Drop support for anything below GHC 8.0.0, base 4.9.0.0, Cabal 1.24.0.0

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

@@ -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/GHC.hs

@@ -199,8 +199,8 @@ 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
 
@@ -1106,23 +1106,9 @@ 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