| blob | d74eb19580f08ac052feb669f566f44fd267ab5f |
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);
206 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
207 NAME can take many forms... */
209 bool
211 {
212 /* Just accept something we've already complained about. */
221 {
227 else
229 }
230 else
231 {
232 /* In the case of:
234 template <class T> struct S { ~S(); };
235 int i;
236 i.~S();
238 NAME will be a class template. */
241 }
246 }
248 /* We want the address of a function or method. We avoid creating a
249 pointer-to-member function. */
251 tree
253 {
256 /* We have to do these by hand to avoid real pointer to member
257 functions. */
259 {
261 {
265 }
267 }
268 else
272 }
274 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
275 POINTER_TYPE to those. Note, pointer to member function types
276 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
277 two variants. build_call_a is the primitive taking an array of
278 arguments, while build_call_n is a wrapper that handles varargs. */
280 tree
282 {
285 else
286 {
296 }
297 }
299 tree
301 {
304 tree decl;
305 tree result_type;
306 tree fntype;
316 /* An rvalue has no cv-qualifiers. */
322 {
325 {
326 /* We invoke build_call directly for several library
327 functions. These may have been declared normally if
328 we're building libgcc, so we can't just check
329 DECL_ARTIFICIAL. */
334 }
335 }
336 else
339 /* We check both the decl and the type; a function may be known not to
340 throw without being declared throw(). */
354 /* Don't pass empty class objects by value. This is useful
355 for tags in STL, which are used to control overload resolution.
356 We don't need to handle other cases of copying empty classes. */
361 {
365 }
373 }
375 /* Build something of the form ptr->method (args)
376 or object.method (args). This can also build
377 calls to constructors, and find friends.
379 Member functions always take their class variable
380 as a pointer.
382 INSTANCE is a class instance.
384 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
386 PARMS help to figure out what that NAME really refers to.
388 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
389 down to the real instance type to use for access checking. We need this
390 information to get protected accesses correct.
392 FLAGS is the logical disjunction of zero or more LOOKUP_
393 flags. See cp-tree.h for more info.
395 If this is all OK, calls build_function_call with the resolved
396 member function.
398 This function must also handle being called to perform
399 initialization, promotion/coercion of arguments, and
400 instantiation of default parameters.
402 Note that NAME may refer to an instance variable name. If
403 `operator()()' is defined for the type of that field, then we return
404 that result. */
406 /* New overloading code. */
414 };
417 /* The FUNCTION_DECL that will be called if this candidate is
418 selected by overload resolution. */
419 tree fn;
420 /* If not NULL_TREE, the first argument to use when calling this
421 function. */
422 tree first_arg;
423 /* The rest of the arguments to use when calling this function. If
424 there are no further arguments this may be NULL or it may be an
425 empty vector. */
427 /* The implicit conversion sequences for each of the arguments to
428 FN. */
430 /* The number of implicit conversion sequences. */
432 /* If FN is a user-defined conversion, the standard conversion
433 sequence from the type returned by FN to the desired destination
434 type. */
437 /* If FN is a member function, the binfo indicating the path used to
438 qualify the name of FN at the call site. This path is used to
439 determine whether or not FN is accessible if it is selected by
440 overload resolution. The DECL_CONTEXT of FN will always be a
441 (possibly improper) base of this binfo. */
442 tree access_path;
443 /* If FN is a non-static member function, the binfo indicating the
444 subobject to which the `this' pointer should be converted if FN
445 is selected by overload resolution. The type pointed to the by
446 the `this' pointer must correspond to the most derived class
447 indicated by the CONVERSION_PATH. */
448 tree conversion_path;
449 tree template_decl;
452 };
454 /* Returns true iff T is a null pointer constant in the sense of
455 [conv.ptr]. */
457 bool
459 {
460 /* [conv.ptr]
462 A null pointer constant is an integral constant expression
463 (_expr.const_) rvalue of integer type that evaluates to zero or
464 an rvalue of type std::nullptr_t. */
470 {
474 }
476 }
478 /* Returns nonzero if PARMLIST consists of only default parms and/or
479 ellipsis. */
481 bool
483 {
489 }
491 /* Allocate N bytes of memory from the conversion obstack. The memory
492 is zeroed before being returned. */
496 {
499 {
502 }
506 }
508 /* Dynamically allocate a conversion. */
512 {
517 }
519 #ifdef ENABLE_CHECKING
521 /* Make sure that all memory on the conversion obstack has been
522 freed. */
524 void
526 {
530 }
534 /* Dynamically allocate an array of N conversions. */
538 {
540 }
544 {
548 /* Note that the caller is responsible for filling in t->cand for
549 user-defined conversions. */
555 {
571 }
577 }
579 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
580 specialization of std::initializer_list<T>, if such a conversion is
581 possible. */
585 {
591 tree val;
594 {
595 conversion *sub
602 }
610 {
618 }
621 }
623 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
624 aggregate class, if such a conversion is possible. */
628 {
634 {
636 {
644 }
647 }
658 }
660 /* Build a representation of the identity conversion from EXPR to
661 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
665 {
673 }
675 /* Converting from EXPR to TYPE was ambiguous in the sense that there
676 were multiple user-defined conversions to accomplish the job.
677 Build a conversion that indicates that ambiguity. */
681 {
689 }
691 tree
693 {
697 }
699 /* Returns the standard conversion path (see [conv]) from type FROM to type
700 TO, if any. For proper handling of null pointer constants, you must
701 also pass the expression EXPR to convert from. If C_CAST_P is true,
702 this conversion is coming from a C-style cast. */
707 {
714 {
717 }
723 {
731 }
738 {
742 }
744 {
746 {
747 tree bitfield_type;
750 {
753 }
754 }
756 }
758 /* Allow conversion between `__complex__' data types. */
760 {
761 /* The standard conversion sequence to convert FROM to TO is
762 the standard conversion sequence to perform componentwise
763 conversion. */
768 {
771 }
772 else
776 }
781 /* [conv.ptr]
782 A null pointer constant can be converted to a pointer type; ... A
783 null pointer constant of integral type can be converted to an
784 rvalue of type std::nullptr_t. */
791 {
792 /* For backwards brain damage compatibility, allow interconversion of
793 pointers and integers with a pedwarn. */
796 }
798 {
799 /* For backwards brain damage compatibility, allow interconversion of
800 enums and integers with a pedwarn. */
803 }
806 {
807 tree to_pointee;
808 tree from_pointee;
813 ;
817 {
818 from = build_pointer_type
822 }
824 {
829 && (same_type_ignoring_top_level_qualifiers_p
832 {
836 }
839 }
842 /* [conv.ptr]
844 An rvalue of type "pointer to cv D," where D is a
845 class type, can be converted to an rvalue of type
846 "pointer to cv B," where B is a base class (clause
847 _class.derived_) of D. If B is an inaccessible
848 (clause _class.access_) or ambiguous
849 (_class.member.lookup_) base class of D, a program
850 that necessitates this conversion is ill-formed.
851 Therefore, we use DERIVED_FROM_P, and do not check
852 access or uniqueness. */
854 {
855 from =
861 }
864 {
867 }
868 else
869 {
872 }
877 /* In a C-style cast, we ignore CV-qualification because we
878 are allowed to perform a static_cast followed by a
879 const_cast. */
884 /* converting from string constant to char *. */
887 {
890 }
891 else
895 }
897 {
914 }
916 {
917 /* [conv.bool]
919 An rvalue of arithmetic, unscoped enumeration, pointer, or
920 pointer to member type can be converted to an rvalue of type
921 bool. ... An rvalue of type std::nullptr_t can be converted
922 to an rvalue of type bool; */
928 {
937 }
940 }
941 /* We don't check for ENUMERAL_TYPE here because there are no standard
942 conversions to enum type. */
943 /* As an extension, allow conversion to complex type. */
945 {
951 /* Give this a better rank if it's a promotion. */
955 }
961 {
965 /* The derived-to-base conversion indicates the initialization
966 of a parameter with base type from an object of a derived
967 type. A temporary object is created to hold the result of
968 the conversion unless we're binding directly to a reference. */
970 }
971 else
978 }
980 /* Returns nonzero if T1 is reference-related to T2. */
982 bool
984 {
988 /* [dcl.init.ref]
990 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
991 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
992 of T2. */
996 }
998 /* Returns nonzero if T1 is reference-compatible with T2. */
1000 static bool
1002 {
1003 /* [dcl.init.ref]
1005 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
1006 reference-related to T2 and cv1 is the same cv-qualification as,
1007 or greater cv-qualification than, cv2. */
1010 }
1012 /* Determine whether or not the EXPR (of class type S) can be
1013 converted to T as in [over.match.ref]. */
1017 {
1018 tree conversions;
1019 tree first_arg;
1021 tree t;
1030 /* [over.match.ref]
1032 Assuming that "cv1 T" is the underlying type of the reference
1033 being initialized, and "cv S" is the type of the initializer
1034 expression, with S a class type, the candidate functions are
1035 selected as follows:
1037 --The conversion functions of S and its base classes are
1038 considered. Those that are not hidden within S and yield type
1039 "reference to cv2 T2", where "cv1 T" is reference-compatible
1040 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1042 The argument list has one argument, which is the initializer
1043 expression. */
1047 /* Conceptually, we should take the address of EXPR and put it in
1048 the argument list. Unfortunately, however, that can result in
1049 error messages, which we should not issue now because we are just
1050 trying to find a conversion operator. Therefore, we use NULL,
1051 cast to the appropriate type. */
1057 {
1061 {
1071 /* If this is a template function, try to get an exact
1072 match. */
1074 {
1077 NULL_TREE,
1078 first_arg,
1079 NULL,
1080 reference_type,
1083 LOOKUP_NORMAL,
1084 DEDUCE_CONV);
1087 {
1088 /* Now, see if the conversion function really returns
1089 an lvalue of the appropriate type. From the
1090 point of view of unification, simply returning an
1091 rvalue of the right type is good enough. */
1096 {
1099 }
1100 }
1101 }
1107 LOOKUP_NORMAL);
1110 {
1112 /* Build a standard conversion sequence indicating the
1113 binding from the reference type returned by the
1114 function to the desired REFERENCE_TYPE. */
1115 identity_conv
1118 NULL_TREE);
1119 cand->second_conv
1120 = (direct_reference_binding
1127 /* Don't allow binding of lvalues to rvalue references. */
1131 }
1132 }
1133 }
1136 /* If none of the conversion functions worked out, let our caller
1137 know. */
1145 /* Now that we know that this is the function we're going to use fix
1146 the dummy first argument. */
1151 /* Build a user-defined conversion sequence representing the
1152 conversion. */
1161 /* Merge it with the standard conversion sequence from the
1162 conversion function's return type to the desired type. */
1166 }
1168 /* A reference of the indicated TYPE is being bound directly to the
1169 expression represented by the implicit conversion sequence CONV.
1170 Return a conversion sequence for this binding. */
1174 {
1175 tree t;
1182 /* [over.ics.rank]
1184 When a parameter of reference type binds directly
1185 (_dcl.init.ref_) to an argument expression, the implicit
1186 conversion sequence is the identity conversion, unless the
1187 argument expression has a type that is a derived class of the
1188 parameter type, in which case the implicit conversion sequence is
1189 a derived-to-base Conversion.
1191 If the parameter binds directly to the result of applying a
1192 conversion function to the argument expression, the implicit
1193 conversion sequence is a user-defined conversion sequence
1194 (_over.ics.user_), with the second standard conversion sequence
1195 either an identity conversion or, if the conversion function
1196 returns an entity of a type that is a derived class of the
1197 parameter type, a derived-to-base conversion. */
1199 {
1200 /* Represent the derived-to-base conversion. */
1202 /* We will actually be binding to the base-class subobject in
1203 the derived class, so we mark this conversion appropriately.
1204 That way, convert_like knows not to generate a temporary. */
1206 }
1208 }
1210 /* Returns the conversion path from type FROM to reference type TO for
1211 purposes of reference binding. For lvalue binding, either pass a
1212 reference type to FROM or an lvalue expression to EXPR. If the
1213 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1214 the conversion returned. If C_CAST_P is true, this
1215 conversion is coming from a C-style cast. */
1219 {
1223 tree tfrom;
1229 {
1234 }
1237 {
1238 /* Anything with reference type is an lvalue. */
1241 }
1244 {
1247 flags);
1250 {
1255 }
1256 }
1265 /* Figure out whether or not the types are reference-related and
1266 reference compatible. We have do do this after stripping
1267 references from FROM. */
1269 /* If this is a C cast, first convert to an appropriately qualified
1270 type, so that we can later do a const_cast to the desired type. */
1276 /* Directly bind reference when target expression's type is compatible with
1277 the reference and expression is an lvalue. In DR391, the wording in
1278 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1279 const and rvalue references to rvalues of compatible class type.
1280 We should also do direct bindings for non-class "rvalues" derived from
1281 rvalue references. */
1283 && (is_lvalue
1288 {
1289 /* [dcl.init.ref]
1291 If the initializer expression
1293 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1294 is reference-compatible with "cv2 T2,"
1296 the reference is bound directly to the initializer expression
1297 lvalue.
1299 [...]
1300 If the initializer expression is an rvalue, with T2 a class type,
1301 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1302 is bound to the object represented by the rvalue or to a sub-object
1303 within that object. */
1309 /* The top-level caller requested that we pretend that the lvalue
1310 be treated as an rvalue. */
1312 else
1313 conv->rvaluedness_matches_p
1318 /* For the purposes of overload resolution, we ignore the fact
1319 this expression is a bitfield or packed field. (In particular,
1320 [over.ics.ref] says specifically that a function with a
1321 non-const reference parameter is viable even if the
1322 argument is a bitfield.)
1324 However, when we actually call the function we must create
1325 a temporary to which to bind the reference. If the
1326 reference is volatile, or isn't const, then we cannot make
1327 a temporary, so we just issue an error when the conversion
1328 actually occurs. */
1331 /* Don't allow binding of lvalues to rvalue references. */
1337 }
1338 /* [class.conv.fct] A conversion function is never used to convert a
1339 (possibly cv-qualified) object to the (possibly cv-qualified) same
1340 object type (or a reference to it), to a (possibly cv-qualified) base
1341 class of that type (or a reference to it).... */
1344 {
1345 /* [dcl.init.ref]
1347 If the initializer expression
1349 -- has a class type (i.e., T2 is a class type) can be
1350 implicitly converted to an lvalue of type "cv3 T3," where
1351 "cv1 T1" is reference-compatible with "cv3 T3". (this
1352 conversion is selected by enumerating the applicable
1353 conversion functions (_over.match.ref_) and choosing the
1354 best one through overload resolution. (_over.match_).
1356 the reference is bound to the lvalue result of the conversion
1357 in the second case. */
1361 }
1363 /* From this point on, we conceptually need temporaries, even if we
1364 elide them. Only the cases above are "direct bindings". */
1368 /* [over.ics.rank]
1370 When a parameter of reference type is not bound directly to an
1371 argument expression, the conversion sequence is the one required
1372 to convert the argument expression to the underlying type of the
1373 reference according to _over.best.ics_. Conceptually, this
1374 conversion sequence corresponds to copy-initializing a temporary
1375 of the underlying type with the argument expression. Any
1376 difference in top-level cv-qualification is subsumed by the
1377 initialization itself and does not constitute a conversion. */
1379 /* [dcl.init.ref]
1381 Otherwise, the reference shall be to a non-volatile const type.
1383 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1387 /* [dcl.init.ref]
1389 Otherwise, a temporary of type "cv1 T1" is created and
1390 initialized from the initializer expression using the rules for a
1391 non-reference copy initialization. If T1 is reference-related to
1392 T2, cv1 must be the same cv-qualification as, or greater
1393 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1397 /* We're generating a temporary now, but don't bind any more in the
1398 conversion (specifically, don't slice the temporary returned by a
1399 conversion operator). */
1402 /* Temporaries are copy-initialized, except for this hack to allow
1403 explicit conversion ops to the copy ctor. See also
1404 add_function_candidate. */
1410 flags);
1415 /* This reference binding, unlike those above, requires the
1416 creation of a temporary. */
1421 }
1423 /* Returns the implicit conversion sequence (see [over.ics]) from type
1424 FROM to type TO. The optional expression EXPR may affect the
1425 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1426 true, this conversion is coming from a C-style cast. */
1431 {
1440 else
1447 {
1451 /* Allow conversion from an initializer-list with one element to a
1452 scalar type. */
1454 {
1456 tree elt;
1462 else
1468 {
1471 /* Too many levels of braces, i.e. '{{1}}'. */
1474 }
1475 }
1476 }
1482 {
1495 /* We used to try to bind a reference to a temporary here, but that
1496 is now handled after the recursive call to this function at the end
1497 of reference_binding. */
1499 }
1502 }
1504 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1505 functions. ARGS will not be changed until a single candidate is
1506 selected. */
1514 {
1530 }
1532 /* Create an overload candidate for the function or method FN called
1533 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1534 FLAGS is passed on to implicit_conversion.
1536 This does not change ARGS.
1538 CTYPE, if non-NULL, is the type we want to pretend this function
1539 comes from for purposes of overload resolution. */
1546 {
1550 tree parmnode;
1555 /* At this point we should not see any functions which haven't been
1556 explicitly declared, except for friend functions which will have
1557 been found using argument dependent lookup. */
1560 /* The `this', `in_chrg' and VTT arguments to constructors are not
1561 considered in overload resolution. */
1563 {
1567 {
1570 }
1571 }
1572 else
1578 /* 13.3.2 - Viable functions [over.match.viable]
1579 First, to be a viable function, a candidate function shall have enough
1580 parameters to agree in number with the arguments in the list.
1582 We need to check this first; otherwise, checking the ICSes might cause
1583 us to produce an ill-formed template instantiation. */
1587 {
1591 }
1596 /* Make sure there are default args for the rest of the parms. */
1603 /* Second, for F to be a viable function, there shall exist for each
1604 argument an implicit conversion sequence that converts that argument
1605 to the corresponding parameter of F. */
1610 {
1620 else
1629 {
1633 /* The type of the implicit object parameter ('this') for
1634 overload resolution is not always the same as for the
1635 function itself; conversion functions are considered to
1636 be members of the class being converted, and functions
1637 introduced by a using-declaration are considered to be
1638 members of the class that uses them.
1640 Since build_over_call ignores the ICS for the `this'
1641 parameter, we can just change the parm type. */
1643 {
1644 parmtype
1648 }
1652 {
1653 /* Hack: Direct-initialize copy parm (i.e. suppress
1654 LOOKUP_ONLYCONVERTING) to make explicit conversion ops
1655 work. See also reference_binding. */
1659 }
1660 else
1665 }
1666 else
1667 {
1670 }
1677 {
1680 }
1687 }
1689 out:
1692 }
1694 /* Create an overload candidate for the conversion function FN which will
1695 be invoked for expression OBJ, producing a pointer-to-function which
1696 will in turn be called with the argument list FIRST_ARG/ARGLIST,
1697 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
1698 passed on to implicit_conversion.
1700 Actually, we don't really care about FN; we care about the type it
1701 converts to. There may be multiple conversion functions that will
1702 convert to that type, and we rely on build_user_type_conversion_1 to
1703 choose the best one; so when we create our candidate, we record the type
1704 instead of the function. */
1710 {
1726 /* Don't bother looking up the same type twice. */
1731 {
1739 else
1746 flags);
1752 else
1753 {
1756 }
1770 }
1780 }
1782 static void
1786 {
1799 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
1800 conversion ops are allowed. We handle that here by just checking for
1801 boolean_type_node because other operators don't ask for it. COND_EXPR
1802 also does contextual conversion to bool for the first operand, but we
1803 handle that in build_conditional_expr, and type1 here is operand 2. */
1808 {
1815 {
1817 /* We need something for printing the candidate. */
1819 }
1823 }
1825 /* For COND_EXPR we rearranged the arguments; undo that now. */
1827 {
1834 else
1836 }
1842 viable);
1843 }
1845 static bool
1847 {
1849 }
1851 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1853 static bool
1855 {
1856 /* [over.built]
1858 In this section, the term promoted integral type is used to refer
1859 to those integral types which are preserved by integral promotion
1860 (including e.g. int and long but excluding e.g. char).
1861 Similarly, the term promoted arithmetic type refers to promoted
1862 integral types plus floating types. */
1866 }
1868 /* Create any builtin operator overload candidates for the operator in
1869 question given the converted operand types TYPE1 and TYPE2. The other
1870 args are passed through from add_builtin_candidates to
1871 build_builtin_candidate.
1873 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1874 If CODE is requires candidates operands of the same type of the kind
1875 of which TYPE1 and TYPE2 are, we add both candidates
1876 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1878 static void
1882 {
1884 {
1892 }
1895 {
1897 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1898 and VQ is either volatile or empty, there exist candidate operator
1899 functions of the form
1900 VQ T& operator++(VQ T&);
1901 T operator++(VQ T&, int);
1902 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1903 type other than bool, and VQ is either volatile or empty, there exist
1904 candidate operator functions of the form
1905 VQ T& operator--(VQ T&);
1906 T operator--(VQ T&, int);
1907 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1908 complete object type, and VQ is either volatile or empty, there exist
1909 candidate operator functions of the form
1910 T*VQ& operator++(T*VQ&);
1911 T*VQ& operator--(T*VQ&);
1912 T* operator++(T*VQ&, int);
1913 T* operator--(T*VQ&, int); */
1922 {
1925 }
1928 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1929 exist candidate operator functions of the form
1931 T& operator*(T*);
1933 8 For every function type T, there exist candidate operator functions of
1934 the form
1935 T& operator*(T*); */
1944 /* 9 For every type T, there exist candidate operator functions of the form
1945 T* operator+(T*);
1947 10For every promoted arithmetic type T, there exist candidate operator
1948 functions of the form
1949 T operator+(T);
1950 T operator-(T); */
1960 /* 11For every promoted integral type T, there exist candidate operator
1961 functions of the form
1962 T operator~(T); */
1969 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1970 is the same type as C2 or is a derived class of C2, T is a complete
1971 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1972 there exist candidate operator functions of the form
1973 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1974 where CV12 is the union of CV1 and CV2. */
1979 {
1987 }
1990 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1991 didate operator functions of the form
1992 LR operator*(L, R);
1993 LR operator/(L, R);
1994 LR operator+(L, R);
1995 LR operator-(L, R);
1996 bool operator<(L, R);
1997 bool operator>(L, R);
1998 bool operator<=(L, R);
1999 bool operator>=(L, R);
2000 bool operator==(L, R);
2001 bool operator!=(L, R);
2002 where LR is the result of the usual arithmetic conversions between
2003 types L and R.
2005 14For every pair of types T and I, where T is a cv-qualified or cv-
2006 unqualified complete object type and I is a promoted integral type,
2007 there exist candidate operator functions of the form
2008 T* operator+(T*, I);
2009 T& operator[](T*, I);
2010 T* operator-(T*, I);
2011 T* operator+(I, T*);
2012 T& operator[](I, T*);
2014 15For every T, where T is a pointer to complete object type, there exist
2015 candidate operator functions of the form112)
2016 ptrdiff_t operator-(T, T);
2018 16For every pointer or enumeration type T, there exist candidate operator
2019 functions of the form
2020 bool operator<(T, T);
2021 bool operator>(T, T);
2022 bool operator<=(T, T);
2023 bool operator>=(T, T);
2024 bool operator==(T, T);
2025 bool operator!=(T, T);
2027 17For every pointer to member type T, there exist candidate operator
2028 functions of the form
2029 bool operator==(T, T);
2030 bool operator!=(T, T); */
2037 {
2040 }
2053 {
2056 }
2058 {
2061 }
2062 /* Fall through. */
2079 {
2082 }
2086 {
2089 }
2097 {
2100 }
2102 {
2105 }
2108 /* 18For every pair of promoted integral types L and R, there exist candi-
2109 date operator functions of the form
2110 LR operator%(L, R);
2111 LR operator&(L, R);
2112 LR operator^(L, R);
2113 LR operator|(L, R);
2114 L operator<<(L, R);
2115 L operator>>(L, R);
2116 where LR is the result of the usual arithmetic conversions between
2117 types L and R. */
2125 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2129 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2130 type, VQ is either volatile or empty, and R is a promoted arithmetic
2131 type, there exist candidate operator functions of the form
2132 VQ L& operator=(VQ L&, R);
2133 VQ L& operator*=(VQ L&, R);
2134 VQ L& operator/=(VQ L&, R);
2135 VQ L& operator+=(VQ L&, R);
2136 VQ L& operator-=(VQ L&, R);
2138 20For every pair T, VQ), where T is any type and VQ is either volatile
2139 or empty, there exist candidate operator functions of the form
2140 T*VQ& operator=(T*VQ&, T*);
2142 21For every pair T, VQ), where T is a pointer to member type and VQ is
2143 either volatile or empty, there exist candidate operator functions of
2144 the form
2145 VQ T& operator=(VQ T&, T);
2147 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2148 unqualified complete object type, VQ is either volatile or empty, and
2149 I is a promoted integral type, there exist candidate operator func-
2150 tions of the form
2151 T*VQ& operator+=(T*VQ&, I);
2152 T*VQ& operator-=(T*VQ&, I);
2154 23For every triple L, VQ, R), where L is an integral or enumeration
2155 type, VQ is either volatile or empty, and R is a promoted integral
2156 type, there exist candidate operator functions of the form
2158 VQ L& operator%=(VQ L&, R);
2159 VQ L& operator<<=(VQ L&, R);
2160 VQ L& operator>>=(VQ L&, R);
2161 VQ L& operator&=(VQ L&, R);
2162 VQ L& operator^=(VQ L&, R);
2163 VQ L& operator|=(VQ L&, R); */
2167 {
2171 {
2174 }
2187 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2200 {
2203 }
2208 }
2213 /* [over.built]
2215 For every pair of promoted arithmetic types L and R, there
2216 exist candidate operator functions of the form
2218 LR operator?(bool, L, R);
2220 where LR is the result of the usual arithmetic conversions
2221 between types L and R.
2223 For every type T, where T is a pointer or pointer-to-member
2224 type, there exist candidate operator functions of the form T
2225 operator?(bool, T, T); */
2229 /* That's OK. */
2232 /* Otherwise, the types should be pointers. */
2237 /* We don't check that the two types are the same; the logic
2238 below will actually create two candidates; one in which both
2239 parameter types are TYPE1, and one in which both parameter
2240 types are TYPE2. */
2245 }
2247 /* If we're dealing with two pointer types or two enumeral types,
2248 we need candidates for both of them. */
2257 {
2258 build_builtin_candidate
2260 build_builtin_candidate
2263 }
2265 build_builtin_candidate
2267 }
2269 tree
2271 {
2279 }
2281 /* There are three conditions of builtin candidates:
2283 1) bool-taking candidates. These are the same regardless of the input.
2284 2) pointer-pair taking candidates. These are generated for each type
2285 one of the input types converts to.
2286 3) arithmetic candidates. According to the standard, we should generate
2287 all of these, but I'm trying not to...
2289 Here we generate a superset of the possible candidates for this particular
2290 case. That is a subset of the full set the standard defines, plus some
2291 other cases which the standard disallows. add_builtin_candidate will
2292 filter out the invalid set. */
2294 static void
2298 {
2302 /* TYPES[i] is the set of possible builtin-operator parameter types
2303 we will consider for the Ith argument. These are represented as
2304 a TREE_LIST; the TREE_VALUE of each node is the potential
2305 parameter type. */
2309 {
2312 else
2314 }
2317 {
2318 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2319 and VQ is either volatile or empty, there exist candidate operator
2320 functions of the form
2321 VQ T& operator++(VQ T&); */
2331 /* 24There also exist candidate operator functions of the form
2332 bool operator!(bool);
2333 bool operator&&(bool, bool);
2334 bool operator||(bool, bool); */
2337 build_builtin_candidate
2344 build_builtin_candidate
2362 /* Fall through. */
2366 }
2371 {
2373 ;
2375 {
2376 tree convs;
2385 {
2392 }
2398 {
2411 {
2417 }
2421 }
2422 }
2423 else
2424 {
2430 {
2436 }
2438 }
2439 }
2441 /* Run through the possible parameter types of both arguments,
2442 creating candidates with those parameter types. */
2444 {
2447 add_builtin_candidate
2450 else
2451 add_builtin_candidate
2454 }
2455 }
2458 /* If TMPL can be successfully instantiated as indicated by
2459 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2461 TMPL is the template. EXPLICIT_TARGS are any explicit template
2462 arguments. ARGLIST is the arguments provided at the call-site.
2463 This does not change ARGLIST. The RETURN_TYPE is the desired type
2464 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2465 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2466 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2474 {
2484 tree arg;
2487 tree fn;
2489 /* We don't do deduction on the in-charge parameter, the VTT
2490 parameter or 'this'. */
2492 {
2495 else
2497 }
2502 {
2505 else
2507 }
2517 {
2520 }
2524 {
2527 }
2531 args_without_in_chrg,
2532 nargs_without_in_chrg,
2542 /* In [class.copy]:
2544 A member function template is never instantiated to perform the
2545 copy of a class object to an object of its class type.
2547 It's a little unclear what this means; the standard explicitly
2548 does allow a template to be used to copy a class. For example,
2549 in:
2551 struct A {
2552 A(A&);
2553 template <class T> A(const T&);
2554 };
2555 const A f ();
2556 void g () { A a (f ()); }
2558 the member template will be used to make the copy. The section
2559 quoted above appears in the paragraph that forbids constructors
2560 whose only parameter is (a possibly cv-qualified variant of) the
2561 class type, and a logical interpretation is that the intent was
2562 to forbid the instantiation of member templates which would then
2563 have that form. */
2565 {
2568 ctype))
2570 }
2573 /* Aha, this is a conversion function. */
2576 else
2581 /* This situation can occur if a member template of a template
2582 class is specialized. Then, instantiate_template might return
2583 an instantiation of the specialization, in which case the
2584 DECL_TI_TEMPLATE field will point at the original
2585 specialization. For example:
2587 template <class T> struct S { template <class U> void f(U);
2588 template <> void f(int) {}; };
2589 S<double> sd;
2590 sd.f(3);
2592 Here, TMPL will be template <class U> S<double>::f(U).
2593 And, instantiate template will give us the specialization
2594 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2595 for this will point at template <class T> template <> S<T>::f(int),
2596 so that we can find the definition. For the purposes of
2597 overload resolution, however, we want the original TMPL. */
2599 else
2603 }
2611 unification_kind_t strict)
2612 {
2613 return
2618 }
2626 tree conversion_path)
2627 {
2628 return
2632 }
2634 /* The CANDS are the set of candidates that were considered for
2635 overload resolution. Return the set of viable candidates. If none
2636 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2637 is true if a candidate should be considered viable only if it is
2638 strictly viable. */
2644 {
2655 {
2658 {
2664 }
2665 else
2667 }
2670 }
2672 static bool
2674 {
2679 }
2681 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2682 words, it is about to become the "this" pointer for a member
2683 function call. Take the address of the object. */
2685 static tree
2687 {
2688 /* In a template, we are only concerned about the type of the
2689 expression, so we can take a shortcut. */
2694 }
2696 /* Returns true iff functions are equivalent. Equivalent functions are
2697 not '==' only if one is a function-local extern function or if
2698 both are extern "C". */
2702 {
2707 }
2709 /* Print information about one overload candidate CANDIDATE. MSGSTR
2710 is the text to print before the candidate itself.
2712 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2713 to have been run through gettext by the caller. This wart makes
2714 life simpler in print_z_candidates and for the translators. */
2716 static void
2718 {
2720 {
2730 else
2733 }
2740 else
2742 }
2744 static void
2746 {
2755 /* Remove deleted candidates. */
2758 {
2762 else
2764 }
2765 /* ...if there are any non-deleted ones. */
2769 /* There may be duplicates in the set of candidates. We put off
2770 checking this condition as long as possible, since we have no way
2771 to eliminate duplicates from a set of functions in less than n^2
2772 time. Now we are about to emit an error message, so it is more
2773 permissible to go slowly. */
2775 {
2777 /* Skip builtin candidates and conversion functions. */
2782 {
2786 else
2788 }
2789 }
2794 {
2797 }
2799 }
2801 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2802 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2803 the result of the conversion function to convert it to the final
2804 desired type. Merge the two sequences into a single sequence,
2805 and return the merged sequence. */
2809 {
2814 /* Find the end of the second conversion sequence. */
2819 /* Replace the identity conversion with the user conversion
2820 sequence. */
2823 /* The entire sequence is a user-conversion sequence. */
2827 }
2829 /* Returns the best overload candidate to perform the requested
2830 conversion. This function is used for three the overloading situations
2831 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2832 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2833 per [dcl.init.ref], so we ignore temporary bindings. */
2837 {
2848 /* We represent conversion within a hierarchy using RVALUE_CONV and
2849 BASE_CONV, as specified by [over.best.ics]; these become plain
2850 constructor calls, as specified in [dcl.init]. */
2858 {
2863 {
2864 /* [class.conv.fct] A conversion function is never used to
2865 convert a (possibly cv-qualified) object to the (possibly
2866 cv-qualified) same object type (or a reference to it), to a
2867 (possibly cv-qualified) base class of that type (or a
2868 reference to it)... */
2869 }
2870 else
2873 }
2878 /* It's OK to bind a temporary for converting constructor arguments, but
2879 not in converting the return value of a conversion operator. */
2884 {
2890 {
2892 /* We still allow more conversions within an init-list. */
2894 /* But not for the copy ctor. */
2895 |LOOKUP_NO_COPY_CTOR_CONVERSION
2897 }
2898 else
2901 /* We should never try to call the abstract or base constructor
2902 from here. */
2905 }
2907 {
2918 flags,
2919 DEDUCE_CALL);
2920 else
2924 flags);
2927 {
2930 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
2931 set, then this is copy-initialization. In that case, "The
2932 result of the call is then used to direct-initialize the
2933 object that is the destination of the copy-initialization."
2934 [dcl.init]
2936 We represent this in the conversion sequence with an
2937 rvalue conversion, which means a constructor call. */
2940 cand->second_conv
2942 }
2943 }
2949 {
2950 tree fns;
2953 /* If we are called to convert to a reference type, we are trying to
2954 find an lvalue binding, so don't even consider temporaries. If
2955 we don't find an lvalue binding, the caller will try again to
2956 look for a temporary binding. */
2961 {
2968 /* [over.match.funcs] For conversion functions, the function
2969 is considered to be a member of the class of the implicit
2970 object argument for the purpose of defining the type of
2971 the implicit object parameter.
2973 So we pass fromtype as CTYPE to add_*_candidate. */
2977 NULL_TREE,
2980 conversion_path,
2981 flags,
2982 DEDUCE_CONV);
2983 else
2987 conversion_path,
2988 flags);
2991 {
2992 conversion *ics
2998 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
2999 copy-initialization. In that case, "The result of the
3000 call is then used to direct-initialize the object that is
3001 the destination of the copy-initialization." [dcl.init]
3003 We represent this in the conversion sequence with an
3004 rvalue conversion, which means a constructor call. But
3005 don't add a second rvalue conversion if there's already
3006 one there. Which there really shouldn't be, but it's
3007 harmless since we'd add it here anyway. */
3018 }
3019 }
3020 }
3028 {
3030 {
3034 }
3041 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
3042 ambiguous conversion is no worse than another user-defined
3043 conversion. */
3046 }
3048 /* Build the user conversion sequence. */
3049 conv = build_conv
3056 /* Remember that this was a list-initialization. */
3060 /* Combine it with the second conversion sequence. */
3068 }
3070 tree
3072 {
3077 {
3082 }
3084 }
3086 /* Do any initial processing on the arguments to a function call. */
3090 {
3092 tree arg;
3095 {
3099 {
3102 }
3105 }
3107 }
3109 /* Perform overload resolution on FN, which is called with the ARGS.
3111 Return the candidate function selected by overload resolution, or
3112 NULL if the event that overload resolution failed. In the case
3113 that overload resolution fails, *CANDIDATES will be the set of
3114 candidates considered, and ANY_VIABLE_P will be set to true or
3115 false to indicate whether or not any of the candidates were
3116 viable.
3118 The ARGS should already have gone through RESOLVE_ARGS before this
3119 function is called. */
3126 {
3134 /* Check FN. */
3141 {
3145 }
3147 /* Add the various candidate functions. */
3151 LOOKUP_NORMAL,
3152 candidates);
3160 }
3162 /* Return an expression for a call to FN (a namespace-scope function,
3163 or a static member function) with the ARGS. This may change
3164 ARGS. */
3166 tree
3168 tsubst_flags_t complain)
3169 {
3173 tree result;
3176 {
3180 }
3182 /* If this function was found without using argument dependent
3183 lookup, then we want to ignore any undeclared friend
3184 functions. */
3186 {
3191 {
3197 }
3198 }
3200 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3206 {
3208 {
3216 else
3221 }
3223 }
3224 else
3227 /* Free all the conversions we allocated. */
3231 }
3233 /* Build a call to a global operator new. FNNAME is the name of the
3234 operator (either "operator new" or "operator new[]") and ARGS are
3235 the arguments provided. This may change ARGS. *SIZE points to the
3236 total number of bytes required by the allocation, and is updated if
3237 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
3238 be used. If this function determines that no cookie should be
3239 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is
3240 non-NULL, it will be set, upon return, to the allocation function
3241 called. */
3243 tree
3247 {
3248 tree fns;
3260 /* Based on:
3262 [expr.new]
3264 If this lookup fails to find the name, or if the allocated type
3265 is not a class type, the allocation function's name is looked
3266 up in the global scope.
3268 we disregard block-scope declarations of "operator new". */
3271 /* Figure out what function is being called. */
3274 /* If no suitable function could be found, issue an error message
3275 and give up. */
3277 {
3281 else
3287 }
3289 /* If a cookie is required, add some extra space. Whether
3290 or not a cookie is required cannot be determined until
3291 after we know which function was called. */
3293 {
3296 {
3297 /* In G++ 3.2, the check was implemented incorrectly; it
3298 looked at the placement expression, rather than the
3299 type of the function. */
3302 ptr_type_node))
3304 }
3305 else
3306 {
3307 tree arg_types;
3310 /* Skip the size_t parameter. */
3312 /* Check the remaining parameters (if any). */
3316 ptr_type_node))
3318 }
3319 /* If we need a cookie, adjust the number of bytes allocated. */
3321 {
3322 /* Update the total size. */
3324 /* Update the argument list to reflect the adjusted size. */
3326 }
3327 else
3329 }
3331 /* Tell our caller which function we decided to call. */
3335 /* Build the CALL_EXPR. */
3337 }
3339 /* Build a new call to operator(). This may change ARGS. */
3341 tree
3343 {
3357 {
3359 /* It's no good looking for an overloaded operator() on a
3360 pointer-to-member-function. */
3361 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3363 }
3366 {
3370 }
3371 else
3375 {
3379 }
3381 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3385 {
3390 {
3399 else
3400 add_function_candidate
3403 }
3404 }
3409 {
3421 {
3428 add_template_conv_candidate
3432 else
3436 }
3437 }
3441 {
3443 {
3447 }
3449 }
3450 else
3451 {
3454 {
3456 {
3460 }
3462 }
3463 /* Since cand->fn will be a type, not a function, for a conversion
3464 function, we must be careful not to unconditionally look at
3465 DECL_NAME here. */
3469 else
3470 {
3472 complain);
3475 }
3476 }
3478 /* Free all the conversions we allocated. */
3482 }
3484 static void
3487 {
3492 else
3496 {
3501 else
3511 else
3520 else
3530 else
3540 else
3543 else
3547 else
3551 }
3552 }
3554 /* Return the implicit conversion sequence that could be used to
3555 convert E1 to E2 in [expr.cond]. */
3559 {
3565 /* [expr.cond]
3567 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3568 implicitly converted (clause _conv_) to the type "reference to
3569 T2", subject to the constraint that in the conversion the
3570 reference must bind directly (_dcl.init.ref_) to E1. */
3572 {
3574 t1,
3575 e1,
3580 }
3582 /* [expr.cond]
3584 If E1 and E2 have class type, and the underlying class types are
3585 the same or one is a base class of the other: E1 can be converted
3586 to match E2 if the class of T2 is the same type as, or a base
3587 class of, the class of T1, and the cv-qualification of T2 is the
3588 same cv-qualification as, or a greater cv-qualification than, the
3589 cv-qualification of T1. If the conversion is applied, E1 is
3590 changed to an rvalue of type T2 that still refers to the original
3591 source class object (or the appropriate subobject thereof). */
3594 {
3596 {
3601 else
3604 }
3605 else
3607 }
3608 else
3609 /* [expr.cond]
3611 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3612 converted to the type that expression E2 would have if E2 were
3613 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3615 LOOKUP_IMPLICIT);
3616 }
3618 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3619 arguments to the conditional expression. */
3621 tree
3623 tsubst_flags_t complain)
3624 {
3625 tree arg2_type;
3626 tree arg3_type;
3628 tree result_save;
3635 /* As a G++ extension, the second argument to the conditional can be
3636 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3637 c'.) If the second operand is omitted, make sure it is
3638 calculated only once. */
3640 {
3645 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3648 else
3650 }
3652 /* [expr.cond]
3654 The first expression is implicitly converted to bool (clause
3655 _conv_). */
3657 LOOKUP_NORMAL);
3659 /* If something has already gone wrong, just pass that fact up the
3660 tree. */
3666 /* [expr.cond]
3668 If either the second or the third operand has type (possibly
3669 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3670 array-to-pointer (_conv.array_), and function-to-pointer
3671 (_conv.func_) standard conversions are performed on the second
3672 and third operands. */
3676 {
3677 /* Do the conversions. We don't these for `void' type arguments
3678 since it can't have any effect and since decay_conversion
3679 does not handle that case gracefully. */
3687 /* [expr.cond]
3689 One of the following shall hold:
3691 --The second or the third operand (but not both) is a
3692 throw-expression (_except.throw_); the result is of the
3693 type of the other and is an rvalue.
3695 --Both the second and the third operands have type void; the
3696 result is of type void and is an rvalue.
3698 We must avoid calling force_rvalue for expressions of type
3699 "void" because it will complain that their value is being
3700 used. */
3703 {
3708 }
3711 {
3716 }
3719 else
3720 {
3722 {
3725 "is of type %<void%>, "
3726 "but the third operand is neither a throw-expression "
3728 else
3730 "is of type %<void%>, "
3731 "but the second operand is neither a throw-expression "
3733 }
3735 }
3739 }
3740 /* [expr.cond]
3742 Otherwise, if the second and third operand have different types,
3743 and either has (possibly cv-qualified) class type, an attempt is
3744 made to convert each of those operands to the type of the other. */
3747 {
3751 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3757 /* [expr.cond]
3759 If both can be converted, or one can be converted but the
3760 conversion is ambiguous, the program is ill-formed. If
3761 neither can be converted, the operands are left unchanged and
3762 further checking is performed as described below. If exactly
3763 one conversion is possible, that conversion is applied to the
3764 chosen operand and the converted operand is used in place of
3765 the original operand for the remainder of this section. */
3770 {
3774 }
3776 {
3780 /* Even if CONV2 is a valid conversion, the result of the
3781 conversion may be invalid. For example, if ARG3 has type
3782 "volatile X", and X does not have a copy constructor
3783 accepting a "volatile X&", then even if ARG2 can be
3784 converted to X, the conversion will fail. */
3787 }
3789 {
3795 }
3797 /* Free all the conversions we allocated. */
3803 /* If, after the conversion, both operands have class type,
3804 treat the cv-qualification of both operands as if it were the
3805 union of the cv-qualification of the operands.
3807 The standard is not clear about what to do in this
3808 circumstance. For example, if the first operand has type
3809 "const X" and the second operand has a user-defined
3810 conversion to "volatile X", what is the type of the second
3811 operand after this step? Making it be "const X" (matching
3812 the first operand) seems wrong, as that discards the
3813 qualification without actually performing a copy. Leaving it
3814 as "volatile X" seems wrong as that will result in the
3815 conditional expression failing altogether, even though,
3816 according to this step, the one operand could be converted to
3817 the type of the other. */
3825 }
3827 /* [expr.cond]
3829 If the second and third operands are lvalues and have the same
3830 type, the result is of that type and is an lvalue. */
3834 {
3837 }
3839 /* [expr.cond]
3841 Otherwise, the result is an rvalue. If the second and third
3842 operand do not have the same type, and either has (possibly
3843 cv-qualified) class type, overload resolution is used to
3844 determine the conversions (if any) to be applied to the operands
3845 (_over.match.oper_, _over.built_). */
3849 {
3854 /* Rearrange the arguments so that add_builtin_candidate only has
3855 to know about two args. In build_builtin_candidate, the
3856 arguments are unscrambled. */
3861 COND_EXPR,
3862 NOP_EXPR,
3864 args,
3865 LOOKUP_NORMAL);
3867 /* [expr.cond]
3869 If the overload resolution fails, the program is
3870 ill-formed. */
3873 {
3875 {
3878 }
3880 }
3883 {
3885 {
3888 }
3890 }
3892 /* [expr.cond]
3894 Otherwise, the conversions thus determined are applied, and
3895 the converted operands are used in place of the original
3896 operands for the remainder of this section. */
3905 }
3907 /* [expr.cond]
3909 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3910 and function-to-pointer (_conv.func_) standard conversions are
3911 performed on the second and third operands.
3913 We need to force the lvalue-to-rvalue conversion here for class types,
3914 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3915 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3916 regions. */
3929 /* [expr.cond]
3931 After those conversions, one of the following shall hold:
3933 --The second and third operands have the same type; the result is of
3934 that type. */
3937 /* [expr.cond]
3939 --The second and third operands have arithmetic or enumeration
3940 type; the usual arithmetic conversions are performed to bring
3941 them to a common type, and the result is of that type. */
3946 {
3947 /* In this case, there is always a common type. */
3949 arg3_type);
3953 {
3958 }
3964 {
3968 }
3972 }
3973 /* [expr.cond]
3975 --The second and third operands have pointer type, or one has
3976 pointer type and the other is a null pointer constant; pointer
3977 conversions (_conv.ptr_) and qualification conversions
3978 (_conv.qual_) are performed to bring them to their composite
3979 pointer type (_expr.rel_). The result is of the composite
3980 pointer type.
3982 --The second and third operands have pointer to member type, or
3983 one has pointer to member type and the other is a null pointer
3984 constant; pointer to member conversions (_conv.mem_) and
3985 qualification conversions (_conv.qual_) are performed to bring
3986 them to a common type, whose cv-qualification shall match the
3987 cv-qualification of either the second or the third operand.
3988 The result is of the common type. */
3996 {
3999 complain);
4004 }
4007 {
4012 }
4014 valid_operands:
4019 /* Avoid folding to a CALL_EXPR within decltype (c++/42013). */
4022 /* We can't use result_type below, as fold might have returned a
4023 throw_expr. */
4026 {
4027 /* Expand both sides into the same slot, hopefully the target of
4028 the ?: expression. We used to check for TARGET_EXPRs here,
4029 but now we sometimes wrap them in NOP_EXPRs so the test would
4030 fail. */
4033 /* If this expression is an rvalue, but might be mistaken for an
4034 lvalue, we must add a NON_LVALUE_EXPR. */
4036 }
4039 }
4041 /* OPERAND is an operand to an expression. Perform necessary steps
4042 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
4043 returned. */
4045 static tree
4047 {
4049 {
4052 /* Make sure the template type is instantiated now. */
4054 }
4057 }
4059 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
4060 OVERLOAD) to the CANDIDATES, returning an updated list of
4061 CANDIDATES. The ARGS are the arguments provided to the call,
4062 without any implicit object parameter. This may change ARGS. The
4063 EXPLICIT_TARGS are explicit template arguments provided.
4064 TEMPLATE_ONLY is true if only template functions should be
4065 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
4066 add_function_candidate. */
4068 static void
4074 {
4075 tree ctype;
4077 tree first_arg;
4080 /* Delay creating the implicit this parameter until it is needed. */
4085 {
4086 tree fn;
4087 tree fn_first_arg;
4091 /* Figure out which set of arguments to use. */
4093 {
4094 /* If this function is a non-static member, prepend the implicit
4095 object parameter. */
4097 {
4099 tree arg;
4105 }
4110 }
4111 else
4112 {
4113 /* Otherwise, just use the list of arguments provided. */
4116 }
4120 fn,
4121 ctype,
4122 explicit_targs,
4123 fn_first_arg,
4124 fn_args,
4125 NULL_TREE,
4126 access_path,
4127 conversion_path,
4128 flags,
4129 DEDUCE_CALL);
4132 fn,
4133 ctype,
4134 fn_first_arg,
4135 fn_args,
4136 access_path,
4137 conversion_path,
4138 flags);
4140 }
4141 }
4143 /* Even unsigned enum types promote to signed int. We don't want to
4144 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the
4145 original argument and ARG is the argument after any conversions
4146 have been applied. We set TREE_NO_WARNING if we have added a cast
4147 from an unsigned enum type to a signed integer type. */
4149 static void
4151 {
4160 }
4162 tree
4165 {
4171 tree fnname;
4189 {
4193 }
4194 else
4200 {
4205 /* Use build_op_new_call and build_op_delete_call instead. */
4209 /* Use build_op_call instead. */
4216 /* These are saved for the sake of warn_logical_operator. */
4222 }
4228 /* Use build_conditional_expr instead. */
4244 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4247 /* Add namespace-scope operators to the list of functions to
4248 consider. */
4252 /* Add class-member operators to the candidate set. */
4254 {
4255 tree fns;
4259 {
4262 }
4269 }
4278 {
4281 /* For these, the built-in candidates set is empty
4282 [over.match.oper]/3. We don't want non-strict matches
4283 because exact matches are always possible with built-in
4284 operators. The built-in candidate set for COMPONENT_REF
4285 would be empty too, but since there are no such built-in
4286 operators, we accept non-strict matches for them. */
4293 }
4297 {
4299 {
4302 /* Don't try anything fancy if we're not allowed to produce
4303 errors. */
4307 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
4308 distinguish between prefix and postfix ++ and
4309 operator++() was used for both, so we allow this with
4310 -fpermissive. */
4312 {
4319 }
4326 else
4332 /* The caller will deal with these. */
4342 {
4343 /* If one of the arguments of the operator represents
4344 an invalid use of member function pointer, try to report
4345 a meaningful error ... */
4350 else
4351 {
4352 /* ... Otherwise, report the more generic
4353 "no matching operator found" error */
4356 }
4357 }
4360 }
4361 }
4362 else
4363 {
4366 {
4368 {
4371 }
4373 }
4375 {
4381 else
4383 }
4384 else
4385 {
4386 /* Give any warnings we noticed during overload resolution. */
4388 {
4392 }
4394 /* Check for comparison of different enum types. */
4396 {
4408 {
4412 }
4416 }
4418 /* We need to strip any leading REF_BIND so that bitfields
4419 don't cause errors. This should not remove any important
4420 conversions, because builtins don't apply to class
4421 objects directly. */
4428 {
4429 /* We need to call warn_logical_operator before
4430 converting arg2 to a boolean_type. */
4440 }
4442 {
4447 }
4449 }
4450 }
4452 user_defined_result_ready:
4454 /* Free all the conversions we allocated. */
4460 builtin:
4466 {
4479 /* Fall through. */
4517 complain),
4518 arg2);
4520 /* The caller will deal with these. */
4528 }
4530 }
4532 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
4533 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
4535 static bool
4537 {
4538 /* A template instance is never a usual deallocation function,
4539 regardless of its signature. */
4544 /* If a class T has a member deallocation function named operator delete
4545 with exactly one parameter, then that function is a usual
4546 (non-placement) deallocation function. If class T does not declare
4547 such an operator delete but does declare a member deallocation
4548 function named operator delete with exactly two parameters, the second
4549 of which has type std::size_t (18.2), then this function is a usual
4550 deallocation function. */
4557 }
4559 /* Build a call to operator delete. This has to be handled very specially,
4560 because the restrictions on what signatures match are different from all
4561 other call instances. For a normal delete, only a delete taking (void *)
4562 or (void *, size_t) is accepted. For a placement delete, only an exact
4563 match with the placement new is accepted.
4565 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4566 ADDR is the pointer to be deleted.
4567 SIZE is the size of the memory block to be deleted.
4568 GLOBAL_P is true if the delete-expression should not consider
4569 class-specific delete operators.
4570 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4572 If this call to "operator delete" is being generated as part to
4573 deallocate memory allocated via a new-expression (as per [expr.new]
4574 which requires that if the initialization throws an exception then
4575 we call a deallocation function), then ALLOC_FN is the allocation
4576 function. */
4578 tree
4581 tree alloc_fn)
4582 {
4596 /* In [class.free]
4598 If the result of the lookup is ambiguous or inaccessible, or if
4599 the lookup selects a placement deallocation function, the
4600 program is ill-formed.
4602 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4603 {
4607 }
4608 else
4614 /* Strip const and volatile from addr. */
4618 {
4619 /* "A declaration of a placement deallocation function matches the
4620 declaration of a placement allocation function if it has the same
4621 number of parameters and, after parameter transformations (8.3.5),
4622 all parameter types except the first are identical."
4624 So we build up the function type we want and ask instantiate_type
4625 to get it for us. */
4637 /* "If the lookup finds the two-parameter form of a usual deallocation
4638 function (3.7.4.2) and that function, considered as a placement
4639 deallocation function, would have been selected as a match for the
4640 allocation function, the program is ill-formed." */
4642 {
4643 /* But if the class has an operator delete (void *), then that is
4644 the usual deallocation function, so we shouldn't complain
4645 about using the operator delete (void *, size_t). */
4648 {
4653 }
4656 ok:;
4657 }
4658 }
4659 else
4660 /* "Any non-placement deallocation function matches a non-placement
4661 allocation function. If the lookup finds a single matching
4662 deallocation function, that function will be called; otherwise, no
4663 deallocation function will be called." */
4666 {
4669 {
4671 /* "If a class T has a member deallocation function named
4672 operator delete with exactly one parameter, then that
4673 function is a usual (non-placement) deallocation
4674 function. If class T does not declare such an operator
4675 delete but does declare a member deallocation function named
4676 operator delete with exactly two parameters, the second of
4677 which has type std::size_t (18.2), then this function is a
4678 usual deallocation function."
4680 So (void*) beats (void*, size_t). */
4683 }
4684 }
4686 /* If we have a matching function, call it. */
4688 {
4691 /* If the FN is a member function, make sure that it is
4692 accessible. */
4696 /* Core issue 901: It's ok to new a type with deleted delete. */
4701 {
4702 /* The placement args might not be suitable for overload
4703 resolution at this point, so build the call directly. */
4712 }
4713 else
4714 {
4715 tree ret;
4723 }
4724 }
4726 /* [expr.new]
4728 If no unambiguous matching deallocation function can be found,
4729 propagating the exception does not cause the object's memory to
4730 be freed. */
4732 {
4735 alloc_fn);
4737 }
4742 }
4744 /* If the current scope isn't allowed to access DECL along
4745 BASETYPE_PATH, give an error. The most derived class in
4746 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4747 the declaration to use in the error diagnostic. */
4749 bool
4751 {
4755 {
4760 else
4764 }
4767 }
4769 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4770 bitwise or of LOOKUP_* values. If any errors are warnings are
4771 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4772 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4773 to NULL. */
4775 static tree
4778 {
4791 else
4794 }
4796 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4797 EXPR is implicitly converted to type TOTYPE.
4798 FN and ARGNUM are used for diagnostics. */
4800 static void
4802 {
4805 /* Issue warnings about peculiar, but valid, uses of NULL. */
4807 {
4812 else
4815 }
4817 /* Issue warnings if "false" is converted to a NULL pointer */
4822 }
4824 /* Perform the conversions in CONVS on the expression EXPR. FN and
4825 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4826 indicates the `this' argument of a method. INNER is nonzero when
4827 being called to continue a conversion chain. It is negative when a
4828 reference binding will be applied, positive otherwise. If
4829 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4830 conversions will be emitted if appropriate. If C_CAST_P is true,
4831 this conversion is coming from a C-style cast; in that case,
4832 conversions to inaccessible bases are permitted. */
4834 static tree
4838 {
4840 diagnostic_t diag_kind;
4850 {
4853 /* Give a helpful error if this is bad because of excess braces. */
4861 {
4863 {
4867 complain);
4869 }
4874 complain);
4877 }
4879 {
4883 }
4884 else
4888 }
4894 {
4896 {
4903 /* When converting from an init list we consider explicit
4904 constructors, but actually trying to call one is an error. */
4906 {
4910 else
4912 }
4914 /* Set user_conv_p on the argument conversions, so rvalue/base
4915 handling knows not to allow any more UDCs. */
4921 /* If this is a constructor or a function returning an aggr type,
4922 we need to build up a TARGET_EXPR. */
4924 {
4927 /* Remember that this was list-initialization. */
4930 }
4933 }
4937 {
4943 else
4945 }
4949 /* Convert a constant to its underlying value, unless we are
4950 about to bind it to a reference, in which case we need to
4951 leave it as an lvalue. */
4953 {
4956 /* If __null has been converted to an integer type, we do not
4957 want to warn about uses of EXPR as an integer, rather than
4958 as a pointer. */
4960 }
4965 /* Call build_user_type_conversion again for the error. */
4966 return build_user_type_conversion
4970 {
4971 /* Conversion to std::initializer_list<T>. */
4979 /* Convert all the elements. */
4981 {
4988 }
4989 /* Build up the array. */
4990 elttype = cp_build_qualified_type
4998 /* Call the private constructor. */
5000 new_ctor = build_special_member_call
5005 }
5012 };
5017 c_cast_p,
5018 complain);
5023 {
5028 /* Else fall through. */
5031 {
5032 /* We are going to bind a reference directly to a base-class
5033 subobject of EXPR. */
5034 /* Build an expression for `*((base*) &expr)'. */
5040 }
5042 /* Copy-initialization where the cv-unqualified version of the source
5043 type is the same class as, or a derived class of, the class of the
5044 destination [is treated as direct-initialization]. [dcl.init] */
5047 /* This conversion is being done in the context of a user-defined
5048 conversion (i.e. the second step of copy-initialization), so
5049 don't allow any more. */
5053 {
5059 }
5063 {
5068 {
5070 {
5075 }
5077 }
5079 /* If necessary, create a temporary.
5081 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
5082 that need temporaries, even when their types are reference
5083 compatible with the type of reference being bound, so the
5084 upcoming call to cp_build_unary_op (ADDR_EXPR, expr, ...)
5085 doesn't fail. */
5089 {
5095 {
5097 {
5098 /* If the reference is volatile or non-const, we
5099 cannot create a temporary. */
5106 else
5108 }
5110 }
5111 /* If the source is a packed field, and we must use a copy
5112 constructor, then building the target expr will require
5113 binding the field to the reference parameter to the
5114 copy constructor, and we'll end up with an infinite
5115 loop. If we can use a bitwise copy, then we'll be
5116 OK. */
5120 {
5125 }
5127 {
5130 }
5132 }
5134 /* Take the address of the thing to which we will bind the
5135 reference. */
5140 /* Convert it to a pointer to the type referred to by the
5141 reference. This will adjust the pointer if a derived to
5142 base conversion is being performed. */
5144 expr);
5145 /* Convert the pointer to the desired reference type. */
5147 }
5153 /* Warn about deprecated conversion if appropriate. */
5165 c_cast_p);
5169 }
5176 else
5180 }
5182 /* ARG is being passed to a varargs function. Perform any conversions
5183 required. Return the converted value. */
5185 tree
5187 {
5188 /* [expr.call]
5190 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5191 standard conversions are performed. */
5193 /* [expr.call]
5195 If the argument has integral or enumeration type that is subject
5196 to the integral promotions (_conv.prom_), or a floating point
5197 type that is subject to the floating point promotion
5198 (_conv.fpprom_), the value of the argument is converted to the
5199 promoted type before the call. */
5215 {
5216 /* [expr.call] 5.2.2/7:
5217 Passing a potentially-evaluated argument of class type (Clause 9)
5218 with a non-trivial copy constructor or a non-trivial destructor
5219 with no corresponding parameter is conditionally-supported, with
5220 implementation-defined semantics.
5222 We used to just warn here and do a bitwise copy, but now
5223 cp_expr_size will abort if we try to do that.
5225 If the call appears in the context of a sizeof expression,
5226 it is not potentially-evaluated. */
5230 }
5233 }
5235 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
5237 tree
5239 {
5253 {
5254 /* Remove reference types so we don't ICE later on. */
5256 /* conditionally-supported behavior [expr.call] 5.2.2/7. */
5262 }
5265 }
5267 /* TYPE has been given to va_arg. Apply the default conversions which
5268 would have happened when passed via ellipsis. Return the promoted
5269 type, or the passed type if there is no change. */
5271 tree
5273 {
5274 tree promote;
5276 /* Perform the array-to-pointer and function-to-pointer
5277 conversions. */
5285 }
5287 /* ARG is a default argument expression being passed to a parameter of
5288 the indicated TYPE, which is a parameter to FN. Do any required
5289 conversions. Return the converted value. */
5293 tree
5295 {
5297 tree t;
5299 /* If the ARG is an unparsed default argument expression, the
5300 conversion cannot be performed. */
5302 {
5307 }
5309 /* Detect recursion. */
5312 {
5315 }
5321 /* Due to:
5323 [dcl.fct.default]
5325 The names in the expression are bound, and the semantic
5326 constraints are checked, at the point where the default
5327 expressions appears.
5329 we must not perform access checks here. */
5333 {
5337 tf_warning_or_error);
5338 }
5339 else
5340 {
5341 /* We must make a copy of ARG, in case subsequent processing
5342 alters any part of it. For example, during gimplification a
5343 cast of the form (T) &X::f (where "f" is a member function)
5344 will lead to replacing the PTRMEM_CST for &X::f with a
5345 VAR_DECL. We can avoid the copy for constants, since they
5346 are never modified in place. */
5351 tf_warning_or_error);
5353 }
5359 }
5361 /* Returns the type which will really be used for passing an argument of
5362 type TYPE. */
5364 tree
5366 {
5367 /* Pass classes with copy ctors by invisible reference. */
5369 {
5371 /* There are no other pointers to this temporary. */
5373 }
5382 }
5384 /* Actually perform the appropriate conversion. */
5386 tree
5388 {
5389 tree bitfield_type;
5391 /* If VAL is a bitfield, then -- since it has already been converted
5392 to TYPE -- it cannot have a precision greater than TYPE.
5394 If it has a smaller precision, we must widen it here. For
5395 example, passing "int f:3;" to a function expecting an "int" will
5396 not result in any conversion before this point.
5398 If the precision is the same we must not risk widening. For
5399 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5400 often have type "int", even though the C++ type for the field is
5401 "long long". If the value is being passed to a function
5402 expecting an "int", then no conversions will be required. But,
5403 if we call convert_bitfield_to_declared_type, the bitfield will
5404 be converted to "long long". */
5411 ;
5412 /* Pass classes with copy ctors by invisible reference. */
5422 {
5431 }
5433 }
5435 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5436 which no conversions at all should be done. This is true for some
5437 builtins which don't act like normal functions. */
5439 static bool
5441 {
5444 {
5454 }
5457 }
5459 /* Subroutine of the various build_*_call functions. Overload resolution
5460 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5461 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5462 bitmask of various LOOKUP_* flags which apply to the call itself. */
5464 static tree
5466 {
5474 tree val;
5483 /* In a template, there is no need to perform all of the work that
5484 is normally done. We are only interested in the type of the call
5485 expression, i.e., the return type of the function. Any semantic
5486 errors will be deferred until the template is instantiated. */
5488 {
5489 tree expr;
5490 tree return_type;
5498 else
5499 {
5502 tree arg;
5510 }
5513 argarray);
5519 }
5521 /* Give any warnings we noticed during overload resolution. */
5523 {
5527 }
5529 /* Make =delete work with SFINAE. */
5534 {
5535 /* If FN is a template function, two cases must be considered.
5536 For example:
5538 struct A {
5539 protected:
5540 template <class T> void f();
5541 };
5542 template <class T> struct B {
5543 protected:
5544 void g();
5545 };
5546 struct C : A, B<int> {
5547 using A::f; // #1
5548 using B<int>::g; // #2
5549 };
5551 In case #1 where `A::f' is a member template, DECL_ACCESS is
5552 recorded in the primary template but not in its specialization.
5553 We check access of FN using its primary template.
5555 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
5556 because it is a member of class template B, DECL_ACCESS is
5557 recorded in the specialization `B<int>::g'. We cannot use its
5558 primary template because `B<T>::g' and `B<int>::g' may have
5559 different access. */
5564 else
5566 }
5568 /* Find maximum size of vector to hold converted arguments. */
5575 /* The implicit parameters to a constructor are not considered by overload
5576 resolution, and must be of the proper type. */
5578 {
5580 {
5583 }
5584 else
5585 {
5588 }
5590 /* We should never try to call the abstract constructor. */
5594 {
5598 }
5599 }
5600 /* Bypass access control for 'this' parameter. */
5602 {
5605 ? first_arg
5608 tree converted_arg;
5609 tree base_binfo;
5612 {
5616 else
5618 }
5620 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
5621 X is called for an object that is not of type X, or of a type
5622 derived from X, the behavior is undefined.
5624 So we can assume that anything passed as 'this' is non-null, and
5625 optimize accordingly. */
5627 /* Convert to the base in which the function was declared. */
5630 arg,
5633 /* Check that the base class is accessible. */
5639 /* If fn was found by a using declaration, the conversion path
5640 will be to the derived class, not the base declaring fn. We
5641 must convert from derived to base. */
5651 else
5655 }
5660 {
5665 /* Don't make a copy here if build_call is going to. */
5671 /* Warn about initializer_list deduction that isn't currently in the
5672 working draft. */
5674 && flag_deduce_init_list
5677 {
5687 {
5694 }
5695 }
5697 val = convert_like_with_context
5699 complain);
5704 else
5706 }
5708 /* Default arguments */
5713 /* Ellipsis */
5715 {
5718 /* Do no conversions for magic varargs. */
5720 else
5723 }
5731 /* Avoid actually calling copy constructors and copy assignment operators,
5732 if possible. */
5739 {
5740 tree targ;
5742 tree fa;
5744 /* Pull out the real argument, disregarding const-correctness. */
5750 {
5755 }
5756 else
5761 else
5766 {
5767 /* Copy-list-initialization doesn't require the copy constructor
5768 to be defined. */
5769 }
5770 /* [class.copy]: the copy constructor is implicitly defined even if
5771 the implementation elided its use. */
5773 {
5776 }
5778 /* If we're creating a temp and we already have one, don't create a
5779 new one. If we're not creating a temp but we get one, use
5780 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5781 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5782 temp or an INIT_EXPR otherwise. */
5787 {
5792 }
5796 {
5798 complain));
5802 }
5803 }
5807 {
5808 tree to = stabilize_reference
5815 {
5816 /* Avoid copying empty classes. */
5821 }
5823 {
5826 }
5827 else
5828 {
5829 /* We must only copy the non-tail padding parts.
5830 Use __builtin_memcpy for the bitwise copy.
5831 FIXME fix 22488 so we can go back to using MODIFY_EXPR
5832 instead of an explicit call to memcpy. */
5842 {
5843 /* If we can't be sure about pointer alignment, a call
5844 to __builtin_memcpy is expanded as a call to memcpy, which
5845 is invalid with identical args. Otherwise it is
5846 expanded as a block move, which should be safe. */
5850 }
5859 }
5862 }
5868 {
5869 tree t;
5875 /* Warn about deprecated virtual functions now, since we're about
5876 to throw away the decl. */
5886 else
5889 }
5890 else
5894 }
5896 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5897 This function performs no overload resolution, conversion, or other
5898 high-level operations. */
5900 tree
5902 {
5903 tree fndecl;
5907 /* If this call might throw an exception, note that fact. */
5914 /* Check that arguments to builtin functions match the expectations. */
5921 /* Some built-in function calls will be evaluated at compile-time in
5922 fold (). */
5935 }
5939 /* Make an expression which yields the address of the Java interface
5940 method FN. This is achieved by generating a call to libjava's
5941 _Jv_LookupInterfaceMethodIdx(). */
5943 static tree
5945 {
5951 {
5956 endlink)));
5957 java_iface_lookup_fn
5961 }
5963 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5964 This is the first entry in the vtable. */
5966 tf_warning_or_error),
5967 integer_zero_node);
5969 /* Get the java.lang.Class pointer for the interface being called. */
5974 {
5976 iface);
5978 }
5982 /* Determine the itable index of FN. */
5985 {
5990 i++;
5991 }
5996 java_iface_lookup_fn);
5999 }
6001 /* Returns the value to use for the in-charge parameter when making a
6002 call to a function with the indicated NAME.
6004 FIXME:Can't we find a neater way to do this mapping? */
6006 tree
6008 {
6019 /* This function should only be called with one of the names listed
6020 above. */
6023 }
6025 /* Build a call to a constructor, destructor, or an assignment
6026 operator for INSTANCE, an expression with class type. NAME
6027 indicates the special member function to call; *ARGS are the
6028 arguments. ARGS may be NULL. This may change ARGS. BINFO
6029 indicates the base of INSTANCE that is to be passed as the `this'
6030 parameter to the member function called.
6032 FLAGS are the LOOKUP_* flags to use when processing the call.
6034 If NAME indicates a complete object constructor, INSTANCE may be
6035 NULL_TREE. In this case, the caller will call build_cplus_new to
6036 store the newly constructed object into a VAR_DECL. */
6038 tree
6041 {
6042 tree fns;
6043 /* The type of the subobject to be constructed or destroyed. */
6044 tree class_type;
6046 tree ret;
6055 {
6056 /* Resolve the name. */
6061 }
6067 /* Handle the special case where INSTANCE is NULL_TREE. */
6069 {
6072 }
6073 else
6074 {
6080 /* Convert to the base class, if necessary. */
6083 {
6085 /* For constructors and destructors, either the base is
6086 non-virtual, or it is virtual but we are doing the
6087 conversion from a constructor or destructor for the
6088 complete object. In either case, we can convert
6089 statically. */
6091 else
6092 /* However, for assignment operators, we must convert
6093 dynamically if the base is virtual. */
6096 }
6097 }
6103 /* When making a call to a constructor or destructor for a subobject
6104 that uses virtual base classes, pass down a pointer to a VTT for
6105 the subobject. */
6109 {
6110 tree vtt;
6111 tree sub_vtt;
6113 /* If the current function is a complete object constructor
6114 or destructor, then we fetch the VTT directly.
6115 Otherwise, we look it up using the VTT we were given. */
6121 current_vtt_parm,
6122 vtt);
6128 {
6131 }
6134 }
6139 complain);
6145 }
6147 /* Return the NAME, as a C string. The NAME indicates a function that
6148 is a member of TYPE. *FREE_P is set to true if the caller must
6149 free the memory returned.
6151 Rather than go through all of this, we should simply set the names
6152 of constructors and destructors appropriately, and dispense with
6153 ctor_identifier, dtor_identifier, etc. */
6157 {
6160 /* Assume that we will not allocate memory. */
6162 /* Constructors and destructors are special. */
6164 {
6165 pretty_name
6167 /* For a destructor, add the '~'. */
6171 {
6173 /* Remember that we need to free the memory allocated. */
6175 }
6176 }
6178 {
6181 TFF_PLAIN_IDENTIFIER),
6182 NULL);
6183 /* Remember that we need to free the memory allocated. */
6185 }
6186 else
6190 }
6192 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
6193 be set, upon return, to the function called. ARGS may be NULL.
6194 This may change ARGS. */
6196 tree
6200 {
6204 tree access_binfo;
6205 tree optype;
6207 tree instance_ptr;
6208 tree name;
6211 tree call;
6212 tree fn;
6213 tree class_type;
6216 tree orig_instance;
6217 tree orig_fns;
6223 /* We don't know what function we're going to call, yet. */
6232 {
6236 }
6241 /* Dismantle the baselink to collect all the information we need. */
6248 {
6252 }
6263 {
6268 }
6271 /* Under DR 147 A::A() is an invalid constructor call,
6272 not a functional cast. */
6274 {
6284 complain);
6286 }
6288 /* Figure out whether to skip the first argument for the error
6289 message we will display to users if an error occurs. We don't
6290 want to display any compiler-generated arguments. The "this"
6291 pointer hasn't been added yet. However, we must remove the VTT
6292 pointer if this is a call to a base-class constructor or
6293 destructor. */
6296 {
6297 /* Callers should explicitly indicate whether they want to construct
6298 the complete object or just the part without virtual bases. */
6300 /* Similarly for destructors. */
6302 /* Remove the VTT pointer, if present. */
6306 }
6308 /* Process the argument list. */
6310 {
6314 }
6318 /* It's OK to call destructors and constructors on cv-qualified objects.
6319 Therefore, convert the INSTANCE_PTR to the unqualified type, if
6320 necessary. */
6323 {
6327 }
6331 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
6332 initializer, not T({ }). If the type doesn't have a list ctor,
6333 break apart the list into separate ctor args. */
6338 {
6341 }
6346 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6350 {
6352 tree this_first_arg;
6354 /* We can end up here for copy-init of same or base class. */
6361 else
6365 /* A member template. */
6367 class_type,
6368 explicit_targs,
6369 this_first_arg,
6371 optype,
6372 access_binfo,
6373 conversion_path,
6374 flags,
6375 DEDUCE_CALL);
6378 class_type,
6379 this_first_arg,
6381 access_binfo,
6382 conversion_path,
6383 flags);
6384 }
6388 {
6390 {
6393 else
6394 {
6397 tree arglist;
6408 }
6410 }
6412 }
6413 else
6414 {
6417 {
6420 tree arglist;
6423 {
6429 arglist);
6433 }
6435 }
6436 else
6437 {
6446 /* This is not an error, it is runtime undefined
6447 behavior. */
6449 "abstract virtual %q#D called from constructor"
6451 fn);
6455 {
6458 fn);
6460 }
6461 else
6462 {
6466 /* Now we know what function is being called. */
6469 /* Build the actual CALL_EXPR. */
6471 /* In an expression of the form `a->f()' where `f' turns
6472 out to be a static member function, `a' is
6473 none-the-less evaluated. */
6482 /* An explicit call of the form "x->~X()" has type
6483 "void". However, on platforms where destructors
6484 return "this" (i.e., those where
6485 targetm.cxx.cdtor_returns_this is true), such calls
6486 will appear to have a return value of pointer type
6487 to the low-level call machinery. We do not want to
6488 change the low-level machinery, since we want to be
6489 able to optimize "delete f()" on such platforms as
6490 "operator delete(~X(f()))" (rather than generating
6491 "t = f(), ~X(t), operator delete (t)"). */
6493 }
6494 }
6495 }
6498 {
6504 {
6507 }
6510 call = (build_min_non_dep_call_vec
6514 orig_args));
6518 }
6520 /* Free all the conversions we allocated. */
6527 }
6529 /* Returns true iff standard conversion sequence ICS1 is a proper
6530 subsequence of ICS2. */
6532 static bool
6534 {
6535 /* We can assume that a conversion of the same code
6536 between the same types indicates a subsequence since we only get
6537 here if the types we are converting from are the same. */
6544 {
6552 /* At this point, ICS1 cannot be a proper subsequence of
6553 ICS2. We can get a USER_CONV when we are comparing the
6554 second standard conversion sequence of two user conversion
6555 sequences. */
6565 }
6566 }
6568 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
6569 be any _TYPE nodes. */
6571 bool
6573 {
6577 /* We only allow proper derivation here. The DERIVED_FROM_P macro
6578 considers every class derived from itself. */
6581 }
6583 /* We build the ICS for an implicit object parameter as a pointer
6584 conversion sequence. However, such a sequence should be compared
6585 as if it were a reference conversion sequence. If ICS is the
6586 implicit conversion sequence for an implicit object parameter,
6587 modify it accordingly. */
6589 static void
6591 {
6593 {
6594 /* [over.match.funcs]
6596 For non-static member functions, the type of the
6597 implicit object parameter is "reference to cv X"
6598 where X is the class of which the function is a
6599 member and cv is the cv-qualification on the member
6600 function declaration. */
6602 tree reference_type;
6604 /* The `this' parameter is a pointer to a class type. Make the
6605 implicit conversion talk about a reference to that same class
6606 type. */
6619 }
6620 }
6622 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
6623 and return the initial reference binding conversion. Otherwise,
6624 leave *ICS unchanged and return NULL. */
6628 {
6630 {
6635 }
6638 }
6640 /* Compare two implicit conversion sequences according to the rules set out in
6641 [over.ics.rank]. Return values:
6643 1: ics1 is better than ics2
6644 -1: ics2 is better than ics1
6645 0: ics1 and ics2 are indistinguishable */
6647 static int
6649 {
6650 tree from_type1;
6651 tree from_type2;
6652 tree to_type1;
6653 tree to_type2;
6660 /* REF_BINDING is nonzero if the result of the conversion sequence
6661 is a reference type. In that case REF_CONV is the reference
6662 binding conversion. */
6666 /* Handle implicit object parameters. */
6670 /* Handle reference parameters. */
6674 /* List-initialization sequence L1 is a better conversion sequence than
6675 list-initialization sequence L2 if L1 converts to
6676 std::initializer_list<X> for some X and L2 does not. */
6682 /* [over.ics.rank]
6684 When comparing the basic forms of implicit conversion sequences (as
6685 defined in _over.best.ics_)
6687 --a standard conversion sequence (_over.ics.scs_) is a better
6688 conversion sequence than a user-defined conversion sequence
6689 or an ellipsis conversion sequence, and
6691 --a user-defined conversion sequence (_over.ics.user_) is a
6692 better conversion sequence than an ellipsis conversion sequence
6693 (_over.ics.ellipsis_). */
6703 {
6704 /* XXX Isn't this an extension? */
6705 /* Both ICS are bad. We try to make a decision based on what
6706 would have happened if they'd been good. */
6714 /* We couldn't make up our minds; try to figure it out below. */
6715 }
6718 /* Both conversions are ellipsis conversions or both are building a
6719 std::initializer_list. */
6722 /* User-defined conversion sequence U1 is a better conversion sequence
6723 than another user-defined conversion sequence U2 if they contain the
6724 same user-defined conversion operator or constructor and if the sec-
6725 ond standard conversion sequence of U1 is better than the second
6726 standard conversion sequence of U2. */
6729 {
6743 /* We can just fall through here, after setting up
6744 FROM_TYPE1 and FROM_TYPE2. */
6747 }
6748 else
6749 {
6753 /* We're dealing with two standard conversion sequences.
6755 [over.ics.rank]
6757 Standard conversion sequence S1 is a better conversion
6758 sequence than standard conversion sequence S2 if
6760 --S1 is a proper subsequence of S2 (comparing the conversion
6761 sequences in the canonical form defined by _over.ics.scs_,
6762 excluding any Lvalue Transformation; the identity
6763 conversion sequence is considered to be a subsequence of
6764 any non-identity conversion sequence */
6775 }
6777 /* One sequence can only be a subsequence of the other if they start with
6778 the same type. They can start with different types when comparing the
6779 second standard conversion sequence in two user-defined conversion
6780 sequences. */
6782 {
6787 }
6789 /* [over.ics.rank]
6791 Or, if not that,
6793 --the rank of S1 is better than the rank of S2 (by the rules
6794 defined below):
6796 Standard conversion sequences are ordered by their ranks: an Exact
6797 Match is a better conversion than a Promotion, which is a better
6798 conversion than a Conversion.
6800 Two conversion sequences with the same rank are indistinguishable
6801 unless one of the following rules applies:
6803 --A conversion that does not a convert a pointer, pointer to member,
6804 or std::nullptr_t to bool is better than one that does.
6806 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
6807 so that we do not have to check it explicitly. */
6816 /* A conversion from scalar arithmetic type to complex is worse than a
6817 conversion between scalar arithmetic types. */
6824 {
6827 else
6829 }
6835 {
6840 }
6841 /* The rules for pointers to members A::* are just like the rules
6842 for pointers A*, except opposite: if B is derived from A then
6843 A::* converts to B::*, not vice versa. For that reason, we
6844 switch the from_ and to_ variables here. */
6851 {
6856 }
6861 {
6862 /* This was one of the pointer or pointer-like conversions.
6864 [over.ics.rank]
6866 --If class B is derived directly or indirectly from class A,
6867 conversion of B* to A* is better than conversion of B* to
6868 void*, and conversion of A* to void* is better than
6869 conversion of B* to void*. */
6872 {
6874 deref_from_type2))
6877 deref_from_type1))
6879 }
6882 {
6884 {
6886 {
6888 deref_to_type1))
6890 }
6891 /* We know that DEREF_TO_TYPE1 is `void' here. */
6893 deref_to_type2))
6895 }
6896 }
6899 {
6900 /* [over.ics.rank]
6902 --If class B is derived directly or indirectly from class A
6903 and class C is derived directly or indirectly from B,
6905 --conversion of C* to B* is better than conversion of C* to
6906 A*,
6908 --conversion of B* to A* is better than conversion of C* to
6909 A* */
6911 {
6913 deref_to_type2))
6916 deref_to_type1))
6918 }
6920 {
6922 deref_from_type1))
6925 deref_from_type2))
6927 }
6928 }
6929 }
6932 {
6935 /* [over.ics.rank]
6937 --binding of an expression of type C to a reference of type
6938 B& is better than binding an expression of type C to a
6939 reference of type A&
6941 --conversion of C to B is better than conversion of C to A, */
6944 {
6949 }
6950 }
6953 {
6956 /* [over.ics.rank]
6958 --binding of an expression of type B to a reference of type
6959 A& is better than binding an expression of type C to a
6960 reference of type A&,
6962 --conversion of B to A is better than conversion of C to A */
6965 {
6970 }
6971 }
6973 /* [over.ics.rank]
6975 --S1 and S2 differ only in their qualification conversion and yield
6976 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6977 qualification signature of type T1 is a proper subset of the cv-
6978 qualification signature of type T2 */
6982 {
6986 }
6988 /* [over.ics.rank]
6990 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6991 to an implicit object parameter, and either S1 binds an lvalue reference
6992 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6993 reference to an rvalue and S2 binds an lvalue reference
6994 (C++0x draft standard, 13.3.3.2)
6996 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6997 types to which the references refer are the same type except for
6998 top-level cv-qualifiers, and the type to which the reference
6999 initialized by S2 refers is more cv-qualified than the type to
7000 which the reference initialized by S1 refers */
7003 {
7007 {
7012 }
7017 }
7019 /* Neither conversion sequence is better than the other. */
7021 }
7023 /* The source type for this standard conversion sequence. */
7025 static tree
7027 {
7029 {
7034 }
7036 }
7038 /* Note a warning about preferring WINNER to LOSER. We do this by storing
7039 a pointer to LOSER and re-running joust to produce the warning if WINNER
7040 is actually used. */
7042 static void
7044 {
7050 }
7052 /* Compare two candidates for overloading as described in
7053 [over.match.best]. Return values:
7055 1: cand1 is better than cand2
7056 -1: cand2 is better than cand1
7057 0: cand1 and cand2 are indistinguishable */
7059 static int
7061 {
7067 /* Candidates that involve bad conversions are always worse than those
7068 that don't. */
7074 /* If we have two pseudo-candidates for conversions to the same type,
7075 or two candidates for the same function, arbitrarily pick one. */
7080 /* a viable function F1
7081 is defined to be a better function than another viable function F2 if
7082 for all arguments i, ICSi(F1) is not a worse conversion sequence than
7083 ICSi(F2), and then */
7085 /* for some argument j, ICSj(F1) is a better conversion sequence than
7086 ICSj(F2) */
7088 /* For comparing static and non-static member functions, we ignore
7089 the implicit object parameter of the non-static function. The
7090 standard says to pretend that the static function has an object
7091 parm, but that won't work with operator overloading. */
7094 {
7102 else
7103 {
7106 }
7107 }
7110 {
7116 {
7129 {
7136 else
7141 {
7145 }
7146 else
7148 }
7151 {
7154 }
7156 }
7157 }
7159 /* warn about confusing overload resolution for user-defined conversions,
7160 either between a constructor and a conversion op, or between two
7161 conversion ops. */
7165 {
7171 else
7174 /* We don't want to complain about `X::operator T1 ()'
7175 beating `X::operator T2 () const', when T2 is a no less
7176 cv-qualified version of T1. */
7179 {
7184 {
7187 }
7190 }
7191 else
7197 {
7204 {
7206 }
7207 }
7208 else
7210 }
7215 /* or, if not that,
7216 F1 is a non-template function and F2 is a template function
7217 specialization. */
7224 /* or, if not that,
7225 F1 and F2 are template functions and the function template for F1 is
7226 more specialized than the template for F2 according to the partial
7227 ordering rules. */
7230 {
7231 winner = more_specialized_fn
7234 /* [temp.func.order]: The presence of unused ellipsis and default
7235 arguments has no effect on the partial ordering of function
7236 templates. add_function_candidate() will not have
7237 counted the "this" argument for constructors. */
7241 }
7243 /* or, if not that,
7244 the context is an initialization by user-defined conversion (see
7245 _dcl.init_ and _over.match.user_) and the standard conversion
7246 sequence from the return type of F1 to the destination type (i.e.,
7247 the type of the entity being initialized) is a better conversion
7248 sequence than the standard conversion sequence from the return type
7249 of F2 to the destination type. */
7252 {
7256 }
7258 /* Check whether we can discard a builtin candidate, either because we
7259 have two identical ones or matching builtin and non-builtin candidates.
7261 (Pedantically in the latter case the builtin which matched the user
7262 function should not be added to the overload set, but we spot it here.
7264 [over.match.oper]
7265 ... the builtin candidates include ...
7266 - do not have the same parameter type list as any non-template
7267 non-member candidate. */
7271 {
7277 {
7279 /* Two built-in candidates; arbitrarily pick one. */
7282 /* cand1 is built-in; prefer cand2. */
7284 else
7285 /* cand2 is built-in; prefer cand1. */
7287 }
7288 }
7290 /* If the two function declarations represent the same function (this can
7291 happen with declarations in multiple scopes and arg-dependent lookup),
7292 arbitrarily choose one. But first make sure the default args we're
7293 using match. */
7296 {
7303 {
7304 /* Don't crash if the fn is variadic. */
7309 }
7317 {
7320 {
7322 {
7329 }
7330 else
7333 }
7336 }
7339 }
7341 tweak:
7343 /* Extension: If the worst conversion for one candidate is worse than the
7344 worst conversion for the other, take the first. */
7346 {
7351 {
7356 }
7362 {
7364 {
7366 "ISO C++ says that these are ambiguous, even "
7367 "though the worst conversion for the first is better than "
7371 }
7372 else
7375 }
7376 }
7380 }
7382 /* Given a list of candidates for overloading, find the best one, if any.
7383 This algorithm has a worst case of O(2n) (winner is last), and a best
7384 case of O(n/2) (totally ambiguous); much better than a sorting
7385 algorithm. */
7389 {
7394 /* Walk through the list once, comparing each current champ to the next
7395 candidate, knocking out a candidate or two with each comparison. */
7398 {
7402 else
7403 {
7405 {
7410 }
7411 else
7412 {
7415 }
7418 }
7419 }
7421 /* Make sure the champ is better than all the candidates it hasn't yet
7422 been compared to. */
7425 challenger != champ
7428 {
7432 }
7435 }
7437 /* Returns nonzero if things of type FROM can be converted to TO. */
7439 bool
7441 {
7443 }
7445 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7447 bool
7449 {
7454 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7458 flags);
7461 /* Free all the conversions we allocated. */
7465 }
7467 /* Like can_convert_arg, but allows dubious conversions as well. */
7469 bool
7471 {
7475 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7477 /* Try to perform the conversion. */
7479 flags);
7480 /* Free all the conversions we allocated. */
7484 }
7486 /* Convert EXPR to TYPE. Return the converted expression.
7488 Note that we allow bad conversions here because by the time we get to
7489 this point we are committed to doing the conversion. If we end up
7490 doing a bad conversion, convert_like will complain. */
7492 tree
7494 {
7501 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7506 flags);
7509 {
7511 {
7512 /* If expr has unknown type, then it is an overloaded function.
7513 Call instantiate_type to get good error messages. */
7518 else
7520 }
7522 }
7524 {
7525 /* In a template, we are only concerned about determining the
7526 type of non-dependent expressions, so we do not have to
7527 perform the actual conversion. */
7530 }
7531 else
7534 /* Free all the conversions we allocated. */
7538 }
7540 tree
7542 {
7544 }
7546 /* Convert EXPR to TYPE (as a direct-initialization) if that is
7547 permitted. If the conversion is valid, the converted expression is
7548 returned. Otherwise, NULL_TREE is returned, except in the case
7549 that TYPE is a class type; in that case, an error is issued. If
7550 C_CAST_P is true, then this direction initialization is taking
7551 place as part of a static_cast being attempted as part of a C-style
7552 cast. */
7554 tree
7556 tree expr,
7558 tsubst_flags_t complain)
7559 {
7565 /* [dcl.init]
7567 If the destination type is a (possibly cv-qualified) class type:
7569 -- If the initialization is direct-initialization ...,
7570 constructors are considered. ... If no constructor applies, or
7571 the overload resolution is ambiguous, the initialization is
7572 ill-formed. */
7574 {
7580 }
7582 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7586 c_cast_p,
7587 LOOKUP_NORMAL);
7590 else
7593 c_cast_p,
7594 complain);
7596 /* Free all the conversions we allocated. */
7600 }
7602 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
7603 is being bound to a temporary. Create and return a new VAR_DECL
7604 with the indicated TYPE; this variable will store the value to
7605 which the reference is bound. */
7607 tree
7609 {
7610 tree var;
7612 /* Create the variable. */
7615 /* Register the variable. */
7617 {
7618 /* Namespace-scope or local static; give it a mangled name. */
7619 tree name;
7626 }
7627 else
7628 /* Create a new cleanup level if necessary. */
7632 }
7634 /* EXPR is the initializer for a variable DECL of reference or
7635 std::initializer_list type. Create, push and return a new VAR_DECL
7636 for the initializer so that it will live as long as DECL. Any
7637 cleanup for the new variable is returned through CLEANUP, and the
7638 code to initialize the new variable is returned through INITP. */
7640 tree
7642 {
7643 tree init;
7644 tree type;
7645 tree var;
7647 /* Create the temporary variable. */
7651 /* If the rvalue is the result of a function call it will be
7652 a TARGET_EXPR. If it is some other construct (such as a
7653 member access expression where the underlying object is
7654 itself the result of a function call), turn it into a
7655 TARGET_EXPR here. It is important that EXPR be a
7656 TARGET_EXPR below since otherwise the INIT_EXPR will
7657 attempt to make a bitwise copy of EXPR to initialize
7658 VAR. */
7661 /* Create the INIT_EXPR that will initialize the temporary
7662 variable. */
7665 {
7670 else
7673 /* We must be careful to destroy the temporary only
7674 after its initialization has taken place. If the
7675 initialization throws an exception, then the
7676 destructor should not be run. We cannot simply
7677 transform INIT into something like:
7679 (INIT, ({ CLEANUP_STMT; }))
7681 because emit_local_var always treats the
7682 initializer as a full-expression. Thus, the
7683 destructor would run too early; it would run at the
7684 end of initializing the reference variable, rather
7685 than at the end of the block enclosing the
7686 reference variable.
7688 The solution is to pass back a cleanup expression
7689 which the caller is responsible for attaching to
7690 the statement tree. */
7691 }
7692 else
7693 {
7697 static_aggregates);
7698 }
7702 }
7704 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
7705 initializing a variable of that TYPE. If DECL is non-NULL, it is
7706 the VAR_DECL being initialized with the EXPR. (In that case, the
7707 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
7708 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
7709 return, if *CLEANUP is no longer NULL, it will be an expression
7710 that should be pushed as a cleanup after the returned expression
7711 is used to initialize DECL.
7713 Return the converted expression. */
7715 tree
7717 tsubst_flags_t complain)
7718 {
7725 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7729 LOOKUP_NORMAL);
7731 {
7733 {
7740 else
7744 }
7746 }
7748 /* If DECL is non-NULL, then this special rule applies:
7750 [class.temporary]
7752 The temporary to which the reference is bound or the temporary
7753 that is the complete object to which the reference is bound
7754 persists for the lifetime of the reference.
7756 The temporaries created during the evaluation of the expression
7757 initializing the reference, except the temporary to which the
7758 reference is bound, are destroyed at the end of the
7759 full-expression in which they are created.
7761 In that case, we store the converted expression into a new
7762 VAR_DECL in a new scope.
7764 However, we want to be careful not to create temporaries when
7765 they are not required. For example, given:
7767 struct B {};
7768 struct D : public B {};
7769 D f();
7770 const B& b = f();
7772 there is no need to copy the return value from "f"; we can just
7773 extend its lifetime. Similarly, given:
7775 struct S {};
7776 struct T { operator S(); };
7777 T t;
7778 const S& s = t;
7780 we can extend the lifetime of the return value of the conversion
7781 operator. */
7784 {
7785 tree var;
7786 tree base_conv_type;
7788 /* Skip over the REF_BIND. */
7790 /* If the next conversion is a BASE_CONV, skip that too -- but
7791 remember that the conversion was required. */
7793 {
7796 }
7797 else
7799 /* Perform the remainder of the conversion. */
7805 tf_warning_or_error);
7808 else
7809 {
7811 {
7812 tree init;
7814 /* Use its address to initialize the reference variable. */
7822 }
7823 else
7824 /* Take the address of EXPR. */
7826 /* If a BASE_CONV was required, perform it now. */
7828 expr = (perform_implicit_conversion
7830 tf_warning_or_error));
7832 }
7833 }
7834 else
7835 /* Perform the conversion. */
7838 /* Free all the conversions we allocated. */
7842 }
7844 /* Returns true iff TYPE is some variant of std::initializer_list. */
7846 bool
7848 {
7852 }
7854 /* Returns true iff DECL is a list constructor: i.e. a constructor which
7855 will accept an argument list of a single std::initializer_list<T>. */
7857 bool
7859 {
7861 tree arg;
7873 /* There are more non-defaulted parms. */
7877 }