| blob | 8e3e4895264de7a3b79ad06ceec2f639715a30d7 |
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. */
432 /* Get an lvalue for the data member. */
436 tf_warning_or_error);
441 {
442 /* mem() means value-initialization. */
444 {
448 tf_warning_or_error);
450 }
451 else
452 {
457 else
458 {
461 }
462 }
463 }
464 /* Deal with this here, as we will get confused if we try to call the
465 assignment op for an anonymous union. This can happen in a
466 synthesized copy constructor. */
468 {
470 {
473 }
474 }
476 {
481 {
482 /* Initialization of one array from another. */
486 tf_warning_or_error));
487 }
488 else
489 {
493 /* TYPE_NEEDS_CONSTRUCTING can be set just because we have a
494 vtable; still give this diagnostic. */
498 tf_warning_or_error));
499 }
500 }
501 else
502 {
504 {
505 /* member traversal: note it leaves init NULL */
512 }
514 /* There was an explicit member initialization. Do some work
515 in that case. */
520 tf_warning_or_error));
521 }
524 {
525 tree expr;
530 tf_warning_or_error);
536 }
537 }
539 /* Returns a TREE_LIST containing (as the TREE_PURPOSE of each node) all
540 the FIELD_DECLs on the TYPE_FIELDS list for T, in reverse order. */
542 static tree
544 {
545 tree fields;
549 /* Note whether or not T is a union. */
554 {
555 /* Skip CONST_DECLs for enumeration constants and so forth. */
559 /* Keep track of whether or not any fields are unions. */
563 /* For an anonymous struct or union, we must recursively
564 consider the fields of the anonymous type. They can be
565 directly initialized from the constructor. */
567 {
568 /* Add this field itself. Synthesized copy constructors
569 initialize the entire aggregate. */
571 /* And now add the fields in the anonymous aggregate. */
573 uses_unions_p);
574 }
575 /* Add this field. */
578 }
581 }
583 /* The MEM_INITS are a TREE_LIST. The TREE_PURPOSE of each list gives
584 a FIELD_DECL or BINFO in T that needs initialization. The
585 TREE_VALUE gives the initializer, or list of initializer arguments.
587 Return a TREE_LIST containing all of the initializations required
588 for T, in the order in which they should be performed. The output
589 list has the same format as the input. */
591 static tree
593 {
594 tree init;
596 tree sorted_inits;
597 tree next_subobject;
602 /* Build up a list of initializations. The TREE_PURPOSE of entry
603 will be the subobject (a FIELD_DECL or BINFO) to initialize. The
604 TREE_VALUE will be the constructor arguments, or NULL if no
605 explicit initialization was provided. */
608 /* Process the virtual bases. */
613 /* Process the direct bases. */
619 /* Process the non-static data members. */
621 /* Reverse the entire list of initializations, so that they are in
622 the order that they will actually be performed. */
625 /* If the user presented the initializers in an order different from
626 that in which they will actually occur, we issue a warning. Keep
627 track of the next subobject which can be explicitly initialized
628 without issuing a warning. */
631 /* Go through the explicit initializers, filling in TREE_PURPOSE in
632 the SORTED_INITS. */
634 {
635 tree subobject;
636 tree subobject_init;
640 /* If the explicit initializers are in sorted order, then
641 SUBOBJECT will be NEXT_SUBOBJECT, or something following
642 it. */
644 subobject_init;
649 /* Issue a warning if the explicit initializer order does not
650 match that which will actually occur.
651 ??? Are all these on the correct lines? */
653 {
657 else
662 else
665 }
667 /* Look again, from the beginning of the list. */
669 {
673 }
675 /* It is invalid to initialize the same subobject more than
676 once. */
678 {
682 else
685 }
687 /* Record the initialization. */
690 }
692 /* [class.base.init]
694 If a ctor-initializer specifies more than one mem-initializer for
695 multiple members of the same union (including members of
696 anonymous unions), the ctor-initializer is ill-formed. */
698 {
701 {
702 tree field;
703 tree field_type;
706 /* Skip uninitialized members and base classes. */
710 /* See if this field is a member of a union, or a member of a
711 structure contained in a union, etc. */
718 /* If this field is not a member of a union, skip it. */
722 /* It's only an error if we have two initializers for the same
723 union type. */
725 {
728 }
730 /* See if LAST_FIELD and the field initialized by INIT are
731 members of the same union. If so, there's a problem,
732 unless they're actually members of the same structure
733 which is itself a member of a union. For example, given:
735 union { struct { int i; int j; }; };
737 initializing both `i' and `j' makes sense. */
740 do
741 {
742 tree last_field_type;
746 {
748 {
754 }
760 }
762 /* If we've reached the outermost class, then we're
763 done. */
768 }
772 }
773 }
776 }
778 /* Initialize all bases and members of CURRENT_CLASS_TYPE. MEM_INITS
779 is a TREE_LIST giving the explicit mem-initializer-list for the
780 constructor. The TREE_PURPOSE of each entry is a subobject (a
781 FIELD_DECL or a BINFO) of the CURRENT_CLASS_TYPE. The TREE_VALUE
782 is a TREE_LIST giving the arguments to the constructor or
783 void_type_node for an empty list of arguments. */
785 void
787 {
788 /* We will already have issued an error message about the fact that
789 the type is incomplete. */
793 /* Sort the mem-initializers into the order in which the
794 initializations should be performed. */
799 /* Initialize base classes. */
802 {
806 /* If these initializations are taking place in a copy constructor,
807 the base class should probably be explicitly initialized if there
808 is a user-defined constructor in the base class (other than the
809 default constructor, which will be called anyway). */
817 /* Initialize the base. */
820 else
821 {
822 tree base_addr;
828 tf_warning_or_error),
829 arguments,
830 LOOKUP_NORMAL,
831 tf_warning_or_error);
833 }
836 }
839 /* Initialize the vptrs. */
842 /* Initialize the data members. */
844 {
848 }
849 }
851 /* Returns the address of the vtable (i.e., the value that should be
852 assigned to the vptr) for BINFO. */
854 static tree
856 {
858 tree vtbl;
861 /* If this is a virtual primary base, then the vtable we want to store
862 is that for the base this is being used as the primary base of. We
863 can't simply skip the initialization, because we may be expanding the
864 inits of a subobject constructor where the virtual base layout
865 can be different. */
869 /* Figure out what vtable BINFO's vtable is based on, and mark it as
870 used. */
875 /* Now compute the address to use when initializing the vptr. */
881 }
883 /* This code sets up the virtual function tables appropriate for
884 the pointer DECL. It is a one-ply initialization.
886 BINFO is the exact type that DECL is supposed to be. In
887 multiple inheritance, this might mean "C's A" if C : A, B. */
889 static void
891 {
893 tree vtt_index;
895 /* Compute the initializer for vptr. */
898 /* We may get this vptr from a VTT, if this is a subobject
899 constructor or subobject destructor. */
902 {
903 tree vtbl2;
904 tree vtt_parm;
906 /* Compute the value to use, when there's a VTT. */
910 vtt_parm,
911 vtt_index);
915 /* The actual initializer is the VTT value only in the subobject
916 constructor. In maybe_clone_body we'll substitute NULL for
917 the vtt_parm in the case of the non-subobject constructor. */
922 vtbl2,
923 vtbl);
924 }
926 /* Compute the location of the vtpr. */
928 tf_warning_or_error),
932 /* Assign the vtable to the vptr. */
935 tf_warning_or_error));
936 }
938 /* If an exception is thrown in a constructor, those base classes already
939 constructed must be destroyed. This function creates the cleanup
940 for BINFO, which has just been constructed. If FLAG is non-NULL,
941 it is a DECL which is nonzero when this base needs to be
942 destroyed. */
944 static void
946 {
947 tree expr;
952 /* Call the destructor. */
954 base_dtor_identifier,
955 NULL_TREE,
956 binfo,
958 tf_warning_or_error);
965 }
967 /* Construct the virtual base-class VBASE passing the ARGUMENTS to its
968 constructor. */
970 static void
972 {
973 tree inner_if_stmt;
974 tree exp;
975 tree flag;
977 /* If there are virtual base classes with destructors, we need to
978 emit cleanups to destroy them if an exception is thrown during
979 the construction process. These exception regions (i.e., the
980 period during which the cleanups must occur) begin from the time
981 the construction is complete to the end of the function. If we
982 create a conditional block in which to initialize the
983 base-classes, then the cleanup region for the virtual base begins
984 inside a block, and ends outside of that block. This situation
985 confuses the sjlj exception-handling code. Therefore, we do not
986 create a single conditional block, but one for each
987 initialization. (That way the cleanup regions always begin
988 in the outer block.) We trust the back end to figure out
989 that the FLAG will not change across initializations, and
990 avoid doing multiple tests. */
995 /* Compute the location of the virtual base. If we're
996 constructing virtual bases, then we must be the most derived
997 class. Therefore, we don't have to look up the virtual base;
998 we already know where it is. */
1007 }
1009 /* Find the context in which this FIELD can be initialized. */
1011 static tree
1013 {
1016 /* Anonymous union members can be initialized in the first enclosing
1017 non-anonymous union context. */
1021 }
1023 /* Function to give error message if member initialization specification
1024 is erroneous. FIELD is the member we decided to initialize.
1025 TYPE is the type for which the initialization is being performed.
1026 FIELD must be a member of TYPE.
1028 MEMBER_NAME is the name of the member. */
1030 static int
1032 {
1036 {
1038 member_name);
1040 }
1042 {
1045 field);
1047 }
1049 {
1053 }
1055 {
1057 member_name);
1059 }
1062 }
1064 /* NAME is a FIELD_DECL, an IDENTIFIER_NODE which names a field, or it
1065 is a _TYPE node or TYPE_DECL which names a base for that type.
1066 Check the validity of NAME, and return either the base _TYPE, base
1067 binfo, or the FIELD_DECL of the member. If NAME is invalid, return
1068 NULL_TREE and issue a diagnostic.
1070 An old style unnamed direct single base construction is permitted,
1071 where NAME is NULL. */
1073 tree
1075 {
1076 tree basetype;
1077 tree field;
1083 {
1084 /* This is an obsolete unnamed base class initializer. The
1085 parser will already have warned about its use. */
1087 {
1090 current_class_type);
1093 basetype = BINFO_TYPE
1098 current_class_type);
1100 }
1101 }
1103 {
1106 }
1109 else
1113 {
1114 tree class_binfo;
1115 tree direct_binfo;
1116 tree virtual_binfo;
1126 /* Look for a direct base. */
1131 /* Look for a virtual base -- unless the direct base is itself
1132 virtual. */
1136 /* [class.base.init]
1138 If a mem-initializer-id is ambiguous because it designates
1139 both a direct non-virtual base class and an inherited virtual
1140 base class, the mem-initializer is ill-formed. */
1142 {
1144 basetype);
1146 }
1149 {
1153 else
1157 }
1160 }
1161 else
1162 {
1165 else
1170 }
1173 }
1175 /* This is like `expand_member_init', only it stores one aggregate
1176 value into another.
1178 INIT comes in two flavors: it is either a value which
1179 is to be stored in EXP, or it is a parameter list
1180 to go to a constructor, which will operate on EXP.
1181 If INIT is not a parameter list for a constructor, then set
1182 LOOKUP_ONLYCONVERTING.
1183 If FLAGS is LOOKUP_ONLYCONVERTING then it is the = init form of
1184 the initializer, if FLAGS is 0, then it is the (init) form.
1185 If `init' is a CONSTRUCTOR, then we emit a warning message,
1186 explaining that such initializations are invalid.
1188 If INIT resolves to a CALL_EXPR which happens to return
1189 something of the type we are looking for, then we know
1190 that we can safely use that call to perform the
1191 initialization.
1193 The virtual function table pointer cannot be set up here, because
1194 we do not really know its type.
1196 This never calls operator=().
1198 When initializing, nothing is CONST.
1200 A default copy constructor may have to be used to perform the
1201 initialization.
1203 A constructor or a conversion operator may have to be used to
1204 perform the initialization, but not both, as it would be ambiguous. */
1206 tree
1208 {
1209 tree stmt_expr;
1210 tree compound_stmt;
1227 {
1228 tree itype;
1230 /* An array may not be initialized use the parenthesized
1231 initialization form -- unless the initializer is "()". */
1233 {
1237 }
1238 /* Must arrange to initialize each element of EXP
1239 from elements of INIT. */
1249 complain);
1256 }
1259 /* Just know that we've seen something for this node. */
1273 }
1275 static void
1277 tsubst_flags_t complain)
1278 {
1280 tree ctor_name;
1282 /* It fails because there may not be a constructor which takes
1283 its own type as the first (or only parameter), but which does
1284 take other types via a conversion. So, if the thing initializing
1285 the expression is a unit element of type X, first try X(X&),
1286 followed by initialization by X. If neither of these work
1287 out, then look hard. */
1288 tree rval;
1289 tree parms;
1293 {
1294 /* Base subobjects should only get direct-initialization. */
1298 /* Do nothing. We hit this in two cases: Reference initialization,
1299 where we aren't initializing a real variable, so we don't want
1300 to run a new constructor; and catching an exception, where we
1301 have already built up the constructor call so we could wrap it
1305 {
1306 /* A brace-enclosed initializer for an aggregate. */
1308 }
1309 else
1313 /* We need to protect the initialization of a catch parm with a
1314 call to terminate(), which shows up as a MUST_NOT_THROW_EXPR
1315 around the TARGET_EXPR for the copy constructor. See
1316 initialize_handler_parm. */
1317 {
1321 }
1322 else
1327 }
1331 {
1335 }
1336 else
1341 else
1345 complain);
1348 }
1350 /* This function is responsible for initializing EXP with INIT
1351 (if any).
1353 BINFO is the binfo of the type for who we are performing the
1354 initialization. For example, if W is a virtual base class of A and B,
1355 and C : A, B.
1356 If we are initializing B, then W must contain B's W vtable, whereas
1357 were we initializing C, W must contain C's W vtable.
1359 TRUE_EXP is nonzero if it is the true expression being initialized.
1360 In this case, it may be EXP, or may just contain EXP. The reason we
1361 need this is because if EXP is a base element of TRUE_EXP, we
1362 don't necessarily know by looking at EXP where its virtual
1363 baseclass fields should really be pointing. But we do know
1364 from TRUE_EXP. In constructors, we don't know anything about
1365 the value being initialized.
1367 FLAGS is just passed to `build_new_method_call'. See that function
1368 for its description. */
1370 static void
1372 tsubst_flags_t complain)
1373 {
1379 /* Use a function returning the desired type to initialize EXP for us.
1380 If the function is a constructor, and its first argument is
1381 NULL_TREE, know that it was meant for us--just slide exp on
1382 in and expand the constructor. Constructors now come
1383 as TARGET_EXPRs. */
1387 {
1388 /* If store_init_value returns NULL_TREE, the INIT has been
1389 recorded as the DECL_INITIAL for EXP. That means there's
1390 nothing more we have to do. */
1395 }
1397 /* If an explicit -- but empty -- initializer list was present,
1398 that's value-initialization. */
1400 {
1401 /* If there's a user-provided constructor, we just call that. */
1404 /* If there isn't, but we still need to call the constructor,
1405 zero out the object first. */
1407 {
1411 /* And then call the constructor. */
1412 }
1413 /* If we don't need to mess with the constructor at all,
1414 then just zero out the object and we're done. */
1415 else
1416 {
1420 }
1422 }
1424 /* We know that expand_default_init can handle everything we want
1425 at this point. */
1427 }
1429 /* Report an error if TYPE is not a user-defined, class type. If
1430 OR_ELSE is nonzero, give an error message. */
1432 int
1434 {
1439 {
1443 }
1445 }
1447 tree
1449 {
1455 else
1457 }
1459 /* Build a reference to a member of an aggregate. This is not a C++
1460 `&', but really something which can have its address taken, and
1461 then act as a pointer to member, for example TYPE :: FIELD can have
1462 its address taken by saying & TYPE :: FIELD. ADDRESS_P is true if
1463 this expression is the operand of "&".
1465 @@ Prints out lousy diagnostics for operator <typename>
1466 @@ fields.
1468 @@ This function should be rewritten and placed in search.c. */
1470 tree
1472 {
1473 tree decl;
1476 /* class templates can come in as TEMPLATE_DECLs here. */
1489 /* Callers should call mark_used before this point. */
1494 {
1497 }
1499 /* Entities other than non-static members need no further
1500 processing. */
1507 {
1510 }
1512 /* Set up BASEBINFO for member lookup. */
1515 /* A lot of this logic is now handled in lookup_member. */
1517 {
1518 /* Go from the TREE_BASELINK to the member function info. */
1522 {
1523 /* Get rid of a potential OVERLOAD around it. */
1526 /* Unique functions are handled easily. */
1528 /* For non-static member of base class, we need a special rule
1529 for access checking [class.protected]:
1531 If the access is to form a pointer to member, the
1532 nested-name-specifier shall name the derived class
1533 (or any class derived from that class). */
1537 else
1543 }
1544 else
1546 }
1548 /* We need additional test besides the one in
1549 check_accessibility_of_qualified_id in case it is
1550 a pointer to non-static member. */
1554 {
1555 /* If MEMBER is non-static, then the program has fallen afoul of
1556 [expr.prim]:
1558 An id-expression that denotes a nonstatic data member or
1559 nonstatic member function of a class can only be used:
1561 -- as part of a class member access (_expr.ref_) in which the
1562 object-expression refers to the member's class or a class
1563 derived from that class, or
1565 -- to form a pointer to member (_expr.unary.op_), or
1567 -- in the body of a nonstatic member function of that class or
1568 of a class derived from that class (_class.mfct.nonstatic_), or
1570 -- in a mem-initializer for a constructor for that class or for
1571 a class derived from that class (_class.base.init_). */
1573 {
1574 /* Build a representation of the qualified name suitable
1575 for use as the operand to "&" -- even though the "&" is
1576 not actually present. */
1578 /* In Microsoft mode, treat a non-static member function as if
1579 it were a pointer-to-member. */
1581 {
1584 tf_warning_or_error);
1585 }
1589 }
1591 {
1594 }
1596 }
1601 }
1603 /* If DECL is a scalar enumeration constant or variable with a
1604 constant initializer, return the initializer (or, its initializers,
1605 recursively); otherwise, return DECL. If INTEGRAL_P, the
1606 initializer is only returned if DECL is an integral
1607 constant-expression. */
1609 static tree
1611 {
1613 || (integral_p
1617 {
1618 tree init;
1619 /* Static data members in template classes may have
1620 non-dependent initializers. References to such non-static
1621 data members are not value-dependent, so we must retrieve the
1622 initializer here. The DECL_INITIAL will have the right type,
1623 but will not have been folded because that would prevent us
1624 from performing all appropriate semantic checks at
1625 instantiation time. */
1630 {
1634 }
1635 else
1636 {
1637 /* If DECL is a static data member in a template
1638 specialization, we must instantiate it here. The
1639 initializer for the static data member is not processed
1640 until needed; we need it now. */
1643 }
1646 /* Initializers in templates are generally expanded during
1647 instantiation, so before that for const int i(2)
1648 INIT is a TREE_LIST with the actual initializer as
1649 TREE_VALUE. */
1651 && init
1657 || (integral_p
1660 /* Do not return an aggregate constant (of which
1661 string literals are a special case), as we do not
1662 want to make inadvertent copies of such entities,
1663 and we must be sure that their addresses are the
1664 same everywhere. */
1669 }
1671 }
1673 /* If DECL is a CONST_DECL, or a constant VAR_DECL initialized by
1674 constant of integral or enumeration type, then return that value.
1675 These are those variables permitted in constant expressions by
1676 [5.19/1]. */
1678 tree
1680 {
1682 }
1684 /* A more relaxed version of integral_constant_value, used by the
1685 common C/C++ code and by the C++ front end for optimization
1686 purposes. */
1688 tree
1690 {
1693 }
1694 \f
1695 /* Common subroutines of build_new and build_vec_delete. */
1697 /* Call the global __builtin_delete to delete ADDR. */
1699 static tree
1701 {
1704 }
1705 \f
1706 /* Build and return a NEW_EXPR. If NELTS is non-NULL, TYPE[NELTS] is
1707 the type of the object being allocated; otherwise, it's just TYPE.
1708 INIT is the initializer, if any. USE_GLOBAL_NEW is true if the
1709 user explicitly wrote "::operator new". PLACEMENT, if non-NULL, is
1710 the TREE_LIST of arguments to be provided as arguments to a
1711 placement new operator. This routine performs no semantic checks;
1712 it just creates and returns a NEW_EXPR. */
1714 static tree
1717 {
1718 tree new_expr;
1726 }
1728 /* Make sure that there are no aliasing issues with T, a placement new
1729 expression applied to PLACEMENT, by recording the change in dynamic
1730 type. If placement new is inlined, as it is with libstdc++, and if
1731 the type of the placement new differs from the type of the
1732 placement location itself, then alias analysis may think it is OK
1733 to interchange writes to the location from before the placement new
1734 and from after the placement new. We have to prevent type-based
1735 alias analysis from applying. PLACEMENT may be NULL, which means
1736 that we couldn't capture it in a temporary variable, in which case
1737 we use a memory clobber. */
1739 static tree
1741 {
1742 tree type_change;
1747 /* If we are not using type based aliasing, we don't have to do
1748 anything. */
1752 /* If we have a pointer and a location, record the change in dynamic
1753 type. Otherwise we need a general memory clobber. */
1759 placement);
1760 else
1761 {
1762 /* Build a memory clobber. */
1765 NULL_TREE,
1766 NULL_TREE,
1769 NULL_TREE));
1772 }
1775 }
1777 /* Generate code for a new-expression, including calling the "operator
1778 new" function, initializing the object, and, if an exception occurs
1779 during construction, cleaning up. The arguments are as for
1780 build_raw_new_expr. */
1782 static tree
1785 {
1787 /* True iff this is a call to "operator new[]" instead of just
1788 "operator new". */
1790 /* If ARRAY_P is true, the element type of the array. This is never
1791 an ARRAY_TYPE; for something like "new int[3][4]", the
1792 ELT_TYPE is "int". If ARRAY_P is false, this is the same type as
1793 TYPE. */
1794 tree elt_type;
1795 /* The type of the new-expression. (This type is always a pointer
1796 type.) */
1797 tree pointer_type;
1800 /* The address returned by the call to "operator new". This node is
1801 a VAR_DECL and is therefore reusable. */
1802 tree alloc_node;
1803 tree alloc_fn;
1807 /* If non-NULL, the number of extra bytes to allocate at the
1808 beginning of the storage allocated for an array-new expression in
1809 order to store the number of elements. */
1812 /* True if the function we are calling is a placement allocation
1813 function. */
1816 /* True if the storage must be initialized, either by a constructor
1817 or due to an explicit new-initializer. */
1819 /* The address of the thing allocated, not including any cookie. In
1820 particular, if an array cookie is in use, DATA_ADDR is the
1821 address of the first array element. This node is a VAR_DECL, and
1822 is therefore reusable. */
1823 tree data_addr;
1827 {
1830 }
1832 {
1837 }
1839 /* If our base type is an array, then make sure we know how many elements
1840 it has. */
1847 complain);
1850 {
1854 }
1863 {
1867 }
1875 /* Allocate the object. */
1877 {
1878 tree class_addr;
1888 {
1892 }
1894 {
1898 }
1901 alloc_call = (cp_build_function_call
1904 complain));
1905 }
1907 {
1910 }
1911 else
1912 {
1913 tree fnname;
1914 tree fns;
1920 && (array_p
1923 {
1924 /* Use a class-specific operator new. */
1925 /* If a cookie is required, add some extra space. */
1927 {
1930 }
1931 /* Create the argument list. */
1933 /* Do name-lookup to find the appropriate operator. */
1936 {
1940 }
1942 {
1944 {
1947 }
1949 }
1953 LOOKUP_NORMAL,
1955 complain);
1956 }
1957 else
1958 {
1959 /* Use a global operator new. */
1960 /* See if a cookie might be required. */
1963 else
1969 }
1970 }
1977 /* If PLACEMENT is a simple pointer type and is not passed by reference,
1978 then copy it into PLACEMENT_EXPR. */
1987 {
1992 {
1996 }
1997 }
1999 /* In the simple case, we can stop now. */
2002 {
2007 }
2009 /* Store the result of the allocation call in a variable so that we can
2010 use it more than once. */
2014 /* Strip any COMPOUND_EXPRs from ALLOC_CALL. */
2018 /* Now, check to see if this function is actually a placement
2019 allocation function. This can happen even when PLACEMENT is NULL
2020 because we might have something like:
2022 struct S { void* operator new (size_t, int i = 0); };
2024 A call to `new S' will get this allocation function, even though
2025 there is no explicit placement argument. If there is more than
2026 one argument, or there are variable arguments, then this is a
2027 placement allocation function. */
2028 placement_allocation_fn_p
2032 /* Preevaluate the placement args so that we don't reevaluate them for a
2033 placement delete. */
2035 {
2036 tree inits;
2040 alloc_expr);
2041 }
2043 /* unless an allocation function is declared with an empty excep-
2044 tion-specification (_except.spec_), throw(), it indicates failure to
2045 allocate storage by throwing a bad_alloc exception (clause _except_,
2046 _lib.bad.alloc_); it returns a non-null pointer otherwise If the allo-
2047 cation function is declared with an empty exception-specification,
2048 throw(), it returns null to indicate failure to allocate storage and a
2049 non-null pointer otherwise.
2051 So check for a null exception spec on the op new we just called. */
2057 {
2058 tree cookie;
2059 tree cookie_ptr;
2060 tree size_ptr_type;
2062 /* Adjust so we're pointing to the start of the object. */
2066 /* Store the number of bytes allocated so that we can know how
2067 many elements to destroy later. We use the last sizeof
2068 (size_t) bytes to store the number of elements. */
2079 {
2080 /* Also store the element size. */
2090 }
2091 }
2092 else
2093 {
2096 }
2098 /* Now use a pointer to the type we've actually allocated. */
2100 /* Any further uses of alloc_node will want this type, too. */
2103 /* Now initialize the allocated object. Note that we preevaluate the
2104 initialization expression, apart from the actual constructor call or
2105 assignment--we do this because we want to delay the allocation as long
2106 as possible in order to minimize the size of the exception region for
2107 placement delete. */
2109 {
2114 {
2117 }
2120 {
2122 {
2125 else
2127 }
2128 init_expr
2132 integer_one_node,
2133 complain),
2134 init,
2135 explicit_value_init_p,
2137 complain);
2139 /* An array initialization is stable because the initialization
2140 of each element is a full-expression, so the temporaries don't
2141 leak out. */
2143 }
2144 else
2145 {
2149 {
2151 complete_ctor_identifier,
2153 LOOKUP_NORMAL,
2154 complain);
2155 }
2157 {
2158 /* Something like `new int()'. */
2161 }
2162 else
2163 {
2164 /* We are processing something like `new int (10)', which
2165 means allocate an int, and initialize it with 10. */
2170 else
2175 complain);
2176 }
2178 }
2183 /* If any part of the object initialization terminates by throwing an
2184 exception and a suitable deallocation function can be found, the
2185 deallocation function is called to free the memory in which the
2186 object was being constructed, after which the exception continues
2187 to propagate in the context of the new-expression. If no
2188 unambiguous matching deallocation function can be found,
2189 propagating the exception does not cause the object's memory to be
2190 freed. */
2192 {
2194 tree cleanup;
2196 /* The Standard is unclear here, but the right thing to do
2197 is to use the same method for finding deallocation
2198 functions that we use for finding allocation functions. */
2199 cleanup = (build_op_delete_call
2201 alloc_node,
2202 size,
2203 globally_qualified_p,
2205 alloc_fn));
2210 /* This is much simpler if we were able to preevaluate all of
2211 the arguments to the constructor call. */
2214 else
2215 /* Ack! First we allocate the memory. Then we set our sentry
2216 variable to true, and expand a cleanup that deletes the
2217 memory if sentry is true. Then we run the constructor, and
2218 finally clear the sentry.
2220 We need to do this because we allocate the space first, so
2221 if there are any temporaries with cleanups in the
2222 constructor args and we weren't able to preevaluate them, we
2223 need this EH region to extend until end of full-expression
2224 to preserve nesting. */
2225 {
2240 init_expr
2243 end));
2244 }
2246 }
2247 }
2248 else
2251 /* Now build up the return value in reverse order. */
2261 /* If we don't have an initializer or a cookie, strip the TARGET_EXPR
2262 and return the call (which doesn't need to be adjusted). */
2264 else
2265 {
2267 {
2270 integer_zero_node,
2271 complain);
2273 complain);
2274 }
2276 /* Perform the allocation before anything else, so that ALLOC_NODE
2277 has been initialized before we start using it. */
2279 }
2284 /* A new-expression is never an lvalue. */
2291 }
2293 /* Generate a representation for a C++ "new" expression. PLACEMENT is
2294 a TREE_LIST of placement-new arguments (or NULL_TREE if none). If
2295 NELTS is NULL, TYPE is the type of the storage to be allocated. If
2296 NELTS is not NULL, then this is an array-new allocation; TYPE is
2297 the type of the elements in the array and NELTS is the number of
2298 elements in the array. INIT, if non-NULL, is the initializer for
2299 the new object, or void_zero_node to indicate an initializer of
2300 "()". If USE_GLOBAL_NEW is true, then the user explicitly wrote
2301 "::new" rather than just "new". */
2303 tree
2306 {
2307 tree rval;
2308 tree orig_placement;
2309 tree orig_nelts;
2310 tree orig_init;
2321 {
2325 }
2328 {
2335 use_global_new);
2341 }
2344 {
2346 {
2349 else
2351 }
2353 }
2355 /* ``A reference cannot be created by the new operator. A reference
2356 is not an object (8.2.2, 8.4.3), so a pointer to it could not be
2357 returned by new.'' ARM 5.3.3 */
2359 {
2362 else
2365 }
2368 {
2372 }
2374 /* The type allocated must be complete. If the new-type-id was
2375 "T[N]" then we are just checking that "T" is complete here, but
2376 that is equivalent, since the value of "N" doesn't matter. */
2386 use_global_new);
2388 /* Wrap it in a NOP_EXPR so warn_if_unused_value doesn't complain. */
2393 }
2395 /* Given a Java class, return a decl for the corresponding java.lang.Class. */
2397 tree
2399 {
2405 {
2408 {
2411 }
2413 }
2415 /* Mangle the class$ field. */
2416 {
2417 tree field;
2420 {
2424 }
2426 {
2429 }
2430 }
2434 {
2443 }
2445 }
2446 \f
2447 static tree
2450 {
2451 tree virtual_size;
2455 /* Temporary variables used by the loop. */
2458 /* This is the body of the loop that implements the deletion of a
2459 single element, and moves temp variables to next elements. */
2460 tree body;
2462 /* This is the LOOP_EXPR that governs the deletion of the elements. */
2465 /* This is the thing that governs what to do after the loop has run. */
2468 /* This is the BIND_EXPR which holds the outermost iterator of the
2469 loop. It is convenient to set this variable up and test it before
2470 executing any other code in the loop.
2471 This is also the containing expression returned by this function. */
2473 tree tmp;
2475 /* We should only have 1-D arrays here. */
2481 /* The below is short by the cookie size. */
2489 virtual_size),
2490 tf_warning_or_error);
2500 body = build_compound_expr
2503 tf_warning_or_error));
2504 body = build_compound_expr
2511 no_destructor:
2512 /* If the delete flag is one, or anything else with the low bit set,
2513 delete the storage. */
2515 {
2516 tree base_tbd;
2518 /* The below is short by the cookie size. */
2523 /* no header */
2525 else
2526 {
2527 tree cookie_size;
2530 base_tbd
2533 MINUS_EXPR,
2535 base),
2536 cookie_size,
2537 tf_warning_or_error));
2538 /* True size with header. */
2540 }
2548 }
2552 ;
2555 else
2561 /* Outermost wrapper: If pointer is null, punt. */
2565 integer_zero_node)),
2570 {
2573 }
2576 /* Pre-evaluate the SAVE_EXPR outside of the BIND_EXPR. */
2580 }
2582 /* Create an unnamed variable of the indicated TYPE. */
2584 tree
2586 {
2587 tree decl;
2597 }
2599 /* Create a new temporary variable of the indicated TYPE, initialized
2600 to INIT.
2602 It is not entered into current_binding_level, because that breaks
2603 things when it comes time to do final cleanups (which take place
2604 "outside" the binding contour of the function). */
2606 static tree
2608 {
2609 tree decl;
2615 tf_warning_or_error));
2618 }
2620 /* `build_vec_init' returns tree structure that performs
2621 initialization of a vector of aggregate types.
2623 BASE is a reference to the vector, of ARRAY_TYPE, or a pointer
2624 to the first element, of POINTER_TYPE.
2625 MAXINDEX is the maximum index of the array (one less than the
2626 number of elements). It is only used if BASE is a pointer or
2627 TYPE_DOMAIN (TREE_TYPE (BASE)) == NULL_TREE.
2629 INIT is the (possibly NULL) initializer.
2631 If EXPLICIT_VALUE_INIT_P is true, then INIT must be NULL. All
2632 elements in the array are value-initialized.
2634 FROM_ARRAY is 0 if we should init everything with INIT
2635 (i.e., every element initialized from INIT).
2636 FROM_ARRAY is 1 if we should index into INIT in parallel
2637 with initialization of DECL.
2638 FROM_ARRAY is 2 if we should index into INIT in parallel,
2639 but use assignment instead of initialization. */
2641 tree
2645 {
2646 tree rval;
2648 tree size;
2650 tree iterator;
2651 /* The type of BASE. */
2653 /* The type of an element in the array. */
2655 /* The element type reached after removing all outer array
2656 types. */
2657 tree inner_elt_type;
2658 /* The type of a pointer to an element in the array. */
2659 tree ptype;
2660 tree stmt_expr;
2661 tree compound_stmt;
2683 /* Don't do this if the CONSTRUCTOR might contain something
2684 that might throw and require us to clean up. */
2688 {
2689 /* Do non-default initialization of POD arrays resulting from
2690 brace-enclosed initializers. In this case, digest_init and
2691 store_constructor will handle the semantics for us. */
2696 }
2701 {
2704 }
2705 else
2708 /* The code we are generating looks like:
2709 ({
2710 T* t1 = (T*) base;
2711 T* rval = t1;
2712 ptrdiff_t iterator = maxindex;
2713 try {
2714 for (; iterator != -1; --iterator) {
2715 ... initialize *t1 ...
2716 ++t1;
2717 }
2718 } catch (...) {
2719 ... destroy elements that were constructed ...
2720 }
2721 rval;
2722 })
2724 We can omit the try and catch blocks if we know that the
2725 initialization will never throw an exception, or if the array
2726 elements do not have destructors. We can omit the loop completely if
2727 the elements of the array do not have constructors.
2729 We actually wrap the entire body of the above in a STMT_EXPR, for
2730 tidiness.
2732 When copying from array to another, when the array elements have
2733 only trivial copy constructors, we should use __builtin_memcpy
2734 rather than generating a loop. That way, we could take advantage
2735 of whatever cleverness the back end has for dealing with copies
2736 of blocks of memory. */
2745 /* Protect the entire array initialization so that we can destroy
2746 the partially constructed array if an exception is thrown.
2747 But don't do this if we're assigning. */
2750 {
2752 }
2755 {
2756 /* Do non-default initialization of non-POD arrays resulting from
2757 brace-enclosed initializers. */
2759 tree elt;
2763 {
2766 num_initialized_elts++;
2771 else
2777 complain));
2779 complain));
2780 }
2782 /* Clear out INIT so that we don't get confused below. */
2784 }
2786 {
2787 /* If initializing one array from another, initialize element by
2788 element. We rely upon the below calls the do argument
2789 checking. */
2791 {
2796 }
2800 {
2804 }
2805 }
2807 /* Now, default-initialize any remaining elements. We don't need to
2808 do that if a) the type does not need constructing, or b) we've
2809 already initialized all the elements.
2811 We do need to keep going if we're copying an array. */
2816 && (num_initialized_elts
2818 {
2819 /* If the ITERATOR is equal to -1, then we don't have to loop;
2820 we've already initialized all the elements. */
2821 tree for_stmt;
2822 tree elt_init;
2823 tree to;
2829 for_stmt);
2831 complain),
2832 for_stmt);
2837 {
2838 tree from;
2842 else
2847 complain);
2852 complain);
2853 else
2855 }
2857 {
2859 sorry
2863 explicit_value_init_p,
2865 }
2869 else
2870 {
2873 }
2880 complain));
2883 complain));
2886 }
2888 /* Make sure to cleanup any partially constructed elements. */
2891 {
2892 tree e;
2895 complain);
2897 /* Flatten multi-dimensional array since build_vec_delete only
2898 expects one-dimensional array. */
2903 complain);
2910 }
2912 /* The value of the array initialization is the array itself, RVAL
2913 is a pointer to the first element. */
2918 /* Now make the result have the correct type. */
2920 {
2924 }
2928 }
2930 /* Call the DTOR_KIND destructor for EXP. FLAGS are as for
2931 build_delete. */
2933 static tree
2935 {
2936 tree name;
2937 tree fn;
2939 {
2954 }
2959 flags,
2961 tf_warning_or_error);
2962 }
2964 /* Generate a call to a destructor. TYPE is the type to cast ADDR to.
2965 ADDR is an expression which yields the store to be destroyed.
2966 AUTO_DELETE is the name of the destructor to call, i.e., either
2967 sfk_complete_destructor, sfk_base_destructor, or
2968 sfk_deleting_destructor.
2970 FLAGS is the logical disjunction of zero or more LOOKUP_
2971 flags. See cp-tree.h for more info. */
2973 tree
2976 {
2977 tree expr;
2982 /* Can happen when CURRENT_EXCEPTION_OBJECT gets its type
2983 set to `error_mark_node' before it gets properly cleaned up. */
2990 {
2997 /* We don't want to warn about delete of void*, only other
2998 incomplete types. Deleting other incomplete types
2999 invokes undefined behavior, but it is not ill-formed, so
3000 compile to something that would even do The Right Thing
3001 (TM) should the type have a trivial dtor and no delete
3002 operator. */
3004 {
3007 {
3010 {
3013 "operator delete will be called, even if they are "
3015 }
3017 }
3018 }
3020 /* Call the builtin operator delete. */
3025 /* Throw away const and volatile on target type of addr. */
3027 }
3029 {
3030 handle_array:
3033 {
3036 }
3039 }
3040 else
3041 {
3042 /* Don't check PROTECT here; leave that decision to the
3043 destructor. If the destructor is accessible, call it,
3044 else report error. */
3050 }
3055 {
3061 use_global_delete,
3064 }
3065 else
3066 {
3069 tree ifexp;
3074 /* For `::delete x', we must not use the deleting destructor
3075 since then we would not be sure to get the global `operator
3076 delete'. */
3078 {
3079 /* We will use ADDR multiple times so we must save it. */
3082 /* Delete the object. */
3084 /* Otherwise, treat this like a complete object destructor
3085 call. */
3087 }
3088 /* If the destructor is non-virtual, there is no deleting
3089 variant. Instead, we must explicitly call the appropriate
3090 `operator delete' here. */
3093 {
3094 /* We will use ADDR multiple times so we must save it. */
3096 /* Build the call. */
3098 addr,
3103 /* Call the complete object destructor. */
3105 }
3108 {
3109 /* Make sure we have access to the member op delete, even though
3110 we'll actually be calling it from the destructor. */
3115 }
3118 tf_warning_or_error),
3123 /* We need to calculate this before the dtor changes the vptr. */
3128 /* Explicit destructor call; don't check for null pointer. */
3130 else
3131 /* Handle deleting a null pointer. */
3134 tf_warning_or_error));
3141 }
3142 }
3144 /* At the beginning of a destructor, push cleanups that will call the
3145 destructors for our base classes and members.
3147 Called from begin_destructor_body. */
3149 void
3151 {
3154 tree member;
3155 tree expr;
3158 /* Run destructors for all virtual baseclasses. */
3160 {
3161 tree cond = (condition_conversion
3163 current_in_charge_parm,
3164 integer_two_node)));
3166 /* The CLASSTYPE_VBASECLASSES vector is in initialization
3167 order, which is also the right order for pushing cleanups. */
3170 {
3172 {
3174 base_dtor_identifier,
3175 NULL_TREE,
3176 base_binfo,
3177 (LOOKUP_NORMAL
3179 tf_warning_or_error);
3183 }
3184 }
3185 }
3187 /* Take care of the remaining baseclasses. */
3190 {
3196 base_dtor_identifier,
3199 tf_warning_or_error);
3201 }
3205 {
3211 {
3212 tree this_member = (build_class_member_access_expr
3216 tf_warning_or_error));
3219 sfk_complete_destructor,
3223 }
3224 }
3225 }
3227 /* Build a C++ vector delete expression.
3228 MAXINDEX is the number of elements to be deleted.
3229 ELT_SIZE is the nominal size of each element in the vector.
3230 BASE is the expression that should yield the store to be deleted.
3231 This function expands (or synthesizes) these calls itself.
3232 AUTO_DELETE_VEC says whether the container (vector) should be deallocated.
3234 This also calls delete for virtual baseclasses of elements of the vector.
3236 Update: MAXINDEX is no longer needed. The size can be extracted from the
3237 start of the vector for pointers, and from the type for arrays. We still
3238 use MAXINDEX for arrays because it happens to already have one of the
3239 values we'd have to extract. (We could use MAXINDEX with pointers to
3240 confirm the size, and trap if the numbers differ; not clear that it'd
3241 be worth bothering.) */
3243 tree
3246 {
3247 tree type;
3248 tree rval;
3254 {
3255 /* Step back one from start of vector, and read dimension. */
3256 tree cookie_addr;
3260 {
3263 }
3267 size_ptr_type,
3269 cookie_addr);
3271 }
3273 {
3274 /* Get the total number of things in the array, maxindex is a
3275 bad name. */
3280 {
3283 }
3284 }
3285 else
3286 {
3290 }
3293 use_global_delete);
3298 }