Index: par-ch6.adb
===================================================================
--- par-ch6.adb	(revision 179984)
+++ par-ch6.adb	(working copy)
@@ -1677,6 +1677,14 @@
          Scan; -- past ALIASED
          Set_Aliased_Present (Decl_Node);
 
+         if Ada_Version < Ada_2012 then
+            Error_Msg_SC -- CODEFIX
+              ("ALIASED not allowed in extended return in Ada2012?");
+         else
+            Error_Msg_SC -- CODEFIX
+              ("ALIASED not allowed in extended return");
+         end if;
+
          if Token = Tok_Constant then
             Scan; -- past CONSTANT
             Set_Constant_Present (Decl_Node);