type check.

Types.hs

@@ -1,19 +1,57 @@
 module Types where
 
+import Control.Monad
+import DynFlags
 import Exception
 import GHC
 import GHC.Paths (libdir)
 
+----------------------------------------------------------------
+
 data Options = Options {
     convert   :: [String] -> String
   , hlintOpts :: [String]
   }
 
-withGHC :: Ghc [String] -> IO [String]
+withGHC :: (MonadPlus m) => Ghc (m a) -> IO (m a)
 withGHC body = ghandle ignore $ runGhc (Just libdir) body
   where
-    ignore :: SomeException -> IO [String]
-    ignore _ = return []
+    ignore :: (MonadPlus m) => SomeException -> IO (m a)
+    ignore _ = return mzero
+
+----------------------------------------------------------------
 
 initSession0 :: Ghc [PackageId]
 initSession0 = getSessionDynFlags >>= setSessionDynFlags
+
+initSession :: [String] -> Ghc [PackageId]
+initSession cmdOpts = do
+    dflags <- getSessionDynFlags
+    let opts = map noLoc cmdOpts
+    (dflags',_,_) <- parseDynamicFlags dflags opts
+    setSessionDynFlags $ setFlags dflags'
+
+----------------------------------------------------------------
+
+setFlags :: DynFlags -> DynFlags
+setFlags d = d {
+    importPaths = importPaths d ++ importDirs
+  , packageFlags = ghcPackage : packageFlags d
+  , ghcLink = NoLink
+-- GHC.desugarModule does not produces the pattern warnings, why?
+--  , hscTarget = HscNothing
+  , hscTarget = HscInterpreted
+  }
+
+importDirs :: [String]
+importDirs = ["..","../..","../../..","../../../../.."]
+
+ghcPackage :: PackageFlag
+ghcPackage = ExposePackage "ghc"
+
+----------------------------------------------------------------
+
+setTargetFile :: (GhcMonad m) => String -> m ()
+setTargetFile file = do
+    target <- guessTarget file Nothing
+    setTargets [target]