, so I guess we should explicitly
7430 reject it. What the compiler internals care about is that it's a
7431 template and has a pointer field followed by an integer field. */
7434 {
7437 {
7441 }
7442 }
7445 "definition of std::initializer_list does not match "
7447 }
7455 else
7459 /* Lambdas are defined by the LAMBDA_EXPR. */
7464 }
7465 \f
7466 /* Hash table to avoid endless recursion when handling references. */
7469 /* Return the dynamic type of INSTANCE, if known.
7470 Used to determine whether the virtual function table is needed
7471 or not.
7473 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7474 of our knowledge of its type. *NONNULL should be initialized
7475 before this function is called. */
7477 static tree
7479 {
7480 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
7483 {
7487 else
7491 /* This is a call to a constructor, hence it's never zero. */
7493 {
7497 }
7501 /* This is a call to a constructor, hence it's never zero. */
7503 {
7507 }
7516 /* Propagate nonnull. */
7521 CASE_CONVERT:
7527 {
7528 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7529 with a real object -- given &p->f, p can still be null. */
7531 /* ??? Probably should check DECL_WEAK here. */
7534 }
7538 /* If this component is really a base class reference, then the field
7539 itself isn't definitive. */
7548 {
7552 }
7553 /* fall through. */
7558 {
7562 }
7564 {
7568 /* if we're in a ctor or dtor, we know our type. If
7569 current_class_ptr is set but we aren't in a function, we're in
7570 an NSDMI (and therefore a constructor). */
7575 {
7579 }
7580 }
7582 {
7583 /* We only need one hash table because it is always left empty. */
7585 fixed_type_or_null_ref_ht
7588 /* Reference variables should be references to objects. */
7592 /* Enter the INSTANCE in a table to prevent recursion; a
7593 variable's initializer may refer to the variable
7594 itself. */
7599 {
7600 tree type;
7609 }
7610 }
7615 }
7616 #undef RECUR
7617 }
7619 /* Return nonzero if the dynamic type of INSTANCE is known, and
7620 equivalent to the static type. We also handle the case where
7621 INSTANCE is really a pointer. Return negative if this is a
7622 ctor/dtor. There the dynamic type is known, but this might not be
7623 the most derived base of the original object, and hence virtual
7624 bases may not be laid out according to this type.
7626 Used to determine whether the virtual function table is needed
7627 or not.
7629 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7630 of our knowledge of its type. *NONNULL should be initialized
7631 before this function is called. */
7633 int
7635 {
7638 tree fixed;
7640 /* processing_template_decl can be false in a template if we're in
7641 instantiate_non_dependent_expr, but we still want to suppress
7642 this check. */
7644 {
7645 /* In a template we only care about the type of the result. */
7649 }
7659 }
7661 \f
7662 void
7664 {
7667 current_class_stack
7675 }
7677 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7679 static void
7681 {
7682 tree type;
7684 /* We are re-entering the same class we just left, so we don't
7685 have to search the whole inheritance matrix to find all the
7686 decls to bind again. Instead, we install the cached
7687 class_shadowed list and walk through it binding names. */
7690 /* Restore IDENTIFIER_TYPE_VALUE. */
7692 type;
7695 }
7697 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7698 appropriate for TYPE.
7700 So that we may avoid calls to lookup_name, we cache the _TYPE
7701 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7703 For multiple inheritance, we perform a two-pass depth-first search
7704 of the type lattice. */
7706 void
7708 {
7709 class_stack_node_t csn;
7713 /* Make sure there is enough room for the new entry on the stack. */
7715 {
7717 current_class_stack
7719 current_class_stack_size);
7720 }
7722 /* Insert a new entry on the class stack. */
7729 current_class_depth++;
7731 /* Now set up the new type. */
7737 /* By default, things in classes are private, while things in
7738 structures or unions are public. */
7740 ? access_private_node
7746 {
7747 /* Forcibly remove any old class remnants. */
7749 }
7755 else
7757 }
7759 /* When we exit a toplevel class scope, we save its binding level so
7760 that we can restore it quickly. Here, we've entered some other
7761 class, so we must invalidate our cache. */
7763 void
7765 {
7767 }
7769 /* Get out of the current class scope. If we were in a class scope
7770 previously, that is the one popped to. */
7772 void
7774 {
7777 current_class_depth--;
7783 }
7785 /* Mark the top of the class stack as hidden. */
7787 void
7789 {
7792 }
7794 /* Mark the top of the class stack as un-hidden. */
7796 void
7798 {
7801 }
7803 /* Returns 1 if the class type currently being defined is either T or
7804 a nested type of T. Returns the type from the current_class_stack,
7805 which might be equivalent to but not equal to T in case of
7806 constrained partial specializations. */
7808 tree
7810 {
7818 /* We start looking from 1 because entry 0 is from global scope,
7819 and has no type. */
7821 {
7822 tree c;
7825 else
7826 {
7830 }
7835 }
7837 }
7839 /* If either current_class_type or one of its enclosing classes are derived
7840 from T, return the appropriate type. Used to determine how we found
7841 something via unqualified lookup. */
7843 tree
7845 {
7848 /* The bases of a dependent type are unknown. */
7859 {
7864 }
7867 }
7869 /* Return the outermost enclosing class type that is still open, or
7870 NULL_TREE. */
7872 tree
7874 {
7881 {
7888 }
7890 }
7892 /* Returns the innermost class type which is not a lambda closure type. */
7894 tree
7896 {
7899 /* We start looking from 1 because entry 0 is from global scope,
7900 and has no type. */
7902 {
7903 tree c;
7906 else
7907 {
7911 }
7916 }
7918 }
7920 /* When entering a class scope, all enclosing class scopes' names with
7921 static meaning (static variables, static functions, types and
7922 enumerators) have to be visible. This recursive function calls
7923 pushclass for all enclosing class contexts until global or a local
7924 scope is reached. TYPE is the enclosed class. */
7926 void
7928 {
7929 /* A namespace might be passed in error cases, like A::B:C. */
7937 }
7939 /* Undoes a push_nested_class call. */
7941 void
7943 {
7949 }
7951 /* Returns the number of extern "LANG" blocks we are nested within. */
7953 int
7955 {
7957 }
7959 /* Set global variables CURRENT_LANG_NAME to appropriate value
7960 so that behavior of name-mangling machinery is correct. */
7962 void
7964 {
7971 else
7973 }
7975 /* Get out of the current language scope. */
7977 void
7979 {
7981 }
7982 \f
7983 /* Type instantiation routines. */
7985 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7986 matches the TARGET_TYPE. If there is no satisfactory match, return
7987 error_mark_node, and issue an error & warning messages under
7988 control of FLAGS. Permit pointers to member function if FLAGS
7989 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7990 a template-id, and EXPLICIT_TARGS are the explicitly provided
7991 template arguments.
7993 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7994 is the base path used to reference those member functions. If
7995 the address is resolved to a member function, access checks will be
7996 performed and errors issued if appropriate. */
7998 static tree
8000 tree overload,
8001 tsubst_flags_t complain,
8003 tree explicit_targs,
8004 tree access_path)
8005 {
8006 /* Here's what the standard says:
8008 [over.over]
8010 If the name is a function template, template argument deduction
8011 is done, and if the argument deduction succeeds, the deduced
8012 arguments are used to generate a single template function, which
8013 is added to the set of overloaded functions considered.
8015 Non-member functions and static member functions match targets of
8016 type "pointer-to-function" or "reference-to-function." Nonstatic
8017 member functions match targets of type "pointer-to-member
8018 function;" the function type of the pointer to member is used to
8019 select the member function from the set of overloaded member
8020 functions. If a nonstatic member function is selected, the
8021 reference to the overloaded function name is required to have the
8022 form of a pointer to member as described in 5.3.1.
8024 If more than one function is selected, any template functions in
8025 the set are eliminated if the set also contains a non-template
8026 function, and any given template function is eliminated if the
8027 set contains a second template function that is more specialized
8028 than the first according to the partial ordering rules 14.5.5.2.
8029 After such eliminations, if any, there shall remain exactly one
8030 selected function. */
8033 /* We store the matches in a TREE_LIST rooted here. The functions
8034 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
8035 interoperability with most_specialized_instantiation. */
8037 tree fn;
8038 tree target_fn_type;
8040 /* By the time we get here, we should be seeing only real
8041 pointer-to-member types, not the internal POINTER_TYPE to
8042 METHOD_TYPE representation. */
8048 /* Check that the TARGET_TYPE is reasonable. */
8053 /* This is OK, too. */
8056 /* This is OK, too. This comes from a conversion to reference
8057 type. */
8059 else
8060 {
8066 }
8068 /* Non-member functions and static member functions match targets of type
8069 "pointer-to-function" or "reference-to-function." Nonstatic member
8070 functions match targets of type "pointer-to-member-function;" the
8071 function type of the pointer to member is used to select the member
8072 function from the set of overloaded member functions.
8074 So figure out the FUNCTION_TYPE that we want to match against. */
8077 /* If we can find a non-template function that matches, we can just
8078 use it. There's no point in generating template instantiations
8079 if we're just going to throw them out anyhow. But, of course, we
8080 can only do this when we don't *need* a template function. */
8083 {
8087 /* We're not looking for templates just yet. */
8091 /* We're looking for a non-static member, and this isn't
8092 one, or vice versa. */
8095 /* In C++17 we need the noexcept-qualifier to compare types. */
8099 /* See if there's a match. */
8104 }
8106 /* Now, if we've already got a match (or matches), there's no need
8107 to proceed to the template functions. But, if we don't have a
8108 match we need to look at them, too. */
8110 {
8111 tree target_arg_types;
8112 tree target_ret_type;
8115 tree arg;
8129 {
8131 tree instantiation;
8132 tree targs;
8135 /* We're only looking for templates. */
8140 /* We're not looking for a non-static member, and this is
8141 one, or vice versa. */
8146 /* If the template has a deduced return type, don't expose it to
8147 template argument deduction. */
8151 /* Try to do argument deduction. */
8158 /* Instantiation failed. */
8161 /* Constraints must be satisfied. This is done before
8162 return type deduction since that instantiates the
8163 function. */
8167 /* And now force instantiation to do return type deduction. */
8169 {
8175 }
8177 /* In C++17 we need the noexcept-qualifier to compare types. */
8181 /* See if there's a match. */
8186 }
8188 /* Now, remove all but the most specialized of the matches. */
8190 {
8195 NULL_TREE,
8196 NULL_TREE);
8197 }
8198 }
8200 /* Now we should have exactly one function in MATCHES. */
8202 {
8203 /* There were *no* matches. */
8205 {
8210 }
8212 }
8214 {
8215 /* There were too many matches. First check if they're all
8216 the same function. */
8221 /* For multi-versioned functions, more than one match is just fine and
8222 decls_match will return false as they are different. */
8230 {
8232 {
8236 /* Since print_candidates expects the functions in the
8237 TREE_VALUE slot, we flip them here. */
8242 }
8245 }
8246 }
8248 /* Good, exactly one match. Now, convert it to the correct type. */
8253 {
8261 {
8264 }
8265 }
8267 /* If a pointer to a function that is multi-versioned is requested, the
8268 pointer to the dispatcher function is returned instead. This works
8269 well because indirectly calling the function will dispatch the right
8270 function version at run-time. */
8272 {
8276 /* Mark all the versions corresponding to the dispatcher as used. */
8279 }
8281 /* If we're doing overload resolution purely for the purpose of
8282 determining conversion sequences, we should not consider the
8283 function used. If this conversion sequence is selected, the
8284 function will be marked as used at this point. */
8286 {
8287 /* Make =delete work with SFINAE. */
8292 }
8294 /* We could not check access to member functions when this
8295 expression was originally created since we did not know at that
8296 time to which function the expression referred. */
8298 {
8301 }
8305 else
8306 {
8307 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
8308 will mark the function as addressed, but here we must do it
8309 explicitly. */
8313 }
8314 }
8316 /* This function will instantiate the type of the expression given in
8317 RHS to match the type of LHSTYPE. If errors exist, then return
8318 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
8319 we complain on errors. If we are not complaining, never modify rhs,
8320 as overload resolution wants to try many possible instantiations, in
8321 the hope that at least one will work.
8323 For non-recursive calls, LHSTYPE should be a function, pointer to
8324 function, or a pointer to member function. */
8326 tree
8328 {
8335 {
8339 }
8342 {
8351 /* Microsoft allows `A::f' to be resolved to a
8352 pointer-to-member. */
8353 ;
8354 else
8355 {
8360 }
8361 }
8364 {
8367 }
8369 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
8370 deduce any type information. */
8372 {
8376 }
8378 /* If we instantiate a template, and it is a A ?: C expression
8379 with omitted B, look through the SAVE_EXPR. */
8383 /* There are only a few kinds of expressions that may have a type
8384 dependent on overload resolution. */
8390 /* This should really only be used when attempting to distinguish
8391 what sort of a pointer to function we have. For now, any
8392 arithmetic operation which is not supported on pointers
8393 is rejected as an error. */
8396 {
8398 {
8404 /* Do not lose object's side effects. */
8408 }
8415 /* This can happen if we are forming a pointer-to-member for a
8416 member template. */
8419 /* Fall through. */
8422 {
8426 return
8430 }
8434 return
8438 access_path);
8441 {
8446 }
8453 }
8455 }
8456 \f
8457 /* Return the name of the virtual function pointer field
8458 (as an IDENTIFIER_NODE) for the given TYPE. Note that
8459 this may have to look back through base types to find the
8460 ultimate field name. (For single inheritance, these could
8461 all be the same name. Who knows for multiple inheritance). */
8463 static tree
8465 {
8471 {
8477 }
8485 }
8487 void
8489 {
8496 {
8501 }
8502 }
8504 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
8505 according to [class]:
8506 The class-name is also inserted
8507 into the scope of the class itself. For purposes of access checking,
8508 the inserted class name is treated as if it were a public member name. */
8510 void
8512 {
8529 }
8531 /* Returns 1 if TYPE contains only padding bytes. */
8533 int
8535 {
8543 }
8545 /* Returns true if TYPE contains no actual data, just various
8546 possible combinations of empty classes and possibly a vptr. */
8548 bool
8550 {
8552 {
8553 tree field;
8554 tree binfo;
8555 tree base_binfo;
8558 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8559 out, but we'd like to be able to check this before then. */
8570 /* An unnamed bit-field is not a data member. */
8575 }
8580 }
8582 /* Note that NAME was looked up while the current class was being
8583 defined and that the result of that lookup was DECL. */
8585 void
8587 {
8588 splay_tree names_used;
8590 /* If we're not defining a class, there's nothing to do. */
8596 /* If there's already a binding for this NAME, then we don't have
8597 anything to worry about. */
8610 }
8612 /* Note that NAME was declared (as DECL) in the current class. Check
8613 to see that the declaration is valid. */
8615 void
8617 {
8618 splay_tree names_used;
8619 splay_tree_node n;
8621 /* Look to see if we ever used this name. */
8622 names_used
8626 /* The C language allows members to be declared with a type of the same
8627 name, and the C++ standard says this diagnostic is not required. So
8628 allow it in extern "C" blocks unless predantic is specified.
8629 Allow it in all cases if -ms-extensions is specified. */
8635 {
8636 /* [basic.scope.class]
8638 A name N used in a class S shall refer to the same declaration
8639 in its context and when re-evaluated in the completed scope of
8640 S. */
8645 }
8646 }
8648 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8649 Secondary vtables are merged with primary vtables; this function
8650 will return the VAR_DECL for the primary vtable. */
8652 tree
8654 {
8655 tree decl;
8659 {
8662 }
8666 }
8669 /* Returns the binfo for the primary base of BINFO. If the resulting
8670 BINFO is a virtual base, and it is inherited elsewhere in the
8671 hierarchy, then the returned binfo might not be the primary base of
8672 BINFO in the complete object. Check BINFO_PRIMARY_P or
8673 BINFO_LOST_PRIMARY_P to be sure. */
8675 static tree
8677 {
8678 tree primary_base;
8685 }
8687 /* As above, but iterate until we reach the binfo that actually provides the
8688 vptr for BINFO. */
8690 static tree
8692 {
8696 {
8701 }
8703 }
8705 /* Returns true if BINFO gets its vptr from a virtual base of the most derived
8706 type. Note that the virtual inheritance might be above or below BINFO in
8707 the hierarchy. */
8709 bool
8711 {
8715 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is
8716 a morally virtual base. */
8719 }
8721 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8723 static int
8725 {
8729 }
8731 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8732 INDENT should be zero when called from the top level; it is
8733 incremented recursively. IGO indicates the next expected BINFO in
8734 inheritance graph ordering. */
8736 static tree
8738 dump_flags_t flags,
8739 tree binfo,
8740 tree igo,
8742 {
8744 tree base_binfo;
8752 {
8755 }
8770 {
8774 TFF_PLAIN_IDENTIFIER),
8776 }
8778 {
8781 }
8786 {
8790 {
8794 TFF_PLAIN_IDENTIFIER));
8795 }
8797 {
8801 TFF_PLAIN_IDENTIFIER));
8802 }
8804 {
8808 TFF_PLAIN_IDENTIFIER));
8809 }
8811 {
8815 TFF_PLAIN_IDENTIFIER));
8816 }
8820 }
8826 }
8828 /* Dump the BINFO hierarchy for T. */
8830 static void
8832 {
8844 }
8846 /* Debug interface to hierarchy dumping. */
8848 void
8850 {
8852 }
8854 static void
8856 {
8857 dump_flags_t flags;
8859 {
8862 }
8863 }
8865 static void
8867 {
8868 tree value;
8870 HOST_WIDE_INT elt;
8878 TFF_PLAIN_IDENTIFIER));
8885 }
8887 static void
8889 {
8890 dump_flags_t flags;
8897 {
8904 {
8909 }
8913 }
8916 }
8918 static void
8920 {
8921 dump_flags_t flags;
8928 {
8933 }
8936 }
8938 /* Dump a function or thunk and its thunkees. */
8940 static void
8942 {
8945 tree thunks;
8953 {
8963 else
8969 }
8973 }
8975 /* Dump the thunks for FN. */
8977 void
8979 {
8981 }
8983 /* Virtual function table initialization. */
8985 /* Create all the necessary vtables for T and its base classes. */
8987 static void
8989 {
8990 tree vbase;
8994 /* We lay out the primary and secondary vtables in one contiguous
8995 vtable. The primary vtable is first, followed by the non-virtual
8996 secondary vtables in inheritance graph order. */
9000 /* Then come the virtual bases, also in inheritance graph order. */
9002 {
9006 }
9010 }
9012 /* Initialize the vtable for BINFO with the INITS. */
9014 static void
9016 {
9017 tree decl;
9023 }
9025 /* Build the VTT (virtual table table) for T.
9026 A class requires a VTT if it has virtual bases.
9028 This holds
9029 1 - primary virtual pointer for complete object T
9030 2 - secondary VTTs for each direct non-virtual base of T which requires a
9031 VTT
9032 3 - secondary virtual pointers for each direct or indirect base of T which
9033 has virtual bases or is reachable via a virtual path from T.
9034 4 - secondary VTTs for each direct or indirect virtual base of T.
9036 Secondary VTTs look like complete object VTTs without part 4. */
9038 static void
9040 {
9041 tree type;
9042 tree vtt;
9043 tree index;
9046 /* Build up the initializers for the VTT. */
9051 /* If we didn't need a VTT, we're done. */
9055 /* Figure out the type of the VTT. */
9059 /* Now, build the VTT object itself. */
9062 /* Add the VTT to the vtables list. */
9067 }
9069 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
9070 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
9071 and CHAIN the vtable pointer for this binfo after construction is
9072 complete. VALUE can also be another BINFO, in which case we recurse. */
9074 static tree
9076 {
9077 tree vt;
9080 {
9086 else
9088 }
9091 }
9093 /* Data for secondary VTT initialization. */
9094 struct secondary_vptr_vtt_init_data
9095 {
9096 /* Is this the primary VTT? */
9099 /* Current index into the VTT. */
9100 tree index;
9102 /* Vector of initializers built up. */
9105 /* The type being constructed by this secondary VTT. */
9106 tree type_being_constructed;
9107 };
9109 /* Recursively build the VTT-initializer for BINFO (which is in the
9110 hierarchy dominated by T). INITS points to the end of the initializer
9111 list to date. INDEX is the VTT index where the next element will be
9112 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
9113 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
9114 for virtual bases of T. When it is not so, we build the constructor
9115 vtables for the BINFO-in-T variant. */
9117 static void
9120 {
9122 tree b;
9123 tree init;
9124 secondary_vptr_vtt_init_data data;
9127 /* We only need VTTs for subobjects with virtual bases. */
9131 /* We need to use a construction vtable if this is not the primary
9132 VTT. */
9134 {
9137 /* Record the offset in the VTT where this sub-VTT can be found. */
9139 }
9141 /* Add the address of the primary vtable for the complete object. */
9145 {
9148 }
9151 /* Recursively add the secondary VTTs for non-virtual bases. */
9156 /* Add secondary virtual pointers for all subobjects of BINFO with
9157 either virtual bases or reachable along a virtual path, except
9158 subobjects that are non-virtual primary bases. */
9168 /* data.inits might have grown as we added secondary virtual pointers.
9169 Make sure our caller knows about the new vector. */
9173 /* Add the secondary VTTs for virtual bases in inheritance graph
9174 order. */
9176 {
9181 }
9182 else
9183 /* Remove the ctor vtables we created. */
9185 }
9187 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
9188 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
9190 static tree
9192 {
9195 /* We don't care about bases that don't have vtables. */
9199 /* We're only interested in proper subobjects of the type being
9200 constructed. */
9204 /* We're only interested in bases with virtual bases or reachable
9205 via a virtual path from the type being constructed. */
9210 /* We're not interested in non-virtual primary bases. */
9214 /* Record the index where this secondary vptr can be found. */
9216 {
9221 {
9222 /* It's a primary virtual base, and this is not a
9223 construction vtable. Find the base this is primary of in
9224 the inheritance graph, and use that base's vtable
9225 now. */
9228 }
9229 }
9231 /* Add the initializer for the secondary vptr itself. */
9234 /* Advance the vtt index. */
9239 }
9241 /* Called from build_vtt_inits via dfs_walk. After building
9242 constructor vtables and generating the sub-vtt from them, we need
9243 to restore the BINFO_VTABLES that were scribbled on. DATA is the
9244 binfo of the base whose sub vtt was generated. */
9246 static tree
9248 {
9252 /* If this class has no vtable, none of its bases do. */
9256 /* This might be a primary base, so have no vtable in this
9257 hierarchy. */
9260 /* If we scribbled the construction vtable vptr into BINFO, clear it
9261 out now. */
9267 }
9269 /* Build the construction vtable group for BINFO which is in the
9270 hierarchy dominated by T. */
9272 static void
9274 {
9275 tree type;
9276 tree vtbl;
9277 tree id;
9278 tree vbase;
9281 /* See if we've already created this construction vtable group. */
9287 /* Build a version of VTBL (with the wrong type) for use in
9288 constructing the addresses of secondary vtables in the
9289 construction vtable group. */
9292 /* Don't export construction vtables from shared libraries. Even on
9293 targets that don't support hidden visibility, this tells
9294 can_refer_decl_in_current_unit_p not to assume that it's safe to
9295 access from a different compilation unit (bz 54314). */
9303 /* Add the vtables for each of our virtual bases using the vbase in T
9304 binfo. */
9306 vbase;
9308 {
9309 tree b;
9316 }
9318 /* Figure out the type of the construction vtable. */
9325 /* Initialize the construction vtable. */
9329 }
9331 /* Add the vtbl initializers for BINFO (and its bases other than
9332 non-virtual primaries) to the list of INITS. BINFO is in the
9333 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
9334 the constructor the vtbl inits should be accumulated for. (If this
9335 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
9336 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
9337 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
9338 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
9339 but are not necessarily the same in terms of layout. */
9341 static void
9343 tree orig_binfo,
9344 tree rtti_binfo,
9345 tree vtbl,
9346 tree t,
9348 {
9350 tree base_binfo;
9355 /* If it doesn't have a vptr, we don't do anything. */
9359 /* If we're building a construction vtable, we're not interested in
9360 subobjects that don't require construction vtables. */
9366 /* Build the initializers for the BINFO-in-T vtable. */
9369 /* Walk the BINFO and its bases. We walk in preorder so that as we
9370 initialize each vtable we can figure out at what offset the
9371 secondary vtable lies from the primary vtable. We can't use
9372 dfs_walk here because we need to iterate through bases of BINFO
9373 and RTTI_BINFO simultaneously. */
9375 {
9376 /* Skip virtual bases. */
9382 inits);
9383 }
9384 }
9386 /* Called from accumulate_vtbl_inits. Adds the initializers for the
9387 BINFO vtable to L. */
9389 static void
9391 tree orig_binfo,
9392 tree rtti_binfo,
9393 tree orig_vtbl,
9394 tree t,
9396 {
9403 {
9404 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
9405 primary virtual base. If it is not the same primary in
9406 the hierarchy of T, we'll need to generate a ctor vtable
9407 for it, to place at its location in T. If it is the same
9408 primary, we still need a VTT entry for the vtable, but it
9409 should point to the ctor vtable for the base it is a
9410 primary for within the sub-hierarchy of RTTI_BINFO.
9412 There are three possible cases:
9414 1) We are in the same place.
9415 2) We are a primary base within a lost primary virtual base of
9416 RTTI_BINFO.
9417 3) We are primary to something not a base of RTTI_BINFO. */
9419 tree b;
9422 /* First, look through the bases we are primary to for RTTI_BINFO
9423 or a virtual base. */
9426 {
9431 }
9432 /* If we run out of primary links, keep looking down our
9433 inheritance chain; we might be an indirect primary. */
9437 found:
9439 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
9440 base B and it is a base of RTTI_BINFO, this is case 2. In
9441 either case, we share our vtable with LAST, i.e. the
9442 derived-most base within B of which we are a primary. */
9445 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
9446 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
9447 binfo_ctor_vtable after everything's been set up. */
9450 /* Otherwise, this is case 3 and we get our own. */
9451 }
9458 {
9459 tree index;
9462 /* Add the initializer for this vtable. */
9466 /* Figure out the position to which the VPTR should point. */
9472 }
9475 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
9476 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
9477 straighten this out. */
9480 /* Throw away any unneeded intializers. */
9482 else
9483 /* For an ordinary vtable, set BINFO_VTABLE. */
9485 }
9490 /* Construct the initializer for BINFO's virtual function table. BINFO
9491 is part of the hierarchy dominated by T. If we're building a
9492 construction vtable, the ORIG_BINFO is the binfo we should use to
9493 find the actual function pointers to put in the vtable - but they
9494 can be overridden on the path to most-derived in the graph that
9495 ORIG_BINFO belongs. Otherwise,
9496 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
9497 BINFO that should be indicated by the RTTI information in the
9498 vtable; it will be a base class of T, rather than T itself, if we
9499 are building a construction vtable.
9501 The value returned is a TREE_LIST suitable for wrapping in a
9502 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
9503 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
9504 number of non-function entries in the vtable.
9506 It might seem that this function should never be called with a
9507 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
9508 base is always subsumed by a derived class vtable. However, when
9509 we are building construction vtables, we do build vtables for
9510 primary bases; we need these while the primary base is being
9511 constructed. */
9513 static void
9515 tree orig_binfo,
9516 tree t,
9517 tree rtti_binfo,
9520 {
9521 tree v;
9522 vtbl_init_data vid;
9524 tree vbinfo;
9528 /* Initialize VID. */
9536 /* The first vbase or vcall offset is at index -3 in the vtable. */
9539 /* Add entries to the vtable for RTTI. */
9542 /* Create an array for keeping track of the functions we've
9543 processed. When we see multiple functions with the same
9544 signature, we share the vcall offsets. */
9546 /* Add the vcall and vbase offset entries. */
9549 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
9550 build_vbase_offset_vtbl_entries. */
9555 /* If the target requires padding between data entries, add that now. */
9557 {
9562 /* Move data entries into their new positions and add padding
9563 after the new positions. Iterate backwards so we don't
9564 overwrite entries that we would need to process later. */
9567 ix--)
9568 {
9576 {
9580 null_pointer_node);
9581 }
9582 }
9583 }
9588 /* The initializers for virtual functions were built up in reverse
9589 order. Straighten them out and add them to the running list in one
9590 step. */
9599 /* Go through all the ordinary virtual functions, building up
9600 initializers. */
9602 {
9603 tree delta;
9604 tree vcall_index;
9611 {
9615 {
9618 }
9620 }
9622 /* If the only definition of this function signature along our
9623 primary base chain is from a lost primary, this vtable slot will
9624 never be used, so just zero it out. This is important to avoid
9625 requiring extra thunks which cannot be generated with the function.
9627 We first check this in update_vtable_entry_for_fn, so we handle
9628 restored primary bases properly; we also need to do it here so we
9629 zero out unused slots in ctor vtables, rather than filling them
9630 with erroneous values (though harmless, apart from relocation
9631 costs). */
9636 {
9637 /* Pull the offset for `this', and the function to call, out of
9638 the list. */
9645 /* You can't call an abstract virtual function; it's abstract.
9646 So, we replace these functions with __pure_virtual. */
9648 {
9651 {
9653 abort_fndecl_addr
9657 }
9658 }
9659 /* Likewise for deleted virtuals. */
9661 {
9663 {
9667 dvirt_fn = push_library_fn
9671 }
9676 }
9677 else
9678 {
9680 {
9685 }
9686 /* Take the address of the function, considering it to be of an
9687 appropriate generic type. */
9691 /* Don't refer to a virtual destructor from a constructor
9692 vtable or a vtable for an abstract class, since destroying
9693 an object under construction is undefined behavior and we
9694 don't want it to be considered a candidate for speculative
9695 devirtualization. But do create the thunk for ABI
9696 compliance. */
9701 }
9702 }
9704 /* And add it to the chain of initializers. */
9706 {
9711 else
9713 {
9719 }
9720 }
9721 else
9723 }
9724 }
9726 /* Adds to vid->inits the initializers for the vbase and vcall
9727 offsets in BINFO, which is in the hierarchy dominated by T. */
9729 static void
9731 {
9732 tree b;
9734 /* If this is a derived class, we must first create entries
9735 corresponding to the primary base class. */
9740 /* Add the vbase entries for this base. */
9742 /* Add the vcall entries for this base. */
9744 }
9746 /* Returns the initializers for the vbase offset entries in the vtable
9747 for BINFO (which is part of the class hierarchy dominated by T), in
9748 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9749 where the next vbase offset will go. */
9751 static void
9753 {
9754 tree vbase;
9755 tree t;
9756 tree non_primary_binfo;
9758 /* If there are no virtual baseclasses, then there is nothing to
9759 do. */
9765 /* We might be a primary base class. Go up the inheritance hierarchy
9766 until we find the most derived class of which we are a primary base:
9767 it is the offset of that which we need to use. */
9770 {
9771 tree b;
9773 /* If we have reached a virtual base, then it must be a primary
9774 base (possibly multi-level) of vid->binfo, or we wouldn't
9775 have called build_vcall_and_vbase_vtbl_entries for it. But it
9776 might be a lost primary, so just skip down to vid->binfo. */
9778 {
9781 }
9787 }
9789 /* Go through the virtual bases, adding the offsets. */
9791 vbase;
9793 {
9794 tree b;
9795 tree delta;
9800 /* Find the instance of this virtual base in the complete
9801 object. */
9804 /* If we've already got an offset for this virtual base, we
9805 don't need another one. */
9810 /* Figure out where we can find this vbase offset. */
9819 /* The vbase offset had better be the same. */
9822 /* The next vbase will come at a more negative offset. */
9826 /* The initializer is the delta from BINFO to this virtual base.
9827 The vbase offsets go in reverse inheritance-graph order, and
9828 we are walking in inheritance graph order so these end up in
9829 the right order. */
9836 }
9837 }
9839 /* Adds the initializers for the vcall offset entries in the vtable
9840 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9841 to VID->INITS. */
9843 static void
9845 {
9846 /* We only need these entries if this base is a virtual base. We
9847 compute the indices -- but do not add to the vtable -- when
9848 building the main vtable for a class. */
9851 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9852 correspond to VID->DERIVED), we are building a primary
9853 construction virtual table. Since this is a primary
9854 virtual table, we do not need the vcall offsets for
9855 BINFO. */
9857 {
9858 /* We need a vcall offset for each of the virtual functions in this
9859 vtable. For example:
9861 class A { virtual void f (); };
9862 class B1 : virtual public A { virtual void f (); };
9863 class B2 : virtual public A { virtual void f (); };
9864 class C: public B1, public B2 { virtual void f (); };
9866 A C object has a primary base of B1, which has a primary base of A. A
9867 C also has a secondary base of B2, which no longer has a primary base
9868 of A. So the B2-in-C construction vtable needs a secondary vtable for
9869 A, which will adjust the A* to a B2* to call f. We have no way of
9870 knowing what (or even whether) this offset will be when we define B2,
9871 so we store this "vcall offset" in the A sub-vtable and look it up in
9872 a "virtual thunk" for B2::f.
9874 We need entries for all the functions in our primary vtable and
9875 in our non-virtual bases' secondary vtables. */
9877 /* If we are just computing the vcall indices -- but do not need
9878 the actual entries -- not that. */
9881 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9883 }
9884 }
9886 /* Build vcall offsets, starting with those for BINFO. */
9888 static void
9890 {
9892 tree primary_binfo;
9893 tree base_binfo;
9895 /* Don't walk into virtual bases -- except, of course, for the
9896 virtual base for which we are building vcall offsets. Any
9897 primary virtual base will have already had its offsets generated
9898 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9902 /* If BINFO has a primary base, process it first. */
9907 /* Add BINFO itself to the list. */
9910 /* Scan the non-primary bases of BINFO. */
9914 }
9916 /* Called from build_vcall_offset_vtbl_entries_r. */
9918 static void
9920 {
9921 /* Make entries for the rest of the virtuals. */
9922 tree orig_fn;
9924 /* The ABI requires that the methods be processed in declaration
9925 order. */
9927 orig_fn;
9931 }
9933 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9935 static void
9937 {
9939 tree vcall_offset;
9940 tree derived_entry;
9942 /* If there is already an entry for a function with the same
9943 signature as FN, then we do not need a second vcall offset.
9944 Check the list of functions already present in the derived
9945 class vtable. */
9947 {
9949 /* We only use one vcall offset for virtual destructors,
9950 even though there are two virtual table entries. */
9954 }
9956 /* If we are building these vcall offsets as part of building
9957 the vtable for the most derived class, remember the vcall
9958 offset. */
9960 {
9963 }
9965 /* The next vcall offset will be found at a more negative
9966 offset. */
9970 /* Keep track of this function. */
9974 {
9975 tree base;
9976 tree fn;
9978 /* Find the overriding function. */
9982 else
9983 {
9986 /* The vbase we're working on is a primary base of
9987 vid->binfo. But it might be a lost primary, so its
9988 BINFO_OFFSET might be wrong, so we just use the
9989 BINFO_OFFSET from vid->binfo. */
9995 vcall_offset);
9996 }
9997 /* Add the initializer to the vtable. */
9999 }
10000 }
10002 /* Return vtbl initializers for the RTTI entries corresponding to the
10003 BINFO's vtable. The RTTI entries should indicate the object given
10004 by VID->rtti_binfo. */
10006 static void
10008 {
10009 tree b;
10010 tree t;
10011 tree offset;
10012 tree decl;
10013 tree init;
10017 /* To find the complete object, we will first convert to our most
10018 primary base, and then add the offset in the vtbl to that value. */
10023 /* The second entry is the address of the typeinfo object. */
10026 else
10029 /* Convert the declaration to a type that can be stored in the
10030 vtable. */
10034 /* Add the offset-to-top entry. It comes earlier in the vtable than
10035 the typeinfo entry. Convert the offset to look like a
10036 function pointer, so that we can put it in the vtable. */
10039 }
10041 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
10042 accessibility. */
10044 bool
10046 {
10049 }
10051 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
10053 bool
10055 {
10059 }
10061 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
10062 class between them, if any. */
10064 tree
10066 {
10078 {
10081 }
10085 }