Follow changes in the base library

[ghc-hetmet.git] / compiler / main / ErrUtils.lhs

diff --git a/compiler/main/ErrUtils.lhs b/compiler/main/ErrUtils.lhs
index d6cb5d0..d4e8e8f 100644 (file)
--- a/compiler/main/ErrUtils.lhs
+++ b/compiler/main/ErrUtils.lhs
@@ -8,7 +8,7 @@ module ErrUtils (
        Message, mkLocMessage, printError,
        Severity(..),
 
-       ErrMsg, WarnMsg,
+       ErrMsg, WarnMsg, throwErrMsg, handleErrMsg,
        errMsgSpans, errMsgContext, errMsgShortDoc, errMsgExtraInfo,
        Messages, errorsFound, emptyMessages,
        mkErrMsg, mkWarnMsg, mkPlainErrMsg, mkLongErrMsg,
@@ -44,6 +44,7 @@ import System.Exit    ( ExitCode(..), exitWith )
 import Data.Dynamic
 import Data.List
 import System.IO
+import Exception
 
 -- -----------------------------------------------------------------------------
 -- Basic error messages: just render a message with a source location.
@@ -81,6 +82,27 @@ data ErrMsg = ErrMsg {
        -- NB  Pretty.Doc not SDoc: we deal with the printing style (in ptic 
        -- whether to qualify an External Name) at the error occurrence
 
+#if __GLASGOW_HASKELL__ >= 609
+instance Exception ErrMsg
+#endif
+
+instance Show ErrMsg where
+    show em = showSDoc (errMsgShortDoc em)
+
+throwErrMsg :: ErrMsg -> a
+#if __GLASGOW_HASKELL__ < 609
+throwErrMsg = throwDyn
+#else
+throwErrMsg = throw
+#endif
+
+handleErrMsg :: (ErrMsg -> IO a) -> IO a -> IO a
+#if __GLASGOW_HASKELL__ < 609
+handleErrMsg = flip catchDyn
+#else
+handleErrMsg = handle
+#endif
+
 -- So we can throw these things as exceptions
 errMsgTc :: TyCon
 errMsgTc = mkTyCon "ErrMsg"