rts: Add no-ghc-internal flag

Author: angerman

compiler/GHC/Driver/DynFlags.hs

@@ -878,7 +878,8 @@ packageFlagsChanged idflags1 idflags0 =
      [ Opt_HideAllPackages
      , Opt_HideAllPluginPackages
      , Opt_AutoLinkPackages
-     , Opt_NoRts ]
+     , Opt_NoRts
+     , Opt_NoGhcInternal ]
 
 instance Outputable PackageFlag where
     ppr (ExposePackage n arg rn) = text n <> braces (ppr arg <+> ppr rn)

compiler/GHC/Driver/Flags.hs

@@ -863,6 +863,7 @@ data GeneralFlag
    -- temporary flags
    | Opt_AutoLinkPackages
    | Opt_NoRts
+   | Opt_NoGhcInternal
    | Opt_ImplicitImportQualified
 
    -- keeping stuff

compiler/GHC/Driver/Session.hs

@@ -1314,6 +1314,8 @@ dynamic_flags_deps = [
         (NoArg (setGeneralFlag Opt_NoHsMain))
   , make_ord_flag defGhcFlag "no-rts"
         (NoArg (setGeneralFlag Opt_NoRts))
+  , make_ord_flag defGhcFlag "no-ghc-internal"
+        (NoArg (setGeneralFlag Opt_NoGhcInternal))
   , make_ord_flag defGhcFlag "fno-state-hack"
         (NoArg (setGeneralFlag Opt_G_NoStateHack))
   , make_ord_flag defGhcFlag "fno-opt-coercion"

compiler/GHC/Unit/State.hs

@@ -1636,7 +1636,11 @@ mkUnitState logger dflags cfg = do
   -- it modifies the unit ids of wired in packages, but when we process
   -- package arguments we need to key against the old versions.
   --
-  (pkgs2, wired_map) <- findWiredInUnits logger (rtsWayUnitId dflags:wiredInUnitIds) prec_map pkgs1 vis_map2
+  let wired_ids_all = rtsWayUnitId dflags : wiredInUnitIds
+      wired_ids
+        | gopt Opt_NoGhcInternal dflags = filter (/= ghcInternalUnitId) wired_ids_all
+        | otherwise                     = wired_ids_all
+  (pkgs2, wired_map) <- findWiredInUnits logger wired_ids prec_map pkgs1 vis_map2
 
   --
   -- Sanity check. If the rtsWayUnitId is not in the database, then we have a
@@ -1648,6 +1652,7 @@ mkUnitState logger dflags cfg = do
         , nest 2 $ vcat
             [ text "pkgs1_count =" <+> ppr (length pkgs1)
             , text "Opt_NoRts   =" <+> ppr (gopt Opt_NoRts dflags)
+            , text "Opt_NoGhcInternal =" <+> ppr (gopt Opt_NoGhcInternal dflags)
             , text "ghcLink     =" <+> text (show (ghcLink dflags))
             , text "platform    =" <+> text (show (targetPlatform dflags))
             , text "rtsWayUnitId=" <+> ppr (rtsWayUnitId dflags)
@@ -1664,7 +1669,9 @@ mkUnitState logger dflags cfg = do
       <> text " Please check your installation."
       <> text " If this target doesn't need the RTS (e.g. building a shared library), you can add -no-rts to the relevant package's ghc-options in cabal.project to bypass this check."
 
-  let pkgs3 = if gopt Opt_NoRts dflags && not (anyUniqMap (== ghcInternalUnitId) wired_map)
+  let pkgs3 = if gopt Opt_NoGhcInternal dflags
+         then pkgs2
+         else if gopt Opt_NoRts dflags && not (anyUniqMap (== ghcInternalUnitId) wired_map)
               then pkgs2
               else
               -- At this point we should have `ghcInternalUnitId`, and the `rtsWiredUnitId dflags`.