| blob | b4b6cdb0a4c6f00076d007990309f44f3d66b069 |
1 /* Handle initialization things in C++.
2 Copyright (C) 1987-2016 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com)
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 /* High-level class interface. */
48 /* We are about to generate some complex initialization code.
49 Conceptually, it is all a single expression. However, we may want
50 to include conditionals, loops, and other such statement-level
51 constructs. Therefore, we build the initialization code inside a
52 statement-expression. This function starts such an expression.
53 STMT_EXPR_P and COMPOUND_STMT_P are filled in by this function;
54 pass them back to finish_init_stmts when the expression is
55 complete. */
57 static bool
59 {
66 }
68 /* Finish out the statement-expression begun by the previous call to
69 begin_init_stmts. Returns the statement-expression itself. */
71 static tree
73 {
81 }
83 /* Constructors */
85 /* Called from initialize_vtbl_ptrs via dfs_walk. BINFO is the base
86 which we want to initialize the vtable pointer for, DATA is
87 TREE_LIST whose TREE_VALUE is the this ptr expression. */
89 static tree
91 {
96 {
100 tf_warning_or_error);
103 }
106 }
108 /* Initialize all the vtable pointers in the object pointed to by
109 ADDR. */
111 void
113 {
114 tree list;
115 tree type;
120 /* Walk through the hierarchy, initializing the vptr in each base
121 class. We do these in pre-order because we can't find the virtual
122 bases for a class until we've initialized the vtbl for that
123 class. */
125 }
127 /* Return an expression for the zero-initialization of an object with
128 type T. This expression will either be a constant (in the case
129 that T is a scalar), or a CONSTRUCTOR (in the case that T is an
130 aggregate), or NULL (in the case that T does not require
131 initialization). In either case, the value can be used as
132 DECL_INITIAL for a decl of the indicated TYPE; it is a valid static
133 initializer. If NELTS is non-NULL, and TYPE is an ARRAY_TYPE, NELTS
134 is the number of elements in the array. If STATIC_STORAGE_P is
135 TRUE, initializers are only generated for entities for which
136 zero-initialization does not simply mean filling the storage with
137 zero bytes. FIELD_SIZE, if non-NULL, is the bit size of the field,
138 subfields with bit positions at or above that bit size shouldn't
139 be added. Note that this only works when the result is assigned
140 to a base COMPONENT_REF; if we only have a pointer to the base subobject,
141 expand_assignment will end up clearing the full size of TYPE. */
143 static tree
145 tree field_size)
146 {
149 /* [dcl.init]
151 To zero-initialize an object of type T means:
153 -- if T is a scalar type, the storage is set to the value of zero
154 converted to T.
156 -- if T is a non-union class type, the storage for each nonstatic
157 data member and each base-class subobject is zero-initialized.
159 -- if T is a union type, the storage for its first data member is
160 zero-initialized.
162 -- if T is an array type, the storage for each element is
163 zero-initialized.
165 -- if T is a reference type, no initialization is performed. */
170 ;
172 /* In order to save space, we do not explicitly build initializers
173 for items that do not need them. GCC's semantics are that
174 items with static storage duration that are not otherwise
175 initialized are initialized to zero. */
176 ;
182 {
183 tree field;
186 /* Iterate over the fields, building initializations. */
188 {
195 /* Don't add virtual bases for base classes if they are beyond
196 the size of the current field, that means it is present
197 somewhere else in the object. */
199 {
204 }
206 /* Note that for class types there will be FIELD_DECLs
207 corresponding to base classes as well. Thus, iterating
208 over TYPE_FIELDs will result in correct initialization of
209 all of the subobjects. */
211 {
212 tree new_field_size
219 static_storage_p,
220 new_field_size);
223 }
225 /* For unions, only the first field is initialized. */
228 }
230 /* Build a constructor to contain the initializations. */
232 }
234 {
235 tree max_index;
238 /* Iterate over the array elements, building initializations. */
243 else
246 /* If we have an error_mark here, we should just return error mark
247 as we don't know the size of the array yet. */
252 /* A zero-sized array, which is accepted as an extension, will
253 have an upper bound of -1. */
255 {
256 constructor_elt ce;
258 /* If this is a one element array, we just use a regular init. */
261 else
263 max_index);
269 {
272 }
273 }
275 /* Build a constructor to contain the initializations. */
277 }
280 else
283 /* In all cases, the initializer is a constant. */
288 }
290 /* Return an expression for the zero-initialization of an object with
291 type T. This expression will either be a constant (in the case
292 that T is a scalar), or a CONSTRUCTOR (in the case that T is an
293 aggregate), or NULL (in the case that T does not require
294 initialization). In either case, the value can be used as
295 DECL_INITIAL for a decl of the indicated TYPE; it is a valid static
296 initializer. If NELTS is non-NULL, and TYPE is an ARRAY_TYPE, NELTS
297 is the number of elements in the array. If STATIC_STORAGE_P is
298 TRUE, initializers are only generated for entities for which
299 zero-initialization does not simply mean filling the storage with
300 zero bytes. */
302 tree
304 {
306 }
308 /* Return a suitable initializer for value-initializing an object of type
309 TYPE, as described in [dcl.init]. */
311 tree
313 {
314 /* [dcl.init]
316 To value-initialize an object of type T means:
318 - if T is a class type (clause 9) with either no default constructor
319 (12.1) or a default constructor that is user-provided or deleted,
320 then the object is default-initialized;
322 - if T is a (possibly cv-qualified) class type without a user-provided
323 or deleted default constructor, then the object is zero-initialized
324 and the semantic constraints for default-initialization are checked,
325 and if T has a non-trivial default constructor, the object is
326 default-initialized;
328 - if T is an array type, then each element is value-initialized;
330 - otherwise, the object is zero-initialized.
332 A program that calls for default-initialization or
333 value-initialization of an entity of reference type is ill-formed. */
335 /* The AGGR_INIT_EXPR tweaking below breaks in templates. */
341 {
342 tree ctor =
345 complain);
355 {
356 /* This is a class that needs constructing, but doesn't have
357 a user-provided constructor. So we need to zero-initialize
358 the object and then call the implicitly defined ctor.
359 This will be handled in simplify_aggr_init_expr. */
362 }
363 }
365 /* Discard any access checking during subobject initialization;
366 the checks are implied by the call to the ctor which we have
367 verified is OK (cpp0x/defaulted46.C). */
372 }
374 /* Like build_value_init, but don't call the constructor for TYPE. Used
375 for base initializers. */
377 tree
379 {
381 {
385 }
386 /* FIXME the class and array cases should just use digest_init once it is
387 SFINAE-enabled. */
389 {
394 {
395 tree field;
398 /* Iterate over the fields, building initializations. */
400 {
411 /* We could skip vfields and fields of types with
412 user-defined constructors, but I think that won't improve
413 performance at all; it should be simpler in general just
414 to zero out the entire object than try to only zero the
415 bits that actually need it. */
417 /* Note that for class types there will be FIELD_DECLs
418 corresponding to base classes as well. Thus, iterating
419 over TYPE_FIELDs will result in correct initialization of
420 all of the subobjects. */
429 /* We shouldn't have gotten here for anything that would need
430 non-trivial initialization, and gimplify_init_ctor_preeval
431 would need to be fixed to allow it. */
434 }
436 /* Build a constructor to contain the zero- initializations. */
438 }
439 }
441 {
444 /* Iterate over the array elements, building initializations. */
447 /* If we have an error_mark here, we should just return error mark
448 as we don't know the size of the array yet. */
450 {
453 type);
455 }
458 /* A zero-sized array, which is accepted as an extension, will
459 have an upper bound of -1. */
461 {
462 constructor_elt ce;
464 /* If this is a one element array, we just use a regular init. */
467 else
478 /* We shouldn't have gotten here for anything that would need
479 non-trivial initialization, and gimplify_init_ctor_preeval
480 would need to be fixed to allow it. */
483 }
485 /* Build a constructor to contain the initializations. */
487 }
489 {
493 }
495 {
499 }
502 }
504 /* Initialize current class with INIT, a TREE_LIST of
505 arguments for a target constructor. If TREE_LIST is void_type_node,
506 an empty initializer list was given. */
508 static void
510 {
516 tf_warning_or_error));
518 {
520 LOOKUP_NORMAL
521 |LOOKUP_NONVIRTUAL
527 }
528 }
530 /* Return the non-static data initializer for FIELD_DECL MEMBER. */
532 tree
534 {
535 tree init;
540 {
541 /* Use a PLACEHOLDER_EXPR when we don't have a 'this' parameter to
542 refer to; constexpr evaluation knows what to do with it. */
545 }
548 {
553 /* Check recursive instantiation. */
555 {
559 }
560 else
561 {
564 /* Do deferred instantiation of the NSDMI. */
565 init = (tsubst_copy_and_build
572 }
573 }
574 else
575 {
578 {
579 unparsed:
584 }
585 /* Strip redundant TARGET_EXPR so we don't need to remap it, and
586 so the aggregate init code below will see a CONSTRUCTOR. */
592 /* Now put it back so C++17 copy elision works. */
594 }
598 }
600 /* Initialize MEMBER, a FIELD_DECL, with INIT, a TREE_LIST of
601 arguments. If TREE_LIST is void_type_node, an empty initializer
602 list was given; if NULL_TREE no initializer was given. */
604 static void
606 {
607 tree decl;
610 /* Use the non-static data member initializer if there was no
611 mem-initializer for this field. */
618 /* Effective C++ rule 12 requires that all data members be
619 initialized. */
623 member);
625 /* Get an lvalue for the data member. */
629 tf_warning_or_error);
635 {
637 /* Handle references. */
644 member);
645 }
648 {
649 /* mem() means value-initialization. */
651 {
655 }
656 else
657 {
663 }
664 }
665 /* Deal with this here, as we will get confused if we try to call the
666 assignment op for an anonymous union. This can happen in a
667 synthesized copy constructor. */
669 {
671 {
674 }
675 }
678 /* Pre-digested NSDMI. */
681 /* { } mem-initializer. */
686 {
687 /* With references and list-initialization, we need to deal with
688 extending temporary lifetimes. 12.2p5: "A temporary bound to a
689 reference member in a constructor’s ctor-initializer (12.6.2)
690 persists until the constructor exits." */
695 tf_warning_or_error);
697 {
702 }
705 /* A FIELD_DECL doesn't really have a suitable lifetime, but
706 make_temporary_var_for_ref_to_temp will treat it as automatic and
707 set_up_extended_ref_temp wants to use the decl in a warning. */
717 }
720 {
722 {
724 {
727 else
731 }
735 {
737 {
738 /* Initialize the array only if it's not a flexible
739 array member (i.e., if it has an upper bound). */
743 }
744 }
745 else
747 }
748 else
749 {
756 {
757 /* TYPE_NEEDS_CONSTRUCTING can be set just because we have a
758 vtable; still give this diagnostic. */
763 }
765 tf_warning_or_error));
766 }
767 }
768 else
769 {
771 {
772 tree core_type;
773 /* member traversal: note it leaves init NULL */
775 {
780 }
782 {
787 }
797 }
799 /* There was an explicit member initialization. Do some work
800 in that case. */
802 tf_warning_or_error);
807 tf_warning_or_error));
808 }
811 {
812 tree expr;
817 tf_warning_or_error);
820 tf_warning_or_error);
825 }
826 }
828 /* Returns a TREE_LIST containing (as the TREE_PURPOSE of each node) all
829 the FIELD_DECLs on the TYPE_FIELDS list for T, in reverse order. */
831 static tree
833 {
834 tree fields;
836 /* Note whether or not T is a union. */
841 {
842 tree fieldtype;
844 /* Skip CONST_DECLs for enumeration constants and so forth. */
850 /* For an anonymous struct or union, we must recursively
851 consider the fields of the anonymous type. They can be
852 directly initialized from the constructor. */
854 {
855 /* Add this field itself. Synthesized copy constructors
856 initialize the entire aggregate. */
858 /* And now add the fields in the anonymous aggregate. */
861 }
862 /* Add this field. */
865 }
868 }
870 /* Return the innermost aggregate scope for FIELD, whether that is
871 the enclosing class or an anonymous aggregate within it. */
873 static tree
875 {
878 else
880 }
882 /* The MEM_INITS are a TREE_LIST. The TREE_PURPOSE of each list gives
883 a FIELD_DECL or BINFO in T that needs initialization. The
884 TREE_VALUE gives the initializer, or list of initializer arguments.
886 Return a TREE_LIST containing all of the initializations required
887 for T, in the order in which they should be performed. The output
888 list has the same format as the input. */
890 static tree
892 {
893 tree init;
895 tree sorted_inits;
896 tree next_subobject;
901 /* Build up a list of initializations. The TREE_PURPOSE of entry
902 will be the subobject (a FIELD_DECL or BINFO) to initialize. The
903 TREE_VALUE will be the constructor arguments, or NULL if no
904 explicit initialization was provided. */
907 /* Process the virtual bases. */
912 /* Process the direct bases. */
918 /* Process the non-static data members. */
920 /* Reverse the entire list of initializations, so that they are in
921 the order that they will actually be performed. */
924 /* If the user presented the initializers in an order different from
925 that in which they will actually occur, we issue a warning. Keep
926 track of the next subobject which can be explicitly initialized
927 without issuing a warning. */
930 /* Go through the explicit initializers, filling in TREE_PURPOSE in
931 the SORTED_INITS. */
933 {
934 tree subobject;
935 tree subobject_init;
939 /* If the explicit initializers are in sorted order, then
940 SUBOBJECT will be NEXT_SUBOBJECT, or something following
941 it. */
943 subobject_init;
948 /* Issue a warning if the explicit initializer order does not
949 match that which will actually occur.
950 ??? Are all these on the correct lines? */
952 {
957 else
963 else
967 }
969 /* Look again, from the beginning of the list. */
971 {
975 }
977 /* It is invalid to initialize the same subobject more than
978 once. */
980 {
984 subobject);
985 else
988 subobject);
989 }
991 /* Record the initialization. */
994 }
996 /* [class.base.init]
998 If a ctor-initializer specifies more than one mem-initializer for
999 multiple members of the same union (including members of
1000 anonymous unions), the ctor-initializer is ill-formed.
1002 Here we also splice out uninitialized union members. */
1004 {
1008 {
1009 tree field;
1010 tree ctx;
1016 /* Skip base classes. */
1020 /* If this is an anonymous aggregate with no explicit initializer,
1021 splice it out. */
1025 /* See if this field is a member of a union, or a member of a
1026 structure contained in a union, etc. */
1029 /* If this field is not a member of a union, skip it. */
1034 /* If this union member has no explicit initializer and no NSDMI,
1035 splice it out. */
1038 else
1041 /* It's only an error if we have two initializers for the same
1042 union type. */
1044 {
1047 }
1049 /* See if LAST_FIELD and the field initialized by INIT are
1050 members of the same union (or the union itself). If so, there's
1051 a problem, unless they're actually members of the same structure
1052 which is itself a member of a union. For example, given:
1054 union { struct { int i; int j; }; };
1056 initializing both `i' and `j' makes sense. */
1057 ctx = common_enclosing_class
1063 {
1064 /* A mem-initializer hides an NSDMI. */
1069 else
1070 {
1073 ctx);
1075 }
1076 }
1080 next:
1083 splice:
1086 }
1087 }
1090 }
1092 /* Initialize all bases and members of CURRENT_CLASS_TYPE. MEM_INITS
1093 is a TREE_LIST giving the explicit mem-initializer-list for the
1094 constructor. The TREE_PURPOSE of each entry is a subobject (a
1095 FIELD_DECL or a BINFO) of the CURRENT_CLASS_TYPE. The TREE_VALUE
1096 is a TREE_LIST giving the arguments to the constructor or
1097 void_type_node for an empty list of arguments. */
1099 void
1101 {
1104 /* We will already have issued an error message about the fact that
1105 the type is incomplete. */
1112 {
1113 /* Delegating constructor. */
1117 }
1123 /* Sort the mem-initializers into the order in which the
1124 initializations should be performed. */
1129 /* Initialize base classes. */
1133 {
1137 /* We already have issued an error message. */
1141 /* Suppress access control when calling the inherited ctor. */
1143 && flag_new_inheriting_ctors
1149 {
1150 /* If these initializations are taking place in a copy constructor,
1151 the base class should probably be explicitly initialized if there
1152 is a user-defined constructor in the base class (other than the
1153 default constructor, which will be called anyway). */
1161 }
1163 /* Initialize the base. */
1165 {
1166 tree base_addr;
1172 tf_warning_or_error),
1173 arguments,
1174 flags,
1175 tf_warning_or_error);
1177 }
1179 /* C++14 DR1658 Means we do not have to construct vbases of
1180 abstract classes. */
1185 }
1188 /* Initialize the vptrs. */
1191 /* Initialize the data members. */
1193 {
1197 }
1198 }
1200 /* Returns the address of the vtable (i.e., the value that should be
1201 assigned to the vptr) for BINFO. */
1203 tree
1205 {
1207 tree vtbl;
1210 /* If this is a virtual primary base, then the vtable we want to store
1211 is that for the base this is being used as the primary base of. We
1212 can't simply skip the initialization, because we may be expanding the
1213 inits of a subobject constructor where the virtual base layout
1214 can be different. */
1218 /* Figure out what vtable BINFO's vtable is based on, and mark it as
1219 used. */
1223 /* Now compute the address to use when initializing the vptr. */
1229 }
1231 /* This code sets up the virtual function tables appropriate for
1232 the pointer DECL. It is a one-ply initialization.
1234 BINFO is the exact type that DECL is supposed to be. In
1235 multiple inheritance, this might mean "C's A" if C : A, B. */
1237 static void
1239 {
1241 tree vtt_index;
1243 /* Compute the initializer for vptr. */
1246 /* We may get this vptr from a VTT, if this is a subobject
1247 constructor or subobject destructor. */
1250 {
1251 tree vtbl2;
1252 tree vtt_parm;
1254 /* Compute the value to use, when there's a VTT. */
1260 /* The actual initializer is the VTT value only in the subobject
1261 constructor. In maybe_clone_body we'll substitute NULL for
1262 the vtt_parm in the case of the non-subobject constructor. */
1264 }
1266 /* Compute the location of the vtpr. */
1268 tf_warning_or_error),
1272 /* Assign the vtable to the vptr. */
1276 }
1278 /* If an exception is thrown in a constructor, those base classes already
1279 constructed must be destroyed. This function creates the cleanup
1280 for BINFO, which has just been constructed. If FLAG is non-NULL,
1281 it is a DECL which is nonzero when this base needs to be
1282 destroyed. */
1284 static void
1286 {
1287 tree expr;
1292 /* Call the destructor. */
1294 base_dtor_identifier,
1295 NULL,
1296 binfo,
1298 tf_warning_or_error);
1310 }
1312 /* Construct the virtual base-class VBASE passing the ARGUMENTS to its
1313 constructor. */
1315 static void
1317 {
1318 tree inner_if_stmt;
1319 tree exp;
1320 tree flag;
1322 /* If there are virtual base classes with destructors, we need to
1323 emit cleanups to destroy them if an exception is thrown during
1324 the construction process. These exception regions (i.e., the
1325 period during which the cleanups must occur) begin from the time
1326 the construction is complete to the end of the function. If we
1327 create a conditional block in which to initialize the
1328 base-classes, then the cleanup region for the virtual base begins
1329 inside a block, and ends outside of that block. This situation
1330 confuses the sjlj exception-handling code. Therefore, we do not
1331 create a single conditional block, but one for each
1332 initialization. (That way the cleanup regions always begin
1333 in the outer block.) We trust the back end to figure out
1334 that the FLAG will not change across initializations, and
1335 avoid doing multiple tests. */
1340 /* Compute the location of the virtual base. If we're
1341 constructing virtual bases, then we must be the most derived
1342 class. Therefore, we don't have to look up the virtual base;
1343 we already know where it is. */
1352 }
1354 /* Find the context in which this FIELD can be initialized. */
1356 static tree
1358 {
1361 /* Anonymous union members can be initialized in the first enclosing
1362 non-anonymous union context. */
1366 }
1368 /* Function to give error message if member initialization specification
1369 is erroneous. FIELD is the member we decided to initialize.
1370 TYPE is the type for which the initialization is being performed.
1371 FIELD must be a member of TYPE.
1373 MEMBER_NAME is the name of the member. */
1375 static int
1377 {
1381 {
1383 member_name);
1385 }
1387 {
1390 field);
1392 }
1394 {
1398 }
1400 {
1402 member_name);
1404 }
1407 }
1409 /* NAME is a FIELD_DECL, an IDENTIFIER_NODE which names a field, or it
1410 is a _TYPE node or TYPE_DECL which names a base for that type.
1411 Check the validity of NAME, and return either the base _TYPE, base
1412 binfo, or the FIELD_DECL of the member. If NAME is invalid, return
1413 NULL_TREE and issue a diagnostic.
1415 An old style unnamed direct single base construction is permitted,
1416 where NAME is NULL. */
1418 tree
1420 {
1421 tree basetype;
1422 tree field;
1428 {
1429 /* This is an obsolete unnamed base class initializer. The
1430 parser will already have warned about its use. */
1432 {
1435 current_class_type);
1438 basetype = BINFO_TYPE
1443 current_class_type);
1445 }
1446 }
1448 {
1451 }
1454 else
1458 {
1459 tree class_binfo;
1460 tree direct_binfo;
1461 tree virtual_binfo;
1472 /* Look for a direct base. */
1477 /* Look for a virtual base -- unless the direct base is itself
1478 virtual. */
1482 /* [class.base.init]
1484 If a mem-initializer-id is ambiguous because it designates
1485 both a direct non-virtual base class and an inherited virtual
1486 base class, the mem-initializer is ill-formed. */
1488 {
1490 basetype);
1492 }
1495 {
1499 else
1503 }
1506 }
1507 else
1508 {
1511 else
1516 }
1519 }
1521 /* This is like `expand_member_init', only it stores one aggregate
1522 value into another.
1524 INIT comes in two flavors: it is either a value which
1525 is to be stored in EXP, or it is a parameter list
1526 to go to a constructor, which will operate on EXP.
1527 If INIT is not a parameter list for a constructor, then set
1528 LOOKUP_ONLYCONVERTING.
1529 If FLAGS is LOOKUP_ONLYCONVERTING then it is the = init form of
1530 the initializer, if FLAGS is 0, then it is the (init) form.
1531 If `init' is a CONSTRUCTOR, then we emit a warning message,
1532 explaining that such initializations are invalid.
1534 If INIT resolves to a CALL_EXPR which happens to return
1535 something of the type we are looking for, then we know
1536 that we can safely use that call to perform the
1537 initialization.
1539 The virtual function table pointer cannot be set up here, because
1540 we do not really know its type.
1542 This never calls operator=().
1544 When initializing, nothing is CONST.
1546 A default copy constructor may have to be used to perform the
1547 initialization.
1549 A constructor or a conversion operator may have to be used to
1550 perform the initialization, but not both, as it would be ambiguous. */
1552 tree
1554 {
1555 tree stmt_expr;
1556 tree compound_stmt;
1577 {
1583 else
1584 {
1585 /* An array may not be initialized use the parenthesized
1586 initialization form -- unless the initializer is "()". */
1588 {
1592 }
1593 /* Must arrange to initialize each element of EXP
1594 from elements of INIT. */
1601 }
1605 from_array,
1606 complain);
1610 /* Restore the type of init unless it was used directly. */
1614 }
1618 /* Just know that we've seen something for this node. */
1632 }
1634 static void
1636 tsubst_flags_t complain)
1637 {
1639 tree ctor_name;
1641 /* It fails because there may not be a constructor which takes
1642 its own type as the first (or only parameter), but which does
1643 take other types via a conversion. So, if the thing initializing
1644 the expression is a unit element of type X, first try X(X&),
1645 followed by initialization by X. If neither of these work
1646 out, then look hard. */
1647 tree rval;
1650 /* If we have direct-initialization from an initializer list, pull
1651 it out of the TREE_LIST so the code below can see it. */
1654 {
1658 /* Only call reshape_init if it has not been called earlier
1659 by the callers. */
1662 }
1666 /* A brace-enclosed initializer for an aggregate. In C++0x this can
1667 happen for direct-initialization, too. */
1670 /* A CONSTRUCTOR of the target's type is a previously digested
1671 initializer, whether that happened just above or in
1672 cp_parser_late_parsing_nsdmi.
1674 A TARGET_EXPR with TARGET_EXPR_DIRECT_INIT_P or TARGET_EXPR_LIST_INIT_P
1675 set represents the whole initialization, so we shouldn't build up
1676 another ctor call. */
1683 {
1684 /* Early initialization via a TARGET_EXPR only works for
1685 complete objects. */
1692 }
1696 {
1697 /* Base subobjects should only get direct-initialization. */
1701 /* Do nothing. We hit this in two cases: Reference initialization,
1702 where we aren't initializing a real variable, so we don't want
1703 to run a new constructor; and catching an exception, where we
1704 have already built up the constructor call so we could wrap it
1706 else
1711 /* We need to protect the initialization of a catch parm with a
1712 call to terminate(), which shows up as a MUST_NOT_THROW_EXPR
1713 around the TARGET_EXPR for the copy constructor. See
1714 initialize_handler_parm. */
1715 {
1719 }
1720 else
1725 }
1730 {
1734 }
1735 else
1740 {
1741 /* Delegating constructor. */
1742 tree complete;
1743 tree base;
1746 /* Unshare the arguments for the second call. */
1749 {
1752 }
1755 complain);
1761 complain);
1764 }
1765 else
1766 {
1769 else
1772 complain);
1773 }
1779 {
1782 {
1786 }
1787 }
1789 /* FIXME put back convert_to_void? */
1792 }
1794 /* This function is responsible for initializing EXP with INIT
1795 (if any).
1797 BINFO is the binfo of the type for who we are performing the
1798 initialization. For example, if W is a virtual base class of A and B,
1799 and C : A, B.
1800 If we are initializing B, then W must contain B's W vtable, whereas
1801 were we initializing C, W must contain C's W vtable.
1803 TRUE_EXP is nonzero if it is the true expression being initialized.
1804 In this case, it may be EXP, or may just contain EXP. The reason we
1805 need this is because if EXP is a base element of TRUE_EXP, we
1806 don't necessarily know by looking at EXP where its virtual
1807 baseclass fields should really be pointing. But we do know
1808 from TRUE_EXP. In constructors, we don't know anything about
1809 the value being initialized.
1811 FLAGS is just passed to `build_new_method_call'. See that function
1812 for its description. */
1814 static void
1816 tsubst_flags_t complain)
1817 {
1823 /* Use a function returning the desired type to initialize EXP for us.
1824 If the function is a constructor, and its first argument is
1825 NULL_TREE, know that it was meant for us--just slide exp on
1826 in and expand the constructor. Constructors now come
1827 as TARGET_EXPRs. */
1831 {
1833 /* If store_init_value returns NULL_TREE, the INIT has been
1834 recorded as the DECL_INITIAL for EXP. That means there's
1835 nothing more we have to do. */
1841 }
1843 /* List-initialization from {} becomes value-initialization for non-aggregate
1844 classes with default constructors. Handle this here when we're
1845 initializing a base, so protected access works. */
1847 {
1854 }
1856 /* If an explicit -- but empty -- initializer list was present,
1857 that's value-initialization. */
1859 {
1860 /* If the type has data but no user-provided ctor, we need to zero
1861 out the object. */
1864 {
1867 /* Don't clobber already initialized virtual bases. */
1870 field_size);
1873 }
1875 /* If we don't need to mess with the constructor at all,
1876 then we're done. */
1880 /* Otherwise fall through and call the constructor. */
1882 }
1884 /* We know that expand_default_init can handle everything we want
1885 at this point. */
1887 }
1889 /* Report an error if TYPE is not a user-defined, class type. If
1890 OR_ELSE is nonzero, give an error message. */
1892 int
1894 {
1899 {
1903 }
1905 }
1907 tree
1909 {
1915 else
1917 }
1919 /* Build a reference to a member of an aggregate. This is not a C++
1920 `&', but really something which can have its address taken, and
1921 then act as a pointer to member, for example TYPE :: FIELD can have
1922 its address taken by saying & TYPE :: FIELD. ADDRESS_P is true if
1923 this expression is the operand of "&".
1925 @@ Prints out lousy diagnostics for operator <typename>
1926 @@ fields.
1928 @@ This function should be rewritten and placed in search.c. */
1930 tree
1932 tsubst_flags_t complain)
1933 {
1934 tree decl;
1937 /* class templates can come in as TEMPLATE_DECLs here. */
1950 /* Callers should call mark_used before this point. */
1955 {
1959 }
1961 /* Entities other than non-static members need no further
1962 processing. */
1969 {
1973 }
1975 /* Set up BASEBINFO for member lookup. */
1978 /* A lot of this logic is now handled in lookup_member. */
1980 {
1981 /* Go from the TREE_BASELINK to the member function info. */
1985 {
1986 /* Get rid of a potential OVERLOAD around it. */
1989 /* Unique functions are handled easily. */
1991 /* For non-static member of base class, we need a special rule
1992 for access checking [class.protected]:
1994 If the access is to form a pointer to member, the
1995 nested-name-specifier shall name the derived class
1996 (or any class derived from that class). */
2000 complain);
2001 else
2003 complain);
2008 }
2009 else
2011 }
2013 /* We need additional test besides the one in
2014 check_accessibility_of_qualified_id in case it is
2015 a pointer to non-static member. */
2017 complain);
2020 {
2021 /* If MEMBER is non-static, then the program has fallen afoul of
2022 [expr.prim]:
2024 An id-expression that denotes a nonstatic data member or
2025 nonstatic member function of a class can only be used:
2027 -- as part of a class member access (_expr.ref_) in which the
2028 object-expression refers to the member's class or a class
2029 derived from that class, or
2031 -- to form a pointer to member (_expr.unary.op_), or
2033 -- in the body of a nonstatic member function of that class or
2034 of a class derived from that class (_class.mfct.nonstatic_), or
2036 -- in a mem-initializer for a constructor for that class or for
2037 a class derived from that class (_class.base.init_). */
2039 {
2040 /* Build a representation of the qualified name suitable
2041 for use as the operand to "&" -- even though the "&" is
2042 not actually present. */
2044 /* In Microsoft mode, treat a non-static member function as if
2045 it were a pointer-to-member. */
2047 {
2050 }
2055 }
2057 {
2061 }
2063 }
2068 }
2070 /* If DECL is a scalar enumeration constant or variable with a
2071 constant initializer, return the initializer (or, its initializers,
2072 recursively); otherwise, return DECL. If STRICT_P, the
2073 initializer is only returned if DECL is a
2074 constant-expression. If RETURN_AGGREGATE_CST_OK_P, it is ok to
2075 return an aggregate constant. */
2077 static tree
2079 {
2084 {
2085 tree init;
2086 /* If DECL is a static data member in a template
2087 specialization, we must instantiate it here. The
2088 initializer for the static data member is not processed
2089 until needed; we need it now. */
2094 {
2096 /* Treat the error as a constant to avoid cascading errors on
2097 excessively recursive template instantiation (c++/9335). */
2099 else
2101 }
2102 /* Initializers in templates are generally expanded during
2103 instantiation, so before that for const int i(2)
2104 INIT is a TREE_LIST with the actual initializer as
2105 TREE_VALUE. */
2107 && init
2111 /* Instantiate a non-dependent initializer for user variables. We
2112 mustn't do this for the temporary for an array compound literal;
2113 trying to instatiate the initializer will keep creating new
2114 temporaries until we crash. Probably it's not useful to do it for
2115 other artificial variables, either. */
2121 || (!return_aggregate_cst_ok_p
2122 /* Unless RETURN_AGGREGATE_CST_OK_P is true, do not
2123 return an aggregate constant (of which string
2124 literals are a special case), as we do not want
2125 to make inadvertent copies of such entities, and
2126 we must be sure that their addresses are the
2127 same everywhere. */
2131 /* Don't return a CONSTRUCTOR for a variable with partial run-time
2132 initialization, since it doesn't represent the entire value. */
2137 }
2139 }
2141 /* If DECL is a CONST_DECL, or a constant VAR_DECL initialized by constant
2142 of integral or enumeration type, or a constexpr variable of scalar type,
2143 then return that value. These are those variables permitted in constant
2144 expressions by [5.19/1]. */
2146 tree
2148 {
2151 }
2153 /* Like scalar_constant_value, but can also return aggregate initializers. */
2155 tree
2157 {
2160 }
2162 /* A more relaxed version of scalar_constant_value, used by the
2163 common C/C++ code. */
2165 tree
2167 {
2170 }
2171 \f
2172 /* Common subroutines of build_new and build_vec_delete. */
2173 \f
2174 /* Build and return a NEW_EXPR. If NELTS is non-NULL, TYPE[NELTS] is
2175 the type of the object being allocated; otherwise, it's just TYPE.
2176 INIT is the initializer, if any. USE_GLOBAL_NEW is true if the
2177 user explicitly wrote "::operator new". PLACEMENT, if non-NULL, is
2178 a vector of arguments to be provided as arguments to a placement
2179 new operator. This routine performs no semantic checks; it just
2180 creates and returns a NEW_EXPR. */
2182 static tree
2185 {
2186 tree init_list;
2187 tree new_expr;
2189 /* If INIT is NULL, the we want to store NULL_TREE in the NEW_EXPR.
2190 If INIT is not NULL, then we want to store VOID_ZERO_NODE. This
2191 permits us to distinguish the case of a missing initializer "new
2192 int" from an empty initializer "new int()". */
2197 else
2202 init_list);
2207 }
2209 /* Diagnose uninitialized const members or reference members of type
2210 TYPE. USING_NEW is used to disambiguate the diagnostic between a
2211 new expression without a new-initializer and a declaration. Returns
2212 the error count. */
2214 static int
2217 {
2218 tree field;
2225 {
2226 tree field_type;
2237 {
2240 {
2242 {
2246 else
2248 }
2249 else
2250 {
2255 else
2258 }
2261 }
2262 }
2265 {
2268 {
2270 {
2274 else
2276 }
2277 else
2278 {
2283 else
2286 }
2289 }
2290 }
2293 error_count
2296 }
2298 }
2300 int
2302 {
2304 }
2306 /* Call __cxa_bad_array_new_length to indicate that the size calculation
2307 overflowed. Pretend it returns sizetype so that it plays nicely in the
2308 COND_EXPR. */
2310 tree
2312 {
2316 NULL_TREE));
2319 }
2321 /* Attempt to find the initializer for field T in the initializer INIT,
2322 when non-null. Returns the initializer when successful and NULL
2323 otherwise. */
2324 static tree
2326 {
2333 /* Iterate over all top-level initializer elements. */
2335 {
2336 /* If the member T is found, return it. */
2340 /* Otherwise continue and/or recurse into nested initializers. */
2344 }
2346 }
2348 /* Attempt to verify that the argument, OPER, of a placement new expression
2349 refers to an object sufficiently large for an object of TYPE or an array
2350 of NELTS of such objects when NELTS is non-null, and issue a warning when
2351 it does not. SIZE specifies the size needed to construct the object or
2352 array and captures the result of NELTS * sizeof (TYPE). (SIZE could be
2353 greater when the array under construction requires a cookie to store
2354 NELTS. GCC's placement new expression stores the cookie when invoking
2355 a user-defined placement new operator function but not the default one.
2356 Placement new expressions with user-defined placement new operator are
2357 not diagnosed since we don't know how they use the buffer (this could
2358 be a future extension). */
2359 static void
2361 {
2364 /* The number of bytes to add to or subtract from the size of the provided
2365 buffer based on an offset into an array or an array element reference.
2366 Although intermediate results may be negative (as in a[3] - 2) the final
2367 result cannot be. */
2369 /* True when the size of the entire destination object should be used
2370 to compute the possibly optimistic estimate of the available space. */
2372 /* True when the reference to the destination buffer is an ADDR_EXPR. */
2377 /* Using a function argument or a (non-array) variable as an argument
2378 to placement new is not checked since it's unknown what it might
2379 point to. */
2385 /* Evaluate any constant expressions. */
2388 /* Handle the common case of array + offset expression when the offset
2389 is a constant. */
2391 {
2392 /* If the offset is comple-time constant, use it to compute a more
2393 accurate estimate of the size of the buffer. Since the operand
2394 of POINTER_PLUS_EXPR is represented as an unsigned type, convert
2395 it to signed first.
2396 Otherwise, use the size of the entire array as an optimistic
2397 estimate (this may lead to false negatives). */
2401 else
2407 }
2412 {
2415 }
2421 {
2422 /* Similar to the offset computed above, see if the array index
2423 is a compile-time constant. If so, and unless the offset was
2424 not a compile-time constant, use the index to determine the
2425 size of the buffer. Otherwise, use the entire array as
2426 an optimistic estimate of the size. */
2430 else
2431 {
2434 }
2437 }
2439 /* Refers to the declared object that constains the subobject referenced
2440 by OPER. When the object is initialized, makes it possible to determine
2441 the actual size of a flexible array member used as the buffer passed
2442 as OPER to placement new. */
2444 /* True when operand is a COMPONENT_REF, to distinguish flexible array
2445 members from arrays of unspecified size. */
2448 /* Descend into a struct or union to find the member whose address
2449 is being used as the argument. */
2451 {
2457 }
2463 {
2464 /* A possibly optimistic estimate of the number of bytes available
2465 in the destination buffer. */
2467 /* True when the estimate above is in fact the exact size
2468 of the destination buffer rather than an estimate. */
2471 /* Treat members of unions and members of structs uniformly, even
2472 though the size of a member of a union may be viewed as extending
2473 to the end of the union itself (it is by __builtin_object_size). */
2477 {
2478 /* Use the size of the entire array object when the expression
2479 refers to a variable or its size depends on an expression
2480 that's not a compile-time constant. */
2483 }
2486 {
2487 /* Use the size of the type of the destination buffer object
2488 as the optimistic estimate of the available space in it. */
2490 }
2492 {
2493 /* Constructing into a buffer provided by the flexible array
2494 member of a declared object (which is permitted as a G++
2495 extension). If the array member has been initialized,
2496 determine its size from the initializer. Otherwise,
2497 the array size is zero. */
2502 }
2503 else
2504 {
2505 /* Bail if neither the size of the object nor its type is known. */
2507 }
2512 {
2513 /* Avoid diagnosing flexible array members (which are accepted
2514 as an extension and diagnosed with -Wpedantic) and zero-length
2515 arrays (also an extension).
2516 Overflowing construction in one-element arrays is diagnosed
2517 only at level 2. */
2525 && !var_decl
2528 }
2530 /* The size of the buffer can only be adjusted down but not up. */
2533 /* Reduce the size of the buffer by the adjustment computed above
2534 from the offset and/or the index into the array. */
2537 else
2540 /* The minimum amount of space needed for the allocation. This
2541 is an optimistic estimate that makes it possible to detect
2542 placement new invocation for some undersize buffers but not
2543 others. */
2553 else
2554 {
2555 /* The type is a VLA. */
2557 }
2560 {
2564 exact_size ?
2565 "placement new constructing an object of type "
2566 "%<%T [%wu]%> and size %qwu in a region of type %qT "
2567 "and size %qwi"
2569 "%<%T [%wu]%> and size %qwu in a region of type %qT "
2573 bytes_avail);
2574 else
2576 exact_size ?
2577 "placement new constructing an array of objects "
2578 "of type %qT and size %qwu in a region of type %qT "
2579 "and size %qwi"
2581 "of type %qT and size %qwu in a region of type %qT "
2584 bytes_avail);
2585 else
2587 exact_size ?
2588 "placement new constructing an object of type %qT "
2589 "and size %qwu in a region of type %qT and size %qwi"
2591 "and size %qwu in a region of type %qT and size "
2594 bytes_avail);
2595 }
2596 }
2597 }
2599 /* True if alignof(T) > __STDCPP_DEFAULT_NEW_ALIGNMENT__. */
2601 bool
2603 {
2606 }
2608 /* Return the alignment we expect malloc to guarantee. This should just be
2609 MALLOC_ABI_ALIGNMENT, but that macro defaults to only BITS_PER_WORD for some
2610 reason, so don't let the threshold be smaller than max_align_t_align. */
2612 unsigned
2614 {
2616 }
2618 /* Generate code for a new-expression, including calling the "operator
2619 new" function, initializing the object, and, if an exception occurs
2620 during construction, cleaning up. The arguments are as for
2621 build_raw_new_expr. This may change PLACEMENT and INIT.
2622 TYPE is the type of the object being constructed, possibly an array
2623 of NELTS elements when NELTS is non-null (in "new T[NELTS]", T may
2624 be an array of the form U[inner], with the whole expression being
2625 "new U[NELTS][inner]"). */
2627 static tree
2630 tsubst_flags_t complain)
2631 {
2633 /* True iff this is a call to "operator new[]" instead of just
2634 "operator new". */
2636 /* If ARRAY_P is true, the element type of the array. This is never
2637 an ARRAY_TYPE; for something like "new int[3][4]", the
2638 ELT_TYPE is "int". If ARRAY_P is false, this is the same type as
2639 TYPE. */
2640 tree elt_type;
2641 /* The type of the new-expression. (This type is always a pointer
2642 type.) */
2643 tree pointer_type;
2644 tree non_const_pointer_type;
2645 /* The most significant array bound in int[OUTER_NELTS][inner]. */
2647 /* For arrays with a non-constant number of elements, a bounds checks
2648 on the NELTS parameter to avoid integer overflow at runtime. */
2651 /* Number of the "inner" elements in "new T[OUTER_NELTS][inner]". */
2654 /* Size of the inner array elements (those with constant dimensions). */
2655 offset_int inner_size;
2656 /* The address returned by the call to "operator new". This node is
2657 a VAR_DECL and is therefore reusable. */
2658 tree alloc_node;
2659 tree alloc_fn;
2662 /* If non-NULL, the number of extra bytes to allocate at the
2663 beginning of the storage allocated for an array-new expression in
2664 order to store the number of elements. */
2666 tree placement_first;
2668 /* True if the function we are calling is a placement allocation
2669 function. */
2671 /* True if the storage must be initialized, either by a constructor
2672 or due to an explicit new-initializer. */
2674 /* The address of the thing allocated, not including any cookie. In
2675 particular, if an array cookie is in use, DATA_ADDR is the
2676 address of the first array element. This node is a VAR_DECL, and
2677 is therefore reusable. */
2678 tree data_addr;
2683 {
2686 }
2688 {
2689 /* Transforms new (T[N]) to new T[N]. The former is a GNU
2690 extension for variable N. (This also covers new T where T is
2691 a VLA typedef.) */
2697 }
2699 /* Lots of logic below. depends on whether we have a constant number of
2700 elements, so go ahead and fold it now. */
2704 /* If our base type is an array, then make sure we know how many elements
2705 it has. */
2709 {
2713 {
2718 {
2722 }
2724 }
2725 else
2726 {
2728 {
2732 }
2734 }
2738 inner_nelts_cst,
2739 complain);
2740 }
2743 {
2746 }
2751 /* Warn if we performed the (T[N]) to T[N] transformation and N is
2752 variable. */
2755 {
2757 {
2762 else
2767 }
2768 else
2770 }
2773 {
2777 }
2785 {
2787 /* A program that calls for default-initialization [...] of an
2788 entity of reference type is ill-formed. */
2792 /* A new-expression that creates an object of type T initializes
2793 that object as follows:
2794 - If the new-initializer is omitted:
2795 -- If T is a (possibly cv-qualified) non-POD class type
2796 (or array thereof), the object is default-initialized (8.5).
2797 [...]
2798 -- Otherwise, the object created has indeterminate
2799 value. If T is a const-qualified type, or a (possibly
2800 cv-qualified) POD class type (or array thereof)
2801 containing (directly or indirectly) a member of
2802 const-qualified type, the program is ill-formed; */
2812 }
2816 {
2820 }
2824 {
2825 /* Maximum available size in bytes. Half of the address space
2826 minus the cookie size. */
2827 offset_int max_size
2829 /* Maximum number of outer elements which can be allocated. */
2830 offset_int max_outer_nelts;
2831 tree max_outer_nelts_tree;
2837 /* Unconditionally subtract the cookie size. This decreases the
2838 maximum object size and is safe even if we choose not to use
2839 a cookie after all. */
2845 {
2849 }
2857 {
2859 {
2860 /* When the array size is constant, check it at compile time
2861 to make sure it doesn't exceed the implementation-defined
2862 maximum, as required by C++ 14 (in C++ 11 this requirement
2863 isn't explicitly stated but it's enforced anyway -- see
2864 grokdeclarator in cp/decl.c). */
2868 }
2869 }
2870 else
2871 {
2872 /* When a runtime check is necessary because the array size
2873 isn't constant, keep only the top-most seven bits (starting
2874 with the most significant non-zero bit) of the maximum size
2875 to compare the array size against, to simplify encoding the
2876 constant maximum size in the instruction stream. */
2883 outer_nelts,
2884 max_outer_nelts_tree);
2885 }
2886 }
2894 /* If PLACEMENT is a single simple pointer type not passed by
2895 reference, prepare to capture it in a temporary variable. Do
2896 this now, since PLACEMENT will change in the calls below. */
2904 /* Allocate the object. */
2905 tree fnname;
2906 tree fns;
2910 member_new_p = !globally_qualified_p
2912 && (array_p
2917 {
2918 /* Use a class-specific operator new. */
2919 /* If a cookie is required, add some extra space. */
2922 else
2923 {
2925 /* No size arithmetic necessary, so the size check is
2926 not needed. */
2929 }
2930 /* Perform the overflow check. */
2937 /* Create the argument list. */
2939 /* Do name-lookup to find the appropriate operator. */
2942 {
2946 }
2948 {
2950 {
2953 }
2955 }
2959 {
2962 alloc_call
2966 /* If no matching function is found and the allocated object type
2967 has new-extended alignment, the alignment argument is removed
2968 from the argument list, and overload resolution is performed
2969 again. */
2972 }
2976 LOOKUP_NORMAL,
2978 }
2979 else
2980 {
2981 /* Use a global operator new. */
2982 /* See if a cookie might be required. */
2984 {
2986 /* No size arithmetic necessary, so the size check is
2987 not needed. */
2990 }
2996 }
3003 /* Now, check to see if this function is actually a placement
3004 allocation function. This can happen even when PLACEMENT is NULL
3005 because we might have something like:
3007 struct S { void* operator new (size_t, int i = 0); };
3009 A call to `new S' will get this allocation function, even though
3010 there is no explicit placement argument. If there is more than
3011 one argument, or there are variable arguments, then this is a
3012 placement allocation function. */
3013 placement_allocation_fn_p
3018 && !placement_allocation_fn_p
3023 {
3031 }
3033 /* If we found a simple case of PLACEMENT_EXPR above, then copy it
3034 into a temporary variable. */
3040 {
3046 {
3050 }
3054 {
3055 /* Attempt to make the warning point at the operator new argument. */
3060 }
3061 }
3063 /* In the simple case, we can stop now. */
3068 /* Store the result of the allocation call in a variable so that we can
3069 use it more than once. */
3073 /* Strip any COMPOUND_EXPRs from ALLOC_CALL. */
3077 /* Preevaluate the placement args so that we don't reevaluate them for a
3078 placement delete. */
3080 {
3081 tree inits;
3085 alloc_expr);
3086 }
3088 /* unless an allocation function is declared with an empty excep-
3089 tion-specification (_except.spec_), throw(), it indicates failure to
3090 allocate storage by throwing a bad_alloc exception (clause _except_,
3091 _lib.bad.alloc_); it returns a non-null pointer otherwise If the allo-
3092 cation function is declared with an empty exception-specification,
3093 throw(), it returns null to indicate failure to allocate storage and a
3094 non-null pointer otherwise.
3096 So check for a null exception spec on the op new we just called. */
3102 {
3103 tree cookie;
3104 tree cookie_ptr;
3105 tree size_ptr_type;
3107 /* Adjust so we're pointing to the start of the object. */
3110 /* Store the number of bytes allocated so that we can know how
3111 many elements to destroy later. We use the last sizeof
3112 (size_t) bytes to store the number of elements. */
3123 {
3124 /* Also store the element size. */
3135 }
3136 }
3137 else
3138 {
3141 }
3143 /* Now use a pointer to the type we've actually allocated. */
3145 /* But we want to operate on a non-const version to start with,
3146 since we'll be modifying the elements. */
3147 non_const_pointer_type = build_pointer_type
3151 /* Any further uses of alloc_node will want this type, too. */
3154 /* Now initialize the allocated object. Note that we preevaluate the
3155 initialization expression, apart from the actual constructor call or
3156 assignment--we do this because we want to delay the allocation as long
3157 as possible in order to minimize the size of the exception region for
3158 placement delete. */
3160 {
3165 {
3168 }
3171 {
3172 /* build_value_init doesn't work in templates, and we don't need
3173 the initializer anyway since we're going to throw it away and
3174 rebuild it at instantiation time, so just build up a single
3175 constructor call to get any appropriate diagnostics. */
3179 complete_ctor_identifier,
3181 LOOKUP_NORMAL,
3182 complain);
3184 }
3186 {
3190 {
3194 else
3195 {
3199 complain);
3200 else
3201 /* We'll check the length at runtime. */
3205 }
3206 }
3208 {
3212 else
3215 }
3216 init_expr
3220 integer_one_node,
3221 complain),
3222 vecinit,
3223 explicit_value_init_p,
3225 complain);
3227 /* An array initialization is stable because the initialization
3228 of each element is a full-expression, so the temporaries don't
3229 leak out. */
3231 }
3232 else
3233 {
3237 {
3239 complete_ctor_identifier,
3241 LOOKUP_NORMAL,
3242 complain);
3243 }
3245 {
3246 /* Something like `new int()'. */
3251 }
3252 else
3253 {
3254 tree ie;
3256 /* We are processing something like `new int (10)', which
3257 means allocate an int, and initialize it with 10. */
3260 complain);
3263 }
3265 }
3270 /* If any part of the object initialization terminates by throwing an
3271 exception and a suitable deallocation function can be found, the
3272 deallocation function is called to free the memory in which the
3273 object was being constructed, after which the exception continues
3274 to propagate in the context of the new-expression. If no
3275 unambiguous matching deallocation function can be found,
3276 propagating the exception does not cause the object's memory to be
3277 freed. */
3279 {
3281 tree cleanup;
3283 /* The Standard is unclear here, but the right thing to do
3284 is to use the same method for finding deallocation
3285 functions that we use for finding allocation functions. */
3286 cleanup = (build_op_delete_call
3288 alloc_node,
3289 size,
3290 globally_qualified_p,
3292 alloc_fn,
3293 complain));
3298 /* This is much simpler if we were able to preevaluate all of
3299 the arguments to the constructor call. */
3300 {
3301 /* CLEANUP is compiler-generated, so no diagnostics. */
3305 /* Likewise, this try-catch is compiler-generated. */
3307 }
3308 else
3309 /* Ack! First we allocate the memory. Then we set our sentry
3310 variable to true, and expand a cleanup that deletes the
3311 memory if sentry is true. Then we run the constructor, and
3312 finally clear the sentry.
3314 We need to do this because we allocate the space first, so
3315 if there are any temporaries with cleanups in the
3316 constructor args and we weren't able to preevaluate them, we
3317 need this EH region to extend until end of full-expression
3318 to preserve nesting. */
3319 {
3327 /* CLEANUP is compiler-generated, so no diagnostics. */
3337 init_expr
3340 end));
3341 /* Likewise, this is compiler-generated. */
3343 }
3344 }
3345 }
3346 else
3349 /* Now build up the return value in reverse order. */
3359 /* If we don't have an initializer or a cookie, strip the TARGET_EXPR
3360 and return the call (which doesn't need to be adjusted). */
3362 else
3363 {
3365 {
3368 nullptr_node,
3369 complain);
3372 }
3374 /* Perform the allocation before anything else, so that ALLOC_NODE
3375 has been initialized before we start using it. */
3377 }
3382 /* A new-expression is never an lvalue. */
3386 }
3388 /* Generate a representation for a C++ "new" expression. *PLACEMENT
3389 is a vector of placement-new arguments (or NULL if none). If NELTS
3390 is NULL, TYPE is the type of the storage to be allocated. If NELTS
3391 is not NULL, then this is an array-new allocation; TYPE is the type
3392 of the elements in the array and NELTS is the number of elements in
3393 the array. *INIT, if non-NULL, is the initializer for the new
3394 object, or an empty vector to indicate an initializer of "()". If
3395 USE_GLOBAL_NEW is true, then the user explicitly wrote "::new"
3396 rather than just "new". This may change PLACEMENT and INIT. */
3398 tree
3401 {
3402 tree rval;
3411 /* Don't do auto deduction where it might affect mangling. */
3413 {
3416 {
3420 }
3421 }
3424 {
3431 use_global_new);
3442 }
3445 {
3447 {
3450 else
3452 }
3454 /* Try to determine the constant value only for the purposes
3455 of the diagnostic below but continue to use the original
3456 value and handle const folding later. */
3459 /* The expression in a noptr-new-declarator is erroneous if it's of
3460 non-class type and its value before converting to std::size_t is
3461 less than zero. ... If the expression is a constant expression,
3462 the program is ill-fomed. */
3465 {
3469 }
3473 }
3475 /* ``A reference cannot be created by the new operator. A reference
3476 is not an object (8.2.2, 8.4.3), so a pointer to it could not be
3477 returned by new.'' ARM 5.3.3 */
3479 {
3482 else
3485 }
3488 {
3492 }
3494 /* The type allocated must be complete. If the new-type-id was
3495 "T[N]" then we are just checking that "T" is complete here, but
3496 that is equivalent, since the value of "N" doesn't matter. */
3505 {
3511 }
3513 /* Wrap it in a NOP_EXPR so warn_if_unused_value doesn't complain. */
3518 }
3519 \f
3520 static tree
3522 special_function_kind auto_delete_vec,
3524 {
3525 tree virtual_size;
3527 tree size_exp;
3529 /* Temporary variables used by the loop. */
3532 /* This is the body of the loop that implements the deletion of a
3533 single element, and moves temp variables to next elements. */
3534 tree body;
3536 /* This is the LOOP_EXPR that governs the deletion of the elements. */
3539 /* This is the thing that governs what to do after the loop has run. */
3542 /* This is the BIND_EXPR which holds the outermost iterator of the
3543 loop. It is convenient to set this variable up and test it before
3544 executing any other code in the loop.
3545 This is also the containing expression returned by this function. */
3547 tree tmp;
3549 /* We should only have 1-D arrays here. */
3556 {
3559 "possible problem detected in invocation of "
3561 {
3564 "class-specific operator delete [] will be called, "
3566 }
3567 /* This size won't actually be used. */
3570 }
3577 {
3578 /* Make sure the destructor is callable. */
3580 {
3583 complain);
3586 }
3588 }
3590 /* The below is short by the cookie size. */
3595 tbase_init
3599 base),
3600 virtual_size),
3601 complain);
3619 complain);
3627 no_destructor:
3628 /* Delete the storage if appropriate. */
3630 {
3631 tree base_tbd;
3633 /* The below is short by the cookie size. */
3638 /* no header */
3640 else
3641 {
3642 tree cookie_size;
3646 MINUS_EXPR,
3649 cookie_size,
3650 complain);
3654 /* True size with header. */
3656 }
3663 complain);
3664 }
3668 ;
3671 else
3672 /* The delete operator mist be called, even if a destructor
3673 throws. */
3679 /* Outermost wrapper: If pointer is null, punt. */
3682 /* This is a compiler generated comparison, don't emit
3683 e.g. -Wnonnull-compare warning for it. */
3691 {
3694 }
3697 /* Pre-evaluate the SAVE_EXPR outside of the BIND_EXPR. */
3701 }
3703 /* Create an unnamed variable of the indicated TYPE. */
3705 tree
3707 {
3708 tree decl;
3718 }
3720 /* Create a new temporary variable of the indicated TYPE, initialized
3721 to INIT.
3723 It is not entered into current_binding_level, because that breaks
3724 things when it comes time to do final cleanups (which take place
3725 "outside" the binding contour of the function). */
3727 tree
3729 {
3730 tree decl;
3739 }
3741 /* Subroutine of build_vec_init. Returns true if assigning to an array of
3742 INNER_ELT_TYPE from INIT is trivial. */
3744 static bool
3746 {
3751 }
3753 /* `build_vec_init' returns tree structure that performs
3754 initialization of a vector of aggregate types.
3756 BASE is a reference to the vector, of ARRAY_TYPE, or a pointer
3757 to the first element, of POINTER_TYPE.
3758 MAXINDEX is the maximum index of the array (one less than the
3759 number of elements). It is only used if BASE is a pointer or
3760 TYPE_DOMAIN (TREE_TYPE (BASE)) == NULL_TREE.
3762 INIT is the (possibly NULL) initializer.
3764 If EXPLICIT_VALUE_INIT_P is true, then INIT must be NULL. All
3765 elements in the array are value-initialized.
3767 FROM_ARRAY is 0 if we should init everything with INIT
3768 (i.e., every element initialized from INIT).
3769 FROM_ARRAY is 1 if we should index into INIT in parallel
3770 with initialization of DECL.
3771 FROM_ARRAY is 2 if we should index into INIT in parallel,
3772 but use assignment instead of initialization. */
3774 tree
3778 {
3779 tree rval;
3782 tree iterator;
3783 /* The type of BASE. */
3785 /* The type of an element in the array. */
3787 /* The element type reached after removing all outer array
3788 types. */
3789 tree inner_elt_type;
3790 /* The type of a pointer to an element in the array. */
3791 tree ptype;
3792 tree stmt_expr;
3793 tree compound_stmt;
3814 /* Look through the TARGET_EXPR around a compound literal. */
3820 /* If we have a braced-init-list, make sure that the array
3821 is big enough for all the initializers. */
3833 /* Don't do this if the CONSTRUCTOR might contain something
3834 that might throw and require us to clean up. */
3838 {
3839 /* Do non-default initialization of trivial arrays resulting from
3840 brace-enclosed initializers. In this case, digest_init and
3841 store_constructor will handle the semantics for us. */
3847 }
3853 {
3859 }
3860 else
3863 /* The code we are generating looks like:
3864 ({
3865 T* t1 = (T*) base;
3866 T* rval = t1;
3867 ptrdiff_t iterator = maxindex;
3868 try {
3869 for (; iterator != -1; --iterator) {
3870 ... initialize *t1 ...
3871 ++t1;
3872 }
3873 } catch (...) {
3874 ... destroy elements that were constructed ...
3875 }
3876 rval;
3877 })
3879 We can omit the try and catch blocks if we know that the
3880 initialization will never throw an exception, or if the array
3881 elements do not have destructors. We can omit the loop completely if
3882 the elements of the array do not have constructors.
3884 We actually wrap the entire body of the above in a STMT_EXPR, for
3885 tidiness.
3887 When copying from array to another, when the array elements have
3888 only trivial copy constructors, we should use __builtin_memcpy
3889 rather than generating a loop. That way, we could take advantage
3890 of whatever cleverness the back end has for dealing with copies
3891 of blocks of memory. */
3903 {
3906 {
3909 }
3910 }
3912 /* If initializing one array from another, initialize element by
3913 element. We rely upon the below calls to do the argument
3914 checking. Evaluate the initializer before entering the try block. */
3916 {
3925 }
3927 /* Protect the entire array initialization so that we can destroy
3928 the partially constructed array if an exception is thrown.
3929 But don't do this if we're assigning. */
3932 {
3934 }
3936 /* Should we try to create a constant initializer? */
3940 : (type_has_constexpr_default_constructor
3946 /* If we're initializing a static array, we want to do static
3947 initialization of any elements with constant initializers even if
3948 some are non-constant. */
3954 /* Skip over the handling of non-empty init lists. */
3957 /* Maybe pull out constant value when from_array? */
3960 {
3961 /* Do non-default initialization of non-trivial arrays resulting from
3962 brace-enclosed initializers. */
3965 /* If the constructor already has the array type, it's been through
3966 digest_init, so we shouldn't try to do anything more. */
3971 {
3975 {
3977 {
3979 nelts);
3983 }
3984 /* Don't check an array new when -fno-exceptions. */
3985 }
3988 {
3989 /* Make sure the last element of the initializer is in bounds. */
3990 finish_expr_stmt
3991 (ubsan_instrument_bounds
3993 }
3994 }
4000 {
4002 tree one_init;
4004 num_initialized_elts++;
4011 else
4017 {
4020 {
4024 else
4026 }
4027 else
4028 {
4030 {
4035 }
4037 }
4038 }
4045 complain);
4048 else
4052 complain);
4055 else
4057 }
4059 /* Any elements without explicit initializers get T{}. */
4061 }
4063 {
4068 {
4072 }
4073 }
4075 /* Now, default-initialize any remaining elements. We don't need to
4076 do that if a) the type does not need constructing, or b) we've
4077 already initialized all the elements.
4079 We do need to keep going if we're copying an array. */
4082 /* With a constexpr default constructor, which we checked for when
4083 setting try_const above, default-initialization is equivalent to
4084 value-initialization, and build_value_init gives us something more
4085 friendly to maybe_constant_init. */
4090 && (num_initialized_elts
4092 {
4093 /* If the ITERATOR is lesser or equal to -1, then we don't have to loop;
4094 we've already initialized all the elements. */
4095 tree for_stmt;
4096 tree elt_init;
4097 tree to;
4105 complain);
4112 /* If the initializer is {}, then all elements are initialized from T{}.
4113 But for non-classes, that's the same as value-initialization. */
4115 {
4117 {
4119 }
4120 else
4121 {
4124 }
4125 }
4128 {
4129 tree from;
4132 {
4138 }
4139 else
4149 complain);
4150 else
4152 }
4154 {
4156 sorry
4160 explicit_value_init_p,
4162 }
4164 {
4168 }
4169 else
4170 {
4174 else
4175 {
4178 complain);
4180 }
4181 }
4187 {
4188 /* FIXME refs to earlier elts */
4191 {
4193 /* Don't fill the CONSTRUCTOR with zeros. */
4197 }
4198 else
4199 {
4203 else
4205 }
4208 {
4211 {
4214 }
4215 }
4216 }
4224 complain));
4227 complain));
4230 }
4232 /* Make sure to cleanup any partially constructed elements. */
4235 {
4236 tree e;
4239 complain);
4241 /* Flatten multi-dimensional array since build_vec_delete only
4242 expects one-dimensional array. */
4246 /* Avoid mixing signed and unsigned. */
4249 complain);
4258 }
4260 /* The value of the array initialization is the array itself, RVAL
4261 is a pointer to the first element. */
4272 {
4274 {
4277 }
4280 else
4282 }
4284 /* Now make the result have the correct type. */
4286 {
4291 }
4294 }
4296 /* Call the DTOR_KIND destructor for EXP. FLAGS are as for
4297 build_delete. */
4299 static tree
4301 tsubst_flags_t complain)
4302 {
4303 tree name;
4304 tree fn;
4306 {
4321 }
4326 flags,
4328 complain);
4329 }
4331 /* Generate a call to a destructor. TYPE is the type to cast ADDR to.
4332 ADDR is an expression which yields the store to be destroyed.
4333 AUTO_DELETE is the name of the destructor to call, i.e., either
4334 sfk_complete_destructor, sfk_base_destructor, or
4335 sfk_deleting_destructor.
4337 FLAGS is the logical disjunction of zero or more LOOKUP_
4338 flags. See cp-tree.h for more info. */
4340 tree
4343 {
4344 tree expr;
4351 /* Can happen when CURRENT_EXCEPTION_OBJECT gets its type
4352 set to `error_mark_node' before it gets properly cleaned up. */
4360 {
4362 {
4366 }
4369 }
4372 {
4375 /* We don't want to warn about delete of void*, only other
4376 incomplete types. Deleting other incomplete types
4377 invokes undefined behavior, but it is not ill-formed, so
4378 compile to something that would even do The Right Thing
4379 (TM) should the type have a trivial dtor and no delete
4380 operator. */
4382 {
4385 {
4388 "possible problem detected in invocation of "
4390 {
4393 "neither the destructor nor the class-specific "
4394 "operator delete will be called, even if they are "
4396 }
4397 }
4401 {
4402 tree dtor;
4405 {
4408 "deleting object of abstract class type %qT"
4409 " which has non-virtual destructor"
4411 else
4413 "deleting object of polymorphic class type %qT"
4414 " which has non-virtual destructor"
4416 }
4417 }
4418 }
4422 /* Throw away const and volatile on target type of addr. */
4424 }
4425 else
4426 {
4427 /* Don't check PROTECT here; leave that decision to the
4428 destructor. If the destructor is accessible, call it,
4429 else report error. */
4437 }
4440 {
4441 /* Make sure the destructor is callable. */
4443 {
4445 complain),
4449 }
4456 use_global_delete,
4459 complain);
4460 }
4461 else
4462 {
4465 tree ifexp;
4470 /* For `::delete x', we must not use the deleting destructor
4471 since then we would not be sure to get the global `operator
4472 delete'. */
4474 {
4475 /* We will use ADDR multiple times so we must save it. */
4478 /* Delete the object. */
4480 head,
4485 complain);
4486 /* Otherwise, treat this like a complete object destructor
4487 call. */
4489 }
4490 /* If the destructor is non-virtual, there is no deleting
4491 variant. Instead, we must explicitly call the appropriate
4492 `operator delete' here. */
4495 {
4496 /* We will use ADDR multiple times so we must save it. */
4498 /* Build the call. */
4500 addr,
4505 complain);
4506 /* Call the complete object destructor. */
4508 }
4511 {
4512 /* Make sure we have access to the member op delete, even though
4513 we'll actually be calling it from the destructor. */
4518 complain);
4519 }
4526 /* The delete operator must be called, regardless of whether
4527 the destructor throws.
4529 [expr.delete]/7 The deallocation function is called
4530 regardless of whether the destructor for the object or some
4531 element of the array throws an exception. */
4534 /* We need to calculate this before the dtor changes the vptr. */
4539 /* Explicit destructor call; don't check for null pointer. */
4541 else
4542 {
4543 /* Handle deleting a null pointer. */
4549 /* This is a compiler generated comparison, don't emit
4550 e.g. -Wnonnull-compare warning for it. */
4553 }
4559 }
4560 }
4562 /* At the beginning of a destructor, push cleanups that will call the
4563 destructors for our base classes and members.
4565 Called from begin_destructor_body. */
4567 void
4569 {
4572 tree member;
4573 tree expr;
4576 /* Run destructors for all virtual baseclasses. */
4579 {
4580 tree cond = (condition_conversion
4582 current_in_charge_parm,
4583 integer_two_node)));
4585 /* The CLASSTYPE_VBASECLASSES vector is in initialization
4586 order, which is also the right order for pushing cleanups. */
4589 {
4591 {
4593 base_dtor_identifier,
4594 NULL,
4595 base_binfo,
4596 (LOOKUP_NORMAL
4598 tf_warning_or_error);
4600 {
4604 }
4605 }
4606 }
4607 }
4609 /* Take care of the remaining baseclasses. */
4612 {
4618 base_dtor_identifier,
4621 tf_warning_or_error);
4624 }
4626 /* Don't automatically destroy union members. */
4632 {
4641 {
4642 tree this_member = (build_class_member_access_expr
4646 tf_warning_or_error));
4648 sfk_complete_destructor,
4653 }
4654 }
4655 }
4657 /* Build a C++ vector delete expression.
4658 MAXINDEX is the number of elements to be deleted.
4659 ELT_SIZE is the nominal size of each element in the vector.
4660 BASE is the expression that should yield the store to be deleted.
4661 This function expands (or synthesizes) these calls itself.
4662 AUTO_DELETE_VEC says whether the container (vector) should be deallocated.
4664 This also calls delete for virtual baseclasses of elements of the vector.
4666 Update: MAXINDEX is no longer needed. The size can be extracted from the
4667 start of the vector for pointers, and from the type for arrays. We still
4668 use MAXINDEX for arrays because it happens to already have one of the
4669 values we'd have to extract. (We could use MAXINDEX with pointers to
4670 confirm the size, and trap if the numbers differ; not clear that it'd
4671 be worth bothering.) */
4673 tree
4675 special_function_kind auto_delete_vec,
4677 {
4678 tree type;
4679 tree rval;
4685 {
4686 /* Step back one from start of vector, and read dimension. */
4687 tree cookie_addr;
4692 {
4695 }
4700 cookie_addr);
4702 }
4704 {
4705 /* Get the total number of things in the array, maxindex is a
4706 bad name. */
4713 {
4716 }
4717 }
4718 else
4719 {
4723 }
4731 }