\begin{code}
module Panic
(
- GhcException(..), ghcError, progName,
+ GhcException(..), showGhcException, ghcError, progName,
+ pgmError,
+
panic, panic#, assertPanic, trace,
- showGhcException
+
+ Exception.Exception(..), showException, try, tryJust, tryMost, tryUser,
+ catchJust, ioErrors, throwTo,
+
+ installSignalHandlers,
) where
#include "HsVersions.h"
import Config
import FastTypes
+#ifndef mingw32_HOST_OS
+# if __GLASGOW_HASKELL__ > 504
+import System.Posix.Signals
+# else
+import Posix ( Handler(Catch), installHandler, sigINT, sigQUIT )
+# endif /* GHC > 504 */
+#endif /* mingw32_HOST_OS */
+
+#if defined(mingw32_HOST_OS) && __GLASGOW_HASKELL__ >= 603
+import GHC.ConsoleHandler
+#endif
+
+# if __GLASGOW_HASKELL__ < 500
+import EXCEPTION ( raiseInThread )
+# else
+import EXCEPTION ( throwTo )
+# endif /* GHC < 500 */
+
+#if __GLASGOW_HASKELL__ > 408
+import EXCEPTION ( catchJust, tryJust, ioErrors )
+#endif
+
+import CONCURRENT ( myThreadId )
import DYNAMIC
-import EXCEPTION
+import qualified EXCEPTION as Exception
import TRACE ( trace )
import UNSAFE_IO ( unsafePerformIO )
+import IO ( isUserError )
import System
\end{code}
\begin{code}
ghcError :: GhcException -> a
-ghcError e = throwDyn e
+ghcError e = Exception.throwDyn e
-- error messages all take the form
--
short_usage = "Usage: For basic information, try the `--help' option."
+showException :: Exception.Exception -> String
+-- Show expected dynamic exceptions specially
+showException (Exception.DynException d) | Just e <- fromDynamic d
+ = show (e::GhcException)
+showException other_exn = show other_exn
+
instance Show GhcException where
showsPrec _ e@(ProgramError _) = showGhcException e
showsPrec _ e = showString progName . showString ": " . showGhcException e
++ "to glasgow-haskell-bugs@haskell.org,\n"
++ "or http://sourceforge.net/projects/ghc/.\n\n")
+#if __GLASGOW_HASKELL__ < 603
+myMkTyConApp = mkAppTy
+#else
+myMkTyConApp = mkTyConApp
+#endif
+
ghcExceptionTc = mkTyCon "GhcException"
{-# NOINLINE ghcExceptionTc #-}
instance Typeable GhcException where
- typeOf _ = mkAppTy ghcExceptionTc []
+ typeOf _ = myMkTyConApp ghcExceptionTc []
\end{code}
Panics and asserts.
\begin{code}
-panic :: String -> a
-panic x = throwDyn (Panic x)
+panic, pgmError :: String -> a
+panic x = Exception.throwDyn (Panic x)
+pgmError x = Exception.throwDyn (ProgramError x)
--- #-versions because panic can't return an unboxed int, and that's
+-- #-versions because panic can't return an unboxed int, and that's
-- what TAG_ is with GHC at the moment. Ugh. (Simon)
-- No, man -- Too Beautiful! (Will)
assertPanic :: String -> Int -> a
assertPanic file line =
- throw (AssertionFailed
+ Exception.throw (Exception.AssertionFailed
("ASSERT failed! file " ++ file ++ ", line " ++ show line))
\end{code}
+
+\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 <- try 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
+
+-- | tryUser is like try, but catches only UserErrors.
+-- These are the ones that are thrown by the TcRn monad
+-- to signal an error in the program being compiled
+tryUser :: IO a -> IO (Either Exception.Exception a)
+tryUser action = tryJust tc_errors action
+ where
+#if __GLASGOW_HASKELL__ > 504 || __GLASGOW_HASKELL__ < 500
+ tc_errors e@(Exception.IOException ioe) | isUserError ioe = Just e
+#elif __GLASGOW_HASKELL__ == 502
+ tc_errors e@(UserError _) = Just e
+#else
+ tc_errors e@(Exception.IOException ioe) | isUserError e = Just e
+#endif
+ tc_errors _other = Nothing
+\end{code}
+
+Compatibility stuff:
+
+\begin{code}
+#if __GLASGOW_HASKELL__ <= 408
+try = Exception.tryAllIO
+#else
+try = Exception.try
+#endif
+
+#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
+ main_thread <- myThreadId
+ let
+ interrupt_exn = Exception.DynException (toDyn Interrupted)
+ interrupt = throwTo main_thread interrupt_exn
+ --
+#if !defined(mingw32_HOST_OS)
+ installHandler sigQUIT (Catch interrupt) Nothing
+ installHandler sigINT (Catch interrupt) Nothing
+ return ()
+#elif __GLASGOW_HASKELL__ >= 603
+ -- GHC 6.3+ has support for console events on Windows
+ -- NOTE: running GHCi under a bash shell for some reason requires
+ -- you to press Ctrl-Break rather than Ctrl-C to provoke
+ -- an interrupt. Ctrl-C is getting blocked somewhere, I don't know
+ -- why --SDM 17/12/2004
+ let sig_handler ControlC = interrupt
+ sig_handler Break = interrupt
+ sig_handler _ = return ()
+
+ installHandler (Catch sig_handler)
+ return ()
+#else
+ return () -- nothing
+#endif
+\end{code}