[project @ 2005-12-13 12:09:42 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 00c9e2f..7ad2e5a 100644 (file)
--- a/ghc/compiler/utils/Panic.lhs
+++ b/ghc/compiler/utils/Panic.lhs
@@ -11,16 +11,18 @@ some unnecessary loops in the module dependency graph.
 \begin{code}
 module Panic  
    ( 
-     GhcException(..), ghcError, progName, 
+     GhcException(..), showGhcException, ghcError, progName, 
+     pgmError,
+
      panic, panic#, assertPanic, trace,
-     showException, showGhcException, tryMost,
-     installSignalHandlers,
+     
+     Exception.Exception(..), showException, try, tryJust, tryMost, tryUser,
+     catchJust, ioErrors, throwTo,
 
-     catchJust, tryJust, ioErrors, throwTo,
+     installSignalHandlers, 
    ) where
 
 #include "HsVersions.h"
-#include "config.h"
 
 import Config
 import FastTypes
@@ -31,10 +33,12 @@ import System.Posix.Signals
 # else
 import Posix           ( Handler(Catch), installHandler, sigINT, sigQUIT )
 # endif /* GHC > 504 */
-
-import CONCURRENT      ( myThreadId )
 #endif /* mingw32_HOST_OS */
 
+#if defined(mingw32_HOST_OS) && __GLASGOW_HASKELL__ >= 603
+import GHC.ConsoleHandler
+#endif
+
 # if __GLASGOW_HASKELL__ < 500
 import EXCEPTION        ( raiseInThread )
 # else
@@ -45,10 +49,12 @@ import EXCEPTION    ( throwTo )
 import EXCEPTION       ( catchJust, tryJust, ioErrors )
 #endif
 
+import CONCURRENT      ( myThreadId )
 import DYNAMIC
 import qualified EXCEPTION as Exception
 import TRACE           ( trace )
 import UNSAFE_IO       ( unsafePerformIO )
+import IO              ( isUserError )
 
 import System
 \end{code}
@@ -117,9 +123,8 @@ 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"
-                ++ "or http://sourceforge.net/projects/ghc/.\n\n")
+                ++ "Please report this as a compiler bug.  See:\n"
+                ++ "  http://www.haskell.org/ghc/docs/latest/html/users_guide/bug-reporting.html\n")
 
 #if __GLASGOW_HASKELL__ < 603
 myMkTyConApp = mkAppTy
@@ -136,10 +141,11 @@ instance Typeable GhcException where
 Panics and asserts.
 
 \begin{code}
-panic :: String -> a
-panic x = Exception.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)
 
@@ -158,7 +164,7 @@ assertPanic file line =
 -- files, for example.
 
 tryMost :: IO a -> IO (Either Exception.Exception a)
-tryMost action = do r <- myTry action; filter r
+tryMost action = do r <- try action; filter r
   where
    filter (Left e@(Exception.DynException d))
            | Just ghc_ex <- fromDynamic d
@@ -169,17 +175,32 @@ tryMost action = do r <- myTry action; filter r
    filter other 
      = return other
 
-#if __GLASGOW_HASKELL__ <= 408
-myTry = Exception.tryAllIO
-#else
-myTry = Exception.try
+-- | 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
@@ -194,12 +215,28 @@ 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
+  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}