[project @ 2004-08-13 13:04:50 by simonmar]

[ghc-hetmet.git] / ghc / compiler / utils / Panic.lhs

diff --git a/ghc/compiler/utils/Panic.lhs b/ghc/compiler/utils/Panic.lhs
index 1f677fc..2a5d3a4 100644 (file)
--- a/ghc/compiler/utils/Panic.lhs
+++ b/ghc/compiler/utils/Panic.lhs
@@ -13,16 +13,40 @@ module Panic
    ( 
      GhcException(..), ghcError, progName, 
      panic, panic#, assertPanic, trace,
-     showException, showGhcException, throwDyn
+     showException, showGhcException, tryMost,
+     installSignalHandlers,
+
+     catchJust, tryJust, ioErrors, throwTo,
    ) where
 
 #include "HsVersions.h"
+#include "../includes/ghcconfig.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 */
+
+import CONCURRENT      ( myThreadId )
+#endif /* mingw32_HOST_OS */
+
+# 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 DYNAMIC
-import EXCEPTION
+import qualified EXCEPTION as Exception
 import TRACE           ( trace )
 import UNSAFE_IO       ( unsafePerformIO )
 
@@ -33,7 +57,7 @@ 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
 --
@@ -60,11 +84,11 @@ progName = unsafePerformIO (getProgName)
 
 short_usage = "Usage: For basic information, try the `--help' option."
    
-showException :: Exception -> String
+showException :: Exception.Exception -> String
 -- Show expected dynamic exceptions specially
-showException (DynException d) | Just e <- fromDynamic d 
-                              = show (e::GhcException)
-showException other_exn               = show other_exn
+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
@@ -97,17 +121,23 @@ showGhcException (Panic s)
                 ++ "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 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)
@@ -118,6 +148,58 @@ panic# s = case (panic s) of () -> _ILIT 0
 
 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
+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}