Add CPP to support both ghc-8.10 and ghc-9

Author: junjihashimoto

package.yaml

@@ -25,10 +25,11 @@ dependencies:
 library:
   source-dirs:      src
   dependencies:
-    - ghc >= 8.10.2 && < 9.0
+    - ghc >= 8.10.2 && <= 9.1
     - containers >= 0.6.2.1
     - term-rewriting >= 0.3.0.1
     - transformers >= 0.5.6.2
+  default-extensions:  CPP
 
 tests:
   should-compile:

src/TypeLevel/Rewrite.hs

@@ -8,6 +8,7 @@ import Data.Foldable
 import Data.Traversable
 
 -- GHC API
+#if MIN_VERSION_ghc(9,0,0)
 import GHC.Core.Coercion (Role(Representational), mkUnivCo)
 import GHC.Tc.Types.Constraint (CtEvidence(ctev_loc), Ct, ctEvExpr, ctLoc, mkNonCanonical)
 import GHC.Plugins (PredType, SDoc, eqType, fsep, ppr)
@@ -17,6 +18,17 @@ import GHC.Tc.Plugin (newWanted)
 import GHC.Core.TyCo.Rep (UnivCoProvenance(PluginProv))
 import GHC.Plugins (synTyConDefn_maybe)
 import GHC.Tc.Types (TcPluginResult(..), TcPluginM, ErrCtxt, pushErrCtxtSameOrigin, TcPlugin(..))
+#else
+import Coercion (Role(Representational), mkUnivCo)
+import Constraint (CtEvidence(ctev_loc), Ct, ctEvExpr, ctLoc, mkNonCanonical)
+import GhcPlugins (PredType, SDoc, eqType, fsep, ppr)
+import Plugins (Plugin(pluginRecompile, tcPlugin), CommandLineOption, defaultPlugin, purePlugin)
+import TcEvidence (EvExpr, EvTerm, evCast)
+import TcPluginM (newWanted)
+import TcRnTypes
+import TyCoRep (UnivCoProvenance(PluginProv))
+import TyCon (synTyConDefn_maybe)
+#endif
 
 import TypeLevel.Rewrite.Internal.ApplyRules
 import TypeLevel.Rewrite.Internal.DecomposedConstraint

src/TypeLevel/Rewrite/Internal/ApplyRules.hs

@@ -13,7 +13,11 @@ import Data.Traversable
 import qualified Data.Map as Map
 
 -- GHC API
+#if MIN_VERSION_ghc(9,0,0)
 import GHC.Plugins (TyVar)
+#else
+import Type (TyVar)
+#endif
 
 -- term-rewriting API
 import Data.Rewriting.Rule (Rule(..))

src/TypeLevel/Rewrite/Internal/DecomposedConstraint.hs

@@ -5,8 +5,13 @@ import Control.Applicative
 
 -- GHC API
 import GHC (Class, Type)
+#if MIN_VERSION_ghc(9,0,0)
 import GHC.Tc.Types.Constraint (Ct, ctEvPred, ctEvidence)
 import GHC.Core.Predicate (EqRel(NomEq), Pred(ClassPred, EqPred), classifyPredType, mkClassPred, mkPrimEqPred)
+#else
+import Constraint (Ct, ctEvPred, ctEvidence)
+import Predicate (EqRel(NomEq), Pred(ClassPred, EqPred), classifyPredType, mkClassPred, mkPrimEqPred)
+#endif
 
 
 data DecomposedConstraint a

src/TypeLevel/Rewrite/Internal/Lookup.hs

@@ -5,8 +5,9 @@ import Control.Arrow ((***), first)
 import Data.Tuple (swap)
 
 -- GHC API
-import GHC.Driver.Finder (cannotFindModule)
 import GHC (DataCon, TyCon, dataConTyCon)
+#if MIN_VERSION_ghc(9,0,0)
+import GHC.Driver.Finder (cannotFindModule)
 import GHC (Module, ModuleName, mkModuleName)
 import GHC.Plugins (mkDataOcc, mkTcOcc)
 import GHC.Utils.Panic (panicDoc)
@@ -15,7 +16,14 @@ import GHC.Tc.Plugin
   , unsafeTcPluginTcM
   )
 import GHC.Tc.Solver.Monad (getDynFlags)
-
+#else
+import Finder (cannotFindModule)
+import Module (Module, ModuleName, mkModuleName)
+import OccName (mkDataOcc, mkTcOcc)
+import Panic (panicDoc)
+import TcPluginM
+import TcSMonad (getDynFlags)
+#endif
 
 lookupModule
   :: String  -- ^ module name

src/TypeLevel/Rewrite/Internal/PrettyPrint.hs

@@ -4,9 +4,15 @@ module TypeLevel.Rewrite.Internal.PrettyPrint where
 import Data.List (intercalate)
 
 -- GHC API
+#if MIN_VERSION_ghc(9,0,0)
 import GHC.Utils.Outputable (ppr, showSDocUnsafe)
 import GHC.Plugins (TyCon)
 import GHC.Plugins (TyVar, Type)
+#else
+import Outputable (ppr, showSDocUnsafe)
+import TyCon (TyCon)
+import Type (TyVar, Type)
+#endif
 
 -- term-rewriting API
 import Data.Rewriting.Rule (Rule(..))

src/TypeLevel/Rewrite/Internal/TypeEq.hs

@@ -2,7 +2,11 @@ module TypeLevel.Rewrite.Internal.TypeEq where
 
 import Data.Function
 
+#if MIN_VERSION_ghc(9,0,0)
 import GHC.Plugins (Type, eqType)
+#else
+import GhcPlugins (Type, eqType)
+#endif
 
 
 -- | A newtype around 'Type' which has an 'Eq' instance.

src/TypeLevel/Rewrite/Internal/TypeNode.hs

@@ -2,8 +2,13 @@
 module TypeLevel.Rewrite.Internal.TypeNode where
 
 -- GHC API
+#if MIN_VERSION_ghc(9,0,0)
 import GHC (TyCon)
 import GHC.Plugins (Type, isNumLitTy, isStrLitTy, mkTyConApp, splitTyConApp_maybe)
+#else
+import TyCon (TyCon)
+import Type (Type, isNumLitTy, isStrLitTy, mkTyConApp, splitTyConApp_maybe)
+#endif
 
 import TypeLevel.Rewrite.Internal.TypeEq
 

src/TypeLevel/Rewrite/Internal/TypeRule.hs

@@ -3,9 +3,15 @@
 module TypeLevel.Rewrite.Internal.TypeRule where
 
 -- GHC API
+#if MIN_VERSION_ghc(9,0,0)
 import GHC.Plugins (getOccString)
 import GHC.Core.Predicate (mkPrimEqPred)
 import GHC.Plugins (TyVar, Type, mkTyVarTy)
+#else
+import Name (getOccString)
+import Predicate (mkPrimEqPred)
+import Type (TyVar, Type, mkTyVarTy)
+#endif
 
 -- term-rewriting API
 import Data.Rewriting.Rule (Rule(..))

src/TypeLevel/Rewrite/Internal/TypeTemplate.hs

@@ -2,7 +2,11 @@
 module TypeLevel.Rewrite.Internal.TypeTemplate where
 
 -- GHC API
+#if MIN_VERSION_ghc(9,0,0)
 import GHC.Plugins (TyVar, Type, getTyVar_maybe)
+#else
+import Type (TyVar, Type, getTyVar_maybe)
+#endif
 
 -- term-rewriting API
 import Data.Rewriting.Term (Term(Fun, Var))