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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
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_rvalue
60 /* The rank of the conversion. Order of the enumerals matters; better
61 conversions should come earlier in the list. */
64 cr_identity,
65 cr_exact,
66 cr_promotion,
67 cr_std,
68 cr_pbool,
69 cr_user,
70 cr_ellipsis,
71 cr_bad
74 /* An implicit conversion sequence, in the sense of [over.best.ics].
75 The first conversion to be performed is at the end of the chain.
76 That conversion is always a cr_identity conversion. */
80 /* The kind of conversion represented by this step. */
81 conversion_kind kind;
82 /* The rank of this conversion. */
83 conversion_rank rank;
88 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
89 temporary should be created to hold the result of the
90 conversion. */
92 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
93 from a pointer-to-derived to pointer-to-base is being performed. */
95 /* If KIND is ck_ref_bind, true when either an lvalue reference is
96 being bound to an lvalue expression or an rvalue reference is
97 being bound to an rvalue expression. */
99 /* The type of the expression resulting from the conversion. */
100 tree type;
102 /* The next conversion in the chain. Since the conversions are
103 arranged from outermost to innermost, the NEXT conversion will
104 actually be performed before this conversion. This variant is
105 used only when KIND is neither ck_identity nor ck_ambig. */
107 /* The expression at the beginning of the conversion chain. This
108 variant is used only if KIND is ck_identity or ck_ambig. */
109 tree expr;
111 /* The function candidate corresponding to this conversion
112 sequence. This field is only used if KIND is ck_user. */
114 };
116 #define CONVERSION_RANK(NODE) \
117 ((NODE)->bad_p ? cr_bad \
118 : (NODE)->ellipsis_p ? cr_ellipsis \
119 : (NODE)->user_conv_p ? cr_user \
120 : (NODE)->rank)
131 #define convert_like(CONV, EXPR) \
132 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
135 #define convert_like_with_context(CONV, EXPR, FN, ARGNO) \
136 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
159 static void add_builtin_candidates
162 static void add_builtin_candidate
166 static void build_builtin_candidate
201 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
202 NAME can take many forms... */
204 bool
206 {
207 /* Just accept something we've already complained about. */
216 {
221 else
223 }
224 else
225 {
226 /* In the case of:
228 template <class T> struct S { ~S(); };
229 int i;
230 i.~S();
232 NAME will be a class template. */
235 }
240 }
242 /* We want the address of a function or method. We avoid creating a
243 pointer-to-member function. */
245 tree
247 {
250 /* We have to do these by hand to avoid real pointer to member
251 functions. */
253 {
255 {
259 }
261 }
262 else
266 }
268 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
269 POINTER_TYPE to those. Note, pointer to member function types
270 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
271 two variants. build_call_a is the primitive taking an array of
272 arguments, while build_call_n is a wrapper that handles varargs. */
274 tree
276 {
279 else
280 {
290 }
291 }
293 tree
295 {
298 tree decl;
299 tree result_type;
300 tree fntype;
313 {
316 {
317 /* We invoke build_call directly for several library
318 functions. These may have been declared normally if
319 we're building libgcc, so we can't just check
320 DECL_ARTIFICIAL. */
325 }
326 }
327 else
330 /* We check both the decl and the type; a function may be known not to
331 throw without being declared throw(). */
345 /* Don't pass empty class objects by value. This is useful
346 for tags in STL, which are used to control overload resolution.
347 We don't need to handle other cases of copying empty classes. */
352 {
356 }
363 }
365 /* Build something of the form ptr->method (args)
366 or object.method (args). This can also build
367 calls to constructors, and find friends.
369 Member functions always take their class variable
370 as a pointer.
372 INSTANCE is a class instance.
374 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
376 PARMS help to figure out what that NAME really refers to.
378 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
379 down to the real instance type to use for access checking. We need this
380 information to get protected accesses correct.
382 FLAGS is the logical disjunction of zero or more LOOKUP_
383 flags. See cp-tree.h for more info.
385 If this is all OK, calls build_function_call with the resolved
386 member function.
388 This function must also handle being called to perform
389 initialization, promotion/coercion of arguments, and
390 instantiation of default parameters.
392 Note that NAME may refer to an instance variable name. If
393 `operator()()' is defined for the type of that field, then we return
394 that result. */
396 /* New overloading code. */
404 };
407 /* The FUNCTION_DECL that will be called if this candidate is
408 selected by overload resolution. */
409 tree fn;
410 /* The arguments to use when calling this function. */
411 tree args;
412 /* The implicit conversion sequences for each of the arguments to
413 FN. */
415 /* The number of implicit conversion sequences. */
417 /* If FN is a user-defined conversion, the standard conversion
418 sequence from the type returned by FN to the desired destination
419 type. */
422 /* If FN is a member function, the binfo indicating the path used to
423 qualify the name of FN at the call site. This path is used to
424 determine whether or not FN is accessible if it is selected by
425 overload resolution. The DECL_CONTEXT of FN will always be a
426 (possibly improper) base of this binfo. */
427 tree access_path;
428 /* If FN is a non-static member function, the binfo indicating the
429 subobject to which the `this' pointer should be converted if FN
430 is selected by overload resolution. The type pointed to the by
431 the `this' pointer must correspond to the most derived class
432 indicated by the CONVERSION_PATH. */
433 tree conversion_path;
434 tree template_decl;
437 };
439 /* Returns true iff T is a null pointer constant in the sense of
440 [conv.ptr]. */
442 bool
444 {
445 /* [conv.ptr]
447 A null pointer constant is an integral constant expression
448 (_expr.const_) rvalue of integer type that evaluates to zero. */
453 {
457 }
459 }
461 /* Returns nonzero if PARMLIST consists of only default parms and/or
462 ellipsis. */
464 bool
466 {
472 }
474 /* Allocate N bytes of memory from the conversion obstack. The memory
475 is zeroed before being returned. */
479 {
482 {
485 }
489 }
491 /* Dynamically allocate a conversion. */
495 {
500 }
502 #ifdef ENABLE_CHECKING
504 /* Make sure that all memory on the conversion obstack has been
505 freed. */
507 void
509 {
513 }
517 /* Dynamically allocate an array of N conversions. */
521 {
523 }
527 {
531 /* We can't use buildl1 here because CODE could be USER_CONV, which
532 takes two arguments. In that case, the caller is responsible for
533 filling in the second argument. */
539 {
555 }
561 }
563 /* Build a representation of the identity conversion from EXPR to
564 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
568 {
576 }
578 /* Converting from EXPR to TYPE was ambiguous in the sense that there
579 were multiple user-defined conversions to accomplish the job.
580 Build a conversion that indicates that ambiguity. */
584 {
592 }
594 tree
596 {
600 }
602 /* Returns the standard conversion path (see [conv]) from type FROM to type
603 TO, if any. For proper handling of null pointer constants, you must
604 also pass the expression EXPR to convert from. If C_CAST_P is true,
605 this conversion is coming from a C-style cast. */
610 {
617 {
620 }
626 {
631 }
638 {
642 }
644 {
646 {
647 tree bitfield_type;
650 {
653 }
654 }
656 }
658 /* Allow conversion between `__complex__' data types. */
660 {
661 /* The standard conversion sequence to convert FROM to TO is
662 the standard conversion sequence to perform componentwise
663 conversion. */
668 {
671 }
672 else
676 }
686 {
687 /* For backwards brain damage compatibility, allow interconversion of
688 pointers and integers with a pedwarn. */
691 }
693 {
694 /* For backwards brain damage compatibility, allow interconversion of
695 enums and integers with a pedwarn. */
698 }
701 {
702 tree to_pointee;
703 tree from_pointee;
708 ;
712 {
713 from = build_pointer_type
717 }
719 {
724 && (same_type_ignoring_top_level_qualifiers_p
727 {
731 }
734 }
737 /* [conv.ptr]
739 An rvalue of type "pointer to cv D," where D is a
740 class type, can be converted to an rvalue of type
741 "pointer to cv B," where B is a base class (clause
742 _class.derived_) of D. If B is an inaccessible
743 (clause _class.access_) or ambiguous
744 (_class.member.lookup_) base class of D, a program
745 that necessitates this conversion is ill-formed.
746 Therefore, we use DERIVED_FROM_P, and do not check
747 access or uniqueness. */
749 /* If FROM is not yet complete, then we must be parsing
750 the body of a class. We know what's derived from
751 what, but we can't actually perform a
752 derived-to-base conversion. For example, in:
754 struct D : public B {
755 static const int i = sizeof((B*)(D*)0);
756 };
758 the D*-to-B* conversion is a reinterpret_cast, not a
759 static_cast. */
761 {
762 from =
768 }
771 {
774 }
775 else
776 {
779 }
784 /* In a C-style cast, we ignore CV-qualification because we
785 are allowed to perform a static_cast followed by a
786 const_cast. */
791 /* converting from string constant to char *. */
794 {
797 }
798 else
802 }
804 {
824 }
826 {
827 /* [conv.bool]
829 An rvalue of arithmetic, enumeration, pointer, or pointer to
830 member type can be converted to an rvalue of type bool. */
835 {
843 }
846 }
847 /* We don't check for ENUMERAL_TYPE here because there are no standard
848 conversions to enum type. */
851 {
856 /* Give this a better rank if it's a promotion. */
860 }
864 /* A derived-to-base conversion sequence is a user-defined conversion
865 because it involves a constructor call, even though it has the rank of
866 a standard conversion, so we don't consider it if we aren't allowing
867 user-defined conversions. But if we're binding directly to a
868 reference, it's only a pointer conversion. */
873 {
877 /* The derived-to-base conversion indicates the initialization
878 of a parameter with base type from an object of a derived
879 type. A temporary object is created to hold the result of
880 the conversion unless we're binding directly to a reference. */
882 }
883 else
887 }
889 /* Returns nonzero if T1 is reference-related to T2. */
891 static bool
893 {
897 /* [dcl.init.ref]
899 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
900 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
901 of T2. */
905 }
907 /* Returns nonzero if T1 is reference-compatible with T2. */
909 static bool
911 {
912 /* [dcl.init.ref]
914 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
915 reference-related to T2 and cv1 is the same cv-qualification as,
916 or greater cv-qualification than, cv2. */
919 }
921 /* Determine whether or not the EXPR (of class type S) can be
922 converted to T as in [over.match.ref]. */
926 {
927 tree conversions;
928 tree arglist;
930 tree t;
939 /* [over.match.ref]
941 Assuming that "cv1 T" is the underlying type of the reference
942 being initialized, and "cv S" is the type of the initializer
943 expression, with S a class type, the candidate functions are
944 selected as follows:
946 --The conversion functions of S and its base classes are
947 considered. Those that are not hidden within S and yield type
948 "reference to cv2 T2", where "cv1 T" is reference-compatible
949 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
951 The argument list has one argument, which is the initializer
952 expression. */
956 /* Conceptually, we should take the address of EXPR and put it in
957 the argument list. Unfortunately, however, that can result in
958 error messages, which we should not issue now because we are just
959 trying to find a conversion operator. Therefore, we use NULL,
960 cast to the appropriate type. */
967 {
971 {
977 /* If this is a template function, try to get an exact
978 match. */
980 {
983 NULL_TREE,
984 arglist,
985 reference_type,
988 LOOKUP_NORMAL,
989 DEDUCE_CONV);
992 {
993 /* Now, see if the conversion function really returns
994 an lvalue of the appropriate type. From the
995 point of view of unification, simply returning an
996 rvalue of the right type is good enough. */
1001 {
1004 }
1005 }
1006 }
1012 LOOKUP_NORMAL);
1015 {
1017 /* Build a standard conversion sequence indicating the
1018 binding from the reference type returned by the
1019 function to the desired REFERENCE_TYPE. */
1020 identity_conv
1023 NULL_TREE);
1024 cand->second_conv
1025 = (direct_reference_binding
1031 }
1032 }
1034 }
1037 /* If none of the conversion functions worked out, let our caller
1038 know. */
1046 /* Now that we know that this is the function we're going to use fix
1047 the dummy first argument. */
1052 /* Build a user-defined conversion sequence representing the
1053 conversion. */
1059 /* Merge it with the standard conversion sequence from the
1060 conversion function's return type to the desired type. */
1067 }
1069 /* A reference of the indicated TYPE is being bound directly to the
1070 expression represented by the implicit conversion sequence CONV.
1071 Return a conversion sequence for this binding. */
1075 {
1076 tree t;
1083 /* [over.ics.rank]
1085 When a parameter of reference type binds directly
1086 (_dcl.init.ref_) to an argument expression, the implicit
1087 conversion sequence is the identity conversion, unless the
1088 argument expression has a type that is a derived class of the
1089 parameter type, in which case the implicit conversion sequence is
1090 a derived-to-base Conversion.
1092 If the parameter binds directly to the result of applying a
1093 conversion function to the argument expression, the implicit
1094 conversion sequence is a user-defined conversion sequence
1095 (_over.ics.user_), with the second standard conversion sequence
1096 either an identity conversion or, if the conversion function
1097 returns an entity of a type that is a derived class of the
1098 parameter type, a derived-to-base conversion. */
1100 {
1101 /* Represent the derived-to-base conversion. */
1103 /* We will actually be binding to the base-class subobject in
1104 the derived class, so we mark this conversion appropriately.
1105 That way, convert_like knows not to generate a temporary. */
1107 }
1109 }
1111 /* Returns the conversion path from type FROM to reference type TO for
1112 purposes of reference binding. For lvalue binding, either pass a
1113 reference type to FROM or an lvalue expression to EXPR. If the
1114 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1115 the conversion returned. If C_CAST_P is true, this
1116 conversion is coming from a C-style cast. */
1120 {
1129 {
1134 }
1137 {
1138 /* Anything with reference type is an lvalue. */
1141 }
1145 /* Figure out whether or not the types are reference-related and
1146 reference compatible. We have do do this after stripping
1147 references from FROM. */
1149 /* If this is a C cast, first convert to an appropriately qualified
1150 type, so that we can later do a const_cast to the desired type. */
1156 /* Directly bind reference when target expression's type is compatible with
1157 the reference and expression is an lvalue. In DR391, the wording in
1158 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1159 const and rvalue references to rvalues of compatible class type. */
1161 && (lvalue_p
1164 {
1165 /* [dcl.init.ref]
1167 If the initializer expression
1169 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1170 is reference-compatible with "cv2 T2,"
1172 the reference is bound directly to the initializer expression
1173 lvalue.
1175 [...]
1176 If the initializer expression is an rvalue, with T2 a class type,
1177 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1178 is bound to the object represented by the rvalue or to a sub-object
1179 within that object. */
1185 /* The top-level caller requested that we pretend that the lvalue
1186 be treated as an rvalue. */
1188 else
1189 conv->rvaluedness_matches_p
1194 /* For the purposes of overload resolution, we ignore the fact
1195 this expression is a bitfield or packed field. (In particular,
1196 [over.ics.ref] says specifically that a function with a
1197 non-const reference parameter is viable even if the
1198 argument is a bitfield.)
1200 However, when we actually call the function we must create
1201 a temporary to which to bind the reference. If the
1202 reference is volatile, or isn't const, then we cannot make
1203 a temporary, so we just issue an error when the conversion
1204 actually occurs. */
1208 }
1209 /* [class.conv.fct] A conversion function is never used to convert a
1210 (possibly cv-qualified) object to the (possibly cv-qualified) same
1211 object type (or a reference to it), to a (possibly cv-qualified) base
1212 class of that type (or a reference to it).... */
1215 {
1216 /* [dcl.init.ref]
1218 If the initializer expression
1220 -- has a class type (i.e., T2 is a class type) can be
1221 implicitly converted to an lvalue of type "cv3 T3," where
1222 "cv1 T1" is reference-compatible with "cv3 T3". (this
1223 conversion is selected by enumerating the applicable
1224 conversion functions (_over.match.ref_) and choosing the
1225 best one through overload resolution. (_over.match_).
1227 the reference is bound to the lvalue result of the conversion
1228 in the second case. */
1232 }
1234 /* From this point on, we conceptually need temporaries, even if we
1235 elide them. Only the cases above are "direct bindings". */
1239 /* [over.ics.rank]
1241 When a parameter of reference type is not bound directly to an
1242 argument expression, the conversion sequence is the one required
1243 to convert the argument expression to the underlying type of the
1244 reference according to _over.best.ics_. Conceptually, this
1245 conversion sequence corresponds to copy-initializing a temporary
1246 of the underlying type with the argument expression. Any
1247 difference in top-level cv-qualification is subsumed by the
1248 initialization itself and does not constitute a conversion. */
1250 /* [dcl.init.ref]
1252 Otherwise, the reference shall be to a non-volatile const type.
1254 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1258 /* [dcl.init.ref]
1260 Otherwise, a temporary of type "cv1 T1" is created and
1261 initialized from the initializer expression using the rules for a
1262 non-reference copy initialization. If T1 is reference-related to
1263 T2, cv1 must be the same cv-qualification as, or greater
1264 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1268 /* We're generating a temporary now, but don't bind any more in the
1269 conversion (specifically, don't slice the temporary returned by a
1270 conversion operator). */
1274 flags);
1279 /* This reference binding, unlike those above, requires the
1280 creation of a temporary. */
1285 }
1287 /* Returns the implicit conversion sequence (see [over.ics]) from type
1288 FROM to type TO. The optional expression EXPR may affect the
1289 conversion. FLAGS are the usual overloading flags. Only
1290 LOOKUP_NO_CONVERSION is significant. If C_CAST_P is true, this
1291 conversion is coming from a C-style cast. */
1296 {
1305 else
1315 {
1324 /* We used to try to bind a reference to a temporary here, but that
1325 is now handled after the recursive call to this function at the end
1326 of reference_binding. */
1328 }
1331 }
1333 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1334 functions. */
1342 {
1357 }
1359 /* Create an overload candidate for the function or method FN called with
1360 the argument list ARGLIST and add it to CANDIDATES. FLAGS is passed on
1361 to implicit_conversion.
1363 CTYPE, if non-NULL, is the type we want to pretend this function
1364 comes from for purposes of overload resolution. */
1371 {
1376 tree orig_arglist;
1379 /* At this point we should not see any functions which haven't been
1380 explicitly declared, except for friend functions which will have
1381 been found using argument dependent lookup. */
1384 /* The `this', `in_chrg' and VTT arguments to constructors are not
1385 considered in overload resolution. */
1387 {
1391 }
1392 else
1398 /* 13.3.2 - Viable functions [over.match.viable]
1399 First, to be a viable function, a candidate function shall have enough
1400 parameters to agree in number with the arguments in the list.
1402 We need to check this first; otherwise, checking the ICSes might cause
1403 us to produce an ill-formed template instantiation. */
1407 {
1411 }
1416 /* Make sure there are default args for the rest of the parms. */
1423 /* Second, for F to be a viable function, there shall exist for each
1424 argument an implicit conversion sequence that converts that argument
1425 to the corresponding parameter of F. */
1431 {
1444 {
1447 /* The type of the implicit object parameter ('this') for
1448 overload resolution is not always the same as for the
1449 function itself; conversion functions are considered to
1450 be members of the class being converted, and functions
1451 introduced by a using-declaration are considered to be
1452 members of the class that uses them.
1454 Since build_over_call ignores the ICS for the `this'
1455 parameter, we can just change the parm type. */
1457 {
1458 parmtype
1462 }
1466 }
1467 else
1468 {
1471 }
1478 {
1481 }
1489 }
1491 out:
1494 }
1496 /* Create an overload candidate for the conversion function FN which will
1497 be invoked for expression OBJ, producing a pointer-to-function which
1498 will in turn be called with the argument list ARGLIST, and add it to
1499 CANDIDATES. FLAGS is passed on to implicit_conversion.
1501 Actually, we don't really care about FN; we care about the type it
1502 converts to. There may be multiple conversion functions that will
1503 convert to that type, and we rely on build_user_type_conversion_1 to
1504 choose the best one; so when we create our candidate, we record the type
1505 instead of the function. */
1510 {
1527 /* Don't bother looking up the same type twice. */
1532 {
1539 flags);
1545 else
1546 {
1549 }
1564 }
1574 }
1576 static void
1580 {
1594 {
1601 {
1603 /* We need something for printing the candidate. */
1605 }
1609 }
1611 /* For COND_EXPR we rearranged the arguments; undo that now. */
1613 {
1620 else
1622 }
1628 viable);
1629 }
1631 static bool
1633 {
1635 }
1637 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1639 static bool
1641 {
1642 /* [over.built]
1644 In this section, the term promoted integral type is used to refer
1645 to those integral types which are preserved by integral promotion
1646 (including e.g. int and long but excluding e.g. char).
1647 Similarly, the term promoted arithmetic type refers to promoted
1648 integral types plus floating types. */
1652 }
1654 /* Create any builtin operator overload candidates for the operator in
1655 question given the converted operand types TYPE1 and TYPE2. The other
1656 args are passed through from add_builtin_candidates to
1657 build_builtin_candidate.
1659 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1660 If CODE is requires candidates operands of the same type of the kind
1661 of which TYPE1 and TYPE2 are, we add both candidates
1662 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1664 static void
1668 {
1670 {
1678 }
1681 {
1683 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1684 and VQ is either volatile or empty, there exist candidate operator
1685 functions of the form
1686 VQ T& operator++(VQ T&);
1687 T operator++(VQ T&, int);
1688 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1689 type other than bool, and VQ is either volatile or empty, there exist
1690 candidate operator functions of the form
1691 VQ T& operator--(VQ T&);
1692 T operator--(VQ T&, int);
1693 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1694 complete object type, and VQ is either volatile or empty, there exist
1695 candidate operator functions of the form
1696 T*VQ& operator++(T*VQ&);
1697 T*VQ& operator--(T*VQ&);
1698 T* operator++(T*VQ&, int);
1699 T* operator--(T*VQ&, int); */
1708 {
1711 }
1714 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1715 exist candidate operator functions of the form
1717 T& operator*(T*);
1719 8 For every function type T, there exist candidate operator functions of
1720 the form
1721 T& operator*(T*); */
1730 /* 9 For every type T, there exist candidate operator functions of the form
1731 T* operator+(T*);
1733 10For every promoted arithmetic type T, there exist candidate operator
1734 functions of the form
1735 T operator+(T);
1736 T operator-(T); */
1746 /* 11For every promoted integral type T, there exist candidate operator
1747 functions of the form
1748 T operator~(T); */
1755 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1756 is the same type as C2 or is a derived class of C2, T is a complete
1757 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1758 there exist candidate operator functions of the form
1759 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1760 where CV12 is the union of CV1 and CV2. */
1765 {
1773 }
1776 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1777 didate operator functions of the form
1778 LR operator*(L, R);
1779 LR operator/(L, R);
1780 LR operator+(L, R);
1781 LR operator-(L, R);
1782 bool operator<(L, R);
1783 bool operator>(L, R);
1784 bool operator<=(L, R);
1785 bool operator>=(L, R);
1786 bool operator==(L, R);
1787 bool operator!=(L, R);
1788 where LR is the result of the usual arithmetic conversions between
1789 types L and R.
1791 14For every pair of types T and I, where T is a cv-qualified or cv-
1792 unqualified complete object type and I is a promoted integral type,
1793 there exist candidate operator functions of the form
1794 T* operator+(T*, I);
1795 T& operator[](T*, I);
1796 T* operator-(T*, I);
1797 T* operator+(I, T*);
1798 T& operator[](I, T*);
1800 15For every T, where T is a pointer to complete object type, there exist
1801 candidate operator functions of the form112)
1802 ptrdiff_t operator-(T, T);
1804 16For every pointer or enumeration type T, there exist candidate operator
1805 functions of the form
1806 bool operator<(T, T);
1807 bool operator>(T, T);
1808 bool operator<=(T, T);
1809 bool operator>=(T, T);
1810 bool operator==(T, T);
1811 bool operator!=(T, T);
1813 17For every pointer to member type T, there exist candidate operator
1814 functions of the form
1815 bool operator==(T, T);
1816 bool operator!=(T, T); */
1822 {
1825 }
1838 {
1841 }
1843 {
1846 }
1847 /* Fall through. */
1864 {
1867 }
1871 {
1874 }
1882 {
1885 }
1887 {
1890 }
1893 /* 18For every pair of promoted integral types L and R, there exist candi-
1894 date operator functions of the form
1895 LR operator%(L, R);
1896 LR operator&(L, R);
1897 LR operator^(L, R);
1898 LR operator|(L, R);
1899 L operator<<(L, R);
1900 L operator>>(L, R);
1901 where LR is the result of the usual arithmetic conversions between
1902 types L and R. */
1914 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
1915 type, VQ is either volatile or empty, and R is a promoted arithmetic
1916 type, there exist candidate operator functions of the form
1917 VQ L& operator=(VQ L&, R);
1918 VQ L& operator*=(VQ L&, R);
1919 VQ L& operator/=(VQ L&, R);
1920 VQ L& operator+=(VQ L&, R);
1921 VQ L& operator-=(VQ L&, R);
1923 20For every pair T, VQ), where T is any type and VQ is either volatile
1924 or empty, there exist candidate operator functions of the form
1925 T*VQ& operator=(T*VQ&, T*);
1927 21For every pair T, VQ), where T is a pointer to member type and VQ is
1928 either volatile or empty, there exist candidate operator functions of
1929 the form
1930 VQ T& operator=(VQ T&, T);
1932 22For every triple T, VQ, I), where T is a cv-qualified or cv-
1933 unqualified complete object type, VQ is either volatile or empty, and
1934 I is a promoted integral type, there exist candidate operator func-
1935 tions of the form
1936 T*VQ& operator+=(T*VQ&, I);
1937 T*VQ& operator-=(T*VQ&, I);
1939 23For every triple L, VQ, R), where L is an integral or enumeration
1940 type, VQ is either volatile or empty, and R is a promoted integral
1941 type, there exist candidate operator functions of the form
1943 VQ L& operator%=(VQ L&, R);
1944 VQ L& operator<<=(VQ L&, R);
1945 VQ L& operator>>=(VQ L&, R);
1946 VQ L& operator&=(VQ L&, R);
1947 VQ L& operator^=(VQ L&, R);
1948 VQ L& operator|=(VQ L&, R); */
1952 {
1956 {
1959 }
1985 {
1988 }
1993 }
1998 /* [over.built]
2000 For every pair of promoted arithmetic types L and R, there
2001 exist candidate operator functions of the form
2003 LR operator?(bool, L, R);
2005 where LR is the result of the usual arithmetic conversions
2006 between types L and R.
2008 For every type T, where T is a pointer or pointer-to-member
2009 type, there exist candidate operator functions of the form T
2010 operator?(bool, T, T); */
2014 /* That's OK. */
2017 /* Otherwise, the types should be pointers. */
2022 /* We don't check that the two types are the same; the logic
2023 below will actually create two candidates; one in which both
2024 parameter types are TYPE1, and one in which both parameter
2025 types are TYPE2. */
2030 }
2032 /* If we're dealing with two pointer types or two enumeral types,
2033 we need candidates for both of them. */
2042 {
2043 build_builtin_candidate
2045 build_builtin_candidate
2048 }
2050 build_builtin_candidate
2052 }
2054 tree
2056 {
2062 }
2064 /* There are three conditions of builtin candidates:
2066 1) bool-taking candidates. These are the same regardless of the input.
2067 2) pointer-pair taking candidates. These are generated for each type
2068 one of the input types converts to.
2069 3) arithmetic candidates. According to the standard, we should generate
2070 all of these, but I'm trying not to...
2072 Here we generate a superset of the possible candidates for this particular
2073 case. That is a subset of the full set the standard defines, plus some
2074 other cases which the standard disallows. add_builtin_candidate will
2075 filter out the invalid set. */
2077 static void
2081 {
2085 /* TYPES[i] is the set of possible builtin-operator parameter types
2086 we will consider for the Ith argument. These are represented as
2087 a TREE_LIST; the TREE_VALUE of each node is the potential
2088 parameter type. */
2092 {
2095 else
2097 }
2100 {
2101 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2102 and VQ is either volatile or empty, there exist candidate operator
2103 functions of the form
2104 VQ T& operator++(VQ T&); */
2114 /* 24There also exist candidate operator functions of the form
2115 bool operator!(bool);
2116 bool operator&&(bool, bool);
2117 bool operator||(bool, bool); */
2120 build_builtin_candidate
2127 build_builtin_candidate
2145 /* Fall through. */
2149 }
2154 {
2156 ;
2158 {
2159 tree convs;
2167 {
2174 }
2180 {
2193 {
2199 }
2203 }
2204 }
2205 else
2206 {
2212 {
2218 }
2220 }
2221 }
2223 /* Run through the possible parameter types of both arguments,
2224 creating candidates with those parameter types. */
2226 {
2229 add_builtin_candidate
2232 else
2233 add_builtin_candidate
2236 }
2237 }
2240 /* If TMPL can be successfully instantiated as indicated by
2241 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2243 TMPL is the template. EXPLICIT_TARGS are any explicit template
2244 arguments. ARGLIST is the arguments provided at the call-site.
2245 The RETURN_TYPE is the desired type for conversion operators. If
2246 OBJ is NULL_TREE, FLAGS and CTYPE are as for add_function_candidate.
2247 If an OBJ is supplied, FLAGS and CTYPE are ignored, and OBJ is as for
2248 add_conv_candidate. */
2255 unification_kind_t strict)
2256 {
2262 tree fn;
2264 /* We don't do deduction on the in-charge parameter, the VTT
2265 parameter or 'this'. */
2275 args_without_in_chrg,
2285 /* In [class.copy]:
2287 A member function template is never instantiated to perform the
2288 copy of a class object to an object of its class type.
2290 It's a little unclear what this means; the standard explicitly
2291 does allow a template to be used to copy a class. For example,
2292 in:
2294 struct A {
2295 A(A&);
2296 template <class T> A(const T&);
2297 };
2298 const A f ();
2299 void g () { A a (f ()); }
2301 the member template will be used to make the copy. The section
2302 quoted above appears in the paragraph that forbids constructors
2303 whose only parameter is (a possibly cv-qualified variant of) the
2304 class type, and a logical interpretation is that the intent was
2305 to forbid the instantiation of member templates which would then
2306 have that form. */
2308 {
2311 ctype))
2313 }
2316 /* Aha, this is a conversion function. */
2319 else
2324 /* This situation can occur if a member template of a template
2325 class is specialized. Then, instantiate_template might return
2326 an instantiation of the specialization, in which case the
2327 DECL_TI_TEMPLATE field will point at the original
2328 specialization. For example:
2330 template <class T> struct S { template <class U> void f(U);
2331 template <> void f(int) {}; };
2332 S<double> sd;
2333 sd.f(3);
2335 Here, TMPL will be template <class U> S<double>::f(U).
2336 And, instantiate template will give us the specialization
2337 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2338 for this will point at template <class T> template <> S<T>::f(int),
2339 so that we can find the definition. For the purposes of
2340 overload resolution, however, we want the original TMPL. */
2342 else
2346 }
2353 unification_kind_t strict)
2354 {
2355 return
2360 }
2367 {
2368 return
2372 }
2374 /* The CANDS are the set of candidates that were considered for
2375 overload resolution. Return the set of viable candidates. If none
2376 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2377 is true if a candidate should be considered viable only if it is
2378 strictly viable. */
2384 {
2395 {
2398 {
2404 }
2405 else
2407 }
2410 }
2412 static bool
2414 {
2419 }
2421 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2422 words, it is about to become the "this" pointer for a member
2423 function call. Take the address of the object. */
2425 static tree
2427 {
2428 /* In a template, we are only concerned about the type of the
2429 expression, so we can take a shortcut. */
2434 }
2436 /* Returns true iff functions are equivalent. Equivalent functions are
2437 not '==' only if one is a function-local extern function or if
2438 both are extern "C". */
2442 {
2447 }
2449 /* Print information about one overload candidate CANDIDATE. MSGSTR
2450 is the text to print before the candidate itself.
2452 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2453 to have been run through gettext by the caller. This wart makes
2454 life simpler in print_z_candidates and for the translators. */
2456 static void
2458 {
2460 {
2470 else
2473 }
2478 else
2480 }
2482 static void
2484 {
2489 /* There may be duplicates in the set of candidates. We put off
2490 checking this condition as long as possible, since we have no way
2491 to eliminate duplicates from a set of functions in less than n^2
2492 time. Now we are about to emit an error message, so it is more
2493 permissible to go slowly. */
2495 {
2497 /* Skip builtin candidates and conversion functions. */
2502 {
2506 else
2508 }
2509 }
2517 {
2518 /* Indent successive candidates by the width of the translation
2519 of the above string. */
2526 do
2527 {
2530 }
2532 }
2533 }
2535 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2536 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2537 the result of the conversion function to convert it to the final
2538 desired type. Merge the two sequences into a single sequence,
2539 and return the merged sequence. */
2543 {
2548 /* Find the end of the second conversion sequence. */
2553 /* Replace the identity conversion with the user conversion
2554 sequence. */
2557 /* The entire sequence is a user-conversion sequence. */
2561 }
2563 /* Returns the best overload candidate to perform the requested
2564 conversion. This function is used for three the overloading situations
2565 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2566 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2567 per [dcl.init.ref], so we ignore temporary bindings. */
2571 {
2581 /* We represent conversion within a hierarchy using RVALUE_CONV and
2582 BASE_CONV, as specified by [over.best.ics]; these become plain
2583 constructor calls, as specified in [dcl.init]. */
2591 {
2596 {
2597 /* [class.conv.fct] A conversion function is never used to
2598 convert a (possibly cv-qualified) object to the (possibly
2599 cv-qualified) same object type (or a reference to it), to a
2600 (possibly cv-qualified) base class of that type (or a
2601 reference to it)... */
2602 }
2603 else
2605 }
2610 /* It's OK to bind a temporary for converting constructor arguments, but
2611 not in converting the return value of a conversion operator. */
2616 {
2617 tree t;
2623 /* We should never try to call the abstract or base constructor
2624 from here. */
2628 }
2630 {
2640 flags,
2641 DEDUCE_CALL);
2642 else
2646 flags);
2650 }
2656 {
2657 tree fns;
2660 /* If we are called to convert to a reference type, we are trying to
2661 find an lvalue binding, so don't even consider temporaries. If
2662 we don't find an lvalue binding, the caller will try again to
2663 look for a temporary binding. */
2668 {
2671 /* [over.match.funcs] For conversion functions, the function
2672 is considered to be a member of the class of the implicit
2673 object argument for the purpose of defining the type of
2674 the implicit object parameter.
2676 So we pass fromtype as CTYPE to add_*_candidate. */
2680 NULL_TREE,
2683 conversion_path,
2684 flags,
2685 DEDUCE_CONV);
2686 else
2688 args,
2690 conversion_path,
2691 flags);
2694 {
2695 conversion *ics
2707 }
2708 }
2709 }
2717 {
2719 {
2723 }
2730 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2731 ambiguous conversion is no worse than another user-defined
2732 conversion. */
2735 }
2737 /* Build the user conversion sequence. */
2738 conv = build_conv
2745 /* Combine it with the second conversion sequence. */
2753 }
2755 tree
2757 {
2762 {
2767 }
2769 }
2771 /* Do any initial processing on the arguments to a function call. */
2773 static tree
2775 {
2776 tree t;
2778 {
2784 {
2787 }
2790 }
2792 }
2794 /* Perform overload resolution on FN, which is called with the ARGS.
2796 Return the candidate function selected by overload resolution, or
2797 NULL if the event that overload resolution failed. In the case
2798 that overload resolution fails, *CANDIDATES will be the set of
2799 candidates considered, and ANY_VIABLE_P will be set to true or
2800 false to indicate whether or not any of the candidates were
2801 viable.
2803 The ARGS should already have gone through RESOLVE_ARGS before this
2804 function is called. */
2808 tree args,
2811 {
2819 /* Check FN and ARGS. */
2827 {
2831 }
2833 /* Add the various candidate functions. */
2837 LOOKUP_NORMAL,
2838 candidates);
2846 }
2848 /* Return an expression for a call to FN (a namespace-scope function,
2849 or a static member function) with the ARGS. */
2851 tree
2853 {
2857 tree result;
2863 /* If this function was found without using argument dependent
2864 lookup, then we want to ignore any undeclared friend
2865 functions. */
2867 {
2872 {
2876 }
2877 }
2879 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2885 {
2893 else
2899 }
2900 else
2903 /* Free all the conversions we allocated. */
2907 }
2909 /* Build a call to a global operator new. FNNAME is the name of the
2910 operator (either "operator new" or "operator new[]") and ARGS are
2911 the arguments provided. *SIZE points to the total number of bytes
2912 required by the allocation, and is updated if that is changed here.
2913 *COOKIE_SIZE is non-NULL if a cookie should be used. If this
2914 function determines that no cookie should be used, after all,
2915 *COOKIE_SIZE is set to NULL_TREE. If FN is non-NULL, it will be
2916 set, upon return, to the allocation function called. */
2918 tree
2922 {
2923 tree fns;
2935 /* Based on:
2937 [expr.new]
2939 If this lookup fails to find the name, or if the allocated type
2940 is not a class type, the allocation function's name is looked
2941 up in the global scope.
2943 we disregard block-scope declarations of "operator new". */
2946 /* Figure out what function is being called. */
2949 /* If no suitable function could be found, issue an error message
2950 and give up. */
2952 {
2956 else
2962 }
2964 /* If a cookie is required, add some extra space. Whether
2965 or not a cookie is required cannot be determined until
2966 after we know which function was called. */
2968 {
2971 {
2973 /* In G++ 3.2, the check was implemented incorrectly; it
2974 looked at the placement expression, rather than the
2975 type of the function. */
2978 ptr_type_node))
2980 }
2981 else
2982 {
2983 tree arg_types;
2986 /* Skip the size_t parameter. */
2988 /* Check the remaining parameters (if any). */
2992 ptr_type_node))
2994 }
2995 /* If we need a cookie, adjust the number of bytes allocated. */
2997 {
2998 /* Update the total size. */
3000 /* Update the argument list to reflect the adjusted size. */
3002 }
3003 else
3005 }
3007 /* Tell our caller which function we decided to call. */
3011 /* Build the CALL_EXPR. */
3013 }
3015 static tree
3017 {
3026 {
3027 /* It's no good looking for an overloaded operator() on a
3028 pointer-to-member-function. */
3029 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3031 }
3034 {
3038 }
3039 else
3047 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3051 {
3056 {
3064 else
3065 add_function_candidate
3068 }
3069 }
3074 {
3086 {
3089 add_template_conv_candidate
3093 else
3097 }
3098 }
3102 {
3106 }
3107 else
3108 {
3111 {
3115 }
3116 /* Since cand->fn will be a type, not a function, for a conversion
3117 function, we must be careful not to unconditionally look at
3118 DECL_NAME here. */
3122 else
3123 {
3127 }
3128 }
3130 /* Free all the conversions we allocated. */
3134 }
3136 static void
3139 {
3144 else
3148 {
3172 else
3176 }
3177 }
3179 /* Return the implicit conversion sequence that could be used to
3180 convert E1 to E2 in [expr.cond]. */
3184 {
3190 /* [expr.cond]
3192 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3193 implicitly converted (clause _conv_) to the type "reference to
3194 T2", subject to the constraint that in the conversion the
3195 reference must bind directly (_dcl.init.ref_) to E1. */
3197 {
3199 t1,
3200 e1,
3202 LOOKUP_NO_TEMP_BIND);
3205 }
3207 /* [expr.cond]
3209 If E1 and E2 have class type, and the underlying class types are
3210 the same or one is a base class of the other: E1 can be converted
3211 to match E2 if the class of T2 is the same type as, or a base
3212 class of, the class of T1, and the cv-qualification of T2 is the
3213 same cv-qualification as, or a greater cv-qualification than, the
3214 cv-qualification of T1. If the conversion is applied, E1 is
3215 changed to an rvalue of type T2 that still refers to the original
3216 source class object (or the appropriate subobject thereof). */
3219 {
3221 {
3226 else
3229 }
3230 else
3232 }
3233 else
3234 /* [expr.cond]
3236 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3237 converted to the type that expression E2 would have if E2 were
3238 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3240 LOOKUP_NORMAL);
3241 }
3243 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3244 arguments to the conditional expression. */
3246 tree
3248 {
3249 tree arg2_type;
3250 tree arg3_type;
3258 /* As a G++ extension, the second argument to the conditional can be
3259 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3260 c'.) If the second operand is omitted, make sure it is
3261 calculated only once. */
3263 {
3267 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3270 else
3272 }
3274 /* [expr.cond]
3276 The first expr ession is implicitly converted to bool (clause
3277 _conv_). */
3280 /* If something has already gone wrong, just pass that fact up the
3281 tree. */
3287 /* [expr.cond]
3289 If either the second or the third operand has type (possibly
3290 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3291 array-to-pointer (_conv.array_), and function-to-pointer
3292 (_conv.func_) standard conversions are performed on the second
3293 and third operands. */
3297 {
3298 /* Do the conversions. We don't these for `void' type arguments
3299 since it can't have any effect and since decay_conversion
3300 does not handle that case gracefully. */
3308 /* [expr.cond]
3310 One of the following shall hold:
3312 --The second or the third operand (but not both) is a
3313 throw-expression (_except.throw_); the result is of the
3314 type of the other and is an rvalue.
3316 --Both the second and the third operands have type void; the
3317 result is of type void and is an rvalue.
3319 We must avoid calling force_rvalue for expressions of type
3320 "void" because it will complain that their value is being
3321 used. */
3324 {
3329 }
3332 {
3337 }
3340 else
3341 {
3344 "is of type %<void%>, "
3345 "but the third operand is neither a throw-expression "
3347 else
3349 "is of type %<void%>, "
3350 "but the second operand is neither a throw-expression "
3353 }
3357 }
3358 /* [expr.cond]
3360 Otherwise, if the second and third operand have different types,
3361 and either has (possibly cv-qualified) class type, an attempt is
3362 made to convert each of those operands to the type of the other. */
3365 {
3369 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3375 /* [expr.cond]
3377 If both can be converted, or one can be converted but the
3378 conversion is ambiguous, the program is ill-formed. If
3379 neither can be converted, the operands are left unchanged and
3380 further checking is performed as described below. If exactly
3381 one conversion is possible, that conversion is applied to the
3382 chosen operand and the converted operand is used in place of
3383 the original operand for the remainder of this section. */
3388 {
3392 }
3394 {
3398 /* Even if CONV2 is a valid conversion, the result of the
3399 conversion may be invalid. For example, if ARG3 has type
3400 "volatile X", and X does not have a copy constructor
3401 accepting a "volatile X&", then even if ARG2 can be
3402 converted to X, the conversion will fail. */
3405 }
3407 {
3413 }
3415 /* Free all the conversions we allocated. */
3421 /* If, after the conversion, both operands have class type,
3422 treat the cv-qualification of both operands as if it were the
3423 union of the cv-qualification of the operands.
3425 The standard is not clear about what to do in this
3426 circumstance. For example, if the first operand has type
3427 "const X" and the second operand has a user-defined
3428 conversion to "volatile X", what is the type of the second
3429 operand after this step? Making it be "const X" (matching
3430 the first operand) seems wrong, as that discards the
3431 qualification without actually performing a copy. Leaving it
3432 as "volatile X" seems wrong as that will result in the
3433 conditional expression failing altogether, even though,
3434 according to this step, the one operand could be converted to
3435 the type of the other. */
3443 }
3445 /* [expr.cond]
3447 If the second and third operands are lvalues and have the same
3448 type, the result is of that type and is an lvalue. */
3452 {
3455 }
3457 /* [expr.cond]
3459 Otherwise, the result is an rvalue. If the second and third
3460 operand do not have the same type, and either has (possibly
3461 cv-qualified) class type, overload resolution is used to
3462 determine the conversions (if any) to be applied to the operands
3463 (_over.match.oper_, _over.built_). */
3467 {
3472 /* Rearrange the arguments so that add_builtin_candidate only has
3473 to know about two args. In build_builtin_candidates, the
3474 arguments are unscrambled. */
3479 COND_EXPR,
3480 NOP_EXPR,
3482 args,
3483 LOOKUP_NORMAL);
3485 /* [expr.cond]
3487 If the overload resolution fails, the program is
3488 ill-formed. */
3491 {
3495 }
3498 {
3502 }
3504 /* [expr.cond]
3506 Otherwise, the conversions thus determined are applied, and
3507 the converted operands are used in place of the original
3508 operands for the remainder of this section. */
3515 }
3517 /* [expr.cond]
3519 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3520 and function-to-pointer (_conv.func_) standard conversions are
3521 performed on the second and third operands.
3523 We need to force the lvalue-to-rvalue conversion here for class types,
3524 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3525 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3526 regions. */
3539 /* [expr.cond]
3541 After those conversions, one of the following shall hold:
3543 --The second and third operands have the same type; the result is of
3544 that type. */
3547 /* [expr.cond]
3549 --The second and third operands have arithmetic or enumeration
3550 type; the usual arithmetic conversions are performed to bring
3551 them to a common type, and the result is of that type. */
3556 {
3557 /* In this case, there is always a common type. */
3559 arg3_type);
3574 }
3575 /* [expr.cond]
3577 --The second and third operands have pointer type, or one has
3578 pointer type and the other is a null pointer constant; pointer
3579 conversions (_conv.ptr_) and qualification conversions
3580 (_conv.qual_) are performed to bring them to their composite
3581 pointer type (_expr.rel_). The result is of the composite
3582 pointer type.
3584 --The second and third operands have pointer to member type, or
3585 one has pointer to member type and the other is a null pointer
3586 constant; pointer to member conversions (_conv.mem_) and
3587 qualification conversions (_conv.qual_) are performed to bring
3588 them to a common type, whose cv-qualification shall match the
3589 cv-qualification of either the second or the third operand.
3590 The result is of the common type. */
3598 {
3605 }
3608 {
3612 }
3614 valid_operands:
3617 /* We can't use result_type below, as fold might have returned a
3618 throw_expr. */
3621 {
3622 /* Expand both sides into the same slot, hopefully the target of
3623 the ?: expression. We used to check for TARGET_EXPRs here,
3624 but now we sometimes wrap them in NOP_EXPRs so the test would
3625 fail. */
3628 /* If this expression is an rvalue, but might be mistaken for an
3629 lvalue, we must add a NON_LVALUE_EXPR. */
3631 }
3634 }
3636 /* OPERAND is an operand to an expression. Perform necessary steps
3637 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3638 returned. */
3640 static tree
3642 {
3644 {
3647 /* Make sure the template type is instantiated now. */
3649 }
3652 }
3654 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3655 OVERLOAD) to the CANDIDATES, returning an updated list of
3656 CANDIDATES. The ARGS are the arguments provided to the call,
3657 without any implicit object parameter. The EXPLICIT_TARGS are
3658 explicit template arguments provided. TEMPLATE_ONLY is true if
3659 only template functions should be considered. CONVERSION_PATH,
3660 ACCESS_PATH, and FLAGS are as for add_function_candidate. */
3662 static void
3668 {
3669 tree ctype;
3670 tree non_static_args;
3673 /* Delay creating the implicit this parameter until it is needed. */
3677 {
3678 tree fn;
3679 tree fn_args;
3682 /* Figure out which set of arguments to use. */
3684 {
3685 /* If this function is a non-static member, prepend the implicit
3686 object parameter. */
3692 }
3693 else
3694 /* Otherwise, just use the list of arguments provided. */
3699 fn,
3700 ctype,
3701 explicit_targs,
3702 fn_args,
3703 NULL_TREE,
3704 access_path,
3705 conversion_path,
3706 flags,
3707 DEDUCE_CALL);
3710 fn,
3711 ctype,
3712 fn_args,
3713 access_path,
3714 conversion_path,
3715 flags);
3717 }
3718 }
3720 tree
3723 {
3742 {
3746 }
3747 else
3753 {
3758 /* Use build_op_new_call and build_op_delete_call instead. */
3772 }
3778 {
3785 }
3800 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3803 /* Add namespace-scope operators to the list of functions to
3804 consider. */
3808 /* Add class-member operators to the candidate set. */
3810 {
3811 tree fns;
3815 {
3818 }
3825 }
3827 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
3828 to know about two args; a builtin candidate will always have a first
3829 parameter of type bool. We'll handle that in
3830 build_builtin_candidate. */
3832 {
3836 }
3837 else
3838 {
3842 }
3847 {
3850 /* For these, the built-in candidates set is empty
3851 [over.match.oper]/3. We don't want non-strict matches
3852 because exact matches are always possible with built-in
3853 operators. The built-in candidate set for COMPONENT_REF
3854 would be empty too, but since there are no such built-in
3855 operators, we accept non-strict matches for them. */
3862 }
3866 {
3868 {
3871 /* Look for an `operator++ (int)'. If they didn't have
3872 one, then we fall back to the old way of doing things. */
3876 fnname,
3880 else
3883 overloaded_p);
3886 /* The caller will deal with these. */
3896 {
3899 }
3902 }
3903 }
3904 else
3905 {
3908 {
3910 {
3913 }
3915 }
3917 {
3922 }
3923 else
3924 {
3925 /* Give any warnings we noticed during overload resolution. */
3927 {
3931 }
3933 /* Check for comparison of different enum types. */
3935 {
3946 {
3949 }
3953 }
3955 /* We need to strip any leading REF_BIND so that bitfields
3956 don't cause errors. This should not remove any important
3957 conversions, because builtins don't apply to class
3958 objects directly. */
3964 {
3969 }
3971 {
3976 }
3979 {
3982 }
3983 }
3984 }
3986 user_defined_result_ready:
3988 /* Free all the conversions we allocated. */
3994 builtin:
3996 {
4050 /* The caller will deal with these. */
4058 }
4060 }
4062 /* Build a call to operator delete. This has to be handled very specially,
4063 because the restrictions on what signatures match are different from all
4064 other call instances. For a normal delete, only a delete taking (void *)
4065 or (void *, size_t) is accepted. For a placement delete, only an exact
4066 match with the placement new is accepted.
4068 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4069 ADDR is the pointer to be deleted.
4070 SIZE is the size of the memory block to be deleted.
4071 GLOBAL_P is true if the delete-expression should not consider
4072 class-specific delete operators.
4073 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4075 If this call to "operator delete" is being generated as part to
4076 deallocate memory allocated via a new-expression (as per [expr.new]
4077 which requires that if the initialization throws an exception then
4078 we call a deallocation function), then ALLOC_FN is the allocation
4079 function. */
4081 tree
4084 tree alloc_fn)
4085 {
4100 /* In [class.free]
4102 If the result of the lookup is ambiguous or inaccessible, or if
4103 the lookup selects a placement deallocation function, the
4104 program is ill-formed.
4106 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4107 {
4111 }
4112 else
4118 /* Strip const and volatile from addr. */
4122 {
4123 /* Get the parameter types for the allocation function that is
4124 being called. */
4127 }
4128 else
4129 {
4130 /* First try it without the size argument. */
4132 }
4134 /* We make two tries at finding a matching `operator delete'. On
4135 the first pass, we look for a one-operator (or placement)
4136 operator delete. If we're not doing placement delete, then on
4137 the second pass we look for a two-argument delete. */
4139 {
4140 /* Go through the `operator delete' functions looking for one
4141 with a matching type. */
4143 fn;
4145 {
4146 tree t;
4148 /* The first argument must be "void *". */
4153 /* On the first pass, check the rest of the arguments. */
4155 {
4158 {
4163 }
4166 }
4167 /* On the second pass, look for a function with exactly two
4168 arguments: "void *" and "size_t". */
4170 /* For "operator delete(void *, ...)" there will be
4171 no second argument, but we will not get an exact
4172 match above. */
4173 && t
4177 }
4179 /* If we found a match, we're done. */
4182 }
4184 /* If we have a matching function, call it. */
4186 {
4187 /* Make sure we have the actual function, and not an
4188 OVERLOAD. */
4191 /* If the FN is a member function, make sure that it is
4192 accessible. */
4197 {
4198 /* The placement args might not be suitable for overload
4199 resolution at this point, so build the call directly. */
4208 }
4209 else
4210 {
4211 tree args;
4214 else
4218 }
4219 }
4221 /* [expr.new]
4223 If no unambiguous matching deallocation function can be found,
4224 propagating the exception does not cause the object's memory to
4225 be freed. */
4227 {
4230 alloc_fn);
4232 }
4237 }
4239 /* If the current scope isn't allowed to access DECL along
4240 BASETYPE_PATH, give an error. The most derived class in
4241 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4242 the declaration to use in the error diagnostic. */
4244 bool
4246 {
4250 {
4255 else
4259 }
4262 }
4264 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4265 bitwise or of LOOKUP_* values. If any errors are warnings are
4266 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4267 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4268 to NULL. */
4270 static tree
4273 {
4278 complete_ctor_identifier,
4285 else
4288 }
4290 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4291 EXPR is implicitly converted to type TOTYPE.
4292 FN and ARGNUM are used for diagnostics. */
4294 static void
4296 {
4299 /* Issue warnings about peculiar, but valid, uses of NULL. */
4301 {
4305 else
4307 }
4309 /* Issue warnings if "false" is converted to a NULL pointer */
4314 }
4316 /* Perform the conversions in CONVS on the expression EXPR. FN and
4317 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4318 indicates the `this' argument of a method. INNER is nonzero when
4319 being called to continue a conversion chain. It is negative when a
4320 reference binding will be applied, positive otherwise. If
4321 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4322 conversions will be emitted if appropriate. If C_CAST_P is true,
4323 this conversion is coming from a C-style cast; in that case,
4324 conversions to inaccessible bases are permitted. */
4326 static tree
4330 {
4332 diagnostic_fn_t diagnostic_fn;
4338 {
4341 {
4343 {
4348 }
4355 }
4360 }
4366 {
4368 {
4374 /* If this is a constructor or a function returning an aggr type,
4375 we need to build up a TARGET_EXPR. */
4379 /* The result of the call is then used to direct-initialize the object
4380 that is the destination of the copy-initialization. [dcl.init]
4382 Note that this step is not reflected in the conversion sequence;
4383 it affects the semantics when we actually perform the
4384 conversion, but is not considered during overload resolution.
4386 If the target is a class, that means call a ctor. */
4389 {
4390 expr = (build_temp
4392 /* Core issue 84, now a DR, says that we don't
4393 allow UDCs for these args (which deliberately
4394 breaks copy-init of an auto_ptr<Base> from an
4395 auto_ptr<Derived>). */
4400 {
4402 diagnostic_fn
4405 else
4406 diagnostic_fn
4408 }
4410 }
4412 }
4416 /* Convert a constant to its underlying value, unless we are
4417 about to bind it to a reference, in which case we need to
4418 leave it as an lvalue. */
4423 /* Call build_user_type_conversion again for the error. */
4424 return build_user_type_conversion
4429 };
4434 c_cast_p);
4439 {
4444 /* Else fall through. */
4447 {
4448 /* We are going to bind a reference directly to a base-class
4449 subobject of EXPR. */
4450 /* Build an expression for `*((base*) &expr)'. */
4456 }
4458 /* Copy-initialization where the cv-unqualified version of the source
4459 type is the same class as, or a derived class of, the class of the
4460 destination [is treated as direct-initialization]. [dcl.init] */
4468 {
4471 /* If necessary, create a temporary.
4473 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
4474 that need temporaries, even when their types are reference
4475 compatible with the type of reference being bound, so the
4476 upcoming call to build_unary_op (ADDR_EXPR, expr, ...)
4477 doesn't fail. */
4481 {
4487 {
4488 /* If the reference is volatile or non-const, we
4489 cannot create a temporary. */
4496 else
4499 }
4500 /* If the source is a packed field, and we must use a copy
4501 constructor, then building the target expr will require
4502 binding the field to the reference parameter to the
4503 copy constructor, and we'll end up with an infinite
4504 loop. If we can use a bitwise copy, then we'll be
4505 OK. */
4509 {
4513 }
4515 }
4517 /* Take the address of the thing to which we will bind the
4518 reference. */
4523 /* Convert it to a pointer to the type referred to by the
4524 reference. This will adjust the pointer if a derived to
4525 base conversion is being performed. */
4527 expr);
4528 /* Convert the pointer to the desired reference type. */
4530 }
4536 /* Warn about deprecated conversion if appropriate. */
4548 c_cast_p);
4552 }
4556 else
4560 }
4562 /* Build a call to __builtin_trap. */
4564 static tree
4566 {
4572 }
4574 /* ARG is being passed to a varargs function. Perform any conversions
4575 required. Return the converted value. */
4577 tree
4579 {
4580 /* [expr.call]
4582 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
4583 standard conversions are performed. */
4585 /* [expr.call]
4587 If the argument has integral or enumeration type that is subject
4588 to the integral promotions (_conv.prom_), or a floating point
4589 type that is subject to the floating point promotion
4590 (_conv.fpprom_), the value of the argument is converted to the
4591 promoted type before the call. */
4603 {
4604 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
4605 here and do a bitwise copy, but now cp_expr_size will abort if we
4606 try to do that.
4607 If the call appears in the context of a sizeof expression,
4608 there is no need to emit a warning, since the expression won't be
4609 evaluated. We keep the builtin_trap just as a safety check. */
4615 integer_zero_node);
4616 }
4619 }
4621 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
4623 tree
4625 {
4635 {
4636 /* Remove reference types so we don't ICE later on. */
4638 /* Undefined behavior [expr.call] 5.2.2/7. */
4646 }
4649 }
4651 /* TYPE has been given to va_arg. Apply the default conversions which
4652 would have happened when passed via ellipsis. Return the promoted
4653 type, or the passed type if there is no change. */
4655 tree
4657 {
4658 tree promote;
4660 /* Perform the array-to-pointer and function-to-pointer
4661 conversions. */
4669 }
4671 /* ARG is a default argument expression being passed to a parameter of
4672 the indicated TYPE, which is a parameter to FN. Do any required
4673 conversions. Return the converted value. */
4677 tree
4679 {
4681 tree t;
4683 /* If the ARG is an unparsed default argument expression, the
4684 conversion cannot be performed. */
4686 {
4691 }
4693 /* Detect recursion. */
4696 {
4699 }
4708 {
4712 }
4713 else
4714 {
4715 /* We must make a copy of ARG, in case subsequent processing
4716 alters any part of it. For example, during gimplification a
4717 cast of the form (T) &X::f (where "f" is a member function)
4718 will lead to replacing the PTRMEM_CST for &X::f with a
4719 VAR_DECL. We can avoid the copy for constants, since they
4720 are never modified in place. */
4726 }
4731 }
4733 /* Returns the type which will really be used for passing an argument of
4734 type TYPE. */
4736 tree
4738 {
4739 /* Pass classes with copy ctors by invisible reference. */
4741 {
4743 /* There are no other pointers to this temporary. */
4745 }
4754 }
4756 /* Actually perform the appropriate conversion. */
4758 tree
4760 {
4761 tree bitfield_type;
4763 /* If VAL is a bitfield, then -- since it has already been converted
4764 to TYPE -- it cannot have a precision greater than TYPE.
4766 If it has a smaller precision, we must widen it here. For
4767 example, passing "int f:3;" to a function expecting an "int" will
4768 not result in any conversion before this point.
4770 If the precision is the same we must not risk widening. For
4771 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
4772 often have type "int", even though the C++ type for the field is
4773 "long long". If the value is being passed to a function
4774 expecting an "int", then no conversions will be required. But,
4775 if we call convert_bitfield_to_declared_type, the bitfield will
4776 be converted to "long long". */
4783 ;
4784 /* Pass classes with copy ctors by invisible reference. */
4794 {
4803 }
4805 }
4807 /* Returns true iff FN is a function with magic varargs, i.e. ones for
4808 which no conversions at all should be done. This is true for some
4809 builtins which don't act like normal functions. */
4811 static bool
4813 {
4816 {
4827 }
4830 }
4832 /* Subroutine of the various build_*_call functions. Overload resolution
4833 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
4834 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
4835 bitmask of various LOOKUP_* flags which apply to the call itself. */
4837 static tree
4839 {
4853 /* In a template, there is no need to perform all of the work that
4854 is normally done. We are only interested in the type of the call
4855 expression, i.e., the return type of the function. Any semantic
4856 errors will be deferred until the template is instantiated. */
4858 {
4859 tree expr;
4860 tree return_type;
4868 }
4870 /* Give any warnings we noticed during overload resolution. */
4872 {
4876 }
4879 {
4880 /* If FN is a template function, two cases must be considered.
4881 For example:
4883 struct A {
4884 protected:
4885 template <class T> void f();
4886 };
4887 template <class T> struct B {
4888 protected:
4889 void g();
4890 };
4891 struct C : A, B<int> {
4892 using A::f; // #1
4893 using B<int>::g; // #2
4894 };
4896 In case #1 where `A::f' is a member template, DECL_ACCESS is
4897 recorded in the primary template but not in its specialization.
4898 We check access of FN using its primary template.
4900 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
4901 because it is a member of class template B, DECL_ACCESS is
4902 recorded in the specialization `B<int>::g'. We cannot use its
4903 primary template because `B<T>::g' and `B<int>::g' may have
4904 different access. */
4909 else
4911 }
4917 /* Find maximum size of vector to hold converted arguments. */
4924 /* The implicit parameters to a constructor are not considered by overload
4925 resolution, and must be of the proper type. */
4927 {
4931 /* We should never try to call the abstract constructor. */
4935 {
4939 }
4940 }
4941 /* Bypass access control for 'this' parameter. */
4943 {
4946 tree converted_arg;
4947 tree base_binfo;
4953 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
4954 X is called for an object that is not of type X, or of a type
4955 derived from X, the behavior is undefined.
4957 So we can assume that anything passed as 'this' is non-null, and
4958 optimize accordingly. */
4960 /* Convert to the base in which the function was declared. */
4966 /* Check that the base class is accessible. */
4972 /* If fn was found by a using declaration, the conversion path
4973 will be to the derived class, not the base declaring fn. We
4974 must convert from derived to base. */
4985 }
4989 {
4994 /* Don't make a copy here if build_call is going to. */
4999 val = convert_like_with_context
5004 }
5006 /* Default arguments */
5011 /* Ellipsis */
5013 {
5017 else
5020 }
5028 /* Avoid actually calling copy constructors and copy assignment operators,
5029 if possible. */
5036 {
5037 tree targ;
5040 /* Pull out the real argument, disregarding const-correctness. */
5047 {
5052 }
5053 else
5058 else
5061 /* [class.copy]: the copy constructor is implicitly defined even if
5062 the implementation elided its use. */
5066 /* If we're creating a temp and we already have one, don't create a
5067 new one. If we're not creating a temp but we get one, use
5068 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5069 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5070 temp or an INIT_EXPR otherwise. */
5072 {
5077 }
5080 {
5081 tree to = stabilize_reference
5086 }
5087 }
5091 {
5092 tree to = stabilize_reference
5099 {
5102 }
5103 else
5104 {
5105 /* We must only copy the non-tail padding parts.
5106 Use __builtin_memcpy for the bitwise copy. */
5118 }
5121 }
5126 {
5127 tree t;
5133 /* Warn about deprecated virtual functions now, since we're about
5134 to throw away the decl. */
5144 else
5147 }
5150 else
5154 }
5156 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5157 This function performs no overload resolution, conversion, or other
5158 high-level operations. */
5160 tree
5162 {
5163 tree fndecl;
5167 /* If this call might throw an exception, note that fact. */
5174 /* Some built-in function calls will be evaluated at compile-time in
5175 fold (). */
5188 }
5192 /* Make an expression which yields the address of the Java interface
5193 method FN. This is achieved by generating a call to libjava's
5194 _Jv_LookupInterfaceMethodIdx(). */
5196 static tree
5198 {
5204 {
5209 endlink)));
5210 java_iface_lookup_fn
5214 }
5216 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5217 This is the first entry in the vtable. */
5219 integer_zero_node);
5221 /* Get the java.lang.Class pointer for the interface being called. */
5226 {
5228 iface);
5230 }
5234 /* Determine the itable index of FN. */
5237 {
5242 i++;
5243 }
5248 java_iface_lookup_fn);
5251 }
5253 /* Returns the value to use for the in-charge parameter when making a
5254 call to a function with the indicated NAME.
5256 FIXME:Can't we find a neater way to do this mapping? */
5258 tree
5260 {
5271 /* This function should only be called with one of the names listed
5272 above. */
5275 }
5277 /* Build a call to a constructor, destructor, or an assignment
5278 operator for INSTANCE, an expression with class type. NAME
5279 indicates the special member function to call; ARGS are the
5280 arguments. BINFO indicates the base of INSTANCE that is to be
5281 passed as the `this' parameter to the member function called.
5283 FLAGS are the LOOKUP_* flags to use when processing the call.
5285 If NAME indicates a complete object constructor, INSTANCE may be
5286 NULL_TREE. In this case, the caller will call build_cplus_new to
5287 store the newly constructed object into a VAR_DECL. */
5289 tree
5292 {
5293 tree fns;
5294 /* The type of the subobject to be constructed or destroyed. */
5295 tree class_type;
5304 {
5305 /* Resolve the name. */
5310 }
5316 /* Handle the special case where INSTANCE is NULL_TREE. */
5318 {
5321 }
5322 else
5323 {
5329 /* Convert to the base class, if necessary. */
5332 {
5334 /* For constructors and destructors, either the base is
5335 non-virtual, or it is virtual but we are doing the
5336 conversion from a constructor or destructor for the
5337 complete object. In either case, we can convert
5338 statically. */
5340 else
5341 /* However, for assignment operators, we must convert
5342 dynamically if the base is virtual. */
5345 }
5346 }
5352 /* When making a call to a constructor or destructor for a subobject
5353 that uses virtual base classes, pass down a pointer to a VTT for
5354 the subobject. */
5358 {
5359 tree vtt;
5360 tree sub_vtt;
5362 /* If the current function is a complete object constructor
5363 or destructor, then we fetch the VTT directly.
5364 Otherwise, we look it up using the VTT we were given. */
5370 current_vtt_parm,
5371 vtt);
5377 }
5382 }
5384 /* Return the NAME, as a C string. The NAME indicates a function that
5385 is a member of TYPE. *FREE_P is set to true if the caller must
5386 free the memory returned.
5388 Rather than go through all of this, we should simply set the names
5389 of constructors and destructors appropriately, and dispense with
5390 ctor_identifier, dtor_identifier, etc. */
5394 {
5397 /* Assume that we will not allocate memory. */
5399 /* Constructors and destructors are special. */
5401 {
5402 pretty_name
5404 /* For a destructor, add the '~'. */
5408 {
5410 /* Remember that we need to free the memory allocated. */
5412 }
5413 }
5415 {
5418 TFF_PLAIN_IDENTIFIER),
5419 NULL);
5420 /* Remember that we need to free the memory allocated. */
5422 }
5423 else
5427 }
5429 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
5430 be set, upon return, to the function called. */
5432 tree
5436 {
5440 tree access_binfo;
5441 tree optype;
5443 tree name;
5444 tree user_args;
5445 tree call;
5446 tree fn;
5447 tree class_type;
5450 tree orig_instance;
5451 tree orig_fns;
5452 tree orig_args;
5457 /* We don't know what function we're going to call, yet. */
5467 {
5470 }
5476 /* Dismantle the baselink to collect all the information we need. */
5483 {
5487 }
5498 {
5501 }
5503 /* The USER_ARGS are the arguments we will display to users if an
5504 error occurs. The USER_ARGS should not include any
5505 compiler-generated arguments. The "this" pointer hasn't been
5506 added yet. However, we must remove the VTT pointer if this is a
5507 call to a base-class constructor or destructor. */
5510 {
5511 /* Callers should explicitly indicate whether they want to construct
5512 the complete object or just the part without virtual bases. */
5514 /* Similarly for destructors. */
5516 /* Remove the VTT pointer, if present. */
5520 }
5522 /* Process the argument list. */
5529 /* It's OK to call destructors and constructors on cv-qualified objects.
5530 Therefore, convert the INSTANCE_PTR to the unqualified type, if
5531 necessary. */
5534 {
5538 }
5545 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5549 {
5551 tree this_arglist;
5553 /* We can end up here for copy-init of same or base class. */
5560 else
5564 /* A member template. */
5566 class_type,
5567 explicit_targs,
5569 access_binfo,
5570 conversion_path,
5571 flags,
5572 DEDUCE_CALL);
5575 class_type,
5576 this_arglist,
5577 access_binfo,
5578 conversion_path,
5579 flags);
5580 }
5584 {
5587 else
5588 {
5598 }
5601 }
5602 else
5603 {
5606 {
5612 user_args);
5617 }
5618 else
5619 {
5627 /* This is not an error, it is runtime undefined
5628 behavior. */
5630 "abstract virtual %q#D called from constructor"
5632 fn);
5636 {
5638 fn);
5640 }
5641 else
5642 {
5646 /* Now we know what function is being called. */
5649 /* Build the actual CALL_EXPR. */
5651 /* In an expression of the form `a->f()' where `f' turns
5652 out to be a static member function, `a' is
5653 none-the-less evaluated. */
5662 /* An explicit call of the form "x->~X()" has type
5663 "void". However, on platforms where destructors
5664 return "this" (i.e., those where
5665 targetm.cxx.cdtor_returns_this is true), such calls
5666 will appear to have a return value of pointer type
5667 to the low-level call machinery. We do not want to
5668 change the low-level machinery, since we want to be
5669 able to optimize "delete f()" on such platforms as
5670 "operator delete(~X(f()))" (rather than generating
5671 "t = f(), ~X(t), operator delete (t)"). */
5673 }
5674 }
5675 }
5678 call = (build_min_non_dep_call_list
5681 orig_args));
5683 /* Free all the conversions we allocated. */
5687 }
5689 /* Returns true iff standard conversion sequence ICS1 is a proper
5690 subsequence of ICS2. */
5692 static bool
5694 {
5695 /* We can assume that a conversion of the same code
5696 between the same types indicates a subsequence since we only get
5697 here if the types we are converting from are the same. */
5704 {
5712 /* At this point, ICS1 cannot be a proper subsequence of
5713 ICS2. We can get a USER_CONV when we are comparing the
5714 second standard conversion sequence of two user conversion
5715 sequences. */
5725 }
5726 }
5728 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
5729 be any _TYPE nodes. */
5731 bool
5733 {
5738 /* We only allow proper derivation here. The DERIVED_FROM_P macro
5739 considers every class derived from itself. */
5742 }
5744 /* We build the ICS for an implicit object parameter as a pointer
5745 conversion sequence. However, such a sequence should be compared
5746 as if it were a reference conversion sequence. If ICS is the
5747 implicit conversion sequence for an implicit object parameter,
5748 modify it accordingly. */
5750 static void
5752 {
5754 {
5755 /* [over.match.funcs]
5757 For non-static member functions, the type of the
5758 implicit object parameter is "reference to cv X"
5759 where X is the class of which the function is a
5760 member and cv is the cv-qualification on the member
5761 function declaration. */
5763 tree reference_type;
5765 /* The `this' parameter is a pointer to a class type. Make the
5766 implicit conversion talk about a reference to that same class
5767 type. */
5780 }
5781 }
5783 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
5784 and return the initial reference binding conversion. Otherwise,
5785 leave *ICS unchanged and return NULL. */
5789 {
5791 {
5797 }
5800 }
5802 /* Compare two implicit conversion sequences according to the rules set out in
5803 [over.ics.rank]. Return values:
5805 1: ics1 is better than ics2
5806 -1: ics2 is better than ics1
5807 0: ics1 and ics2 are indistinguishable */
5809 static int
5811 {
5812 tree from_type1;
5813 tree from_type2;
5814 tree to_type1;
5815 tree to_type2;
5822 /* REF_BINDING is nonzero if the result of the conversion sequence
5823 is a reference type. In that case REF_CONV is the reference
5824 binding conversion. */
5828 /* Handle implicit object parameters. */
5832 /* Handle reference parameters. */
5836 /* [over.ics.rank]
5838 When comparing the basic forms of implicit conversion sequences (as
5839 defined in _over.best.ics_)
5841 --a standard conversion sequence (_over.ics.scs_) is a better
5842 conversion sequence than a user-defined conversion sequence
5843 or an ellipsis conversion sequence, and
5845 --a user-defined conversion sequence (_over.ics.user_) is a
5846 better conversion sequence than an ellipsis conversion sequence
5847 (_over.ics.ellipsis_). */
5857 {
5858 /* XXX Isn't this an extension? */
5859 /* Both ICS are bad. We try to make a decision based on what
5860 would have happened if they'd been good. */
5868 /* We couldn't make up our minds; try to figure it out below. */
5869 }
5872 /* Both conversions are ellipsis conversions. */
5875 /* User-defined conversion sequence U1 is a better conversion sequence
5876 than another user-defined conversion sequence U2 if they contain the
5877 same user-defined conversion operator or constructor and if the sec-
5878 ond standard conversion sequence of U1 is better than the second
5879 standard conversion sequence of U2. */
5882 {
5896 /* We can just fall through here, after setting up
5897 FROM_TYPE1 and FROM_TYPE2. */
5900 }
5901 else
5902 {
5906 /* We're dealing with two standard conversion sequences.
5908 [over.ics.rank]
5910 Standard conversion sequence S1 is a better conversion
5911 sequence than standard conversion sequence S2 if
5913 --S1 is a proper subsequence of S2 (comparing the conversion
5914 sequences in the canonical form defined by _over.ics.scs_,
5915 excluding any Lvalue Transformation; the identity
5916 conversion sequence is considered to be a subsequence of
5917 any non-identity conversion sequence */
5928 }
5931 {
5936 }
5937 /* Otherwise, one sequence cannot be a subsequence of the other; they
5938 don't start with the same type. This can happen when comparing the
5939 second standard conversion sequence in two user-defined conversion
5940 sequences. */
5942 /* [over.ics.rank]
5944 Or, if not that,
5946 --the rank of S1 is better than the rank of S2 (by the rules
5947 defined below):
5949 Standard conversion sequences are ordered by their ranks: an Exact
5950 Match is a better conversion than a Promotion, which is a better
5951 conversion than a Conversion.
5953 Two conversion sequences with the same rank are indistinguishable
5954 unless one of the following rules applies:
5956 --A conversion that is not a conversion of a pointer, or pointer
5957 to member, to bool is better than another conversion that is such
5958 a conversion.
5960 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
5961 so that we do not have to check it explicitly. */
5974 {
5979 }
5980 /* The rules for pointers to members A::* are just like the rules
5981 for pointers A*, except opposite: if B is derived from A then
5982 A::* converts to B::*, not vice versa. For that reason, we
5983 switch the from_ and to_ variables here. */
5990 {
5995 }
6000 {
6001 /* This was one of the pointer or pointer-like conversions.
6003 [over.ics.rank]
6005 --If class B is derived directly or indirectly from class A,
6006 conversion of B* to A* is better than conversion of B* to
6007 void*, and conversion of A* to void* is better than
6008 conversion of B* to void*. */
6011 {
6013 deref_from_type2))
6016 deref_from_type1))
6018 }
6021 {
6023 {
6025 {
6027 deref_to_type1))
6029 }
6030 /* We know that DEREF_TO_TYPE1 is `void' here. */
6032 deref_to_type2))
6034 }
6035 }
6038 {
6039 /* [over.ics.rank]
6041 --If class B is derived directly or indirectly from class A
6042 and class C is derived directly or indirectly from B,
6044 --conversion of C* to B* is better than conversion of C* to
6045 A*,
6047 --conversion of B* to A* is better than conversion of C* to
6048 A* */
6050 {
6052 deref_to_type2))
6055 deref_to_type1))
6057 }
6059 {
6061 deref_from_type1))
6064 deref_from_type2))
6066 }
6067 }
6068 }
6071 {
6074 /* [over.ics.rank]
6076 --binding of an expression of type C to a reference of type
6077 B& is better than binding an expression of type C to a
6078 reference of type A&
6080 --conversion of C to B is better than conversion of C to A, */
6083 {
6088 }
6089 }
6092 {
6095 /* [over.ics.rank]
6097 --binding of an expression of type B to a reference of type
6098 A& is better than binding an expression of type C to a
6099 reference of type A&,
6101 --conversion of B to A is better than conversion of C to A */
6104 {
6109 }
6110 }
6112 /* [over.ics.rank]
6114 --S1 and S2 differ only in their qualification conversion and yield
6115 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6116 qualification signature of type T1 is a proper subset of the cv-
6117 qualification signature of type T2 */
6123 /* [over.ics.rank]
6125 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6126 to an implicit object parameter, and either S1 binds an lvalue reference
6127 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6128 reference to an rvalue and S2 binds an lvalue reference
6129 (C++0x draft standard, 13.3.3.2)
6131 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6132 types to which the references refer are the same type except for
6133 top-level cv-qualifiers, and the type to which the reference
6134 initialized by S2 refers is more cv-qualified than the type to
6135 which the reference initialized by S1 refers */
6138 {
6142 {
6147 }
6152 }
6154 /* Neither conversion sequence is better than the other. */
6156 }
6158 /* The source type for this standard conversion sequence. */
6160 static tree
6162 {
6164 {
6169 }
6171 }
6173 /* Note a warning about preferring WINNER to LOSER. We do this by storing
6174 a pointer to LOSER and re-running joust to produce the warning if WINNER
6175 is actually used. */
6177 static void
6179 {
6185 }
6187 /* Compare two candidates for overloading as described in
6188 [over.match.best]. Return values:
6190 1: cand1 is better than cand2
6191 -1: cand2 is better than cand1
6192 0: cand1 and cand2 are indistinguishable */
6194 static int
6196 {
6202 /* Candidates that involve bad conversions are always worse than those
6203 that don't. */
6209 /* If we have two pseudo-candidates for conversions to the same type,
6210 or two candidates for the same function, arbitrarily pick one. */
6215 /* a viable function F1
6216 is defined to be a better function than another viable function F2 if
6217 for all arguments i, ICSi(F1) is not a worse conversion sequence than
6218 ICSi(F2), and then */
6220 /* for some argument j, ICSj(F1) is a better conversion sequence than
6221 ICSj(F2) */
6223 /* For comparing static and non-static member functions, we ignore
6224 the implicit object parameter of the non-static function. The
6225 standard says to pretend that the static function has an object
6226 parm, but that won't work with operator overloading. */
6229 {
6237 else
6238 {
6241 }
6242 }
6245 {
6251 {
6264 {
6271 else
6276 {
6280 }
6281 else
6283 }
6286 {
6289 }
6291 }
6292 }
6294 /* warn about confusing overload resolution for user-defined conversions,
6295 either between a constructor and a conversion op, or between two
6296 conversion ops. */
6300 {
6306 else
6309 /* We don't want to complain about `X::operator T1 ()'
6310 beating `X::operator T2 () const', when T2 is a no less
6311 cv-qualified version of T1. */
6314 {
6319 {
6322 }
6325 }
6326 else
6332 {
6340 }
6341 else
6343 }
6348 /* or, if not that,
6349 F1 is a non-template function and F2 is a template function
6350 specialization. */
6357 /* or, if not that,
6358 F1 and F2 are template functions and the function template for F1 is
6359 more specialized than the template for F2 according to the partial
6360 ordering rules. */
6363 {
6364 winner = more_specialized_fn
6367 /* [temp.func.order]: The presence of unused ellipsis and default
6368 arguments has no effect on the partial ordering of function
6369 templates. add_function_candidate() will not have
6370 counted the "this" argument for constructors. */
6374 }
6376 /* or, if not that,
6377 the context is an initialization by user-defined conversion (see
6378 _dcl.init_ and _over.match.user_) and the standard conversion
6379 sequence from the return type of F1 to the destination type (i.e.,
6380 the type of the entity being initialized) is a better conversion
6381 sequence than the standard conversion sequence from the return type
6382 of F2 to the destination type. */
6385 {
6389 }
6391 /* Check whether we can discard a builtin candidate, either because we
6392 have two identical ones or matching builtin and non-builtin candidates.
6394 (Pedantically in the latter case the builtin which matched the user
6395 function should not be added to the overload set, but we spot it here.
6397 [over.match.oper]
6398 ... the builtin candidates include ...
6399 - do not have the same parameter type list as any non-template
6400 non-member candidate. */
6404 {
6410 {
6412 /* Two built-in candidates; arbitrarily pick one. */
6415 /* cand1 is built-in; prefer cand2. */
6417 else
6418 /* cand2 is built-in; prefer cand1. */
6420 }
6421 }
6423 /* If the two functions are the same (this can happen with declarations
6424 in multiple scopes and arg-dependent lookup), arbitrarily choose one. */
6429 tweak:
6431 /* Extension: If the worst conversion for one candidate is worse than the
6432 worst conversion for the other, take the first. */
6434 {
6439 {
6444 }
6450 {
6452 {
6454 ISO C++ says that these are ambiguous, even \
6455 though the worst conversion for the first is better than \
6459 }
6460 else
6463 }
6464 }
6468 }
6470 /* Given a list of candidates for overloading, find the best one, if any.
6471 This algorithm has a worst case of O(2n) (winner is last), and a best
6472 case of O(n/2) (totally ambiguous); much better than a sorting
6473 algorithm. */
6477 {
6482 /* Walk through the list once, comparing each current champ to the next
6483 candidate, knocking out a candidate or two with each comparison. */
6486 {
6490 else
6491 {
6493 {
6498 }
6499 else
6500 {
6503 }
6506 }
6507 }
6509 /* Make sure the champ is better than all the candidates it hasn't yet
6510 been compared to. */
6513 challenger != champ
6516 {
6520 }
6523 }
6525 /* Returns nonzero if things of type FROM can be converted to TO. */
6527 bool
6529 {
6531 }
6533 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
6535 bool
6537 {
6542 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6546 flags);
6549 /* Free all the conversions we allocated. */
6553 }
6555 /* Like can_convert_arg, but allows dubious conversions as well. */
6557 bool
6559 {
6563 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6565 /* Try to perform the conversion. */
6567 LOOKUP_NORMAL);
6568 /* Free all the conversions we allocated. */
6572 }
6574 /* Convert EXPR to TYPE. Return the converted expression.
6576 Note that we allow bad conversions here because by the time we get to
6577 this point we are committed to doing the conversion. If we end up
6578 doing a bad conversion, convert_like will complain. */
6580 tree
6582 {
6589 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6594 LOOKUP_NORMAL);
6596 {
6599 }
6601 {
6602 /* In a template, we are only concerned about determining the
6603 type of non-dependent expressions, so we do not have to
6604 perform the actual conversion. */
6607 }
6608 else
6611 /* Free all the conversions we allocated. */
6615 }
6617 /* Convert EXPR to TYPE (as a direct-initialization) if that is
6618 permitted. If the conversion is valid, the converted expression is
6619 returned. Otherwise, NULL_TREE is returned, except in the case
6620 that TYPE is a class type; in that case, an error is issued. If
6621 C_CAST_P is true, then this direction initialization is taking
6622 place as part of a static_cast being attempted as part of a C-style
6623 cast. */
6625 tree
6627 tree expr,
6629 {
6635 /* [dcl.init]
6637 If the destination type is a (possibly cv-qualified) class type:
6639 -- If the initialization is direct-initialization ...,
6640 constructors are considered. ... If no constructor applies, or
6641 the overload resolution is ambiguous, the initialization is
6642 ill-formed. */
6644 {
6649 }
6651 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6655 c_cast_p,
6656 LOOKUP_NORMAL);
6659 else
6662 c_cast_p);
6664 /* Free all the conversions we allocated. */
6668 }
6670 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
6671 is being bound to a temporary. Create and return a new VAR_DECL
6672 with the indicated TYPE; this variable will store the value to
6673 which the reference is bound. */
6675 tree
6677 {
6678 tree var;
6680 /* Create the variable. */
6683 /* Register the variable. */
6685 {
6686 /* Namespace-scope or local static; give it a mangled name. */
6687 tree name;
6694 }
6695 else
6696 /* Create a new cleanup level if necessary. */
6700 }
6702 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
6703 initializing a variable of that TYPE. If DECL is non-NULL, it is
6704 the VAR_DECL being initialized with the EXPR. (In that case, the
6705 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
6706 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
6707 return, if *CLEANUP is no longer NULL, it will be an expression
6708 that should be pushed as a cleanup after the returned expression
6709 is used to initialize DECL.
6711 Return the converted expression. */
6713 tree
6715 {
6722 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6726 LOOKUP_NORMAL);
6728 {
6734 else
6739 }
6741 /* If DECL is non-NULL, then this special rule applies:
6743 [class.temporary]
6745 The temporary to which the reference is bound or the temporary
6746 that is the complete object to which the reference is bound
6747 persists for the lifetime of the reference.
6749 The temporaries created during the evaluation of the expression
6750 initializing the reference, except the temporary to which the
6751 reference is bound, are destroyed at the end of the
6752 full-expression in which they are created.
6754 In that case, we store the converted expression into a new
6755 VAR_DECL in a new scope.
6757 However, we want to be careful not to create temporaries when
6758 they are not required. For example, given:
6760 struct B {};
6761 struct D : public B {};
6762 D f();
6763 const B& b = f();
6765 there is no need to copy the return value from "f"; we can just
6766 extend its lifetime. Similarly, given:
6768 struct S {};
6769 struct T { operator S(); };
6770 T t;
6771 const S& s = t;
6773 we can extend the lifetime of the return value of the conversion
6774 operator. */
6777 {
6778 tree var;
6779 tree base_conv_type;
6781 /* Skip over the REF_BIND. */
6783 /* If the next conversion is a BASE_CONV, skip that too -- but
6784 remember that the conversion was required. */
6786 {
6789 }
6790 else
6792 /* Perform the remainder of the conversion. */
6800 else
6801 {
6803 {
6804 tree init;
6805 tree type;
6807 /* Create the temporary variable. */
6811 /* If the rvalue is the result of a function call it will be
6812 a TARGET_EXPR. If it is some other construct (such as a
6813 member access expression where the underlying object is
6814 itself the result of a function call), turn it into a
6815 TARGET_EXPR here. It is important that EXPR be a
6816 TARGET_EXPR below since otherwise the INIT_EXPR will
6817 attempt to make a bitwise copy of EXPR to initialize
6818 VAR. */
6821 /* Create the INIT_EXPR that will initialize the temporary
6822 variable. */
6825 {
6830 else
6833 /* We must be careful to destroy the temporary only
6834 after its initialization has taken place. If the
6835 initialization throws an exception, then the
6836 destructor should not be run. We cannot simply
6837 transform INIT into something like:
6839 (INIT, ({ CLEANUP_STMT; }))
6841 because emit_local_var always treats the
6842 initializer as a full-expression. Thus, the
6843 destructor would run too early; it would run at the
6844 end of initializing the reference variable, rather
6845 than at the end of the block enclosing the
6846 reference variable.
6848 The solution is to pass back a cleanup expression
6849 which the caller is responsible for attaching to
6850 the statement tree. */
6851 }
6852 else
6853 {
6857 static_aggregates);
6858 }
6859 /* Use its address to initialize the reference variable. */
6867 }
6868 else
6869 /* Take the address of EXPR. */
6871 /* If a BASE_CONV was required, perform it now. */
6873 expr = (perform_implicit_conversion
6876 }
6877 }
6878 else
6879 /* Perform the conversion. */
6882 /* Free all the conversions we allocated. */
6886 }