Use GHC2021

exe/Main.hs

@@ -1,9 +1,7 @@
 -- Copyright (c) 2019 The DAML Authors. All rights reserved.
 -- SPDX-License-Identifier: Apache-2.0
-{-# LANGUAGE LambdaCase          #-}
-{-# LANGUAGE NamedFieldPuns      #-}
-{-# LANGUAGE OverloadedStrings   #-}
-{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE LambdaCase        #-}
+{-# LANGUAGE OverloadedStrings #-}
 module Main(main) where
 
 import           Control.Exception             (displayException)

exe/Wrapper.hs

@@ -1,12 +1,8 @@
-{-# LANGUAGE CPP                        #-}
-{-# LANGUAGE DataKinds                  #-}
-{-# LANGUAGE ExplicitNamespaces         #-}
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE LambdaCase                 #-}
-{-# LANGUAGE NamedFieldPuns             #-}
-{-# LANGUAGE OverloadedStrings          #-}
-{-# LANGUAGE RecordWildCards            #-}
-{-# LANGUAGE ScopedTypeVariables        #-}
+{-# LANGUAGE CPP               #-}
+{-# LANGUAGE DataKinds         #-}
+{-# LANGUAGE LambdaCase        #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RecordWildCards   #-}
 -- | This module is based on the hie-wrapper.sh script in
 -- https://github.com/alanz/vscode-hie-server
 module Main where

ghcide-bench/ghcide-bench.cabal

@@ -19,7 +19,7 @@ source-repository head
     location: https://github.com/haskell/haskell-language-server.git
 
 executable ghcide-bench
-    default-language: Haskell2010
+    default-language: GHC2021
     build-depends:
         aeson,
         base,
@@ -45,23 +45,13 @@ executable ghcide-bench
     ghc-options: -threaded -Wall -Wno-name-shadowing -rtsopts
     main-is: Main.hs
     default-extensions:
-        BangPatterns
-        DeriveFunctor
-        DeriveGeneric
-        FlexibleContexts
-        GeneralizedNewtypeDeriving
         LambdaCase
-        NamedFieldPuns
         OverloadedStrings
         RecordWildCards
-        ScopedTypeVariables
-        StandaloneDeriving
-        TupleSections
-        TypeApplications
         ViewPatterns
 
 library
-    default-language: Haskell2010
+    default-language: GHC2021
     hs-source-dirs: src
     ghc-options: -Wall -Wno-name-shadowing
     exposed-modules:
@@ -91,23 +81,13 @@ library
         text,
         row-types
     default-extensions:
-        BangPatterns
-        DeriveFunctor
-        DeriveGeneric
-        FlexibleContexts
-        GeneralizedNewtypeDeriving
         LambdaCase
-        NamedFieldPuns
         RecordWildCards
-        ScopedTypeVariables
-        StandaloneDeriving
-        TupleSections
-        TypeApplications
         ViewPatterns
 
 test-suite test
     type: exitcode-stdio-1.0
-    default-language: Haskell2010
+    default-language: GHC2021
     build-tool-depends:
         ghcide:ghcide,
         implicit-hie:gen-hie
@@ -124,17 +104,7 @@ test-suite test
         tasty-hunit >= 0.10,
         tasty-rerun,
     default-extensions:
-        BangPatterns
-        DeriveFunctor
-        DeriveGeneric
-        FlexibleContexts
-        GeneralizedNewtypeDeriving
         LambdaCase
-        NamedFieldPuns
         OverloadedStrings
         RecordWildCards
-        ScopedTypeVariables
-        StandaloneDeriving
-        TupleSections
-        TypeApplications
         ViewPatterns

ghcide-bench/src/Experiments.hs

@@ -1,12 +1,9 @@
-{-# LANGUAGE ConstraintKinds           #-}
-{-# LANGUAGE DataKinds                 #-}
-{-# LANGUAGE ExistentialQuantification #-}
-{-# LANGUAGE GADTs                     #-}
-{-# LANGUAGE ImplicitParams            #-}
-{-# LANGUAGE ImpredicativeTypes        #-}
-{-# LANGUAGE OverloadedLabels          #-}
-{-# LANGUAGE OverloadedStrings         #-}
-{-# LANGUAGE PolyKinds                 #-}
+{-# LANGUAGE DataKinds          #-}
+{-# LANGUAGE GADTs              #-}
+{-# LANGUAGE ImplicitParams     #-}
+{-# LANGUAGE ImpredicativeTypes #-}
+{-# LANGUAGE OverloadedLabels   #-}
+{-# LANGUAGE OverloadedStrings  #-}
 {-# OPTIONS_GHC -Wno-deprecations -Wno-unticked-promoted-constructors #-}
 
 module Experiments

ghcide-bench/test/Main.hs

@@ -7,7 +7,6 @@
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE GADTs                 #-}
 {-# LANGUAGE ImplicitParams        #-}
-{-# LANGUAGE PolyKinds             #-}
 {-# OPTIONS_GHC -Wno-deprecations -Wno-unticked-promoted-constructors #-}
 
 module Main (main) where

ghcide/ghcide.cabal

@@ -47,7 +47,7 @@ common warnings
     -fno-ignore-asserts
 
 library
-  default-language:   Haskell2010
+  default-language:   GHC2021
   build-depends:
     , aeson
     , array
@@ -123,24 +123,11 @@ library
     build-depends: unix
 
   default-extensions:
-    BangPatterns
     DataKinds
-    DeriveFoldable
-    DeriveFunctor
-    DeriveGeneric
-    DeriveTraversable
-    FlexibleContexts
-    GeneralizedNewtypeDeriving
-    KindSignatures
+    ExplicitNamespaces
     LambdaCase
-    NamedFieldPuns
     OverloadedStrings
     RecordWildCards
-    ScopedTypeVariables
-    StandaloneDeriving
-    TupleSections
-    TypeApplications
-    TypeOperators
     ViewPatterns
 
   hs-source-dirs:     src session-loader
@@ -249,7 +236,7 @@ flag test-exe
 
 executable ghcide-test-preprocessor
   import: warnings
-  default-language: Haskell2010
+  default-language:   GHC2021
   hs-source-dirs:   test/preprocessor
   ghc-options:      -Wno-name-shadowing
   main-is:          Main.hs
@@ -264,7 +251,7 @@ flag executable
 
 executable ghcide
   import: warnings
-  default-language:   Haskell2010
+  default-language:   GHC2021
   hs-source-dirs:     exe
   ghc-options:        -threaded -rtsopts "-with-rtsopts=-I0 -A128M -T" -Wno-name-shadowing
 
@@ -291,19 +278,9 @@ executable ghcide
 
   autogen-modules:    Paths_ghcide
   default-extensions:
-    BangPatterns
-    DeriveFunctor
-    DeriveGeneric
-    FlexibleContexts
-    GeneralizedNewtypeDeriving
     LambdaCase
-    NamedFieldPuns
     OverloadedStrings
     RecordWildCards
-    ScopedTypeVariables
-    StandaloneDeriving
-    TupleSections
-    TypeApplications
     ViewPatterns
 
   if !flag(executable)
@@ -319,7 +296,7 @@ executable ghcide
 test-suite ghcide-tests
   import: warnings
   type:               exitcode-stdio-1.0
-  default-language:   Haskell2010
+  default-language:   GHC2021
   build-tool-depends:
     , ghcide:ghcide
     , ghcide:ghcide-test-preprocessor
@@ -420,17 +397,7 @@ test-suite ghcide-tests
 
   -- Tests that have been pulled out of the main file
   default-extensions:
-    BangPatterns
-    DeriveFunctor
-    DeriveGeneric
-    FlexibleContexts
-    GeneralizedNewtypeDeriving
     LambdaCase
-    NamedFieldPuns
     OverloadedStrings
     RecordWildCards
-    ScopedTypeVariables
-    StandaloneDeriving
-    TupleSections
-    TypeApplications
     ViewPatterns

ghcide/session-loader/Development/IDE/Session.hs

@@ -1,7 +1,5 @@
-{-# LANGUAGE CPP                       #-}
-{-# LANGUAGE ExistentialQuantification #-}
-{-# LANGUAGE RankNTypes                #-}
-{-# LANGUAGE TypeFamilies              #-}
+{-# LANGUAGE CPP          #-}
+{-# LANGUAGE TypeFamilies #-}
 
 {-|
 The logic for setting up a ghcide session by tapping into hie-bios.

ghcide/session-loader/Development/IDE/Session/Diagnostics.hs

@@ -1,5 +1,4 @@
 {-# LANGUAGE DeriveAnyClass #-}
-{-# LANGUAGE DeriveGeneric  #-}
 
 module Development.IDE.Session.Diagnostics where
 import           Control.Applicative

ghcide/src/Development/IDE/Core/Actions.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE RankNTypes   #-}
 {-# LANGUAGE TypeFamilies #-}
 module Development.IDE.Core.Actions
 ( getAtPoint

ghcide/src/Development/IDE/Core/Compile.hs

@@ -3,7 +3,6 @@
 
 {-# LANGUAGE CPP        #-}
 {-# LANGUAGE GADTs      #-}
-{-# LANGUAGE RankNTypes #-}
 
 -- | Based on https://ghc.haskell.org/trac/ghc/wiki/Commentary/Compiler/API.
 --   Given a list of paths to find libraries, and a file to compile, produce a list of 'CoreModule' values.

ghcide/src/Development/IDE/Core/OfInterest.hs

@@ -1,8 +1,7 @@
 -- Copyright (c) 2019 The DAML Authors. All rights reserved.
 -- SPDX-License-Identifier: Apache-2.0
 
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE TypeFamilies      #-}
+{-# LANGUAGE TypeFamilies #-}
 
 -- | Utilities and state for the files of interest - those which are currently
 --   open in the editor. The rule is 'IsFileOfInterest'

ghcide/src/Development/IDE/Core/ProgressReporting.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE RankNTypes #-}
 module Development.IDE.Core.ProgressReporting
   ( ProgressEvent(..)
   , ProgressReporting(..)

ghcide/src/Development/IDE/Core/RuleTypes.hs

@@ -2,7 +2,6 @@
 -- SPDX-License-Identifier: Apache-2.0
 
 {-# LANGUAGE DerivingStrategies #-}
-{-# LANGUAGE FlexibleInstances  #-}
 {-# LANGUAGE GADTs              #-}
 {-# LANGUAGE PatternSynonyms    #-}
 {-# LANGUAGE TemplateHaskell    #-}

ghcide/src/Development/IDE/Core/Rules.hs

@@ -3,7 +3,6 @@
 
 {-# LANGUAGE CPP                   #-}
 {-# LANGUAGE DuplicateRecordFields #-}
-{-# LANGUAGE FlexibleInstances     #-}
 {-# LANGUAGE TypeFamilies          #-}
 
 -- | A Shake implementation of the compiler service, built

ghcide/src/Development/IDE/Core/Service.hs

@@ -1,9 +1,7 @@
 -- Copyright (c) 2019 The DAML Authors. All rights reserved.
 -- SPDX-License-Identifier: Apache-2.0
 
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE RankNTypes        #-}
-{-# LANGUAGE TypeFamilies      #-}
+{-# LANGUAGE TypeFamilies #-}
 
 -- | A Shake implementation of the compiler service, built
 --   using the "Shaker" abstraction layer for in-memory use.

ghcide/src/Development/IDE/Core/Shake.hs

@@ -1,16 +1,12 @@
 -- Copyright (c) 2019 The DAML Authors. All rights reserved.
 -- SPDX-License-Identifier: Apache-2.0
 
-{-# LANGUAGE CPP                       #-}
-{-# LANGUAGE ConstraintKinds           #-}
-{-# LANGUAGE DerivingStrategies        #-}
-{-# LANGUAGE DuplicateRecordFields     #-}
-{-# LANGUAGE ExistentialQuantification #-}
-{-# LANGUAGE PackageImports            #-}
-{-# LANGUAGE PolyKinds                 #-}
-{-# LANGUAGE RankNTypes                #-}
-{-# LANGUAGE RecursiveDo               #-}
-{-# LANGUAGE TypeFamilies              #-}
+{-# LANGUAGE CPP                   #-}
+{-# LANGUAGE DerivingStrategies    #-}
+{-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE PackageImports        #-}
+{-# LANGUAGE RecursiveDo           #-}
+{-# LANGUAGE TypeFamilies          #-}
 
 -- | A Shake implementation of the compiler service.
 --

ghcide/src/Development/IDE/Core/UseStale.hs

@@ -1,7 +1,5 @@
-{-# LANGUAGE DerivingVia    #-}
-{-# LANGUAGE GADTs          #-}
-{-# LANGUAGE KindSignatures #-}
-{-# LANGUAGE RankNTypes     #-}
+{-# LANGUAGE DerivingVia #-}
+{-# LANGUAGE GADTs       #-}
 
 module Development.IDE.Core.UseStale
   ( Age(..)

ghcide/src/Development/IDE/GHC/Compat.hs

@@ -2,8 +2,6 @@
 -- SPDX-License-Identifier: Apache-2.0
 
 {-# LANGUAGE CPP               #-}
-{-# LANGUAGE ConstraintKinds   #-}
-{-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE PatternSynonyms   #-}
 
 -- | Attempt at hiding the GHC version differences we can.

ghcide/src/Development/IDE/GHC/Compat/CmdLine.hs

@@ -1,5 +1,4 @@
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE RankNTypes #-}
 
 -- | Compat module Interface file relevant code.
 module Development.IDE.GHC.Compat.CmdLine (
@@ -15,12 +14,13 @@ module Development.IDE.GHC.Compat.CmdLine (
     ) where
 
 #if MIN_VERSION_ghc(9,3,0)
-import GHC.Driver.Session (processCmdLineP, CmdLineP (..), getCmdLineState, putCmdLineState)
-import GHC.Driver.CmdLine
+import           GHC.Driver.CmdLine
+import           GHC.Driver.Session     (CmdLineP (..), getCmdLineState,
+                                         processCmdLineP, putCmdLineState)
 #else
-import GHC.Driver.CmdLine
-import Control.Monad.IO.Class
-import GHC (Located)
+import           Control.Monad.IO.Class
+import           GHC                    (Located)
+import           GHC.Driver.CmdLine
 #endif
 
 #if !MIN_VERSION_ghc(9,3,0)

ghcide/src/Development/IDE/GHC/Compat/Core.hs

@@ -1,6 +1,4 @@
 {-# LANGUAGE CPP               #-}
-{-# LANGUAGE ConstraintKinds   #-}
-{-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE PatternSynonyms   #-}
 {-# LANGUAGE ViewPatterns      #-}
 

ghcide/src/Development/IDE/GHC/Compat/Util.hs

@@ -1,5 +1,4 @@
-{-# LANGUAGE CPP             #-}
-{-# LANGUAGE ConstraintKinds #-}
+{-# LANGUAGE CPP #-}
 -- | GHC Utils and Datastructures re-exports.
 --
 -- Mainly handles module hierarchy re-organisation of GHC

ghcide/src/Development/IDE/GHC/CoreFile.hs

@@ -1,6 +1,5 @@
-{-# LANGUAGE CPP               #-}
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE RecordWildCards   #-}
+{-# LANGUAGE CPP             #-}
+{-# LANGUAGE RecordWildCards #-}
 
 -- | CoreFiles let us serialize Core to a file in order to later recover it
 -- without reparsing or retypechecking