9 files changed, 30 insertions, 19 deletions
diff --git a/compiler/ghc.cabal.in b/compiler/ghc.cabal.in
index e8e6bf7317..e1f0bec2b0 100644
--- a/compiler/ghc.cabal.in
+++ b/compiler/ghc.cabal.in
@@ -25,6 +25,11 @@ Flag ghci
     Default: False
     Manual: True
 
+Flag ext-interp
+    Description: Support external interpreter
+    Default: True
+    Manual: True
+
 Flag stage1
     Description: Is this stage 1?
     Default: False
@@ -90,9 +95,15 @@ Library
                  -Wnoncanonical-monoid-instances
 
     if flag(ghci)
-        CPP-Options: -DGHCI
+        CPP-Options: -DHAVE_INTERNAL_INTERPRETER
         Include-Dirs: ../rts/dist/build @FFIIncludeDir@
 
+    if flag(ext-interp)
+        CPP-Options: -DHAVE_EXTERNAL_INTERPRETER
+
+    if flag(ghci) || flag(ext-interp)
+        CPP-Options: -DHAVE_INTERPRETER
+
     -- sanity-check to ensure not more than one integer flag is set
     if flag(integer-gmp) && flag(integer-simple)
         build-depends: invalid-cabal-flag-settings<0
diff --git a/compiler/ghci/GHCi.hs b/compiler/ghci/GHCi.hs
index 7ec07fec78..8795b30973 100644
--- a/compiler/ghci/GHCi.hs
+++ b/compiler/ghci/GHCi.hs
@@ -51,7 +51,7 @@ module GHCi
 import GhcPrelude
 
 import GHCi.Message
-#if defined(GHCI)
+#if defined(HAVE_INTERNAL_INTERPRETER)
 import GHCi.Run
 #endif
 import GHCi.RemoteTypes
@@ -157,7 +157,7 @@ Other Notes on Remote GHCi
   * Note [Remote Template Haskell] in libraries/ghci/GHCi/TH.hs
 -}
 
-#if !defined(GHCI)
+#if !defined(HAVE_INTERNAL_INTERPRETER)
 needExtInt :: IO a
 needExtInt = throwIO
   (InstallationError "this operation requires -fexternal-interpreter")
@@ -175,7 +175,7 @@ iservCmd hsc_env@HscEnv{..} msg
        uninterruptibleMask_ $ do -- Note [uninterruptibleMask_]
          iservCall iserv msg
  | otherwise = -- Just run it directly
-#if defined(GHCI)
+#if defined(HAVE_INTERNAL_INTERPRETER)
    run msg
 #else
    needExtInt
@@ -391,7 +391,7 @@ lookupSymbol hsc_env@HscEnv{..} str
                writeIORef iservLookupSymbolCache $! addToUFM cache str p
                return (Just p)
  | otherwise =
-#if defined(GHCI)
+#if defined(HAVE_INTERNAL_INTERPRETER)
    fmap fromRemotePtr <$> run (LookupSymbol (unpackFS str))
 #else
    needExtInt
@@ -642,7 +642,7 @@ wormholeRef dflags _r
   | gopt Opt_ExternalInterpreter dflags
   = throwIO (InstallationError
       "this operation requires -fno-external-interpreter")
-#if defined(GHCI)
+#if defined(HAVE_INTERNAL_INTERPRETER)
   | otherwise
   = localRef _r
 #else
diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index 5217fced5f..0b2b32d5bb 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -320,8 +320,8 @@ import qualified EnumSet
 import GHC.Foreign (withCString, peekCString)
 import qualified GHC.LanguageExtensions as LangExt
 
-#if defined(GHCI)
-import Foreign (Ptr) -- needed for 2nd stage
+#if defined(HAVE_INTERPRETER)
+import Foreign (Ptr)
 #endif
 
 -- Note [Updating flag description in the User's Guide]
@@ -4342,7 +4342,7 @@ supportedExtensions :: [String]
 supportedExtensions = concatMap toFlagSpecNamePair xFlags
   where
     toFlagSpecNamePair flg
-#if !defined(GHCI)
+#if !defined(HAVE_INTERPRETER)
       -- IMPORTANT! Make sure that `ghc --supported-extensions` omits
       -- "TemplateHaskell"/"QuasiQuotes" when it's known not to work out of the
       -- box. See also GHC #11102 and #16331 for more details about
diff --git a/compiler/main/DynamicLoading.hs b/compiler/main/DynamicLoading.hs
index 0a5264e3f2..64cc0a1216 100644
--- a/compiler/main/DynamicLoading.hs
+++ b/compiler/main/DynamicLoading.hs
@@ -3,7 +3,7 @@
 -- | Dynamically lookup up values from modules and loading them.
 module DynamicLoading (
         initializePlugins,
-#if defined(GHCI)
+#if defined(HAVE_INTERPRETER)
         -- * Loading plugins
         loadFrontendPlugin,
 
@@ -27,7 +27,7 @@ module DynamicLoading (
 import GhcPrelude
 import DynFlags
 
-#if defined(GHCI)
+#if defined(HAVE_INTERPRETER)
 import Linker           ( linkModule, getHValue )
 import GHCi             ( wormhole )
 import SrcLoc           ( noSrcSpan )
@@ -76,7 +76,7 @@ import Control.Monad    ( unless )
 -- actual compilation starts. Idempotent operation. Should be re-called if
 -- pluginModNames or pluginModNameOpts changes.
 initializePlugins :: HscEnv -> DynFlags -> IO DynFlags
-#if !defined(GHCI)
+#if !defined(HAVE_INTERPRETER)
 initializePlugins _ df
   = do let pluginMods = pluginModNames df
        unless (null pluginMods) (pluginError pluginMods)
@@ -96,7 +96,7 @@ initializePlugins hsc_env df
 #endif
 
 
-#if defined(GHCI)
+#if defined(HAVE_INTERPRETER)
 
 loadPlugins :: HscEnv -> IO [LoadedPlugin]
 loadPlugins hsc_env
diff --git a/compiler/rename/RnExpr.hs b/compiler/rename/RnExpr.hs
index 7b00a62403..98d487df2d 100644
--- a/compiler/rename/RnExpr.hs
+++ b/compiler/rename/RnExpr.hs
@@ -208,7 +208,7 @@ rnExpr (NegApp _ e _)
 
 ------------------------------------------
 -- Template Haskell extensions
--- Don't ifdef-GHCI them because we want to fail gracefully
+-- Don't ifdef-HAVE_INTERPRETER them because we want to fail gracefully
 -- (not with an rnExpr crash) in a stage-1 compiler.
 rnExpr e@(HsBracket _ br_body) = rnBracket e br_body
 
diff --git a/compiler/simplCore/SimplCore.hs b/compiler/simplCore/SimplCore.hs
index ade9816a1b..572084c420 100644
--- a/compiler/simplCore/SimplCore.hs
+++ b/compiler/simplCore/SimplCore.hs
@@ -462,7 +462,7 @@ doCorePass (CoreDoRuleCheck phase pat)  = ruleCheckPass phase pat
 doCorePass CoreDoNothing                = return
 doCorePass (CoreDoPasses passes)        = runCorePasses passes
 
-#if defined(GHCI)
+#if defined(HAVE_INTERPRETER)
 doCorePass (CoreDoPluginPass _ pass) = {-# SCC "Plugin" #-} pass
 #else
 doCorePass pass@CoreDoPluginPass {}  = pprPanic "doCorePass" (ppr pass)
diff --git a/compiler/typecheck/TcAnnotations.hs b/compiler/typecheck/TcAnnotations.hs
index 050c5db977..60f21ccce7 100644
--- a/compiler/typecheck/TcAnnotations.hs
+++ b/compiler/typecheck/TcAnnotations.hs
@@ -28,7 +28,7 @@ import Outputable
 -- Some platforms don't support the external interpreter, and
 -- compilation on those platforms shouldn't fail just due to
 -- annotations
-#ifndef GHCI
+#if !defined(HAVE_INTERNAL_INTERPRETER)
 tcAnnotations :: [LAnnDecl GhcRn] -> TcM [Annotation]
 tcAnnotations anns = do
   dflags <- getDynFlags
diff --git a/compiler/typecheck/TcPluginM.hs b/compiler/typecheck/TcPluginM.hs
index a112003ef9..3785a4aac5 100644
--- a/compiler/typecheck/TcPluginM.hs
+++ b/compiler/typecheck/TcPluginM.hs
@@ -3,7 +3,7 @@
 -- access select functions of the 'TcM', principally those to do with
 -- reading parts of the state.
 module TcPluginM (
-#if defined(GHCI)
+#if defined(HAVE_INTERPRETER)
         -- * Basic TcPluginM functionality
         TcPluginM,
         tcPluginIO,
@@ -52,7 +52,7 @@ module TcPluginM (
 #endif
     ) where
 
-#if defined(GHCI)
+#if defined(HAVE_INTERPRETER)
 import GhcPrelude
 
 import qualified TcRnMonad as TcM
diff --git a/compiler/utils/Util.hs b/compiler/utils/Util.hs
index b9a138902f..5770f2ffdc 100644
--- a/compiler/utils/Util.hs
+++ b/compiler/utils/Util.hs
@@ -188,7 +188,7 @@ the flags are off.
 -}
 
 ghciSupported :: Bool
-#if defined(GHCI)
+#if defined(HAVE_INTERNAL_INTERPRETER)
 ghciSupported = True
 #else
 ghciSupported = False