Remove unused extension pragmas from the compiler code base

18 files changed, 17 insertions, 26 deletions

diff --git a/compiler/GHC/Core/Opt/ConstantFold.hs b/compiler/GHC/Core/Opt/ConstantFold.hs
index 0b5abdc711..948914e92a 100644
--- a/compiler/GHC/Core/Opt/ConstantFold.hs
+++ b/compiler/GHC/Core/Opt/ConstantFold.hs
@@ -10,8 +10,14 @@ ToDo:
    (i1 + i2) only if it results in a valid Float.
 -}
 
-{-# LANGUAGE CPP, RankNTypes, PatternSynonyms, ViewPatterns, RecordWildCards,
-    DeriveFunctor, LambdaCase, TypeApplications, MultiWayIf #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE DeriveFunctor #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE MultiWayIf #-}
+{-# LANGUAGE PatternSynonyms #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE ViewPatterns #-}
 
 {-# OPTIONS_GHC -optc-DNON_POSIX_SOURCE -Wno-incomplete-uni-patterns #-}
 
diff --git a/compiler/GHC/Data/Graph/Directed.hs b/compiler/GHC/Data/Graph/Directed.hs
index e6adf612ea..451d31f125 100644
--- a/compiler/GHC/Data/Graph/Directed.hs
+++ b/compiler/GHC/Data/Graph/Directed.hs
@@ -2,7 +2,6 @@
 
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
-{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE ViewPatterns #-}
 
diff --git a/compiler/GHC/Driver/Env.hs b/compiler/GHC/Driver/Env.hs
index 5608c12b15..50c2b5caf6 100644
--- a/compiler/GHC/Driver/Env.hs
+++ b/compiler/GHC/Driver/Env.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE DeriveFunctor #-}
 
 module GHC.Driver.Env
    ( Hsc(..)
diff --git a/compiler/GHC/Driver/Errors.hs b/compiler/GHC/Driver/Errors.hs
index de66b60a2c..0cfa0d20f5 100644
--- a/compiler/GHC/Driver/Errors.hs
+++ b/compiler/GHC/Driver/Errors.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE ViewPatterns #-}
-
 module GHC.Driver.Errors (
     warningsToMessages
   , printOrThrowWarnings
diff --git a/compiler/GHC/Driver/Main.hs b/compiler/GHC/Driver/Main.hs
index fe49f2a8e2..38d55e61f2 100644
--- a/compiler/GHC/Driver/Main.hs
+++ b/compiler/GHC/Driver/Main.hs
@@ -1,7 +1,6 @@
 {-# LANGUAGE CPP                      #-}
 {-# LANGUAGE BangPatterns             #-}
 {-# LANGUAGE NondecreasingIndentation #-}
-{-# LANGUAGE LambdaCase               #-}
 {-# OPTIONS_GHC -fprof-auto-top #-}
 
 -------------------------------------------------------------------------------
@@ -1211,8 +1210,7 @@ checkSafeImports tcg_env
     cond' :: ImportedModsVal -> ImportedModsVal -> Hsc ImportedModsVal
     cond' v1 v2
         | imv_is_safe v1 /= imv_is_safe v2
-        = do
-            throwOneError $ mkPlainErrMsg (imv_span v1)
+        = throwOneError $ mkPlainErrMsg (imv_span v1)
               (text "Module" <+> ppr (imv_name v1) <+>
               (text $ "is imported both as a safe and unsafe import!"))
         | otherwise
diff --git a/compiler/GHC/Driver/MakeFile.hs b/compiler/GHC/Driver/MakeFile.hs
index 220e1bf5b2..8d4db19f92 100644
--- a/compiler/GHC/Driver/MakeFile.hs
+++ b/compiler/GHC/Driver/MakeFile.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE LambdaCase #-}
 
 -----------------------------------------------------------------------------
 --
diff --git a/compiler/GHC/Hs/Binds.hs b/compiler/GHC/Hs/Binds.hs
index 201eb06255..1f895c20ec 100644
--- a/compiler/GHC/Hs/Binds.hs
+++ b/compiler/GHC/Hs/Binds.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE ConstraintKinds #-}
 {-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE LambdaCase #-}
diff --git a/compiler/GHC/Parser/PostProcess.hs b/compiler/GHC/Parser/PostProcess.hs
index 59280962d3..de94c185ea 100644
--- a/compiler/GHC/Parser/PostProcess.hs
+++ b/compiler/GHC/Parser/PostProcess.hs
@@ -982,7 +982,7 @@ checkPat loc (L l e@(PatBuilderVar (L _ c))) tyargs args
   | not (null args) && patIsRec c =
       add_hint SuggestRecursiveDo $
       patFail l (ppr e)
-checkPat loc (L _ (PatBuilderAppType f t)) tyargs args = do
+checkPat loc (L _ (PatBuilderAppType f t)) tyargs args =
   checkPat loc f (t : tyargs) args
 checkPat loc (L _ (PatBuilderApp f e)) [] args = do
   p <- checkLPat e
diff --git a/compiler/GHC/Rename/HsType.hs b/compiler/GHC/Rename/HsType.hs
index b4498c80ee..3cc51b651c 100644
--- a/compiler/GHC/Rename/HsType.hs
+++ b/compiler/GHC/Rename/HsType.hs
@@ -2,7 +2,6 @@
 {-# LANGUAGE LambdaCase          #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeFamilies        #-}
-{-# LANGUAGE ViewPatterns        #-}
 
 {-
 (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
diff --git a/compiler/GHC/Rename/Pat.hs b/compiler/GHC/Rename/Pat.hs
index b2a3874c0a..80ab505ee5 100644
--- a/compiler/GHC/Rename/Pat.hs
+++ b/compiler/GHC/Rename/Pat.hs
@@ -1,7 +1,6 @@
 {-# LANGUAGE CPP                 #-}
 {-# LANGUAGE DeriveFunctor       #-}
 {-# LANGUAGE FlexibleContexts    #-}
-{-# LANGUAGE LambdaCase          #-}
 {-# LANGUAGE RankNTypes          #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeFamilies        #-}
diff --git a/compiler/GHC/StgToCmm/Prim.hs b/compiler/GHC/StgToCmm/Prim.hs
index afb495e9e7..b7efb3b8ee 100644
--- a/compiler/GHC/StgToCmm/Prim.hs
+++ b/compiler/GHC/StgToCmm/Prim.hs
@@ -2955,7 +2955,7 @@ doAtomicAddrRMW
             -> CmmType       -- ^ Pointed value type
             -> CmmExpr       -- ^ Op argument (e.g. amount to add)
             -> FCode ()
-doAtomicAddrRMW res amop addr ty n = do
+doAtomicAddrRMW res amop addr ty n =
     emitPrimCall
         [ res ]
         (MO_AtomicRMW (typeWidth ty) amop)
@@ -2982,7 +2982,7 @@ doAtomicReadAddr
     -> CmmExpr   -- ^ Addr#
     -> CmmType   -- ^ Type of element by which we are indexing
     -> FCode ()
-doAtomicReadAddr res addr ty = do
+doAtomicReadAddr res addr ty =
     emitPrimCall
         [ res ]
         (MO_AtomicRead (typeWidth ty))
@@ -3009,7 +3009,7 @@ doAtomicWriteAddr
     -> CmmType   -- ^ Type of element by which we are indexing
     -> CmmExpr   -- ^ Value to write
     -> FCode ()
-doAtomicWriteAddr addr ty val = do
+doAtomicWriteAddr addr ty val =
     emitPrimCall
         [ {- no results -} ]
         (MO_AtomicWrite (typeWidth ty))
diff --git a/compiler/GHC/Tc/Solver/Interact.hs b/compiler/GHC/Tc/Solver/Interact.hs
index e8ab8ad82a..62e289b543 100644
--- a/compiler/GHC/Tc/Solver/Interact.hs
+++ b/compiler/GHC/Tc/Solver/Interact.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, MultiWayIf #-}
+{-# LANGUAGE CPP #-}
 
 {-# OPTIONS_GHC -Wno-incomplete-record-updates #-}
 {-# OPTIONS_GHC -Wno-incomplete-uni-patterns   #-}
diff --git a/compiler/GHC/Tc/Types/Constraint.hs b/compiler/GHC/Tc/Types/Constraint.hs
index c714bee20f..3862d842b0 100644
--- a/compiler/GHC/Tc/Types/Constraint.hs
+++ b/compiler/GHC/Tc/Types/Constraint.hs
@@ -1,4 +1,5 @@
-{-# LANGUAGE CPP, GeneralizedNewtypeDeriving, MultiWayIf #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 
 {-# OPTIONS_GHC -Wno-incomplete-record-updates #-}
 
diff --git a/compiler/GHC/Tc/Utils/Unify.hs b/compiler/GHC/Tc/Utils/Unify.hs
index 892ab050d5..735edc8ff0 100644
--- a/compiler/GHC/Tc/Utils/Unify.hs
+++ b/compiler/GHC/Tc/Utils/Unify.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE CPP                 #-}
-{-# LANGUAGE DeriveFunctor       #-}
 {-# LANGUAGE MultiWayIf          #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TupleSections       #-}
diff --git a/compiler/GHC/Tc/Utils/Zonk.hs b/compiler/GHC/Tc/Utils/Zonk.hs
index fbcc8444ed..9e2908fff8 100644
--- a/compiler/GHC/Tc/Utils/Zonk.hs
+++ b/compiler/GHC/Tc/Utils/Zonk.hs
@@ -1,7 +1,6 @@
 {-# LANGUAGE CPP              #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE TypeFamilies     #-}
-{-# LANGUAGE TypeApplications #-}
 
 {-# OPTIONS_GHC -Wno-incomplete-record-updates #-}
 
diff --git a/compiler/GHC/Types/FieldLabel.hs b/compiler/GHC/Types/FieldLabel.hs
index 226a854f6f..87f0b9eed8 100644
--- a/compiler/GHC/Types/FieldLabel.hs
+++ b/compiler/GHC/Types/FieldLabel.hs
@@ -1,7 +1,5 @@
 {-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE DeriveTraversable  #-}
 {-# LANGUAGE FlexibleContexts   #-}
-{-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE UndecidableInstances #-}
 
 {-
diff --git a/compiler/GHC/Types/Unique/DFM.hs b/compiler/GHC/Types/Unique/DFM.hs
index ef78dbe6af..f3009de2a2 100644
--- a/compiler/GHC/Types/Unique/DFM.hs
+++ b/compiler/GHC/Types/Unique/DFM.hs
@@ -15,8 +15,6 @@ is not deterministic.
 -}
 
 {-# LANGUAGE DeriveDataTypeable #-}
-{-# LANGUAGE DeriveFoldable #-}
-{-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE DeriveTraversable #-}
 {-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE FlexibleContexts #-}
diff --git a/compiler/GHC/Utils/Error.hs b/compiler/GHC/Utils/Error.hs
index 2c7edd30e9..2e47601e8c 100644
--- a/compiler/GHC/Utils/Error.hs
+++ b/compiler/GHC/Utils/Error.hs
@@ -521,7 +521,7 @@ withTiming' dflags what force_result prtimings action
 
     where whenPrintTimings = liftIO . when (prtimings == PrintTimings)
 
-          recordAllocs alloc = do
+          recordAllocs alloc =
             liftIO $ traceMarkerIO $ "GHC:allocs:" ++ show alloc
 
           eventBegins ctx w = do