| blob | 26f996b7f4bff5f02639646e58a562911ca29a24 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2020 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. */
142 /* Used by find_flexarrays and related functions. */
190 tree *);
199 splay_tree_key k2);
210 /* Return a COND_EXPR that executes TRUE_STMT if this execution of the
211 'structor is in charge of 'structing virtual bases, or FALSE_STMT
212 otherwise. */
214 tree
216 {
226 }
228 /* Convert to or from a base subobject. EXPR is an expression of type
229 `A' or `A*', an expression of type `B' or `B*' is returned. To
230 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
231 the B base instance within A. To convert base A to derived B, CODE
232 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
233 In this latter case, A must not be a morally virtual base of B.
234 NONNULL is true if EXPR is known to be non-NULL (this is only
235 needed when EXPR is of pointer type). CV qualifiers are preserved
236 from EXPR. */
238 tree
240 tree expr,
241 tree binfo,
243 tsubst_flags_t complain)
244 {
247 tree probe;
248 tree offset;
249 tree target_type;
251 tree ptr_target_type;
262 {
268 }
279 {
280 /* This can happen when adjust_result_of_qualified_name_lookup can't
281 find a unique base binfo in a call to a member function. We
282 couldn't give the diagnostic then since we might have been calling
283 a static member function, so we do it now. In other cases, eg.
284 during error recovery (c++/71979), we may not have a base at all. */
286 {
290 }
292 }
299 /* Nothing to do. */
303 {
305 {
307 {
310 "pointer to derived class %qT because the base is "
312 else
316 }
317 else
318 {
324 else
328 }
329 }
331 }
334 {
336 /* This must happen before the call to save_expr. */
338 }
339 else
345 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
346 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
347 expression returned matches the input. */
348 target_type = cp_build_qualified_type
352 /* Do we need to look in the vtable for the real offset? */
355 /* Don't bother with the calculations inside sizeof; they'll ICE if the
356 source type is incomplete and the pointer value doesn't matter. In a
357 template (even in instantiate_non_dependent_expr), we don't have vtables
358 set up properly yet, and the value doesn't matter there either; we're
359 just interested in the result of overload resolution. */
361 || processing_template_decl
363 {
366 }
369 {
375 }
377 /* If we're in an NSDMI, we don't have the full constructor context yet
378 that we need for converting to a virtual base, so just build a stub
379 CONVERT_EXPR and expand it later in bot_replace. */
382 {
386 }
388 /* Do we need to check for a null pointer? */
390 {
391 /* If we know the conversion will not actually change the value
392 of EXPR, then we can avoid testing the expression for NULL.
393 We have to avoid generating a COMPONENT_REF for a base class
394 field, because other parts of the compiler know that such
395 expressions are always non-NULL. */
399 }
401 /* Protect against multiple evaluation if necessary. */
405 /* Now that we've saved expr, build the real null test. */
407 {
411 /* This is a compiler generated comparison, don't emit
412 e.g. -Wnonnull-compare warning for it. */
414 }
416 /* If this is a simple base reference, express it as a COMPONENT_REF. */
418 /* We don't build base fields for empty bases, and they aren't very
419 interesting to the optimizers anyway. */
421 {
430 }
433 {
434 /* Going via virtual base V_BINFO. We need the static offset
435 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
436 V_BINFO. That offset is an entry in D_BINFO's vtable. */
437 tree v_offset;
440 {
441 /* In a base member initializer, we cannot rely on the
442 vtable being set up. We have to indirect via the
443 vtt_parm. */
444 tree t;
450 }
451 else
452 {
456 {
461 }
464 }
472 v_offset);
484 /* Negative fixed_type_p means this is a constructor or destructor;
485 virtual base layout is fixed in in-charge [cd]tors, but not in
486 base [cd]tors. */
487 offset = build_if_in_charge
489 v_offset);
490 else
492 }
500 {
505 }
506 else
509 indout:
511 {
515 }
517 out:
519 {
522 /* Avoid warning for the whole conditional expression (in addition
523 to NULL_TEST itself -- see above) in case the result is used in
524 a nonnull context that the front end -Wnonnull checks. */
526 }
529 }
531 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
532 Perform a derived-to-base conversion by recursively building up a
533 sequence of COMPONENT_REFs to the appropriate base fields. */
535 static tree
537 {
540 tree field;
543 {
544 tree temp;
548 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
549 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
550 an lvalue in the front end; only _DECLs and _REFs are lvalues
551 in the back end. */
557 }
559 /* Recurse. */
564 /* Is this the base field created by build_base_field? */
568 /* If we're looking for a field in the most-derived class,
569 also check the field offset; we can have two base fields
570 of the same type if one is an indirect virtual base and one
571 is a direct non-virtual base. */
575 {
576 /* We don't use build_class_member_access_expr here, as that
577 has unnecessary checks, and more importantly results in
578 recursive calls to dfs_walk_once. */
584 /* Mark the expression const or volatile, as appropriate.
585 Even though we've dealt with the type above, we still have
586 to mark the expression itself. */
593 }
595 /* Didn't find the base field?!? */
597 }
599 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
600 type is a class type or a pointer to a class type. In the former
601 case, TYPE is also a class type; in the latter it is another
602 pointer type. If CHECK_ACCESS is true, an error message is emitted
603 if TYPE is inaccessible. If OBJECT has pointer type, the value is
604 assumed to be non-NULL. */
606 tree
608 tsubst_flags_t complain)
609 {
610 tree binfo;
611 tree object_type;
614 {
617 }
618 else
627 }
629 /* EXPR is an expression with unqualified class type. BASE is a base
630 binfo of that class type. Returns EXPR, converted to the BASE
631 type. This function assumes that EXPR is the most derived class;
632 therefore virtual bases can be found at their static offsets. */
634 tree
636 {
637 tree expr_type;
641 {
642 /* If this is a non-empty base, use a COMPONENT_REF. */
646 /* We use fold_build2 and fold_convert below to simplify the trees
647 provided to the optimizers. It is not safe to call these functions
648 when processing a template because they do not handle C++-specific
649 trees. */
657 }
660 }
662 \f
663 tree
665 {
669 /* Can happen in case of duplicate base types (c++/59082). */
673 /* First, convert to the requested type. */
678 /* Second, the requested type may not be the owner of its own vptr.
679 If not, convert to the base class that owns it. We cannot use
680 convert_to_base here, because VCONTEXT may appear more than once
681 in the inheritance hierarchy of TYPE, and thus direct conversion
682 between the types may be ambiguous. Following the path back up
683 one step at a time via primary bases avoids the problem. */
687 {
690 }
693 }
695 /* Given an object INSTANCE, return an expression which yields the
696 vtable element corresponding to INDEX. There are many special
697 cases for INSTANCE which we take care of here, mainly to avoid
698 creating extra tree nodes when we don't have to. */
700 tree
702 {
703 tree aref;
706 /* Try to figure out what a reference refers to, and
707 access its virtual function table directly. */
715 {
720 }
729 }
731 /* Given a stable object pointer INSTANCE_PTR, return an expression which
732 yields a function pointer corresponding to vtable element INDEX. */
734 tree
736 {
737 tree aref;
741 /* When using function descriptors, the address of the
742 vtable entry is treated as a function pointer. */
747 /* Remember this as a method reference, for later devirtualization. */
751 }
753 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
754 for the given TYPE. */
756 static tree
758 {
760 }
762 /* DECL is an entity associated with TYPE, like a virtual table or an
763 implicitly generated constructor. Determine whether or not DECL
764 should have external or internal linkage at the object file
765 level. This routine does not deal with COMDAT linkage and other
766 similar complexities; it simply sets TREE_PUBLIC if it possible for
767 entities in other translation units to contain copies of DECL, in
768 the abstract. */
770 void
772 {
775 }
777 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
778 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
779 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
781 static tree
783 {
784 tree decl;
787 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
788 now to avoid confusion in mangle_decl. */
799 /* The vtable has not been defined -- yet. */
803 /* Mark the VAR_DECL node representing the vtable itself as a
804 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
805 is rather important that such things be ignored because any
806 effort to actually generate DWARF for them will run into
807 trouble when/if we encounter code like:
809 #pragma interface
810 struct S { virtual void member (); };
812 because the artificial declaration of the vtable itself (as
813 manufactured by the g++ front end) will say that the vtable is
814 a static member of `S' but only *after* the debug output for
815 the definition of `S' has already been output. This causes
816 grief because the DWARF entry for the definition of the vtable
817 will try to refer back to an earlier *declaration* of the
818 vtable as a static member of `S' and there won't be one. We
819 might be able to arrange to have the "vtable static member"
820 attached to the member list for `S' before the debug info for
821 `S' get written (which would solve the problem) but that would
822 require more intrusive changes to the g++ front end. */
826 }
828 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
829 or even complete. If this does not exist, create it. If COMPLETE is
830 nonzero, then complete the definition of it -- that will render it
831 impossible to actually build the vtable, but is useful to get at those
832 which are known to exist in the runtime. */
834 tree
836 {
837 tree decl;
846 {
849 }
852 }
854 /* Build the primary virtual function table for TYPE. If BINFO is
855 non-NULL, build the vtable starting with the initial approximation
856 that it is the same as the one which is the head of the association
857 list. Returns a nonzero value if a new vtable is actually
858 created. */
860 static int
862 {
863 tree decl;
864 tree virtuals;
869 {
871 /* We have already created a vtable for this base, so there's
872 no need to do it again. */
879 }
880 else
881 {
884 }
886 /* Initialize the association list for this type, based
887 on our first approximation. */
892 }
894 /* Give BINFO a new virtual function table which is initialized
895 with a skeleton-copy of its original initialization. The only
896 entry that changes is the `delta' entry, so we can really
897 share a lot of structure.
899 FOR_TYPE is the most derived type which caused this table to
900 be needed.
902 Returns nonzero if we haven't met BINFO before.
904 The order in which vtables are built (by calling this function) for
905 an object must remain the same, otherwise a binary incompatibility
906 can result. */
908 static int
910 {
912 /* We already created a vtable for this base. There's no need to
913 do it again. */
916 /* Remember that we've created a vtable for this BINFO, so that we
917 don't try to do so again. */
920 /* Make fresh virtual list, so we can smash it later. */
923 /* Secondary vtables are laid out as part of the same structure as
924 the primary vtable. */
927 }
929 /* Create a new vtable for BINFO which is the hierarchy dominated by
930 T. Return nonzero if we actually created a new vtable. */
932 static int
934 {
936 /* In this case, it is *type*'s vtable we are modifying. We start
937 with the approximation that its vtable is that of the
938 immediate base class. */
940 else
941 /* This is our very own copy of `basetype' to play with. Later,
942 we will fill in all the virtual functions that override the
943 virtual functions in these base classes which are not defined
944 by the current type. */
946 }
948 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
949 (which is in the hierarchy dominated by T) list FNDECL as its
950 BV_FN. DELTA is the required constant adjustment from the `this'
951 pointer where the vtable entry appears to the `this' required when
952 the function is actually called. */
954 static void
956 tree binfo,
957 tree fndecl,
958 tree delta,
960 {
961 tree v;
967 {
968 /* We need a new vtable for BINFO. */
970 {
971 /* If we really did make a new vtable, we also made a copy
972 of the BINFO_VIRTUALS list. Now, we have to find the
973 corresponding entry in that list. */
978 }
983 }
984 }
986 \f
987 /* Add method METHOD to class TYPE. If VIA_USING indicates whether
988 METHOD is being injected via a using_decl. Returns true if the
989 method could be added to the method vec. */
991 bool
993 {
1002 /* See below. */
1005 /* Check to see if we've already got this method. */
1007 {
1013 /* Two using-declarations can coexist, we'll complain about ambiguity in
1014 overload resolution. */
1016 /* Except handle inherited constructors specially. */
1020 /* [over.load] Member function declarations with the
1021 same name and the same parameter types cannot be
1022 overloaded if any of them is a static member
1023 function declaration.
1025 [over.load] Member function declarations with the same name and
1026 the same parameter-type-list as well as member function template
1027 declarations with the same name, the same parameter-type-list, and
1028 the same template parameter lists cannot be overloaded if any of
1029 them, but not all, have a ref-qualifier.
1031 [namespace.udecl] When a using-declaration brings names
1032 from a base class into a derived class scope, member
1033 functions in the derived class override and/or hide member
1034 functions with the same name and parameter types in a base
1035 class (rather than conflicting). */
1039 /* Compare the quals on the 'this' parm. Don't compare
1040 the whole types, as used functions are treated as
1041 coming from the using class in overload resolution. */
1044 /* Either both or neither need to be ref-qualified for
1045 differing quals to allow overloading. */
1055 /* Templates and conversion ops must match return types. */
1060 /* For templates, the template parameters must be identical. */
1062 {
1069 }
1078 /* Bring back parameters omitted from an inherited ctor. The
1079 method and the function can have different omittedness. */
1083 parms2 = (FUNCTION_FIRST_USER_PARMTYPE
1090 {
1092 /* We can't check satisfaction in dependent context, wait until
1093 the class is instantiated. */
1101 /* Member function templates and non-special member functions
1102 coexist if they are not equivalently constrained. A member
1103 function is not hidden by an inherited constructor. */
1106 /* P0848: For special member functions, deleted, unsatisfied, or
1107 less constrained overloads are ineligible. We implement this
1108 by removing them from CLASSTYPE_MEMBER_VEC. Destructors don't
1109 use the notion of eligibility, and the selected destructor can
1110 be deleted, but removing unsatisfied or less constrained
1111 overloads has the same effect as overload resolution. */
1121 else
1124 /* Leave FN in the method vec, discard METHOD. */
1127 {
1128 /* Remove FN, add METHOD. */
1131 }
1132 else
1133 /* Let them coexist for now. */
1135 }
1137 /* If these are versions of the same function, process and
1138 move on. */
1144 {
1146 /* Defer to the other function. */
1152 {
1154 {
1155 /* Inheriting the same constructor along different
1156 paths, combine them. */
1157 SET_DECL_INHERITED_CTOR
1160 /* And discard the new one. */
1162 }
1163 else
1164 /* Inherited ctors can coexist until overload
1165 resolution. */
1167 }
1174 basef);
1176 }
1179 /* Defer to the local function. */
1183 {
1184 /* Remove the inherited constructor. */
1187 }
1188 else
1189 {
1195 }
1196 }
1207 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1213 }
1215 /* Subroutines of finish_struct. */
1217 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1218 legit, otherwise return 0. */
1220 static int
1222 {
1223 tree elem;
1231 {
1233 {
1237 else
1240 }
1241 else
1242 {
1243 /* They're changing the access to the same thing they changed
1244 it to before. That's OK. */
1245 ;
1246 }
1247 }
1248 else
1249 {
1251 tf_warning_or_error);
1254 }
1256 }
1258 /* Return the access node for DECL's access in its enclosing class. */
1260 tree
1262 {
1266 }
1268 /* Process the USING_DECL, which is a member of T. */
1270 static void
1272 {
1277 tree old_value;
1282 tf_warning_or_error);
1284 {
1289 else
1291 }
1299 ;
1301 {
1303 /* It's OK to use functions from a base when there are functions with
1305 else
1306 {
1313 }
1314 }
1316 {
1323 }
1325 /* Make type T see field decl FDECL with access ACCESS. */
1328 {
1331 }
1332 else
1334 }
1335 \f
1336 /* Data structure for find_abi_tags_r, below. */
1338 struct abi_tag_data
1339 {
1343 };
1345 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1346 in the context of P. TAG can be either an identifier (the DECL_NAME of
1347 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1349 static void
1351 {
1353 {
1355 {
1356 /* We're collecting tags from template arguments or from
1357 the type of a variable or function return type. */
1360 /* Don't inherit this tag multiple times. */
1364 {
1365 /* Tags inherited from type template arguments are only used
1366 to avoid warnings. */
1369 }
1370 /* For functions and variables we want to warn, too. */
1371 }
1373 /* Otherwise we're diagnosing missing tags. */
1375 {
1376 auto_diagnostic_group d;
1381 }
1383 {
1384 auto_diagnostic_group d;
1388 }
1390 {
1391 auto_diagnostic_group d;
1396 }
1397 else
1398 {
1399 auto_diagnostic_group d;
1403 {
1407 }
1408 }
1409 }
1410 }
1412 /* Find all the ABI tags in the attribute list ATTR and either call
1413 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1415 static void
1417 {
1424 {
1429 else
1431 }
1432 }
1434 /* Find all the ABI tags on T and its enclosing scopes and either call
1435 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1437 static void
1439 {
1441 {
1442 tree attr;
1444 {
1447 }
1448 else
1449 {
1452 }
1454 }
1455 }
1457 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1458 types with ABI tags, add the corresponding identifiers to the VEC in
1459 *DATA and set IDENTIFIER_MARKED. */
1461 static tree
1463 {
1467 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1468 anyway, but let's make sure of it. */
1476 }
1478 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1479 IDENTIFIER_MARKED on its ABI tags. */
1481 static tree
1483 {
1487 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1488 anyway, but let's make sure of it. */
1496 }
1498 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1499 scopes. */
1501 static void
1503 {
1506 {
1509 {
1510 /* Template arguments are part of the signature. */
1513 {
1516 }
1517 }
1519 /* A function's parameter types are part of the signature, so
1520 we don't need to inherit any tags that are also in them. */
1525 }
1526 }
1528 /* Check that T has all the ABI tags that subobject SUBOB has, or
1529 warn if not. If T is a (variable or function) declaration, also
1530 return any missing tags, and add them to T if JUST_CHECKING is false. */
1532 static tree
1534 {
1542 /* No need to worry about things local to this TU. */
1558 {
1561 }
1562 else
1563 {
1567 else
1570 }
1575 }
1577 /* Check that DECL has all the ABI tags that are used in parts of its type
1578 that are not reflected in its mangled name. */
1580 void
1582 {
1589 }
1591 /* Return any ABI tags that are used in parts of the type of DECL
1592 that are not reflected in its mangled name. This function is only
1593 used in backward-compatible mangling for ABI <11. */
1595 tree
1597 {
1601 /* Don't check DECL_CONV_FN_P here like we do in check_abi_tags, so
1602 that we can use this function for setting need_abi_warning
1603 regardless of the current flag_abi_version. */
1606 else
1608 }
1610 void
1612 {
1622 {
1625 {
1629 }
1630 }
1632 // If we found some tags on our template arguments, add them to our
1633 // abi_tag attribute.
1635 {
1639 else
1642 }
1645 }
1647 /* Return true, iff class T has a non-virtual destructor that is
1648 accessible from outside the class heirarchy (i.e. is public, or
1649 there's a suitable friend. */
1651 static bool
1653 {
1656 /* An implicitly declared destructor is always public. And,
1657 if it were virtual, we would have created it by now. */
1672 }
1674 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1675 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1676 properties of the bases. */
1678 static void
1682 {
1686 tree base_binfo;
1687 tree binfo;
1697 {
1706 /* If any base class is non-literal, so is the derived class. */
1710 /* If the base class doesn't have copy constructors or
1711 assignment operators that take const references, then the
1712 derived class cannot have such a member automatically
1713 generated. */
1722 /* A virtual base does not effect nearly emptiness. */
1723 ;
1725 {
1727 /* And if there is more than one nearly empty base, then the
1728 derived class is not nearly empty either. */
1730 else
1731 /* Remember we've seen one. */
1733 }
1735 /* If the base class is not empty or nearly empty, then this
1736 class cannot be nearly empty. */
1739 /* A lot of properties from the bases also apply to the derived
1740 class. */
1757 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1760 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1766 /* A standard-layout class is a class that:
1767 ...
1768 * has no non-standard-layout base classes, */
1771 {
1772 tree basefield;
1773 /* ...has no base classes of the same type as the first non-static
1774 data member... */
1776 && (same_type_ignoring_top_level_qualifiers_p
1779 /* DR 1813:
1780 ...has at most one base class subobject of any given type... */
1783 else
1784 /* ...either has no non-static data members in the most-derived
1785 class and at most one base class with non-static data
1786 members, or has no base classes with non-static data
1787 members. FIXME This was reworded in DR 1813. */
1793 {
1796 else
1799 }
1800 }
1802 /* Don't bother collecting tm attributes if transactional memory
1803 support is not enabled. */
1805 {
1809 }
1812 }
1814 /* If one of the base classes had TM attributes, and the current class
1815 doesn't define its own, then the current class inherits one. */
1817 {
1820 }
1821 }
1823 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1824 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1825 that have had a nearly-empty virtual primary base stolen by some
1826 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1827 T. */
1829 static void
1831 {
1835 tree base_binfo;
1837 /* Determine the primary bases of our bases. */
1840 {
1843 /* See if we're the non-virtual primary of our inheritance
1844 chain. */
1846 {
1853 /* We are the primary binfo. */
1855 }
1856 /* Determine if we have a virtual primary base, and mark it so.
1857 */
1859 {
1863 /* Someone already claimed this base. */
1865 else
1866 {
1867 tree delta;
1872 /* A virtual binfo might have been copied from within
1873 another hierarchy. As we're about to use it as a
1874 primary base, make sure the offsets match. */
1882 }
1883 }
1884 }
1886 /* First look for a dynamic direct non-virtual base. */
1888 {
1892 {
1895 }
1896 }
1898 /* A "nearly-empty" virtual base class can be the primary base
1899 class, if no non-virtual polymorphic base can be found. Look for
1900 a nearly-empty virtual dynamic base that is not already a primary
1901 base of something in the hierarchy. If there is no such base,
1902 just pick the first nearly-empty virtual base. */
1908 {
1910 {
1911 /* Found one that is not primary. */
1914 }
1916 /* Remember the first candidate. */
1918 }
1920 found:
1921 /* If we've got a primary base, use it. */
1923 {
1928 /* We are stealing a primary base. */
1932 {
1933 tree delta;
1936 /* A virtual binfo might have been copied from within
1937 another hierarchy. As we're about to use it as a primary
1938 base, make sure the offsets match. */
1943 }
1950 }
1951 }
1953 /* Update the variant types of T. */
1955 void
1957 {
1958 tree variants;
1964 variants;
1966 {
1967 /* These fields are in the _TYPE part of the node, not in
1968 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1979 /* Copy whatever these are holding today. */
1985 }
1986 }
1988 /* KLASS is a class that we're applying may_alias to after the body is
1989 parsed. Fixup any POINTER_TO and REFERENCE_TO types. The
1990 canonical type(s) will be implicitly updated. */
1992 static void
1994 {
2003 }
2005 /* Early variant fixups: we apply attributes at the beginning of the class
2006 definition, and we need to fix up any variants that have already been
2007 made via elaborated-type-specifier so that check_qualified_type works. */
2009 void
2011 {
2012 tree variants;
2027 variants;
2029 {
2030 /* These are the two fields that check_qualified_type looks at and
2031 are affected by attributes. */
2036 else
2042 }
2043 }
2044 \f
2045 /* Set memoizing fields and bits of T (and its variants) for later
2046 use. */
2048 static void
2050 {
2051 /* Fix up variants (if any). */
2055 /* For a class w/o baseclasses, 'finish_struct' has set
2056 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2057 Similarly for a class whose base classes do not have vtables.
2058 When neither of these is true, we might have removed abstract
2059 virtuals (by providing a definition), added some (by declaring
2060 new ones), or redeclared ones from a base class. We need to
2061 recalculate what's really an abstract virtual at this point (by
2062 looking in the vtables). */
2065 /* If this type has a copy constructor or a destructor, force its
2066 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2067 nonzero. This will cause it to be passed by invisible reference
2068 and prevent it from being returned in a register. */
2071 {
2072 tree variants;
2075 {
2078 }
2079 }
2080 }
2082 /* Issue warnings about T having private constructors, but no friends,
2083 and so forth.
2085 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2086 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2087 non-private static member functions. */
2089 static void
2091 {
2097 /* If the class has friends, those entities might create and
2098 access instances, so we should not warn. */
2101 /* We will have warned when the template was declared; there's
2102 no need to warn on every instantiation. */
2104 /* There's no reason to even consider warning about this
2105 class. */
2108 /* We only issue one warning, if more than one applies, because
2109 otherwise, on code like:
2111 class A {
2112 // Oops - forgot `public:'
2113 A();
2114 A(const A&);
2115 ~A();
2116 };
2118 we warn several times about essentially the same problem. */
2120 /* Check to see if all (non-constructor, non-destructor) member
2121 functions are private. (Since there are no friends or
2122 non-private statics, we can't ever call any of the private member
2123 functions.) */
2132 /* We're not interested in compiler-generated methods; they don't
2135 {
2137 /* A non-private static member function is just like a
2138 friend; it can create and invoke private member
2139 functions, and be accessed without a class
2140 instance. */
2144 /* Keep searching for a static member function. */
2145 }
2150 {
2151 /* There are no non-private methods, and there's at least one
2152 private member function that isn't a constructor or
2153 destructor. (If all the private members are
2154 constructors/destructors we want to use the code below that
2155 issues error messages specifically referring to
2156 constructors/destructors.) */
2162 {
2165 }
2167 {
2171 }
2172 }
2174 /* Even if some of the member functions are non-private, the class
2175 won't be useful for much if all the constructors or destructors
2176 are private: such an object can never be created or destroyed. */
2179 {
2182 t);
2184 }
2186 /* Warn about classes that have private constructors and no friends. */
2188 /* Implicitly generated constructors are always public. */
2190 {
2193 /* If a non-template class does not define a copy
2194 constructor, one is defined for it, enabling it to avoid
2195 this warning. For a template class, this does not
2196 happen, and so we would normally get a warning on:
2198 template <class T> class C { private: C(); };
2200 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2201 complete non-template or fully instantiated classes have this
2202 flag set. */
2205 else
2211 /* Ideally, we wouldn't count any constructor that takes
2212 an argument of the class type as a parameter, because
2213 such things cannot be used to construct an instance of
2214 the class unless you already have one. */
2216 else
2220 {
2222 "%q#T only defines private constructors and has "
2229 }
2230 }
2231 }
2233 /* Make BINFO's vtable have N entries, including RTTI entries,
2234 vbase and vcall offsets, etc. Set its type and call the back end
2235 to lay it out. */
2237 static void
2239 {
2240 tree atype;
2241 tree vtable;
2246 /* We may have to grow the vtable. */
2249 {
2253 }
2254 }
2256 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2257 have the same signature. */
2259 int
2261 {
2262 /* One destructor overrides another if they are the same kind of
2263 destructor. */
2267 /* But a non-destructor never overrides a destructor, nor vice
2268 versa, nor do different kinds of destructors override
2269 one-another. For example, a complete object destructor does not
2270 override a deleting destructor. */
2279 {
2287 }
2289 }
2291 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2292 subobject. */
2294 static bool
2296 {
2297 tree probe;
2300 {
2304 /* If we meet a virtual base, we can't follow the inheritance
2305 any more. See if the complete type of DERIVED contains
2306 such a virtual base. */
2309 }
2311 }
2314 /* The function for which we are trying to find a final overrider. */
2315 tree fn;
2316 /* The base class in which the function was declared. */
2317 tree declaring_base;
2318 /* The candidate overriders. */
2319 tree candidates;
2320 /* Path to most derived. */
2322 };
2324 /* Add the overrider along the current path to FFOD->CANDIDATES.
2325 Returns true if an overrider was found; false otherwise. */
2327 static bool
2331 {
2332 tree method;
2334 /* If BINFO is not the most derived type, try a more derived class.
2335 A definition there will overrider a definition here. */
2337 {
2338 depth--;
2342 }
2346 {
2349 /* Remove any candidates overridden by this new function. */
2351 {
2352 /* If *CANDIDATE overrides METHOD, then METHOD
2353 cannot override anything else on the list. */
2356 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2359 else
2361 }
2363 /* Add the new function. */
2366 }
2369 }
2371 /* Called from find_final_overrider via dfs_walk. */
2373 static tree
2375 {
2383 }
2385 static tree
2387 {
2392 }
2394 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2395 FN and whose TREE_VALUE is the binfo for the base where the
2396 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2397 DERIVED) is the base object in which FN is declared. */
2399 static tree
2401 {
2402 find_final_overrider_data ffod;
2404 /* Getting this right is a little tricky. This is valid:
2406 struct S { virtual void f (); };
2407 struct T { virtual void f (); };
2408 struct U : public S, public T { };
2410 even though calling `f' in `U' is ambiguous. But,
2412 struct R { virtual void f(); };
2413 struct S : virtual public R { virtual void f (); };
2414 struct T : virtual public R { virtual void f (); };
2415 struct U : public S, public T { };
2417 is not -- there's no way to decide whether to put `S::f' or
2418 `T::f' in the vtable for `R'.
2420 The solution is to look at all paths to BINFO. If we find
2421 different overriders along any two, then there is a problem. */
2425 /* Determine the depth of the hierarchy. */
2436 /* If there was no winner, issue an error message. */
2441 }
2443 /* Return the index of the vcall offset for FN when TYPE is used as a
2444 virtual base. */
2446 static tree
2448 {
2450 tree_pair_p p;
2458 /* There should always be an appropriate index. */
2460 }
2462 /* Given a DECL_VINDEX of a virtual function found in BINFO, return the final
2463 overrider at that index in the vtable. This should only be used when we
2464 know that BINFO is correct for the dynamic type of the object. */
2466 tree
2468 {
2473 /* BINFO_VIRTUALS in a primary base isn't accurate, find the derived
2474 class that actually owns the vtable. */
2478 }
2480 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2481 dominated by T. FN is the old function; VIRTUALS points to the
2482 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2483 of that entry in the list. */
2485 static void
2488 {
2489 tree b;
2490 tree overrider;
2491 tree delta;
2492 tree virtual_base;
2493 tree first_defn;
2499 /* Find the nearest primary base (possibly binfo itself) which defines
2500 this function; this is the class the caller will convert to when
2501 calling FN through BINFO. */
2503 {
2508 /* The nearest definition is from a lost primary. */
2511 }
2514 /* Find the final overrider. */
2517 {
2520 }
2523 /* Check for adjusting covariant return types. */
2531 /* If the overrider is invalid, don't even try. */
2533 {
2534 /* If FN is a covariant thunk, we must figure out the adjustment
2535 to the final base FN was converting to. As OVERRIDER_TARGET might
2536 also be converting to the return type of FN, we have to
2537 combine the two conversions here. */
2544 {
2548 }
2549 else
2553 /* Find the equivalent binfo within the return type of the
2554 overriding function. We will want the vbase offset from
2555 there. */
2557 over_return);
2560 {
2561 /* There was no existing virtual thunk (which takes
2562 precedence). So find the binfo of the base function's
2563 return type within the overriding function's return type.
2564 Fortunately we know the covariancy is valid (it
2565 has already been checked), so we can just iterate along
2566 the binfos, which have been chained in inheritance graph
2567 order. Of course it is lame that we have to repeat the
2568 search here anyway -- we should really be caching pieces
2569 of the vtable and avoiding this repeated work. */
2573 /* Find the base binfo within the overriding function's
2574 return type. We will always find a thunk_binfo, except
2575 when the covariancy is invalid (which we will have
2576 already diagnosed). */
2585 /* See if virtual inheritance is involved. */
2587 virtual_offset;
2594 {
2598 {
2599 /* We convert via virtual base. Adjust the fixed
2600 offset to be from there. */
2601 offset =
2605 }
2607 /* There was an existing fixed offset, this must be
2608 from the base just converted to, and the base the
2609 FN was thunking to. */
2611 else
2613 }
2614 }
2617 /* Replace the overriding function with a covariant thunk. We
2618 will emit the overriding function in its own slot as
2619 well. */
2622 }
2623 else
2627 /* If we need a covariant thunk, then we may need to adjust first_defn.
2628 The ABI specifies that the thunks emitted with a function are
2629 determined by which bases the function overrides, so we need to be
2630 sure that we're using a thunk for some overridden base; even if we
2631 know that the necessary this adjustment is zero, there may not be an
2632 appropriate zero-this-adjustment thunk for us to use since thunks for
2633 overriding virtual bases always use the vcall offset.
2635 Furthermore, just choosing any base that overrides this function isn't
2636 quite right, as this slot won't be used for calls through a type that
2637 puts a covariant thunk here. Calling the function through such a type
2638 will use a different slot, and that slot is the one that determines
2639 the thunk emitted for that base.
2641 So, keep looking until we find the base that we're really overriding
2642 in this slot: the nearest primary base that doesn't use a covariant
2643 thunk in this slot. */
2645 {
2647 /* We already know that the overrider needs a covariant thunk. */
2650 {
2657 }
2659 }
2661 /* Assume that we will produce a thunk that convert all the way to
2662 the final overrider, and not to an intermediate virtual base. */
2665 /* See if we can convert to an intermediate virtual base first, and then
2666 use the vcall offset located there to finish the conversion. */
2668 {
2669 /* If we find the final overrider, then we can stop
2670 walking. */
2675 /* If we find a virtual base, and we haven't yet found the
2676 overrider, then there is a virtual base between the
2677 declaring base (first_defn) and the final overrider. */
2679 {
2682 }
2683 }
2685 /* Compute the constant adjustment to the `this' pointer. The
2686 `this' pointer, when this function is called, will point at BINFO
2687 (or one of its primary bases, which are at the same offset). */
2689 /* The `this' pointer needs to be adjusted from the declaration to
2690 the nearest virtual base. */
2695 /* If the nearest definition is in a lost primary, we don't need an
2696 entry in our vtable. Except possibly in a constructor vtable,
2697 if we happen to get our primary back. In that case, the offset
2698 will be zero, as it will be a primary base. */
2700 else
2701 /* The `this' pointer needs to be adjusted from pointing to
2702 BINFO to pointing at the base where the final overrider
2703 appears. */
2714 else
2718 }
2720 /* Called from modify_all_vtables via dfs_walk. */
2722 static tree
2724 {
2726 tree virtuals;
2727 tree old_virtuals;
2731 /* A base without a vtable needs no modification, and its bases
2732 are uninteresting. */
2737 /* Don't do the primary vtable, if it's new. */
2741 /* There's no need to modify the vtable for a non-virtual primary
2742 base; we're not going to use that vtable anyhow. We do still
2743 need to do this for virtual primary bases, as they could become
2744 non-primary in a construction vtable. */
2749 /* Now, go through each of the virtual functions in the virtual
2750 function table for BINFO. Find the final overrider, and update
2751 the BINFO_VIRTUALS list appropriately. */
2754 virtuals;
2758 binfo,
2763 }
2765 /* Update all of the primary and secondary vtables for T. Create new
2766 vtables as required, and initialize their RTTI information. Each
2767 of the functions in VIRTUALS is declared in T and may override a
2768 virtual function from a base class; find and modify the appropriate
2769 entries to point to the overriding functions. Returns a list, in
2770 declaration order, of the virtual functions that are declared in T,
2771 but do not appear in the primary base class vtable, and which
2772 should therefore be appended to the end of the vtable for T. */
2774 static tree
2776 {
2780 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2784 /* Update all of the vtables. */
2787 /* Add virtual functions not already in our primary vtable. These
2788 will be both those introduced by this class, and those overridden
2789 from secondary bases. It does not include virtuals merely
2790 inherited from secondary bases. */
2792 {
2797 {
2798 /* We don't need to adjust the `this' pointer when
2799 calling this function. */
2803 /* This is a function not already in our vtable. Keep it. */
2805 }
2806 else
2807 /* We've already got an entry for this function. Skip it. */
2809 }
2812 }
2814 /* Get the base virtual function declarations in T that have the
2815 indicated NAME. */
2817 static void
2819 {
2822 /* Find virtual functions in T with the indicated NAME. */
2824 {
2828 {
2831 }
2832 }
2839 {
2842 }
2843 }
2845 /* If this method overrides a virtual method from a base, then mark
2846 this member function as being virtual as well. Do 'final' and
2847 'override' checks too. */
2849 void
2851 {
2853 /* In [temp.mem] we have:
2855 A specialization of a member function template does not
2856 override a virtual function from a base class. */
2859 /* IDENTIFIER_VIRTUAL_P indicates whether the name has ever been
2860 used for a vfunc. That avoids the expensive look_for_overrides
2861 call that when we know there's nothing to find. As conversion
2862 operators for the same type can have distinct identifiers, we
2863 cannot optimize those in that way. */
2867 /* Check staticness after we've checked if we 'override'. */
2869 {
2870 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2871 the error_mark_node so that we know it is an overriding
2872 function. */
2881 }
2886 {
2887 /* Remember this identifier is virtual name. */
2891 /* It's a new vfunc. */
2896 }
2899 }
2901 /* Warn about hidden virtual functions that are not overridden in t.
2902 We know that constructors and destructors don't apply. */
2904 static void
2906 {
2909 {
2917 tree base_binfo;
2918 tree binfo;
2921 /* Iterate through all of the base classes looking for possibly
2922 hidden functions. */
2925 {
2928 }
2930 /* If there are no functions to hide, continue. */
2934 /* Remove any overridden functions. */
2936 {
2940 {
2941 /* If the method from the base class has the same
2942 signature as the method from the derived class, it
2943 has been overridden. */
2948 }
2949 }
2951 /* Now give a warning for all base functions without overriders,
2952 as they are hidden. */
2953 tree base_fndecl;
2956 {
2957 auto_diagnostic_group d;
2958 /* Here we know it is a hider, and no overrider exists. */
2960 OPT_Woverloaded_virtual,
2963 }
2964 }
2965 }
2967 /* Recursive helper for finish_struct_anon. */
2969 static void
2971 {
2973 {
2974 /* We're generally only interested in entities the user
2975 declared, but we also find nested classes by noticing
2976 the TYPE_DECL that we create implicitly. You're
2977 allowed to put one anonymous union inside another,
2978 though, so we explicitly tolerate that. We use
2979 TYPE_UNNAMED_P rather than ANON_AGGR_TYPE_P so that
2980 we also allow unnamed types used for defining fields. */
2989 {
2990 /* We already complained about static data members in
2991 finish_static_data_member_decl. */
2993 {
2994 auto_diagnostic_group d;
2998 "only have public non-static data members"
3001 {
3004 {
3007 "this flexibility is deprecated and will be "
3009 }
3010 }
3011 }
3012 }
3017 /* Recurse into the anonymous aggregates to correctly handle
3018 access control (c++/24926):
3020 class A {
3021 union {
3022 union {
3023 int i;
3024 };
3025 };
3026 };
3028 int j=A().i; */
3032 }
3033 }
3035 /* Check for things that are invalid. There are probably plenty of other
3036 things we should check for also. */
3038 static void
3040 {
3042 {
3051 }
3052 }
3054 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3055 will be used later during class template instantiation.
3056 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3057 a non-static member data (FIELD_DECL), a member function
3058 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3059 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3060 When FRIEND_P is nonzero, T is either a friend class
3061 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3062 (FUNCTION_DECL, TEMPLATE_DECL). */
3064 void
3066 {
3069 {
3074 }
3075 }
3077 /* This function is called from declare_virt_assop_and_dtor via
3078 dfs_walk_all.
3080 DATA is a type that direcly or indirectly inherits the base
3081 represented by BINFO. If BINFO contains a virtual assignment [copy
3082 assignment or move assigment] operator or a virtual constructor,
3083 declare that function in DATA if it hasn't been already declared. */
3085 static tree
3087 {
3095 /* A base without a vtable needs no modification, and its bases
3096 are uninteresting. */
3100 /* If this is a primary base, then we have already looked at the
3101 virtual functions of its vtable. */
3105 {
3109 {
3114 }
3118 }
3121 }
3123 /* If the class type T has a direct or indirect base that contains a
3124 virtual assignment operator or a virtual destructor, declare that
3125 function in T if it hasn't been already declared. */
3127 static void
3129 {
3137 dfs_declare_virt_assop_and_dtor,
3139 }
3141 /* Declare the inheriting constructor for class T inherited from base
3142 constructor CTOR with the parameter array PARMS of size NPARMS. */
3144 static void
3146 {
3149 /* We don't declare an inheriting ctor that would be a default,
3150 copy or move ctor for derived or base. */
3155 {
3159 }
3168 {
3171 }
3172 }
3174 /* Declare all the inheriting constructors for class T inherited from base
3175 constructor CTOR. */
3177 static void
3179 {
3183 {
3188 }
3193 {
3197 }
3200 {
3201 auto_diagnostic_group d;
3205 }
3206 }
3208 /* Create default constructors, assignment operators, and so forth for
3209 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3210 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3211 the class cannot have a default constructor, copy constructor
3212 taking a const reference argument, or an assignment operator taking
3213 a const reference, respectively. */
3215 static void
3219 {
3220 /* Destructor. */
3222 /* In general, we create destructors lazily. */
3231 /* [class.ctor]
3233 If there is no user-declared constructor for a class, a default
3234 constructor is implicitly declared. */
3236 {
3241 /* Don't force the declaration to get a hard answer; if the
3242 definition would have made the class non-literal, it will still be
3243 non-literal because of the base or member in question, and that
3244 gives a better diagnostic. */
3246 }
3248 /* [class.ctor]
3250 If a class definition does not explicitly declare a copy
3251 constructor, one is declared implicitly. */
3253 {
3259 }
3261 /* If there is no assignment operator, one will be created if and
3262 when it is needed. For now, just record whether or not the type
3263 of the parameter to the assignment operator will be a const or
3264 non-const reference. */
3266 {
3272 }
3274 /* We can't be lazy about declaring functions that might override
3275 a virtual function from a base class. */
3278 /* If the class definition does not explicitly declare an == operator
3279 function, but declares a defaulted three-way comparison operator function,
3280 an == operator function is declared implicitly. */
3283 {
3285 NULL_TREE);
3290 else
3291 {
3295 }
3297 }
3300 {
3304 {
3305 /* declare, then remove the decl */
3313 }
3314 else
3316 }
3317 }
3319 /* Cache of enum_min_precision values. */
3322 /* Return the minimum precision of a bit-field needed to store all
3323 enumerators of ENUMERAL_TYPE TYPE. */
3325 static int
3327 {
3329 /* For unscoped enums without fixed underlying type and without mode
3330 attribute we can just use precision of the underlying type. */
3346 {
3350 {
3361 }
3362 }
3363 else
3371 }
3373 /* FIELD is a bit-field. We are finishing the processing for its
3374 enclosing type. Issue any appropriate messages and set appropriate
3375 flags. Returns false if an error has been diagnosed. */
3377 static bool
3379 {
3381 tree w;
3383 /* Extract the declared width of the bitfield, which has been
3384 temporarily stashed in DECL_BIT_FIELD_REPRESENTATIVE by grokbitfield. */
3387 /* Remove the bit-field width indicator so that the rest of the
3388 compiler does not treat that value as a qualifier. */
3391 /* Detect invalid bit-field type. */
3393 {
3397 }
3398 else
3399 {
3401 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3404 /* detect invalid field size. */
3410 {
3413 }
3415 {
3418 }
3420 {
3423 }
3433 {
3439 }
3440 }
3443 {
3447 }
3448 else
3449 {
3450 /* Non-bit-fields are aligned for their type. */
3454 }
3455 }
3457 /* FIELD is a non bit-field. We are finishing the processing for its
3458 enclosing type T. Issue any appropriate messages and set appropriate
3459 flags. */
3461 static bool
3463 tree t,
3466 {
3470 /* In C++98 an anonymous union cannot contain any fields which would change
3471 the settings of CANT_HAVE_CONST_CTOR and friends. */
3473 ;
3474 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3475 structs. So, we recurse through their fields here. */
3477 {
3482 cant_have_const_ctor,
3483 no_const_asn_ref);
3484 }
3485 /* Check members with class type for constructors, destructors,
3486 etc. */
3488 {
3489 /* Never let anything with uninheritable virtuals
3490 make it through without complaint. */
3494 {
3499 field);
3504 field);
3506 {
3510 }
3511 }
3512 else
3513 {
3526 }
3535 }
3540 /* `build_class_init_list' does not recognize
3541 non-FIELD_DECLs. */
3545 }
3547 /* Check the data members (both static and non-static), class-scoped
3548 typedefs, etc., appearing in the declaration of T. Issue
3549 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3550 declaration order) of access declarations; each TREE_VALUE in this
3551 list is a USING_DECL.
3553 In addition, set the following flags:
3555 EMPTY_P
3556 The class is empty, i.e., contains no non-static data members.
3558 CANT_HAVE_CONST_CTOR_P
3559 This class cannot have an implicitly generated copy constructor
3560 taking a const reference.
3562 CANT_HAVE_CONST_ASN_REF
3563 This class cannot have an implicitly generated assignment
3564 operator taking a const reference.
3566 All of these flags should be initialized before calling this
3567 function. */
3569 static void
3573 {
3576 /* Assume there are no access declarations. */
3578 /* Effective C has things to say about classes with pointer members. */
3580 /* Default initialized members affect the whole class. */
3582 /* Lack of any non-static data member of non-volatile literal
3583 type affects a union. */
3585 /* Standard layout requires all FIELDS have same access. */
3589 {
3593 {
3598 /* Save the access declarations for our caller. */
3607 /* FIXME: We should fold in the checking from check_methods. */
3617 {
3618 /* [class.union]
3620 (C++98) If a union contains a static data member,
3621 ... the program is ill-formed. */
3625 }
3630 {
3631 /* [class.union]
3633 If a union contains ... or a [non-static data] member
3634 of reference type, the program is ill-formed. */
3638 }
3640 data_member:
3641 /* Common VAR_DECL & FIELD_DECL processing. */
3645 /* Template instantiation can cause this. Perhaps this
3646 should be a specific instantiation check? */
3648 {
3652 }
3654 {
3658 }
3661 }
3669 /* If it is not a union and at least one non-static data member is
3670 non-literal, the whole class becomes non-literal. Per Core/1453,
3671 volatile non-static data members and base classes are also not allowed.
3672 If it is a union, we might set CLASSTYPE_LITERAL_P after we've seen all
3673 members.
3674 Note: if the type is incomplete we will complain later on. */
3676 {
3679 else
3681 }
3686 {
3687 /* A standard-layout class is a class that:
3689 ... has the same access control (Clause 11) for all
3690 non-static data members, */
3693 else
3696 /* Aggregates must be public. */
3699 }
3701 /* If this is of reference type, check if it needs an init. */
3703 {
3709 {
3710 /* ARM $12.6.2: [A member initializer list] (or, for an
3711 aggregate, initialization by a brace-enclosed list) is the
3712 only way to initialize non-static const and reference
3713 members. */
3716 }
3717 }
3722 {
3724 {
3726 "ignoring packed attribute because of"
3729 }
3733 }
3737 /* We don't treat zero-width bitfields as making a class
3738 non-empty. */
3739 ;
3742 /* Empty data members also don't make a class non-empty. */
3744 else
3745 {
3746 /* The class is non-empty. */
3748 /* The class is not even nearly empty. */
3750 /* If one of the data members contains an empty class, so
3751 does T. */
3755 }
3757 /* This is used by -Weffc++ (see below). Warn only for pointers
3758 to members which might hold dynamic memory. So do not warn
3759 for pointers to functions or pointers to members. */
3765 {
3770 }
3776 {
3783 }
3786 /* DR 148 now allows pointers to members (which are POD themselves),
3787 to be allowed in POD structs. */
3791 /* A potentially-overlapping non-static data member makes the class
3792 non-layout-POD. */
3801 /* We set DECL_C_BIT_FIELD in grokbitfield.
3802 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3808 {
3811 {
3815 default_init_member);
3816 }
3818 }
3820 /* Now that we've removed bit-field widths from DECL_INITIAL,
3821 anything left in DECL_INITIAL is an NSDMI that makes the class
3822 non-aggregate in C++11. */
3827 {
3828 /* If any field is const, the structure type is pseudo-const. */
3833 {
3834 /* ARM $12.6.2: [A member initializer list] (or, for an
3835 aggregate, initialization by a brace-enclosed list) is the
3836 only way to initialize non-static const and reference
3837 members. */
3840 }
3841 }
3842 /* A field that is pseudo-const makes the structure likewise. */
3844 {
3849 }
3851 /* Core issue 80: A non-static data member is required to have a
3852 different name from the class iff the class has a
3853 user-declared constructor. */
3858 }
3860 /* Per CWG 2096, a type is a literal type if it is a union, and at least
3861 one of its non-static data members is of non-volatile literal type. */
3865 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3866 it should also define a copy constructor and an assignment operator to
3867 implement the correct copy semantic (deep vs shallow, etc.). As it is
3868 not feasible to check whether the constructors do allocate dynamic memory
3869 and store it within members, we approximate the warning like this:
3871 -- Warn only if there are members which are pointers
3872 -- Warn only if there is a non-trivial constructor (otherwise,
3873 there cannot be memory allocated).
3874 -- Warn only if there is a non-trivial destructor. We assume that the
3875 user at least implemented the cleanup correctly, and a destructor
3876 is needed to free dynamic memory.
3878 This seems enough for practical purposes. */
3880 && pointer_member
3884 {
3886 {
3888 {
3893 }
3899 }
3900 }
3902 /* Non-static data member initializers make the default constructor
3903 non-trivial. */
3905 {
3908 }
3910 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3914 /* Check anonymous struct/anonymous union fields. */
3917 /* We've built up the list of access declarations in reverse order.
3918 Fix that now. */
3920 }
3922 /* If TYPE is an empty class type, records its OFFSET in the table of
3923 OFFSETS. */
3925 static int
3927 {
3928 splay_tree_node n;
3933 /* Record the location of this empty object in OFFSETS. */
3941 type,
3945 }
3947 /* Returns nonzero if TYPE is an empty class type and there is
3948 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3950 static int
3952 {
3953 splay_tree_node n;
3954 tree t;
3959 /* Record the location of this empty object in OFFSETS. */
3969 }
3971 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3972 F for every subobject, passing it the type, offset, and table of
3973 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3974 be traversed.
3976 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3977 than MAX_OFFSET will not be walked.
3979 If F returns a nonzero value, the traversal ceases, and that value
3980 is returned. Otherwise, returns zero. */
3982 static int
3984 subobject_offset_fn f,
3985 tree offset,
3986 splay_tree offsets,
3987 tree max_offset,
3989 {
3993 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3994 stop. */
4002 {
4005 }
4008 {
4009 tree field;
4010 tree binfo;
4013 /* Avoid recursing into objects that are not interesting. */
4017 /* Record the location of TYPE. */
4022 /* Iterate through the direct base classes of TYPE. */
4026 {
4027 tree binfo_offset;
4032 tree orig_binfo;
4033 /* We cannot rely on BINFO_OFFSET being set for the base
4034 class yet, but the offsets for direct non-virtual
4035 bases can be calculated by going back to the TYPE. */
4038 offset,
4042 f,
4043 binfo_offset,
4044 offsets,
4045 max_offset,
4049 }
4052 {
4056 /* Iterate through the virtual base classes of TYPE. In G++
4057 3.2, we included virtual bases in the direct base class
4058 loop above, which results in incorrect results; the
4059 correct offsets for virtual bases are only known when
4060 working with the most derived type. */
4064 {
4066 f,
4068 offset,
4070 offsets,
4071 max_offset,
4075 }
4076 else
4077 {
4078 /* We still have to walk the primary base, if it is
4079 virtual. (If it is non-virtual, then it was walked
4080 above.) */
4086 {
4087 r = (walk_subobject_offsets
4092 }
4093 }
4094 }
4096 /* Iterate through the fields of TYPE. */
4101 {
4102 tree field_offset;
4107 f,
4109 offset,
4110 field_offset),
4111 offsets,
4112 max_offset,
4116 }
4117 }
4119 {
4122 tree index;
4124 /* Avoid recursing into objects that are not interesting. */
4127 || !domain
4131 /* Step through each of the elements in the array. */
4135 {
4137 f,
4138 offset,
4139 offsets,
4140 max_offset,
4146 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4147 there's no point in iterating through the remaining
4148 elements of the array. */
4151 }
4152 }
4155 }
4157 /* Return true iff FIELD_DECL DECL is potentially overlapping. */
4159 static bool
4161 {
4162 /* Base fields are actually potentially overlapping, but C++ bases go through
4163 a different code path based on binfos, and ObjC++ base fields are laid out
4164 in objc-act, so we don't want layout_class_type to mess with them. */
4166 {
4169 }
4173 }
4175 /* Record all of the empty subobjects of DECL_OR_BINFO. */
4177 static void
4179 splay_tree offsets)
4180 {
4185 {
4191 }
4192 else
4193 {
4198 }
4200 tree max_offset;
4201 /* If recording subobjects for a non-static data member or a
4202 non-empty base class, we do not need to record offsets beyond
4203 the size of the biggest empty class. Additional data members
4204 will go at the end of the class. Additional base classes will go
4205 either at offset zero (if empty, in which case they cannot
4206 overlap with offsets past the size of the biggest empty class) or
4207 at the end of the class.
4209 However, if we are placing an empty base class, then we must record
4210 all offsets, as either the empty class is at offset zero (where
4211 other empty classes might later be placed) or at the end of the
4212 class (where other objects might then be placed, so other empty
4213 subobjects might later overlap). */
4217 else
4221 }
4223 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4224 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4225 virtual bases of TYPE are examined. */
4227 static int
4229 tree offset,
4230 splay_tree offsets,
4232 {
4233 splay_tree_node max_node;
4235 /* Get the node in OFFSETS that indicates the maximum offset where
4236 an empty subobject is located. */
4238 /* If there aren't any empty subobjects, then there's no point in
4239 performing this check. */
4245 vbases_p);
4246 }
4248 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4249 non-static data member of the type indicated by RLI. BINFO is the
4250 binfo corresponding to the base subobject, OFFSETS maps offsets to
4251 types already located at those offsets. This function determines
4252 the position of the DECL. */
4254 static void
4256 tree decl,
4257 tree binfo,
4258 splay_tree offsets)
4259 {
4262 tree type;
4265 {
4266 /* For the purposes of determining layout conflicts, we want to
4267 use the class type of BINFO; TREE_TYPE (DECL) will be the
4268 CLASSTYPE_AS_BASE version, which does not contain entries for
4269 zero-sized bases. */
4272 }
4273 else
4274 {
4277 }
4279 /* Try to place the field. It may take more than one try if we have
4280 a hard time placing the field without putting two objects of the
4281 same type at the same address. */
4283 {
4286 /* Place this field. */
4290 /* We have to check to see whether or not there is already
4291 something of the same type at the offset we're about to use.
4292 For example, consider:
4294 struct S {};
4295 struct T : public S { int i; };
4296 struct U : public S, public T {};
4298 Here, we put S at offset zero in U. Then, we can't put T at
4299 offset zero -- its S component would be at the same address
4300 as the S we already allocated. So, we have to skip ahead.
4301 Since all data members, including those whose type is an
4302 empty class, have nonzero size, any overlap can happen only
4303 with a direct or indirect base-class -- it can't happen with
4304 a data member. */
4305 /* In a union, overlap is permitted; all members are placed at
4306 offset zero. */
4311 {
4312 /* Strip off the size allocated to this field. That puts us
4313 at the first place we could have put the field with
4314 proper alignment. */
4317 /* Bump up by the alignment required for the type. */
4318 rli->bitpos
4324 }
4327 {
4328 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4329 the offset wasn't aligned like a pointer when we started to
4330 layout this field, that affects its position. */
4333 {
4336 "alignment of %qD increased in %<-fabi-version=9%> "
4338 else
4341 decl);
4342 }
4344 }
4345 else
4346 /* There was no conflict. We're done laying out this field. */
4348 }
4350 /* Now that we know where it will be placed, update its
4351 BINFO_OFFSET. */
4353 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4354 this point because their BINFO_OFFSET is copied from another
4355 hierarchy. Therefore, we may not need to add the entire
4356 OFFSET. */
4362 }
4364 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4366 static int
4368 tree offset,
4370 {
4372 }
4374 /* Layout the empty base BINFO. EOC indicates the byte currently just
4375 past the end of the class, and should be correctly aligned for a
4376 class of the type indicated by BINFO; OFFSETS gives the offsets of
4377 the empty bases allocated so far. T is the most derived
4378 type. Return nonzero iff we added it at the end. */
4380 static bool
4382 splay_tree offsets)
4383 {
4384 tree alignment;
4388 tree type;
4390 {
4393 }
4394 else
4395 {
4398 }
4400 /* On some platforms (ARM), even empty classes will not be
4401 byte-aligned. */
4406 /* This routine should only be used for empty classes. */
4411 else
4414 /* This is an empty base class. We first try to put it at offset
4415 zero. */
4419 offset,
4420 offsets,
4422 {
4423 /* That didn't work. Now, we move forward from the next
4424 available spot in the class. */
4428 {
4430 offset,
4431 offsets,
4433 /* We finally found a spot where there's no overlap. */
4436 /* There's overlap here, too. Bump along to the next spot. */
4438 }
4439 }
4442 {
4447 }
4449 {
4454 }
4457 /* Adjust BINFO_OFFSET (binfo) to be exactly OFFSET. */
4460 else
4461 {
4465 }
4468 }
4470 /* Build the FIELD_DECL for BASETYPE as a base of T, add it to the chain of
4471 fields at NEXT_FIELD, and return it. */
4473 static tree
4475 {
4476 /* Create the FIELD_DECL. */
4486 /* CLASSTYPE_SIZE is one byte, but the field needs to have size zero. */
4488 else
4489 {
4492 }
4503 /* Add the new FIELD_DECL to the list of fields for T. */
4509 }
4511 /* Layout the base given by BINFO in the class indicated by RLI.
4512 *BASE_ALIGN is a running maximum of the alignments of
4513 any base class. OFFSETS gives the location of empty base
4514 subobjects. T is the most derived type. Return nonzero if the new
4515 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4516 *NEXT_FIELD, unless BINFO is for an empty base class.
4518 Returns the location at which the next field should be inserted. */
4523 {
4528 /* This error is now reported in xref_tag, thus giving better
4529 location information. */
4532 /* Place the base class. */
4534 {
4535 tree decl;
4537 /* The containing class is non-empty because it has a non-empty
4538 base class. */
4541 /* Create the FIELD_DECL. */
4544 /* Try to place the field. It may take more than one try if we
4545 have a hard time placing the field without putting two
4546 objects of the same type at the same address. */
4548 }
4549 else
4550 {
4552 /* A nearly-empty class "has no proper base class that is empty,
4553 not morally virtual, and at an offset other than zero." */
4555 {
4558 /* The check above (used in G++ 3.2) is insufficient because
4559 an empty class placed at offset zero might itself have an
4560 empty base at a nonzero offset. */
4562 empty_base_at_nonzero_offset_p,
4563 size_zero_node,
4568 }
4570 /* We used to not create a FIELD_DECL for empty base classes because of
4571 back end issues with overlapping FIELD_DECLs, but that doesn't seem to
4572 be a problem anymore. We need them to handle initialization of C++17
4573 aggregate bases. */
4575 {
4581 }
4583 /* An empty virtual base causes a class to be non-empty
4584 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4585 here because that was already done when the virtual table
4586 pointer was created. */
4587 }
4589 /* Record the offsets of BINFO and its base subobjects. */
4593 }
4595 /* Layout all of the non-virtual base classes. Record empty
4596 subobjects in OFFSETS. T is the most derived type. Return nonzero
4597 if the type cannot be nearly empty. The fields created
4598 corresponding to the base classes will be inserted at
4599 *NEXT_FIELD. */
4601 static void
4604 {
4605 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4606 subobjects. */
4611 /* The primary base class is always allocated first. */
4614 {
4615 /* We need to walk BINFO_BASE_BINFO to find the access of the primary
4616 base, if it is direct. Indirect base fields are private. */
4619 {
4622 {
4625 }
4626 }
4628 primary_access,
4630 }
4632 /* Now allocate the rest of the bases. */
4634 {
4637 /* The primary base was already allocated above, so we don't
4638 need to allocate it again here. */
4642 /* Virtual bases are added at the end (a primary virtual base
4643 will have already been added). */
4650 }
4651 }
4653 /* Go through the TYPE_FIELDS of T issuing any appropriate
4654 diagnostics, figuring out which methods override which other
4655 methods, and so forth. */
4657 static void
4659 {
4662 {
4668 /* The name of the field is the original field name
4669 Save this in auxiliary field for later overloading. */
4671 {
4675 }
4681 "%<transaction_safe_dynamic%> may only be specified for "
4683 }
4685 /* Check whether the eligible special member functions (P0848) are
4686 user-provided. add_method arranged that the CLASSTYPE_MEMBER_VEC only
4687 has the eligible ones; TYPE_FIELDS also contains ineligible overloads,
4688 which is why this needs to be separate from the loop above. */
4691 {
4693 {
4694 /* P0848: At the end of the definition of a class, overload
4695 resolution is performed among the prospective destructors declared
4696 in that class with an empty argument list to select the destructor
4697 for the class, also known as the selected destructor. The program
4698 is ill-formed if overload resolution fails. */
4699 auto_diagnostic_group d;
4702 }
4705 }
4708 {
4716 }
4720 {
4728 }
4729 }
4731 /* FN is constructor, destructor or operator function. Clone the
4732 declaration to create a NAME'd variant. NEED_VTT_PARM_P and
4733 OMIT_INHERITED_PARMS_P are relevant if it's a cdtor. */
4735 static tree
4738 {
4739 /* Copy the function. */
4741 /* Reset the function name. */
4745 /* Clone constraints. */
4750 /* There's no pending inline data for this function. */
4755 {
4756 /* The base-class destructor is not virtual. */
4759 }
4761 {
4762 /* Set the operator code. */
4766 /* The operator could be virtual. */
4769 }
4774 /* If there was an in-charge parameter, drop it from the function
4775 type. */
4777 {
4780 /* Skip the `this' parameter. */
4782 /* Skip the in-charge parameter. */
4784 /* And the VTT parm, in a complete [cd]tor. */
4788 {
4789 /* If we're omitting inherited parms, that just leaves the VTT. */
4792 }
4796 parmtypes);
4802 }
4804 /* Copy the function parameters. */
4807 /* Remove the in-charge parameter. */
4809 {
4813 }
4815 /* And the VTT parm, in a complete [cd]tor. */
4817 {
4820 else
4821 {
4825 }
4826 }
4828 /* A base constructor inheriting from a virtual base doesn't get the
4829 arguments. */
4834 {
4837 }
4839 /* Create the RTL for this function. */
4844 }
4846 /* FN is an operator function, create a variant for CODE. */
4848 tree
4850 {
4853 }
4855 /* FN is a constructor or destructor. Clone the declaration to create
4856 a specialized in-charge or not-in-charge version, as indicated by
4857 NAME. */
4859 static tree
4862 {
4863 tree clone;
4865 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4867 {
4879 }
4880 else
4881 {
4885 }
4887 /* Remember where this function came from. */
4890 /* Make it easy to find the CLONE given the FN. Note the
4891 template_result of a template will be chained this way too. */
4896 }
4898 /* Build the clones of FN, return the number of clones built. These
4899 will be inserted onto DECL_CHAIN of FN. */
4901 static unsigned
4903 {
4907 {
4908 /* For each constructor, we need two variants: an in-charge version
4909 and a not-in-charge version. */
4912 base_omits_inherited_p);
4914 }
4915 else
4916 {
4919 /* For each destructor, we need three variants: an in-charge
4920 version, a not-in-charge version, and an in-charge deleting
4921 version. We clone the deleting version first because that
4922 means it will go second on the TYPE_FIELDS list -- and that
4923 corresponds to the correct layout order in the virtual
4924 function table.
4926 For a non-virtual destructor, we do not build a deleting
4927 destructor. */
4929 {
4931 count++;
4932 }
4936 }
4939 }
4941 /* Produce declarations for all appropriate clones of FN. If
4942 UPDATE_METHODS is true, the clones are added to the
4943 CLASSTYPE_MEMBER_VEC. */
4945 void
4947 {
4948 /* Avoid inappropriate cloning. */
4953 /* Base cdtors need a vtt parm if there are virtual bases. */
4956 /* Base ctor omits inherited parms it needs a vttparm and inherited
4957 from a virtual nase ctor. */
4963 /* Note that this is an abstract function that is never emitted. */
4968 {
4971 }
4972 }
4974 /* DECL is an in charge constructor, which is being defined. This will
4975 have had an in class declaration, from whence clones were
4976 declared. An out-of-class definition can specify additional default
4977 arguments. As it is the clones that are involved in overload
4978 resolution, we must propagate the information from the DECL to its
4979 clones. */
4981 void
4983 {
4984 tree clone;
4988 {
4993 /* Skip the 'this' parameter. */
5009 {
5011 {
5015 }
5021 {
5022 /* A default parameter has been added. Adjust the
5023 clone's parameters. */
5027 {
5030 clone_parms);
5032 }
5035 tree type
5038 clone_parms);
5046 }
5047 }
5049 }
5050 }
5052 /* For each of the constructors and destructors in T, create an
5053 in-charge and not-in-charge variant. */
5055 static void
5057 {
5058 /* While constructors can be via a using declaration, at this point
5059 we no longer need to know that. */
5065 }
5067 /* Deduce noexcept for a destructor DTOR. */
5069 void
5071 {
5074 noexcept_deferred_spec);
5075 }
5077 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
5078 of TYPE for virtual functions which FNDECL overrides. Return a
5079 mask of the tm attributes found therein. */
5081 static int
5083 {
5085 tree base_binfo;
5089 {
5097 {
5101 else
5104 }
5105 else
5107 }
5110 }
5112 /* Subroutine of set_method_tm_attributes. Handle the checks and
5113 inheritance for one virtual method FNDECL. */
5115 static void
5117 {
5118 tree tm_attr;
5123 /* If FNDECL doesn't actually override anything (i.e. T is the
5124 class that first declares FNDECL virtual), then we're done. */
5131 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
5132 tm_pure must match exactly, otherwise no weakening of
5133 tm_safe > tm_callable > nothing. */
5134 /* ??? The tm_pure attribute didn't make the transition to the
5135 multivendor language spec. */
5137 {
5139 {
5142 }
5143 }
5144 /* If the overridden function is tm_pure, then FNDECL must be. */
5147 /* Look for base class combinations that cannot be satisfied. */
5149 {
5155 }
5156 /* If FNDECL did not declare an attribute, then inherit the most
5157 restrictive one. */
5159 {
5161 }
5162 /* Otherwise validate that we're not weaker than a function
5163 that is being overridden. */
5164 else
5165 {
5169 }
5172 err_override:
5176 }
5178 /* For each of the methods in T, propagate a class-level tm attribute. */
5180 static void
5182 {
5185 /* Don't bother collecting tm attributes if transactional memory
5186 support is not enabled. */
5190 /* Process virtual methods first, as they inherit directly from the
5191 base virtual function and also require validation of new attributes. */
5193 {
5194 tree vchain;
5197 {
5202 }
5203 }
5205 /* If the class doesn't have an attribute, nothing more to do. */
5210 /* Any method that does not yet have a tm attribute inherits
5211 the one from the class. */
5216 }
5218 /* Returns true if FN is a default constructor. */
5220 bool
5222 {
5225 }
5227 /* Returns true iff class T has a user-provided constructor that can be called
5228 with more than zero arguments. */
5230 bool
5232 {
5237 {
5244 }
5247 }
5249 /* Returns the defaulted constructor if T has one. Otherwise, returns
5250 NULL_TREE. */
5252 tree
5254 {
5259 {
5265 }
5268 }
5270 /* Returns true iff FN is a user-provided function, i.e. user-declared
5271 and not defaulted at its first declaration. */
5273 bool
5275 {
5280 }
5282 /* Returns true iff class T has a user-provided constructor. */
5284 bool
5286 {
5298 }
5300 /* Returns true iff class T has a user-provided or explicit constructor. */
5302 bool
5304 {
5312 {
5316 }
5319 }
5321 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5322 declared or explicitly defaulted in the class body) default
5323 constructor. */
5325 bool
5327 {
5334 {
5340 }
5343 }
5345 /* TYPE is being used as a virtual base, and has a non-trivial move
5346 assignment. Return true if this is due to there being a user-provided
5347 move assignment in TYPE or one of its subobjects; if there isn't, then
5348 multiple move assignment can't cause any harm. */
5350 bool
5352 {
5353 /* Does the type itself have a user-provided move assignment operator? */
5361 /* Do any of its bases? */
5363 tree base_binfo;
5368 /* Or non-static data members? */
5370 {
5375 }
5377 /* Seems not. */
5379 }
5381 /* If default-initialization leaves part of TYPE uninitialized, returns
5382 a DECL for the field or TYPE itself (DR 253). */
5384 tree
5386 {
5397 {
5401 }
5406 {
5410 }
5413 }
5415 /* Returns true iff for class T, a trivial synthesized default constructor
5416 would be constexpr. */
5418 bool
5420 {
5421 /* A defaulted trivial default constructor is constexpr
5422 if there is nothing to initialize. */
5424 /* A class with a vptr doesn't have a trivial default ctor.
5425 In C++20, a class can have transient uninitialized members, e.g.:
5427 struct S { int i; constexpr S() = default; };
5429 should work. */
5432 }
5434 /* Returns true iff class T has a constexpr default constructor. */
5436 bool
5438 {
5439 tree fns;
5442 {
5443 /* The caller should have stripped an enclosing array. */
5446 }
5448 {
5451 /* Non-trivial, we need to check subobject constructors. */
5453 }
5456 }
5458 /* Returns true iff class T has a constexpr default constructor or has an
5459 implicitly declared default constructor that we can't tell if it's constexpr
5460 without forcing a lazy declaration (which might cause undesired
5461 instantiations). */
5463 static bool
5465 {
5468 /* Assume it's constexpr. */
5471 }
5473 /* Returns true iff class T has a constexpr destructor. */
5475 bool
5477 {
5478 tree fns;
5481 /* Non-trivial, we need to check subobject destructors. */
5485 }
5487 /* Returns true iff class T has a constexpr destructor or has an
5488 implicitly declared destructor that we can't tell if it's constexpr
5489 without forcing a lazy declaration (which might cause undesired
5490 instantiations). */
5492 static bool
5494 {
5496 /* Assume it's constexpr. */
5499 }
5501 /* Returns true iff class TYPE has a virtual destructor. */
5503 bool
5505 {
5506 tree dtor;
5514 }
5516 /* Returns true iff T, a class, has a move-assignment or
5517 move-constructor. Does not lazily declare either.
5518 If USER_P is false, any move function will do. If it is true, the
5519 move function must be user-declared.
5521 Note that user-declared here is different from "user-provided",
5522 which doesn't include functions that are defaulted in the
5523 class. */
5525 bool
5527 {
5547 }
5549 /* True iff T has a move constructor that is not deleted. */
5551 bool
5553 {
5560 }
5562 /* True iff T has a copy constructor that is not deleted. */
5564 bool
5566 {
5573 }
5575 /* If T, a class, has a user-provided copy constructor, copy assignment
5576 operator, or destructor, returns that function. Otherwise, null. */
5578 tree
5580 {
5583 {
5587 }
5593 {
5597 }
5600 {
5604 }
5607 }
5609 /* True iff T has a member or friend declaration of operator OP. */
5611 bool
5613 {
5621 }
5624 /* If T has a defaulted member or friend declaration of OP, return it. */
5626 tree
5628 {
5631 {
5635 }
5639 {
5643 }
5645 }
5647 /* Nonzero if we need to build up a constructor call when initializing an
5648 object of this class, either because it has a user-declared constructor
5649 or because it doesn't have a default constructor (so we need to give an
5650 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5651 what you care about is whether or not an object can be produced by a
5652 constructor (e.g. so we don't set TREE_READONLY on const variables of
5653 such type); use this function when what you care about is whether or not
5654 to try to call a constructor to create an object. The latter case is
5655 the former plus some cases of constructors that cannot be called. */
5657 bool
5659 {
5660 tree inner;
5670 /* A user-declared constructor might be private, and a constructor might
5671 be trivial but deleted. */
5674 {
5680 }
5682 }
5684 /* Like type_build_ctor_call, but for destructors. */
5686 bool
5688 {
5689 tree inner;
5698 /* A user-declared destructor might be private, and a destructor might
5699 be trivial but deleted. */
5702 {
5708 }
5710 }
5712 /* Remove all zero-width bit-fields from T. */
5714 static void
5716 {
5721 {
5724 /* We should not be confused by the fact that grokbitfield
5725 temporarily sets the width of the bit field into
5726 DECL_BIT_FIELD_REPRESENTATIVE (*fieldsp).
5727 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5728 to that width. */
5732 else
5734 }
5735 }
5737 /* Returns TRUE iff we need a cookie when dynamically allocating an
5738 array whose elements have the indicated class TYPE. */
5740 static bool
5742 {
5743 tree fns;
5748 /* If there's a non-trivial destructor, we need a cookie. In order
5749 to iterate through the array calling the destructor for each
5750 element, we'll have to know how many elements there are. */
5754 /* If the usual deallocation function is a two-argument whose second
5755 argument is of type `size_t', then we have to pass the size of
5756 the array to the deallocation function, so we will need to store
5757 a cookie. */
5761 /* If there are no `operator []' members, or the lookup is
5762 ambiguous, then we don't need a cookie. */
5765 /* Loop through all of the functions. */
5767 {
5770 /* See if this function is a one-argument delete function. If
5771 it is, then it will be the usual deallocation function. */
5775 /* Do not consider this function if its second argument is an
5776 ellipsis. */
5779 /* Otherwise, if we have a two-argument function and the second
5780 argument is `size_t', it will be the usual deallocation
5781 function -- unless there is one-argument function, too. */
5785 }
5788 }
5790 /* Finish computing the `literal type' property of class type T.
5792 At this point, we have already processed base classes and
5793 non-static data members. We need to check whether the copy
5794 constructor is trivial, the destructor is trivial, and there
5795 is a trivial default constructor or at least one constexpr
5796 constructor other than the copy constructor. */
5798 static void
5800 {
5801 tree fn;
5816 /* C++14 DR 1684 removed this restriction. */
5824 {
5827 {
5828 auto_diagnostic_group d;
5830 "enclosing class of %<constexpr%> non-static "
5833 }
5834 }
5835 }
5837 /* T is a non-literal type used in a context which requires a constant
5838 expression. Explain why it isn't literal. */
5840 void
5842 {
5852 /* Already explained. */
5855 auto_diagnostic_group d;
5859 " %qT is a closure type, which is only literal in "
5866 t);
5871 {
5873 " %q+T is not an aggregate, does not have a trivial "
5874 "default constructor, and has no %<constexpr%> constructor that "
5877 /* Note that we can't simply call locate_ctor because when the
5878 constructor is deleted it just returns NULL_TREE. */
5880 {
5887 {
5890 else
5893 }
5894 }
5895 }
5896 else
5897 {
5901 {
5904 {
5910 }
5911 }
5913 {
5914 tree ftype;
5919 {
5922 field);
5925 }
5929 }
5930 }
5931 }
5933 /* Check the validity of the bases and members declared in T. Add any
5934 implicitly-generated functions (like copy-constructors and
5935 assignment operators). Compute various flag bits (like
5936 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5937 level: i.e., independently of the ABI in use. */
5939 static void
5941 {
5942 /* Nonzero if the implicitly generated copy constructor should take
5943 a non-const reference argument. */
5945 /* Nonzero if the implicitly generated assignment operator
5946 should take a non-const reference argument. */
5948 tree access_decls;
5951 tree fn;
5953 /* By default, we use const reference arguments and generate default
5954 constructors. */
5958 /* Check all the base-classes and set FMEM members to point to arrays
5959 of potential interest. */
5962 /* Deduce noexcept on destructor. This needs to happen after we've set
5963 triviality flags appropriately for our bases. */
5968 /* Check all the method declarations. */
5971 /* Save the initial values of these flags which only indicate whether
5972 or not the class has user-provided functions. As we analyze the
5973 bases and members we can set these flags for other reasons. */
5977 /* Check all the data member declarations. We cannot call
5978 check_field_decls until we have called check_bases check_methods,
5979 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5980 being set appropriately. */
5985 /* A nearly-empty class has to be vptr-containing; a nearly empty
5986 class contains just a vptr. */
5990 /* Do some bookkeeping that will guide the generation of implicitly
5991 declared member functions. */
5994 /* We need to call a constructor for this class if it has a
5995 user-provided constructor, or if the default constructor is going
5996 to initialize the vptr. (This is not an if-and-only-if;
5997 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5998 themselves need constructing.) */
6001 /* [dcl.init.aggr]
6003 An aggregate is an array or a class with no user-provided
6004 constructors ... and no virtual functions.
6006 Again, other conditions for being an aggregate are checked
6007 elsewhere. */
6013 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
6014 retain the old definition internally for ABI reasons. */
6023 /* If the only explicitly declared default constructor is user-provided,
6024 set TYPE_HAS_COMPLEX_DFLT. */
6030 /* Warn if a public base of a polymorphic type has an accessible
6031 non-virtual destructor. It is only now that we know the class is
6032 polymorphic. Although a polymorphic base will have a already
6033 been diagnosed during its definition, we warn on use too. */
6035 {
6038 tree base_binfo;
6042 {
6050 basetype);
6051 }
6052 }
6054 /* If the class has no user-declared constructor, but does have
6055 non-static const or reference data members that can never be
6056 initialized, issue a warning. */
6058 /* Classes with user-declared constructors are presumed to
6059 initialize these members. */
6061 /* Aggregates can be initialized with brace-enclosed
6062 initializers. */
6064 {
6065 tree field;
6068 {
6069 tree type;
6086 }
6087 }
6089 /* Synthesize any needed methods. */
6091 cant_have_const_ctor,
6092 no_const_asn_ref);
6094 /* Check defaulted declarations here so we have cant_have_const_ctor
6095 and don't need to worry about clones. */
6100 {
6103 {
6104 bool imp_const_p
6110 /* If the function is defaulted outside the class, we just
6111 give the synthesis error. Core Issue #1331 says this is
6112 no longer ill-formed, it is defined as deleted instead. */
6114 }
6116 }
6119 /* "This class type is not an aggregate." */
6122 /* Compute the 'literal type' property before we
6123 do anything with non-static member functions. */
6126 /* Create the in-charge and not-in-charge variants of constructors
6127 and destructors. */
6130 /* Process the using-declarations. */
6134 /* Figure out whether or not we will need a cookie when dynamically
6135 allocating an array of this type. */
6138 }
6140 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
6141 accordingly. If a new vfield was created (because T doesn't have a
6142 primary base class), then the newly created field is returned. It
6143 is not added to the TYPE_FIELDS list; it is the caller's
6144 responsibility to do that. Accumulate declared virtual functions
6145 on VIRTUALS_P. */
6147 static tree
6149 {
6150 tree fn;
6152 /* Collect the virtual functions declared in T. */
6157 {
6166 }
6168 /* If we couldn't find an appropriate base class, create a new field
6169 here. Even if there weren't any new virtual functions, we might need a
6170 new virtual function table if we're supposed to include vptrs in
6171 all classes that need them. */
6173 {
6174 /* We build this decl with vtbl_ptr_type_node, which is a
6175 `vtable_entry_type*'. It might seem more precise to use
6176 `vtable_entry_type (*)[N]' where N is the number of virtual
6177 functions. However, that would require the vtable pointer in
6178 base classes to have a different type than the vtable pointer
6179 in derived classes. We could make that happen, but that
6180 still wouldn't solve all the problems. In particular, the
6181 type-based alias analysis code would decide that assignments
6182 to the base class vtable pointer can't alias assignments to
6183 the derived class vtable pointer, since they have different
6184 types. Thus, in a derived class destructor, where the base
6185 class constructor was inlined, we could generate bad code for
6186 setting up the vtable pointer.
6188 Therefore, we use one type for all vtable pointers. We still
6189 use a type-correct type; it's just doesn't indicate the array
6190 bounds. That's better than using `void*' or some such; it's
6191 cleaner, and it let's the alias analysis code know that these
6192 stores cannot alias stores to void*! */
6193 tree field;
6206 /* This class is non-empty. */
6210 }
6213 }
6215 /* Add OFFSET to all base types of BINFO which is a base in the
6216 hierarchy dominated by T.
6218 OFFSET, which is a type offset, is number of bytes. */
6220 static void
6222 {
6224 tree primary_binfo;
6225 tree base_binfo;
6227 /* Update BINFO's offset. */
6232 offset));
6234 /* Find the primary base class. */
6240 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
6241 downwards. */
6243 {
6244 /* Don't do the primary base twice. */
6252 }
6253 }
6255 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
6256 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
6257 empty subobjects of T. */
6259 static void
6261 {
6262 tree vbase;
6269 /* Find the last field. The artificial fields created for virtual
6270 bases will go after the last extant field to date. */
6275 /* Go through the virtual bases, allocating space for each virtual
6276 base that is not already a primary base class. These are
6277 allocated in inheritance graph order. */
6279 {
6284 {
6285 /* This virtual base is not a primary base of any class in the
6286 hierarchy, so we have to add space for it. */
6288 access_private_node,
6290 }
6291 }
6292 }
6294 /* Returns the offset of the byte just past the end of the base class
6295 BINFO. */
6297 static tree
6299 {
6300 tree size;
6305 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6306 allocate some space for it. It cannot have virtual bases, so
6307 TYPE_SIZE_UNIT is fine. */
6309 else
6313 }
6315 /* Returns the offset of the byte just past the end of the base class or empty
6316 data member with the highest offset in T. If INCLUDE_VIRTUALS_P is zero,
6317 then only non-virtual bases are included. */
6319 static tree
6321 {
6324 tree binfo;
6325 tree base_binfo;
6326 tree offset;
6331 {
6341 }
6343 /* Also consider empty data members. */
6349 {
6350 /* Update sizeof(C) to max (sizeof(C), offset(D)+sizeof(D)) */
6355 }
6360 {
6364 }
6367 }
6369 /* Warn about bases of T that are inaccessible because they are
6370 ambiguous. For example:
6372 struct S {};
6373 struct T : public S {};
6374 struct U : public S, public T {};
6376 Here, `(S*) new U' is not allowed because there are two `S'
6377 subobjects of U. */
6379 static void
6381 {
6384 tree basetype;
6385 tree binfo;
6386 tree base_binfo;
6388 /* If not checking for warning then return early. */
6392 /* If there are no repeated bases, nothing can be ambiguous. */
6396 /* Check direct bases. */
6399 {
6405 }
6407 /* Check for ambiguous virtual bases. */
6411 {
6417 }
6418 }
6420 /* Compare two INTEGER_CSTs K1 and K2. */
6422 static int
6424 {
6426 }
6428 /* Increase the size indicated in RLI to account for empty classes
6429 that are "off the end" of the class. */
6431 static void
6433 {
6434 tree eoc;
6435 tree rli_size;
6437 /* It might be the case that we grew the class to allocate a
6438 zero-sized base class. That won't be reflected in RLI, yet,
6439 because we are willing to overlay multiple bases at the same
6440 offset. However, now we need to make sure that RLI is big enough
6441 to reflect the entire class. */
6446 {
6447 /* The size should have been rounded to a whole byte. */
6450 rli->bitpos
6459 }
6460 }
6462 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6463 BINFO_OFFSETs for all of the base-classes. Position the vtable
6464 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6466 static void
6468 {
6469 tree non_static_data_members;
6470 tree field;
6471 tree vptr;
6472 record_layout_info rli;
6473 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6474 types that appear at that offset. */
6475 splay_tree empty_base_offsets;
6476 /* True if the last field laid out was a bit-field. */
6478 /* The location at which the next field should be inserted. */
6481 /* Keep track of the first non-static data member. */
6484 /* Start laying out the record. */
6487 /* Mark all the primary bases in the hierarchy. */
6490 /* Create a pointer to our virtual function table. */
6493 /* The vptr is always the first thing in the class. */
6495 {
6500 }
6501 else
6504 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6509 /* Layout the non-static data members. */
6511 {
6512 tree type;
6513 tree padding;
6515 /* We still pass things that aren't non-static data members to
6516 the back end, in case it wants to do something with them. */
6518 {
6520 /* If the static data member has incomplete type, keep track
6521 of it so that it can be completed later. (The handling
6522 of pending statics in finish_record_layout is
6523 insufficient; consider:
6525 struct S1;
6526 struct S2 { static S1 s1; };
6528 At this point, finish_record_layout will be called, but
6529 S1 is still incomplete.) */
6531 {
6533 /* The visibility of static data members is determined
6534 at their point of declaration, not their point of
6535 definition. */
6537 }
6539 }
6551 {
6552 /* if D is a potentially-overlapping data member, update sizeof(C) to
6553 max (sizeof(C), offset(D)+max (nvsize(D), dsize(D))). */
6555 /* end_of_class doesn't always give dsize, but it does in the case of
6556 a class with virtual bases, which is when dsize > nvsize. */
6559 {
6562 }
6563 else
6564 {
6567 }
6568 }
6570 /* If this field is a bit-field whose width is greater than its
6571 type, then there are some special rules for allocating
6572 it. */
6575 {
6577 /* We must allocate the bits as if suitably aligned for the
6578 longest integer type that fits in this many bits. Then,
6579 we are supposed to use the left over bits as additional
6580 padding. */
6582 /* Do not pick a type bigger than MAX_FIXED_MODE_SIZE. */
6590 {
6592 /* Too big, so our current guess is what we want. */
6594 /* Not bigger than limit, ok */
6596 }
6598 /* Figure out how much additional padding is required. */
6600 /* In a union, the padding field must have the full width
6601 of the bit-field; all fields start at offset zero. */
6603 else
6610 /* An unnamed bitfield does not normally affect the
6611 alignment of the containing class on a target where
6612 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6613 make any exceptions for unnamed bitfields when the
6614 bitfields are longer than their types. Therefore, we
6615 temporarily give the field a name. */
6617 {
6620 }
6626 empty_base_offsets);
6629 /* Now that layout has been performed, set the size of the
6630 field to the size of its declared type; the rest of the
6631 field is effectively invisible. */
6633 /* We must also reset the DECL_MODE of the field. */
6635 }
6637 {
6640 }
6641 else
6643 empty_base_offsets);
6645 /* Remember the location of any empty classes in FIELD. */
6648 /* If a bit-field does not immediately follow another bit-field,
6649 and yet it starts in the middle of a byte, we have failed to
6650 comply with the ABI. */
6653 /* The TREE_NO_WARNING flag gets set by Objective-C when
6654 laying out an Objective-C class. The ObjC ABI differs
6655 from the C++ ABI, and so we do not want a warning
6656 here. */
6658 && !last_field_was_bitfield
6661 bitsize_unit_node)))
6663 "offset of %qD is not ABI-compliant and may "
6666 /* The middle end uses the type of expressions to determine the
6667 possible range of expression values. In order to optimize
6668 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6669 must be made aware of the width of "i", via its type.
6671 Because C++ does not have integer types of arbitrary width,
6672 we must (for the purposes of the front end) convert from the
6673 type assigned here to the declared type of the bitfield
6674 whenever a bitfield expression is used as an rvalue.
6675 Similarly, when assigning a value to a bitfield, the value
6676 must be converted to the type given the bitfield here. */
6678 {
6683 {
6690 }
6691 }
6693 /* If we needed additional padding after this field, add it
6694 now. */
6696 {
6697 tree padding_field;
6700 FIELD_DECL,
6701 NULL_TREE,
6702 char_type_node);
6710 NULL_TREE,
6711 empty_base_offsets);
6712 }
6715 }
6718 {
6719 /* Make sure that we are on a byte boundary so that the size of
6720 the class without virtual bases will always be a round number
6721 of bytes. */
6724 }
6726 /* Delete all zero-width bit-fields from the list of fields. Now
6727 that the type is laid out they are no longer important. */
6731 {
6732 /* T needs a different layout as a base (eliding virtual bases
6733 or whatever). Create that version. */
6740 /* If the ABI version is not at least two, and the last
6741 field was a bit-field, RLI may not be on a byte
6742 boundary. In particular, rli_size_unit_so_far might
6743 indicate the last complete byte, while rli_size_so_far
6744 indicates the total number of bits used. Therefore,
6745 rli_size_so_far, rather than rli_size_unit_so_far, is
6746 used to compute TYPE_SIZE_UNIT. */
6748 /* Set the size and alignment for the new type. */
6756 eoc);
6768 /* Copy the non-static data members of T. This will include its
6769 direct non-virtual bases & vtable. */
6773 {
6775 /* Zap any NSDMI, it's not needed and might be a deferred
6776 parse. */
6780 }
6783 /* We use the base type for trivial assignments, and hence it
6784 needs a mode. */
6787 /* Record the base version of the type. */
6789 }
6790 else
6793 /* Every empty class contains an empty class. */
6797 /* Set the TYPE_DECL for this type to contain the right
6798 value for DECL_OFFSET, so that we can use it as part
6799 of a COMPONENT_REF for multiple inheritance. */
6802 /* Now fix up any virtual base class types that we left lying
6803 around. We must get these done before we try to lay out the
6804 virtual function table. As a side-effect, this will remove the
6805 base subobject fields. */
6808 /* Make sure that empty classes are reflected in RLI at this
6809 point. */
6812 /* Make sure not to create any structures with zero size. */
6818 /* If this is a non-POD, declaring it packed makes a difference to how it
6819 can be used as a field; don't let finalize_record_size undo it. */
6823 /* Let the back end lay out the type. */
6826 /* If we didn't end up needing an as-base type, don't use it. */
6828 /* If T's CLASSTYPE_AS_BASE is TYPE_USER_ALIGN, but T is not,
6829 replacing the as-base type would change CLASSTYPE_USER_ALIGN,
6830 causing us to lose the user-specified alignment as in PR94050. */
6842 /* Warn about bases that can't be talked about due to ambiguity. */
6845 /* Now that we're done with layout, give the base fields the real types. */
6850 /* Clean up. */
6857 }
6859 /* Determine the "key method" for the class type indicated by TYPE,
6860 and set CLASSTYPE_KEY_METHOD accordingly. */
6862 void
6864 {
6865 tree method;
6872 /* The key method is the first non-pure virtual function that is not
6873 inline at the point of class definition. On some targets the
6874 key function may not be inline; those targets should not call
6875 this function until the end of the translation unit. */
6881 {
6884 }
6887 }
6889 /* Helper of find_flexarrays. Return true when FLD refers to a non-static
6890 class data member of non-zero size, otherwise false. */
6894 {
6902 {
6906 }
6909 }
6911 /* Used by find_flexarrays and related functions. */
6913 struct flexmems_t
6914 {
6915 /* The first flexible array member or non-zero array member found
6916 in the order of layout. */
6917 tree array;
6918 /* First non-static non-empty data member in the class or its bases. */
6919 tree first;
6920 /* The first non-static non-empty data member following either
6921 the flexible array member, if found, or the zero-length array member
6922 otherwise. AFTER[1] refers to the first such data member of a union
6923 of which the struct containing the flexible array member or zero-length
6924 array is a member, or NULL when no such union exists. This element is
6925 only used during searching, not for diagnosing problems. AFTER[0]
6926 refers to the first such data member that is not a member of such
6927 a union. */
6930 /* Refers to a struct (not union) in which the struct of which the flexible
6931 array is member is defined. Used to diagnose strictly (according to C)
6932 invalid uses of the latter structs. */
6933 tree enclosing;
6934 };
6936 /* Find either the first flexible array member or the first zero-length
6937 array, in that order of preference, among members of class T (but not
6938 its base classes), and set members of FMEM accordingly.
6939 BASE_P is true if T is a base class of another class.
6940 PUN is set to the outermost union in which the flexible array member
6941 (or zero-length array) is defined if one such union exists, otherwise
6942 to NULL.
6943 Similarly, PSTR is set to a data member of the outermost struct of
6944 which the flexible array is a member if one such struct exists,
6945 otherwise to NULL. */
6947 static void
6951 {
6952 /* Set the "pointer" to the outermost enclosing union if not set
6953 yet and maintain it for the remainder of the recursion. */
6958 {
6962 /* Is FLD a typedef for an anonymous struct? */
6964 /* FIXME: Note that typedefs (as well as arrays) need to be fully
6965 handled elsewhere so that errors like the following are detected
6966 as well:
6967 typedef struct { int i, a[], j; } S; // bug c++/72753
6968 S s [2]; // bug c++/68489
6969 */
6974 {
6975 /* Check the nested unnamed type referenced via a typedef
6976 independently of FMEM (since it's not a data member of
6977 the enclosing class). */
6980 }
6982 /* Skip anything that's GCC-generated or not a (non-static) data
6983 member. */
6987 /* Type of the member. */
6992 /* Determine the type of the array element or object referenced
6993 by the member so that it can be checked for flexible array
6994 members if it hasn't been yet. */
7001 {
7003 {
7004 /* Once the member after the flexible array has been found
7005 we're done. */
7008 }
7011 {
7012 /* Descend into the non-static member struct or union and try
7013 to find a flexible array member or zero-length array among
7014 its members. This is only necessary for anonymous types
7015 and types in whose context the current type T has not been
7016 defined (the latter must not be checked again because they
7017 are already in the process of being checked by one of the
7018 recursive calls). */
7023 /* If this member isn't anonymous and a prior non-flexible array
7024 member has been seen in one of the enclosing structs, clear
7025 the FIRST member since it doesn't contribute to the flexible
7026 array struct's members. */
7037 {
7038 /* Restore the FIRST member reset above if no flexible
7039 array member has been found in this member's struct. */
7041 }
7043 /* If the member struct contains the first flexible array
7044 member, or if this member is a base class, continue to
7045 the next member and avoid setting the FMEM->NEXT pointer
7046 to point to it. */
7049 }
7050 }
7053 {
7054 /* Remember the first non-static data member. */
7058 /* Remember the first non-static data member after the flexible
7059 array member, if one has been found, or the zero-length array
7060 if it has been found. */
7063 }
7065 /* Skip non-arrays. */
7069 /* Determine the upper bound of the array if it has one. */
7071 {
7073 {
7074 /* Make a record of the zero-length array if either one
7075 such field or a flexible array member has been seen to
7076 handle the pathological and unlikely case of multiple
7077 such members. */
7080 }
7082 {
7083 /* Remember the first zero-length array unless a flexible array
7084 member has already been seen. */
7087 }
7088 }
7089 else
7090 {
7091 /* Flexible array members have no upper bound. */
7093 {
7095 {
7096 /* Replace the zero-length array if it's been stored and
7097 reset the after pointer. */
7101 }
7103 /* Make a record of another flexible array member. */
7105 }
7106 else
7107 {
7110 }
7111 }
7112 }
7113 }
7115 /* Diagnose a strictly (by the C standard) invalid use of a struct with
7116 a flexible array member (or the zero-length array extension). */
7118 static void
7120 {
7122 {
7123 auto_diagnostic_group d;
7134 }
7135 }
7137 /* Issue diagnostics for invalid flexible array members or zero-length
7138 arrays that are not the last elements of the containing class or its
7139 base classes or that are its sole members. */
7141 static void
7143 {
7148 {
7151 }
7153 /* Has a diagnostic been issued? */
7159 {
7166 {
7169 auto_diagnostic_group d;
7171 {
7174 }
7175 }
7176 }
7177 else
7178 {
7185 {
7189 auto_diagnostic_group d;
7192 /* In the unlikely event that the member following the flexible
7193 array member is declared in a different class, or the member
7194 overlaps another member of a common union, point to it.
7195 Otherwise it should be obvious. */
7199 {
7204 }
7205 }
7206 }
7210 }
7213 /* Recursively check to make sure that any flexible array or zero-length
7214 array members of class T or its bases are valid (i.e., not the sole
7215 non-static data member of T and, if one exists, that it is the last
7216 non-static data member of T and its base classes. FMEM is expected
7217 to be initially null and is used internally by recursive calls to
7218 the function. Issue the appropriate diagnostics for the array member
7219 that fails the checks. */
7221 static void
7224 {
7225 /* Initialize the result of a search for flexible array and zero-length
7226 array members. Avoid doing any work if the most interesting FMEM data
7227 have already been populated. */
7236 /* Recursively check the primary base class first. */
7238 {
7241 }
7243 /* Recursively check the base classes. */
7246 {
7249 /* The primary base class was already checked above. */
7253 /* Virtual base classes are at the end. */
7257 /* Check the base class. */
7259 }
7262 {
7263 /* Check virtual base classes only once per derived class.
7264 I.e., this check is not performed recursively for base
7265 classes. */
7267 tree base_binfo;
7271 {
7272 /* Check the virtual base class. */
7276 }
7277 }
7279 /* Is the type unnamed (and therefore a member of it potentially
7280 an anonymous struct or union)? */
7285 /* Search the members of the current (possibly derived) class, skipping
7286 unnamed structs and unions since those could be anonymous. */
7291 {
7292 /* Issue diagnostics for invalid flexible and zero-length array
7293 members found in base classes or among the members of the current
7294 class. Ignore anonymous structs and unions whose members are
7295 considered to be members of the enclosing class and thus will
7296 be diagnosed when checking it. */
7298 }
7299 }
7301 /* Perform processing required when the definition of T (a class type)
7302 is complete. Diagnose invalid definitions of flexible array members
7303 and zero-size arrays. */
7305 void
7307 {
7308 tree x;
7309 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
7313 {
7318 }
7320 /* If this type was previously laid out as a forward reference,
7321 make sure we lay it out again. */
7325 /* Make assumptions about the class; we'll reset the flags if
7326 necessary. */
7332 /* Do end-of-class semantic processing: checking the validity of the
7333 bases and members and add implicitly generated methods. */
7336 /* Find the key method. */
7338 {
7339 /* The Itanium C++ ABI permits the key method to be chosen when
7340 the class is defined -- even though the key method so
7341 selected may later turn out to be an inline function. On
7342 some systems (such as ARM Symbian OS) the key method cannot
7343 be determined until the end of the translation unit. On such
7344 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
7345 will cause the class to be added to KEYED_CLASSES. Then, in
7346 finish_file we will determine the key method. */
7350 /* If a polymorphic class has no key method, we may emit the vtable
7351 in every translation unit where the class definition appears. If
7352 we're devirtualizing, we can look into the vtable even if we
7353 aren't emitting it. */
7356 }
7358 /* Layout the class itself. */
7360 /* COMPLETE_TYPE_P is now true. */
7364 /* With the layout complete, check for flexible array members and
7365 zero-length arrays that might overlap other members in the final
7366 layout. */
7371 /* If necessary, create the primary vtable for this class. */
7373 {
7374 /* We must enter these virtuals into the table. */
7378 /* Here we know enough to change the type of our virtual
7379 function table, but we will wait until later this function. */
7382 /* If we're warning about ABI tags, check the types of the new
7383 virtual functions. */
7387 }
7390 {
7392 tree fn;
7399 /* Add entries for virtual functions introduced by this class. */
7403 /* Set DECL_VINDEX for all functions declared in this class. */
7405 fn;
7407 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
7409 {
7413 /* A thunk. We should never be calling this entry directly
7414 from this vtable -- we'd use the entry for the non
7415 thunk base function. */
7419 }
7420 }
7428 /* Clear DECL_IN_AGGR_P for all member functions. Complete the rtl
7429 for any static member objects of the type we're working on. */
7438 /* Complain if one of the field types requires lower visibility. */
7441 /* Make the rtl for any new vtables we have created, and unmark
7442 the base types we marked. */
7445 /* Build the VTT for T. */
7452 "%q#T has virtual functions and accessible"
7460 /* Class layout, assignment of virtual table slots, etc., is now
7461 complete. Give the back end a chance to tweak the visibility of
7462 the class or perform any other required target modifications. */
7472 /* Finish debugging output for this type. */
7475 /* Recalculate satisfaction that might depend on completeness. */
7479 {
7482 {
7485 }
7487 {
7490 else
7491 {
7494 }
7496 }
7498 {
7500 "the type of the first field has a different ABI from the "
7503 }
7504 }
7505 }
7507 /* When T was built up, the member declarations were added in reverse
7508 order. Rearrange them to declaration order. */
7510 void
7512 {
7513 tree next;
7514 tree prev;
7515 tree x;
7517 /* The following lists are all in reverse order. Put them in
7518 declaration order now. */
7521 /* For the TYPE_FIELDS, only the non TYPE_DECLs are in reverse
7522 order, so we can't just use nreverse. Due to stat_hack
7523 chicanery in finish_member_declaration. */
7528 {
7532 }
7535 {
7538 }
7539 }
7541 tree
7543 {
7546 /* Now that we've got all the field declarations, reverse everything
7547 as necessary. */
7553 /* Nadger the current location so that diagnostics point to the start of
7554 the struct, not the end. */
7558 {
7559 tree x;
7561 /* We need to add the target functions of USING_DECLS, so that
7562 they can be found when the using declaration is not
7563 instantiated yet. */
7566 {
7571 }
7573 {
7577 }
7579 {
7582 }
7584 /* Also add a USING_DECL for operator=. We know there'll be (at
7585 least) one, but we don't know the signature(s). We want name
7586 lookup not to fail or recurse into bases. This isn't added
7587 to the template decl list so we drop this at instantiation
7588 time. */
7590 NULL_TREE);
7600 /* COMPLETE_TYPE_P is now true. */
7604 /* We need to emit an error message if this type was used as a parameter
7605 and it is an abstract type, even if it is a template. We construct
7606 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
7607 account and we call complete_vars with this type, which will check
7608 the PARM_DECLS. Note that while the type is being defined,
7609 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
7610 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
7617 /* Remember current #pragma pack value. */
7621 {
7625 }
7629 /* Fix up any variants we've already built. */
7631 }
7632 else
7634 /* COMPLETE_TYPE_P is now true. */
7639 {
7640 /* People keep complaining that the compiler crashes on an invalid
7641 definition of initializer_list, so I guess we should explicitly
7642 reject it. What the compiler internals care about is that it's a
7643 template and has a pointer field followed by size_type field. */
7646 {
7649 {
7653 }
7654 }
7658 }
7666 else
7678 /* Lambdas are defined by the LAMBDA_EXPR. */
7683 }
7684 \f
7685 /* Hash table to avoid endless recursion when handling references. */
7688 /* Return the dynamic type of INSTANCE, if known.
7689 Used to determine whether the virtual function table is needed
7690 or not.
7692 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7693 of our knowledge of its type. *NONNULL should be initialized
7694 before this function is called. */
7696 static tree
7698 {
7699 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
7702 {
7706 else
7710 /* This is a call to a constructor, hence it's never zero. */
7713 {
7717 }
7721 /* This is a call to a constructor, hence it's never zero. */
7723 {
7727 }
7736 /* Propagate nonnull. */
7741 CASE_CONVERT:
7747 {
7748 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7749 with a real object -- given &p->f, p can still be null. */
7751 /* ??? Probably should check DECL_WEAK here. */
7754 }
7758 /* If this component is really a base class reference, then the field
7759 itself isn't definitive. */
7768 {
7772 }
7773 /* fall through. */
7778 {
7782 }
7784 {
7788 /* if we're in a ctor or dtor, we know our type. If
7789 current_class_ptr is set but we aren't in a function, we're in
7790 an NSDMI (and therefore a constructor). */
7795 {
7799 }
7800 }
7802 {
7803 /* We only need one hash table because it is always left empty. */
7805 fixed_type_or_null_ref_ht
7808 /* Reference variables should be references to objects. */
7812 /* Enter the INSTANCE in a table to prevent recursion; a
7813 variable's initializer may refer to the variable
7814 itself. */
7819 {
7820 tree type;
7829 }
7830 }
7836 else
7837 /* TODO: Recursion may be correct for some non-location-wrapper
7838 uses of VIEW_CONVERT_EXPR. */
7843 }
7844 #undef RECUR
7845 }
7847 /* Return nonzero if the dynamic type of INSTANCE is known, and
7848 equivalent to the static type. We also handle the case where
7849 INSTANCE is really a pointer. Return negative if this is a
7850 ctor/dtor. There the dynamic type is known, but this might not be
7851 the most derived base of the original object, and hence virtual
7852 bases may not be laid out according to this type.
7854 Used to determine whether the virtual function table is needed
7855 or not.
7857 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7858 of our knowledge of its type. *NONNULL should be initialized
7859 before this function is called. */
7861 int
7863 {
7866 tree fixed;
7868 /* processing_template_decl can be false in a template if we're in
7869 instantiate_non_dependent_expr, but we still want to suppress
7870 this check. */
7872 {
7873 /* In a template we only care about the type of the result. */
7877 }
7889 }
7891 \f
7892 void
7894 {
7897 current_class_stack
7904 }
7906 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7908 static void
7910 {
7911 tree type;
7913 /* We are re-entering the same class we just left, so we don't
7914 have to search the whole inheritance matrix to find all the
7915 decls to bind again. Instead, we install the cached
7916 class_shadowed list and walk through it binding names. */
7919 /* Restore IDENTIFIER_TYPE_VALUE. */
7921 type;
7924 }
7926 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7927 appropriate for TYPE.
7929 So that we may avoid calls to lookup_name, we cache the _TYPE
7930 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7932 For multiple inheritance, we perform a two-pass depth-first search
7933 of the type lattice. */
7935 void
7937 {
7938 class_stack_node_t csn;
7942 /* Make sure there is enough room for the new entry on the stack. */
7944 {
7946 current_class_stack
7948 current_class_stack_size);
7949 }
7951 /* Insert a new entry on the class stack. */
7958 current_class_depth++;
7960 /* Now set up the new type. */
7966 /* By default, things in classes are private, while things in
7967 structures or unions are public. */
7969 ? access_private_node
7975 {
7976 /* Forcibly remove any old class remnants. */
7978 }
7984 else
7986 }
7988 /* Get out of the current class scope. If we were in a class scope
7989 previously, that is the one popped to. */
7991 void
7993 {
7996 current_class_depth--;
8002 }
8004 /* Mark the top of the class stack as hidden. */
8006 void
8008 {
8011 }
8013 /* Mark the top of the class stack as un-hidden. */
8015 void
8017 {
8020 }
8022 /* If the class type currently being defined is either T or
8023 a nested type of T, returns the type from the current_class_stack,
8024 which might be equivalent to but not equal to T in case of
8025 constrained partial specializations. */
8027 tree
8029 {
8037 /* We start looking from 1 because entry 0 is from global scope,
8038 and has no type. */
8040 {
8041 tree c;
8044 else
8045 {
8049 }
8054 }
8056 }
8058 /* If either current_class_type or one of its enclosing classes are derived
8059 from T, return the appropriate type. Used to determine how we found
8060 something via unqualified lookup. */
8062 tree
8064 {
8067 /* The bases of a dependent type are unknown. */
8078 {
8083 }
8086 }
8088 /* Return the outermost enclosing class type that is still open, or
8089 NULL_TREE. */
8091 tree
8093 {
8100 {
8107 }
8109 }
8111 /* Returns the innermost class type which is not a lambda closure type. */
8113 tree
8115 {
8120 }
8122 /* When entering a class scope, all enclosing class scopes' names with
8123 static meaning (static variables, static functions, types and
8124 enumerators) have to be visible. This recursive function calls
8125 pushclass for all enclosing class contexts until global or a local
8126 scope is reached. TYPE is the enclosed class. */
8128 void
8130 {
8131 /* A namespace might be passed in error cases, like A::B:C. */
8139 }
8141 /* Undoes a push_nested_class call. */
8143 void
8145 {
8151 }
8153 /* Returns the number of extern "LANG" blocks we are nested within. */
8155 int
8157 {
8159 }
8161 /* Set global variables CURRENT_LANG_NAME to appropriate value
8162 so that behavior of name-mangling machinery is correct. */
8164 void
8166 {
8173 else
8175 }
8177 /* Get out of the current language scope. */
8179 void
8181 {
8183 }
8184 \f
8185 /* Type instantiation routines. */
8187 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
8188 matches the TARGET_TYPE. If there is no satisfactory match, return
8189 error_mark_node, and issue an error & warning messages under
8190 control of FLAGS. Permit pointers to member function if FLAGS
8191 permits. If TEMPLATE_ONLY, the name of the overloaded function was
8192 a template-id, and EXPLICIT_TARGS are the explicitly provided
8193 template arguments.
8195 If OVERLOAD is for one or more member functions, then ACCESS_PATH
8196 is the base path used to reference those member functions. If
8197 the address is resolved to a member function, access checks will be
8198 performed and errors issued if appropriate. */
8200 static tree
8202 tree overload,
8203 tsubst_flags_t complain,
8205 tree explicit_targs,
8206 tree access_path)
8207 {
8208 /* Here's what the standard says:
8210 [over.over]
8212 If the name is a function template, template argument deduction
8213 is done, and if the argument deduction succeeds, the deduced
8214 arguments are used to generate a single template function, which
8215 is added to the set of overloaded functions considered.
8217 Non-member functions and static member functions match targets of
8218 type "pointer-to-function" or "reference-to-function." Nonstatic
8219 member functions match targets of type "pointer-to-member
8220 function;" the function type of the pointer to member is used to
8221 select the member function from the set of overloaded member
8222 functions. If a non-static member function is selected, the
8223 reference to the overloaded function name is required to have the
8224 form of a pointer to member as described in 5.3.1.
8226 If more than one function is selected, any template functions in
8227 the set are eliminated if the set also contains a non-template
8228 function, and any given template function is eliminated if the
8229 set contains a second template function that is more specialized
8230 than the first according to the partial ordering rules 14.5.5.2.
8231 After such eliminations, if any, there shall remain exactly one
8232 selected function. */
8235 /* We store the matches in a TREE_LIST rooted here. The functions
8236 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
8237 interoperability with most_specialized_instantiation. */
8239 tree fn;
8240 tree target_fn_type;
8242 /* By the time we get here, we should be seeing only real
8243 pointer-to-member types, not the internal POINTER_TYPE to
8244 METHOD_TYPE representation. */
8250 /* Check that the TARGET_TYPE is reasonable. */
8255 /* This is OK, too. */
8258 /* This is OK, too. This comes from a conversion to reference
8259 type. */
8261 else
8262 {
8268 }
8270 /* Non-member functions and static member functions match targets of type
8271 "pointer-to-function" or "reference-to-function." Nonstatic member
8272 functions match targets of type "pointer-to-member-function;" the
8273 function type of the pointer to member is used to select the member
8274 function from the set of overloaded member functions.
8276 So figure out the FUNCTION_TYPE that we want to match against. */
8279 /* If we can find a non-template function that matches, we can just
8280 use it. There's no point in generating template instantiations
8281 if we're just going to throw them out anyhow. But, of course, we
8282 can only do this when we don't *need* a template function. */
8285 {
8289 /* We're not looking for templates just yet. */
8293 /* We're looking for a non-static member, and this isn't
8294 one, or vice versa. */
8297 /* Constraints must be satisfied. This is done before
8298 return type deduction since that instantiates the
8299 function. */
8304 {
8305 /* Force instantiation to do return type deduction. */
8308 }
8310 /* In C++17 we need the noexcept-qualifier to compare types. */
8315 /* See if there's a match. */
8320 }
8322 /* Now, if we've already got a match (or matches), there's no need
8323 to proceed to the template functions. But, if we don't have a
8324 match we need to look at them, too. */
8326 {
8327 tree target_arg_types;
8328 tree target_ret_type;
8331 tree arg;
8345 {
8347 tree instantiation;
8348 tree targs;
8351 /* We're only looking for templates. */
8356 /* We're not looking for a non-static member, and this is
8357 one, or vice versa. */
8362 /* If the template has a deduced return type, don't expose it to
8363 template argument deduction. */
8367 /* Try to do argument deduction. */
8374 /* Instantiation failed. */
8377 /* Constraints must be satisfied. This is done before
8378 return type deduction since that instantiates the
8379 function. */
8383 /* And now force instantiation to do return type deduction. */
8385 {
8391 }
8393 /* In C++17 we need the noexcept-qualifier to compare types. */
8397 /* See if there's a match. */
8402 }
8404 /* Now, remove all but the most specialized of the matches. */
8406 {
8411 NULL_TREE,
8412 NULL_TREE);
8413 }
8414 }
8416 /* Now we should have exactly one function in MATCHES. */
8418 {
8419 /* There were *no* matches. */
8421 {
8426 }
8428 }
8430 {
8431 /* There were too many matches. First check if they're all
8432 the same function. */
8437 /* For multi-versioned functions, more than one match is just fine and
8438 decls_match will return false as they are different. */
8446 {
8448 {
8452 /* Since print_candidates expects the functions in the
8453 TREE_VALUE slot, we flip them here. */
8458 }
8461 }
8462 }
8464 /* Good, exactly one match. Now, convert it to the correct type. */
8469 {
8475 auto_diagnostic_group d;
8478 {
8482 }
8483 }
8485 /* If a pointer to a function that is multi-versioned is requested, the
8486 pointer to the dispatcher function is returned instead. This works
8487 well because indirectly calling the function will dispatch the right
8488 function version at run-time. */
8490 {
8494 /* Mark all the versions corresponding to the dispatcher as used. */
8497 }
8499 /* If we're doing overload resolution purely for the purpose of
8500 determining conversion sequences, we should not consider the
8501 function used. If this conversion sequence is selected, the
8502 function will be marked as used at this point. */
8504 {
8505 /* Make =delete work with SFINAE. */
8510 }
8512 /* We could not check access to member functions when this
8513 expression was originally created since we did not know at that
8514 time to which function the expression referred. */
8516 {
8519 }
8523 else
8524 {
8525 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
8526 will mark the function as addressed, but here we must do it
8527 explicitly. */
8531 }
8532 }
8534 /* This function will instantiate the type of the expression given in
8535 RHS to match the type of LHSTYPE. If errors exist, then return
8536 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
8537 we complain on errors. If we are not complaining, never modify rhs,
8538 as overload resolution wants to try many possible instantiations, in
8539 the hope that at least one will work.
8541 For non-recursive calls, LHSTYPE should be a function, pointer to
8542 function, or a pointer to member function. */
8544 tree
8546 {
8553 {
8557 }
8560 {
8569 /* Microsoft allows `A::f' to be resolved to a
8570 pointer-to-member. */
8571 ;
8572 else
8573 {
8578 }
8579 }
8581 /* If we instantiate a template, and it is a A ?: C expression
8582 with omitted B, look through the SAVE_EXPR. */
8587 {
8590 }
8592 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
8593 deduce any type information. */
8595 {
8599 }
8601 /* There are only a few kinds of expressions that may have a type
8602 dependent on overload resolution. */
8608 /* This should really only be used when attempting to distinguish
8609 what sort of a pointer to function we have. For now, any
8610 arithmetic operation which is not supported on pointers
8611 is rejected as an error. */
8614 {
8616 {
8622 /* Do not lose object's side effects. */
8626 }
8633 /* This can happen if we are forming a pointer-to-member for a
8634 member template. */
8637 /* Fall through. */
8640 {
8644 return
8648 }
8652 return
8656 access_path);
8659 {
8664 }
8671 }
8673 }
8674 \f
8675 /* Return the name of the virtual function pointer field
8676 (as an IDENTIFIER_NODE) for the given TYPE. Note that
8677 this may have to look back through base types to find the
8678 ultimate field name. (For single inheritance, these could
8679 all be the same name. Who knows for multiple inheritance). */
8681 static tree
8683 {
8689 {
8695 }
8703 }
8705 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
8706 according to [class]:
8707 The class-name is also inserted
8708 into the scope of the class itself. For purposes of access checking,
8709 the inserted class name is treated as if it were a public member name. */
8711 void
8713 {
8730 }
8732 /* Returns 1 if TYPE contains only padding bytes. */
8734 int
8736 {
8744 }
8746 /* Returns true if TYPE contains no actual data, just various
8747 possible combinations of empty classes. If IGNORE_VPTR is true,
8748 a vptr doesn't prevent the class from being considered empty. Typically
8749 we want to ignore the vptr on assignment, and not on initialization. */
8751 bool
8753 {
8755 {
8756 tree field;
8757 tree binfo;
8758 tree base_binfo;
8761 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8762 out, but we'd like to be able to check this before then. */
8776 /* An unnamed bit-field is not a data member. */
8781 }
8786 }
8788 /* Note that NAME was looked up while the current class was being
8789 defined and that the result of that lookup was DECL. */
8791 void
8793 {
8794 splay_tree names_used;
8796 /* If we're not defining a class, there's nothing to do. */
8802 /* If there's already a binding for this NAME, then we don't have
8803 anything to worry about. */
8816 }
8818 /* Note that NAME was declared (as DECL) in the current class. Check
8819 to see that the declaration is valid. */
8821 void
8823 {
8824 splay_tree names_used;
8825 splay_tree_node n;
8827 /* Look to see if we ever used this name. */
8828 names_used
8832 /* The C language allows members to be declared with a type of the same
8833 name, and the C++ standard says this diagnostic is not required. So
8834 allow it in extern "C" blocks unless predantic is specified.
8835 Allow it in all cases if -ms-extensions is specified. */
8841 {
8842 /* [basic.scope.class]
8844 A name N used in a class S shall refer to the same declaration
8845 in its context and when re-evaluated in the completed scope of
8846 S. */
8853 }
8854 }
8856 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8857 Secondary vtables are merged with primary vtables; this function
8858 will return the VAR_DECL for the primary vtable. */
8860 tree
8862 {
8863 tree decl;
8867 {
8870 }
8874 }
8877 /* Returns the binfo for the primary base of BINFO. If the resulting
8878 BINFO is a virtual base, and it is inherited elsewhere in the
8879 hierarchy, then the returned binfo might not be the primary base of
8880 BINFO in the complete object. Check BINFO_PRIMARY_P or
8881 BINFO_LOST_PRIMARY_P to be sure. */
8883 static tree
8885 {
8886 tree primary_base;
8893 }
8895 /* As above, but iterate until we reach the binfo that actually provides the
8896 vptr for BINFO. */
8898 static tree
8900 {
8904 {
8909 }
8911 }
8913 /* Returns true if BINFO gets its vptr from a virtual base of the most derived
8914 type. Note that the virtual inheritance might be above or below BINFO in
8915 the hierarchy. */
8917 bool
8919 {
8923 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is
8924 a morally virtual base. */
8927 }
8929 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8931 static int
8933 {
8937 }
8939 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8940 INDENT should be zero when called from the top level; it is
8941 incremented recursively. IGO indicates the next expected BINFO in
8942 inheritance graph ordering. */
8944 static tree
8946 dump_flags_t flags,
8947 tree binfo,
8948 tree igo,
8950 {
8952 tree base_binfo;
8959 {
8962 }
8976 {
8980 TFF_PLAIN_IDENTIFIER),
8982 }
8984 {
8987 }
8992 {
8996 {
9000 TFF_PLAIN_IDENTIFIER));
9001 }
9003 {
9007 TFF_PLAIN_IDENTIFIER));
9008 }
9010 {
9014 TFF_PLAIN_IDENTIFIER));
9015 }
9017 {
9021 TFF_PLAIN_IDENTIFIER));
9022 }
9026 }
9032 }
9034 /* Dump the BINFO hierarchy for T. */
9036 static void
9038 {
9050 }
9052 /* Debug interface to hierarchy dumping. */
9054 void
9056 {
9058 }
9060 static void
9062 {
9063 dump_flags_t flags;
9065 {
9068 }
9069 }
9071 static void
9073 {
9074 tree value;
9076 HOST_WIDE_INT elt;
9084 TFF_PLAIN_IDENTIFIER));
9091 }
9093 static void
9095 {
9096 dump_flags_t flags;
9103 {
9110 {
9115 }
9119 }
9122 }
9124 static void
9126 {
9127 dump_flags_t flags;
9134 {
9139 }
9142 }
9144 /* Dump a function or thunk and its thunkees. */
9146 static void
9148 {
9151 tree thunks;
9159 {
9169 else
9175 }
9179 }
9181 /* Dump the thunks for FN. */
9183 void
9185 {
9187 }
9189 /* Virtual function table initialization. */
9191 /* Create all the necessary vtables for T and its base classes. */
9193 static void
9195 {
9196 tree vbase;
9200 /* We lay out the primary and secondary vtables in one contiguous
9201 vtable. The primary vtable is first, followed by the non-virtual
9202 secondary vtables in inheritance graph order. */
9206 /* Then come the virtual bases, also in inheritance graph order. */
9208 {
9212 }
9216 }
9218 /* Initialize the vtable for BINFO with the INITS. */
9220 static void
9222 {
9223 tree decl;
9229 }
9231 /* Build the VTT (virtual table table) for T.
9232 A class requires a VTT if it has virtual bases.
9234 This holds
9235 1 - primary virtual pointer for complete object T
9236 2 - secondary VTTs for each direct non-virtual base of T which requires a
9237 VTT
9238 3 - secondary virtual pointers for each direct or indirect base of T which
9239 has virtual bases or is reachable via a virtual path from T.
9240 4 - secondary VTTs for each direct or indirect virtual base of T.
9242 Secondary VTTs look like complete object VTTs without part 4. */
9244 static void
9246 {
9247 tree type;
9248 tree vtt;
9249 tree index;
9252 /* Build up the initializers for the VTT. */
9257 /* If we didn't need a VTT, we're done. */
9261 /* Figure out the type of the VTT. */
9265 /* Now, build the VTT object itself. */
9268 /* Add the VTT to the vtables list. */
9273 }
9275 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
9276 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
9277 and CHAIN the vtable pointer for this binfo after construction is
9278 complete. VALUE can also be another BINFO, in which case we recurse. */
9280 static tree
9282 {
9283 tree vt;
9286 {
9292 else
9294 }
9297 }
9299 /* Data for secondary VTT initialization. */
9300 struct secondary_vptr_vtt_init_data
9301 {
9302 /* Is this the primary VTT? */
9305 /* Current index into the VTT. */
9306 tree index;
9308 /* Vector of initializers built up. */
9311 /* The type being constructed by this secondary VTT. */
9312 tree type_being_constructed;
9313 };
9315 /* Recursively build the VTT-initializer for BINFO (which is in the
9316 hierarchy dominated by T). INITS points to the end of the initializer
9317 list to date. INDEX is the VTT index where the next element will be
9318 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
9319 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
9320 for virtual bases of T. When it is not so, we build the constructor
9321 vtables for the BINFO-in-T variant. */
9323 static void
9326 {
9328 tree b;
9329 tree init;
9330 secondary_vptr_vtt_init_data data;
9333 /* We only need VTTs for subobjects with virtual bases. */
9337 /* We need to use a construction vtable if this is not the primary
9338 VTT. */
9340 {
9343 /* Record the offset in the VTT where this sub-VTT can be found. */
9345 }
9347 /* Add the address of the primary vtable for the complete object. */
9351 {
9354 }
9357 /* Recursively add the secondary VTTs for non-virtual bases. */
9362 /* Add secondary virtual pointers for all subobjects of BINFO with
9363 either virtual bases or reachable along a virtual path, except
9364 subobjects that are non-virtual primary bases. */
9374 /* data.inits might have grown as we added secondary virtual pointers.
9375 Make sure our caller knows about the new vector. */
9379 /* Add the secondary VTTs for virtual bases in inheritance graph
9380 order. */
9382 {
9387 }
9388 else
9389 /* Remove the ctor vtables we created. */
9391 }
9393 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
9394 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
9396 static tree
9398 {
9401 /* We don't care about bases that don't have vtables. */
9405 /* We're only interested in proper subobjects of the type being
9406 constructed. */
9410 /* We're only interested in bases with virtual bases or reachable
9411 via a virtual path from the type being constructed. */
9416 /* We're not interested in non-virtual primary bases. */
9420 /* Record the index where this secondary vptr can be found. */
9422 {
9427 {
9428 /* It's a primary virtual base, and this is not a
9429 construction vtable. Find the base this is primary of in
9430 the inheritance graph, and use that base's vtable
9431 now. */
9434 }
9435 }
9437 /* Add the initializer for the secondary vptr itself. */
9440 /* Advance the vtt index. */
9445 }
9447 /* Called from build_vtt_inits via dfs_walk. After building
9448 constructor vtables and generating the sub-vtt from them, we need
9449 to restore the BINFO_VTABLES that were scribbled on. DATA is the
9450 binfo of the base whose sub vtt was generated. */
9452 static tree
9454 {
9458 /* If this class has no vtable, none of its bases do. */
9462 /* This might be a primary base, so have no vtable in this
9463 hierarchy. */
9466 /* If we scribbled the construction vtable vptr into BINFO, clear it
9467 out now. */
9473 }
9475 /* Build the construction vtable group for BINFO which is in the
9476 hierarchy dominated by T. */
9478 static void
9480 {
9481 tree type;
9482 tree vtbl;
9483 tree id;
9484 tree vbase;
9487 /* See if we've already created this construction vtable group. */
9493 /* Build a version of VTBL (with the wrong type) for use in
9494 constructing the addresses of secondary vtables in the
9495 construction vtable group. */
9498 /* Don't export construction vtables from shared libraries. Even on
9499 targets that don't support hidden visibility, this tells
9500 can_refer_decl_in_current_unit_p not to assume that it's safe to
9501 access from a different compilation unit (bz 54314). */
9509 /* Add the vtables for each of our virtual bases using the vbase in T
9510 binfo. */
9512 vbase;
9514 {
9515 tree b;
9522 }
9524 /* Figure out the type of the construction vtable. */
9531 /* Initialize the construction vtable. */
9535 }
9537 /* Add the vtbl initializers for BINFO (and its bases other than
9538 non-virtual primaries) to the list of INITS. BINFO is in the
9539 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
9540 the constructor the vtbl inits should be accumulated for. (If this
9541 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
9542 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
9543 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
9544 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
9545 but are not necessarily the same in terms of layout. */
9547 static void
9549 tree orig_binfo,
9550 tree rtti_binfo,
9551 tree vtbl,
9552 tree t,
9554 {
9556 tree base_binfo;
9561 /* If it doesn't have a vptr, we don't do anything. */
9565 /* If we're building a construction vtable, we're not interested in
9566 subobjects that don't require construction vtables. */
9572 /* Build the initializers for the BINFO-in-T vtable. */
9575 /* Walk the BINFO and its bases. We walk in preorder so that as we
9576 initialize each vtable we can figure out at what offset the
9577 secondary vtable lies from the primary vtable. We can't use
9578 dfs_walk here because we need to iterate through bases of BINFO
9579 and RTTI_BINFO simultaneously. */
9581 {
9582 /* Skip virtual bases. */
9588 inits);
9589 }
9590 }
9592 /* Called from accumulate_vtbl_inits. Adds the initializers for the
9593 BINFO vtable to L. */
9595 static void
9597 tree orig_binfo,
9598 tree rtti_binfo,
9599 tree orig_vtbl,
9600 tree t,
9602 {
9609 {
9610 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
9611 primary virtual base. If it is not the same primary in
9612 the hierarchy of T, we'll need to generate a ctor vtable
9613 for it, to place at its location in T. If it is the same
9614 primary, we still need a VTT entry for the vtable, but it
9615 should point to the ctor vtable for the base it is a
9616 primary for within the sub-hierarchy of RTTI_BINFO.
9618 There are three possible cases:
9620 1) We are in the same place.
9621 2) We are a primary base within a lost primary virtual base of
9622 RTTI_BINFO.
9623 3) We are primary to something not a base of RTTI_BINFO. */
9625 tree b;
9628 /* First, look through the bases we are primary to for RTTI_BINFO
9629 or a virtual base. */
9632 {
9637 }
9638 /* If we run out of primary links, keep looking down our
9639 inheritance chain; we might be an indirect primary. */
9643 found:
9645 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
9646 base B and it is a base of RTTI_BINFO, this is case 2. In
9647 either case, we share our vtable with LAST, i.e. the
9648 derived-most base within B of which we are a primary. */
9651 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
9652 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
9653 binfo_ctor_vtable after everything's been set up. */
9656 /* Otherwise, this is case 3 and we get our own. */
9657 }
9664 {
9665 tree index;
9668 /* Add the initializer for this vtable. */
9672 /* Figure out the position to which the VPTR should point. */
9678 }
9681 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
9682 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
9683 straighten this out. */
9686 /* Throw away any unneeded intializers. */
9688 else
9689 /* For an ordinary vtable, set BINFO_VTABLE. */
9691 }
9696 /* Construct the initializer for BINFO's virtual function table. BINFO
9697 is part of the hierarchy dominated by T. If we're building a
9698 construction vtable, the ORIG_BINFO is the binfo we should use to
9699 find the actual function pointers to put in the vtable - but they
9700 can be overridden on the path to most-derived in the graph that
9701 ORIG_BINFO belongs. Otherwise,
9702 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
9703 BINFO that should be indicated by the RTTI information in the
9704 vtable; it will be a base class of T, rather than T itself, if we
9705 are building a construction vtable.
9707 The value returned is a TREE_LIST suitable for wrapping in a
9708 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
9709 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
9710 number of non-function entries in the vtable.
9712 It might seem that this function should never be called with a
9713 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
9714 base is always subsumed by a derived class vtable. However, when
9715 we are building construction vtables, we do build vtables for
9716 primary bases; we need these while the primary base is being
9717 constructed. */
9719 static void
9721 tree orig_binfo,
9722 tree t,
9723 tree rtti_binfo,
9726 {
9727 tree v;
9728 vtbl_init_data vid;
9730 tree vbinfo;
9734 /* Initialize VID. */
9742 /* The first vbase or vcall offset is at index -3 in the vtable. */
9745 /* Add entries to the vtable for RTTI. */
9748 /* Create an array for keeping track of the functions we've
9749 processed. When we see multiple functions with the same
9750 signature, we share the vcall offsets. */
9752 /* Add the vcall and vbase offset entries. */
9755 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
9756 build_vbase_offset_vtbl_entries. */
9761 /* If the target requires padding between data entries, add that now. */
9763 {
9769 /* Move data entries into their new positions and add padding
9770 after the new positions. Iterate backwards so we don't
9771 overwrite entries that we would need to process later. */
9774 ix--)
9775 {
9783 {
9787 null_pointer_node);
9788 }
9789 }
9790 }
9795 /* The initializers for virtual functions were built up in reverse
9796 order. Straighten them out and add them to the running list in one
9797 step. */
9806 /* Go through all the ordinary virtual functions, building up
9807 initializers. */
9809 {
9810 tree delta;
9811 tree vcall_index;
9818 {
9822 {
9825 }
9827 }
9829 /* If the only definition of this function signature along our
9830 primary base chain is from a lost primary, this vtable slot will
9831 never be used, so just zero it out. This is important to avoid
9832 requiring extra thunks which cannot be generated with the function.
9834 We first check this in update_vtable_entry_for_fn, so we handle
9835 restored primary bases properly; we also need to do it here so we
9836 zero out unused slots in ctor vtables, rather than filling them
9837 with erroneous values (though harmless, apart from relocation
9838 costs). */
9843 {
9844 /* Pull the offset for `this', and the function to call, out of
9845 the list. */
9852 /* You can't call an abstract virtual function; it's abstract.
9853 So, we replace these functions with __pure_virtual. */
9855 {
9858 {
9860 abort_fndecl_addr
9864 }
9865 }
9866 /* Likewise for deleted virtuals. */
9868 {
9870 {
9874 dvirt_fn = push_library_fn
9878 }
9883 }
9884 else
9885 {
9887 {
9892 }
9893 /* Take the address of the function, considering it to be of an
9894 appropriate generic type. */
9898 /* Don't refer to a virtual destructor from a constructor
9899 vtable or a vtable for an abstract class, since destroying
9900 an object under construction is undefined behavior and we
9901 don't want it to be considered a candidate for speculative
9902 devirtualization. But do create the thunk for ABI
9903 compliance. */
9908 }
9909 }
9911 /* And add it to the chain of initializers. */
9913 {
9918 else
9920 {
9926 }
9927 }
9928 else
9930 }
9931 }
9933 /* Adds to vid->inits the initializers for the vbase and vcall
9934 offsets in BINFO, which is in the hierarchy dominated by T. */
9936 static void
9938 {
9939 tree b;
9941 /* If this is a derived class, we must first create entries
9942 corresponding to the primary base class. */
9947 /* Add the vbase entries for this base. */
9949 /* Add the vcall entries for this base. */
9951 }
9953 /* Returns the initializers for the vbase offset entries in the vtable
9954 for BINFO (which is part of the class hierarchy dominated by T), in
9955 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9956 where the next vbase offset will go. */
9958 static void
9960 {
9961 tree vbase;
9962 tree t;
9963 tree non_primary_binfo;
9965 /* If there are no virtual baseclasses, then there is nothing to
9966 do. */
9972 /* We might be a primary base class. Go up the inheritance hierarchy
9973 until we find the most derived class of which we are a primary base:
9974 it is the offset of that which we need to use. */
9977 {
9978 tree b;
9980 /* If we have reached a virtual base, then it must be a primary
9981 base (possibly multi-level) of vid->binfo, or we wouldn't
9982 have called build_vcall_and_vbase_vtbl_entries for it. But it
9983 might be a lost primary, so just skip down to vid->binfo. */
9985 {
9988 }
9994 }
9996 /* Go through the virtual bases, adding the offsets. */
9998 vbase;
10000 {
10001 tree b;
10002 tree delta;
10007 /* Find the instance of this virtual base in the complete
10008 object. */
10011 /* If we've already got an offset for this virtual base, we
10012 don't need another one. */
10017 /* Figure out where we can find this vbase offset. */
10026 /* The vbase offset had better be the same. */
10029 /* The next vbase will come at a more negative offset. */
10033 /* The initializer is the delta from BINFO to this virtual base.
10034 The vbase offsets go in reverse inheritance-graph order, and
10035 we are walking in inheritance graph order so these end up in
10036 the right order. */
10043 }
10044 }
10046 /* Adds the initializers for the vcall offset entries in the vtable
10047 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
10048 to VID->INITS. */
10050 static void
10052 {
10053 /* We only need these entries if this base is a virtual base. We
10054 compute the indices -- but do not add to the vtable -- when
10055 building the main vtable for a class. */
10058 /* If BINFO is RTTI_BINFO, then (since BINFO does not
10059 correspond to VID->DERIVED), we are building a primary
10060 construction virtual table. Since this is a primary
10061 virtual table, we do not need the vcall offsets for
10062 BINFO. */
10064 {
10065 /* We need a vcall offset for each of the virtual functions in this
10066 vtable. For example:
10068 class A { virtual void f (); };
10069 class B1 : virtual public A { virtual void f (); };
10070 class B2 : virtual public A { virtual void f (); };
10071 class C: public B1, public B2 { virtual void f (); };
10073 A C object has a primary base of B1, which has a primary base of A. A
10074 C also has a secondary base of B2, which no longer has a primary base
10075 of A. So the B2-in-C construction vtable needs a secondary vtable for
10076 A, which will adjust the A* to a B2* to call f. We have no way of
10077 knowing what (or even whether) this offset will be when we define B2,
10078 so we store this "vcall offset" in the A sub-vtable and look it up in
10079 a "virtual thunk" for B2::f.
10081 We need entries for all the functions in our primary vtable and
10082 in our non-virtual bases' secondary vtables. */
10084 /* If we are just computing the vcall indices -- but do not need
10085 the actual entries -- not that. */
10088 /* Now, walk through the non-virtual bases, adding vcall offsets. */
10090 }
10091 }
10093 /* Build vcall offsets, starting with those for BINFO. */
10095 static void
10097 {
10099 tree primary_binfo;
10100 tree base_binfo;
10102 /* Don't walk into virtual bases -- except, of course, for the
10103 virtual base for which we are building vcall offsets. Any
10104 primary virtual base will have already had its offsets generated
10105 through the recursion in build_vcall_and_vbase_vtbl_entries. */
10109 /* If BINFO has a primary base, process it first. */
10114 /* Add BINFO itself to the list. */
10117 /* Scan the non-primary bases of BINFO. */
10121 }
10123 /* Called from build_vcall_offset_vtbl_entries_r. */
10125 static void
10127 {
10128 /* Make entries for the rest of the virtuals. */
10129 tree orig_fn;
10131 /* The ABI requires that the methods be processed in declaration
10132 order. */
10134 orig_fn;
10138 }
10140 /* Add a vcall offset entry for ORIG_FN to the vtable. */
10142 static void
10144 {
10146 tree vcall_offset;
10147 tree derived_entry;
10149 /* If there is already an entry for a function with the same
10150 signature as FN, then we do not need a second vcall offset.
10151 Check the list of functions already present in the derived
10152 class vtable. */
10154 {
10156 /* We only use one vcall offset for virtual destructors,
10157 even though there are two virtual table entries. */
10161 }
10163 /* If we are building these vcall offsets as part of building
10164 the vtable for the most derived class, remember the vcall
10165 offset. */
10167 {
10170 }
10172 /* The next vcall offset will be found at a more negative
10173 offset. */
10177 /* Keep track of this function. */
10181 {
10182 tree base;
10183 tree fn;
10185 /* Find the overriding function. */
10189 else
10190 {
10193 /* The vbase we're working on is a primary base of
10194 vid->binfo. But it might be a lost primary, so its
10195 BINFO_OFFSET might be wrong, so we just use the
10196 BINFO_OFFSET from vid->binfo. */
10202 vcall_offset);
10203 }
10204 /* Add the initializer to the vtable. */
10206 }
10207 }
10209 /* Return vtbl initializers for the RTTI entries corresponding to the
10210 BINFO's vtable. The RTTI entries should indicate the object given
10211 by VID->rtti_binfo. */
10213 static void
10215 {
10216 tree b;
10217 tree t;
10218 tree offset;
10219 tree decl;
10220 tree init;
10224 /* To find the complete object, we will first convert to our most
10225 primary base, and then add the offset in the vtbl to that value. */
10230 /* The second entry is the address of the typeinfo object. */
10233 else
10236 /* Convert the declaration to a type that can be stored in the
10237 vtable. */
10241 /* Add the offset-to-top entry. It comes earlier in the vtable than
10242 the typeinfo entry. Convert the offset to look like a
10243 function pointer, so that we can put it in the vtable. */
10246 }
10248 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
10249 accessibility. */
10251 bool
10253 {
10256 }
10258 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
10260 bool
10262 {
10266 }
10268 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
10269 class between them, if any. */
10271 tree
10273 {
10285 {
10288 }
10292 }