[project @ 2005-04-26 00:08:17 by sof]

runSomething: 'rawSystem' might raise an exception to indicate that
'pgm' couldn't be executed, so catch this here & report.

Merge to STABLE.

diff --git a/ghc/compiler/main/SysTools.lhs b/ghc/compiler/main/SysTools.lhs
index e94ca9d..1124728 100644 (file)
--- a/ghc/compiler/main/SysTools.lhs
+++ b/ghc/compiler/main/SysTools.lhs
@@ -61,8 +61,8 @@ import DATA_INT
 import Monad           ( when, unless )
 import System          ( ExitCode(..), getEnv, system )
 import IO              ( try, catch,
-                         openFile, hPutStr, hClose, hFlush, IOMode(..),
-                         stderr )
+                         openFile, hPutStr, hClose, hFlush, IOMode(..), 
+                         stderr, ioError, isDoesNotExistError )
 import Directory       ( doesFileExist, removeFile )
 import List             ( partition )
 
@@ -88,6 +88,8 @@ import CString                ( CString, peekCString )
 #if __GLASGOW_HASKELL__ < 603
 -- rawSystem comes from libghccompat.a in stage1
 import Compat.RawSystem        ( rawSystem )
+import GHC.IOBase       ( IOErrorType(..) ) 
+import System.IO.Error  ( ioeGetErrorType )
 #else
 import System.Cmd      ( rawSystem )
 #endif
@@ -596,19 +598,36 @@ runSomething :: DynFlags
 runSomething dflags phase_name pgm args = do
   let real_args = filter notNull (map showOpt args)
   traceCmd dflags phase_name (unwords (pgm:real_args)) $ do
-  exit_code <- rawSystem pgm real_args
-  case exit_code of
-     ExitSuccess -> 
-       return ()
-     -- rawSystem returns (ExitFailure 127) if the exec failed for any
-     -- reason (eg. the program doesn't exist).  This is the only clue
-     -- we have, but we need to report something to the user because in
-     -- the case of a missing program there will otherwise be no output
-     -- at all.
-     ExitFailure 127 -> 
-       throwDyn (InstallationError ("could not execute: " ++ pgm))
-     ExitFailure _other ->
-       throwDyn (PhaseFailed phase_name exit_code)
+  (exit_code, doesn'tExist) <- 
+     IO.catch (do
+         rc <- rawSystem pgm real_args
+        case rc of
+          ExitSuccess{} -> return (rc, False)
+          ExitFailure n 
+             -- rawSystem returns (ExitFailure 127) if the exec failed for any
+             -- reason (eg. the program doesn't exist).  This is the only clue
+             -- we have, but we need to report something to the user because in
+             -- the case of a missing program there will otherwise be no output
+             -- at all.
+           | n == 127  -> return (rc, True)
+           | otherwise -> return (rc, False))
+               -- Should 'rawSystem' generate an IO exception indicating that
+               -- 'pgm' couldn't be run rather than a funky return code, catch
+               -- this here (the win32 version does this, but it doesn't hurt
+               -- to test for this in general.)
+              (\ err -> 
+               if IO.isDoesNotExistError err 
+#if defined(mingw32_HOST_OS) && __GLASGOW_HASKELL__ < 604
+               -- the 'compat' version of rawSystem under mingw32 always
+               -- maps 'errno' to EINVAL to failure.
+                  || case (ioeGetErrorType err ) of { InvalidArgument{} -> True ; _ -> False}
+#endif
+                then return (ExitFailure 1, True)
+                else IO.ioError err)
+  case (doesn'tExist, exit_code) of
+     (True, _)        -> throwDyn (InstallationError ("could not execute: " ++ pgm))
+     (_, ExitSuccess) -> return ()
+     _                -> throwDyn (PhaseFailed phase_name exit_code)
 
 showOpt (FileOption pre f) = pre ++ platformPath f
 showOpt (Option "") = ""