re PR c++/23293 (Misleading names in diagnostics for typedefs in functions)

	PR c++/23293
	* pt.c (convert_template_argument): Use canonical type variants in
	template specializations.
	PR c++/23293
	* g++.dg/template/error19.C: New test.

From-SVN: r105561

gcc/cp/ChangeLog

+2005-10-18  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/23293
+	* pt.c (convert_template_argument): Use canonical type variants in
+	template specializations.
+
 2005-10-18  Nathan Sidwell  <nathan@codesourcery.com>
 
 	PR c++/21383

gcc/cp/pt.c

@@ -3930,6 +3930,13 @@ convert_template_argument (tree parm,
 	}
       else
 	val = arg;
+      /* We only form one instance of each template specialization.
+	 Therefore, if we use a non-canonical variant (i.e., a
+	 typedef), any future messages referring to the type will use 
+	 the typedef, which is confusing if those future uses do not
+	 themselves also use the typedef.  */
+      if (TYPE_P (val))
+	val = canonical_type_variant (val);
     }
   else
     {

gcc/testsuite/ChangeLog

+2005-10-18  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/23293
+	* g++.dg/template/error19.C: New test.
+
 2005-10-18  Nathan Sidwell  <nathan@codesourcery.com>
 
 	PR c++/21383

gcc/testsuite/g++.dg/template/error19.C

+// PR c++/23293
+
+template < typename > struct P;
+struct S;
+
+void *unrelated_function()
+{
+  typedef S K;
+  P < K > * p;
+  return p;
+}
+
+template < typename U >
+void generate_warning()
+{ 
+  U::x(); // { dg-error "P<S>" }
+}
+
+int main()
+{
+  generate_warning< P < S > >();
+}