| blob | 4b9b93a77a778131bbb4870848142d87170f316e |
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. */
1042 /* Create slots for constructors and destructors. */
1046 }
1048 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1051 /* Constructors and destructors go in special slots. */
1056 else
1057 {
1058 tree m;
1061 /* See if we already have an entry with this name. */
1065 {
1068 {
1073 }
1077 {
1080 }
1085 }
1086 }
1089 /* Check to see if we've already got this method. */
1091 {
1093 tree fn_type;
1094 tree method_type;
1095 tree parms1;
1096 tree parms2;
1101 /* Two using-declarations can coexist, we'll complain about ambiguity in
1102 overload resolution. */
1104 /* Except handle inherited constructors specially. */
1108 /* [over.load] Member function declarations with the
1109 same name and the same parameter types cannot be
1110 overloaded if any of them is a static member
1111 function declaration.
1113 [over.load] Member function declarations with the same name and
1114 the same parameter-type-list as well as member function template
1115 declarations with the same name, the same parameter-type-list, and
1116 the same template parameter lists cannot be overloaded if any of
1117 them, but not all, have a ref-qualifier.
1119 [namespace.udecl] When a using-declaration brings names
1120 from a base class into a derived class scope, member
1121 functions in the derived class override and/or hide member
1122 functions with the same name and parameter types in a base
1123 class (rather than conflicting). */
1129 /* Compare the quals on the 'this' parm. Don't compare
1130 the whole types, as used functions are treated as
1131 coming from the using class in overload resolution. */
1134 /* Either both or neither need to be ref-qualified for
1135 differing quals to allow overloading. */
1142 /* For templates, the return type and template parameters
1143 must be identical. */
1156 /* Bring back parameters omitted from an inherited ctor. */
1167 {
1168 /* For function versions, their parms and types match
1169 but they are not duplicates. Record function versions
1170 as and when they are found. extern "C" functions are
1171 not treated as versions. */
1177 {
1178 /* Mark functions as versions if necessary. Modify the mangled
1179 decl name if necessary. */
1181 {
1185 }
1187 {
1191 }
1194 }
1197 {
1199 {
1203 {
1205 {
1206 /* Inheriting the same constructor along different
1207 paths, combine them. */
1208 SET_DECL_INHERITED_CTOR
1211 /* And discard the new one. */
1213 }
1214 else
1215 /* Inherited ctors can coexist until overload
1216 resolution. */
1218 }
1224 basef);
1225 }
1226 /* Otherwise defer to the other function. */
1228 }
1231 /* Defer to the local function. */
1235 {
1236 /* Remove the inherited constructor. */
1239 }
1240 else
1241 {
1247 }
1248 }
1249 }
1251 /* A class should never have more than one destructor. */
1263 {
1266 /* We only expect to add few methods in the COMPLETE_P case, so
1267 just make room for one more method in that case. */
1270 else
1276 else
1278 }
1279 else
1280 /* Replace the current slot. */
1283 }
1285 /* Subroutines of finish_struct. */
1287 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1288 legit, otherwise return 0. */
1290 static int
1292 {
1293 tree elem;
1301 {
1303 {
1307 else
1310 }
1311 else
1312 {
1313 /* They're changing the access to the same thing they changed
1314 it to before. That's OK. */
1315 ;
1316 }
1317 }
1318 else
1319 {
1321 tf_warning_or_error);
1324 }
1326 }
1328 /* Return the access node for DECL's access in its enclosing class. */
1330 tree
1332 {
1336 }
1338 /* Process the USING_DECL, which is a member of T. */
1340 static void
1342 {
1347 tree old_value;
1352 tf_warning_or_error);
1354 {
1359 else
1361 }
1369 ;
1371 {
1373 /* It's OK to use functions from a base when there are functions with
1375 else
1376 {
1383 }
1384 }
1386 {
1393 }
1395 /* Make type T see field decl FDECL with access ACCESS. */
1398 {
1401 }
1402 else
1404 }
1405 \f
1406 /* Data structure for find_abi_tags_r, below. */
1408 struct abi_tag_data
1409 {
1413 };
1415 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1416 in the context of P. TAG can be either an identifier (the DECL_NAME of
1417 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1419 static void
1421 {
1423 {
1425 {
1426 /* We're collecting tags from template arguments or from
1427 the type of a variable or function return type. */
1430 /* Don't inherit this tag multiple times. */
1434 {
1435 /* Tags inherited from type template arguments are only used
1436 to avoid warnings. */
1439 }
1440 /* For functions and variables we want to warn, too. */
1441 }
1443 /* Otherwise we're diagnosing missing tags. */
1445 {
1450 }
1452 {
1456 }
1458 {
1463 }
1464 else
1465 {
1469 {
1473 }
1474 }
1475 }
1476 }
1478 /* Find all the ABI tags in the attribute list ATTR and either call
1479 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1481 static void
1483 {
1490 {
1495 else
1497 }
1498 }
1500 /* Find all the ABI tags on T and its enclosing scopes and either call
1501 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1503 static void
1505 {
1507 {
1508 tree attr;
1510 {
1513 }
1514 else
1515 {
1518 }
1520 }
1521 }
1523 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1524 types with ABI tags, add the corresponding identifiers to the VEC in
1525 *DATA and set IDENTIFIER_MARKED. */
1527 static tree
1529 {
1533 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1534 anyway, but let's make sure of it. */
1542 }
1544 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1545 IDENTIFIER_MARKED on its ABI tags. */
1547 static tree
1549 {
1553 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1554 anyway, but let's make sure of it. */
1562 }
1564 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1565 scopes. */
1567 static void
1569 {
1572 {
1575 {
1576 /* Template arguments are part of the signature. */
1579 {
1582 }
1583 }
1585 /* A function's parameter types are part of the signature, so
1586 we don't need to inherit any tags that are also in them. */
1591 }
1592 }
1594 /* Check that T has all the ABI tags that subobject SUBOB has, or
1595 warn if not. If T is a (variable or function) declaration, also
1596 return any missing tags, and add them to T if JUST_CHECKING is false. */
1598 static tree
1600 {
1608 /* No need to worry about things local to this TU. */
1624 {
1627 }
1628 else
1629 {
1633 else
1637 }
1642 }
1644 /* Check that DECL has all the ABI tags that are used in parts of its type
1645 that are not reflected in its mangled name. */
1647 void
1649 {
1656 }
1658 /* Return any ABI tags that are used in parts of the type of DECL
1659 that are not reflected in its mangled name. This function is only
1660 used in backward-compatible mangling for ABI <11. */
1662 tree
1664 {
1668 /* Don't check DECL_CONV_FN_P here like we do in check_abi_tags, so
1669 that we can use this function for setting need_abi_warning
1670 regardless of the current flag_abi_version. */
1673 else
1675 }
1677 void
1679 {
1689 {
1692 {
1696 }
1697 }
1699 // If we found some tags on our template arguments, add them to our
1700 // abi_tag attribute.
1702 {
1706 else
1710 }
1713 }
1715 /* Return true, iff class T has a non-virtual destructor that is
1716 accessible from outside the class heirarchy (i.e. is public, or
1717 there's a suitable friend. */
1719 static bool
1721 {
1724 /* An implicitly declared destructor is always public. And,
1725 if it were virtual, we would have created it by now. */
1740 }
1742 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1743 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1744 properties of the bases. */
1746 static void
1750 {
1754 tree base_binfo;
1755 tree binfo;
1765 {
1774 /* If any base class is non-literal, so is the derived class. */
1778 /* If the base class doesn't have copy constructors or
1779 assignment operators that take const references, then the
1780 derived class cannot have such a member automatically
1781 generated. */
1790 /* A virtual base does not effect nearly emptiness. */
1791 ;
1793 {
1795 /* And if there is more than one nearly empty base, then the
1796 derived class is not nearly empty either. */
1798 else
1799 /* Remember we've seen one. */
1801 }
1803 /* If the base class is not empty or nearly empty, then this
1804 class cannot be nearly empty. */
1807 /* A lot of properties from the bases also apply to the derived
1808 class. */
1825 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1828 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1834 /* A standard-layout class is a class that:
1835 ...
1836 * has no non-standard-layout base classes, */
1839 {
1840 tree basefield;
1841 /* ...has no base classes of the same type as the first non-static
1842 data member... */
1844 && (same_type_ignoring_top_level_qualifiers_p
1847 else
1848 /* ...either has no non-static data members in the most-derived
1849 class and at most one base class with non-static data
1850 members, or has no base classes with non-static data
1851 members */
1857 {
1860 else
1863 }
1864 }
1866 /* Don't bother collecting tm attributes if transactional memory
1867 support is not enabled. */
1869 {
1873 }
1876 }
1878 /* If one of the base classes had TM attributes, and the current class
1879 doesn't define its own, then the current class inherits one. */
1881 {
1884 }
1885 }
1887 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1888 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1889 that have had a nearly-empty virtual primary base stolen by some
1890 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1891 T. */
1893 static void
1895 {
1899 tree base_binfo;
1901 /* Determine the primary bases of our bases. */
1904 {
1907 /* See if we're the non-virtual primary of our inheritance
1908 chain. */
1910 {
1917 /* We are the primary binfo. */
1919 }
1920 /* Determine if we have a virtual primary base, and mark it so.
1921 */
1923 {
1927 /* Someone already claimed this base. */
1929 else
1930 {
1931 tree delta;
1936 /* A virtual binfo might have been copied from within
1937 another hierarchy. As we're about to use it as a
1938 primary base, make sure the offsets match. */
1946 }
1947 }
1948 }
1950 /* First look for a dynamic direct non-virtual base. */
1952 {
1956 {
1959 }
1960 }
1962 /* A "nearly-empty" virtual base class can be the primary base
1963 class, if no non-virtual polymorphic base can be found. Look for
1964 a nearly-empty virtual dynamic base that is not already a primary
1965 base of something in the hierarchy. If there is no such base,
1966 just pick the first nearly-empty virtual base. */
1972 {
1974 {
1975 /* Found one that is not primary. */
1978 }
1980 /* Remember the first candidate. */
1982 }
1984 found:
1985 /* If we've got a primary base, use it. */
1987 {
1992 /* We are stealing a primary base. */
1996 {
1997 tree delta;
2000 /* A virtual binfo might have been copied from within
2001 another hierarchy. As we're about to use it as a primary
2002 base, make sure the offsets match. */
2007 }
2014 }
2015 }
2017 /* Update the variant types of T. */
2019 void
2021 {
2022 tree variants;
2028 variants;
2030 {
2031 /* These fields are in the _TYPE part of the node, not in
2032 the TYPE_LANG_SPECIFIC component, so they are not shared. */
2042 /* Copy whatever these are holding today. */
2045 }
2046 }
2048 /* KLASS is a class that we're applying may_alias to after the body is
2049 parsed. Fixup any POINTER_TO and REFERENCE_TO types. The
2050 canonical type(s) will be implicitly updated. */
2052 static void
2054 {
2063 }
2065 /* Early variant fixups: we apply attributes at the beginning of the class
2066 definition, and we need to fix up any variants that have already been
2067 made via elaborated-type-specifier so that check_qualified_type works. */
2069 void
2071 {
2072 tree variants;
2086 variants;
2088 {
2089 /* These are the two fields that check_qualified_type looks at and
2090 are affected by attributes. */
2095 else
2100 }
2101 }
2102 \f
2103 /* Set memoizing fields and bits of T (and its variants) for later
2104 use. */
2106 static void
2108 {
2109 /* Fix up variants (if any). */
2113 /* For a class w/o baseclasses, 'finish_struct' has set
2114 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2115 Similarly for a class whose base classes do not have vtables.
2116 When neither of these is true, we might have removed abstract
2117 virtuals (by providing a definition), added some (by declaring
2118 new ones), or redeclared ones from a base class. We need to
2119 recalculate what's really an abstract virtual at this point (by
2120 looking in the vtables). */
2123 /* If this type has a copy constructor or a destructor, force its
2124 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2125 nonzero. This will cause it to be passed by invisible reference
2126 and prevent it from being returned in a register. */
2129 {
2130 tree variants;
2133 {
2136 }
2137 }
2138 }
2140 /* Issue warnings about T having private constructors, but no friends,
2141 and so forth.
2143 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2144 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2145 non-private static member functions. */
2147 static void
2149 {
2152 tree fn;
2155 /* If the class has friends, those entities might create and
2156 access instances, so we should not warn. */
2159 /* We will have warned when the template was declared; there's
2160 no need to warn on every instantiation. */
2162 /* There's no reason to even consider warning about this
2163 class. */
2166 /* We only issue one warning, if more than one applies, because
2167 otherwise, on code like:
2169 class A {
2170 // Oops - forgot `public:'
2171 A();
2172 A(const A&);
2173 ~A();
2174 };
2176 we warn several times about essentially the same problem. */
2178 /* Check to see if all (non-constructor, non-destructor) member
2179 functions are private. (Since there are no friends or
2180 non-private statics, we can't ever call any of the private member
2181 functions.) */
2183 /* We're not interested in compiler-generated methods; they don't
2184 provide any way to call private members. */
2186 {
2188 {
2190 /* A non-private static member function is just like a
2191 friend; it can create and invoke private member
2192 functions, and be accessed without a class
2193 instance. */
2197 /* Keep searching for a static member function. */
2198 }
2201 }
2204 {
2205 /* There are no non-private methods, and there's at least one
2206 private member function that isn't a constructor or
2207 destructor. (If all the private members are
2208 constructors/destructors we want to use the code below that
2209 issues error messages specifically referring to
2210 constructors/destructors.) */
2216 {
2219 }
2221 {
2225 }
2226 }
2228 /* Even if some of the member functions are non-private, the class
2229 won't be useful for much if all the constructors or destructors
2230 are private: such an object can never be created or destroyed. */
2233 {
2236 t);
2238 }
2240 /* Warn about classes that have private constructors and no friends. */
2242 /* Implicitly generated constructors are always public. */
2244 {
2248 /* If a non-template class does not define a copy
2249 constructor, one is defined for it, enabling it to avoid
2250 this warning. For a template class, this does not
2251 happen, and so we would normally get a warning on:
2253 template <class T> class C { private: C(); };
2255 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2256 complete non-template or fully instantiated classes have this
2257 flag set. */
2260 else
2266 /* Ideally, we wouldn't count any constructor that takes
2267 an argument of the class type as a parameter, because
2268 such things cannot be used to construct an instance of
2269 the class unless you already have one. */
2271 else
2275 {
2278 t);
2284 }
2285 }
2286 }
2289 gt_pointer_operator new_value;
2293 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2295 static int
2297 {
2310 }
2312 /* This routine compares two fields like method_name_cmp but using the
2313 pointer operator in resort_field_decl_data. */
2315 static int
2317 {
2326 {
2333 }
2335 }
2337 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2339 void
2342 gt_pointer_operator new_value,
2344 {
2346 {
2350 /* The type conversion ops have to live at the front of the vec, so we
2351 can't sort them. */
2358 {
2362 resort_method_name_cmp);
2363 }
2364 }
2365 }
2367 /* Warn about duplicate methods in fn_fields.
2369 Sort methods that are not special (i.e., constructors, destructors,
2370 and type conversion operators) so that we can find them faster in
2371 search. */
2373 static void
2375 {
2376 tree fn_fields;
2386 /* Clear DECL_IN_AGGR_P for all functions. */
2391 /* Issue warnings about private constructors and such. If there are
2392 no methods, then some public defaults are generated. */
2395 /* The type conversion ops have to live at the front of the vec, so we
2396 can't sort them. */
2405 }
2407 /* Make BINFO's vtable have N entries, including RTTI entries,
2408 vbase and vcall offsets, etc. Set its type and call the back end
2409 to lay it out. */
2411 static void
2413 {
2414 tree atype;
2415 tree vtable;
2420 /* We may have to grow the vtable. */
2423 {
2427 }
2428 }
2430 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2431 have the same signature. */
2433 int
2435 {
2436 /* One destructor overrides another if they are the same kind of
2437 destructor. */
2441 /* But a non-destructor never overrides a destructor, nor vice
2442 versa, nor do different kinds of destructors override
2443 one-another. For example, a complete object destructor does not
2444 override a deleting destructor. */
2453 {
2461 }
2463 }
2465 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2466 subobject. */
2468 static bool
2470 {
2471 tree probe;
2474 {
2478 /* If we meet a virtual base, we can't follow the inheritance
2479 any more. See if the complete type of DERIVED contains
2480 such a virtual base. */
2483 }
2485 }
2488 /* The function for which we are trying to find a final overrider. */
2489 tree fn;
2490 /* The base class in which the function was declared. */
2491 tree declaring_base;
2492 /* The candidate overriders. */
2493 tree candidates;
2494 /* Path to most derived. */
2496 };
2498 /* Add the overrider along the current path to FFOD->CANDIDATES.
2499 Returns true if an overrider was found; false otherwise. */
2501 static bool
2505 {
2506 tree method;
2508 /* If BINFO is not the most derived type, try a more derived class.
2509 A definition there will overrider a definition here. */
2511 {
2512 depth--;
2516 }
2520 {
2523 /* Remove any candidates overridden by this new function. */
2525 {
2526 /* If *CANDIDATE overrides METHOD, then METHOD
2527 cannot override anything else on the list. */
2530 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2533 else
2535 }
2537 /* Add the new function. */
2540 }
2543 }
2545 /* Called from find_final_overrider via dfs_walk. */
2547 static tree
2549 {
2557 }
2559 static tree
2561 {
2566 }
2568 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2569 FN and whose TREE_VALUE is the binfo for the base where the
2570 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2571 DERIVED) is the base object in which FN is declared. */
2573 static tree
2575 {
2576 find_final_overrider_data ffod;
2578 /* Getting this right is a little tricky. This is valid:
2580 struct S { virtual void f (); };
2581 struct T { virtual void f (); };
2582 struct U : public S, public T { };
2584 even though calling `f' in `U' is ambiguous. But,
2586 struct R { virtual void f(); };
2587 struct S : virtual public R { virtual void f (); };
2588 struct T : virtual public R { virtual void f (); };
2589 struct U : public S, public T { };
2591 is not -- there's no way to decide whether to put `S::f' or
2592 `T::f' in the vtable for `R'.
2594 The solution is to look at all paths to BINFO. If we find
2595 different overriders along any two, then there is a problem. */
2599 /* Determine the depth of the hierarchy. */
2610 /* If there was no winner, issue an error message. */
2615 }
2617 /* Return the index of the vcall offset for FN when TYPE is used as a
2618 virtual base. */
2620 static tree
2622 {
2624 tree_pair_p p;
2632 /* There should always be an appropriate index. */
2634 }
2636 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2637 dominated by T. FN is the old function; VIRTUALS points to the
2638 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2639 of that entry in the list. */
2641 static void
2644 {
2645 tree b;
2646 tree overrider;
2647 tree delta;
2648 tree virtual_base;
2649 tree first_defn;
2655 /* Find the nearest primary base (possibly binfo itself) which defines
2656 this function; this is the class the caller will convert to when
2657 calling FN through BINFO. */
2659 {
2664 /* The nearest definition is from a lost primary. */
2667 }
2670 /* Find the final overrider. */
2673 {
2676 }
2679 /* Check for adjusting covariant return types. */
2687 /* If the overrider is invalid, don't even try. */
2689 {
2690 /* If FN is a covariant thunk, we must figure out the adjustment
2691 to the final base FN was converting to. As OVERRIDER_TARGET might
2692 also be converting to the return type of FN, we have to
2693 combine the two conversions here. */
2700 {
2704 }
2705 else
2709 /* Find the equivalent binfo within the return type of the
2710 overriding function. We will want the vbase offset from
2711 there. */
2713 over_return);
2716 {
2717 /* There was no existing virtual thunk (which takes
2718 precedence). So find the binfo of the base function's
2719 return type within the overriding function's return type.
2720 Fortunately we know the covariancy is valid (it
2721 has already been checked), so we can just iterate along
2722 the binfos, which have been chained in inheritance graph
2723 order. Of course it is lame that we have to repeat the
2724 search here anyway -- we should really be caching pieces
2725 of the vtable and avoiding this repeated work. */
2728 /* Find the base binfo within the overriding function's
2729 return type. We will always find a thunk_binfo, except
2730 when the covariancy is invalid (which we will have
2731 already diagnosed). */
2734 thunk_binfo;
2740 /* See if virtual inheritance is involved. */
2742 virtual_offset;
2749 {
2753 {
2754 /* We convert via virtual base. Adjust the fixed
2755 offset to be from there. */
2756 offset =
2760 }
2762 /* There was an existing fixed offset, this must be
2763 from the base just converted to, and the base the
2764 FN was thunking to. */
2766 else
2768 }
2769 }
2772 /* Replace the overriding function with a covariant thunk. We
2773 will emit the overriding function in its own slot as
2774 well. */
2777 }
2778 else
2782 /* If we need a covariant thunk, then we may need to adjust first_defn.
2783 The ABI specifies that the thunks emitted with a function are
2784 determined by which bases the function overrides, so we need to be
2785 sure that we're using a thunk for some overridden base; even if we
2786 know that the necessary this adjustment is zero, there may not be an
2787 appropriate zero-this-adjustment thunk for us to use since thunks for
2788 overriding virtual bases always use the vcall offset.
2790 Furthermore, just choosing any base that overrides this function isn't
2791 quite right, as this slot won't be used for calls through a type that
2792 puts a covariant thunk here. Calling the function through such a type
2793 will use a different slot, and that slot is the one that determines
2794 the thunk emitted for that base.
2796 So, keep looking until we find the base that we're really overriding
2797 in this slot: the nearest primary base that doesn't use a covariant
2798 thunk in this slot. */
2800 {
2802 /* We already know that the overrider needs a covariant thunk. */
2805 {
2812 }
2814 }
2816 /* Assume that we will produce a thunk that convert all the way to
2817 the final overrider, and not to an intermediate virtual base. */
2820 /* See if we can convert to an intermediate virtual base first, and then
2821 use the vcall offset located there to finish the conversion. */
2823 {
2824 /* If we find the final overrider, then we can stop
2825 walking. */
2830 /* If we find a virtual base, and we haven't yet found the
2831 overrider, then there is a virtual base between the
2832 declaring base (first_defn) and the final overrider. */
2834 {
2837 }
2838 }
2840 /* Compute the constant adjustment to the `this' pointer. The
2841 `this' pointer, when this function is called, will point at BINFO
2842 (or one of its primary bases, which are at the same offset). */
2844 /* The `this' pointer needs to be adjusted from the declaration to
2845 the nearest virtual base. */
2850 /* If the nearest definition is in a lost primary, we don't need an
2851 entry in our vtable. Except possibly in a constructor vtable,
2852 if we happen to get our primary back. In that case, the offset
2853 will be zero, as it will be a primary base. */
2855 else
2856 /* The `this' pointer needs to be adjusted from pointing to
2857 BINFO to pointing at the base where the final overrider
2858 appears. */
2869 else
2873 }
2875 /* Called from modify_all_vtables via dfs_walk. */
2877 static tree
2879 {
2881 tree virtuals;
2882 tree old_virtuals;
2886 /* A base without a vtable needs no modification, and its bases
2887 are uninteresting. */
2892 /* Don't do the primary vtable, if it's new. */
2896 /* There's no need to modify the vtable for a non-virtual primary
2897 base; we're not going to use that vtable anyhow. We do still
2898 need to do this for virtual primary bases, as they could become
2899 non-primary in a construction vtable. */
2904 /* Now, go through each of the virtual functions in the virtual
2905 function table for BINFO. Find the final overrider, and update
2906 the BINFO_VIRTUALS list appropriately. */
2909 virtuals;
2913 binfo,
2918 }
2920 /* Update all of the primary and secondary vtables for T. Create new
2921 vtables as required, and initialize their RTTI information. Each
2922 of the functions in VIRTUALS is declared in T and may override a
2923 virtual function from a base class; find and modify the appropriate
2924 entries to point to the overriding functions. Returns a list, in
2925 declaration order, of the virtual functions that are declared in T,
2926 but do not appear in the primary base class vtable, and which
2927 should therefore be appended to the end of the vtable for T. */
2929 static tree
2931 {
2935 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2939 /* Update all of the vtables. */
2942 /* Add virtual functions not already in our primary vtable. These
2943 will be both those introduced by this class, and those overridden
2944 from secondary bases. It does not include virtuals merely
2945 inherited from secondary bases. */
2947 {
2952 {
2953 /* We don't need to adjust the `this' pointer when
2954 calling this function. */
2958 /* This is a function not already in our vtable. Keep it. */
2960 }
2961 else
2962 /* We've already got an entry for this function. Skip it. */
2964 }
2967 }
2969 /* Get the base virtual function declarations in T that have the
2970 indicated NAME. */
2972 static void
2974 {
2977 /* Find virtual functions in T with the indicated NAME. */
2979 {
2983 {
2986 }
2987 }
2994 {
2997 }
2998 }
3000 /* If this declaration supersedes the declaration of
3001 a method declared virtual in the base class, then
3002 mark this field as being virtual as well. */
3004 void
3006 {
3009 /* In [temp.mem] we have:
3011 A specialization of a member function template does not
3012 override a virtual function from a base class. */
3019 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
3020 the error_mark_node so that we know it is an overriding
3021 function. */
3022 {
3029 }
3032 {
3038 }
3043 }
3045 /* Warn about hidden virtual functions that are not overridden in t.
3046 We know that constructors and destructors don't apply. */
3048 static void
3050 {
3052 tree fns;
3055 /* We go through each separately named virtual function. */
3059 {
3060 tree fndecl;
3061 tree base_binfo;
3062 tree binfo;
3065 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
3066 have the same name. Figure out what name that is. */
3068 /* There are no possibly hidden functions yet. */
3070 /* Iterate through all of the base classes looking for possibly
3071 hidden functions. */
3074 {
3077 }
3079 /* If there are no functions to hide, continue. */
3083 /* Remove any overridden functions. */
3085 {
3089 {
3090 /* If the method from the base class has the same
3091 signature as the method from the derived class, it
3092 has been overridden. */
3097 }
3098 }
3100 /* Now give a warning for all base functions without overriders,
3101 as they are hidden. */
3103 tree base_fndecl;
3106 {
3107 /* Here we know it is a hider, and no overrider exists. */
3109 OPT_Woverloaded_virtual,
3113 }
3114 }
3115 }
3117 /* Recursive helper for finish_struct_anon. */
3119 static void
3121 {
3125 {
3126 /* We're generally only interested in entities the user
3127 declared, but we also find nested classes by noticing
3128 the TYPE_DECL that we create implicitly. You're
3129 allowed to put one anonymous union inside another,
3130 though, so we explicitly tolerate that. We use
3131 TYPE_UNNAMED_P rather than ANON_AGGR_TYPE_P so that
3132 we also allow unnamed types used for defining fields. */
3139 {
3140 /* We already complained about static data members in
3141 finish_static_data_member_decl. */
3143 {
3146 "%q#D invalid; an anonymous union can "
3148 else
3150 "%q#D invalid; an anonymous struct can "
3152 }
3154 }
3157 {
3159 {
3163 else
3166 }
3168 {
3172 else
3175 }
3176 }
3181 /* Recurse into the anonymous aggregates to handle correctly
3182 access control (c++/24926):
3184 class A {
3185 union {
3186 union {
3187 int i;
3188 };
3189 };
3190 };
3192 int j=A().i; */
3196 }
3197 }
3199 /* Check for things that are invalid. There are probably plenty of other
3200 things we should check for also. */
3202 static void
3204 {
3206 {
3215 }
3216 }
3218 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3219 will be used later during class template instantiation.
3220 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3221 a non-static member data (FIELD_DECL), a member function
3222 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3223 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3224 When FRIEND_P is nonzero, T is either a friend class
3225 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3226 (FUNCTION_DECL, TEMPLATE_DECL). */
3228 void
3230 {
3231 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3236 }
3238 /* This function is called from declare_virt_assop_and_dtor via
3239 dfs_walk_all.
3241 DATA is a type that direcly or indirectly inherits the base
3242 represented by BINFO. If BINFO contains a virtual assignment [copy
3243 assignment or move assigment] operator or a virtual constructor,
3244 declare that function in DATA if it hasn't been already declared. */
3246 static tree
3248 {
3256 /* A base without a vtable needs no modification, and its bases
3257 are uninteresting. */
3261 /* If this is a primary base, then we have already looked at the
3262 virtual functions of its vtable. */
3266 {
3270 {
3275 }
3279 }
3282 }
3284 /* If the class type T has a direct or indirect base that contains a
3285 virtual assignment operator or a virtual destructor, declare that
3286 function in T if it hasn't been already declared. */
3288 static void
3290 {
3298 dfs_declare_virt_assop_and_dtor,
3300 }
3302 /* Declare the inheriting constructor for class T inherited from base
3303 constructor CTOR with the parameter array PARMS of size NPARMS. */
3305 static void
3307 {
3308 /* We don't declare an inheriting ctor that would be a default,
3309 copy or move ctor for derived or base. */
3314 {
3318 }
3327 {
3330 }
3331 }
3333 /* Declare all the inheriting constructors for class T inherited from base
3334 constructor CTOR. */
3336 static void
3338 {
3342 {
3348 }
3353 {
3357 }
3360 {
3364 }
3365 }
3367 /* Create default constructors, assignment operators, and so forth for
3368 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3369 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3370 the class cannot have a default constructor, copy constructor
3371 taking a const reference argument, or an assignment operator taking
3372 a const reference, respectively. */
3374 static void
3378 {
3379 /* Destructor. */
3381 /* In general, we create destructors lazily. */
3390 /* [class.ctor]
3392 If there is no user-declared constructor for a class, a default
3393 constructor is implicitly declared. */
3395 {
3400 /* Don't force the declaration to get a hard answer; if the
3401 definition would have made the class non-literal, it will still be
3402 non-literal because of the base or member in question, and that
3403 gives a better diagnostic. */
3405 }
3407 /* [class.ctor]
3409 If a class definition does not explicitly declare a copy
3410 constructor, one is declared implicitly. */
3412 {
3418 }
3420 /* If there is no assignment operator, one will be created if and
3421 when it is needed. For now, just record whether or not the type
3422 of the parameter to the assignment operator will be a const or
3423 non-const reference. */
3425 {
3431 }
3433 /* We can't be lazy about declaring functions that might override
3434 a virtual function from a base class. */
3438 {
3442 {
3443 /* declare, then remove the decl */
3451 }
3452 else
3454 }
3455 }
3457 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3458 count the number of fields in TYPE, including anonymous union
3459 members. */
3461 static int
3463 {
3464 tree x;
3467 {
3470 else
3472 }
3474 }
3476 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3477 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3478 elts, starting at offset IDX. */
3480 static int
3482 {
3483 tree x;
3485 {
3488 else
3490 }
3492 }
3494 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3495 starting at offset IDX. */
3497 static int
3501 {
3502 tree values;
3506 }
3508 /* FIELD is a bit-field. We are finishing the processing for its
3509 enclosing type. Issue any appropriate messages and set appropriate
3510 flags. Returns false if an error has been diagnosed. */
3512 static bool
3514 {
3516 tree w;
3518 /* Extract the declared width of the bitfield, which has been
3519 temporarily stashed in DECL_INITIAL. */
3522 /* Remove the bit-field width indicator so that the rest of the
3523 compiler does not treat that value as an initializer. */
3526 /* Detect invalid bit-field type. */
3528 {
3531 }
3532 else
3533 {
3535 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3538 /* detect invalid field size. */
3544 {
3547 }
3549 {
3552 }
3554 {
3557 }
3572 }
3575 {
3579 }
3580 else
3581 {
3582 /* Non-bit-fields are aligned for their type. */
3586 }
3587 }
3589 /* FIELD is a non bit-field. We are finishing the processing for its
3590 enclosing type T. Issue any appropriate messages and set appropriate
3591 flags. */
3593 static bool
3595 tree t,
3598 {
3602 /* In C++98 an anonymous union cannot contain any fields which would change
3603 the settings of CANT_HAVE_CONST_CTOR and friends. */
3605 ;
3606 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3607 structs. So, we recurse through their fields here. */
3609 {
3614 cant_have_const_ctor,
3615 no_const_asn_ref);
3616 }
3617 /* Check members with class type for constructors, destructors,
3618 etc. */
3620 {
3621 /* Never let anything with uninheritable virtuals
3622 make it through without complaint. */
3626 {
3631 field);
3636 field);
3638 {
3642 }
3643 }
3644 else
3645 {
3658 }
3667 }
3672 /* `build_class_init_list' does not recognize
3673 non-FIELD_DECLs. */
3677 }
3679 /* Check the data members (both static and non-static), class-scoped
3680 typedefs, etc., appearing in the declaration of T. Issue
3681 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3682 declaration order) of access declarations; each TREE_VALUE in this
3683 list is a USING_DECL.
3685 In addition, set the following flags:
3687 EMPTY_P
3688 The class is empty, i.e., contains no non-static data members.
3690 CANT_HAVE_CONST_CTOR_P
3691 This class cannot have an implicitly generated copy constructor
3692 taking a const reference.
3694 CANT_HAVE_CONST_ASN_REF
3695 This class cannot have an implicitly generated assignment
3696 operator taking a const reference.
3698 All of these flags should be initialized before calling this
3699 function.
3701 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3702 fields can be added by adding to this chain. */
3704 static void
3708 {
3716 /* Assume there are no access declarations. */
3718 /* Assume this class has no pointer members. */
3720 /* Assume none of the members of this class have default
3721 initializations. */
3725 {
3733 {
3734 /* Save the access declarations for our caller. */
3737 }
3743 /* If we've gotten this far, it's a data member, possibly static,
3744 or an enumerator. */
3748 /* When this goes into scope, it will be a non-local reference. */
3752 {
3753 /* [class.union] (C++98)
3755 If a union contains a static data member, or a member of
3756 reference type, the program is ill-formed.
3758 In C++11 [class.union] says:
3759 If a union contains a non-static data member of reference type
3760 the program is ill-formed. */
3762 {
3766 }
3769 {
3773 }
3774 }
3776 /* Perform error checking that did not get done in
3777 grokdeclarator. */
3779 {
3783 }
3785 {
3789 }
3797 /* Now it can only be a FIELD_DECL. */
3802 /* If at least one non-static data member is non-literal, the whole
3803 class becomes non-literal. Per Core/1453, volatile non-static
3804 data members and base classes are also not allowed.
3805 Note: if the type is incomplete we will complain later on. */
3810 /* A standard-layout class is a class that:
3811 ...
3812 has the same access control (Clause 11) for all non-static data members,
3813 ... */
3820 /* If this is of reference type, check if it needs an init. */
3822 {
3828 {
3829 /* ARM $12.6.2: [A member initializer list] (or, for an
3830 aggregate, initialization by a brace-enclosed list) is the
3831 only way to initialize nonstatic const and reference
3832 members. */
3835 }
3836 }
3841 {
3843 {
3844 warning_at
3847 x);
3849 }
3853 }
3856 /* We don't treat zero-width bitfields as making a class
3857 non-empty. */
3858 ;
3859 else
3860 {
3861 /* The class is non-empty. */
3863 /* The class is not even nearly empty. */
3865 /* If one of the data members contains an empty class,
3866 so does T. */
3870 }
3872 /* This is used by -Weffc++ (see below). Warn only for pointers
3873 to members which might hold dynamic memory. So do not warn
3874 for pointers to functions or pointers to members. */
3880 {
3885 }
3891 {
3893 {
3897 }
3899 {
3903 }
3904 }
3907 /* DR 148 now allows pointers to members (which are POD themselves),
3908 to be allowed in POD structs. */
3917 /* We set DECL_C_BIT_FIELD in grokbitfield.
3918 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3921 cant_have_const_ctor_p,
3922 no_const_asn_ref_p))
3923 {
3928 }
3930 /* Now that we've removed bit-field widths from DECL_INITIAL,
3931 anything left in DECL_INITIAL is an NSDMI that makes the class
3932 non-aggregate in C++11. */
3936 /* If any field is const, the structure type is pseudo-const. */
3938 {
3943 {
3944 /* ARM $12.6.2: [A member initializer list] (or, for an
3945 aggregate, initialization by a brace-enclosed list) is the
3946 only way to initialize nonstatic const and reference
3947 members. */
3950 }
3951 }
3952 /* A field that is pseudo-const makes the structure likewise. */
3954 {
3959 }
3961 /* Core issue 80: A nonstatic data member is required to have a
3962 different name from the class iff the class has a
3963 user-declared constructor. */
3968 }
3970 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3971 it should also define a copy constructor and an assignment operator to
3972 implement the correct copy semantic (deep vs shallow, etc.). As it is
3973 not feasible to check whether the constructors do allocate dynamic memory
3974 and store it within members, we approximate the warning like this:
3976 -- Warn only if there are members which are pointers
3977 -- Warn only if there is a non-trivial constructor (otherwise,
3978 there cannot be memory allocated).
3979 -- Warn only if there is a non-trivial destructor. We assume that the
3980 user at least implemented the cleanup correctly, and a destructor
3981 is needed to free dynamic memory.
3983 This seems enough for practical purposes. */
3985 && has_pointers
3989 {
3993 {
3998 }
4002 }
4004 /* Non-static data member initializers make the default constructor
4005 non-trivial. */
4007 {
4010 }
4012 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
4016 /* Check anonymous struct/anonymous union fields. */
4019 /* We've built up the list of access declarations in reverse order.
4020 Fix that now. */
4022 }
4024 /* If TYPE is an empty class type, records its OFFSET in the table of
4025 OFFSETS. */
4027 static int
4029 {
4030 splay_tree_node n;
4035 /* Record the location of this empty object in OFFSETS. */
4043 type,
4047 }
4049 /* Returns nonzero if TYPE is an empty class type and there is
4050 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
4052 static int
4054 {
4055 splay_tree_node n;
4056 tree t;
4061 /* Record the location of this empty object in OFFSETS. */
4071 }
4073 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
4074 F for every subobject, passing it the type, offset, and table of
4075 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
4076 be traversed.
4078 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
4079 than MAX_OFFSET will not be walked.
4081 If F returns a nonzero value, the traversal ceases, and that value
4082 is returned. Otherwise, returns zero. */
4084 static int
4086 subobject_offset_fn f,
4087 tree offset,
4088 splay_tree offsets,
4089 tree max_offset,
4091 {
4095 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
4096 stop. */
4104 {
4107 }
4110 {
4111 tree field;
4112 tree binfo;
4115 /* Avoid recursing into objects that are not interesting. */
4119 /* Record the location of TYPE. */
4124 /* Iterate through the direct base classes of TYPE. */
4128 {
4129 tree binfo_offset;
4134 tree orig_binfo;
4135 /* We cannot rely on BINFO_OFFSET being set for the base
4136 class yet, but the offsets for direct non-virtual
4137 bases can be calculated by going back to the TYPE. */
4140 offset,
4144 f,
4145 binfo_offset,
4146 offsets,
4147 max_offset,
4151 }
4154 {
4158 /* Iterate through the virtual base classes of TYPE. In G++
4159 3.2, we included virtual bases in the direct base class
4160 loop above, which results in incorrect results; the
4161 correct offsets for virtual bases are only known when
4162 working with the most derived type. */
4166 {
4168 f,
4170 offset,
4172 offsets,
4173 max_offset,
4177 }
4178 else
4179 {
4180 /* We still have to walk the primary base, if it is
4181 virtual. (If it is non-virtual, then it was walked
4182 above.) */
4188 {
4189 r = (walk_subobject_offsets
4194 }
4195 }
4196 }
4198 /* Iterate through the fields of TYPE. */
4203 {
4204 tree field_offset;
4209 f,
4211 offset,
4212 field_offset),
4213 offsets,
4214 max_offset,
4218 }
4219 }
4221 {
4224 tree index;
4226 /* Avoid recursing into objects that are not interesting. */
4229 || !domain
4233 /* Step through each of the elements in the array. */
4237 {
4239 f,
4240 offset,
4241 offsets,
4242 max_offset,
4248 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4249 there's no point in iterating through the remaining
4250 elements of the array. */
4253 }
4254 }
4257 }
4259 /* Record all of the empty subobjects of TYPE (either a type or a
4260 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4261 is being placed at OFFSET; otherwise, it is a base class that is
4262 being placed at OFFSET. */
4264 static void
4266 tree offset,
4267 splay_tree offsets,
4269 {
4270 tree max_offset;
4271 /* If recording subobjects for a non-static data member or a
4272 non-empty base class , we do not need to record offsets beyond
4273 the size of the biggest empty class. Additional data members
4274 will go at the end of the class. Additional base classes will go
4275 either at offset zero (if empty, in which case they cannot
4276 overlap with offsets past the size of the biggest empty class) or
4277 at the end of the class.
4279 However, if we are placing an empty base class, then we must record
4280 all offsets, as either the empty class is at offset zero (where
4281 other empty classes might later be placed) or at the end of the
4282 class (where other objects might then be placed, so other empty
4283 subobjects might later overlap). */
4287 else
4291 }
4293 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4294 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4295 virtual bases of TYPE are examined. */
4297 static int
4299 tree offset,
4300 splay_tree offsets,
4302 {
4303 splay_tree_node max_node;
4305 /* Get the node in OFFSETS that indicates the maximum offset where
4306 an empty subobject is located. */
4308 /* If there aren't any empty subobjects, then there's no point in
4309 performing this check. */
4315 vbases_p);
4316 }
4318 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4319 non-static data member of the type indicated by RLI. BINFO is the
4320 binfo corresponding to the base subobject, OFFSETS maps offsets to
4321 types already located at those offsets. This function determines
4322 the position of the DECL. */
4324 static void
4326 tree decl,
4327 tree binfo,
4328 splay_tree offsets)
4329 {
4332 tree type;
4335 {
4336 /* For the purposes of determining layout conflicts, we want to
4337 use the class type of BINFO; TREE_TYPE (DECL) will be the
4338 CLASSTYPE_AS_BASE version, which does not contain entries for
4339 zero-sized bases. */
4342 }
4343 else
4344 {
4347 }
4349 /* Try to place the field. It may take more than one try if we have
4350 a hard time placing the field without putting two objects of the
4351 same type at the same address. */
4353 {
4356 /* Place this field. */
4360 /* We have to check to see whether or not there is already
4361 something of the same type at the offset we're about to use.
4362 For example, consider:
4364 struct S {};
4365 struct T : public S { int i; };
4366 struct U : public S, public T {};
4368 Here, we put S at offset zero in U. Then, we can't put T at
4369 offset zero -- its S component would be at the same address
4370 as the S we already allocated. So, we have to skip ahead.
4371 Since all data members, including those whose type is an
4372 empty class, have nonzero size, any overlap can happen only
4373 with a direct or indirect base-class -- it can't happen with
4374 a data member. */
4375 /* In a union, overlap is permitted; all members are placed at
4376 offset zero. */
4381 {
4382 /* Strip off the size allocated to this field. That puts us
4383 at the first place we could have put the field with
4384 proper alignment. */
4387 /* Bump up by the alignment required for the type. */
4388 rli->bitpos
4394 }
4397 {
4398 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4399 the offset wasn't aligned like a pointer when we started to
4400 layout this field, that affects its position. */
4403 {
4406 "alignment of %qD increased in -fabi-version=9 "
4408 else
4411 }
4413 }
4414 else
4415 /* There was no conflict. We're done laying out this field. */
4417 }
4419 /* Now that we know where it will be placed, update its
4420 BINFO_OFFSET. */
4422 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4423 this point because their BINFO_OFFSET is copied from another
4424 hierarchy. Therefore, we may not need to add the entire
4425 OFFSET. */
4431 }
4433 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4435 static int
4437 tree offset,
4439 {
4441 }
4443 /* Layout the empty base BINFO. EOC indicates the byte currently just
4444 past the end of the class, and should be correctly aligned for a
4445 class of the type indicated by BINFO; OFFSETS gives the offsets of
4446 the empty bases allocated so far. T is the most derived
4447 type. Return nonzero iff we added it at the end. */
4449 static bool
4452 {
4453 tree alignment;
4457 /* This routine should only be used for empty classes. */
4462 propagate_binfo_offsets
4466 /* This is an empty base class. We first try to put it at offset
4467 zero. */
4470 offsets,
4472 {
4473 /* That didn't work. Now, we move forward from the next
4474 available spot in the class. */
4478 {
4481 offsets,
4483 /* We finally found a spot where there's no overlap. */
4486 /* There's overlap here, too. Bump along to the next spot. */
4488 }
4489 }
4492 {
4497 }
4500 }
4502 /* Build the FIELD_DECL for BASETYPE as a base of T, add it to the chain of
4503 fields at NEXT_FIELD, and return it. */
4505 static tree
4507 {
4508 /* Create the FIELD_DECL. */
4522 /* Add the new FIELD_DECL to the list of fields for T. */
4528 }
4530 /* Layout the base given by BINFO in the class indicated by RLI.
4531 *BASE_ALIGN is a running maximum of the alignments of
4532 any base class. OFFSETS gives the location of empty base
4533 subobjects. T is the most derived type. Return nonzero if the new
4534 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4535 *NEXT_FIELD, unless BINFO is for an empty base class.
4537 Returns the location at which the next field should be inserted. */
4542 {
4547 /* This error is now reported in xref_tag, thus giving better
4548 location information. */
4551 /* Place the base class. */
4553 {
4554 tree decl;
4556 /* The containing class is non-empty because it has a non-empty
4557 base class. */
4560 /* Create the FIELD_DECL. */
4563 /* Try to place the field. It may take more than one try if we
4564 have a hard time placing the field without putting two
4565 objects of the same type at the same address. */
4567 }
4568 else
4569 {
4570 tree eoc;
4573 /* On some platforms (ARM), even empty classes will not be
4574 byte-aligned. */
4579 /* A nearly-empty class "has no proper base class that is empty,
4580 not morally virtual, and at an offset other than zero." */
4582 {
4585 /* The check above (used in G++ 3.2) is insufficient because
4586 an empty class placed at offset zero might itself have an
4587 empty base at a nonzero offset. */
4589 empty_base_at_nonzero_offset_p,
4590 size_zero_node,
4595 }
4597 /* We used to not create a FIELD_DECL for empty base classes because of
4598 back end issues with overlapping FIELD_DECLs, but that doesn't seem to
4599 be a problem anymore. We need them to handle initialization of C++17
4600 aggregate bases. */
4602 {
4607 }
4609 /* An empty virtual base causes a class to be non-empty
4610 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4611 here because that was already done when the virtual table
4612 pointer was created. */
4613 }
4615 /* Record the offsets of BINFO and its base subobjects. */
4618 offsets,
4622 }
4624 /* Layout all of the non-virtual base classes. Record empty
4625 subobjects in OFFSETS. T is the most derived type. Return nonzero
4626 if the type cannot be nearly empty. The fields created
4627 corresponding to the base classes will be inserted at
4628 *NEXT_FIELD. */
4630 static void
4633 {
4634 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4635 subobjects. */
4640 /* The primary base class is always allocated first. */
4645 /* Now allocate the rest of the bases. */
4647 {
4648 tree base_binfo;
4652 /* The primary base was already allocated above, so we don't
4653 need to allocate it again here. */
4657 /* Virtual bases are added at the end (a primary virtual base
4658 will have already been added). */
4664 }
4665 }
4667 /* Go through the TYPE_METHODS of T issuing any appropriate
4668 diagnostics, figuring out which methods override which other
4669 methods, and so forth. */
4671 static void
4673 {
4674 tree x;
4677 {
4681 /* The name of the field is the original field name
4682 Save this in auxiliary field for later overloading. */
4684 {
4688 }
4689 /* All user-provided destructors are non-trivial.
4690 Constructors and assignment ops are handled in
4691 grok_special_member_properties. */
4697 "%<transaction_safe_dynamic%> may only be specified for "
4699 }
4700 }
4702 /* FN is a constructor or destructor. Clone the declaration to create
4703 a specialized in-charge or not-in-charge version, as indicated by
4704 NAME. */
4706 static tree
4708 {
4709 tree parms;
4710 tree clone;
4712 /* Copy the function. */
4714 /* Reset the function name. */
4716 /* Remember where this function came from. */
4718 /* Make it easy to find the CLONE given the FN. */
4722 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4724 {
4731 }
4732 else
4733 {
4734 // Clone constraints.
4738 }
4743 /* There's no pending inline data for this function. */
4747 /* The base-class destructor is not virtual. */
4749 {
4753 }
4759 /* If there was an in-charge parameter, drop it from the function
4760 type. */
4762 {
4763 tree basetype;
4764 tree parmtypes;
4765 tree exceptions;
4770 /* Skip the `this' parameter. */
4772 /* Skip the in-charge parameter. */
4774 /* And the VTT parm, in a complete [cd]tor. */
4779 {
4780 /* If we're omitting inherited parms, that just leaves the VTT. */
4783 }
4787 parmtypes);
4790 exceptions);
4794 }
4796 /* Copy the function parameters. */
4798 /* Remove the in-charge parameter. */
4800 {
4804 }
4805 /* And the VTT parm, in a complete [cd]tor. */
4807 {
4810 else
4811 {
4815 }
4816 }
4818 /* A base constructor inheriting from a virtual base doesn't get the
4819 arguments. */
4824 {
4827 }
4829 /* Create the RTL for this function. */
4834 }
4836 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4837 not invoke this function directly.
4839 For a non-thunk function, returns the address of the slot for storing
4840 the function it is a clone of. Otherwise returns NULL_TREE.
4842 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4843 cloned_function is unset. This is to support the separate
4844 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4845 on a template makes sense, but not the former. */
4847 tree *
4849 {
4857 {
4858 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4861 else
4862 #endif
4864 }
4869 else
4871 }
4873 /* Produce declarations for all appropriate clones of FN. If
4874 UPDATE_METHODS is true, the clones are added to the
4875 CLASSTYPE_METHOD_VEC. */
4877 void
4879 {
4880 tree clone;
4882 /* Avoid inappropriate cloning. */
4888 {
4889 /* For each constructor, we need two variants: an in-charge version
4890 and a not-in-charge version. */
4897 }
4898 else
4899 {
4902 /* For each destructor, we need three variants: an in-charge
4903 version, a not-in-charge version, and an in-charge deleting
4904 version. We clone the deleting version first because that
4905 means it will go second on the TYPE_METHODS list -- and that
4906 corresponds to the correct layout order in the virtual
4907 function table.
4909 For a non-virtual destructor, we do not build a deleting
4910 destructor. */
4912 {
4916 }
4923 }
4925 /* Note that this is an abstract function that is never emitted. */
4927 }
4929 /* DECL is an in charge constructor, which is being defined. This will
4930 have had an in class declaration, from whence clones were
4931 declared. An out-of-class definition can specify additional default
4932 arguments. As it is the clones that are involved in overload
4933 resolution, we must propagate the information from the DECL to its
4934 clones. */
4936 void
4938 {
4939 tree clone;
4943 {
4950 /* Skip the 'this' parameter. */
4966 {
4968 {
4972 }
4978 {
4979 /* A default parameter has been added. Adjust the
4980 clone's parameters. */
4984 tree type;
4989 {
4992 clone_parms);
4994 }
4997 clone_parms);
5006 }
5007 }
5009 }
5010 }
5012 /* For each of the constructors and destructors in T, create an
5013 in-charge and not-in-charge variant. */
5015 static void
5017 {
5018 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
5019 out now. */
5023 /* While constructors can be via a using declaration, at this point
5024 we no longer need to know that. */
5030 }
5032 /* Deduce noexcept for a destructor DTOR. */
5034 void
5036 {
5039 noexcept_deferred_spec);
5040 }
5042 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
5043 of TYPE for virtual functions which FNDECL overrides. Return a
5044 mask of the tm attributes found therein. */
5046 static int
5048 {
5050 tree base_binfo;
5054 {
5062 {
5066 else
5069 }
5070 else
5072 }
5075 }
5077 /* Subroutine of set_method_tm_attributes. Handle the checks and
5078 inheritance for one virtual method FNDECL. */
5080 static void
5082 {
5083 tree tm_attr;
5088 /* If FNDECL doesn't actually override anything (i.e. T is the
5089 class that first declares FNDECL virtual), then we're done. */
5096 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
5097 tm_pure must match exactly, otherwise no weakening of
5098 tm_safe > tm_callable > nothing. */
5099 /* ??? The tm_pure attribute didn't make the transition to the
5100 multivendor language spec. */
5102 {
5104 {
5107 }
5108 }
5109 /* If the overridden function is tm_pure, then FNDECL must be. */
5112 /* Look for base class combinations that cannot be satisfied. */
5114 {
5120 }
5121 /* If FNDECL did not declare an attribute, then inherit the most
5122 restrictive one. */
5124 {
5126 }
5127 /* Otherwise validate that we're not weaker than a function
5128 that is being overridden. */
5129 else
5130 {
5134 }
5137 err_override:
5141 }
5143 /* For each of the methods in T, propagate a class-level tm attribute. */
5145 static void
5147 {
5150 /* Don't bother collecting tm attributes if transactional memory
5151 support is not enabled. */
5155 /* Process virtual methods first, as they inherit directly from the
5156 base virtual function and also require validation of new attributes. */
5158 {
5159 tree vchain;
5162 {
5167 }
5168 }
5170 /* If the class doesn't have an attribute, nothing more to do. */
5175 /* Any method that does not yet have a tm attribute inherits
5176 the one from the class. */
5178 {
5181 }
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. */
5929 {
5932 {
5933 bool imp_const_p
5939 /* If the function is defaulted outside the class, we just
5940 give the synthesis error. */
5943 }
5945 }
5948 {
5949 /* "This class type is not an aggregate." */
5951 }
5953 /* Compute the 'literal type' property before we
5954 do anything with non-static member functions. */
5957 /* Create the in-charge and not-in-charge variants of constructors
5958 and destructors. */
5961 /* Process the using-declarations. */
5965 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5968 /* Figure out whether or not we will need a cookie when dynamically
5969 allocating an array of this type. */
5972 }
5974 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5975 accordingly. If a new vfield was created (because T doesn't have a
5976 primary base class), then the newly created field is returned. It
5977 is not added to the TYPE_FIELDS list; it is the caller's
5978 responsibility to do that. Accumulate declared virtual functions
5979 on VIRTUALS_P. */
5981 static tree
5983 {
5984 tree fn;
5986 /* Collect the virtual functions declared in T. */
5991 {
6000 }
6002 /* If we couldn't find an appropriate base class, create a new field
6003 here. Even if there weren't any new virtual functions, we might need a
6004 new virtual function table if we're supposed to include vptrs in
6005 all classes that need them. */
6007 {
6008 /* We build this decl with vtbl_ptr_type_node, which is a
6009 `vtable_entry_type*'. It might seem more precise to use
6010 `vtable_entry_type (*)[N]' where N is the number of virtual
6011 functions. However, that would require the vtable pointer in
6012 base classes to have a different type than the vtable pointer
6013 in derived classes. We could make that happen, but that
6014 still wouldn't solve all the problems. In particular, the
6015 type-based alias analysis code would decide that assignments
6016 to the base class vtable pointer can't alias assignments to
6017 the derived class vtable pointer, since they have different
6018 types. Thus, in a derived class destructor, where the base
6019 class constructor was inlined, we could generate bad code for
6020 setting up the vtable pointer.
6022 Therefore, we use one type for all vtable pointers. We still
6023 use a type-correct type; it's just doesn't indicate the array
6024 bounds. That's better than using `void*' or some such; it's
6025 cleaner, and it let's the alias analysis code know that these
6026 stores cannot alias stores to void*! */
6027 tree field;
6040 /* This class is non-empty. */
6044 }
6047 }
6049 /* Add OFFSET to all base types of BINFO which is a base in the
6050 hierarchy dominated by T.
6052 OFFSET, which is a type offset, is number of bytes. */
6054 static void
6056 {
6058 tree primary_binfo;
6059 tree base_binfo;
6061 /* Update BINFO's offset. */
6066 offset));
6068 /* Find the primary base class. */
6074 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
6075 downwards. */
6077 {
6078 /* Don't do the primary base twice. */
6086 }
6087 }
6089 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
6090 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
6091 empty subobjects of T. */
6093 static void
6095 {
6096 tree vbase;
6103 /* Find the last field. The artificial fields created for virtual
6104 bases will go after the last extant field to date. */
6109 /* Go through the virtual bases, allocating space for each virtual
6110 base that is not already a primary base class. These are
6111 allocated in inheritance graph order. */
6113 {
6118 {
6119 /* This virtual base is not a primary base of any class in the
6120 hierarchy, so we have to add space for it. */
6123 }
6124 }
6125 }
6127 /* Returns the offset of the byte just past the end of the base class
6128 BINFO. */
6130 static tree
6132 {
6133 tree size;
6138 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6139 allocate some space for it. It cannot have virtual bases, so
6140 TYPE_SIZE_UNIT is fine. */
6142 else
6146 }
6148 /* Returns the offset of the byte just past the end of the base class
6149 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
6150 only non-virtual bases are included. */
6152 static tree
6154 {
6157 tree binfo;
6158 tree base_binfo;
6159 tree offset;
6164 {
6174 }
6179 {
6183 }
6186 }
6188 /* Warn about bases of T that are inaccessible because they are
6189 ambiguous. For example:
6191 struct S {};
6192 struct T : public S {};
6193 struct U : public S, public T {};
6195 Here, `(S*) new U' is not allowed because there are two `S'
6196 subobjects of U. */
6198 static void
6200 {
6203 tree basetype;
6204 tree binfo;
6205 tree base_binfo;
6207 /* If there are no repeated bases, nothing can be ambiguous. */
6211 /* Check direct bases. */
6214 {
6220 }
6222 /* Check for ambiguous virtual bases. */
6226 {
6232 }
6233 }
6235 /* Compare two INTEGER_CSTs K1 and K2. */
6237 static int
6239 {
6241 }
6243 /* Increase the size indicated in RLI to account for empty classes
6244 that are "off the end" of the class. */
6246 static void
6248 {
6249 tree eoc;
6250 tree rli_size;
6252 /* It might be the case that we grew the class to allocate a
6253 zero-sized base class. That won't be reflected in RLI, yet,
6254 because we are willing to overlay multiple bases at the same
6255 offset. However, now we need to make sure that RLI is big enough
6256 to reflect the entire class. */
6261 {
6262 /* The size should have been rounded to a whole byte. */
6265 rli->bitpos
6274 }
6275 }
6277 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6278 BINFO_OFFSETs for all of the base-classes. Position the vtable
6279 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6281 static void
6283 {
6284 tree non_static_data_members;
6285 tree field;
6286 tree vptr;
6287 record_layout_info rli;
6288 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6289 types that appear at that offset. */
6290 splay_tree empty_base_offsets;
6291 /* True if the last field laid out was a bit-field. */
6293 /* The location at which the next field should be inserted. */
6295 /* T, as a base class. */
6296 tree base_t;
6298 /* Keep track of the first non-static data member. */
6301 /* Start laying out the record. */
6304 /* Mark all the primary bases in the hierarchy. */
6307 /* Create a pointer to our virtual function table. */
6310 /* The vptr is always the first thing in the class. */
6312 {
6317 }
6318 else
6321 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6326 /* Layout the non-static data members. */
6328 {
6329 tree type;
6330 tree padding;
6332 /* We still pass things that aren't non-static data members to
6333 the back end, in case it wants to do something with them. */
6335 {
6337 /* If the static data member has incomplete type, keep track
6338 of it so that it can be completed later. (The handling
6339 of pending statics in finish_record_layout is
6340 insufficient; consider:
6342 struct S1;
6343 struct S2 { static S1 s1; };
6345 At this point, finish_record_layout will be called, but
6346 S1 is still incomplete.) */
6348 {
6350 /* The visibility of static data members is determined
6351 at their point of declaration, not their point of
6352 definition. */
6354 }
6356 }
6364 /* If this field is a bit-field whose width is greater than its
6365 type, then there are some special rules for allocating
6366 it. */
6369 {
6371 /* We must allocate the bits as if suitably aligned for the
6372 longest integer type that fits in this many bits. Then,
6373 we are supposed to use the left over bits as additional
6374 padding. */
6376 /* Do not pick a type bigger than MAX_FIXED_MODE_SIZE. */
6384 {
6386 /* Too big, so our current guess is what we want. */
6388 /* Not bigger than limit, ok */
6390 }
6392 /* Figure out how much additional padding is required. */
6394 /* In a union, the padding field must have the full width
6395 of the bit-field; all fields start at offset zero. */
6397 else
6404 /* An unnamed bitfield does not normally affect the
6405 alignment of the containing class on a target where
6406 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6407 make any exceptions for unnamed bitfields when the
6408 bitfields are longer than their types. Therefore, we
6409 temporarily give the field a name. */
6411 {
6414 }
6420 empty_base_offsets);
6423 /* Now that layout has been performed, set the size of the
6424 field to the size of its declared type; the rest of the
6425 field is effectively invisible. */
6427 /* We must also reset the DECL_MODE of the field. */
6429 }
6430 else
6432 empty_base_offsets);
6434 /* Remember the location of any empty classes in FIELD. */
6437 empty_base_offsets,
6440 /* If a bit-field does not immediately follow another bit-field,
6441 and yet it starts in the middle of a byte, we have failed to
6442 comply with the ABI. */
6445 /* The TREE_NO_WARNING flag gets set by Objective-C when
6446 laying out an Objective-C class. The ObjC ABI differs
6447 from the C++ ABI, and so we do not want a warning
6448 here. */
6450 && !last_field_was_bitfield
6453 bitsize_unit_node)))
6455 "offset of %qD is not ABI-compliant and may "
6458 /* The middle end uses the type of expressions to determine the
6459 possible range of expression values. In order to optimize
6460 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6461 must be made aware of the width of "i", via its type.
6463 Because C++ does not have integer types of arbitrary width,
6464 we must (for the purposes of the front end) convert from the
6465 type assigned here to the declared type of the bitfield
6466 whenever a bitfield expression is used as an rvalue.
6467 Similarly, when assigning a value to a bitfield, the value
6468 must be converted to the type given the bitfield here. */
6470 {
6475 {
6482 }
6483 }
6485 /* If we needed additional padding after this field, add it
6486 now. */
6488 {
6489 tree padding_field;
6492 FIELD_DECL,
6493 NULL_TREE,
6494 char_type_node);
6501 NULL_TREE,
6502 empty_base_offsets);
6503 }
6506 }
6509 {
6510 /* Make sure that we are on a byte boundary so that the size of
6511 the class without virtual bases will always be a round number
6512 of bytes. */
6515 }
6517 /* Delete all zero-width bit-fields from the list of fields. Now
6518 that the type is laid out they are no longer important. */
6521 /* Create the version of T used for virtual bases. We do not use
6522 make_class_type for this version; this is an artificial type. For
6523 a POD type, we just reuse T. */
6525 {
6528 /* Set the size and alignment for the new type. */
6529 tree eoc;
6531 /* If the ABI version is not at least two, and the last
6532 field was a bit-field, RLI may not be on a byte
6533 boundary. In particular, rli_size_unit_so_far might
6534 indicate the last complete byte, while rli_size_so_far
6535 indicates the total number of bits used. Therefore,
6536 rli_size_so_far, rather than rli_size_unit_so_far, is
6537 used to compute TYPE_SIZE_UNIT. */
6545 eoc);
6555 /* Copy the fields from T. */
6559 {
6563 }
6566 /* Record the base version of the type. */
6569 }
6570 else
6573 /* Every empty class contains an empty class. */
6577 /* Set the TYPE_DECL for this type to contain the right
6578 value for DECL_OFFSET, so that we can use it as part
6579 of a COMPONENT_REF for multiple inheritance. */
6582 /* Now fix up any virtual base class types that we left lying
6583 around. We must get these done before we try to lay out the
6584 virtual function table. As a side-effect, this will remove the
6585 base subobject fields. */
6588 /* Make sure that empty classes are reflected in RLI at this
6589 point. */
6592 /* Make sure not to create any structures with zero size. */
6598 /* If this is a non-POD, declaring it packed makes a difference to how it
6599 can be used as a field; don't let finalize_record_size undo it. */
6603 /* Let the back end lay out the type. */
6612 /* Warn about bases that can't be talked about due to ambiguity. */
6615 /* Now that we're done with layout, give the base fields the real types. */
6620 /* Clean up. */
6627 }
6629 /* Determine the "key method" for the class type indicated by TYPE,
6630 and set CLASSTYPE_KEY_METHOD accordingly. */
6632 void
6634 {
6635 tree method;
6642 /* The key method is the first non-pure virtual function that is not
6643 inline at the point of class definition. On some targets the
6644 key function may not be inline; those targets should not call
6645 this function until the end of the translation unit. */
6652 {
6655 }
6658 }
6661 /* Allocate and return an instance of struct sorted_fields_type with
6662 N fields. */
6666 {
6673 }
6675 /* Helper of find_flexarrays. Return true when FLD refers to a non-static
6676 class data member of non-zero size, otherwise false. */
6680 {
6688 {
6692 }
6695 }
6697 /* Used by find_flexarrays and related functions. */
6699 struct flexmems_t
6700 {
6701 /* The first flexible array member or non-zero array member found
6702 in the order of layout. */
6703 tree array;
6704 /* First non-static non-empty data member in the class or its bases. */
6705 tree first;
6706 /* The first non-static non-empty data member following either
6707 the flexible array member, if found, or the zero-length array member
6708 otherwise. AFTER[1] refers to the first such data member of a union
6709 of which the struct containing the flexible array member or zero-length
6710 array is a member, or NULL when no such union exists. This element is
6711 only used during searching, not for diagnosing problems. AFTER[0]
6712 refers to the first such data member that is not a member of such
6713 a union. */
6716 /* Refers to a struct (not union) in which the struct of which the flexible
6717 array is member is defined. Used to diagnose strictly (according to C)
6718 invalid uses of the latter structs. */
6719 tree enclosing;
6720 };
6722 /* Find either the first flexible array member or the first zero-length
6723 array, in that order of preference, among members of class T (but not
6724 its base classes), and set members of FMEM accordingly.
6725 BASE_P is true if T is a base class of another class.
6726 PUN is set to the outermost union in which the flexible array member
6727 (or zero-length array) is defined if one such union exists, otherwise
6728 to NULL.
6729 Similarly, PSTR is set to a data member of the outermost struct of
6730 which the flexible array is a member if one such struct exists,
6731 otherwise to NULL. */
6733 static void
6737 {
6738 /* Set the "pointer" to the outermost enclosing union if not set
6739 yet and maintain it for the remainder of the recursion. */
6744 {
6748 /* Is FLD a typedef for an anonymous struct? */
6750 /* FIXME: Note that typedefs (as well as arrays) need to be fully
6751 handled elsewhere so that errors like the following are detected
6752 as well:
6753 typedef struct { int i, a[], j; } S; // bug c++/72753
6754 S s [2]; // bug c++/68489
6755 */
6760 {
6761 /* Check the nested unnamed type referenced via a typedef
6762 independently of FMEM (since it's not a data member of
6763 the enclosing class). */
6766 }
6768 /* Skip anything that's GCC-generated or not a (non-static) data
6769 member. */
6773 /* Type of the member. */
6778 /* Determine the type of the array element or object referenced
6779 by the member so that it can be checked for flexible array
6780 members if it hasn't been yet. */
6788 {
6790 {
6791 /* Once the member after the flexible array has been found
6792 we're done. */
6795 }
6798 {
6799 /* Descend into the non-static member struct or union and try
6800 to find a flexible array member or zero-length array among
6801 its members. This is only necessary for anonymous types
6802 and types in whose context the current type T has not been
6803 defined (the latter must not be checked again because they
6804 are already in the process of being checked by one of the
6805 recursive calls). */
6810 /* If this member isn't anonymous and a prior non-flexible array
6811 member has been seen in one of the enclosing structs, clear
6812 the FIRST member since it doesn't contribute to the flexible
6813 array struct's members. */
6824 {
6825 /* Restore the FIRST member reset above if no flexible
6826 array member has been found in this member's struct. */
6828 }
6830 /* If the member struct contains the first flexible array
6831 member, or if this member is a base class, continue to
6832 the next member and avoid setting the FMEM->NEXT pointer
6833 to point to it. */
6836 }
6837 }
6840 {
6841 /* Remember the first non-static data member. */
6845 /* Remember the first non-static data member after the flexible
6846 array member, if one has been found, or the zero-length array
6847 if it has been found. */
6850 }
6852 /* Skip non-arrays. */
6856 /* Determine the upper bound of the array if it has one. */
6858 {
6860 {
6861 /* Make a record of the zero-length array if either one
6862 such field or a flexible array member has been seen to
6863 handle the pathological and unlikely case of multiple
6864 such members. */
6867 }
6869 {
6870 /* Remember the first zero-length array unless a flexible array
6871 member has already been seen. */
6874 }
6875 }
6876 else
6877 {
6878 /* Flexible array members have no upper bound. */
6880 {
6881 /* Replace the zero-length array if it's been stored and
6882 reset the after pointer. */
6884 {
6888 }
6889 }
6890 else
6891 {
6894 }
6895 }
6896 }
6897 }
6899 /* Diagnose a strictly (by the C standard) invalid use of a struct with
6900 a flexible array member (or the zero-length array extension). */
6902 static void
6904 {
6916 }
6918 /* Issue diagnostics for invalid flexible array members or zero-length
6919 arrays that are not the last elements of the containing class or its
6920 base classes or that are its sole members. */
6922 static void
6924 {
6929 {
6932 }
6934 /* Has a diagnostic been issued? */
6940 {
6947 {
6951 {
6954 }
6955 }
6956 }
6957 else
6958 {
6965 {
6971 /* In the unlikely event that the member following the flexible
6972 array member is declared in a different class, or the member
6973 overlaps another member of a common union, point to it.
6974 Otherwise it should be obvious. */
6978 {
6983 }
6984 }
6985 }
6989 }
6992 /* Recursively check to make sure that any flexible array or zero-length
6993 array members of class T or its bases are valid (i.e., not the sole
6994 non-static data member of T and, if one exists, that it is the last
6995 non-static data member of T and its base classes. FMEM is expected
6996 to be initially null and is used internally by recursive calls to
6997 the function. Issue the appropriate diagnostics for the array member
6998 that fails the checks. */
7000 static void
7003 {
7004 /* Initialize the result of a search for flexible array and zero-length
7005 array members. Avoid doing any work if the most interesting FMEM data
7006 have already been populated. */
7015 /* Recursively check the primary base class first. */
7017 {
7020 }
7022 /* Recursively check the base classes. */
7025 {
7028 /* The primary base class was already checked above. */
7032 /* Virtual base classes are at the end. */
7036 /* Check the base class. */
7038 }
7041 {
7042 /* Check virtual base classes only once per derived class.
7043 I.e., this check is not performed recursively for base
7044 classes. */
7046 tree base_binfo;
7050 {
7051 /* Check the virtual base class. */
7055 }
7056 }
7058 /* Is the type unnamed (and therefore a member of it potentially
7059 an anonymous struct or union)? */
7062 /* Search the members of the current (possibly derived) class, skipping
7063 unnamed structs and unions since those could be anonymous. */
7068 {
7069 /* Issue diagnostics for invalid flexible and zero-length array
7070 members found in base classes or among the members of the current
7071 class. Ignore anonymous structs and unions whose members are
7072 considered to be members of the enclosing class and thus will
7073 be diagnosed when checking it. */
7075 }
7076 }
7078 /* Perform processing required when the definition of T (a class type)
7079 is complete. Diagnose invalid definitions of flexible array members
7080 and zero-size arrays. */
7082 void
7084 {
7085 tree x;
7086 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
7090 {
7095 }
7097 /* If this type was previously laid out as a forward reference,
7098 make sure we lay it out again. */
7102 /* Make assumptions about the class; we'll reset the flags if
7103 necessary. */
7109 /* Do end-of-class semantic processing: checking the validity of the
7110 bases and members and add implicitly generated methods. */
7113 /* Find the key method. */
7115 {
7116 /* The Itanium C++ ABI permits the key method to be chosen when
7117 the class is defined -- even though the key method so
7118 selected may later turn out to be an inline function. On
7119 some systems (such as ARM Symbian OS) the key method cannot
7120 be determined until the end of the translation unit. On such
7121 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
7122 will cause the class to be added to KEYED_CLASSES. Then, in
7123 finish_file we will determine the key method. */
7127 /* If a polymorphic class has no key method, we may emit the vtable
7128 in every translation unit where the class definition appears. If
7129 we're devirtualizing, we can look into the vtable even if we
7130 aren't emitting it. */
7133 }
7135 /* Layout the class itself. */
7138 /* We use the base type for trivial assignments, and hence it
7139 needs a mode. */
7142 /* With the layout complete, check for flexible array members and
7143 zero-length arrays that might overlap other members in the final
7144 layout. */
7149 /* If necessary, create the primary vtable for this class. */
7151 {
7152 /* We must enter these virtuals into the table. */
7156 /* Here we know enough to change the type of our virtual
7157 function table, but we will wait until later this function. */
7160 /* If we're warning about ABI tags, check the types of the new
7161 virtual functions. */
7165 }
7168 {
7170 tree fn;
7177 /* Add entries for virtual functions introduced by this class. */
7181 /* Set DECL_VINDEX for all functions declared in this class. */
7183 fn;
7185 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
7187 {
7191 /* A thunk. We should never be calling this entry directly
7192 from this vtable -- we'd use the entry for the non
7193 thunk base function. */
7197 }
7198 }
7205 /* Complete the rtl for any static member objects of the type we're
7206 working on. */
7213 /* Done with FIELDS...now decide whether to sort these for
7214 faster lookups later.
7216 We use a small number because most searches fail (succeeding
7217 ultimately as the search bores through the inheritance
7218 hierarchy), and we want this failure to occur quickly. */
7222 /* Complain if one of the field types requires lower visibility. */
7225 /* Make the rtl for any new vtables we have created, and unmark
7226 the base types we marked. */
7229 /* Build the VTT for T. */
7236 "%q#T has virtual functions and accessible"
7244 /* Class layout, assignment of virtual table slots, etc., is now
7245 complete. Give the back end a chance to tweak the visibility of
7246 the class or perform any other required target modifications. */
7256 /* Finish debugging output for this type. */
7260 {
7263 {
7266 }
7268 {
7271 else
7272 {
7275 }
7277 }
7279 {
7281 "the type of the first field has a different ABI from the "
7284 }
7285 }
7286 }
7288 /* Insert FIELDS into T for the sorted case if the FIELDS count is
7289 equal to THRESHOLD or greater than THRESHOLD. */
7291 static void
7293 {
7296 {
7301 }
7302 }
7304 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
7306 void
7308 {
7311 {
7313 int n_fields
7324 }
7325 }
7327 /* When T was built up, the member declarations were added in reverse
7328 order. Rearrange them to declaration order. */
7330 void
7332 {
7333 tree next;
7334 tree prev;
7335 tree x;
7337 /* The following lists are all in reverse order. Put them in
7338 declaration order now. */
7342 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
7343 reverse order, so we can't just use nreverse. */
7348 {
7352 }
7354 {
7358 }
7359 }
7361 tree
7363 {
7366 /* Now that we've got all the field declarations, reverse everything
7367 as necessary. */
7373 /* Nadger the current location so that diagnostics point to the start of
7374 the struct, not the end. */
7378 {
7379 tree x;
7385 /* We need to emit an error message if this type was used as a parameter
7386 and it is an abstract type, even if it is a template. We construct
7387 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
7388 account and we call complete_vars with this type, which will check
7389 the PARM_DECLS. Note that while the type is being defined,
7390 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
7391 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
7397 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
7398 an enclosing scope is a template class, so that this function be
7399 found by lookup_fnfields_1 when the using declaration is not
7400 instantiated yet. */
7403 {
7408 }
7410 /* Remember current #pragma pack value. */
7413 /* Fix up any variants we've already built. */
7415 {
7420 }
7421 }
7422 else
7426 {
7427 /* People keep complaining that the compiler crashes on an invalid
7428 definition of initializer_list, so I guess we should explicitly
7429 reject it. What the compiler internals care about is that it's a
7430 template and has a pointer field followed by an integer field. */
7433 {
7436 {
7440 }
7441 }
7444 "definition of std::initializer_list does not match "
7446 }
7454 else
7458 /* Lambdas are defined by the LAMBDA_EXPR. */
7463 }
7464 \f
7465 /* Hash table to avoid endless recursion when handling references. */
7468 /* Return the dynamic type of INSTANCE, if known.
7469 Used to determine whether the virtual function table is needed
7470 or not.
7472 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7473 of our knowledge of its type. *NONNULL should be initialized
7474 before this function is called. */
7476 static tree
7478 {
7479 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
7482 {
7486 else
7490 /* This is a call to a constructor, hence it's never zero. */
7492 {
7496 }
7500 /* This is a call to a constructor, hence it's never zero. */
7502 {
7506 }
7515 /* Propagate nonnull. */
7520 CASE_CONVERT:
7526 {
7527 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7528 with a real object -- given &p->f, p can still be null. */
7530 /* ??? Probably should check DECL_WEAK here. */
7533 }
7537 /* If this component is really a base class reference, then the field
7538 itself isn't definitive. */
7547 {
7551 }
7552 /* fall through. */
7557 {
7561 }
7563 {
7567 /* if we're in a ctor or dtor, we know our type. If
7568 current_class_ptr is set but we aren't in a function, we're in
7569 an NSDMI (and therefore a constructor). */
7574 {
7578 }
7579 }
7581 {
7582 /* We only need one hash table because it is always left empty. */
7584 fixed_type_or_null_ref_ht
7587 /* Reference variables should be references to objects. */
7591 /* Enter the INSTANCE in a table to prevent recursion; a
7592 variable's initializer may refer to the variable
7593 itself. */
7598 {
7599 tree type;
7608 }
7609 }
7614 }
7615 #undef RECUR
7616 }
7618 /* Return nonzero if the dynamic type of INSTANCE is known, and
7619 equivalent to the static type. We also handle the case where
7620 INSTANCE is really a pointer. Return negative if this is a
7621 ctor/dtor. There the dynamic type is known, but this might not be
7622 the most derived base of the original object, and hence virtual
7623 bases may not be laid out according to this type.
7625 Used to determine whether the virtual function table is needed
7626 or not.
7628 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7629 of our knowledge of its type. *NONNULL should be initialized
7630 before this function is called. */
7632 int
7634 {
7637 tree fixed;
7639 /* processing_template_decl can be false in a template if we're in
7640 instantiate_non_dependent_expr, but we still want to suppress
7641 this check. */
7643 {
7644 /* In a template we only care about the type of the result. */
7648 }
7658 }
7660 \f
7661 void
7663 {
7666 current_class_stack
7674 }
7676 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7678 static void
7680 {
7681 tree type;
7683 /* We are re-entering the same class we just left, so we don't
7684 have to search the whole inheritance matrix to find all the
7685 decls to bind again. Instead, we install the cached
7686 class_shadowed list and walk through it binding names. */
7689 /* Restore IDENTIFIER_TYPE_VALUE. */
7691 type;
7694 }
7696 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7697 appropriate for TYPE.
7699 So that we may avoid calls to lookup_name, we cache the _TYPE
7700 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7702 For multiple inheritance, we perform a two-pass depth-first search
7703 of the type lattice. */
7705 void
7707 {
7708 class_stack_node_t csn;
7712 /* Make sure there is enough room for the new entry on the stack. */
7714 {
7716 current_class_stack
7718 current_class_stack_size);
7719 }
7721 /* Insert a new entry on the class stack. */
7728 current_class_depth++;
7730 /* Now set up the new type. */
7736 /* By default, things in classes are private, while things in
7737 structures or unions are public. */
7739 ? access_private_node
7745 {
7746 /* Forcibly remove any old class remnants. */
7748 }
7754 else
7756 }
7758 /* When we exit a toplevel class scope, we save its binding level so
7759 that we can restore it quickly. Here, we've entered some other
7760 class, so we must invalidate our cache. */
7762 void
7764 {
7766 }
7768 /* Get out of the current class scope. If we were in a class scope
7769 previously, that is the one popped to. */
7771 void
7773 {
7776 current_class_depth--;
7782 }
7784 /* Mark the top of the class stack as hidden. */
7786 void
7788 {
7791 }
7793 /* Mark the top of the class stack as un-hidden. */
7795 void
7797 {
7800 }
7802 /* Returns 1 if the class type currently being defined is either T or
7803 a nested type of T. Returns the type from the current_class_stack,
7804 which might be equivalent to but not equal to T in case of
7805 constrained partial specializations. */
7807 tree
7809 {
7817 /* We start looking from 1 because entry 0 is from global scope,
7818 and has no type. */
7820 {
7821 tree c;
7824 else
7825 {
7829 }
7834 }
7836 }
7838 /* If either current_class_type or one of its enclosing classes are derived
7839 from T, return the appropriate type. Used to determine how we found
7840 something via unqualified lookup. */
7842 tree
7844 {
7847 /* The bases of a dependent type are unknown. */
7858 {
7863 }
7866 }
7868 /* Return the outermost enclosing class type that is still open, or
7869 NULL_TREE. */
7871 tree
7873 {
7880 {
7887 }
7889 }
7891 /* Returns the innermost class type which is not a lambda closure type. */
7893 tree
7895 {
7898 /* We start looking from 1 because entry 0 is from global scope,
7899 and has no type. */
7901 {
7902 tree c;
7905 else
7906 {
7910 }
7915 }
7917 }
7919 /* When entering a class scope, all enclosing class scopes' names with
7920 static meaning (static variables, static functions, types and
7921 enumerators) have to be visible. This recursive function calls
7922 pushclass for all enclosing class contexts until global or a local
7923 scope is reached. TYPE is the enclosed class. */
7925 void
7927 {
7928 /* A namespace might be passed in error cases, like A::B:C. */
7936 }
7938 /* Undoes a push_nested_class call. */
7940 void
7942 {
7948 }
7950 /* Returns the number of extern "LANG" blocks we are nested within. */
7952 int
7954 {
7956 }
7958 /* Set global variables CURRENT_LANG_NAME to appropriate value
7959 so that behavior of name-mangling machinery is correct. */
7961 void
7963 {
7970 else
7972 }
7974 /* Get out of the current language scope. */
7976 void
7978 {
7980 }
7981 \f
7982 /* Type instantiation routines. */
7984 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7985 matches the TARGET_TYPE. If there is no satisfactory match, return
7986 error_mark_node, and issue an error & warning messages under
7987 control of FLAGS. Permit pointers to member function if FLAGS
7988 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7989 a template-id, and EXPLICIT_TARGS are the explicitly provided
7990 template arguments.
7992 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7993 is the base path used to reference those member functions. If
7994 the address is resolved to a member function, access checks will be
7995 performed and errors issued if appropriate. */
7997 static tree
7999 tree overload,
8000 tsubst_flags_t complain,
8002 tree explicit_targs,
8003 tree access_path)
8004 {
8005 /* Here's what the standard says:
8007 [over.over]
8009 If the name is a function template, template argument deduction
8010 is done, and if the argument deduction succeeds, the deduced
8011 arguments are used to generate a single template function, which
8012 is added to the set of overloaded functions considered.
8014 Non-member functions and static member functions match targets of
8015 type "pointer-to-function" or "reference-to-function." Nonstatic
8016 member functions match targets of type "pointer-to-member
8017 function;" the function type of the pointer to member is used to
8018 select the member function from the set of overloaded member
8019 functions. If a nonstatic member function is selected, the
8020 reference to the overloaded function name is required to have the
8021 form of a pointer to member as described in 5.3.1.
8023 If more than one function is selected, any template functions in
8024 the set are eliminated if the set also contains a non-template
8025 function, and any given template function is eliminated if the
8026 set contains a second template function that is more specialized
8027 than the first according to the partial ordering rules 14.5.5.2.
8028 After such eliminations, if any, there shall remain exactly one
8029 selected function. */
8032 /* We store the matches in a TREE_LIST rooted here. The functions
8033 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
8034 interoperability with most_specialized_instantiation. */
8036 tree fn;
8037 tree target_fn_type;
8039 /* By the time we get here, we should be seeing only real
8040 pointer-to-member types, not the internal POINTER_TYPE to
8041 METHOD_TYPE representation. */
8047 /* Check that the TARGET_TYPE is reasonable. */
8052 /* This is OK, too. */
8055 /* This is OK, too. This comes from a conversion to reference
8056 type. */
8058 else
8059 {
8065 }
8067 /* Non-member functions and static member functions match targets of type
8068 "pointer-to-function" or "reference-to-function." Nonstatic member
8069 functions match targets of type "pointer-to-member-function;" the
8070 function type of the pointer to member is used to select the member
8071 function from the set of overloaded member functions.
8073 So figure out the FUNCTION_TYPE that we want to match against. */
8076 /* If we can find a non-template function that matches, we can just
8077 use it. There's no point in generating template instantiations
8078 if we're just going to throw them out anyhow. But, of course, we
8079 can only do this when we don't *need* a template function. */
8082 {
8086 /* We're not looking for templates just yet. */
8090 /* We're looking for a non-static member, and this isn't
8091 one, or vice versa. */
8094 /* In C++17 we need the noexcept-qualifier to compare types. */
8098 /* See if there's a match. */
8103 }
8105 /* Now, if we've already got a match (or matches), there's no need
8106 to proceed to the template functions. But, if we don't have a
8107 match we need to look at them, too. */
8109 {
8110 tree target_arg_types;
8111 tree target_ret_type;
8114 tree arg;
8128 {
8130 tree instantiation;
8131 tree targs;
8134 /* We're only looking for templates. */
8139 /* We're not looking for a non-static member, and this is
8140 one, or vice versa. */
8145 /* If the template has a deduced return type, don't expose it to
8146 template argument deduction. */
8150 /* Try to do argument deduction. */
8157 /* Instantiation failed. */
8160 /* Constraints must be satisfied. This is done before
8161 return type deduction since that instantiates the
8162 function. */
8166 /* And now force instantiation to do return type deduction. */
8168 {
8174 }
8176 /* In C++17 we need the noexcept-qualifier to compare types. */
8180 /* See if there's a match. */
8185 }
8187 /* Now, remove all but the most specialized of the matches. */
8189 {
8194 NULL_TREE,
8195 NULL_TREE);
8196 }
8197 }
8199 /* Now we should have exactly one function in MATCHES. */
8201 {
8202 /* There were *no* matches. */
8204 {
8209 }
8211 }
8213 {
8214 /* There were too many matches. First check if they're all
8215 the same function. */
8220 /* For multi-versioned functions, more than one match is just fine and
8221 decls_match will return false as they are different. */
8229 {
8231 {
8235 /* Since print_candidates expects the functions in the
8236 TREE_VALUE slot, we flip them here. */
8241 }
8244 }
8245 }
8247 /* Good, exactly one match. Now, convert it to the correct type. */
8252 {
8260 {
8263 }
8264 }
8266 /* If a pointer to a function that is multi-versioned is requested, the
8267 pointer to the dispatcher function is returned instead. This works
8268 well because indirectly calling the function will dispatch the right
8269 function version at run-time. */
8271 {
8275 /* Mark all the versions corresponding to the dispatcher as used. */
8278 }
8280 /* If we're doing overload resolution purely for the purpose of
8281 determining conversion sequences, we should not consider the
8282 function used. If this conversion sequence is selected, the
8283 function will be marked as used at this point. */
8285 {
8286 /* Make =delete work with SFINAE. */
8291 }
8293 /* We could not check access to member functions when this
8294 expression was originally created since we did not know at that
8295 time to which function the expression referred. */
8297 {
8300 }
8304 else
8305 {
8306 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
8307 will mark the function as addressed, but here we must do it
8308 explicitly. */
8312 }
8313 }
8315 /* This function will instantiate the type of the expression given in
8316 RHS to match the type of LHSTYPE. If errors exist, then return
8317 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
8318 we complain on errors. If we are not complaining, never modify rhs,
8319 as overload resolution wants to try many possible instantiations, in
8320 the hope that at least one will work.
8322 For non-recursive calls, LHSTYPE should be a function, pointer to
8323 function, or a pointer to member function. */
8325 tree
8327 {
8334 {
8338 }
8341 {
8350 /* Microsoft allows `A::f' to be resolved to a
8351 pointer-to-member. */
8352 ;
8353 else
8354 {
8359 }
8360 }
8363 {
8366 }
8368 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
8369 deduce any type information. */
8371 {
8375 }
8377 /* If we instantiate a template, and it is a A ?: C expression
8378 with omitted B, look through the SAVE_EXPR. */
8382 /* There are only a few kinds of expressions that may have a type
8383 dependent on overload resolution. */
8389 /* This should really only be used when attempting to distinguish
8390 what sort of a pointer to function we have. For now, any
8391 arithmetic operation which is not supported on pointers
8392 is rejected as an error. */
8395 {
8397 {
8403 /* Do not lose object's side effects. */
8407 }
8414 /* This can happen if we are forming a pointer-to-member for a
8415 member template. */
8418 /* Fall through. */
8421 {
8425 return
8429 }
8433 return
8437 access_path);
8440 {
8445 }
8452 }
8454 }
8455 \f
8456 /* Return the name of the virtual function pointer field
8457 (as an IDENTIFIER_NODE) for the given TYPE. Note that
8458 this may have to look back through base types to find the
8459 ultimate field name. (For single inheritance, these could
8460 all be the same name. Who knows for multiple inheritance). */
8462 static tree
8464 {
8470 {
8476 }
8484 }
8486 void
8488 {
8495 {
8500 }
8501 }
8503 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
8504 according to [class]:
8505 The class-name is also inserted
8506 into the scope of the class itself. For purposes of access checking,
8507 the inserted class name is treated as if it were a public member name. */
8509 void
8511 {
8528 }
8530 /* Returns 1 if TYPE contains only padding bytes. */
8532 int
8534 {
8542 }
8544 /* Returns true if TYPE contains no actual data, just various
8545 possible combinations of empty classes and possibly a vptr. */
8547 bool
8549 {
8551 {
8552 tree field;
8553 tree binfo;
8554 tree base_binfo;
8557 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8558 out, but we'd like to be able to check this before then. */
8569 /* An unnamed bit-field is not a data member. */
8574 }
8579 }
8581 /* Note that NAME was looked up while the current class was being
8582 defined and that the result of that lookup was DECL. */
8584 void
8586 {
8587 splay_tree names_used;
8589 /* If we're not defining a class, there's nothing to do. */
8595 /* If there's already a binding for this NAME, then we don't have
8596 anything to worry about. */
8609 }
8611 /* Note that NAME was declared (as DECL) in the current class. Check
8612 to see that the declaration is valid. */
8614 void
8616 {
8617 splay_tree names_used;
8618 splay_tree_node n;
8620 /* Look to see if we ever used this name. */
8621 names_used
8625 /* The C language allows members to be declared with a type of the same
8626 name, and the C++ standard says this diagnostic is not required. So
8627 allow it in extern "C" blocks unless predantic is specified.
8628 Allow it in all cases if -ms-extensions is specified. */
8634 {
8635 /* [basic.scope.class]
8637 A name N used in a class S shall refer to the same declaration
8638 in its context and when re-evaluated in the completed scope of
8639 S. */
8644 }
8645 }
8647 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8648 Secondary vtables are merged with primary vtables; this function
8649 will return the VAR_DECL for the primary vtable. */
8651 tree
8653 {
8654 tree decl;
8658 {
8661 }
8665 }
8668 /* Returns the binfo for the primary base of BINFO. If the resulting
8669 BINFO is a virtual base, and it is inherited elsewhere in the
8670 hierarchy, then the returned binfo might not be the primary base of
8671 BINFO in the complete object. Check BINFO_PRIMARY_P or
8672 BINFO_LOST_PRIMARY_P to be sure. */
8674 static tree
8676 {
8677 tree primary_base;
8684 }
8686 /* As above, but iterate until we reach the binfo that actually provides the
8687 vptr for BINFO. */
8689 static tree
8691 {
8695 {
8700 }
8702 }
8704 /* Returns true if BINFO gets its vptr from a virtual base of the most derived
8705 type. Note that the virtual inheritance might be above or below BINFO in
8706 the hierarchy. */
8708 bool
8710 {
8714 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is
8715 a morally virtual base. */
8718 }
8720 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8722 static int
8724 {
8728 }
8730 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8731 INDENT should be zero when called from the top level; it is
8732 incremented recursively. IGO indicates the next expected BINFO in
8733 inheritance graph ordering. */
8735 static tree
8737 dump_flags_t flags,
8738 tree binfo,
8739 tree igo,
8741 {
8743 tree base_binfo;
8751 {
8754 }
8769 {
8773 TFF_PLAIN_IDENTIFIER),
8775 }
8777 {
8780 }
8785 {
8789 {
8793 TFF_PLAIN_IDENTIFIER));
8794 }
8796 {
8800 TFF_PLAIN_IDENTIFIER));
8801 }
8803 {
8807 TFF_PLAIN_IDENTIFIER));
8808 }
8810 {
8814 TFF_PLAIN_IDENTIFIER));
8815 }
8819 }
8825 }
8827 /* Dump the BINFO hierarchy for T. */
8829 static void
8831 {
8843 }
8845 /* Debug interface to hierarchy dumping. */
8847 void
8849 {
8851 }
8853 static void
8855 {
8856 dump_flags_t flags;
8858 {
8861 }
8862 }
8864 static void
8866 {
8867 tree value;
8869 HOST_WIDE_INT elt;
8877 TFF_PLAIN_IDENTIFIER));
8884 }
8886 static void
8888 {
8889 dump_flags_t flags;
8896 {
8903 {
8908 }
8912 }
8915 }
8917 static void
8919 {
8920 dump_flags_t flags;
8927 {
8932 }
8935 }
8937 /* Dump a function or thunk and its thunkees. */
8939 static void
8941 {
8944 tree thunks;
8952 {
8962 else
8968 }
8972 }
8974 /* Dump the thunks for FN. */
8976 void
8978 {
8980 }
8982 /* Virtual function table initialization. */
8984 /* Create all the necessary vtables for T and its base classes. */
8986 static void
8988 {
8989 tree vbase;
8993 /* We lay out the primary and secondary vtables in one contiguous
8994 vtable. The primary vtable is first, followed by the non-virtual
8995 secondary vtables in inheritance graph order. */
8999 /* Then come the virtual bases, also in inheritance graph order. */
9001 {
9005 }
9009 }
9011 /* Initialize the vtable for BINFO with the INITS. */
9013 static void
9015 {
9016 tree decl;
9022 }
9024 /* Build the VTT (virtual table table) for T.
9025 A class requires a VTT if it has virtual bases.
9027 This holds
9028 1 - primary virtual pointer for complete object T
9029 2 - secondary VTTs for each direct non-virtual base of T which requires a
9030 VTT
9031 3 - secondary virtual pointers for each direct or indirect base of T which
9032 has virtual bases or is reachable via a virtual path from T.
9033 4 - secondary VTTs for each direct or indirect virtual base of T.
9035 Secondary VTTs look like complete object VTTs without part 4. */
9037 static void
9039 {
9040 tree type;
9041 tree vtt;
9042 tree index;
9045 /* Build up the initializers for the VTT. */
9050 /* If we didn't need a VTT, we're done. */
9054 /* Figure out the type of the VTT. */
9058 /* Now, build the VTT object itself. */
9061 /* Add the VTT to the vtables list. */
9066 }
9068 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
9069 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
9070 and CHAIN the vtable pointer for this binfo after construction is
9071 complete. VALUE can also be another BINFO, in which case we recurse. */
9073 static tree
9075 {
9076 tree vt;
9079 {
9085 else
9087 }
9090 }
9092 /* Data for secondary VTT initialization. */
9093 struct secondary_vptr_vtt_init_data
9094 {
9095 /* Is this the primary VTT? */
9098 /* Current index into the VTT. */
9099 tree index;
9101 /* Vector of initializers built up. */
9104 /* The type being constructed by this secondary VTT. */
9105 tree type_being_constructed;
9106 };
9108 /* Recursively build the VTT-initializer for BINFO (which is in the
9109 hierarchy dominated by T). INITS points to the end of the initializer
9110 list to date. INDEX is the VTT index where the next element will be
9111 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
9112 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
9113 for virtual bases of T. When it is not so, we build the constructor
9114 vtables for the BINFO-in-T variant. */
9116 static void
9119 {
9121 tree b;
9122 tree init;
9123 secondary_vptr_vtt_init_data data;
9126 /* We only need VTTs for subobjects with virtual bases. */
9130 /* We need to use a construction vtable if this is not the primary
9131 VTT. */
9133 {
9136 /* Record the offset in the VTT where this sub-VTT can be found. */
9138 }
9140 /* Add the address of the primary vtable for the complete object. */
9144 {
9147 }
9150 /* Recursively add the secondary VTTs for non-virtual bases. */
9155 /* Add secondary virtual pointers for all subobjects of BINFO with
9156 either virtual bases or reachable along a virtual path, except
9157 subobjects that are non-virtual primary bases. */
9167 /* data.inits might have grown as we added secondary virtual pointers.
9168 Make sure our caller knows about the new vector. */
9172 /* Add the secondary VTTs for virtual bases in inheritance graph
9173 order. */
9175 {
9180 }
9181 else
9182 /* Remove the ctor vtables we created. */
9184 }
9186 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
9187 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
9189 static tree
9191 {
9194 /* We don't care about bases that don't have vtables. */
9198 /* We're only interested in proper subobjects of the type being
9199 constructed. */
9203 /* We're only interested in bases with virtual bases or reachable
9204 via a virtual path from the type being constructed. */
9209 /* We're not interested in non-virtual primary bases. */
9213 /* Record the index where this secondary vptr can be found. */
9215 {
9220 {
9221 /* It's a primary virtual base, and this is not a
9222 construction vtable. Find the base this is primary of in
9223 the inheritance graph, and use that base's vtable
9224 now. */
9227 }
9228 }
9230 /* Add the initializer for the secondary vptr itself. */
9233 /* Advance the vtt index. */
9238 }
9240 /* Called from build_vtt_inits via dfs_walk. After building
9241 constructor vtables and generating the sub-vtt from them, we need
9242 to restore the BINFO_VTABLES that were scribbled on. DATA is the
9243 binfo of the base whose sub vtt was generated. */
9245 static tree
9247 {
9251 /* If this class has no vtable, none of its bases do. */
9255 /* This might be a primary base, so have no vtable in this
9256 hierarchy. */
9259 /* If we scribbled the construction vtable vptr into BINFO, clear it
9260 out now. */
9266 }
9268 /* Build the construction vtable group for BINFO which is in the
9269 hierarchy dominated by T. */
9271 static void
9273 {
9274 tree type;
9275 tree vtbl;
9276 tree id;
9277 tree vbase;
9280 /* See if we've already created this construction vtable group. */
9286 /* Build a version of VTBL (with the wrong type) for use in
9287 constructing the addresses of secondary vtables in the
9288 construction vtable group. */
9291 /* Don't export construction vtables from shared libraries. Even on
9292 targets that don't support hidden visibility, this tells
9293 can_refer_decl_in_current_unit_p not to assume that it's safe to
9294 access from a different compilation unit (bz 54314). */
9302 /* Add the vtables for each of our virtual bases using the vbase in T
9303 binfo. */
9305 vbase;
9307 {
9308 tree b;
9315 }
9317 /* Figure out the type of the construction vtable. */
9324 /* Initialize the construction vtable. */
9328 }
9330 /* Add the vtbl initializers for BINFO (and its bases other than
9331 non-virtual primaries) to the list of INITS. BINFO is in the
9332 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
9333 the constructor the vtbl inits should be accumulated for. (If this
9334 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
9335 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
9336 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
9337 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
9338 but are not necessarily the same in terms of layout. */
9340 static void
9342 tree orig_binfo,
9343 tree rtti_binfo,
9344 tree vtbl,
9345 tree t,
9347 {
9349 tree base_binfo;
9354 /* If it doesn't have a vptr, we don't do anything. */
9358 /* If we're building a construction vtable, we're not interested in
9359 subobjects that don't require construction vtables. */
9365 /* Build the initializers for the BINFO-in-T vtable. */
9368 /* Walk the BINFO and its bases. We walk in preorder so that as we
9369 initialize each vtable we can figure out at what offset the
9370 secondary vtable lies from the primary vtable. We can't use
9371 dfs_walk here because we need to iterate through bases of BINFO
9372 and RTTI_BINFO simultaneously. */
9374 {
9375 /* Skip virtual bases. */
9381 inits);
9382 }
9383 }
9385 /* Called from accumulate_vtbl_inits. Adds the initializers for the
9386 BINFO vtable to L. */
9388 static void
9390 tree orig_binfo,
9391 tree rtti_binfo,
9392 tree orig_vtbl,
9393 tree t,
9395 {
9402 {
9403 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
9404 primary virtual base. If it is not the same primary in
9405 the hierarchy of T, we'll need to generate a ctor vtable
9406 for it, to place at its location in T. If it is the same
9407 primary, we still need a VTT entry for the vtable, but it
9408 should point to the ctor vtable for the base it is a
9409 primary for within the sub-hierarchy of RTTI_BINFO.
9411 There are three possible cases:
9413 1) We are in the same place.
9414 2) We are a primary base within a lost primary virtual base of
9415 RTTI_BINFO.
9416 3) We are primary to something not a base of RTTI_BINFO. */
9418 tree b;
9421 /* First, look through the bases we are primary to for RTTI_BINFO
9422 or a virtual base. */
9425 {
9430 }
9431 /* If we run out of primary links, keep looking down our
9432 inheritance chain; we might be an indirect primary. */
9436 found:
9438 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
9439 base B and it is a base of RTTI_BINFO, this is case 2. In
9440 either case, we share our vtable with LAST, i.e. the
9441 derived-most base within B of which we are a primary. */
9444 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
9445 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
9446 binfo_ctor_vtable after everything's been set up. */
9449 /* Otherwise, this is case 3 and we get our own. */
9450 }
9457 {
9458 tree index;
9461 /* Add the initializer for this vtable. */
9465 /* Figure out the position to which the VPTR should point. */
9471 }
9474 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
9475 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
9476 straighten this out. */
9479 /* Throw away any unneeded intializers. */
9481 else
9482 /* For an ordinary vtable, set BINFO_VTABLE. */
9484 }
9489 /* Construct the initializer for BINFO's virtual function table. BINFO
9490 is part of the hierarchy dominated by T. If we're building a
9491 construction vtable, the ORIG_BINFO is the binfo we should use to
9492 find the actual function pointers to put in the vtable - but they
9493 can be overridden on the path to most-derived in the graph that
9494 ORIG_BINFO belongs. Otherwise,
9495 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
9496 BINFO that should be indicated by the RTTI information in the
9497 vtable; it will be a base class of T, rather than T itself, if we
9498 are building a construction vtable.
9500 The value returned is a TREE_LIST suitable for wrapping in a
9501 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
9502 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
9503 number of non-function entries in the vtable.
9505 It might seem that this function should never be called with a
9506 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
9507 base is always subsumed by a derived class vtable. However, when
9508 we are building construction vtables, we do build vtables for
9509 primary bases; we need these while the primary base is being
9510 constructed. */
9512 static void
9514 tree orig_binfo,
9515 tree t,
9516 tree rtti_binfo,
9519 {
9520 tree v;
9521 vtbl_init_data vid;
9523 tree vbinfo;
9527 /* Initialize VID. */
9535 /* The first vbase or vcall offset is at index -3 in the vtable. */
9538 /* Add entries to the vtable for RTTI. */
9541 /* Create an array for keeping track of the functions we've
9542 processed. When we see multiple functions with the same
9543 signature, we share the vcall offsets. */
9545 /* Add the vcall and vbase offset entries. */
9548 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
9549 build_vbase_offset_vtbl_entries. */
9554 /* If the target requires padding between data entries, add that now. */
9556 {
9561 /* Move data entries into their new positions and add padding
9562 after the new positions. Iterate backwards so we don't
9563 overwrite entries that we would need to process later. */
9566 ix--)
9567 {
9575 {
9579 null_pointer_node);
9580 }
9581 }
9582 }
9587 /* The initializers for virtual functions were built up in reverse
9588 order. Straighten them out and add them to the running list in one
9589 step. */
9598 /* Go through all the ordinary virtual functions, building up
9599 initializers. */
9601 {
9602 tree delta;
9603 tree vcall_index;
9610 {
9614 {
9617 }
9619 }
9621 /* If the only definition of this function signature along our
9622 primary base chain is from a lost primary, this vtable slot will
9623 never be used, so just zero it out. This is important to avoid
9624 requiring extra thunks which cannot be generated with the function.
9626 We first check this in update_vtable_entry_for_fn, so we handle
9627 restored primary bases properly; we also need to do it here so we
9628 zero out unused slots in ctor vtables, rather than filling them
9629 with erroneous values (though harmless, apart from relocation
9630 costs). */
9635 {
9636 /* Pull the offset for `this', and the function to call, out of
9637 the list. */
9644 /* You can't call an abstract virtual function; it's abstract.
9645 So, we replace these functions with __pure_virtual. */
9647 {
9650 {
9652 abort_fndecl_addr
9656 }
9657 }
9658 /* Likewise for deleted virtuals. */
9660 {
9662 {
9666 dvirt_fn = push_library_fn
9670 }
9675 }
9676 else
9677 {
9679 {
9684 }
9685 /* Take the address of the function, considering it to be of an
9686 appropriate generic type. */
9690 /* Don't refer to a virtual destructor from a constructor
9691 vtable or a vtable for an abstract class, since destroying
9692 an object under construction is undefined behavior and we
9693 don't want it to be considered a candidate for speculative
9694 devirtualization. But do create the thunk for ABI
9695 compliance. */
9700 }
9701 }
9703 /* And add it to the chain of initializers. */
9705 {
9710 else
9712 {
9718 }
9719 }
9720 else
9722 }
9723 }
9725 /* Adds to vid->inits the initializers for the vbase and vcall
9726 offsets in BINFO, which is in the hierarchy dominated by T. */
9728 static void
9730 {
9731 tree b;
9733 /* If this is a derived class, we must first create entries
9734 corresponding to the primary base class. */
9739 /* Add the vbase entries for this base. */
9741 /* Add the vcall entries for this base. */
9743 }
9745 /* Returns the initializers for the vbase offset entries in the vtable
9746 for BINFO (which is part of the class hierarchy dominated by T), in
9747 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9748 where the next vbase offset will go. */
9750 static void
9752 {
9753 tree vbase;
9754 tree t;
9755 tree non_primary_binfo;
9757 /* If there are no virtual baseclasses, then there is nothing to
9758 do. */
9764 /* We might be a primary base class. Go up the inheritance hierarchy
9765 until we find the most derived class of which we are a primary base:
9766 it is the offset of that which we need to use. */
9769 {
9770 tree b;
9772 /* If we have reached a virtual base, then it must be a primary
9773 base (possibly multi-level) of vid->binfo, or we wouldn't
9774 have called build_vcall_and_vbase_vtbl_entries for it. But it
9775 might be a lost primary, so just skip down to vid->binfo. */
9777 {
9780 }
9786 }
9788 /* Go through the virtual bases, adding the offsets. */
9790 vbase;
9792 {
9793 tree b;
9794 tree delta;
9799 /* Find the instance of this virtual base in the complete
9800 object. */
9803 /* If we've already got an offset for this virtual base, we
9804 don't need another one. */
9809 /* Figure out where we can find this vbase offset. */
9818 /* The vbase offset had better be the same. */
9821 /* The next vbase will come at a more negative offset. */
9825 /* The initializer is the delta from BINFO to this virtual base.
9826 The vbase offsets go in reverse inheritance-graph order, and
9827 we are walking in inheritance graph order so these end up in
9828 the right order. */
9835 }
9836 }
9838 /* Adds the initializers for the vcall offset entries in the vtable
9839 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9840 to VID->INITS. */
9842 static void
9844 {
9845 /* We only need these entries if this base is a virtual base. We
9846 compute the indices -- but do not add to the vtable -- when
9847 building the main vtable for a class. */
9850 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9851 correspond to VID->DERIVED), we are building a primary
9852 construction virtual table. Since this is a primary
9853 virtual table, we do not need the vcall offsets for
9854 BINFO. */
9856 {
9857 /* We need a vcall offset for each of the virtual functions in this
9858 vtable. For example:
9860 class A { virtual void f (); };
9861 class B1 : virtual public A { virtual void f (); };
9862 class B2 : virtual public A { virtual void f (); };
9863 class C: public B1, public B2 { virtual void f (); };
9865 A C object has a primary base of B1, which has a primary base of A. A
9866 C also has a secondary base of B2, which no longer has a primary base
9867 of A. So the B2-in-C construction vtable needs a secondary vtable for
9868 A, which will adjust the A* to a B2* to call f. We have no way of
9869 knowing what (or even whether) this offset will be when we define B2,
9870 so we store this "vcall offset" in the A sub-vtable and look it up in
9871 a "virtual thunk" for B2::f.
9873 We need entries for all the functions in our primary vtable and
9874 in our non-virtual bases' secondary vtables. */
9876 /* If we are just computing the vcall indices -- but do not need
9877 the actual entries -- not that. */
9880 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9882 }
9883 }
9885 /* Build vcall offsets, starting with those for BINFO. */
9887 static void
9889 {
9891 tree primary_binfo;
9892 tree base_binfo;
9894 /* Don't walk into virtual bases -- except, of course, for the
9895 virtual base for which we are building vcall offsets. Any
9896 primary virtual base will have already had its offsets generated
9897 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9901 /* If BINFO has a primary base, process it first. */
9906 /* Add BINFO itself to the list. */
9909 /* Scan the non-primary bases of BINFO. */
9913 }
9915 /* Called from build_vcall_offset_vtbl_entries_r. */
9917 static void
9919 {
9920 /* Make entries for the rest of the virtuals. */
9921 tree orig_fn;
9923 /* The ABI requires that the methods be processed in declaration
9924 order. */
9926 orig_fn;
9930 }
9932 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9934 static void
9936 {
9938 tree vcall_offset;
9939 tree derived_entry;
9941 /* If there is already an entry for a function with the same
9942 signature as FN, then we do not need a second vcall offset.
9943 Check the list of functions already present in the derived
9944 class vtable. */
9946 {
9948 /* We only use one vcall offset for virtual destructors,
9949 even though there are two virtual table entries. */
9953 }
9955 /* If we are building these vcall offsets as part of building
9956 the vtable for the most derived class, remember the vcall
9957 offset. */
9959 {
9962 }
9964 /* The next vcall offset will be found at a more negative
9965 offset. */
9969 /* Keep track of this function. */
9973 {
9974 tree base;
9975 tree fn;
9977 /* Find the overriding function. */
9981 else
9982 {
9985 /* The vbase we're working on is a primary base of
9986 vid->binfo. But it might be a lost primary, so its
9987 BINFO_OFFSET might be wrong, so we just use the
9988 BINFO_OFFSET from vid->binfo. */
9994 vcall_offset);
9995 }
9996 /* Add the initializer to the vtable. */
9998 }
9999 }
10001 /* Return vtbl initializers for the RTTI entries corresponding to the
10002 BINFO's vtable. The RTTI entries should indicate the object given
10003 by VID->rtti_binfo. */
10005 static void
10007 {
10008 tree b;
10009 tree t;
10010 tree offset;
10011 tree decl;
10012 tree init;
10016 /* To find the complete object, we will first convert to our most
10017 primary base, and then add the offset in the vtbl to that value. */
10022 /* The second entry is the address of the typeinfo object. */
10025 else
10028 /* Convert the declaration to a type that can be stored in the
10029 vtable. */
10033 /* Add the offset-to-top entry. It comes earlier in the vtable than
10034 the typeinfo entry. Convert the offset to look like a
10035 function pointer, so that we can put it in the vtable. */
10038 }
10040 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
10041 accessibility. */
10043 bool
10045 {
10048 }
10050 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
10052 bool
10054 {
10058 }
10060 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
10061 class between them, if any. */
10063 tree
10065 {
10077 {
10080 }
10084 }