call.c (add_candidates): Distinguish between type(x) and x.operator type().

	* call.c (add_candidates): Distinguish between type(x) and
	x.operator type().
	(convert_class_to_reference): Set LOOKUP_NO_CONVERSION.
	(build_new_method_call): Give better error for conversion op.

From-SVN: r159333

gcc/cp/ChangeLog

 2010-05-12  Jason Merrill  <jason@redhat.com>
 
+	* call.c (add_candidates): Distinguish between type(x) and
+	x.operator type().
+	(convert_class_to_reference): Set LOOKUP_NO_CONVERSION.
+	(build_new_method_call): Give better error for conversion op.
+
 	* call.c (add_candidates): Add first_arg and return_type parms.
 	Add special constructor/conversion op handling.
 	(convert_class_to_reference): Use it.

gcc/cp/call.c

@@ -1053,6 +1053,10 @@ convert_class_to_reference (tree reference_type, tree s, tree expr, int flags)
 
   t = TREE_TYPE (reference_type);
 
+  /* We're performing a user-defined conversion to a desired type, so set
+     this for the benefit of add_candidates.  */
+  flags |= LOOKUP_NO_CONVERSION;
+
   for (; conversions; conversions = TREE_CHAIN (conversions))
     {
       tree fns = TREE_VALUE (conversions);
@@ -4017,7 +4021,12 @@ add_candidates (tree fns, tree first_arg, const VEC(tree,gc) *args,
   if (DECL_CONV_FN_P (fn))
     {
       check_converting = !!(flags & LOOKUP_ONLYCONVERTING);
-      strict = DEDUCE_CONV;
+      if (flags & LOOKUP_NO_CONVERSION)
+	/* We're doing return_type(x).  */
+	strict = DEDUCE_CONV;
+      else
+	/* We're doing x.operator return_type().  */
+	strict = DEDUCE_EXACT;
       /* [over.match.funcs] For conversion functions, the function
 	 is considered to be a member of the class of the implicit
 	 object argument for the purpose of defining the type of
@@ -6318,6 +6327,10 @@ build_new_method_call (tree instance, tree fns, VEC(tree,gc) **args,
 	{
 	  if (!COMPLETE_TYPE_P (basetype))
 	    cxx_incomplete_type_error (instance_ptr, basetype);
+	  else if (optype)
+	    error ("no matching function for call to %<%T::operator %T(%A)%#V%>",
+		   basetype, optype, build_tree_list_vec (user_args),
+		   TREE_TYPE (TREE_TYPE (instance_ptr)));
 	  else
 	    {
 	      char *pretty_name;

gcc/cp/cp-tree.h

@@ -4109,8 +4109,8 @@ enum overload_flags { NO_SPECIAL = 0, DTOR_FLAG, TYPENAME_FLAG };
    have already generated a temporary, such as reference
    initialization and the catch parameter.  */
 #define DIRECT_BIND (1 << 4)
-/* User-defined conversions are not permitted.  (Built-in conversions
-   are permitted.)  */
+/* We're performing a user-defined conversion, so more user-defined
+   conversions are not permitted (only built-in conversions).  */
 #define LOOKUP_NO_CONVERSION (1 << 5)
 /* The user has explicitly called a destructor.  (Therefore, we do
    not need to check that the object is non-NULL before calling the

gcc/testsuite/ChangeLog

 2010-05-12  Jason Merrill  <jason@redhat.com>
 
+	* g++.dg/template/conv11.C: New.
+	* g++.dg/conversion/op1.C: Adjust expected error.
+
 	* g++.old-deja/g++.robertl/eb43.C: Prune "candidates" messages.
 
 2010-05-12  H.J. Lu  <hongjiu.lu@intel.com>

gcc/testsuite/g++.dg/conversion/op1.C

@@ -6,5 +6,5 @@ class C
 
 int fn (C c) 
 { 
-  return C::operator float(c); // { dg-error "operator U" }
+  return C::operator float(c); // { dg-error "operator float.C" }
 }

gcc/testsuite/g++.dg/template/conv11.C

+int i;
+struct A
+{
+  template <class T> operator T&() { return i; }
+};
+
+int main()
+{
+  A().operator int();		// { dg-error "operator int" }
+}