[project @ 2005-02-15 12:15:25 by simonmar]

ghc -e 'System.Exit.exitWith (System.Exit.ExitFailure 99)'

should just exit 99, rather than printing out the exception.  Also
while I'm here, make all other exceptions cause 'ghc -e' to exit(1),
which is probably what we want.

ghc/compiler/ghci/InteractiveUI.hs

 {-# OPTIONS -#include "Linker.h" #-}
 -----------------------------------------------------------------------------
--- $Id: InteractiveUI.hs,v 1.187 2005/02/04 13:32:28 simonmar Exp $
+-- $Id: InteractiveUI.hs,v 1.188 2005/02/15 12:15:25 simonmar Exp $
 --
 -- GHC Interactive User Interface
 --
@@ -58,6 +58,7 @@ import Data.Int		( Int64 )
 import System.Cmd
 import System.CPUTime
 import System.Environment
+import System.Exit	( exitWith, ExitCode(..) )
 import System.Directory
 import System.IO
 import System.IO.Error as IO
@@ -246,7 +247,7 @@ runGHCi paths dflags maybe_expr = do
 	    interactiveLoop is_tty show_prompt
 	Just expr -> do
 	    -- just evaluate the expression we were given
-	    runCommand expr
+	    runCommandEval expr
 	    return ()
 
   -- and finally, exit
@@ -356,6 +357,15 @@ readlineLoop = do
 runCommand :: String -> GHCi Bool
 runCommand c = ghciHandle handler (doCommand c)
 
+-- This version is for the GHC command-line option -e.  The only difference
+-- from runCommand is that it catches the ExitException exception and
+-- exits, rather than printing out the exception.
+runCommandEval c = ghciHandle handleEval (doCommand c)
+  where 
+    handleEval (ExitException code) = io (exitWith code)
+    handleEval e                    = do showException e
+				         io (exitWith (ExitFailure 1))
+
 -- This is the exception handler for exceptions generated by the
 -- user's code; it normally just prints out the exception.  The
 -- handler must be recursive, in case showing the exception causes
@@ -399,7 +409,7 @@ runStmt stmt
       setGHCiState st{cmstate = new_cmstate}
       case result of
 	CmRunFailed      -> return []
-	CmRunException e -> showException e >> return []
+	CmRunException e -> throw e  -- this is caught by runCommand(Eval)
 	CmRunOk names    -> return names
 
 -- possibly print the type and revert CAFs after evaluating an expression