Use a proper exception for IOEnvFailure, not just a UserError

[ghc-hetmet.git] / compiler / typecheck / TcSplice.lhs

diff --git a/compiler/typecheck/TcSplice.lhs b/compiler/typecheck/TcSplice.lhs
index 6d33b16..b4cb316 100644 (file)
--- a/compiler/typecheck/TcSplice.lhs
+++ b/compiler/typecheck/TcSplice.lhs
@@ -596,15 +596,9 @@ runMeta convert expr
            Right v -> return v
            Left se ->
                     case fromException se of
-                    Just (ErrorCall "IOEnv failure") ->
+                    Just IOEnvFailure ->
                         failM -- Error already in Tc monad
-                    _ ->
-                        case fromException se of
-                        Just ioe
-                         | isUserError ioe &&
-                           (ioeGetErrorString ioe == "IOEnv failure") ->
-                            failM -- Error already in Tc monad
-                        _ -> failWithTc (mk_msg "run" se)      -- Exception
+                    _ -> failWithTc (mk_msg "run" se)  -- Exception
         }}}
   where
     mk_msg s exn = vcat [text "Exception when trying to" <+> text s <+> text "compile-time code:",
@@ -633,11 +627,10 @@ like that.  Here's how it's processed:
 
   * The TcM monad is an instance of Quasi (see TcSplice), and it implements
     (qReport True s) by using addErr to add an error message to the bag of errors.
-    The 'fail' in TcM raises a UserError, with the uninteresting string
-       "IOEnv failure"
+    The 'fail' in TcM raises an IOEnvFailure exception
 
   * So, when running a splice, we catch all exceptions; then for 
-       - a UserError "IOEnv failure", we assume the error is already 
+       - an IOEnvFailure exception, we assume the error is already 
                in the error-bag (above)
        - other errors, we add an error to the bag
     and then fail