Move loader state into Interp

The loader state was stored into HscEnv. As we need to have two
interpreters and one loader state per interpreter in #14335, it's
natural to make the loader state a field of the Interp type.

As a side effect, many functions now only require a Interp parameter
instead of HscEnv. Sadly we can't fully free GHC.Linker.Loader of HscEnv
yet because the loader is initialised lazily from the HscEnv the first
time it is used. This is left as future work.

HscEnv may not contain an Interp value (i.e. hsc_interp :: Maybe Interp).
So a side effect of the previous side effect is that callers of the
modified functions now have to provide an Interp. It is satisfying as it
pushes upstream the handling of the case where HscEnv doesn't contain an
Interpreter. It is better than raising a panic (less partial functions,
"parse, don't validate", etc.).

1 files changed, 8 insertions, 5 deletions

diff --git a/compiler/GHC.hs b/compiler/GHC.hs
index 9d2d6fb65f..7a237b2146 100644
--- a/compiler/GHC.hs
+++ b/compiler/GHC.hs
@@ -319,11 +319,11 @@ import GHC.Driver.Monad
 import GHC.Driver.Ppr
 
 import GHC.ByteCode.Types
+import qualified GHC.Linker.Loader as Loader
 import GHC.Runtime.Loader
 import GHC.Runtime.Eval
 import GHC.Runtime.Eval.Types
 import GHC.Runtime.Interpreter
-import GHC.Runtime.Interpreter.Types
 import GHC.Runtime.Context
 import GHCi.RemoteTypes
 
@@ -535,7 +535,7 @@ withCleanupSession ghc = ghc `MC.finally` cleanup
       liftIO $ do
           cleanTempFiles logger tmpfs dflags
           cleanTempDirs logger tmpfs dflags
-          stopInterp hsc_env -- shut down the IServ
+          traverse_ stopInterp (hsc_interp hsc_env)
           --  exceptions will be blocked while we clean the temporary files,
           -- so there shouldn't be any difficulty if we receive further
           -- signals.
@@ -642,7 +642,7 @@ setSessionDynFlags dflags0 = do
   (dbs,unit_state,home_unit) <- liftIO $ initUnits logger dflags (hsc_unit_dbs hsc_env)
 
   -- Interpreter
-  interp  <- if gopt Opt_ExternalInterpreter dflags
+  interp <- if gopt Opt_ExternalInterpreter dflags
     then do
          let
            prog = pgm_i dflags ++ flavour
@@ -666,10 +666,13 @@ setSessionDynFlags dflags0 = do
             , iservConfTrace    = tr
             }
          s <- liftIO $ newMVar IServPending
-         return (Just (ExternalInterp conf (IServ s)))
+         loader <- liftIO Loader.uninitializedLoader
+         return (Just (Interp (ExternalInterp conf (IServ s)) loader))
     else
 #if defined(HAVE_INTERNAL_INTERPRETER)
-      return (Just InternalInterp)
+     do
+      loader <- liftIO Loader.uninitializedLoader
+      return (Just (Interp InternalInterp loader))
 #else
       return Nothing
 #endif