WIP. It compiles with ghc-8.4.3, but not all features of the indexer are supported yet.

2 files changed, 173 insertions, 60 deletions

diff --git a/src/HaskellCodeExplorer/AST/RenamedSource.hs b/src/HaskellCodeExplorer/AST/RenamedSource.hs
index c1bf463..ea5a87a 100644
--- a/src/HaskellCodeExplorer/AST/RenamedSource.hs
+++ b/src/HaskellCodeExplorer/AST/RenamedSource.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE StrictData #-}
@@ -54,10 +55,16 @@ import GHC
   , PatSynBind(..)
   , Sig(..)
   , TyClDecl(..)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+#else
   , TyFamEqn(..)
+#endif
   , Type
   , unLoc
   )
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+import HsExtension (GhcRn)
+#endif
 import HaskellCodeExplorer.GhcUtils (hsPatSynDetails, ieLocNames)
 import Prelude hiding (span)
 import TysWiredIn
@@ -86,9 +93,12 @@ namesFromRenamedSource =
      hsTypeNames `extQ`
      tyClDeclNames `extQ`
      familyDeclNames `extQ`
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+#else
      tyFamilyEqNames `extQ`
      tyFamilyDefEqNames `extQ`
      dataFamInstDeclNames `extQ`
+#endif     
      conDeclNames `extQ`
      importNames `extQ`
      hsTyVarBndrNames `extQ`
@@ -99,7 +109,9 @@ namesFromRenamedSource =
      hsRecFieldPatNames `extQ`
      foreignDeclNames)
 
-fieldOccName :: Bool -> FieldOcc Name -> NameOccurrence
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+fieldOccName :: Bool -> FieldOcc GhcRn -> NameOccurrence
+#endif    
 fieldOccName isBinder (FieldOcc (L span _) name) =
   NameOccurrence
     { locatedName = L span (Just name)
@@ -107,16 +119,20 @@ fieldOccName isBinder (FieldOcc (L span _) name) =
     , isBinder = isBinder
     }
 
-conDeclFieldNames :: ConDeclField Name -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+conDeclFieldNames :: ConDeclField GhcRn -> [NameOccurrence]
+#endif    
 conDeclFieldNames ConDeclField {..} =
   map (fieldOccName True . unLoc) cd_fld_names
 
-hsRecFieldExprNames ::
-     HsRecField' (FieldOcc Name) (LHsExpr Name) -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+hsRecFieldExprNames :: HsRecField' (FieldOcc GhcRn) (LHsExpr GhcRn) -> [NameOccurrence]
+#endif    
 hsRecFieldExprNames HsRecField {..} = [fieldOccName False $ unLoc hsRecFieldLbl]
 
-hsRecAmbFieldExprNames ::
-     HsRecField' (AmbiguousFieldOcc Name) (LHsExpr Name) -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+hsRecAmbFieldExprNames :: HsRecField' (AmbiguousFieldOcc GhcRn) (LHsExpr GhcRn) -> [NameOccurrence]
+#endif
 hsRecAmbFieldExprNames HsRecField {..} =
   let (L span recField) = hsRecFieldLbl
       mbName =
@@ -130,11 +146,14 @@ hsRecAmbFieldExprNames HsRecField {..} =
           }
       ]
 
-hsRecFieldPatNames ::
-     HsRecField' (FieldOcc Name) (LPat Name) -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+hsRecFieldPatNames :: HsRecField' (FieldOcc GhcRn) (LPat GhcRn) -> [NameOccurrence]
+#endif    
 hsRecFieldPatNames HsRecField {..} = [fieldOccName False $ unLoc hsRecFieldLbl]
 
-hsExprNames :: LHsExpr Name -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+hsExprNames :: LHsExpr GhcRn -> [NameOccurrence]
+#endif    
 hsExprNames (L _span (HsVar name)) =
   [ NameOccurrence
     { locatedName = Just <$> name
@@ -174,7 +193,9 @@ hsExprNames (L _span (HsRecFld (Ambiguous (L span _) _name))) =
   ]
 hsExprNames _ = []
 
-matchGroupNames :: MatchGroup Name (LHsExpr Name) -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+matchGroupNames :: MatchGroup GhcRn (LHsExpr GhcRn) -> [NameOccurrence]
+#endif
 matchGroupNames =
 #if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)      
   mapMaybe (fmap toNameOcc . matchContextName . m_ctxt . unLoc) .
@@ -184,20 +205,22 @@ matchGroupNames =
   unLoc . mg_alts
   where
 #if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)    
-    matchContextName :: HsMatchContext Name -> Maybe (Located Name)
+    --matchContextName :: HsMatchContext Name -> Maybe (Located Name)
     matchContextName (FunRhs name _ _bool) = Just name
     matchContextName _ = Nothing   
 #else
-    matchFixityName :: MatchFixity Name -> Maybe (Located Name)
+    --matchFixityName :: MatchFixity Name -> Maybe (Located Name)
     matchFixityName NonFunBindMatch = Nothing
     matchFixityName (FunBindMatch name _bool) = Just name
 #endif
-    toNameOcc :: Located Name -> NameOccurrence
+    --toNameOcc :: Located Name -> NameOccurrence
     toNameOcc n =
       NameOccurrence
         {locatedName = Just <$> n, description = "Match", isBinder = True}
 
-bindNames :: LHsBindLR Name Name -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+bindNames :: LHsBindLR GhcRn GhcRn -> [NameOccurrence]
+#endif
 bindNames (L _span (PatSynBind PSB {..})) =
   [ NameOccurrence
       { locatedName = Just <$> psb_id
@@ -207,7 +230,6 @@ bindNames (L _span (PatSynBind PSB {..})) =
   ]
 bindNames _ = []
 
-hsPatSynDetailsNames :: HsPatSynDetails (Located Name) -> [NameOccurrence]
 hsPatSynDetailsNames =
   map
     (\name ->
@@ -218,7 +240,10 @@ hsPatSynDetailsNames =
          }) .
   hsPatSynDetails
 
-importNames :: IE Name -> [NameOccurrence]
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+importNames :: IE GhcRn -> [NameOccurrence]
+#endif
 importNames =
   map
     (\name ->
@@ -229,7 +254,10 @@ importNames =
         }) .
   ieLocNames
 
-patNames :: LPat Name -> [NameOccurrence]
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+patNames :: LPat GhcRn -> [NameOccurrence]
+#endif    
 patNames (L _span (VarPat name)) =
   [ NameOccurrence
     { locatedName = Just <$> name
@@ -260,7 +288,10 @@ patNames (L _span (NPlusKPat name _ _ _ _ _)) =
   ]
 patNames _ = []
 
-sigNames :: LSig Name -> [NameOccurrence]
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+sigNames :: LSig GhcRn -> [NameOccurrence]
+#endif    
 sigNames (L _span (TypeSig names _)) =
   map
     (\n ->
@@ -332,7 +363,10 @@ sigNames (L _span (MinimalSig _ (L _ boolFormula))) =
     boolFormulaNames (Parens (L _ f)) = boolFormulaNames f
 sigNames (L _ _) = []
 
-hsTypeNames :: LHsType Name -> [NameOccurrence]
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+hsTypeNames :: LHsType GhcRn -> [NameOccurrence]
+#endif 
 #if MIN_VERSION_GLASGOW_HASKELL(8,2,2,0)
 hsTypeNames (L _span (HsTyVar _promoted name)) =
 #else
@@ -382,7 +416,10 @@ hsTypeNames (L span (HsTupleTy tupleSort types))
 --hsTypeNames (L span (HsExplicitTupleTy _kind types)) = ...
 hsTypeNames _ = []
 
-hsTyVarBndrNames :: HsTyVarBndr Name -> [NameOccurrence]
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+hsTyVarBndrNames :: HsTyVarBndr GhcRn -> [NameOccurrence]
+#endif
 hsTyVarBndrNames (UserTyVar n) =
   [ NameOccurrence
     { locatedName = Just <$> n
@@ -398,7 +435,9 @@ hsTyVarBndrNames (KindedTyVar n _) =
     }
   ]
 
-tyClDeclNames :: LTyClDecl Name -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+tyClDeclNames :: LTyClDecl GhcRn -> [NameOccurrence]
+#endif    
 tyClDeclNames (L _span DataDecl {..}) =
   [ NameOccurrence
     { locatedName = Just <$> tcdLName
@@ -432,7 +471,9 @@ tyClDeclNames (L _span ClassDecl {..}) =
       }
 tyClDeclNames _ = []
 
-familyDeclNames :: FamilyDecl Name -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+familyDeclNames :: FamilyDecl GhcRn -> [NameOccurrence]
+#endif    
 familyDeclNames FamilyDecl {..} =
   [ NameOccurrence
     { locatedName = Just <$> fdLName
@@ -441,7 +482,11 @@ familyDeclNames FamilyDecl {..} =
     }
   ]
 
-tyFamilyEqNames :: TyFamEqn Name (HsTyPats Name) -> [NameOccurrence]
+
+--TODO
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+#else    
+--tyFamilyEqNames :: TyFamEqn Name (HsTyPats Name) -> [NameOccurrence]
 tyFamilyEqNames TyFamEqn {tfe_tycon = tyCon} =
   [ NameOccurrence
     { locatedName = Just <$> tyCon
@@ -450,7 +495,7 @@ tyFamilyEqNames TyFamEqn {tfe_tycon = tyCon} =
     }
   ]
 
-tyFamilyDefEqNames :: TyFamEqn Name (LHsQTyVars Name) -> [NameOccurrence]
+--tyFamilyDefEqNames :: TyFamEqn Name (LHsQTyVars Name) -> [NameOccurrence]
 tyFamilyDefEqNames TyFamEqn {tfe_tycon = tyCon} =
   [ NameOccurrence
     { locatedName = Just <$> tyCon
@@ -459,7 +504,8 @@ tyFamilyDefEqNames TyFamEqn {tfe_tycon = tyCon} =
     }
   ]
 
-dataFamInstDeclNames :: DataFamInstDecl Name -> [NameOccurrence]
+
+--dataFamInstDeclNames :: DataFamInstDecl Name -> [NameOccurrence]
 dataFamInstDeclNames DataFamInstDecl {dfid_tycon = tyCon} =
   [ NameOccurrence
     { locatedName = Just <$> tyCon
@@ -467,8 +513,11 @@ dataFamInstDeclNames DataFamInstDecl {dfid_tycon = tyCon} =
     , isBinder = False
     }
   ]
+#endif 
 
-conDeclNames :: ConDecl Name -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+conDeclNames :: ConDecl GhcRn -> [NameOccurrence]
+#endif
 conDeclNames con =
   case con of
     ConDeclGADT {con_names = names} ->
@@ -488,7 +537,9 @@ conDeclNames con =
         }
       ]
 
-foreignDeclNames :: ForeignDecl Name -> [NameOccurrence]
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foreignDeclNames :: ForeignDecl GhcRn -> [NameOccurrence]
+#endif    
 foreignDeclNames decl =
   [ NameOccurrence
     { locatedName = Just <$> fd_name decl
diff --git a/src/HaskellCodeExplorer/AST/TypecheckedSource.hs b/src/HaskellCodeExplorer/AST/TypecheckedSource.hs
index f97c33b..4dfbd8b 100644
--- a/src/HaskellCodeExplorer/AST/TypecheckedSource.hs
+++ b/src/HaskellCodeExplorer/AST/TypecheckedSource.hs
@@ -80,6 +80,7 @@ import HsSyn
   , selectorAmbiguousFieldOcc
   )
 import HscTypes (TypeEnv, lookupTypeEnv)
+import HsExtension (GhcTc)
 import Id (idType)
 import IdInfo (IdDetails(..))
 import InstEnv
@@ -541,11 +542,15 @@ tidyType typ = do
   let (tidyEnv', typ') = tidyOpenType tidyEnv typ
   modify' (\s -> s {astStateTidyEnv = tidyEnv'})
   return typ'
-  
-foldTypecheckedSource :: LHsBinds Id -> State ASTState ()
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldTypecheckedSource :: LHsBinds GhcTc -> State ASTState ()
+#endif
 foldTypecheckedSource = foldLHsBindsLR
 
-foldLHsExpr :: LHsExpr Var -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldLHsExpr :: LHsExpr GhcTc -> State ASTState (Maybe Type)
+#endif
 foldLHsExpr (L span (HsVar (L _ identifier))) =
   restoreTidyEnv $ do
     (identifier', mbTypes) <- tidyIdentifier identifier
@@ -801,8 +806,10 @@ foldLHsExpr (L span (HsWrap wrapper expr)) =
       Composite -> return () -- Not sure if it is possible
     typ <- foldLHsExpr (L span expr)
     return $ applyWrapper wrapper <$> typ
-  
-foldHsRecFields :: HsRecFields Id (LHsExpr Id) -> State ASTState (Maybe Type)
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldHsRecFields :: HsRecFields GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldHsRecFields HsRecFields {..} = do
   let userWritten =
         case rec_dotdot of
@@ -810,8 +817,10 @@ foldHsRecFields HsRecFields {..} = do
           Nothing -> id
   mapM_ foldLHsRecField $ userWritten rec_flds
   return Nothing
-  
-foldLHsRecField :: LHsRecField Id (LHsExpr Id) -> State ASTState (Maybe Type)
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldLHsRecField :: LHsRecField GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldLHsRecField (L span (HsRecField (L idSpan (FieldOcc _ identifier)) arg pun)) =
   restoreTidyEnv $ do
     (identifier', mbTypes) <- tidyIdentifier identifier
@@ -820,7 +829,9 @@ foldLHsRecField (L span (HsRecField (L idSpan (FieldOcc _ identifier)) arg pun))
     unless pun $ void (foldLHsExpr arg)
     return . Just . varType $ identifier'
 
-foldLHsRecUpdField :: LHsRecUpdField Id -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldLHsRecUpdField :: LHsRecUpdField GhcTc -> State ASTState (Maybe Type)
+#endif
 foldLHsRecUpdField (L span (HsRecField (L idSpan recField) arg pun)) =
   restoreTidyEnv $ do
     let selectorId = selectorAmbiguousFieldOcc recField
@@ -844,7 +855,9 @@ data TupArg
   | TupArgMissing
   deriving (Show, Eq)
 
-foldLHsTupArg :: LHsTupArg Id -> State ASTState (Maybe Type, TupArg)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldLHsTupArg :: LHsTupArg GhcTc -> State ASTState (Maybe Type, TupArg)
+#endif
 foldLHsTupArg (L _span (Present expr)) =
   restoreTidyEnv $ do
     typ <- foldLHsExpr expr
@@ -858,31 +871,41 @@ foldLHsTupArg (L _ (Missing typ)) =
     typ' <- tidyType typ
     return (Just typ', TupArgMissing)
 
-foldLMatch :: LMatch Id (LHsExpr Var) -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldLMatch :: LMatch GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldLMatch (L _span Match {..}) = do
   mapM_ foldLPat m_pats
   _ <- foldGRHSs m_grhss
   return Nothing    
-       
-foldLMatchCmd :: LMatch Id (LHsCmd Var) -> State ASTState (Maybe Type)
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)      
+foldLMatchCmd :: LMatch GhcTc (LHsCmd GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldLMatchCmd (L _span Match {..}) = do
   mapM_ foldLPat m_pats
   _ <- foldGRHSsCmd m_grhss
   return Nothing
 
-foldGRHSsCmd :: GRHSs Id (LHsCmd Id) -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)      
+foldGRHSsCmd :: GRHSs GhcTc (LHsCmd GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldGRHSsCmd GRHSs {..} = do
   mapM_ foldLGRHSCmd grhssGRHSs
   _ <- foldHsLocalBindsLR (unLoc grhssLocalBinds)
   return Nothing
 
-foldGRHSs :: GRHSs Id (LHsExpr Var) -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldGRHSs :: GRHSs GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldGRHSs GRHSs {..} = do
   mapM_ foldLGRHS grhssGRHSs
   _ <- foldHsLocalBindsLR (unLoc grhssLocalBinds)
   return Nothing
 
-foldLStmtLR :: LStmtLR Id Id (LHsExpr Var) -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldLStmtLR :: LStmtLR GhcTc GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldLStmtLR (L span (LastStmt body _ _)) =  
   do typ <- foldLHsExpr body
      addExprInfo span typ "LastStmt" Composite
@@ -916,10 +939,16 @@ foldLStmtLR (L span (ApplicativeStmt args _ typ)) =
     addExprInfo span (Just typ') "ApplicativeStmt" Composite
     return Nothing
 
-foldApplicativeArg :: ApplicativeArg Id Id -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldApplicativeArg :: ApplicativeArg GhcTc GhcTc -> State ASTState (Maybe Type)
+#endif
 foldApplicativeArg appArg =
   case appArg of
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)    
+    ApplicativeArgOne pat expr _bool -> do
+#else
     ApplicativeArgOne pat expr -> do
+#endif
       _ <- foldLPat pat
       _ <- foldLHsExpr expr
       return Nothing
@@ -927,9 +956,10 @@ foldApplicativeArg appArg =
       _ <- mapM_ foldLStmtLR exprStmts
       _ <- foldLPat pat
       return Nothing  
-
-foldLStmtLRCmd :: LStmtLR Id Id (LHsCmd Var) 
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldLStmtLRCmd :: LStmtLR GhcTc GhcTc (LHsCmd GhcTc) 
                -> State ASTState (Maybe Type)
+#endif                  
 foldLStmtLRCmd (L span (LastStmt body _syntaxExpr _)) = do
   typ <- foldLHsCmd body
   addExprInfo span typ "LastStmt Cmd" Composite
@@ -962,43 +992,57 @@ foldLStmtLRCmd (L span (ApplicativeStmt args _ typ)) =
     mapM_ (foldApplicativeArg . snd) args
     addExprInfo span (Just typ') "ApplicativeStmt Cmd" Composite
     return Nothing  
-  
-foldLGRHS :: LGRHS Id (LHsExpr Id) -> State ASTState (Maybe Type)
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)    
+foldLGRHS :: LGRHS GhcTc (LHsExpr GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldLGRHS (L _span (GRHS guards body)) = do
   typ <- foldLHsExpr body
   mapM_ foldLStmtLR guards
   return typ
-  
-foldLGRHSCmd :: LGRHS Id (LHsCmd Var) -> State ASTState (Maybe Type)
+
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldLGRHSCmd :: LGRHS GhcTc (LHsCmd GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldLGRHSCmd (L _span (GRHS guards body)) = do
   typ <- foldLHsCmd body
   mapM_ foldLStmtLR guards
   return typ   
 
-foldParStmtBlock :: ParStmtBlock Id Id -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldParStmtBlock :: ParStmtBlock GhcTc GhcTc -> State ASTState (Maybe Type)
+#endif
 foldParStmtBlock (ParStmtBlock exprStmts _ids _syntaxExpr) = do
   mapM_ foldLStmtLR exprStmts
   return Nothing
 
-foldHsLocalBindsLR :: HsLocalBindsLR Id Id -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldHsLocalBindsLR :: HsLocalBindsLR GhcTc GhcTc -> State ASTState (Maybe Type)
+#endif
 foldHsLocalBindsLR (HsValBinds binds) = do
   _ <- foldHsValBindsLR binds
   return Nothing
 foldHsLocalBindsLR (HsIPBinds _binds) = return Nothing
 foldHsLocalBindsLR EmptyLocalBinds = return Nothing
 
-foldHsValBindsLR :: HsValBindsLR Id Var -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldHsValBindsLR :: HsValBindsLR GhcTc GhcTc -> State ASTState (Maybe Type)
+#endif
 foldHsValBindsLR (ValBindsIn _ _) = return Nothing
 foldHsValBindsLR (ValBindsOut binds _) = do
   _ <- mapM_ (foldLHsBindsLR . snd) binds
   return Nothing
 
-foldLHsBindsLR :: LHsBinds Id -> State ASTState ()
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldLHsBindsLR :: LHsBinds GhcTc -> State ASTState ()
+#endif
 foldLHsBindsLR = mapM_ (`foldLHsBindLR` Nothing) . bagToList
 
-foldLHsBindLR :: LHsBindLR Id Var
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldLHsBindLR :: LHsBindLR GhcTc GhcTc
               -> Maybe Id -- ^ Polymorphic id
               -> State ASTState (Maybe Type)
+#endif              
 foldLHsBindLR (L _span FunBind {..}) mbPolyId
   | mg_origin fun_matches == FromSource =
     restoreTidyEnv $ do
@@ -1024,12 +1068,17 @@ foldLHsBindLR (L _ AbsBinds {..}) _ = do
     mapM_ (\(bind, typ) -> foldLHsBindLR bind (Just typ)) $
     zip (bagToList abs_binds) (map abe_poly abs_exports)
   return Nothing
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+#else
 foldLHsBindLR (L _ AbsBindsSig {..}) _ = do
   _ <- foldLHsBindLR abs_sig_bind (Just abs_sig_export)
   return Nothing
+#endif
 foldLHsBindLR (L _ (PatSynBind PSB {..})) _ =
   restoreTidyEnv $ do
     _ <- foldLPat psb_def
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+#else    
     _ <-
       let addId :: GenLocated SrcSpan Id -> State ASTState ()
           addId (L span i) = do
@@ -1043,9 +1092,12 @@ foldLHsBindLR (L _ (PatSynBind PSB {..})) _ =
                 (\(RecordPatSynField selId patVar) ->
                    addId selId >> addId patVar)
                 recs
+#endif
     return Nothing
 
-foldLPat :: LPat Id -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
+foldLPat :: LPat GhcTc -> State ASTState (Maybe Type)
+#endif
 foldLPat (L span (VarPat (L _ identifier))) = do
   (identifier', _) <- tidyIdentifier identifier
   addIdentifierToIdSrcSpanMap span identifier' Nothing
@@ -1151,9 +1203,11 @@ foldLPat (L span p@(CoPat _ pat typ)) = do
   _ <- foldLPat (L span pat)
   return Nothing 
 
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)  
 foldHsConPatDetails
-  :: HsConPatDetails Id
+  :: HsConPatDetails GhcTc
   -> State ASTState (Maybe Type)
+#endif  
 foldHsConPatDetails (PrefixCon args) = do
   _ <- mapM_ foldLPat args
   return Nothing
@@ -1165,7 +1219,9 @@ foldHsConPatDetails (InfixCon arg1 arg2) = do
   _ <- foldLPat arg2
   return Nothing
 
-foldHsRecFieldsPat :: HsRecFields Id (LPat Id) -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldHsRecFieldsPat :: HsRecFields GhcTc (LPat GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldHsRecFieldsPat HsRecFields {..} = do
   let onlyUserWritten =
         case rec_dotdot of
@@ -1174,20 +1230,26 @@ foldHsRecFieldsPat HsRecFields {..} = do
   _ <- mapM_ foldLHsRecFieldPat $ onlyUserWritten rec_flds
   return Nothing
 
-foldLHsRecFieldPat :: LHsRecField Id (LPat Id) -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldLHsRecFieldPat :: LHsRecField GhcTc (LPat GhcTc) -> State ASTState (Maybe Type)
+#endif
 foldLHsRecFieldPat (L _ (HsRecField (L idSpan (FieldOcc _ identifier)) arg pun)) = do
   (identifier', mbTypes) <- tidyIdentifier identifier
   addIdentifierToIdSrcSpanMap idSpan identifier' mbTypes
   unless pun $ void $ foldLPat arg
   return . Just . varType $ identifier'
 
-foldLHsCmdTop :: LHsCmdTop Id -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldLHsCmdTop :: LHsCmdTop GhcTc -> State ASTState (Maybe Type)
+#endif
 foldLHsCmdTop (L span (HsCmdTop cmd _ _ _)) = do
   mbTyp <- foldLHsCmd cmd
   addExprInfo span mbTyp "HsCmdTop" Composite
   return mbTyp
 
-foldLHsCmd :: LHsCmd Id -> State ASTState (Maybe Type)
+#if MIN_VERSION_GLASGOW_HASKELL(8,4,3,0)
+foldLHsCmd :: LHsCmd GhcTc -> State ASTState (Maybe Type)
+#endif
 foldLHsCmd (L _ (HsCmdArrApp expr1 expr2 _ _ _)) = do
   _ <- foldLHsExpr expr1
   _ <- foldLHsExpr expr2