| blob | 68b62086340bcd1ab357907308b52b64c680b994 |
1 /* Functions related to building -*- C++ -*- classes and their related objects.
2 Copyright (C) 1987-2023 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. */
141 /* Used by find_flexarrays and related functions. */
189 tree *);
198 splay_tree_key k2);
209 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
211 void
213 {
218 else
220 }
222 /* Return a COND_EXPR that executes TRUE_STMT if this execution of the
223 'structor is in charge of 'structing virtual bases, or FALSE_STMT
224 otherwise. */
226 tree
228 {
238 }
240 /* Convert to or from a base subobject. EXPR is an expression of type
241 `A' or `A*', an expression of type `B' or `B*' is returned. To
242 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
243 the B base instance within A. To convert base A to derived B, CODE
244 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
245 In this latter case, A must not be a morally virtual base of B.
246 NONNULL is true if EXPR is known to be non-NULL (this is only
247 needed when EXPR is of pointer type). CV qualifiers are preserved
248 from EXPR. */
250 tree
252 tree expr,
253 tree binfo,
255 tsubst_flags_t complain)
256 {
259 tree probe;
260 tree offset;
261 tree target_type;
263 tree ptr_target_type;
274 {
280 }
291 {
292 /* This can happen when adjust_result_of_qualified_name_lookup can't
293 find a unique base binfo in a call to a member function. We
294 couldn't give the diagnostic then since we might have been calling
295 a static member function, so we do it now. In other cases, eg.
296 during error recovery (c++/71979), we may not have a base at all. */
298 {
302 }
304 }
311 /* Nothing to do. */
315 {
317 {
319 {
322 "pointer to derived class %qT because the base is "
324 else
328 }
329 else
330 {
336 else
340 }
341 }
343 }
346 || processing_template_decl
349 /* For a non-pointer simple base reference, express it as a COMPONENT_REF
350 without taking its address (and so causing lambda capture, 91933). */
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 {
385 }
388 {
394 }
396 /* If we're in an NSDMI, we don't have the full constructor context yet
397 that we need for converting to a virtual base, so just build a stub
398 CONVERT_EXPR and expand it later in bot_replace. */
401 {
405 }
407 /* Do we need to check for a null pointer? */
409 {
410 /* If we know the conversion will not actually change the value
411 of EXPR, then we can avoid testing the expression for NULL.
412 We have to avoid generating a COMPONENT_REF for a base class
413 field, because other parts of the compiler know that such
414 expressions are always non-NULL. */
418 }
420 /* Protect against multiple evaluation if necessary. */
424 /* Store EXPR and build the real null test just before returning. */
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 }
476 }
484 v_offset);
496 /* Negative fixed_type_p means this is a constructor or destructor;
497 virtual base layout is fixed in in-charge [cd]tors, but not in
498 base [cd]tors. */
499 offset = build_if_in_charge
501 v_offset);
502 else
504 }
510 {
515 }
516 else
521 indout:
523 {
527 }
529 out:
531 /* Wrap EXPR in a null test. */
535 }
537 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
538 Perform a derived-to-base conversion by recursively building up a
539 sequence of COMPONENT_REFs to the appropriate base fields. */
541 static tree
543 {
546 tree field;
549 {
550 tree temp;
554 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
555 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
556 an lvalue in the front end; only _DECLs and _REFs are lvalues
557 in the back end. */
563 }
565 /* Recurse. */
570 /* Is this the base field created by build_base_field? */
574 /* If we're looking for a field in the most-derived class,
575 also check the field offset; we can have two base fields
576 of the same type if one is an indirect virtual base and one
577 is a direct non-virtual base. */
581 {
582 /* We don't use build_class_member_access_expr here, as that
583 has unnecessary checks, and more importantly results in
584 recursive calls to dfs_walk_once. */
590 /* Mark the expression const or volatile, as appropriate.
591 Even though we've dealt with the type above, we still have
592 to mark the expression itself. */
599 }
601 /* Didn't find the base field?!? */
603 }
605 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
606 type is a class type or a pointer to a class type. In the former
607 case, TYPE is also a class type; in the latter it is another
608 pointer type. If CHECK_ACCESS is true, an error message is emitted
609 if TYPE is inaccessible. If OBJECT has pointer type, the value is
610 assumed to be non-NULL. */
612 tree
614 tsubst_flags_t complain)
615 {
616 tree binfo;
617 tree object_type;
620 {
623 }
624 else
633 }
635 /* EXPR is an expression with unqualified class type. BASE is a base
636 binfo of that class type. Returns EXPR, converted to the BASE
637 type. This function assumes that EXPR is the most derived class;
638 therefore virtual bases can be found at their static offsets. */
640 tree
642 {
643 tree expr_type;
647 {
648 /* If this is a non-empty base, use a COMPONENT_REF. */
652 /* We use fold_build2 and fold_convert below to simplify the trees
653 provided to the optimizers. It is not safe to call these functions
654 when processing a template because they do not handle C++-specific
655 trees. */
663 }
666 }
668 /* True IFF EXPR is a reference to an empty base class "subobject", as built in
669 convert_to_base_statically. We look for the result of the fold_convert
670 call, a NOP_EXPR from one pointer type to another, where the target is an
671 empty base of the original type. */
673 bool
675 {
694 }
695 \f
696 tree
698 {
702 /* Can happen in case of duplicate base types (c++/59082). */
706 /* First, convert to the requested type. */
711 /* Second, the requested type may not be the owner of its own vptr.
712 If not, convert to the base class that owns it. We cannot use
713 convert_to_base here, because VCONTEXT may appear more than once
714 in the inheritance hierarchy of TYPE, and thus direct conversion
715 between the types may be ambiguous. Following the path back up
716 one step at a time via primary bases avoids the problem. */
720 {
723 }
726 }
728 /* Given an object INSTANCE, return an expression which yields the
729 vtable element corresponding to INDEX. There are many special
730 cases for INSTANCE which we take care of here, mainly to avoid
731 creating extra tree nodes when we don't have to. */
733 tree
735 {
736 tree aref;
739 /* Try to figure out what a reference refers to, and
740 access its virtual function table directly. */
748 {
753 }
762 }
764 /* Given a stable object pointer INSTANCE_PTR, return an expression which
765 yields a function pointer corresponding to vtable element INDEX. */
767 tree
769 {
770 tree aref;
774 /* When using function descriptors, the address of the
775 vtable entry is treated as a function pointer. */
780 /* Remember this as a method reference, for later devirtualization. */
785 }
787 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
788 for the given TYPE. */
790 static tree
792 {
794 }
796 /* DECL is an entity associated with TYPE, like a virtual table or an
797 implicitly generated constructor. Determine whether or not DECL
798 should have external or internal linkage at the object file
799 level. This routine does not deal with COMDAT linkage and other
800 similar complexities; it simply sets TREE_PUBLIC if it possible for
801 entities in other translation units to contain copies of DECL, in
802 the abstract. */
804 void
806 {
809 }
811 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
812 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
813 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
815 static tree
817 {
818 tree decl;
821 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
822 now to avoid confusion in mangle_decl. */
833 /* The vtable has not been defined -- yet. */
837 /* Mark the VAR_DECL node representing the vtable itself as a
838 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
839 is rather important that such things be ignored because any
840 effort to actually generate DWARF for them will run into
841 trouble when/if we encounter code like:
843 #pragma interface
844 struct S { virtual void member (); };
846 because the artificial declaration of the vtable itself (as
847 manufactured by the g++ front end) will say that the vtable is
848 a static member of `S' but only *after* the debug output for
849 the definition of `S' has already been output. This causes
850 grief because the DWARF entry for the definition of the vtable
851 will try to refer back to an earlier *declaration* of the
852 vtable as a static member of `S' and there won't be one. We
853 might be able to arrange to have the "vtable static member"
854 attached to the member list for `S' before the debug info for
855 `S' get written (which would solve the problem) but that would
856 require more intrusive changes to the g++ front end. */
860 }
862 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
863 or even complete. If this does not exist, create it. If COMPLETE is
864 nonzero, then complete the definition of it -- that will render it
865 impossible to actually build the vtable, but is useful to get at those
866 which are known to exist in the runtime. */
868 tree
870 {
871 tree decl;
880 {
883 }
886 }
888 /* Build the primary virtual function table for TYPE. If BINFO is
889 non-NULL, build the vtable starting with the initial approximation
890 that it is the same as the one which is the head of the association
891 list. Returns a nonzero value if a new vtable is actually
892 created. */
894 static int
896 {
897 tree decl;
898 tree virtuals;
903 {
905 /* We have already created a vtable for this base, so there's
906 no need to do it again. */
913 }
914 else
915 {
918 }
920 /* Initialize the association list for this type, based
921 on our first approximation. */
926 }
928 /* Give BINFO a new virtual function table which is initialized
929 with a skeleton-copy of its original initialization. The only
930 entry that changes is the `delta' entry, so we can really
931 share a lot of structure.
933 FOR_TYPE is the most derived type which caused this table to
934 be needed.
936 Returns nonzero if we haven't met BINFO before.
938 The order in which vtables are built (by calling this function) for
939 an object must remain the same, otherwise a binary incompatibility
940 can result. */
942 static int
944 {
946 /* We already created a vtable for this base. There's no need to
947 do it again. */
950 /* Remember that we've created a vtable for this BINFO, so that we
951 don't try to do so again. */
954 /* Make fresh virtual list, so we can smash it later. */
957 /* Secondary vtables are laid out as part of the same structure as
958 the primary vtable. */
961 }
963 /* Create a new vtable for BINFO which is the hierarchy dominated by
964 T. Return nonzero if we actually created a new vtable. */
966 static int
968 {
970 /* In this case, it is *type*'s vtable we are modifying. We start
971 with the approximation that its vtable is that of the
972 immediate base class. */
974 else
975 /* This is our very own copy of `basetype' to play with. Later,
976 we will fill in all the virtual functions that override the
977 virtual functions in these base classes which are not defined
978 by the current type. */
980 }
982 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
983 (which is in the hierarchy dominated by T) list FNDECL as its
984 BV_FN. DELTA is the required constant adjustment from the `this'
985 pointer where the vtable entry appears to the `this' required when
986 the function is actually called. */
988 static void
990 tree binfo,
991 tree fndecl,
992 tree delta,
994 {
995 tree v;
1001 {
1002 /* We need a new vtable for BINFO. */
1004 {
1005 /* If we really did make a new vtable, we also made a copy
1006 of the BINFO_VIRTUALS list. Now, we have to find the
1007 corresponding entry in that list. */
1012 }
1017 }
1018 }
1020 \f
1021 /* Add method METHOD to class TYPE. If VIA_USING indicates whether
1022 METHOD is being injected via a using_decl. Returns true if the
1023 method could be added to the method vec. */
1025 bool
1027 {
1036 /* See below. */
1039 /* Check to see if we've already got this method. */
1041 {
1047 /* Two using-declarations can coexist, we'll complain about ambiguity in
1048 overload resolution. */
1050 /* Except handle inherited constructors specially. */
1052 {
1054 /* Don't add the same one twice. */
1057 }
1059 /* [over.load] Member function declarations with the
1060 same name and the same parameter types cannot be
1061 overloaded if any of them is a static member
1062 function declaration.
1064 [over.load] Member function declarations with the same name and
1065 the same parameter-type-list as well as member function template
1066 declarations with the same name, the same parameter-type-list, and
1067 the same template parameter lists cannot be overloaded if any of
1068 them, but not all, have a ref-qualifier.
1070 [namespace.udecl] When a using-declaration brings names
1071 from a base class into a derived class scope, member
1072 functions in the derived class override and/or hide member
1073 functions with the same name and parameter types in a base
1074 class (rather than conflicting). */
1078 /* Compare the quals on the 'this' parm. Don't compare
1079 the whole types, as used functions are treated as
1080 coming from the using class in overload resolution. */
1083 /* Either both or neither need to be ref-qualified for
1084 differing quals to allow overloading. */
1094 /* Templates and conversion ops must match return types. */
1099 /* For templates, the template parameters must be identical. */
1101 {
1108 }
1117 /* Bring back parameters omitted from an inherited ctor. The
1118 method and the function can have different omittedness. */
1122 parms2 = (FUNCTION_FIRST_USER_PARMTYPE
1129 {
1131 /* We can't check satisfaction in dependent context, wait until
1132 the class is instantiated. */
1140 /* Member function templates and non-special member functions
1141 coexist if they are not equivalently constrained. A member
1142 function is not hidden by an inherited constructor. */
1145 /* P0848: For special member functions, deleted, unsatisfied, or
1146 less constrained overloads are ineligible. We implement this
1147 by removing them from CLASSTYPE_MEMBER_VEC. Destructors don't
1148 use the notion of eligibility, and the selected destructor can
1149 be deleted, but removing unsatisfied or less constrained
1150 overloads has the same effect as overload resolution. */
1160 else
1163 /* Leave FN in the method vec, discard METHOD. */
1166 {
1167 /* Remove FN, add METHOD. */
1170 }
1171 else
1172 /* Let them coexist for now. */
1174 }
1176 /* If these are versions of the same function, process and
1177 move on. */
1183 {
1185 /* Defer to the other function. */
1191 {
1193 {
1194 /* Inheriting the same constructor along different
1195 paths, combine them. */
1196 SET_DECL_INHERITED_CTOR
1199 /* And discard the new one. */
1201 }
1202 else
1203 /* Inherited ctors can coexist until overload
1204 resolution. */
1206 }
1213 basef);
1215 }
1218 /* Defer to the local function. */
1221 || (flag_new_inheriting_ctors
1223 {
1224 /* Remove the inherited function. */
1227 }
1228 else
1229 {
1235 }
1236 }
1247 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1253 }
1255 /* Subroutines of finish_struct. */
1257 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1258 legit, otherwise return 0. */
1260 static int
1262 {
1263 tree elem;
1271 {
1273 {
1277 else
1280 }
1281 else
1282 {
1283 /* They're changing the access to the same thing they changed
1284 it to before. That's OK. */
1285 ;
1286 }
1287 }
1288 else
1289 {
1291 tf_warning_or_error);
1294 }
1296 }
1298 /* Return the access node for DECL's access in its enclosing class. */
1300 tree
1302 {
1306 }
1308 /* If DECL is a non-dependent using of non-ctor function members, push them
1309 and return true, otherwise return false. Called from
1310 finish_member_declaration. */
1312 bool
1314 {
1321 /* Add the functions to CLASSTYPE_MEMBER_VEC so that overload resolution
1322 works within the class body. */
1324 {
1326 /* Inheriting constructors are handled separately. */
1334 /* If add_method returns false because f was already declared, look
1335 for a duplicate using-declaration. */
1336 else
1341 {
1344 }
1345 }
1347 }
1349 /* Process the USING_DECL, which is a member of T. */
1351 static void
1353 {
1361 /* Handled in maybe_push_used_methods. */
1366 tf_warning_or_error);
1368 {
1373 else
1375 }
1378 ;
1380 {
1387 }
1389 {
1396 }
1401 /* Make type T see field decl FDECL with access ACCESS. */
1403 {
1404 /* C++20 using enum can import non-inherited enumerators into class
1405 scope. We implement that by making a copy of the CONST_DECL for which
1406 CONST_DECL_USING_P is true. */
1413 /* We emitted debug info for the USING_DECL above; make sure we don't
1414 also emit anything for this clone. */
1419 }
1420 else
1422 }
1423 \f
1424 /* Data structure for find_abi_tags_r, below. */
1426 struct abi_tag_data
1427 {
1431 };
1433 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1434 in the context of P. TAG can be either an identifier (the DECL_NAME of
1435 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1437 static void
1439 {
1441 {
1443 {
1444 /* We're collecting tags from template arguments or from
1445 the type of a variable or function return type. */
1448 /* Don't inherit this tag multiple times. */
1452 {
1453 /* Tags inherited from type template arguments are only used
1454 to avoid warnings. */
1457 }
1458 /* For functions and variables we want to warn, too. */
1459 }
1461 /* Otherwise we're diagnosing missing tags. */
1463 {
1464 auto_diagnostic_group d;
1469 }
1471 {
1472 auto_diagnostic_group d;
1476 }
1478 {
1479 auto_diagnostic_group d;
1484 }
1485 else
1486 {
1487 auto_diagnostic_group d;
1491 {
1495 }
1496 }
1497 }
1498 }
1500 /* Find all the ABI tags in the attribute list ATTR and either call
1501 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1503 static void
1505 {
1512 {
1517 else
1519 }
1520 }
1522 /* Find all the ABI tags on T and its enclosing scopes and either call
1523 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1525 static void
1527 {
1529 {
1530 tree attr;
1532 {
1535 }
1536 else
1537 {
1540 }
1542 }
1543 }
1545 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1546 types with ABI tags, add the corresponding identifiers to the VEC in
1547 *DATA and set IDENTIFIER_MARKED. */
1549 static tree
1551 {
1553 /* Tell cp_walk_subtrees to look though typedefs. [PR98481] */
1559 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1560 anyway, but let's make sure of it. */
1568 }
1570 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1571 IDENTIFIER_MARKED on its ABI tags. */
1573 static tree
1575 {
1577 /* Tell cp_walk_subtrees to look though typedefs. */
1583 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1584 anyway, but let's make sure of it. */
1592 }
1594 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1595 scopes. */
1597 static void
1599 {
1602 {
1605 {
1606 /* Template arguments are part of the signature. */
1609 {
1612 }
1613 }
1615 /* A function's parameter types are part of the signature, so
1616 we don't need to inherit any tags that are also in them. */
1621 }
1622 }
1624 /* Check that T has all the ABI tags that subobject SUBOB has, or
1625 warn if not. If T is a (variable or function) declaration, also
1626 return any missing tags, and add them to T if JUST_CHECKING is false. */
1628 static tree
1630 {
1638 /* No need to worry about things local to this TU. */
1654 {
1657 }
1658 else
1659 {
1663 else
1666 }
1671 }
1673 /* Check that DECL has all the ABI tags that are used in parts of its type
1674 that are not reflected in its mangled name. */
1676 void
1678 {
1685 }
1687 /* Return any ABI tags that are used in parts of the type of DECL
1688 that are not reflected in its mangled name. This function is only
1689 used in backward-compatible mangling for ABI <11. */
1691 tree
1693 {
1697 /* Don't check DECL_CONV_FN_P here like we do in check_abi_tags, so
1698 that we can use this function for setting need_abi_warning
1699 regardless of the current flag_abi_version. */
1702 else
1704 }
1706 void
1708 {
1718 {
1721 {
1725 }
1726 }
1728 // If we found some tags on our template arguments, add them to our
1729 // abi_tag attribute.
1731 {
1735 else
1738 }
1741 }
1743 /* Return true, iff class T has a non-virtual destructor that is
1744 accessible from outside the class heirarchy (i.e. is public, or
1745 there's a suitable friend. */
1747 static bool
1749 {
1752 /* An implicitly declared destructor is always public. And,
1753 if it were virtual, we would have created it by now. */
1768 }
1770 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1771 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1772 properties of the bases. */
1774 static void
1778 {
1782 tree base_binfo;
1783 tree binfo;
1793 {
1802 /* If any base class is non-literal, so is the derived class. */
1806 /* If the base class doesn't have copy constructors or
1807 assignment operators that take const references, then the
1808 derived class cannot have such a member automatically
1809 generated. */
1818 /* A virtual base does not effect nearly emptiness. */
1819 ;
1821 {
1823 /* And if there is more than one nearly empty base, then the
1824 derived class is not nearly empty either. */
1826 else
1827 /* Remember we've seen one. */
1829 }
1831 /* If the base class is not empty or nearly empty, then this
1832 class cannot be nearly empty. */
1835 /* A lot of properties from the bases also apply to the derived
1836 class. */
1853 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1856 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1862 /* A standard-layout class is a class that:
1863 ...
1864 * has no non-standard-layout base classes, */
1867 {
1868 tree basefield;
1869 /* ...has no base classes of the same type as the first non-static
1870 data member... */
1872 && (same_type_ignoring_top_level_qualifiers_p
1875 /* DR 1813:
1876 ...has at most one base class subobject of any given type... */
1879 else
1880 /* ...has all non-static data members and bit-fields in the class
1881 and its base classes first declared in the same class. */
1887 {
1890 else
1893 }
1894 }
1896 /* Don't bother collecting tm attributes if transactional memory
1897 support is not enabled. */
1899 {
1903 }
1906 }
1908 /* If one of the base classes had TM attributes, and the current class
1909 doesn't define its own, then the current class inherits one. */
1911 {
1914 }
1915 }
1917 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1918 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1919 that have had a nearly-empty virtual primary base stolen by some
1920 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1921 T. */
1923 static void
1925 {
1929 tree base_binfo;
1931 /* Determine the primary bases of our bases. */
1934 {
1937 /* See if we're the non-virtual primary of our inheritance
1938 chain. */
1940 {
1947 /* We are the primary binfo. */
1949 }
1950 /* Determine if we have a virtual primary base, and mark it so.
1951 */
1953 {
1957 /* Someone already claimed this base. */
1959 else
1960 {
1961 tree delta;
1966 /* A virtual binfo might have been copied from within
1967 another hierarchy. As we're about to use it as a
1968 primary base, make sure the offsets match. */
1976 }
1977 }
1978 }
1980 /* First look for a dynamic direct non-virtual base. */
1982 {
1986 {
1989 }
1990 }
1992 /* A "nearly-empty" virtual base class can be the primary base
1993 class, if no non-virtual polymorphic base can be found. Look for
1994 a nearly-empty virtual dynamic base that is not already a primary
1995 base of something in the hierarchy. If there is no such base,
1996 just pick the first nearly-empty virtual base. */
2002 {
2004 {
2005 /* Found one that is not primary. */
2008 }
2010 /* Remember the first candidate. */
2012 }
2014 found:
2015 /* If we've got a primary base, use it. */
2017 {
2022 /* We are stealing a primary base. */
2026 {
2027 tree delta;
2030 /* A virtual binfo might have been copied from within
2031 another hierarchy. As we're about to use it as a primary
2032 base, make sure the offsets match. */
2037 }
2044 }
2045 }
2047 /* Update the variant types of T. */
2049 void
2051 {
2056 variant;
2058 {
2059 /* These fields are in the _TYPE part of the node, not in
2060 the TYPE_LANG_SPECIFIC component, so they are not shared. */
2071 /* Copy whatever these are holding today. */
2081 {
2084 }
2089 }
2090 }
2092 /* KLASS is a class that we're applying may_alias to after the body is
2093 parsed. Fixup any POINTER_TO and REFERENCE_TO types. The
2094 canonical type(s) will be implicitly updated. */
2096 static void
2098 {
2107 }
2109 /* Early variant fixups: we apply attributes at the beginning of the class
2110 definition, and we need to fix up any variants that have already been
2111 made via elaborated-type-specifier so that check_qualified_type works. */
2113 void
2115 {
2116 tree variants;
2131 variants;
2133 {
2134 /* These are the two fields that check_qualified_type looks at and
2135 are affected by attributes. */
2140 else
2146 }
2147 }
2148 \f
2149 /* Set memoizing fields and bits of T (and its variants) for later
2150 use. */
2152 static void
2154 {
2155 /* Fix up variants (if any). */
2159 /* For a class w/o baseclasses, 'finish_struct' has set
2160 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2161 Similarly for a class whose base classes do not have vtables.
2162 When neither of these is true, we might have removed abstract
2163 virtuals (by providing a definition), added some (by declaring
2164 new ones), or redeclared ones from a base class. We need to
2165 recalculate what's really an abstract virtual at this point (by
2166 looking in the vtables). */
2169 /* If this type has a copy constructor or a destructor, force its
2170 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2171 nonzero. This will cause it to be passed by invisible reference
2172 and prevent it from being returned in a register. */
2175 {
2176 tree variants;
2179 {
2182 }
2183 }
2184 }
2186 /* Issue warnings about T having private constructors, but no friends,
2187 and so forth.
2189 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2190 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2191 non-private static member functions. */
2193 static void
2195 {
2201 /* If the class has friends, those entities might create and
2202 access instances, so we should not warn. */
2205 /* We will have warned when the template was declared; there's
2206 no need to warn on every instantiation. */
2208 /* There's no reason to even consider warning about this
2209 class. */
2212 /* We only issue one warning, if more than one applies, because
2213 otherwise, on code like:
2215 class A {
2216 // Oops - forgot `public:'
2217 A();
2218 A(const A&);
2219 ~A();
2220 };
2222 we warn several times about essentially the same problem. */
2224 /* Check to see if all (non-constructor, non-destructor) member
2225 functions are private. (Since there are no friends or
2226 non-private statics, we can't ever call any of the private member
2227 functions.) */
2236 /* We're not interested in compiler-generated methods; they don't
2239 {
2241 /* A non-private static member function is just like a
2242 friend; it can create and invoke private member
2243 functions, and be accessed without a class
2244 instance. */
2248 /* Keep searching for a static member function. */
2249 }
2254 {
2255 /* There are no non-private methods, and there's at least one
2256 private member function that isn't a constructor or
2257 destructor. (If all the private members are
2258 constructors/destructors we want to use the code below that
2259 issues error messages specifically referring to
2260 constructors/destructors.) */
2266 {
2269 }
2271 {
2275 }
2276 }
2278 /* Even if some of the member functions are non-private, the class
2279 won't be useful for much if all the constructors or destructors
2280 are private: such an object can never be created or destroyed. */
2283 {
2286 t);
2288 }
2290 /* Warn about classes that have private constructors and no friends. */
2292 /* Implicitly generated constructors are always public. */
2294 {
2297 /* If a non-template class does not define a copy
2298 constructor, one is defined for it, enabling it to avoid
2299 this warning. For a template class, this does not
2300 happen, and so we would normally get a warning on:
2302 template <class T> class C { private: C(); };
2304 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2305 complete non-template or fully instantiated classes have this
2306 flag set. */
2309 else
2314 /* Ideally, we wouldn't count any constructor that takes
2315 an argument of the class type as a parameter, because
2316 such things cannot be used to construct an instance of
2317 the class unless you already have one. */
2319 else
2320 {
2323 }
2326 {
2328 "%q#T only defines private constructors and has "
2335 }
2336 }
2337 }
2339 /* Make BINFO's vtable have N entries, including RTTI entries,
2340 vbase and vcall offsets, etc. Set its type and call the back end
2341 to lay it out. */
2343 static void
2345 {
2346 tree atype;
2347 tree vtable;
2352 /* We may have to grow the vtable. */
2355 {
2359 }
2360 }
2362 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2363 have the same signature. */
2365 int
2367 {
2368 /* One destructor overrides another if they are the same kind of
2369 destructor. */
2373 /* But a non-destructor never overrides a destructor, nor vice
2374 versa, nor do different kinds of destructors override
2375 one-another. For example, a complete object destructor does not
2376 override a deleting destructor. */
2385 {
2393 }
2395 }
2397 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2398 subobject. */
2400 static bool
2402 {
2403 tree probe;
2406 {
2410 /* If we meet a virtual base, we can't follow the inheritance
2411 any more. See if the complete type of DERIVED contains
2412 such a virtual base. */
2415 }
2417 }
2420 /* The function for which we are trying to find a final overrider. */
2421 tree fn;
2422 /* The base class in which the function was declared. */
2423 tree declaring_base;
2424 /* The candidate overriders. */
2425 tree candidates;
2426 /* Path to most derived. */
2428 };
2430 /* Add the overrider along the current path to FFOD->CANDIDATES.
2431 Returns true if an overrider was found; false otherwise. */
2433 static bool
2437 {
2438 tree method;
2440 /* If BINFO is not the most derived type, try a more derived class.
2441 A definition there will overrider a definition here. */
2443 {
2444 depth--;
2448 }
2452 {
2455 /* Remove any candidates overridden by this new function. */
2457 {
2458 /* If *CANDIDATE overrides METHOD, then METHOD
2459 cannot override anything else on the list. */
2462 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2465 else
2467 }
2469 /* Add the new function. */
2472 }
2475 }
2477 /* Called from find_final_overrider via dfs_walk. */
2479 static tree
2481 {
2489 }
2491 static tree
2493 {
2498 }
2500 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2501 FN and whose TREE_VALUE is the binfo for the base where the
2502 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2503 DERIVED) is the base object in which FN is declared. */
2505 static tree
2507 {
2508 find_final_overrider_data ffod;
2510 /* Getting this right is a little tricky. This is valid:
2512 struct S { virtual void f (); };
2513 struct T { virtual void f (); };
2514 struct U : public S, public T { };
2516 even though calling `f' in `U' is ambiguous. But,
2518 struct R { virtual void f(); };
2519 struct S : virtual public R { virtual void f (); };
2520 struct T : virtual public R { virtual void f (); };
2521 struct U : public S, public T { };
2523 is not -- there's no way to decide whether to put `S::f' or
2524 `T::f' in the vtable for `R'.
2526 The solution is to look at all paths to BINFO. If we find
2527 different overriders along any two, then there is a problem. */
2531 /* Determine the depth of the hierarchy. */
2540 /* If there was no winner, issue an error message. */
2545 }
2547 /* Return the index of the vcall offset for FN when TYPE is used as a
2548 virtual base. */
2550 static tree
2552 {
2554 tree_pair_p p;
2562 /* There should always be an appropriate index. */
2564 }
2566 /* Given a DECL_VINDEX of a virtual function found in BINFO, return the final
2567 overrider at that index in the vtable. This should only be used when we
2568 know that BINFO is correct for the dynamic type of the object. */
2570 tree
2572 {
2577 /* BINFO_VIRTUALS in a primary base isn't accurate, find the derived
2578 class that actually owns the vtable. */
2582 }
2584 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2585 dominated by T. FN is the old function; VIRTUALS points to the
2586 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2587 of that entry in the list. */
2589 static void
2592 {
2593 tree b;
2594 tree overrider;
2595 tree delta;
2596 tree virtual_base;
2597 tree first_defn;
2603 /* Find the nearest primary base (possibly binfo itself) which defines
2604 this function; this is the class the caller will convert to when
2605 calling FN through BINFO. */
2607 {
2612 /* The nearest definition is from a lost primary. */
2615 }
2618 /* Find the final overrider. */
2621 {
2624 }
2627 /* Check for adjusting covariant return types. */
2635 /* If the overrider is invalid, don't even try. */
2637 {
2638 /* If FN is a covariant thunk, we must figure out the adjustment
2639 to the final base FN was converting to. As OVERRIDER_TARGET might
2640 also be converting to the return type of FN, we have to
2641 combine the two conversions here. */
2648 {
2652 }
2653 else
2657 /* Find the equivalent binfo within the return type of the
2658 overriding function. We will want the vbase offset from
2659 there. */
2661 over_return);
2664 {
2665 /* There was no existing virtual thunk (which takes
2666 precedence). So find the binfo of the base function's
2667 return type within the overriding function's return type.
2668 Fortunately we know the covariancy is valid (it
2669 has already been checked), so we can just iterate along
2670 the binfos, which have been chained in inheritance graph
2671 order. Of course it is lame that we have to repeat the
2672 search here anyway -- we should really be caching pieces
2673 of the vtable and avoiding this repeated work. */
2677 /* Find the base binfo within the overriding function's
2678 return type. We will always find a thunk_binfo, except
2679 when the covariancy is invalid (which we will have
2680 already diagnosed). */
2689 /* See if virtual inheritance is involved. */
2691 virtual_offset;
2698 {
2702 {
2703 /* We convert via virtual base. Adjust the fixed
2704 offset to be from there. */
2705 offset =
2709 }
2711 /* There was an existing fixed offset, this must be
2712 from the base just converted to, and the base the
2713 FN was thunking to. */
2715 else
2717 }
2718 }
2721 /* Replace the overriding function with a covariant thunk. We
2722 will emit the overriding function in its own slot as
2723 well. */
2726 }
2727 else
2731 /* If we need a covariant thunk, then we may need to adjust first_defn.
2732 The ABI specifies that the thunks emitted with a function are
2733 determined by which bases the function overrides, so we need to be
2734 sure that we're using a thunk for some overridden base; even if we
2735 know that the necessary this adjustment is zero, there may not be an
2736 appropriate zero-this-adjustment thunk for us to use since thunks for
2737 overriding virtual bases always use the vcall offset.
2739 Furthermore, just choosing any base that overrides this function isn't
2740 quite right, as this slot won't be used for calls through a type that
2741 puts a covariant thunk here. Calling the function through such a type
2742 will use a different slot, and that slot is the one that determines
2743 the thunk emitted for that base.
2745 So, keep looking until we find the base that we're really overriding
2746 in this slot: the nearest primary base that doesn't use a covariant
2747 thunk in this slot. */
2749 {
2751 /* We already know that the overrider needs a covariant thunk. */
2754 {
2761 }
2763 }
2765 /* Assume that we will produce a thunk that convert all the way to
2766 the final overrider, and not to an intermediate virtual base. */
2769 /* See if we can convert to an intermediate virtual base first, and then
2770 use the vcall offset located there to finish the conversion. */
2772 {
2773 /* If we find the final overrider, then we can stop
2774 walking. */
2779 /* If we find a virtual base, and we haven't yet found the
2780 overrider, then there is a virtual base between the
2781 declaring base (first_defn) and the final overrider. */
2783 {
2786 }
2787 }
2789 /* Compute the constant adjustment to the `this' pointer. The
2790 `this' pointer, when this function is called, will point at BINFO
2791 (or one of its primary bases, which are at the same offset). */
2793 /* The `this' pointer needs to be adjusted from the declaration to
2794 the nearest virtual base. */
2799 /* If the nearest definition is in a lost primary, we don't need an
2800 entry in our vtable. Except possibly in a constructor vtable,
2801 if we happen to get our primary back. In that case, the offset
2802 will be zero, as it will be a primary base. */
2804 else
2805 /* The `this' pointer needs to be adjusted from pointing to
2806 BINFO to pointing at the base where the final overrider
2807 appears. */
2818 else
2822 }
2824 /* Called from modify_all_vtables via dfs_walk. */
2826 static tree
2828 {
2830 tree virtuals;
2831 tree old_virtuals;
2835 /* A base without a vtable needs no modification, and its bases
2836 are uninteresting. */
2841 /* Don't do the primary vtable, if it's new. */
2845 /* There's no need to modify the vtable for a non-virtual primary
2846 base; we're not going to use that vtable anyhow. We do still
2847 need to do this for virtual primary bases, as they could become
2848 non-primary in a construction vtable. */
2853 /* Now, go through each of the virtual functions in the virtual
2854 function table for BINFO. Find the final overrider, and update
2855 the BINFO_VIRTUALS list appropriately. */
2858 virtuals;
2862 binfo,
2867 }
2869 /* Update all of the primary and secondary vtables for T. Create new
2870 vtables as required, and initialize their RTTI information. Each
2871 of the functions in VIRTUALS is declared in T and may override a
2872 virtual function from a base class; find and modify the appropriate
2873 entries to point to the overriding functions. Returns a list, in
2874 declaration order, of the virtual functions that are declared in T,
2875 but do not appear in the primary base class vtable, and which
2876 should therefore be appended to the end of the vtable for T. */
2878 static tree
2880 {
2884 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2888 /* Update all of the vtables. */
2891 /* Add virtual functions not already in our primary vtable. These
2892 will be both those introduced by this class, and those overridden
2893 from secondary bases. It does not include virtuals merely
2894 inherited from secondary bases. */
2896 {
2901 {
2902 /* We don't need to adjust the `this' pointer when
2903 calling this function. */
2907 /* This is a function not already in our vtable. Keep it. */
2909 }
2910 else
2911 /* We've already got an entry for this function. Skip it. */
2913 }
2916 }
2918 /* Get the base virtual function declarations in T that have the
2919 indicated NAME. */
2921 static void
2923 {
2926 /* Find virtual functions in T with the indicated NAME. */
2928 {
2930 {
2933 }
2934 }
2941 {
2944 }
2945 }
2947 /* If this method overrides a virtual method from a base, then mark
2948 this member function as being virtual as well. Do 'final' and
2949 'override' checks too. */
2951 void
2953 {
2955 /* In [temp.mem] we have:
2957 A specialization of a member function template does not
2958 override a virtual function from a base class. */
2961 /* IDENTIFIER_VIRTUAL_P indicates whether the name has ever been
2962 used for a vfunc. That avoids the expensive look_for_overrides
2963 call that when we know there's nothing to find. As conversion
2964 operators for the same type can have distinct identifiers, we
2965 cannot optimize those in that way. */
2969 /* Check staticness after we've checked if we 'override'. */
2971 {
2972 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2973 the error_mark_node so that we know it is an overriding
2974 function. */
2983 }
2988 {
2989 /* Remember this identifier is virtual name. */
2993 /* It's a new vfunc. */
2998 }
3001 }
3003 /* Warn about hidden virtual functions that are not overridden in t.
3004 We know that constructors and destructors don't apply. */
3006 static void
3008 {
3011 {
3019 tree base_binfo;
3020 tree binfo;
3026 /* Iterate through all of the base classes looking for possibly
3027 hidden functions. */
3030 {
3033 }
3035 /* If there are no functions to hide, continue. */
3039 /* Remove any overridden functions. */
3042 {
3046 {
3047 /* If the method from the base class has the same
3048 signature as the method from the derived class, it
3049 has been overridden. Note that we can't move on
3050 after finding one match: fndecl might override
3051 multiple base fns. */
3055 {
3058 }
3059 }
3062 }
3065 /* All the derived fns override base virtuals. */
3068 /* Now give a warning for all base functions without overriders,
3069 as they are hidden. */
3072 {
3073 auto_diagnostic_group d;
3074 /* Here we know it is a hider, and no overrider exists. */
3076 OPT_Woverloaded_virtual_,
3079 }
3080 }
3081 }
3083 /* Recursive helper for finish_struct_anon. */
3085 static void
3087 {
3089 {
3090 /* We're generally only interested in entities the user
3091 declared, but we also find nested classes by noticing
3092 the TYPE_DECL that we create implicitly. You're
3093 allowed to put one anonymous union inside another,
3094 though, so we explicitly tolerate that. We use
3095 TYPE_UNNAMED_P rather than ANON_AGGR_TYPE_P so that
3096 we also allow unnamed types used for defining fields. */
3105 /* Recurse into the anonymous aggregates to correctly handle
3106 access control (c++/24926):
3108 class A {
3109 union {
3110 union {
3111 int i;
3112 };
3113 };
3114 };
3116 int j=A().i; */
3120 }
3121 }
3123 /* Fix up any anonymous union/struct members of T. */
3125 static void
3127 {
3129 {
3138 }
3139 }
3141 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3142 will be used later during class template instantiation.
3143 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3144 a non-static member data (FIELD_DECL), a member function
3145 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3146 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3147 When FRIEND_P is nonzero, T is either a friend class
3148 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3149 (FUNCTION_DECL, TEMPLATE_DECL). */
3151 void
3153 {
3156 {
3161 }
3162 }
3164 /* This function is called from declare_virt_assop_and_dtor via
3165 dfs_walk_all.
3167 DATA is a type that direcly or indirectly inherits the base
3168 represented by BINFO. If BINFO contains a virtual assignment [copy
3169 assignment or move assigment] operator or a virtual constructor,
3170 declare that function in DATA if it hasn't been already declared. */
3172 static tree
3174 {
3182 /* A base without a vtable needs no modification, and its bases
3183 are uninteresting. */
3187 /* If this is a primary base, then we have already looked at the
3188 virtual functions of its vtable. */
3192 {
3196 {
3201 }
3205 }
3208 }
3210 /* If the class type T has a direct or indirect base that contains a
3211 virtual assignment operator or a virtual destructor, declare that
3212 function in T if it hasn't been already declared. */
3214 static void
3216 {
3224 dfs_declare_virt_assop_and_dtor,
3226 }
3228 /* Declare the inheriting constructor for class T inherited from base
3229 constructor CTOR with the parameter array PARMS of size NPARMS. */
3231 static void
3233 {
3236 /* We don't declare an inheriting ctor that would be a default,
3237 copy or move ctor for derived or base. */
3242 {
3246 }
3255 {
3258 }
3259 }
3261 /* Declare all the inheriting constructors for class T inherited from base
3262 constructor CTOR. */
3264 static void
3266 {
3270 {
3275 }
3280 {
3284 }
3287 {
3288 auto_diagnostic_group d;
3292 }
3293 }
3295 /* Create default constructors, assignment operators, and so forth for
3296 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3297 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3298 the class cannot have a default constructor, copy constructor
3299 taking a const reference argument, or an assignment operator taking
3300 a const reference, respectively. */
3302 static void
3306 {
3307 /* Destructor. */
3309 /* In general, we create destructors lazily. */
3318 /* [class.ctor]
3320 If there is no user-declared constructor for a class, a default
3321 constructor is implicitly declared. */
3323 {
3328 /* Don't force the declaration to get a hard answer; if the
3329 definition would have made the class non-literal, it will still be
3330 non-literal because of the base or member in question, and that
3331 gives a better diagnostic. */
3333 }
3335 /* [class.ctor]
3337 If a class definition does not explicitly declare a copy
3338 constructor, one is declared implicitly. */
3340 {
3346 }
3348 /* If there is no assignment operator, one will be created if and
3349 when it is needed. For now, just record whether or not the type
3350 of the parameter to the assignment operator will be a const or
3351 non-const reference. */
3353 {
3359 }
3361 /* We can't be lazy about declaring functions that might override
3362 a virtual function from a base class. */
3365 /* If the class definition does not explicitly declare an == operator
3366 function, but declares a defaulted three-way comparison operator function,
3367 an == operator function is declared implicitly. */
3370 {
3372 NULL_TREE);
3377 else
3378 {
3382 }
3384 }
3387 {
3391 {
3392 /* declare, then remove the decl */
3400 }
3401 else
3403 }
3404 }
3406 /* Cache of enum_min_precision values. */
3409 /* Return the minimum precision of a bit-field needed to store all
3410 enumerators of ENUMERAL_TYPE TYPE. */
3412 static int
3414 {
3416 /* For unscoped enums without fixed underlying type and without mode
3417 attribute we can just use precision of the underlying type. */
3433 {
3437 {
3448 }
3449 }
3450 else
3458 }
3460 /* FIELD is a bit-field. We are finishing the processing for its
3461 enclosing type. Issue any appropriate messages and set appropriate
3462 flags. Returns false if an error has been diagnosed. */
3464 static bool
3466 {
3468 tree w;
3470 /* Extract the declared width of the bitfield, which has been
3471 temporarily stashed in DECL_BIT_FIELD_REPRESENTATIVE by grokbitfield. */
3474 /* Remove the bit-field width indicator so that the rest of the
3475 compiler does not treat that value as a qualifier. */
3478 /* Detect invalid bit-field type. */
3480 {
3484 }
3485 else
3486 {
3488 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3491 /* detect invalid field size. */
3497 {
3500 }
3502 {
3505 }
3507 {
3510 }
3520 {
3526 }
3527 }
3530 {
3534 }
3535 else
3536 {
3537 /* Non-bit-fields are aligned for their type. */
3541 }
3542 }
3544 /* FIELD is a non bit-field. We are finishing the processing for its
3545 enclosing type T. Issue any appropriate messages and set appropriate
3546 flags. */
3548 static bool
3550 tree t,
3553 {
3557 /* In C++98 an anonymous union cannot contain any fields which would change
3558 the settings of CANT_HAVE_CONST_CTOR and friends. */
3560 ;
3561 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3562 structs. So, we recurse through their fields here. */
3564 {
3569 cant_have_const_ctor,
3570 no_const_asn_ref);
3571 }
3572 /* Check members with class type for constructors, destructors,
3573 etc. */
3575 {
3576 /* Never let anything with uninheritable virtuals
3577 make it through without complaint. */
3581 {
3586 field);
3591 field);
3593 {
3597 }
3598 }
3599 else
3600 {
3613 }
3622 }
3627 /* `build_class_init_list' does not recognize
3628 non-FIELD_DECLs. */
3632 }
3634 /* Check the data members (both static and non-static), class-scoped
3635 typedefs, etc., appearing in the declaration of T. Issue
3636 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3637 declaration order) of access declarations; each TREE_VALUE in this
3638 list is a USING_DECL.
3640 In addition, set the following flags:
3642 EMPTY_P
3643 The class is empty, i.e., contains no non-static data members.
3645 CANT_HAVE_CONST_CTOR_P
3646 This class cannot have an implicitly generated copy constructor
3647 taking a const reference.
3649 CANT_HAVE_CONST_ASN_REF
3650 This class cannot have an implicitly generated assignment
3651 operator taking a const reference.
3653 All of these flags should be initialized before calling this
3654 function. */
3656 static void
3660 {
3663 /* Assume there are no access declarations. */
3665 /* Effective C has things to say about classes with pointer members. */
3667 /* Default initialized members affect the whole class. */
3669 /* Lack of any non-static data member of non-volatile literal
3670 type affects a union. */
3672 /* Standard layout requires all FIELDS have same access. */
3676 {
3680 {
3685 /* Save the access declarations for our caller. */
3694 /* FIXME: We should fold in the checking from check_methods. */
3704 {
3705 /* [class.union]
3707 (C++98) If a union contains a static data member,
3708 ... the program is ill-formed. */
3712 }
3717 {
3718 /* [class.union]
3720 If a union contains ... or a [non-static data] member
3721 of reference type, the program is ill-formed. */
3725 }
3727 data_member:
3728 /* Common VAR_DECL & FIELD_DECL processing. */
3732 /* Template instantiation can cause this. Perhaps this
3733 should be a specific instantiation check? */
3735 {
3739 }
3741 {
3745 }
3748 }
3756 /* If it is not a union and at least one non-static data member is
3757 non-literal, the whole class becomes non-literal. Per Core/1453,
3758 volatile non-static data members and base classes are also not allowed.
3759 If it is a union, we might set CLASSTYPE_LITERAL_P after we've seen all
3760 members.
3761 Note: if the type is incomplete we will complain later on. */
3763 {
3766 else
3768 }
3773 {
3774 /* A standard-layout class is a class that:
3776 ... has the same access control (Clause 11) for all
3777 non-static data members, */
3780 else
3783 /* Aggregates must be public. */
3786 }
3788 /* If this is of reference type, check if it needs an init. */
3790 {
3796 {
3797 /* ARM $12.6.2: [A member initializer list] (or, for an
3798 aggregate, initialization by a brace-enclosed list) is the
3799 only way to initialize non-static const and reference
3800 members. */
3803 }
3804 }
3809 {
3811 {
3813 "ignoring packed attribute because of"
3816 }
3820 }
3824 /* We don't treat zero-width bitfields as making a class
3825 non-empty. */
3826 ;
3829 /* Empty data members also don't make a class non-empty. */
3831 else
3832 {
3833 /* The class is non-empty. */
3835 /* The class is not even nearly empty. */
3837 /* If one of the data members contains an empty class, so
3838 does T. */
3842 }
3844 /* This is used by -Weffc++ (see below). Warn only for pointers
3845 to members which might hold dynamic memory. So do not warn
3846 for pointers to functions or pointers to members. */
3852 {
3857 }
3863 {
3870 }
3873 /* DR 148 now allows pointers to members (which are POD themselves),
3874 to be allowed in POD structs. */
3878 /* A potentially-overlapping non-static data member makes the class
3879 non-layout-POD. */
3888 /* We set DECL_C_BIT_FIELD in grokbitfield.
3889 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3895 {
3898 {
3902 default_init_member);
3903 }
3905 }
3907 /* Now that we've removed bit-field widths from DECL_INITIAL,
3908 anything left in DECL_INITIAL is an NSDMI that makes the class
3909 non-aggregate in C++11, and non-layout-POD always. */
3911 {
3914 else
3916 }
3919 {
3920 /* If any field is const, the structure type is pseudo-const. */
3925 {
3926 /* ARM $12.6.2: [A member initializer list] (or, for an
3927 aggregate, initialization by a brace-enclosed list) is the
3928 only way to initialize non-static const and reference
3929 members. */
3932 }
3933 }
3934 /* A field that is pseudo-const makes the structure likewise. */
3936 {
3941 }
3943 /* Core issue 80: A non-static data member is required to have a
3944 different name from the class iff the class has a
3945 user-declared constructor. */
3950 }
3952 /* Per CWG 2096, a type is a literal type if it is a union, and at least
3953 one of its non-static data members is of non-volatile literal type. */
3957 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3958 it should also define a copy constructor and an assignment operator to
3959 implement the correct copy semantic (deep vs shallow, etc.). As it is
3960 not feasible to check whether the constructors do allocate dynamic memory
3961 and store it within members, we approximate the warning like this:
3963 -- Warn only if there are members which are pointers
3964 -- Warn only if there is a non-trivial constructor (otherwise,
3965 there cannot be memory allocated).
3966 -- Warn only if there is a non-trivial destructor. We assume that the
3967 user at least implemented the cleanup correctly, and a destructor
3968 is needed to free dynamic memory.
3970 This seems enough for practical purposes. */
3972 && pointer_member
3976 {
3978 {
3980 {
3985 }
3991 }
3992 }
3994 /* Non-static data member initializers make the default constructor
3995 non-trivial. */
3997 {
4000 }
4002 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
4006 /* Check anonymous struct/anonymous union fields. */
4009 /* We've built up the list of access declarations in reverse order.
4010 Fix that now. */
4012 }
4014 /* If TYPE is an empty class type, records its OFFSET in the table of
4015 OFFSETS. */
4017 static int
4019 {
4020 splay_tree_node n;
4025 /* Record the location of this empty object in OFFSETS. */
4033 type,
4037 }
4039 /* Returns nonzero if TYPE is an empty class type and there is
4040 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
4042 static int
4044 {
4045 splay_tree_node n;
4046 tree t;
4051 /* Record the location of this empty object in OFFSETS. */
4061 }
4063 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
4064 F for every subobject, passing it the type, offset, and table of
4065 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
4066 be traversed.
4068 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
4069 than MAX_OFFSET will not be walked.
4071 If F returns a nonzero value, the traversal ceases, and that value
4072 is returned. Otherwise, returns zero. */
4074 static int
4076 subobject_offset_fn f,
4077 tree offset,
4078 splay_tree offsets,
4079 tree max_offset,
4081 {
4085 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
4086 stop. */
4094 {
4097 }
4100 {
4101 tree field;
4102 tree binfo;
4105 /* Avoid recursing into objects that are not interesting. */
4109 /* Record the location of TYPE. */
4114 /* Iterate through the direct base classes of TYPE. */
4118 {
4119 tree binfo_offset;
4124 tree orig_binfo;
4125 /* We cannot rely on BINFO_OFFSET being set for the base
4126 class yet, but the offsets for direct non-virtual
4127 bases can be calculated by going back to the TYPE. */
4130 offset,
4134 f,
4135 binfo_offset,
4136 offsets,
4137 max_offset,
4141 }
4144 {
4148 /* Iterate through the virtual base classes of TYPE. In G++
4149 3.2, we included virtual bases in the direct base class
4150 loop above, which results in incorrect results; the
4151 correct offsets for virtual bases are only known when
4152 working with the most derived type. */
4156 {
4158 f,
4160 offset,
4162 offsets,
4163 max_offset,
4167 }
4168 else
4169 {
4170 /* We still have to walk the primary base, if it is
4171 virtual. (If it is non-virtual, then it was walked
4172 above.) */
4178 {
4179 r = (walk_subobject_offsets
4184 }
4185 }
4186 }
4188 /* Iterate through the fields of TYPE. */
4193 {
4194 tree field_offset;
4199 f,
4201 offset,
4202 field_offset),
4203 offsets,
4204 max_offset,
4208 }
4209 }
4211 {
4214 tree index;
4216 /* Avoid recursing into objects that are not interesting. */
4219 || !domain
4223 /* Step through each of the elements in the array. */
4227 {
4229 f,
4230 offset,
4231 offsets,
4232 max_offset,
4238 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4239 there's no point in iterating through the remaining
4240 elements of the array. */
4243 }
4244 }
4247 }
4249 /* Return true iff FIELD_DECL DECL is potentially overlapping. */
4251 static bool
4253 {
4254 /* Base fields are actually potentially overlapping, but C++ bases go through
4255 a different code path based on binfos, and ObjC++ base fields are laid out
4256 in objc-act, so we don't want layout_class_type to mess with them. */
4258 {
4261 }
4265 }
4267 /* Return true iff DECL is an empty field, either for an empty base or a
4268 [[no_unique_address]] data member. */
4270 bool
4272 {
4280 /* Empty fields should have size zero. */
4284 }
4286 /* Record all of the empty subobjects of DECL_OR_BINFO. */
4288 static void
4290 splay_tree offsets)
4291 {
4296 {
4302 }
4303 else
4304 {
4309 }
4311 tree max_offset;
4312 /* If recording subobjects for a non-static data member or a
4313 non-empty base class, we do not need to record offsets beyond
4314 the size of the biggest empty class. Additional data members
4315 will go at the end of the class. Additional base classes will go
4316 either at offset zero (if empty, in which case they cannot
4317 overlap with offsets past the size of the biggest empty class) or
4318 at the end of the class.
4320 However, if we are placing an empty base class, then we must record
4321 all offsets, as either the empty class is at offset zero (where
4322 other empty classes might later be placed) or at the end of the
4323 class (where other objects might then be placed, so other empty
4324 subobjects might later overlap). */
4328 else
4332 }
4334 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4335 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4336 virtual bases of TYPE are examined. */
4338 static int
4340 tree offset,
4341 splay_tree offsets,
4343 {
4344 splay_tree_node max_node;
4346 /* Get the node in OFFSETS that indicates the maximum offset where
4347 an empty subobject is located. */
4349 /* If there aren't any empty subobjects, then there's no point in
4350 performing this check. */
4356 vbases_p);
4357 }
4359 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4360 non-static data member of the type indicated by RLI. BINFO is the
4361 binfo corresponding to the base subobject, OFFSETS maps offsets to
4362 types already located at those offsets. This function determines
4363 the position of the DECL. */
4365 static void
4367 tree decl,
4368 tree binfo,
4369 splay_tree offsets)
4370 {
4373 tree type;
4376 {
4377 /* For the purposes of determining layout conflicts, we want to
4378 use the class type of BINFO; TREE_TYPE (DECL) will be the
4379 CLASSTYPE_AS_BASE version, which does not contain entries for
4380 zero-sized bases. */
4383 }
4384 else
4385 {
4388 }
4390 /* Try to place the field. It may take more than one try if we have
4391 a hard time placing the field without putting two objects of the
4392 same type at the same address. */
4394 {
4397 /* Place this field. */
4401 /* We have to check to see whether or not there is already
4402 something of the same type at the offset we're about to use.
4403 For example, consider:
4405 struct S {};
4406 struct T : public S { int i; };
4407 struct U : public S, public T {};
4409 Here, we put S at offset zero in U. Then, we can't put T at
4410 offset zero -- its S component would be at the same address
4411 as the S we already allocated. So, we have to skip ahead.
4412 Since all data members, including those whose type is an
4413 empty class, have nonzero size, any overlap can happen only
4414 with a direct or indirect base-class -- it can't happen with
4415 a data member. */
4416 /* In a union, overlap is permitted; all members are placed at
4417 offset zero. */
4422 {
4423 /* Strip off the size allocated to this field. That puts us
4424 at the first place we could have put the field with
4425 proper alignment. */
4428 /* Bump up by the alignment required for the type. */
4429 rli->bitpos
4435 }
4438 {
4439 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4440 the offset wasn't aligned like a pointer when we started to
4441 layout this field, that affects its position. */
4444 {
4447 "alignment of %qD increased in %<-fabi-version=9%> "
4449 else
4452 decl);
4453 }
4455 }
4456 else
4457 /* There was no conflict. We're done laying out this field. */
4459 }
4461 /* Now that we know where it will be placed, update its
4462 BINFO_OFFSET. */
4464 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4465 this point because their BINFO_OFFSET is copied from another
4466 hierarchy. Therefore, we may not need to add the entire
4467 OFFSET. */
4473 }
4475 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4477 static int
4479 tree offset,
4481 {
4483 }
4485 /* Layout the empty base BINFO. EOC indicates the byte currently just
4486 past the end of the class, and should be correctly aligned for a
4487 class of the type indicated by BINFO; OFFSETS gives the offsets of
4488 the empty bases allocated so far. T is the most derived
4489 type. Return nonzero iff we added it at the end. */
4491 static bool
4493 splay_tree offsets)
4494 {
4495 tree alignment;
4499 tree type;
4501 {
4504 }
4505 else
4506 {
4509 }
4511 /* On some platforms (ARM), even empty classes will not be
4512 byte-aligned. */
4517 /* This routine should only be used for empty classes. */
4522 else
4525 /* This is an empty base class. We first try to put it at offset
4526 zero. */
4530 offset,
4531 offsets,
4533 {
4534 /* That didn't work. Now, we move forward from the next
4535 available spot in the class. */
4539 {
4541 offset,
4542 offsets,
4544 /* We finally found a spot where there's no overlap. */
4547 /* There's overlap here, too. Bump along to the next spot. */
4549 }
4550 }
4553 {
4558 }
4560 {
4565 }
4568 /* Adjust BINFO_OFFSET (binfo) to be exactly OFFSET. */
4571 else
4572 {
4576 }
4579 }
4581 /* Build the FIELD_DECL for BASETYPE as a base of T, add it to the chain of
4582 fields at NEXT_FIELD, and return it. */
4584 static tree
4586 {
4587 /* Create the FIELD_DECL. */
4597 /* CLASSTYPE_SIZE is one byte, but the field needs to have size zero. */
4599 else
4600 {
4603 }
4614 /* Add the new FIELD_DECL to the list of fields for T. */
4620 }
4622 /* Layout the base given by BINFO in the class indicated by RLI.
4623 *BASE_ALIGN is a running maximum of the alignments of
4624 any base class. OFFSETS gives the location of empty base
4625 subobjects. T is the most derived type. Return nonzero if the new
4626 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4627 *NEXT_FIELD, unless BINFO is for an empty base class.
4629 Returns the location at which the next field should be inserted. */
4634 {
4639 /* This error is now reported in xref_tag, thus giving better
4640 location information. */
4643 /* Place the base class. */
4645 {
4646 tree decl;
4648 /* The containing class is non-empty because it has a non-empty
4649 base class. */
4652 /* Create the FIELD_DECL. */
4655 /* Try to place the field. It may take more than one try if we
4656 have a hard time placing the field without putting two
4657 objects of the same type at the same address. */
4659 }
4660 else
4661 {
4663 /* A nearly-empty class "has no proper base class that is empty,
4664 not morally virtual, and at an offset other than zero." */
4666 {
4669 /* The check above (used in G++ 3.2) is insufficient because
4670 an empty class placed at offset zero might itself have an
4671 empty base at a nonzero offset. */
4673 empty_base_at_nonzero_offset_p,
4674 size_zero_node,
4679 }
4681 /* We used to not create a FIELD_DECL for empty base classes because of
4682 back end issues with overlapping FIELD_DECLs, but that doesn't seem to
4683 be a problem anymore. We need them to handle initialization of C++17
4684 aggregate bases. */
4686 {
4692 }
4694 /* An empty virtual base causes a class to be non-empty
4695 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4696 here because that was already done when the virtual table
4697 pointer was created. */
4698 }
4700 /* Record the offsets of BINFO and its base subobjects. */
4704 }
4706 /* Layout all of the non-virtual base classes. Record empty
4707 subobjects in OFFSETS. T is the most derived type. Return nonzero
4708 if the type cannot be nearly empty. The fields created
4709 corresponding to the base classes will be inserted at
4710 *NEXT_FIELD. */
4712 static void
4715 {
4716 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4717 subobjects. */
4722 /* The primary base class is always allocated first. */
4725 {
4726 /* We need to walk BINFO_BASE_BINFO to find the access of the primary
4727 base, if it is direct. Indirect base fields are private. */
4730 {
4733 {
4736 }
4737 }
4739 primary_access,
4741 }
4743 /* Now allocate the rest of the bases. */
4745 {
4748 /* The primary base was already allocated above, so we don't
4749 need to allocate it again here. */
4753 /* Virtual bases are added at the end (a primary virtual base
4754 will have already been added). */
4761 }
4762 }
4764 /* Go through the TYPE_FIELDS of T issuing any appropriate
4765 diagnostics, figuring out which methods override which other
4766 methods, and so forth. */
4768 static void
4770 {
4773 {
4779 /* The name of the field is the original field name
4780 Save this in auxiliary field for later overloading. */
4782 {
4786 }
4792 "%<transaction_safe_dynamic%> may only be specified for "
4794 }
4796 /* Check whether the eligible special member functions (P0848) are
4797 user-provided. add_method arranged that the CLASSTYPE_MEMBER_VEC only
4798 has the eligible ones, unless none are eligible; TYPE_FIELDS also contains
4799 ineligible overloads, which is why this needs to be separate from the loop
4800 above. */
4803 {
4805 {
4806 /* P0848: At the end of the definition of a class, overload
4807 resolution is performed among the prospective destructors declared
4808 in that class with an empty argument list to select the destructor
4809 for the class, also known as the selected destructor. The program
4810 is ill-formed if overload resolution fails. */
4817 auto_diagnostic_group d;
4820 else
4824 /* Arbitrarily prune the overload set to a single function for
4825 sake of error recovery. */
4828 }
4831 }
4834 {
4845 }
4848 {
4859 }
4860 }
4862 /* FN is constructor, destructor or operator function. Clone the
4863 declaration to create a NAME'd variant. NEED_VTT_PARM_P and
4864 OMIT_INHERITED_PARMS_P are relevant if it's a cdtor. */
4866 static tree
4869 {
4870 /* Copy the function. */
4872 /* Reset the function name. */
4876 /* Clone constraints. */
4881 /* There's no pending inline data for this function. */
4886 {
4887 /* The base-class destructor is not virtual. */
4890 }
4892 {
4893 /* Set the operator code. */
4897 /* The operator could be virtual. */
4900 }
4905 /* If there was an in-charge parameter, drop it from the function
4906 type. */
4908 {
4911 /* Skip the `this' parameter. */
4913 /* Skip the in-charge parameter. */
4915 /* And the VTT parm, in a complete [cd]tor. */
4919 {
4920 /* If we're omitting inherited parms, that just leaves the VTT. */
4923 }
4927 parmtypes);
4933 }
4935 /* Copy the function parameters. */
4938 /* Remove the in-charge parameter. */
4940 {
4944 }
4946 /* And the VTT parm, in a complete [cd]tor. */
4948 {
4951 else
4952 {
4956 }
4957 }
4959 /* A base constructor inheriting from a virtual base doesn't get the
4960 arguments. */
4965 {
4968 }
4970 /* Create the RTL for this function. */
4973 /* Regardless of the current scope, this is a member function, so
4974 not at namespace scope. */
4978 }
4980 /* FN is an operator function, create a variant for CODE. */
4982 tree
4984 {
4987 }
4989 /* FN is a constructor or destructor. Clone the declaration to create
4990 a specialized in-charge or not-in-charge version, as indicated by
4991 NAME. */
4993 static tree
4996 {
4997 tree clone;
4999 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
5001 {
5013 }
5014 else
5015 {
5019 }
5021 /* Remember where this function came from. */
5024 /* Make it easy to find the CLONE given the FN. Note the
5025 template_result of a template will be chained this way too. */
5030 }
5032 /* Build the clones of FN, return the number of clones built. These
5033 will be inserted onto DECL_CHAIN of FN. */
5035 void
5038 {
5042 {
5043 /* For each constructor, we need two variants: an in-charge version
5044 and a not-in-charge version. */
5047 base_omits_inherited_p);
5049 }
5050 else
5051 {
5054 /* For each destructor, we need three variants: an in-charge
5055 version, a not-in-charge version, and an in-charge deleting
5056 version. We clone the deleting version first because that
5057 means it will go second on the TYPE_FIELDS list -- and that
5058 corresponds to the correct layout order in the virtual
5059 function table.
5061 For a non-virtual destructor, we do not build a deleting
5062 destructor. */
5064 {
5066 count++;
5067 }
5071 }
5073 /* The original is now an abstract function that is never
5074 emitted. */
5079 {
5082 }
5083 }
5085 /* Produce declarations for all appropriate clones of FN. If
5086 UPDATE_METHODS is true, the clones are added to the
5087 CLASSTYPE_MEMBER_VEC. */
5089 void
5091 {
5092 /* Avoid inappropriate cloning. */
5097 /* Base cdtors need a vtt parm if there are virtual bases. */
5100 /* Base ctor omits inherited parms it needs a vttparm and inherited
5101 from a virtual nase ctor. */
5106 }
5108 /* DECL is an in charge constructor, which is being defined. This will
5109 have had an in class declaration, from whence clones were
5110 declared. An out-of-class definition can specify additional default
5111 arguments. As it is the clones that are involved in overload
5112 resolution, we must propagate the information from the DECL to its
5113 clones. */
5115 void
5117 {
5118 tree clone;
5122 {
5127 /* Skip the 'this' parameter. */
5143 {
5145 {
5149 }
5155 {
5156 /* A default parameter has been added. Adjust the
5157 clone's parameters. */
5161 {
5164 clone_parms);
5166 }
5169 tree type
5172 clone_parms);
5180 }
5181 }
5183 }
5184 }
5186 /* For each of the constructors and destructors in T, create an
5187 in-charge and not-in-charge variant. */
5189 static void
5191 {
5192 /* We do not need to propagate the usingness to the clone, at this
5193 point that is not needed. */
5199 }
5201 /* Deduce noexcept for a destructor DTOR. */
5203 void
5205 {
5208 noexcept_deferred_spec);
5209 }
5211 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
5212 of TYPE for virtual functions which FNDECL overrides. Return a
5213 mask of the tm attributes found therein. */
5215 static int
5217 {
5219 tree base_binfo;
5223 {
5231 {
5235 else
5238 }
5239 else
5241 }
5244 }
5246 /* Subroutine of set_method_tm_attributes. Handle the checks and
5247 inheritance for one virtual method FNDECL. */
5249 static void
5251 {
5252 tree tm_attr;
5257 /* If FNDECL doesn't actually override anything (i.e. T is the
5258 class that first declares FNDECL virtual), then we're done. */
5265 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
5266 tm_pure must match exactly, otherwise no weakening of
5267 tm_safe > tm_callable > nothing. */
5268 /* ??? The tm_pure attribute didn't make the transition to the
5269 multivendor language spec. */
5271 {
5273 {
5276 }
5277 }
5278 /* If the overridden function is tm_pure, then FNDECL must be. */
5281 /* Look for base class combinations that cannot be satisfied. */
5283 {
5289 }
5290 /* If FNDECL did not declare an attribute, then inherit the most
5291 restrictive one. */
5293 {
5295 }
5296 /* Otherwise validate that we're not weaker than a function
5297 that is being overridden. */
5298 else
5299 {
5303 }
5306 err_override:
5310 }
5312 /* For each of the methods in T, propagate a class-level tm attribute. */
5314 static void
5316 {
5319 /* Don't bother collecting tm attributes if transactional memory
5320 support is not enabled. */
5324 /* Process virtual methods first, as they inherit directly from the
5325 base virtual function and also require validation of new attributes. */
5327 {
5328 tree vchain;
5331 {
5336 }
5337 }
5339 /* If the class doesn't have an attribute, nothing more to do. */
5344 /* Any method that does not yet have a tm attribute inherits
5345 the one from the class. */
5350 }
5352 /* Returns true if FN is a default constructor. */
5354 bool
5356 {
5359 }
5361 /* Returns true iff class T has a user-provided constructor that can be called
5362 with more than zero arguments. */
5364 bool
5366 {
5371 {
5377 }
5380 }
5382 /* Returns the defaulted constructor if T has one. Otherwise, returns
5383 NULL_TREE. */
5385 tree
5387 {
5392 {
5398 }
5401 }
5403 /* Returns true iff FN is a user-provided function, i.e. user-declared
5404 and not defaulted at its first declaration. */
5406 bool
5408 {
5413 }
5415 /* Returns true iff class T has a user-provided constructor. */
5417 bool
5419 {
5431 }
5433 /* Returns true iff class T has a user-provided or explicit constructor. */
5435 bool
5437 {
5445 {
5449 }
5452 }
5454 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5455 declared or explicitly defaulted in the class body) default
5456 constructor. */
5458 bool
5460 {
5467 {
5473 }
5476 }
5478 /* TYPE is being used as a virtual base, and has a non-trivial move
5479 assignment. Return true if this is due to there being a user-provided
5480 move assignment in TYPE or one of its subobjects; if there isn't, then
5481 multiple move assignment can't cause any harm. */
5483 bool
5485 {
5486 /* Does the type itself have a user-provided move assignment operator? */
5494 /* Do any of its bases? */
5496 tree base_binfo;
5501 /* Or non-static data members? */
5503 {
5508 }
5510 /* Seems not. */
5512 }
5514 /* If default-initialization leaves part of TYPE uninitialized, returns
5515 a DECL for the field or TYPE itself (DR 253). */
5517 tree
5519 {
5530 {
5534 }
5538 {
5542 }
5545 }
5547 /* Returns true iff for class T, a trivial synthesized default constructor
5548 would be constexpr. */
5550 bool
5552 {
5553 /* A defaulted trivial default constructor is constexpr
5554 if there is nothing to initialize. */
5556 /* A class with a vptr doesn't have a trivial default ctor.
5557 In C++20, a class can have transient uninitialized members, e.g.:
5559 struct S { int i; constexpr S() = default; };
5561 should work. */
5564 }
5566 /* Returns true iff class T has a constexpr default constructor. */
5568 bool
5570 {
5571 tree fns;
5574 {
5575 /* The caller should have stripped an enclosing array. */
5578 }
5580 {
5583 /* Non-trivial, we need to check subobject constructors. */
5585 }
5588 }
5590 /* Returns true iff class T has a constexpr default constructor or has an
5591 implicitly declared default constructor that we can't tell if it's constexpr
5592 without forcing a lazy declaration (which might cause undesired
5593 instantiations). */
5595 static bool
5597 {
5600 /* Assume it's constexpr. */
5603 }
5605 /* Returns true iff class T has a constexpr destructor. */
5607 bool
5609 {
5610 tree fns;
5613 /* Non-trivial, we need to check subobject destructors. */
5617 }
5619 /* Returns true iff class T has a constexpr destructor or has an
5620 implicitly declared destructor that we can't tell if it's constexpr
5621 without forcing a lazy declaration (which might cause undesired
5622 instantiations). */
5624 static bool
5626 {
5627 /* Until C++20, only trivial destruction is constexpr. */
5633 /* Assume it's constexpr. */
5637 }
5639 /* Returns true iff class TYPE has a virtual destructor. */
5641 bool
5643 {
5644 tree dtor;
5652 }
5654 /* Returns true iff T, a class, has a move-assignment or
5655 move-constructor. Does not lazily declare either.
5656 If USER_P is false, any move function will do. If it is true, the
5657 move function must be user-declared.
5659 Note that user-declared here is different from "user-provided",
5660 which doesn't include functions that are defaulted in the
5661 class. */
5663 bool
5665 {
5685 }
5687 /* True iff T has a move constructor that is not deleted. */
5689 bool
5691 {
5698 }
5700 /* If T, a class, has a user-provided copy constructor, copy assignment
5701 operator, or destructor, returns that function. Otherwise, null. */
5703 tree
5705 {
5708 {
5712 }
5718 {
5723 }
5726 {
5730 }
5733 }
5735 /* True iff T has a member or friend declaration of operator OP. */
5737 bool
5739 {
5747 }
5750 /* If T has a defaulted member or friend declaration of OP, return it. */
5752 tree
5754 {
5757 {
5761 }
5765 {
5769 }
5771 }
5773 /* Nonzero if we need to build up a constructor call when initializing an
5774 object of this class, either because it has a user-declared constructor
5775 or because it doesn't have a default constructor (so we need to give an
5776 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5777 what you care about is whether or not an object can be produced by a
5778 constructor (e.g. so we don't set TREE_READONLY on const variables of
5779 such type); use this function when what you care about is whether or not
5780 to try to call a constructor to create an object. The latter case is
5781 the former plus some cases of constructors that cannot be called. */
5783 bool
5785 {
5786 tree inner;
5796 /* A user-declared constructor might be private, and a constructor might
5797 be trivial but deleted. */
5800 {
5807 }
5809 }
5811 /* Like type_build_ctor_call, but for destructors. */
5813 bool
5815 {
5816 tree inner;
5825 /* A user-declared destructor might be private, and a destructor might
5826 be trivial but deleted. */
5829 {
5836 }
5838 }
5840 /* Returns TRUE iff we need a cookie when dynamically allocating an
5841 array whose elements have the indicated class TYPE. */
5843 static bool
5845 {
5846 tree fns;
5851 /* If there's a non-trivial destructor, we need a cookie. In order
5852 to iterate through the array calling the destructor for each
5853 element, we'll have to know how many elements there are. */
5857 /* If the usual deallocation function is a two-argument whose second
5858 argument is of type `size_t', then we have to pass the size of
5859 the array to the deallocation function, so we will need to store
5860 a cookie. */
5864 /* If there are no `operator []' members, or the lookup is
5865 ambiguous, then we don't need a cookie. */
5868 /* Loop through all of the functions. */
5870 {
5873 /* See if this function is a one-argument delete function. If
5874 it is, then it will be the usual deallocation function. */
5878 /* Do not consider this function if its second argument is an
5879 ellipsis. */
5882 /* Otherwise, if we have a two-argument function and the second
5883 argument is `size_t', it will be the usual deallocation
5884 function -- unless there is one-argument function, too. */
5888 }
5891 }
5893 /* Finish computing the `literal type' property of class type T.
5895 At this point, we have already processed base classes and
5896 non-static data members. We need to check whether the copy
5897 constructor is trivial, the destructor is trivial, and there
5898 is a trivial default constructor or at least one constexpr
5899 constructor other than the copy constructor. */
5901 static void
5903 {
5904 tree fn;
5918 /* C++14 DR 1684 removed this restriction. */
5926 {
5929 {
5930 auto_diagnostic_group d;
5932 "enclosing class of %<constexpr%> non-static "
5935 }
5936 }
5937 }
5939 /* T is a non-literal type used in a context which requires a constant
5940 expression. Explain why it isn't literal. */
5942 void
5944 {
5954 /* Already explained. */
5957 auto_diagnostic_group d;
5961 " %qT is a closure type, which is only literal in "
5968 t);
5973 {
5975 " %q+T is not an aggregate, does not have a trivial "
5976 "default constructor, and has no %<constexpr%> constructor that "
5979 /* Note that we can't simply call locate_ctor because when the
5980 constructor is deleted it just returns NULL_TREE. */
5982 {
5989 {
5992 else
5995 }
5996 }
5997 }
5998 else
5999 {
6003 {
6006 {
6012 }
6013 }
6015 {
6016 tree ftype;
6021 {
6024 field);
6027 }
6031 }
6032 }
6033 }
6035 /* Check the validity of the bases and members declared in T. Add any
6036 implicitly-generated functions (like copy-constructors and
6037 assignment operators). Compute various flag bits (like
6038 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
6039 level: i.e., independently of the ABI in use. */
6041 static void
6043 {
6044 /* Nonzero if the implicitly generated copy constructor should take
6045 a non-const reference argument. */
6047 /* Nonzero if the implicitly generated assignment operator
6048 should take a non-const reference argument. */
6050 tree access_decls;
6053 tree fn;
6055 /* By default, we use const reference arguments and generate default
6056 constructors. */
6060 /* Check all the base-classes and set FMEM members to point to arrays
6061 of potential interest. */
6064 /* Deduce noexcept on destructor. This needs to happen after we've set
6065 triviality flags appropriately for our bases, and before checking
6066 overriden virtual functions via check_methods. */
6072 /* Check all the method declarations. */
6075 /* Save the initial values of these flags which only indicate whether
6076 or not the class has user-provided functions. As we analyze the
6077 bases and members we can set these flags for other reasons. */
6081 /* Check all the data member declarations. We cannot call
6082 check_field_decls until we have called check_bases check_methods,
6083 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
6084 being set appropriately. */
6089 /* A nearly-empty class has to be vptr-containing; a nearly empty
6090 class contains just a vptr. */
6094 /* Do some bookkeeping that will guide the generation of implicitly
6095 declared member functions. */
6098 /* We need to call a constructor for this class if it has a
6099 user-provided constructor, or if the default constructor is going
6100 to initialize the vptr. (This is not an if-and-only-if;
6101 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
6102 themselves need constructing.) */
6105 /* [dcl.init.aggr]
6107 An aggregate is an array or a class with no user-provided
6108 constructors ... and no virtual functions.
6110 Again, other conditions for being an aggregate are checked
6111 elsewhere. */
6117 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
6118 retain the old definition internally for ABI reasons. */
6127 /* Is this class non-layout-POD because it wasn't an aggregate in C++98? */
6129 {
6131 /* It's non-POD for another reason. */
6135 }
6137 /* If the only explicitly declared default constructor is user-provided,
6138 set TYPE_HAS_COMPLEX_DFLT. */
6144 /* Warn if a public base of a polymorphic type has an accessible
6145 non-virtual destructor. It is only now that we know the class is
6146 polymorphic. Although a polymorphic base will have a already
6147 been diagnosed during its definition, we warn on use too. */
6149 {
6152 tree base_binfo;
6156 {
6164 basetype);
6165 }
6166 }
6168 /* If the class has no user-declared constructor, but does have
6169 non-static const or reference data members that can never be
6170 initialized, issue a warning. */
6172 /* Classes with user-declared constructors are presumed to
6173 initialize these members. */
6175 /* Aggregates can be initialized with brace-enclosed
6176 initializers. */
6178 {
6179 tree field;
6182 {
6183 tree type;
6200 }
6201 }
6203 /* Synthesize any needed methods. */
6205 cant_have_const_ctor,
6206 no_const_asn_ref);
6208 /* Check defaulted declarations here so we have cant_have_const_ctor
6209 and don't need to worry about clones. */
6214 {
6215 /* ...except handle comparisons later, in finish_struct_1. */
6221 {
6222 bool imp_const_p
6228 /* If the function is defaulted outside the class, we just
6229 give the synthesis error. Core Issue #1331 says this is
6230 no longer ill-formed, it is defined as deleted instead. */
6232 }
6234 }
6237 /* "This class type is not an aggregate." */
6240 /* Compute the 'literal type' property before we
6241 do anything with non-static member functions. */
6244 /* Create the in-charge and not-in-charge variants of constructors
6245 and destructors. */
6248 /* Process the using-declarations. */
6252 /* Figure out whether or not we will need a cookie when dynamically
6253 allocating an array of this type. */
6256 }
6258 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
6259 accordingly. If a new vfield was created (because T doesn't have a
6260 primary base class), then the newly created field is returned. It
6261 is not added to the TYPE_FIELDS list; it is the caller's
6262 responsibility to do that. Accumulate declared virtual functions
6263 on VIRTUALS_P. */
6265 static tree
6267 {
6268 tree fn;
6270 /* Collect the virtual functions declared in T. */
6275 {
6284 }
6286 /* If we couldn't find an appropriate base class, create a new field
6287 here. Even if there weren't any new virtual functions, we might need a
6288 new virtual function table if we're supposed to include vptrs in
6289 all classes that need them. */
6291 {
6292 /* We build this decl with vtbl_ptr_type_node, which is a
6293 `vtable_entry_type*'. It might seem more precise to use
6294 `vtable_entry_type (*)[N]' where N is the number of virtual
6295 functions. However, that would require the vtable pointer in
6296 base classes to have a different type than the vtable pointer
6297 in derived classes. We could make that happen, but that
6298 still wouldn't solve all the problems. In particular, the
6299 type-based alias analysis code would decide that assignments
6300 to the base class vtable pointer can't alias assignments to
6301 the derived class vtable pointer, since they have different
6302 types. Thus, in a derived class destructor, where the base
6303 class constructor was inlined, we could generate bad code for
6304 setting up the vtable pointer.
6306 Therefore, we use one type for all vtable pointers. We still
6307 use a type-correct type; it's just doesn't indicate the array
6308 bounds. That's better than using `void*' or some such; it's
6309 cleaner, and it let's the alias analysis code know that these
6310 stores cannot alias stores to void*! */
6311 tree field;
6324 /* This class is non-empty. */
6328 }
6331 }
6333 /* Add OFFSET to all base types of BINFO which is a base in the
6334 hierarchy dominated by T.
6336 OFFSET, which is a type offset, is number of bytes. */
6338 static void
6340 {
6342 tree primary_binfo;
6343 tree base_binfo;
6345 /* Update BINFO's offset. */
6350 offset));
6352 /* Find the primary base class. */
6358 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
6359 downwards. */
6361 {
6362 /* Don't do the primary base twice. */
6370 }
6371 }
6373 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
6374 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
6375 empty subobjects of T. */
6377 static void
6379 {
6380 tree vbase;
6387 /* Find the last field. The artificial fields created for virtual
6388 bases will go after the last extant field to date. */
6393 /* Go through the virtual bases, allocating space for each virtual
6394 base that is not already a primary base class. These are
6395 allocated in inheritance graph order. */
6397 {
6402 {
6403 /* This virtual base is not a primary base of any class in the
6404 hierarchy, so we have to add space for it. */
6406 access_private_node,
6408 }
6409 }
6410 }
6412 /* Returns the offset of the byte just past the end of the base class
6413 BINFO. */
6415 static tree
6417 {
6418 tree size;
6423 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6424 allocate some space for it. It cannot have virtual bases, so
6425 TYPE_SIZE_UNIT is fine. */
6427 else
6431 }
6433 /* Returns one of three variations of the ending offset of T. If MODE is
6434 eoc_nvsize, the result is the ABI "nvsize" (i.e. sizeof before allocating
6435 vbases). If MODE is eoc_vsize, the result is the sizeof after allocating
6436 vbases but before rounding, which is not named in the ABI. If MODE is
6437 eoc_nv_or_dsize, the result is the greater of "nvsize" and "dsize" (the size
6438 of the actual data in the class, kinda), as used for allocation of
6439 potentially-overlapping fields. */
6442 static tree
6444 {
6447 tree binfo;
6448 tree base_binfo;
6449 tree offset;
6454 {
6463 }
6468 {
6471 /* DECL_SIZE_UNIT can be null for a flexible array. */
6475 /* For empty fields DECL_SIZE_UNIT is 0, but we want the
6476 size of the type (usually 1) for computing nvsize. */
6480 {
6485 }
6486 else
6490 }
6495 {
6497 /* For dsize, don't count trailing empty bases. */
6500 else
6504 }
6507 }
6509 /* Warn as appropriate about the change in whether we pack into the tail
6510 padding of FIELD, a base field which has a C++14 aggregate type with default
6511 member initializers. */
6513 static void
6515 {
6535 {
6539 "%<-std=c++14%> and up changes in "
6541 else
6543 "%<-std=c++14%> and up changes in "
6545 }
6546 }
6548 /* Warn about bases of T that are inaccessible because they are
6549 ambiguous. For example:
6551 struct S {};
6552 struct T : public S {};
6553 struct U : public S, public T {};
6555 Here, `(S*) new U' is not allowed because there are two `S'
6556 subobjects of U. */
6558 static void
6560 {
6563 tree basetype;
6564 tree binfo;
6565 tree base_binfo;
6567 /* If not checking for warning then return early. */
6571 /* If there are no repeated bases, nothing can be ambiguous. */
6575 /* Check direct bases. */
6578 {
6584 }
6586 /* Check for ambiguous virtual bases. */
6590 {
6596 }
6597 }
6599 /* Compare two INTEGER_CSTs K1 and K2. */
6601 static int
6603 {
6605 }
6607 /* Increase the size indicated in RLI to account for empty classes
6608 that are "off the end" of the class. */
6610 static void
6612 {
6613 tree eoc;
6614 tree rli_size;
6616 /* It might be the case that we grew the class to allocate a
6617 zero-sized base class. That won't be reflected in RLI, yet,
6618 because we are willing to overlay multiple bases at the same
6619 offset. However, now we need to make sure that RLI is big enough
6620 to reflect the entire class. */
6625 {
6626 /* The size should have been rounded to a whole byte. */
6629 rli->bitpos
6638 }
6639 }
6641 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6642 BINFO_OFFSETs for all of the base-classes. Position the vtable
6643 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6645 static void
6647 {
6648 tree non_static_data_members;
6649 tree field;
6650 tree vptr;
6651 record_layout_info rli;
6652 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6653 types that appear at that offset. */
6654 splay_tree empty_base_offsets;
6655 /* True if the last field laid out was a bit-field. */
6657 /* The location at which the next field should be inserted. */
6660 /* Keep track of the first non-static data member. */
6663 /* Start laying out the record. */
6666 /* Mark all the primary bases in the hierarchy. */
6669 /* Create a pointer to our virtual function table. */
6672 /* The vptr is always the first thing in the class. */
6674 {
6679 }
6680 else
6683 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6688 /* Layout the non-static data members. */
6690 {
6691 tree type;
6692 tree padding;
6694 /* We still pass things that aren't non-static data members to
6695 the back end, in case it wants to do something with them. */
6697 {
6699 /* If the static data member has incomplete type, keep track
6700 of it so that it can be completed later. (The handling
6701 of pending statics in finish_record_layout is
6702 insufficient; consider:
6704 struct S1;
6705 struct S2 { static S1 s1; };
6707 At this point, finish_record_layout will be called, but
6708 S1 is still incomplete.) */
6710 {
6712 /* The visibility of static data members is determined
6713 at their point of declaration, not their point of
6714 definition. */
6716 }
6718 }
6730 {
6731 /* if D is a potentially-overlapping data member, update sizeof(C) to
6732 max (sizeof(C), offset(D)+max (nvsize(D), dsize(D))). */
6735 else
6736 {
6740 }
6741 }
6743 /* If this field is a bit-field whose width is greater than its
6744 type, then there are some special rules for allocating
6745 it. */
6748 {
6750 /* We must allocate the bits as if suitably aligned for the
6751 longest integer type that fits in this many bits. Then,
6752 we are supposed to use the left over bits as additional
6753 padding. */
6755 /* Do not pick a type bigger than MAX_FIXED_MODE_SIZE. */
6763 {
6765 /* Too big, so our current guess is what we want. */
6767 /* Not bigger than limit, ok */
6769 }
6771 /* Figure out how much additional padding is required. */
6773 /* In a union, the padding field must have the full width
6774 of the bit-field; all fields start at offset zero. */
6776 else
6783 /* An unnamed bitfield does not normally affect the
6784 alignment of the containing class on a target where
6785 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6786 make any exceptions for unnamed bitfields when the
6787 bitfields are longer than their types. Therefore, we
6788 temporarily give the field a name. */
6790 {
6793 }
6799 empty_base_offsets);
6802 /* Now that layout has been performed, set the size of the
6803 field to the size of its declared type; the rest of the
6804 field is effectively invisible. */
6806 /* We must also reset the DECL_MODE of the field. */
6808 }
6810 {
6813 }
6814 else
6816 empty_base_offsets);
6818 /* Remember the location of any empty classes in FIELD. */
6821 /* If a bit-field does not immediately follow another bit-field,
6822 and yet it starts in the middle of a byte, we have failed to
6823 comply with the ABI. */
6826 /* The TREE_NO_WARNING flag gets set by Objective-C when
6827 laying out an Objective-C class. The ObjC ABI differs
6828 from the C++ ABI, and so we do not want a warning
6829 here. */
6831 && !last_field_was_bitfield
6834 bitsize_unit_node)))
6836 "offset of %qD is not ABI-compliant and may "
6839 /* The middle end uses the type of expressions to determine the
6840 possible range of expression values. In order to optimize
6841 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6842 must be made aware of the width of "i", via its type.
6844 Because C++ does not have integer types of arbitrary width,
6845 we must (for the purposes of the front end) convert from the
6846 type assigned here to the declared type of the bitfield
6847 whenever a bitfield expression is used as an rvalue.
6848 Similarly, when assigning a value to a bitfield, the value
6849 must be converted to the type given the bitfield here. */
6851 {
6856 {
6863 }
6864 }
6866 /* If we needed additional padding after this field, add it
6867 now. */
6869 {
6870 tree padding_field;
6873 FIELD_DECL,
6874 NULL_TREE,
6875 char_type_node);
6883 NULL_TREE,
6884 empty_base_offsets);
6885 }
6888 }
6891 {
6892 /* Make sure that we are on a byte boundary so that the size of
6893 the class without virtual bases will always be a round number
6894 of bytes. */
6897 }
6899 /* We used to remove zero width bitfields at this point since PR42217,
6900 while the C FE never did that. That caused ABI differences on various
6901 targets. Set the DECL_FIELD_CXX_ZERO_WIDTH_BIT_FIELD flag on them
6902 instead, so that the backends can emit -Wpsabi warnings in the cases
6903 where the ABI changed. */
6905 {
6908 /* We should not be confused by the fact that grokbitfield
6909 temporarily sets the width of the bit field into
6910 DECL_BIT_FIELD_REPRESENTATIVE (field).
6911 check_bitfield_decl eventually sets DECL_SIZE (field)
6912 to that width. */
6917 }
6920 {
6921 /* T needs a different layout as a base (eliding virtual bases
6922 or whatever). Create that version. */
6931 /* If the ABI version is not at least two, and the last
6932 field was a bit-field, RLI may not be on a byte
6933 boundary. In particular, rli_size_unit_so_far might
6934 indicate the last complete byte, while rli_size_so_far
6935 indicates the total number of bits used. Therefore,
6936 rli_size_so_far, rather than rli_size_unit_so_far, is
6937 used to compute TYPE_SIZE_UNIT. */
6939 /* Set the size and alignment for the new type. */
6947 eoc);
6959 /* Copy the non-static data members of T. This will include its
6960 direct non-virtual bases & vtable. */
6964 {
6966 /* Zap any NSDMI, it's not needed and might be a deferred
6967 parse. */
6971 }
6974 /* We use the base type for trivial assignments, and hence it
6975 needs a mode. */
6978 /* Record the base version of the type. */
6980 }
6981 else
6984 /* Every empty class contains an empty class. */
6988 /* Set the TYPE_DECL for this type to contain the right
6989 value for DECL_OFFSET, so that we can use it as part
6990 of a COMPONENT_REF for multiple inheritance. */
6993 /* Now fix up any virtual base class types that we left lying
6994 around. We must get these done before we try to lay out the
6995 virtual function table. As a side-effect, this will remove the
6996 base subobject fields. */
6999 /* Make sure that empty classes are reflected in RLI at this
7000 point. */
7003 /* Make sure not to create any structures with zero size. */
7009 /* If this is a non-POD, declaring it packed makes a difference to how it
7010 can be used as a field; don't let finalize_record_size undo it. */
7014 /* Let the back end lay out the type. */
7017 /* If we didn't end up needing an as-base type, don't use it. */
7019 /* If T's CLASSTYPE_AS_BASE is TYPE_USER_ALIGN, but T is not,
7020 replacing the as-base type would change CLASSTYPE_USER_ALIGN,
7021 causing us to lose the user-specified alignment as in PR94050. */
7033 /* Warn about bases that can't be talked about due to ambiguity. */
7036 /* Now that we're done with layout, give the base fields the real types. */
7041 /* Clean up. */
7048 }
7050 /* Determine the "key method" for the class type indicated by TYPE,
7051 and set CLASSTYPE_KEY_METHOD accordingly. */
7053 void
7055 {
7056 tree method;
7063 /* The key method is the first non-pure virtual function that is not
7064 inline at the point of class definition. On some targets the
7065 key function may not be inline; those targets should not call
7066 this function until the end of the translation unit. */
7072 {
7075 }
7078 }
7080 /* Helper of find_flexarrays. Return true when FLD refers to a non-static
7081 class data member of non-zero size, otherwise false. */
7085 {
7093 {
7097 }
7100 }
7102 /* Used by find_flexarrays and related functions. */
7104 struct flexmems_t
7105 {
7106 /* The first flexible array member or non-zero array member found
7107 in the order of layout. */
7108 tree array;
7109 /* First non-static non-empty data member in the class or its bases. */
7110 tree first;
7111 /* The first non-static non-empty data member following either
7112 the flexible array member, if found, or the zero-length array member
7113 otherwise. AFTER[1] refers to the first such data member of a union
7114 of which the struct containing the flexible array member or zero-length
7115 array is a member, or NULL when no such union exists. This element is
7116 only used during searching, not for diagnosing problems. AFTER[0]
7117 refers to the first such data member that is not a member of such
7118 a union. */
7121 /* Refers to a struct (not union) in which the struct of which the flexible
7122 array is member is defined. Used to diagnose strictly (according to C)
7123 invalid uses of the latter structs. */
7124 tree enclosing;
7125 };
7127 /* Find either the first flexible array member or the first zero-length
7128 array, in that order of preference, among members of class T (but not
7129 its base classes), and set members of FMEM accordingly.
7130 BASE_P is true if T is a base class of another class.
7131 PUN is set to the outermost union in which the flexible array member
7132 (or zero-length array) is defined if one such union exists, otherwise
7133 to NULL.
7134 Similarly, PSTR is set to a data member of the outermost struct of
7135 which the flexible array is a member if one such struct exists,
7136 otherwise to NULL. */
7138 static void
7142 {
7143 /* Set the "pointer" to the outermost enclosing union if not set
7144 yet and maintain it for the remainder of the recursion. */
7149 {
7153 /* Is FLD a typedef for an anonymous struct? */
7155 /* FIXME: Note that typedefs (as well as arrays) need to be fully
7156 handled elsewhere so that errors like the following are detected
7157 as well:
7158 typedef struct { int i, a[], j; } S; // bug c++/72753
7159 S s [2]; // bug c++/68489
7160 */
7165 {
7166 /* Check the nested unnamed type referenced via a typedef
7167 independently of FMEM (since it's not a data member of
7168 the enclosing class). */
7171 }
7173 /* Skip anything that's GCC-generated or not a (non-static) data
7174 member. */
7178 /* Type of the member. */
7183 /* Determine the type of the array element or object referenced
7184 by the member so that it can be checked for flexible array
7185 members if it hasn't been yet. */
7192 {
7194 {
7195 /* Once the member after the flexible array has been found
7196 we're done. */
7199 }
7202 {
7203 /* Descend into the non-static member struct or union and try
7204 to find a flexible array member or zero-length array among
7205 its members. This is only necessary for anonymous types
7206 and types in whose context the current type T has not been
7207 defined (the latter must not be checked again because they
7208 are already in the process of being checked by one of the
7209 recursive calls). */
7214 /* If this member isn't anonymous and a prior non-flexible array
7215 member has been seen in one of the enclosing structs, clear
7216 the FIRST member since it doesn't contribute to the flexible
7217 array struct's members. */
7228 {
7229 /* Restore the FIRST member reset above if no flexible
7230 array member has been found in this member's struct. */
7232 }
7234 /* If the member struct contains the first flexible array
7235 member, or if this member is a base class, continue to
7236 the next member and avoid setting the FMEM->NEXT pointer
7237 to point to it. */
7240 }
7241 }
7244 {
7245 /* Remember the first non-static data member. */
7249 /* Remember the first non-static data member after the flexible
7250 array member, if one has been found, or the zero-length array
7251 if it has been found. */
7254 }
7256 /* Skip non-arrays. */
7260 /* Determine the upper bound of the array if it has one. */
7262 {
7264 {
7265 /* Make a record of the zero-length array if either one
7266 such field or a flexible array member has been seen to
7267 handle the pathological and unlikely case of multiple
7268 such members. */
7271 }
7273 {
7274 /* Remember the first zero-length array unless a flexible array
7275 member has already been seen. */
7278 }
7279 }
7280 else
7281 {
7282 /* Flexible array members have no upper bound. */
7284 {
7286 {
7287 /* Replace the zero-length array if it's been stored and
7288 reset the after pointer. */
7292 }
7294 /* Make a record of another flexible array member. */
7296 }
7297 else
7298 {
7301 }
7302 }
7303 }
7304 }
7306 /* Diagnose a strictly (by the C standard) invalid use of a struct with
7307 a flexible array member (or the zero-length array extension). */
7309 static void
7311 {
7313 {
7314 auto_diagnostic_group d;
7325 }
7326 }
7328 /* Issue diagnostics for invalid flexible array members or zero-length
7329 arrays that are not the last elements of the containing class or its
7330 base classes or that are its sole members. */
7332 static void
7334 {
7339 {
7342 }
7344 /* Has a diagnostic been issued? */
7350 {
7357 {
7360 auto_diagnostic_group d;
7362 {
7365 }
7366 }
7367 }
7368 else
7369 {
7376 {
7380 auto_diagnostic_group d;
7383 /* In the unlikely event that the member following the flexible
7384 array member is declared in a different class, or the member
7385 overlaps another member of a common union, point to it.
7386 Otherwise it should be obvious. */
7390 {
7395 }
7396 }
7397 }
7401 }
7404 /* Recursively check to make sure that any flexible array or zero-length
7405 array members of class T or its bases are valid (i.e., not the sole
7406 non-static data member of T and, if one exists, that it is the last
7407 non-static data member of T and its base classes. FMEM is expected
7408 to be initially null and is used internally by recursive calls to
7409 the function. Issue the appropriate diagnostics for the array member
7410 that fails the checks. */
7412 static void
7415 {
7416 /* Initialize the result of a search for flexible array and zero-length
7417 array members. Avoid doing any work if the most interesting FMEM data
7418 have already been populated. */
7427 /* Recursively check the primary base class first. */
7429 {
7432 }
7434 /* Recursively check the base classes. */
7437 {
7440 /* The primary base class was already checked above. */
7444 /* Virtual base classes are at the end. */
7448 /* Check the base class. */
7450 }
7453 {
7454 /* Check virtual base classes only once per derived class.
7455 I.e., this check is not performed recursively for base
7456 classes. */
7458 tree base_binfo;
7462 {
7463 /* Check the virtual base class. */
7467 }
7468 }
7470 /* Is the type unnamed (and therefore a member of it potentially
7471 an anonymous struct or union)? */
7476 /* Search the members of the current (possibly derived) class, skipping
7477 unnamed structs and unions since those could be anonymous. */
7482 {
7483 /* Issue diagnostics for invalid flexible and zero-length array
7484 members found in base classes or among the members of the current
7485 class. Ignore anonymous structs and unions whose members are
7486 considered to be members of the enclosing class and thus will
7487 be diagnosed when checking it. */
7489 }
7490 }
7492 /* Perform processing required when the definition of T (a class type)
7493 is complete. Diagnose invalid definitions of flexible array members
7494 and zero-size arrays. */
7496 void
7498 {
7499 tree x;
7500 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
7504 {
7509 }
7511 /* If this type was previously laid out as a forward reference,
7512 make sure we lay it out again. */
7516 /* Make assumptions about the class; we'll reset the flags if
7517 necessary. */
7523 /* Do end-of-class semantic processing: checking the validity of the
7524 bases and members and add implicitly generated methods. */
7527 /* Find the key method. */
7529 {
7530 /* The Itanium C++ ABI permits the key method to be chosen when
7531 the class is defined -- even though the key method so
7532 selected may later turn out to be an inline function. On
7533 some systems (such as ARM Symbian OS) the key method cannot
7534 be determined until the end of the translation unit. On such
7535 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
7536 will cause the class to be added to KEYED_CLASSES. Then, in
7537 finish_file we will determine the key method. */
7541 /* If a polymorphic class has no key method, we may emit the vtable
7542 in every translation unit where the class definition appears. If
7543 we're devirtualizing, we can look into the vtable even if we
7544 aren't emitting it. */
7547 }
7549 /* Layout the class itself. */
7551 /* COMPLETE_TYPE_P is now true. */
7555 /* With the layout complete, check for flexible array members and
7556 zero-length arrays that might overlap other members in the final
7557 layout. */
7562 /* If necessary, create the primary vtable for this class. */
7564 {
7565 /* We must enter these virtuals into the table. */
7569 /* Here we know enough to change the type of our virtual
7570 function table, but we will wait until later this function. */
7573 /* If we're warning about ABI tags, check the types of the new
7574 virtual functions. */
7578 }
7581 {
7583 tree fn;
7590 /* Add entries for virtual functions introduced by this class. */
7594 /* Set DECL_VINDEX for all functions declared in this class. */
7596 fn;
7598 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
7600 {
7604 /* A thunk. We should never be calling this entry directly
7605 from this vtable -- we'd use the entry for the non
7606 thunk base function. */
7610 }
7611 }
7619 /* Clear DECL_IN_AGGR_P for all member functions. Complete the rtl
7620 for any static member objects of the type we're working on. */
7623 {
7624 /* Synthesize constexpr defaulted comparisons. */
7630 }
7636 /* Complain if one of the field types requires lower visibility. */
7639 /* Make the rtl for any new vtables we have created, and unmark
7640 the base types we marked. */
7643 /* Build the VTT for T. */
7650 "%q#T has virtual functions and accessible"
7658 /* Class layout, assignment of virtual table slots, etc., is now
7659 complete. Give the back end a chance to tweak the visibility of
7660 the class or perform any other required target modifications. */
7670 /* Finish debugging output for this type. */
7674 {
7677 {
7680 }
7682 {
7685 else
7686 {
7689 }
7691 }
7693 {
7695 "the type of the first field has a different ABI from the "
7698 }
7699 }
7700 }
7702 /* When T was built up, the member declarations were added in reverse
7703 order. Rearrange them to declaration order. */
7705 void
7707 {
7708 tree next;
7709 tree prev;
7710 tree x;
7712 /* The following lists are all in reverse order. Put them in
7713 declaration order now. */
7716 /* For the TYPE_FIELDS, only the non TYPE_DECLs are in reverse
7717 order, so we can't just use nreverse. Due to stat_hack
7718 chicanery in finish_member_declaration. */
7723 {
7727 }
7730 {
7733 }
7734 }
7736 tree
7738 {
7741 /* Now that we've got all the field declarations, reverse everything
7742 as necessary. */
7748 /* Nadger the current location so that diagnostics point to the start of
7749 the struct, not the end. */
7753 {
7754 tree x;
7758 {
7762 }
7764 {
7767 }
7769 /* Also add a USING_DECL for operator=. We know there'll be (at
7770 least) one, but we don't know the signature(s). We want name
7771 lookup not to fail or recurse into bases. This isn't added
7772 to the template decl list so we drop this at instantiation
7773 time. */
7775 NULL_TREE);
7785 /* COMPLETE_TYPE_P is now true. */
7789 /* We need to emit an error message if this type was used as a parameter
7790 and it is an abstract type, even if it is a template. We construct
7791 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
7792 account and we call complete_vars with this type, which will check
7793 the PARM_DECLS. Note that while the type is being defined,
7794 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
7795 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
7802 /* Remember current #pragma pack value. */
7806 {
7810 }
7814 /* Fix up any variants we've already built. */
7816 }
7817 else
7819 /* COMPLETE_TYPE_P is now true. */
7824 {
7825 /* People keep complaining that the compiler crashes on an invalid
7826 definition of initializer_list, so I guess we should explicitly
7827 reject it. What the compiler internals care about is that it's a
7828 template and has a pointer field followed by size_type field. */
7831 {
7834 {
7838 }
7839 }
7840 /* It also cannot be a union. */
7845 }
7853 else
7865 /* Lambdas are defined by the LAMBDA_EXPR. */
7870 }
7871 \f
7872 /* Hash table to avoid endless recursion when handling references. */
7875 /* Return the dynamic type of INSTANCE, if known.
7876 Used to determine whether the virtual function table is needed
7877 or not.
7879 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7880 of our knowledge of its type. *NONNULL should be initialized
7881 before this function is called. */
7883 static tree
7885 {
7886 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
7889 {
7893 else
7897 /* This is a call to a constructor, hence it's never zero. */
7900 {
7904 }
7908 /* This is a call to a constructor, hence it's never zero. */
7910 {
7914 }
7923 /* Propagate nonnull. */
7928 CASE_CONVERT:
7934 {
7935 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7936 with a real object -- given &p->f, p can still be null. */
7938 /* ??? Probably should check DECL_WEAK here. */
7941 }
7945 /* If this component is really a base class reference, then the field
7946 itself isn't definitive. */
7955 {
7959 }
7960 /* fall through. */
7965 {
7969 }
7971 {
7975 /* if we're in a ctor or dtor, we know our type. If
7976 current_class_ptr is set but we aren't in a function, we're in
7977 an NSDMI (and therefore a constructor). */
7982 {
7986 }
7987 }
7989 {
7990 /* We only need one hash table because it is always left empty. */
7992 fixed_type_or_null_ref_ht
7995 /* Reference variables should be references to objects. */
7999 /* Enter the INSTANCE in a table to prevent recursion; a
8000 variable's initializer may refer to the variable
8001 itself. */
8006 {
8007 tree type;
8016 }
8017 }
8023 else
8024 /* TODO: Recursion may be correct for some non-location-wrapper
8025 uses of VIEW_CONVERT_EXPR. */
8030 }
8031 #undef RECUR
8032 }
8034 /* Return nonzero if the dynamic type of INSTANCE is known, and
8035 equivalent to the static type. We also handle the case where
8036 INSTANCE is really a pointer. Return negative if this is a
8037 ctor/dtor. There the dynamic type is known, but this might not be
8038 the most derived base of the original object, and hence virtual
8039 bases may not be laid out according to this type.
8041 Used to determine whether the virtual function table is needed
8042 or not.
8044 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
8045 of our knowledge of its type. *NONNULL should be initialized
8046 before this function is called. */
8048 int
8050 {
8053 tree fixed;
8055 /* processing_template_decl can be false in a template if we're in
8056 instantiate_non_dependent_expr, but we still want to suppress
8057 this check. */
8059 {
8060 /* In a template we only care about the type of the result. */
8064 }
8076 }
8078 \f
8079 void
8081 {
8084 current_class_stack
8091 }
8093 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
8095 static void
8097 {
8098 tree type;
8100 /* We are re-entering the same class we just left, so we don't
8101 have to search the whole inheritance matrix to find all the
8102 decls to bind again. Instead, we install the cached
8103 class_shadowed list and walk through it binding names. */
8106 /* Restore IDENTIFIER_TYPE_VALUE. */
8108 type;
8111 }
8113 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
8114 appropriate for TYPE.
8116 So that we may avoid calls to lookup_name, we cache the _TYPE
8117 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
8119 For multiple inheritance, we perform a two-pass depth-first search
8120 of the type lattice. */
8122 void
8124 {
8125 class_stack_node_t csn;
8129 /* Make sure there is enough room for the new entry on the stack. */
8131 {
8133 current_class_stack
8135 current_class_stack_size);
8136 }
8138 /* Insert a new entry on the class stack. */
8145 current_class_depth++;
8147 /* Now set up the new type. */
8153 /* By default, things in classes are private, while things in
8154 structures or unions are public. */
8156 ? access_private_node
8162 {
8163 /* Forcibly remove any old class remnants. */
8165 }
8171 else
8173 }
8175 /* Get out of the current class scope. If we were in a class scope
8176 previously, that is the one popped to. */
8178 void
8180 {
8183 current_class_depth--;
8189 }
8191 /* Mark the top of the class stack as hidden. */
8193 void
8195 {
8198 }
8200 /* Mark the top of the class stack as un-hidden. */
8202 void
8204 {
8207 }
8209 /* If the class type currently being defined is either T or
8210 a nested type of T, returns the type from the current_class_stack,
8211 which might be equivalent to but not equal to T in case of
8212 constrained partial specializations. */
8214 tree
8216 {
8224 /* We start looking from 1 because entry 0 is from global scope,
8225 and has no type. */
8227 {
8228 tree c;
8231 else
8232 {
8236 }
8241 }
8243 }
8245 /* If either current_class_type or one of its enclosing classes are derived
8246 from T, return the appropriate type. Used to determine how we found
8247 something via unqualified lookup. */
8249 tree
8251 {
8254 /* The bases of a dependent type are unknown. */
8265 {
8270 }
8273 }
8275 /* Return the outermost enclosing class type that is still open, or
8276 NULL_TREE. */
8278 tree
8280 {
8287 {
8294 }
8296 }
8298 /* Returns the innermost class type which is not a lambda closure type. */
8300 tree
8302 {
8307 }
8309 /* When entering a class scope, all enclosing class scopes' names with
8310 static meaning (static variables, static functions, types and
8311 enumerators) have to be visible. This recursive function calls
8312 pushclass for all enclosing class contexts until global or a local
8313 scope is reached. TYPE is the enclosed class. */
8315 void
8317 {
8318 /* A namespace might be passed in error cases, like A::B:C. */
8326 }
8328 /* Undoes a push_nested_class call. */
8330 void
8332 {
8338 }
8340 /* Returns the number of extern "LANG" blocks we are nested within. */
8342 int
8344 {
8346 }
8348 /* Set global variables CURRENT_LANG_NAME to appropriate value
8349 so that behavior of name-mangling machinery is correct. */
8351 void
8353 {
8360 else
8362 }
8364 /* Get out of the current language scope. */
8366 void
8368 {
8370 }
8371 \f
8372 /* Type instantiation routines. */
8374 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
8375 matches the TARGET_TYPE. If there is no satisfactory match, return
8376 error_mark_node, and issue an error & warning messages under
8377 control of FLAGS. Permit pointers to member function if FLAGS
8378 permits. If TEMPLATE_ONLY, the name of the overloaded function was
8379 a template-id, and EXPLICIT_TARGS are the explicitly provided
8380 template arguments.
8382 If OVERLOAD is for one or more member functions, then ACCESS_PATH
8383 is the base path used to reference those member functions. If
8384 the address is resolved to a member function, access checks will be
8385 performed and errors issued if appropriate. */
8387 static tree
8389 tree overload,
8390 tsubst_flags_t complain,
8392 tree explicit_targs,
8393 tree access_path)
8394 {
8395 /* Here's what the standard says:
8397 [over.over]
8399 If the name is a function template, template argument deduction
8400 is done, and if the argument deduction succeeds, the deduced
8401 arguments are used to generate a single template function, which
8402 is added to the set of overloaded functions considered.
8404 Non-member functions and static member functions match targets of
8405 type "pointer-to-function" or "reference-to-function." Nonstatic
8406 member functions match targets of type "pointer-to-member
8407 function;" the function type of the pointer to member is used to
8408 select the member function from the set of overloaded member
8409 functions. If a non-static member function is selected, the
8410 reference to the overloaded function name is required to have the
8411 form of a pointer to member as described in 5.3.1.
8413 If more than one function is selected, any template functions in
8414 the set are eliminated if the set also contains a non-template
8415 function, and any given template function is eliminated if the
8416 set contains a second template function that is more specialized
8417 than the first according to the partial ordering rules 14.5.5.2.
8418 After such eliminations, if any, there shall remain exactly one
8419 selected function. */
8422 /* We store the matches in a TREE_LIST rooted here. The functions
8423 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
8424 interoperability with most_specialized_instantiation. */
8426 tree fn;
8427 tree target_fn_type;
8429 /* By the time we get here, we should be seeing only real
8430 pointer-to-member types, not the internal POINTER_TYPE to
8431 METHOD_TYPE representation. */
8437 /* Check that the TARGET_TYPE is reasonable. */
8442 /* This is OK, too. */
8445 /* This is OK, too. This comes from a conversion to reference
8446 type. */
8448 else
8449 {
8455 }
8457 /* Non-member functions and static member functions match targets of type
8458 "pointer-to-function" or "reference-to-function." Nonstatic member
8459 functions match targets of type "pointer-to-member-function;" the
8460 function type of the pointer to member is used to select the member
8461 function from the set of overloaded member functions.
8463 So figure out the FUNCTION_TYPE that we want to match against. */
8466 /* If we can find a non-template function that matches, we can just
8467 use it. There's no point in generating template instantiations
8468 if we're just going to throw them out anyhow. But, of course, we
8469 can only do this when we don't *need* a template function. */
8472 {
8476 /* We're not looking for templates just yet. */
8480 /* We're looking for a non-static member, and this isn't
8481 one, or vice versa. */
8484 /* Constraints must be satisfied. This is done before
8485 return type deduction since that instantiates the
8486 function. */
8491 {
8492 /* Force instantiation to do return type deduction. */
8495 }
8497 /* In C++17 we need the noexcept-qualifier to compare types. */
8502 /* See if there's a match. */
8507 }
8509 /* Now, if we've already got a match (or matches), there's no need
8510 to proceed to the template functions. But, if we don't have a
8511 match we need to look at them, too. */
8513 {
8514 tree target_arg_types;
8515 tree target_ret_type;
8518 tree arg;
8532 {
8534 tree instantiation;
8535 tree targs;
8538 /* We're only looking for templates. */
8543 /* We're not looking for a non-static member, and this is
8544 one, or vice versa. */
8549 /* If the template has a deduced return type, don't expose it to
8550 template argument deduction. */
8554 /* Try to do argument deduction. */
8561 /* Instantiation failed. */
8564 /* Constraints must be satisfied. This is done before
8565 return type deduction since that instantiates the
8566 function. */
8570 /* And now force instantiation to do return type deduction. */
8572 {
8578 }
8580 /* In C++17 we need the noexcept-qualifier to compare types. */
8584 /* See if there's a match. */
8589 }
8591 /* Now, remove all but the most specialized of the matches. */
8593 {
8598 NULL_TREE,
8599 NULL_TREE);
8600 }
8601 }
8603 /* Now we should have exactly one function in MATCHES. */
8605 {
8606 /* There were *no* matches. */
8608 {
8613 }
8615 }
8617 {
8618 /* There were too many matches. First check if they're all
8619 the same function. */
8624 /* For multi-versioned functions, more than one match is just fine and
8625 decls_match will return false as they are different. */
8633 {
8635 {
8639 /* Since print_candidates expects the functions in the
8640 TREE_VALUE slot, we flip them here. */
8645 }
8648 }
8649 }
8651 /* Good, exactly one match. Now, convert it to the correct type. */
8656 {
8662 auto_diagnostic_group d;
8665 {
8669 }
8670 }
8672 /* If a pointer to a function that is multi-versioned is requested, the
8673 pointer to the dispatcher function is returned instead. This works
8674 well because indirectly calling the function will dispatch the right
8675 function version at run-time. */
8677 {
8681 /* Mark all the versions corresponding to the dispatcher as used. */
8684 }
8686 /* If we're doing overload resolution purely for the purpose of
8687 determining conversion sequences, we should not consider the
8688 function used. If this conversion sequence is selected, the
8689 function will be marked as used at this point. */
8691 {
8692 /* Make =delete work with SFINAE. */
8697 }
8699 /* We could not check access to member functions when this
8700 expression was originally created since we did not know at that
8701 time to which function the expression referred. */
8703 {
8706 }
8710 else
8711 {
8712 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
8713 will mark the function as addressed, but here we must do it
8714 explicitly. */
8718 }
8719 }
8721 /* This function will instantiate the type of the expression given in
8722 RHS to match the type of LHSTYPE. If errors exist, then return
8723 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
8724 we complain on errors. If we are not complaining, never modify rhs,
8725 as overload resolution wants to try many possible instantiations, in
8726 the hope that at least one will work.
8728 For non-recursive calls, LHSTYPE should be a function, pointer to
8729 function, or a pointer to member function. */
8731 tree
8733 {
8742 {
8746 }
8749 {
8758 /* Microsoft allows `A::f' to be resolved to a
8759 pointer-to-member. */
8760 ;
8761 else
8762 {
8767 }
8768 }
8770 /* If we instantiate a template, and it is a A ?: C expression
8771 with omitted B, look through the SAVE_EXPR. */
8776 {
8779 }
8781 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
8782 deduce any type information. */
8784 {
8788 }
8790 /* There are only a few kinds of expressions that may have a type
8791 dependent on overload resolution. */
8797 /* This should really only be used when attempting to distinguish
8798 what sort of a pointer to function we have. For now, any
8799 arithmetic operation which is not supported on pointers
8800 is rejected as an error. */
8803 {
8805 {
8811 /* Do not lose object's side effects. */
8815 }
8822 /* This can happen if we are forming a pointer-to-member for a
8823 member template. */
8826 /* Fall through. */
8829 {
8833 return
8837 }
8841 return
8845 access_path);
8848 {
8853 }
8860 }
8862 }
8863 \f
8864 /* Return the name of the virtual function pointer field
8865 (as an IDENTIFIER_NODE) for the given TYPE. Note that
8866 this may have to look back through base types to find the
8867 ultimate field name. (For single inheritance, these could
8868 all be the same name. Who knows for multiple inheritance). */
8870 static tree
8872 {
8878 {
8884 }
8892 }
8894 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
8895 according to [class]:
8896 The class-name is also inserted
8897 into the scope of the class itself. For purposes of access checking,
8898 the inserted class name is treated as if it were a public member name. */
8900 void
8902 {
8920 }
8922 /* Returns 1 if TYPE contains only padding bytes. */
8924 int
8926 {
8934 }
8936 /* Returns true if TYPE contains no actual data, just various
8937 possible combinations of empty classes. If IGNORE_VPTR is true,
8938 a vptr doesn't prevent the class from being considered empty. Typically
8939 we want to ignore the vptr on assignment, and not on initialization. */
8941 bool
8943 {
8945 {
8946 tree field;
8947 tree binfo;
8948 tree base_binfo;
8951 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8952 out, but we'd like to be able to check this before then. */
8966 /* An unnamed bit-field is not a data member. */
8971 }
8976 }
8978 /* Note that NAME was looked up while the current class was being
8979 defined and that the result of that lookup was DECL. */
8981 void
8983 {
8984 /* If we're not defining a class, there's nothing to do. */
8995 /* Record the binding in the names_used tables for classes inside blev. */
8997 {
8999 ? current_class_type
9003 {
9005 /* We found the declaration. */
9008 /* This class is inside the declaration scope. */
9010 }
9022 }
9023 }
9025 /* Note that NAME was declared (as DECL) in the current class. Check
9026 to see that the declaration is valid under [class.member.lookup]:
9028 If [the result of a search in T for N at point P] differs from the result of
9029 a search in T for N from immediately after the class-specifier of T, the
9030 program is ill-formed, no diagnostic required. */
9032 void
9034 {
9035 splay_tree names_used;
9036 splay_tree_node n;
9038 /* Look to see if we ever used this name. */
9039 names_used
9043 /* The C language allows members to be declared with a type of the same
9044 name, and the C++ standard says this diagnostic is not required. So
9045 allow it in extern "C" blocks unless pedantic is specified.
9046 Allow it in all cases if -ms-extensions is specified. */
9052 {
9056 /* [basic.scope.class]
9058 A name N used in a class S shall refer to the same declaration
9059 in its context and when re-evaluated in the completed scope of
9060 S. */
9068 else
9069 /* Make it an error. */
9074 {
9077 }
9078 }
9079 }
9081 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
9082 Secondary vtables are merged with primary vtables; this function
9083 will return the VAR_DECL for the primary vtable. */
9085 tree
9087 {
9088 tree decl;
9092 {
9095 }
9099 }
9102 /* Returns the binfo for the primary base of BINFO. If the resulting
9103 BINFO is a virtual base, and it is inherited elsewhere in the
9104 hierarchy, then the returned binfo might not be the primary base of
9105 BINFO in the complete object. Check BINFO_PRIMARY_P or
9106 BINFO_LOST_PRIMARY_P to be sure. */
9108 static tree
9110 {
9111 tree primary_base;
9118 }
9120 /* As above, but iterate until we reach the binfo that actually provides the
9121 vptr for BINFO. */
9123 static tree
9125 {
9129 {
9134 }
9136 }
9138 /* Returns true if BINFO gets its vptr from a virtual base of the most derived
9139 type. Note that the virtual inheritance might be above or below BINFO in
9140 the hierarchy. */
9142 bool
9144 {
9148 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is
9149 a morally virtual base. */
9152 }
9154 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
9156 static int
9158 {
9162 }
9164 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
9165 INDENT should be zero when called from the top level; it is
9166 incremented recursively. IGO indicates the next expected BINFO in
9167 inheritance graph ordering. */
9169 static tree
9171 dump_flags_t flags,
9172 tree binfo,
9173 tree igo,
9175 {
9177 tree base_binfo;
9184 {
9187 }
9201 {
9205 TFF_PLAIN_IDENTIFIER),
9207 }
9209 {
9212 }
9217 {
9221 {
9225 TFF_PLAIN_IDENTIFIER));
9226 }
9228 {
9232 TFF_PLAIN_IDENTIFIER));
9233 }
9235 {
9239 TFF_PLAIN_IDENTIFIER));
9240 }
9242 {
9246 TFF_PLAIN_IDENTIFIER));
9247 }
9251 }
9257 }
9259 /* Dump the BINFO hierarchy for T. */
9261 static void
9263 {
9275 }
9277 /* Debug interface to hierarchy dumping. */
9279 void
9281 {
9283 }
9285 static void
9287 {
9288 dump_flags_t flags;
9290 {
9293 }
9294 }
9296 static void
9298 {
9299 tree value;
9301 HOST_WIDE_INT elt;
9309 TFF_PLAIN_IDENTIFIER));
9316 }
9318 static void
9320 {
9321 dump_flags_t flags;
9328 {
9335 {
9340 }
9344 }
9347 }
9349 static void
9351 {
9352 dump_flags_t flags;
9359 {
9364 }
9367 }
9369 /* Dump a function or thunk and its thunkees. */
9371 static void
9373 {
9376 tree thunks;
9384 {
9394 else
9400 }
9404 }
9406 /* Dump the thunks for FN. */
9408 void
9410 {
9412 }
9414 /* Virtual function table initialization. */
9416 /* Create all the necessary vtables for T and its base classes. */
9418 static void
9420 {
9421 tree vbase;
9425 /* We lay out the primary and secondary vtables in one contiguous
9426 vtable. The primary vtable is first, followed by the non-virtual
9427 secondary vtables in inheritance graph order. */
9431 /* Then come the virtual bases, also in inheritance graph order. */
9433 {
9437 }
9441 }
9443 /* Initialize the vtable for BINFO with the INITS. */
9445 static void
9447 {
9448 tree decl;
9454 }
9456 /* Build the VTT (virtual table table) for T.
9457 A class requires a VTT if it has virtual bases.
9459 This holds
9460 1 - primary virtual pointer for complete object T
9461 2 - secondary VTTs for each direct non-virtual base of T which requires a
9462 VTT
9463 3 - secondary virtual pointers for each direct or indirect base of T which
9464 has virtual bases or is reachable via a virtual path from T.
9465 4 - secondary VTTs for each direct or indirect virtual base of T.
9467 Secondary VTTs look like complete object VTTs without part 4. */
9469 static void
9471 {
9472 tree type;
9473 tree vtt;
9474 tree index;
9477 /* Build up the initializers for the VTT. */
9482 /* If we didn't need a VTT, we're done. */
9486 /* Figure out the type of the VTT. */
9490 /* Now, build the VTT object itself. */
9493 /* Add the VTT to the vtables list. */
9498 }
9500 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
9501 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
9502 and CHAIN the vtable pointer for this binfo after construction is
9503 complete. VALUE can also be another BINFO, in which case we recurse. */
9505 static tree
9507 {
9508 tree vt;
9511 {
9517 else
9519 }
9522 }
9524 /* Data for secondary VTT initialization. */
9525 struct secondary_vptr_vtt_init_data
9526 {
9527 /* Is this the primary VTT? */
9530 /* Current index into the VTT. */
9531 tree index;
9533 /* Vector of initializers built up. */
9536 /* The type being constructed by this secondary VTT. */
9537 tree type_being_constructed;
9538 };
9540 /* Recursively build the VTT-initializer for BINFO (which is in the
9541 hierarchy dominated by T). INITS points to the end of the initializer
9542 list to date. INDEX is the VTT index where the next element will be
9543 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
9544 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
9545 for virtual bases of T. When it is not so, we build the constructor
9546 vtables for the BINFO-in-T variant. */
9548 static void
9551 {
9553 tree b;
9554 tree init;
9555 secondary_vptr_vtt_init_data data;
9558 /* We only need VTTs for subobjects with virtual bases. */
9562 /* We need to use a construction vtable if this is not the primary
9563 VTT. */
9565 {
9568 /* Record the offset in the VTT where this sub-VTT can be found. */
9570 }
9572 /* Add the address of the primary vtable for the complete object. */
9576 {
9579 }
9582 /* Recursively add the secondary VTTs for non-virtual bases. */
9587 /* Add secondary virtual pointers for all subobjects of BINFO with
9588 either virtual bases or reachable along a virtual path, except
9589 subobjects that are non-virtual primary bases. */
9599 /* data.inits might have grown as we added secondary virtual pointers.
9600 Make sure our caller knows about the new vector. */
9604 /* Add the secondary VTTs for virtual bases in inheritance graph
9605 order. */
9607 {
9612 }
9613 else
9614 /* Remove the ctor vtables we created. */
9616 }
9618 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
9619 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
9621 static tree
9623 {
9626 /* We don't care about bases that don't have vtables. */
9630 /* We're only interested in proper subobjects of the type being
9631 constructed. */
9635 /* We're only interested in bases with virtual bases or reachable
9636 via a virtual path from the type being constructed. */
9641 /* We're not interested in non-virtual primary bases. */
9645 /* Record the index where this secondary vptr can be found. */
9647 {
9652 {
9653 /* It's a primary virtual base, and this is not a
9654 construction vtable. Find the base this is primary of in
9655 the inheritance graph, and use that base's vtable
9656 now. */
9659 }
9660 }
9662 /* Add the initializer for the secondary vptr itself. */
9665 /* Advance the vtt index. */
9670 }
9672 /* Called from build_vtt_inits via dfs_walk. After building
9673 constructor vtables and generating the sub-vtt from them, we need
9674 to restore the BINFO_VTABLES that were scribbled on. DATA is the
9675 binfo of the base whose sub vtt was generated. */
9677 static tree
9679 {
9683 /* If this class has no vtable, none of its bases do. */
9687 /* This might be a primary base, so have no vtable in this
9688 hierarchy. */
9691 /* If we scribbled the construction vtable vptr into BINFO, clear it
9692 out now. */
9698 }
9700 /* Build the construction vtable group for BINFO which is in the
9701 hierarchy dominated by T. */
9703 static void
9705 {
9706 tree type;
9707 tree vtbl;
9708 tree id;
9709 tree vbase;
9712 /* See if we've already created this construction vtable group. */
9718 /* Build a version of VTBL (with the wrong type) for use in
9719 constructing the addresses of secondary vtables in the
9720 construction vtable group. */
9723 /* Don't export construction vtables from shared libraries. Even on
9724 targets that don't support hidden visibility, this tells
9725 can_refer_decl_in_current_unit_p not to assume that it's safe to
9726 access from a different compilation unit (bz 54314). */
9734 /* Add the vtables for each of our virtual bases using the vbase in T
9735 binfo. */
9737 vbase;
9739 {
9740 tree b;
9747 }
9749 /* Figure out the type of the construction vtable. */
9756 /* Initialize the construction vtable. */
9760 }
9762 /* Add the vtbl initializers for BINFO (and its bases other than
9763 non-virtual primaries) to the list of INITS. BINFO is in the
9764 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
9765 the constructor the vtbl inits should be accumulated for. (If this
9766 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
9767 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
9768 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
9769 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
9770 but are not necessarily the same in terms of layout. */
9772 static void
9774 tree orig_binfo,
9775 tree rtti_binfo,
9776 tree vtbl,
9777 tree t,
9779 {
9781 tree base_binfo;
9786 /* If it doesn't have a vptr, we don't do anything. */
9790 /* If we're building a construction vtable, we're not interested in
9791 subobjects that don't require construction vtables. */
9797 /* Build the initializers for the BINFO-in-T vtable. */
9800 /* Walk the BINFO and its bases. We walk in preorder so that as we
9801 initialize each vtable we can figure out at what offset the
9802 secondary vtable lies from the primary vtable. We can't use
9803 dfs_walk here because we need to iterate through bases of BINFO
9804 and RTTI_BINFO simultaneously. */
9806 {
9807 /* Skip virtual bases. */
9813 inits);
9814 }
9815 }
9817 /* Called from accumulate_vtbl_inits. Adds the initializers for the
9818 BINFO vtable to L. */
9820 static void
9822 tree orig_binfo,
9823 tree rtti_binfo,
9824 tree orig_vtbl,
9825 tree t,
9827 {
9834 {
9835 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
9836 primary virtual base. If it is not the same primary in
9837 the hierarchy of T, we'll need to generate a ctor vtable
9838 for it, to place at its location in T. If it is the same
9839 primary, we still need a VTT entry for the vtable, but it
9840 should point to the ctor vtable for the base it is a
9841 primary for within the sub-hierarchy of RTTI_BINFO.
9843 There are three possible cases:
9845 1) We are in the same place.
9846 2) We are a primary base within a lost primary virtual base of
9847 RTTI_BINFO.
9848 3) We are primary to something not a base of RTTI_BINFO. */
9850 tree b;
9853 /* First, look through the bases we are primary to for RTTI_BINFO
9854 or a virtual base. */
9857 {
9862 }
9863 /* If we run out of primary links, keep looking down our
9864 inheritance chain; we might be an indirect primary. */
9868 found:
9870 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
9871 base B and it is a base of RTTI_BINFO, this is case 2. In
9872 either case, we share our vtable with LAST, i.e. the
9873 derived-most base within B of which we are a primary. */
9876 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
9877 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
9878 binfo_ctor_vtable after everything's been set up. */
9881 /* Otherwise, this is case 3 and we get our own. */
9882 }
9889 {
9890 tree index;
9893 /* Add the initializer for this vtable. */
9897 /* Figure out the position to which the VPTR should point. */
9903 }
9906 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
9907 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
9908 straighten this out. */
9911 /* Throw away any unneeded intializers. */
9913 else
9914 /* For an ordinary vtable, set BINFO_VTABLE. */
9916 }
9921 /* Construct the initializer for BINFO's virtual function table. BINFO
9922 is part of the hierarchy dominated by T. If we're building a
9923 construction vtable, the ORIG_BINFO is the binfo we should use to
9924 find the actual function pointers to put in the vtable - but they
9925 can be overridden on the path to most-derived in the graph that
9926 ORIG_BINFO belongs. Otherwise,
9927 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
9928 BINFO that should be indicated by the RTTI information in the
9929 vtable; it will be a base class of T, rather than T itself, if we
9930 are building a construction vtable.
9932 The value returned is a TREE_LIST suitable for wrapping in a
9933 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
9934 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
9935 number of non-function entries in the vtable.
9937 It might seem that this function should never be called with a
9938 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
9939 base is always subsumed by a derived class vtable. However, when
9940 we are building construction vtables, we do build vtables for
9941 primary bases; we need these while the primary base is being
9942 constructed. */
9944 static void
9946 tree orig_binfo,
9947 tree t,
9948 tree rtti_binfo,
9951 {
9952 tree v;
9953 vtbl_init_data vid;
9955 tree vbinfo;
9959 /* Initialize VID. */
9967 /* The first vbase or vcall offset is at index -3 in the vtable. */
9970 /* Add entries to the vtable for RTTI. */
9973 /* Create an array for keeping track of the functions we've
9974 processed. When we see multiple functions with the same
9975 signature, we share the vcall offsets. */
9977 /* Add the vcall and vbase offset entries. */
9980 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
9981 build_vbase_offset_vtbl_entries. */
9986 /* If the target requires padding between data entries, add that now. */
9988 {
9994 /* Move data entries into their new positions and add padding
9995 after the new positions. Iterate backwards so we don't
9996 overwrite entries that we would need to process later. */
9999 ix--)
10000 {
10008 {
10012 null_pointer_node);
10013 }
10014 }
10015 }
10020 /* The initializers for virtual functions were built up in reverse
10021 order. Straighten them out and add them to the running list in one
10022 step. */
10031 /* Go through all the ordinary virtual functions, building up
10032 initializers. */
10034 {
10035 tree delta;
10036 tree vcall_index;
10043 {
10047 {
10050 }
10052 }
10054 /* If the only definition of this function signature along our
10055 primary base chain is from a lost primary, this vtable slot will
10056 never be used, so just zero it out. This is important to avoid
10057 requiring extra thunks which cannot be generated with the function.
10059 We first check this in update_vtable_entry_for_fn, so we handle
10060 restored primary bases properly; we also need to do it here so we
10061 zero out unused slots in ctor vtables, rather than filling them
10062 with erroneous values (though harmless, apart from relocation
10063 costs). */
10068 {
10069 /* Pull the offset for `this', and the function to call, out of
10070 the list. */
10077 /* You can't call an abstract virtual function; it's abstract.
10078 So, we replace these functions with __pure_virtual. */
10080 {
10083 {
10085 abort_fndecl_addr
10089 }
10090 }
10091 /* Likewise for deleted virtuals. */
10093 {
10095 {
10099 dvirt_fn = push_library_fn
10103 }
10108 }
10109 else
10110 {
10112 {
10117 }
10118 /* Take the address of the function, considering it to be of an
10119 appropriate generic type. */
10123 /* Don't refer to a virtual destructor from a constructor
10124 vtable or a vtable for an abstract class, since destroying
10125 an object under construction is undefined behavior and we
10126 don't want it to be considered a candidate for speculative
10127 devirtualization. But do create the thunk for ABI
10128 compliance. */
10133 }
10134 }
10136 /* And add it to the chain of initializers. */
10138 {
10143 else
10145 {
10151 }
10152 }
10153 else
10155 }
10156 }
10158 /* Adds to vid->inits the initializers for the vbase and vcall
10159 offsets in BINFO, which is in the hierarchy dominated by T. */
10161 static void
10163 {
10164 tree b;
10166 /* If this is a derived class, we must first create entries
10167 corresponding to the primary base class. */
10172 /* Add the vbase entries for this base. */
10174 /* Add the vcall entries for this base. */
10176 }
10178 /* Returns the initializers for the vbase offset entries in the vtable
10179 for BINFO (which is part of the class hierarchy dominated by T), in
10180 reverse order. VBASE_OFFSET_INDEX gives the vtable index
10181 where the next vbase offset will go. */
10183 static void
10185 {
10186 tree vbase;
10187 tree t;
10188 tree non_primary_binfo;
10190 /* If there are no virtual baseclasses, then there is nothing to
10191 do. */
10197 /* We might be a primary base class. Go up the inheritance hierarchy
10198 until we find the most derived class of which we are a primary base:
10199 it is the offset of that which we need to use. */
10202 {
10203 tree b;
10205 /* If we have reached a virtual base, then it must be a primary
10206 base (possibly multi-level) of vid->binfo, or we wouldn't
10207 have called build_vcall_and_vbase_vtbl_entries for it. But it
10208 might be a lost primary, so just skip down to vid->binfo. */
10210 {
10213 }
10219 }
10221 /* Go through the virtual bases, adding the offsets. */
10223 vbase;
10225 {
10226 tree b;
10227 tree delta;
10232 /* Find the instance of this virtual base in the complete
10233 object. */
10236 /* If we've already got an offset for this virtual base, we
10237 don't need another one. */
10242 /* Figure out where we can find this vbase offset. */
10251 /* The vbase offset had better be the same. */
10254 /* The next vbase will come at a more negative offset. */
10258 /* The initializer is the delta from BINFO to this virtual base.
10259 The vbase offsets go in reverse inheritance-graph order, and
10260 we are walking in inheritance graph order so these end up in
10261 the right order. */
10268 }
10269 }
10271 /* Adds the initializers for the vcall offset entries in the vtable
10272 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
10273 to VID->INITS. */
10275 static void
10277 {
10278 /* We only need these entries if this base is a virtual base. We
10279 compute the indices -- but do not add to the vtable -- when
10280 building the main vtable for a class. */
10283 /* If BINFO is RTTI_BINFO, then (since BINFO does not
10284 correspond to VID->DERIVED), we are building a primary
10285 construction virtual table. Since this is a primary
10286 virtual table, we do not need the vcall offsets for
10287 BINFO. */
10289 {
10290 /* We need a vcall offset for each of the virtual functions in this
10291 vtable. For example:
10293 class A { virtual void f (); };
10294 class B1 : virtual public A { virtual void f (); };
10295 class B2 : virtual public A { virtual void f (); };
10296 class C: public B1, public B2 { virtual void f (); };
10298 A C object has a primary base of B1, which has a primary base of A. A
10299 C also has a secondary base of B2, which no longer has a primary base
10300 of A. So the B2-in-C construction vtable needs a secondary vtable for
10301 A, which will adjust the A* to a B2* to call f. We have no way of
10302 knowing what (or even whether) this offset will be when we define B2,
10303 so we store this "vcall offset" in the A sub-vtable and look it up in
10304 a "virtual thunk" for B2::f.
10306 We need entries for all the functions in our primary vtable and
10307 in our non-virtual bases' secondary vtables. */
10309 /* If we are just computing the vcall indices -- but do not need
10310 the actual entries -- not that. */
10313 /* Now, walk through the non-virtual bases, adding vcall offsets. */
10315 }
10316 }
10318 /* Build vcall offsets, starting with those for BINFO. */
10320 static void
10322 {
10324 tree primary_binfo;
10325 tree base_binfo;
10327 /* Don't walk into virtual bases -- except, of course, for the
10328 virtual base for which we are building vcall offsets. Any
10329 primary virtual base will have already had its offsets generated
10330 through the recursion in build_vcall_and_vbase_vtbl_entries. */
10334 /* If BINFO has a primary base, process it first. */
10339 /* Add BINFO itself to the list. */
10342 /* Scan the non-primary bases of BINFO. */
10346 }
10348 /* Called from build_vcall_offset_vtbl_entries_r. */
10350 static void
10352 {
10353 /* Make entries for the rest of the virtuals. */
10354 tree orig_fn;
10356 /* The ABI requires that the methods be processed in declaration
10357 order. */
10359 orig_fn;
10363 }
10365 /* Add a vcall offset entry for ORIG_FN to the vtable. */
10367 static void
10369 {
10371 tree vcall_offset;
10372 tree derived_entry;
10374 /* If there is already an entry for a function with the same
10375 signature as FN, then we do not need a second vcall offset.
10376 Check the list of functions already present in the derived
10377 class vtable. */
10379 {
10381 /* We only use one vcall offset for virtual destructors,
10382 even though there are two virtual table entries. */
10386 }
10388 /* If we are building these vcall offsets as part of building
10389 the vtable for the most derived class, remember the vcall
10390 offset. */
10392 {
10395 }
10397 /* The next vcall offset will be found at a more negative
10398 offset. */
10402 /* Keep track of this function. */
10406 {
10407 tree base;
10408 tree fn;
10410 /* Find the overriding function. */
10414 else
10415 {
10418 /* The vbase we're working on is a primary base of
10419 vid->binfo. But it might be a lost primary, so its
10420 BINFO_OFFSET might be wrong, so we just use the
10421 BINFO_OFFSET from vid->binfo. */
10427 vcall_offset);
10428 }
10429 /* Add the initializer to the vtable. */
10431 }
10432 }
10434 /* Return vtbl initializers for the RTTI entries corresponding to the
10435 BINFO's vtable. The RTTI entries should indicate the object given
10436 by VID->rtti_binfo. */
10438 static void
10440 {
10441 tree b;
10442 tree t;
10443 tree offset;
10444 tree decl;
10445 tree init;
10449 /* To find the complete object, we will first convert to our most
10450 primary base, and then add the offset in the vtbl to that value. */
10455 /* The second entry is the address of the typeinfo object. */
10458 else
10461 /* Convert the declaration to a type that can be stored in the
10462 vtable. */
10466 /* Add the offset-to-top entry. It comes earlier in the vtable than
10467 the typeinfo entry. Convert the offset to look like a
10468 function pointer, so that we can put it in the vtable. */
10471 }
10473 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
10474 accessibility. */
10476 bool
10478 {
10481 }
10483 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
10485 bool
10487 {
10491 }
10493 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
10494 class between them, if any. */
10496 tree
10498 {
10510 {
10513 }
10517 }