Revert "Bump ghc-head (#1445)"

This reverts commit b29a78ef6926101338f62e84f456dac8659dc9d2.

This should not have been merged.

3 files changed, 19 insertions, 21 deletions

diff --git a/haddock-api/src/Haddock/GhcUtils.hs b/haddock-api/src/Haddock/GhcUtils.hs
index 85e6fcf4..599404a0 100644
--- a/haddock-api/src/Haddock/GhcUtils.hs
+++ b/haddock-api/src/Haddock/GhcUtils.hs
@@ -114,7 +114,7 @@ pretty = showPpr
 -- instantiated at DocNameI instead of (GhcPass _).
 
 -- | Like 'hsTyVarName' from GHC API, but not instantiated at (GhcPass _)
-hsTyVarBndrName :: forall flag n. (XXTyVarBndr n ~ DataConCantHappen, UnXRec n)
+hsTyVarBndrName :: forall flag n. (XXTyVarBndr n ~ NoExtCon, UnXRec n)
                 => HsTyVarBndr flag n -> IdP n
 hsTyVarBndrName (UserTyVar _ _ name) = unXRec @n name
 hsTyVarBndrName (KindedTyVar _ _ name _) = unXRec @n name
diff --git a/haddock-api/src/Haddock/Interface.hs b/haddock-api/src/Haddock/Interface.hs
index e4934711..ba7d9d30 100644
--- a/haddock-api/src/Haddock/Interface.hs
+++ b/haddock-api/src/Haddock/Interface.hs
@@ -56,11 +56,11 @@ import qualified Data.Set as Set
 import GHC hiding (verbosity)
 import GHC.Data.FastString (unpackFS)
 import GHC.Data.Graph.Directed
-import GHC.Driver.Env
+import GHC.Driver.Env (hscUpdateFlags, hsc_home_unit, hsc_logger, hsc_static_plugins, hsc_units)
 import GHC.Driver.Monad (modifySession, withTimingM)
 import GHC.Driver.Session hiding (verbosity)
 import GHC.HsToCore.Docs (getMainDeclBinder)
-import GHC.Plugins
+import GHC.Plugins (Outputable, Plugin (..), PluginWithArgs (..), StaticPlugin (..), defaultPlugin, keepRenamedSource)
 import GHC.Tc.Types (TcGblEnv (..), TcM)
 import GHC.Tc.Utils.Env (tcLookupGlobal)
 import GHC.Tc.Utils.Monad (getTopEnv, setGblEnv)
@@ -145,12 +145,10 @@ createIfaces verbosity modules flags instIfaceMap = do
 
   let
     installHaddockPlugin :: HscEnv -> HscEnv
-    installHaddockPlugin hsc_env =
-      let 
-        old_plugins = hsc_plugins hsc_env
-        new_plugins = old_plugins { staticPlugins = haddockPlugin : staticPlugins old_plugins }
-        hsc_env'    = hsc_env { hsc_plugins = new_plugins }
-      in hscUpdateFlags (flip gopt_set Opt_PluginTrustworthy) hsc_env'
+    installHaddockPlugin hsc_env = hscUpdateFlags (flip gopt_set Opt_PluginTrustworthy) $ hsc_env
+      { hsc_static_plugins =
+          haddockPlugin : hsc_static_plugins hsc_env
+      }
 
   -- Note that we would rather use withTempSession but as long as we
   -- have the separate attachInstances step we need to keep the session
diff --git a/haddock-api/src/Haddock/Types.hs b/haddock-api/src/Haddock/Types.hs
index 30f583b0..05375185 100644
--- a/haddock-api/src/Haddock/Types.hs
+++ b/haddock-api/src/Haddock/Types.hs
@@ -319,7 +319,7 @@ type instance NoGhcTc DocNameI = DocNameI
 type instance IdP DocNameI = DocName
 
 instance CollectPass DocNameI where
-  collectXXPat _ _ ext = dataConCantHappen ext
+  collectXXPat _ _ ext = noExtCon ext
 
 instance NamedThing DocName where
   getName (Documented name _) = name
@@ -760,11 +760,11 @@ type instance XXType           DocNameI = HsCoreTy
 
 type instance XHsForAllVis        DocNameI = NoExtField
 type instance XHsForAllInvis      DocNameI = NoExtField
-type instance XXHsForAllTelescope DocNameI = DataConCantHappen
+type instance XXHsForAllTelescope DocNameI = NoExtCon
 
 type instance XUserTyVar    DocNameI = NoExtField
 type instance XKindedTyVar  DocNameI = NoExtField
-type instance XXTyVarBndr   DocNameI = DataConCantHappen
+type instance XXTyVarBndr   DocNameI = NoExtCon
 
 type instance XCFieldOcc   DocNameI = DocName
 type instance XXFieldOcc   DocNameI = NoExtField
@@ -780,7 +780,7 @@ type instance XForeignExport  DocNameI = NoExtField
 type instance XForeignImport  DocNameI = NoExtField
 type instance XConDeclGADT    DocNameI = NoExtField
 type instance XConDeclH98     DocNameI = NoExtField
-type instance XXConDecl       DocNameI = DataConCantHappen
+type instance XXConDecl       DocNameI = NoExtCon
 
 type instance XDerivD     DocNameI = NoExtField
 type instance XInstD      DocNameI = NoExtField
@@ -791,10 +791,10 @@ type instance XTyClD      DocNameI = NoExtField
 type instance XNoSig            DocNameI = NoExtField
 type instance XCKindSig         DocNameI = NoExtField
 type instance XTyVarSig         DocNameI = NoExtField
-type instance XXFamilyResultSig DocNameI = DataConCantHappen
+type instance XXFamilyResultSig DocNameI = NoExtCon
 
 type instance XCFamEqn       DocNameI _ = NoExtField
-type instance XXFamEqn       DocNameI _ = DataConCantHappen
+type instance XXFamEqn       DocNameI _ = NoExtCon
 
 type instance XCClsInstDecl DocNameI = NoExtField
 type instance XCDerivDecl   DocNameI = NoExtField
@@ -811,23 +811,23 @@ type instance XClassDecl    DocNameI = NoExtField
 type instance XDataDecl     DocNameI = NoExtField
 type instance XSynDecl      DocNameI = NoExtField
 type instance XFamDecl      DocNameI = NoExtField
-type instance XXFamilyDecl  DocNameI = DataConCantHappen
-type instance XXTyClDecl    DocNameI = DataConCantHappen
+type instance XXFamilyDecl  DocNameI = NoExtCon
+type instance XXTyClDecl    DocNameI = NoExtCon
 
 type instance XHsWC DocNameI _ = NoExtField
 
 type instance XHsOuterExplicit    DocNameI _ = NoExtField
 type instance XHsOuterImplicit    DocNameI   = NoExtField
-type instance XXHsOuterTyVarBndrs DocNameI   = DataConCantHappen
+type instance XXHsOuterTyVarBndrs DocNameI   = NoExtCon
 
 type instance XHsSig      DocNameI = NoExtField
-type instance XXHsSigType DocNameI = DataConCantHappen
+type instance XXHsSigType DocNameI = NoExtCon
 
 type instance XHsQTvs        DocNameI = NoExtField
 type instance XConDeclField  DocNameI = NoExtField
-type instance XXConDeclField DocNameI = DataConCantHappen
+type instance XXConDeclField DocNameI = NoExtCon
 
-type instance XXPat DocNameI = DataConCantHappen
+type instance XXPat DocNameI = NoExtCon
 
 type instance XCInjectivityAnn DocNameI = NoExtField