| blob | 68ffe3a3dd02be912bcf4d13485f31c8de47818d |
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. */
224 else
227 /* If we have an error_mark here, we should just return error mark
228 as we don't know the size of the array yet. */
233 /* A zero-sized array, which is accepted as an extension, will
234 have an upper bound of -1. */
236 {
242 /* If this is a one element array, we just use a regular init. */
245 else
247 max_index);
251 static_storage_p);
252 }
254 /* Build a constructor to contain the initializations. */
256 }
259 else
262 /* In all cases, the initializer is a constant. */
267 }
269 /* Return a suitable initializer for value-initializing an object of type
270 TYPE, as described in [dcl.init]. */
272 tree
274 {
275 /* [dcl.init]
277 To value-initialize an object of type T means:
279 - if T is a class type (clause 9) with a user-provided constructor
280 (12.1), then the default constructor for T is called (and the
281 initialization is ill-formed if T has no accessible default
282 constructor);
284 - if T is a non-union class type without a user-provided constructor,
285 then every non-static data member and base-class component of T is
286 value-initialized;92)
288 - if T is an array type, then each element is value-initialized;
290 - otherwise, the object is zero-initialized.
292 A program that calls for default-initialization or
293 value-initialization of an entity of reference type is ill-formed.
295 92) Value-initialization for such a class object may be implemented by
296 zero-initializing the object and then calling the default
297 constructor. */
300 {
302 return build_aggr_init_expr
306 tf_warning_or_error));
308 {
309 /* This is a class that needs constructing, but doesn't have
310 a user-provided constructor. So we need to zero-initialize
311 the object and then call the implicitly defined ctor.
312 This will be handled in simplify_aggr_init_expr. */
313 tree ctor = build_special_member_call
320 }
321 }
323 }
325 /* Like build_value_init, but don't call the constructor for TYPE. Used
326 for base initializers. */
328 tree
330 {
332 {
336 {
337 tree field;
340 /* Iterate over the fields, building initializations. */
342 {
353 /* We could skip vfields and fields of types with
354 user-defined constructors, but I think that won't improve
355 performance at all; it should be simpler in general just
356 to zero out the entire object than try to only zero the
357 bits that actually need it. */
359 /* Note that for class types there will be FIELD_DECLs
360 corresponding to base classes as well. Thus, iterating
361 over TYPE_FIELDs will result in correct initialization of
362 all of the subobjects. */
367 }
369 /* Build a constructor to contain the zero- initializations. */
371 }
372 }
374 {
377 /* Iterate over the array elements, building initializations. */
380 /* If we have an error_mark here, we should just return error mark
381 as we don't know the size of the array yet. */
386 /* A zero-sized array, which is accepted as an extension, will
387 have an upper bound of -1. */
389 {
395 /* If this is a one element array, we just use a regular init. */
398 else
400 max_index);
404 /* The gimplifier can't deal with a RANGE_EXPR of TARGET_EXPRs. */
407 }
409 /* Build a constructor to contain the initializations. */
411 }
414 }
416 /* Initialize MEMBER, a FIELD_DECL, with INIT, a TREE_LIST of
417 arguments. If TREE_LIST is void_type_node, an empty initializer
418 list was given; if NULL_TREE no initializer was given. */
420 static void
422 {
423 tree decl;
426 /* Effective C++ rule 12 requires that all data members be
427 initialized. */
431 member);
433 /* Get an lvalue for the data member. */
437 tf_warning_or_error);
442 {
443 /* mem() means value-initialization. */
445 {
449 tf_warning_or_error);
451 }
452 else
453 {
457 member);
458 else
459 {
462 }
463 }
464 }
465 /* Deal with this here, as we will get confused if we try to call the
466 assignment op for an anonymous union. This can happen in a
467 synthesized copy constructor. */
469 {
471 {
474 }
475 }
477 {
482 {
483 /* Initialization of one array from another. */
487 tf_warning_or_error));
488 }
489 else
490 {
494 /* TYPE_NEEDS_CONSTRUCTING can be set just because we have a
495 vtable; still give this diagnostic. */
500 tf_warning_or_error));
501 }
502 }
503 else
504 {
506 {
507 /* member traversal: note it leaves init NULL */
511 member);
516 }
518 /* There was an explicit member initialization. Do some work
519 in that case. */
524 tf_warning_or_error));
525 }
528 {
529 tree expr;
534 tf_warning_or_error);
540 }
541 }
543 /* Returns a TREE_LIST containing (as the TREE_PURPOSE of each node) all
544 the FIELD_DECLs on the TYPE_FIELDS list for T, in reverse order. */
546 static tree
548 {
549 tree fields;
553 /* Note whether or not T is a union. */
558 {
559 /* Skip CONST_DECLs for enumeration constants and so forth. */
563 /* Keep track of whether or not any fields are unions. */
567 /* For an anonymous struct or union, we must recursively
568 consider the fields of the anonymous type. They can be
569 directly initialized from the constructor. */
571 {
572 /* Add this field itself. Synthesized copy constructors
573 initialize the entire aggregate. */
575 /* And now add the fields in the anonymous aggregate. */
577 uses_unions_p);
578 }
579 /* Add this field. */
582 }
585 }
587 /* The MEM_INITS are a TREE_LIST. The TREE_PURPOSE of each list gives
588 a FIELD_DECL or BINFO in T that needs initialization. The
589 TREE_VALUE gives the initializer, or list of initializer arguments.
591 Return a TREE_LIST containing all of the initializations required
592 for T, in the order in which they should be performed. The output
593 list has the same format as the input. */
595 static tree
597 {
598 tree init;
600 tree sorted_inits;
601 tree next_subobject;
606 /* Build up a list of initializations. The TREE_PURPOSE of entry
607 will be the subobject (a FIELD_DECL or BINFO) to initialize. The
608 TREE_VALUE will be the constructor arguments, or NULL if no
609 explicit initialization was provided. */
612 /* Process the virtual bases. */
617 /* Process the direct bases. */
623 /* Process the non-static data members. */
625 /* Reverse the entire list of initializations, so that they are in
626 the order that they will actually be performed. */
629 /* If the user presented the initializers in an order different from
630 that in which they will actually occur, we issue a warning. Keep
631 track of the next subobject which can be explicitly initialized
632 without issuing a warning. */
635 /* Go through the explicit initializers, filling in TREE_PURPOSE in
636 the SORTED_INITS. */
638 {
639 tree subobject;
640 tree subobject_init;
644 /* If the explicit initializers are in sorted order, then
645 SUBOBJECT will be NEXT_SUBOBJECT, or something following
646 it. */
648 subobject_init;
653 /* Issue a warning if the explicit initializer order does not
654 match that which will actually occur.
655 ??? Are all these on the correct lines? */
657 {
661 else
666 else
670 }
672 /* Look again, from the beginning of the list. */
674 {
678 }
680 /* It is invalid to initialize the same subobject more than
681 once. */
683 {
687 subobject);
688 else
691 subobject);
692 }
694 /* Record the initialization. */
697 }
699 /* [class.base.init]
701 If a ctor-initializer specifies more than one mem-initializer for
702 multiple members of the same union (including members of
703 anonymous unions), the ctor-initializer is ill-formed. */
705 {
708 {
709 tree field;
710 tree field_type;
713 /* Skip uninitialized members and base classes. */
717 /* See if this field is a member of a union, or a member of a
718 structure contained in a union, etc. */
725 /* If this field is not a member of a union, skip it. */
729 /* It's only an error if we have two initializers for the same
730 union type. */
732 {
735 }
737 /* See if LAST_FIELD and the field initialized by INIT are
738 members of the same union. If so, there's a problem,
739 unless they're actually members of the same structure
740 which is itself a member of a union. For example, given:
742 union { struct { int i; int j; }; };
744 initializing both `i' and `j' makes sense. */
747 do
748 {
749 tree last_field_type;
753 {
755 {
759 last_field_type);
762 }
768 }
770 /* If we've reached the outermost class, then we're
771 done. */
776 }
780 }
781 }
784 }
786 /* Initialize all bases and members of CURRENT_CLASS_TYPE. MEM_INITS
787 is a TREE_LIST giving the explicit mem-initializer-list for the
788 constructor. The TREE_PURPOSE of each entry is a subobject (a
789 FIELD_DECL or a BINFO) of the CURRENT_CLASS_TYPE. The TREE_VALUE
790 is a TREE_LIST giving the arguments to the constructor or
791 void_type_node for an empty list of arguments. */
793 void
795 {
796 /* We will already have issued an error message about the fact that
797 the type is incomplete. */
801 /* Sort the mem-initializers into the order in which the
802 initializations should be performed. */
807 /* Initialize base classes. */
810 {
814 /* If these initializations are taking place in a copy constructor,
815 the base class should probably be explicitly initialized if there
816 is a user-defined constructor in the base class (other than the
817 default constructor, which will be called anyway). */
822 "base class %q#T should be explicitly initialized in the "
826 /* Initialize the base. */
829 else
830 {
831 tree base_addr;
837 tf_warning_or_error),
838 arguments,
839 LOOKUP_NORMAL,
840 tf_warning_or_error);
842 }
845 }
848 /* Initialize the vptrs. */
851 /* Initialize the data members. */
853 {
857 }
858 }
860 /* Returns the address of the vtable (i.e., the value that should be
861 assigned to the vptr) for BINFO. */
863 static tree
865 {
867 tree vtbl;
870 /* If this is a virtual primary base, then the vtable we want to store
871 is that for the base this is being used as the primary base of. We
872 can't simply skip the initialization, because we may be expanding the
873 inits of a subobject constructor where the virtual base layout
874 can be different. */
878 /* Figure out what vtable BINFO's vtable is based on, and mark it as
879 used. */
883 /* Now compute the address to use when initializing the vptr. */
889 }
891 /* This code sets up the virtual function tables appropriate for
892 the pointer DECL. It is a one-ply initialization.
894 BINFO is the exact type that DECL is supposed to be. In
895 multiple inheritance, this might mean "C's A" if C : A, B. */
897 static void
899 {
901 tree vtt_index;
903 /* Compute the initializer for vptr. */
906 /* We may get this vptr from a VTT, if this is a subobject
907 constructor or subobject destructor. */
910 {
911 tree vtbl2;
912 tree vtt_parm;
914 /* Compute the value to use, when there's a VTT. */
918 vtt_parm,
919 vtt_index);
923 /* The actual initializer is the VTT value only in the subobject
924 constructor. In maybe_clone_body we'll substitute NULL for
925 the vtt_parm in the case of the non-subobject constructor. */
930 vtbl2,
931 vtbl);
932 }
934 /* Compute the location of the vtpr. */
936 tf_warning_or_error),
940 /* Assign the vtable to the vptr. */
943 tf_warning_or_error));
944 }
946 /* If an exception is thrown in a constructor, those base classes already
947 constructed must be destroyed. This function creates the cleanup
948 for BINFO, which has just been constructed. If FLAG is non-NULL,
949 it is a DECL which is nonzero when this base needs to be
950 destroyed. */
952 static void
954 {
955 tree expr;
960 /* Call the destructor. */
962 base_dtor_identifier,
963 NULL,
964 binfo,
966 tf_warning_or_error);
973 }
975 /* Construct the virtual base-class VBASE passing the ARGUMENTS to its
976 constructor. */
978 static void
980 {
981 tree inner_if_stmt;
982 tree exp;
983 tree flag;
985 /* If there are virtual base classes with destructors, we need to
986 emit cleanups to destroy them if an exception is thrown during
987 the construction process. These exception regions (i.e., the
988 period during which the cleanups must occur) begin from the time
989 the construction is complete to the end of the function. If we
990 create a conditional block in which to initialize the
991 base-classes, then the cleanup region for the virtual base begins
992 inside a block, and ends outside of that block. This situation
993 confuses the sjlj exception-handling code. Therefore, we do not
994 create a single conditional block, but one for each
995 initialization. (That way the cleanup regions always begin
996 in the outer block.) We trust the back end to figure out
997 that the FLAG will not change across initializations, and
998 avoid doing multiple tests. */
1003 /* Compute the location of the virtual base. If we're
1004 constructing virtual bases, then we must be the most derived
1005 class. Therefore, we don't have to look up the virtual base;
1006 we already know where it is. */
1015 }
1017 /* Find the context in which this FIELD can be initialized. */
1019 static tree
1021 {
1024 /* Anonymous union members can be initialized in the first enclosing
1025 non-anonymous union context. */
1029 }
1031 /* Function to give error message if member initialization specification
1032 is erroneous. FIELD is the member we decided to initialize.
1033 TYPE is the type for which the initialization is being performed.
1034 FIELD must be a member of TYPE.
1036 MEMBER_NAME is the name of the member. */
1038 static int
1040 {
1044 {
1046 member_name);
1048 }
1050 {
1053 field);
1055 }
1057 {
1061 }
1063 {
1065 member_name);
1067 }
1070 }
1072 /* NAME is a FIELD_DECL, an IDENTIFIER_NODE which names a field, or it
1073 is a _TYPE node or TYPE_DECL which names a base for that type.
1074 Check the validity of NAME, and return either the base _TYPE, base
1075 binfo, or the FIELD_DECL of the member. If NAME is invalid, return
1076 NULL_TREE and issue a diagnostic.
1078 An old style unnamed direct single base construction is permitted,
1079 where NAME is NULL. */
1081 tree
1083 {
1084 tree basetype;
1085 tree field;
1091 {
1092 /* This is an obsolete unnamed base class initializer. The
1093 parser will already have warned about its use. */
1095 {
1098 current_class_type);
1101 basetype = BINFO_TYPE
1106 current_class_type);
1108 }
1109 }
1111 {
1114 }
1117 else
1121 {
1122 tree class_binfo;
1123 tree direct_binfo;
1124 tree virtual_binfo;
1134 /* Look for a direct base. */
1139 /* Look for a virtual base -- unless the direct base is itself
1140 virtual. */
1144 /* [class.base.init]
1146 If a mem-initializer-id is ambiguous because it designates
1147 both a direct non-virtual base class and an inherited virtual
1148 base class, the mem-initializer is ill-formed. */
1150 {
1152 basetype);
1154 }
1157 {
1161 else
1165 }
1168 }
1169 else
1170 {
1173 else
1178 }
1181 }
1183 /* This is like `expand_member_init', only it stores one aggregate
1184 value into another.
1186 INIT comes in two flavors: it is either a value which
1187 is to be stored in EXP, or it is a parameter list
1188 to go to a constructor, which will operate on EXP.
1189 If INIT is not a parameter list for a constructor, then set
1190 LOOKUP_ONLYCONVERTING.
1191 If FLAGS is LOOKUP_ONLYCONVERTING then it is the = init form of
1192 the initializer, if FLAGS is 0, then it is the (init) form.
1193 If `init' is a CONSTRUCTOR, then we emit a warning message,
1194 explaining that such initializations are invalid.
1196 If INIT resolves to a CALL_EXPR which happens to return
1197 something of the type we are looking for, then we know
1198 that we can safely use that call to perform the
1199 initialization.
1201 The virtual function table pointer cannot be set up here, because
1202 we do not really know its type.
1204 This never calls operator=().
1206 When initializing, nothing is CONST.
1208 A default copy constructor may have to be used to perform the
1209 initialization.
1211 A constructor or a conversion operator may have to be used to
1212 perform the initialization, but not both, as it would be ambiguous. */
1214 tree
1216 {
1217 tree stmt_expr;
1218 tree compound_stmt;
1235 {
1236 tree itype;
1238 /* An array may not be initialized use the parenthesized
1239 initialization form -- unless the initializer is "()". */
1241 {
1245 }
1246 /* Must arrange to initialize each element of EXP
1247 from elements of INIT. */
1257 complain);
1264 }
1267 /* Just know that we've seen something for this node. */
1281 }
1283 static void
1285 tsubst_flags_t complain)
1286 {
1288 tree ctor_name;
1290 /* It fails because there may not be a constructor which takes
1291 its own type as the first (or only parameter), but which does
1292 take other types via a conversion. So, if the thing initializing
1293 the expression is a unit element of type X, first try X(X&),
1294 followed by initialization by X. If neither of these work
1295 out, then look hard. */
1296 tree rval;
1301 {
1302 /* Base subobjects should only get direct-initialization. */
1306 /* Do nothing. We hit this in two cases: Reference initialization,
1307 where we aren't initializing a real variable, so we don't want
1308 to run a new constructor; and catching an exception, where we
1309 have already built up the constructor call so we could wrap it
1313 {
1314 /* A brace-enclosed initializer for an aggregate. */
1316 }
1317 else
1321 /* We need to protect the initialization of a catch parm with a
1322 call to terminate(), which shows up as a MUST_NOT_THROW_EXPR
1323 around the TARGET_EXPR for the copy constructor. See
1324 initialize_handler_parm. */
1325 {
1329 }
1330 else
1335 }
1340 {
1344 }
1345 else
1350 else
1354 complain);
1361 }
1363 /* This function is responsible for initializing EXP with INIT
1364 (if any).
1366 BINFO is the binfo of the type for who we are performing the
1367 initialization. For example, if W is a virtual base class of A and B,
1368 and C : A, B.
1369 If we are initializing B, then W must contain B's W vtable, whereas
1370 were we initializing C, W must contain C's W vtable.
1372 TRUE_EXP is nonzero if it is the true expression being initialized.
1373 In this case, it may be EXP, or may just contain EXP. The reason we
1374 need this is because if EXP is a base element of TRUE_EXP, we
1375 don't necessarily know by looking at EXP where its virtual
1376 baseclass fields should really be pointing. But we do know
1377 from TRUE_EXP. In constructors, we don't know anything about
1378 the value being initialized.
1380 FLAGS is just passed to `build_new_method_call'. See that function
1381 for its description. */
1383 static void
1385 tsubst_flags_t complain)
1386 {
1392 /* Use a function returning the desired type to initialize EXP for us.
1393 If the function is a constructor, and its first argument is
1394 NULL_TREE, know that it was meant for us--just slide exp on
1395 in and expand the constructor. Constructors now come
1396 as TARGET_EXPRs. */
1400 {
1401 /* If store_init_value returns NULL_TREE, the INIT has been
1402 recorded as the DECL_INITIAL for EXP. That means there's
1403 nothing more we have to do. */
1408 }
1410 /* If an explicit -- but empty -- initializer list was present,
1411 that's value-initialization. */
1413 {
1414 /* If there's a user-provided constructor, we just call that. */
1417 /* If there isn't, but we still need to call the constructor,
1418 zero out the object first. */
1420 {
1424 /* And then call the constructor. */
1425 }
1426 /* If we don't need to mess with the constructor at all,
1427 then just zero out the object and we're done. */
1428 else
1429 {
1433 }
1435 }
1437 /* We know that expand_default_init can handle everything we want
1438 at this point. */
1440 }
1442 /* Report an error if TYPE is not a user-defined, class type. If
1443 OR_ELSE is nonzero, give an error message. */
1445 int
1447 {
1452 {
1456 }
1458 }
1460 tree
1462 {
1468 else
1470 }
1472 /* Build a reference to a member of an aggregate. This is not a C++
1473 `&', but really something which can have its address taken, and
1474 then act as a pointer to member, for example TYPE :: FIELD can have
1475 its address taken by saying & TYPE :: FIELD. ADDRESS_P is true if
1476 this expression is the operand of "&".
1478 @@ Prints out lousy diagnostics for operator <typename>
1479 @@ fields.
1481 @@ This function should be rewritten and placed in search.c. */
1483 tree
1485 {
1486 tree decl;
1489 /* class templates can come in as TEMPLATE_DECLs here. */
1502 /* Callers should call mark_used before this point. */
1507 {
1510 }
1512 /* Entities other than non-static members need no further
1513 processing. */
1520 {
1523 }
1525 /* Set up BASEBINFO for member lookup. */
1528 /* A lot of this logic is now handled in lookup_member. */
1530 {
1531 /* Go from the TREE_BASELINK to the member function info. */
1535 {
1536 /* Get rid of a potential OVERLOAD around it. */
1539 /* Unique functions are handled easily. */
1541 /* For non-static member of base class, we need a special rule
1542 for access checking [class.protected]:
1544 If the access is to form a pointer to member, the
1545 nested-name-specifier shall name the derived class
1546 (or any class derived from that class). */
1550 else
1556 }
1557 else
1559 }
1561 /* We need additional test besides the one in
1562 check_accessibility_of_qualified_id in case it is
1563 a pointer to non-static member. */
1567 {
1568 /* If MEMBER is non-static, then the program has fallen afoul of
1569 [expr.prim]:
1571 An id-expression that denotes a nonstatic data member or
1572 nonstatic member function of a class can only be used:
1574 -- as part of a class member access (_expr.ref_) in which the
1575 object-expression refers to the member's class or a class
1576 derived from that class, or
1578 -- to form a pointer to member (_expr.unary.op_), or
1580 -- in the body of a nonstatic member function of that class or
1581 of a class derived from that class (_class.mfct.nonstatic_), or
1583 -- in a mem-initializer for a constructor for that class or for
1584 a class derived from that class (_class.base.init_). */
1586 {
1587 /* Build a representation of the qualified name suitable
1588 for use as the operand to "&" -- even though the "&" is
1589 not actually present. */
1591 /* In Microsoft mode, treat a non-static member function as if
1592 it were a pointer-to-member. */
1594 {
1597 tf_warning_or_error);
1598 }
1602 }
1604 {
1607 }
1609 }
1614 }
1616 /* If DECL is a scalar enumeration constant or variable with a
1617 constant initializer, return the initializer (or, its initializers,
1618 recursively); otherwise, return DECL. If INTEGRAL_P, the
1619 initializer is only returned if DECL is an integral
1620 constant-expression. */
1622 static tree
1624 {
1626 || (integral_p
1630 {
1631 tree init;
1632 /* Static data members in template classes may have
1633 non-dependent initializers. References to such non-static
1634 data members are not value-dependent, so we must retrieve the
1635 initializer here. The DECL_INITIAL will have the right type,
1636 but will not have been folded because that would prevent us
1637 from performing all appropriate semantic checks at
1638 instantiation time. */
1643 {
1647 }
1648 else
1649 {
1650 /* If DECL is a static data member in a template
1651 specialization, we must instantiate it here. The
1652 initializer for the static data member is not processed
1653 until needed; we need it now. */
1656 }
1659 /* Initializers in templates are generally expanded during
1660 instantiation, so before that for const int i(2)
1661 INIT is a TREE_LIST with the actual initializer as
1662 TREE_VALUE. */
1664 && init
1670 || (integral_p
1673 /* Do not return an aggregate constant (of which
1674 string literals are a special case), as we do not
1675 want to make inadvertent copies of such entities,
1676 and we must be sure that their addresses are the
1677 same everywhere. */
1682 }
1684 }
1686 /* If DECL is a CONST_DECL, or a constant VAR_DECL initialized by
1687 constant of integral or enumeration type, then return that value.
1688 These are those variables permitted in constant expressions by
1689 [5.19/1]. */
1691 tree
1693 {
1695 }
1697 /* A more relaxed version of integral_constant_value, used by the
1698 common C/C++ code and by the C++ front end for optimization
1699 purposes. */
1701 tree
1703 {
1706 }
1707 \f
1708 /* Common subroutines of build_new and build_vec_delete. */
1710 /* Call the global __builtin_delete to delete ADDR. */
1712 static tree
1714 {
1717 }
1718 \f
1719 /* Build and return a NEW_EXPR. If NELTS is non-NULL, TYPE[NELTS] is
1720 the type of the object being allocated; otherwise, it's just TYPE.
1721 INIT is the initializer, if any. USE_GLOBAL_NEW is true if the
1722 user explicitly wrote "::operator new". PLACEMENT, if non-NULL, is
1723 a vector of arguments to be provided as arguments to a placement
1724 new operator. This routine performs no semantic checks; it just
1725 creates and returns a NEW_EXPR. */
1727 static tree
1730 {
1731 tree init_list;
1732 tree new_expr;
1734 /* If INIT is NULL, the we want to store NULL_TREE in the NEW_EXPR.
1735 If INIT is not NULL, then we want to store VOID_ZERO_NODE. This
1736 permits us to distinguish the case of a missing initializer "new
1737 int" from an empty initializer "new int()". */
1742 else
1747 init_list);
1752 }
1754 /* Generate code for a new-expression, including calling the "operator
1755 new" function, initializing the object, and, if an exception occurs
1756 during construction, cleaning up. The arguments are as for
1757 build_raw_new_expr. This may change PLACEMENT and INIT. */
1759 static tree
1762 tsubst_flags_t complain)
1763 {
1765 /* True iff this is a call to "operator new[]" instead of just
1766 "operator new". */
1768 /* If ARRAY_P is true, the element type of the array. This is never
1769 an ARRAY_TYPE; for something like "new int[3][4]", the
1770 ELT_TYPE is "int". If ARRAY_P is false, this is the same type as
1771 TYPE. */
1772 tree elt_type;
1773 /* The type of the new-expression. (This type is always a pointer
1774 type.) */
1775 tree pointer_type;
1778 /* The address returned by the call to "operator new". This node is
1779 a VAR_DECL and is therefore reusable. */
1780 tree alloc_node;
1781 tree alloc_fn;
1785 /* If non-NULL, the number of extra bytes to allocate at the
1786 beginning of the storage allocated for an array-new expression in
1787 order to store the number of elements. */
1789 tree placement_first;
1791 /* True if the function we are calling is a placement allocation
1792 function. */
1794 /* True if the storage must be initialized, either by a constructor
1795 or due to an explicit new-initializer. */
1797 /* The address of the thing allocated, not including any cookie. In
1798 particular, if an array cookie is in use, DATA_ADDR is the
1799 address of the first array element. This node is a VAR_DECL, and
1800 is therefore reusable. */
1801 tree data_addr;
1805 {
1808 }
1810 {
1815 }
1817 /* If our base type is an array, then make sure we know how many elements
1818 it has. */
1825 complain);
1828 {
1832 }
1841 {
1845 }
1853 /* If PLACEMENT is a single simple pointer type not passed by
1854 reference, prepare to capture it in a temporary variable. Do
1855 this now, since PLACEMENT will change in the calls below. */
1862 /* Allocate the object. */
1864 {
1865 tree class_addr;
1875 {
1879 }
1881 {
1885 }
1888 alloc_call = (cp_build_function_call
1891 complain));
1892 }
1894 {
1897 }
1898 else
1899 {
1900 tree fnname;
1901 tree fns;
1907 && (array_p
1910 {
1911 /* Use a class-specific operator new. */
1912 /* If a cookie is required, add some extra space. */
1914 {
1917 }
1918 /* Create the argument list. */
1920 /* Do name-lookup to find the appropriate operator. */
1923 {
1927 }
1929 {
1931 {
1934 }
1936 }
1940 LOOKUP_NORMAL,
1942 complain);
1943 }
1944 else
1945 {
1946 /* Use a global operator new. */
1947 /* See if a cookie might be required. */
1950 else
1956 }
1957 }
1964 /* If we found a simple case of PLACEMENT_EXPR above, then copy it
1965 into a temporary variable. */
1972 {
1977 {
1981 }
1982 }
1984 /* In the simple case, we can stop now. */
1989 /* Store the result of the allocation call in a variable so that we can
1990 use it more than once. */
1994 /* Strip any COMPOUND_EXPRs from ALLOC_CALL. */
1998 /* Now, check to see if this function is actually a placement
1999 allocation function. This can happen even when PLACEMENT is NULL
2000 because we might have something like:
2002 struct S { void* operator new (size_t, int i = 0); };
2004 A call to `new S' will get this allocation function, even though
2005 there is no explicit placement argument. If there is more than
2006 one argument, or there are variable arguments, then this is a
2007 placement allocation function. */
2008 placement_allocation_fn_p
2012 /* Preevaluate the placement args so that we don't reevaluate them for a
2013 placement delete. */
2015 {
2016 tree inits;
2020 alloc_expr);
2021 }
2023 /* unless an allocation function is declared with an empty excep-
2024 tion-specification (_except.spec_), throw(), it indicates failure to
2025 allocate storage by throwing a bad_alloc exception (clause _except_,
2026 _lib.bad.alloc_); it returns a non-null pointer otherwise If the allo-
2027 cation function is declared with an empty exception-specification,
2028 throw(), it returns null to indicate failure to allocate storage and a
2029 non-null pointer otherwise.
2031 So check for a null exception spec on the op new we just called. */
2037 {
2038 tree cookie;
2039 tree cookie_ptr;
2040 tree size_ptr_type;
2042 /* Adjust so we're pointing to the start of the object. */
2046 /* Store the number of bytes allocated so that we can know how
2047 many elements to destroy later. We use the last sizeof
2048 (size_t) bytes to store the number of elements. */
2059 {
2060 /* Also store the element size. */
2070 }
2071 }
2072 else
2073 {
2076 }
2078 /* Now use a pointer to the type we've actually allocated. */
2080 /* Any further uses of alloc_node will want this type, too. */
2083 /* Now initialize the allocated object. Note that we preevaluate the
2084 initialization expression, apart from the actual constructor call or
2085 assignment--we do this because we want to delay the allocation as long
2086 as possible in order to minimize the size of the exception region for
2087 placement delete. */
2089 {
2094 {
2097 }
2100 {
2102 {
2105 else
2107 }
2108 init_expr
2112 integer_one_node,
2113 complain),
2115 explicit_value_init_p,
2117 complain);
2119 /* An array initialization is stable because the initialization
2120 of each element is a full-expression, so the temporaries don't
2121 leak out. */
2123 }
2124 else
2125 {
2129 {
2131 complete_ctor_identifier,
2133 LOOKUP_NORMAL,
2134 complain);
2135 }
2137 {
2138 /* Something like `new int()'. */
2141 }
2142 else
2143 {
2144 tree ie;
2146 /* We are processing something like `new int (10)', which
2147 means allocate an int, and initialize it with 10. */
2151 complain);
2152 }
2154 }
2159 /* If any part of the object initialization terminates by throwing an
2160 exception and a suitable deallocation function can be found, the
2161 deallocation function is called to free the memory in which the
2162 object was being constructed, after which the exception continues
2163 to propagate in the context of the new-expression. If no
2164 unambiguous matching deallocation function can be found,
2165 propagating the exception does not cause the object's memory to be
2166 freed. */
2168 {
2170 tree cleanup;
2172 /* The Standard is unclear here, but the right thing to do
2173 is to use the same method for finding deallocation
2174 functions that we use for finding allocation functions. */
2175 cleanup = (build_op_delete_call
2177 alloc_node,
2178 size,
2179 globally_qualified_p,
2181 alloc_fn));
2186 /* This is much simpler if we were able to preevaluate all of
2187 the arguments to the constructor call. */
2188 {
2189 /* CLEANUP is compiler-generated, so no diagnostics. */
2193 /* Likewise, this try-catch is compiler-generated. */
2195 }
2196 else
2197 /* Ack! First we allocate the memory. Then we set our sentry
2198 variable to true, and expand a cleanup that deletes the
2199 memory if sentry is true. Then we run the constructor, and
2200 finally clear the sentry.
2202 We need to do this because we allocate the space first, so
2203 if there are any temporaries with cleanups in the
2204 constructor args and we weren't able to preevaluate them, we
2205 need this EH region to extend until end of full-expression
2206 to preserve nesting. */
2207 {
2215 /* CLEANUP is compiler-generated, so no diagnostics. */
2225 init_expr
2228 end));
2229 /* Likewise, this is compiler-generated. */
2231 }
2232 }
2233 }
2234 else
2237 /* Now build up the return value in reverse order. */
2247 /* If we don't have an initializer or a cookie, strip the TARGET_EXPR
2248 and return the call (which doesn't need to be adjusted). */
2250 else
2251 {
2253 {
2256 integer_zero_node,
2257 complain);
2259 complain);
2260 }
2262 /* Perform the allocation before anything else, so that ALLOC_NODE
2263 has been initialized before we start using it. */
2265 }
2270 /* A new-expression is never an lvalue. */
2274 }
2276 /* Generate a representation for a C++ "new" expression. *PLACEMENT
2277 is a vector of placement-new arguments (or NULL if none). If NELTS
2278 is NULL, TYPE is the type of the storage to be allocated. If NELTS
2279 is not NULL, then this is an array-new allocation; TYPE is the type
2280 of the elements in the array and NELTS is the number of elements in
2281 the array. *INIT, if non-NULL, is the initializer for the new
2282 object, or an empty vector to indicate an initializer of "()". If
2283 USE_GLOBAL_NEW is true, then the user explicitly wrote "::new"
2284 rather than just "new". This may change PLACEMENT and INIT. */
2286 tree
2289 {
2290 tree rval;
2299 {
2303 }
2306 {
2312 use_global_new);
2322 }
2325 {
2327 {
2330 else
2332 }
2334 }
2336 /* ``A reference cannot be created by the new operator. A reference
2337 is not an object (8.2.2, 8.4.3), so a pointer to it could not be
2338 returned by new.'' ARM 5.3.3 */
2340 {
2343 else
2346 }
2349 {
2353 }
2355 /* The type allocated must be complete. If the new-type-id was
2356 "T[N]" then we are just checking that "T" is complete here, but
2357 that is equivalent, since the value of "N" doesn't matter. */
2366 {
2372 }
2374 /* Wrap it in a NOP_EXPR so warn_if_unused_value doesn't complain. */
2379 }
2381 /* Given a Java class, return a decl for the corresponding java.lang.Class. */
2383 tree
2385 {
2391 {
2394 {
2397 }
2399 }
2401 /* Mangle the class$ field. */
2402 {
2403 tree field;
2406 {
2410 }
2412 {
2415 }
2416 }
2420 {
2430 }
2432 }
2433 \f
2434 static tree
2437 {
2438 tree virtual_size;
2442 /* Temporary variables used by the loop. */
2445 /* This is the body of the loop that implements the deletion of a
2446 single element, and moves temp variables to next elements. */
2447 tree body;
2449 /* This is the LOOP_EXPR that governs the deletion of the elements. */
2452 /* This is the thing that governs what to do after the loop has run. */
2455 /* This is the BIND_EXPR which holds the outermost iterator of the
2456 loop. It is convenient to set this variable up and test it before
2457 executing any other code in the loop.
2458 This is also the containing expression returned by this function. */
2460 tree tmp;
2462 /* We should only have 1-D arrays here. */
2468 /* The below is short by the cookie size. */
2476 virtual_size),
2477 tf_warning_or_error);
2487 body = build_compound_expr
2491 tf_warning_or_error));
2492 body = build_compound_expr
2500 no_destructor:
2501 /* If the delete flag is one, or anything else with the low bit set,
2502 delete the storage. */
2504 {
2505 tree base_tbd;
2507 /* The below is short by the cookie size. */
2512 /* no header */
2514 else
2515 {
2516 tree cookie_size;
2519 base_tbd
2522 MINUS_EXPR,
2524 base),
2525 cookie_size,
2526 tf_warning_or_error));
2527 /* True size with header. */
2529 }
2537 }
2541 ;
2544 else
2550 /* Outermost wrapper: If pointer is null, punt. */
2554 integer_zero_node)),
2559 {
2562 }
2565 /* Pre-evaluate the SAVE_EXPR outside of the BIND_EXPR. */
2569 }
2571 /* Create an unnamed variable of the indicated TYPE. */
2573 tree
2575 {
2576 tree decl;
2586 }
2588 /* Create a new temporary variable of the indicated TYPE, initialized
2589 to INIT.
2591 It is not entered into current_binding_level, because that breaks
2592 things when it comes time to do final cleanups (which take place
2593 "outside" the binding contour of the function). */
2595 static tree
2597 {
2598 tree decl;
2604 tf_warning_or_error));
2607 }
2609 /* `build_vec_init' returns tree structure that performs
2610 initialization of a vector of aggregate types.
2612 BASE is a reference to the vector, of ARRAY_TYPE, or a pointer
2613 to the first element, of POINTER_TYPE.
2614 MAXINDEX is the maximum index of the array (one less than the
2615 number of elements). It is only used if BASE is a pointer or
2616 TYPE_DOMAIN (TREE_TYPE (BASE)) == NULL_TREE.
2618 INIT is the (possibly NULL) initializer.
2620 If EXPLICIT_VALUE_INIT_P is true, then INIT must be NULL. All
2621 elements in the array are value-initialized.
2623 FROM_ARRAY is 0 if we should init everything with INIT
2624 (i.e., every element initialized from INIT).
2625 FROM_ARRAY is 1 if we should index into INIT in parallel
2626 with initialization of DECL.
2627 FROM_ARRAY is 2 if we should index into INIT in parallel,
2628 but use assignment instead of initialization. */
2630 tree
2634 {
2635 tree rval;
2637 tree size;
2639 tree iterator;
2640 /* The type of BASE. */
2642 /* The type of an element in the array. */
2644 /* The element type reached after removing all outer array
2645 types. */
2646 tree inner_elt_type;
2647 /* The type of a pointer to an element in the array. */
2648 tree ptype;
2649 tree stmt_expr;
2650 tree compound_stmt;
2672 /* Don't do this if the CONSTRUCTOR might contain something
2673 that might throw and require us to clean up. */
2677 {
2678 /* Do non-default initialization of POD arrays resulting from
2679 brace-enclosed initializers. In this case, digest_init and
2680 store_constructor will handle the semantics for us. */
2685 }
2690 {
2693 }
2694 else
2697 /* The code we are generating looks like:
2698 ({
2699 T* t1 = (T*) base;
2700 T* rval = t1;
2701 ptrdiff_t iterator = maxindex;
2702 try {
2703 for (; iterator != -1; --iterator) {
2704 ... initialize *t1 ...
2705 ++t1;
2706 }
2707 } catch (...) {
2708 ... destroy elements that were constructed ...
2709 }
2710 rval;
2711 })
2713 We can omit the try and catch blocks if we know that the
2714 initialization will never throw an exception, or if the array
2715 elements do not have destructors. We can omit the loop completely if
2716 the elements of the array do not have constructors.
2718 We actually wrap the entire body of the above in a STMT_EXPR, for
2719 tidiness.
2721 When copying from array to another, when the array elements have
2722 only trivial copy constructors, we should use __builtin_memcpy
2723 rather than generating a loop. That way, we could take advantage
2724 of whatever cleverness the back end has for dealing with copies
2725 of blocks of memory. */
2734 /* Protect the entire array initialization so that we can destroy
2735 the partially constructed array if an exception is thrown.
2736 But don't do this if we're assigning. */
2739 {
2741 }
2744 {
2745 /* Do non-default initialization of non-POD arrays resulting from
2746 brace-enclosed initializers. */
2748 tree elt;
2752 {
2755 num_initialized_elts++;
2760 else
2766 complain));
2768 complain));
2769 }
2771 /* Clear out INIT so that we don't get confused below. */
2773 }
2775 {
2776 /* If initializing one array from another, initialize element by
2777 element. We rely upon the below calls the do argument
2778 checking. */
2780 {
2785 }
2789 {
2793 }
2794 }
2796 /* Now, default-initialize any remaining elements. We don't need to
2797 do that if a) the type does not need constructing, or b) we've
2798 already initialized all the elements.
2800 We do need to keep going if we're copying an array. */
2805 && (num_initialized_elts
2807 {
2808 /* If the ITERATOR is equal to -1, then we don't have to loop;
2809 we've already initialized all the elements. */
2810 tree for_stmt;
2811 tree elt_init;
2812 tree to;
2818 for_stmt);
2820 complain),
2821 for_stmt);
2826 {
2827 tree from;
2831 else
2836 complain);
2841 complain);
2842 else
2844 }
2846 {
2848 sorry
2852 explicit_value_init_p,
2854 }
2858 else
2859 {
2862 }
2869 complain));
2872 complain));
2875 }
2877 /* Make sure to cleanup any partially constructed elements. */
2880 {
2881 tree e;
2884 complain);
2886 /* Flatten multi-dimensional array since build_vec_delete only
2887 expects one-dimensional array. */
2892 complain);
2899 }
2901 /* The value of the array initialization is the array itself, RVAL
2902 is a pointer to the first element. */
2907 /* Now make the result have the correct type. */
2909 {
2914 }
2918 }
2920 /* Call the DTOR_KIND destructor for EXP. FLAGS are as for
2921 build_delete. */
2923 static tree
2925 {
2926 tree name;
2927 tree fn;
2929 {
2944 }
2949 flags,
2951 tf_warning_or_error);
2952 }
2954 /* Generate a call to a destructor. TYPE is the type to cast ADDR to.
2955 ADDR is an expression which yields the store to be destroyed.
2956 AUTO_DELETE is the name of the destructor to call, i.e., either
2957 sfk_complete_destructor, sfk_base_destructor, or
2958 sfk_deleting_destructor.
2960 FLAGS is the logical disjunction of zero or more LOOKUP_
2961 flags. See cp-tree.h for more info. */
2963 tree
2966 {
2967 tree expr;
2972 /* Can happen when CURRENT_EXCEPTION_OBJECT gets its type
2973 set to `error_mark_node' before it gets properly cleaned up. */
2980 {
2987 /* We don't want to warn about delete of void*, only other
2988 incomplete types. Deleting other incomplete types
2989 invokes undefined behavior, but it is not ill-formed, so
2990 compile to something that would even do The Right Thing
2991 (TM) should the type have a trivial dtor and no delete
2992 operator. */
2994 {
2997 {
3000 {
3003 "operator delete will be called, even if they are "
3005 }
3007 }
3008 }
3010 /* Call the builtin operator delete. */
3015 /* Throw away const and volatile on target type of addr. */
3017 }
3019 {
3020 handle_array:
3023 {
3026 }
3029 }
3030 else
3031 {
3032 /* Don't check PROTECT here; leave that decision to the
3033 destructor. If the destructor is accessible, call it,
3034 else report error. */
3040 }
3045 {
3051 use_global_delete,
3054 }
3055 else
3056 {
3059 tree ifexp;
3064 /* For `::delete x', we must not use the deleting destructor
3065 since then we would not be sure to get the global `operator
3066 delete'. */
3068 {
3069 /* We will use ADDR multiple times so we must save it. */
3072 /* Delete the object. */
3074 /* Otherwise, treat this like a complete object destructor
3075 call. */
3077 }
3078 /* If the destructor is non-virtual, there is no deleting
3079 variant. Instead, we must explicitly call the appropriate
3080 `operator delete' here. */
3083 {
3084 /* We will use ADDR multiple times so we must save it. */
3086 /* Build the call. */
3088 addr,
3093 /* Call the complete object destructor. */
3095 }
3098 {
3099 /* Make sure we have access to the member op delete, even though
3100 we'll actually be calling it from the destructor. */
3105 }
3108 tf_warning_or_error),
3113 /* We need to calculate this before the dtor changes the vptr. */
3118 /* Explicit destructor call; don't check for null pointer. */
3120 else
3121 /* Handle deleting a null pointer. */
3124 tf_warning_or_error));
3131 }
3132 }
3134 /* At the beginning of a destructor, push cleanups that will call the
3135 destructors for our base classes and members.
3137 Called from begin_destructor_body. */
3139 void
3141 {
3144 tree member;
3145 tree expr;
3148 /* Run destructors for all virtual baseclasses. */
3150 {
3151 tree cond = (condition_conversion
3153 current_in_charge_parm,
3154 integer_two_node)));
3156 /* The CLASSTYPE_VBASECLASSES vector is in initialization
3157 order, which is also the right order for pushing cleanups. */
3160 {
3162 {
3164 base_dtor_identifier,
3165 NULL,
3166 base_binfo,
3167 (LOOKUP_NORMAL
3169 tf_warning_or_error);
3173 }
3174 }
3175 }
3177 /* Take care of the remaining baseclasses. */
3180 {
3186 base_dtor_identifier,
3189 tf_warning_or_error);
3191 }
3195 {
3201 {
3202 tree this_member = (build_class_member_access_expr
3206 tf_warning_or_error));
3209 sfk_complete_destructor,
3213 }
3214 }
3215 }
3217 /* Build a C++ vector delete expression.
3218 MAXINDEX is the number of elements to be deleted.
3219 ELT_SIZE is the nominal size of each element in the vector.
3220 BASE is the expression that should yield the store to be deleted.
3221 This function expands (or synthesizes) these calls itself.
3222 AUTO_DELETE_VEC says whether the container (vector) should be deallocated.
3224 This also calls delete for virtual baseclasses of elements of the vector.
3226 Update: MAXINDEX is no longer needed. The size can be extracted from the
3227 start of the vector for pointers, and from the type for arrays. We still
3228 use MAXINDEX for arrays because it happens to already have one of the
3229 values we'd have to extract. (We could use MAXINDEX with pointers to
3230 confirm the size, and trap if the numbers differ; not clear that it'd
3231 be worth bothering.) */
3233 tree
3236 {
3237 tree type;
3238 tree rval;
3244 {
3245 /* Step back one from start of vector, and read dimension. */
3246 tree cookie_addr;
3250 {
3253 }
3257 size_ptr_type,
3259 cookie_addr);
3261 }
3263 {
3264 /* Get the total number of things in the array, maxindex is a
3265 bad name. */
3270 {
3273 }
3274 }
3275 else
3276 {
3280 }
3283 use_global_delete);
3288 }