re PR c++/58504 (ICE with type trait as default template parameter)

	PR c++/58504
	* pt.c (tsubst_copy_and_build) [TRAIT_EXPR]: Use tsubst for
	types.

From-SVN: r207168

gcc/cp/ChangeLog

 2014-01-27  Jason Merrill  <jason@redhat.com>
 
+	PR c++/58504
+	* pt.c (tsubst_copy_and_build) [TRAIT_EXPR]: Use tsubst for
+	types.
+
 	PR c++/58606
 	* pt.c (template_parm_to_arg): Call convert_from_reference.
 	(tsubst_template_arg): Don't strip reference refs.

gcc/cp/pt.c

@@ -14974,12 +14974,12 @@ tsubst_copy_and_build (tree t,
 
     case TRAIT_EXPR:
       {
-	tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
-				  complain, in_decl);
+	tree type1 = tsubst (TRAIT_EXPR_TYPE1 (t), args,
+			     complain, in_decl);
 
 	tree type2 = TRAIT_EXPR_TYPE2 (t);
 	if (type2)
-	  type2 = tsubst_copy (type2, args, complain, in_decl);
+	  type2 = tsubst (type2, args, complain, in_decl);
 	
 	RETURN (finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2));
       }

gcc/testsuite/g++.dg/ext/traits1.C

+// PR c++/58504
+
+template<bool = __has_nothrow_assign(void)> struct A {};
+A<> a;