Drop support for anything below GHC 8.0.0, base 4.9.0.0, Cabal 2.0.0.0

Cabal-syntax/Cabal-syntax.cabal

@@ -52,9 +52,8 @@ library
     -Wincomplete-uni-patterns
     -Wincomplete-record-updates
     -Wno-unticked-promoted-constructors
-
-  if impl(ghc >= 8.0)
-    ghc-options: -Wcompat -Wnoncanonical-monad-instances
+    -Wcompat
+    -Wnoncanonical-monad-instances
 
   if impl(ghc >= 8.0) && impl(ghc < 8.8)
     ghc-options: -Wnoncanonical-monadfail-instances

Cabal/src/Distribution/Simple/Build.hs

@@ -920,7 +920,7 @@ createInternalPackageDB
 createInternalPackageDB verbosity lbi distPref = do
   existsAlready <- doesPackageDBExist dbPath
   when existsAlready $ deletePackageDB dbPath
-  createPackageDB verbosity (compiler lbi) (withPrograms lbi) False dbPath
+  createPackageDB verbosity (compiler lbi) (withPrograms lbi) dbPath
   return (SpecificPackageDB dbRelPath)
   where
     dbRelPath = internalPackageDBPath lbi distPref
@@ -1188,7 +1188,7 @@ builtinAutogenFiles pkg lbi clbi =
     pathsFile = AutogenModule (autogenPathsModuleName pkg) (Suffix "hs")
     pathsContents = toUTF8LBS $ generatePathsModule pkg lbi clbi
     packageInfoFile = AutogenModule (autogenPackageInfoModuleName pkg) (Suffix "hs")
-    packageInfoContents = toUTF8LBS $ generatePackageInfoModule pkg lbi
+    packageInfoContents = toUTF8LBS $ generatePackageInfoModule pkg
     cppHeaderFile = AutogenFile $ toShortText cppHeaderName
     cppHeaderContents = toUTF8LBS $ generateCabalMacrosHeader pkg lbi clbi
 

Cabal/src/Distribution/Simple/Build/PackageInfoModule.hs

@@ -19,11 +19,14 @@ import Distribution.Compat.Prelude
 import Prelude ()
 
 import Distribution.Package
-import Distribution.PackageDescription
-import Distribution.Simple.Compiler
-import Distribution.Simple.LocalBuildInfo
-import Distribution.Utils.ShortText
-import Distribution.Version
+  ( PackageName
+  , packageName
+  , packageVersion
+  , unPackageName
+  )
+import Distribution.Types.PackageDescription (PackageDescription (..))
+import Distribution.Types.Version (versionNumbers)
+import Distribution.Utils.ShortText (fromShortText)
 
 import qualified Distribution.Simple.Build.PackageInfoModule.Z as Z
 
@@ -33,24 +36,16 @@ import qualified Distribution.Simple.Build.PackageInfoModule.Z as Z
 
 -- ------------------------------------------------------------
 
-generatePackageInfoModule :: PackageDescription -> LocalBuildInfo -> String
-generatePackageInfoModule pkg_descr lbi =
+generatePackageInfoModule :: PackageDescription -> String
+generatePackageInfoModule pkg_descr =
   Z.render
     Z.Z
       { Z.zPackageName = showPkgName $ packageName pkg_descr
       , Z.zVersionDigits = show $ versionNumbers $ packageVersion pkg_descr
       , Z.zSynopsis = fromShortText $ synopsis pkg_descr
       , Z.zCopyright = fromShortText $ copyright pkg_descr
       , Z.zHomepage = fromShortText $ homepage pkg_descr
-      , Z.zSupportsNoRebindableSyntax = supports_rebindable_syntax
       }
-  where
-    supports_rebindable_syntax = ghc_newer_than (mkVersion [7, 0, 1])
-
-    ghc_newer_than minVersion =
-      case compilerCompatVersion GHC (compiler lbi) of
-        Nothing -> False
-        Just version -> version `withinRange` orLaterVersion minVersion
 
 showPkgName :: PackageName -> String
 showPkgName = map fixchar . unPackageName

Cabal/src/Distribution/Simple/Build/PackageInfoModule/Z.hs

@@ -2,26 +2,20 @@
 
 module Distribution.Simple.Build.PackageInfoModule.Z (render, Z (..)) where
 
-import Distribution.ZinzaPrelude
+import Distribution.ZinzaPrelude (Generic, execWriter, tell)
 
 data Z = Z
   { zPackageName :: String
   , zVersionDigits :: String
   , zSynopsis :: String
   , zCopyright :: String
   , zHomepage :: String
-  , zSupportsNoRebindableSyntax :: Bool
   }
   deriving (Generic)
 
 render :: Z -> String
 render z_root = execWriter $ do
-  if (zSupportsNoRebindableSyntax z_root)
-    then do
-      tell "{-# LANGUAGE NoRebindableSyntax #-}\n"
-      return ()
-    else do
-      return ()
+  tell "{-# LANGUAGE NoRebindableSyntax #-}\n"
   tell "{-# OPTIONS_GHC -w #-}\n"
   tell "\n"
   tell "{-|\n"

Cabal/src/Distribution/Simple/Build/PathsModule.hs

@@ -44,8 +44,6 @@ generatePathsModule pkg_descr lbi clbi =
     Z.Z
       { Z.zPackageName = packageName pkg_descr
       , Z.zVersionDigits = show $ versionNumbers $ packageVersion pkg_descr
-      , Z.zSupportsCpp = supports_cpp
-      , Z.zSupportsNoRebindableSyntax = supports_rebindable_syntax
       , Z.zAbsolute = absolute
       , Z.zRelocatable = relocatable lbi
       , Z.zIsWindows = isWindows
@@ -63,15 +61,6 @@ generatePathsModule pkg_descr lbi clbi =
       , Z.zSysconfdir = zSysconfdir
       }
   where
-    supports_cpp = supports_language_pragma
-    supports_rebindable_syntax = ghc_newer_than (mkVersion [7, 0, 1])
-    supports_language_pragma = ghc_newer_than (mkVersion [6, 6, 1])
-
-    ghc_newer_than minVersion =
-      case compilerCompatVersion GHC (compiler lbi) of
-        Nothing -> False
-        Just version -> version `withinRange` orLaterVersion minVersion
-
     -- In several cases we cannot make relocatable installations
     absolute =
       hasLibs pkg_descr -- we can only make progs relocatable

Cabal/src/Distribution/Simple/Build/PathsModule/Z.hs

@@ -5,8 +5,6 @@ import Distribution.ZinzaPrelude
 data Z
     = Z {zPackageName :: PackageName,
          zVersionDigits :: String,
-         zSupportsCpp :: Bool,
-         zSupportsNoRebindableSyntax :: Bool,
          zAbsolute :: Bool,
          zRelocatable :: Bool,
          zIsWindows :: Bool,
@@ -25,18 +23,8 @@ data Z
     deriving Generic
 render :: Z -> String
 render z_root = execWriter $ do
-  if (zSupportsCpp z_root)
-  then do
-    tell "{-# LANGUAGE CPP #-}\n"
-    return ()
-  else do
-    return ()
-  if (zSupportsNoRebindableSyntax z_root)
-  then do
-    tell "{-# LANGUAGE NoRebindableSyntax #-}\n"
-    return ()
-  else do
-    return ()
+  tell "{-# LANGUAGE CPP #-}\n"
+  tell "{-# LANGUAGE NoRebindableSyntax #-}\n"
   if (zNot z_root (zAbsolute z_root))
   then do
     tell "{-# LANGUAGE ForeignFunctionInterface #-}\n"
@@ -91,25 +79,8 @@ render z_root = execWriter $ do
   else do
     return ()
   tell "\n"
-  if (zSupportsCpp z_root)
-  then do
-    tell "#if defined(VERSION_base)\n"
-    tell "\n"
-    tell "#if MIN_VERSION_base(4,0,0)\n"
-    tell "catchIO :: IO a -> (Exception.IOException -> IO a) -> IO a\n"
-    tell "#else\n"
-    tell "catchIO :: IO a -> (Exception.Exception -> IO a) -> IO a\n"
-    tell "#endif\n"
-    tell "\n"
-    tell "#else\n"
-    tell "catchIO :: IO a -> (Exception.IOException -> IO a) -> IO a\n"
-    tell "#endif\n"
-    tell "catchIO = Exception.catch\n"
-    return ()
-  else do
-    tell "catchIO :: IO a -> (Exception.IOException -> IO a) -> IO a\n"
-    tell "catchIO = Exception.catch\n"
-    return ()
+  tell "catchIO :: IO a -> (Exception.IOException -> IO a) -> IO a\n"
+  tell "catchIO = Exception.catch\n"
   tell "\n"
   tell "-- |The package version.\n"
   tell "version :: Version\n"

Cabal/src/Distribution/Simple/Compiler.hs

@@ -492,15 +492,8 @@ reexportedAsSupported comp = case compilerFlavor comp of
 -- "dynamic-library-dirs"?
 libraryDynDirSupported :: Compiler -> Bool
 libraryDynDirSupported comp = case compilerFlavor comp of
-  GHC ->
-    -- Not just v >= mkVersion [8,0,1,20161022], as there
-    -- are many GHC 8.1 nightlies which don't support this.
-    ( (v >= mkVersion [8, 0, 1, 20161022] && v < mkVersion [8, 1])
-        || v >= mkVersion [8, 1, 20161021]
-    )
+  GHC -> True
   _ -> False
-  where
-    v = compilerVersion comp
 
 -- | Does this compiler's "ar" command supports response file
 -- arguments (i.e. @file-style arguments).

Cabal/src/Distribution/Simple/Configure.hs

@@ -2095,7 +2095,7 @@ getInstalledPackages verbosity comp mbWorkDir packageDBs progdb = do
   -- do not check empty packagedbs (ghc-pkg would error out)
   packageDBs' <- filterM packageDBExists packageDBs
   case compilerFlavor comp of
-    GHC -> GHC.getInstalledPackages verbosity comp mbWorkDir packageDBs' progdb
+    GHC -> GHC.getInstalledPackages verbosity mbWorkDir packageDBs' progdb
     GHCJS -> GHCJS.getInstalledPackages verbosity mbWorkDir packageDBs' progdb
     UHC -> UHC.getInstalledPackages verbosity comp mbWorkDir packageDBs' progdb
     flv ->
@@ -2922,12 +2922,7 @@ checkForeignLibSupported :: Compiler -> Platform -> ForeignLib -> Maybe String
 checkForeignLibSupported comp platform flib = go (compilerFlavor comp)
   where
     go :: CompilerFlavor -> Maybe String
-    go GHC
-      | compilerVersion comp < mkVersion [7, 8] =
-          unsupported
-            [ "Building foreign libraries is only supported with GHC >= 7.8"
-            ]
-      | otherwise = goGhcPlatform platform
+    go GHC = goGhcPlatform platform
     go _ =
       unsupported
         [ "Building foreign libraries is currently only supported with ghc"

Cabal/src/Distribution/Simple/Errors.hs

@@ -96,8 +96,7 @@ data CabalException
   | AmbiguousBuildTarget [(String, [(String, String)])]
   | CheckBuildTargets String
   | VersionMismatchGHC FilePath Version FilePath Version
-  | CheckPackageDbStackPost76
-  | CheckPackageDbStackPre76
+  | CheckPackageDbStack
   | GlobalPackageDbSpecifiedFirst
   | CantInstallForeignLib
   | NoSupportForPreProcessingTest TestType
@@ -230,8 +229,7 @@ exceptionCode e = case e of
   AmbiguousBuildTarget{} -> 7865
   CheckBuildTargets{} -> 4733
   VersionMismatchGHC{} -> 4000
-  CheckPackageDbStackPost76{} -> 3000
-  CheckPackageDbStackPre76{} -> 5640
+  CheckPackageDbStack{} -> 3000
   GlobalPackageDbSpecifiedFirst{} -> 2345
   CantInstallForeignLib{} -> 8221
   NoSupportForPreProcessingTest{} -> 3008
@@ -470,13 +468,9 @@ exceptionMessage e = case e of
       ++ ghcPkgProgPath
       ++ " is version "
       ++ prettyShow ghcPkgVersion
-  CheckPackageDbStackPost76 ->
+  CheckPackageDbStack ->
     "If the global package db is specified, it must be "
       ++ "specified first and cannot be specified multiple times"
-  CheckPackageDbStackPre76 ->
-    "With current ghc versions the global package db is always used "
-      ++ "and must be listed first. This ghc limitation is lifted in GHC 7.6,"
-      ++ "see https://gitlab.haskell.org/ghc/ghc/-/issues/5977"
   GlobalPackageDbSpecifiedFirst ->
     "If the global package db is specified, it must be "
       ++ "specified first and cannot be specified multiple times"

Cabal/src/Distribution/Simple/GHC.hs

@@ -200,8 +200,8 @@ configureCompiler verbosity hcPath conf0 = do
         ++ prettyShow ghcVersion
 
   let implInfo = ghcVersionImplInfo ghcVersion
-  languages <- Internal.getLanguages verbosity implInfo ghcProg
-  extensions0 <- Internal.getExtensions verbosity implInfo ghcProg
+  languages <- Internal.getLanguages implInfo
+  extensions0 <- Internal.getExtensions verbosity ghcProg
 
   ghcInfo <- Internal.getGhcInfo verbosity implInfo ghcProg
 
@@ -489,14 +489,13 @@ getPackageDBContents verbosity mbWorkDir packagedb progdb = do
 -- | Given a package DB stack, return all installed packages.
 getInstalledPackages
   :: Verbosity
-  -> Compiler
   -> Maybe (SymbolicPath CWD (Dir from))
   -> PackageDBStackX (SymbolicPath from (Dir PkgDB))
   -> ProgramDb
   -> IO InstalledPackageIndex
-getInstalledPackages verbosity comp mbWorkDir packagedbs progdb = do
+getInstalledPackages verbosity mbWorkDir packagedbs progdb = do
   checkPackageDbEnvVar verbosity
-  checkPackageDbStack verbosity comp packagedbs
+  checkPackageDbStack verbosity packagedbs
   pkgss <- getInstalledPackages' verbosity mbWorkDir packagedbs progdb
   index <- toPackageIndex verbosity pkgss progdb
   return $! hackRtsPackage index
@@ -576,30 +575,13 @@ checkPackageDbEnvVar :: Verbosity -> IO ()
 checkPackageDbEnvVar verbosity =
   Internal.checkPackageDbEnvVar verbosity "GHC" "GHC_PACKAGE_PATH"
 
-checkPackageDbStack :: Eq fp => Verbosity -> Compiler -> PackageDBStackX fp -> IO ()
-checkPackageDbStack verbosity comp =
-  if flagPackageConf implInfo
-    then checkPackageDbStackPre76 verbosity
-    else checkPackageDbStackPost76 verbosity
-  where
-    implInfo = ghcVersionImplInfo (compilerVersion comp)
-
-checkPackageDbStackPost76 :: Eq fp => Verbosity -> PackageDBStackX fp -> IO ()
-checkPackageDbStackPost76 _ (GlobalPackageDB : rest)
+checkPackageDbStack :: Eq fp => Verbosity -> PackageDBStackX fp -> IO ()
+checkPackageDbStack _ (GlobalPackageDB : rest)
   | GlobalPackageDB `notElem` rest = return ()
-checkPackageDbStackPost76 verbosity rest
+checkPackageDbStack verbosity rest
   | GlobalPackageDB `elem` rest =
-      dieWithException verbosity CheckPackageDbStackPost76
-checkPackageDbStackPost76 _ _ = return ()
-
-checkPackageDbStackPre76 :: Eq fp => Verbosity -> PackageDBStackX fp -> IO ()
-checkPackageDbStackPre76 _ (GlobalPackageDB : rest)
-  | GlobalPackageDB `notElem` rest = return ()
-checkPackageDbStackPre76 verbosity rest
-  | GlobalPackageDB `notElem` rest =
-      dieWithException verbosity CheckPackageDbStackPre76
-checkPackageDbStackPre76 verbosity _ =
-  dieWithException verbosity GlobalPackageDbSpecifiedFirst
+      dieWithException verbosity CheckPackageDbStack
+checkPackageDbStack _ _ = return ()
 
 -- GHC < 6.10 put "$topdir/include/mingw" in rts's installDirs. This
 -- breaks when you want to use a different gcc, so we need to filter
@@ -710,7 +692,7 @@ startInterpreter verbosity progdb comp platform packageDBs = do
           { ghcOptMode = toFlag GhcModeInteractive
           , ghcOptPackageDBs = packageDBs
           }
-  checkPackageDbStack verbosity comp packageDBs
+  checkPackageDbStack verbosity packageDBs
   (ghcProg, _) <- requireProgram verbosity ghcProgram progdb
   -- This doesn't pass source file arguments to GHC, so we don't have to worry
   -- about using a response file here.
@@ -1134,23 +1116,9 @@ installLib verbosity lbi targetDir dynlibTargetDir bytecodeTargetDir _builtDir p
 -- -----------------------------------------------------------------------------
 -- Registering
 
-hcPkgInfo :: ProgramDb -> HcPkg.HcPkgInfo
+hcPkgInfo :: ProgramDb -> HcPkg.ConfiguredProgram
 hcPkgInfo progdb =
-  HcPkg.HcPkgInfo
-    { HcPkg.hcPkgProgram = ghcPkgProg
-    , HcPkg.noPkgDbStack = v < [6, 9]
-    , HcPkg.noVerboseFlag = v < [6, 11]
-    , HcPkg.flagPackageConf = v < [7, 5]
-    , HcPkg.supportsDirDbs = v >= [6, 8]
-    , HcPkg.requiresDirDbs = v >= [7, 10]
-    , HcPkg.nativeMultiInstance = v >= [7, 10]
-    , HcPkg.recacheMultiInstance = v >= [6, 12]
-    , HcPkg.suppressFilesCheck = v >= [6, 6]
-    }
-  where
-    v = versionNumbers ver
-    ghcPkgProg = fromMaybe (error "GHC.hcPkgInfo: no ghc program") $ lookupProgram ghcPkgProgram progdb
-    ver = fromMaybe (error "GHC.hcPkgInfo: no ghc version") $ programVersion ghcPkgProg
+  fromMaybe (error "GHC.hcPkgInfo: no ghc program") $ lookupProgram ghcPkgProgram progdb
 
 registerPackage
   :: Verbosity