module Panic
(
GhcException(..), ghcError, progName,
- panic, panic#, assertPanic, trace
+ panic, panic#, assertPanic, trace,
+ showException, showGhcException, tryMost,
+
+#if __GLASGOW_HASKELL__ <= 408
+ catchJust, ioErrors, throwTo,
+#endif
) where
+#include "HsVersions.h"
+
+import Config
import FastTypes
-import Dynamic
-import IOExts
-import Exception
+import DYNAMIC
+import qualified EXCEPTION as Exception
+import TRACE ( trace )
+import UNSAFE_IO ( unsafePerformIO )
import System
-#include "HsVersions.h"
\end{code}
GHC's own exception type.
\begin{code}
ghcError :: GhcException -> a
-ghcError e = throwDyn e
+ghcError e = Exception.throwDyn e
+
+-- error messages all take the form
+--
+-- <location>: <error>
+--
+-- If the location is on the command line, or in GHC itself, then
+-- <location>="ghc". All of the error types below correspond to
+-- a <location> of "ghc", except for ProgramError (where the string is
+-- assumed to contain a location already, so we don't print one).
data GhcException
- = PhaseFailed String ExitCode
- | Interrupted
+ = PhaseFailed String -- name of phase
+ ExitCode -- an external phase (eg. cpp) failed
+ | Interrupted -- someone pressed ^C
| UsageError String -- prints the short usage msg after the error
+ | CmdLineError String -- cmdline prob, but doesn't print usage
| Panic String -- the `impossible' happened
- | OtherError String -- just prints the error message
+ | InstallationError String -- an installation problem
+ | ProgramError String -- error in the user's code, probably
deriving Eq
progName = unsafePerformIO (getProgName)
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 = showString progName . showString ": " . showBarf e
+ showsPrec _ e@(ProgramError _) = showGhcException e
+ showsPrec _ e = showString progName . showString ": " . showGhcException e
-showBarf (UsageError str)
+showGhcException (UsageError str)
= showString str . showChar '\n' . showString short_usage
-showBarf (OtherError str)
+showGhcException (PhaseFailed phase code)
+ = showString "phase `" . showString phase .
+ showString "' failed (exitcode = " . shows int_code .
+ showString ")"
+ where
+ int_code =
+ case code of
+ ExitSuccess -> (0::Int)
+ ExitFailure x -> x
+showGhcException (CmdLineError str)
+ = showString str
+showGhcException (ProgramError str)
= showString str
-showBarf (PhaseFailed phase code)
- = showString phase . showString " failed, code = " . shows code
-showBarf (Interrupted)
+showGhcException (InstallationError str)
+ = showString str
+showGhcException (Interrupted)
= showString "interrupted"
-showBarf (Panic s)
- = showString ("panic! (the `impossible' happened):\n\t"
+showGhcException (Panic s)
+ = showString ("panic! (the `impossible' happened, GHC version "
+ ++ cProjectVersion ++ "):\n\t"
++ s ++ "\n\n"
++ "Please report it as a compiler bug "
- ++ "to glasgow-haskell-bugs@haskell.org.\n\n")
+ ++ "to glasgow-haskell-bugs@haskell.org,\n"
+ ++ "or http://sourceforge.net/projects/ghc/.\n\n")
ghcExceptionTc = mkTyCon "GhcException"
{-# NOINLINE ghcExceptionTc #-}
\begin{code}
panic :: String -> a
-panic x = throwDyn (Panic x)
+panic x = Exception.throwDyn (Panic x)
-- #-versions because panic can't return an unboxed int, and that's
-- what TAG_ is with GHC at the moment. Ugh. (Simon)
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 <- 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
+ioErrors = Exception.justIoErrors
+throwTo = Exception.raiseInThread
+#endif
+\end{code}