FFI: Define ForeignSrc when FFI disabled

src/Cryptol/Backend/FFI.hs

@@ -1,5 +1,7 @@
 {-# LANGUAGE BlockArguments            #-}
 {-# LANGUAGE CPP                       #-}
+{-# LANGUAGE DeriveAnyClass            #-}
+{-# LANGUAGE DeriveGeneric             #-}
 {-# LANGUAGE ExistentialQuantification #-}
 {-# LANGUAGE LambdaCase                #-}
 {-# LANGUAGE RecordWildCards           #-}
@@ -9,24 +11,27 @@
 -- | The implementation of loading and calling external functions from shared
 -- libraries. Currently works on Unix only.
 module Cryptol.Backend.FFI
-#ifdef FFI_ENABLED
   ( ForeignSrc
   , loadForeignSrc
   , unloadForeignSrc
+#ifdef FFI_ENABLED
   , ForeignImpl
   , loadForeignImpl
   , FFIArg
   , FFIRet
   , SomeFFIArg (..)
   , callForeignImpl
-  )
 #endif
+  )
   where
 
+import           Control.DeepSeq
+
+import           Cryptol.Backend.FFI.Error
+
 #ifdef FFI_ENABLED
 
 import           Control.Concurrent.MVar
-import           Control.DeepSeq
 import           Control.Exception
 import           Control.Monad
 import           Data.Bifunctor
@@ -39,9 +44,16 @@ import           System.FilePath            ((-<.>))
 import           System.IO.Error
 import           System.Posix.DynamicLinker
 
-import           Cryptol.Backend.FFI.Error
 import           Cryptol.Utils.Panic
 
+#else
+
+import           GHC.Generics
+
+#endif
+
+#ifdef FFI_ENABLED
+
 -- | A source from which we can retrieve implementations of foreign functions.
 data ForeignSrc = ForeignSrc
   { -- | The 'ForeignPtr' wraps the pointer returned by 'dlopen', where the
@@ -200,4 +212,14 @@ callForeignImpl ForeignImpl {..} xs = withForeignSrc foreignImplSrc \_ ->
   callFFI foreignImplFun (ffiRet @a) $ map toArg xs
   where toArg (SomeFFIArg x) = ffiArg x
 
+#else
+
+data ForeignSrc = ForeignSrc deriving (Show, Generic, NFData)
+
+loadForeignSrc :: FilePath -> IO (Either FFILoadError ForeignSrc)
+loadForeignSrc _ = pure $ Right ForeignSrc
+
+unloadForeignSrc :: ForeignSrc -> IO ()
+unloadForeignSrc _ = pure ()
+
 #endif

src/Cryptol/Eval/FFI.hs

@@ -15,6 +15,7 @@ module Cryptol.Eval.FFI
   ( evalForeignDecls
   ) where
 
+import           Cryptol.Backend.FFI
 import           Cryptol.Backend.FFI.Error
 import           Cryptol.Eval
 import           Cryptol.ModuleSystem.Env
@@ -36,7 +37,6 @@ import           LibBF                           (bfFromDouble, bfToDouble,
 import           System.Directory
 
 import           Cryptol.Backend.Concrete
-import           Cryptol.Backend.FFI
 import           Cryptol.Backend.FloatHelpers
 import           Cryptol.Backend.Monad
 import           Cryptol.Backend.SeqMap
@@ -276,7 +276,7 @@ withWordType FFIWord64 f = f $ Proxy @Word64
 -- | Dummy implementation for when FFI is disabled. Does not add anything to
 -- the environment.
 evalForeignDecls :: ModulePath -> Module -> EvalEnv ->
-  Eval (Either [FFILoadError] EvalEnv)
-evalForeignDecls _ _ env = pure $ Right env
+  Eval (Either [FFILoadError] (ForeignSrc, EvalEnv))
+evalForeignDecls _ _ _ = pure $ Left []
 
 #endif