| blob | 1bd80ffa0f8656152230a574013d0f451396fc14 |
1 /* Handle initialization things in C++.
2 Copyright (C) 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
12 any later version.
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
23 /* High-level class interface. */
58 /* We are about to generate some complex initialization code.
59 Conceptually, it is all a single expression. However, we may want
60 to include conditionals, loops, and other such statement-level
61 constructs. Therefore, we build the initialization code inside a
62 statement-expression. This function starts such an expression.
63 STMT_EXPR_P and COMPOUND_STMT_P are filled in by this function;
64 pass them back to finish_init_stmts when the expression is
65 complete. */
67 static bool
69 {
76 }
78 /* Finish out the statement-expression begun by the previous call to
79 begin_init_stmts. Returns the statement-expression itself. */
81 static tree
83 {
91 }
93 /* Constructors */
95 /* Called from initialize_vtbl_ptrs via dfs_walk. BINFO is the base
96 which we want to initialize the vtable pointer for, DATA is
97 TREE_LIST whose TREE_VALUE is the this ptr expression. */
99 static tree
101 {
106 {
112 }
115 }
117 /* Initialize all the vtable pointers in the object pointed to by
118 ADDR. */
120 void
122 {
123 tree list;
124 tree type;
129 /* Walk through the hierarchy, initializing the vptr in each base
130 class. We do these in pre-order because we can't find the virtual
131 bases for a class until we've initialized the vtbl for that
132 class. */
134 }
136 /* Return an expression for the zero-initialization of an object with
137 type T. This expression will either be a constant (in the case
138 that T is a scalar), or a CONSTRUCTOR (in the case that T is an
139 aggregate), or NULL (in the case that T does not require
140 initialization). In either case, the value can be used as
141 DECL_INITIAL for a decl of the indicated TYPE; it is a valid static
142 initializer. If NELTS is non-NULL, and TYPE is an ARRAY_TYPE, NELTS
143 is the number of elements in the array. If STATIC_STORAGE_P is
144 TRUE, initializers are only generated for entities for which
145 zero-initialization does not simply mean filling the storage with
146 zero bytes. */
148 tree
150 {
153 /* [dcl.init]
155 To zero-initialize an object of type T means:
157 -- if T is a scalar type, the storage is set to the value of zero
158 converted to T.
160 -- if T is a non-union class type, the storage for each nonstatic
161 data member and each base-class subobject is zero-initialized.
163 -- if T is a union type, the storage for its first data member is
164 zero-initialized.
166 -- if T is an array type, the storage for each element is
167 zero-initialized.
169 -- if T is a reference type, no initialization is performed. */
174 ;
176 /* In order to save space, we do not explicitly build initializers
177 for items that do not need them. GCC's semantics are that
178 items with static storage duration that are not otherwise
179 initialized are initialized to zero. */
180 ;
184 {
185 tree field;
188 /* Iterate over the fields, building initializations. */
190 {
194 /* Note that for class types there will be FIELD_DECLs
195 corresponding to base classes as well. Thus, iterating
196 over TYPE_FIELDs will result in correct initialization of
197 all of the subobjects. */
199 {
202 static_storage_p);
205 }
207 /* For unions, only the first field is initialized. */
210 }
212 /* Build a constructor to contain the initializations. */
214 }
216 {
217 tree max_index;
220 /* Iterate over the array elements, building initializations. */
225 else
228 /* If we have an error_mark here, we should just return error mark
229 as we don't know the size of the array yet. */
234 /* A zero-sized array, which is accepted as an extension, will
235 have an upper bound of -1. */
237 {
243 /* If this is a one element array, we just use a regular init. */
246 else
248 max_index);
252 static_storage_p);
253 }
255 /* Build a constructor to contain the initializations. */
257 }
260 else
263 /* In all cases, the initializer is a constant. */
268 }
270 /* Return a suitable initializer for value-initializing an object of type
271 TYPE, as described in [dcl.init]. */
273 tree
275 {
276 /* [dcl.init]
278 To value-initialize an object of type T means:
280 - if T is a class type (clause 9) with a user-provided constructor
281 (12.1), then the default constructor for T is called (and the
282 initialization is ill-formed if T has no accessible default
283 constructor);
285 - if T is a non-union class type without a user-provided constructor,
286 then every non-static data member and base-class component of T is
287 value-initialized;92)
289 - if T is an array type, then each element is value-initialized;
291 - otherwise, the object is zero-initialized.
293 A program that calls for default-initialization or
294 value-initialization of an entity of reference type is ill-formed.
296 92) Value-initialization for such a class object may be implemented by
297 zero-initializing the object and then calling the default
298 constructor. */
301 {
303 return build_aggr_init_expr
307 tf_warning_or_error));
309 {
310 /* This is a class that needs constructing, but doesn't have
311 a user-provided constructor. So we need to zero-initialize
312 the object and then call the implicitly defined ctor.
313 This will be handled in simplify_aggr_init_expr. */
314 tree ctor = build_special_member_call
321 }
322 }
324 }
326 /* Like build_value_init, but don't call the constructor for TYPE. Used
327 for base initializers. */
329 tree
331 {
333 {
337 {
338 tree field;
341 /* Iterate over the fields, building initializations. */
343 {
354 /* We could skip vfields and fields of types with
355 user-defined constructors, but I think that won't improve
356 performance at all; it should be simpler in general just
357 to zero out the entire object than try to only zero the
358 bits that actually need it. */
360 /* Note that for class types there will be FIELD_DECLs
361 corresponding to base classes as well. Thus, iterating
362 over TYPE_FIELDs will result in correct initialization of
363 all of the subobjects. */
368 }
370 /* Build a constructor to contain the zero- initializations. */
372 }
373 }
375 {
378 /* Iterate over the array elements, building initializations. */
381 /* If we have an error_mark here, we should just return error mark
382 as we don't know the size of the array yet. */
387 /* A zero-sized array, which is accepted as an extension, will
388 have an upper bound of -1. */
390 {
396 /* If this is a one element array, we just use a regular init. */
399 else
401 max_index);
405 /* The gimplifier can't deal with a RANGE_EXPR of TARGET_EXPRs. */
408 }
410 /* Build a constructor to contain the initializations. */
412 }
415 }
417 /* Initialize MEMBER, a FIELD_DECL, with INIT, a TREE_LIST of
418 arguments. If TREE_LIST is void_type_node, an empty initializer
419 list was given; if NULL_TREE no initializer was given. */
421 static void
423 {
424 tree decl;
427 /* Effective C++ rule 12 requires that all data members be
428 initialized. */
432 member);
434 /* Get an lvalue for the data member. */
438 tf_warning_or_error);
443 {
444 /* mem() means value-initialization. */
446 {
450 tf_warning_or_error);
452 }
453 else
454 {
458 member);
459 else
460 {
463 }
464 }
465 }
466 /* Deal with this here, as we will get confused if we try to call the
467 assignment op for an anonymous union. This can happen in a
468 synthesized copy constructor. */
470 {
472 {
475 }
476 }
478 {
483 {
484 /* Initialization of one array from another. */
488 tf_warning_or_error));
489 }
490 else
491 {
495 /* TYPE_NEEDS_CONSTRUCTING can be set just because we have a
496 vtable; still give this diagnostic. */
501 tf_warning_or_error));
502 }
503 }
504 else
505 {
507 {
508 /* member traversal: note it leaves init NULL */
512 member);
517 }
519 /* There was an explicit member initialization. Do some work
520 in that case. */
525 tf_warning_or_error));
526 }
529 {
530 tree expr;
535 tf_warning_or_error);
541 }
542 }
544 /* Returns a TREE_LIST containing (as the TREE_PURPOSE of each node) all
545 the FIELD_DECLs on the TYPE_FIELDS list for T, in reverse order. */
547 static tree
549 {
550 tree fields;
554 /* Note whether or not T is a union. */
559 {
560 /* Skip CONST_DECLs for enumeration constants and so forth. */
564 /* Keep track of whether or not any fields are unions. */
568 /* For an anonymous struct or union, we must recursively
569 consider the fields of the anonymous type. They can be
570 directly initialized from the constructor. */
572 {
573 /* Add this field itself. Synthesized copy constructors
574 initialize the entire aggregate. */
576 /* And now add the fields in the anonymous aggregate. */
578 uses_unions_p);
579 }
580 /* Add this field. */
583 }
586 }
588 /* The MEM_INITS are a TREE_LIST. The TREE_PURPOSE of each list gives
589 a FIELD_DECL or BINFO in T that needs initialization. The
590 TREE_VALUE gives the initializer, or list of initializer arguments.
592 Return a TREE_LIST containing all of the initializations required
593 for T, in the order in which they should be performed. The output
594 list has the same format as the input. */
596 static tree
598 {
599 tree init;
601 tree sorted_inits;
602 tree next_subobject;
607 /* Build up a list of initializations. The TREE_PURPOSE of entry
608 will be the subobject (a FIELD_DECL or BINFO) to initialize. The
609 TREE_VALUE will be the constructor arguments, or NULL if no
610 explicit initialization was provided. */
613 /* Process the virtual bases. */
618 /* Process the direct bases. */
624 /* Process the non-static data members. */
626 /* Reverse the entire list of initializations, so that they are in
627 the order that they will actually be performed. */
630 /* If the user presented the initializers in an order different from
631 that in which they will actually occur, we issue a warning. Keep
632 track of the next subobject which can be explicitly initialized
633 without issuing a warning. */
636 /* Go through the explicit initializers, filling in TREE_PURPOSE in
637 the SORTED_INITS. */
639 {
640 tree subobject;
641 tree subobject_init;
645 /* If the explicit initializers are in sorted order, then
646 SUBOBJECT will be NEXT_SUBOBJECT, or something following
647 it. */
649 subobject_init;
654 /* Issue a warning if the explicit initializer order does not
655 match that which will actually occur.
656 ??? Are all these on the correct lines? */
658 {
662 else
667 else
671 }
673 /* Look again, from the beginning of the list. */
675 {
679 }
681 /* It is invalid to initialize the same subobject more than
682 once. */
684 {
688 subobject);
689 else
692 subobject);
693 }
695 /* Record the initialization. */
698 }
700 /* [class.base.init]
702 If a ctor-initializer specifies more than one mem-initializer for
703 multiple members of the same union (including members of
704 anonymous unions), the ctor-initializer is ill-formed. */
706 {
709 {
710 tree field;
711 tree field_type;
714 /* Skip uninitialized members and base classes. */
718 /* See if this field is a member of a union, or a member of a
719 structure contained in a union, etc. */
726 /* If this field is not a member of a union, skip it. */
730 /* It's only an error if we have two initializers for the same
731 union type. */
733 {
736 }
738 /* See if LAST_FIELD and the field initialized by INIT are
739 members of the same union. If so, there's a problem,
740 unless they're actually members of the same structure
741 which is itself a member of a union. For example, given:
743 union { struct { int i; int j; }; };
745 initializing both `i' and `j' makes sense. */
748 do
749 {
750 tree last_field_type;
754 {
756 {
760 last_field_type);
763 }
769 }
771 /* If we've reached the outermost class, then we're
772 done. */
777 }
781 }
782 }
785 }
787 /* Initialize all bases and members of CURRENT_CLASS_TYPE. MEM_INITS
788 is a TREE_LIST giving the explicit mem-initializer-list for the
789 constructor. The TREE_PURPOSE of each entry is a subobject (a
790 FIELD_DECL or a BINFO) of the CURRENT_CLASS_TYPE. The TREE_VALUE
791 is a TREE_LIST giving the arguments to the constructor or
792 void_type_node for an empty list of arguments. */
794 void
796 {
797 /* We will already have issued an error message about the fact that
798 the type is incomplete. */
802 /* Sort the mem-initializers into the order in which the
803 initializations should be performed. */
808 /* Initialize base classes. */
811 {
815 /* If these initializations are taking place in a copy constructor,
816 the base class should probably be explicitly initialized if there
817 is a user-defined constructor in the base class (other than the
818 default constructor, which will be called anyway). */
823 "base class %q#T should be explicitly initialized in the "
827 /* Initialize the base. */
830 else
831 {
832 tree base_addr;
838 tf_warning_or_error),
839 arguments,
840 LOOKUP_NORMAL,
841 tf_warning_or_error);
843 }
846 }
849 /* Initialize the vptrs. */
852 /* Initialize the data members. */
854 {
858 }
859 }
861 /* Returns the address of the vtable (i.e., the value that should be
862 assigned to the vptr) for BINFO. */
864 static tree
866 {
868 tree vtbl;
871 /* If this is a virtual primary base, then the vtable we want to store
872 is that for the base this is being used as the primary base of. We
873 can't simply skip the initialization, because we may be expanding the
874 inits of a subobject constructor where the virtual base layout
875 can be different. */
879 /* Figure out what vtable BINFO's vtable is based on, and mark it as
880 used. */
884 /* Now compute the address to use when initializing the vptr. */
890 }
892 /* This code sets up the virtual function tables appropriate for
893 the pointer DECL. It is a one-ply initialization.
895 BINFO is the exact type that DECL is supposed to be. In
896 multiple inheritance, this might mean "C's A" if C : A, B. */
898 static void
900 {
902 tree vtt_index;
904 /* Compute the initializer for vptr. */
907 /* We may get this vptr from a VTT, if this is a subobject
908 constructor or subobject destructor. */
911 {
912 tree vtbl2;
913 tree vtt_parm;
915 /* Compute the value to use, when there's a VTT. */
919 vtt_parm,
920 vtt_index);
924 /* The actual initializer is the VTT value only in the subobject
925 constructor. In maybe_clone_body we'll substitute NULL for
926 the vtt_parm in the case of the non-subobject constructor. */
931 vtbl2,
932 vtbl);
933 }
935 /* Compute the location of the vtpr. */
937 tf_warning_or_error),
941 /* Assign the vtable to the vptr. */
944 tf_warning_or_error));
945 }
947 /* If an exception is thrown in a constructor, those base classes already
948 constructed must be destroyed. This function creates the cleanup
949 for BINFO, which has just been constructed. If FLAG is non-NULL,
950 it is a DECL which is nonzero when this base needs to be
951 destroyed. */
953 static void
955 {
956 tree expr;
961 /* Call the destructor. */
963 base_dtor_identifier,
964 NULL,
965 binfo,
967 tf_warning_or_error);
975 }
977 /* Construct the virtual base-class VBASE passing the ARGUMENTS to its
978 constructor. */
980 static void
982 {
983 tree inner_if_stmt;
984 tree exp;
985 tree flag;
987 /* If there are virtual base classes with destructors, we need to
988 emit cleanups to destroy them if an exception is thrown during
989 the construction process. These exception regions (i.e., the
990 period during which the cleanups must occur) begin from the time
991 the construction is complete to the end of the function. If we
992 create a conditional block in which to initialize the
993 base-classes, then the cleanup region for the virtual base begins
994 inside a block, and ends outside of that block. This situation
995 confuses the sjlj exception-handling code. Therefore, we do not
996 create a single conditional block, but one for each
997 initialization. (That way the cleanup regions always begin
998 in the outer block.) We trust the back end to figure out
999 that the FLAG will not change across initializations, and
1000 avoid doing multiple tests. */
1005 /* Compute the location of the virtual base. If we're
1006 constructing virtual bases, then we must be the most derived
1007 class. Therefore, we don't have to look up the virtual base;
1008 we already know where it is. */
1017 }
1019 /* Find the context in which this FIELD can be initialized. */
1021 static tree
1023 {
1026 /* Anonymous union members can be initialized in the first enclosing
1027 non-anonymous union context. */
1031 }
1033 /* Function to give error message if member initialization specification
1034 is erroneous. FIELD is the member we decided to initialize.
1035 TYPE is the type for which the initialization is being performed.
1036 FIELD must be a member of TYPE.
1038 MEMBER_NAME is the name of the member. */
1040 static int
1042 {
1046 {
1048 member_name);
1050 }
1052 {
1055 field);
1057 }
1059 {
1063 }
1065 {
1067 member_name);
1069 }
1072 }
1074 /* NAME is a FIELD_DECL, an IDENTIFIER_NODE which names a field, or it
1075 is a _TYPE node or TYPE_DECL which names a base for that type.
1076 Check the validity of NAME, and return either the base _TYPE, base
1077 binfo, or the FIELD_DECL of the member. If NAME is invalid, return
1078 NULL_TREE and issue a diagnostic.
1080 An old style unnamed direct single base construction is permitted,
1081 where NAME is NULL. */
1083 tree
1085 {
1086 tree basetype;
1087 tree field;
1093 {
1094 /* This is an obsolete unnamed base class initializer. The
1095 parser will already have warned about its use. */
1097 {
1100 current_class_type);
1103 basetype = BINFO_TYPE
1108 current_class_type);
1110 }
1111 }
1113 {
1116 }
1119 else
1123 {
1124 tree class_binfo;
1125 tree direct_binfo;
1126 tree virtual_binfo;
1136 /* Look for a direct base. */
1141 /* Look for a virtual base -- unless the direct base is itself
1142 virtual. */
1146 /* [class.base.init]
1148 If a mem-initializer-id is ambiguous because it designates
1149 both a direct non-virtual base class and an inherited virtual
1150 base class, the mem-initializer is ill-formed. */
1152 {
1154 basetype);
1156 }
1159 {
1163 else
1167 }
1170 }
1171 else
1172 {
1175 else
1180 }
1183 }
1185 /* This is like `expand_member_init', only it stores one aggregate
1186 value into another.
1188 INIT comes in two flavors: it is either a value which
1189 is to be stored in EXP, or it is a parameter list
1190 to go to a constructor, which will operate on EXP.
1191 If INIT is not a parameter list for a constructor, then set
1192 LOOKUP_ONLYCONVERTING.
1193 If FLAGS is LOOKUP_ONLYCONVERTING then it is the = init form of
1194 the initializer, if FLAGS is 0, then it is the (init) form.
1195 If `init' is a CONSTRUCTOR, then we emit a warning message,
1196 explaining that such initializations are invalid.
1198 If INIT resolves to a CALL_EXPR which happens to return
1199 something of the type we are looking for, then we know
1200 that we can safely use that call to perform the
1201 initialization.
1203 The virtual function table pointer cannot be set up here, because
1204 we do not really know its type.
1206 This never calls operator=().
1208 When initializing, nothing is CONST.
1210 A default copy constructor may have to be used to perform the
1211 initialization.
1213 A constructor or a conversion operator may have to be used to
1214 perform the initialization, but not both, as it would be ambiguous. */
1216 tree
1218 {
1219 tree stmt_expr;
1220 tree compound_stmt;
1237 {
1238 tree itype;
1240 /* An array may not be initialized use the parenthesized
1241 initialization form -- unless the initializer is "()". */
1243 {
1247 }
1248 /* Must arrange to initialize each element of EXP
1249 from elements of INIT. */
1259 complain);
1266 }
1269 /* Just know that we've seen something for this node. */
1283 }
1285 static void
1287 tsubst_flags_t complain)
1288 {
1290 tree ctor_name;
1292 /* It fails because there may not be a constructor which takes
1293 its own type as the first (or only parameter), but which does
1294 take other types via a conversion. So, if the thing initializing
1295 the expression is a unit element of type X, first try X(X&),
1296 followed by initialization by X. If neither of these work
1297 out, then look hard. */
1298 tree rval;
1303 {
1304 /* Base subobjects should only get direct-initialization. */
1308 /* Do nothing. We hit this in two cases: Reference initialization,
1309 where we aren't initializing a real variable, so we don't want
1310 to run a new constructor; and catching an exception, where we
1311 have already built up the constructor call so we could wrap it
1315 {
1316 /* A brace-enclosed initializer for an aggregate. */
1318 }
1319 else
1323 /* We need to protect the initialization of a catch parm with a
1324 call to terminate(), which shows up as a MUST_NOT_THROW_EXPR
1325 around the TARGET_EXPR for the copy constructor. See
1326 initialize_handler_parm. */
1327 {
1331 }
1332 else
1337 }
1342 {
1346 }
1347 else
1352 else
1356 complain);
1363 }
1365 /* This function is responsible for initializing EXP with INIT
1366 (if any).
1368 BINFO is the binfo of the type for who we are performing the
1369 initialization. For example, if W is a virtual base class of A and B,
1370 and C : A, B.
1371 If we are initializing B, then W must contain B's W vtable, whereas
1372 were we initializing C, W must contain C's W vtable.
1374 TRUE_EXP is nonzero if it is the true expression being initialized.
1375 In this case, it may be EXP, or may just contain EXP. The reason we
1376 need this is because if EXP is a base element of TRUE_EXP, we
1377 don't necessarily know by looking at EXP where its virtual
1378 baseclass fields should really be pointing. But we do know
1379 from TRUE_EXP. In constructors, we don't know anything about
1380 the value being initialized.
1382 FLAGS is just passed to `build_new_method_call'. See that function
1383 for its description. */
1385 static void
1387 tsubst_flags_t complain)
1388 {
1394 /* Use a function returning the desired type to initialize EXP for us.
1395 If the function is a constructor, and its first argument is
1396 NULL_TREE, know that it was meant for us--just slide exp on
1397 in and expand the constructor. Constructors now come
1398 as TARGET_EXPRs. */
1402 {
1403 /* If store_init_value returns NULL_TREE, the INIT has been
1404 recorded as the DECL_INITIAL for EXP. That means there's
1405 nothing more we have to do. */
1410 }
1412 /* If an explicit -- but empty -- initializer list was present,
1413 that's value-initialization. */
1415 {
1416 /* If there's a user-provided constructor, we just call that. */
1419 /* If there isn't, but we still need to call the constructor,
1420 zero out the object first. */
1422 {
1426 /* And then call the constructor. */
1427 }
1428 /* If we don't need to mess with the constructor at all,
1429 then just zero out the object and we're done. */
1430 else
1431 {
1435 }
1437 }
1439 /* We know that expand_default_init can handle everything we want
1440 at this point. */
1442 }
1444 /* Report an error if TYPE is not a user-defined, class type. If
1445 OR_ELSE is nonzero, give an error message. */
1447 int
1449 {
1454 {
1458 }
1460 }
1462 tree
1464 {
1470 else
1472 }
1474 /* Build a reference to a member of an aggregate. This is not a C++
1475 `&', but really something which can have its address taken, and
1476 then act as a pointer to member, for example TYPE :: FIELD can have
1477 its address taken by saying & TYPE :: FIELD. ADDRESS_P is true if
1478 this expression is the operand of "&".
1480 @@ Prints out lousy diagnostics for operator <typename>
1481 @@ fields.
1483 @@ This function should be rewritten and placed in search.c. */
1485 tree
1487 {
1488 tree decl;
1491 /* class templates can come in as TEMPLATE_DECLs here. */
1504 /* Callers should call mark_used before this point. */
1509 {
1512 }
1514 /* Entities other than non-static members need no further
1515 processing. */
1522 {
1525 }
1527 /* Set up BASEBINFO for member lookup. */
1530 /* A lot of this logic is now handled in lookup_member. */
1532 {
1533 /* Go from the TREE_BASELINK to the member function info. */
1537 {
1538 /* Get rid of a potential OVERLOAD around it. */
1541 /* Unique functions are handled easily. */
1543 /* For non-static member of base class, we need a special rule
1544 for access checking [class.protected]:
1546 If the access is to form a pointer to member, the
1547 nested-name-specifier shall name the derived class
1548 (or any class derived from that class). */
1552 else
1558 }
1559 else
1561 }
1563 /* We need additional test besides the one in
1564 check_accessibility_of_qualified_id in case it is
1565 a pointer to non-static member. */
1569 {
1570 /* If MEMBER is non-static, then the program has fallen afoul of
1571 [expr.prim]:
1573 An id-expression that denotes a nonstatic data member or
1574 nonstatic member function of a class can only be used:
1576 -- as part of a class member access (_expr.ref_) in which the
1577 object-expression refers to the member's class or a class
1578 derived from that class, or
1580 -- to form a pointer to member (_expr.unary.op_), or
1582 -- in the body of a nonstatic member function of that class or
1583 of a class derived from that class (_class.mfct.nonstatic_), or
1585 -- in a mem-initializer for a constructor for that class or for
1586 a class derived from that class (_class.base.init_). */
1588 {
1589 /* Build a representation of the qualified name suitable
1590 for use as the operand to "&" -- even though the "&" is
1591 not actually present. */
1593 /* In Microsoft mode, treat a non-static member function as if
1594 it were a pointer-to-member. */
1596 {
1599 tf_warning_or_error);
1600 }
1604 }
1606 {
1609 }
1611 }
1616 }
1618 /* If DECL is a scalar enumeration constant or variable with a
1619 constant initializer, return the initializer (or, its initializers,
1620 recursively); otherwise, return DECL. If INTEGRAL_P, the
1621 initializer is only returned if DECL is an integral
1622 constant-expression. */
1624 static tree
1626 {
1628 || (integral_p
1632 {
1633 tree init;
1634 /* Static data members in template classes may have
1635 non-dependent initializers. References to such non-static
1636 data members are not value-dependent, so we must retrieve the
1637 initializer here. The DECL_INITIAL will have the right type,
1638 but will not have been folded because that would prevent us
1639 from performing all appropriate semantic checks at
1640 instantiation time. */
1645 {
1649 }
1650 else
1651 {
1652 /* If DECL is a static data member in a template
1653 specialization, we must instantiate it here. The
1654 initializer for the static data member is not processed
1655 until needed; we need it now. */
1658 }
1661 /* Initializers in templates are generally expanded during
1662 instantiation, so before that for const int i(2)
1663 INIT is a TREE_LIST with the actual initializer as
1664 TREE_VALUE. */
1666 && init
1672 || (integral_p
1675 /* Do not return an aggregate constant (of which
1676 string literals are a special case), as we do not
1677 want to make inadvertent copies of such entities,
1678 and we must be sure that their addresses are the
1679 same everywhere. */
1684 }
1686 }
1688 /* If DECL is a CONST_DECL, or a constant VAR_DECL initialized by
1689 constant of integral or enumeration type, then return that value.
1690 These are those variables permitted in constant expressions by
1691 [5.19/1]. */
1693 tree
1695 {
1697 }
1699 /* A more relaxed version of integral_constant_value, used by the
1700 common C/C++ code and by the C++ front end for optimization
1701 purposes. */
1703 tree
1705 {
1708 }
1709 \f
1710 /* Common subroutines of build_new and build_vec_delete. */
1712 /* Call the global __builtin_delete to delete ADDR. */
1714 static tree
1716 {
1719 }
1720 \f
1721 /* Build and return a NEW_EXPR. If NELTS is non-NULL, TYPE[NELTS] is
1722 the type of the object being allocated; otherwise, it's just TYPE.
1723 INIT is the initializer, if any. USE_GLOBAL_NEW is true if the
1724 user explicitly wrote "::operator new". PLACEMENT, if non-NULL, is
1725 a vector of arguments to be provided as arguments to a placement
1726 new operator. This routine performs no semantic checks; it just
1727 creates and returns a NEW_EXPR. */
1729 static tree
1732 {
1733 tree init_list;
1734 tree new_expr;
1736 /* If INIT is NULL, the we want to store NULL_TREE in the NEW_EXPR.
1737 If INIT is not NULL, then we want to store VOID_ZERO_NODE. This
1738 permits us to distinguish the case of a missing initializer "new
1739 int" from an empty initializer "new int()". */
1744 else
1749 init_list);
1754 }
1756 /* Generate code for a new-expression, including calling the "operator
1757 new" function, initializing the object, and, if an exception occurs
1758 during construction, cleaning up. The arguments are as for
1759 build_raw_new_expr. This may change PLACEMENT and INIT. */
1761 static tree
1764 tsubst_flags_t complain)
1765 {
1767 /* True iff this is a call to "operator new[]" instead of just
1768 "operator new". */
1770 /* If ARRAY_P is true, the element type of the array. This is never
1771 an ARRAY_TYPE; for something like "new int[3][4]", the
1772 ELT_TYPE is "int". If ARRAY_P is false, this is the same type as
1773 TYPE. */
1774 tree elt_type;
1775 /* The type of the new-expression. (This type is always a pointer
1776 type.) */
1777 tree pointer_type;
1778 tree non_const_pointer_type;
1781 /* The address returned by the call to "operator new". This node is
1782 a VAR_DECL and is therefore reusable. */
1783 tree alloc_node;
1784 tree alloc_fn;
1788 /* If non-NULL, the number of extra bytes to allocate at the
1789 beginning of the storage allocated for an array-new expression in
1790 order to store the number of elements. */
1792 tree placement_first;
1794 /* True if the function we are calling is a placement allocation
1795 function. */
1797 /* True if the storage must be initialized, either by a constructor
1798 or due to an explicit new-initializer. */
1800 /* The address of the thing allocated, not including any cookie. In
1801 particular, if an array cookie is in use, DATA_ADDR is the
1802 address of the first array element. This node is a VAR_DECL, and
1803 is therefore reusable. */
1804 tree data_addr;
1808 {
1811 }
1813 {
1818 }
1820 /* If our base type is an array, then make sure we know how many elements
1821 it has. */
1828 complain);
1831 {
1835 }
1844 {
1848 }
1856 /* If PLACEMENT is a single simple pointer type not passed by
1857 reference, prepare to capture it in a temporary variable. Do
1858 this now, since PLACEMENT will change in the calls below. */
1865 /* Allocate the object. */
1867 {
1868 tree class_addr;
1878 {
1882 }
1884 {
1888 }
1891 alloc_call = (cp_build_function_call
1894 complain));
1895 }
1897 {
1900 }
1901 else
1902 {
1903 tree fnname;
1904 tree fns;
1910 && (array_p
1913 {
1914 /* Use a class-specific operator new. */
1915 /* If a cookie is required, add some extra space. */
1917 {
1920 }
1921 /* Create the argument list. */
1923 /* Do name-lookup to find the appropriate operator. */
1926 {
1930 }
1932 {
1934 {
1937 }
1939 }
1943 LOOKUP_NORMAL,
1945 complain);
1946 }
1947 else
1948 {
1949 /* Use a global operator new. */
1950 /* See if a cookie might be required. */
1953 else
1959 }
1960 }
1967 /* If we found a simple case of PLACEMENT_EXPR above, then copy it
1968 into a temporary variable. */
1975 {
1980 {
1984 }
1985 }
1987 /* In the simple case, we can stop now. */
1992 /* Store the result of the allocation call in a variable so that we can
1993 use it more than once. */
1997 /* Strip any COMPOUND_EXPRs from ALLOC_CALL. */
2001 /* Now, check to see if this function is actually a placement
2002 allocation function. This can happen even when PLACEMENT is NULL
2003 because we might have something like:
2005 struct S { void* operator new (size_t, int i = 0); };
2007 A call to `new S' will get this allocation function, even though
2008 there is no explicit placement argument. If there is more than
2009 one argument, or there are variable arguments, then this is a
2010 placement allocation function. */
2011 placement_allocation_fn_p
2015 /* Preevaluate the placement args so that we don't reevaluate them for a
2016 placement delete. */
2018 {
2019 tree inits;
2023 alloc_expr);
2024 }
2026 /* unless an allocation function is declared with an empty excep-
2027 tion-specification (_except.spec_), throw(), it indicates failure to
2028 allocate storage by throwing a bad_alloc exception (clause _except_,
2029 _lib.bad.alloc_); it returns a non-null pointer otherwise If the allo-
2030 cation function is declared with an empty exception-specification,
2031 throw(), it returns null to indicate failure to allocate storage and a
2032 non-null pointer otherwise.
2034 So check for a null exception spec on the op new we just called. */
2040 {
2041 tree cookie;
2042 tree cookie_ptr;
2043 tree size_ptr_type;
2045 /* Adjust so we're pointing to the start of the object. */
2049 /* Store the number of bytes allocated so that we can know how
2050 many elements to destroy later. We use the last sizeof
2051 (size_t) bytes to store the number of elements. */
2063 {
2064 /* Also store the element size. */
2075 }
2076 }
2077 else
2078 {
2081 }
2083 /* Now use a pointer to the type we've actually allocated. */
2085 /* But we want to operate on a non-const version to start with,
2086 since we'll be modifying the elements. */
2087 non_const_pointer_type = build_pointer_type
2091 /* Any further uses of alloc_node will want this type, too. */
2094 /* Now initialize the allocated object. Note that we preevaluate the
2095 initialization expression, apart from the actual constructor call or
2096 assignment--we do this because we want to delay the allocation as long
2097 as possible in order to minimize the size of the exception region for
2098 placement delete. */
2100 {
2105 {
2108 }
2111 {
2116 {
2121 else
2122 {
2127 }
2130 }
2132 {
2135 else
2138 }
2139 init_expr
2143 integer_one_node,
2144 complain),
2145 vecinit,
2146 explicit_value_init_p,
2148 complain);
2150 /* An array initialization is stable because the initialization
2151 of each element is a full-expression, so the temporaries don't
2152 leak out. */
2154 }
2155 else
2156 {
2160 {
2162 complete_ctor_identifier,
2164 LOOKUP_NORMAL,
2165 complain);
2166 }
2168 {
2169 /* Something like `new int()'. */
2172 }
2173 else
2174 {
2175 tree ie;
2177 /* We are processing something like `new int (10)', which
2178 means allocate an int, and initialize it with 10. */
2182 complain);
2183 }
2185 }
2190 /* If any part of the object initialization terminates by throwing an
2191 exception and a suitable deallocation function can be found, the
2192 deallocation function is called to free the memory in which the
2193 object was being constructed, after which the exception continues
2194 to propagate in the context of the new-expression. If no
2195 unambiguous matching deallocation function can be found,
2196 propagating the exception does not cause the object's memory to be
2197 freed. */
2199 {
2201 tree cleanup;
2203 /* The Standard is unclear here, but the right thing to do
2204 is to use the same method for finding deallocation
2205 functions that we use for finding allocation functions. */
2206 cleanup = (build_op_delete_call
2208 alloc_node,
2209 size,
2210 globally_qualified_p,
2212 alloc_fn));
2217 /* This is much simpler if we were able to preevaluate all of
2218 the arguments to the constructor call. */
2219 {
2220 /* CLEANUP is compiler-generated, so no diagnostics. */
2224 /* Likewise, this try-catch is compiler-generated. */
2226 }
2227 else
2228 /* Ack! First we allocate the memory. Then we set our sentry
2229 variable to true, and expand a cleanup that deletes the
2230 memory if sentry is true. Then we run the constructor, and
2231 finally clear the sentry.
2233 We need to do this because we allocate the space first, so
2234 if there are any temporaries with cleanups in the
2235 constructor args and we weren't able to preevaluate them, we
2236 need this EH region to extend until end of full-expression
2237 to preserve nesting. */
2238 {
2246 /* CLEANUP is compiler-generated, so no diagnostics. */
2256 init_expr
2259 end));
2260 /* Likewise, this is compiler-generated. */
2262 }
2263 }
2264 }
2265 else
2268 /* Now build up the return value in reverse order. */
2278 /* If we don't have an initializer or a cookie, strip the TARGET_EXPR
2279 and return the call (which doesn't need to be adjusted). */
2281 else
2282 {
2284 {
2287 integer_zero_node,
2288 complain);
2290 complain);
2291 }
2293 /* Perform the allocation before anything else, so that ALLOC_NODE
2294 has been initialized before we start using it. */
2296 }
2301 /* A new-expression is never an lvalue. */
2305 }
2307 /* Generate a representation for a C++ "new" expression. *PLACEMENT
2308 is a vector of placement-new arguments (or NULL if none). If NELTS
2309 is NULL, TYPE is the type of the storage to be allocated. If NELTS
2310 is not NULL, then this is an array-new allocation; TYPE is the type
2311 of the elements in the array and NELTS is the number of elements in
2312 the array. *INIT, if non-NULL, is the initializer for the new
2313 object, or an empty vector to indicate an initializer of "()". If
2314 USE_GLOBAL_NEW is true, then the user explicitly wrote "::new"
2315 rather than just "new". This may change PLACEMENT and INIT. */
2317 tree
2320 {
2321 tree rval;
2330 {
2334 }
2337 {
2343 use_global_new);
2353 }
2356 {
2358 {
2361 else
2363 }
2365 }
2367 /* ``A reference cannot be created by the new operator. A reference
2368 is not an object (8.2.2, 8.4.3), so a pointer to it could not be
2369 returned by new.'' ARM 5.3.3 */
2371 {
2374 else
2377 }
2380 {
2384 }
2386 /* The type allocated must be complete. If the new-type-id was
2387 "T[N]" then we are just checking that "T" is complete here, but
2388 that is equivalent, since the value of "N" doesn't matter. */
2397 {
2403 }
2405 /* Wrap it in a NOP_EXPR so warn_if_unused_value doesn't complain. */
2410 }
2412 /* Given a Java class, return a decl for the corresponding java.lang.Class. */
2414 tree
2416 {
2422 {
2425 {
2428 }
2430 }
2432 /* Mangle the class$ field. */
2433 {
2434 tree field;
2437 {
2441 }
2443 {
2446 }
2447 }
2451 {
2461 }
2463 }
2464 \f
2465 static tree
2468 {
2469 tree virtual_size;
2473 /* Temporary variables used by the loop. */
2476 /* This is the body of the loop that implements the deletion of a
2477 single element, and moves temp variables to next elements. */
2478 tree body;
2480 /* This is the LOOP_EXPR that governs the deletion of the elements. */
2483 /* This is the thing that governs what to do after the loop has run. */
2486 /* This is the BIND_EXPR which holds the outermost iterator of the
2487 loop. It is convenient to set this variable up and test it before
2488 executing any other code in the loop.
2489 This is also the containing expression returned by this function. */
2491 tree tmp;
2493 /* We should only have 1-D arrays here. */
2499 /* The below is short by the cookie size. */
2508 virtual_size),
2509 tf_warning_or_error);
2518 body = build_compound_expr
2522 tf_warning_or_error));
2523 body = build_compound_expr
2531 no_destructor:
2532 /* If the delete flag is one, or anything else with the low bit set,
2533 delete the storage. */
2535 {
2536 tree base_tbd;
2538 /* The below is short by the cookie size. */
2543 /* no header */
2545 else
2546 {
2547 tree cookie_size;
2550 base_tbd
2553 MINUS_EXPR,
2555 base),
2556 cookie_size,
2557 tf_warning_or_error));
2558 /* True size with header. */
2560 }
2568 }
2572 ;
2575 else
2581 /* Outermost wrapper: If pointer is null, punt. */
2586 integer_zero_node)),
2591 {
2594 }
2597 /* Pre-evaluate the SAVE_EXPR outside of the BIND_EXPR. */
2601 }
2603 /* Create an unnamed variable of the indicated TYPE. */
2605 tree
2607 {
2608 tree decl;
2618 }
2620 /* Create a new temporary variable of the indicated TYPE, initialized
2621 to INIT.
2623 It is not entered into current_binding_level, because that breaks
2624 things when it comes time to do final cleanups (which take place
2625 "outside" the binding contour of the function). */
2627 static tree
2629 {
2630 tree decl;
2636 tf_warning_or_error));
2639 }
2641 /* `build_vec_init' returns tree structure that performs
2642 initialization of a vector of aggregate types.
2644 BASE is a reference to the vector, of ARRAY_TYPE, or a pointer
2645 to the first element, of POINTER_TYPE.
2646 MAXINDEX is the maximum index of the array (one less than the
2647 number of elements). It is only used if BASE is a pointer or
2648 TYPE_DOMAIN (TREE_TYPE (BASE)) == NULL_TREE.
2650 INIT is the (possibly NULL) initializer.
2652 If EXPLICIT_VALUE_INIT_P is true, then INIT must be NULL. All
2653 elements in the array are value-initialized.
2655 FROM_ARRAY is 0 if we should init everything with INIT
2656 (i.e., every element initialized from INIT).
2657 FROM_ARRAY is 1 if we should index into INIT in parallel
2658 with initialization of DECL.
2659 FROM_ARRAY is 2 if we should index into INIT in parallel,
2660 but use assignment instead of initialization. */
2662 tree
2666 {
2667 tree rval;
2670 tree iterator;
2671 /* The type of BASE. */
2673 /* The type of an element in the array. */
2675 /* The element type reached after removing all outer array
2676 types. */
2677 tree inner_elt_type;
2678 /* The type of a pointer to an element in the array. */
2679 tree ptype;
2680 tree stmt_expr;
2681 tree compound_stmt;
2698 /* Look through the TARGET_EXPR around a compound literal. */
2711 /* Don't do this if the CONSTRUCTOR might contain something
2712 that might throw and require us to clean up. */
2716 {
2717 /* Do non-default initialization of trivial arrays resulting from
2718 brace-enclosed initializers. In this case, digest_init and
2719 store_constructor will handle the semantics for us. */
2723 }
2727 {
2730 }
2731 else
2734 /* The code we are generating looks like:
2735 ({
2736 T* t1 = (T*) base;
2737 T* rval = t1;
2738 ptrdiff_t iterator = maxindex;
2739 try {
2740 for (; iterator != -1; --iterator) {
2741 ... initialize *t1 ...
2742 ++t1;
2743 }
2744 } catch (...) {
2745 ... destroy elements that were constructed ...
2746 }
2747 rval;
2748 })
2750 We can omit the try and catch blocks if we know that the
2751 initialization will never throw an exception, or if the array
2752 elements do not have destructors. We can omit the loop completely if
2753 the elements of the array do not have constructors.
2755 We actually wrap the entire body of the above in a STMT_EXPR, for
2756 tidiness.
2758 When copying from array to another, when the array elements have
2759 only trivial copy constructors, we should use __builtin_memcpy
2760 rather than generating a loop. That way, we could take advantage
2761 of whatever cleverness the back end has for dealing with copies
2762 of blocks of memory. */
2771 /* If initializing one array from another, initialize element by
2772 element. We rely upon the below calls to do the argument
2773 checking. Evaluate the initializer before entering the try block. */
2775 {
2780 }
2782 /* Protect the entire array initialization so that we can destroy
2783 the partially constructed array if an exception is thrown.
2784 But don't do this if we're assigning. */
2787 {
2789 }
2792 {
2793 /* Do non-default initialization of non-trivial arrays resulting from
2794 brace-enclosed initializers. */
2796 tree elt;
2800 {
2803 num_initialized_elts++;
2808 else
2814 complain));
2816 complain));
2817 }
2819 /* Clear out INIT so that we don't get confused below. */
2821 }
2823 {
2829 {
2833 }
2834 }
2836 /* Now, default-initialize any remaining elements. We don't need to
2837 do that if a) the type does not need constructing, or b) we've
2838 already initialized all the elements.
2840 We do need to keep going if we're copying an array. */
2845 && (num_initialized_elts
2847 {
2848 /* If the ITERATOR is equal to -1, then we don't have to loop;
2849 we've already initialized all the elements. */
2850 tree for_stmt;
2851 tree elt_init;
2852 tree to;
2858 for_stmt);
2860 complain),
2861 for_stmt);
2866 {
2867 tree from;
2871 else
2876 complain);
2881 complain);
2882 else
2884 }
2886 {
2888 sorry
2892 explicit_value_init_p,
2894 }
2898 else
2899 {
2902 }
2909 complain));
2912 complain));
2915 }
2917 /* Make sure to cleanup any partially constructed elements. */
2920 {
2921 tree e;
2924 complain);
2926 /* Flatten multi-dimensional array since build_vec_delete only
2927 expects one-dimensional array. */
2932 complain);
2939 }
2941 /* The value of the array initialization is the array itself, RVAL
2942 is a pointer to the first element. */
2947 /* Now make the result have the correct type. */
2949 {
2954 }
2958 }
2960 /* Call the DTOR_KIND destructor for EXP. FLAGS are as for
2961 build_delete. */
2963 static tree
2965 {
2966 tree name;
2967 tree fn;
2969 {
2984 }
2989 flags,
2991 tf_warning_or_error);
2992 }
2994 /* Generate a call to a destructor. TYPE is the type to cast ADDR to.
2995 ADDR is an expression which yields the store to be destroyed.
2996 AUTO_DELETE is the name of the destructor to call, i.e., either
2997 sfk_complete_destructor, sfk_base_destructor, or
2998 sfk_deleting_destructor.
3000 FLAGS is the logical disjunction of zero or more LOOKUP_
3001 flags. See cp-tree.h for more info. */
3003 tree
3006 {
3007 tree expr;
3012 /* Can happen when CURRENT_EXCEPTION_OBJECT gets its type
3013 set to `error_mark_node' before it gets properly cleaned up. */
3020 {
3027 /* We don't want to warn about delete of void*, only other
3028 incomplete types. Deleting other incomplete types
3029 invokes undefined behavior, but it is not ill-formed, so
3030 compile to something that would even do The Right Thing
3031 (TM) should the type have a trivial dtor and no delete
3032 operator. */
3034 {
3037 {
3040 {
3043 "operator delete will be called, even if they are "
3045 }
3047 }
3048 }
3050 /* Call the builtin operator delete. */
3055 /* Throw away const and volatile on target type of addr. */
3057 }
3059 {
3060 handle_array:
3063 {
3066 }
3069 }
3070 else
3071 {
3072 /* Don't check PROTECT here; leave that decision to the
3073 destructor. If the destructor is accessible, call it,
3074 else report error. */
3080 }
3085 {
3091 use_global_delete,
3094 }
3095 else
3096 {
3099 tree ifexp;
3104 /* For `::delete x', we must not use the deleting destructor
3105 since then we would not be sure to get the global `operator
3106 delete'. */
3108 {
3109 /* We will use ADDR multiple times so we must save it. */
3112 /* Delete the object. */
3114 /* Otherwise, treat this like a complete object destructor
3115 call. */
3117 }
3118 /* If the destructor is non-virtual, there is no deleting
3119 variant. Instead, we must explicitly call the appropriate
3120 `operator delete' here. */
3123 {
3124 /* We will use ADDR multiple times so we must save it. */
3126 /* Build the call. */
3128 addr,
3133 /* Call the complete object destructor. */
3135 }
3138 {
3139 /* Make sure we have access to the member op delete, even though
3140 we'll actually be calling it from the destructor. */
3145 }
3148 tf_warning_or_error),
3153 /* We need to calculate this before the dtor changes the vptr. */
3158 /* Explicit destructor call; don't check for null pointer. */
3160 else
3161 /* Handle deleting a null pointer. */
3164 tf_warning_or_error));
3171 }
3172 }
3174 /* At the beginning of a destructor, push cleanups that will call the
3175 destructors for our base classes and members.
3177 Called from begin_destructor_body. */
3179 void
3181 {
3184 tree member;
3185 tree expr;
3188 /* Run destructors for all virtual baseclasses. */
3190 {
3191 tree cond = (condition_conversion
3193 current_in_charge_parm,
3194 integer_two_node)));
3196 /* The CLASSTYPE_VBASECLASSES vector is in initialization
3197 order, which is also the right order for pushing cleanups. */
3200 {
3202 {
3204 base_dtor_identifier,
3205 NULL,
3206 base_binfo,
3207 (LOOKUP_NORMAL
3209 tf_warning_or_error);
3213 }
3214 }
3215 }
3217 /* Take care of the remaining baseclasses. */
3220 {
3226 base_dtor_identifier,
3229 tf_warning_or_error);
3231 }
3235 {
3241 {
3242 tree this_member = (build_class_member_access_expr
3246 tf_warning_or_error));
3249 sfk_complete_destructor,
3253 }
3254 }
3255 }
3257 /* Build a C++ vector delete expression.
3258 MAXINDEX is the number of elements to be deleted.
3259 ELT_SIZE is the nominal size of each element in the vector.
3260 BASE is the expression that should yield the store to be deleted.
3261 This function expands (or synthesizes) these calls itself.
3262 AUTO_DELETE_VEC says whether the container (vector) should be deallocated.
3264 This also calls delete for virtual baseclasses of elements of the vector.
3266 Update: MAXINDEX is no longer needed. The size can be extracted from the
3267 start of the vector for pointers, and from the type for arrays. We still
3268 use MAXINDEX for arrays because it happens to already have one of the
3269 values we'd have to extract. (We could use MAXINDEX with pointers to
3270 confirm the size, and trap if the numbers differ; not clear that it'd
3271 be worth bothering.) */
3273 tree
3276 {
3277 tree type;
3278 tree rval;
3284 {
3285 /* Step back one from start of vector, and read dimension. */
3286 tree cookie_addr;
3290 {
3293 }
3298 size_ptr_type,
3300 cookie_addr);
3302 }
3304 {
3305 /* Get the total number of things in the array, maxindex is a
3306 bad name. */
3311 {
3314 }
3315 }
3316 else
3317 {
3321 }
3324 use_global_delete);
3329 }