| blob | 34d10ba5cde6bd15cd17820ad3069c3761e5ed01 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2016 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. */
40 /* The number of nested classes being processed. If we are not in the
41 scope of any class, this is zero. */
45 /* In order to deal with nested classes, we keep a stack of classes.
46 The topmost entry is the innermost class, and is the entry at index
47 CURRENT_CLASS_DEPTH */
50 /* The name of the class. */
51 tree name;
53 /* The _TYPE node for the class. */
54 tree type;
56 /* The access specifier pending for new declarations in the scope of
57 this class. */
58 tree access;
60 /* If were defining TYPE, the names used in this class. */
61 splay_tree names_used;
63 /* Nonzero if this class is no longer open, because of a call to
64 push_to_top_level. */
68 struct vtbl_init_data
69 {
70 /* The base for which we're building initializers. */
71 tree binfo;
72 /* The type of the most-derived type. */
73 tree derived;
74 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
75 unless ctor_vtbl_p is true. */
76 tree rtti_binfo;
77 /* The negative-index vtable initializers built up so far. These
78 are in order from least negative index to most negative index. */
80 /* The binfo for the virtual base for which we're building
81 vcall offset initializers. */
82 tree vbase;
83 /* The functions in vbase for which we have already provided vcall
84 offsets. */
86 /* The vtable index of the next vcall or vbase offset. */
87 tree index;
88 /* Nonzero if we are building the initializer for the primary
89 vtable. */
91 /* Nonzero if we are building the initializer for a construction
92 vtable. */
94 /* True when adding vcall offset entries to the vtable. False when
95 merely computing the indices. */
97 };
99 /* The type of a function passed to walk_subobject_offsets. */
102 /* The stack itself. This is a dynamically resized array. The
103 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
107 /* The size of the largest empty class seen in this translation unit. */
110 /* An array of all local classes present in this translation unit, in
111 declaration order. */
150 /* Used by find_flexarrays and related. */
200 tree *);
210 splay_tree_key k2);
219 /* Variables shared between class.c and call.c. */
229 /* Return a COND_EXPR that executes TRUE_STMT if this execution of the
230 'structor is in charge of 'structing virtual bases, or FALSE_STMT
231 otherwise. */
233 tree
235 {
245 }
247 /* Convert to or from a base subobject. EXPR is an expression of type
248 `A' or `A*', an expression of type `B' or `B*' is returned. To
249 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
250 the B base instance within A. To convert base A to derived B, CODE
251 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
252 In this latter case, A must not be a morally virtual base of B.
253 NONNULL is true if EXPR is known to be non-NULL (this is only
254 needed when EXPR is of pointer type). CV qualifiers are preserved
255 from EXPR. */
257 tree
259 tree expr,
260 tree binfo,
262 tsubst_flags_t complain)
263 {
266 tree probe;
267 tree offset;
268 tree target_type;
270 tree ptr_target_type;
281 {
287 }
295 {
296 /* This can happen when adjust_result_of_qualified_name_lookup can't
297 find a unique base binfo in a call to a member function. We
298 couldn't give the diagnostic then since we might have been calling
299 a static member function, so we do it now. In other cases, eg.
300 during error recovery (c++/71979), we may not have a base at all. */
302 {
306 }
308 }
315 /* Nothing to do. */
319 {
321 {
323 {
326 "pointer to derived class %qT because the base is "
328 else
332 }
333 else
334 {
340 else
344 }
345 }
347 }
350 {
352 /* This must happen before the call to save_expr. */
354 }
355 else
361 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
362 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
363 expression returned matches the input. */
364 target_type = cp_build_qualified_type
368 /* Do we need to look in the vtable for the real offset? */
371 /* Don't bother with the calculations inside sizeof; they'll ICE if the
372 source type is incomplete and the pointer value doesn't matter. In a
373 template (even in instantiate_non_dependent_expr), we don't have vtables
374 set up properly yet, and the value doesn't matter there either; we're
375 just interested in the result of overload resolution. */
378 {
381 }
383 /* If we're in an NSDMI, we don't have the full constructor context yet
384 that we need for converting to a virtual base, so just build a stub
385 CONVERT_EXPR and expand it later in bot_replace. */
388 {
392 }
394 /* Do we need to check for a null pointer? */
396 {
397 /* If we know the conversion will not actually change the value
398 of EXPR, then we can avoid testing the expression for NULL.
399 We have to avoid generating a COMPONENT_REF for a base class
400 field, because other parts of the compiler know that such
401 expressions are always non-NULL. */
405 }
407 /* Protect against multiple evaluation if necessary. */
411 /* Now that we've saved expr, build the real null test. */
413 {
417 /* This is a compiler generated comparison, don't emit
418 e.g. -Wnonnull-compare warning for it. */
420 }
422 /* If this is a simple base reference, express it as a COMPONENT_REF. */
424 /* We don't build base fields for empty bases, and they aren't very
425 interesting to the optimizers anyway. */
427 {
436 }
439 {
440 /* Going via virtual base V_BINFO. We need the static offset
441 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
442 V_BINFO. That offset is an entry in D_BINFO's vtable. */
443 tree v_offset;
446 {
447 /* In a base member initializer, we cannot rely on the
448 vtable being set up. We have to indirect via the
449 vtt_parm. */
450 tree t;
456 }
457 else
458 {
461 {
466 }
468 complain),
470 }
478 v_offset);
490 /* Negative fixed_type_p means this is a constructor or destructor;
491 virtual base layout is fixed in in-charge [cd]tors, but not in
492 base [cd]tors. */
493 offset = build_if_in_charge
495 v_offset);
496 else
498 }
506 {
511 }
512 else
515 indout:
517 {
521 }
523 out:
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 static 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 tree
733 {
737 }
739 /* Given a stable object pointer INSTANCE_PTR, return an expression which
740 yields a function pointer corresponding to vtable element INDEX. */
742 tree
744 {
745 tree aref;
748 tf_warning_or_error),
749 idx);
751 /* When using function descriptors, the address of the
752 vtable entry is treated as a function pointer. */
757 /* Remember this as a method reference, for later devirtualization. */
761 }
763 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
764 for the given TYPE. */
766 static tree
768 {
770 }
772 /* DECL is an entity associated with TYPE, like a virtual table or an
773 implicitly generated constructor. Determine whether or not DECL
774 should have external or internal linkage at the object file
775 level. This routine does not deal with COMDAT linkage and other
776 similar complexities; it simply sets TREE_PUBLIC if it possible for
777 entities in other translation units to contain copies of DECL, in
778 the abstract. */
780 void
782 {
785 }
787 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
788 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
789 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
791 static tree
793 {
794 tree decl;
797 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
798 now to avoid confusion in mangle_decl. */
809 /* The vtable has not been defined -- yet. */
813 /* Mark the VAR_DECL node representing the vtable itself as a
814 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
815 is rather important that such things be ignored because any
816 effort to actually generate DWARF for them will run into
817 trouble when/if we encounter code like:
819 #pragma interface
820 struct S { virtual void member (); };
822 because the artificial declaration of the vtable itself (as
823 manufactured by the g++ front end) will say that the vtable is
824 a static member of `S' but only *after* the debug output for
825 the definition of `S' has already been output. This causes
826 grief because the DWARF entry for the definition of the vtable
827 will try to refer back to an earlier *declaration* of the
828 vtable as a static member of `S' and there won't be one. We
829 might be able to arrange to have the "vtable static member"
830 attached to the member list for `S' before the debug info for
831 `S' get written (which would solve the problem) but that would
832 require more intrusive changes to the g++ front end. */
836 }
838 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
839 or even complete. If this does not exist, create it. If COMPLETE is
840 nonzero, then complete the definition of it -- that will render it
841 impossible to actually build the vtable, but is useful to get at those
842 which are known to exist in the runtime. */
844 tree
846 {
847 tree decl;
856 {
859 }
862 }
864 /* Build the primary virtual function table for TYPE. If BINFO is
865 non-NULL, build the vtable starting with the initial approximation
866 that it is the same as the one which is the head of the association
867 list. Returns a nonzero value if a new vtable is actually
868 created. */
870 static int
872 {
873 tree decl;
874 tree virtuals;
879 {
881 /* We have already created a vtable for this base, so there's
882 no need to do it again. */
889 }
890 else
891 {
894 }
897 {
900 }
902 /* Initialize the association list for this type, based
903 on our first approximation. */
908 }
910 /* Give BINFO a new virtual function table which is initialized
911 with a skeleton-copy of its original initialization. The only
912 entry that changes is the `delta' entry, so we can really
913 share a lot of structure.
915 FOR_TYPE is the most derived type which caused this table to
916 be needed.
918 Returns nonzero if we haven't met BINFO before.
920 The order in which vtables are built (by calling this function) for
921 an object must remain the same, otherwise a binary incompatibility
922 can result. */
924 static int
926 {
928 /* We already created a vtable for this base. There's no need to
929 do it again. */
932 /* Remember that we've created a vtable for this BINFO, so that we
933 don't try to do so again. */
936 /* Make fresh virtual list, so we can smash it later. */
939 /* Secondary vtables are laid out as part of the same structure as
940 the primary vtable. */
943 }
945 /* Create a new vtable for BINFO which is the hierarchy dominated by
946 T. Return nonzero if we actually created a new vtable. */
948 static int
950 {
952 /* In this case, it is *type*'s vtable we are modifying. We start
953 with the approximation that its vtable is that of the
954 immediate base class. */
956 else
957 /* This is our very own copy of `basetype' to play with. Later,
958 we will fill in all the virtual functions that override the
959 virtual functions in these base classes which are not defined
960 by the current type. */
962 }
964 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
965 (which is in the hierarchy dominated by T) list FNDECL as its
966 BV_FN. DELTA is the required constant adjustment from the `this'
967 pointer where the vtable entry appears to the `this' required when
968 the function is actually called. */
970 static void
972 tree binfo,
973 tree fndecl,
974 tree delta,
976 {
977 tree v;
983 {
984 /* We need a new vtable for BINFO. */
986 {
987 /* If we really did make a new vtable, we also made a copy
988 of the BINFO_VIRTUALS list. Now, we have to find the
989 corresponding entry in that list. */
994 }
999 }
1000 }
1002 \f
1003 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
1004 the USING_DECL naming METHOD. Returns true if the method could be
1005 added to the method vec. */
1007 bool
1009 {
1011 tree overload;
1017 tree current_fns;
1018 tree fns;
1031 {
1032 /* Make a new method vector. We start with 8 entries. We must
1033 allocate at least two (for constructors and destructors), and
1034 we're going to end up with an assignment operator at some
1035 point as well. */
1037 /* Create slots for constructors and destructors. */
1041 }
1043 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1046 /* Constructors and destructors go in special slots. */
1051 else
1052 {
1053 tree m;
1056 /* See if we already have an entry with this name. */
1060 {
1063 {
1068 }
1072 {
1075 }
1080 }
1081 }
1084 /* Check to see if we've already got this method. */
1086 {
1088 tree fn_type;
1089 tree method_type;
1090 tree parms1;
1091 tree parms2;
1096 /* [over.load] Member function declarations with the
1097 same name and the same parameter types cannot be
1098 overloaded if any of them is a static member
1099 function declaration.
1101 [over.load] Member function declarations with the same name and
1102 the same parameter-type-list as well as member function template
1103 declarations with the same name, the same parameter-type-list, and
1104 the same template parameter lists cannot be overloaded if any of
1105 them, but not all, have a ref-qualifier.
1107 [namespace.udecl] When a using-declaration brings names
1108 from a base class into a derived class scope, member
1109 functions in the derived class override and/or hide member
1110 functions with the same name and parameter types in a base
1111 class (rather than conflicting). */
1117 /* Compare the quals on the 'this' parm. Don't compare
1118 the whole types, as used functions are treated as
1119 coming from the using class in overload resolution. */
1122 /* Either both or neither need to be ref-qualified for
1123 differing quals to allow overloading. */
1130 /* For templates, the return type and template parameters
1131 must be identical. */
1149 {
1150 /* For function versions, their parms and types match
1151 but they are not duplicates. Record function versions
1152 as and when they are found. extern "C" functions are
1153 not treated as versions. */
1159 {
1160 /* Mark functions as versions if necessary. Modify the mangled
1161 decl name if necessary. */
1163 {
1167 }
1169 {
1173 }
1176 }
1178 {
1180 {
1187 }
1188 /* Otherwise defer to the other function. */
1190 }
1192 {
1194 /* Defer to the local function. */
1196 }
1197 else
1198 {
1201 }
1203 /* We don't call duplicate_decls here to merge the
1204 declarations because that will confuse things if the
1205 methods have inline definitions. In particular, we
1206 will crash while processing the definitions. */
1208 }
1209 }
1211 /* A class should never have more than one destructor. */
1215 /* Add the new binding. */
1217 {
1220 }
1221 else
1230 {
1233 /* We only expect to add few methods in the COMPLETE_P case, so
1234 just make room for one more method in that case. */
1237 else
1243 else
1245 }
1246 else
1247 /* Replace the current slot. */
1250 }
1252 /* Subroutines of finish_struct. */
1254 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1255 legit, otherwise return 0. */
1257 static int
1259 {
1260 tree elem;
1269 {
1271 {
1275 else
1278 }
1279 else
1280 {
1281 /* They're changing the access to the same thing they changed
1282 it to before. That's OK. */
1283 ;
1284 }
1285 }
1286 else
1287 {
1289 tf_warning_or_error);
1292 }
1294 }
1296 /* Process the USING_DECL, which is a member of T. */
1298 static void
1300 {
1303 tree access
1308 tree old_value;
1313 tf_warning_or_error);
1315 {
1321 else
1323 }
1331 ;
1333 {
1335 /* It's OK to use functions from a base when there are functions with
1337 else
1338 {
1343 }
1344 }
1346 {
1350 }
1352 /* Make type T see field decl FDECL with access ACCESS. */
1355 {
1358 }
1359 else
1361 }
1362 \f
1363 /* Data structure for find_abi_tags_r, below. */
1365 struct abi_tag_data
1366 {
1370 };
1372 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1373 in the context of P. TAG can be either an identifier (the DECL_NAME of
1374 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1376 static void
1378 {
1380 {
1382 {
1383 /* We're collecting tags from template arguments or from
1384 the type of a variable or function return type. */
1387 /* Don't inherit this tag multiple times. */
1391 {
1392 /* Tags inherited from type template arguments are only used
1393 to avoid warnings. */
1396 }
1397 /* For functions and variables we want to warn, too. */
1398 }
1400 /* Otherwise we're diagnosing missing tags. */
1402 {
1407 }
1409 {
1413 }
1415 {
1420 }
1421 else
1422 {
1426 {
1430 }
1431 }
1432 }
1433 }
1435 /* Find all the ABI tags in the attribute list ATTR and either call
1436 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1438 static void
1440 {
1447 {
1452 else
1454 }
1455 }
1457 /* Find all the ABI tags on T and its enclosing scopes and either call
1458 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1460 static void
1462 {
1464 {
1465 tree attr;
1467 {
1470 }
1471 else
1472 {
1475 }
1477 }
1478 }
1480 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1481 types with ABI tags, add the corresponding identifiers to the VEC in
1482 *DATA and set IDENTIFIER_MARKED. */
1484 static tree
1486 {
1490 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1491 anyway, but let's make sure of it. */
1499 }
1501 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1502 IDENTIFIER_MARKED on its ABI tags. */
1504 static tree
1506 {
1510 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1511 anyway, but let's make sure of it. */
1519 }
1521 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1522 scopes. */
1524 static void
1526 {
1529 {
1532 {
1533 /* Template arguments are part of the signature. */
1536 {
1539 }
1540 }
1542 /* A function's parameter types are part of the signature, so
1543 we don't need to inherit any tags that are also in them. */
1548 }
1549 }
1551 /* Check that T has all the ABI tags that subobject SUBOB has, or
1552 warn if not. If T is a (variable or function) declaration, also
1553 return any missing tags, and add them to T if JUST_CHECKING is false. */
1555 static tree
1557 {
1565 /* No need to worry about things local to this TU. */
1581 {
1584 }
1585 else
1586 {
1590 else
1594 }
1599 }
1601 /* Check that DECL has all the ABI tags that are used in parts of its type
1602 that are not reflected in its mangled name. */
1604 void
1606 {
1613 }
1615 /* Return any ABI tags that are used in parts of the type of DECL
1616 that are not reflected in its mangled name. This function is only
1617 used in backward-compatible mangling for ABI <11. */
1619 tree
1621 {
1625 /* Don't check DECL_CONV_FN_P here like we do in check_abi_tags, so
1626 that we can use this function for setting need_abi_warning
1627 regardless of the current flag_abi_version. */
1630 else
1632 }
1634 void
1636 {
1646 {
1649 {
1653 }
1654 }
1656 // If we found some tags on our template arguments, add them to our
1657 // abi_tag attribute.
1659 {
1663 else
1667 }
1670 }
1672 /* Return true, iff class T has a non-virtual destructor that is
1673 accessible from outside the class heirarchy (i.e. is public, or
1674 there's a suitable friend. */
1676 static bool
1678 {
1681 /* An implicitly declared destructor is always public. And,
1682 if it were virtual, we would have created it by now. */
1697 }
1699 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1700 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1701 properties of the bases. */
1703 static void
1707 {
1711 tree base_binfo;
1712 tree binfo;
1722 {
1731 /* If any base class is non-literal, so is the derived class. */
1735 /* If the base class doesn't have copy constructors or
1736 assignment operators that take const references, then the
1737 derived class cannot have such a member automatically
1738 generated. */
1747 /* A virtual base does not effect nearly emptiness. */
1748 ;
1750 {
1752 /* And if there is more than one nearly empty base, then the
1753 derived class is not nearly empty either. */
1755 else
1756 /* Remember we've seen one. */
1758 }
1760 /* If the base class is not empty or nearly empty, then this
1761 class cannot be nearly empty. */
1764 /* A lot of properties from the bases also apply to the derived
1765 class. */
1782 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1785 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1791 /* A standard-layout class is a class that:
1792 ...
1793 * has no non-standard-layout base classes, */
1796 {
1797 tree basefield;
1798 /* ...has no base classes of the same type as the first non-static
1799 data member... */
1801 && (same_type_ignoring_top_level_qualifiers_p
1804 else
1805 /* ...either has no non-static data members in the most-derived
1806 class and at most one base class with non-static data
1807 members, or has no base classes with non-static data
1808 members */
1812 {
1815 else
1818 }
1819 }
1821 /* Don't bother collecting tm attributes if transactional memory
1822 support is not enabled. */
1824 {
1828 }
1831 }
1833 /* If one of the base classes had TM attributes, and the current class
1834 doesn't define its own, then the current class inherits one. */
1836 {
1839 }
1840 }
1842 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1843 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1844 that have had a nearly-empty virtual primary base stolen by some
1845 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1846 T. */
1848 static void
1850 {
1854 tree base_binfo;
1856 /* Determine the primary bases of our bases. */
1859 {
1862 /* See if we're the non-virtual primary of our inheritance
1863 chain. */
1865 {
1872 /* We are the primary binfo. */
1874 }
1875 /* Determine if we have a virtual primary base, and mark it so.
1876 */
1878 {
1882 /* Someone already claimed this base. */
1884 else
1885 {
1886 tree delta;
1891 /* A virtual binfo might have been copied from within
1892 another hierarchy. As we're about to use it as a
1893 primary base, make sure the offsets match. */
1901 }
1902 }
1903 }
1905 /* First look for a dynamic direct non-virtual base. */
1907 {
1911 {
1914 }
1915 }
1917 /* A "nearly-empty" virtual base class can be the primary base
1918 class, if no non-virtual polymorphic base can be found. Look for
1919 a nearly-empty virtual dynamic base that is not already a primary
1920 base of something in the hierarchy. If there is no such base,
1921 just pick the first nearly-empty virtual base. */
1927 {
1929 {
1930 /* Found one that is not primary. */
1933 }
1935 /* Remember the first candidate. */
1937 }
1939 found:
1940 /* If we've got a primary base, use it. */
1942 {
1947 /* We are stealing a primary base. */
1951 {
1952 tree delta;
1955 /* A virtual binfo might have been copied from within
1956 another hierarchy. As we're about to use it as a primary
1957 base, make sure the offsets match. */
1962 }
1969 }
1970 }
1972 /* Update the variant types of T. */
1974 void
1976 {
1977 tree variants;
1983 variants;
1985 {
1986 /* These fields are in the _TYPE part of the node, not in
1987 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1997 /* Copy whatever these are holding today. */
2000 }
2001 }
2003 /* KLASS is a class that we're applying may_alias to after the body is
2004 parsed. Fixup any POINTER_TO and REFERENCE_TO types. The
2005 canonical type(s) will be implicitly updated. */
2007 static void
2009 {
2010 tree t;
2016 }
2018 /* Early variant fixups: we apply attributes at the beginning of the class
2019 definition, and we need to fix up any variants that have already been
2020 made via elaborated-type-specifier so that check_qualified_type works. */
2022 void
2024 {
2025 tree variants;
2039 variants;
2041 {
2042 /* These are the two fields that check_qualified_type looks at and
2043 are affected by attributes. */
2048 else
2053 }
2054 }
2055 \f
2056 /* Set memoizing fields and bits of T (and its variants) for later
2057 use. */
2059 static void
2061 {
2062 /* Fix up variants (if any). */
2066 /* For a class w/o baseclasses, 'finish_struct' has set
2067 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2068 Similarly for a class whose base classes do not have vtables.
2069 When neither of these is true, we might have removed abstract
2070 virtuals (by providing a definition), added some (by declaring
2071 new ones), or redeclared ones from a base class. We need to
2072 recalculate what's really an abstract virtual at this point (by
2073 looking in the vtables). */
2076 /* If this type has a copy constructor or a destructor, force its
2077 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2078 nonzero. This will cause it to be passed by invisible reference
2079 and prevent it from being returned in a register. */
2082 {
2083 tree variants;
2086 {
2089 }
2090 }
2091 }
2093 /* Issue warnings about T having private constructors, but no friends,
2094 and so forth.
2096 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2097 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2098 non-private static member functions. */
2100 static void
2102 {
2105 tree fn;
2108 /* If the class has friends, those entities might create and
2109 access instances, so we should not warn. */
2112 /* We will have warned when the template was declared; there's
2113 no need to warn on every instantiation. */
2115 /* There's no reason to even consider warning about this
2116 class. */
2119 /* We only issue one warning, if more than one applies, because
2120 otherwise, on code like:
2122 class A {
2123 // Oops - forgot `public:'
2124 A();
2125 A(const A&);
2126 ~A();
2127 };
2129 we warn several times about essentially the same problem. */
2131 /* Check to see if all (non-constructor, non-destructor) member
2132 functions are private. (Since there are no friends or
2133 non-private statics, we can't ever call any of the private member
2134 functions.) */
2136 /* We're not interested in compiler-generated methods; they don't
2137 provide any way to call private members. */
2139 {
2141 {
2143 /* A non-private static member function is just like a
2144 friend; it can create and invoke private member
2145 functions, and be accessed without a class
2146 instance. */
2150 /* Keep searching for a static member function. */
2151 }
2154 }
2157 {
2158 /* There are no non-private methods, and there's at least one
2159 private member function that isn't a constructor or
2160 destructor. (If all the private members are
2161 constructors/destructors we want to use the code below that
2162 issues error messages specifically referring to
2163 constructors/destructors.) */
2169 {
2172 }
2174 {
2178 }
2179 }
2181 /* Even if some of the member functions are non-private, the class
2182 won't be useful for much if all the constructors or destructors
2183 are private: such an object can never be created or destroyed. */
2186 {
2189 t);
2191 }
2193 /* Warn about classes that have private constructors and no friends. */
2195 /* Implicitly generated constructors are always public. */
2198 {
2201 /* If a non-template class does not define a copy
2202 constructor, one is defined for it, enabling it to avoid
2203 this warning. For a template class, this does not
2204 happen, and so we would normally get a warning on:
2206 template <class T> class C { private: C(); };
2208 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2209 complete non-template or fully instantiated classes have this
2210 flag set. */
2213 else
2215 {
2217 /* Ideally, we wouldn't count copy constructors (or, in
2218 fact, any constructor that takes an argument of the
2219 class type as a parameter) because such things cannot
2220 be used to construct an instance of the class unless
2221 you already have one. But, for now at least, we're
2222 more generous. */
2224 {
2227 }
2228 }
2231 {
2234 t);
2236 }
2237 }
2238 }
2241 gt_pointer_operator new_value;
2245 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2247 static int
2249 {
2262 }
2264 /* This routine compares two fields like method_name_cmp but using the
2265 pointer operator in resort_field_decl_data. */
2267 static int
2269 {
2278 {
2285 }
2287 }
2289 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2291 void
2294 gt_pointer_operator new_value,
2296 {
2300 tree fn;
2302 /* The type conversion ops have to live at the front of the vec, so we
2303 can't sort them. */
2311 {
2315 resort_method_name_cmp);
2316 }
2317 }
2319 /* Warn about duplicate methods in fn_fields.
2321 Sort methods that are not special (i.e., constructors, destructors,
2322 and type conversion operators) so that we can find them faster in
2323 search. */
2325 static void
2327 {
2328 tree fn_fields;
2338 /* Clear DECL_IN_AGGR_P for all functions. */
2343 /* Issue warnings about private constructors and such. If there are
2344 no methods, then some public defaults are generated. */
2347 /* The type conversion ops have to live at the front of the vec, so we
2348 can't sort them. */
2357 }
2359 /* Make BINFO's vtable have N entries, including RTTI entries,
2360 vbase and vcall offsets, etc. Set its type and call the back end
2361 to lay it out. */
2363 static void
2365 {
2366 tree atype;
2367 tree vtable;
2372 /* We may have to grow the vtable. */
2375 {
2379 }
2380 }
2382 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2383 have the same signature. */
2385 int
2387 {
2388 /* One destructor overrides another if they are the same kind of
2389 destructor. */
2393 /* But a non-destructor never overrides a destructor, nor vice
2394 versa, nor do different kinds of destructors override
2395 one-another. For example, a complete object destructor does not
2396 override a deleting destructor. */
2405 {
2413 }
2415 }
2417 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2418 subobject. */
2420 static bool
2422 {
2423 tree probe;
2426 {
2430 /* If we meet a virtual base, we can't follow the inheritance
2431 any more. See if the complete type of DERIVED contains
2432 such a virtual base. */
2435 }
2437 }
2440 /* The function for which we are trying to find a final overrider. */
2441 tree fn;
2442 /* The base class in which the function was declared. */
2443 tree declaring_base;
2444 /* The candidate overriders. */
2445 tree candidates;
2446 /* Path to most derived. */
2448 };
2450 /* Add the overrider along the current path to FFOD->CANDIDATES.
2451 Returns true if an overrider was found; false otherwise. */
2453 static bool
2457 {
2458 tree method;
2460 /* If BINFO is not the most derived type, try a more derived class.
2461 A definition there will overrider a definition here. */
2463 {
2464 depth--;
2468 }
2472 {
2475 /* Remove any candidates overridden by this new function. */
2477 {
2478 /* If *CANDIDATE overrides METHOD, then METHOD
2479 cannot override anything else on the list. */
2482 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2485 else
2487 }
2489 /* Add the new function. */
2492 }
2495 }
2497 /* Called from find_final_overrider via dfs_walk. */
2499 static tree
2501 {
2509 }
2511 static tree
2513 {
2518 }
2520 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2521 FN and whose TREE_VALUE is the binfo for the base where the
2522 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2523 DERIVED) is the base object in which FN is declared. */
2525 static tree
2527 {
2528 find_final_overrider_data ffod;
2530 /* Getting this right is a little tricky. This is valid:
2532 struct S { virtual void f (); };
2533 struct T { virtual void f (); };
2534 struct U : public S, public T { };
2536 even though calling `f' in `U' is ambiguous. But,
2538 struct R { virtual void f(); };
2539 struct S : virtual public R { virtual void f (); };
2540 struct T : virtual public R { virtual void f (); };
2541 struct U : public S, public T { };
2543 is not -- there's no way to decide whether to put `S::f' or
2544 `T::f' in the vtable for `R'.
2546 The solution is to look at all paths to BINFO. If we find
2547 different overriders along any two, then there is a problem. */
2551 /* Determine the depth of the hierarchy. */
2562 /* If there was no winner, issue an error message. */
2567 }
2569 /* Return the index of the vcall offset for FN when TYPE is used as a
2570 virtual base. */
2572 static tree
2574 {
2576 tree_pair_p p;
2584 /* There should always be an appropriate index. */
2586 }
2588 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2589 dominated by T. FN is the old function; VIRTUALS points to the
2590 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2591 of that entry in the list. */
2593 static void
2596 {
2597 tree b;
2598 tree overrider;
2599 tree delta;
2600 tree virtual_base;
2601 tree first_defn;
2607 /* Find the nearest primary base (possibly binfo itself) which defines
2608 this function; this is the class the caller will convert to when
2609 calling FN through BINFO. */
2611 {
2616 /* The nearest definition is from a lost primary. */
2619 }
2622 /* Find the final overrider. */
2625 {
2628 }
2631 /* Check for adjusting covariant return types. */
2639 /* If the overrider is invalid, don't even try. */
2641 {
2642 /* If FN is a covariant thunk, we must figure out the adjustment
2643 to the final base FN was converting to. As OVERRIDER_TARGET might
2644 also be converting to the return type of FN, we have to
2645 combine the two conversions here. */
2652 {
2656 }
2657 else
2661 /* Find the equivalent binfo within the return type of the
2662 overriding function. We will want the vbase offset from
2663 there. */
2665 over_return);
2668 {
2669 /* There was no existing virtual thunk (which takes
2670 precedence). So find the binfo of the base function's
2671 return type within the overriding function's return type.
2672 Fortunately we know the covariancy is valid (it
2673 has already been checked), so we can just iterate along
2674 the binfos, which have been chained in inheritance graph
2675 order. Of course it is lame that we have to repeat the
2676 search here anyway -- we should really be caching pieces
2677 of the vtable and avoiding this repeated work. */
2680 /* Find the base binfo within the overriding function's
2681 return type. We will always find a thunk_binfo, except
2682 when the covariancy is invalid (which we will have
2683 already diagnosed). */
2686 thunk_binfo;
2692 /* See if virtual inheritance is involved. */
2694 virtual_offset;
2701 {
2705 {
2706 /* We convert via virtual base. Adjust the fixed
2707 offset to be from there. */
2708 offset =
2712 }
2714 /* There was an existing fixed offset, this must be
2715 from the base just converted to, and the base the
2716 FN was thunking to. */
2718 else
2720 }
2721 }
2724 /* Replace the overriding function with a covariant thunk. We
2725 will emit the overriding function in its own slot as
2726 well. */
2729 }
2730 else
2734 /* If we need a covariant thunk, then we may need to adjust first_defn.
2735 The ABI specifies that the thunks emitted with a function are
2736 determined by which bases the function overrides, so we need to be
2737 sure that we're using a thunk for some overridden base; even if we
2738 know that the necessary this adjustment is zero, there may not be an
2739 appropriate zero-this-adjusment thunk for us to use since thunks for
2740 overriding virtual bases always use the vcall offset.
2742 Furthermore, just choosing any base that overrides this function isn't
2743 quite right, as this slot won't be used for calls through a type that
2744 puts a covariant thunk here. Calling the function through such a type
2745 will use a different slot, and that slot is the one that determines
2746 the thunk emitted for that base.
2748 So, keep looking until we find the base that we're really overriding
2749 in this slot: the nearest primary base that doesn't use a covariant
2750 thunk in this slot. */
2752 {
2754 /* We already know that the overrider needs a covariant thunk. */
2757 {
2764 }
2766 }
2768 /* Assume that we will produce a thunk that convert all the way to
2769 the final overrider, and not to an intermediate virtual base. */
2772 /* See if we can convert to an intermediate virtual base first, and then
2773 use the vcall offset located there to finish the conversion. */
2775 {
2776 /* If we find the final overrider, then we can stop
2777 walking. */
2782 /* If we find a virtual base, and we haven't yet found the
2783 overrider, then there is a virtual base between the
2784 declaring base (first_defn) and the final overrider. */
2786 {
2789 }
2790 }
2792 /* Compute the constant adjustment to the `this' pointer. The
2793 `this' pointer, when this function is called, will point at BINFO
2794 (or one of its primary bases, which are at the same offset). */
2796 /* The `this' pointer needs to be adjusted from the declaration to
2797 the nearest virtual base. */
2802 /* If the nearest definition is in a lost primary, we don't need an
2803 entry in our vtable. Except possibly in a constructor vtable,
2804 if we happen to get our primary back. In that case, the offset
2805 will be zero, as it will be a primary base. */
2807 else
2808 /* The `this' pointer needs to be adjusted from pointing to
2809 BINFO to pointing at the base where the final overrider
2810 appears. */
2821 else
2825 }
2827 /* Called from modify_all_vtables via dfs_walk. */
2829 static tree
2831 {
2833 tree virtuals;
2834 tree old_virtuals;
2838 /* A base without a vtable needs no modification, and its bases
2839 are uninteresting. */
2844 /* Don't do the primary vtable, if it's new. */
2848 /* There's no need to modify the vtable for a non-virtual primary
2849 base; we're not going to use that vtable anyhow. We do still
2850 need to do this for virtual primary bases, as they could become
2851 non-primary in a construction vtable. */
2856 /* Now, go through each of the virtual functions in the virtual
2857 function table for BINFO. Find the final overrider, and update
2858 the BINFO_VIRTUALS list appropriately. */
2861 virtuals;
2865 binfo,
2870 }
2872 /* Update all of the primary and secondary vtables for T. Create new
2873 vtables as required, and initialize their RTTI information. Each
2874 of the functions in VIRTUALS is declared in T and may override a
2875 virtual function from a base class; find and modify the appropriate
2876 entries to point to the overriding functions. Returns a list, in
2877 declaration order, of the virtual functions that are declared in T,
2878 but do not appear in the primary base class vtable, and which
2879 should therefore be appended to the end of the vtable for T. */
2881 static tree
2883 {
2887 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2891 /* Update all of the vtables. */
2894 /* Add virtual functions not already in our primary vtable. These
2895 will be both those introduced by this class, and those overridden
2896 from secondary bases. It does not include virtuals merely
2897 inherited from secondary bases. */
2899 {
2904 {
2905 /* We don't need to adjust the `this' pointer when
2906 calling this function. */
2910 /* This is a function not already in our vtable. Keep it. */
2912 }
2913 else
2914 /* We've already got an entry for this function. Skip it. */
2916 }
2919 }
2921 /* Get the base virtual function declarations in T that have the
2922 indicated NAME. */
2924 static void
2926 {
2927 tree methods;
2931 /* Find virtual functions in T with the indicated NAME. */
2936 methods;
2938 {
2943 {
2946 }
2947 }
2953 {
2956 }
2957 }
2959 /* If this declaration supersedes the declaration of
2960 a method declared virtual in the base class, then
2961 mark this field as being virtual as well. */
2963 void
2965 {
2968 /* In [temp.mem] we have:
2970 A specialization of a member function template does not
2971 override a virtual function from a base class. */
2978 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2979 the error_mark_node so that we know it is an overriding
2980 function. */
2981 {
2988 }
2991 {
2997 }
3002 }
3004 /* Warn about hidden virtual functions that are not overridden in t.
3005 We know that constructors and destructors don't apply. */
3007 static void
3009 {
3011 tree fns;
3014 /* We go through each separately named virtual function. */
3018 {
3019 tree fn;
3020 tree name;
3021 tree fndecl;
3022 tree base_binfo;
3023 tree binfo;
3026 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
3027 have the same name. Figure out what name that is. */
3029 /* There are no possibly hidden functions yet. */
3031 /* Iterate through all of the base classes looking for possibly
3032 hidden functions. */
3035 {
3038 }
3040 /* If there are no functions to hide, continue. */
3044 /* Remove any overridden functions. */
3046 {
3050 {
3051 /* If the method from the base class has the same
3052 signature as the method from the derived class, it
3053 has been overridden. */
3058 }
3059 }
3061 /* Now give a warning for all base functions without overriders,
3062 as they are hidden. */
3064 tree base_fndecl;
3067 {
3068 /* Here we know it is a hider, and no overrider exists. */
3070 OPT_Woverloaded_virtual,
3074 }
3075 }
3076 }
3078 /* Recursive helper for finish_struct_anon. */
3080 static void
3082 {
3086 {
3087 /* We're generally only interested in entities the user
3088 declared, but we also find nested classes by noticing
3089 the TYPE_DECL that we create implicitly. You're
3090 allowed to put one anonymous union inside another,
3091 though, so we explicitly tolerate that. We use
3092 TYPE_UNNAMED_P rather than ANON_AGGR_TYPE_P so that
3093 we also allow unnamed types used for defining fields. */
3100 {
3101 /* We already complained about static data members in
3102 finish_static_data_member_decl. */
3104 {
3107 "%q#D invalid; an anonymous union can "
3109 else
3111 "%q#D invalid; an anonymous struct can "
3113 }
3115 }
3118 {
3120 {
3124 else
3127 }
3129 {
3133 else
3136 }
3137 }
3142 /* Recurse into the anonymous aggregates to handle correctly
3143 access control (c++/24926):
3145 class A {
3146 union {
3147 union {
3148 int i;
3149 };
3150 };
3151 };
3153 int j=A().i; */
3157 }
3158 }
3160 /* Check for things that are invalid. There are probably plenty of other
3161 things we should check for also. */
3163 static void
3165 {
3167 {
3176 }
3177 }
3179 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3180 will be used later during class template instantiation.
3181 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3182 a non-static member data (FIELD_DECL), a member function
3183 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3184 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3185 When FRIEND_P is nonzero, T is either a friend class
3186 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3187 (FUNCTION_DECL, TEMPLATE_DECL). */
3189 void
3191 {
3192 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3197 }
3199 /* This function is called from declare_virt_assop_and_dtor via
3200 dfs_walk_all.
3202 DATA is a type that direcly or indirectly inherits the base
3203 represented by BINFO. If BINFO contains a virtual assignment [copy
3204 assignment or move assigment] operator or a virtual constructor,
3205 declare that function in DATA if it hasn't been already declared. */
3207 static tree
3209 {
3217 /* A base without a vtable needs no modification, and its bases
3218 are uninteresting. */
3222 /* If this is a primary base, then we have already looked at the
3223 virtual functions of its vtable. */
3227 {
3231 {
3236 }
3240 }
3243 }
3245 /* If the class type T has a direct or indirect base that contains a
3246 virtual assignment operator or a virtual destructor, declare that
3247 function in T if it hasn't been already declared. */
3249 static void
3251 {
3259 dfs_declare_virt_assop_and_dtor,
3261 }
3263 /* Declare the inheriting constructor for class T inherited from base
3264 constructor CTOR with the parameter array PARMS of size NPARMS. */
3266 static void
3268 {
3269 /* We don't declare an inheriting ctor that would be a default,
3270 copy or move ctor for derived or base. */
3275 {
3279 }
3288 {
3291 }
3292 }
3294 /* Declare all the inheriting constructors for class T inherited from base
3295 constructor CTOR. */
3297 static void
3299 {
3305 {
3309 }
3312 {
3316 }
3317 }
3319 /* Create default constructors, assignment operators, and so forth for
3320 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3321 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3322 the class cannot have a default constructor, copy constructor
3323 taking a const reference argument, or an assignment operator taking
3324 a const reference, respectively. */
3326 static void
3330 {
3338 /* Destructor. */
3340 /* In general, we create destructors lazily. */
3343 /* [class.ctor]
3345 If there is no user-declared constructor for a class, a default
3346 constructor is implicitly declared. */
3348 {
3353 /* Don't force the declaration to get a hard answer; if the
3354 definition would have made the class non-literal, it will still be
3355 non-literal because of the base or member in question, and that
3356 gives a better diagnostic. */
3358 }
3360 /* [class.ctor]
3362 If a class definition does not explicitly declare a copy
3363 constructor, one is declared implicitly. */
3365 {
3371 }
3373 /* If there is no assignment operator, one will be created if and
3374 when it is needed. For now, just record whether or not the type
3375 of the parameter to the assignment operator will be a const or
3376 non-const reference. */
3378 {
3384 }
3386 /* We can't be lazy about declaring functions that might override
3387 a virtual function from a base class. */
3391 {
3395 {
3396 /* declare, then remove the decl */
3405 }
3406 else
3408 }
3409 }
3411 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3412 count the number of fields in TYPE, including anonymous union
3413 members. */
3415 static int
3417 {
3418 tree x;
3421 {
3424 else
3426 }
3428 }
3430 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3431 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3432 elts, starting at offset IDX. */
3434 static int
3436 {
3437 tree x;
3439 {
3442 else
3444 }
3446 }
3448 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3449 starting at offset IDX. */
3451 static int
3455 {
3456 tree values;
3460 }
3462 /* FIELD is a bit-field. We are finishing the processing for its
3463 enclosing type. Issue any appropriate messages and set appropriate
3464 flags. Returns false if an error has been diagnosed. */
3466 static bool
3468 {
3470 tree w;
3472 /* Extract the declared width of the bitfield, which has been
3473 temporarily stashed in DECL_INITIAL. */
3476 /* Remove the bit-field width indicator so that the rest of the
3477 compiler does not treat that value as an initializer. */
3480 /* Detect invalid bit-field type. */
3482 {
3485 }
3486 else
3487 {
3489 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3492 /* detect invalid field size. */
3498 {
3501 }
3503 {
3506 }
3508 {
3511 }
3526 }
3529 {
3533 }
3534 else
3535 {
3536 /* Non-bit-fields are aligned for their type. */
3540 }
3541 }
3543 /* FIELD is a non bit-field. We are finishing the processing for its
3544 enclosing type T. Issue any appropriate messages and set appropriate
3545 flags. */
3547 static bool
3549 tree t,
3552 {
3556 /* In C++98 an anonymous union cannot contain any fields which would change
3557 the settings of CANT_HAVE_CONST_CTOR and friends. */
3559 ;
3560 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3561 structs. So, we recurse through their fields here. */
3563 {
3568 cant_have_const_ctor,
3569 no_const_asn_ref);
3570 }
3571 /* Check members with class type for constructors, destructors,
3572 etc. */
3574 {
3575 /* Never let anything with uninheritable virtuals
3576 make it through without complaint. */
3580 {
3585 field);
3590 field);
3592 {
3596 }
3597 }
3598 else
3599 {
3612 }
3621 }
3626 /* `build_class_init_list' does not recognize
3627 non-FIELD_DECLs. */
3631 }
3633 /* Check the data members (both static and non-static), class-scoped
3634 typedefs, etc., appearing in the declaration of T. Issue
3635 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3636 declaration order) of access declarations; each TREE_VALUE in this
3637 list is a USING_DECL.
3639 In addition, set the following flags:
3641 EMPTY_P
3642 The class is empty, i.e., contains no non-static data members.
3644 CANT_HAVE_CONST_CTOR_P
3645 This class cannot have an implicitly generated copy constructor
3646 taking a const reference.
3648 CANT_HAVE_CONST_ASN_REF
3649 This class cannot have an implicitly generated assignment
3650 operator taking a const reference.
3652 All of these flags should be initialized before calling this
3653 function.
3655 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3656 fields can be added by adding to this chain. */
3658 static void
3662 {
3670 /* Assume there are no access declarations. */
3672 /* Assume this class has no pointer members. */
3674 /* Assume none of the members of this class have default
3675 initializations. */
3679 {
3687 {
3688 /* Save the access declarations for our caller. */
3691 }
3697 /* If we've gotten this far, it's a data member, possibly static,
3698 or an enumerator. */
3702 /* When this goes into scope, it will be a non-local reference. */
3707 {
3708 /* [class.union] (C++98)
3710 If a union contains a static data member, or a member of
3711 reference type, the program is ill-formed.
3713 In C++11 this limitation doesn't exist anymore. */
3715 {
3719 }
3721 {
3725 }
3726 }
3728 /* Perform error checking that did not get done in
3729 grokdeclarator. */
3731 {
3735 }
3737 {
3741 }
3749 /* Now it can only be a FIELD_DECL. */
3754 /* If at least one non-static data member is non-literal, the whole
3755 class becomes non-literal. Per Core/1453, volatile non-static
3756 data members and base classes are also not allowed.
3757 Note: if the type is incomplete we will complain later on. */
3762 /* A standard-layout class is a class that:
3763 ...
3764 has the same access control (Clause 11) for all non-static data members,
3765 ... */
3772 /* If this is of reference type, check if it needs an init. */
3774 {
3780 {
3781 /* ARM $12.6.2: [A member initializer list] (or, for an
3782 aggregate, initialization by a brace-enclosed list) is the
3783 only way to initialize nonstatic const and reference
3784 members. */
3787 }
3788 }
3793 {
3795 {
3796 warning_at
3799 x);
3801 }
3805 }
3808 /* We don't treat zero-width bitfields as making a class
3809 non-empty. */
3810 ;
3811 else
3812 {
3813 /* The class is non-empty. */
3815 /* The class is not even nearly empty. */
3817 /* If one of the data members contains an empty class,
3818 so does T. */
3822 }
3824 /* This is used by -Weffc++ (see below). Warn only for pointers
3825 to members which might hold dynamic memory. So do not warn
3826 for pointers to functions or pointers to members. */
3832 {
3837 }
3843 {
3845 {
3849 }
3851 {
3855 }
3856 }
3859 /* DR 148 now allows pointers to members (which are POD themselves),
3860 to be allowed in POD structs. */
3869 /* We set DECL_C_BIT_FIELD in grokbitfield.
3870 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3873 cant_have_const_ctor_p,
3874 no_const_asn_ref_p))
3875 {
3880 }
3882 /* Now that we've removed bit-field widths from DECL_INITIAL,
3883 anything left in DECL_INITIAL is an NSDMI that makes the class
3884 non-aggregate in C++11. */
3888 /* If any field is const, the structure type is pseudo-const. */
3890 {
3895 {
3896 /* ARM $12.6.2: [A member initializer list] (or, for an
3897 aggregate, initialization by a brace-enclosed list) is the
3898 only way to initialize nonstatic const and reference
3899 members. */
3902 }
3903 }
3904 /* A field that is pseudo-const makes the structure likewise. */
3906 {
3911 }
3913 /* Core issue 80: A nonstatic data member is required to have a
3914 different name from the class iff the class has a
3915 user-declared constructor. */
3920 }
3922 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3923 it should also define a copy constructor and an assignment operator to
3924 implement the correct copy semantic (deep vs shallow, etc.). As it is
3925 not feasible to check whether the constructors do allocate dynamic memory
3926 and store it within members, we approximate the warning like this:
3928 -- Warn only if there are members which are pointers
3929 -- Warn only if there is a non-trivial constructor (otherwise,
3930 there cannot be memory allocated).
3931 -- Warn only if there is a non-trivial destructor. We assume that the
3932 user at least implemented the cleanup correctly, and a destructor
3933 is needed to free dynamic memory.
3935 This seems enough for practical purposes. */
3937 && has_pointers
3941 {
3945 {
3950 }
3954 }
3956 /* Non-static data member initializers make the default constructor
3957 non-trivial. */
3959 {
3962 }
3964 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3968 /* Check anonymous struct/anonymous union fields. */
3971 /* We've built up the list of access declarations in reverse order.
3972 Fix that now. */
3974 }
3976 /* If TYPE is an empty class type, records its OFFSET in the table of
3977 OFFSETS. */
3979 static int
3981 {
3982 splay_tree_node n;
3987 /* Record the location of this empty object in OFFSETS. */
3995 type,
3999 }
4001 /* Returns nonzero if TYPE is an empty class type and there is
4002 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
4004 static int
4006 {
4007 splay_tree_node n;
4008 tree t;
4013 /* Record the location of this empty object in OFFSETS. */
4023 }
4025 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
4026 F for every subobject, passing it the type, offset, and table of
4027 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
4028 be traversed.
4030 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
4031 than MAX_OFFSET will not be walked.
4033 If F returns a nonzero value, the traversal ceases, and that value
4034 is returned. Otherwise, returns zero. */
4036 static int
4038 subobject_offset_fn f,
4039 tree offset,
4040 splay_tree offsets,
4041 tree max_offset,
4043 {
4047 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
4048 stop. */
4056 {
4059 }
4062 {
4063 tree field;
4064 tree binfo;
4067 /* Avoid recursing into objects that are not interesting. */
4071 /* Record the location of TYPE. */
4076 /* Iterate through the direct base classes of TYPE. */
4080 {
4081 tree binfo_offset;
4086 tree orig_binfo;
4087 /* We cannot rely on BINFO_OFFSET being set for the base
4088 class yet, but the offsets for direct non-virtual
4089 bases can be calculated by going back to the TYPE. */
4092 offset,
4096 f,
4097 binfo_offset,
4098 offsets,
4099 max_offset,
4103 }
4106 {
4110 /* Iterate through the virtual base classes of TYPE. In G++
4111 3.2, we included virtual bases in the direct base class
4112 loop above, which results in incorrect results; the
4113 correct offsets for virtual bases are only known when
4114 working with the most derived type. */
4118 {
4120 f,
4122 offset,
4124 offsets,
4125 max_offset,
4129 }
4130 else
4131 {
4132 /* We still have to walk the primary base, if it is
4133 virtual. (If it is non-virtual, then it was walked
4134 above.) */
4140 {
4141 r = (walk_subobject_offsets
4146 }
4147 }
4148 }
4150 /* Iterate through the fields of TYPE. */
4155 {
4156 tree field_offset;
4161 f,
4163 offset,
4164 field_offset),
4165 offsets,
4166 max_offset,
4170 }
4171 }
4173 {
4176 tree index;
4178 /* Avoid recursing into objects that are not interesting. */
4181 || !domain
4185 /* Step through each of the elements in the array. */
4189 {
4191 f,
4192 offset,
4193 offsets,
4194 max_offset,
4200 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4201 there's no point in iterating through the remaining
4202 elements of the array. */
4205 }
4206 }
4209 }
4211 /* Record all of the empty subobjects of TYPE (either a type or a
4212 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4213 is being placed at OFFSET; otherwise, it is a base class that is
4214 being placed at OFFSET. */
4216 static void
4218 tree offset,
4219 splay_tree offsets,
4221 {
4222 tree max_offset;
4223 /* If recording subobjects for a non-static data member or a
4224 non-empty base class , we do not need to record offsets beyond
4225 the size of the biggest empty class. Additional data members
4226 will go at the end of the class. Additional base classes will go
4227 either at offset zero (if empty, in which case they cannot
4228 overlap with offsets past the size of the biggest empty class) or
4229 at the end of the class.
4231 However, if we are placing an empty base class, then we must record
4232 all offsets, as either the empty class is at offset zero (where
4233 other empty classes might later be placed) or at the end of the
4234 class (where other objects might then be placed, so other empty
4235 subobjects might later overlap). */
4239 else
4243 }
4245 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4246 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4247 virtual bases of TYPE are examined. */
4249 static int
4251 tree offset,
4252 splay_tree offsets,
4254 {
4255 splay_tree_node max_node;
4257 /* Get the node in OFFSETS that indicates the maximum offset where
4258 an empty subobject is located. */
4260 /* If there aren't any empty subobjects, then there's no point in
4261 performing this check. */
4267 vbases_p);
4268 }
4270 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4271 non-static data member of the type indicated by RLI. BINFO is the
4272 binfo corresponding to the base subobject, OFFSETS maps offsets to
4273 types already located at those offsets. This function determines
4274 the position of the DECL. */
4276 static void
4278 tree decl,
4279 tree binfo,
4280 splay_tree offsets)
4281 {
4284 tree type;
4287 {
4288 /* For the purposes of determining layout conflicts, we want to
4289 use the class type of BINFO; TREE_TYPE (DECL) will be the
4290 CLASSTYPE_AS_BASE version, which does not contain entries for
4291 zero-sized bases. */
4294 }
4295 else
4296 {
4299 }
4301 /* Try to place the field. It may take more than one try if we have
4302 a hard time placing the field without putting two objects of the
4303 same type at the same address. */
4305 {
4308 /* Place this field. */
4312 /* We have to check to see whether or not there is already
4313 something of the same type at the offset we're about to use.
4314 For example, consider:
4316 struct S {};
4317 struct T : public S { int i; };
4318 struct U : public S, public T {};
4320 Here, we put S at offset zero in U. Then, we can't put T at
4321 offset zero -- its S component would be at the same address
4322 as the S we already allocated. So, we have to skip ahead.
4323 Since all data members, including those whose type is an
4324 empty class, have nonzero size, any overlap can happen only
4325 with a direct or indirect base-class -- it can't happen with
4326 a data member. */
4327 /* In a union, overlap is permitted; all members are placed at
4328 offset zero. */
4333 {
4334 /* Strip off the size allocated to this field. That puts us
4335 at the first place we could have put the field with
4336 proper alignment. */
4339 /* Bump up by the alignment required for the type. */
4340 rli->bitpos
4346 }
4349 {
4350 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4351 the offset wasn't aligned like a pointer when we started to
4352 layout this field, that affects its position. */
4355 {
4358 "alignment of %qD increased in -fabi-version=9 "
4360 else
4363 }
4365 }
4366 else
4367 /* There was no conflict. We're done laying out this field. */
4369 }
4371 /* Now that we know where it will be placed, update its
4372 BINFO_OFFSET. */
4374 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4375 this point because their BINFO_OFFSET is copied from another
4376 hierarchy. Therefore, we may not need to add the entire
4377 OFFSET. */
4383 }
4385 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4387 static int
4389 tree offset,
4391 {
4393 }
4395 /* Layout the empty base BINFO. EOC indicates the byte currently just
4396 past the end of the class, and should be correctly aligned for a
4397 class of the type indicated by BINFO; OFFSETS gives the offsets of
4398 the empty bases allocated so far. T is the most derived
4399 type. Return nonzero iff we added it at the end. */
4401 static bool
4404 {
4405 tree alignment;
4409 /* This routine should only be used for empty classes. */
4414 propagate_binfo_offsets
4418 /* This is an empty base class. We first try to put it at offset
4419 zero. */
4422 offsets,
4424 {
4425 /* That didn't work. Now, we move forward from the next
4426 available spot in the class. */
4430 {
4433 offsets,
4435 /* We finally found a spot where there's no overlap. */
4438 /* There's overlap here, too. Bump along to the next spot. */
4440 }
4441 }
4444 {
4449 }
4452 }
4454 /* Layout the base given by BINFO in the class indicated by RLI.
4455 *BASE_ALIGN is a running maximum of the alignments of
4456 any base class. OFFSETS gives the location of empty base
4457 subobjects. T is the most derived type. Return nonzero if the new
4458 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4459 *NEXT_FIELD, unless BINFO is for an empty base class.
4461 Returns the location at which the next field should be inserted. */
4466 {
4471 /* This error is now reported in xref_tag, thus giving better
4472 location information. */
4475 /* Place the base class. */
4477 {
4478 tree decl;
4480 /* The containing class is non-empty because it has a non-empty
4481 base class. */
4484 /* Create the FIELD_DECL. */
4491 {
4499 /* Try to place the field. It may take more than one try if we
4500 have a hard time placing the field without putting two
4501 objects of the same type at the same address. */
4503 /* Add the new FIELD_DECL to the list of fields for T. */
4507 }
4508 }
4509 else
4510 {
4511 tree eoc;
4514 /* On some platforms (ARM), even empty classes will not be
4515 byte-aligned. */
4520 /* A nearly-empty class "has no proper base class that is empty,
4521 not morally virtual, and at an offset other than zero." */
4523 {
4526 /* The check above (used in G++ 3.2) is insufficient because
4527 an empty class placed at offset zero might itself have an
4528 empty base at a nonzero offset. */
4530 empty_base_at_nonzero_offset_p,
4531 size_zero_node,
4536 }
4538 /* We do not create a FIELD_DECL for empty base classes because
4539 it might overlap some other field. We want to be able to
4540 create CONSTRUCTORs for the class by iterating over the
4541 FIELD_DECLs, and the back end does not handle overlapping
4542 FIELD_DECLs. */
4544 /* An empty virtual base causes a class to be non-empty
4545 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4546 here because that was already done when the virtual table
4547 pointer was created. */
4548 }
4550 /* Record the offsets of BINFO and its base subobjects. */
4553 offsets,
4557 }
4559 /* Layout all of the non-virtual base classes. Record empty
4560 subobjects in OFFSETS. T is the most derived type. Return nonzero
4561 if the type cannot be nearly empty. The fields created
4562 corresponding to the base classes will be inserted at
4563 *NEXT_FIELD. */
4565 static void
4568 {
4569 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4570 subobjects. */
4575 /* The primary base class is always allocated first. */
4580 /* Now allocate the rest of the bases. */
4582 {
4583 tree base_binfo;
4587 /* The primary base was already allocated above, so we don't
4588 need to allocate it again here. */
4592 /* Virtual bases are added at the end (a primary virtual base
4593 will have already been added). */
4599 }
4600 }
4602 /* Go through the TYPE_METHODS of T issuing any appropriate
4603 diagnostics, figuring out which methods override which other
4604 methods, and so forth. */
4606 static void
4608 {
4609 tree x;
4612 {
4616 /* The name of the field is the original field name
4617 Save this in auxiliary field for later overloading. */
4619 {
4623 }
4624 /* All user-provided destructors are non-trivial.
4625 Constructors and assignment ops are handled in
4626 grok_special_member_properties. */
4632 "%<transaction_safe_dynamic%> may only be specified for "
4634 }
4635 }
4637 /* FN is a constructor or destructor. Clone the declaration to create
4638 a specialized in-charge or not-in-charge version, as indicated by
4639 NAME. */
4641 static tree
4643 {
4644 tree parms;
4645 tree clone;
4647 /* Copy the function. */
4649 /* Reset the function name. */
4651 /* Remember where this function came from. */
4653 /* Make it easy to find the CLONE given the FN. */
4657 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4659 {
4666 }
4667 else
4668 {
4669 // Clone constraints.
4673 }
4678 /* There's no pending inline data for this function. */
4682 /* The base-class destructor is not virtual. */
4684 {
4688 }
4690 /* If there was an in-charge parameter, drop it from the function
4691 type. */
4693 {
4694 tree basetype;
4695 tree parmtypes;
4696 tree exceptions;
4701 /* Skip the `this' parameter. */
4703 /* Skip the in-charge parameter. */
4705 /* And the VTT parm, in a complete [cd]tor. */
4709 /* If this is subobject constructor or destructor, add the vtt
4710 parameter. */
4714 parmtypes);
4717 exceptions);
4721 }
4723 /* Copy the function parameters. */
4725 /* Remove the in-charge parameter. */
4727 {
4731 }
4732 /* And the VTT parm, in a complete [cd]tor. */
4734 {
4737 else
4738 {
4742 }
4743 }
4746 {
4749 }
4751 /* Create the RTL for this function. */
4756 }
4758 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4759 not invoke this function directly.
4761 For a non-thunk function, returns the address of the slot for storing
4762 the function it is a clone of. Otherwise returns NULL_TREE.
4764 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4765 cloned_function is unset. This is to support the separate
4766 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4767 on a template makes sense, but not the former. */
4769 tree *
4771 {
4779 {
4780 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4783 else
4784 #endif
4786 }
4791 else
4793 }
4795 /* Produce declarations for all appropriate clones of FN. If
4796 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4797 CLASTYPE_METHOD_VEC as well. */
4799 void
4801 {
4802 tree clone;
4804 /* Avoid inappropriate cloning. */
4810 {
4811 /* For each constructor, we need two variants: an in-charge version
4812 and a not-in-charge version. */
4819 }
4820 else
4821 {
4824 /* For each destructor, we need three variants: an in-charge
4825 version, a not-in-charge version, and an in-charge deleting
4826 version. We clone the deleting version first because that
4827 means it will go second on the TYPE_METHODS list -- and that
4828 corresponds to the correct layout order in the virtual
4829 function table.
4831 For a non-virtual destructor, we do not build a deleting
4832 destructor. */
4834 {
4838 }
4845 }
4847 /* Note that this is an abstract function that is never emitted. */
4849 }
4851 /* DECL is an in charge constructor, which is being defined. This will
4852 have had an in class declaration, from whence clones were
4853 declared. An out-of-class definition can specify additional default
4854 arguments. As it is the clones that are involved in overload
4855 resolution, we must propagate the information from the DECL to its
4856 clones. */
4858 void
4860 {
4861 tree clone;
4865 {
4872 /* Skip the 'this' parameter. */
4888 {
4893 {
4894 /* A default parameter has been added. Adjust the
4895 clone's parameters. */
4899 tree type;
4904 {
4907 clone_parms);
4909 }
4912 clone_parms);
4921 }
4922 }
4924 }
4925 }
4927 /* For each of the constructors and destructors in T, create an
4928 in-charge and not-in-charge variant. */
4930 static void
4932 {
4933 tree fns;
4935 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4936 out now. */
4944 }
4946 /* Deduce noexcept for a destructor DTOR. */
4948 void
4950 {
4952 {
4955 }
4956 }
4958 /* For each destructor in T, deduce noexcept:
4960 12.4/3: A declaration of a destructor that does not have an
4961 exception-specification is implicitly considered to have the
4962 same exception-specification as an implicit declaration (15.4). */
4964 static void
4966 {
4967 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4968 out now. */
4974 }
4976 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4977 of TYPE for virtual functions which FNDECL overrides. Return a
4978 mask of the tm attributes found therein. */
4980 static int
4982 {
4984 tree base_binfo;
4988 {
4996 {
5000 else
5003 }
5004 else
5006 }
5009 }
5011 /* Subroutine of set_method_tm_attributes. Handle the checks and
5012 inheritance for one virtual method FNDECL. */
5014 static void
5016 {
5017 tree tm_attr;
5022 /* If FNDECL doesn't actually override anything (i.e. T is the
5023 class that first declares FNDECL virtual), then we're done. */
5030 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
5031 tm_pure must match exactly, otherwise no weakening of
5032 tm_safe > tm_callable > nothing. */
5033 /* ??? The tm_pure attribute didn't make the transition to the
5034 multivendor language spec. */
5036 {
5038 {
5041 }
5042 }
5043 /* If the overridden function is tm_pure, then FNDECL must be. */
5046 /* Look for base class combinations that cannot be satisfied. */
5048 {
5054 }
5055 /* If FNDECL did not declare an attribute, then inherit the most
5056 restrictive one. */
5058 {
5060 }
5061 /* Otherwise validate that we're not weaker than a function
5062 that is being overridden. */
5063 else
5064 {
5068 }
5071 err_override:
5075 }
5077 /* For each of the methods in T, propagate a class-level tm attribute. */
5079 static void
5081 {
5084 /* Don't bother collecting tm attributes if transactional memory
5085 support is not enabled. */
5089 /* Process virtual methods first, as they inherit directly from the
5090 base virtual function and also require validation of new attributes. */
5092 {
5093 tree vchain;
5096 {
5101 }
5102 }
5104 /* If the class doesn't have an attribute, nothing more to do. */
5109 /* Any method that does not yet have a tm attribute inherits
5110 the one from the class. */
5112 {
5115 }
5116 }
5118 /* Returns true if FN is a default constructor. */
5120 bool
5122 {
5125 }
5127 /* Returns true iff class T has a user-defined constructor that can be called
5128 with more than zero arguments. */
5130 bool
5132 {
5133 tree fns;
5139 {
5146 }
5149 }
5151 /* Returns the defaulted constructor if T has one. Otherwise, returns
5152 NULL_TREE. */
5154 tree
5156 {
5161 {
5167 }
5170 }
5172 /* Returns true iff FN is a user-provided function, i.e. user-declared
5173 and not defaulted at its first declaration. */
5175 bool
5177 {
5180 else
5184 }
5186 /* Returns true iff class T has a user-provided constructor. */
5188 bool
5190 {
5191 tree fns;
5199 /* This can happen in error cases; avoid crashing. */
5208 }
5210 /* Returns true iff class T has a user-provided or explicit constructor. */
5212 bool
5214 {
5215 tree fns;
5223 /* This can happen in error cases; avoid crashing. */
5228 {
5232 }
5235 }
5237 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5238 declared or explicitly defaulted in the class body) default
5239 constructor. */
5241 bool
5243 {
5244 tree fns;
5252 {
5258 }
5261 }
5263 /* TYPE is being used as a virtual base, and has a non-trivial move
5264 assignment. Return true if this is due to there being a user-provided
5265 move assignment in TYPE or one of its subobjects; if there isn't, then
5266 multiple move assignment can't cause any harm. */
5268 bool
5270 {
5271 /* Does the type itself have a user-provided move assignment operator? */
5275 {
5279 }
5281 /* Do any of its bases? */
5283 tree base_binfo;
5288 /* Or non-static data members? */
5290 {
5295 }
5297 /* Seems not. */
5299 }
5301 /* If default-initialization leaves part of TYPE uninitialized, returns
5302 a DECL for the field or TYPE itself (DR 253). */
5304 tree
5306 {
5317 {
5321 }
5326 {
5330 }
5333 }
5335 /* Returns true iff for class T, a trivial synthesized default constructor
5336 would be constexpr. */
5338 bool
5340 {
5341 /* A defaulted trivial default constructor is constexpr
5342 if there is nothing to initialize. */
5345 }
5347 /* Returns true iff class T has a constexpr default constructor. */
5349 bool
5351 {
5352 tree fns;
5355 {
5356 /* The caller should have stripped an enclosing array. */
5359 }
5361 {
5364 /* Non-trivial, we need to check subobject constructors. */
5366 }
5369 }
5371 /* Returns true iff class T has a constexpr default constructor or has an
5372 implicitly declared default constructor that we can't tell if it's constexpr
5373 without forcing a lazy declaration (which might cause undesired
5374 instantiations). */
5376 bool
5378 {
5381 /* Assume it's constexpr. */
5384 }
5386 /* Returns true iff class TYPE has a virtual destructor. */
5388 bool
5390 {
5391 tree dtor;
5399 }
5401 /* Returns true iff class T has a move constructor. */
5403 bool
5405 {
5406 tree fns;
5409 {
5412 }
5422 }
5424 /* Returns true iff class T has a move assignment operator. */
5426 bool
5428 {
5429 tree fns;
5432 {
5435 }
5443 }
5445 /* Returns true iff class T has a move constructor that was explicitly
5446 declared in the class body. Note that this is different from
5447 "user-provided", which doesn't include functions that are defaulted in
5448 the class. */
5450 bool
5452 {
5453 tree fns;
5462 {
5466 }
5469 }
5471 /* Returns true iff class T has a move assignment operator that was
5472 explicitly declared in the class body. */
5474 bool
5476 {
5477 tree fns;
5484 {
5488 }
5491 }
5493 /* Nonzero if we need to build up a constructor call when initializing an
5494 object of this class, either because it has a user-declared constructor
5495 or because it doesn't have a default constructor (so we need to give an
5496 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5497 what you care about is whether or not an object can be produced by a
5498 constructor (e.g. so we don't set TREE_READONLY on const variables of
5499 such type); use this function when what you care about is whether or not
5500 to try to call a constructor to create an object. The latter case is
5501 the former plus some cases of constructors that cannot be called. */
5503 bool
5505 {
5506 tree inner;
5516 /* A user-declared constructor might be private, and a constructor might
5517 be trivial but deleted. */
5520 {
5525 }
5527 }
5529 /* Like type_build_ctor_call, but for destructors. */
5531 bool
5533 {
5534 tree inner;
5543 /* A user-declared destructor might be private, and a destructor might
5544 be trivial but deleted. */
5547 {
5552 }
5554 }
5556 /* Remove all zero-width bit-fields from T. */
5558 static void
5560 {
5565 {
5568 /* We should not be confused by the fact that grokbitfield
5569 temporarily sets the width of the bit field into
5570 DECL_INITIAL (*fieldsp).
5571 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5572 to that width. */
5576 else
5578 }
5579 }
5581 /* Returns TRUE iff we need a cookie when dynamically allocating an
5582 array whose elements have the indicated class TYPE. */
5584 static bool
5586 {
5587 tree fns;
5592 /* If there's a non-trivial destructor, we need a cookie. In order
5593 to iterate through the array calling the destructor for each
5594 element, we'll have to know how many elements there are. */
5598 /* If the usual deallocation function is a two-argument whose second
5599 argument is of type `size_t', then we have to pass the size of
5600 the array to the deallocation function, so we will need to store
5601 a cookie. */
5605 /* If there are no `operator []' members, or the lookup is
5606 ambiguous, then we don't need a cookie. */
5609 /* Loop through all of the functions. */
5611 {
5612 tree fn;
5613 tree second_parm;
5615 /* Select the current function. */
5617 /* See if this function is a one-argument delete function. If
5618 it is, then it will be the usual deallocation function. */
5622 /* Do not consider this function if its second argument is an
5623 ellipsis. */
5626 /* Otherwise, if we have a two-argument function and the second
5627 argument is `size_t', it will be the usual deallocation
5628 function -- unless there is one-argument function, too. */
5632 }
5635 }
5637 /* Finish computing the `literal type' property of class type T.
5639 At this point, we have already processed base classes and
5640 non-static data members. We need to check whether the copy
5641 constructor is trivial, the destructor is trivial, and there
5642 is a trivial default constructor or at least one constexpr
5643 constructor other than the copy constructor. */
5645 static void
5647 {
5648 tree fn;
5664 {
5667 {
5671 }
5672 }
5673 }
5675 /* T is a non-literal type used in a context which requires a constant
5676 expression. Explain why it isn't literal. */
5678 void
5680 {
5690 /* Already explained. */
5699 {
5701 "default constructor, and has no constexpr constructor that "
5704 {
5705 /* Note that we can't simply call locate_ctor because when the
5706 constructor is deleted it just returns NULL_TREE. */
5707 tree fns;
5709 {
5716 {
5719 else
5722 }
5723 }
5724 }
5725 }
5726 else
5727 {
5731 {
5734 {
5739 }
5740 }
5742 {
5743 tree ftype;
5748 {
5751 field);
5754 }
5758 }
5759 }
5760 }
5762 /* Check the validity of the bases and members declared in T. Add any
5763 implicitly-generated functions (like copy-constructors and
5764 assignment operators). Compute various flag bits (like
5765 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5766 level: i.e., independently of the ABI in use. */
5768 static void
5770 {
5771 /* Nonzero if the implicitly generated copy constructor should take
5772 a non-const reference argument. */
5774 /* Nonzero if the implicitly generated assignment operator
5775 should take a non-const reference argument. */
5777 tree access_decls;
5780 tree fn;
5782 /* By default, we use const reference arguments and generate default
5783 constructors. */
5787 /* Check all the base-classes and set FMEM members to point to arrays
5788 of potential interest. */
5791 /* Deduce noexcept on destructors. This needs to happen after we've set
5792 triviality flags appropriately for our bases. */
5796 /* Check all the method declarations. */
5799 /* Save the initial values of these flags which only indicate whether
5800 or not the class has user-provided functions. As we analyze the
5801 bases and members we can set these flags for other reasons. */
5805 /* Check all the data member declarations. We cannot call
5806 check_field_decls until we have called check_bases check_methods,
5807 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5808 being set appropriately. */
5813 /* A nearly-empty class has to be vptr-containing; a nearly empty
5814 class contains just a vptr. */
5818 /* Do some bookkeeping that will guide the generation of implicitly
5819 declared member functions. */
5822 /* We need to call a constructor for this class if it has a
5823 user-provided constructor, or if the default constructor is going
5824 to initialize the vptr. (This is not an if-and-only-if;
5825 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5826 themselves need constructing.) */
5829 /* [dcl.init.aggr]
5831 An aggregate is an array or a class with no user-provided
5832 constructors ... and no virtual functions.
5834 Again, other conditions for being an aggregate are checked
5835 elsewhere. */
5839 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5840 retain the old definition internally for ABI reasons. */
5849 /* If the only explicitly declared default constructor is user-provided,
5850 set TYPE_HAS_COMPLEX_DFLT. */
5856 /* Warn if a public base of a polymorphic type has an accessible
5857 non-virtual destructor. It is only now that we know the class is
5858 polymorphic. Although a polymorphic base will have a already
5859 been diagnosed during its definition, we warn on use too. */
5861 {
5864 tree base_binfo;
5868 {
5876 basetype);
5877 }
5878 }
5880 /* If the class has no user-declared constructor, but does have
5881 non-static const or reference data members that can never be
5882 initialized, issue a warning. */
5884 /* Classes with user-declared constructors are presumed to
5885 initialize these members. */
5887 /* Aggregates can be initialized with brace-enclosed
5888 initializers. */
5890 {
5891 tree field;
5894 {
5895 tree type;
5912 }
5913 }
5915 /* Synthesize any needed methods. */
5917 cant_have_const_ctor,
5918 no_const_asn_ref);
5920 /* Check defaulted declarations here so we have cant_have_const_ctor
5921 and don't need to worry about clones. */
5924 {
5927 {
5928 bool imp_const_p
5934 /* If the function is defaulted outside the class, we just
5935 give the synthesis error. */
5938 }
5940 }
5943 {
5944 /* "This class type is not an aggregate." */
5946 }
5948 /* Compute the 'literal type' property before we
5949 do anything with non-static member functions. */
5952 /* Create the in-charge and not-in-charge variants of constructors
5953 and destructors. */
5956 /* Process the using-declarations. */
5960 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5963 /* Figure out whether or not we will need a cookie when dynamically
5964 allocating an array of this type. */
5967 }
5969 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5970 accordingly. If a new vfield was created (because T doesn't have a
5971 primary base class), then the newly created field is returned. It
5972 is not added to the TYPE_FIELDS list; it is the caller's
5973 responsibility to do that. Accumulate declared virtual functions
5974 on VIRTUALS_P. */
5976 static tree
5978 {
5979 tree fn;
5981 /* Collect the virtual functions declared in T. */
5986 {
5995 }
5997 /* If we couldn't find an appropriate base class, create a new field
5998 here. Even if there weren't any new virtual functions, we might need a
5999 new virtual function table if we're supposed to include vptrs in
6000 all classes that need them. */
6002 {
6003 /* We build this decl with vtbl_ptr_type_node, which is a
6004 `vtable_entry_type*'. It might seem more precise to use
6005 `vtable_entry_type (*)[N]' where N is the number of virtual
6006 functions. However, that would require the vtable pointer in
6007 base classes to have a different type than the vtable pointer
6008 in derived classes. We could make that happen, but that
6009 still wouldn't solve all the problems. In particular, the
6010 type-based alias analysis code would decide that assignments
6011 to the base class vtable pointer can't alias assignments to
6012 the derived class vtable pointer, since they have different
6013 types. Thus, in a derived class destructor, where the base
6014 class constructor was inlined, we could generate bad code for
6015 setting up the vtable pointer.
6017 Therefore, we use one type for all vtable pointers. We still
6018 use a type-correct type; it's just doesn't indicate the array
6019 bounds. That's better than using `void*' or some such; it's
6020 cleaner, and it let's the alias analysis code know that these
6021 stores cannot alias stores to void*! */
6022 tree field;
6035 /* This class is non-empty. */
6039 }
6042 }
6044 /* Add OFFSET to all base types of BINFO which is a base in the
6045 hierarchy dominated by T.
6047 OFFSET, which is a type offset, is number of bytes. */
6049 static void
6051 {
6053 tree primary_binfo;
6054 tree base_binfo;
6056 /* Update BINFO's offset. */
6061 offset));
6063 /* Find the primary base class. */
6069 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
6070 downwards. */
6072 {
6073 /* Don't do the primary base twice. */
6081 }
6082 }
6084 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
6085 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
6086 empty subobjects of T. */
6088 static void
6090 {
6091 tree vbase;
6098 /* Find the last field. The artificial fields created for virtual
6099 bases will go after the last extant field to date. */
6104 /* Go through the virtual bases, allocating space for each virtual
6105 base that is not already a primary base class. These are
6106 allocated in inheritance graph order. */
6108 {
6113 {
6114 /* This virtual base is not a primary base of any class in the
6115 hierarchy, so we have to add space for it. */
6118 }
6119 }
6120 }
6122 /* Returns the offset of the byte just past the end of the base class
6123 BINFO. */
6125 static tree
6127 {
6128 tree size;
6133 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6134 allocate some space for it. It cannot have virtual bases, so
6135 TYPE_SIZE_UNIT is fine. */
6137 else
6141 }
6143 /* Returns the offset of the byte just past the end of the base class
6144 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
6145 only non-virtual bases are included. */
6147 static tree
6149 {
6152 tree binfo;
6153 tree base_binfo;
6154 tree offset;
6159 {
6169 }
6174 {
6178 }
6181 }
6183 /* Warn about bases of T that are inaccessible because they are
6184 ambiguous. For example:
6186 struct S {};
6187 struct T : public S {};
6188 struct U : public S, public T {};
6190 Here, `(S*) new U' is not allowed because there are two `S'
6191 subobjects of U. */
6193 static void
6195 {
6198 tree basetype;
6199 tree binfo;
6200 tree base_binfo;
6202 /* If there are no repeated bases, nothing can be ambiguous. */
6206 /* Check direct bases. */
6209 {
6215 }
6217 /* Check for ambiguous virtual bases. */
6221 {
6227 }
6228 }
6230 /* Compare two INTEGER_CSTs K1 and K2. */
6232 static int
6234 {
6236 }
6238 /* Increase the size indicated in RLI to account for empty classes
6239 that are "off the end" of the class. */
6241 static void
6243 {
6244 tree eoc;
6245 tree rli_size;
6247 /* It might be the case that we grew the class to allocate a
6248 zero-sized base class. That won't be reflected in RLI, yet,
6249 because we are willing to overlay multiple bases at the same
6250 offset. However, now we need to make sure that RLI is big enough
6251 to reflect the entire class. */
6257 {
6258 /* The size should have been rounded to a whole byte. */
6261 rli->bitpos
6270 }
6271 }
6273 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6274 BINFO_OFFSETs for all of the base-classes. Position the vtable
6275 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6277 static void
6279 {
6280 tree non_static_data_members;
6281 tree field;
6282 tree vptr;
6283 record_layout_info rli;
6284 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6285 types that appear at that offset. */
6286 splay_tree empty_base_offsets;
6287 /* True if the last field laid out was a bit-field. */
6289 /* The location at which the next field should be inserted. */
6291 /* T, as a base class. */
6292 tree base_t;
6294 /* Keep track of the first non-static data member. */
6297 /* Start laying out the record. */
6300 /* Mark all the primary bases in the hierarchy. */
6303 /* Create a pointer to our virtual function table. */
6306 /* The vptr is always the first thing in the class. */
6308 {
6313 }
6314 else
6317 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6322 /* Layout the non-static data members. */
6324 {
6325 tree type;
6326 tree padding;
6328 /* We still pass things that aren't non-static data members to
6329 the back end, in case it wants to do something with them. */
6331 {
6333 /* If the static data member has incomplete type, keep track
6334 of it so that it can be completed later. (The handling
6335 of pending statics in finish_record_layout is
6336 insufficient; consider:
6338 struct S1;
6339 struct S2 { static S1 s1; };
6341 At this point, finish_record_layout will be called, but
6342 S1 is still incomplete.) */
6344 {
6346 /* The visibility of static data members is determined
6347 at their point of declaration, not their point of
6348 definition. */
6350 }
6352 }
6360 /* If this field is a bit-field whose width is greater than its
6361 type, then there are some special rules for allocating
6362 it. */
6365 {
6367 tree integer_type;
6369 /* We must allocate the bits as if suitably aligned for the
6370 longest integer type that fits in this many bits. type
6371 of the field. Then, we are supposed to use the left over
6372 bits as additional padding. */
6381 /* ITK now indicates a type that is too large for the
6382 field. We have to back up by one to find the largest
6383 type that fits. */
6384 do
6385 {
6390 /* Figure out how much additional padding is required. */
6392 {
6394 /* In a union, the padding field must have the full width
6395 of the bit-field; all fields start at offset zero. */
6397 else
6400 }
6402 /* An unnamed bitfield does not normally affect the
6403 alignment of the containing class on a target where
6404 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6405 make any exceptions for unnamed bitfields when the
6406 bitfields are longer than their types. Therefore, we
6407 temporarily give the field a name. */
6409 {
6412 }
6418 empty_base_offsets);
6421 /* Now that layout has been performed, set the size of the
6422 field to the size of its declared type; the rest of the
6423 field is effectively invisible. */
6425 /* We must also reset the DECL_MODE of the field. */
6427 }
6428 else
6430 empty_base_offsets);
6432 /* Remember the location of any empty classes in FIELD. */
6435 empty_base_offsets,
6438 /* If a bit-field does not immediately follow another bit-field,
6439 and yet it starts in the middle of a byte, we have failed to
6440 comply with the ABI. */
6443 /* The TREE_NO_WARNING flag gets set by Objective-C when
6444 laying out an Objective-C class. The ObjC ABI differs
6445 from the C++ ABI, and so we do not want a warning
6446 here. */
6448 && !last_field_was_bitfield
6451 bitsize_unit_node)))
6453 "offset of %qD is not ABI-compliant and may "
6456 /* The middle end uses the type of expressions to determine the
6457 possible range of expression values. In order to optimize
6458 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6459 must be made aware of the width of "i", via its type.
6461 Because C++ does not have integer types of arbitrary width,
6462 we must (for the purposes of the front end) convert from the
6463 type assigned here to the declared type of the bitfield
6464 whenever a bitfield expression is used as an rvalue.
6465 Similarly, when assigning a value to a bitfield, the value
6466 must be converted to the type given the bitfield here. */
6468 {
6473 {
6480 }
6481 }
6483 /* If we needed additional padding after this field, add it
6484 now. */
6486 {
6487 tree padding_field;
6490 FIELD_DECL,
6491 NULL_TREE,
6492 char_type_node);
6499 NULL_TREE,
6500 empty_base_offsets);
6501 }
6504 }
6507 {
6508 /* Make sure that we are on a byte boundary so that the size of
6509 the class without virtual bases will always be a round number
6510 of bytes. */
6513 }
6515 /* Delete all zero-width bit-fields from the list of fields. Now
6516 that the type is laid out they are no longer important. */
6519 /* Create the version of T used for virtual bases. We do not use
6520 make_class_type for this version; this is an artificial type. For
6521 a POD type, we just reuse T. */
6523 {
6526 /* Set the size and alignment for the new type. */
6527 tree eoc;
6529 /* If the ABI version is not at least two, and the last
6530 field was a bit-field, RLI may not be on a byte
6531 boundary. In particular, rli_size_unit_so_far might
6532 indicate the last complete byte, while rli_size_so_far
6533 indicates the total number of bits used. Therefore,
6534 rli_size_so_far, rather than rli_size_unit_so_far, is
6535 used to compute TYPE_SIZE_UNIT. */
6543 eoc);
6553 /* Copy the fields from T. */
6557 {
6561 }
6564 /* Record the base version of the type. */
6567 }
6568 else
6571 /* Every empty class contains an empty class. */
6575 /* Set the TYPE_DECL for this type to contain the right
6576 value for DECL_OFFSET, so that we can use it as part
6577 of a COMPONENT_REF for multiple inheritance. */
6580 /* Now fix up any virtual base class types that we left lying
6581 around. We must get these done before we try to lay out the
6582 virtual function table. As a side-effect, this will remove the
6583 base subobject fields. */
6586 /* Make sure that empty classes are reflected in RLI at this
6587 point. */
6590 /* Make sure not to create any structures with zero size. */
6596 /* If this is a non-POD, declaring it packed makes a difference to how it
6597 can be used as a field; don't let finalize_record_size undo it. */
6601 /* Let the back end lay out the type. */
6610 /* Warn about bases that can't be talked about due to ambiguity. */
6613 /* Now that we're done with layout, give the base fields the real types. */
6618 /* Clean up. */
6625 }
6627 /* Determine the "key method" for the class type indicated by TYPE,
6628 and set CLASSTYPE_KEY_METHOD accordingly. */
6630 void
6632 {
6633 tree method;
6640 /* The key method is the first non-pure virtual function that is not
6641 inline at the point of class definition. On some targets the
6642 key function may not be inline; those targets should not call
6643 this function until the end of the translation unit. */
6650 {
6653 }
6656 }
6659 /* Allocate and return an instance of struct sorted_fields_type with
6660 N fields. */
6664 {
6671 }
6673 /* Helper of find_flexarrays. Return true when FLD refers to a non-static
6674 class data member of non-zero size, otherwise false. */
6678 {
6686 {
6690 }
6693 }
6695 /* Used by find_flexarrays and related. */
6697 /* The first flexible array member or non-zero array member found
6698 in order of layout. */
6699 tree array;
6700 /* First non-static non-empty data member in the class or its bases. */
6701 tree first;
6702 /* First non-static non-empty data member following either the flexible
6703 array member, if found, or the zero-length array member. */
6704 tree after;
6705 };
6707 /* Find either the first flexible array member or the first zero-length
6708 array, in that order or preference, among members of class T (but not
6709 its base classes), and set members of FMEM accordingly. */
6711 static void
6713 {
6715 {
6716 /* Find the next non-static data member if it exists. */
6725 {
6726 /* Members of anonymous structs and unions are treated as if
6727 they were members of the containing class. Descend into
6728 the anonymous struct or union and find a flexible array
6729 member or zero-length array among its fields. */
6732 }
6734 /* Skip anything that's not a (non-static) data member. */
6738 /* Skip virtual table pointers. */
6743 {
6744 /* Remember the first non-static data member. */
6748 /* Remember the first non-static data member after the flexible
6749 array member, if one has been found, or the zero-length array
6750 if it has been found. */
6753 }
6755 /* Skip non-arrays. */
6759 /* Determine the upper bound of the array if it has one. */
6761 {
6763 {
6764 /* Make a record of the zero-length array if either one
6765 such field or a flexible array member has been seen to
6766 handle the pathological and unlikely case of multiple
6767 such members. */
6770 }
6772 /* Remember the first zero-length array unless a flexible array
6773 member has already been seen. */
6775 }
6776 else
6777 {
6778 /* Flexible array members have no upper bound. */
6780 {
6781 /* Replace the zero-length array if it's been stored and
6782 reset the after pointer. */
6784 {
6787 }
6788 }
6789 else
6791 }
6792 }
6793 }
6795 /* Issue diagnostics for invalid flexible array members or zero-length
6796 arrays that are not the last elements of the containing class or its
6797 base classes or that are its sole members. */
6799 static void
6801 {
6802 /* Members of anonymous structs and unions are considered to be members
6803 of the containing struct or union. */
6810 {
6820 }
6821 else
6822 {
6829 {
6833 /* In the unlikely event that the member following the flexible
6834 array member is declared in a different class, point to it.
6835 Otherwise it should be obvious. */
6843 }
6844 }
6845 }
6848 /* Recursively check to make sure that any flexible array or zero-length
6849 array members of class T or its bases are valid (i.e., not the sole
6850 non-static data member of T and, if one exists, that it is the last
6851 non-static data member of T and its base classes. FMEM is expected
6852 to be initially null and is used internally by recursive calls to
6853 the function. Issue the appropriate diagnostics for the array member
6854 that fails the checks. */
6856 static void
6858 {
6859 /* Initialize the result of a search for flexible array and zero-length
6860 array members. Avoid doing any work if the most interesting FMEM data
6861 have already been populated. */
6868 /* Recursively check the primary base class first. */
6870 {
6873 }
6875 /* Recursively check the base classes. */
6878 {
6881 /* The primary base class was already checked above. */
6885 /* Virtual base classes are at the end. */
6889 /* Check the base class. */
6891 }
6894 {
6895 /* Check virtual base classes only once per derived class.
6896 I.e., this check is not performed recursively for base
6897 classes. */
6899 tree base_binfo;
6903 {
6904 /* Check the virtual base class. */
6908 }
6909 }
6911 /* Search the members of the current (derived) class. */
6915 {
6916 /* Issue diagnostics for invalid flexible and zero-length array members
6917 found in base classes or among the members of the current class. */
6919 }
6920 }
6922 /* Perform processing required when the definition of T (a class type)
6923 is complete. Diagnose invalid definitions of flexible array members
6924 and zero-size arrays. */
6926 void
6928 {
6929 tree x;
6930 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6934 {
6939 }
6941 /* If this type was previously laid out as a forward reference,
6942 make sure we lay it out again. */
6946 /* Make assumptions about the class; we'll reset the flags if
6947 necessary. */
6953 /* Do end-of-class semantic processing: checking the validity of the
6954 bases and members and add implicitly generated methods. */
6957 /* Find the key method. */
6959 {
6960 /* The Itanium C++ ABI permits the key method to be chosen when
6961 the class is defined -- even though the key method so
6962 selected may later turn out to be an inline function. On
6963 some systems (such as ARM Symbian OS) the key method cannot
6964 be determined until the end of the translation unit. On such
6965 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6966 will cause the class to be added to KEYED_CLASSES. Then, in
6967 finish_file we will determine the key method. */
6971 /* If a polymorphic class has no key method, we may emit the vtable
6972 in every translation unit where the class definition appears. If
6973 we're devirtualizing, we can look into the vtable even if we
6974 aren't emitting it. */
6977 }
6979 /* Layout the class itself. */
6982 /* We use the base type for trivial assignments, and hence it
6983 needs a mode. */
6986 /* With the layout complete, check for flexible array members and
6987 zero-length arrays that might overlap other members in the final
6988 layout. */
6993 /* If necessary, create the primary vtable for this class. */
6995 {
6996 /* We must enter these virtuals into the table. */
7000 /* Here we know enough to change the type of our virtual
7001 function table, but we will wait until later this function. */
7004 /* If we're warning about ABI tags, check the types of the new
7005 virtual functions. */
7009 }
7012 {
7014 tree fn;
7021 /* Add entries for virtual functions introduced by this class. */
7025 /* Set DECL_VINDEX for all functions declared in this class. */
7027 fn;
7029 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
7031 {
7035 /* A thunk. We should never be calling this entry directly
7036 from this vtable -- we'd use the entry for the non
7037 thunk base function. */
7041 }
7042 }
7049 /* Complete the rtl for any static member objects of the type we're
7050 working on. */
7057 /* Done with FIELDS...now decide whether to sort these for
7058 faster lookups later.
7060 We use a small number because most searches fail (succeeding
7061 ultimately as the search bores through the inheritance
7062 hierarchy), and we want this failure to occur quickly. */
7066 /* Complain if one of the field types requires lower visibility. */
7069 /* Make the rtl for any new vtables we have created, and unmark
7070 the base types we marked. */
7073 /* Build the VTT for T. */
7080 "%q#T has virtual functions and accessible"
7088 /* Class layout, assignment of virtual table slots, etc., is now
7089 complete. Give the back end a chance to tweak the visibility of
7090 the class or perform any other required target modifications. */
7100 /* Finish debugging output for this type. */
7104 {
7107 {
7110 }
7112 {
7115 else
7116 {
7119 }
7121 }
7123 {
7125 "the type of the first field has a different ABI from the "
7128 }
7129 }
7130 }
7132 /* Insert FIELDS into T for the sorted case if the FIELDS count is
7133 equal to THRESHOLD or greater than THRESHOLD. */
7135 static void
7137 {
7140 {
7145 }
7146 }
7148 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
7150 void
7152 {
7155 {
7157 int n_fields
7168 }
7169 }
7171 /* When T was built up, the member declarations were added in reverse
7172 order. Rearrange them to declaration order. */
7174 void
7176 {
7177 tree next;
7178 tree prev;
7179 tree x;
7181 /* The following lists are all in reverse order. Put them in
7182 declaration order now. */
7186 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
7187 reverse order, so we can't just use nreverse. */
7192 {
7196 }
7198 {
7202 }
7203 }
7205 tree
7207 {
7210 /* Now that we've got all the field declarations, reverse everything
7211 as necessary. */
7217 /* Nadger the current location so that diagnostics point to the start of
7218 the struct, not the end. */
7222 {
7223 tree x;
7229 /* We need to emit an error message if this type was used as a parameter
7230 and it is an abstract type, even if it is a template. We construct
7231 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
7232 account and we call complete_vars with this type, which will check
7233 the PARM_DECLS. Note that while the type is being defined,
7234 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
7235 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
7241 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
7242 an enclosing scope is a template class, so that this function be
7243 found by lookup_fnfields_1 when the using declaration is not
7244 instantiated yet. */
7247 {
7252 }
7254 /* Remember current #pragma pack value. */
7257 /* Fix up any variants we've already built. */
7259 {
7264 }
7265 }
7266 else
7270 {
7271 /* People keep complaining that the compiler crashes on an invalid
7272 definition of initializer_list, so I guess we should explicitly
7273 reject it. What the compiler internals care about is that it's a
7274 template and has a pointer field followed by an integer field. */
7277 {
7280 {
7284 }
7285 }
7288 "definition of std::initializer_list does not match "
7290 }
7298 else
7302 /* Lambdas are defined by the LAMBDA_EXPR. */
7307 }
7308 \f
7309 /* Hash table to avoid endless recursion when handling references. */
7312 /* Return the dynamic type of INSTANCE, if known.
7313 Used to determine whether the virtual function table is needed
7314 or not.
7316 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7317 of our knowledge of its type. *NONNULL should be initialized
7318 before this function is called. */
7320 static tree
7322 {
7323 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
7326 {
7330 else
7334 /* This is a call to a constructor, hence it's never zero. */
7336 {
7340 }
7344 /* This is a call to a constructor, hence it's never zero. */
7346 {
7350 }
7359 /* Propagate nonnull. */
7364 CASE_CONVERT:
7370 {
7371 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7372 with a real object -- given &p->f, p can still be null. */
7374 /* ??? Probably should check DECL_WEAK here. */
7377 }
7381 /* If this component is really a base class reference, then the field
7382 itself isn't definitive. */
7391 {
7395 }
7396 /* fall through. */
7401 {
7405 }
7407 {
7411 /* if we're in a ctor or dtor, we know our type. If
7412 current_class_ptr is set but we aren't in a function, we're in
7413 an NSDMI (and therefore a constructor). */
7418 {
7422 }
7423 }
7425 {
7426 /* We only need one hash table because it is always left empty. */
7428 fixed_type_or_null_ref_ht
7431 /* Reference variables should be references to objects. */
7435 /* Enter the INSTANCE in a table to prevent recursion; a
7436 variable's initializer may refer to the variable
7437 itself. */
7442 {
7443 tree type;
7452 }
7453 }
7458 }
7459 #undef RECUR
7460 }
7462 /* Return nonzero if the dynamic type of INSTANCE is known, and
7463 equivalent to the static type. We also handle the case where
7464 INSTANCE is really a pointer. Return negative if this is a
7465 ctor/dtor. There the dynamic type is known, but this might not be
7466 the most derived base of the original object, and hence virtual
7467 bases may not be laid out according to this type.
7469 Used to determine whether the virtual function table is needed
7470 or not.
7472 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7473 of our knowledge of its type. *NONNULL should be initialized
7474 before this function is called. */
7476 int
7478 {
7481 tree fixed;
7483 /* processing_template_decl can be false in a template if we're in
7484 instantiate_non_dependent_expr, but we still want to suppress
7485 this check. */
7487 {
7488 /* In a template we only care about the type of the result. */
7492 }
7502 }
7504 \f
7505 void
7507 {
7510 current_class_stack
7518 }
7520 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7522 static void
7524 {
7525 tree type;
7527 /* We are re-entering the same class we just left, so we don't
7528 have to search the whole inheritance matrix to find all the
7529 decls to bind again. Instead, we install the cached
7530 class_shadowed list and walk through it binding names. */
7533 /* Restore IDENTIFIER_TYPE_VALUE. */
7535 type;
7538 }
7540 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7541 appropriate for TYPE.
7543 So that we may avoid calls to lookup_name, we cache the _TYPE
7544 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7546 For multiple inheritance, we perform a two-pass depth-first search
7547 of the type lattice. */
7549 void
7551 {
7552 class_stack_node_t csn;
7556 /* Make sure there is enough room for the new entry on the stack. */
7558 {
7560 current_class_stack
7562 current_class_stack_size);
7563 }
7565 /* Insert a new entry on the class stack. */
7572 current_class_depth++;
7574 /* Now set up the new type. */
7580 /* By default, things in classes are private, while things in
7581 structures or unions are public. */
7583 ? access_private_node
7589 {
7590 /* Forcibly remove any old class remnants. */
7592 }
7598 else
7600 }
7602 /* When we exit a toplevel class scope, we save its binding level so
7603 that we can restore it quickly. Here, we've entered some other
7604 class, so we must invalidate our cache. */
7606 void
7608 {
7610 }
7612 /* Get out of the current class scope. If we were in a class scope
7613 previously, that is the one popped to. */
7615 void
7617 {
7620 current_class_depth--;
7626 }
7628 /* Mark the top of the class stack as hidden. */
7630 void
7632 {
7635 }
7637 /* Mark the top of the class stack as un-hidden. */
7639 void
7641 {
7644 }
7646 /* Returns 1 if the class type currently being defined is either T or
7647 a nested type of T. Returns the type from the current_class_stack,
7648 which might be equivalent to but not equal to T in case of
7649 constrained partial specializations. */
7651 tree
7653 {
7661 /* We start looking from 1 because entry 0 is from global scope,
7662 and has no type. */
7664 {
7665 tree c;
7668 else
7669 {
7673 }
7678 }
7680 }
7682 /* If either current_class_type or one of its enclosing classes are derived
7683 from T, return the appropriate type. Used to determine how we found
7684 something via unqualified lookup. */
7686 tree
7688 {
7691 /* The bases of a dependent type are unknown. */
7702 {
7707 }
7710 }
7712 /* Return the outermost enclosing class type that is still open, or
7713 NULL_TREE. */
7715 tree
7717 {
7724 {
7731 }
7733 }
7735 /* Returns the innermost class type which is not a lambda closure type. */
7737 tree
7739 {
7742 /* We start looking from 1 because entry 0 is from global scope,
7743 and has no type. */
7745 {
7746 tree c;
7749 else
7750 {
7754 }
7759 }
7761 }
7763 /* When entering a class scope, all enclosing class scopes' names with
7764 static meaning (static variables, static functions, types and
7765 enumerators) have to be visible. This recursive function calls
7766 pushclass for all enclosing class contexts until global or a local
7767 scope is reached. TYPE is the enclosed class. */
7769 void
7771 {
7772 /* A namespace might be passed in error cases, like A::B:C. */
7780 }
7782 /* Undoes a push_nested_class call. */
7784 void
7786 {
7792 }
7794 /* Returns the number of extern "LANG" blocks we are nested within. */
7796 int
7798 {
7800 }
7802 /* Set global variables CURRENT_LANG_NAME to appropriate value
7803 so that behavior of name-mangling machinery is correct. */
7805 void
7807 {
7814 else
7816 }
7818 /* Get out of the current language scope. */
7820 void
7822 {
7824 }
7825 \f
7826 /* Type instantiation routines. */
7828 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7829 matches the TARGET_TYPE. If there is no satisfactory match, return
7830 error_mark_node, and issue an error & warning messages under
7831 control of FLAGS. Permit pointers to member function if FLAGS
7832 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7833 a template-id, and EXPLICIT_TARGS are the explicitly provided
7834 template arguments.
7836 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7837 is the base path used to reference those member functions. If
7838 the address is resolved to a member function, access checks will be
7839 performed and errors issued if appropriate. */
7841 static tree
7843 tree overload,
7844 tsubst_flags_t complain,
7846 tree explicit_targs,
7847 tree access_path)
7848 {
7849 /* Here's what the standard says:
7851 [over.over]
7853 If the name is a function template, template argument deduction
7854 is done, and if the argument deduction succeeds, the deduced
7855 arguments are used to generate a single template function, which
7856 is added to the set of overloaded functions considered.
7858 Non-member functions and static member functions match targets of
7859 type "pointer-to-function" or "reference-to-function." Nonstatic
7860 member functions match targets of type "pointer-to-member
7861 function;" the function type of the pointer to member is used to
7862 select the member function from the set of overloaded member
7863 functions. If a nonstatic member function is selected, the
7864 reference to the overloaded function name is required to have the
7865 form of a pointer to member as described in 5.3.1.
7867 If more than one function is selected, any template functions in
7868 the set are eliminated if the set also contains a non-template
7869 function, and any given template function is eliminated if the
7870 set contains a second template function that is more specialized
7871 than the first according to the partial ordering rules 14.5.5.2.
7872 After such eliminations, if any, there shall remain exactly one
7873 selected function. */
7876 /* We store the matches in a TREE_LIST rooted here. The functions
7877 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7878 interoperability with most_specialized_instantiation. */
7880 tree fn;
7881 tree target_fn_type;
7883 /* By the time we get here, we should be seeing only real
7884 pointer-to-member types, not the internal POINTER_TYPE to
7885 METHOD_TYPE representation. */
7891 /* Check that the TARGET_TYPE is reasonable. */
7896 /* This is OK, too. */
7899 /* This is OK, too. This comes from a conversion to reference
7900 type. */
7902 else
7903 {
7909 }
7911 /* Non-member functions and static member functions match targets of type
7912 "pointer-to-function" or "reference-to-function." Nonstatic member
7913 functions match targets of type "pointer-to-member-function;" the
7914 function type of the pointer to member is used to select the member
7915 function from the set of overloaded member functions.
7917 So figure out the FUNCTION_TYPE that we want to match against. */
7920 /* If we can find a non-template function that matches, we can just
7921 use it. There's no point in generating template instantiations
7922 if we're just going to throw them out anyhow. But, of course, we
7923 can only do this when we don't *need* a template function. */
7925 {
7926 tree fns;
7929 {
7933 /* We're not looking for templates just yet. */
7938 /* We're looking for a non-static member, and this isn't
7939 one, or vice versa. */
7942 /* Ignore functions which haven't been explicitly
7943 declared. */
7947 /* See if there's a match. */
7952 }
7953 }
7955 /* Now, if we've already got a match (or matches), there's no need
7956 to proceed to the template functions. But, if we don't have a
7957 match we need to look at them, too. */
7959 {
7960 tree target_arg_types;
7961 tree target_ret_type;
7962 tree fns;
7965 tree arg;
7979 {
7981 tree instantiation;
7982 tree targs;
7985 /* We're only looking for templates. */
7990 /* We're not looking for a non-static member, and this is
7991 one, or vice versa. */
7996 /* If the template has a deduced return type, don't expose it to
7997 template argument deduction. */
8001 /* Try to do argument deduction. */
8008 /* Instantiation failed. */
8011 /* Constraints must be satisfied. This is done before
8012 return type deduction since that instantiates the
8013 function. */
8017 /* And now force instantiation to do return type deduction. */
8019 {
8025 }
8027 /* See if there's a match. */
8032 }
8034 /* Now, remove all but the most specialized of the matches. */
8036 {
8041 NULL_TREE,
8042 NULL_TREE);
8043 }
8044 }
8046 /* Now we should have exactly one function in MATCHES. */
8048 {
8049 /* There were *no* matches. */
8051 {
8054 target_type);
8057 }
8059 }
8061 {
8062 /* There were too many matches. First check if they're all
8063 the same function. */
8068 /* For multi-versioned functions, more than one match is just fine and
8069 decls_match will return false as they are different. */
8077 {
8079 {
8082 target_type);
8084 /* Since print_candidates expects the functions in the
8085 TREE_VALUE slot, we flip them here. */
8090 }
8093 }
8094 }
8096 /* Good, exactly one match. Now, convert it to the correct type. */
8101 {
8109 {
8112 }
8113 }
8115 /* If a pointer to a function that is multi-versioned is requested, the
8116 pointer to the dispatcher function is returned instead. This works
8117 well because indirectly calling the function will dispatch the right
8118 function version at run-time. */
8120 {
8124 /* Mark all the versions corresponding to the dispatcher as used. */
8127 }
8129 /* If we're doing overload resolution purely for the purpose of
8130 determining conversion sequences, we should not consider the
8131 function used. If this conversion sequence is selected, the
8132 function will be marked as used at this point. */
8134 {
8135 /* Make =delete work with SFINAE. */
8140 }
8142 /* We could not check access to member functions when this
8143 expression was originally created since we did not know at that
8144 time to which function the expression referred. */
8146 {
8149 }
8153 else
8154 {
8155 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
8156 will mark the function as addressed, but here we must do it
8157 explicitly. */
8161 }
8162 }
8164 /* This function will instantiate the type of the expression given in
8165 RHS to match the type of LHSTYPE. If errors exist, then return
8166 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
8167 we complain on errors. If we are not complaining, never modify rhs,
8168 as overload resolution wants to try many possible instantiations, in
8169 the hope that at least one will work.
8171 For non-recursive calls, LHSTYPE should be a function, pointer to
8172 function, or a pointer to member function. */
8174 tree
8176 {
8183 {
8187 }
8190 {
8197 /* Microsoft allows `A::f' to be resolved to a
8198 pointer-to-member. */
8199 ;
8200 else
8201 {
8206 }
8207 }
8210 {
8213 }
8215 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
8216 deduce any type information. */
8218 {
8222 }
8224 /* If we instantiate a template, and it is a A ?: C expression
8225 with omitted B, look through the SAVE_EXPR. */
8229 /* There are only a few kinds of expressions that may have a type
8230 dependent on overload resolution. */
8236 /* This should really only be used when attempting to distinguish
8237 what sort of a pointer to function we have. For now, any
8238 arithmetic operation which is not supported on pointers
8239 is rejected as an error. */
8242 {
8244 {
8250 /* Do not lose object's side effects. */
8254 }
8261 /* This can happen if we are forming a pointer-to-member for a
8262 member template. */
8265 /* Fall through. */
8268 {
8272 return
8276 }
8280 return
8284 access_path);
8287 {
8292 }
8299 }
8301 }
8302 \f
8303 /* Return the name of the virtual function pointer field
8304 (as an IDENTIFIER_NODE) for the given TYPE. Note that
8305 this may have to look back through base types to find the
8306 ultimate field name. (For single inheritance, these could
8307 all be the same name. Who knows for multiple inheritance). */
8309 static tree
8311 {
8318 {
8324 }
8332 }
8334 void
8336 {
8343 {
8348 }
8349 }
8351 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
8352 according to [class]:
8353 The class-name is also inserted
8354 into the scope of the class itself. For purposes of access checking,
8355 the inserted class name is treated as if it were a public member name. */
8357 void
8359 {
8362 tree saved_cas;
8377 }
8379 /* Returns 1 if TYPE contains only padding bytes. */
8381 int
8383 {
8391 }
8393 /* Returns true if TYPE contains no actual data, just various
8394 possible combinations of empty classes and possibly a vptr. */
8396 bool
8398 {
8400 {
8401 tree field;
8402 tree binfo;
8403 tree base_binfo;
8406 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8407 out, but we'd like to be able to check this before then. */
8418 /* An unnamed bit-field is not a data member. */
8423 }
8428 }
8430 /* Note that NAME was looked up while the current class was being
8431 defined and that the result of that lookup was DECL. */
8433 void
8435 {
8436 splay_tree names_used;
8438 /* If we're not defining a class, there's nothing to do. */
8444 /* If there's already a binding for this NAME, then we don't have
8445 anything to worry about. */
8458 }
8460 /* Note that NAME was declared (as DECL) in the current class. Check
8461 to see that the declaration is valid. */
8463 void
8465 {
8466 splay_tree names_used;
8467 splay_tree_node n;
8469 /* Look to see if we ever used this name. */
8470 names_used
8474 /* The C language allows members to be declared with a type of the same
8475 name, and the C++ standard says this diagnostic is not required. So
8476 allow it in extern "C" blocks unless predantic is specified.
8477 Allow it in all cases if -ms-extensions is specified. */
8483 {
8484 /* [basic.scope.class]
8486 A name N used in a class S shall refer to the same declaration
8487 in its context and when re-evaluated in the completed scope of
8488 S. */
8493 }
8494 }
8496 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8497 Secondary vtables are merged with primary vtables; this function
8498 will return the VAR_DECL for the primary vtable. */
8500 tree
8502 {
8503 tree decl;
8507 {
8510 }
8514 }
8517 /* Returns the binfo for the primary base of BINFO. If the resulting
8518 BINFO is a virtual base, and it is inherited elsewhere in the
8519 hierarchy, then the returned binfo might not be the primary base of
8520 BINFO in the complete object. Check BINFO_PRIMARY_P or
8521 BINFO_LOST_PRIMARY_P to be sure. */
8523 static tree
8525 {
8526 tree primary_base;
8533 }
8535 /* As above, but iterate until we reach the binfo that actually provides the
8536 vptr for BINFO. */
8538 static tree
8540 {
8544 {
8549 }
8551 }
8553 /* Returns true if BINFO gets its vptr from a virtual base of the most derived
8554 type. Note that the virtual inheritance might be above or below BINFO in
8555 the hierarchy. */
8557 bool
8559 {
8563 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is
8564 a morally virtual base. */
8567 }
8569 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8571 static int
8573 {
8577 }
8579 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8580 INDENT should be zero when called from the top level; it is
8581 incremented recursively. IGO indicates the next expected BINFO in
8582 inheritance graph ordering. */
8584 static tree
8587 tree binfo,
8588 tree igo,
8590 {
8592 tree base_binfo;
8600 {
8603 }
8618 {
8622 TFF_PLAIN_IDENTIFIER),
8624 }
8626 {
8629 }
8634 {
8638 {
8642 TFF_PLAIN_IDENTIFIER));
8643 }
8645 {
8649 TFF_PLAIN_IDENTIFIER));
8650 }
8652 {
8656 TFF_PLAIN_IDENTIFIER));
8657 }
8659 {
8663 TFF_PLAIN_IDENTIFIER));
8664 }
8668 }
8674 }
8676 /* Dump the BINFO hierarchy for T. */
8678 static void
8680 {
8692 }
8694 /* Debug interface to hierarchy dumping. */
8696 void
8698 {
8700 }
8702 static void
8704 {
8709 {
8711 }
8712 }
8714 static void
8716 {
8717 tree value;
8719 HOST_WIDE_INT elt;
8727 TFF_PLAIN_IDENTIFIER));
8734 }
8736 static void
8738 {
8746 {
8753 {
8758 }
8762 }
8763 }
8765 static void
8767 {
8775 {
8780 }
8781 }
8783 /* Dump a function or thunk and its thunkees. */
8785 static void
8787 {
8790 tree thunks;
8798 {
8808 else
8814 }
8818 }
8820 /* Dump the thunks for FN. */
8822 void
8824 {
8826 }
8828 /* Virtual function table initialization. */
8830 /* Create all the necessary vtables for T and its base classes. */
8832 static void
8834 {
8835 tree vbase;
8839 /* We lay out the primary and secondary vtables in one contiguous
8840 vtable. The primary vtable is first, followed by the non-virtual
8841 secondary vtables in inheritance graph order. */
8845 /* Then come the virtual bases, also in inheritance graph order. */
8847 {
8851 }
8855 }
8857 /* Initialize the vtable for BINFO with the INITS. */
8859 static void
8861 {
8862 tree decl;
8868 }
8870 /* Build the VTT (virtual table table) for T.
8871 A class requires a VTT if it has virtual bases.
8873 This holds
8874 1 - primary virtual pointer for complete object T
8875 2 - secondary VTTs for each direct non-virtual base of T which requires a
8876 VTT
8877 3 - secondary virtual pointers for each direct or indirect base of T which
8878 has virtual bases or is reachable via a virtual path from T.
8879 4 - secondary VTTs for each direct or indirect virtual base of T.
8881 Secondary VTTs look like complete object VTTs without part 4. */
8883 static void
8885 {
8886 tree type;
8887 tree vtt;
8888 tree index;
8891 /* Build up the initializers for the VTT. */
8896 /* If we didn't need a VTT, we're done. */
8900 /* Figure out the type of the VTT. */
8904 /* Now, build the VTT object itself. */
8907 /* Add the VTT to the vtables list. */
8912 }
8914 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8915 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8916 and CHAIN the vtable pointer for this binfo after construction is
8917 complete. VALUE can also be another BINFO, in which case we recurse. */
8919 static tree
8921 {
8922 tree vt;
8925 {
8931 else
8933 }
8936 }
8938 /* Data for secondary VTT initialization. */
8939 struct secondary_vptr_vtt_init_data
8940 {
8941 /* Is this the primary VTT? */
8944 /* Current index into the VTT. */
8945 tree index;
8947 /* Vector of initializers built up. */
8950 /* The type being constructed by this secondary VTT. */
8951 tree type_being_constructed;
8952 };
8954 /* Recursively build the VTT-initializer for BINFO (which is in the
8955 hierarchy dominated by T). INITS points to the end of the initializer
8956 list to date. INDEX is the VTT index where the next element will be
8957 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8958 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8959 for virtual bases of T. When it is not so, we build the constructor
8960 vtables for the BINFO-in-T variant. */
8962 static void
8965 {
8967 tree b;
8968 tree init;
8969 secondary_vptr_vtt_init_data data;
8972 /* We only need VTTs for subobjects with virtual bases. */
8976 /* We need to use a construction vtable if this is not the primary
8977 VTT. */
8979 {
8982 /* Record the offset in the VTT where this sub-VTT can be found. */
8984 }
8986 /* Add the address of the primary vtable for the complete object. */
8990 {
8993 }
8996 /* Recursively add the secondary VTTs for non-virtual bases. */
9001 /* Add secondary virtual pointers for all subobjects of BINFO with
9002 either virtual bases or reachable along a virtual path, except
9003 subobjects that are non-virtual primary bases. */
9013 /* data.inits might have grown as we added secondary virtual pointers.
9014 Make sure our caller knows about the new vector. */
9018 /* Add the secondary VTTs for virtual bases in inheritance graph
9019 order. */
9021 {
9026 }
9027 else
9028 /* Remove the ctor vtables we created. */
9030 }
9032 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
9033 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
9035 static tree
9037 {
9040 /* We don't care about bases that don't have vtables. */
9044 /* We're only interested in proper subobjects of the type being
9045 constructed. */
9049 /* We're only interested in bases with virtual bases or reachable
9050 via a virtual path from the type being constructed. */
9055 /* We're not interested in non-virtual primary bases. */
9059 /* Record the index where this secondary vptr can be found. */
9061 {
9066 {
9067 /* It's a primary virtual base, and this is not a
9068 construction vtable. Find the base this is primary of in
9069 the inheritance graph, and use that base's vtable
9070 now. */
9073 }
9074 }
9076 /* Add the initializer for the secondary vptr itself. */
9079 /* Advance the vtt index. */
9084 }
9086 /* Called from build_vtt_inits via dfs_walk. After building
9087 constructor vtables and generating the sub-vtt from them, we need
9088 to restore the BINFO_VTABLES that were scribbled on. DATA is the
9089 binfo of the base whose sub vtt was generated. */
9091 static tree
9093 {
9097 /* If this class has no vtable, none of its bases do. */
9101 /* This might be a primary base, so have no vtable in this
9102 hierarchy. */
9105 /* If we scribbled the construction vtable vptr into BINFO, clear it
9106 out now. */
9112 }
9114 /* Build the construction vtable group for BINFO which is in the
9115 hierarchy dominated by T. */
9117 static void
9119 {
9120 tree type;
9121 tree vtbl;
9122 tree id;
9123 tree vbase;
9126 /* See if we've already created this construction vtable group. */
9132 /* Build a version of VTBL (with the wrong type) for use in
9133 constructing the addresses of secondary vtables in the
9134 construction vtable group. */
9137 /* Don't export construction vtables from shared libraries. Even on
9138 targets that don't support hidden visibility, this tells
9139 can_refer_decl_in_current_unit_p not to assume that it's safe to
9140 access from a different compilation unit (bz 54314). */
9148 /* Add the vtables for each of our virtual bases using the vbase in T
9149 binfo. */
9151 vbase;
9153 {
9154 tree b;
9161 }
9163 /* Figure out the type of the construction vtable. */
9170 /* Initialize the construction vtable. */
9174 }
9176 /* Add the vtbl initializers for BINFO (and its bases other than
9177 non-virtual primaries) to the list of INITS. BINFO is in the
9178 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
9179 the constructor the vtbl inits should be accumulated for. (If this
9180 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
9181 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
9182 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
9183 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
9184 but are not necessarily the same in terms of layout. */
9186 static void
9188 tree orig_binfo,
9189 tree rtti_binfo,
9190 tree vtbl,
9191 tree t,
9193 {
9195 tree base_binfo;
9200 /* If it doesn't have a vptr, we don't do anything. */
9204 /* If we're building a construction vtable, we're not interested in
9205 subobjects that don't require construction vtables. */
9211 /* Build the initializers for the BINFO-in-T vtable. */
9214 /* Walk the BINFO and its bases. We walk in preorder so that as we
9215 initialize each vtable we can figure out at what offset the
9216 secondary vtable lies from the primary vtable. We can't use
9217 dfs_walk here because we need to iterate through bases of BINFO
9218 and RTTI_BINFO simultaneously. */
9220 {
9221 /* Skip virtual bases. */
9227 inits);
9228 }
9229 }
9231 /* Called from accumulate_vtbl_inits. Adds the initializers for the
9232 BINFO vtable to L. */
9234 static void
9236 tree orig_binfo,
9237 tree rtti_binfo,
9238 tree orig_vtbl,
9239 tree t,
9241 {
9248 {
9249 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
9250 primary virtual base. If it is not the same primary in
9251 the hierarchy of T, we'll need to generate a ctor vtable
9252 for it, to place at its location in T. If it is the same
9253 primary, we still need a VTT entry for the vtable, but it
9254 should point to the ctor vtable for the base it is a
9255 primary for within the sub-hierarchy of RTTI_BINFO.
9257 There are three possible cases:
9259 1) We are in the same place.
9260 2) We are a primary base within a lost primary virtual base of
9261 RTTI_BINFO.
9262 3) We are primary to something not a base of RTTI_BINFO. */
9264 tree b;
9267 /* First, look through the bases we are primary to for RTTI_BINFO
9268 or a virtual base. */
9271 {
9276 }
9277 /* If we run out of primary links, keep looking down our
9278 inheritance chain; we might be an indirect primary. */
9282 found:
9284 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
9285 base B and it is a base of RTTI_BINFO, this is case 2. In
9286 either case, we share our vtable with LAST, i.e. the
9287 derived-most base within B of which we are a primary. */
9290 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
9291 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
9292 binfo_ctor_vtable after everything's been set up. */
9295 /* Otherwise, this is case 3 and we get our own. */
9296 }
9303 {
9304 tree index;
9307 /* Add the initializer for this vtable. */
9311 /* Figure out the position to which the VPTR should point. */
9317 }
9320 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
9321 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
9322 straighten this out. */
9325 /* Throw away any unneeded intializers. */
9327 else
9328 /* For an ordinary vtable, set BINFO_VTABLE. */
9330 }
9334 /* Construct the initializer for BINFO's virtual function table. BINFO
9335 is part of the hierarchy dominated by T. If we're building a
9336 construction vtable, the ORIG_BINFO is the binfo we should use to
9337 find the actual function pointers to put in the vtable - but they
9338 can be overridden on the path to most-derived in the graph that
9339 ORIG_BINFO belongs. Otherwise,
9340 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
9341 BINFO that should be indicated by the RTTI information in the
9342 vtable; it will be a base class of T, rather than T itself, if we
9343 are building a construction vtable.
9345 The value returned is a TREE_LIST suitable for wrapping in a
9346 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
9347 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
9348 number of non-function entries in the vtable.
9350 It might seem that this function should never be called with a
9351 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
9352 base is always subsumed by a derived class vtable. However, when
9353 we are building construction vtables, we do build vtables for
9354 primary bases; we need these while the primary base is being
9355 constructed. */
9357 static void
9359 tree orig_binfo,
9360 tree t,
9361 tree rtti_binfo,
9364 {
9365 tree v;
9366 vtbl_init_data vid;
9368 tree vbinfo;
9372 /* Initialize VID. */
9380 /* The first vbase or vcall offset is at index -3 in the vtable. */
9383 /* Add entries to the vtable for RTTI. */
9386 /* Create an array for keeping track of the functions we've
9387 processed. When we see multiple functions with the same
9388 signature, we share the vcall offsets. */
9390 /* Add the vcall and vbase offset entries. */
9393 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
9394 build_vbase_offset_vtbl_entries. */
9399 /* If the target requires padding between data entries, add that now. */
9401 {
9406 /* Move data entries into their new positions and add padding
9407 after the new positions. Iterate backwards so we don't
9408 overwrite entries that we would need to process later. */
9411 ix--)
9412 {
9420 {
9424 null_pointer_node);
9425 }
9426 }
9427 }
9432 /* The initializers for virtual functions were built up in reverse
9433 order. Straighten them out and add them to the running list in one
9434 step. */
9443 /* Go through all the ordinary virtual functions, building up
9444 initializers. */
9446 {
9447 tree delta;
9448 tree vcall_index;
9455 {
9459 {
9462 }
9464 }
9466 /* If the only definition of this function signature along our
9467 primary base chain is from a lost primary, this vtable slot will
9468 never be used, so just zero it out. This is important to avoid
9469 requiring extra thunks which cannot be generated with the function.
9471 We first check this in update_vtable_entry_for_fn, so we handle
9472 restored primary bases properly; we also need to do it here so we
9473 zero out unused slots in ctor vtables, rather than filling them
9474 with erroneous values (though harmless, apart from relocation
9475 costs). */
9480 {
9481 /* Pull the offset for `this', and the function to call, out of
9482 the list. */
9489 /* You can't call an abstract virtual function; it's abstract.
9490 So, we replace these functions with __pure_virtual. */
9492 {
9495 {
9497 abort_fndecl_addr
9501 }
9502 }
9503 /* Likewise for deleted virtuals. */
9505 {
9514 }
9515 else
9516 {
9518 {
9522 }
9523 /* Take the address of the function, considering it to be of an
9524 appropriate generic type. */
9528 /* Don't refer to a virtual destructor from a constructor
9529 vtable or a vtable for an abstract class, since destroying
9530 an object under construction is undefined behavior and we
9531 don't want it to be considered a candidate for speculative
9532 devirtualization. But do create the thunk for ABI
9533 compliance. */
9538 }
9539 }
9541 /* And add it to the chain of initializers. */
9543 {
9548 else
9550 {
9556 }
9557 }
9558 else
9560 }
9561 }
9563 /* Adds to vid->inits the initializers for the vbase and vcall
9564 offsets in BINFO, which is in the hierarchy dominated by T. */
9566 static void
9568 {
9569 tree b;
9571 /* If this is a derived class, we must first create entries
9572 corresponding to the primary base class. */
9577 /* Add the vbase entries for this base. */
9579 /* Add the vcall entries for this base. */
9581 }
9583 /* Returns the initializers for the vbase offset entries in the vtable
9584 for BINFO (which is part of the class hierarchy dominated by T), in
9585 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9586 where the next vbase offset will go. */
9588 static void
9590 {
9591 tree vbase;
9592 tree t;
9593 tree non_primary_binfo;
9595 /* If there are no virtual baseclasses, then there is nothing to
9596 do. */
9602 /* We might be a primary base class. Go up the inheritance hierarchy
9603 until we find the most derived class of which we are a primary base:
9604 it is the offset of that which we need to use. */
9607 {
9608 tree b;
9610 /* If we have reached a virtual base, then it must be a primary
9611 base (possibly multi-level) of vid->binfo, or we wouldn't
9612 have called build_vcall_and_vbase_vtbl_entries for it. But it
9613 might be a lost primary, so just skip down to vid->binfo. */
9615 {
9618 }
9624 }
9626 /* Go through the virtual bases, adding the offsets. */
9628 vbase;
9630 {
9631 tree b;
9632 tree delta;
9637 /* Find the instance of this virtual base in the complete
9638 object. */
9641 /* If we've already got an offset for this virtual base, we
9642 don't need another one. */
9647 /* Figure out where we can find this vbase offset. */
9656 /* The vbase offset had better be the same. */
9659 /* The next vbase will come at a more negative offset. */
9663 /* The initializer is the delta from BINFO to this virtual base.
9664 The vbase offsets go in reverse inheritance-graph order, and
9665 we are walking in inheritance graph order so these end up in
9666 the right order. */
9673 }
9674 }
9676 /* Adds the initializers for the vcall offset entries in the vtable
9677 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9678 to VID->INITS. */
9680 static void
9682 {
9683 /* We only need these entries if this base is a virtual base. We
9684 compute the indices -- but do not add to the vtable -- when
9685 building the main vtable for a class. */
9688 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9689 correspond to VID->DERIVED), we are building a primary
9690 construction virtual table. Since this is a primary
9691 virtual table, we do not need the vcall offsets for
9692 BINFO. */
9694 {
9695 /* We need a vcall offset for each of the virtual functions in this
9696 vtable. For example:
9698 class A { virtual void f (); };
9699 class B1 : virtual public A { virtual void f (); };
9700 class B2 : virtual public A { virtual void f (); };
9701 class C: public B1, public B2 { virtual void f (); };
9703 A C object has a primary base of B1, which has a primary base of A. A
9704 C also has a secondary base of B2, which no longer has a primary base
9705 of A. So the B2-in-C construction vtable needs a secondary vtable for
9706 A, which will adjust the A* to a B2* to call f. We have no way of
9707 knowing what (or even whether) this offset will be when we define B2,
9708 so we store this "vcall offset" in the A sub-vtable and look it up in
9709 a "virtual thunk" for B2::f.
9711 We need entries for all the functions in our primary vtable and
9712 in our non-virtual bases' secondary vtables. */
9714 /* If we are just computing the vcall indices -- but do not need
9715 the actual entries -- not that. */
9718 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9720 }
9721 }
9723 /* Build vcall offsets, starting with those for BINFO. */
9725 static void
9727 {
9729 tree primary_binfo;
9730 tree base_binfo;
9732 /* Don't walk into virtual bases -- except, of course, for the
9733 virtual base for which we are building vcall offsets. Any
9734 primary virtual base will have already had its offsets generated
9735 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9739 /* If BINFO has a primary base, process it first. */
9744 /* Add BINFO itself to the list. */
9747 /* Scan the non-primary bases of BINFO. */
9751 }
9753 /* Called from build_vcall_offset_vtbl_entries_r. */
9755 static void
9757 {
9758 /* Make entries for the rest of the virtuals. */
9759 tree orig_fn;
9761 /* The ABI requires that the methods be processed in declaration
9762 order. */
9764 orig_fn;
9768 }
9770 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9772 static void
9774 {
9776 tree vcall_offset;
9777 tree derived_entry;
9779 /* If there is already an entry for a function with the same
9780 signature as FN, then we do not need a second vcall offset.
9781 Check the list of functions already present in the derived
9782 class vtable. */
9784 {
9786 /* We only use one vcall offset for virtual destructors,
9787 even though there are two virtual table entries. */
9791 }
9793 /* If we are building these vcall offsets as part of building
9794 the vtable for the most derived class, remember the vcall
9795 offset. */
9797 {
9800 }
9802 /* The next vcall offset will be found at a more negative
9803 offset. */
9807 /* Keep track of this function. */
9811 {
9812 tree base;
9813 tree fn;
9815 /* Find the overriding function. */
9819 else
9820 {
9823 /* The vbase we're working on is a primary base of
9824 vid->binfo. But it might be a lost primary, so its
9825 BINFO_OFFSET might be wrong, so we just use the
9826 BINFO_OFFSET from vid->binfo. */
9832 vcall_offset);
9833 }
9834 /* Add the initializer to the vtable. */
9836 }
9837 }
9839 /* Return vtbl initializers for the RTTI entries corresponding to the
9840 BINFO's vtable. The RTTI entries should indicate the object given
9841 by VID->rtti_binfo. */
9843 static void
9845 {
9846 tree b;
9847 tree t;
9848 tree offset;
9849 tree decl;
9850 tree init;
9854 /* To find the complete object, we will first convert to our most
9855 primary base, and then add the offset in the vtbl to that value. */
9860 /* The second entry is the address of the typeinfo object. */
9863 else
9866 /* Convert the declaration to a type that can be stored in the
9867 vtable. */
9871 /* Add the offset-to-top entry. It comes earlier in the vtable than
9872 the typeinfo entry. Convert the offset to look like a
9873 function pointer, so that we can put it in the vtable. */
9876 }
9878 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9879 accessibility. */
9881 bool
9883 {
9886 }
9888 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9890 bool
9892 {
9896 }
9898 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9899 class between them, if any. */
9901 tree
9903 {
9915 {
9918 }
9922 }