Drop support for GHC < 8.0

main/IHaskellPrelude.hs

@@ -7,12 +7,10 @@ module IHaskellPrelude (
   Data.Typeable.Typeable,
   Data.Typeable.cast,
 
-#if MIN_VERSION_ghc(7,8,0)
   Data.Typeable.Proxy,
 
   GHC.Exts.IsString,
   GHC.Exts.IsList,
-#endif
 
   System.IO.hPutStrLn,
   System.IO.hPutStr,
@@ -78,13 +76,7 @@ import           GHC.Enum               as X
 import           GHC.Num                as X
 import           GHC.Real               as X
 import           GHC.Err                as X hiding (absentErr)
-#if MIN_VERSION_ghc(8,0,0)
 import           GHC.Base               as X hiding (Any, mapM, foldr, sequence, many, (<|>), Module(..))
-#elif MIN_VERSION_ghc(7,10,0)
-import           GHC.Base               as X hiding (Any, mapM, foldr, sequence, many, (<|>))
-#else
-import           GHC.Base               as X hiding (Any)
-#endif
 import           Data.List              as X hiding (head, last, tail, init, transpose, subsequences, permutations,
                                         foldl, foldl1, maximum, minimum, scanl, scanl1, scanr, scanr1,
                                         span, break, mapAccumL, mapAccumR, dropWhileEnd, (!!),

main/Main.hs

@@ -22,9 +22,7 @@ import           System.Process (readProcess, readProcessWithExitCode)
 import           System.Exit (exitSuccess, ExitCode(ExitSuccess))
 import           Control.Exception (try, SomeException)
 import           System.Environment (getArgs)
-#if MIN_VERSION_ghc(7,8,0)
 import           System.Environment (setEnv)
-#endif
 import           System.Posix.Signals
 import qualified Data.Map as Map
 import qualified Data.Text.Encoding as E
@@ -142,7 +140,6 @@ runKernel kernelOpts profileSrc = do
   dir <- getIHaskellDir
   Stdin.recordKernelProfile dir profile
 
-#if MIN_VERSION_ghc(7,8,0)
   when useStack $ do
     -- Detect if we have stack
     runResult <- try $ readProcessWithExitCode "stack" [] ""
@@ -160,7 +157,6 @@ runKernel kernelOpts profileSrc = do
         in case tailMay val of
             Nothing -> return ()
             Just val' -> setEnv var val'
-#endif
 
   -- Serve on all sockets and ports defined in the profile.
   interface <- serveProfile profile debug

src/IHaskell/Eval/Completion.hs

@@ -31,7 +31,7 @@ import           System.Environment (getEnv)
 import           GHC hiding (Qualified)
 #if MIN_VERSION_ghc(8,2,0)
 import           GHC.PackageDb
-#elif MIN_VERSION_ghc(7,10,0)
+#else
 import           GHC.PackageDb (ExposedModule(exposedName))
 #endif
 import           DynFlags
@@ -63,16 +63,14 @@ data CompletionType = Empty
                     | KernelOption String
                     | Extension String
   deriving (Show, Eq)
+
 #if MIN_VERSION_ghc(8,2,0)
+exposedName :: (a, b) -> a
 exposedName = fst
 #endif
-#if MIN_VERSION_ghc(7,10,0)
-extName (FlagSpec { flagSpecName = name }) = name
-#else
-extName (name, _, _) = name
 
-exposedName = id
-#endif
+extName (FlagSpec { flagSpecName = name }) = name
+
 complete :: String -> Int -> Interpreter (String, [String])
 complete code posOffset = do
   -- Get the line of code which is being completed and offset within that line
@@ -93,11 +91,7 @@ complete code posOffset = do
 
   let Just db = pkgDatabase flags
       getNames = map (moduleNameString . exposedName) . exposedModules
-#if MIN_VERSION_ghc(8,0,0)
       moduleNames = nub $ concatMap getNames $ concatMap snd db
-#else
-      moduleNames = nub $ concatMap getNames db
-#endif
 
   let target = completionTarget line pos
       completion = completionType line pos target
@@ -127,17 +121,12 @@ complete code posOffset = do
                  return $ filter (prefix `isPrefixOf`) moduleNames
 
                DynFlag ext -> do
-                 -- Possibly leave out the fLangFlags? The -XUndecidableInstances vs. obsolete
-                 -- -fallow-undecidable-instances.
+                 -- Possibly leave out the fLangFlags?
                  let kernelOptNames = concatMap getSetName kernelOpts
                      otherNames = ["-package", "-Wall", "-w"]
 
                      fNames = map extName fFlags ++
-#if MIN_VERSION_ghc(8,0,0)
                               map extName wWarningFlags ++
-#else
-                              map extName fWarningFlags ++
-#endif
                               map extName fLangFlags
                      fNoNames = map ("no" ++) fNames
                      fAllNames = map ("-f" ++) (fNames ++ fNoNames)

src/IHaskell/Eval/Evaluate.hs

@@ -65,11 +65,7 @@ import qualified Linker
 import           TcType
 import           Unify
 import           InstEnv
-#if MIN_VERSION_ghc(7, 8, 0)
 import           GhcMonad (liftIO, withSession)
-#else
-import           GhcMonad (withSession)
-#endif
 import           GHC hiding (Stmt, TypeSig)
 import           Exception hiding (evaluate)
 import           Outputable hiding ((<>))
@@ -126,12 +122,7 @@ write :: (MonadIO m, GhcMonad m) => KernelState -> String -> m ()
 write state x = when (kernelDebug state) $ liftIO $ hPutStrLn stderr $ "DEBUG: " ++ x
 
 type Interpreter = Ghc
-#if MIN_VERSION_ghc(7, 8, 0)
-   -- GHC 7.8 exports a MonadIO instance for Ghc
-#else
-instance MonadIO.MonadIO Interpreter where
-  liftIO = MonadUtils.liftIO
-#endif
+
 requiredGlobalImports :: [String]
 requiredGlobalImports =
   [ "import qualified Prelude as IHaskellPrelude"
@@ -194,23 +185,13 @@ packageIdString' dflags pkg_cfg =
       Just cfg -> let
         PackageName name = packageName cfg
         in unpackFS name
-#elif MIN_VERSION_ghc(8,0,0)
-    fromMaybe "(unknown)" (unitIdPackageIdString dflags $ packageConfigId pkg_cfg)
-#elif MIN_VERSION_ghc(7,10,2)
-    fromMaybe "(unknown)" (packageKeyPackageIdString dflags $ packageConfigId pkg_cfg)
-#elif MIN_VERSION_ghc(7,10,0)
-    packageKeyPackageIdString dflags . packageConfigId
 #else
-    packageIdString . packageConfigId
+    fromMaybe "(unknown)" (unitIdPackageIdString dflags $ packageConfigId pkg_cfg)
 #endif
 
 getPackageConfigs :: DynFlags -> [PackageConfig]
 getPackageConfigs dflags =
-#if MIN_VERSION_ghc(8,0,0)
     foldMap snd pkgDb
-#else
-    pkgDb
-#endif
   where
     Just pkgDb = pkgDatabase dflags
 
@@ -236,10 +217,6 @@ initializeImports = do
       iHaskellPkgName = initStr ++ intercalate "." (map show (versionBranch version))
 #endif
 
-#if !MIN_VERSION_ghc(8,0,0)
-      unitId = packageId
-#endif
-
       dependsOnRight pkg = not $ null $ do
         pkg <- db
         depId <- depends pkg
@@ -449,11 +426,7 @@ flushWidgetMessages state evalMsgs widgetHandler = do
 
 
 getErrMsgDoc :: ErrUtils.ErrMsg -> SDoc
-#if MIN_VERSION_ghc(8,0,0)
 getErrMsgDoc = ErrUtils.pprLocErrMsg
-#else
-getErrMsgDoc msg = ErrUtils.errMsgShortString msg $$ ErrUtils.errMsgContext msg
-#endif
 
 safely :: KernelState -> Interpreter EvalOut -> Interpreter EvalOut
 safely state = ghandle handler . ghandle sourceErrorHandler
@@ -1083,11 +1056,7 @@ doLoadModule name modName = do
     setSessionDynFlags $ flip gopt_set Opt_BuildDynamicToo
       flags
         { hscTarget = objTarget flags
-#if MIN_VERSION_ghc(8,0,0)
         , log_action = \dflags sev srcspan ppr _style msg -> modifyIORef' errRef (showSDoc flags msg :)
-#else
-        , log_action = \dflags sev srcspan ppr msg -> modifyIORef' errRef (showSDoc flags msg :)
-#endif
         }
 
     -- Load the new target.
@@ -1138,11 +1107,9 @@ doLoadModule name modName = do
       initializeItVariable
 
       return $ displayError $ "Failed to load module " ++ modName ++ ": " ++ show exception
-#if MIN_VERSION_ghc(7,8,0)
+
 objTarget flags = defaultObjectTarget $ targetPlatform flags
-#else
-objTarget flags = defaultObjectTarget
-#endif
+
 keepingItVariable :: Interpreter a -> Interpreter a
 keepingItVariable act = do
   -- Generate the it variable temp name
@@ -1217,7 +1184,6 @@ capturedEval output stmt = do
   -- Initialize evaluation context.
   results <- forM initStmts goStmt
 
-#if __GLASGOW_HASKELL__ >= 800
   -- This works fine on GHC 8.0 and newer
   dyn <- dynCompileExpr readVariable
   pipe <- case fromDynamic dyn of
@@ -1226,26 +1192,7 @@ capturedEval output stmt = do
                 handle <- fdToHandle fd
                 hSetEncoding handle utf8
                 return handle
-#else
-  -- Get the pipe to read printed output from. This is effectively the source code of dynCompileExpr
-  -- from GHC API's InteractiveEval. However, instead of using a `Dynamic` as an intermediary, it just
-  -- directly reads the value. This is incredibly unsafe! However, for some reason the `getContext`
-  -- and `setContext` required by dynCompileExpr (to import and clear Data.Dynamic) cause issues with
-  -- data declarations being updated (e.g. it drops newer versions of data declarations for older ones
-  -- for unknown reasons). First, compile down to an HValue.
-  let pipeExpr = printf "let %s = %s" (var "pipe_var_") readVariable
-  Just (_, hValues, _) <- withSession $ liftIO . flip hscStmt pipeExpr
-  -- Then convert the HValue into an executable bit, and read the value.
-  pipe <- liftIO $ do
-            fds <- unsafeCoerce hValues
-            fd <- case fds of
-              fd : _ -> return fd
-              []     -> fail "Failed to evaluate pipes"
-              _      -> fail $ "Expected one fd, saw "++show (length fds)
-            handle <- fdToHandle fd
-            hSetEncoding handle utf8
-            return handle
-#endif
+
   -- Keep track of whether execution has completed.
   completed <- liftIO $ newMVar False
   finishedReading <- liftIO newEmptyMVar

src/IHaskell/Eval/Util.hs

@@ -91,11 +91,7 @@ extensionFlag ext =
 
     -- Check if a FlagSpec matches "No<ExtensionName>". In that case, we disable the extension.
     flagMatchesNo ext fs = ext == "No" ++ flagSpecName fs
-#if !MIN_VERSION_ghc(7,10,0)
-flagSpecName (name, _, _) = name
 
-flagSpecFlag (_, flag, _) = flag
-#endif
 -- | Pretty-print dynamic flags (taken from 'InteractiveUI' module of `ghc-bin`)
 pprDynFlags :: Bool       -- ^ Whether to include flags which are on by default
             -> DynFlags
@@ -111,17 +107,10 @@ pprDynFlags show_all dflags =
     ]
   where
 
-#if MIN_VERSION_ghc(8,0,0)
     warningFlags = DynFlags.wWarningFlags
-#else
-    warningFlags = DynFlags.fWarningFlags
-#endif
 
-#if MIN_VERSION_ghc(7,8,0)
     opt = gopt
-#else
-    opt = dopt
-#endif
+
     setting test flag
       | quiet = O.empty :: O.SDoc
       | is_on = fstr name :: O.SDoc
@@ -150,11 +139,8 @@ pprDynFlags show_all dflags =
     flgs = concat [flgs1, flgs2, flgs3]
 
     flgs1 = [Opt_PrintExplicitForalls]
-#if MIN_VERSION_ghc(7,8,0)
     flgs2 = [Opt_PrintExplicitKinds]
-#else
-    flgs2 = []
-#endif
+
 flgs3 = [Opt_PrintBindResult, Opt_BreakOnException, Opt_BreakOnError, Opt_PrintEvldWithShow]
 
 -- | Pretty-print the base language and active options (taken from `InteractiveUI` module of
@@ -395,21 +381,11 @@ cleanUpDuplicateInstances = modifySession $ \hscEnv ->
   in hscEnv { hsc_IC = ic { ic_instances = (clsInsts', famInsts) } }
   where
     instEq :: ClsInst -> ClsInst -> Bool
-#if MIN_VERSION_ghc(8,0,0)
     -- Only support replacing instances on GHC 7.8 and up
     instEq c1 c2
       | ClsInst { is_tvs = tpl_tvs, is_tys = tpl_tys, is_cls = cls } <- c1,
         ClsInst { is_tys = tpl_tys', is_cls = cls' } <- c2
       = cls == cls' && isJust (tcMatchTys tpl_tys tpl_tys')
-#elif MIN_VERSION_ghc(7,8,0)
-    instEq c1 c2
-      | ClsInst { is_tvs = tpl_tvs, is_tys = tpl_tys, is_cls = cls } <- c1,
-        ClsInst { is_tys = tpl_tys', is_cls = cls' } <- c2
-      = let tpl_tv_set = mkVarSet tpl_tvs
-        in cls == cls' && isJust (tcMatchTys tpl_tv_set tpl_tys tpl_tys')
-#else
-    instEq _ _ = False
-#endif
 
 
 -- | Get the type of an expression and convert it to a string.
@@ -450,18 +426,12 @@ getDescription str = do
 
   where
 
-#if MIN_VERSION_ghc(7,8,0)
     getInfo' = getInfo False
-#else
-    getInfo' = getInfo
-#endif
 
 #if MIN_VERSION_ghc(8,4,0)
     getType (theType, _, _, _, _) = theType
-#elif MIN_VERSION_ghc(7,8,0)
-    getType (theType, _, _, _) = theType
 #else
-    getType (theType, _, _) = theType
+    getType (theType, _, _, _) = theType
 #endif
 
 #if MIN_VERSION_ghc(8,4,0)
@@ -470,16 +440,12 @@ getDescription str = do
       showFixity thing fixity O.$$
       O.vcat (map GHC.pprInstance classInstances) O.$$
       O.vcat (map GHC.pprFamInst famInstances)
-#elif MIN_VERSION_ghc(7,8,0)
+#else
     printInfo (thing, fixity, classInstances, famInstances) =
       pprTyThingInContextLoc thing O.$$
       showFixity thing fixity O.$$
       O.vcat (map GHC.pprInstance classInstances) O.$$
       O.vcat (map GHC.pprFamInst famInstances)
-#else
-    printInfo (thing, fixity, classInstances) =
-      pprTyThingInContextLoc False thing O.$$ showFixity thing fixity O.$$
-      O.vcat (map GHC.pprInstance classInstances)
 #endif
     showFixity thing fixity =
       if fixity == GHC.defaultFixity

src/IHaskellPrelude.hs

@@ -8,12 +8,10 @@ module IHaskellPrelude (
   Data.Typeable.Typeable,
   Data.Typeable.cast,
 
-#if MIN_VERSION_ghc(7,8,0)
   Data.Typeable.Proxy,
 
   GHC.Exts.IsString,
   GHC.Exts.IsList,
-#endif
 
   System.IO.hPutStrLn,
   System.IO.hPutStr,
@@ -80,13 +78,7 @@ import           GHC.Enum               as X
 import           GHC.Num                as X
 import           GHC.Real               as X
 import           GHC.Err                as X hiding (absentErr)
-#if MIN_VERSION_ghc(8,0,0)
 import           GHC.Base               as X hiding (Any, mapM, foldr, sequence, many, (<|>), Module(..))
-#elif MIN_VERSION_ghc(7,10,0)
-import           GHC.Base               as X hiding (Any, mapM, foldr, sequence, many, (<|>))
-#else
-import           GHC.Base               as X hiding (Any)
-#endif
 import           Data.List              as X hiding (head, last, tail, init, transpose, subsequences, permutations,
                                         foldl, foldl1, maximum, minimum, scanl, scanl1, scanr, scanr1,
                                         span, break, mapAccumL, mapAccumR, dropWhileEnd, (!!),

src/tests/IHaskell/Test/Eval.hs

@@ -89,14 +89,7 @@ pages string expected = evaluationComparing comparison string
             Nothing  -> dropScriptTag $ tail str
 
     fixQuotes :: String -> String
-#if MIN_VERSION_ghc(7, 8, 0)
     fixQuotes = id
-#else
-    fixQuotes = map $ \char -> case char of
-      '\8216' -> '`'
-      '\8217' -> '\''
-      c       -> c
-#endif
 
 
 testEval :: Spec

src/tests/IHaskell/Test/Parser.hs

@@ -234,10 +234,4 @@ testParseString = describe "Parser" $ do
        |]) >>= (`shouldBe` [Located 2 (Expression "first"), Located 4 (Expression "second")])
   where
     dataKindsError = ParseError (Loc 1 10) msg
-#if MIN_VERSION_ghc(7, 10, 0)
     msg = "Cannot parse data constructor in a data/newtype declaration: 3"
-#elif MIN_VERSION_ghc(7, 8, 0)
-    msg = "Illegal literal in type (use DataKinds to enable): 3"
-#else
-    msg = "Illegal literal in type (use -XDataKinds to enable): 3"
-#endif