+
+-----------------------------------------
+-- Cut and pasted from ghc/compiler/SysTools
+
+#if defined(mingw32_HOST_OS)
+subst a b ls = map (\ x -> if x == a then b else x) ls
+unDosifyPath xs = subst '\\' '/' xs
+
+getExecDir :: String -> IO (Maybe String)
+-- (getExecDir cmd) returns the directory in which the current
+-- executable, which should be called 'cmd', is running
+-- So if the full path is /a/b/c/d/e, and you pass "d/e" as cmd,
+-- you'll get "/a/b/c" back as the result
+getExecDir cmd
+ = allocaArray len $ \buf -> do
+ ret <- getModuleFileName nullPtr buf len
+ if ret == 0 then return Nothing
+ else do s <- peekCString buf
+ return (Just (reverse (drop (length cmd)
+ (reverse (unDosifyPath s)))))
+ where
+ len = 2048::Int -- Plenty, PATH_MAX is 512 under Win32.
+
+foreign import stdcall "GetModuleFileNameA" unsafe
+ getModuleFileName :: Ptr () -> CString -> Int -> IO Int32
+#else
+getExecDir :: String -> IO (Maybe String)
+getExecDir _ = return Nothing
+#endif