(C++) fix for function conversion overloading
Jason Merrill
jason@cygnus.com
Tue Nov 24 02:33:00 GMT 1998
Fixes g++.other/overload7.C. We were adding multiple candidates for
conversion ops overloaded on `this' quals, and calling it ambiguous.
1998-11-24 Jason Merrill <jason@yorick.cygnus.com>
* class.c (add_method): Build up OVERLOADs properly for conversion ops.
* search.c (lookup_conversions): Handle getting real OVERLOADs.
(add_conversions): Likewise. Revert last change.
* call.c (add_conv_candidate): Pass totype to add_candidate instead
of fn. Don't add a new candidate if the last one was for the same
type.
(print_z_candidates): Handle getting a type as a function.
(joust): If we got two conversion candidates to the same type,
just pick one.
(build_object_call): Lose 'templates'.
(build_user_type_conversion_1): Handle getting real OVERLOADs
Index: call.c
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/cp/call.c,v
retrieving revision 1.120
diff -c -p -r1.120 call.c
*** call.c 1998/11/18 12:27:21 1.120
--- call.c 1998/11/24 10:30:28
*************** add_function_candidate (candidates, fn,
*** 1217,1224 ****
/* Create an overload candidate for the conversion function FN which will
be invoked for expression OBJ, producing a pointer-to-function which
will in turn be called with the argument list ARGLIST, and add it to
! CANDIDATES. FLAGS is passed on to implicit_conversion. */
static struct z_candidate *
add_conv_candidate (candidates, fn, obj, arglist)
struct z_candidate *candidates;
--- 1217,1230 ----
/* Create an overload candidate for the conversion function FN which will
be invoked for expression OBJ, producing a pointer-to-function which
will in turn be called with the argument list ARGLIST, and add it to
! CANDIDATES. FLAGS is passed on to implicit_conversion.
+ Actually, we don't really care about FN; we care about the type it
+ converts to. There may be multiple conversion functions that will
+ convert to that type, and we rely on build_user_type_conversion_1 to
+ choose the best one; so when we create our candidate, we record the type
+ instead of the function. */
+
static struct z_candidate *
add_conv_candidate (candidates, fn, obj, arglist)
struct z_candidate *candidates;
*************** add_conv_candidate (candidates, fn, obj,
*** 1233,1238 ****
--- 1239,1248 ----
int viable = 1;
int flags = LOOKUP_NORMAL;
+ /* Don't bother looking up the same type twice. */
+ if (candidates && candidates->fn == totype)
+ return candidates;
+
for (i = 0; i < len; ++i)
{
tree arg = i == 0 ? obj : TREE_VALUE (argnode);
*************** add_conv_candidate (candidates, fn, obj,
*** 1277,1283 ****
break;
}
! return add_candidate (candidates, fn, convs, viable);
}
static struct z_candidate *
--- 1287,1293 ----
break;
}
! return add_candidate (candidates, totype, convs, viable);
}
static struct z_candidate *
*************** print_z_candidates (candidates)
*** 2058,2063 ****
--- 2068,2075 ----
cp_error ("%s %D(%T) <builtin>", str, candidates->fn,
TREE_TYPE (TREE_VEC_ELT (candidates->convs, 0)));
}
+ else if (TYPE_P (candidates->fn))
+ cp_error ("%s %T <conversion>", str, candidates->fn);
else
cp_error_at ("%s %+D%s", str, candidates->fn,
candidates->viable == -1 ? " <near match>" : "");
*************** build_user_type_conversion_1 (totype, ex
*** 2143,2149 ****
if (TREE_CODE (totype) == REFERENCE_TYPE)
convflags |= LOOKUP_NO_TEMP_BIND;
! if (TREE_CODE (fns) != TEMPLATE_DECL)
ics = implicit_conversion
(totype, TREE_TYPE (TREE_TYPE (OVL_CURRENT (fns))), 0, convflags);
else
--- 2155,2161 ----
if (TREE_CODE (totype) == REFERENCE_TYPE)
convflags |= LOOKUP_NO_TEMP_BIND;
! if (TREE_CODE (OVL_CURRENT (fns)) != TEMPLATE_DECL)
ics = implicit_conversion
(totype, TREE_TYPE (TREE_TYPE (OVL_CURRENT (fns))), 0, convflags);
else
*************** build_object_call (obj, args)
*** 2369,2375 ****
struct z_candidate *candidates = 0, *cand;
tree fns, convs, mem_args = NULL_TREE;
tree type = TREE_TYPE (obj);
- tree templates = NULL_TREE;
if (TYPE_PTRMEMFUNC_P (type))
{
--- 2381,2386 ----
*************** build_object_call (obj, args)
*** 2399,2405 ****
tree fn = OVL_CURRENT (fns);
if (TREE_CODE (fn) == TEMPLATE_DECL)
{
- templates = scratch_tree_cons (NULL_TREE, fn, templates);
candidates
= add_template_candidate (candidates, fn, NULL_TREE,
mem_args, NULL_TREE,
--- 2410,2415 ----
*************** build_object_call (obj, args)
*** 2429,2435 ****
tree fn = OVL_CURRENT (fns);
if (TREE_CODE (fn) == TEMPLATE_DECL)
{
- templates = scratch_tree_cons (NULL_TREE, fn, templates);
candidates = add_template_conv_candidate (candidates,
fn,
obj,
--- 2439,2444 ----
*************** joust (cand1, cand2, warn)
*** 4218,4223 ****
--- 4227,4237 ----
return 1;
if (cand1->viable < cand2->viable)
return -1;
+
+ /* If we have two pseudo-candidates for conversions to the same type,
+ arbitrarily pick one. */
+ if (TYPE_P (cand1->fn) && cand1->fn == cand2->fn)
+ return 1;
/* a viable function F1
is defined to be a better function than another viable function F2 if
Index: class.c
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/cp/class.c,v
retrieving revision 1.113
diff -c -p -r1.113 class.c
*** class.c 1998/11/23 23:59:48 1.113
--- class.c 1998/11/24 10:30:29
*************** add_method (type, fields, method)
*** 1235,1241 ****
}
}
! if (DECL_CONV_FN_P (method))
{
/* Type conversion operators have to come before
ordinary methods; add_conversions depends on this to
--- 1235,1243 ----
}
}
! if (TREE_VEC_ELT (method_vec, i))
! /* We found a match. */;
! else if (DECL_CONV_FN_P (method))
{
/* Type conversion operators have to come before
ordinary methods; add_conversions depends on this to
Index: search.c
===================================================================
RCS file: /egcs/carton/cvsfiles/egcs/gcc/cp/search.c,v
retrieving revision 1.72
diff -c -p -r1.72 search.c
*** search.c 1998/11/23 03:12:30 1.72
--- search.c 1998/11/24 10:30:30
*************** add_conversions (binfo)
*** 3302,3341 ****
{
int i;
tree method_vec = CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo));
- tree name = NULL_TREE;
for (i = 2; i < TREE_VEC_LENGTH (method_vec); ++i)
{
tree tmp = TREE_VEC_ELT (method_vec, i);
if (!tmp || ! DECL_CONV_FN_P (OVL_CURRENT (tmp)))
break;
! if (TREE_CODE (tmp) == OVERLOAD)
! {
! my_friendly_assert (TREE_CHAIN (tmp) == NULL_TREE, 981121);
! tmp = OVL_FUNCTION (tmp);
! }
- /* We don't want to mark 'name' until we've seen all the overloads
- in this class; we could be overloading on the quals of 'this'. */
- if (name && name != DECL_NAME (tmp))
- {
- IDENTIFIER_MARKED (name) = 1;
- name = NULL_TREE;
- }
-
/* Make sure we don't already have this conversion. */
! if (! IDENTIFIER_MARKED (DECL_NAME (tmp)))
{
conversions = scratch_tree_cons (binfo, tmp, conversions);
! name = DECL_NAME (tmp);
}
}
-
- if (name)
- IDENTIFIER_MARKED (name) = 1;
-
return NULL_TREE;
}
--- 3302,3325 ----
{
int i;
tree method_vec = CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo));
for (i = 2; i < TREE_VEC_LENGTH (method_vec); ++i)
{
tree tmp = TREE_VEC_ELT (method_vec, i);
+ tree name;
if (!tmp || ! DECL_CONV_FN_P (OVL_CURRENT (tmp)))
break;
! name = DECL_NAME (OVL_CURRENT (tmp));
/* Make sure we don't already have this conversion. */
! if (! IDENTIFIER_MARKED (name))
{
conversions = scratch_tree_cons (binfo, tmp, conversions);
! IDENTIFIER_MARKED (name) = 1;
}
}
return NULL_TREE;
}
*************** lookup_conversions (type)
*** 3351,3357 ****
breadth_first_search (TYPE_BINFO (type), add_conversions, 0);
for (t = conversions; t; t = TREE_CHAIN (t))
! IDENTIFIER_MARKED (DECL_NAME (TREE_VALUE (t))) = 0;
return conversions;
}
--- 3335,3341 ----
breadth_first_search (TYPE_BINFO (type), add_conversions, 0);
for (t = conversions; t; t = TREE_CHAIN (t))
! IDENTIFIER_MARKED (DECL_NAME (OVL_CURRENT (TREE_VALUE (t)))) = 0;
return conversions;
}
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