Revert "Allow use of the external interpreter in stage1."

This reverts commit 52ba9470a7e85d025dc84a6789aa809cdd68b566.

33 files changed, 405 insertions, 195 deletions

diff --git a/compiler/deSugar/Coverage.hs b/compiler/deSugar/Coverage.hs
index 1f6effa6b9..51bfb1811d 100644
--- a/compiler/deSugar/Coverage.hs
+++ b/compiler/deSugar/Coverage.hs
@@ -7,14 +7,12 @@
 
 module Coverage (addTicksToBinds, hpcInitCode) where
 
+#ifdef GHCI
 import qualified GHCi
 import GHCi.RemoteTypes
 import Data.Array
 import ByteCodeTypes
-#if MIN_VERSION_base(4,9,0)
 import GHC.Stack.CCS
-#else
-import GHC.Stack as GHC.Stack.CCS
 #endif
 import Type
 import HsSyn
@@ -131,6 +129,9 @@ guessSourceFile binds orig_file =
 
 
 mkModBreaks :: HscEnv -> Module -> Int -> [MixEntry_] -> IO ModBreaks
+#ifndef GHCI
+mkModBreaks _hsc_env _mod _count _entries = return emptyModBreaks
+#else
 mkModBreaks hsc_env mod count entries
   | HscInterpreted <- hscTarget (hsc_dflags hsc_env) = do
     breakArray <- GHCi.newBreakArray hsc_env (length entries)
@@ -164,6 +165,7 @@ mkCCSArray hsc_env modul count entries = do
     mk_one (srcspan, decl_path, _, _) = (name, src)
       where name = concat (intersperse "." decl_path)
             src = showSDoc dflags (ppr srcspan)
+#endif
 
 
 writeMixEntries
diff --git a/compiler/ghc.cabal.in b/compiler/ghc.cabal.in
index 99bb463f54..4875753a1c 100644
--- a/compiler/ghc.cabal.in
+++ b/compiler/ghc.cabal.in
@@ -64,7 +64,6 @@ Library
                    transformers == 0.5.*,
                    ghc-boot   == @ProjectVersionMunged@,
                    ghc-boot-th == @ProjectVersionMunged@,
-                   ghci == @ProjectVersionMunged@,
                    hoopl      >= 3.10.2 && < 3.11
 
     if os(windows)
@@ -74,6 +73,9 @@ Library
             Build-Depends: terminfo == 0.4.*
         Build-Depends: unix   == 2.7.*
 
+    if flag(ghci)
+        Build-Depends: ghci == @ProjectVersionMunged@
+
     GHC-Options: -Wall -fno-warn-name-shadowing
 
     if flag(ghci)
@@ -603,6 +605,16 @@ Library
             Dwarf
             Dwarf.Types
             Dwarf.Constants
+
+    if !flag(stage1)
+        -- ghc:Serialized moved to ghc-boot:GHC.Serialized.  So for
+        -- compatibility with GHC 7.10 and earlier, we reexport it
+        -- under the old name.
+        reexported-modules:
+            ghc-boot:GHC.Serialized as Serialized
+
+    if flag(ghci)
+        Exposed-Modules:
             Convert
             ByteCodeTypes
             ByteCodeAsm
@@ -615,10 +627,3 @@ Library
             RtClosureInspect
             DebuggerUtils
             GHCi
-
-    if !flag(stage1)
-        -- ghc:Serialized moved to ghc-boot:GHC.Serialized.  So for
-        -- compatibility with GHC 7.10 and earlier, we reexport it
-        -- under the old name.
-        reexported-modules:
-            ghc-boot:GHC.Serialized as Serialized
diff --git a/compiler/ghci/ByteCodeGen.hs b/compiler/ghci/ByteCodeGen.hs
index 9a5e4141f1..0e7aea493e 100644
--- a/compiler/ghci/ByteCodeGen.hs
+++ b/compiler/ghci/ByteCodeGen.hs
@@ -66,11 +66,7 @@ import qualified Data.Map as Map
 import qualified Data.IntMap as IntMap
 import qualified FiniteMap as Map
 import Data.Ord
-#if MIN_VERSION_base(4,9,0)
 import GHC.Stack.CCS
-#else
-import GHC.Stack as GHC.Stack.CCS
-#endif
 
 -- -----------------------------------------------------------------------------
 -- Generating byte code for a complete module
diff --git a/compiler/ghci/ByteCodeInstr.hs b/compiler/ghci/ByteCodeInstr.hs
index 43444321de..f1f6f70e57 100644
--- a/compiler/ghci/ByteCodeInstr.hs
+++ b/compiler/ghci/ByteCodeInstr.hs
@@ -30,11 +30,7 @@ import PrimOp
 import SMRep
 
 import Data.Word
-#if MIN_VERSION_base(4,9,0)
 import GHC.Stack.CCS (CostCentre)
-#else
-import GHC.Stack (CostCentre)
-#endif
 
 -- ----------------------------------------------------------------------------
 -- Bytecode instructions
diff --git a/compiler/ghci/ByteCodeTypes.hs b/compiler/ghci/ByteCodeTypes.hs
index ec962c886b..3537a2bff3 100644
--- a/compiler/ghci/ByteCodeTypes.hs
+++ b/compiler/ghci/ByteCodeTypes.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, MagicHash, RecordWildCards, GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE MagicHash, RecordWildCards, GeneralizedNewtypeDeriving #-}
 --
 --  (c) The University of Glasgow 2002-2006
 --
@@ -34,11 +34,7 @@ import Data.Array.Base  ( UArray(..) )
 import Data.ByteString (ByteString)
 import Data.IntMap (IntMap)
 import qualified Data.IntMap as IntMap
-#if MIN_VERSION_base(4,9,0)
 import GHC.Stack.CCS
-#else
-import GHC.Stack as GHC.Stack.CCS
-#endif
 
 -- -----------------------------------------------------------------------------
 -- Compiled Byte Code
diff --git a/compiler/ghci/GHCi.hs b/compiler/ghci/GHCi.hs
index a5667c361e..472251db04 100644
--- a/compiler/ghci/GHCi.hs
+++ b/compiler/ghci/GHCi.hs
@@ -46,9 +46,7 @@ module GHCi
   ) where
 
 import GHCi.Message
-#ifdef GHCI
 import GHCi.Run
-#endif
 import GHCi.RemoteTypes
 import GHCi.ResolvedBCO
 import GHCi.BreakArray (BreakArray)
@@ -73,11 +71,7 @@ import Data.ByteString (ByteString)
 import qualified Data.ByteString.Lazy as LB
 import Data.IORef
 import Foreign hiding (void)
-#if MIN_VERSION_base(4,9,0)
 import GHC.Stack.CCS (CostCentre,CostCentreStack)
-#else
-import GHC.Stack (CostCentre,CostCentreStack)
-#endif
 import System.Exit
 import Data.Maybe
 import GHC.IO.Handle.Types (Handle)
@@ -154,12 +148,6 @@ Other Notes on Remote GHCi
   * Note [Remote Template Haskell] in libraries/ghci/GHCi/TH.hs
 -}
 
-#ifndef GHCI
-needExtInt :: IO a
-needExtInt = throwIO
-  (InstallationError "this operation requires -fexternal-interpreter")
-#endif
-
 -- | Run a command in the interpreter's context.  With
 -- @-fexternal-interpreter@, the command is serialized and sent to an
 -- external iserv process, and the response is deserialized (hence the
@@ -172,11 +160,8 @@ iservCmd hsc_env@HscEnv{..} msg
        uninterruptibleMask_ $ do -- Note [uninterruptibleMask_]
          iservCall iserv msg
  | otherwise = -- Just run it directly
-#ifdef GHCI
    run msg
-#else
-   needExtInt
-#endif
+
 
 -- Note [uninterruptibleMask_ and iservCmd]
 --
@@ -372,11 +357,7 @@ lookupSymbol hsc_env@HscEnv{..} str
                writeIORef iservLookupSymbolCache $! addToUFM cache str p
                return (Just p)
  | otherwise =
-#ifdef GHCI
    fmap fromRemotePtr <$> run (LookupSymbol (unpackFS str))
-#else
-   needExtInt
-#endif
 
 lookupClosure :: HscEnv -> String -> IO (Maybe HValueRef)
 lookupClosure hsc_env str =
@@ -622,14 +603,8 @@ wormholeRef dflags r
   | gopt Opt_ExternalInterpreter dflags
   = throwIO (InstallationError
       "this operation requires -fno-external-interpreter")
-#ifdef GHCI
   | otherwise
   = localRef r
-#else
-  | otherwise
-  = throwIO (InstallationError
-      "can't wormhole a value in a stage1 compiler")
-#endif
 
 -- -----------------------------------------------------------------------------
 -- Misc utils
diff --git a/compiler/ghci/Linker.hs b/compiler/ghci/Linker.hs
index 6a0483ce1b..7379c46772 100644
--- a/compiler/ghci/Linker.hs
+++ b/compiler/ghci/Linker.hs
@@ -709,16 +709,6 @@ getLinkDeps hsc_env hpt pls replace_osuf span mods
             adjust_ul _ (DotA fp) = panic ("adjust_ul DotA " ++ show fp)
             adjust_ul _ (DotDLL fp) = panic ("adjust_ul DotDLL " ++ show fp)
             adjust_ul _ l@(BCOs {}) = return l
-#if !MIN_VERSION_filepath(1,4,1)
-    stripExtension :: String -> FilePath -> Maybe FilePath
-    stripExtension []        path = Just path
-    stripExtension ext@(x:_) path = stripSuffix dotExt path
-        where dotExt = if isExtSeparator x then ext else '.':ext
-
-    stripSuffix :: Eq a => [a] -> [a] -> Maybe [a]
-    stripSuffix xs ys = fmap reverse $ stripPrefix (reverse xs) (reverse ys)
-#endif
-
 
 
 {- **********************************************************************
diff --git a/compiler/hsSyn/HsExpr.hs b/compiler/hsSyn/HsExpr.hs
index d695d8e651..8cead39c68 100644
--- a/compiler/hsSyn/HsExpr.hs
+++ b/compiler/hsSyn/HsExpr.hs
@@ -48,8 +48,10 @@ import Data.Data hiding (Fixity(..))
 import qualified Data.Data as Data (Fixity(..))
 import Data.Maybe (isNothing)
 
+#ifdef GHCI
 import GHCi.RemoteTypes ( ForeignRef )
 import qualified Language.Haskell.TH as TH (Q)
+#endif
 
 {-
 ************************************************************************
@@ -2045,13 +2047,24 @@ isTypedSplice _                  = False   -- Quasi-quotes are untyped splices
 -- See Note [Delaying modFinalizers in untyped splices] in RnSplice. For how
 -- this is used.
 --
+#ifdef GHCI
 newtype ThModFinalizers = ThModFinalizers [ForeignRef (TH.Q ())]
+#else
+data ThModFinalizers = ThModFinalizers
+#endif
 
 -- A Data instance which ignores the argument of 'ThModFinalizers'.
+#ifdef GHCI
 instance Data ThModFinalizers where
   gunfold _ z _ = z $ ThModFinalizers []
   toConstr  a   = mkConstr (dataTypeOf a) "ThModFinalizers" [] Data.Prefix
   dataTypeOf a  = mkDataType "HsExpr.ThModFinalizers" [toConstr a]
+#else
+instance Data ThModFinalizers where
+  gunfold _ z _ = z ThModFinalizers
+  toConstr  a   = mkConstr (dataTypeOf a) "ThModFinalizers" [] Data.Prefix
+  dataTypeOf a  = mkDataType "HsExpr.ThModFinalizers" [toConstr a]
+#endif
 
 -- | Haskell Spliced Thing
 --
diff --git a/compiler/main/DriverPipeline.hs b/compiler/main/DriverPipeline.hs
index 133bdde283..ea0c6eded1 100644
--- a/compiler/main/DriverPipeline.hs
+++ b/compiler/main/DriverPipeline.hs
@@ -2054,7 +2054,11 @@ doCpp dflags raw input_fn output_fn = do
 
     backend_defs <- getBackendDefs dflags
 
+#ifdef GHCI
     let th_defs = [ "-D__GLASGOW_HASKELL_TH__" ]
+#else
+    let th_defs = [ "-D__GLASGOW_HASKELL_TH__=0" ]
+#endif
     -- Default CPP defines in Haskell source
     ghcVersionH <- getGhcVersionPathName dflags
     let hsSourceCppOpts = [ "-include", ghcVersionH ]
diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index 6ecf8ca9a9..aee5edce85 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -124,7 +124,9 @@ module DynFlags (
         -- * Compiler configuration suitable for display to the user
         compilerInfo,
 
+#ifdef GHCI
         rtsIsProfiled,
+#endif
         dynamicGhc,
 
 #include "GHCConstantsHaskellExports.hs"
@@ -3611,6 +3613,12 @@ supportedExtensions :: [String]
 supportedExtensions = concatMap toFlagSpecNamePair xFlags
   where
     toFlagSpecNamePair flg
+#ifndef GHCI
+      -- make sure that `ghc --supported-extensions` omits
+      -- "TemplateHaskell" when it's known to be unsupported. See also
+      -- GHC #11102 for rationale
+      | flagSpecFlag flg == LangExt.TemplateHaskell  = [noName]
+#endif
       | otherwise = [name, noName]
       where
         noName = "No" ++ name
@@ -4147,6 +4155,7 @@ foreign import ccall unsafe "rts_isProfiled" rtsIsProfiledIO :: IO CInt
 rtsIsProfiled :: Bool
 rtsIsProfiled = unsafeDupablePerformIO rtsIsProfiledIO /= 0
 
+#ifdef GHCI
 -- Consult the RTS to find whether GHC itself has been built with
 -- dynamic linking.  This can't be statically known at compile-time,
 -- because we build both the static and dynamic versions together with
@@ -4155,6 +4164,10 @@ foreign import ccall unsafe "rts_isDynamic" rtsIsDynamicIO :: IO CInt
 
 dynamicGhc :: Bool
 dynamicGhc = unsafeDupablePerformIO rtsIsDynamicIO /= 0
+#else
+dynamicGhc :: Bool
+dynamicGhc = False
+#endif
 
 setWarnSafe :: Bool -> DynP ()
 setWarnSafe True  = getCurLoc >>= \l -> upd (\d -> d { warnSafeOnLoc = l })
@@ -4187,8 +4200,24 @@ setIncoherentInsts True = do
   upd (\d -> d { incoherentOnLoc = l })
 
 checkTemplateHaskellOk :: TurnOnFlag -> DynP ()
+#ifdef GHCI
 checkTemplateHaskellOk _turn_on
   = getCurLoc >>= \l -> upd (\d -> d { thOnLoc = l })
+#else
+-- In stage 1, Template Haskell is simply illegal, except with -M
+-- We don't bleat with -M because there's no problem with TH there,
+-- and in fact GHC's build system does ghc -M of the DPH libraries
+-- with a stage1 compiler
+checkTemplateHaskellOk turn_on
+  | turn_on = do dfs <- liftEwM getCmdLineState
+                 case ghcMode dfs of
+                    MkDepend -> return ()
+                    _        -> addErr msg
+  | otherwise = return ()
+  where
+    msg = "Template Haskell requires GHC with interpreter support\n    " ++
+          "Perhaps you are using a stage-1 compiler?"
+#endif
 
 {- **********************************************************************
 %*                                                                      *
diff --git a/compiler/main/GHC.hs b/compiler/main/GHC.hs
index 59e42f9c75..cf066d0ea7 100644
--- a/compiler/main/GHC.hs
+++ b/compiler/main/GHC.hs
@@ -91,6 +91,7 @@ module GHC (
 
         -- * Interactive evaluation
 
+#ifdef GHCI
         -- ** Executing statements
         execStmt, ExecOptions(..), execOptions, ExecResult(..),
         resumeExec,
@@ -102,10 +103,11 @@ module GHC (
         parseImportDecl,
         setContext, getContext,
         setGHCiMonad, getGHCiMonad,
-
+#endif
         -- ** Inspecting the current context
         getBindings, getInsts, getPrintUnqual,
         findModule, lookupModule,
+#ifdef GHCI
         isModuleTrusted, moduleTrustReqs,
         getNamesInScope,
         getRdrNamesInScope,
@@ -121,8 +123,9 @@ module GHC (
 
         -- ** Looking up a Name
         parseName,
+#endif
         lookupName,
-
+#ifdef GHCI
         -- ** Compiling expressions
         HValue, parseExpr, compileParsedExpr,
         InteractiveEval.compileExpr, dynCompileExpr,
@@ -151,6 +154,7 @@ module GHC (
         RunResult(..),
         runStmt, runStmtWithLocation,
         resume,
+#endif
 
         -- * Abstract syntax elements
 
@@ -286,12 +290,14 @@ module GHC (
 
 #include "HsVersions.h"
 
+#ifdef GHCI
 import ByteCodeTypes
 import InteractiveEval
 import InteractiveEvalTypes
 import TcRnDriver       ( runTcInteractive )
 import GHCi
 import GHCi.RemoteTypes
+#endif
 
 import PprTyThing       ( pprFamInst )
 import HscMain
@@ -463,7 +469,9 @@ withCleanupSession ghc = ghc `gfinally` cleanup
       liftIO $ do
           cleanTempFiles dflags
           cleanTempDirs dflags
+#ifdef GHCI
           stopIServ hsc_env -- shut down the IServ
+#endif
           --  exceptions will be blocked while we clean the temporary files,
           -- so there shouldn't be any difficulty if we receive further
           -- signals.
@@ -881,8 +889,10 @@ typecheckModule pmod = do
            minf_rdr_env   = Just (tcg_rdr_env tc_gbl_env),
            minf_instances = fixSafeInstances safe $ md_insts details,
            minf_iface     = Nothing,
-           minf_safe      = safe,
-           minf_modBreaks = emptyModBreaks
+           minf_safe      = safe
+#ifdef GHCI
+          ,minf_modBreaks = emptyModBreaks
+#endif
          }}
 
 -- | Desugar a typechecked module.
@@ -1070,8 +1080,10 @@ data ModuleInfo = ModuleInfo {
         minf_rdr_env   :: Maybe GlobalRdrEnv,   -- Nothing for a compiled/package mod
         minf_instances :: [ClsInst],
         minf_iface     :: Maybe ModIface,
-        minf_safe      :: SafeHaskellMode,
-        minf_modBreaks :: ModBreaks
+        minf_safe      :: SafeHaskellMode
+#ifdef GHCI
+       ,minf_modBreaks :: ModBreaks
+#endif
   }
         -- We don't want HomeModInfo here, because a ModuleInfo applies
         -- to package modules too.
@@ -1094,6 +1106,7 @@ getModuleInfo mdl = withSession $ \hsc_env -> do
    -- exist... hence the isHomeModule test here.  (ToDo: reinstate)
 
 getPackageModuleInfo :: HscEnv -> Module -> IO (Maybe ModuleInfo)
+#ifdef GHCI
 getPackageModuleInfo hsc_env mdl
   = do  eps <- hscEPS hsc_env
         iface <- hscGetModuleInterface hsc_env mdl
@@ -1112,6 +1125,11 @@ getPackageModuleInfo hsc_env mdl
                         minf_safe      = getSafeMode $ mi_trust iface,
                         minf_modBreaks = emptyModBreaks
                 }))
+#else
+-- bogusly different for non-GHCI (ToDo)
+getPackageModuleInfo _hsc_env _mdl = do
+  return Nothing
+#endif
 
 getHomeModuleInfo :: HscEnv -> Module -> IO (Maybe ModuleInfo)
 getHomeModuleInfo hsc_env mdl =
@@ -1127,7 +1145,9 @@ getHomeModuleInfo hsc_env mdl =
                         minf_instances = md_insts details,
                         minf_iface     = Just iface,
                         minf_safe      = getSafeMode $ mi_trust iface
+#ifdef GHCI
                        ,minf_modBreaks = getModBreaks hmi
+#endif
                         }))
 
 -- | The list of top-level entities defined in a module
@@ -1176,8 +1196,10 @@ modInfoIface = minf_iface
 modInfoSafe :: ModuleInfo -> SafeHaskellMode
 modInfoSafe = minf_safe
 
+#ifdef GHCI
 modInfoModBreaks :: ModuleInfo -> ModBreaks
 modInfoModBreaks = minf_modBreaks
+#endif
 
 isDictonaryId :: Id -> Bool
 isDictonaryId id
@@ -1197,9 +1219,11 @@ findGlobalAnns deserialize target = withSession $ \hsc_env -> do
     ann_env <- liftIO $ prepareAnnotations hsc_env Nothing
     return (findAnns deserialize ann_env target)
 
+#ifdef GHCI
 -- | get the GlobalRdrEnv for a session
 getGRE :: GhcMonad m => m GlobalRdrEnv
 getGRE = withSession $ \hsc_env-> return $ ic_rn_gbl_env (hsc_IC hsc_env)
+#endif
 
 -- -----------------------------------------------------------------------------
 
@@ -1398,6 +1422,7 @@ lookupLoadedHomeModule mod_name = withSession $ \hsc_env ->
     Just mod_info      -> return (Just (mi_module (hm_iface mod_info)))
     _not_a_home_module -> return Nothing
 
+#ifdef GHCI
 -- | Check that a module is safe to import (according to Safe Haskell).
 --
 -- We return True to indicate the import is safe and False otherwise
@@ -1439,6 +1464,7 @@ obtainTermFromId :: GhcMonad m => Int -> Bool -> Id -> m Term
 obtainTermFromId bound force id = withSession $ \hsc_env ->
     liftIO $ InteractiveEval.obtainTermFromId hsc_env bound force id
 
+#endif
 
 -- | Returns the 'TyThing' for a 'Name'.  The 'Name' may refer to any
 -- entity known to GHC, including 'Name's defined using 'runStmt'.
diff --git a/compiler/main/GhcMake.hs b/compiler/main/GhcMake.hs
index be6510bcb2..6b103c9e1b 100644
--- a/compiler/main/GhcMake.hs
+++ b/compiler/main/GhcMake.hs
@@ -31,7 +31,9 @@ module GhcMake(
 
 #include "HsVersions.h"
 
+#ifdef GHCI
 import qualified Linker         ( unload )
+#endif
 
 import DriverPhases
 import DriverPipeline
@@ -561,7 +563,13 @@ findPartiallyCompletedCycles modsDone theGraph
 unload :: HscEnv -> [Linkable] -> IO ()
 unload hsc_env stable_linkables -- Unload everthing *except* 'stable_linkables'
   = case ghcLink (hsc_dflags hsc_env) of
+#ifdef GHCI
         LinkInMemory -> Linker.unload hsc_env stable_linkables
+#else
+        LinkInMemory -> panic "unload: no interpreter"
+                                -- urgh.  avoid warnings:
+                                hsc_env stable_linkables
+#endif
         _other -> return ()
 
 -- -----------------------------------------------------------------------------
diff --git a/compiler/main/Hooks.hs b/compiler/main/Hooks.hs
index eefdde4b88..8d706d8fa5 100644
--- a/compiler/main/Hooks.hs
+++ b/compiler/main/Hooks.hs
@@ -15,14 +15,18 @@ module Hooks ( Hooks
              , tcForeignImportsHook
              , tcForeignExportsHook
              , hscFrontendHook
+#ifdef GHCI
              , hscCompileCoreExprHook
+#endif
              , ghcPrimIfaceHook
              , runPhaseHook
              , runMetaHook
              , linkHook
              , runRnSpliceHook
+#ifdef GHCI
              , getValueSafelyHook
              , createIservProcessHook
+#endif
              ) where
 
 import DynFlags
@@ -38,10 +42,12 @@ import TcRnTypes
 import Bag
 import RdrName
 import CoreSyn
+#ifdef GHCI
 import GHCi.RemoteTypes
 import SrcLoc
 import Type
 import System.Process
+#endif
 import BasicTypes
 
 import Data.Maybe
@@ -64,14 +70,18 @@ emptyHooks = Hooks
   , tcForeignImportsHook   = Nothing
   , tcForeignExportsHook   = Nothing
   , hscFrontendHook        = Nothing
+#ifdef GHCI
   , hscCompileCoreExprHook = Nothing
+#endif
   , ghcPrimIfaceHook       = Nothing
   , runPhaseHook           = Nothing
   , runMetaHook            = Nothing
   , linkHook               = Nothing
   , runRnSpliceHook        = Nothing
+#ifdef GHCI
   , getValueSafelyHook     = Nothing
   , createIservProcessHook = Nothing
+#endif
   }
 
 data Hooks = Hooks
@@ -79,14 +89,18 @@ data Hooks = Hooks
   , tcForeignImportsHook   :: Maybe ([LForeignDecl Name] -> TcM ([Id], [LForeignDecl Id], Bag GlobalRdrElt))
   , tcForeignExportsHook   :: Maybe ([LForeignDecl Name] -> TcM (LHsBinds TcId, [LForeignDecl TcId], Bag GlobalRdrElt))
   , hscFrontendHook        :: Maybe (ModSummary -> Hsc FrontendResult)
+#ifdef GHCI
   , hscCompileCoreExprHook :: Maybe (HscEnv -> SrcSpan -> CoreExpr -> IO ForeignHValue)
+#endif
   , ghcPrimIfaceHook       :: Maybe ModIface
   , runPhaseHook           :: Maybe (PhasePlus -> FilePath -> DynFlags -> CompPipeline (PhasePlus, FilePath))
   , runMetaHook            :: Maybe (MetaHook TcM)
   , linkHook               :: Maybe (GhcLink -> DynFlags -> Bool -> HomePackageTable -> IO SuccessFlag)
   , runRnSpliceHook        :: Maybe (HsSplice Name -> RnM (HsSplice Name))
+#ifdef GHCI
   , getValueSafelyHook     :: Maybe (HscEnv -> Name -> Type -> IO (Maybe HValue))
   , createIservProcessHook :: Maybe (CreateProcess -> IO ProcessHandle)
+#endif
   }
 
 getHooked :: (Functor f, HasDynFlags f) => (Hooks -> Maybe a) -> a -> f a
diff --git a/compiler/main/HscMain.hs b/compiler/main/HscMain.hs
index 7d809126bf..9a64794b77 100644
--- a/compiler/main/HscMain.hs
+++ b/compiler/main/HscMain.hs
@@ -59,6 +59,7 @@ module HscMain
     , hscParseIdentifier
     , hscTcRcLookupName
     , hscTcRnGetInfo
+#ifdef GHCI
     , hscIsGHCiMonad
     , hscGetModuleInterface
     , hscRnImportDecls
@@ -70,6 +71,7 @@ module HscMain
     , hscCompileCoreExpr
     -- * Low-level exports for hooks
     , hscCompileCoreExpr'
+#endif
       -- We want to make sure that we export enough to be able to redefine
       -- hscFileFrontEnd in client code
     , hscParse', hscSimplify', hscDesugar', tcRnModule'
@@ -81,6 +83,7 @@ module HscMain
     , showModuleIndex
     ) where
 
+#ifdef GHCI
 import Id
 import GHCi.RemoteTypes ( ForeignHValue )
 import ByteCodeGen      ( byteCodeGen, coreExprToBCOs )
@@ -93,6 +96,7 @@ import VarEnv           ( emptyTidyEnv )
 import Panic
 import ConLike
 import Control.Concurrent
+#endif
 
 import Module
 import Packages
@@ -174,7 +178,9 @@ newHscEnv dflags = do
     us      <- mkSplitUniqSupply 'r'
     nc_var  <- newIORef (initNameCache us knownKeyNames)
     fc_var  <- newIORef emptyInstalledModuleEnv
+#ifdef GHCI
     iserv_mvar <- newMVar Nothing
+#endif
     return HscEnv {  hsc_dflags       = dflags
                   ,  hsc_targets      = []
                   ,  hsc_mod_graph    = []
@@ -184,7 +190,9 @@ newHscEnv dflags = do
                   ,  hsc_NC           = nc_var
                   ,  hsc_FC           = fc_var
                   ,  hsc_type_env_var = Nothing
+#ifdef GHCI
                   , hsc_iserv        = iserv_mvar
+#endif
                   }
 
 -- -----------------------------------------------------------------------------
@@ -254,11 +262,13 @@ ioMsgMaybe' ioA = do
 -- -----------------------------------------------------------------------------
 -- | Lookup things in the compiler's environment
 
+#ifdef GHCI
 hscTcRnLookupRdrName :: HscEnv -> Located RdrName -> IO [Name]
 hscTcRnLookupRdrName hsc_env0 rdr_name
   = runInteractiveHsc hsc_env0 $
     do { hsc_env <- getHscEnv
        ; ioMsgMaybe $ tcRnLookupRdrName hsc_env rdr_name }
+#endif
 
 hscTcRcLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
 hscTcRcLookupName hsc_env0 name = runInteractiveHsc hsc_env0 $ do
@@ -274,6 +284,7 @@ hscTcRnGetInfo hsc_env0 name
     do { hsc_env <- getHscEnv
        ; ioMsgMaybe' $ tcRnGetInfo hsc_env name }
 
+#ifdef GHCI
 hscIsGHCiMonad :: HscEnv -> String -> IO Name
 hscIsGHCiMonad hsc_env name
   = runHsc hsc_env $ ioMsgMaybe $ isGHCiMonad hsc_env name
@@ -289,6 +300,7 @@ hscRnImportDecls :: HscEnv -> [LImportDecl RdrName] -> IO GlobalRdrEnv
 hscRnImportDecls hsc_env0 import_decls = runInteractiveHsc hsc_env0 $ do
   hsc_env <- getHscEnv
   ioMsgMaybe $ tcRnImportDecls hsc_env import_decls
+#endif
 
 -- -----------------------------------------------------------------------------
 -- | parse a file, returning the abstract syntax
@@ -1061,6 +1073,7 @@ hscCheckSafe' dflags m l = do
         let pkgIfaceT = eps_PIT hsc_eps
             homePkgT  = hsc_HPT hsc_env
             iface     = lookupIfaceByModule dflags homePkgT pkgIfaceT m
+#ifdef GHCI
         -- the 'lookupIfaceByModule' method will always fail when calling from GHCi
         -- as the compiler hasn't filled in the various module tables
         -- so we need to call 'getModuleInterface' to load from disk
@@ -1068,6 +1081,9 @@ hscCheckSafe' dflags m l = do
             Just _  -> return iface
             Nothing -> snd `fmap` (liftIO $ getModuleInterface hsc_env m)
         return iface'
+#else
+        return iface
+#endif
 
 
     isHomePkg :: Module -> Bool
@@ -1304,6 +1320,7 @@ hscInteractive :: HscEnv
                -> CgGuts
                -> ModSummary
                -> IO (Maybe FilePath, CompiledByteCode)
+#ifdef GHCI
 hscInteractive hsc_env cgguts mod_summary = do
     let dflags = hsc_dflags hsc_env
     let CgGuts{ -- This is the last use of the ModGuts in a compilation.
@@ -1330,6 +1347,9 @@ hscInteractive hsc_env cgguts mod_summary = do
     (_istub_h_exists, istub_c_exists)
         <- outputForeignStubs dflags this_mod location foreign_stubs
     return (istub_c_exists, comp_bc)
+#else
+hscInteractive _ _ = panic "GHC not compiled with interpreter"
+#endif
 
 ------------------------------
 
@@ -1452,6 +1472,7 @@ A naked expression returns a singleton Name [it]. The stmt is lifted into the
 IO monad as explained in Note [Interactively-bound Ids in GHCi] in HscTypes
 -}
 
+#ifdef GHCI
 -- | Compile a stmt all the way to an HValue, but don't run it
 --
 -- We return Nothing to indicate an empty statement (or comment only), not a
@@ -1655,6 +1676,7 @@ hscParseStmtWithLocation source linenumber stmt =
 
 hscParseType :: String -> Hsc (LHsType RdrName)
 hscParseType = hscParseThing parseType
+#endif
 
 hscParseIdentifier :: HscEnv -> String -> IO (Located RdrName)
 hscParseIdentifier hsc_env str =
@@ -1691,6 +1713,7 @@ hscParseThingWithLocation source linenumber parser str
 %*                                                                      *
 %********************************************************************* -}
 
+#ifdef GHCI
 hscCompileCoreExpr :: HscEnv -> SrcSpan -> CoreExpr -> IO ForeignHValue
 hscCompileCoreExpr hsc_env =
   lookupHook hscCompileCoreExprHook hscCompileCoreExpr' (hsc_dflags hsc_env) hsc_env
@@ -1719,6 +1742,7 @@ hscCompileCoreExpr' hsc_env srcspan ds_expr
          ; hval <- linkExpr hsc_env srcspan bcos
 
          ; return hval }
+#endif
 
 
 {- **********************************************************************
diff --git a/compiler/main/HscTypes.hs b/compiler/main/HscTypes.hs
index 5b3c058d35..e5f824f2e4 100644
--- a/compiler/main/HscTypes.hs
+++ b/compiler/main/HscTypes.hs
@@ -14,7 +14,9 @@ module HscTypes (
         Target(..), TargetId(..), pprTarget, pprTargetId,
         ModuleGraph, emptyMG,
         HscStatus(..),
+#ifdef GHCI
         IServ(..),
+#endif
 
         -- * Hsc monad
         Hsc(..), runHsc, runInteractiveHsc,
@@ -135,10 +137,12 @@ module HscTypes (
 
 #include "HsVersions.h"
 
+#ifdef GHCI
 import ByteCodeTypes
 import InteractiveEvalTypes ( Resume )
 import GHCi.Message         ( Pipe )
 import GHCi.RemoteTypes
+#endif
 
 import UniqFM
 import HsSyn
@@ -198,8 +202,10 @@ import Data.IORef
 import Data.Time
 import Exception
 import System.FilePath
+#ifdef GHCI
 import Control.Concurrent
 import System.Process   ( ProcessHandle )
+#endif
 
 -- -----------------------------------------------------------------------------
 -- Compilation state
@@ -397,9 +403,11 @@ data HscEnv
                 -- the 'IfGblEnv'. See 'TcRnTypes.tcg_type_env_var' for
                 -- 'TcRnTypes.TcGblEnv'.  See also Note [hsc_type_env_var hack]
 
+#ifdef GHCI
         , hsc_iserv :: MVar (Maybe IServ)
                 -- ^ interactive server process.  Created the first
                 -- time it is needed.
+#endif
  }
 
 -- Note [hsc_type_env_var hack]
@@ -445,12 +453,14 @@ data HscEnv
 -- another day.
 
 
+#ifdef GHCI
 data IServ = IServ
   { iservPipe :: Pipe
   , iservProcess :: ProcessHandle
   , iservLookupSymbolCache :: IORef (UniqFM (Ptr ()))
   , iservPendingFrees :: [HValueRef]
   }
+#endif
 
 -- | Retrieve the ExternalPackageState cache.
 hscEPS :: HscEnv -> IO ExternalPackageState
@@ -1480,8 +1490,10 @@ data InteractiveContext
          ic_default :: Maybe [Type],
              -- ^ The current default types, set by a 'default' declaration
 
+#ifdef GHCI
           ic_resume :: [Resume],
              -- ^ The stack of breakpoint contexts
+#endif
 
          ic_monad      :: Name,
              -- ^ The monad that GHCi is executing in
@@ -1519,7 +1531,9 @@ emptyInteractiveContext dflags
        ic_monad      = ioTyConName,  -- IO monad by default
        ic_int_print  = printName,    -- System.IO.print by default
        ic_default    = Nothing,
+#ifdef GHCI
        ic_resume     = [],
+#endif
        ic_cwd        = Nothing }
 
 icInteractiveModule :: InteractiveContext -> Module
@@ -2936,11 +2950,25 @@ data Unlinked
    | DotDLL FilePath    -- ^ Dynamically linked library file (.so, .dll, .dylib)
    | BCOs CompiledByteCode    -- ^ A byte-code object, lives only in memory
 
+#ifndef GHCI
+data CompiledByteCode = CompiledByteCodeUndefined
+_unusedCompiledByteCode :: CompiledByteCode
+_unusedCompiledByteCode = CompiledByteCodeUndefined
+
+data ModBreaks = ModBreaksUndefined
+emptyModBreaks :: ModBreaks
+emptyModBreaks = ModBreaksUndefined
+#endif
+
 instance Outputable Unlinked where
    ppr (DotO path)   = text "DotO" <+> text path
    ppr (DotA path)   = text "DotA" <+> text path
    ppr (DotDLL path) = text "DotDLL" <+> text path
+#ifdef GHCI
    ppr (BCOs bcos) = text "BCOs" <+> ppr bcos
+#else
+   ppr (BCOs _)    = text "No byte code"
+#endif
 
 -- | Is this an actual file on disk we can link in somehow?
 isObject :: Unlinked -> Bool
diff --git a/compiler/main/InteractiveEval.hs b/compiler/main/InteractiveEval.hs
index 3cb1856725..a421c72baf 100644
--- a/compiler/main/InteractiveEval.hs
+++ b/compiler/main/InteractiveEval.hs
@@ -10,6 +10,7 @@
 -- -----------------------------------------------------------------------------
 
 module InteractiveEval (
+#ifdef GHCI
         Resume(..), History(..),
         execStmt, ExecOptions(..), execOptions, ExecResult(..), resumeExec,
         runDecls, runDeclsWithLocation,
@@ -39,14 +40,17 @@ module InteractiveEval (
         Term(..), obtainTermFromId, obtainTermFromVal, reconstructType,
         -- * Depcreated API (remove in GHC 7.14)
         RunResult(..), runStmt, runStmtWithLocation,
+#endif
         ) where
 
+#ifdef GHCI
+
 #include "HsVersions.h"
 
 import InteractiveEvalTypes
 
 import GHCi
-import GHCi.Message
+import GHCi.Run
 import GHCi.RemoteTypes
 import GhcMonad
 import HscMain
@@ -975,3 +979,4 @@ reconstructType hsc_env bound id = do
 
 mkRuntimeUnkTyVar :: Name -> Kind -> TyVar
 mkRuntimeUnkTyVar name kind = mkTcTyVar name kind RuntimeUnk
+#endif /* GHCI */
diff --git a/compiler/main/InteractiveEvalTypes.hs b/compiler/main/InteractiveEvalTypes.hs
index cb0121950f..34ae2ccaa0 100644
--- a/compiler/main/InteractiveEvalTypes.hs
+++ b/compiler/main/InteractiveEvalTypes.hs
@@ -9,11 +9,15 @@
 -- -----------------------------------------------------------------------------
 
 module InteractiveEvalTypes (
+#ifdef GHCI
         Resume(..), History(..), ExecResult(..),
         SingleStep(..), isStep, ExecOptions(..),
         BreakInfo(..)
+#endif
         ) where
 
+#ifdef GHCI
+
 import GHCi.RemoteTypes
 import GHCi.Message (EvalExpr, ResumeContext)
 import Id
@@ -25,11 +29,7 @@ import SrcLoc
 import Exception
 
 import Data.Word
-#if MIN_VERSION_base(4,9,0)
 import GHC.Stack.CCS
-#else
-import GHC.Stack as GHC.Stack.CCS
-#endif
 
 data ExecOptions
  = ExecOptions
@@ -91,3 +91,4 @@ data History
         historyBreakInfo :: BreakInfo,
         historyEnclosingDecls :: [String]  -- declarations enclosing the breakpoint
    }
+#endif
diff --git a/compiler/rename/RnEnv.hs b/compiler/rename/RnEnv.hs
index 97718f88d2..f8969a8e13 100644
--- a/compiler/rename/RnEnv.hs
+++ b/compiler/rename/RnEnv.hs
@@ -341,12 +341,16 @@ lookupExactOcc_either name
                        ; if name `inLocalRdrEnvScope` lcl_env
                          then return (Right name)
                          else
+#ifdef GHCI
                          do { th_topnames_var <- fmap tcg_th_topnames getGblEnv
                             ; th_topnames <- readTcRef th_topnames_var
                             ; if name `elemNameSet` th_topnames
                               then return (Right name)
                               else return (Left exact_nm_err)
                             }
+#else /* !GHCI */
+                         return (Left exact_nm_err)
+#endif /* !GHCI */
                        }
            gres -> return (Left (sameNameErr gres))   -- Ugh!  See Note [Template Haskell ambiguity]
        }
diff --git a/compiler/rename/RnSplice.hs b/compiler/rename/RnSplice.hs
index ccfd00257b..0c41ed30b6 100644
--- a/compiler/rename/RnSplice.hs
+++ b/compiler/rename/RnSplice.hs
@@ -5,7 +5,9 @@ module RnSplice (
         rnSpliceType, rnSpliceExpr, rnSplicePat, rnSpliceDecl,
         rnBracket,
         checkThLocalName
+#ifdef GHCI
         , traceSplice, SpliceInfo(..)
+#endif
   ) where
 
 #include "HsVersions.h"
@@ -33,6 +35,7 @@ import {-# SOURCE #-} RnExpr   ( rnLExpr )
 import TcEnv            ( checkWellStaged )
 import THNames          ( liftName )
 
+#ifdef GHCI
 import DynFlags
 import FastString
 import ErrUtils         ( dumpIfSet_dyn_printer )
@@ -54,6 +57,7 @@ import {-# SOURCE #-} TcSplice
 
 import GHCi.RemoteTypes ( ForeignRef )
 import qualified Language.Haskell.TH as TH (Q)
+#endif
 
 import qualified GHC.LanguageExtensions as LangExt
 
@@ -197,6 +201,23 @@ quotedNameStageErr br
   = sep [ text "Stage error: the non-top-level quoted name" <+> ppr br
         , text "must be used at the same stage at which is is bound" ]
 
+#ifndef GHCI
+rnTopSpliceDecls :: HsSplice RdrName -> RnM ([LHsDecl RdrName], FreeVars)
+rnTopSpliceDecls e = failTH e "Template Haskell top splice"
+
+rnSpliceType :: HsSplice RdrName -> PostTc Name Kind
+             -> RnM (HsType Name, FreeVars)
+rnSpliceType e _ = failTH e "Template Haskell type splice"
+
+rnSpliceExpr :: HsSplice RdrName -> RnM (HsExpr Name, FreeVars)
+rnSpliceExpr e = failTH e "Template Haskell splice"
+
+rnSplicePat :: HsSplice RdrName -> RnM (Either (Pat RdrName) (Pat Name), FreeVars)
+rnSplicePat e = failTH e "Template Haskell pattern splice"
+
+rnSpliceDecl :: SpliceDecl RdrName -> RnM (SpliceDecl Name, FreeVars)
+rnSpliceDecl e = failTH e "Template Haskell declaration splice"
+#else
 
 {-
 *********************************************************
@@ -739,6 +760,7 @@ illegalUntypedSplice = text "Untyped splices may not appear in typed brackets"
 --  = vcat [ hang (text "In the splice:")
 --              2 (char '$' <> pprParendExpr expr)
 --        , text "To see what the splice expanded to, use -ddump-splices" ]
+#endif
 
 checkThLocalName :: Name -> RnM ()
 checkThLocalName name
diff --git a/compiler/simplCore/CoreMonad.hs b/compiler/simplCore/CoreMonad.hs
index ea94d9b20e..03c990a83d 100644
--- a/compiler/simplCore/CoreMonad.hs
+++ b/compiler/simplCore/CoreMonad.hs
@@ -49,12 +49,16 @@ module CoreMonad (
     debugTraceMsg, debugTraceMsgS,
     dumpIfSet_dyn,
 
+#ifdef GHCI
     -- * Getting 'Name's
     thNameToGhcName
+#endif
   ) where
 
+#ifdef GHCI
 import Name( Name )
 import TcRnMonad        ( initTcForLookup )
+#endif
 import CoreSyn
 import HscTypes
 import Module
@@ -90,8 +94,10 @@ import Control.Applicative ( Alternative(..) )
 
 import Prelude hiding   ( read )
 
+#ifdef GHCI
 import {-# SOURCE #-} TcSplice ( lookupThName_maybe )
 import qualified Language.Haskell.TH as TH
+#endif
 
 {-
 ************************************************************************
@@ -806,6 +812,7 @@ instance MonadThings CoreM where
 ************************************************************************
 -}
 
+#ifdef GHCI
 -- | Attempt to convert a Template Haskell name to one that GHC can
 -- understand. Original TH names such as those you get when you use
 -- the @'foo@ syntax will be translated to their equivalent GHC name
@@ -816,3 +823,4 @@ thNameToGhcName :: TH.Name -> CoreM (Maybe Name)
 thNameToGhcName th_name = do
     hsc_env <- getHscEnv
     liftIO $ initTcForLookup hsc_env (lookupThName_maybe th_name)
+#endif
diff --git a/compiler/specialise/SpecConstr.hs b/compiler/specialise/SpecConstr.hs
index 2f2087cd2e..60632255d8 100644
--- a/compiler/specialise/SpecConstr.hs
+++ b/compiler/specialise/SpecConstr.hs
@@ -13,8 +13,10 @@ ToDo [Oct 2013]
 {-# LANGUAGE CPP #-}
 
 module SpecConstr(
-        specConstrProgram,
-        SpecConstrAnnotation(..)
+        specConstrProgram
+#ifdef GHCI
+        , SpecConstrAnnotation(..)
+#endif
     ) where
 
 #include "HsVersions.h"
@@ -59,9 +61,12 @@ import PrelNames        ( specTyConName )
 import Module
 
 -- See Note [Forcing specialisation]
-
+#ifndef GHCI
+type SpecConstrAnnotation = ()
+#else
 import TyCon ( TyCon )
 import GHC.Exts( SpecConstrAnnotation(..) )
+#endif
 
 {-
 -----------------------------------------------------
@@ -949,6 +954,11 @@ ignoreType    :: ScEnv -> Type   -> Bool
 ignoreDataCon  :: ScEnv -> DataCon -> Bool
 forceSpecBndr :: ScEnv -> Var    -> Bool
 
+#ifndef GHCI
+ignoreType    _ _  = False
+ignoreDataCon  _ _ = False
+#else /* GHCI */
+
 ignoreDataCon env dc = ignoreTyCon env (dataConTyCon dc)
 
 ignoreType env ty
@@ -959,6 +969,7 @@ ignoreType env ty
 ignoreTyCon :: ScEnv -> TyCon -> Bool
 ignoreTyCon env tycon
   = lookupUFM (sc_annotations env) tycon == Just NoSpecConstr
+#endif /* GHCI */
 
 forceSpecBndr env var = forceSpecFunTy env . snd . splitForAllTys . varType $ var
 
@@ -973,7 +984,9 @@ forceSpecArgTy env ty
   | Just (tycon, tys) <- splitTyConApp_maybe ty
   , tycon /= funTyCon
       = tyConName tycon == specTyConName
+#ifdef GHCI
         || lookupUFM (sc_annotations env) tycon == Just ForceSpecConstr
+#endif
         || any (forceSpecArgTy env) tys
 
 forceSpecArgTy _ _ = False
diff --git a/compiler/typecheck/TcAnnotations.hs b/compiler/typecheck/TcAnnotations.hs
index 7b3cc65dd1..33eb83b401 100644
--- a/compiler/typecheck/TcAnnotations.hs
+++ b/compiler/typecheck/TcAnnotations.hs
@@ -10,10 +10,14 @@
 
 module TcAnnotations ( tcAnnotations, annCtxt ) where
 
+#ifdef GHCI
 import {-# SOURCE #-} TcSplice ( runAnnotation )
 import Module
 import DynFlags
 import Control.Monad ( when )
+#else
+import DynFlags ( WarnReason(NoReason) )
+#endif
 
 import HsSyn
 import Annotations
@@ -22,7 +26,21 @@ import TcRnMonad
 import SrcLoc
 import Outputable
 
+#ifndef GHCI
+
+tcAnnotations :: [LAnnDecl Name] -> TcM [Annotation]
+-- No GHCI; emit a warning (not an error) and ignore. cf Trac #4268
+tcAnnotations [] = return []
+tcAnnotations anns@(L loc _ : _)
+  = do { setSrcSpan loc $ addWarnTc NoReason $
+             (text "Ignoring ANN annotation" <> plural anns <> comma
+             <+> text "because this is a stage-1 compiler or doesn't support GHCi")
+       ; return [] }
+
+#else
+
 tcAnnotations :: [LAnnDecl Name] -> TcM [Annotation]
+-- GHCI exists, typecheck the annotations
 tcAnnotations anns = mapM tcAnnotation anns
 
 tcAnnotation :: LAnnDecl Name -> TcM Annotation
@@ -45,6 +63,7 @@ annProvenanceToTarget :: Module -> AnnProvenance Name -> AnnTarget Name
 annProvenanceToTarget _   (ValueAnnProvenance (L _ name)) = NamedTarget name
 annProvenanceToTarget _   (TypeAnnProvenance (L _ name))  = NamedTarget name
 annProvenanceToTarget mod ModuleAnnProvenance             = ModuleTarget mod
+#endif
 
 annCtxt :: (OutputableBndrId id) => AnnDecl id -> SDoc
 annCtxt ann
diff --git a/compiler/typecheck/TcRnDriver.hs b/compiler/typecheck/TcRnDriver.hs
index ad49ca0601..0aa2924966 100644
--- a/compiler/typecheck/TcRnDriver.hs
+++ b/compiler/typecheck/TcRnDriver.hs
@@ -14,6 +14,7 @@ https://ghc.haskell.org/trac/ghc/wiki/Commentary/Compiler/TypeChecker
 {-# LANGUAGE ScopedTypeVariables #-}
 
 module TcRnDriver (
+#ifdef GHCI
         tcRnStmt, tcRnExpr, TcRnExprMode(..), tcRnType,
         tcRnImportDecls,
         tcRnLookupRdrName,
@@ -21,6 +22,7 @@ module TcRnDriver (
         tcRnDeclsi,
         isGHCiMonad,
         runTcInteractive,    -- Used by GHC API clients (Trac #8878)
+#endif
         tcRnLookupName,
         tcRnGetInfo,
         tcRnModule, tcRnModuleTcRnM,
@@ -40,6 +42,7 @@ module TcRnDriver (
         missingBootThing,
     ) where
 
+#ifdef GHCI
 import {-# SOURCE #-} TcSplice ( finishTH )
 import RnSplice ( rnTopSpliceDecls, traceSplice, SpliceInfo(..) )
 import IfaceEnv( externaliseName )
@@ -51,7 +54,6 @@ import RnExpr
 import MkId
 import TidyPgm    ( globaliseAndTidyId )
 import TysWiredIn ( unitTy, mkListTy )
-#ifdef GHCI
 import DynamicLoading ( loadPlugins )
 import Plugins ( tcPlugin )
 #endif
@@ -390,12 +392,14 @@ tcRnSrcDecls explicit_mod_hdr decls
       ; new_ev_binds <- {-# SCC "simplifyTop" #-}
                         simplifyTop lie
 
+#ifdef GHCI
         -- Finalizers must run after constraints are simplified, or some types
         -- might not be complete when using reify (see #12777).
       ; (tcg_env, tcl_env) <- run_th_modfinalizers
       ; setEnvs (tcg_env, tcl_env) $ do {
 
       ; finishTH
+#endif /* GHCI */
 
       ; traceTc "Tc9" empty
 
@@ -432,9 +436,12 @@ tcRnSrcDecls explicit_mod_hdr decls
 
       ; setGlobalTypeEnv tcg_env' final_type_env
 
+#ifdef GHCI
    }
+#endif /* GHCI */
    } }
 
+#ifdef GHCI
 -- | Runs TH finalizers and renames and typechecks the top-level declarations
 -- that they could introduce.
 run_th_modfinalizers :: TcM (TcGblEnv, TcLclEnv)
@@ -460,6 +467,7 @@ run_th_modfinalizers = do
         )
         -- addTopDecls can add declarations which add new finalizers.
         run_th_modfinalizers
+#endif /* GHCI */
 
 tc_rn_src_decls :: [LHsDecl RdrName]
                 -> TcM (TcGblEnv, TcLclEnv)
@@ -474,6 +482,7 @@ tc_rn_src_decls ds
       ; (tcg_env, rn_decls) <- rnTopSrcDecls first_group
                 -- rnTopSrcDecls fails if there are any errors
 
+#ifdef GHCI
         -- Get TH-generated top-level declarations and make sure they don't
         -- contain any splices since we don't handle that at the moment
         --
@@ -506,6 +515,7 @@ tc_rn_src_decls ds
 
                     ; return (tcg_env, appendGroups rn_decls th_rn_decls)
                     }
+#endif /* GHCI */
 
       -- Type check all declarations
       ; (tcg_env, tcl_env) <- setGblEnv tcg_env $
@@ -516,6 +526,12 @@ tc_rn_src_decls ds
         case group_tail of
           { Nothing -> return (tcg_env, tcl_env)
 
+#ifndef GHCI
+            -- There shouldn't be a splice
+          ; Just (SpliceDecl {}, _) ->
+            failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
+          }
+#else
             -- If there's a splice, we must carry on
           ; Just (SpliceDecl (L loc splice) _, rest_ds) ->
             do { recordTopLevelSpliceLoc loc
@@ -529,6 +545,7 @@ tc_rn_src_decls ds
                  tc_rn_src_decls (spliced_decls ++ rest_ds)
                }
           }
+#endif /* GHCI */
       }
 
 {-
@@ -1741,6 +1758,7 @@ lead to duplicate "perhaps you meant..." suggestions (e.g. T5564).
 We don't bother with the tcl_th_bndrs environment either.
 -}
 
+#ifdef GHCI
 -- | The returned [Id] is the list of new Ids bound by this statement. It can
 -- be used to extend the InteractiveContext via extendInteractiveContext.
 --
@@ -2242,6 +2260,7 @@ externaliseAndTidyId this_mod id
   = do { name' <- externaliseName this_mod (idName id)
        ; return (globaliseAndTidyId (setIdName id name')) }
 
+#endif /* GHCi */
 
 {-
 ************************************************************************
@@ -2251,6 +2270,7 @@ externaliseAndTidyId this_mod id
 ************************************************************************
 -}
 
+#ifdef GHCI
 -- | ASSUMES that the module is either in the 'HomePackageTable' or is
 -- a package module with an interface on disk.  If neither of these is
 -- true, then the result will be an error indicating the interface
@@ -2274,6 +2294,7 @@ tcRnLookupRdrName hsc_env (L loc rdr_name)
        ; let names = concat names_s
        ; when (null names) (addErrTc (text "Not in scope:" <+> quotes (ppr rdr_name)))
        ; return names }
+#endif
 
 tcRnLookupName :: HscEnv -> Name -> IO (Messages, Maybe TyThing)
 tcRnLookupName hsc_env name
diff --git a/compiler/typecheck/TcRnMonad.hs b/compiler/typecheck/TcRnMonad.hs
index 8c117f0936..a77541cf3a 100644
--- a/compiler/typecheck/TcRnMonad.hs
+++ b/compiler/typecheck/TcRnMonad.hs
@@ -177,8 +177,10 @@ import Control.Monad
 import Data.Set ( Set )
 import qualified Data.Set as Set
 
+#ifdef GHCI
 import {-# SOURCE #-} TcSplice ( runRemoteModFinalizers )
 import qualified Data.Map as Map
+#endif
 
 {-
 ************************************************************************
@@ -216,11 +218,13 @@ initTc hsc_env hsc_src keep_rn_syntax mod loc do_this
 
         dependent_files_var <- newIORef [] ;
         static_wc_var       <- newIORef emptyWC ;
+#ifdef GHCI
         th_topdecls_var      <- newIORef [] ;
         th_topnames_var      <- newIORef emptyNameSet ;
         th_modfinalizers_var <- newIORef [] ;
         th_state_var         <- newIORef Map.empty ;
         th_remote_state_var  <- newIORef Nothing ;
+#endif /* GHCI */
         let {
              dflags = hsc_dflags hsc_env ;
 
@@ -230,11 +234,13 @@ initTc hsc_env hsc_src keep_rn_syntax mod loc do_this
                 | otherwise      = Nothing ;
 
              gbl_env = TcGblEnv {
+#ifdef GHCI
                 tcg_th_topdecls      = th_topdecls_var,
                 tcg_th_topnames      = th_topnames_var,
                 tcg_th_modfinalizers = th_modfinalizers_var,
                 tcg_th_state         = th_state_var,
                 tcg_th_remote_state  = th_remote_state_var,
+#endif /* GHCI */
 
                 tcg_mod            = mod,
                 tcg_semantic_mod   =
@@ -1078,8 +1084,13 @@ failIfErrsM :: TcRn ()
 -- Useful to avoid error cascades
 failIfErrsM = ifErrsM failM (return ())
 
+#ifdef GHCI
 checkTH :: a -> String -> TcRn ()
 checkTH _ _ = return () -- OK
+#else
+checkTH :: Outputable a => a -> String -> TcRn ()
+checkTH e what = failTH e what  -- Raise an error in a stage-1 compiler
+#endif
 
 failTH :: Outputable a => a -> String -> TcRn x
 failTH e what  -- Raise an error in a stage-1 compiler
@@ -1600,6 +1611,7 @@ getStageAndBindLevel name
 setStage :: ThStage -> TcM a -> TcRn a
 setStage s = updLclEnv (\ env -> env { tcl_th_ctxt = s })
 
+#ifdef GHCI
 -- | Adds the given modFinalizers to the global environment and set them to use
 -- the current local environment.
 addModFinalizersWithLclEnv :: ThModFinalizers -> TcM ()
@@ -1609,6 +1621,10 @@ addModFinalizersWithLclEnv mod_finalizers
        updTcRef th_modfinalizers_var $ \fins ->
          setLclEnv lcl_env (runRemoteModFinalizers mod_finalizers)
          : fins
+#else
+addModFinalizersWithLclEnv :: ThModFinalizers -> TcM ()
+addModFinalizersWithLclEnv ThModFinalizers = return ()
+#endif
 
 {-
 ************************************************************************
diff --git a/compiler/typecheck/TcRnTypes.hs b/compiler/typecheck/TcRnTypes.hs
index 6d902b32e0..ef94fb6310 100644
--- a/compiler/typecheck/TcRnTypes.hs
+++ b/compiler/typecheck/TcRnTypes.hs
@@ -181,6 +181,7 @@ import qualified Control.Monad.Fail as MonadFail
 #endif
 import Data.Set      ( Set )
 
+#ifdef GHCI
 import Data.Map      ( Map )
 import Data.Dynamic  ( Dynamic )
 import Data.Typeable ( TypeRep )
@@ -188,6 +189,7 @@ import GHCi.Message
 import GHCi.RemoteTypes
 
 import qualified Language.Haskell.TH as TH
+#endif
 
 -- | A 'NameShape' is a substitution on 'Name's that can be used
 -- to refine the identities of a hole while we are renaming interfaces
@@ -585,6 +587,7 @@ data TcGblEnv
 
         tcg_dependent_files :: TcRef [FilePath], -- ^ dependencies from addDependentFile
 
+#ifdef GHCI
         tcg_th_topdecls :: TcRef [LHsDecl RdrName],
         -- ^ Top-level declarations from addTopDecls
 
@@ -600,6 +603,7 @@ data TcGblEnv
         tcg_th_state :: TcRef (Map TypeRep Dynamic),
         tcg_th_remote_state :: TcRef (Maybe (ForeignRef (IORef QState))),
         -- ^ Template Haskell state
+#endif /* GHCI */
 
         tcg_ev_binds  :: Bag EvBind,        -- Top-level evidence bindings
 
@@ -865,6 +869,7 @@ data ThStage    -- See Note [Template Haskell state diagram] in TcSplice
                       --   the result replaces the splice
                       -- Binding level = 0
 
+#ifdef GHCI
   | RunSplice (TcRef [ForeignRef (TH.Q ())])
       -- Set when running a splice, i.e. NOT when renaming or typechecking the
       -- Haskell code for the splice. See Note [RunSplice ThLevel].
@@ -879,6 +884,9 @@ data ThStage    -- See Note [Template Haskell state diagram] in TcSplice
       -- inserts them in the list of finalizers in the global environment.
       --
       -- See Note [Collecting modFinalizers in typed splices] in "TcSplice".
+#else
+  | RunSplice ()
+#endif
 
   | Comp        -- Ordinary Haskell code
                 -- Binding level = 1
diff --git a/compiler/typecheck/TcSplice.hs b/compiler/typecheck/TcSplice.hs
index 9942107c45..1e35eec144 100644
--- a/compiler/typecheck/TcSplice.hs
+++ b/compiler/typecheck/TcSplice.hs
@@ -17,15 +17,21 @@ TcSplice: Template Haskell splices
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 
 module TcSplice(
+     -- These functions are defined in stage1 and stage2
+     -- The raise civilised errors in stage1
      tcSpliceExpr, tcTypedBracket, tcUntypedBracket,
 --     runQuasiQuoteExpr, runQuasiQuotePat,
 --     runQuasiQuoteDecl, runQuasiQuoteType,
      runAnnotation,
 
+#ifdef GHCI
+     -- These ones are defined only in stage2, and are
+     -- called only in stage2 (ie GHCI is on)
      runMetaE, runMetaP, runMetaT, runMetaD, runQuasi,
      tcTopSpliceExpr, lookupThName_maybe,
      defaultRunMeta, runMeta', runRemoteModFinalizers,
      finishTH
+#endif
       ) where
 
 #include "HsVersions.h"
@@ -45,6 +51,7 @@ import TcEnv
 
 import Control.Monad
 
+#ifdef GHCI
 import GHCi.Message
 import GHCi.RemoteTypes
 import GHCi
@@ -123,6 +130,7 @@ import Data.Typeable ( typeOf, Typeable, TypeRep, typeRep )
 import Data.Data (Data)
 import Data.Proxy    ( Proxy (..) )
 import GHC.Exts         ( unsafeCoerce# )
+#endif
 
 {-
 ************************************************************************
@@ -230,6 +238,16 @@ quotationCtxtDoc br_body
          2 (ppr br_body)
 
 
+#ifndef GHCI
+tcSpliceExpr  e _      = failTH e "Template Haskell splice"
+
+-- runQuasiQuoteExpr q = failTH q "quasiquote"
+-- runQuasiQuotePat  q = failTH q "pattern quasiquote"
+-- runQuasiQuoteType q = failTH q "type quasiquote"
+-- runQuasiQuoteDecl q = failTH q "declaration quasiquote"
+runAnnotation   _ q = failTH q "annotation"
+
+#else
   -- The whole of the rest of the file is the else-branch (ie stage2 only)
 
 {-
@@ -1997,3 +2015,5 @@ such fields defined in the module (see the test case
 overloadedrecflds/should_fail/T11103.hs).  The "proper" fix requires changes to
 the TH AST to make it able to represent duplicate record fields.
 -}
+
+#endif  /* GHCI */
diff --git a/compiler/typecheck/TcSplice.hs-boot b/compiler/typecheck/TcSplice.hs-boot
index db75436d4d..14e479a04e 100644
--- a/compiler/typecheck/TcSplice.hs-boot
+++ b/compiler/typecheck/TcSplice.hs-boot
@@ -8,10 +8,12 @@ import TcRnTypes( TcM, TcId )
 import TcType   ( ExpRhoType )
 import Annotations ( Annotation, CoreAnnTarget )
 
+#ifdef GHCI
 import HsSyn      ( LHsType, LPat, LHsDecl, ThModFinalizers )
 import RdrName    ( RdrName )
 import TcRnTypes  ( SpliceType )
 import qualified Language.Haskell.TH as TH
+#endif
 
 tcSpliceExpr :: HsSplice Name
              -> ExpRhoType
@@ -27,6 +29,7 @@ tcTypedBracket :: HsBracket Name
 
 runAnnotation     :: CoreAnnTarget -> LHsExpr Name -> TcM Annotation
 
+#ifdef GHCI
 tcTopSpliceExpr :: SpliceType -> TcM (LHsExpr TcId) -> TcM (LHsExpr TcId)
 
 runMetaE :: LHsExpr TcId -> TcM (LHsExpr RdrName)
@@ -38,3 +41,4 @@ lookupThName_maybe :: TH.Name -> TcM (Maybe Name)
 runQuasi :: TH.Q a -> TcM a
 runRemoteModFinalizers :: ThModFinalizers -> TcM ()
 finishTH :: TcM ()
+#endif
diff --git a/ghc.mk b/ghc.mk
index e52c4c4091..a06c4a7fae 100644
--- a/ghc.mk
+++ b/ghc.mk
@@ -430,7 +430,7 @@ else # CLEANING
 # programs such as GHC and ghc-pkg, that we do not assume the stage0
 # compiler already has installed (or up-to-date enough).
 
-PACKAGES_STAGE0 = binary Cabal/Cabal hpc ghc-boot-th ghc-boot hoopl transformers template-haskell ghci
+PACKAGES_STAGE0 = binary Cabal/Cabal hpc ghc-boot-th ghc-boot hoopl transformers template-haskell
 ifeq "$(Windows_Host)" "NO"
 PACKAGES_STAGE0 += terminfo
 endif
@@ -589,9 +589,6 @@ ALL_STAGE1_LIBS += $(foreach lib,$(PACKAGES_STAGE1),$(libraries/$(lib)_dist-inst
 endif
 BOOT_LIBS = $(foreach lib,$(PACKAGES_STAGE0),$(libraries/$(lib)_dist-boot_v_LIB))
 
-# Only build internal interpreter support for the stage2 ghci lib
-libraries/ghci_dist-install_CONFIGURE_OPTS += --flags=ghci
-
 # ----------------------------------------
 # Special magic for the ghc-prim package
 
diff --git a/libraries/ghci/GHCi/BreakArray.hs b/libraries/ghci/GHCi/BreakArray.hs
index bece43bdb9..311bbd6c5e 100644
--- a/libraries/ghci/GHCi/BreakArray.hs
+++ b/libraries/ghci/GHCi/BreakArray.hs
@@ -19,17 +19,14 @@
 module GHCi.BreakArray
     (
       BreakArray
-#ifdef GHCI
           (BA) -- constructor is exported only for ByteCodeGen
     , newBreakArray
     , getBreak
     , setBreakOn
     , setBreakOff
     , showBreakArray
-#endif
     ) where
 
-#ifdef GHCI
 import Control.Monad
 import Data.Word
 import GHC.Word
@@ -115,6 +112,3 @@ readBA# array i = IO $ \s ->
 
 readBreakArray :: BreakArray -> Int -> IO Word8
 readBreakArray (BA array) (I# i) = readBA# array i
-#else
-data BreakArray
-#endif
diff --git a/libraries/ghci/GHCi/InfoTable.hsc b/libraries/ghci/GHCi/InfoTable.hsc
index 8a9dfc2fa0..e4deb3b6ff 100644
--- a/libraries/ghci/GHCi/InfoTable.hsc
+++ b/libraries/ghci/GHCi/InfoTable.hsc
@@ -6,11 +6,9 @@
 -- We use the RTS data structures directly via hsc2hs.
 --
 module GHCi.InfoTable
-  ( peekItbl, StgInfoTable(..)
+  ( mkConInfoTable
+  , peekItbl, StgInfoTable(..)
   , conInfoPtr
-#ifdef GHCI
-  , mkConInfoTable
-#endif
   ) where
 
 #if !defined(TABLES_NEXT_TO_CODE)
@@ -22,66 +20,6 @@ import GHC.Ptr
 import GHC.Exts
 import System.IO.Unsafe
 
-type ItblCodes = Either [Word8] [Word32]
-
--- Get definitions for the structs, constants & config etc.
-#include "Rts.h"
-
--- Ultra-minimalist version specially for constructors
-#if SIZEOF_VOID_P == 8
-type HalfWord = Word32
-#elif SIZEOF_VOID_P == 4
-type HalfWord = Word16
-#else
-#error Uknown SIZEOF_VOID_P
-#endif
-
-type EntryFunPtr = FunPtr (Ptr () -> IO (Ptr ()))
-
-data StgInfoTable = StgInfoTable {
-   entry  :: Maybe EntryFunPtr, -- Just <=> not ghciTablesNextToCode
-   ptrs   :: HalfWord,
-   nptrs  :: HalfWord,
-   tipe   :: HalfWord,
-   srtlen :: HalfWord,
-   code   :: Maybe ItblCodes -- Just <=> ghciTablesNextToCode
-  }
-
-peekItbl :: Ptr StgInfoTable -> IO StgInfoTable
-peekItbl a0 = do
-#if defined(TABLES_NEXT_TO_CODE)
-  let entry' = Nothing
-#else
-  entry' <- Just <$> (#peek StgInfoTable, entry) a0
-#endif
-  ptrs' <- (#peek StgInfoTable, layout.payload.ptrs) a0
-  nptrs' <- (#peek StgInfoTable, layout.payload.nptrs) a0
-  tipe' <- (#peek StgInfoTable, type) a0
-  srtlen' <- (#peek StgInfoTable, srt_bitmap) a0
-  return StgInfoTable
-    { entry  = entry'
-    , ptrs   = ptrs'
-    , nptrs  = nptrs'
-    , tipe   = tipe'
-    , srtlen = srtlen'
-    , code   = Nothing
-    }
-
--- | Convert a pointer to an StgConInfo into an info pointer that can be
--- used in the header of a closure.
-conInfoPtr :: Ptr () -> Ptr ()
-conInfoPtr ptr
- | ghciTablesNextToCode = ptr `plusPtr` (#size StgConInfoTable)
- | otherwise            = ptr
-
-ghciTablesNextToCode :: Bool
-#ifdef TABLES_NEXT_TO_CODE
-ghciTablesNextToCode = True
-#else
-ghciTablesNextToCode = False
-#endif
-
-#ifdef GHCI /* To end */
 mkConInfoTable
    :: Int     -- ptr words
    -> Int     -- non-ptr words
@@ -114,6 +52,8 @@ mkConInfoTable ptr_words nonptr_words tag ptrtag con_desc =
 -- -----------------------------------------------------------------------------
 -- Building machine code fragments for a constructor's entry code
 
+type ItblCodes = Either [Word8] [Word32]
+
 funPtrToInt :: FunPtr a -> Int
 funPtrToInt (FunPtr a) = I## (addr2Int## a)
 
@@ -340,6 +280,9 @@ byte7 w = fromIntegral (w `shiftR` 56)
 -- -----------------------------------------------------------------------------
 -- read & write intfo tables
 
+-- Get definitions for the structs, constants & config etc.
+#include "Rts.h"
+
 -- entry point for direct returns for created constr itbls
 foreign import ccall "&stg_interp_constr1_entry" stg_interp_constr1_entry :: EntryFunPtr
 foreign import ccall "&stg_interp_constr2_entry" stg_interp_constr2_entry :: EntryFunPtr
@@ -359,11 +302,30 @@ interpConstrEntry = [ error "pointer tag 0"
                     , stg_interp_constr6_entry
                     , stg_interp_constr7_entry ]
 
+-- Ultra-minimalist version specially for constructors
+#if SIZEOF_VOID_P == 8
+type HalfWord = Word32
+#elif SIZEOF_VOID_P == 4
+type HalfWord = Word16
+#else
+#error Uknown SIZEOF_VOID_P
+#endif
+
 data StgConInfoTable = StgConInfoTable {
    conDesc   :: Ptr Word8,
    infoTable :: StgInfoTable
 }
 
+type EntryFunPtr = FunPtr (Ptr () -> IO (Ptr ()))
+
+data StgInfoTable = StgInfoTable {
+   entry  :: Maybe EntryFunPtr, -- Just <=> not ghciTablesNextToCode
+   ptrs   :: HalfWord,
+   nptrs  :: HalfWord,
+   tipe   :: HalfWord,
+   srtlen :: HalfWord,
+   code   :: Maybe ItblCodes -- Just <=> ghciTablesNextToCode
+  }
 
 pokeConItbl
   :: Ptr StgConInfoTable -> Ptr StgConInfoTable -> StgConInfoTable
@@ -402,6 +364,26 @@ pokeItbl a0 itbl = do
     Just (Right xs) -> pokeArray code_offset xs
 #endif
 
+peekItbl :: Ptr StgInfoTable -> IO StgInfoTable
+peekItbl a0 = do
+#if defined(TABLES_NEXT_TO_CODE)
+  let entry' = Nothing
+#else
+  entry' <- Just <$> (#peek StgInfoTable, entry) a0
+#endif
+  ptrs' <- (#peek StgInfoTable, layout.payload.ptrs) a0
+  nptrs' <- (#peek StgInfoTable, layout.payload.nptrs) a0
+  tipe' <- (#peek StgInfoTable, type) a0
+  srtlen' <- (#peek StgInfoTable, srt_bitmap) a0
+  return StgInfoTable
+    { entry  = entry'
+    , ptrs   = ptrs'
+    , nptrs  = nptrs'
+    , tipe   = tipe'
+    , srtlen = srtlen'
+    , code   = Nothing
+    }
+
 newExecConItbl :: StgInfoTable -> [Word8] -> IO (FunPtr ())
 newExecConItbl obj con_desc
    = alloca $ \pcode -> do
@@ -426,6 +408,13 @@ foreign import ccall unsafe "allocateExec"
 foreign import ccall unsafe "flushExec"
   _flushExec :: CUInt -> Ptr a -> IO ()
 
+-- | Convert a pointer to an StgConInfo into an info pointer that can be
+-- used in the header of a closure.
+conInfoPtr :: Ptr () -> Ptr ()
+conInfoPtr ptr
+ | ghciTablesNextToCode = ptr `plusPtr` (#size StgConInfoTable)
+ | otherwise            = ptr
+
 -- -----------------------------------------------------------------------------
 -- Constants and config
 
@@ -454,4 +443,10 @@ rtsIsProfiled = unsafeDupablePerformIO rtsIsProfiledIO /= 0
 
 cONSTR :: Int   -- Defined in ClosureTypes.h
 cONSTR = (#const CONSTR)
-#endif /* GHCI */
+
+ghciTablesNextToCode :: Bool
+#ifdef TABLES_NEXT_TO_CODE
+ghciTablesNextToCode = True
+#else
+ghciTablesNextToCode = False
+#endif
diff --git a/libraries/ghci/GHCi/Message.hs b/libraries/ghci/GHCi/Message.hs
index fe4e95eb9e..4d0417e2da 100644
--- a/libraries/ghci/GHCi/Message.hs
+++ b/libraries/ghci/GHCi/Message.hs
@@ -1,6 +1,5 @@
-{-# LANGUAGE GADTs, DeriveGeneric, StandaloneDeriving, ScopedTypeVariables,
-    GeneralizedNewtypeDeriving, ExistentialQuantification, RecordWildCards,
-    CPP #-}
+{-# LANGUAGE GADTs, DeriveGeneric, StandaloneDeriving,
+    GeneralizedNewtypeDeriving, ExistentialQuantification, RecordWildCards #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing -fno-warn-orphans #-}
 
 -- |
@@ -15,7 +14,6 @@ module GHCi.Message
   , QResult(..)
   , EvalStatus_(..), EvalStatus, EvalResult(..), EvalOpts(..), EvalExpr(..)
   , SerializableException(..)
-  , toSerializableException, fromSerializableException
   , THResult(..), THResultType(..)
   , ResumeContext(..)
   , QState(..)
@@ -42,11 +40,7 @@ import Data.Dynamic
 import Data.IORef
 import Data.Map (Map)
 import GHC.Generics
-#if MIN_VERSION_base(4,9,0)
 import GHC.Stack.CCS
-#else
-import GHC.Stack as GHC.Stack.CCS
-#endif
 import qualified Language.Haskell.TH        as TH
 import qualified Language.Haskell.TH.Syntax as TH
 import System.Exit
@@ -358,28 +352,7 @@ data SerializableException
   | EOtherException String
   deriving (Generic, Show)
 
-toSerializableException :: SomeException -> SerializableException
-toSerializableException ex
-  | Just UserInterrupt <- fromException ex  = EUserInterrupt
-  | Just (ec::ExitCode) <- fromException ex = (EExitCode ec)
-  | otherwise = EOtherException (show (ex :: SomeException))
-
-fromSerializableException :: SerializableException -> SomeException
-fromSerializableException EUserInterrupt = toException UserInterrupt
-fromSerializableException (EExitCode c) = toException c
-fromSerializableException (EOtherException str) = toException (ErrorCall str)
-
--- NB: Replace this with a derived instance once we depend on GHC 8.0
--- as the minimum
-instance Binary ExitCode where
-  put ExitSuccess      = putWord8 0
-  put (ExitFailure ec) = putWord8 1 `mappend` put ec
-  get = do
-    w <- getWord8
-    case w of
-      0 -> pure ExitSuccess
-      _ -> ExitFailure <$> get
-
+instance Binary ExitCode
 instance Binary SerializableException
 
 data THResult a
diff --git a/libraries/ghci/GHCi/Run.hs b/libraries/ghci/GHCi/Run.hs
index 858b247f65..fefbdc32c1 100644
--- a/libraries/ghci/GHCi/Run.hs
+++ b/libraries/ghci/GHCi/Run.hs
@@ -10,6 +10,7 @@
 --
 module GHCi.Run
   ( run, redirectInterrupts
+  , toSerializableException, fromSerializableException
   ) where
 
 import GHCi.CreateBCO
@@ -35,6 +36,7 @@ import Foreign
 import Foreign.C
 import GHC.Conc.Sync
 import GHC.IO hiding ( bracket )
+import System.Exit
 import System.Mem.Weak  ( deRefWeak )
 import Unsafe.Coerce
 
@@ -221,6 +223,17 @@ tryEval io = do
     Left ex -> return (EvalException (toSerializableException ex))
     Right a -> return (EvalSuccess a)
 
+toSerializableException :: SomeException -> SerializableException
+toSerializableException ex
+  | Just UserInterrupt <- fromException ex  = EUserInterrupt
+  | Just (ec::ExitCode) <- fromException ex = (EExitCode ec)
+  | otherwise = EOtherException (show (ex :: SomeException))
+
+fromSerializableException :: SerializableException -> SomeException
+fromSerializableException EUserInterrupt = toException UserInterrupt
+fromSerializableException (EExitCode c) = toException c
+fromSerializableException (EOtherException str) = toException (ErrorCall str)
+
 -- This function sets up the interpreter for catching breakpoints, and
 -- resets everything when the computation has stopped running.  This
 -- is a not-very-good way to ensure that only the interactive
diff --git a/libraries/ghci/ghci.cabal.in b/libraries/ghci/ghci.cabal.in
index 87b2c4e2fd..9b622e1107 100644
--- a/libraries/ghci/ghci.cabal.in
+++ b/libraries/ghci/ghci.cabal.in
@@ -17,11 +17,6 @@ cabal-version:  >=1.10
 build-type:     Simple
 extra-source-files: changelog.md
 
-Flag ghci
-    Description: Build GHCi support.
-    Default: False
-    Manual: True
-
 source-repository head
     type:     git
     location: http://git.haskell.org/ghc.git
@@ -46,28 +41,24 @@ library
         TupleSections
         UnboxedTuples
 
-    if flag(ghci)
-        CPP-Options: -DGHCI
-        exposed-modules:
-            GHCi.Run
-            GHCi.CreateBCO
-            GHCi.ObjLink
-            GHCi.Signals
-            GHCi.TH
-
     exposed-modules:
         GHCi.BreakArray
         GHCi.Message
         GHCi.ResolvedBCO
         GHCi.RemoteTypes
+        GHCi.ObjLink
+        GHCi.CreateBCO
         GHCi.FFI
         GHCi.InfoTable
+        GHCi.Run
+        GHCi.Signals
+        GHCi.TH
         GHCi.TH.Binary
         SizedSeq
 
     Build-Depends:
         array            == 0.5.*,
-        base             >= 4.8 && < 4.11,
+        base             == 4.10.*,
         binary           == 0.8.*,
         bytestring       == 0.10.*,
         containers       == 0.5.*,