Add a class HasDynFlags(getDynFlags)

We no longer have many separate, clashing getDynFlags functions

I've given each GhcMonad its own HasDynFlags instance, rather than
using UndecidableInstances to make a GhcMonad m => HasDynFlags m
instance.

1 files changed, 7 insertions, 2 deletions

diff --git a/compiler/main/GhcMonad.hs b/compiler/main/GhcMonad.hs
index 816cc4b922..6b8c7bacdf 100644
--- a/compiler/main/GhcMonad.hs
+++ b/compiler/main/GhcMonad.hs
@@ -46,11 +46,10 @@ import Data.IORef
 -- If you do not use 'Ghc' or 'GhcT', make sure to call 'GHC.initGhcMonad'
 -- before any call to the GHC API functions can occur.
 --
-class (Functor m, MonadIO m, ExceptionMonad m) => GhcMonad m where
+class (Functor m, MonadIO m, ExceptionMonad m, HasDynFlags m) => GhcMonad m where
   getSession :: m HscEnv
   setSession :: HscEnv -> m ()
 
-
 -- | Call the argument with the current session.
 withSession :: GhcMonad m => (HscEnv -> m a) -> m a
 withSession f = getSession >>= f
@@ -120,6 +119,9 @@ instance ExceptionMonad Ghc where
                              in
                                 unGhc (f g_restore) s
 
+instance HasDynFlags Ghc where
+  getDynFlags = getSessionDynFlags
+
 instance GhcMonad Ghc where
   getSession = Ghc $ \(Session r) -> readIORef r
   setSession s' = Ghc $ \(Session r) -> writeIORef r s'
@@ -176,6 +178,9 @@ instance ExceptionMonad m => ExceptionMonad (GhcT m) where
                            in
                               unGhcT (f g_restore) s
 
+instance (Functor m, ExceptionMonad m, MonadIO m) => HasDynFlags (GhcT m) where
+  getDynFlags = getSessionDynFlags
+
 instance (Functor m, ExceptionMonad m, MonadIO m) => GhcMonad (GhcT m) where
   getSession = GhcT $ \(Session r) -> liftIO $ readIORef r
   setSession s' = GhcT $ \(Session r) -> liftIO $ writeIORef r s'