| blob | c67f9b8bf22ac6a1ad25b4b5aa0a272fc226bab2 |
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. */
468 {
472 }
474 }
476 /* Returns nonzero if PARMLIST consists of only default parms and/or
477 ellipsis. */
479 bool
481 {
487 }
489 /* Allocate N bytes of memory from the conversion obstack. The memory
490 is zeroed before being returned. */
494 {
497 {
500 }
504 }
506 /* Dynamically allocate a conversion. */
510 {
515 }
517 #ifdef ENABLE_CHECKING
519 /* Make sure that all memory on the conversion obstack has been
520 freed. */
522 void
524 {
528 }
532 /* Dynamically allocate an array of N conversions. */
536 {
538 }
542 {
546 /* Note that the caller is responsible for filling in t->cand for
547 user-defined conversions. */
553 {
569 }
575 }
577 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
578 specialization of std::initializer_list<T>, if such a conversion is
579 possible. */
583 {
589 tree val;
592 {
593 conversion *sub
600 }
608 {
616 }
619 }
621 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
622 aggregate class, if such a conversion is possible. */
626 {
632 {
636 {
641 }
644 }
652 }
654 /* Build a representation of the identity conversion from EXPR to
655 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
659 {
667 }
669 /* Converting from EXPR to TYPE was ambiguous in the sense that there
670 were multiple user-defined conversions to accomplish the job.
671 Build a conversion that indicates that ambiguity. */
675 {
683 }
685 tree
687 {
691 }
693 /* Returns the standard conversion path (see [conv]) from type FROM to type
694 TO, if any. For proper handling of null pointer constants, you must
695 also pass the expression EXPR to convert from. If C_CAST_P is true,
696 this conversion is coming from a C-style cast. */
701 {
708 {
711 }
722 {
730 }
737 {
741 }
743 {
745 {
746 tree bitfield_type;
749 {
752 }
753 }
755 }
757 /* Allow conversion between `__complex__' data types. */
759 {
760 /* The standard conversion sequence to convert FROM to TO is
761 the standard conversion sequence to perform componentwise
762 conversion. */
767 {
770 }
771 else
775 }
785 {
786 /* For backwards brain damage compatibility, allow interconversion of
787 pointers and integers with a pedwarn. */
790 }
792 {
793 /* For backwards brain damage compatibility, allow interconversion of
794 enums and integers with a pedwarn. */
797 }
800 {
801 tree to_pointee;
802 tree from_pointee;
807 ;
811 {
812 from = build_pointer_type
816 }
818 {
823 && (same_type_ignoring_top_level_qualifiers_p
826 {
830 }
833 }
836 /* [conv.ptr]
838 An rvalue of type "pointer to cv D," where D is a
839 class type, can be converted to an rvalue of type
840 "pointer to cv B," where B is a base class (clause
841 _class.derived_) of D. If B is an inaccessible
842 (clause _class.access_) or ambiguous
843 (_class.member.lookup_) base class of D, a program
844 that necessitates this conversion is ill-formed.
845 Therefore, we use DERIVED_FROM_P, and do not check
846 access or uniqueness. */
848 {
849 from =
855 }
858 {
861 }
862 else
863 {
866 }
871 /* In a C-style cast, we ignore CV-qualification because we
872 are allowed to perform a static_cast followed by a
873 const_cast. */
878 /* converting from string constant to char *. */
881 {
884 }
885 else
889 }
891 {
908 }
910 {
911 /* [conv.bool]
913 An rvalue of arithmetic, unscoped enumeration, pointer, or
914 pointer to member type can be converted to an rvalue of type
915 bool. */
920 {
928 }
931 }
932 /* We don't check for ENUMERAL_TYPE here because there are no standard
933 conversions to enum type. */
934 /* As an extension, allow conversion to complex type. */
936 {
942 /* Give this a better rank if it's a promotion. */
946 }
952 {
956 /* The derived-to-base conversion indicates the initialization
957 of a parameter with base type from an object of a derived
958 type. A temporary object is created to hold the result of
959 the conversion unless we're binding directly to a reference. */
961 }
962 else
969 }
971 /* Returns nonzero if T1 is reference-related to T2. */
973 bool
975 {
979 /* [dcl.init.ref]
981 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
982 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
983 of T2. */
987 }
989 /* Returns nonzero if T1 is reference-compatible with T2. */
991 static bool
993 {
994 /* [dcl.init.ref]
996 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
997 reference-related to T2 and cv1 is the same cv-qualification as,
998 or greater cv-qualification than, cv2. */
1001 }
1003 /* Determine whether or not the EXPR (of class type S) can be
1004 converted to T as in [over.match.ref]. */
1008 {
1009 tree conversions;
1010 tree first_arg;
1012 tree t;
1021 /* [over.match.ref]
1023 Assuming that "cv1 T" is the underlying type of the reference
1024 being initialized, and "cv S" is the type of the initializer
1025 expression, with S a class type, the candidate functions are
1026 selected as follows:
1028 --The conversion functions of S and its base classes are
1029 considered. Those that are not hidden within S and yield type
1030 "reference to cv2 T2", where "cv1 T" is reference-compatible
1031 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1033 The argument list has one argument, which is the initializer
1034 expression. */
1038 /* Conceptually, we should take the address of EXPR and put it in
1039 the argument list. Unfortunately, however, that can result in
1040 error messages, which we should not issue now because we are just
1041 trying to find a conversion operator. Therefore, we use NULL,
1042 cast to the appropriate type. */
1048 {
1052 {
1062 /* If this is a template function, try to get an exact
1063 match. */
1065 {
1068 NULL_TREE,
1069 first_arg,
1070 NULL,
1071 reference_type,
1074 LOOKUP_NORMAL,
1075 DEDUCE_CONV);
1078 {
1079 /* Now, see if the conversion function really returns
1080 an lvalue of the appropriate type. From the
1081 point of view of unification, simply returning an
1082 rvalue of the right type is good enough. */
1087 {
1090 }
1091 }
1092 }
1098 LOOKUP_NORMAL);
1101 {
1103 /* Build a standard conversion sequence indicating the
1104 binding from the reference type returned by the
1105 function to the desired REFERENCE_TYPE. */
1106 identity_conv
1109 NULL_TREE);
1110 cand->second_conv
1111 = (direct_reference_binding
1118 /* Don't allow binding of lvalues to rvalue references. */
1122 }
1123 }
1124 }
1127 /* If none of the conversion functions worked out, let our caller
1128 know. */
1136 /* Now that we know that this is the function we're going to use fix
1137 the dummy first argument. */
1142 /* Build a user-defined conversion sequence representing the
1143 conversion. */
1152 /* Merge it with the standard conversion sequence from the
1153 conversion function's return type to the desired type. */
1157 }
1159 /* A reference of the indicated TYPE is being bound directly to the
1160 expression represented by the implicit conversion sequence CONV.
1161 Return a conversion sequence for this binding. */
1165 {
1166 tree t;
1173 /* [over.ics.rank]
1175 When a parameter of reference type binds directly
1176 (_dcl.init.ref_) to an argument expression, the implicit
1177 conversion sequence is the identity conversion, unless the
1178 argument expression has a type that is a derived class of the
1179 parameter type, in which case the implicit conversion sequence is
1180 a derived-to-base Conversion.
1182 If the parameter binds directly to the result of applying a
1183 conversion function to the argument expression, the implicit
1184 conversion sequence is a user-defined conversion sequence
1185 (_over.ics.user_), with the second standard conversion sequence
1186 either an identity conversion or, if the conversion function
1187 returns an entity of a type that is a derived class of the
1188 parameter type, a derived-to-base conversion. */
1190 {
1191 /* Represent the derived-to-base conversion. */
1193 /* We will actually be binding to the base-class subobject in
1194 the derived class, so we mark this conversion appropriately.
1195 That way, convert_like knows not to generate a temporary. */
1197 }
1199 }
1201 /* Returns the conversion path from type FROM to reference type TO for
1202 purposes of reference binding. For lvalue binding, either pass a
1203 reference type to FROM or an lvalue expression to EXPR. If the
1204 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1205 the conversion returned. If C_CAST_P is true, this
1206 conversion is coming from a C-style cast. */
1210 {
1214 tree tfrom;
1220 {
1225 }
1228 {
1229 /* Anything with reference type is an lvalue. */
1232 }
1235 {
1238 flags);
1241 {
1246 }
1247 }
1256 /* Figure out whether or not the types are reference-related and
1257 reference compatible. We have do do this after stripping
1258 references from FROM. */
1260 /* If this is a C cast, first convert to an appropriately qualified
1261 type, so that we can later do a const_cast to the desired type. */
1267 /* Directly bind reference when target expression's type is compatible with
1268 the reference and expression is an lvalue. In DR391, the wording in
1269 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1270 const and rvalue references to rvalues of compatible class type.
1271 We should also do direct bindings for non-class "rvalues" derived from
1272 rvalue references. */
1274 && (is_lvalue
1279 {
1280 /* [dcl.init.ref]
1282 If the initializer expression
1284 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1285 is reference-compatible with "cv2 T2,"
1287 the reference is bound directly to the initializer expression
1288 lvalue.
1290 [...]
1291 If the initializer expression is an rvalue, with T2 a class type,
1292 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1293 is bound to the object represented by the rvalue or to a sub-object
1294 within that object. */
1300 /* The top-level caller requested that we pretend that the lvalue
1301 be treated as an rvalue. */
1303 else
1304 conv->rvaluedness_matches_p
1309 /* For the purposes of overload resolution, we ignore the fact
1310 this expression is a bitfield or packed field. (In particular,
1311 [over.ics.ref] says specifically that a function with a
1312 non-const reference parameter is viable even if the
1313 argument is a bitfield.)
1315 However, when we actually call the function we must create
1316 a temporary to which to bind the reference. If the
1317 reference is volatile, or isn't const, then we cannot make
1318 a temporary, so we just issue an error when the conversion
1319 actually occurs. */
1322 /* Don't allow binding of lvalues to rvalue references. */
1328 }
1329 /* [class.conv.fct] A conversion function is never used to convert a
1330 (possibly cv-qualified) object to the (possibly cv-qualified) same
1331 object type (or a reference to it), to a (possibly cv-qualified) base
1332 class of that type (or a reference to it).... */
1335 {
1336 /* [dcl.init.ref]
1338 If the initializer expression
1340 -- has a class type (i.e., T2 is a class type) can be
1341 implicitly converted to an lvalue of type "cv3 T3," where
1342 "cv1 T1" is reference-compatible with "cv3 T3". (this
1343 conversion is selected by enumerating the applicable
1344 conversion functions (_over.match.ref_) and choosing the
1345 best one through overload resolution. (_over.match_).
1347 the reference is bound to the lvalue result of the conversion
1348 in the second case. */
1352 }
1354 /* From this point on, we conceptually need temporaries, even if we
1355 elide them. Only the cases above are "direct bindings". */
1359 /* [over.ics.rank]
1361 When a parameter of reference type is not bound directly to an
1362 argument expression, the conversion sequence is the one required
1363 to convert the argument expression to the underlying type of the
1364 reference according to _over.best.ics_. Conceptually, this
1365 conversion sequence corresponds to copy-initializing a temporary
1366 of the underlying type with the argument expression. Any
1367 difference in top-level cv-qualification is subsumed by the
1368 initialization itself and does not constitute a conversion. */
1370 /* [dcl.init.ref]
1372 Otherwise, the reference shall be to a non-volatile const type.
1374 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1378 /* [dcl.init.ref]
1380 Otherwise, a temporary of type "cv1 T1" is created and
1381 initialized from the initializer expression using the rules for a
1382 non-reference copy initialization. If T1 is reference-related to
1383 T2, cv1 must be the same cv-qualification as, or greater
1384 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1388 /* We're generating a temporary now, but don't bind any more in the
1389 conversion (specifically, don't slice the temporary returned by a
1390 conversion operator). */
1393 /* Temporaries are copy-initialized, except for this hack to allow
1394 explicit conversion ops to the copy ctor. See also
1395 add_function_candidate. */
1401 flags);
1406 /* This reference binding, unlike those above, requires the
1407 creation of a temporary. */
1412 }
1414 /* Returns the implicit conversion sequence (see [over.ics]) from type
1415 FROM to type TO. The optional expression EXPR may affect the
1416 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1417 true, this conversion is coming from a C-style cast. */
1422 {
1431 else
1438 {
1442 /* Allow conversion from an initializer-list with one element to a
1443 scalar type. */
1445 {
1447 tree elt;
1453 else
1459 {
1462 /* Too many levels of braces, i.e. '{{1}}'. */
1465 }
1466 }
1467 }
1473 {
1486 /* We used to try to bind a reference to a temporary here, but that
1487 is now handled after the recursive call to this function at the end
1488 of reference_binding. */
1490 }
1493 }
1495 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1496 functions. ARGS will not be changed until a single candidate is
1497 selected. */
1505 {
1521 }
1523 /* Create an overload candidate for the function or method FN called
1524 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1525 FLAGS is passed on to implicit_conversion.
1527 This does not change ARGS.
1529 CTYPE, if non-NULL, is the type we want to pretend this function
1530 comes from for purposes of overload resolution. */
1537 {
1541 tree parmnode;
1546 /* At this point we should not see any functions which haven't been
1547 explicitly declared, except for friend functions which will have
1548 been found using argument dependent lookup. */
1551 /* The `this', `in_chrg' and VTT arguments to constructors are not
1552 considered in overload resolution. */
1554 {
1558 {
1561 }
1562 }
1563 else
1569 /* 13.3.2 - Viable functions [over.match.viable]
1570 First, to be a viable function, a candidate function shall have enough
1571 parameters to agree in number with the arguments in the list.
1573 We need to check this first; otherwise, checking the ICSes might cause
1574 us to produce an ill-formed template instantiation. */
1578 {
1582 }
1587 /* Make sure there are default args for the rest of the parms. */
1594 /* Second, for F to be a viable function, there shall exist for each
1595 argument an implicit conversion sequence that converts that argument
1596 to the corresponding parameter of F. */
1601 {
1611 else
1620 {
1624 /* The type of the implicit object parameter ('this') for
1625 overload resolution is not always the same as for the
1626 function itself; conversion functions are considered to
1627 be members of the class being converted, and functions
1628 introduced by a using-declaration are considered to be
1629 members of the class that uses them.
1631 Since build_over_call ignores the ICS for the `this'
1632 parameter, we can just change the parm type. */
1634 {
1635 parmtype
1639 }
1643 {
1644 /* Hack: Direct-initialize copy parm (i.e. suppress
1645 LOOKUP_ONLYCONVERTING) to make explicit conversion ops
1646 work. See also reference_binding. */
1650 }
1651 else
1656 }
1657 else
1658 {
1661 }
1668 {
1671 }
1678 }
1680 out:
1683 }
1685 /* Create an overload candidate for the conversion function FN which will
1686 be invoked for expression OBJ, producing a pointer-to-function which
1687 will in turn be called with the argument list FIRST_ARG/ARGLIST,
1688 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
1689 passed on to implicit_conversion.
1691 Actually, we don't really care about FN; we care about the type it
1692 converts to. There may be multiple conversion functions that will
1693 convert to that type, and we rely on build_user_type_conversion_1 to
1694 choose the best one; so when we create our candidate, we record the type
1695 instead of the function. */
1701 {
1717 /* Don't bother looking up the same type twice. */
1722 {
1730 else
1737 flags);
1743 else
1744 {
1747 }
1761 }
1771 }
1773 static void
1777 {
1790 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
1791 conversion ops are allowed. We handle that here by just checking for
1792 boolean_type_node because other operators don't ask for it. COND_EXPR
1793 also does contextual conversion to bool for the first operand, but we
1794 handle that in build_conditional_expr, and type1 here is operand 2. */
1799 {
1806 {
1808 /* We need something for printing the candidate. */
1810 }
1814 }
1816 /* For COND_EXPR we rearranged the arguments; undo that now. */
1818 {
1825 else
1827 }
1833 viable);
1834 }
1836 static bool
1838 {
1840 }
1842 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1844 static bool
1846 {
1847 /* [over.built]
1849 In this section, the term promoted integral type is used to refer
1850 to those integral types which are preserved by integral promotion
1851 (including e.g. int and long but excluding e.g. char).
1852 Similarly, the term promoted arithmetic type refers to promoted
1853 integral types plus floating types. */
1857 }
1859 /* Create any builtin operator overload candidates for the operator in
1860 question given the converted operand types TYPE1 and TYPE2. The other
1861 args are passed through from add_builtin_candidates to
1862 build_builtin_candidate.
1864 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1865 If CODE is requires candidates operands of the same type of the kind
1866 of which TYPE1 and TYPE2 are, we add both candidates
1867 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1869 static void
1873 {
1875 {
1883 }
1886 {
1888 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1889 and VQ is either volatile or empty, there exist candidate operator
1890 functions of the form
1891 VQ T& operator++(VQ T&);
1892 T operator++(VQ T&, int);
1893 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1894 type other than bool, and VQ is either volatile or empty, there exist
1895 candidate operator functions of the form
1896 VQ T& operator--(VQ T&);
1897 T operator--(VQ T&, int);
1898 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1899 complete object type, and VQ is either volatile or empty, there exist
1900 candidate operator functions of the form
1901 T*VQ& operator++(T*VQ&);
1902 T*VQ& operator--(T*VQ&);
1903 T* operator++(T*VQ&, int);
1904 T* operator--(T*VQ&, int); */
1913 {
1916 }
1919 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1920 exist candidate operator functions of the form
1922 T& operator*(T*);
1924 8 For every function type T, there exist candidate operator functions of
1925 the form
1926 T& operator*(T*); */
1935 /* 9 For every type T, there exist candidate operator functions of the form
1936 T* operator+(T*);
1938 10For every promoted arithmetic type T, there exist candidate operator
1939 functions of the form
1940 T operator+(T);
1941 T operator-(T); */
1951 /* 11For every promoted integral type T, there exist candidate operator
1952 functions of the form
1953 T operator~(T); */
1960 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1961 is the same type as C2 or is a derived class of C2, T is a complete
1962 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1963 there exist candidate operator functions of the form
1964 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1965 where CV12 is the union of CV1 and CV2. */
1970 {
1978 }
1981 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1982 didate operator functions of the form
1983 LR operator*(L, R);
1984 LR operator/(L, R);
1985 LR operator+(L, R);
1986 LR operator-(L, R);
1987 bool operator<(L, R);
1988 bool operator>(L, R);
1989 bool operator<=(L, R);
1990 bool operator>=(L, R);
1991 bool operator==(L, R);
1992 bool operator!=(L, R);
1993 where LR is the result of the usual arithmetic conversions between
1994 types L and R.
1996 14For every pair of types T and I, where T is a cv-qualified or cv-
1997 unqualified complete object type and I is a promoted integral type,
1998 there exist candidate operator functions of the form
1999 T* operator+(T*, I);
2000 T& operator[](T*, I);
2001 T* operator-(T*, I);
2002 T* operator+(I, T*);
2003 T& operator[](I, T*);
2005 15For every T, where T is a pointer to complete object type, there exist
2006 candidate operator functions of the form112)
2007 ptrdiff_t operator-(T, T);
2009 16For every pointer or enumeration type T, there exist candidate operator
2010 functions of the form
2011 bool operator<(T, T);
2012 bool operator>(T, T);
2013 bool operator<=(T, T);
2014 bool operator>=(T, T);
2015 bool operator==(T, T);
2016 bool operator!=(T, T);
2018 17For every pointer to member type T, there exist candidate operator
2019 functions of the form
2020 bool operator==(T, T);
2021 bool operator!=(T, T); */
2028 {
2031 }
2044 {
2047 }
2049 {
2052 }
2053 /* Fall through. */
2070 {
2073 }
2077 {
2080 }
2088 {
2091 }
2093 {
2096 }
2099 /* 18For every pair of promoted integral types L and R, there exist candi-
2100 date operator functions of the form
2101 LR operator%(L, R);
2102 LR operator&(L, R);
2103 LR operator^(L, R);
2104 LR operator|(L, R);
2105 L operator<<(L, R);
2106 L operator>>(L, R);
2107 where LR is the result of the usual arithmetic conversions between
2108 types L and R. */
2116 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2120 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2121 type, VQ is either volatile or empty, and R is a promoted arithmetic
2122 type, there exist candidate operator functions of the form
2123 VQ L& operator=(VQ L&, R);
2124 VQ L& operator*=(VQ L&, R);
2125 VQ L& operator/=(VQ L&, R);
2126 VQ L& operator+=(VQ L&, R);
2127 VQ L& operator-=(VQ L&, R);
2129 20For every pair T, VQ), where T is any type and VQ is either volatile
2130 or empty, there exist candidate operator functions of the form
2131 T*VQ& operator=(T*VQ&, T*);
2133 21For every pair T, VQ), where T is a pointer to member type and VQ is
2134 either volatile or empty, there exist candidate operator functions of
2135 the form
2136 VQ T& operator=(VQ T&, T);
2138 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2139 unqualified complete object type, VQ is either volatile or empty, and
2140 I is a promoted integral type, there exist candidate operator func-
2141 tions of the form
2142 T*VQ& operator+=(T*VQ&, I);
2143 T*VQ& operator-=(T*VQ&, I);
2145 23For every triple L, VQ, R), where L is an integral or enumeration
2146 type, VQ is either volatile or empty, and R is a promoted integral
2147 type, there exist candidate operator functions of the form
2149 VQ L& operator%=(VQ L&, R);
2150 VQ L& operator<<=(VQ L&, R);
2151 VQ L& operator>>=(VQ L&, R);
2152 VQ L& operator&=(VQ L&, R);
2153 VQ L& operator^=(VQ L&, R);
2154 VQ L& operator|=(VQ L&, R); */
2158 {
2162 {
2165 }
2178 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2191 {
2194 }
2199 }
2204 /* [over.built]
2206 For every pair of promoted arithmetic types L and R, there
2207 exist candidate operator functions of the form
2209 LR operator?(bool, L, R);
2211 where LR is the result of the usual arithmetic conversions
2212 between types L and R.
2214 For every type T, where T is a pointer or pointer-to-member
2215 type, there exist candidate operator functions of the form T
2216 operator?(bool, T, T); */
2220 /* That's OK. */
2223 /* Otherwise, the types should be pointers. */
2228 /* We don't check that the two types are the same; the logic
2229 below will actually create two candidates; one in which both
2230 parameter types are TYPE1, and one in which both parameter
2231 types are TYPE2. */
2236 }
2238 /* If we're dealing with two pointer types or two enumeral types,
2239 we need candidates for both of them. */
2248 {
2249 build_builtin_candidate
2251 build_builtin_candidate
2254 }
2256 build_builtin_candidate
2258 }
2260 tree
2262 {
2268 }
2270 /* There are three conditions of builtin candidates:
2272 1) bool-taking candidates. These are the same regardless of the input.
2273 2) pointer-pair taking candidates. These are generated for each type
2274 one of the input types converts to.
2275 3) arithmetic candidates. According to the standard, we should generate
2276 all of these, but I'm trying not to...
2278 Here we generate a superset of the possible candidates for this particular
2279 case. That is a subset of the full set the standard defines, plus some
2280 other cases which the standard disallows. add_builtin_candidate will
2281 filter out the invalid set. */
2283 static void
2287 {
2291 /* TYPES[i] is the set of possible builtin-operator parameter types
2292 we will consider for the Ith argument. These are represented as
2293 a TREE_LIST; the TREE_VALUE of each node is the potential
2294 parameter type. */
2298 {
2301 else
2303 }
2306 {
2307 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2308 and VQ is either volatile or empty, there exist candidate operator
2309 functions of the form
2310 VQ T& operator++(VQ T&); */
2320 /* 24There also exist candidate operator functions of the form
2321 bool operator!(bool);
2322 bool operator&&(bool, bool);
2323 bool operator||(bool, bool); */
2326 build_builtin_candidate
2333 build_builtin_candidate
2351 /* Fall through. */
2355 }
2360 {
2362 ;
2364 {
2365 tree convs;
2374 {
2381 }
2387 {
2400 {
2406 }
2410 }
2411 }
2412 else
2413 {
2419 {
2425 }
2427 }
2428 }
2430 /* Run through the possible parameter types of both arguments,
2431 creating candidates with those parameter types. */
2433 {
2436 add_builtin_candidate
2439 else
2440 add_builtin_candidate
2443 }
2444 }
2447 /* If TMPL can be successfully instantiated as indicated by
2448 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2450 TMPL is the template. EXPLICIT_TARGS are any explicit template
2451 arguments. ARGLIST is the arguments provided at the call-site.
2452 This does not change ARGLIST. The RETURN_TYPE is the desired type
2453 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2454 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2455 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2463 {
2473 tree arg;
2476 tree fn;
2478 /* We don't do deduction on the in-charge parameter, the VTT
2479 parameter or 'this'. */
2481 {
2484 else
2486 }
2491 {
2494 else
2496 }
2506 {
2509 }
2513 {
2516 }
2520 args_without_in_chrg,
2521 nargs_without_in_chrg,
2531 /* In [class.copy]:
2533 A member function template is never instantiated to perform the
2534 copy of a class object to an object of its class type.
2536 It's a little unclear what this means; the standard explicitly
2537 does allow a template to be used to copy a class. For example,
2538 in:
2540 struct A {
2541 A(A&);
2542 template <class T> A(const T&);
2543 };
2544 const A f ();
2545 void g () { A a (f ()); }
2547 the member template will be used to make the copy. The section
2548 quoted above appears in the paragraph that forbids constructors
2549 whose only parameter is (a possibly cv-qualified variant of) the
2550 class type, and a logical interpretation is that the intent was
2551 to forbid the instantiation of member templates which would then
2552 have that form. */
2554 {
2557 ctype))
2559 }
2562 /* Aha, this is a conversion function. */
2565 else
2570 /* This situation can occur if a member template of a template
2571 class is specialized. Then, instantiate_template might return
2572 an instantiation of the specialization, in which case the
2573 DECL_TI_TEMPLATE field will point at the original
2574 specialization. For example:
2576 template <class T> struct S { template <class U> void f(U);
2577 template <> void f(int) {}; };
2578 S<double> sd;
2579 sd.f(3);
2581 Here, TMPL will be template <class U> S<double>::f(U).
2582 And, instantiate template will give us the specialization
2583 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2584 for this will point at template <class T> template <> S<T>::f(int),
2585 so that we can find the definition. For the purposes of
2586 overload resolution, however, we want the original TMPL. */
2588 else
2592 }
2600 unification_kind_t strict)
2601 {
2602 return
2607 }
2615 tree conversion_path)
2616 {
2617 return
2621 }
2623 /* The CANDS are the set of candidates that were considered for
2624 overload resolution. Return the set of viable candidates. If none
2625 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2626 is true if a candidate should be considered viable only if it is
2627 strictly viable. */
2633 {
2644 {
2647 {
2653 }
2654 else
2656 }
2659 }
2661 static bool
2663 {
2668 }
2670 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2671 words, it is about to become the "this" pointer for a member
2672 function call. Take the address of the object. */
2674 static tree
2676 {
2677 /* In a template, we are only concerned about the type of the
2678 expression, so we can take a shortcut. */
2683 }
2685 /* Returns true iff functions are equivalent. Equivalent functions are
2686 not '==' only if one is a function-local extern function or if
2687 both are extern "C". */
2691 {
2696 }
2698 /* Print information about one overload candidate CANDIDATE. MSGSTR
2699 is the text to print before the candidate itself.
2701 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2702 to have been run through gettext by the caller. This wart makes
2703 life simpler in print_z_candidates and for the translators. */
2705 static void
2707 {
2709 {
2719 else
2722 }
2729 else
2731 }
2733 static void
2735 {
2744 /* Remove deleted candidates. */
2747 {
2751 else
2753 }
2754 /* ...if there are any non-deleted ones. */
2758 /* There may be duplicates in the set of candidates. We put off
2759 checking this condition as long as possible, since we have no way
2760 to eliminate duplicates from a set of functions in less than n^2
2761 time. Now we are about to emit an error message, so it is more
2762 permissible to go slowly. */
2764 {
2766 /* Skip builtin candidates and conversion functions. */
2771 {
2775 else
2777 }
2778 }
2783 {
2786 }
2788 }
2790 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2791 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2792 the result of the conversion function to convert it to the final
2793 desired type. Merge the two sequences into a single sequence,
2794 and return the merged sequence. */
2798 {
2803 /* Find the end of the second conversion sequence. */
2808 /* Replace the identity conversion with the user conversion
2809 sequence. */
2812 /* The entire sequence is a user-conversion sequence. */
2816 }
2818 /* Returns the best overload candidate to perform the requested
2819 conversion. This function is used for three the overloading situations
2820 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2821 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2822 per [dcl.init.ref], so we ignore temporary bindings. */
2826 {
2837 /* We represent conversion within a hierarchy using RVALUE_CONV and
2838 BASE_CONV, as specified by [over.best.ics]; these become plain
2839 constructor calls, as specified in [dcl.init]. */
2847 {
2852 {
2853 /* [class.conv.fct] A conversion function is never used to
2854 convert a (possibly cv-qualified) object to the (possibly
2855 cv-qualified) same object type (or a reference to it), to a
2856 (possibly cv-qualified) base class of that type (or a
2857 reference to it)... */
2858 }
2859 else
2862 }
2867 /* It's OK to bind a temporary for converting constructor arguments, but
2868 not in converting the return value of a conversion operator. */
2873 {
2879 {
2881 /* We still allow more conversions within an init-list. */
2883 /* But not for the copy ctor. */
2884 |LOOKUP_NO_COPY_CTOR_CONVERSION
2886 }
2887 else
2890 /* We should never try to call the abstract or base constructor
2891 from here. */
2894 }
2896 {
2907 flags,
2908 DEDUCE_CALL);
2909 else
2913 flags);
2916 {
2919 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
2920 set, then this is copy-initialization. In that case, "The
2921 result of the call is then used to direct-initialize the
2922 object that is the destination of the copy-initialization."
2923 [dcl.init]
2925 We represent this in the conversion sequence with an
2926 rvalue conversion, which means a constructor call. */
2929 cand->second_conv
2931 }
2932 }
2938 {
2939 tree fns;
2942 /* If we are called to convert to a reference type, we are trying to
2943 find an lvalue binding, so don't even consider temporaries. If
2944 we don't find an lvalue binding, the caller will try again to
2945 look for a temporary binding. */
2950 {
2957 /* [over.match.funcs] For conversion functions, the function
2958 is considered to be a member of the class of the implicit
2959 object argument for the purpose of defining the type of
2960 the implicit object parameter.
2962 So we pass fromtype as CTYPE to add_*_candidate. */
2966 NULL_TREE,
2969 conversion_path,
2970 flags,
2971 DEDUCE_CONV);
2972 else
2976 conversion_path,
2977 flags);
2980 {
2981 conversion *ics
2987 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
2988 copy-initialization. In that case, "The result of the
2989 call is then used to direct-initialize the object that is
2990 the destination of the copy-initialization." [dcl.init]
2992 We represent this in the conversion sequence with an
2993 rvalue conversion, which means a constructor call. But
2994 don't add a second rvalue conversion if there's already
2995 one there. Which there really shouldn't be, but it's
2996 harmless since we'd add it here anyway. */
3007 }
3008 }
3009 }
3017 {
3019 {
3023 }
3030 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
3031 ambiguous conversion is no worse than another user-defined
3032 conversion. */
3035 }
3037 /* Build the user conversion sequence. */
3038 conv = build_conv
3045 /* Remember that this was a list-initialization. */
3049 /* Combine it with the second conversion sequence. */
3057 }
3059 tree
3061 {
3066 {
3071 }
3073 }
3075 /* Do any initial processing on the arguments to a function call. */
3079 {
3081 tree arg;
3084 {
3088 {
3091 }
3094 }
3096 }
3098 /* Perform overload resolution on FN, which is called with the ARGS.
3100 Return the candidate function selected by overload resolution, or
3101 NULL if the event that overload resolution failed. In the case
3102 that overload resolution fails, *CANDIDATES will be the set of
3103 candidates considered, and ANY_VIABLE_P will be set to true or
3104 false to indicate whether or not any of the candidates were
3105 viable.
3107 The ARGS should already have gone through RESOLVE_ARGS before this
3108 function is called. */
3115 {
3123 /* Check FN. */
3130 {
3134 }
3136 /* Add the various candidate functions. */
3140 LOOKUP_NORMAL,
3141 candidates);
3149 }
3151 /* Return an expression for a call to FN (a namespace-scope function,
3152 or a static member function) with the ARGS. This may change
3153 ARGS. */
3155 tree
3157 tsubst_flags_t complain)
3158 {
3162 tree result;
3165 {
3169 }
3171 /* If this function was found without using argument dependent
3172 lookup, then we want to ignore any undeclared friend
3173 functions. */
3175 {
3180 {
3186 }
3187 }
3189 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3195 {
3197 {
3205 else
3210 }
3212 }
3213 else
3216 /* Free all the conversions we allocated. */
3220 }
3222 /* Build a call to a global operator new. FNNAME is the name of the
3223 operator (either "operator new" or "operator new[]") and ARGS are
3224 the arguments provided. This may change ARGS. *SIZE points to the
3225 total number of bytes required by the allocation, and is updated if
3226 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
3227 be used. If this function determines that no cookie should be
3228 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is
3229 non-NULL, it will be set, upon return, to the allocation function
3230 called. */
3232 tree
3236 {
3237 tree fns;
3249 /* Based on:
3251 [expr.new]
3253 If this lookup fails to find the name, or if the allocated type
3254 is not a class type, the allocation function's name is looked
3255 up in the global scope.
3257 we disregard block-scope declarations of "operator new". */
3260 /* Figure out what function is being called. */
3263 /* If no suitable function could be found, issue an error message
3264 and give up. */
3266 {
3270 else
3276 }
3278 /* If a cookie is required, add some extra space. Whether
3279 or not a cookie is required cannot be determined until
3280 after we know which function was called. */
3282 {
3285 {
3286 /* In G++ 3.2, the check was implemented incorrectly; it
3287 looked at the placement expression, rather than the
3288 type of the function. */
3291 ptr_type_node))
3293 }
3294 else
3295 {
3296 tree arg_types;
3299 /* Skip the size_t parameter. */
3301 /* Check the remaining parameters (if any). */
3305 ptr_type_node))
3307 }
3308 /* If we need a cookie, adjust the number of bytes allocated. */
3310 {
3311 /* Update the total size. */
3313 /* Update the argument list to reflect the adjusted size. */
3315 }
3316 else
3318 }
3320 /* Tell our caller which function we decided to call. */
3324 /* Build the CALL_EXPR. */
3326 }
3328 /* Build a new call to operator(). This may change ARGS. */
3330 tree
3332 {
3346 {
3348 /* It's no good looking for an overloaded operator() on a
3349 pointer-to-member-function. */
3350 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3352 }
3355 {
3359 }
3360 else
3364 {
3368 }
3370 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3374 {
3379 {
3388 else
3389 add_function_candidate
3392 }
3393 }
3398 {
3410 {
3417 add_template_conv_candidate
3421 else
3425 }
3426 }
3430 {
3432 {
3436 }
3438 }
3439 else
3440 {
3443 {
3445 {
3449 }
3451 }
3452 /* Since cand->fn will be a type, not a function, for a conversion
3453 function, we must be careful not to unconditionally look at
3454 DECL_NAME here. */
3458 else
3459 {
3461 complain);
3464 }
3465 }
3467 /* Free all the conversions we allocated. */
3471 }
3473 static void
3476 {
3481 else
3485 {
3490 else
3500 else
3509 else
3519 else
3529 else
3532 else
3536 else
3540 }
3541 }
3543 /* Return the implicit conversion sequence that could be used to
3544 convert E1 to E2 in [expr.cond]. */
3548 {
3554 /* [expr.cond]
3556 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3557 implicitly converted (clause _conv_) to the type "reference to
3558 T2", subject to the constraint that in the conversion the
3559 reference must bind directly (_dcl.init.ref_) to E1. */
3561 {
3563 t1,
3564 e1,
3569 }
3571 /* [expr.cond]
3573 If E1 and E2 have class type, and the underlying class types are
3574 the same or one is a base class of the other: E1 can be converted
3575 to match E2 if the class of T2 is the same type as, or a base
3576 class of, the class of T1, and the cv-qualification of T2 is the
3577 same cv-qualification as, or a greater cv-qualification than, the
3578 cv-qualification of T1. If the conversion is applied, E1 is
3579 changed to an rvalue of type T2 that still refers to the original
3580 source class object (or the appropriate subobject thereof). */
3583 {
3585 {
3590 else
3593 }
3594 else
3596 }
3597 else
3598 /* [expr.cond]
3600 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3601 converted to the type that expression E2 would have if E2 were
3602 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3604 LOOKUP_IMPLICIT);
3605 }
3607 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3608 arguments to the conditional expression. */
3610 tree
3612 tsubst_flags_t complain)
3613 {
3614 tree arg2_type;
3615 tree arg3_type;
3617 tree result_save;
3624 /* As a G++ extension, the second argument to the conditional can be
3625 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3626 c'.) If the second operand is omitted, make sure it is
3627 calculated only once. */
3629 {
3634 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3637 else
3639 }
3641 /* [expr.cond]
3643 The first expression is implicitly converted to bool (clause
3644 _conv_). */
3646 LOOKUP_NORMAL);
3648 /* If something has already gone wrong, just pass that fact up the
3649 tree. */
3655 /* [expr.cond]
3657 If either the second or the third operand has type (possibly
3658 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3659 array-to-pointer (_conv.array_), and function-to-pointer
3660 (_conv.func_) standard conversions are performed on the second
3661 and third operands. */
3665 {
3666 /* Do the conversions. We don't these for `void' type arguments
3667 since it can't have any effect and since decay_conversion
3668 does not handle that case gracefully. */
3676 /* [expr.cond]
3678 One of the following shall hold:
3680 --The second or the third operand (but not both) is a
3681 throw-expression (_except.throw_); the result is of the
3682 type of the other and is an rvalue.
3684 --Both the second and the third operands have type void; the
3685 result is of type void and is an rvalue.
3687 We must avoid calling force_rvalue for expressions of type
3688 "void" because it will complain that their value is being
3689 used. */
3692 {
3697 }
3700 {
3705 }
3708 else
3709 {
3711 {
3714 "is of type %<void%>, "
3715 "but the third operand is neither a throw-expression "
3717 else
3719 "is of type %<void%>, "
3720 "but the second operand is neither a throw-expression "
3722 }
3724 }
3728 }
3729 /* [expr.cond]
3731 Otherwise, if the second and third operand have different types,
3732 and either has (possibly cv-qualified) class type, an attempt is
3733 made to convert each of those operands to the type of the other. */
3736 {
3740 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3746 /* [expr.cond]
3748 If both can be converted, or one can be converted but the
3749 conversion is ambiguous, the program is ill-formed. If
3750 neither can be converted, the operands are left unchanged and
3751 further checking is performed as described below. If exactly
3752 one conversion is possible, that conversion is applied to the
3753 chosen operand and the converted operand is used in place of
3754 the original operand for the remainder of this section. */
3759 {
3763 }
3765 {
3769 /* Even if CONV2 is a valid conversion, the result of the
3770 conversion may be invalid. For example, if ARG3 has type
3771 "volatile X", and X does not have a copy constructor
3772 accepting a "volatile X&", then even if ARG2 can be
3773 converted to X, the conversion will fail. */
3776 }
3778 {
3784 }
3786 /* Free all the conversions we allocated. */
3792 /* If, after the conversion, both operands have class type,
3793 treat the cv-qualification of both operands as if it were the
3794 union of the cv-qualification of the operands.
3796 The standard is not clear about what to do in this
3797 circumstance. For example, if the first operand has type
3798 "const X" and the second operand has a user-defined
3799 conversion to "volatile X", what is the type of the second
3800 operand after this step? Making it be "const X" (matching
3801 the first operand) seems wrong, as that discards the
3802 qualification without actually performing a copy. Leaving it
3803 as "volatile X" seems wrong as that will result in the
3804 conditional expression failing altogether, even though,
3805 according to this step, the one operand could be converted to
3806 the type of the other. */
3814 }
3816 /* [expr.cond]
3818 If the second and third operands are lvalues and have the same
3819 type, the result is of that type and is an lvalue. */
3823 {
3826 }
3828 /* [expr.cond]
3830 Otherwise, the result is an rvalue. If the second and third
3831 operand do not have the same type, and either has (possibly
3832 cv-qualified) class type, overload resolution is used to
3833 determine the conversions (if any) to be applied to the operands
3834 (_over.match.oper_, _over.built_). */
3838 {
3843 /* Rearrange the arguments so that add_builtin_candidate only has
3844 to know about two args. In build_builtin_candidate, the
3845 arguments are unscrambled. */
3850 COND_EXPR,
3851 NOP_EXPR,
3853 args,
3854 LOOKUP_NORMAL);
3856 /* [expr.cond]
3858 If the overload resolution fails, the program is
3859 ill-formed. */
3862 {
3864 {
3867 }
3869 }
3872 {
3874 {
3877 }
3879 }
3881 /* [expr.cond]
3883 Otherwise, the conversions thus determined are applied, and
3884 the converted operands are used in place of the original
3885 operands for the remainder of this section. */
3894 }
3896 /* [expr.cond]
3898 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3899 and function-to-pointer (_conv.func_) standard conversions are
3900 performed on the second and third operands.
3902 We need to force the lvalue-to-rvalue conversion here for class types,
3903 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3904 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3905 regions. */
3918 /* [expr.cond]
3920 After those conversions, one of the following shall hold:
3922 --The second and third operands have the same type; the result is of
3923 that type. */
3926 /* [expr.cond]
3928 --The second and third operands have arithmetic or enumeration
3929 type; the usual arithmetic conversions are performed to bring
3930 them to a common type, and the result is of that type. */
3935 {
3936 /* In this case, there is always a common type. */
3938 arg3_type);
3942 {
3947 }
3953 {
3957 }
3961 }
3962 /* [expr.cond]
3964 --The second and third operands have pointer type, or one has
3965 pointer type and the other is a null pointer constant; pointer
3966 conversions (_conv.ptr_) and qualification conversions
3967 (_conv.qual_) are performed to bring them to their composite
3968 pointer type (_expr.rel_). The result is of the composite
3969 pointer type.
3971 --The second and third operands have pointer to member type, or
3972 one has pointer to member type and the other is a null pointer
3973 constant; pointer to member conversions (_conv.mem_) and
3974 qualification conversions (_conv.qual_) are performed to bring
3975 them to a common type, whose cv-qualification shall match the
3976 cv-qualification of either the second or the third operand.
3977 The result is of the common type. */
3985 {
3988 complain);
3993 }
3996 {
4001 }
4003 valid_operands:
4008 /* Avoid folding to a CALL_EXPR within decltype (c++/42013). */
4011 /* We can't use result_type below, as fold might have returned a
4012 throw_expr. */
4015 {
4016 /* Expand both sides into the same slot, hopefully the target of
4017 the ?: expression. We used to check for TARGET_EXPRs here,
4018 but now we sometimes wrap them in NOP_EXPRs so the test would
4019 fail. */
4022 /* If this expression is an rvalue, but might be mistaken for an
4023 lvalue, we must add a NON_LVALUE_EXPR. */
4025 }
4028 }
4030 /* OPERAND is an operand to an expression. Perform necessary steps
4031 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
4032 returned. */
4034 static tree
4036 {
4038 {
4041 /* Make sure the template type is instantiated now. */
4043 }
4046 }
4048 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
4049 OVERLOAD) to the CANDIDATES, returning an updated list of
4050 CANDIDATES. The ARGS are the arguments provided to the call,
4051 without any implicit object parameter. This may change ARGS. The
4052 EXPLICIT_TARGS are explicit template arguments provided.
4053 TEMPLATE_ONLY is true if only template functions should be
4054 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
4055 add_function_candidate. */
4057 static void
4063 {
4064 tree ctype;
4066 tree first_arg;
4069 /* Delay creating the implicit this parameter until it is needed. */
4074 {
4075 tree fn;
4076 tree fn_first_arg;
4080 /* Figure out which set of arguments to use. */
4082 {
4083 /* If this function is a non-static member, prepend the implicit
4084 object parameter. */
4086 {
4088 tree arg;
4094 }
4099 }
4100 else
4101 {
4102 /* Otherwise, just use the list of arguments provided. */
4105 }
4109 fn,
4110 ctype,
4111 explicit_targs,
4112 fn_first_arg,
4113 fn_args,
4114 NULL_TREE,
4115 access_path,
4116 conversion_path,
4117 flags,
4118 DEDUCE_CALL);
4121 fn,
4122 ctype,
4123 fn_first_arg,
4124 fn_args,
4125 access_path,
4126 conversion_path,
4127 flags);
4129 }
4130 }
4132 /* Even unsigned enum types promote to signed int. We don't want to
4133 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the
4134 original argument and ARG is the argument after any conversions
4135 have been applied. We set TREE_NO_WARNING if we have added a cast
4136 from an unsigned enum type to a signed integer type. */
4138 static void
4140 {
4149 }
4151 tree
4154 {
4160 tree fnname;
4178 {
4182 }
4183 else
4189 {
4194 /* Use build_op_new_call and build_op_delete_call instead. */
4198 /* Use build_op_call instead. */
4205 /* These are saved for the sake of warn_logical_operator. */
4211 }
4217 /* Use build_conditional_expr instead. */
4233 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4236 /* Add namespace-scope operators to the list of functions to
4237 consider. */
4241 /* Add class-member operators to the candidate set. */
4243 {
4244 tree fns;
4248 {
4251 }
4258 }
4267 {
4270 /* For these, the built-in candidates set is empty
4271 [over.match.oper]/3. We don't want non-strict matches
4272 because exact matches are always possible with built-in
4273 operators. The built-in candidate set for COMPONENT_REF
4274 would be empty too, but since there are no such built-in
4275 operators, we accept non-strict matches for them. */
4282 }
4286 {
4288 {
4291 /* Don't try anything fancy if we're not allowed to produce
4292 errors. */
4296 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
4297 distinguish between prefix and postfix ++ and
4298 operator++() was used for both, so we allow this with
4299 -fpermissive. */
4301 {
4308 }
4315 else
4321 /* The caller will deal with these. */
4331 {
4332 /* If one of the arguments of the operator represents
4333 an invalid use of member function pointer, try to report
4334 a meaningful error ... */
4339 else
4340 {
4341 /* ... Otherwise, report the more generic
4342 "no matching operator found" error */
4345 }
4346 }
4349 }
4350 }
4351 else
4352 {
4355 {
4357 {
4360 }
4362 }
4364 {
4370 else
4372 }
4373 else
4374 {
4375 /* Give any warnings we noticed during overload resolution. */
4377 {
4381 }
4383 /* Check for comparison of different enum types. */
4385 {
4397 {
4401 }
4405 }
4407 /* We need to strip any leading REF_BIND so that bitfields
4408 don't cause errors. This should not remove any important
4409 conversions, because builtins don't apply to class
4410 objects directly. */
4417 {
4418 /* We need to call warn_logical_operator before
4419 converting arg2 to a boolean_type. */
4429 }
4431 {
4436 }
4438 }
4439 }
4441 user_defined_result_ready:
4443 /* Free all the conversions we allocated. */
4449 builtin:
4455 {
4468 /* Fall through. */
4506 complain),
4507 arg2);
4509 /* The caller will deal with these. */
4517 }
4519 }
4521 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
4522 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
4524 static bool
4526 {
4527 /* A template instance is never a usual deallocation function,
4528 regardless of its signature. */
4533 /* If a class T has a member deallocation function named operator delete
4534 with exactly one parameter, then that function is a usual
4535 (non-placement) deallocation function. If class T does not declare
4536 such an operator delete but does declare a member deallocation
4537 function named operator delete with exactly two parameters, the second
4538 of which has type std::size_t (18.2), then this function is a usual
4539 deallocation function. */
4546 }
4548 /* Build a call to operator delete. This has to be handled very specially,
4549 because the restrictions on what signatures match are different from all
4550 other call instances. For a normal delete, only a delete taking (void *)
4551 or (void *, size_t) is accepted. For a placement delete, only an exact
4552 match with the placement new is accepted.
4554 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4555 ADDR is the pointer to be deleted.
4556 SIZE is the size of the memory block to be deleted.
4557 GLOBAL_P is true if the delete-expression should not consider
4558 class-specific delete operators.
4559 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4561 If this call to "operator delete" is being generated as part to
4562 deallocate memory allocated via a new-expression (as per [expr.new]
4563 which requires that if the initialization throws an exception then
4564 we call a deallocation function), then ALLOC_FN is the allocation
4565 function. */
4567 tree
4570 tree alloc_fn)
4571 {
4585 /* In [class.free]
4587 If the result of the lookup is ambiguous or inaccessible, or if
4588 the lookup selects a placement deallocation function, the
4589 program is ill-formed.
4591 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4592 {
4596 }
4597 else
4603 /* Strip const and volatile from addr. */
4607 {
4608 /* "A declaration of a placement deallocation function matches the
4609 declaration of a placement allocation function if it has the same
4610 number of parameters and, after parameter transformations (8.3.5),
4611 all parameter types except the first are identical."
4613 So we build up the function type we want and ask instantiate_type
4614 to get it for us. */
4626 /* "If the lookup finds the two-parameter form of a usual deallocation
4627 function (3.7.4.2) and that function, considered as a placement
4628 deallocation function, would have been selected as a match for the
4629 allocation function, the program is ill-formed." */
4631 {
4632 /* But if the class has an operator delete (void *), then that is
4633 the usual deallocation function, so we shouldn't complain
4634 about using the operator delete (void *, size_t). */
4637 {
4642 }
4645 ok:;
4646 }
4647 }
4648 else
4649 /* "Any non-placement deallocation function matches a non-placement
4650 allocation function. If the lookup finds a single matching
4651 deallocation function, that function will be called; otherwise, no
4652 deallocation function will be called." */
4655 {
4658 {
4660 /* "If a class T has a member deallocation function named
4661 operator delete with exactly one parameter, then that
4662 function is a usual (non-placement) deallocation
4663 function. If class T does not declare such an operator
4664 delete but does declare a member deallocation function named
4665 operator delete with exactly two parameters, the second of
4666 which has type std::size_t (18.2), then this function is a
4667 usual deallocation function."
4669 So (void*) beats (void*, size_t). */
4672 }
4673 }
4675 /* If we have a matching function, call it. */
4677 {
4680 /* If the FN is a member function, make sure that it is
4681 accessible. */
4685 /* Core issue 901: It's ok to new a type with deleted delete. */
4690 {
4691 /* The placement args might not be suitable for overload
4692 resolution at this point, so build the call directly. */
4701 }
4702 else
4703 {
4704 tree ret;
4712 }
4713 }
4715 /* [expr.new]
4717 If no unambiguous matching deallocation function can be found,
4718 propagating the exception does not cause the object's memory to
4719 be freed. */
4721 {
4724 alloc_fn);
4726 }
4731 }
4733 /* If the current scope isn't allowed to access DECL along
4734 BASETYPE_PATH, give an error. The most derived class in
4735 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4736 the declaration to use in the error diagnostic. */
4738 bool
4740 {
4744 {
4749 else
4753 }
4756 }
4758 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4759 bitwise or of LOOKUP_* values. If any errors are warnings are
4760 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4761 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4762 to NULL. */
4764 static tree
4767 {
4780 else
4783 }
4785 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4786 EXPR is implicitly converted to type TOTYPE.
4787 FN and ARGNUM are used for diagnostics. */
4789 static void
4791 {
4794 /* Issue warnings about peculiar, but valid, uses of NULL. */
4796 {
4801 else
4804 }
4806 /* Issue warnings if "false" is converted to a NULL pointer */
4811 }
4813 /* Perform the conversions in CONVS on the expression EXPR. FN and
4814 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4815 indicates the `this' argument of a method. INNER is nonzero when
4816 being called to continue a conversion chain. It is negative when a
4817 reference binding will be applied, positive otherwise. If
4818 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4819 conversions will be emitted if appropriate. If C_CAST_P is true,
4820 this conversion is coming from a C-style cast; in that case,
4821 conversions to inaccessible bases are permitted. */
4823 static tree
4827 {
4829 diagnostic_t diag_kind;
4839 {
4842 /* Give a helpful error if this is bad because of excess braces. */
4850 {
4852 {
4856 complain);
4858 }
4863 complain);
4866 }
4868 {
4872 }
4873 else
4877 }
4883 {
4885 {
4890 /* When converting from an init list we consider explicit
4891 constructors, but actually trying to call one is an error. */
4893 {
4897 else
4899 }
4901 /* Set user_conv_p on the argument conversions, so rvalue/base
4902 handling knows not to allow any more UDCs. */
4908 /* If this is a constructor or a function returning an aggr type,
4909 we need to build up a TARGET_EXPR. */
4911 {
4914 /* Remember that this was list-initialization. */
4917 }
4920 }
4923 {
4929 else
4931 }
4935 /* Convert a constant to its underlying value, unless we are
4936 about to bind it to a reference, in which case we need to
4937 leave it as an lvalue. */
4939 {
4942 /* If __null has been converted to an integer type, we do not
4943 want to warn about uses of EXPR as an integer, rather than
4944 as a pointer. */
4946 }
4949 /* Call build_user_type_conversion again for the error. */
4950 return build_user_type_conversion
4954 {
4955 /* Conversion to std::initializer_list<T>. */
4963 /* Convert all the elements. */
4965 {
4972 }
4973 /* Build up the array. */
4974 elttype = cp_build_qualified_type
4982 /* Call the private constructor. */
4984 new_ctor = build_special_member_call
4989 }
4996 };
5001 c_cast_p,
5002 complain);
5007 {
5012 /* Else fall through. */
5015 {
5016 /* We are going to bind a reference directly to a base-class
5017 subobject of EXPR. */
5018 /* Build an expression for `*((base*) &expr)'. */
5024 }
5026 /* Copy-initialization where the cv-unqualified version of the source
5027 type is the same class as, or a derived class of, the class of the
5028 destination [is treated as direct-initialization]. [dcl.init] */
5031 /* This conversion is being done in the context of a user-defined
5032 conversion (i.e. the second step of copy-initialization), so
5033 don't allow any more. */
5037 {
5043 }
5047 {
5052 {
5054 {
5059 }
5061 }
5063 /* If necessary, create a temporary.
5065 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
5066 that need temporaries, even when their types are reference
5067 compatible with the type of reference being bound, so the
5068 upcoming call to cp_build_unary_op (ADDR_EXPR, expr, ...)
5069 doesn't fail. */
5073 {
5079 {
5081 {
5082 /* If the reference is volatile or non-const, we
5083 cannot create a temporary. */
5090 else
5092 }
5094 }
5095 /* If the source is a packed field, and we must use a copy
5096 constructor, then building the target expr will require
5097 binding the field to the reference parameter to the
5098 copy constructor, and we'll end up with an infinite
5099 loop. If we can use a bitwise copy, then we'll be
5100 OK. */
5104 {
5109 }
5111 {
5114 }
5116 }
5118 /* Take the address of the thing to which we will bind the
5119 reference. */
5124 /* Convert it to a pointer to the type referred to by the
5125 reference. This will adjust the pointer if a derived to
5126 base conversion is being performed. */
5128 expr);
5129 /* Convert the pointer to the desired reference type. */
5131 }
5137 /* Warn about deprecated conversion if appropriate. */
5149 c_cast_p);
5153 }
5160 else
5164 }
5166 /* ARG is being passed to a varargs function. Perform any conversions
5167 required. Return the converted value. */
5169 tree
5171 {
5172 /* [expr.call]
5174 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5175 standard conversions are performed. */
5177 /* [expr.call]
5179 If the argument has integral or enumeration type that is subject
5180 to the integral promotions (_conv.prom_), or a floating point
5181 type that is subject to the floating point promotion
5182 (_conv.fpprom_), the value of the argument is converted to the
5183 promoted type before the call. */
5197 {
5198 /* [expr.call] 5.2.2/7:
5199 Passing a potentially-evaluated argument of class type (Clause 9)
5200 with a non-trivial copy constructor or a non-trivial destructor
5201 with no corresponding parameter is conditionally-supported, with
5202 implementation-defined semantics.
5204 We used to just warn here and do a bitwise copy, but now
5205 cp_expr_size will abort if we try to do that.
5207 If the call appears in the context of a sizeof expression,
5208 it is not potentially-evaluated. */
5212 }
5215 }
5217 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
5219 tree
5221 {
5233 {
5234 /* Remove reference types so we don't ICE later on. */
5236 /* conditionally-supported behavior [expr.call] 5.2.2/7. */
5242 }
5245 }
5247 /* TYPE has been given to va_arg. Apply the default conversions which
5248 would have happened when passed via ellipsis. Return the promoted
5249 type, or the passed type if there is no change. */
5251 tree
5253 {
5254 tree promote;
5256 /* Perform the array-to-pointer and function-to-pointer
5257 conversions. */
5265 }
5267 /* ARG is a default argument expression being passed to a parameter of
5268 the indicated TYPE, which is a parameter to FN. Do any required
5269 conversions. Return the converted value. */
5273 tree
5275 {
5277 tree t;
5279 /* If the ARG is an unparsed default argument expression, the
5280 conversion cannot be performed. */
5282 {
5287 }
5289 /* Detect recursion. */
5292 {
5295 }
5301 /* Due to:
5303 [dcl.fct.default]
5305 The names in the expression are bound, and the semantic
5306 constraints are checked, at the point where the default
5307 expressions appears.
5309 we must not perform access checks here. */
5313 {
5317 tf_warning_or_error);
5318 }
5319 else
5320 {
5321 /* We must make a copy of ARG, in case subsequent processing
5322 alters any part of it. For example, during gimplification a
5323 cast of the form (T) &X::f (where "f" is a member function)
5324 will lead to replacing the PTRMEM_CST for &X::f with a
5325 VAR_DECL. We can avoid the copy for constants, since they
5326 are never modified in place. */
5331 tf_warning_or_error);
5333 }
5339 }
5341 /* Returns the type which will really be used for passing an argument of
5342 type TYPE. */
5344 tree
5346 {
5347 /* Pass classes with copy ctors by invisible reference. */
5349 {
5351 /* There are no other pointers to this temporary. */
5353 }
5362 }
5364 /* Actually perform the appropriate conversion. */
5366 tree
5368 {
5369 tree bitfield_type;
5371 /* If VAL is a bitfield, then -- since it has already been converted
5372 to TYPE -- it cannot have a precision greater than TYPE.
5374 If it has a smaller precision, we must widen it here. For
5375 example, passing "int f:3;" to a function expecting an "int" will
5376 not result in any conversion before this point.
5378 If the precision is the same we must not risk widening. For
5379 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5380 often have type "int", even though the C++ type for the field is
5381 "long long". If the value is being passed to a function
5382 expecting an "int", then no conversions will be required. But,
5383 if we call convert_bitfield_to_declared_type, the bitfield will
5384 be converted to "long long". */
5391 ;
5392 /* Pass classes with copy ctors by invisible reference. */
5402 {
5411 }
5413 }
5415 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5416 which no conversions at all should be done. This is true for some
5417 builtins which don't act like normal functions. */
5419 static bool
5421 {
5424 {
5434 }
5437 }
5439 /* Subroutine of the various build_*_call functions. Overload resolution
5440 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5441 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5442 bitmask of various LOOKUP_* flags which apply to the call itself. */
5444 static tree
5446 {
5454 tree val;
5463 /* In a template, there is no need to perform all of the work that
5464 is normally done. We are only interested in the type of the call
5465 expression, i.e., the return type of the function. Any semantic
5466 errors will be deferred until the template is instantiated. */
5468 {
5469 tree expr;
5470 tree return_type;
5478 else
5479 {
5482 tree arg;
5490 }
5493 argarray);
5499 }
5501 /* Give any warnings we noticed during overload resolution. */
5503 {
5507 }
5509 /* Make =delete work with SFINAE. */
5514 {
5515 /* If FN is a template function, two cases must be considered.
5516 For example:
5518 struct A {
5519 protected:
5520 template <class T> void f();
5521 };
5522 template <class T> struct B {
5523 protected:
5524 void g();
5525 };
5526 struct C : A, B<int> {
5527 using A::f; // #1
5528 using B<int>::g; // #2
5529 };
5531 In case #1 where `A::f' is a member template, DECL_ACCESS is
5532 recorded in the primary template but not in its specialization.
5533 We check access of FN using its primary template.
5535 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
5536 because it is a member of class template B, DECL_ACCESS is
5537 recorded in the specialization `B<int>::g'. We cannot use its
5538 primary template because `B<T>::g' and `B<int>::g' may have
5539 different access. */
5544 else
5546 }
5548 /* Find maximum size of vector to hold converted arguments. */
5555 /* The implicit parameters to a constructor are not considered by overload
5556 resolution, and must be of the proper type. */
5558 {
5560 {
5563 }
5564 else
5565 {
5568 }
5570 /* We should never try to call the abstract constructor. */
5574 {
5578 }
5579 }
5580 /* Bypass access control for 'this' parameter. */
5582 {
5585 ? first_arg
5588 tree converted_arg;
5589 tree base_binfo;
5592 {
5596 else
5598 }
5600 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
5601 X is called for an object that is not of type X, or of a type
5602 derived from X, the behavior is undefined.
5604 So we can assume that anything passed as 'this' is non-null, and
5605 optimize accordingly. */
5607 /* Convert to the base in which the function was declared. */
5610 arg,
5613 /* Check that the base class is accessible. */
5619 /* If fn was found by a using declaration, the conversion path
5620 will be to the derived class, not the base declaring fn. We
5621 must convert from derived to base. */
5631 else
5635 }
5640 {
5645 /* Don't make a copy here if build_call is going to. */
5651 /* Warn about initializer_list deduction that isn't currently in the
5652 working draft. */
5654 && flag_deduce_init_list
5657 {
5667 {
5674 }
5675 }
5677 val = convert_like_with_context
5679 complain);
5684 else
5686 }
5688 /* Default arguments */
5693 /* Ellipsis */
5695 {
5699 else
5702 }
5710 /* Avoid actually calling copy constructors and copy assignment operators,
5711 if possible. */
5718 {
5719 tree targ;
5721 tree fa;
5723 /* Pull out the real argument, disregarding const-correctness. */
5729 {
5734 }
5735 else
5740 else
5745 {
5746 /* Copy-list-initialization doesn't require the copy constructor
5747 to be defined. */
5748 }
5749 /* [class.copy]: the copy constructor is implicitly defined even if
5750 the implementation elided its use. */
5752 {
5755 }
5757 /* If we're creating a temp and we already have one, don't create a
5758 new one. If we're not creating a temp but we get one, use
5759 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5760 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5761 temp or an INIT_EXPR otherwise. */
5766 {
5771 }
5775 {
5777 complain));
5783 {
5784 /* Avoid copying empty classes. */
5789 }
5790 else
5793 }
5794 }
5798 {
5799 tree to = stabilize_reference
5806 {
5807 /* Avoid copying empty classes. */
5812 }
5814 {
5817 }
5818 else
5819 {
5820 /* We must only copy the non-tail padding parts.
5821 Use __builtin_memcpy for the bitwise copy.
5822 FIXME fix 22488 so we can go back to using MODIFY_EXPR
5823 instead of an explicit call to memcpy. */
5833 {
5834 /* If we can't be sure about pointer alignment, a call
5835 to __builtin_memcpy is expanded as a call to memcpy, which
5836 is invalid with identical args. Otherwise it is
5837 expanded as a block move, which should be safe. */
5841 }
5850 }
5853 }
5859 {
5860 tree t;
5866 /* Warn about deprecated virtual functions now, since we're about
5867 to throw away the decl. */
5877 else
5880 }
5881 else
5885 }
5887 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5888 This function performs no overload resolution, conversion, or other
5889 high-level operations. */
5891 tree
5893 {
5894 tree fndecl;
5898 /* If this call might throw an exception, note that fact. */
5905 /* Check that arguments to builtin functions match the expectations. */
5912 /* Some built-in function calls will be evaluated at compile-time in
5913 fold (). */
5926 }
5930 /* Make an expression which yields the address of the Java interface
5931 method FN. This is achieved by generating a call to libjava's
5932 _Jv_LookupInterfaceMethodIdx(). */
5934 static tree
5936 {
5942 {
5947 endlink)));
5948 java_iface_lookup_fn
5952 }
5954 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5955 This is the first entry in the vtable. */
5957 tf_warning_or_error),
5958 integer_zero_node);
5960 /* Get the java.lang.Class pointer for the interface being called. */
5965 {
5967 iface);
5969 }
5973 /* Determine the itable index of FN. */
5976 {
5981 i++;
5982 }
5987 java_iface_lookup_fn);
5990 }
5992 /* Returns the value to use for the in-charge parameter when making a
5993 call to a function with the indicated NAME.
5995 FIXME:Can't we find a neater way to do this mapping? */
5997 tree
5999 {
6010 /* This function should only be called with one of the names listed
6011 above. */
6014 }
6016 /* Build a call to a constructor, destructor, or an assignment
6017 operator for INSTANCE, an expression with class type. NAME
6018 indicates the special member function to call; *ARGS are the
6019 arguments. ARGS may be NULL. This may change ARGS. BINFO
6020 indicates the base of INSTANCE that is to be passed as the `this'
6021 parameter to the member function called.
6023 FLAGS are the LOOKUP_* flags to use when processing the call.
6025 If NAME indicates a complete object constructor, INSTANCE may be
6026 NULL_TREE. In this case, the caller will call build_cplus_new to
6027 store the newly constructed object into a VAR_DECL. */
6029 tree
6032 {
6033 tree fns;
6034 /* The type of the subobject to be constructed or destroyed. */
6035 tree class_type;
6037 tree ret;
6046 {
6047 /* Resolve the name. */
6052 }
6058 /* Handle the special case where INSTANCE is NULL_TREE. */
6060 {
6063 }
6064 else
6065 {
6071 /* Convert to the base class, if necessary. */
6074 {
6076 /* For constructors and destructors, either the base is
6077 non-virtual, or it is virtual but we are doing the
6078 conversion from a constructor or destructor for the
6079 complete object. In either case, we can convert
6080 statically. */
6082 else
6083 /* However, for assignment operators, we must convert
6084 dynamically if the base is virtual. */
6087 }
6088 }
6094 /* When making a call to a constructor or destructor for a subobject
6095 that uses virtual base classes, pass down a pointer to a VTT for
6096 the subobject. */
6100 {
6101 tree vtt;
6102 tree sub_vtt;
6104 /* If the current function is a complete object constructor
6105 or destructor, then we fetch the VTT directly.
6106 Otherwise, we look it up using the VTT we were given. */
6112 current_vtt_parm,
6113 vtt);
6119 {
6122 }
6125 }
6130 complain);
6136 }
6138 /* Return the NAME, as a C string. The NAME indicates a function that
6139 is a member of TYPE. *FREE_P is set to true if the caller must
6140 free the memory returned.
6142 Rather than go through all of this, we should simply set the names
6143 of constructors and destructors appropriately, and dispense with
6144 ctor_identifier, dtor_identifier, etc. */
6148 {
6151 /* Assume that we will not allocate memory. */
6153 /* Constructors and destructors are special. */
6155 {
6156 pretty_name
6158 /* For a destructor, add the '~'. */
6162 {
6164 /* Remember that we need to free the memory allocated. */
6166 }
6167 }
6169 {
6172 TFF_PLAIN_IDENTIFIER),
6173 NULL);
6174 /* Remember that we need to free the memory allocated. */
6176 }
6177 else
6181 }
6183 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
6184 be set, upon return, to the function called. ARGS may be NULL.
6185 This may change ARGS. */
6187 tree
6191 {
6195 tree access_binfo;
6196 tree optype;
6198 tree instance_ptr;
6199 tree name;
6202 tree call;
6203 tree fn;
6204 tree class_type;
6207 tree orig_instance;
6208 tree orig_fns;
6214 /* We don't know what function we're going to call, yet. */
6223 {
6227 }
6232 /* Dismantle the baselink to collect all the information we need. */
6239 {
6243 }
6254 {
6259 }
6262 /* Under DR 147 A::A() is an invalid constructor call,
6263 not a functional cast. */
6265 {
6275 complain);
6277 }
6279 /* Figure out whether to skip the first argument for the error
6280 message we will display to users if an error occurs. We don't
6281 want to display any compiler-generated arguments. The "this"
6282 pointer hasn't been added yet. However, we must remove the VTT
6283 pointer if this is a call to a base-class constructor or
6284 destructor. */
6287 {
6288 /* Callers should explicitly indicate whether they want to construct
6289 the complete object or just the part without virtual bases. */
6291 /* Similarly for destructors. */
6293 /* Remove the VTT pointer, if present. */
6297 }
6299 /* Process the argument list. */
6301 {
6305 }
6309 /* It's OK to call destructors and constructors on cv-qualified objects.
6310 Therefore, convert the INSTANCE_PTR to the unqualified type, if
6311 necessary. */
6314 {
6318 }
6322 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
6323 initializer, not T({ }). If the type doesn't have a list ctor,
6324 break apart the list into separate ctor args. */
6329 {
6332 }
6337 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6341 {
6343 tree this_first_arg;
6345 /* We can end up here for copy-init of same or base class. */
6352 else
6356 /* A member template. */
6358 class_type,
6359 explicit_targs,
6360 this_first_arg,
6362 optype,
6363 access_binfo,
6364 conversion_path,
6365 flags,
6366 DEDUCE_CALL);
6369 class_type,
6370 this_first_arg,
6372 access_binfo,
6373 conversion_path,
6374 flags);
6375 }
6379 {
6381 {
6384 else
6385 {
6388 tree arglist;
6399 }
6401 }
6403 }
6404 else
6405 {
6408 {
6411 tree arglist;
6414 {
6420 arglist);
6424 }
6426 }
6427 else
6428 {
6437 /* This is not an error, it is runtime undefined
6438 behavior. */
6440 "abstract virtual %q#D called from constructor"
6442 fn);
6446 {
6449 fn);
6451 }
6452 else
6453 {
6457 /* Now we know what function is being called. */
6460 /* Build the actual CALL_EXPR. */
6462 /* In an expression of the form `a->f()' where `f' turns
6463 out to be a static member function, `a' is
6464 none-the-less evaluated. */
6473 /* An explicit call of the form "x->~X()" has type
6474 "void". However, on platforms where destructors
6475 return "this" (i.e., those where
6476 targetm.cxx.cdtor_returns_this is true), such calls
6477 will appear to have a return value of pointer type
6478 to the low-level call machinery. We do not want to
6479 change the low-level machinery, since we want to be
6480 able to optimize "delete f()" on such platforms as
6481 "operator delete(~X(f()))" (rather than generating
6482 "t = f(), ~X(t), operator delete (t)"). */
6484 }
6485 }
6486 }
6489 {
6495 {
6498 }
6501 call = (build_min_non_dep_call_vec
6505 orig_args));
6509 }
6511 /* Free all the conversions we allocated. */
6518 }
6520 /* Returns true iff standard conversion sequence ICS1 is a proper
6521 subsequence of ICS2. */
6523 static bool
6525 {
6526 /* We can assume that a conversion of the same code
6527 between the same types indicates a subsequence since we only get
6528 here if the types we are converting from are the same. */
6535 {
6543 /* At this point, ICS1 cannot be a proper subsequence of
6544 ICS2. We can get a USER_CONV when we are comparing the
6545 second standard conversion sequence of two user conversion
6546 sequences. */
6556 }
6557 }
6559 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
6560 be any _TYPE nodes. */
6562 bool
6564 {
6568 /* We only allow proper derivation here. The DERIVED_FROM_P macro
6569 considers every class derived from itself. */
6572 }
6574 /* We build the ICS for an implicit object parameter as a pointer
6575 conversion sequence. However, such a sequence should be compared
6576 as if it were a reference conversion sequence. If ICS is the
6577 implicit conversion sequence for an implicit object parameter,
6578 modify it accordingly. */
6580 static void
6582 {
6584 {
6585 /* [over.match.funcs]
6587 For non-static member functions, the type of the
6588 implicit object parameter is "reference to cv X"
6589 where X is the class of which the function is a
6590 member and cv is the cv-qualification on the member
6591 function declaration. */
6593 tree reference_type;
6595 /* The `this' parameter is a pointer to a class type. Make the
6596 implicit conversion talk about a reference to that same class
6597 type. */
6610 }
6611 }
6613 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
6614 and return the initial reference binding conversion. Otherwise,
6615 leave *ICS unchanged and return NULL. */
6619 {
6621 {
6626 }
6629 }
6631 /* Compare two implicit conversion sequences according to the rules set out in
6632 [over.ics.rank]. Return values:
6634 1: ics1 is better than ics2
6635 -1: ics2 is better than ics1
6636 0: ics1 and ics2 are indistinguishable */
6638 static int
6640 {
6641 tree from_type1;
6642 tree from_type2;
6643 tree to_type1;
6644 tree to_type2;
6651 /* REF_BINDING is nonzero if the result of the conversion sequence
6652 is a reference type. In that case REF_CONV is the reference
6653 binding conversion. */
6657 /* Handle implicit object parameters. */
6661 /* Handle reference parameters. */
6665 /* List-initialization sequence L1 is a better conversion sequence than
6666 list-initialization sequence L2 if L1 converts to
6667 std::initializer_list<X> for some X and L2 does not. */
6673 /* [over.ics.rank]
6675 When comparing the basic forms of implicit conversion sequences (as
6676 defined in _over.best.ics_)
6678 --a standard conversion sequence (_over.ics.scs_) is a better
6679 conversion sequence than a user-defined conversion sequence
6680 or an ellipsis conversion sequence, and
6682 --a user-defined conversion sequence (_over.ics.user_) is a
6683 better conversion sequence than an ellipsis conversion sequence
6684 (_over.ics.ellipsis_). */
6694 {
6695 /* XXX Isn't this an extension? */
6696 /* Both ICS are bad. We try to make a decision based on what
6697 would have happened if they'd been good. */
6705 /* We couldn't make up our minds; try to figure it out below. */
6706 }
6709 /* Both conversions are ellipsis conversions or both are building a
6710 std::initializer_list. */
6713 /* User-defined conversion sequence U1 is a better conversion sequence
6714 than another user-defined conversion sequence U2 if they contain the
6715 same user-defined conversion operator or constructor and if the sec-
6716 ond standard conversion sequence of U1 is better than the second
6717 standard conversion sequence of U2. */
6720 {
6734 /* We can just fall through here, after setting up
6735 FROM_TYPE1 and FROM_TYPE2. */
6738 }
6739 else
6740 {
6744 /* We're dealing with two standard conversion sequences.
6746 [over.ics.rank]
6748 Standard conversion sequence S1 is a better conversion
6749 sequence than standard conversion sequence S2 if
6751 --S1 is a proper subsequence of S2 (comparing the conversion
6752 sequences in the canonical form defined by _over.ics.scs_,
6753 excluding any Lvalue Transformation; the identity
6754 conversion sequence is considered to be a subsequence of
6755 any non-identity conversion sequence */
6766 }
6768 /* One sequence can only be a subsequence of the other if they start with
6769 the same type. They can start with different types when comparing the
6770 second standard conversion sequence in two user-defined conversion
6771 sequences. */
6773 {
6778 }
6780 /* [over.ics.rank]
6782 Or, if not that,
6784 --the rank of S1 is better than the rank of S2 (by the rules
6785 defined below):
6787 Standard conversion sequences are ordered by their ranks: an Exact
6788 Match is a better conversion than a Promotion, which is a better
6789 conversion than a Conversion.
6791 Two conversion sequences with the same rank are indistinguishable
6792 unless one of the following rules applies:
6794 --A conversion that is not a conversion of a pointer, or pointer
6795 to member, to bool is better than another conversion that is such
6796 a conversion.
6798 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
6799 so that we do not have to check it explicitly. */
6808 /* A conversion from scalar arithmetic type to complex is worse than a
6809 conversion between scalar arithmetic types. */
6816 {
6819 else
6821 }
6827 {
6832 }
6833 /* The rules for pointers to members A::* are just like the rules
6834 for pointers A*, except opposite: if B is derived from A then
6835 A::* converts to B::*, not vice versa. For that reason, we
6836 switch the from_ and to_ variables here. */
6843 {
6848 }
6853 {
6854 /* This was one of the pointer or pointer-like conversions.
6856 [over.ics.rank]
6858 --If class B is derived directly or indirectly from class A,
6859 conversion of B* to A* is better than conversion of B* to
6860 void*, and conversion of A* to void* is better than
6861 conversion of B* to void*. */
6864 {
6866 deref_from_type2))
6869 deref_from_type1))
6871 }
6874 {
6876 {
6878 {
6880 deref_to_type1))
6882 }
6883 /* We know that DEREF_TO_TYPE1 is `void' here. */
6885 deref_to_type2))
6887 }
6888 }
6891 {
6892 /* [over.ics.rank]
6894 --If class B is derived directly or indirectly from class A
6895 and class C is derived directly or indirectly from B,
6897 --conversion of C* to B* is better than conversion of C* to
6898 A*,
6900 --conversion of B* to A* is better than conversion of C* to
6901 A* */
6903 {
6905 deref_to_type2))
6908 deref_to_type1))
6910 }
6912 {
6914 deref_from_type1))
6917 deref_from_type2))
6919 }
6920 }
6921 }
6924 {
6927 /* [over.ics.rank]
6929 --binding of an expression of type C to a reference of type
6930 B& is better than binding an expression of type C to a
6931 reference of type A&
6933 --conversion of C to B is better than conversion of C to A, */
6936 {
6941 }
6942 }
6945 {
6948 /* [over.ics.rank]
6950 --binding of an expression of type B to a reference of type
6951 A& is better than binding an expression of type C to a
6952 reference of type A&,
6954 --conversion of B to A is better than conversion of C to A */
6957 {
6962 }
6963 }
6965 /* [over.ics.rank]
6967 --S1 and S2 differ only in their qualification conversion and yield
6968 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6969 qualification signature of type T1 is a proper subset of the cv-
6970 qualification signature of type T2 */
6974 {
6978 }
6980 /* [over.ics.rank]
6982 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6983 to an implicit object parameter, and either S1 binds an lvalue reference
6984 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6985 reference to an rvalue and S2 binds an lvalue reference
6986 (C++0x draft standard, 13.3.3.2)
6988 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6989 types to which the references refer are the same type except for
6990 top-level cv-qualifiers, and the type to which the reference
6991 initialized by S2 refers is more cv-qualified than the type to
6992 which the reference initialized by S1 refers */
6995 {
6999 {
7004 }
7009 }
7011 /* Neither conversion sequence is better than the other. */
7013 }
7015 /* The source type for this standard conversion sequence. */
7017 static tree
7019 {
7021 {
7026 }
7028 }
7030 /* Note a warning about preferring WINNER to LOSER. We do this by storing
7031 a pointer to LOSER and re-running joust to produce the warning if WINNER
7032 is actually used. */
7034 static void
7036 {
7042 }
7044 /* Compare two candidates for overloading as described in
7045 [over.match.best]. Return values:
7047 1: cand1 is better than cand2
7048 -1: cand2 is better than cand1
7049 0: cand1 and cand2 are indistinguishable */
7051 static int
7053 {
7059 /* Candidates that involve bad conversions are always worse than those
7060 that don't. */
7066 /* If we have two pseudo-candidates for conversions to the same type,
7067 or two candidates for the same function, arbitrarily pick one. */
7072 /* a viable function F1
7073 is defined to be a better function than another viable function F2 if
7074 for all arguments i, ICSi(F1) is not a worse conversion sequence than
7075 ICSi(F2), and then */
7077 /* for some argument j, ICSj(F1) is a better conversion sequence than
7078 ICSj(F2) */
7080 /* For comparing static and non-static member functions, we ignore
7081 the implicit object parameter of the non-static function. The
7082 standard says to pretend that the static function has an object
7083 parm, but that won't work with operator overloading. */
7086 {
7094 else
7095 {
7098 }
7099 }
7102 {
7108 {
7121 {
7128 else
7133 {
7137 }
7138 else
7140 }
7143 {
7146 }
7148 }
7149 }
7151 /* warn about confusing overload resolution for user-defined conversions,
7152 either between a constructor and a conversion op, or between two
7153 conversion ops. */
7157 {
7163 else
7166 /* We don't want to complain about `X::operator T1 ()'
7167 beating `X::operator T2 () const', when T2 is a no less
7168 cv-qualified version of T1. */
7171 {
7176 {
7179 }
7182 }
7183 else
7189 {
7196 {
7198 }
7199 }
7200 else
7202 }
7207 /* or, if not that,
7208 F1 is a non-template function and F2 is a template function
7209 specialization. */
7216 /* or, if not that,
7217 F1 and F2 are template functions and the function template for F1 is
7218 more specialized than the template for F2 according to the partial
7219 ordering rules. */
7222 {
7223 winner = more_specialized_fn
7226 /* [temp.func.order]: The presence of unused ellipsis and default
7227 arguments has no effect on the partial ordering of function
7228 templates. add_function_candidate() will not have
7229 counted the "this" argument for constructors. */
7233 }
7235 /* or, if not that,
7236 the context is an initialization by user-defined conversion (see
7237 _dcl.init_ and _over.match.user_) and the standard conversion
7238 sequence from the return type of F1 to the destination type (i.e.,
7239 the type of the entity being initialized) is a better conversion
7240 sequence than the standard conversion sequence from the return type
7241 of F2 to the destination type. */
7244 {
7248 }
7250 /* Check whether we can discard a builtin candidate, either because we
7251 have two identical ones or matching builtin and non-builtin candidates.
7253 (Pedantically in the latter case the builtin which matched the user
7254 function should not be added to the overload set, but we spot it here.
7256 [over.match.oper]
7257 ... the builtin candidates include ...
7258 - do not have the same parameter type list as any non-template
7259 non-member candidate. */
7263 {
7269 {
7271 /* Two built-in candidates; arbitrarily pick one. */
7274 /* cand1 is built-in; prefer cand2. */
7276 else
7277 /* cand2 is built-in; prefer cand1. */
7279 }
7280 }
7282 /* If the two function declarations represent the same function (this can
7283 happen with declarations in multiple scopes and arg-dependent lookup),
7284 arbitrarily choose one. But first make sure the default args we're
7285 using match. */
7288 {
7295 {
7296 /* Don't crash if the fn is variadic. */
7301 }
7309 {
7312 {
7314 {
7321 }
7322 else
7325 }
7328 }
7331 }
7333 tweak:
7335 /* Extension: If the worst conversion for one candidate is worse than the
7336 worst conversion for the other, take the first. */
7338 {
7343 {
7348 }
7354 {
7356 {
7358 "ISO C++ says that these are ambiguous, even "
7359 "though the worst conversion for the first is better than "
7363 }
7364 else
7367 }
7368 }
7372 }
7374 /* Given a list of candidates for overloading, find the best one, if any.
7375 This algorithm has a worst case of O(2n) (winner is last), and a best
7376 case of O(n/2) (totally ambiguous); much better than a sorting
7377 algorithm. */
7381 {
7386 /* Walk through the list once, comparing each current champ to the next
7387 candidate, knocking out a candidate or two with each comparison. */
7390 {
7394 else
7395 {
7397 {
7402 }
7403 else
7404 {
7407 }
7410 }
7411 }
7413 /* Make sure the champ is better than all the candidates it hasn't yet
7414 been compared to. */
7417 challenger != champ
7420 {
7424 }
7427 }
7429 /* Returns nonzero if things of type FROM can be converted to TO. */
7431 bool
7433 {
7435 }
7437 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7439 bool
7441 {
7446 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7450 flags);
7453 /* Free all the conversions we allocated. */
7457 }
7459 /* Like can_convert_arg, but allows dubious conversions as well. */
7461 bool
7463 {
7467 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7469 /* Try to perform the conversion. */
7471 flags);
7472 /* Free all the conversions we allocated. */
7476 }
7478 /* Convert EXPR to TYPE. Return the converted expression.
7480 Note that we allow bad conversions here because by the time we get to
7481 this point we are committed to doing the conversion. If we end up
7482 doing a bad conversion, convert_like will complain. */
7484 tree
7486 {
7493 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7498 flags);
7501 {
7503 {
7504 /* If expr has unknown type, then it is an overloaded function.
7505 Call instantiate_type to get good error messages. */
7510 else
7512 }
7514 }
7516 {
7517 /* In a template, we are only concerned about determining the
7518 type of non-dependent expressions, so we do not have to
7519 perform the actual conversion. */
7522 }
7523 else
7526 /* Free all the conversions we allocated. */
7530 }
7532 tree
7534 {
7536 }
7538 /* Convert EXPR to TYPE (as a direct-initialization) if that is
7539 permitted. If the conversion is valid, the converted expression is
7540 returned. Otherwise, NULL_TREE is returned, except in the case
7541 that TYPE is a class type; in that case, an error is issued. If
7542 C_CAST_P is true, then this direction initialization is taking
7543 place as part of a static_cast being attempted as part of a C-style
7544 cast. */
7546 tree
7548 tree expr,
7550 tsubst_flags_t complain)
7551 {
7557 /* [dcl.init]
7559 If the destination type is a (possibly cv-qualified) class type:
7561 -- If the initialization is direct-initialization ...,
7562 constructors are considered. ... If no constructor applies, or
7563 the overload resolution is ambiguous, the initialization is
7564 ill-formed. */
7566 {
7572 }
7574 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7578 c_cast_p,
7579 LOOKUP_NORMAL);
7582 else
7585 c_cast_p,
7586 tf_warning_or_error);
7588 /* Free all the conversions we allocated. */
7592 }
7594 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
7595 is being bound to a temporary. Create and return a new VAR_DECL
7596 with the indicated TYPE; this variable will store the value to
7597 which the reference is bound. */
7599 tree
7601 {
7602 tree var;
7604 /* Create the variable. */
7607 /* Register the variable. */
7609 {
7610 /* Namespace-scope or local static; give it a mangled name. */
7611 tree name;
7618 }
7619 else
7620 /* Create a new cleanup level if necessary. */
7624 }
7626 /* EXPR is the initializer for a variable DECL of reference or
7627 std::initializer_list type. Create, push and return a new VAR_DECL
7628 for the initializer so that it will live as long as DECL. Any
7629 cleanup for the new variable is returned through CLEANUP, and the
7630 code to initialize the new variable is returned through INITP. */
7632 tree
7634 {
7635 tree init;
7636 tree type;
7637 tree var;
7639 /* Create the temporary variable. */
7643 /* If the rvalue is the result of a function call it will be
7644 a TARGET_EXPR. If it is some other construct (such as a
7645 member access expression where the underlying object is
7646 itself the result of a function call), turn it into a
7647 TARGET_EXPR here. It is important that EXPR be a
7648 TARGET_EXPR below since otherwise the INIT_EXPR will
7649 attempt to make a bitwise copy of EXPR to initialize
7650 VAR. */
7653 /* Create the INIT_EXPR that will initialize the temporary
7654 variable. */
7657 {
7662 else
7665 /* We must be careful to destroy the temporary only
7666 after its initialization has taken place. If the
7667 initialization throws an exception, then the
7668 destructor should not be run. We cannot simply
7669 transform INIT into something like:
7671 (INIT, ({ CLEANUP_STMT; }))
7673 because emit_local_var always treats the
7674 initializer as a full-expression. Thus, the
7675 destructor would run too early; it would run at the
7676 end of initializing the reference variable, rather
7677 than at the end of the block enclosing the
7678 reference variable.
7680 The solution is to pass back a cleanup expression
7681 which the caller is responsible for attaching to
7682 the statement tree. */
7683 }
7684 else
7685 {
7689 static_aggregates);
7690 }
7694 }
7696 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
7697 initializing a variable of that TYPE. If DECL is non-NULL, it is
7698 the VAR_DECL being initialized with the EXPR. (In that case, the
7699 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
7700 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
7701 return, if *CLEANUP is no longer NULL, it will be an expression
7702 that should be pushed as a cleanup after the returned expression
7703 is used to initialize DECL.
7705 Return the converted expression. */
7707 tree
7709 tsubst_flags_t complain)
7710 {
7717 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7721 LOOKUP_NORMAL);
7723 {
7725 {
7732 else
7736 }
7738 }
7740 /* If DECL is non-NULL, then this special rule applies:
7742 [class.temporary]
7744 The temporary to which the reference is bound or the temporary
7745 that is the complete object to which the reference is bound
7746 persists for the lifetime of the reference.
7748 The temporaries created during the evaluation of the expression
7749 initializing the reference, except the temporary to which the
7750 reference is bound, are destroyed at the end of the
7751 full-expression in which they are created.
7753 In that case, we store the converted expression into a new
7754 VAR_DECL in a new scope.
7756 However, we want to be careful not to create temporaries when
7757 they are not required. For example, given:
7759 struct B {};
7760 struct D : public B {};
7761 D f();
7762 const B& b = f();
7764 there is no need to copy the return value from "f"; we can just
7765 extend its lifetime. Similarly, given:
7767 struct S {};
7768 struct T { operator S(); };
7769 T t;
7770 const S& s = t;
7772 we can extend the lifetime of the return value of the conversion
7773 operator. */
7776 {
7777 tree var;
7778 tree base_conv_type;
7780 /* Skip over the REF_BIND. */
7782 /* If the next conversion is a BASE_CONV, skip that too -- but
7783 remember that the conversion was required. */
7785 {
7788 }
7789 else
7791 /* Perform the remainder of the conversion. */
7797 tf_warning_or_error);
7800 else
7801 {
7803 {
7804 tree init;
7806 /* Use its address to initialize the reference variable. */
7814 }
7815 else
7816 /* Take the address of EXPR. */
7818 /* If a BASE_CONV was required, perform it now. */
7820 expr = (perform_implicit_conversion
7822 tf_warning_or_error));
7824 }
7825 }
7826 else
7827 /* Perform the conversion. */
7830 /* Free all the conversions we allocated. */
7834 }
7836 /* Returns true iff TYPE is some variant of std::initializer_list. */
7838 bool
7840 {
7844 }
7846 /* Returns true iff DECL is a list constructor: i.e. a constructor which
7847 will accept an argument list of a single std::initializer_list<T>. */
7849 bool
7851 {
7853 tree arg;
7865 /* There are more non-defaulted parms. */
7869 }