--- a/gcc/c/c-convert.c	2015-03-27 17:34:14.785358885 +0000
+++ b/gcc/c/c-convert.c	2015-03-27 17:34:20.190376731 +0000
@@ -87,7 +87,7 @@ convert (tree type, tree expr)
   if ((invalid_conv_diag
        = targetm.invalid_conversion (TREE_TYPE (expr), type)))
     {
-      error (invalid_conv_diag);
+      error ("%s", invalid_conv_diag);
       return error_mark_node;
     }
 
--- gcc-5.0.0-20150319/gcc-5.0.0-20150319/gcc/c/c-decl.c.orig	2015-03-27 17:39:20.946391721 +0000
+++ gcc-5.0.0-20150319/gcc-5.0.0-20150319/gcc/c/c-decl.c	2015-03-27 17:40:17.882591919 +0000
@@ -6074,7 +6074,7 @@ grokdeclarator (const struct c_declarato
 	    errmsg = targetm.invalid_return_type (type);
 	    if (errmsg)
 	      {
-		error (errmsg);
+		error ("%s", errmsg);
 		type = integer_type_node;
 	      }
 
@@ -6868,7 +6868,7 @@ grokparms (struct c_arg_info *arg_info,
 	  errmsg = targetm.invalid_parameter_type (type);
 	  if (errmsg)
 	    {
-	      error (errmsg);
+	      error ("%s", errmsg);
 	      TREE_VALUE (typelt) = error_mark_node;
 	      TREE_TYPE (parm) = error_mark_node;
 	      arg_types = NULL_TREE;