/* Nope; try looking for others. */
for (conv = lookup_conversions (basetype); conv; conv = TREE_CHAIN (conv))
{
- if (winner && TREE_VALUE (winner) == TREE_VALUE (conv))
+ tree cand = TREE_VALUE (conv);
+
+ if (winner && winner == cand)
continue;
- if (can_convert (xtype, TREE_PURPOSE (conv)))
+ if (can_convert (xtype, TREE_TYPE (TREE_TYPE (cand))))
{
if (winner)
{
{
cp_error ("ambiguous conversion from `%T' to `%T'", basetype,
xtype);
- cp_error (" candidate conversions include `%T' and `%T'",
- TREE_PURPOSE (winner), TREE_PURPOSE (conv));
+ cp_error (" candidate conversions include `%D' and `%D'",
+ winner, cand);
}
return NULL_TREE;
}
else
- winner = conv;
+ winner = cand;
}
}
if (winner)
return build_type_conversion_1 (xtype, basetype, expr,
- DECL_NAME (TREE_VALUE (winner)), for_sure);
+ DECL_NAME (winner), for_sure);
return NULL_TREE;
}
{
int win = 0;
tree candidate;
+ tree cand = TREE_VALUE (conv);
- if (winner && TREE_VALUE (winner) == TREE_VALUE (conv))
+ if (winner && winner == cand)
continue;
- candidate = TREE_PURPOSE (conv);
+ candidate = TREE_TYPE (TREE_TYPE (cand));
if (TREE_CODE (candidate) == REFERENCE_TYPE)
candidate = TREE_TYPE (candidate);
{
cp_error ("ambiguous default type conversion from `%T'",
basetype);
- cp_error (" candidate conversions include `%T' and `%T'",
- TREE_PURPOSE (winner), TREE_PURPOSE (conv));
+ cp_error (" candidate conversions include `%D' and `%D'",
+ winner, cand);
}
return error_mark_node;
}
else
- winner = conv;
+ winner = cand;
}
}
if (winner)
{
- tree type = TREE_PURPOSE (winner);
+ tree type = TREE_TYPE (TREE_TYPE (winner));
if (TREE_CODE (type) == REFERENCE_TYPE)
type = TREE_TYPE (type);
return build_type_conversion_1 (type, basetype, expr,
- DECL_NAME (TREE_VALUE (winner)), 1);
+ DECL_NAME (winner), 1);
}
return NULL_TREE;
int rank = ICS_STD_RANK (from);
switch (code)
{
- case PROMO_CONV:
- if (rank < PROMO_RANK)
- rank = PROMO_RANK;
- break;
-
case PTR_CONV:
case PMEM_CONV:
case BASE_CONV:
rank = STD_RANK;
break;
- case PBOOL_CONV:
- if (rank < PBOOL_RANK)
- rank = PBOOL_RANK;
- break;
-
default:
break;
}
ICS_STD_RANK (t) = rank;
- ICS_USER_FLAG (t) = ICS_USER_FLAG (from);
return t;
}
return from;
conv = build1 (EXACT_CONV, from, expr);
- if (TREE_CODE (expr) == USER_CONV)
- ICS_USER_FLAG (conv) = 1;
if (fcode == FUNCTION_TYPE)
{
|| fcode == POINTER_TYPE || TYPE_PTRMEMFUNC_P (from)))
return 0;
- if (fcode == POINTER_TYPE || TYPE_PTRMEMFUNC_P (from))
- conv = build_conv (PBOOL_CONV, to, conv);
- else
- conv = build_conv (STD_CONV, to, conv);
+ conv = build_conv (STD_CONV, to, conv);
+ if (fcode == POINTER_TYPE || TYPE_PTRMEMFUNC_P (from)
+ && ICS_STD_RANK (conv) < PBOOL_RANK)
+ ICS_STD_RANK (conv) = PBOOL_RANK;
}
else if (INTEGRAL_CODE_P (tcode) || tcode == REAL_TYPE)
{
if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE))
return 0;
- else if (to == type_promotes_to (from))
- conv = build_conv (PROMO_CONV, to, conv);
- else
- conv = build_conv (STD_CONV, to, conv);
+ conv = build_conv (STD_CONV, to, conv);
+
+ /* Give this a better rank if it's a promotion. */
+ if (to == type_promotes_to (from)
+ && ICS_STD_RANK (TREE_OPERAND (conv, 0)) <= PROMO_RANK)
+ ICS_STD_RANK (conv) = PROMO_RANK;
}
else if (IS_AGGR_TYPE (to) && IS_AGGR_TYPE (from)
&& DERIVED_FROM_P (to, from))
- {
- conv = build_conv (BASE_CONV, to, conv);
- }
+ conv = build_conv (BASE_CONV, to, conv);
else
return 0;
if (! cand)
return NULL_TREE;
- conv = cand->second_conv;
-
- for (t = conv; TREE_CODE (TREE_OPERAND (t, 0)) != EXACT_MATCH; )
- t = TREE_OPERAND (t, 0));
-
- TREE_OPERAND (t, 0) = build (USER_CONV
-
- return conv;
+ return cand->second_conv;
}
struct z_candidate *
-add_method_candidate (candidates, method, instance, parms, flags)
+add_function_candidate (candidates, fn, arglist, flags)
struct z_candidate *candidates;
- tree method, instance, parms;
+ tree fn, args;
int flags;
{
-
+ tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
+ int i, len = list_length (args);
+ tree convs = make_tree_vec (len);
+ tree parmnode = parmlist;
+ tree argnode = arglist;
+ int viable = 1;
+ struct z_candidate *cand;
+
+ for (i = 0; i < len; ++i)
+ {
+ tree arg = TREE_VALUE (argnode);
+ tree argtype = TREE_TYPE (arg);
+ tree t;
+
+ if (parmnode == void_list_node)
+ break;
+ else if (parmnode)
+ t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg, flags);
+ else
+ {
+ t = build1 (EXACT_CONV, argtype, arg);
+ ICS_ELLIPSIS_FLAG (t) = 1;
+ }
+
+ TREE_VEC_ELT (convs, i) = t;
+ if (! t)
+ {
+ viable = 0;
+ break;
+ }
+
+ if (parm)
+ parm = TREE_CHAIN (parm);
+ arg = TREE_CHAIN (arg);
+ }
+
+ if (parmnode && parmnode != void_list_node)
+ viable = 0;
+
+ cand = (struct z_candidate *) oballoc (sizeof (struct z_candidate));
+
+ cand->fn = fn;
+ cand->convs = convs;
+ cand->second_conv = NULL_TREE;
+ cand->viable = viable;
+ cand->template = NULL_TREE;
+ cand->basetype_path = NULL_TREE;
+ cand->next = candidates;
+
+ return cand;
}
+/* Returns the best overload candidate to perform the requested
+ conversion. */
+
struct z_candidate *
build_user_type_conversion_1 (totype, expr, flags)
tree totype, expr;
struct z_candidate *candidates, *cand;
tree fromtype = TREE_TYPE (expr);
tree ctors = NULL_TREE, convs = NULL_TREE, t;
+ tree method_args;
if (IS_AGGR_TYPE (totype))
ctors = lookup_fnfields (TYPE_BINFO (totype), ctor_identifier, 0);
for (; ctors; ctors = DECL_CHAIN (ctors))
{
candidates = add_ctor_candidate (candidates, ctors, expr, flags);
+ candidates->basetype_path = TYPE_BINFO (totype);
}
+ method_args = build_tree_list
+ (NULL_TREE, build_unary_op (ADDR_EXPR, expr, 0));
+
for (; convs; convs = TREE_CHAIN (convs))
{
tree fn = TREE_VALUE (convs);
tree ics = standard_conversion (totype, TREE_TYPE (TREE_TYPE (fn)), 0);
if (ics)
{
- candidates = add_method_candidate
- (candidates, fn, expr, NULL_TREE, flags);
+ candidates = add_function_candidate
+ (candidates, fn, method_args, flags);
candidates->second_ics = ics;
+ candidates->basetype_path = TREE_PURPOSE (convs);
}
}
if (! any_viable (candidates))
{
if (flags & LOOKUP_COMPLAIN)
- cp_error ("no viable candidates");
+ {
+ if (candidates && ! candidates->next)
+ /* say why this one won't work or try to be loose */;
+ else
+ cp_error ("no viable candidates");
+ }
+
return 0;
}
cp_error ("ambiguous user-defined type conversion");
}
+ for (t = cand->second_conv; TREE_CODE (TREE_OPERAND (t, 0)) != EXACT_MATCH; )
+ t = TREE_OPERAND (t, 0);
+
+ TREE_OPERAND (t, 0) = build
+ (USER_CONV, TREE_TYPE (TREE_TYPE (cand->fn)),
+ NULL_TREE, cand->fn, cand->convs, cand->basetype_path);
+ ICS_USER_FLAG (cand->second_conv) = 1;
+
return cand;
}
+tree
+build_user_type_conversion (totype, expr, flags)
+ tree totype, expr, flags;
+{
+ struct z_candidate *cand
+ = build_user_type_conversion_1 (totype, expr, flags);
+
+ return convert_like (cand->second_conv, expr);
+}
+
+void
+enforce_access (basetype_path, function)
+ tree basetype_path, function;
+{
+ tree access = compute_access (basetype_path, function);
+
+ if (access == access_private_node)
+ {
+ cp_error_at ("%s `%+#D' is %s", name_kind, function,
+ TREE_PRIVATE (function) ? "private"
+ : "from private base class");
+ error ("within this context");
+ }
+ else if (access == access_protected_node)
+ {
+ cp_error_at ("%s `%+#D' %s", name_kind, function,
+ TREE_PROTECTED (function) ? "is protected"
+ : "has protected accessibility");
+ error ("within this context");
+ }
+}
+
+tree
+convert_like (convs, expr)
+ tree convs, expr;
+{
+ tree previous;
+
+ if (TREE_CODE (convs) == USER_CONV)
+ {
+ tree fn = TREE_OPERAND (convs, 1);
+ enforce_access (TREE_OPERAND (convs, 3), fn);
+ return build_over_call (TREE_OPERAND (convs, 1),
+ TREE_OPERAND (convs, 2), expr, LOOKUP_NORMAL);
+ }
+ else if (TREE_CODE (convs) == EXACT_CONV)
+ return expr;
+
+ previous = convert_like (TREE_OPERAND (convs, 0), expr);
+ return convert (TREE_TYPE (convs), expr);
+}
+
+tree
+build_over_call (fn, convs, args, flags)
+ tree fn, convs, args;
+ int flags;
+{
+ tree converted_args;
+ tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
+ tree conv = convs;
+ tree arg = args;
+
+ if (TREE_CODE (arg) != TREE_LIST)
+ arg = build_tree_list (NULL_TREE, arg);
+
+ for (; arg;
+ parm = TREE_CHAIN (parm), arg = TREE_CHAIN (arg),
+ conv = TREE_CHAIN (conv))
+ converted_args = tree_cons
+ (NULL_TREE, convert_like (TREE_VALUE (conv), TREE_VALUE (arg)),
+ converted_args);
+
+ for (; parm; parm = TREE_CHAIN (parm))
+ converted_args = tree_cons
+ (NULL_TREE,
+ convert_for_ellipsis (TREE_VALUE (parm), TREE_PURPOSE (parm)),
+ converted_args);
+
+ converted_args = nreverse (converted_args);
+
+ return build_x_call (fn, converted_args, flags);
+}
+
+tree
+build_x_call (fn, args, flags)
+ tree fn, args;
+ int flags;
+{
+ if (DECL_FUNCTION_MEMBER_P (fn))
+ {
+ }
+}
+
/* Compare two implicit conversion sequences according to the rules set out in
[over.ics.rank]. Return values:
/* A conversion that is not a conversion of a pointer, or pointer to
member, to bool is better than another conversion that is such a
conversion. */
- {
- int bool1 = TREE_CODE (ics1) == BOOL_CONV;
- int bool2 = TREE_CODE (ics2) == BOOL_CONV;
-
- if (bool1)
- {
- tree it = TREE_TYPE (TREE_OPERAND (ics1, 0));
- if (TREE_CODE (it) != POINTER_TYPE
- && ! TYPE_PTRMEMFUNC_TYPE (it))
- bool1 = 0;
- }
- if (bool2)
- {
- tree it = TREE_TYPE (TREE_OPERAND (ics2, 0));
- if (TREE_CODE (it) != POINTER_TYPE
- && ! TYPE_PTRMEMFUNC_TYPE (it))
- bool2 = 0;
- }
- if (bool1 && ! bool2)
- return 1;
- if (bool2 && ! bool1)
- return -1;
- }
#endif
if (TREE_CODE (ics1) == QUAL_CONV)
return 0;
}
+/* Compare two candidates for overloading as described in
+ [over.match.best]. Return values:
+
+ 1: cand1 is better than cand2
+ -1: cand2 is better than cand1
+ 0: cand1 and cand2 are indistinguishable */
+
int joust (cand1, cand2)
struct z_candidate *cand1, *cand2;
{
int winner = 0;
int i;
+ /* a viable function F1
+ is defined to be a better function than another viable function F2 if
+ for all arguments i, ICSi(F1) is not a worse conversion sequence than
+ ICSi(F2), and then */
+
+ /* for some argument j, ICSj(F1) is a better conversion sequence than
+ ICSj(F2) */
+
for (i = 0; i < TREE_VEC_LENGTH (cand1->convs); ++i)
{
int comp = compare_ics (TREE_VEC_ELT (cand1->convs, i),
}
}
- if (winner == 0 && cand1->second_ics)
+ if (winner)
+ return winner;
+
+ /* or, if not that,
+ F1 is a non-template function and F2 is a template function */
+
+ if (! cand1->template && cand2->template)
+ return 1;
+ else if (cand1->template && ! cand2->template)
+ return -1;
+
+ /* or, if not that,
+ the context is an initialization by user-defined conversion (see
+ _dcl.init_ and _over.match.user_) and the standard conversion
+ sequence from the return type of F1 to the destination type (i.e.,
+ the type of the entity being initialized) is a better conversion
+ sequence than the standard conversion sequence from the return type
+ of F2 to the destination type. */
+
+ if (cand1->second_ics)
winner = compare_ics (cand1->second_ics, cand2->second_ics);
return winner;
}
+/* Given a list of candidates for overloading, find the best one, if any.
+ This algorithm has a worst case of O(2n) (winner is last), and a best
+ case of O(n/2) (totally ambiguous); much better than a sorting
+ algorithm. */
+
struct z_candidate *
tourney (candidates)
struct z_candidate *candidates;
struct z_candidate *champ = candidates, *challenger;
int fate;
- /* This algorithm has a worst case of O(2n) (winner is last) , and a best
- case of O(n/2) (no winner); much better than a sorting algorithm. */
+ /* Walk through the list once, comparing each current champ to the next
+ candidate, knocking out a candidate or two with each comparison. */
for (challenger = champ->next; challenger; )
{
}
}
+ /* Make sure the champ is better than all the candidates it hasn't yet
+ been compared to. This may do one more comparison than necessary. Oh
+ well. */
+
for (challenger = candidates; challenger != champ;
challenger = challenger->next)
{
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