trans.c (Attribute_to_gnu): Abort instead of erroring out for an unimplemented attribute.

	* gcc-interface/trans.c (Attribute_to_gnu): Abort instead of erroring
	out for an unimplemented attribute.

From-SVN: r196507

gcc/ada/ChangeLog

 2013-03-06  Eric Botcazou  <ebotcazou@adacore.com>
 
+	* gcc-interface/trans.c (Attribute_to_gnu): Abort instead of erroring
+	out for an unimplemented attribute.
+
+2013-03-06  Eric Botcazou  <ebotcazou@adacore.com>
+
 	* gcc-interface/decl.c (gnat_to_gnu_field): Remove the wrapper around
 	a misaligned integral type if a size is specified for the field.
 

gcc/ada/gcc-interface/trans.c

@@ -2066,13 +2066,8 @@ Attribute_to_gnu (Node_Id gnat_node, tree *gnu_result_type_p, int attribute)
       break;
 
     default:
-      /* Say we have an unimplemented attribute.  Then set the value to be
-	 returned to be a zero and hope that's something we can convert to
-	 the type of this attribute.  */
-      post_error ("unimplemented attribute", gnat_node);
-      gnu_result_type = get_unpadded_type (Etype (gnat_node));
-      gnu_result = integer_zero_node;
-      break;
+      /* This abort means that we have an unimplemented attribute.  */
+      gcc_unreachable ();
     }
 
   /* If this is an attribute where the prefix was unused, force a use of it if