| blob | f33d64573dd35f93b0028a46b44df57467311b9e |
1 /* Functions related to invoking methods and overloaded functions.
2 Copyright (C) 1987, 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) and
6 modified by Brendan Kehoe (brendan@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
25 /* High-level class interface. */
44 /* The various kinds of conversion. */
47 ck_identity,
48 ck_lvalue,
49 ck_qual,
50 ck_std,
51 ck_ptr,
52 ck_pmem,
53 ck_base,
54 ck_ref_bind,
55 ck_user,
56 ck_ambig,
57 ck_list,
58 ck_aggr,
59 ck_rvalue
62 /* The rank of the conversion. Order of the enumerals matters; better
63 conversions should come earlier in the list. */
66 cr_identity,
67 cr_exact,
68 cr_promotion,
69 cr_std,
70 cr_pbool,
71 cr_user,
72 cr_ellipsis,
73 cr_bad
76 /* An implicit conversion sequence, in the sense of [over.best.ics].
77 The first conversion to be performed is at the end of the chain.
78 That conversion is always a cr_identity conversion. */
82 /* The kind of conversion represented by this step. */
83 conversion_kind kind;
84 /* The rank of this conversion. */
85 conversion_rank rank;
90 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
91 temporary should be created to hold the result of the
92 conversion. */
94 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
95 from a pointer-to-derived to pointer-to-base is being performed. */
97 /* If KIND is ck_ref_bind, true when either an lvalue reference is
98 being bound to an lvalue expression or an rvalue reference is
99 being bound to an rvalue expression. */
102 /* The type of the expression resulting from the conversion. */
103 tree type;
105 /* The next conversion in the chain. Since the conversions are
106 arranged from outermost to innermost, the NEXT conversion will
107 actually be performed before this conversion. This variant is
108 used only when KIND is neither ck_identity nor ck_ambig. */
110 /* The expression at the beginning of the conversion chain. This
111 variant is used only if KIND is ck_identity or ck_ambig. */
112 tree expr;
113 /* The array of conversions for an initializer_list. */
116 /* The function candidate corresponding to this conversion
117 sequence. This field is only used if KIND is ck_user. */
119 };
121 #define CONVERSION_RANK(NODE) \
122 ((NODE)->bad_p ? cr_bad \
123 : (NODE)->ellipsis_p ? cr_ellipsis \
124 : (NODE)->user_conv_p ? cr_user \
125 : (NODE)->rank)
136 #define convert_like(CONV, EXPR, COMPLAIN) \
137 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
140 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \
141 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
164 static void add_builtin_candidates
167 static void add_builtin_candidate
171 static void build_builtin_candidate
176 tree);
208 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
209 NAME can take many forms... */
211 bool
213 {
214 /* Just accept something we've already complained about. */
223 {
229 else
231 }
232 else
233 {
234 /* In the case of:
236 template <class T> struct S { ~S(); };
237 int i;
238 i.~S();
240 NAME will be a class template. */
243 }
248 }
250 /* We want the address of a function or method. We avoid creating a
251 pointer-to-member function. */
253 tree
255 {
258 /* We have to do these by hand to avoid real pointer to member
259 functions. */
261 {
263 {
267 }
269 }
270 else
274 }
276 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
277 POINTER_TYPE to those. Note, pointer to member function types
278 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
279 two variants. build_call_a is the primitive taking an array of
280 arguments, while build_call_n is a wrapper that handles varargs. */
282 tree
284 {
287 else
288 {
298 }
299 }
301 tree
303 {
306 tree decl;
307 tree result_type;
308 tree fntype;
321 {
324 {
325 /* We invoke build_call directly for several library
326 functions. These may have been declared normally if
327 we're building libgcc, so we can't just check
328 DECL_ARTIFICIAL. */
333 }
334 }
335 else
338 /* We check both the decl and the type; a function may be known not to
339 throw without being declared throw(). */
353 /* Don't pass empty class objects by value. This is useful
354 for tags in STL, which are used to control overload resolution.
355 We don't need to handle other cases of copying empty classes. */
360 {
364 }
371 }
373 /* Build something of the form ptr->method (args)
374 or object.method (args). This can also build
375 calls to constructors, and find friends.
377 Member functions always take their class variable
378 as a pointer.
380 INSTANCE is a class instance.
382 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
384 PARMS help to figure out what that NAME really refers to.
386 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
387 down to the real instance type to use for access checking. We need this
388 information to get protected accesses correct.
390 FLAGS is the logical disjunction of zero or more LOOKUP_
391 flags. See cp-tree.h for more info.
393 If this is all OK, calls build_function_call with the resolved
394 member function.
396 This function must also handle being called to perform
397 initialization, promotion/coercion of arguments, and
398 instantiation of default parameters.
400 Note that NAME may refer to an instance variable name. If
401 `operator()()' is defined for the type of that field, then we return
402 that result. */
404 /* New overloading code. */
412 };
415 /* The FUNCTION_DECL that will be called if this candidate is
416 selected by overload resolution. */
417 tree fn;
418 /* If not NULL_TREE, the first argument to use when calling this
419 function. */
420 tree first_arg;
421 /* The rest of the arguments to use when calling this function. If
422 there are no further arguments this may be NULL or it may be an
423 empty vector. */
425 /* The implicit conversion sequences for each of the arguments to
426 FN. */
428 /* The number of implicit conversion sequences. */
430 /* If FN is a user-defined conversion, the standard conversion
431 sequence from the type returned by FN to the desired destination
432 type. */
435 /* If FN is a member function, the binfo indicating the path used to
436 qualify the name of FN at the call site. This path is used to
437 determine whether or not FN is accessible if it is selected by
438 overload resolution. The DECL_CONTEXT of FN will always be a
439 (possibly improper) base of this binfo. */
440 tree access_path;
441 /* If FN is a non-static member function, the binfo indicating the
442 subobject to which the `this' pointer should be converted if FN
443 is selected by overload resolution. The type pointed to the by
444 the `this' pointer must correspond to the most derived class
445 indicated by the CONVERSION_PATH. */
446 tree conversion_path;
447 tree template_decl;
450 };
452 /* Returns true iff T is a null pointer constant in the sense of
453 [conv.ptr]. */
455 bool
457 {
458 /* [conv.ptr]
460 A null pointer constant is an integral constant expression
461 (_expr.const_) rvalue of integer type that evaluates to zero. */
466 {
470 }
472 }
474 /* Returns nonzero if PARMLIST consists of only default parms and/or
475 ellipsis. */
477 bool
479 {
485 }
487 /* Allocate N bytes of memory from the conversion obstack. The memory
488 is zeroed before being returned. */
492 {
495 {
498 }
502 }
504 /* Dynamically allocate a conversion. */
508 {
513 }
515 #ifdef ENABLE_CHECKING
517 /* Make sure that all memory on the conversion obstack has been
518 freed. */
520 void
522 {
526 }
530 /* Dynamically allocate an array of N conversions. */
534 {
536 }
540 {
544 /* Note that the caller is responsible for filling in t->cand for
545 user-defined conversions. */
551 {
567 }
573 }
575 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
576 specialization of std::initializer_list<T>, if such a conversion is
577 possible. */
581 {
587 tree val;
590 {
591 conversion *sub
598 }
606 {
614 }
617 }
619 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
620 aggregate class, if such a conversion is possible. */
624 {
630 {
634 {
639 }
642 }
650 }
652 /* Build a representation of the identity conversion from EXPR to
653 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
657 {
665 }
667 /* Converting from EXPR to TYPE was ambiguous in the sense that there
668 were multiple user-defined conversions to accomplish the job.
669 Build a conversion that indicates that ambiguity. */
673 {
681 }
683 tree
685 {
689 }
691 /* Returns the standard conversion path (see [conv]) from type FROM to type
692 TO, if any. For proper handling of null pointer constants, you must
693 also pass the expression EXPR to convert from. If C_CAST_P is true,
694 this conversion is coming from a C-style cast. */
699 {
706 {
709 }
715 {
723 }
730 {
734 }
736 {
738 {
739 tree bitfield_type;
742 {
745 }
746 }
748 }
750 /* Allow conversion between `__complex__' data types. */
752 {
753 /* The standard conversion sequence to convert FROM to TO is
754 the standard conversion sequence to perform componentwise
755 conversion. */
760 {
763 }
764 else
768 }
778 {
779 /* For backwards brain damage compatibility, allow interconversion of
780 pointers and integers with a pedwarn. */
783 }
785 {
786 /* For backwards brain damage compatibility, allow interconversion of
787 enums and integers with a pedwarn. */
790 }
793 {
794 tree to_pointee;
795 tree from_pointee;
800 ;
804 {
805 from = build_pointer_type
809 }
811 {
816 && (same_type_ignoring_top_level_qualifiers_p
819 {
823 }
826 }
829 /* [conv.ptr]
831 An rvalue of type "pointer to cv D," where D is a
832 class type, can be converted to an rvalue of type
833 "pointer to cv B," where B is a base class (clause
834 _class.derived_) of D. If B is an inaccessible
835 (clause _class.access_) or ambiguous
836 (_class.member.lookup_) base class of D, a program
837 that necessitates this conversion is ill-formed.
838 Therefore, we use DERIVED_FROM_P, and do not check
839 access or uniqueness. */
841 {
842 from =
848 }
851 {
854 }
855 else
856 {
859 }
864 /* In a C-style cast, we ignore CV-qualification because we
865 are allowed to perform a static_cast followed by a
866 const_cast. */
871 /* converting from string constant to char *. */
874 {
877 }
878 else
882 }
884 {
904 }
906 {
907 /* [conv.bool]
909 An rvalue of arithmetic, unscoped enumeration, pointer, or
910 pointer to member type can be converted to an rvalue of type
911 bool. */
916 {
924 }
927 }
928 /* We don't check for ENUMERAL_TYPE here because there are no standard
929 conversions to enum type. */
930 /* As an extension, allow conversion to complex type. */
932 {
938 /* Give this a better rank if it's a promotion. */
942 }
948 {
952 /* The derived-to-base conversion indicates the initialization
953 of a parameter with base type from an object of a derived
954 type. A temporary object is created to hold the result of
955 the conversion unless we're binding directly to a reference. */
957 }
958 else
965 }
967 /* Returns nonzero if T1 is reference-related to T2. */
969 static bool
971 {
975 /* [dcl.init.ref]
977 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
978 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
979 of T2. */
983 }
985 /* Returns nonzero if T1 is reference-compatible with T2. */
987 static bool
989 {
990 /* [dcl.init.ref]
992 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
993 reference-related to T2 and cv1 is the same cv-qualification as,
994 or greater cv-qualification than, cv2. */
997 }
999 /* Determine whether or not the EXPR (of class type S) can be
1000 converted to T as in [over.match.ref]. */
1004 {
1005 tree conversions;
1006 tree first_arg;
1008 tree t;
1017 /* [over.match.ref]
1019 Assuming that "cv1 T" is the underlying type of the reference
1020 being initialized, and "cv S" is the type of the initializer
1021 expression, with S a class type, the candidate functions are
1022 selected as follows:
1024 --The conversion functions of S and its base classes are
1025 considered. Those that are not hidden within S and yield type
1026 "reference to cv2 T2", where "cv1 T" is reference-compatible
1027 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1029 The argument list has one argument, which is the initializer
1030 expression. */
1034 /* Conceptually, we should take the address of EXPR and put it in
1035 the argument list. Unfortunately, however, that can result in
1036 error messages, which we should not issue now because we are just
1037 trying to find a conversion operator. Therefore, we use NULL,
1038 cast to the appropriate type. */
1044 {
1048 {
1058 /* If this is a template function, try to get an exact
1059 match. */
1061 {
1064 NULL_TREE,
1065 first_arg,
1066 NULL,
1067 reference_type,
1070 LOOKUP_NORMAL,
1071 DEDUCE_CONV);
1074 {
1075 /* Now, see if the conversion function really returns
1076 an lvalue of the appropriate type. From the
1077 point of view of unification, simply returning an
1078 rvalue of the right type is good enough. */
1083 {
1086 }
1087 }
1088 }
1094 LOOKUP_NORMAL);
1097 {
1099 /* Build a standard conversion sequence indicating the
1100 binding from the reference type returned by the
1101 function to the desired REFERENCE_TYPE. */
1102 identity_conv
1105 NULL_TREE);
1106 cand->second_conv
1107 = (direct_reference_binding
1113 }
1114 }
1115 }
1118 /* If none of the conversion functions worked out, let our caller
1119 know. */
1127 /* Now that we know that this is the function we're going to use fix
1128 the dummy first argument. */
1133 /* Build a user-defined conversion sequence representing the
1134 conversion. */
1140 /* Merge it with the standard conversion sequence from the
1141 conversion function's return type to the desired type. */
1148 }
1150 /* A reference of the indicated TYPE is being bound directly to the
1151 expression represented by the implicit conversion sequence CONV.
1152 Return a conversion sequence for this binding. */
1156 {
1157 tree t;
1164 /* [over.ics.rank]
1166 When a parameter of reference type binds directly
1167 (_dcl.init.ref_) to an argument expression, the implicit
1168 conversion sequence is the identity conversion, unless the
1169 argument expression has a type that is a derived class of the
1170 parameter type, in which case the implicit conversion sequence is
1171 a derived-to-base Conversion.
1173 If the parameter binds directly to the result of applying a
1174 conversion function to the argument expression, the implicit
1175 conversion sequence is a user-defined conversion sequence
1176 (_over.ics.user_), with the second standard conversion sequence
1177 either an identity conversion or, if the conversion function
1178 returns an entity of a type that is a derived class of the
1179 parameter type, a derived-to-base conversion. */
1181 {
1182 /* Represent the derived-to-base conversion. */
1184 /* We will actually be binding to the base-class subobject in
1185 the derived class, so we mark this conversion appropriately.
1186 That way, convert_like knows not to generate a temporary. */
1188 }
1190 }
1192 /* Returns the conversion path from type FROM to reference type TO for
1193 purposes of reference binding. For lvalue binding, either pass a
1194 reference type to FROM or an lvalue expression to EXPR. If the
1195 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1196 the conversion returned. If C_CAST_P is true, this
1197 conversion is coming from a C-style cast. */
1201 {
1205 tree tfrom;
1211 {
1216 }
1219 {
1220 /* Anything with reference type is an lvalue. */
1223 }
1231 /* Figure out whether or not the types are reference-related and
1232 reference compatible. We have do do this after stripping
1233 references from FROM. */
1235 /* If this is a C cast, first convert to an appropriately qualified
1236 type, so that we can later do a const_cast to the desired type. */
1242 /* Directly bind reference when target expression's type is compatible with
1243 the reference and expression is an lvalue. In DR391, the wording in
1244 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1245 const and rvalue references to rvalues of compatible class type. */
1247 && (lvalue_p
1251 {
1252 /* [dcl.init.ref]
1254 If the initializer expression
1256 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1257 is reference-compatible with "cv2 T2,"
1259 the reference is bound directly to the initializer expression
1260 lvalue.
1262 [...]
1263 If the initializer expression is an rvalue, with T2 a class type,
1264 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1265 is bound to the object represented by the rvalue or to a sub-object
1266 within that object. */
1272 /* The top-level caller requested that we pretend that the lvalue
1273 be treated as an rvalue. */
1275 else
1276 conv->rvaluedness_matches_p
1281 /* For the purposes of overload resolution, we ignore the fact
1282 this expression is a bitfield or packed field. (In particular,
1283 [over.ics.ref] says specifically that a function with a
1284 non-const reference parameter is viable even if the
1285 argument is a bitfield.)
1287 However, when we actually call the function we must create
1288 a temporary to which to bind the reference. If the
1289 reference is volatile, or isn't const, then we cannot make
1290 a temporary, so we just issue an error when the conversion
1291 actually occurs. */
1295 }
1296 /* [class.conv.fct] A conversion function is never used to convert a
1297 (possibly cv-qualified) object to the (possibly cv-qualified) same
1298 object type (or a reference to it), to a (possibly cv-qualified) base
1299 class of that type (or a reference to it).... */
1302 {
1303 /* [dcl.init.ref]
1305 If the initializer expression
1307 -- has a class type (i.e., T2 is a class type) can be
1308 implicitly converted to an lvalue of type "cv3 T3," where
1309 "cv1 T1" is reference-compatible with "cv3 T3". (this
1310 conversion is selected by enumerating the applicable
1311 conversion functions (_over.match.ref_) and choosing the
1312 best one through overload resolution. (_over.match_).
1314 the reference is bound to the lvalue result of the conversion
1315 in the second case. */
1319 }
1321 /* From this point on, we conceptually need temporaries, even if we
1322 elide them. Only the cases above are "direct bindings". */
1326 /* [over.ics.rank]
1328 When a parameter of reference type is not bound directly to an
1329 argument expression, the conversion sequence is the one required
1330 to convert the argument expression to the underlying type of the
1331 reference according to _over.best.ics_. Conceptually, this
1332 conversion sequence corresponds to copy-initializing a temporary
1333 of the underlying type with the argument expression. Any
1334 difference in top-level cv-qualification is subsumed by the
1335 initialization itself and does not constitute a conversion. */
1337 /* [dcl.init.ref]
1339 Otherwise, the reference shall be to a non-volatile const type.
1341 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1345 /* [dcl.init.ref]
1347 Otherwise, a temporary of type "cv1 T1" is created and
1348 initialized from the initializer expression using the rules for a
1349 non-reference copy initialization. If T1 is reference-related to
1350 T2, cv1 must be the same cv-qualification as, or greater
1351 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1355 /* We're generating a temporary now, but don't bind any more in the
1356 conversion (specifically, don't slice the temporary returned by a
1357 conversion operator). */
1360 /* Temporaries are copy-initialized, except for this hack to allow
1361 explicit conversion ops to the copy ctor. See also
1362 add_function_candidate. */
1367 flags);
1372 /* This reference binding, unlike those above, requires the
1373 creation of a temporary. */
1378 }
1380 /* Returns the implicit conversion sequence (see [over.ics]) from type
1381 FROM to type TO. The optional expression EXPR may affect the
1382 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1383 true, this conversion is coming from a C-style cast. */
1388 {
1397 else
1404 {
1408 /* Allow conversion from an initializer-list with one element to a
1409 scalar type. */
1411 {
1413 tree elt;
1419 else
1425 {
1428 /* Too many levels of braces, i.e. '{{1}}'. */
1431 }
1432 }
1433 }
1439 {
1452 /* We used to try to bind a reference to a temporary here, but that
1453 is now handled after the recursive call to this function at the end
1454 of reference_binding. */
1456 }
1459 }
1461 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1462 functions. ARGS will not be changed until a single candidate is
1463 selected. */
1471 {
1487 }
1489 /* Create an overload candidate for the function or method FN called
1490 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1491 FLAGS is passed on to implicit_conversion.
1493 This does not change ARGS.
1495 CTYPE, if non-NULL, is the type we want to pretend this function
1496 comes from for purposes of overload resolution. */
1503 {
1507 tree parmnode;
1512 /* At this point we should not see any functions which haven't been
1513 explicitly declared, except for friend functions which will have
1514 been found using argument dependent lookup. */
1517 /* The `this', `in_chrg' and VTT arguments to constructors are not
1518 considered in overload resolution. */
1520 {
1524 {
1527 }
1528 }
1529 else
1535 /* 13.3.2 - Viable functions [over.match.viable]
1536 First, to be a viable function, a candidate function shall have enough
1537 parameters to agree in number with the arguments in the list.
1539 We need to check this first; otherwise, checking the ICSes might cause
1540 us to produce an ill-formed template instantiation. */
1544 {
1548 }
1553 /* Make sure there are default args for the rest of the parms. */
1560 /* Second, for F to be a viable function, there shall exist for each
1561 argument an implicit conversion sequence that converts that argument
1562 to the corresponding parameter of F. */
1567 {
1577 else
1586 {
1590 /* The type of the implicit object parameter ('this') for
1591 overload resolution is not always the same as for the
1592 function itself; conversion functions are considered to
1593 be members of the class being converted, and functions
1594 introduced by a using-declaration are considered to be
1595 members of the class that uses them.
1597 Since build_over_call ignores the ICS for the `this'
1598 parameter, we can just change the parm type. */
1600 {
1601 parmtype
1605 }
1608 {
1609 /* Hack: Direct-initialize copy parm (i.e. suppress
1610 LOOKUP_ONLYCONVERTING) to make explicit conversion ops
1611 work. See also reference_binding. */
1615 }
1616 else
1621 }
1622 else
1623 {
1626 }
1633 {
1636 }
1643 }
1645 out:
1648 }
1650 /* Create an overload candidate for the conversion function FN which will
1651 be invoked for expression OBJ, producing a pointer-to-function which
1652 will in turn be called with the argument list FIRST_ARG/ARGLIST,
1653 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
1654 passed on to implicit_conversion.
1656 Actually, we don't really care about FN; we care about the type it
1657 converts to. There may be multiple conversion functions that will
1658 convert to that type, and we rely on build_user_type_conversion_1 to
1659 choose the best one; so when we create our candidate, we record the type
1660 instead of the function. */
1666 {
1682 /* Don't bother looking up the same type twice. */
1687 {
1695 else
1702 flags);
1708 else
1709 {
1712 }
1726 }
1736 }
1738 static void
1742 {
1757 {
1764 {
1766 /* We need something for printing the candidate. */
1768 }
1772 }
1774 /* For COND_EXPR we rearranged the arguments; undo that now. */
1776 {
1783 else
1785 }
1791 viable);
1792 }
1794 static bool
1796 {
1798 }
1800 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1802 static bool
1804 {
1805 /* [over.built]
1807 In this section, the term promoted integral type is used to refer
1808 to those integral types which are preserved by integral promotion
1809 (including e.g. int and long but excluding e.g. char).
1810 Similarly, the term promoted arithmetic type refers to promoted
1811 integral types plus floating types. */
1815 }
1817 /* Create any builtin operator overload candidates for the operator in
1818 question given the converted operand types TYPE1 and TYPE2. The other
1819 args are passed through from add_builtin_candidates to
1820 build_builtin_candidate.
1822 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1823 If CODE is requires candidates operands of the same type of the kind
1824 of which TYPE1 and TYPE2 are, we add both candidates
1825 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1827 static void
1831 {
1833 {
1841 }
1844 {
1846 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1847 and VQ is either volatile or empty, there exist candidate operator
1848 functions of the form
1849 VQ T& operator++(VQ T&);
1850 T operator++(VQ T&, int);
1851 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1852 type other than bool, and VQ is either volatile or empty, there exist
1853 candidate operator functions of the form
1854 VQ T& operator--(VQ T&);
1855 T operator--(VQ T&, int);
1856 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1857 complete object type, and VQ is either volatile or empty, there exist
1858 candidate operator functions of the form
1859 T*VQ& operator++(T*VQ&);
1860 T*VQ& operator--(T*VQ&);
1861 T* operator++(T*VQ&, int);
1862 T* operator--(T*VQ&, int); */
1871 {
1874 }
1877 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1878 exist candidate operator functions of the form
1880 T& operator*(T*);
1882 8 For every function type T, there exist candidate operator functions of
1883 the form
1884 T& operator*(T*); */
1893 /* 9 For every type T, there exist candidate operator functions of the form
1894 T* operator+(T*);
1896 10For every promoted arithmetic type T, there exist candidate operator
1897 functions of the form
1898 T operator+(T);
1899 T operator-(T); */
1909 /* 11For every promoted integral type T, there exist candidate operator
1910 functions of the form
1911 T operator~(T); */
1918 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1919 is the same type as C2 or is a derived class of C2, T is a complete
1920 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1921 there exist candidate operator functions of the form
1922 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1923 where CV12 is the union of CV1 and CV2. */
1928 {
1936 }
1939 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1940 didate operator functions of the form
1941 LR operator*(L, R);
1942 LR operator/(L, R);
1943 LR operator+(L, R);
1944 LR operator-(L, R);
1945 bool operator<(L, R);
1946 bool operator>(L, R);
1947 bool operator<=(L, R);
1948 bool operator>=(L, R);
1949 bool operator==(L, R);
1950 bool operator!=(L, R);
1951 where LR is the result of the usual arithmetic conversions between
1952 types L and R.
1954 14For every pair of types T and I, where T is a cv-qualified or cv-
1955 unqualified complete object type and I is a promoted integral type,
1956 there exist candidate operator functions of the form
1957 T* operator+(T*, I);
1958 T& operator[](T*, I);
1959 T* operator-(T*, I);
1960 T* operator+(I, T*);
1961 T& operator[](I, T*);
1963 15For every T, where T is a pointer to complete object type, there exist
1964 candidate operator functions of the form112)
1965 ptrdiff_t operator-(T, T);
1967 16For every pointer or enumeration type T, there exist candidate operator
1968 functions of the form
1969 bool operator<(T, T);
1970 bool operator>(T, T);
1971 bool operator<=(T, T);
1972 bool operator>=(T, T);
1973 bool operator==(T, T);
1974 bool operator!=(T, T);
1976 17For every pointer to member type T, there exist candidate operator
1977 functions of the form
1978 bool operator==(T, T);
1979 bool operator!=(T, T); */
1986 {
1989 }
2002 {
2005 }
2007 {
2010 }
2011 /* Fall through. */
2028 {
2031 }
2035 {
2038 }
2046 {
2049 }
2051 {
2054 }
2057 /* 18For every pair of promoted integral types L and R, there exist candi-
2058 date operator functions of the form
2059 LR operator%(L, R);
2060 LR operator&(L, R);
2061 LR operator^(L, R);
2062 LR operator|(L, R);
2063 L operator<<(L, R);
2064 L operator>>(L, R);
2065 where LR is the result of the usual arithmetic conversions between
2066 types L and R. */
2074 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2078 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2079 type, VQ is either volatile or empty, and R is a promoted arithmetic
2080 type, there exist candidate operator functions of the form
2081 VQ L& operator=(VQ L&, R);
2082 VQ L& operator*=(VQ L&, R);
2083 VQ L& operator/=(VQ L&, R);
2084 VQ L& operator+=(VQ L&, R);
2085 VQ L& operator-=(VQ L&, R);
2087 20For every pair T, VQ), where T is any type and VQ is either volatile
2088 or empty, there exist candidate operator functions of the form
2089 T*VQ& operator=(T*VQ&, T*);
2091 21For every pair T, VQ), where T is a pointer to member type and VQ is
2092 either volatile or empty, there exist candidate operator functions of
2093 the form
2094 VQ T& operator=(VQ T&, T);
2096 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2097 unqualified complete object type, VQ is either volatile or empty, and
2098 I is a promoted integral type, there exist candidate operator func-
2099 tions of the form
2100 T*VQ& operator+=(T*VQ&, I);
2101 T*VQ& operator-=(T*VQ&, I);
2103 23For every triple L, VQ, R), where L is an integral or enumeration
2104 type, VQ is either volatile or empty, and R is a promoted integral
2105 type, there exist candidate operator functions of the form
2107 VQ L& operator%=(VQ L&, R);
2108 VQ L& operator<<=(VQ L&, R);
2109 VQ L& operator>>=(VQ L&, R);
2110 VQ L& operator&=(VQ L&, R);
2111 VQ L& operator^=(VQ L&, R);
2112 VQ L& operator|=(VQ L&, R); */
2116 {
2120 {
2123 }
2136 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2149 {
2152 }
2157 }
2162 /* [over.built]
2164 For every pair of promoted arithmetic types L and R, there
2165 exist candidate operator functions of the form
2167 LR operator?(bool, L, R);
2169 where LR is the result of the usual arithmetic conversions
2170 between types L and R.
2172 For every type T, where T is a pointer or pointer-to-member
2173 type, there exist candidate operator functions of the form T
2174 operator?(bool, T, T); */
2178 /* That's OK. */
2181 /* Otherwise, the types should be pointers. */
2186 /* We don't check that the two types are the same; the logic
2187 below will actually create two candidates; one in which both
2188 parameter types are TYPE1, and one in which both parameter
2189 types are TYPE2. */
2194 }
2196 /* If we're dealing with two pointer types or two enumeral types,
2197 we need candidates for both of them. */
2206 {
2207 build_builtin_candidate
2209 build_builtin_candidate
2212 }
2214 build_builtin_candidate
2216 }
2218 tree
2220 {
2226 }
2228 /* There are three conditions of builtin candidates:
2230 1) bool-taking candidates. These are the same regardless of the input.
2231 2) pointer-pair taking candidates. These are generated for each type
2232 one of the input types converts to.
2233 3) arithmetic candidates. According to the standard, we should generate
2234 all of these, but I'm trying not to...
2236 Here we generate a superset of the possible candidates for this particular
2237 case. That is a subset of the full set the standard defines, plus some
2238 other cases which the standard disallows. add_builtin_candidate will
2239 filter out the invalid set. */
2241 static void
2245 {
2249 /* TYPES[i] is the set of possible builtin-operator parameter types
2250 we will consider for the Ith argument. These are represented as
2251 a TREE_LIST; the TREE_VALUE of each node is the potential
2252 parameter type. */
2256 {
2259 else
2261 }
2264 {
2265 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2266 and VQ is either volatile or empty, there exist candidate operator
2267 functions of the form
2268 VQ T& operator++(VQ T&); */
2278 /* 24There also exist candidate operator functions of the form
2279 bool operator!(bool);
2280 bool operator&&(bool, bool);
2281 bool operator||(bool, bool); */
2284 build_builtin_candidate
2291 build_builtin_candidate
2309 /* Fall through. */
2313 }
2318 {
2320 ;
2322 {
2323 tree convs;
2331 {
2338 }
2344 {
2357 {
2363 }
2367 }
2368 }
2369 else
2370 {
2376 {
2382 }
2384 }
2385 }
2387 /* Run through the possible parameter types of both arguments,
2388 creating candidates with those parameter types. */
2390 {
2393 add_builtin_candidate
2396 else
2397 add_builtin_candidate
2400 }
2401 }
2404 /* If TMPL can be successfully instantiated as indicated by
2405 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2407 TMPL is the template. EXPLICIT_TARGS are any explicit template
2408 arguments. ARGLIST is the arguments provided at the call-site.
2409 This does not change ARGLIST. The RETURN_TYPE is the desired type
2410 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2411 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2412 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2420 {
2425 tree first_arg_without_in_chrg;
2429 tree arg;
2432 tree fn;
2440 /* We don't do deduction on the in-charge parameter, the VTT
2441 parameter or 'this'. */
2443 {
2446 else
2448 }
2453 {
2456 else
2458 }
2466 {
2469 }
2473 {
2476 }
2480 args_without_in_chrg,
2481 nargs_without_in_chrg,
2491 /* In [class.copy]:
2493 A member function template is never instantiated to perform the
2494 copy of a class object to an object of its class type.
2496 It's a little unclear what this means; the standard explicitly
2497 does allow a template to be used to copy a class. For example,
2498 in:
2500 struct A {
2501 A(A&);
2502 template <class T> A(const T&);
2503 };
2504 const A f ();
2505 void g () { A a (f ()); }
2507 the member template will be used to make the copy. The section
2508 quoted above appears in the paragraph that forbids constructors
2509 whose only parameter is (a possibly cv-qualified variant of) the
2510 class type, and a logical interpretation is that the intent was
2511 to forbid the instantiation of member templates which would then
2512 have that form. */
2514 {
2517 ctype))
2519 }
2522 /* Aha, this is a conversion function. */
2525 else
2530 /* This situation can occur if a member template of a template
2531 class is specialized. Then, instantiate_template might return
2532 an instantiation of the specialization, in which case the
2533 DECL_TI_TEMPLATE field will point at the original
2534 specialization. For example:
2536 template <class T> struct S { template <class U> void f(U);
2537 template <> void f(int) {}; };
2538 S<double> sd;
2539 sd.f(3);
2541 Here, TMPL will be template <class U> S<double>::f(U).
2542 And, instantiate template will give us the specialization
2543 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2544 for this will point at template <class T> template <> S<T>::f(int),
2545 so that we can find the definition. For the purposes of
2546 overload resolution, however, we want the original TMPL. */
2548 else
2552 }
2560 unification_kind_t strict)
2561 {
2562 return
2567 }
2575 tree conversion_path)
2576 {
2577 return
2581 }
2583 /* The CANDS are the set of candidates that were considered for
2584 overload resolution. Return the set of viable candidates. If none
2585 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2586 is true if a candidate should be considered viable only if it is
2587 strictly viable. */
2593 {
2604 {
2607 {
2613 }
2614 else
2616 }
2619 }
2621 static bool
2623 {
2628 }
2630 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2631 words, it is about to become the "this" pointer for a member
2632 function call. Take the address of the object. */
2634 static tree
2636 {
2637 /* In a template, we are only concerned about the type of the
2638 expression, so we can take a shortcut. */
2643 }
2645 /* Returns true iff functions are equivalent. Equivalent functions are
2646 not '==' only if one is a function-local extern function or if
2647 both are extern "C". */
2651 {
2656 }
2658 /* Print information about one overload candidate CANDIDATE. MSGSTR
2659 is the text to print before the candidate itself.
2661 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2662 to have been run through gettext by the caller. This wart makes
2663 life simpler in print_z_candidates and for the translators. */
2665 static void
2667 {
2669 {
2679 else
2682 }
2687 else
2689 }
2691 static void
2693 {
2698 /* There may be duplicates in the set of candidates. We put off
2699 checking this condition as long as possible, since we have no way
2700 to eliminate duplicates from a set of functions in less than n^2
2701 time. Now we are about to emit an error message, so it is more
2702 permissible to go slowly. */
2704 {
2706 /* Skip builtin candidates and conversion functions. */
2711 {
2715 else
2717 }
2718 }
2726 {
2727 /* Indent successive candidates by the width of the translation
2728 of the above string. */
2735 do
2736 {
2739 }
2741 }
2742 }
2744 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2745 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2746 the result of the conversion function to convert it to the final
2747 desired type. Merge the two sequences into a single sequence,
2748 and return the merged sequence. */
2752 {
2757 /* Find the end of the second conversion sequence. */
2762 /* Replace the identity conversion with the user conversion
2763 sequence. */
2766 /* The entire sequence is a user-conversion sequence. */
2770 }
2772 /* Returns the best overload candidate to perform the requested
2773 conversion. This function is used for three the overloading situations
2774 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2775 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2776 per [dcl.init.ref], so we ignore temporary bindings. */
2780 {
2791 /* We represent conversion within a hierarchy using RVALUE_CONV and
2792 BASE_CONV, as specified by [over.best.ics]; these become plain
2793 constructor calls, as specified in [dcl.init]. */
2801 {
2806 {
2807 /* [class.conv.fct] A conversion function is never used to
2808 convert a (possibly cv-qualified) object to the (possibly
2809 cv-qualified) same object type (or a reference to it), to a
2810 (possibly cv-qualified) base class of that type (or a
2811 reference to it)... */
2812 }
2813 else
2815 }
2820 /* It's OK to bind a temporary for converting constructor arguments, but
2821 not in converting the return value of a conversion operator. */
2826 {
2832 {
2834 /* We still allow more conversions within an init-list. */
2836 /* But not for the copy ctor. */
2837 |LOOKUP_NO_COPY_CTOR_CONVERSION
2839 }
2840 else
2843 /* We should never try to call the abstract or base constructor
2844 from here. */
2847 }
2849 {
2860 flags,
2861 DEDUCE_CALL);
2862 else
2866 flags);
2869 {
2872 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
2873 set, then this is copy-initialization. In that case, "The
2874 result of the call is then used to direct-initialize the
2875 object that is the destination of the copy-initialization."
2876 [dcl.init]
2878 We represent this in the conversion sequence with an
2879 rvalue conversion, which means a constructor call. */
2882 cand->second_conv
2884 }
2885 }
2891 {
2892 tree fns;
2895 /* If we are called to convert to a reference type, we are trying to
2896 find an lvalue binding, so don't even consider temporaries. If
2897 we don't find an lvalue binding, the caller will try again to
2898 look for a temporary binding. */
2903 {
2910 /* [over.match.funcs] For conversion functions, the function
2911 is considered to be a member of the class of the implicit
2912 object argument for the purpose of defining the type of
2913 the implicit object parameter.
2915 So we pass fromtype as CTYPE to add_*_candidate. */
2919 NULL_TREE,
2922 conversion_path,
2923 flags,
2924 DEDUCE_CONV);
2925 else
2929 conversion_path,
2930 flags);
2933 {
2934 conversion *ics
2940 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
2941 copy-initialization. In that case, "The result of the
2942 call is then used to direct-initialize the object that is
2943 the destination of the copy-initialization." [dcl.init]
2945 We represent this in the conversion sequence with an
2946 rvalue conversion, which means a constructor call. But
2947 don't add a second rvalue conversion if there's already
2948 one there. Which there really shouldn't be, but it's
2949 harmless since we'd add it here anyway. */
2960 }
2961 }
2962 }
2970 {
2972 {
2976 }
2983 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2984 ambiguous conversion is no worse than another user-defined
2985 conversion. */
2988 }
2990 /* Build the user conversion sequence. */
2991 conv = build_conv
2998 /* Remember that this was a list-initialization. */
3002 /* Combine it with the second conversion sequence. */
3010 }
3012 tree
3014 {
3019 {
3024 }
3026 }
3028 /* Do any initial processing on the arguments to a function call. */
3032 {
3034 tree arg;
3037 {
3041 {
3044 }
3047 }
3049 }
3051 /* Perform overload resolution on FN, which is called with the ARGS.
3053 Return the candidate function selected by overload resolution, or
3054 NULL if the event that overload resolution failed. In the case
3055 that overload resolution fails, *CANDIDATES will be the set of
3056 candidates considered, and ANY_VIABLE_P will be set to true or
3057 false to indicate whether or not any of the candidates were
3058 viable.
3060 The ARGS should already have gone through RESOLVE_ARGS before this
3061 function is called. */
3068 {
3076 /* Check FN. */
3083 {
3087 }
3089 /* Add the various candidate functions. */
3093 LOOKUP_NORMAL,
3094 candidates);
3102 }
3104 /* Return an expression for a call to FN (a namespace-scope function,
3105 or a static member function) with the ARGS. This may change
3106 ARGS. */
3108 tree
3110 tsubst_flags_t complain)
3111 {
3115 tree result;
3118 {
3122 }
3124 /* If this function was found without using argument dependent
3125 lookup, then we want to ignore any undeclared friend
3126 functions. */
3128 {
3133 {
3139 }
3140 }
3142 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3148 {
3150 {
3158 else
3163 }
3165 }
3166 else
3169 /* Free all the conversions we allocated. */
3173 }
3175 /* Build a call to a global operator new. FNNAME is the name of the
3176 operator (either "operator new" or "operator new[]") and ARGS are
3177 the arguments provided. This may change ARGS. *SIZE points to the
3178 total number of bytes required by the allocation, and is updated if
3179 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
3180 be used. If this function determines that no cookie should be
3181 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is
3182 non-NULL, it will be set, upon return, to the allocation function
3183 called. */
3185 tree
3189 {
3190 tree fns;
3202 /* Based on:
3204 [expr.new]
3206 If this lookup fails to find the name, or if the allocated type
3207 is not a class type, the allocation function's name is looked
3208 up in the global scope.
3210 we disregard block-scope declarations of "operator new". */
3213 /* Figure out what function is being called. */
3216 /* If no suitable function could be found, issue an error message
3217 and give up. */
3219 {
3223 else
3229 }
3231 /* If a cookie is required, add some extra space. Whether
3232 or not a cookie is required cannot be determined until
3233 after we know which function was called. */
3235 {
3238 {
3239 /* In G++ 3.2, the check was implemented incorrectly; it
3240 looked at the placement expression, rather than the
3241 type of the function. */
3244 ptr_type_node))
3246 }
3247 else
3248 {
3249 tree arg_types;
3252 /* Skip the size_t parameter. */
3254 /* Check the remaining parameters (if any). */
3258 ptr_type_node))
3260 }
3261 /* If we need a cookie, adjust the number of bytes allocated. */
3263 {
3264 /* Update the total size. */
3266 /* Update the argument list to reflect the adjusted size. */
3268 }
3269 else
3271 }
3273 /* Tell our caller which function we decided to call. */
3277 /* Build the CALL_EXPR. */
3279 }
3281 /* Build a new call to operator(). This may change ARGS. */
3283 tree
3285 {
3299 {
3301 /* It's no good looking for an overloaded operator() on a
3302 pointer-to-member-function. */
3303 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3305 }
3308 {
3312 }
3313 else
3317 {
3321 }
3323 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3327 {
3332 {
3340 else
3341 add_function_candidate
3344 }
3345 }
3350 {
3362 {
3369 add_template_conv_candidate
3373 else
3377 }
3378 }
3382 {
3384 {
3388 }
3390 }
3391 else
3392 {
3395 {
3397 {
3401 }
3403 }
3404 /* Since cand->fn will be a type, not a function, for a conversion
3405 function, we must be careful not to unconditionally look at
3406 DECL_NAME here. */
3410 else
3411 {
3413 complain);
3416 }
3417 }
3419 /* Free all the conversions we allocated. */
3423 }
3425 static void
3428 {
3433 else
3437 {
3461 else
3465 }
3466 }
3468 /* Return the implicit conversion sequence that could be used to
3469 convert E1 to E2 in [expr.cond]. */
3473 {
3479 /* [expr.cond]
3481 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3482 implicitly converted (clause _conv_) to the type "reference to
3483 T2", subject to the constraint that in the conversion the
3484 reference must bind directly (_dcl.init.ref_) to E1. */
3486 {
3488 t1,
3489 e1,
3494 }
3496 /* [expr.cond]
3498 If E1 and E2 have class type, and the underlying class types are
3499 the same or one is a base class of the other: E1 can be converted
3500 to match E2 if the class of T2 is the same type as, or a base
3501 class of, the class of T1, and the cv-qualification of T2 is the
3502 same cv-qualification as, or a greater cv-qualification than, the
3503 cv-qualification of T1. If the conversion is applied, E1 is
3504 changed to an rvalue of type T2 that still refers to the original
3505 source class object (or the appropriate subobject thereof). */
3508 {
3510 {
3515 else
3518 }
3519 else
3521 }
3522 else
3523 /* [expr.cond]
3525 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3526 converted to the type that expression E2 would have if E2 were
3527 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3529 LOOKUP_IMPLICIT);
3530 }
3532 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3533 arguments to the conditional expression. */
3535 tree
3537 tsubst_flags_t complain)
3538 {
3539 tree arg2_type;
3540 tree arg3_type;
3548 /* As a G++ extension, the second argument to the conditional can be
3549 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3550 c'.) If the second operand is omitted, make sure it is
3551 calculated only once. */
3553 {
3558 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3561 else
3563 }
3565 /* [expr.cond]
3567 The first expression is implicitly converted to bool (clause
3568 _conv_). */
3571 /* If something has already gone wrong, just pass that fact up the
3572 tree. */
3578 /* [expr.cond]
3580 If either the second or the third operand has type (possibly
3581 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3582 array-to-pointer (_conv.array_), and function-to-pointer
3583 (_conv.func_) standard conversions are performed on the second
3584 and third operands. */
3588 {
3589 /* Do the conversions. We don't these for `void' type arguments
3590 since it can't have any effect and since decay_conversion
3591 does not handle that case gracefully. */
3599 /* [expr.cond]
3601 One of the following shall hold:
3603 --The second or the third operand (but not both) is a
3604 throw-expression (_except.throw_); the result is of the
3605 type of the other and is an rvalue.
3607 --Both the second and the third operands have type void; the
3608 result is of type void and is an rvalue.
3610 We must avoid calling force_rvalue for expressions of type
3611 "void" because it will complain that their value is being
3612 used. */
3615 {
3620 }
3623 {
3628 }
3631 else
3632 {
3634 {
3637 "is of type %<void%>, "
3638 "but the third operand is neither a throw-expression "
3640 else
3642 "is of type %<void%>, "
3643 "but the second operand is neither a throw-expression "
3645 }
3647 }
3651 }
3652 /* [expr.cond]
3654 Otherwise, if the second and third operand have different types,
3655 and either has (possibly cv-qualified) class type, an attempt is
3656 made to convert each of those operands to the type of the other. */
3659 {
3663 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3669 /* [expr.cond]
3671 If both can be converted, or one can be converted but the
3672 conversion is ambiguous, the program is ill-formed. If
3673 neither can be converted, the operands are left unchanged and
3674 further checking is performed as described below. If exactly
3675 one conversion is possible, that conversion is applied to the
3676 chosen operand and the converted operand is used in place of
3677 the original operand for the remainder of this section. */
3682 {
3686 }
3688 {
3692 /* Even if CONV2 is a valid conversion, the result of the
3693 conversion may be invalid. For example, if ARG3 has type
3694 "volatile X", and X does not have a copy constructor
3695 accepting a "volatile X&", then even if ARG2 can be
3696 converted to X, the conversion will fail. */
3699 }
3701 {
3707 }
3709 /* Free all the conversions we allocated. */
3715 /* If, after the conversion, both operands have class type,
3716 treat the cv-qualification of both operands as if it were the
3717 union of the cv-qualification of the operands.
3719 The standard is not clear about what to do in this
3720 circumstance. For example, if the first operand has type
3721 "const X" and the second operand has a user-defined
3722 conversion to "volatile X", what is the type of the second
3723 operand after this step? Making it be "const X" (matching
3724 the first operand) seems wrong, as that discards the
3725 qualification without actually performing a copy. Leaving it
3726 as "volatile X" seems wrong as that will result in the
3727 conditional expression failing altogether, even though,
3728 according to this step, the one operand could be converted to
3729 the type of the other. */
3737 }
3739 /* [expr.cond]
3741 If the second and third operands are lvalues and have the same
3742 type, the result is of that type and is an lvalue. */
3746 {
3749 }
3751 /* [expr.cond]
3753 Otherwise, the result is an rvalue. If the second and third
3754 operand do not have the same type, and either has (possibly
3755 cv-qualified) class type, overload resolution is used to
3756 determine the conversions (if any) to be applied to the operands
3757 (_over.match.oper_, _over.built_). */
3761 {
3766 /* Rearrange the arguments so that add_builtin_candidate only has
3767 to know about two args. In build_builtin_candidates, the
3768 arguments are unscrambled. */
3773 COND_EXPR,
3774 NOP_EXPR,
3776 args,
3777 LOOKUP_NORMAL);
3779 /* [expr.cond]
3781 If the overload resolution fails, the program is
3782 ill-formed. */
3785 {
3787 {
3790 }
3792 }
3795 {
3797 {
3800 }
3802 }
3804 /* [expr.cond]
3806 Otherwise, the conversions thus determined are applied, and
3807 the converted operands are used in place of the original
3808 operands for the remainder of this section. */
3815 }
3817 /* [expr.cond]
3819 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3820 and function-to-pointer (_conv.func_) standard conversions are
3821 performed on the second and third operands.
3823 We need to force the lvalue-to-rvalue conversion here for class types,
3824 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3825 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3826 regions. */
3839 /* [expr.cond]
3841 After those conversions, one of the following shall hold:
3843 --The second and third operands have the same type; the result is of
3844 that type. */
3847 /* [expr.cond]
3849 --The second and third operands have arithmetic or enumeration
3850 type; the usual arithmetic conversions are performed to bring
3851 them to a common type, and the result is of that type. */
3856 {
3857 /* In this case, there is always a common type. */
3859 arg3_type);
3863 {
3868 }
3874 {
3878 }
3882 }
3883 /* [expr.cond]
3885 --The second and third operands have pointer type, or one has
3886 pointer type and the other is a null pointer constant; pointer
3887 conversions (_conv.ptr_) and qualification conversions
3888 (_conv.qual_) are performed to bring them to their composite
3889 pointer type (_expr.rel_). The result is of the composite
3890 pointer type.
3892 --The second and third operands have pointer to member type, or
3893 one has pointer to member type and the other is a null pointer
3894 constant; pointer to member conversions (_conv.mem_) and
3895 qualification conversions (_conv.qual_) are performed to bring
3896 them to a common type, whose cv-qualification shall match the
3897 cv-qualification of either the second or the third operand.
3898 The result is of the common type. */
3906 {
3909 complain);
3914 }
3917 {
3922 }
3924 valid_operands:
3927 /* We can't use result_type below, as fold might have returned a
3928 throw_expr. */
3931 {
3932 /* Expand both sides into the same slot, hopefully the target of
3933 the ?: expression. We used to check for TARGET_EXPRs here,
3934 but now we sometimes wrap them in NOP_EXPRs so the test would
3935 fail. */
3938 /* If this expression is an rvalue, but might be mistaken for an
3939 lvalue, we must add a NON_LVALUE_EXPR. */
3941 }
3944 }
3946 /* OPERAND is an operand to an expression. Perform necessary steps
3947 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3948 returned. */
3950 static tree
3952 {
3954 {
3957 /* Make sure the template type is instantiated now. */
3959 }
3962 }
3964 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3965 OVERLOAD) to the CANDIDATES, returning an updated list of
3966 CANDIDATES. The ARGS are the arguments provided to the call,
3967 without any implicit object parameter. This may change ARGS. The
3968 EXPLICIT_TARGS are explicit template arguments provided.
3969 TEMPLATE_ONLY is true if only template functions should be
3970 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
3971 add_function_candidate. */
3973 static void
3979 {
3980 tree ctype;
3982 tree first_arg;
3985 /* Delay creating the implicit this parameter until it is needed. */
3990 {
3991 tree fn;
3992 tree fn_first_arg;
3996 /* Figure out which set of arguments to use. */
3998 {
3999 /* If this function is a non-static member, prepend the implicit
4000 object parameter. */
4002 {
4004 tree arg;
4010 }
4015 }
4016 else
4017 {
4018 /* Otherwise, just use the list of arguments provided. */
4021 }
4025 fn,
4026 ctype,
4027 explicit_targs,
4028 fn_first_arg,
4029 fn_args,
4030 NULL_TREE,
4031 access_path,
4032 conversion_path,
4033 flags,
4034 DEDUCE_CALL);
4037 fn,
4038 ctype,
4039 fn_first_arg,
4040 fn_args,
4041 access_path,
4042 conversion_path,
4043 flags);
4045 }
4046 }
4048 tree
4051 {
4054 tree fnname;
4072 {
4076 }
4077 else
4083 {
4088 /* Use build_op_new_call and build_op_delete_call instead. */
4092 /* Use build_op_call instead. */
4099 /* These are saved for the sake of warn_logical_operator. */
4105 }
4111 {
4118 }
4133 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4136 /* Add namespace-scope operators to the list of functions to
4137 consider. */
4141 /* Add class-member operators to the candidate set. */
4143 {
4144 tree fns;
4148 {
4151 }
4158 }
4160 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
4161 to know about two args; a builtin candidate will always have a first
4162 parameter of type bool. We'll handle that in
4163 build_builtin_candidate. */
4165 {
4169 }
4170 else
4171 {
4175 }
4180 {
4183 /* For these, the built-in candidates set is empty
4184 [over.match.oper]/3. We don't want non-strict matches
4185 because exact matches are always possible with built-in
4186 operators. The built-in candidate set for COMPONENT_REF
4187 would be empty too, but since there are no such built-in
4188 operators, we accept non-strict matches for them. */
4195 }
4199 {
4201 {
4204 /* Don't try anything fancy if we're not allowed to produce
4205 errors. */
4209 /* Look for an `operator++ (int)'. If they didn't have
4210 one, then we fall back to the old way of doing things. */
4214 fnname,
4218 else
4224 /* The caller will deal with these. */
4234 {
4235 /* If one of the arguments of the operator represents
4236 an invalid use of member function pointer, try to report
4237 a meaningful error ... */
4242 else
4243 {
4244 /* ... Otherwise, report the more generic
4245 "no matching operator found" error */
4248 }
4249 }
4252 }
4253 }
4254 else
4255 {
4258 {
4260 {
4263 }
4265 }
4267 {
4273 else
4275 }
4276 else
4277 {
4278 /* Give any warnings we noticed during overload resolution. */
4280 {
4284 }
4286 /* Check for comparison of different enum types. */
4288 {
4300 {
4304 }
4308 }
4310 /* We need to strip any leading REF_BIND so that bitfields
4311 don't cause errors. This should not remove any important
4312 conversions, because builtins don't apply to class
4313 objects directly. */
4320 {
4321 /* We need to call warn_logical_operator before
4322 converting arg2 to a boolean_type. */
4332 }
4334 {
4339 }
4341 }
4342 }
4344 user_defined_result_ready:
4346 /* Free all the conversions we allocated. */
4352 builtin:
4354 {
4367 /* Fall through. */
4408 complain),
4409 arg2);
4411 /* The caller will deal with these. */
4419 }
4421 }
4423 /* Build a call to operator delete. This has to be handled very specially,
4424 because the restrictions on what signatures match are different from all
4425 other call instances. For a normal delete, only a delete taking (void *)
4426 or (void *, size_t) is accepted. For a placement delete, only an exact
4427 match with the placement new is accepted.
4429 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4430 ADDR is the pointer to be deleted.
4431 SIZE is the size of the memory block to be deleted.
4432 GLOBAL_P is true if the delete-expression should not consider
4433 class-specific delete operators.
4434 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4436 If this call to "operator delete" is being generated as part to
4437 deallocate memory allocated via a new-expression (as per [expr.new]
4438 which requires that if the initialization throws an exception then
4439 we call a deallocation function), then ALLOC_FN is the allocation
4440 function. */
4442 tree
4445 tree alloc_fn)
4446 {
4461 /* In [class.free]
4463 If the result of the lookup is ambiguous or inaccessible, or if
4464 the lookup selects a placement deallocation function, the
4465 program is ill-formed.
4467 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4468 {
4472 }
4473 else
4479 /* Strip const and volatile from addr. */
4483 {
4484 /* Get the parameter types for the allocation function that is
4485 being called. */
4488 }
4489 else
4490 {
4491 /* First try it without the size argument. */
4493 }
4495 /* We make two tries at finding a matching `operator delete'. On
4496 the first pass, we look for a one-operator (or placement)
4497 operator delete. If we're not doing placement delete, then on
4498 the second pass we look for a two-argument delete. */
4500 {
4501 /* Go through the `operator delete' functions looking for one
4502 with a matching type. */
4504 fn;
4506 {
4507 tree t;
4509 /* The first argument must be "void *". */
4514 /* On the first pass, check the rest of the arguments. */
4516 {
4519 {
4524 }
4527 }
4528 /* On the second pass, look for a function with exactly two
4529 arguments: "void *" and "size_t". */
4531 /* For "operator delete(void *, ...)" there will be
4532 no second argument, but we will not get an exact
4533 match above. */
4534 && t
4538 }
4540 /* If we found a match, we're done. */
4543 }
4545 /* If we have a matching function, call it. */
4547 {
4548 /* Make sure we have the actual function, and not an
4549 OVERLOAD. */
4552 /* If the FN is a member function, make sure that it is
4553 accessible. */
4558 {
4559 /* The placement args might not be suitable for overload
4560 resolution at this point, so build the call directly. */
4569 }
4570 else
4571 {
4572 tree ret;
4580 }
4581 }
4583 /* [expr.new]
4585 If no unambiguous matching deallocation function can be found,
4586 propagating the exception does not cause the object's memory to
4587 be freed. */
4589 {
4592 alloc_fn);
4594 }
4599 }
4601 /* If the current scope isn't allowed to access DECL along
4602 BASETYPE_PATH, give an error. The most derived class in
4603 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4604 the declaration to use in the error diagnostic. */
4606 bool
4608 {
4612 {
4617 else
4621 }
4624 }
4626 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4627 bitwise or of LOOKUP_* values. If any errors are warnings are
4628 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4629 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4630 to NULL. */
4632 static tree
4635 {
4648 else
4651 }
4653 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4654 EXPR is implicitly converted to type TOTYPE.
4655 FN and ARGNUM are used for diagnostics. */
4657 static void
4659 {
4662 /* Issue warnings about peculiar, but valid, uses of NULL. */
4664 {
4668 else
4670 }
4672 /* Issue warnings if "false" is converted to a NULL pointer */
4677 }
4679 /* Perform the conversions in CONVS on the expression EXPR. FN and
4680 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4681 indicates the `this' argument of a method. INNER is nonzero when
4682 being called to continue a conversion chain. It is negative when a
4683 reference binding will be applied, positive otherwise. If
4684 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4685 conversions will be emitted if appropriate. If C_CAST_P is true,
4686 this conversion is coming from a C-style cast; in that case,
4687 conversions to inaccessible bases are permitted. */
4689 static tree
4693 {
4695 diagnostic_t diag_kind;
4705 {
4708 /* Give a helpful error if this is bad because of excess braces. */
4716 {
4718 {
4722 complain);
4724 }
4729 complain);
4732 }
4734 {
4738 }
4739 else
4743 }
4749 {
4751 {
4756 /* When converting from an init list we consider explicit
4757 constructors, but actually trying to call one is an error. */
4759 {
4763 else
4765 }
4767 /* Set user_conv_p on the argument conversions, so rvalue/base
4768 handling knows not to allow any more UDCs. */
4774 /* If this is a constructor or a function returning an aggr type,
4775 we need to build up a TARGET_EXPR. */
4777 {
4780 /* Remember that this was list-initialization. */
4783 }
4786 }
4789 {
4795 else
4797 }
4801 /* Convert a constant to its underlying value, unless we are
4802 about to bind it to a reference, in which case we need to
4803 leave it as an lvalue. */
4805 {
4808 /* If __null has been converted to an integer type, we do not
4809 want to warn about uses of EXPR as an integer, rather than
4810 as a pointer. */
4812 }
4815 /* Call build_user_type_conversion again for the error. */
4816 return build_user_type_conversion
4820 {
4821 /* Conversion to std::initializer_list<T>. */
4829 /* Convert all the elements. */
4831 {
4838 }
4839 /* Build up the array. */
4840 elttype = cp_build_qualified_type
4848 /* Call the private constructor. */
4850 new_ctor = build_special_member_call
4855 }
4862 };
4867 c_cast_p,
4868 complain);
4873 {
4878 /* Else fall through. */
4881 {
4882 /* We are going to bind a reference directly to a base-class
4883 subobject of EXPR. */
4884 /* Build an expression for `*((base*) &expr)'. */
4890 }
4892 /* Copy-initialization where the cv-unqualified version of the source
4893 type is the same class as, or a derived class of, the class of the
4894 destination [is treated as direct-initialization]. [dcl.init] */
4897 /* This conversion is being done in the context of a user-defined
4898 conversion (i.e. the second step of copy-initialization), so
4899 don't allow any more. */
4903 {
4909 }
4913 {
4916 /* If necessary, create a temporary.
4918 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
4919 that need temporaries, even when their types are reference
4920 compatible with the type of reference being bound, so the
4921 upcoming call to cp_build_unary_op (ADDR_EXPR, expr, ...)
4922 doesn't fail. */
4926 {
4932 {
4934 {
4935 /* If the reference is volatile or non-const, we
4936 cannot create a temporary. */
4943 else
4945 }
4947 }
4948 /* If the source is a packed field, and we must use a copy
4949 constructor, then building the target expr will require
4950 binding the field to the reference parameter to the
4951 copy constructor, and we'll end up with an infinite
4952 loop. If we can use a bitwise copy, then we'll be
4953 OK. */
4957 {
4962 }
4964 {
4967 }
4969 }
4971 /* Take the address of the thing to which we will bind the
4972 reference. */
4977 /* Convert it to a pointer to the type referred to by the
4978 reference. This will adjust the pointer if a derived to
4979 base conversion is being performed. */
4981 expr);
4982 /* Convert the pointer to the desired reference type. */
4984 }
4990 /* Warn about deprecated conversion if appropriate. */
5002 c_cast_p);
5006 }
5013 else
5017 }
5019 /* Build a call to __builtin_trap. */
5021 static tree
5023 {
5029 }
5031 /* ARG is being passed to a varargs function. Perform any conversions
5032 required. Return the converted value. */
5034 tree
5036 {
5037 /* [expr.call]
5039 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5040 standard conversions are performed. */
5042 /* [expr.call]
5044 If the argument has integral or enumeration type that is subject
5045 to the integral promotions (_conv.prom_), or a floating point
5046 type that is subject to the floating point promotion
5047 (_conv.fpprom_), the value of the argument is converted to the
5048 promoted type before the call. */
5060 {
5061 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
5062 here and do a bitwise copy, but now cp_expr_size will abort if we
5063 try to do that.
5064 If the call appears in the context of a sizeof expression,
5065 there is no need to emit a warning, since the expression won't be
5066 evaluated. We keep the builtin_trap just as a safety check. */
5072 integer_zero_node);
5073 }
5076 }
5078 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
5080 tree
5082 {
5092 {
5093 /* Remove reference types so we don't ICE later on. */
5095 /* Undefined behavior [expr.call] 5.2.2/7. */
5103 }
5106 }
5108 /* TYPE has been given to va_arg. Apply the default conversions which
5109 would have happened when passed via ellipsis. Return the promoted
5110 type, or the passed type if there is no change. */
5112 tree
5114 {
5115 tree promote;
5117 /* Perform the array-to-pointer and function-to-pointer
5118 conversions. */
5126 }
5128 /* ARG is a default argument expression being passed to a parameter of
5129 the indicated TYPE, which is a parameter to FN. Do any required
5130 conversions. Return the converted value. */
5134 tree
5136 {
5138 tree t;
5140 /* If the ARG is an unparsed default argument expression, the
5141 conversion cannot be performed. */
5143 {
5148 }
5150 /* Detect recursion. */
5153 {
5156 }
5162 /* Due to:
5164 [dcl.fct.default]
5166 The names in the expression are bound, and the semantic
5167 constraints are checked, at the point where the default
5168 expressions appears.
5170 we must not perform access checks here. */
5174 {
5178 tf_warning_or_error);
5179 }
5180 else
5181 {
5182 /* We must make a copy of ARG, in case subsequent processing
5183 alters any part of it. For example, during gimplification a
5184 cast of the form (T) &X::f (where "f" is a member function)
5185 will lead to replacing the PTRMEM_CST for &X::f with a
5186 VAR_DECL. We can avoid the copy for constants, since they
5187 are never modified in place. */
5192 tf_warning_or_error);
5194 }
5200 }
5202 /* Returns the type which will really be used for passing an argument of
5203 type TYPE. */
5205 tree
5207 {
5208 /* Pass classes with copy ctors by invisible reference. */
5210 {
5212 /* There are no other pointers to this temporary. */
5214 }
5223 }
5225 /* Actually perform the appropriate conversion. */
5227 tree
5229 {
5230 tree bitfield_type;
5232 /* If VAL is a bitfield, then -- since it has already been converted
5233 to TYPE -- it cannot have a precision greater than TYPE.
5235 If it has a smaller precision, we must widen it here. For
5236 example, passing "int f:3;" to a function expecting an "int" will
5237 not result in any conversion before this point.
5239 If the precision is the same we must not risk widening. For
5240 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5241 often have type "int", even though the C++ type for the field is
5242 "long long". If the value is being passed to a function
5243 expecting an "int", then no conversions will be required. But,
5244 if we call convert_bitfield_to_declared_type, the bitfield will
5245 be converted to "long long". */
5252 ;
5253 /* Pass classes with copy ctors by invisible reference. */
5263 {
5272 }
5274 }
5276 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5277 which no conversions at all should be done. This is true for some
5278 builtins which don't act like normal functions. */
5280 static bool
5282 {
5285 {
5295 }
5298 }
5300 /* Subroutine of the various build_*_call functions. Overload resolution
5301 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5302 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5303 bitmask of various LOOKUP_* flags which apply to the call itself. */
5305 static tree
5307 {
5315 tree val;
5324 /* In a template, there is no need to perform all of the work that
5325 is normally done. We are only interested in the type of the call
5326 expression, i.e., the return type of the function. Any semantic
5327 errors will be deferred until the template is instantiated. */
5329 {
5330 tree expr;
5331 tree return_type;
5339 else
5340 {
5343 tree arg;
5351 }
5353 argarray);
5359 }
5361 /* Give any warnings we noticed during overload resolution. */
5363 {
5367 }
5369 /* Make =delete work with SFINAE. */
5374 {
5375 /* If FN is a template function, two cases must be considered.
5376 For example:
5378 struct A {
5379 protected:
5380 template <class T> void f();
5381 };
5382 template <class T> struct B {
5383 protected:
5384 void g();
5385 };
5386 struct C : A, B<int> {
5387 using A::f; // #1
5388 using B<int>::g; // #2
5389 };
5391 In case #1 where `A::f' is a member template, DECL_ACCESS is
5392 recorded in the primary template but not in its specialization.
5393 We check access of FN using its primary template.
5395 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
5396 because it is a member of class template B, DECL_ACCESS is
5397 recorded in the specialization `B<int>::g'. We cannot use its
5398 primary template because `B<T>::g' and `B<int>::g' may have
5399 different access. */
5404 else
5406 }
5408 /* Find maximum size of vector to hold converted arguments. */
5415 /* The implicit parameters to a constructor are not considered by overload
5416 resolution, and must be of the proper type. */
5418 {
5420 {
5423 }
5424 else
5425 {
5428 }
5430 /* We should never try to call the abstract constructor. */
5434 {
5438 }
5439 }
5440 /* Bypass access control for 'this' parameter. */
5442 {
5445 ? first_arg
5448 tree converted_arg;
5449 tree base_binfo;
5452 {
5456 else
5458 }
5460 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
5461 X is called for an object that is not of type X, or of a type
5462 derived from X, the behavior is undefined.
5464 So we can assume that anything passed as 'this' is non-null, and
5465 optimize accordingly. */
5467 /* Convert to the base in which the function was declared. */
5470 arg,
5473 /* Check that the base class is accessible. */
5479 /* If fn was found by a using declaration, the conversion path
5480 will be to the derived class, not the base declaring fn. We
5481 must convert from derived to base. */
5491 else
5495 }
5500 {
5505 /* Don't make a copy here if build_call is going to. */
5511 val = convert_like_with_context
5513 complain);
5518 else
5520 }
5522 /* Default arguments */
5527 /* Ellipsis */
5529 {
5533 else
5536 }
5544 /* Avoid actually calling copy constructors and copy assignment operators,
5545 if possible. */
5552 {
5553 tree targ;
5555 tree fa;
5557 /* Pull out the real argument, disregarding const-correctness. */
5563 {
5568 }
5569 else
5574 else
5579 {
5580 /* Copy-list-initialization doesn't require the copy constructor
5581 to be defined. */
5582 }
5583 /* [class.copy]: the copy constructor is implicitly defined even if
5584 the implementation elided its use. */
5586 {
5589 }
5591 /* If we're creating a temp and we already have one, don't create a
5592 new one. If we're not creating a temp but we get one, use
5593 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5594 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5595 temp or an INIT_EXPR otherwise. */
5600 {
5605 }
5609 {
5611 complain));
5615 }
5616 }
5620 {
5621 tree to = stabilize_reference
5628 {
5631 }
5632 else
5633 {
5634 /* We must only copy the non-tail padding parts.
5635 Use __builtin_memcpy for the bitwise copy.
5636 FIXME fix 22488 so we can go back to using MODIFY_EXPR
5637 instead of an explicit call to memcpy. */
5647 {
5648 /* When TER is off get_pointer_alignment returns 0, so a call
5649 to __builtin_memcpy is expanded as a call to memcpy, which
5650 is invalid with identical args. When TER is on it is
5651 expanded as a block move, which should be safe. */
5655 }
5664 }
5667 }
5673 {
5674 tree t;
5680 /* Warn about deprecated virtual functions now, since we're about
5681 to throw away the decl. */
5691 else
5694 }
5695 else
5699 }
5701 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5702 This function performs no overload resolution, conversion, or other
5703 high-level operations. */
5705 tree
5707 {
5708 tree fndecl;
5712 /* If this call might throw an exception, note that fact. */
5719 /* Check that arguments to builtin functions match the expectations. */
5726 /* Some built-in function calls will be evaluated at compile-time in
5727 fold (). */
5740 }
5744 /* Make an expression which yields the address of the Java interface
5745 method FN. This is achieved by generating a call to libjava's
5746 _Jv_LookupInterfaceMethodIdx(). */
5748 static tree
5750 {
5756 {
5761 endlink)));
5762 java_iface_lookup_fn
5766 }
5768 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5769 This is the first entry in the vtable. */
5771 tf_warning_or_error),
5772 integer_zero_node);
5774 /* Get the java.lang.Class pointer for the interface being called. */
5779 {
5781 iface);
5783 }
5787 /* Determine the itable index of FN. */
5790 {
5795 i++;
5796 }
5801 java_iface_lookup_fn);
5804 }
5806 /* Returns the value to use for the in-charge parameter when making a
5807 call to a function with the indicated NAME.
5809 FIXME:Can't we find a neater way to do this mapping? */
5811 tree
5813 {
5824 /* This function should only be called with one of the names listed
5825 above. */
5828 }
5830 /* Build a call to a constructor, destructor, or an assignment
5831 operator for INSTANCE, an expression with class type. NAME
5832 indicates the special member function to call; *ARGS are the
5833 arguments. ARGS may be NULL. This may change ARGS. BINFO
5834 indicates the base of INSTANCE that is to be passed as the `this'
5835 parameter to the member function called.
5837 FLAGS are the LOOKUP_* flags to use when processing the call.
5839 If NAME indicates a complete object constructor, INSTANCE may be
5840 NULL_TREE. In this case, the caller will call build_cplus_new to
5841 store the newly constructed object into a VAR_DECL. */
5843 tree
5846 {
5847 tree fns;
5848 /* The type of the subobject to be constructed or destroyed. */
5849 tree class_type;
5851 tree ret;
5860 {
5861 /* Resolve the name. */
5866 }
5872 /* Handle the special case where INSTANCE is NULL_TREE. */
5874 {
5877 }
5878 else
5879 {
5885 /* Convert to the base class, if necessary. */
5888 {
5890 /* For constructors and destructors, either the base is
5891 non-virtual, or it is virtual but we are doing the
5892 conversion from a constructor or destructor for the
5893 complete object. In either case, we can convert
5894 statically. */
5896 else
5897 /* However, for assignment operators, we must convert
5898 dynamically if the base is virtual. */
5901 }
5902 }
5908 /* When making a call to a constructor or destructor for a subobject
5909 that uses virtual base classes, pass down a pointer to a VTT for
5910 the subobject. */
5914 {
5915 tree vtt;
5916 tree sub_vtt;
5918 /* If the current function is a complete object constructor
5919 or destructor, then we fetch the VTT directly.
5920 Otherwise, we look it up using the VTT we were given. */
5926 current_vtt_parm,
5927 vtt);
5933 {
5936 }
5939 }
5944 complain);
5950 }
5952 /* Return the NAME, as a C string. The NAME indicates a function that
5953 is a member of TYPE. *FREE_P is set to true if the caller must
5954 free the memory returned.
5956 Rather than go through all of this, we should simply set the names
5957 of constructors and destructors appropriately, and dispense with
5958 ctor_identifier, dtor_identifier, etc. */
5962 {
5965 /* Assume that we will not allocate memory. */
5967 /* Constructors and destructors are special. */
5969 {
5970 pretty_name
5972 /* For a destructor, add the '~'. */
5976 {
5978 /* Remember that we need to free the memory allocated. */
5980 }
5981 }
5983 {
5986 TFF_PLAIN_IDENTIFIER),
5987 NULL);
5988 /* Remember that we need to free the memory allocated. */
5990 }
5991 else
5995 }
5997 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
5998 be set, upon return, to the function called. ARGS may be NULL.
5999 This may change ARGS. */
6001 tree
6005 {
6009 tree access_binfo;
6010 tree optype;
6012 tree instance_ptr;
6013 tree name;
6016 tree call;
6017 tree fn;
6018 tree class_type;
6021 tree orig_instance;
6022 tree orig_fns;
6028 /* We don't know what function we're going to call, yet. */
6037 {
6041 }
6046 /* Dismantle the baselink to collect all the information we need. */
6053 {
6057 }
6068 {
6073 }
6075 /* Figure out whether to skip the first argument for the error
6076 message we will display to users if an error occurs. We don't
6077 want to display any compiler-generated arguments. The "this"
6078 pointer hasn't been added yet. However, we must remove the VTT
6079 pointer if this is a call to a base-class constructor or
6080 destructor. */
6084 {
6085 /* Callers should explicitly indicate whether they want to construct
6086 the complete object or just the part without virtual bases. */
6088 /* Similarly for destructors. */
6090 /* Remove the VTT pointer, if present. */
6094 }
6096 /* Process the argument list. */
6098 {
6102 }
6106 /* It's OK to call destructors and constructors on cv-qualified objects.
6107 Therefore, convert the INSTANCE_PTR to the unqualified type, if
6108 necessary. */
6111 {
6115 }
6119 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
6120 initializer, not T({ }). If the type doesn't have a list ctor,
6121 break apart the list into separate ctor args. */
6126 {
6129 }
6134 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6138 {
6140 tree this_first_arg;
6142 /* We can end up here for copy-init of same or base class. */
6149 else
6153 /* A member template. */
6155 class_type,
6156 explicit_targs,
6157 this_first_arg,
6159 optype,
6160 access_binfo,
6161 conversion_path,
6162 flags,
6163 DEDUCE_CALL);
6166 class_type,
6167 this_first_arg,
6169 access_binfo,
6170 conversion_path,
6171 flags);
6172 }
6176 {
6178 {
6181 else
6182 {
6185 tree arglist;
6196 }
6198 }
6200 }
6201 else
6202 {
6205 {
6208 tree arglist;
6211 {
6217 arglist);
6221 }
6223 }
6224 else
6225 {
6234 /* This is not an error, it is runtime undefined
6235 behavior. */
6237 "abstract virtual %q#D called from constructor"
6239 fn);
6243 {
6246 fn);
6248 }
6249 else
6250 {
6254 /* Now we know what function is being called. */
6257 /* Build the actual CALL_EXPR. */
6259 /* In an expression of the form `a->f()' where `f' turns
6260 out to be a static member function, `a' is
6261 none-the-less evaluated. */
6270 /* An explicit call of the form "x->~X()" has type
6271 "void". However, on platforms where destructors
6272 return "this" (i.e., those where
6273 targetm.cxx.cdtor_returns_this is true), such calls
6274 will appear to have a return value of pointer type
6275 to the low-level call machinery. We do not want to
6276 change the low-level machinery, since we want to be
6277 able to optimize "delete f()" on such platforms as
6278 "operator delete(~X(f()))" (rather than generating
6279 "t = f(), ~X(t), operator delete (t)"). */
6281 }
6282 }
6283 }
6286 {
6292 {
6295 }
6298 call = (build_min_non_dep_call_vec
6302 orig_args));
6306 }
6308 /* Free all the conversions we allocated. */
6315 }
6317 /* Returns true iff standard conversion sequence ICS1 is a proper
6318 subsequence of ICS2. */
6320 static bool
6322 {
6323 /* We can assume that a conversion of the same code
6324 between the same types indicates a subsequence since we only get
6325 here if the types we are converting from are the same. */
6332 {
6340 /* At this point, ICS1 cannot be a proper subsequence of
6341 ICS2. We can get a USER_CONV when we are comparing the
6342 second standard conversion sequence of two user conversion
6343 sequences. */
6353 }
6354 }
6356 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
6357 be any _TYPE nodes. */
6359 bool
6361 {
6365 /* We only allow proper derivation here. The DERIVED_FROM_P macro
6366 considers every class derived from itself. */
6369 }
6371 /* We build the ICS for an implicit object parameter as a pointer
6372 conversion sequence. However, such a sequence should be compared
6373 as if it were a reference conversion sequence. If ICS is the
6374 implicit conversion sequence for an implicit object parameter,
6375 modify it accordingly. */
6377 static void
6379 {
6381 {
6382 /* [over.match.funcs]
6384 For non-static member functions, the type of the
6385 implicit object parameter is "reference to cv X"
6386 where X is the class of which the function is a
6387 member and cv is the cv-qualification on the member
6388 function declaration. */
6390 tree reference_type;
6392 /* The `this' parameter is a pointer to a class type. Make the
6393 implicit conversion talk about a reference to that same class
6394 type. */
6407 }
6408 }
6410 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
6411 and return the initial reference binding conversion. Otherwise,
6412 leave *ICS unchanged and return NULL. */
6416 {
6418 {
6424 }
6427 }
6429 /* Compare two implicit conversion sequences according to the rules set out in
6430 [over.ics.rank]. Return values:
6432 1: ics1 is better than ics2
6433 -1: ics2 is better than ics1
6434 0: ics1 and ics2 are indistinguishable */
6436 static int
6438 {
6439 tree from_type1;
6440 tree from_type2;
6441 tree to_type1;
6442 tree to_type2;
6449 /* REF_BINDING is nonzero if the result of the conversion sequence
6450 is a reference type. In that case REF_CONV is the reference
6451 binding conversion. */
6455 /* Handle implicit object parameters. */
6459 /* Handle reference parameters. */
6463 /* [over.ics.rank]
6465 When comparing the basic forms of implicit conversion sequences (as
6466 defined in _over.best.ics_)
6468 --a standard conversion sequence (_over.ics.scs_) is a better
6469 conversion sequence than a user-defined conversion sequence
6470 or an ellipsis conversion sequence, and
6472 --a user-defined conversion sequence (_over.ics.user_) is a
6473 better conversion sequence than an ellipsis conversion sequence
6474 (_over.ics.ellipsis_). */
6484 {
6485 /* XXX Isn't this an extension? */
6486 /* Both ICS are bad. We try to make a decision based on what
6487 would have happened if they'd been good. */
6495 /* We couldn't make up our minds; try to figure it out below. */
6496 }
6499 /* Both conversions are ellipsis conversions. */
6502 /* User-defined conversion sequence U1 is a better conversion sequence
6503 than another user-defined conversion sequence U2 if they contain the
6504 same user-defined conversion operator or constructor and if the sec-
6505 ond standard conversion sequence of U1 is better than the second
6506 standard conversion sequence of U2. */
6509 {
6520 /* Conversion to std::initializer_list is better than other
6521 user-defined conversions. */
6524 {
6529 else
6531 }
6536 /* We can just fall through here, after setting up
6537 FROM_TYPE1 and FROM_TYPE2. */
6540 }
6541 else
6542 {
6546 /* We're dealing with two standard conversion sequences.
6548 [over.ics.rank]
6550 Standard conversion sequence S1 is a better conversion
6551 sequence than standard conversion sequence S2 if
6553 --S1 is a proper subsequence of S2 (comparing the conversion
6554 sequences in the canonical form defined by _over.ics.scs_,
6555 excluding any Lvalue Transformation; the identity
6556 conversion sequence is considered to be a subsequence of
6557 any non-identity conversion sequence */
6568 }
6570 /* One sequence can only be a subsequence of the other if they start with
6571 the same type. They can start with different types when comparing the
6572 second standard conversion sequence in two user-defined conversion
6573 sequences. */
6575 {
6580 }
6582 /* [over.ics.rank]
6584 Or, if not that,
6586 --the rank of S1 is better than the rank of S2 (by the rules
6587 defined below):
6589 Standard conversion sequences are ordered by their ranks: an Exact
6590 Match is a better conversion than a Promotion, which is a better
6591 conversion than a Conversion.
6593 Two conversion sequences with the same rank are indistinguishable
6594 unless one of the following rules applies:
6596 --A conversion that is not a conversion of a pointer, or pointer
6597 to member, to bool is better than another conversion that is such
6598 a conversion.
6600 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
6601 so that we do not have to check it explicitly. */
6610 /* A conversion from scalar arithmetic type to complex is worse than a
6611 conversion between scalar arithmetic types. */
6618 {
6621 else
6623 }
6629 {
6634 }
6635 /* The rules for pointers to members A::* are just like the rules
6636 for pointers A*, except opposite: if B is derived from A then
6637 A::* converts to B::*, not vice versa. For that reason, we
6638 switch the from_ and to_ variables here. */
6645 {
6650 }
6655 {
6656 /* This was one of the pointer or pointer-like conversions.
6658 [over.ics.rank]
6660 --If class B is derived directly or indirectly from class A,
6661 conversion of B* to A* is better than conversion of B* to
6662 void*, and conversion of A* to void* is better than
6663 conversion of B* to void*. */
6666 {
6668 deref_from_type2))
6671 deref_from_type1))
6673 }
6676 {
6678 {
6680 {
6682 deref_to_type1))
6684 }
6685 /* We know that DEREF_TO_TYPE1 is `void' here. */
6687 deref_to_type2))
6689 }
6690 }
6693 {
6694 /* [over.ics.rank]
6696 --If class B is derived directly or indirectly from class A
6697 and class C is derived directly or indirectly from B,
6699 --conversion of C* to B* is better than conversion of C* to
6700 A*,
6702 --conversion of B* to A* is better than conversion of C* to
6703 A* */
6705 {
6707 deref_to_type2))
6710 deref_to_type1))
6712 }
6714 {
6716 deref_from_type1))
6719 deref_from_type2))
6721 }
6722 }
6723 }
6726 {
6729 /* [over.ics.rank]
6731 --binding of an expression of type C to a reference of type
6732 B& is better than binding an expression of type C to a
6733 reference of type A&
6735 --conversion of C to B is better than conversion of C to A, */
6738 {
6743 }
6744 }
6747 {
6750 /* [over.ics.rank]
6752 --binding of an expression of type B to a reference of type
6753 A& is better than binding an expression of type C to a
6754 reference of type A&,
6756 --conversion of B to A is better than conversion of C to A */
6759 {
6764 }
6765 }
6767 /* [over.ics.rank]
6769 --S1 and S2 differ only in their qualification conversion and yield
6770 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6771 qualification signature of type T1 is a proper subset of the cv-
6772 qualification signature of type T2 */
6776 {
6780 }
6782 /* [over.ics.rank]
6784 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6785 to an implicit object parameter, and either S1 binds an lvalue reference
6786 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6787 reference to an rvalue and S2 binds an lvalue reference
6788 (C++0x draft standard, 13.3.3.2)
6790 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6791 types to which the references refer are the same type except for
6792 top-level cv-qualifiers, and the type to which the reference
6793 initialized by S2 refers is more cv-qualified than the type to
6794 which the reference initialized by S1 refers */
6797 {
6801 {
6806 }
6811 }
6813 /* Neither conversion sequence is better than the other. */
6815 }
6817 /* The source type for this standard conversion sequence. */
6819 static tree
6821 {
6823 {
6828 }
6830 }
6832 /* Note a warning about preferring WINNER to LOSER. We do this by storing
6833 a pointer to LOSER and re-running joust to produce the warning if WINNER
6834 is actually used. */
6836 static void
6838 {
6844 }
6846 /* Compare two candidates for overloading as described in
6847 [over.match.best]. Return values:
6849 1: cand1 is better than cand2
6850 -1: cand2 is better than cand1
6851 0: cand1 and cand2 are indistinguishable */
6853 static int
6855 {
6861 /* Candidates that involve bad conversions are always worse than those
6862 that don't. */
6868 /* If we have two pseudo-candidates for conversions to the same type,
6869 or two candidates for the same function, arbitrarily pick one. */
6874 /* a viable function F1
6875 is defined to be a better function than another viable function F2 if
6876 for all arguments i, ICSi(F1) is not a worse conversion sequence than
6877 ICSi(F2), and then */
6879 /* for some argument j, ICSj(F1) is a better conversion sequence than
6880 ICSj(F2) */
6882 /* For comparing static and non-static member functions, we ignore
6883 the implicit object parameter of the non-static function. The
6884 standard says to pretend that the static function has an object
6885 parm, but that won't work with operator overloading. */
6888 {
6896 else
6897 {
6900 }
6901 }
6904 {
6910 {
6923 {
6930 else
6935 {
6939 }
6940 else
6942 }
6945 {
6948 }
6950 }
6951 }
6953 /* warn about confusing overload resolution for user-defined conversions,
6954 either between a constructor and a conversion op, or between two
6955 conversion ops. */
6959 {
6965 else
6968 /* We don't want to complain about `X::operator T1 ()'
6969 beating `X::operator T2 () const', when T2 is a no less
6970 cv-qualified version of T1. */
6973 {
6978 {
6981 }
6984 }
6985 else
6991 {
6998 {
7000 }
7001 }
7002 else
7004 }
7009 /* or, if not that,
7010 F1 is a non-template function and F2 is a template function
7011 specialization. */
7018 /* or, if not that,
7019 F1 and F2 are template functions and the function template for F1 is
7020 more specialized than the template for F2 according to the partial
7021 ordering rules. */
7024 {
7025 winner = more_specialized_fn
7028 /* [temp.func.order]: The presence of unused ellipsis and default
7029 arguments has no effect on the partial ordering of function
7030 templates. add_function_candidate() will not have
7031 counted the "this" argument for constructors. */
7035 }
7037 /* or, if not that,
7038 the context is an initialization by user-defined conversion (see
7039 _dcl.init_ and _over.match.user_) and the standard conversion
7040 sequence from the return type of F1 to the destination type (i.e.,
7041 the type of the entity being initialized) is a better conversion
7042 sequence than the standard conversion sequence from the return type
7043 of F2 to the destination type. */
7046 {
7050 }
7052 /* Check whether we can discard a builtin candidate, either because we
7053 have two identical ones or matching builtin and non-builtin candidates.
7055 (Pedantically in the latter case the builtin which matched the user
7056 function should not be added to the overload set, but we spot it here.
7058 [over.match.oper]
7059 ... the builtin candidates include ...
7060 - do not have the same parameter type list as any non-template
7061 non-member candidate. */
7065 {
7071 {
7073 /* Two built-in candidates; arbitrarily pick one. */
7076 /* cand1 is built-in; prefer cand2. */
7078 else
7079 /* cand2 is built-in; prefer cand1. */
7081 }
7082 }
7084 /* If the two function declarations represent the same function (this can
7085 happen with declarations in multiple scopes and arg-dependent lookup),
7086 arbitrarily choose one. But first make sure the default args we're
7087 using match. */
7090 {
7097 {
7098 /* Don't crash if the fn is variadic. */
7103 }
7111 {
7114 {
7116 {
7123 }
7124 else
7127 }
7130 }
7133 }
7135 tweak:
7137 /* Extension: If the worst conversion for one candidate is worse than the
7138 worst conversion for the other, take the first. */
7140 {
7145 {
7150 }
7156 {
7158 {
7160 "ISO C++ says that these are ambiguous, even "
7161 "though the worst conversion for the first is better than "
7165 }
7166 else
7169 }
7170 }
7174 }
7176 /* Given a list of candidates for overloading, find the best one, if any.
7177 This algorithm has a worst case of O(2n) (winner is last), and a best
7178 case of O(n/2) (totally ambiguous); much better than a sorting
7179 algorithm. */
7183 {
7188 /* Walk through the list once, comparing each current champ to the next
7189 candidate, knocking out a candidate or two with each comparison. */
7192 {
7196 else
7197 {
7199 {
7204 }
7205 else
7206 {
7209 }
7212 }
7213 }
7215 /* Make sure the champ is better than all the candidates it hasn't yet
7216 been compared to. */
7219 challenger != champ
7222 {
7226 }
7229 }
7231 /* Returns nonzero if things of type FROM can be converted to TO. */
7233 bool
7235 {
7237 }
7239 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7241 bool
7243 {
7248 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7252 flags);
7255 /* Free all the conversions we allocated. */
7259 }
7261 /* Like can_convert_arg, but allows dubious conversions as well. */
7263 bool
7265 {
7269 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7271 /* Try to perform the conversion. */
7273 flags);
7274 /* Free all the conversions we allocated. */
7278 }
7280 /* Convert EXPR to TYPE. Return the converted expression.
7282 Note that we allow bad conversions here because by the time we get to
7283 this point we are committed to doing the conversion. If we end up
7284 doing a bad conversion, convert_like will complain. */
7286 tree
7288 {
7295 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7300 flags);
7303 {
7305 {
7306 /* If expr has unknown type, then it is an overloaded function.
7307 Call instantiate_type to get good error messages. */
7312 else
7314 }
7316 }
7318 {
7319 /* In a template, we are only concerned about determining the
7320 type of non-dependent expressions, so we do not have to
7321 perform the actual conversion. */
7324 }
7325 else
7328 /* Free all the conversions we allocated. */
7332 }
7334 tree
7336 {
7338 }
7340 /* Convert EXPR to TYPE (as a direct-initialization) if that is
7341 permitted. If the conversion is valid, the converted expression is
7342 returned. Otherwise, NULL_TREE is returned, except in the case
7343 that TYPE is a class type; in that case, an error is issued. If
7344 C_CAST_P is true, then this direction initialization is taking
7345 place as part of a static_cast being attempted as part of a C-style
7346 cast. */
7348 tree
7350 tree expr,
7352 tsubst_flags_t complain)
7353 {
7359 /* [dcl.init]
7361 If the destination type is a (possibly cv-qualified) class type:
7363 -- If the initialization is direct-initialization ...,
7364 constructors are considered. ... If no constructor applies, or
7365 the overload resolution is ambiguous, the initialization is
7366 ill-formed. */
7368 {
7374 }
7376 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7380 c_cast_p,
7381 LOOKUP_NORMAL);
7384 else
7387 c_cast_p,
7388 tf_warning_or_error);
7390 /* Free all the conversions we allocated. */
7394 }
7396 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
7397 is being bound to a temporary. Create and return a new VAR_DECL
7398 with the indicated TYPE; this variable will store the value to
7399 which the reference is bound. */
7401 tree
7403 {
7404 tree var;
7406 /* Create the variable. */
7409 /* Register the variable. */
7411 {
7412 /* Namespace-scope or local static; give it a mangled name. */
7413 tree name;
7420 }
7421 else
7422 /* Create a new cleanup level if necessary. */
7426 }
7428 /* EXPR is the initializer for a variable DECL of reference or
7429 std::initializer_list type. Create, push and return a new VAR_DECL
7430 for the initializer so that it will live as long as DECL. Any
7431 cleanup for the new variable is returned through CLEANUP, and the
7432 code to initialize the new variable is returned through INITP. */
7434 tree
7436 {
7437 tree init;
7438 tree type;
7439 tree var;
7441 /* Create the temporary variable. */
7445 /* If the rvalue is the result of a function call it will be
7446 a TARGET_EXPR. If it is some other construct (such as a
7447 member access expression where the underlying object is
7448 itself the result of a function call), turn it into a
7449 TARGET_EXPR here. It is important that EXPR be a
7450 TARGET_EXPR below since otherwise the INIT_EXPR will
7451 attempt to make a bitwise copy of EXPR to initialize
7452 VAR. */
7455 /* Create the INIT_EXPR that will initialize the temporary
7456 variable. */
7459 {
7464 else
7467 /* We must be careful to destroy the temporary only
7468 after its initialization has taken place. If the
7469 initialization throws an exception, then the
7470 destructor should not be run. We cannot simply
7471 transform INIT into something like:
7473 (INIT, ({ CLEANUP_STMT; }))
7475 because emit_local_var always treats the
7476 initializer as a full-expression. Thus, the
7477 destructor would run too early; it would run at the
7478 end of initializing the reference variable, rather
7479 than at the end of the block enclosing the
7480 reference variable.
7482 The solution is to pass back a cleanup expression
7483 which the caller is responsible for attaching to
7484 the statement tree. */
7485 }
7486 else
7487 {
7491 static_aggregates);
7492 }
7496 }
7498 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
7499 initializing a variable of that TYPE. If DECL is non-NULL, it is
7500 the VAR_DECL being initialized with the EXPR. (In that case, the
7501 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
7502 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
7503 return, if *CLEANUP is no longer NULL, it will be an expression
7504 that should be pushed as a cleanup after the returned expression
7505 is used to initialize DECL.
7507 Return the converted expression. */
7509 tree
7511 {
7518 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7522 LOOKUP_NORMAL);
7524 {
7530 else
7535 }
7537 /* If DECL is non-NULL, then this special rule applies:
7539 [class.temporary]
7541 The temporary to which the reference is bound or the temporary
7542 that is the complete object to which the reference is bound
7543 persists for the lifetime of the reference.
7545 The temporaries created during the evaluation of the expression
7546 initializing the reference, except the temporary to which the
7547 reference is bound, are destroyed at the end of the
7548 full-expression in which they are created.
7550 In that case, we store the converted expression into a new
7551 VAR_DECL in a new scope.
7553 However, we want to be careful not to create temporaries when
7554 they are not required. For example, given:
7556 struct B {};
7557 struct D : public B {};
7558 D f();
7559 const B& b = f();
7561 there is no need to copy the return value from "f"; we can just
7562 extend its lifetime. Similarly, given:
7564 struct S {};
7565 struct T { operator S(); };
7566 T t;
7567 const S& s = t;
7569 we can extend the lifetime of the return value of the conversion
7570 operator. */
7573 {
7574 tree var;
7575 tree base_conv_type;
7577 /* Skip over the REF_BIND. */
7579 /* If the next conversion is a BASE_CONV, skip that too -- but
7580 remember that the conversion was required. */
7582 {
7585 }
7586 else
7588 /* Perform the remainder of the conversion. */
7594 tf_warning_or_error);
7597 else
7598 {
7600 {
7601 tree init;
7603 /* Use its address to initialize the reference variable. */
7611 }
7612 else
7613 /* Take the address of EXPR. */
7615 /* If a BASE_CONV was required, perform it now. */
7617 expr = (perform_implicit_conversion
7619 tf_warning_or_error));
7621 }
7622 }
7623 else
7624 /* Perform the conversion. */
7627 /* Free all the conversions we allocated. */
7631 }
7633 /* Returns true iff TYPE is some variant of std::initializer_list. */
7635 bool
7637 {
7641 }
7643 /* Returns true iff DECL is a list constructor: i.e. a constructor which
7644 will accept an argument list of a single std::initializer_list<T>. */
7646 bool
7648 {
7650 tree arg;
7662 /* There are more non-defaulted parms. */
7666 }