+
+\begin{code}
+-- | tryMost is like try, but passes through Interrupted and Panic
+-- exceptions. Used when we want soft failures when reading interface
+-- files, for example.
+
+tryMost :: IO a -> IO (Either Exception.Exception a)
+tryMost action = do r <- myTry action; filter r
+ where
+ filter (Left e@(Exception.DynException d))
+ | Just ghc_ex <- fromDynamic d
+ = case ghc_ex of
+ Interrupted -> Exception.throw e
+ Panic _ -> Exception.throw e
+ _other -> return (Left e)
+ filter other
+ = return other
+
+#if __GLASGOW_HASKELL__ <= 408
+myTry = Exception.tryAllIO
+#else
+myTry = Exception.try
+#endif
+\end{code}
+
+Compatibility stuff:
+
+\begin{code}
+#if __GLASGOW_HASKELL__ <= 408
+catchJust = Exception.catchIO
+tryJust = Exception.tryIO
+ioErrors = Exception.justIoErrors
+throwTo = Exception.raiseInThread
+#endif
+\end{code}
+
+Standard signal handlers for catching ^C, which just throw an
+exception in the main thread. NOTE: must be called from the main
+thread.
+
+\begin{code}
+installSignalHandlers :: IO ()
+installSignalHandlers = do
+#ifndef mingw32_HOST_OS
+ main_thread <- myThreadId
+ let sig_handler = Catch (throwTo main_thread
+ (Exception.DynException (toDyn Interrupted)))
+ installHandler sigQUIT sig_handler Nothing
+ installHandler sigINT sig_handler Nothing
+#endif
+ return ()
+\end{code}