| blob | 54254c37f1d82d33d7fb0841ad082b77af54d42f |
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 }
717 {
725 }
732 {
736 }
738 {
740 {
741 tree bitfield_type;
744 {
747 }
748 }
750 }
752 /* Allow conversion between `__complex__' data types. */
754 {
755 /* The standard conversion sequence to convert FROM to TO is
756 the standard conversion sequence to perform componentwise
757 conversion. */
762 {
765 }
766 else
770 }
780 {
781 /* For backwards brain damage compatibility, allow interconversion of
782 pointers and integers with a pedwarn. */
785 }
787 {
788 /* For backwards brain damage compatibility, allow interconversion of
789 enums and integers with a pedwarn. */
792 }
795 {
796 tree to_pointee;
797 tree from_pointee;
802 ;
806 {
807 from = build_pointer_type
811 }
813 {
818 && (same_type_ignoring_top_level_qualifiers_p
821 {
825 }
828 }
831 /* [conv.ptr]
833 An rvalue of type "pointer to cv D," where D is a
834 class type, can be converted to an rvalue of type
835 "pointer to cv B," where B is a base class (clause
836 _class.derived_) of D. If B is an inaccessible
837 (clause _class.access_) or ambiguous
838 (_class.member.lookup_) base class of D, a program
839 that necessitates this conversion is ill-formed.
840 Therefore, we use DERIVED_FROM_P, and do not check
841 access or uniqueness. */
843 {
844 from =
850 }
853 {
856 }
857 else
858 {
861 }
866 /* In a C-style cast, we ignore CV-qualification because we
867 are allowed to perform a static_cast followed by a
868 const_cast. */
873 /* converting from string constant to char *. */
876 {
879 }
880 else
884 }
886 {
903 }
905 {
906 /* [conv.bool]
908 An rvalue of arithmetic, unscoped enumeration, pointer, or
909 pointer to member type can be converted to an rvalue of type
910 bool. */
915 {
923 }
926 }
927 /* We don't check for ENUMERAL_TYPE here because there are no standard
928 conversions to enum type. */
929 /* As an extension, allow conversion to complex type. */
931 {
937 /* Give this a better rank if it's a promotion. */
941 }
947 {
951 /* The derived-to-base conversion indicates the initialization
952 of a parameter with base type from an object of a derived
953 type. A temporary object is created to hold the result of
954 the conversion unless we're binding directly to a reference. */
956 }
957 else
964 }
966 /* Returns nonzero if T1 is reference-related to T2. */
968 bool
970 {
974 /* [dcl.init.ref]
976 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
977 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
978 of T2. */
982 }
984 /* Returns nonzero if T1 is reference-compatible with T2. */
986 static bool
988 {
989 /* [dcl.init.ref]
991 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
992 reference-related to T2 and cv1 is the same cv-qualification as,
993 or greater cv-qualification than, cv2. */
996 }
998 /* Determine whether or not the EXPR (of class type S) can be
999 converted to T as in [over.match.ref]. */
1003 {
1004 tree conversions;
1005 tree first_arg;
1007 tree t;
1016 /* [over.match.ref]
1018 Assuming that "cv1 T" is the underlying type of the reference
1019 being initialized, and "cv S" is the type of the initializer
1020 expression, with S a class type, the candidate functions are
1021 selected as follows:
1023 --The conversion functions of S and its base classes are
1024 considered. Those that are not hidden within S and yield type
1025 "reference to cv2 T2", where "cv1 T" is reference-compatible
1026 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1028 The argument list has one argument, which is the initializer
1029 expression. */
1033 /* Conceptually, we should take the address of EXPR and put it in
1034 the argument list. Unfortunately, however, that can result in
1035 error messages, which we should not issue now because we are just
1036 trying to find a conversion operator. Therefore, we use NULL,
1037 cast to the appropriate type. */
1043 {
1047 {
1057 /* If this is a template function, try to get an exact
1058 match. */
1060 {
1063 NULL_TREE,
1064 first_arg,
1065 NULL,
1066 reference_type,
1069 LOOKUP_NORMAL,
1070 DEDUCE_CONV);
1073 {
1074 /* Now, see if the conversion function really returns
1075 an lvalue of the appropriate type. From the
1076 point of view of unification, simply returning an
1077 rvalue of the right type is good enough. */
1082 {
1085 }
1086 }
1087 }
1093 LOOKUP_NORMAL);
1096 {
1098 /* Build a standard conversion sequence indicating the
1099 binding from the reference type returned by the
1100 function to the desired REFERENCE_TYPE. */
1101 identity_conv
1104 NULL_TREE);
1105 cand->second_conv
1106 = (direct_reference_binding
1113 /* Don't allow binding of lvalues to rvalue references. */
1117 }
1118 }
1119 }
1122 /* If none of the conversion functions worked out, let our caller
1123 know. */
1131 /* Now that we know that this is the function we're going to use fix
1132 the dummy first argument. */
1137 /* Build a user-defined conversion sequence representing the
1138 conversion. */
1147 /* Merge it with the standard conversion sequence from the
1148 conversion function's return type to the desired type. */
1152 }
1154 /* A reference of the indicated TYPE is being bound directly to the
1155 expression represented by the implicit conversion sequence CONV.
1156 Return a conversion sequence for this binding. */
1160 {
1161 tree t;
1168 /* [over.ics.rank]
1170 When a parameter of reference type binds directly
1171 (_dcl.init.ref_) to an argument expression, the implicit
1172 conversion sequence is the identity conversion, unless the
1173 argument expression has a type that is a derived class of the
1174 parameter type, in which case the implicit conversion sequence is
1175 a derived-to-base Conversion.
1177 If the parameter binds directly to the result of applying a
1178 conversion function to the argument expression, the implicit
1179 conversion sequence is a user-defined conversion sequence
1180 (_over.ics.user_), with the second standard conversion sequence
1181 either an identity conversion or, if the conversion function
1182 returns an entity of a type that is a derived class of the
1183 parameter type, a derived-to-base conversion. */
1185 {
1186 /* Represent the derived-to-base conversion. */
1188 /* We will actually be binding to the base-class subobject in
1189 the derived class, so we mark this conversion appropriately.
1190 That way, convert_like knows not to generate a temporary. */
1192 }
1194 }
1196 /* Returns the conversion path from type FROM to reference type TO for
1197 purposes of reference binding. For lvalue binding, either pass a
1198 reference type to FROM or an lvalue expression to EXPR. If the
1199 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1200 the conversion returned. If C_CAST_P is true, this
1201 conversion is coming from a C-style cast. */
1205 {
1209 tree tfrom;
1215 {
1220 }
1223 {
1224 /* Anything with reference type is an lvalue. */
1227 }
1230 {
1233 flags);
1236 {
1241 }
1242 }
1251 /* Figure out whether or not the types are reference-related and
1252 reference compatible. We have do do this after stripping
1253 references from FROM. */
1255 /* If this is a C cast, first convert to an appropriately qualified
1256 type, so that we can later do a const_cast to the desired type. */
1262 /* Directly bind reference when target expression's type is compatible with
1263 the reference and expression is an lvalue. In DR391, the wording in
1264 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1265 const and rvalue references to rvalues of compatible class type.
1266 We should also do direct bindings for non-class "rvalues" derived from
1267 rvalue references. */
1269 && (is_lvalue
1274 {
1275 /* [dcl.init.ref]
1277 If the initializer expression
1279 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1280 is reference-compatible with "cv2 T2,"
1282 the reference is bound directly to the initializer expression
1283 lvalue.
1285 [...]
1286 If the initializer expression is an rvalue, with T2 a class type,
1287 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1288 is bound to the object represented by the rvalue or to a sub-object
1289 within that object. */
1295 /* The top-level caller requested that we pretend that the lvalue
1296 be treated as an rvalue. */
1298 else
1299 conv->rvaluedness_matches_p
1304 /* For the purposes of overload resolution, we ignore the fact
1305 this expression is a bitfield or packed field. (In particular,
1306 [over.ics.ref] says specifically that a function with a
1307 non-const reference parameter is viable even if the
1308 argument is a bitfield.)
1310 However, when we actually call the function we must create
1311 a temporary to which to bind the reference. If the
1312 reference is volatile, or isn't const, then we cannot make
1313 a temporary, so we just issue an error when the conversion
1314 actually occurs. */
1317 /* Don't allow binding of lvalues to rvalue references. */
1323 }
1324 /* [class.conv.fct] A conversion function is never used to convert a
1325 (possibly cv-qualified) object to the (possibly cv-qualified) same
1326 object type (or a reference to it), to a (possibly cv-qualified) base
1327 class of that type (or a reference to it).... */
1330 {
1331 /* [dcl.init.ref]
1333 If the initializer expression
1335 -- has a class type (i.e., T2 is a class type) can be
1336 implicitly converted to an lvalue of type "cv3 T3," where
1337 "cv1 T1" is reference-compatible with "cv3 T3". (this
1338 conversion is selected by enumerating the applicable
1339 conversion functions (_over.match.ref_) and choosing the
1340 best one through overload resolution. (_over.match_).
1342 the reference is bound to the lvalue result of the conversion
1343 in the second case. */
1347 }
1349 /* From this point on, we conceptually need temporaries, even if we
1350 elide them. Only the cases above are "direct bindings". */
1354 /* [over.ics.rank]
1356 When a parameter of reference type is not bound directly to an
1357 argument expression, the conversion sequence is the one required
1358 to convert the argument expression to the underlying type of the
1359 reference according to _over.best.ics_. Conceptually, this
1360 conversion sequence corresponds to copy-initializing a temporary
1361 of the underlying type with the argument expression. Any
1362 difference in top-level cv-qualification is subsumed by the
1363 initialization itself and does not constitute a conversion. */
1365 /* [dcl.init.ref]
1367 Otherwise, the reference shall be to a non-volatile const type.
1369 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1373 /* [dcl.init.ref]
1375 Otherwise, a temporary of type "cv1 T1" is created and
1376 initialized from the initializer expression using the rules for a
1377 non-reference copy initialization. If T1 is reference-related to
1378 T2, cv1 must be the same cv-qualification as, or greater
1379 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1383 /* We're generating a temporary now, but don't bind any more in the
1384 conversion (specifically, don't slice the temporary returned by a
1385 conversion operator). */
1388 /* Temporaries are copy-initialized, except for this hack to allow
1389 explicit conversion ops to the copy ctor. See also
1390 add_function_candidate. */
1396 flags);
1401 /* This reference binding, unlike those above, requires the
1402 creation of a temporary. */
1407 }
1409 /* Returns the implicit conversion sequence (see [over.ics]) from type
1410 FROM to type TO. The optional expression EXPR may affect the
1411 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1412 true, this conversion is coming from a C-style cast. */
1417 {
1426 else
1433 {
1437 /* Allow conversion from an initializer-list with one element to a
1438 scalar type. */
1440 {
1442 tree elt;
1448 else
1454 {
1457 /* Too many levels of braces, i.e. '{{1}}'. */
1460 }
1461 }
1462 }
1468 {
1481 /* We used to try to bind a reference to a temporary here, but that
1482 is now handled after the recursive call to this function at the end
1483 of reference_binding. */
1485 }
1488 }
1490 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1491 functions. ARGS will not be changed until a single candidate is
1492 selected. */
1500 {
1516 }
1518 /* Create an overload candidate for the function or method FN called
1519 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1520 FLAGS is passed on to implicit_conversion.
1522 This does not change ARGS.
1524 CTYPE, if non-NULL, is the type we want to pretend this function
1525 comes from for purposes of overload resolution. */
1532 {
1536 tree parmnode;
1541 /* At this point we should not see any functions which haven't been
1542 explicitly declared, except for friend functions which will have
1543 been found using argument dependent lookup. */
1546 /* The `this', `in_chrg' and VTT arguments to constructors are not
1547 considered in overload resolution. */
1549 {
1553 {
1556 }
1557 }
1558 else
1564 /* 13.3.2 - Viable functions [over.match.viable]
1565 First, to be a viable function, a candidate function shall have enough
1566 parameters to agree in number with the arguments in the list.
1568 We need to check this first; otherwise, checking the ICSes might cause
1569 us to produce an ill-formed template instantiation. */
1573 {
1577 }
1582 /* Make sure there are default args for the rest of the parms. */
1589 /* Second, for F to be a viable function, there shall exist for each
1590 argument an implicit conversion sequence that converts that argument
1591 to the corresponding parameter of F. */
1596 {
1606 else
1615 {
1619 /* The type of the implicit object parameter ('this') for
1620 overload resolution is not always the same as for the
1621 function itself; conversion functions are considered to
1622 be members of the class being converted, and functions
1623 introduced by a using-declaration are considered to be
1624 members of the class that uses them.
1626 Since build_over_call ignores the ICS for the `this'
1627 parameter, we can just change the parm type. */
1629 {
1630 parmtype
1634 }
1638 {
1639 /* Hack: Direct-initialize copy parm (i.e. suppress
1640 LOOKUP_ONLYCONVERTING) to make explicit conversion ops
1641 work. See also reference_binding. */
1645 }
1646 else
1651 }
1652 else
1653 {
1656 }
1663 {
1666 }
1673 }
1675 out:
1678 }
1680 /* Create an overload candidate for the conversion function FN which will
1681 be invoked for expression OBJ, producing a pointer-to-function which
1682 will in turn be called with the argument list FIRST_ARG/ARGLIST,
1683 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
1684 passed on to implicit_conversion.
1686 Actually, we don't really care about FN; we care about the type it
1687 converts to. There may be multiple conversion functions that will
1688 convert to that type, and we rely on build_user_type_conversion_1 to
1689 choose the best one; so when we create our candidate, we record the type
1690 instead of the function. */
1696 {
1712 /* Don't bother looking up the same type twice. */
1717 {
1725 else
1732 flags);
1738 else
1739 {
1742 }
1756 }
1766 }
1768 static void
1772 {
1785 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
1786 conversion ops are allowed. We handle that here by just checking for
1787 boolean_type_node because other operators don't ask for it. COND_EXPR
1788 also does contextual conversion to bool for the first operand, but we
1789 handle that in build_conditional_expr, and type1 here is operand 2. */
1794 {
1801 {
1803 /* We need something for printing the candidate. */
1805 }
1809 }
1811 /* For COND_EXPR we rearranged the arguments; undo that now. */
1813 {
1820 else
1822 }
1828 viable);
1829 }
1831 static bool
1833 {
1835 }
1837 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1839 static bool
1841 {
1842 /* [over.built]
1844 In this section, the term promoted integral type is used to refer
1845 to those integral types which are preserved by integral promotion
1846 (including e.g. int and long but excluding e.g. char).
1847 Similarly, the term promoted arithmetic type refers to promoted
1848 integral types plus floating types. */
1852 }
1854 /* Create any builtin operator overload candidates for the operator in
1855 question given the converted operand types TYPE1 and TYPE2. The other
1856 args are passed through from add_builtin_candidates to
1857 build_builtin_candidate.
1859 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1860 If CODE is requires candidates operands of the same type of the kind
1861 of which TYPE1 and TYPE2 are, we add both candidates
1862 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1864 static void
1868 {
1870 {
1878 }
1881 {
1883 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1884 and VQ is either volatile or empty, there exist candidate operator
1885 functions of the form
1886 VQ T& operator++(VQ T&);
1887 T operator++(VQ T&, int);
1888 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1889 type other than bool, and VQ is either volatile or empty, there exist
1890 candidate operator functions of the form
1891 VQ T& operator--(VQ T&);
1892 T operator--(VQ T&, int);
1893 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1894 complete object type, and VQ is either volatile or empty, there exist
1895 candidate operator functions of the form
1896 T*VQ& operator++(T*VQ&);
1897 T*VQ& operator--(T*VQ&);
1898 T* operator++(T*VQ&, int);
1899 T* operator--(T*VQ&, int); */
1908 {
1911 }
1914 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1915 exist candidate operator functions of the form
1917 T& operator*(T*);
1919 8 For every function type T, there exist candidate operator functions of
1920 the form
1921 T& operator*(T*); */
1930 /* 9 For every type T, there exist candidate operator functions of the form
1931 T* operator+(T*);
1933 10For every promoted arithmetic type T, there exist candidate operator
1934 functions of the form
1935 T operator+(T);
1936 T operator-(T); */
1946 /* 11For every promoted integral type T, there exist candidate operator
1947 functions of the form
1948 T operator~(T); */
1955 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1956 is the same type as C2 or is a derived class of C2, T is a complete
1957 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1958 there exist candidate operator functions of the form
1959 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1960 where CV12 is the union of CV1 and CV2. */
1965 {
1973 }
1976 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1977 didate operator functions of the form
1978 LR operator*(L, R);
1979 LR operator/(L, R);
1980 LR operator+(L, R);
1981 LR operator-(L, R);
1982 bool operator<(L, R);
1983 bool operator>(L, R);
1984 bool operator<=(L, R);
1985 bool operator>=(L, R);
1986 bool operator==(L, R);
1987 bool operator!=(L, R);
1988 where LR is the result of the usual arithmetic conversions between
1989 types L and R.
1991 14For every pair of types T and I, where T is a cv-qualified or cv-
1992 unqualified complete object type and I is a promoted integral type,
1993 there exist candidate operator functions of the form
1994 T* operator+(T*, I);
1995 T& operator[](T*, I);
1996 T* operator-(T*, I);
1997 T* operator+(I, T*);
1998 T& operator[](I, T*);
2000 15For every T, where T is a pointer to complete object type, there exist
2001 candidate operator functions of the form112)
2002 ptrdiff_t operator-(T, T);
2004 16For every pointer or enumeration type T, there exist candidate operator
2005 functions of the form
2006 bool operator<(T, T);
2007 bool operator>(T, T);
2008 bool operator<=(T, T);
2009 bool operator>=(T, T);
2010 bool operator==(T, T);
2011 bool operator!=(T, T);
2013 17For every pointer to member type T, there exist candidate operator
2014 functions of the form
2015 bool operator==(T, T);
2016 bool operator!=(T, T); */
2023 {
2026 }
2039 {
2042 }
2044 {
2047 }
2048 /* Fall through. */
2065 {
2068 }
2072 {
2075 }
2083 {
2086 }
2088 {
2091 }
2094 /* 18For every pair of promoted integral types L and R, there exist candi-
2095 date operator functions of the form
2096 LR operator%(L, R);
2097 LR operator&(L, R);
2098 LR operator^(L, R);
2099 LR operator|(L, R);
2100 L operator<<(L, R);
2101 L operator>>(L, R);
2102 where LR is the result of the usual arithmetic conversions between
2103 types L and R. */
2111 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2115 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2116 type, VQ is either volatile or empty, and R is a promoted arithmetic
2117 type, there exist candidate operator functions of the form
2118 VQ L& operator=(VQ L&, R);
2119 VQ L& operator*=(VQ L&, R);
2120 VQ L& operator/=(VQ L&, R);
2121 VQ L& operator+=(VQ L&, R);
2122 VQ L& operator-=(VQ L&, R);
2124 20For every pair T, VQ), where T is any type and VQ is either volatile
2125 or empty, there exist candidate operator functions of the form
2126 T*VQ& operator=(T*VQ&, T*);
2128 21For every pair T, VQ), where T is a pointer to member type and VQ is
2129 either volatile or empty, there exist candidate operator functions of
2130 the form
2131 VQ T& operator=(VQ T&, T);
2133 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2134 unqualified complete object type, VQ is either volatile or empty, and
2135 I is a promoted integral type, there exist candidate operator func-
2136 tions of the form
2137 T*VQ& operator+=(T*VQ&, I);
2138 T*VQ& operator-=(T*VQ&, I);
2140 23For every triple L, VQ, R), where L is an integral or enumeration
2141 type, VQ is either volatile or empty, and R is a promoted integral
2142 type, there exist candidate operator functions of the form
2144 VQ L& operator%=(VQ L&, R);
2145 VQ L& operator<<=(VQ L&, R);
2146 VQ L& operator>>=(VQ L&, R);
2147 VQ L& operator&=(VQ L&, R);
2148 VQ L& operator^=(VQ L&, R);
2149 VQ L& operator|=(VQ L&, R); */
2153 {
2157 {
2160 }
2173 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2186 {
2189 }
2194 }
2199 /* [over.built]
2201 For every pair of promoted arithmetic types L and R, there
2202 exist candidate operator functions of the form
2204 LR operator?(bool, L, R);
2206 where LR is the result of the usual arithmetic conversions
2207 between types L and R.
2209 For every type T, where T is a pointer or pointer-to-member
2210 type, there exist candidate operator functions of the form T
2211 operator?(bool, T, T); */
2215 /* That's OK. */
2218 /* Otherwise, the types should be pointers. */
2223 /* We don't check that the two types are the same; the logic
2224 below will actually create two candidates; one in which both
2225 parameter types are TYPE1, and one in which both parameter
2226 types are TYPE2. */
2231 }
2233 /* If we're dealing with two pointer types or two enumeral types,
2234 we need candidates for both of them. */
2243 {
2244 build_builtin_candidate
2246 build_builtin_candidate
2249 }
2251 build_builtin_candidate
2253 }
2255 tree
2257 {
2263 }
2265 /* There are three conditions of builtin candidates:
2267 1) bool-taking candidates. These are the same regardless of the input.
2268 2) pointer-pair taking candidates. These are generated for each type
2269 one of the input types converts to.
2270 3) arithmetic candidates. According to the standard, we should generate
2271 all of these, but I'm trying not to...
2273 Here we generate a superset of the possible candidates for this particular
2274 case. That is a subset of the full set the standard defines, plus some
2275 other cases which the standard disallows. add_builtin_candidate will
2276 filter out the invalid set. */
2278 static void
2282 {
2286 /* TYPES[i] is the set of possible builtin-operator parameter types
2287 we will consider for the Ith argument. These are represented as
2288 a TREE_LIST; the TREE_VALUE of each node is the potential
2289 parameter type. */
2293 {
2296 else
2298 }
2301 {
2302 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2303 and VQ is either volatile or empty, there exist candidate operator
2304 functions of the form
2305 VQ T& operator++(VQ T&); */
2315 /* 24There also exist candidate operator functions of the form
2316 bool operator!(bool);
2317 bool operator&&(bool, bool);
2318 bool operator||(bool, bool); */
2321 build_builtin_candidate
2328 build_builtin_candidate
2346 /* Fall through. */
2350 }
2355 {
2357 ;
2359 {
2360 tree convs;
2369 {
2376 }
2382 {
2395 {
2401 }
2405 }
2406 }
2407 else
2408 {
2414 {
2420 }
2422 }
2423 }
2425 /* Run through the possible parameter types of both arguments,
2426 creating candidates with those parameter types. */
2428 {
2431 add_builtin_candidate
2434 else
2435 add_builtin_candidate
2438 }
2439 }
2442 /* If TMPL can be successfully instantiated as indicated by
2443 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2445 TMPL is the template. EXPLICIT_TARGS are any explicit template
2446 arguments. ARGLIST is the arguments provided at the call-site.
2447 This does not change ARGLIST. The RETURN_TYPE is the desired type
2448 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2449 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2450 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2458 {
2468 tree arg;
2471 tree fn;
2473 /* We don't do deduction on the in-charge parameter, the VTT
2474 parameter or 'this'. */
2476 {
2479 else
2481 }
2486 {
2489 else
2491 }
2501 {
2504 }
2508 {
2511 }
2515 args_without_in_chrg,
2516 nargs_without_in_chrg,
2526 /* In [class.copy]:
2528 A member function template is never instantiated to perform the
2529 copy of a class object to an object of its class type.
2531 It's a little unclear what this means; the standard explicitly
2532 does allow a template to be used to copy a class. For example,
2533 in:
2535 struct A {
2536 A(A&);
2537 template <class T> A(const T&);
2538 };
2539 const A f ();
2540 void g () { A a (f ()); }
2542 the member template will be used to make the copy. The section
2543 quoted above appears in the paragraph that forbids constructors
2544 whose only parameter is (a possibly cv-qualified variant of) the
2545 class type, and a logical interpretation is that the intent was
2546 to forbid the instantiation of member templates which would then
2547 have that form. */
2549 {
2552 ctype))
2554 }
2557 /* Aha, this is a conversion function. */
2560 else
2565 /* This situation can occur if a member template of a template
2566 class is specialized. Then, instantiate_template might return
2567 an instantiation of the specialization, in which case the
2568 DECL_TI_TEMPLATE field will point at the original
2569 specialization. For example:
2571 template <class T> struct S { template <class U> void f(U);
2572 template <> void f(int) {}; };
2573 S<double> sd;
2574 sd.f(3);
2576 Here, TMPL will be template <class U> S<double>::f(U).
2577 And, instantiate template will give us the specialization
2578 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2579 for this will point at template <class T> template <> S<T>::f(int),
2580 so that we can find the definition. For the purposes of
2581 overload resolution, however, we want the original TMPL. */
2583 else
2587 }
2595 unification_kind_t strict)
2596 {
2597 return
2602 }
2610 tree conversion_path)
2611 {
2612 return
2616 }
2618 /* The CANDS are the set of candidates that were considered for
2619 overload resolution. Return the set of viable candidates. If none
2620 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2621 is true if a candidate should be considered viable only if it is
2622 strictly viable. */
2628 {
2639 {
2642 {
2648 }
2649 else
2651 }
2654 }
2656 static bool
2658 {
2663 }
2665 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2666 words, it is about to become the "this" pointer for a member
2667 function call. Take the address of the object. */
2669 static tree
2671 {
2672 /* In a template, we are only concerned about the type of the
2673 expression, so we can take a shortcut. */
2678 }
2680 /* Returns true iff functions are equivalent. Equivalent functions are
2681 not '==' only if one is a function-local extern function or if
2682 both are extern "C". */
2686 {
2691 }
2693 /* Print information about one overload candidate CANDIDATE. MSGSTR
2694 is the text to print before the candidate itself.
2696 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2697 to have been run through gettext by the caller. This wart makes
2698 life simpler in print_z_candidates and for the translators. */
2700 static void
2702 {
2704 {
2714 else
2717 }
2724 else
2726 }
2728 static void
2730 {
2739 /* Remove deleted candidates. */
2742 {
2746 else
2748 }
2749 /* ...if there are any non-deleted ones. */
2753 /* There may be duplicates in the set of candidates. We put off
2754 checking this condition as long as possible, since we have no way
2755 to eliminate duplicates from a set of functions in less than n^2
2756 time. Now we are about to emit an error message, so it is more
2757 permissible to go slowly. */
2759 {
2761 /* Skip builtin candidates and conversion functions. */
2766 {
2770 else
2772 }
2773 }
2778 {
2781 }
2783 }
2785 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2786 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2787 the result of the conversion function to convert it to the final
2788 desired type. Merge the two sequences into a single sequence,
2789 and return the merged sequence. */
2793 {
2798 /* Find the end of the second conversion sequence. */
2803 /* Replace the identity conversion with the user conversion
2804 sequence. */
2807 /* The entire sequence is a user-conversion sequence. */
2811 }
2813 /* Returns the best overload candidate to perform the requested
2814 conversion. This function is used for three the overloading situations
2815 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2816 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2817 per [dcl.init.ref], so we ignore temporary bindings. */
2821 {
2832 /* We represent conversion within a hierarchy using RVALUE_CONV and
2833 BASE_CONV, as specified by [over.best.ics]; these become plain
2834 constructor calls, as specified in [dcl.init]. */
2842 {
2847 {
2848 /* [class.conv.fct] A conversion function is never used to
2849 convert a (possibly cv-qualified) object to the (possibly
2850 cv-qualified) same object type (or a reference to it), to a
2851 (possibly cv-qualified) base class of that type (or a
2852 reference to it)... */
2853 }
2854 else
2857 }
2862 /* It's OK to bind a temporary for converting constructor arguments, but
2863 not in converting the return value of a conversion operator. */
2868 {
2874 {
2876 /* We still allow more conversions within an init-list. */
2878 /* But not for the copy ctor. */
2879 |LOOKUP_NO_COPY_CTOR_CONVERSION
2881 }
2882 else
2885 /* We should never try to call the abstract or base constructor
2886 from here. */
2889 }
2891 {
2902 flags,
2903 DEDUCE_CALL);
2904 else
2908 flags);
2911 {
2914 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
2915 set, then this is copy-initialization. In that case, "The
2916 result of the call is then used to direct-initialize the
2917 object that is the destination of the copy-initialization."
2918 [dcl.init]
2920 We represent this in the conversion sequence with an
2921 rvalue conversion, which means a constructor call. */
2924 cand->second_conv
2926 }
2927 }
2933 {
2934 tree fns;
2937 /* If we are called to convert to a reference type, we are trying to
2938 find an lvalue binding, so don't even consider temporaries. If
2939 we don't find an lvalue binding, the caller will try again to
2940 look for a temporary binding. */
2945 {
2953 /* Lambdas have a static conversion op. */
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 {
3392 else
3393 add_function_candidate
3396 }
3397 }
3399 /* Rather than mess with handling static conversion ops here, just don't
3400 look at conversions in lambdas. */
3403 else
3407 {
3419 {
3426 add_template_conv_candidate
3430 else
3434 }
3435 }
3439 {
3441 {
3445 }
3447 }
3448 else
3449 {
3452 {
3454 {
3458 }
3460 }
3461 /* Since cand->fn will be a type, not a function, for a conversion
3462 function, we must be careful not to unconditionally look at
3463 DECL_NAME here. */
3467 else
3468 {
3470 complain);
3473 }
3474 }
3476 /* Free all the conversions we allocated. */
3480 }
3482 static void
3485 {
3490 else
3494 {
3499 else
3509 else
3518 else
3528 else
3538 else
3541 else
3545 else
3549 }
3550 }
3552 /* Return the implicit conversion sequence that could be used to
3553 convert E1 to E2 in [expr.cond]. */
3557 {
3563 /* [expr.cond]
3565 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3566 implicitly converted (clause _conv_) to the type "reference to
3567 T2", subject to the constraint that in the conversion the
3568 reference must bind directly (_dcl.init.ref_) to E1. */
3570 {
3572 t1,
3573 e1,
3578 }
3580 /* [expr.cond]
3582 If E1 and E2 have class type, and the underlying class types are
3583 the same or one is a base class of the other: E1 can be converted
3584 to match E2 if the class of T2 is the same type as, or a base
3585 class of, the class of T1, and the cv-qualification of T2 is the
3586 same cv-qualification as, or a greater cv-qualification than, the
3587 cv-qualification of T1. If the conversion is applied, E1 is
3588 changed to an rvalue of type T2 that still refers to the original
3589 source class object (or the appropriate subobject thereof). */
3592 {
3594 {
3599 else
3602 }
3603 else
3605 }
3606 else
3607 /* [expr.cond]
3609 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3610 converted to the type that expression E2 would have if E2 were
3611 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3613 LOOKUP_IMPLICIT);
3614 }
3616 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3617 arguments to the conditional expression. */
3619 tree
3621 tsubst_flags_t complain)
3622 {
3623 tree arg2_type;
3624 tree arg3_type;
3626 tree result_save;
3633 /* As a G++ extension, the second argument to the conditional can be
3634 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3635 c'.) If the second operand is omitted, make sure it is
3636 calculated only once. */
3638 {
3643 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3646 else
3648 }
3650 /* [expr.cond]
3652 The first expression is implicitly converted to bool (clause
3653 _conv_). */
3655 LOOKUP_NORMAL);
3657 /* If something has already gone wrong, just pass that fact up the
3658 tree. */
3664 /* [expr.cond]
3666 If either the second or the third operand has type (possibly
3667 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3668 array-to-pointer (_conv.array_), and function-to-pointer
3669 (_conv.func_) standard conversions are performed on the second
3670 and third operands. */
3674 {
3675 /* Do the conversions. We don't these for `void' type arguments
3676 since it can't have any effect and since decay_conversion
3677 does not handle that case gracefully. */
3685 /* [expr.cond]
3687 One of the following shall hold:
3689 --The second or the third operand (but not both) is a
3690 throw-expression (_except.throw_); the result is of the
3691 type of the other and is an rvalue.
3693 --Both the second and the third operands have type void; the
3694 result is of type void and is an rvalue.
3696 We must avoid calling force_rvalue for expressions of type
3697 "void" because it will complain that their value is being
3698 used. */
3701 {
3706 }
3709 {
3714 }
3717 else
3718 {
3720 {
3723 "is of type %<void%>, "
3724 "but the third operand is neither a throw-expression "
3726 else
3728 "is of type %<void%>, "
3729 "but the second operand is neither a throw-expression "
3731 }
3733 }
3737 }
3738 /* [expr.cond]
3740 Otherwise, if the second and third operand have different types,
3741 and either has (possibly cv-qualified) class type, an attempt is
3742 made to convert each of those operands to the type of the other. */
3745 {
3749 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3755 /* [expr.cond]
3757 If both can be converted, or one can be converted but the
3758 conversion is ambiguous, the program is ill-formed. If
3759 neither can be converted, the operands are left unchanged and
3760 further checking is performed as described below. If exactly
3761 one conversion is possible, that conversion is applied to the
3762 chosen operand and the converted operand is used in place of
3763 the original operand for the remainder of this section. */
3768 {
3772 }
3774 {
3778 /* Even if CONV2 is a valid conversion, the result of the
3779 conversion may be invalid. For example, if ARG3 has type
3780 "volatile X", and X does not have a copy constructor
3781 accepting a "volatile X&", then even if ARG2 can be
3782 converted to X, the conversion will fail. */
3785 }
3787 {
3793 }
3795 /* Free all the conversions we allocated. */
3801 /* If, after the conversion, both operands have class type,
3802 treat the cv-qualification of both operands as if it were the
3803 union of the cv-qualification of the operands.
3805 The standard is not clear about what to do in this
3806 circumstance. For example, if the first operand has type
3807 "const X" and the second operand has a user-defined
3808 conversion to "volatile X", what is the type of the second
3809 operand after this step? Making it be "const X" (matching
3810 the first operand) seems wrong, as that discards the
3811 qualification without actually performing a copy. Leaving it
3812 as "volatile X" seems wrong as that will result in the
3813 conditional expression failing altogether, even though,
3814 according to this step, the one operand could be converted to
3815 the type of the other. */
3823 }
3825 /* [expr.cond]
3827 If the second and third operands are lvalues and have the same
3828 type, the result is of that type and is an lvalue. */
3832 {
3835 }
3837 /* [expr.cond]
3839 Otherwise, the result is an rvalue. If the second and third
3840 operand do not have the same type, and either has (possibly
3841 cv-qualified) class type, overload resolution is used to
3842 determine the conversions (if any) to be applied to the operands
3843 (_over.match.oper_, _over.built_). */
3847 {
3852 /* Rearrange the arguments so that add_builtin_candidate only has
3853 to know about two args. In build_builtin_candidate, the
3854 arguments are unscrambled. */
3859 COND_EXPR,
3860 NOP_EXPR,
3862 args,
3863 LOOKUP_NORMAL);
3865 /* [expr.cond]
3867 If the overload resolution fails, the program is
3868 ill-formed. */
3871 {
3873 {
3876 }
3878 }
3881 {
3883 {
3886 }
3888 }
3890 /* [expr.cond]
3892 Otherwise, the conversions thus determined are applied, and
3893 the converted operands are used in place of the original
3894 operands for the remainder of this section. */
3903 }
3905 /* [expr.cond]
3907 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3908 and function-to-pointer (_conv.func_) standard conversions are
3909 performed on the second and third operands.
3911 We need to force the lvalue-to-rvalue conversion here for class types,
3912 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3913 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3914 regions. */
3927 /* [expr.cond]
3929 After those conversions, one of the following shall hold:
3931 --The second and third operands have the same type; the result is of
3932 that type. */
3935 /* [expr.cond]
3937 --The second and third operands have arithmetic or enumeration
3938 type; the usual arithmetic conversions are performed to bring
3939 them to a common type, and the result is of that type. */
3944 {
3945 /* In this case, there is always a common type. */
3947 arg3_type);
3951 {
3956 }
3962 {
3966 }
3970 }
3971 /* [expr.cond]
3973 --The second and third operands have pointer type, or one has
3974 pointer type and the other is a null pointer constant; pointer
3975 conversions (_conv.ptr_) and qualification conversions
3976 (_conv.qual_) are performed to bring them to their composite
3977 pointer type (_expr.rel_). The result is of the composite
3978 pointer type.
3980 --The second and third operands have pointer to member type, or
3981 one has pointer to member type and the other is a null pointer
3982 constant; pointer to member conversions (_conv.mem_) and
3983 qualification conversions (_conv.qual_) are performed to bring
3984 them to a common type, whose cv-qualification shall match the
3985 cv-qualification of either the second or the third operand.
3986 The result is of the common type. */
3994 {
3997 complain);
4002 }
4005 {
4010 }
4012 valid_operands:
4017 /* Avoid folding to a CALL_EXPR within decltype (c++/42013). */
4020 /* We can't use result_type below, as fold might have returned a
4021 throw_expr. */
4024 {
4025 /* Expand both sides into the same slot, hopefully the target of
4026 the ?: expression. We used to check for TARGET_EXPRs here,
4027 but now we sometimes wrap them in NOP_EXPRs so the test would
4028 fail. */
4031 /* If this expression is an rvalue, but might be mistaken for an
4032 lvalue, we must add a NON_LVALUE_EXPR. */
4034 }
4037 }
4039 /* OPERAND is an operand to an expression. Perform necessary steps
4040 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
4041 returned. */
4043 static tree
4045 {
4047 {
4050 /* Make sure the template type is instantiated now. */
4052 }
4055 }
4057 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
4058 OVERLOAD) to the CANDIDATES, returning an updated list of
4059 CANDIDATES. The ARGS are the arguments provided to the call,
4060 without any implicit object parameter. This may change ARGS. The
4061 EXPLICIT_TARGS are explicit template arguments provided.
4062 TEMPLATE_ONLY is true if only template functions should be
4063 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
4064 add_function_candidate. */
4066 static void
4072 {
4073 tree ctype;
4075 tree first_arg;
4078 /* Delay creating the implicit this parameter until it is needed. */
4083 {
4084 tree fn;
4085 tree fn_first_arg;
4089 /* Figure out which set of arguments to use. */
4091 {
4092 /* If this function is a non-static member, prepend the implicit
4093 object parameter. */
4095 {
4097 tree arg;
4103 }
4108 }
4109 else
4110 {
4111 /* Otherwise, just use the list of arguments provided. */
4114 }
4118 fn,
4119 ctype,
4120 explicit_targs,
4121 fn_first_arg,
4122 fn_args,
4123 NULL_TREE,
4124 access_path,
4125 conversion_path,
4126 flags,
4127 DEDUCE_CALL);
4130 fn,
4131 ctype,
4132 fn_first_arg,
4133 fn_args,
4134 access_path,
4135 conversion_path,
4136 flags);
4138 }
4139 }
4141 /* Even unsigned enum types promote to signed int. We don't want to
4142 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the
4143 original argument and ARG is the argument after any conversions
4144 have been applied. We set TREE_NO_WARNING if we have added a cast
4145 from an unsigned enum type to a signed integer type. */
4147 static void
4149 {
4158 }
4160 tree
4163 {
4169 tree fnname;
4187 {
4191 }
4192 else
4198 {
4203 /* Use build_op_new_call and build_op_delete_call instead. */
4207 /* Use build_op_call instead. */
4214 /* These are saved for the sake of warn_logical_operator. */
4220 }
4226 /* Use build_conditional_expr instead. */
4242 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4245 /* Add namespace-scope operators to the list of functions to
4246 consider. */
4250 /* Add class-member operators to the candidate set. */
4252 {
4253 tree fns;
4257 {
4260 }
4267 }
4276 {
4279 /* For these, the built-in candidates set is empty
4280 [over.match.oper]/3. We don't want non-strict matches
4281 because exact matches are always possible with built-in
4282 operators. The built-in candidate set for COMPONENT_REF
4283 would be empty too, but since there are no such built-in
4284 operators, we accept non-strict matches for them. */
4291 }
4295 {
4297 {
4300 /* Don't try anything fancy if we're not allowed to produce
4301 errors. */
4305 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
4306 distinguish between prefix and postfix ++ and
4307 operator++() was used for both, so we allow this with
4308 -fpermissive. */
4310 {
4317 }
4324 else
4330 /* The caller will deal with these. */
4340 {
4341 /* If one of the arguments of the operator represents
4342 an invalid use of member function pointer, try to report
4343 a meaningful error ... */
4348 else
4349 {
4350 /* ... Otherwise, report the more generic
4351 "no matching operator found" error */
4354 }
4355 }
4358 }
4359 }
4360 else
4361 {
4364 {
4366 {
4369 }
4371 }
4373 {
4379 else
4381 }
4382 else
4383 {
4384 /* Give any warnings we noticed during overload resolution. */
4386 {
4390 }
4392 /* Check for comparison of different enum types. */
4394 {
4406 {
4410 }
4414 }
4416 /* We need to strip any leading REF_BIND so that bitfields
4417 don't cause errors. This should not remove any important
4418 conversions, because builtins don't apply to class
4419 objects directly. */
4426 {
4427 /* We need to call warn_logical_operator before
4428 converting arg2 to a boolean_type. */
4438 }
4440 {
4445 }
4447 }
4448 }
4450 user_defined_result_ready:
4452 /* Free all the conversions we allocated. */
4458 builtin:
4464 {
4477 /* Fall through. */
4515 complain),
4516 arg2);
4518 /* The caller will deal with these. */
4526 }
4528 }
4530 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
4531 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
4533 static bool
4535 {
4536 /* A template instance is never a usual deallocation function,
4537 regardless of its signature. */
4542 /* If a class T has a member deallocation function named operator delete
4543 with exactly one parameter, then that function is a usual
4544 (non-placement) deallocation function. If class T does not declare
4545 such an operator delete but does declare a member deallocation
4546 function named operator delete with exactly two parameters, the second
4547 of which has type std::size_t (18.2), then this function is a usual
4548 deallocation function. */
4555 }
4557 /* Build a call to operator delete. This has to be handled very specially,
4558 because the restrictions on what signatures match are different from all
4559 other call instances. For a normal delete, only a delete taking (void *)
4560 or (void *, size_t) is accepted. For a placement delete, only an exact
4561 match with the placement new is accepted.
4563 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4564 ADDR is the pointer to be deleted.
4565 SIZE is the size of the memory block to be deleted.
4566 GLOBAL_P is true if the delete-expression should not consider
4567 class-specific delete operators.
4568 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4570 If this call to "operator delete" is being generated as part to
4571 deallocate memory allocated via a new-expression (as per [expr.new]
4572 which requires that if the initialization throws an exception then
4573 we call a deallocation function), then ALLOC_FN is the allocation
4574 function. */
4576 tree
4579 tree alloc_fn)
4580 {
4594 /* In [class.free]
4596 If the result of the lookup is ambiguous or inaccessible, or if
4597 the lookup selects a placement deallocation function, the
4598 program is ill-formed.
4600 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4601 {
4605 }
4606 else
4612 /* Strip const and volatile from addr. */
4616 {
4617 /* "A declaration of a placement deallocation function matches the
4618 declaration of a placement allocation function if it has the same
4619 number of parameters and, after parameter transformations (8.3.5),
4620 all parameter types except the first are identical."
4622 So we build up the function type we want and ask instantiate_type
4623 to get it for us. */
4635 /* "If the lookup finds the two-parameter form of a usual deallocation
4636 function (3.7.4.2) and that function, considered as a placement
4637 deallocation function, would have been selected as a match for the
4638 allocation function, the program is ill-formed." */
4640 {
4641 /* But if the class has an operator delete (void *), then that is
4642 the usual deallocation function, so we shouldn't complain
4643 about using the operator delete (void *, size_t). */
4646 {
4651 }
4654 ok:;
4655 }
4656 }
4657 else
4658 /* "Any non-placement deallocation function matches a non-placement
4659 allocation function. If the lookup finds a single matching
4660 deallocation function, that function will be called; otherwise, no
4661 deallocation function will be called." */
4664 {
4667 {
4669 /* "If a class T has a member deallocation function named
4670 operator delete with exactly one parameter, then that
4671 function is a usual (non-placement) deallocation
4672 function. If class T does not declare such an operator
4673 delete but does declare a member deallocation function named
4674 operator delete with exactly two parameters, the second of
4675 which has type std::size_t (18.2), then this function is a
4676 usual deallocation function."
4678 So (void*) beats (void*, size_t). */
4681 }
4682 }
4684 /* If we have a matching function, call it. */
4686 {
4689 /* If the FN is a member function, make sure that it is
4690 accessible. */
4694 /* Core issue 901: It's ok to new a type with deleted delete. */
4699 {
4700 /* The placement args might not be suitable for overload
4701 resolution at this point, so build the call directly. */
4710 }
4711 else
4712 {
4713 tree ret;
4721 }
4722 }
4724 /* [expr.new]
4726 If no unambiguous matching deallocation function can be found,
4727 propagating the exception does not cause the object's memory to
4728 be freed. */
4730 {
4733 alloc_fn);
4735 }
4740 }
4742 /* If the current scope isn't allowed to access DECL along
4743 BASETYPE_PATH, give an error. The most derived class in
4744 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4745 the declaration to use in the error diagnostic. */
4747 bool
4749 {
4753 {
4758 else
4762 }
4765 }
4767 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4768 bitwise or of LOOKUP_* values. If any errors are warnings are
4769 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4770 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4771 to NULL. */
4773 static tree
4776 {
4789 else
4792 }
4794 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4795 EXPR is implicitly converted to type TOTYPE.
4796 FN and ARGNUM are used for diagnostics. */
4798 static void
4800 {
4803 /* Issue warnings about peculiar, but valid, uses of NULL. */
4805 {
4809 else
4811 }
4813 /* Issue warnings if "false" is converted to a NULL pointer */
4818 }
4820 /* Perform the conversions in CONVS on the expression EXPR. FN and
4821 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4822 indicates the `this' argument of a method. INNER is nonzero when
4823 being called to continue a conversion chain. It is negative when a
4824 reference binding will be applied, positive otherwise. If
4825 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4826 conversions will be emitted if appropriate. If C_CAST_P is true,
4827 this conversion is coming from a C-style cast; in that case,
4828 conversions to inaccessible bases are permitted. */
4830 static tree
4834 {
4836 diagnostic_t diag_kind;
4846 {
4849 /* Give a helpful error if this is bad because of excess braces. */
4857 {
4859 {
4863 complain);
4865 }
4870 complain);
4873 }
4875 {
4879 }
4880 else
4884 }
4890 {
4892 {
4897 /* When converting from an init list we consider explicit
4898 constructors, but actually trying to call one is an error. */
4900 {
4904 else
4906 }
4908 /* Set user_conv_p on the argument conversions, so rvalue/base
4909 handling knows not to allow any more UDCs. */
4915 /* If this is a constructor or a function returning an aggr type,
4916 we need to build up a TARGET_EXPR. */
4918 {
4921 /* Remember that this was list-initialization. */
4924 }
4927 }
4930 {
4936 else
4938 }
4942 /* Convert a constant to its underlying value, unless we are
4943 about to bind it to a reference, in which case we need to
4944 leave it as an lvalue. */
4946 {
4949 /* If __null has been converted to an integer type, we do not
4950 want to warn about uses of EXPR as an integer, rather than
4951 as a pointer. */
4953 }
4956 /* Call build_user_type_conversion again for the error. */
4957 return build_user_type_conversion
4961 {
4962 /* Conversion to std::initializer_list<T>. */
4970 /* Convert all the elements. */
4972 {
4979 }
4980 /* Build up the array. */
4981 elttype = cp_build_qualified_type
4989 /* Call the private constructor. */
4991 new_ctor = build_special_member_call
4996 }
5003 };
5008 c_cast_p,
5009 complain);
5014 {
5019 /* Else fall through. */
5022 {
5023 /* We are going to bind a reference directly to a base-class
5024 subobject of EXPR. */
5025 /* Build an expression for `*((base*) &expr)'. */
5031 }
5033 /* Copy-initialization where the cv-unqualified version of the source
5034 type is the same class as, or a derived class of, the class of the
5035 destination [is treated as direct-initialization]. [dcl.init] */
5038 /* This conversion is being done in the context of a user-defined
5039 conversion (i.e. the second step of copy-initialization), so
5040 don't allow any more. */
5044 {
5050 }
5054 {
5059 {
5061 {
5066 }
5068 }
5070 /* If necessary, create a temporary.
5072 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
5073 that need temporaries, even when their types are reference
5074 compatible with the type of reference being bound, so the
5075 upcoming call to cp_build_unary_op (ADDR_EXPR, expr, ...)
5076 doesn't fail. */
5080 {
5086 {
5088 {
5089 /* If the reference is volatile or non-const, we
5090 cannot create a temporary. */
5097 else
5099 }
5101 }
5102 /* If the source is a packed field, and we must use a copy
5103 constructor, then building the target expr will require
5104 binding the field to the reference parameter to the
5105 copy constructor, and we'll end up with an infinite
5106 loop. If we can use a bitwise copy, then we'll be
5107 OK. */
5111 {
5116 }
5118 {
5121 }
5123 }
5125 /* Take the address of the thing to which we will bind the
5126 reference. */
5131 /* Convert it to a pointer to the type referred to by the
5132 reference. This will adjust the pointer if a derived to
5133 base conversion is being performed. */
5135 expr);
5136 /* Convert the pointer to the desired reference type. */
5138 }
5144 /* Warn about deprecated conversion if appropriate. */
5156 c_cast_p);
5160 }
5167 else
5171 }
5173 /* ARG is being passed to a varargs function. Perform any conversions
5174 required. Return the converted value. */
5176 tree
5178 {
5179 /* [expr.call]
5181 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5182 standard conversions are performed. */
5184 /* [expr.call]
5186 If the argument has integral or enumeration type that is subject
5187 to the integral promotions (_conv.prom_), or a floating point
5188 type that is subject to the floating point promotion
5189 (_conv.fpprom_), the value of the argument is converted to the
5190 promoted type before the call. */
5204 {
5205 /* [expr.call] 5.2.2/7:
5206 Passing a potentially-evaluated argument of class type (Clause 9)
5207 with a non-trivial copy constructor or a non-trivial destructor
5208 with no corresponding parameter is conditionally-supported, with
5209 implementation-defined semantics.
5211 We used to just warn here and do a bitwise copy, but now
5212 cp_expr_size will abort if we try to do that.
5214 If the call appears in the context of a sizeof expression,
5215 it is not potentially-evaluated. */
5219 }
5222 }
5224 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
5226 tree
5228 {
5240 {
5241 /* Remove reference types so we don't ICE later on. */
5243 /* conditionally-supported behavior [expr.call] 5.2.2/7. */
5249 }
5252 }
5254 /* TYPE has been given to va_arg. Apply the default conversions which
5255 would have happened when passed via ellipsis. Return the promoted
5256 type, or the passed type if there is no change. */
5258 tree
5260 {
5261 tree promote;
5263 /* Perform the array-to-pointer and function-to-pointer
5264 conversions. */
5272 }
5274 /* ARG is a default argument expression being passed to a parameter of
5275 the indicated TYPE, which is a parameter to FN. Do any required
5276 conversions. Return the converted value. */
5280 tree
5282 {
5284 tree t;
5286 /* If the ARG is an unparsed default argument expression, the
5287 conversion cannot be performed. */
5289 {
5294 }
5296 /* Detect recursion. */
5299 {
5302 }
5308 /* Due to:
5310 [dcl.fct.default]
5312 The names in the expression are bound, and the semantic
5313 constraints are checked, at the point where the default
5314 expressions appears.
5316 we must not perform access checks here. */
5320 {
5324 tf_warning_or_error);
5325 }
5326 else
5327 {
5328 /* We must make a copy of ARG, in case subsequent processing
5329 alters any part of it. For example, during gimplification a
5330 cast of the form (T) &X::f (where "f" is a member function)
5331 will lead to replacing the PTRMEM_CST for &X::f with a
5332 VAR_DECL. We can avoid the copy for constants, since they
5333 are never modified in place. */
5338 tf_warning_or_error);
5340 }
5346 }
5348 /* Returns the type which will really be used for passing an argument of
5349 type TYPE. */
5351 tree
5353 {
5354 /* Pass classes with copy ctors by invisible reference. */
5356 {
5358 /* There are no other pointers to this temporary. */
5360 }
5369 }
5371 /* Actually perform the appropriate conversion. */
5373 tree
5375 {
5376 tree bitfield_type;
5378 /* If VAL is a bitfield, then -- since it has already been converted
5379 to TYPE -- it cannot have a precision greater than TYPE.
5381 If it has a smaller precision, we must widen it here. For
5382 example, passing "int f:3;" to a function expecting an "int" will
5383 not result in any conversion before this point.
5385 If the precision is the same we must not risk widening. For
5386 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5387 often have type "int", even though the C++ type for the field is
5388 "long long". If the value is being passed to a function
5389 expecting an "int", then no conversions will be required. But,
5390 if we call convert_bitfield_to_declared_type, the bitfield will
5391 be converted to "long long". */
5398 ;
5399 /* Pass classes with copy ctors by invisible reference. */
5409 {
5418 }
5420 }
5422 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5423 which no conversions at all should be done. This is true for some
5424 builtins which don't act like normal functions. */
5426 static bool
5428 {
5431 {
5441 }
5444 }
5446 /* Subroutine of the various build_*_call functions. Overload resolution
5447 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5448 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5449 bitmask of various LOOKUP_* flags which apply to the call itself. */
5451 static tree
5453 {
5461 tree val;
5470 /* In a template, there is no need to perform all of the work that
5471 is normally done. We are only interested in the type of the call
5472 expression, i.e., the return type of the function. Any semantic
5473 errors will be deferred until the template is instantiated. */
5475 {
5476 tree expr;
5477 tree return_type;
5485 else
5486 {
5489 tree arg;
5497 }
5500 argarray);
5506 }
5508 /* Give any warnings we noticed during overload resolution. */
5510 {
5514 }
5516 /* Make =delete work with SFINAE. */
5521 {
5522 /* If FN is a template function, two cases must be considered.
5523 For example:
5525 struct A {
5526 protected:
5527 template <class T> void f();
5528 };
5529 template <class T> struct B {
5530 protected:
5531 void g();
5532 };
5533 struct C : A, B<int> {
5534 using A::f; // #1
5535 using B<int>::g; // #2
5536 };
5538 In case #1 where `A::f' is a member template, DECL_ACCESS is
5539 recorded in the primary template but not in its specialization.
5540 We check access of FN using its primary template.
5542 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
5543 because it is a member of class template B, DECL_ACCESS is
5544 recorded in the specialization `B<int>::g'. We cannot use its
5545 primary template because `B<T>::g' and `B<int>::g' may have
5546 different access. */
5551 else
5553 }
5555 /* Find maximum size of vector to hold converted arguments. */
5562 /* The implicit parameters to a constructor are not considered by overload
5563 resolution, and must be of the proper type. */
5565 {
5567 {
5570 }
5571 else
5572 {
5575 }
5577 /* We should never try to call the abstract constructor. */
5581 {
5585 }
5586 }
5587 /* Bypass access control for 'this' parameter. */
5589 {
5592 ? first_arg
5595 tree converted_arg;
5596 tree base_binfo;
5599 {
5603 else
5605 }
5607 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
5608 X is called for an object that is not of type X, or of a type
5609 derived from X, the behavior is undefined.
5611 So we can assume that anything passed as 'this' is non-null, and
5612 optimize accordingly. */
5614 /* Convert to the base in which the function was declared. */
5617 arg,
5620 /* Check that the base class is accessible. */
5626 /* If fn was found by a using declaration, the conversion path
5627 will be to the derived class, not the base declaring fn. We
5628 must convert from derived to base. */
5638 else
5642 }
5647 {
5652 /* Don't make a copy here if build_call is going to. */
5658 /* Warn about initializer_list deduction that isn't currently in the
5659 working draft. */
5661 && flag_deduce_init_list
5664 {
5674 {
5681 }
5682 }
5684 val = convert_like_with_context
5686 complain);
5691 else
5693 }
5695 /* Default arguments */
5700 /* Ellipsis */
5702 {
5706 else
5709 }
5717 /* Avoid actually calling copy constructors and copy assignment operators,
5718 if possible. */
5725 {
5726 tree targ;
5728 tree fa;
5730 /* Pull out the real argument, disregarding const-correctness. */
5736 {
5741 }
5742 else
5747 else
5752 {
5753 /* Copy-list-initialization doesn't require the copy constructor
5754 to be defined. */
5755 }
5756 /* [class.copy]: the copy constructor is implicitly defined even if
5757 the implementation elided its use. */
5759 {
5762 }
5764 /* If we're creating a temp and we already have one, don't create a
5765 new one. If we're not creating a temp but we get one, use
5766 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5767 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5768 temp or an INIT_EXPR otherwise. */
5773 {
5778 }
5782 {
5784 complain));
5788 }
5789 }
5793 {
5794 tree to = stabilize_reference
5801 {
5804 }
5805 else
5806 {
5807 /* We must only copy the non-tail padding parts.
5808 Use __builtin_memcpy for the bitwise copy.
5809 FIXME fix 22488 so we can go back to using MODIFY_EXPR
5810 instead of an explicit call to memcpy. */
5820 {
5821 /* If we can't be sure about pointer alignment, a call
5822 to __builtin_memcpy is expanded as a call to memcpy, which
5823 is invalid with identical args. Otherwise it is
5824 expanded as a block move, which should be safe. */
5828 }
5837 }
5840 }
5846 {
5847 tree t;
5853 /* Warn about deprecated virtual functions now, since we're about
5854 to throw away the decl. */
5864 else
5867 }
5868 else
5872 }
5874 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5875 This function performs no overload resolution, conversion, or other
5876 high-level operations. */
5878 tree
5880 {
5881 tree fndecl;
5885 /* If this call might throw an exception, note that fact. */
5892 /* Check that arguments to builtin functions match the expectations. */
5899 /* Some built-in function calls will be evaluated at compile-time in
5900 fold (). */
5913 }
5917 /* Make an expression which yields the address of the Java interface
5918 method FN. This is achieved by generating a call to libjava's
5919 _Jv_LookupInterfaceMethodIdx(). */
5921 static tree
5923 {
5929 {
5934 endlink)));
5935 java_iface_lookup_fn
5939 }
5941 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5942 This is the first entry in the vtable. */
5944 tf_warning_or_error),
5945 integer_zero_node);
5947 /* Get the java.lang.Class pointer for the interface being called. */
5952 {
5954 iface);
5956 }
5960 /* Determine the itable index of FN. */
5963 {
5968 i++;
5969 }
5974 java_iface_lookup_fn);
5977 }
5979 /* Returns the value to use for the in-charge parameter when making a
5980 call to a function with the indicated NAME.
5982 FIXME:Can't we find a neater way to do this mapping? */
5984 tree
5986 {
5997 /* This function should only be called with one of the names listed
5998 above. */
6001 }
6003 /* Build a call to a constructor, destructor, or an assignment
6004 operator for INSTANCE, an expression with class type. NAME
6005 indicates the special member function to call; *ARGS are the
6006 arguments. ARGS may be NULL. This may change ARGS. BINFO
6007 indicates the base of INSTANCE that is to be passed as the `this'
6008 parameter to the member function called.
6010 FLAGS are the LOOKUP_* flags to use when processing the call.
6012 If NAME indicates a complete object constructor, INSTANCE may be
6013 NULL_TREE. In this case, the caller will call build_cplus_new to
6014 store the newly constructed object into a VAR_DECL. */
6016 tree
6019 {
6020 tree fns;
6021 /* The type of the subobject to be constructed or destroyed. */
6022 tree class_type;
6024 tree ret;
6033 {
6034 /* Resolve the name. */
6039 }
6045 /* Handle the special case where INSTANCE is NULL_TREE. */
6047 {
6050 }
6051 else
6052 {
6058 /* Convert to the base class, if necessary. */
6061 {
6063 /* For constructors and destructors, either the base is
6064 non-virtual, or it is virtual but we are doing the
6065 conversion from a constructor or destructor for the
6066 complete object. In either case, we can convert
6067 statically. */
6069 else
6070 /* However, for assignment operators, we must convert
6071 dynamically if the base is virtual. */
6074 }
6075 }
6081 /* When making a call to a constructor or destructor for a subobject
6082 that uses virtual base classes, pass down a pointer to a VTT for
6083 the subobject. */
6087 {
6088 tree vtt;
6089 tree sub_vtt;
6091 /* If the current function is a complete object constructor
6092 or destructor, then we fetch the VTT directly.
6093 Otherwise, we look it up using the VTT we were given. */
6099 current_vtt_parm,
6100 vtt);
6106 {
6109 }
6112 }
6117 complain);
6123 }
6125 /* Return the NAME, as a C string. The NAME indicates a function that
6126 is a member of TYPE. *FREE_P is set to true if the caller must
6127 free the memory returned.
6129 Rather than go through all of this, we should simply set the names
6130 of constructors and destructors appropriately, and dispense with
6131 ctor_identifier, dtor_identifier, etc. */
6135 {
6138 /* Assume that we will not allocate memory. */
6140 /* Constructors and destructors are special. */
6142 {
6143 pretty_name
6145 /* For a destructor, add the '~'. */
6149 {
6151 /* Remember that we need to free the memory allocated. */
6153 }
6154 }
6156 {
6159 TFF_PLAIN_IDENTIFIER),
6160 NULL);
6161 /* Remember that we need to free the memory allocated. */
6163 }
6164 else
6168 }
6170 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
6171 be set, upon return, to the function called. ARGS may be NULL.
6172 This may change ARGS. */
6174 tree
6178 {
6182 tree access_binfo;
6183 tree optype;
6185 tree instance_ptr;
6186 tree name;
6189 tree call;
6190 tree fn;
6191 tree class_type;
6194 tree orig_instance;
6195 tree orig_fns;
6201 /* We don't know what function we're going to call, yet. */
6210 {
6214 }
6219 /* Dismantle the baselink to collect all the information we need. */
6226 {
6230 }
6241 {
6246 }
6249 /* Under DR 147 A::A() is an invalid constructor call,
6250 not a functional cast. */
6252 {
6262 complain);
6264 }
6266 /* Figure out whether to skip the first argument for the error
6267 message we will display to users if an error occurs. We don't
6268 want to display any compiler-generated arguments. The "this"
6269 pointer hasn't been added yet. However, we must remove the VTT
6270 pointer if this is a call to a base-class constructor or
6271 destructor. */
6274 {
6275 /* Callers should explicitly indicate whether they want to construct
6276 the complete object or just the part without virtual bases. */
6278 /* Similarly for destructors. */
6280 /* Remove the VTT pointer, if present. */
6284 }
6286 /* Process the argument list. */
6288 {
6292 }
6296 /* It's OK to call destructors and constructors on cv-qualified objects.
6297 Therefore, convert the INSTANCE_PTR to the unqualified type, if
6298 necessary. */
6301 {
6305 }
6309 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
6310 initializer, not T({ }). If the type doesn't have a list ctor,
6311 break apart the list into separate ctor args. */
6316 {
6319 }
6324 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6328 {
6330 tree this_first_arg;
6332 /* We can end up here for copy-init of same or base class. */
6339 else
6343 /* A member template. */
6345 class_type,
6346 explicit_targs,
6347 this_first_arg,
6349 optype,
6350 access_binfo,
6351 conversion_path,
6352 flags,
6353 DEDUCE_CALL);
6356 class_type,
6357 this_first_arg,
6359 access_binfo,
6360 conversion_path,
6361 flags);
6362 }
6366 {
6368 {
6371 else
6372 {
6375 tree arglist;
6386 }
6388 }
6390 }
6391 else
6392 {
6395 {
6398 tree arglist;
6401 {
6407 arglist);
6411 }
6413 }
6414 else
6415 {
6424 /* This is not an error, it is runtime undefined
6425 behavior. */
6427 "abstract virtual %q#D called from constructor"
6429 fn);
6433 {
6436 fn);
6438 }
6439 else
6440 {
6444 /* Now we know what function is being called. */
6447 /* Build the actual CALL_EXPR. */
6449 /* In an expression of the form `a->f()' where `f' turns
6450 out to be a static member function, `a' is
6451 none-the-less evaluated. */
6460 /* An explicit call of the form "x->~X()" has type
6461 "void". However, on platforms where destructors
6462 return "this" (i.e., those where
6463 targetm.cxx.cdtor_returns_this is true), such calls
6464 will appear to have a return value of pointer type
6465 to the low-level call machinery. We do not want to
6466 change the low-level machinery, since we want to be
6467 able to optimize "delete f()" on such platforms as
6468 "operator delete(~X(f()))" (rather than generating
6469 "t = f(), ~X(t), operator delete (t)"). */
6471 }
6472 }
6473 }
6476 {
6482 {
6485 }
6488 call = (build_min_non_dep_call_vec
6492 orig_args));
6496 }
6498 /* Free all the conversions we allocated. */
6505 }
6507 /* Returns true iff standard conversion sequence ICS1 is a proper
6508 subsequence of ICS2. */
6510 static bool
6512 {
6513 /* We can assume that a conversion of the same code
6514 between the same types indicates a subsequence since we only get
6515 here if the types we are converting from are the same. */
6522 {
6530 /* At this point, ICS1 cannot be a proper subsequence of
6531 ICS2. We can get a USER_CONV when we are comparing the
6532 second standard conversion sequence of two user conversion
6533 sequences. */
6543 }
6544 }
6546 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
6547 be any _TYPE nodes. */
6549 bool
6551 {
6555 /* We only allow proper derivation here. The DERIVED_FROM_P macro
6556 considers every class derived from itself. */
6559 }
6561 /* We build the ICS for an implicit object parameter as a pointer
6562 conversion sequence. However, such a sequence should be compared
6563 as if it were a reference conversion sequence. If ICS is the
6564 implicit conversion sequence for an implicit object parameter,
6565 modify it accordingly. */
6567 static void
6569 {
6571 {
6572 /* [over.match.funcs]
6574 For non-static member functions, the type of the
6575 implicit object parameter is "reference to cv X"
6576 where X is the class of which the function is a
6577 member and cv is the cv-qualification on the member
6578 function declaration. */
6580 tree reference_type;
6582 /* The `this' parameter is a pointer to a class type. Make the
6583 implicit conversion talk about a reference to that same class
6584 type. */
6597 }
6598 }
6600 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
6601 and return the initial reference binding conversion. Otherwise,
6602 leave *ICS unchanged and return NULL. */
6606 {
6608 {
6613 }
6616 }
6618 /* Compare two implicit conversion sequences according to the rules set out in
6619 [over.ics.rank]. Return values:
6621 1: ics1 is better than ics2
6622 -1: ics2 is better than ics1
6623 0: ics1 and ics2 are indistinguishable */
6625 static int
6627 {
6628 tree from_type1;
6629 tree from_type2;
6630 tree to_type1;
6631 tree to_type2;
6638 /* REF_BINDING is nonzero if the result of the conversion sequence
6639 is a reference type. In that case REF_CONV is the reference
6640 binding conversion. */
6644 /* Handle implicit object parameters. */
6648 /* Handle reference parameters. */
6652 /* List-initialization sequence L1 is a better conversion sequence than
6653 list-initialization sequence L2 if L1 converts to
6654 std::initializer_list<X> for some X and L2 does not. */
6660 /* [over.ics.rank]
6662 When comparing the basic forms of implicit conversion sequences (as
6663 defined in _over.best.ics_)
6665 --a standard conversion sequence (_over.ics.scs_) is a better
6666 conversion sequence than a user-defined conversion sequence
6667 or an ellipsis conversion sequence, and
6669 --a user-defined conversion sequence (_over.ics.user_) is a
6670 better conversion sequence than an ellipsis conversion sequence
6671 (_over.ics.ellipsis_). */
6681 {
6682 /* XXX Isn't this an extension? */
6683 /* Both ICS are bad. We try to make a decision based on what
6684 would have happened if they'd been good. */
6692 /* We couldn't make up our minds; try to figure it out below. */
6693 }
6696 /* Both conversions are ellipsis conversions or both are building a
6697 std::initializer_list. */
6700 /* User-defined conversion sequence U1 is a better conversion sequence
6701 than another user-defined conversion sequence U2 if they contain the
6702 same user-defined conversion operator or constructor and if the sec-
6703 ond standard conversion sequence of U1 is better than the second
6704 standard conversion sequence of U2. */
6707 {
6721 /* We can just fall through here, after setting up
6722 FROM_TYPE1 and FROM_TYPE2. */
6725 }
6726 else
6727 {
6731 /* We're dealing with two standard conversion sequences.
6733 [over.ics.rank]
6735 Standard conversion sequence S1 is a better conversion
6736 sequence than standard conversion sequence S2 if
6738 --S1 is a proper subsequence of S2 (comparing the conversion
6739 sequences in the canonical form defined by _over.ics.scs_,
6740 excluding any Lvalue Transformation; the identity
6741 conversion sequence is considered to be a subsequence of
6742 any non-identity conversion sequence */
6753 }
6755 /* One sequence can only be a subsequence of the other if they start with
6756 the same type. They can start with different types when comparing the
6757 second standard conversion sequence in two user-defined conversion
6758 sequences. */
6760 {
6765 }
6767 /* [over.ics.rank]
6769 Or, if not that,
6771 --the rank of S1 is better than the rank of S2 (by the rules
6772 defined below):
6774 Standard conversion sequences are ordered by their ranks: an Exact
6775 Match is a better conversion than a Promotion, which is a better
6776 conversion than a Conversion.
6778 Two conversion sequences with the same rank are indistinguishable
6779 unless one of the following rules applies:
6781 --A conversion that is not a conversion of a pointer, or pointer
6782 to member, to bool is better than another conversion that is such
6783 a conversion.
6785 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
6786 so that we do not have to check it explicitly. */
6795 /* A conversion from scalar arithmetic type to complex is worse than a
6796 conversion between scalar arithmetic types. */
6803 {
6806 else
6808 }
6814 {
6819 }
6820 /* The rules for pointers to members A::* are just like the rules
6821 for pointers A*, except opposite: if B is derived from A then
6822 A::* converts to B::*, not vice versa. For that reason, we
6823 switch the from_ and to_ variables here. */
6830 {
6835 }
6840 {
6841 /* This was one of the pointer or pointer-like conversions.
6843 [over.ics.rank]
6845 --If class B is derived directly or indirectly from class A,
6846 conversion of B* to A* is better than conversion of B* to
6847 void*, and conversion of A* to void* is better than
6848 conversion of B* to void*. */
6851 {
6853 deref_from_type2))
6856 deref_from_type1))
6858 }
6861 {
6863 {
6865 {
6867 deref_to_type1))
6869 }
6870 /* We know that DEREF_TO_TYPE1 is `void' here. */
6872 deref_to_type2))
6874 }
6875 }
6878 {
6879 /* [over.ics.rank]
6881 --If class B is derived directly or indirectly from class A
6882 and class C is derived directly or indirectly from B,
6884 --conversion of C* to B* is better than conversion of C* to
6885 A*,
6887 --conversion of B* to A* is better than conversion of C* to
6888 A* */
6890 {
6892 deref_to_type2))
6895 deref_to_type1))
6897 }
6899 {
6901 deref_from_type1))
6904 deref_from_type2))
6906 }
6907 }
6908 }
6911 {
6914 /* [over.ics.rank]
6916 --binding of an expression of type C to a reference of type
6917 B& is better than binding an expression of type C to a
6918 reference of type A&
6920 --conversion of C to B is better than conversion of C to A, */
6923 {
6928 }
6929 }
6932 {
6935 /* [over.ics.rank]
6937 --binding of an expression of type B to a reference of type
6938 A& is better than binding an expression of type C to a
6939 reference of type A&,
6941 --conversion of B to A is better than conversion of C to A */
6944 {
6949 }
6950 }
6952 /* [over.ics.rank]
6954 --S1 and S2 differ only in their qualification conversion and yield
6955 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6956 qualification signature of type T1 is a proper subset of the cv-
6957 qualification signature of type T2 */
6961 {
6965 }
6967 /* [over.ics.rank]
6969 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6970 to an implicit object parameter, and either S1 binds an lvalue reference
6971 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6972 reference to an rvalue and S2 binds an lvalue reference
6973 (C++0x draft standard, 13.3.3.2)
6975 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6976 types to which the references refer are the same type except for
6977 top-level cv-qualifiers, and the type to which the reference
6978 initialized by S2 refers is more cv-qualified than the type to
6979 which the reference initialized by S1 refers */
6982 {
6986 {
6991 }
6996 }
6998 /* Neither conversion sequence is better than the other. */
7000 }
7002 /* The source type for this standard conversion sequence. */
7004 static tree
7006 {
7008 {
7013 }
7015 }
7017 /* Note a warning about preferring WINNER to LOSER. We do this by storing
7018 a pointer to LOSER and re-running joust to produce the warning if WINNER
7019 is actually used. */
7021 static void
7023 {
7029 }
7031 /* Compare two candidates for overloading as described in
7032 [over.match.best]. Return values:
7034 1: cand1 is better than cand2
7035 -1: cand2 is better than cand1
7036 0: cand1 and cand2 are indistinguishable */
7038 static int
7040 {
7046 /* Candidates that involve bad conversions are always worse than those
7047 that don't. */
7053 /* If we have two pseudo-candidates for conversions to the same type,
7054 or two candidates for the same function, arbitrarily pick one. */
7059 /* a viable function F1
7060 is defined to be a better function than another viable function F2 if
7061 for all arguments i, ICSi(F1) is not a worse conversion sequence than
7062 ICSi(F2), and then */
7064 /* for some argument j, ICSj(F1) is a better conversion sequence than
7065 ICSj(F2) */
7067 /* For comparing static and non-static member functions, we ignore
7068 the implicit object parameter of the non-static function. The
7069 standard says to pretend that the static function has an object
7070 parm, but that won't work with operator overloading. */
7073 {
7081 else
7082 {
7085 }
7086 }
7089 {
7095 {
7108 {
7115 else
7120 {
7124 }
7125 else
7127 }
7130 {
7133 }
7135 }
7136 }
7138 /* warn about confusing overload resolution for user-defined conversions,
7139 either between a constructor and a conversion op, or between two
7140 conversion ops. */
7144 {
7150 else
7153 /* We don't want to complain about `X::operator T1 ()'
7154 beating `X::operator T2 () const', when T2 is a no less
7155 cv-qualified version of T1. */
7158 {
7163 {
7166 }
7169 }
7170 else
7176 {
7183 {
7185 }
7186 }
7187 else
7189 }
7194 /* or, if not that,
7195 F1 is a non-template function and F2 is a template function
7196 specialization. */
7203 /* or, if not that,
7204 F1 and F2 are template functions and the function template for F1 is
7205 more specialized than the template for F2 according to the partial
7206 ordering rules. */
7209 {
7210 winner = more_specialized_fn
7213 /* [temp.func.order]: The presence of unused ellipsis and default
7214 arguments has no effect on the partial ordering of function
7215 templates. add_function_candidate() will not have
7216 counted the "this" argument for constructors. */
7220 }
7222 /* or, if not that,
7223 the context is an initialization by user-defined conversion (see
7224 _dcl.init_ and _over.match.user_) and the standard conversion
7225 sequence from the return type of F1 to the destination type (i.e.,
7226 the type of the entity being initialized) is a better conversion
7227 sequence than the standard conversion sequence from the return type
7228 of F2 to the destination type. */
7231 {
7235 }
7237 /* Check whether we can discard a builtin candidate, either because we
7238 have two identical ones or matching builtin and non-builtin candidates.
7240 (Pedantically in the latter case the builtin which matched the user
7241 function should not be added to the overload set, but we spot it here.
7243 [over.match.oper]
7244 ... the builtin candidates include ...
7245 - do not have the same parameter type list as any non-template
7246 non-member candidate. */
7250 {
7256 {
7258 /* Two built-in candidates; arbitrarily pick one. */
7261 /* cand1 is built-in; prefer cand2. */
7263 else
7264 /* cand2 is built-in; prefer cand1. */
7266 }
7267 }
7269 /* If the two function declarations represent the same function (this can
7270 happen with declarations in multiple scopes and arg-dependent lookup),
7271 arbitrarily choose one. But first make sure the default args we're
7272 using match. */
7275 {
7282 {
7283 /* Don't crash if the fn is variadic. */
7288 }
7296 {
7299 {
7301 {
7308 }
7309 else
7312 }
7315 }
7318 }
7320 tweak:
7322 /* Extension: If the worst conversion for one candidate is worse than the
7323 worst conversion for the other, take the first. */
7325 {
7330 {
7335 }
7341 {
7343 {
7345 "ISO C++ says that these are ambiguous, even "
7346 "though the worst conversion for the first is better than "
7350 }
7351 else
7354 }
7355 }
7359 }
7361 /* Given a list of candidates for overloading, find the best one, if any.
7362 This algorithm has a worst case of O(2n) (winner is last), and a best
7363 case of O(n/2) (totally ambiguous); much better than a sorting
7364 algorithm. */
7368 {
7373 /* Walk through the list once, comparing each current champ to the next
7374 candidate, knocking out a candidate or two with each comparison. */
7377 {
7381 else
7382 {
7384 {
7389 }
7390 else
7391 {
7394 }
7397 }
7398 }
7400 /* Make sure the champ is better than all the candidates it hasn't yet
7401 been compared to. */
7404 challenger != champ
7407 {
7411 }
7414 }
7416 /* Returns nonzero if things of type FROM can be converted to TO. */
7418 bool
7420 {
7422 }
7424 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7426 bool
7428 {
7433 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7437 flags);
7440 /* Free all the conversions we allocated. */
7444 }
7446 /* Like can_convert_arg, but allows dubious conversions as well. */
7448 bool
7450 {
7454 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7456 /* Try to perform the conversion. */
7458 flags);
7459 /* Free all the conversions we allocated. */
7463 }
7465 /* Convert EXPR to TYPE. Return the converted expression.
7467 Note that we allow bad conversions here because by the time we get to
7468 this point we are committed to doing the conversion. If we end up
7469 doing a bad conversion, convert_like will complain. */
7471 tree
7473 {
7480 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7485 flags);
7488 {
7490 {
7491 /* If expr has unknown type, then it is an overloaded function.
7492 Call instantiate_type to get good error messages. */
7497 else
7499 }
7501 }
7503 {
7504 /* In a template, we are only concerned about determining the
7505 type of non-dependent expressions, so we do not have to
7506 perform the actual conversion. */
7509 }
7510 else
7513 /* Free all the conversions we allocated. */
7517 }
7519 tree
7521 {
7523 }
7525 /* Convert EXPR to TYPE (as a direct-initialization) if that is
7526 permitted. If the conversion is valid, the converted expression is
7527 returned. Otherwise, NULL_TREE is returned, except in the case
7528 that TYPE is a class type; in that case, an error is issued. If
7529 C_CAST_P is true, then this direction initialization is taking
7530 place as part of a static_cast being attempted as part of a C-style
7531 cast. */
7533 tree
7535 tree expr,
7537 tsubst_flags_t complain)
7538 {
7544 /* [dcl.init]
7546 If the destination type is a (possibly cv-qualified) class type:
7548 -- If the initialization is direct-initialization ...,
7549 constructors are considered. ... If no constructor applies, or
7550 the overload resolution is ambiguous, the initialization is
7551 ill-formed. */
7553 {
7559 }
7561 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7565 c_cast_p,
7566 LOOKUP_NORMAL);
7569 else
7572 c_cast_p,
7573 tf_warning_or_error);
7575 /* Free all the conversions we allocated. */
7579 }
7581 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
7582 is being bound to a temporary. Create and return a new VAR_DECL
7583 with the indicated TYPE; this variable will store the value to
7584 which the reference is bound. */
7586 tree
7588 {
7589 tree var;
7591 /* Create the variable. */
7594 /* Register the variable. */
7596 {
7597 /* Namespace-scope or local static; give it a mangled name. */
7598 tree name;
7605 }
7606 else
7607 /* Create a new cleanup level if necessary. */
7611 }
7613 /* EXPR is the initializer for a variable DECL of reference or
7614 std::initializer_list type. Create, push and return a new VAR_DECL
7615 for the initializer so that it will live as long as DECL. Any
7616 cleanup for the new variable is returned through CLEANUP, and the
7617 code to initialize the new variable is returned through INITP. */
7619 tree
7621 {
7622 tree init;
7623 tree type;
7624 tree var;
7626 /* Create the temporary variable. */
7630 /* If the rvalue is the result of a function call it will be
7631 a TARGET_EXPR. If it is some other construct (such as a
7632 member access expression where the underlying object is
7633 itself the result of a function call), turn it into a
7634 TARGET_EXPR here. It is important that EXPR be a
7635 TARGET_EXPR below since otherwise the INIT_EXPR will
7636 attempt to make a bitwise copy of EXPR to initialize
7637 VAR. */
7640 /* Create the INIT_EXPR that will initialize the temporary
7641 variable. */
7644 {
7649 else
7652 /* We must be careful to destroy the temporary only
7653 after its initialization has taken place. If the
7654 initialization throws an exception, then the
7655 destructor should not be run. We cannot simply
7656 transform INIT into something like:
7658 (INIT, ({ CLEANUP_STMT; }))
7660 because emit_local_var always treats the
7661 initializer as a full-expression. Thus, the
7662 destructor would run too early; it would run at the
7663 end of initializing the reference variable, rather
7664 than at the end of the block enclosing the
7665 reference variable.
7667 The solution is to pass back a cleanup expression
7668 which the caller is responsible for attaching to
7669 the statement tree. */
7670 }
7671 else
7672 {
7676 static_aggregates);
7677 }
7681 }
7683 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
7684 initializing a variable of that TYPE. If DECL is non-NULL, it is
7685 the VAR_DECL being initialized with the EXPR. (In that case, the
7686 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
7687 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
7688 return, if *CLEANUP is no longer NULL, it will be an expression
7689 that should be pushed as a cleanup after the returned expression
7690 is used to initialize DECL.
7692 Return the converted expression. */
7694 tree
7696 tsubst_flags_t complain)
7697 {
7704 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7708 LOOKUP_NORMAL);
7710 {
7712 {
7719 else
7723 }
7725 }
7727 /* If DECL is non-NULL, then this special rule applies:
7729 [class.temporary]
7731 The temporary to which the reference is bound or the temporary
7732 that is the complete object to which the reference is bound
7733 persists for the lifetime of the reference.
7735 The temporaries created during the evaluation of the expression
7736 initializing the reference, except the temporary to which the
7737 reference is bound, are destroyed at the end of the
7738 full-expression in which they are created.
7740 In that case, we store the converted expression into a new
7741 VAR_DECL in a new scope.
7743 However, we want to be careful not to create temporaries when
7744 they are not required. For example, given:
7746 struct B {};
7747 struct D : public B {};
7748 D f();
7749 const B& b = f();
7751 there is no need to copy the return value from "f"; we can just
7752 extend its lifetime. Similarly, given:
7754 struct S {};
7755 struct T { operator S(); };
7756 T t;
7757 const S& s = t;
7759 we can extend the lifetime of the return value of the conversion
7760 operator. */
7763 {
7764 tree var;
7765 tree base_conv_type;
7767 /* Skip over the REF_BIND. */
7769 /* If the next conversion is a BASE_CONV, skip that too -- but
7770 remember that the conversion was required. */
7772 {
7775 }
7776 else
7778 /* Perform the remainder of the conversion. */
7784 tf_warning_or_error);
7787 else
7788 {
7790 {
7791 tree init;
7793 /* Use its address to initialize the reference variable. */
7801 }
7802 else
7803 /* Take the address of EXPR. */
7805 /* If a BASE_CONV was required, perform it now. */
7807 expr = (perform_implicit_conversion
7809 tf_warning_or_error));
7811 }
7812 }
7813 else
7814 /* Perform the conversion. */
7817 /* Free all the conversions we allocated. */
7821 }
7823 /* Returns true iff TYPE is some variant of std::initializer_list. */
7825 bool
7827 {
7831 }
7833 /* Returns true iff DECL is a list constructor: i.e. a constructor which
7834 will accept an argument list of a single std::initializer_list<T>. */
7836 bool
7838 {
7840 tree arg;
7852 /* There are more non-defaulted parms. */
7856 }