X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Futils%2FPanic.lhs;h=01d1568c78145a5921690c8ee00466092eff703b;hb=1a4238bccc8be8a71f8ebec15f25d8edf8d084ad;hp=2c226999b1d351beccf89a8eec0755e06599a5a9;hpb=68fe53f5d8af4b405044f3e9a08e44824ad0ae52;p=ghc-hetmet.git

diff --git a/ghc/compiler/utils/Panic.lhs b/ghc/compiler/utils/Panic.lhs
index 2c22699..01d1568 100644
--- a/ghc/compiler/utils/Panic.lhs
+++ b/ghc/compiler/utils/Panic.lhs
@@ -1,5 +1,5 @@
 %
-% (c) The GRASP Project, Glasgow University, 1992-1998
+% (c) The GRASP Project, Glasgow University, 1992-2000
 %
 \section{Panic error messages}
 
@@ -9,27 +9,153 @@ It's hard to put these functions anywhere else without causing
 some unnecessary loops in the module dependency graph.
 
 \begin{code}
-module Panic  ( panic, panic#, assertPanic, trace ) where
+module Panic  
+   ( 
+     GhcException(..), ghcError, progName, 
+     panic, panic#, assertPanic, trace,
+     showException, showGhcException, tryMost,
 
-import IOExts ( trace )
+#if __GLASGOW_HASKELL__ <= 408
+     catchJust, ioErrors, throwTo,
+#endif
+   ) where
 
 #include "HsVersions.h"
+
+import Config
+import FastTypes
+
+import DYNAMIC
+import qualified EXCEPTION as Exception
+import TRACE		( trace )
+import UNSAFE_IO	( unsafePerformIO )
+
+import System
 \end{code}
 
+GHC's own exception type.
+
+\begin{code}
+ghcError :: GhcException -> a
+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		-- 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
+  | InstallationError String	-- an installation problem
+  | ProgramError String		-- error in the user's code, probably
+  deriving Eq
+
+progName = unsafePerformIO (getProgName)
+{-# NOINLINE progName #-}
+
+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
+
+showGhcException (UsageError str)
+   = showString str . showChar '\n' . showString short_usage
+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
+showGhcException (InstallationError str)
+   = showString str
+showGhcException (Interrupted)
+   = showString "interrupted"
+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")
+
+ghcExceptionTc = mkTyCon "GhcException"
+{-# NOINLINE ghcExceptionTc #-}
+instance Typeable GhcException where
+  typeOf _ = mkAppTy ghcExceptionTc []
+\end{code}
+
+Panics and asserts.
+
 \begin{code}
 panic :: String -> a
-panic x = error ("panic! (the `impossible' happened):\n\t"
-	      ++ x ++ "\n\n"
-	      ++ "Please report it as a compiler bug "
-	      ++ "to glasgow-haskell-bugs@dcs.gla.ac.uk.\n\n" )
+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)
 -- No, man -- Too Beautiful! (Will)
 
-panic# :: String -> FAST_INT
-panic# s = case (panic s) of () -> ILIT(0)
+panic# :: String -> FastInt
+panic# s = case (panic s) of () -> _ILIT 0
 
 assertPanic :: String -> Int -> a
-assertPanic file line = panic ("ASSERT failed! file " ++ file ++ ", line " ++ show line)
+assertPanic file line = 
+  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}