Merge pull request #1009 from phadej/cleanup-pre-ghc-8.0

Cleanup pre-GHC-8.0 stuff

servant-client-core/include/overlapping-compat.h

@@ -1,8 +0,0 @@
-#if __GLASGOW_HASKELL__ >= 710
-#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
-#define OVERLAPPING_  {-# OVERLAPPING #-}
-#else
-{-# LANGUAGE OverlappingInstances #-}
-#define OVERLAPPABLE_
-#define OVERLAPPING_
-#endif

servant-client-core/servant-client-core.cabal

@@ -15,7 +15,6 @@ copyright:           2014-2016 Zalora South East Asia Pte Ltd, 2016-2017 Servant
 category:            Web
 build-type:          Simple
 extra-source-files:
-  include/*.h
   CHANGELOG.md
   README.md
 tested-with:
@@ -53,10 +52,6 @@ library
     , text                  >= 1.2.3.0  && < 1.3
     , transformers          >= 0.3.0.0  && < 0.6
 
-  if !impl(ghc >= 8.0)
-    build-depends:
-        semigroups          >=0.18.4 && <0.19
-
   -- Servant dependencies
   build-depends:
         servant            >= 0.14.1 && <0.15
@@ -78,7 +73,6 @@ library
   hs-source-dirs:      src
   default-language:    Haskell2010
   ghc-options:         -Wall
-  include-dirs:        include
 
 test-suite spec
   type:                exitcode-stdio-1.0

servant-client-core/src/Servant/Client/Core/Internal/Generic.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP                   #-}
 {-# LANGUAGE DataKinds             #-}
 {-# LANGUAGE DefaultSignatures     #-}
 {-# LANGUAGE FlexibleContexts      #-}
@@ -8,8 +7,6 @@
 {-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE UndecidableInstances  #-}
 
-#include "overlapping-compat.h"
-
 module Servant.Client.Core.Internal.Generic where
 
 import           Generics.SOP
@@ -142,7 +139,7 @@ instance (GClientList b acc, GClientList a (ClientList b acc))
   => GClientList (a :<|> b) acc where
   gClientList (a :<|> b) acc = gClientList a (gClientList b acc)
 
-instance OVERLAPPABLE_ (ClientList client acc ~ (client ': acc))
+instance {-# OVERLAPPABLE #-} (ClientList client acc ~ (client ': acc))
   => GClientList client acc where
   gClientList c acc = I c :* acc
 

servant-client-core/src/Servant/Client/Core/Internal/HasClient.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP                   #-}
 {-# LANGUAGE DataKinds             #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE FlexibleInstances     #-}
@@ -12,7 +11,6 @@
 {-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE UndecidableInstances  #-}
 
-#include "overlapping-compat.h"
 module Servant.Client.Core.Internal.HasClient where
 
 import           Prelude ()
@@ -209,7 +207,7 @@ instance (KnownSymbol capture, ToHttpApiData a, HasClient m sublayout)
   hoistClientMonad pm _ f cl = \as ->
     hoistClientMonad pm (Proxy :: Proxy sublayout) f (cl as)
 
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
   -- Note [Non-Empty Content Types]
   ( RunClient m, MimeUnrender ct a, ReflectMethod method, cts' ~ (ct ': cts)
   ) => HasClient m (Verb method status cts' a) where
@@ -226,7 +224,7 @@ instance OVERLAPPABLE_
 
   hoistClientMonad _ _ f ma = f ma
 
-instance OVERLAPPING_
+instance {-# OVERLAPPING #-}
   ( RunClient m, ReflectMethod method
   ) => HasClient m (Verb method status cts NoContent) where
   type Client m (Verb method status cts NoContent)
@@ -238,7 +236,7 @@ instance OVERLAPPING_
 
   hoistClientMonad _ _ f ma = f ma
 
-instance OVERLAPPING_
+instance {-# OVERLAPPING #-}
   -- Note [Non-Empty Content Types]
   ( RunClient m, MimeUnrender ct a, BuildHeadersTo ls
   , ReflectMethod method, cts' ~ (ct ': cts)
@@ -261,7 +259,7 @@ instance OVERLAPPING_
 
   hoistClientMonad _ _ f ma = f ma
 
-instance OVERLAPPING_
+instance {-# OVERLAPPING #-}
   ( RunClient m, BuildHeadersTo ls, ReflectMethod method
   ) => HasClient m (Verb method status cts (Headers ls NoContent)) where
   type Client m (Verb method status cts (Headers ls NoContent))
@@ -275,7 +273,7 @@ instance OVERLAPPING_
 
   hoistClientMonad _ _ f ma = f ma
 
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
   ( RunClient m, MonadIO m, MimeUnrender ct a, ReflectMethod method,
     FramingUnrender framing a, FromResultStream a b
   ) => HasClient m (Stream method status framing ct b) where

servant-client/include/overlapping-compat.h

@@ -1,8 +0,0 @@
-#if __GLASGOW_HASKELL__ >= 710
-#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
-#define OVERLAPPING_  {-# OVERLAPPING #-}
-#else
-{-# LANGUAGE OverlappingInstances #-}
-#define OVERLAPPABLE_
-#define OVERLAPPING_
-#endif

servant-client/servant-client.cabal

@@ -23,7 +23,6 @@ tested-with:
 homepage:            http://haskell-servant.readthedocs.org/
 Bug-reports:         http://github.com/haskell-servant/servant/issues
 extra-source-files:
-  include/*.h
   CHANGELOG.md
   README.md
 source-repository head
@@ -48,9 +47,6 @@ library
     , time                  >= 1.4.2    && < 1.9
     , transformers          >= 0.3.0.0  && < 0.6
 
-  if !impl(ghc >= 8.0)
-    build-depends: semigroups >=0.18.4 && <0.19
-
   -- Servant dependencies
   build-depends:
       servant-client-core   == 0.14.*
@@ -71,10 +67,7 @@ library
 
   hs-source-dirs: src
   default-language: Haskell2010
-  ghc-options: -Wall
+  ghc-options: -Wall -Wno-redundant-constraints
-  if impl(ghc >= 8.0)
-    ghc-options: -Wno-redundant-constraints
-  include-dirs: include
 
 test-suite spec
   type: exitcode-stdio-1.0
@@ -104,10 +97,6 @@ test-suite spec
     , wai
     , warp
 
-  if !impl(ghc >= 8.0)
-    build-depends:
-      semigroups
-
   -- Additonal dependencies
   build-depends:
       generics-sop      >= 0.3.2.0 && < 0.4

servant-client/test/Servant/ClientSpec.hs

@@ -15,15 +15,10 @@
 {-# LANGUAGE TypeFamilies           #-}
 {-# LANGUAGE TypeOperators          #-}
 {-# LANGUAGE UndecidableInstances   #-}
-#if __GLASGOW_HASKELL__ >= 800
 {-# OPTIONS_GHC -freduction-depth=100 #-}
-#else
-{-# OPTIONS_GHC -fcontext-stack=100 #-}
-#endif
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing #-}
 
-#include "overlapping-compat.h"
 module Servant.ClientSpec (spec, Person(..), startWaiApp, endWaiApp) where
 
 import           Prelude ()

servant-client/test/Servant/StreamSpec.hs

@@ -15,15 +15,10 @@
 {-# LANGUAGE TypeFamilies           #-}
 {-# LANGUAGE TypeOperators          #-}
 {-# LANGUAGE UndecidableInstances   #-}
-#if __GLASGOW_HASKELL__ >= 800
 {-# OPTIONS_GHC -freduction-depth=100 #-}
-#else
-{-# OPTIONS_GHC -fcontext-stack=100 #-}
-#endif
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 {-# OPTIONS_GHC -fno-warn-name-shadowing #-}
 
-#include "overlapping-compat.h"
 module Servant.StreamSpec (spec) where
 
 import           Control.Monad

servant-docs/include/overlapping-compat.h

@@ -1,8 +0,0 @@
-#if __GLASGOW_HASKELL__ >= 710
-#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
-#define OVERLAPPING_  {-# OVERLAPPING #-}
-#else
-{-# LANGUAGE OverlappingInstances #-}
-#define OVERLAPPABLE_
-#define OVERLAPPING_
-#endif

servant-docs/servant-docs.cabal

@@ -23,7 +23,6 @@ tested-with:
 homepage:            http://haskell-servant.readthedocs.org/
 Bug-reports:         http://github.com/haskell-servant/servant/issues
 extra-source-files:
-  include/*.h
   CHANGELOG.md
   README.md
 source-repository head
@@ -45,10 +44,6 @@ library
     , bytestring >= 0.10.4.0 && < 0.11
     , text       >= 1.2.3.0  && < 1.3
 
-  if !impl(ghc >= 8.0)
-    build-depends:
-      semigroups          >=0.18.3 && <0.19
-
   -- Servant dependencies
   build-depends:
       servant            == 0.13.* || ==0.14.*
@@ -70,10 +65,7 @@ library
 
   hs-source-dirs: src
   default-language: Haskell2010
-  ghc-options: -Wall
+  ghc-options: -Wall -Wno-redundant-constraints
-  if impl(ghc >= 8.0)
-    ghc-options: -Wno-redundant-constraints
-  include-dirs: include
 
 executable greet-docs
   main-is: greet.hs

servant-docs/src/Servant/Docs/Internal.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP                    #-}
 {-# LANGUAGE ConstraintKinds        #-}
 {-# LANGUAGE DataKinds              #-}
 {-# LANGUAGE DefaultSignatures      #-}
@@ -17,7 +16,6 @@
 {-# LANGUAGE TypeOperators          #-}
 {-# LANGUAGE UndecidableInstances   #-}
 
-#include "overlapping-compat.h"
 module Servant.Docs.Internal where
 
 import           Prelude ()
@@ -788,7 +786,7 @@ markdownWith RenderingOptions{..}  api = unlines $
 
 -- | The generated docs for @a ':<|>' b@ just appends the docs
 --   for @a@ with the docs for @b@.
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
          (HasDocs a, HasDocs b)
       => HasDocs (a :<|> b) where
 
@@ -836,7 +834,7 @@ instance (KnownSymbol sym, ToCapture (CaptureAll sym a), HasDocs sublayout)
           symP = Proxy :: Proxy sym
 
 
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
         (ToSample a, AllMimeRender (ct ': cts) a, KnownNat status
         , ReflectMethod method)
     => HasDocs (Verb method status (ct ': cts) a) where
@@ -855,7 +853,7 @@ instance OVERLAPPABLE_
 -- | TODO: mention the endpoint is streaming, its framing strategy
 --
 -- Also there are no samples.
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
         (MimeRender ct a, KnownNat status
         , ReflectMethod method)
     => HasDocs (Stream method status framing ct a) where
@@ -870,7 +868,7 @@ instance OVERLAPPABLE_
           status = fromInteger $ natVal (Proxy :: Proxy status)
           p = Proxy :: Proxy a
 
-instance OVERLAPPING_
+instance {-# OVERLAPPING #-}
         (ToSample a, AllMimeRender (ct ': cts) a, KnownNat status
         , ReflectMethod method, AllHeaderSamples ls, GetHeaders (HList ls))
     => HasDocs (Verb method status (ct ': cts) (Headers ls a)) where

servant-docs/test/Servant/DocsSpec.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP                   #-}
 {-# LANGUAGE DataKinds             #-}
 {-# LANGUAGE DeriveGeneric         #-}
 {-# LANGUAGE FlexibleContexts      #-}
@@ -8,11 +7,7 @@
 {-# LANGUAGE TypeOperators         #-}
 {-# LANGUAGE TypeSynonymInstances  #-}
 {-# OPTIONS_GHC -fno-warn-orphans  #-}
-#if __GLASGOW_HASKELL__ >= 800
 {-# OPTIONS_GHC -freduction-depth=100 #-}
-#else
-{-# OPTIONS_GHC -fcontext-stack=100 #-}
-#endif
 
 module Servant.DocsSpec where
 

servant-foreign/include/overlapping-compat.h

@@ -1,8 +0,0 @@
-#if __GLASGOW_HASKELL__ >= 710
-#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
-#define OVERLAPPING_  {-# OVERLAPPING #-}
-#else
-{-# LANGUAGE OverlappingInstances #-}
-#define OVERLAPPABLE_
-#define OVERLAPPING_
-#endif

servant-foreign/servant-foreign.cabal

@@ -19,7 +19,6 @@ category:            Servant, Web
 build-type:          Simple
 cabal-version:       >=1.10
 extra-source-files:
-  include/*.h
   CHANGELOG.md
   README.md
 bug-reports:         http://github.com/haskell-servant/servant/issues
@@ -45,10 +44,6 @@ library
       base        >= 4.7     && <4.12
     , text        >= 1.2.3.0 && < 1.3
 
-  if !impl(ghc >= 8.0)
-    build-depends:
-        semigroups          >=0.18.3 && <0.19
-
   -- Servant dependencies
   build-depends:
       servant            == 0.13.* || ==0.14.*
@@ -62,16 +57,12 @@ library
 
   hs-source-dirs:      src
   default-language:    Haskell2010
-  ghc-options:         -Wall
+  ghc-options:         -Wall -Wno-redundant-constraints
-  if impl(ghc >= 8.0)
-    ghc-options: -Wno-redundant-constraints
-  include-dirs: include
 
 test-suite spec
   type:              exitcode-stdio-1.0
   hs-source-dirs:    test
   ghc-options:       -Wall
-  include-dirs:      include
   main-is:           Spec.hs
   other-modules:     Servant.ForeignSpec
 

servant-foreign/src/Servant/Foreign/Internal.hs

@@ -12,9 +12,6 @@
 {-# LANGUAGE TypeFamilies               #-}
 {-# LANGUAGE TypeOperators              #-}
 {-# LANGUAGE UndecidableInstances       #-}
-#if !MIN_VERSION_base(4,8,0)
-{-# LANGUAGE NullaryTypeClasses         #-}
-#endif
 
 -- | Generalizes all the data needed to make code generation work with
 -- arbitrary programming languages.

servant-foreign/test/Servant/ForeignSpec.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP                   #-}
 {-# LANGUAGE ConstraintKinds       #-}
 {-# LANGUAGE DataKinds             #-}
 {-# LANGUAGE FlexibleContexts      #-}
@@ -9,10 +8,6 @@
 {-# LANGUAGE ScopedTypeVariables   #-}
 {-# LANGUAGE TypeFamilies          #-}
 {-# LANGUAGE TypeOperators         #-}
-#if __GLASGOW_HASKELL__ < 709
-{-# OPTIONS_GHC -fcontext-stack=41 #-}
-#endif
-#include "overlapping-compat.h"
 
 module Servant.ForeignSpec where
 
@@ -59,10 +54,10 @@ instance HasForeignType LangX String Int where
 instance HasForeignType LangX String Bool where
   typeFor _ _ _ = "boolX"
 
-instance OVERLAPPING_ HasForeignType LangX String String where
+instance {-# OVERLAPPING #-} HasForeignType LangX String String where
   typeFor _ _ _ = "stringX"
 
-instance OVERLAPPABLE_ HasForeignType LangX String a => HasForeignType LangX String [a] where
+instance {-# OVERLAPPABLE #-} HasForeignType LangX String a => HasForeignType LangX String [a] where
   typeFor lang ftype _ = "listX of " <> typeFor lang ftype (Proxy :: Proxy a)
 
 instance (HasForeignType LangX String a) => HasForeignType LangX String (Maybe a) where

servant-server/Setup.hs

@@ -1,4 +1,3 @@
-\begin{code}
 {-# LANGUAGE CPP #-}
 {-# OPTIONS_GHC -Wall #-}
 module Main (main) where
@@ -16,6 +15,11 @@ main = defaultMainWithDoctests "doctests"
 #else
 
 #ifdef MIN_VERSION_Cabal
+-- If the macro is defined, we have new cabal-install,
+-- but for some reason we don't have cabal-doctest in package-db
+--
+-- Probably we are running cabal sdist, when otherwise using new-build
+-- workflow
 #warning You are configuring this package without cabal-doctest installed. \
          The doctests test-suite will not work as a result. \
          To fix this, install cabal-doctest before configuring.
@@ -27,5 +31,3 @@ main :: IO ()
 main = defaultMain
 
 #endif
-
-\end{code}

servant-server/include/overlapping-compat.h

@@ -1,8 +0,0 @@
-#if __GLASGOW_HASKELL__ >= 710
-#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
-#define OVERLAPPING_  {-# OVERLAPPING #-}
-#else
-{-# LANGUAGE OverlappingInstances #-}
-#define OVERLAPPABLE_
-#define OVERLAPPING_
-#endif

servant-server/servant-server.cabal

@@ -26,7 +26,6 @@ tested-with:
   GHC==8.2.2
   GHC==8.4.3
 extra-source-files:
-  include/*.h
   CHANGELOG.md
   README.md
 
@@ -103,10 +102,7 @@ library
 
   hs-source-dirs: src
   default-language: Haskell2010
-  ghc-options: -Wall
+  ghc-options: -Wall -Wno-redundant-constraints
-  if impl(ghc >= 8.0)
-    ghc-options: -Wno-redundant-constraints
-  include-dirs: include
 
 executable greet
   main-is: greet.hs
@@ -187,4 +183,3 @@ test-suite doctests
   ghc-options: -Wall -threaded
   if impl(ghc >= 8.2)
     x-doctest-options: -fdiagnostics-color=never
-  include-dirs: include

servant-server/src/Servant/Server/Internal.hs

@@ -18,8 +18,6 @@
 #define HAS_TYPE_ERROR
 #endif
 
-#include "overlapping-compat.h"
-
 module Servant.Server.Internal
   ( module Servant.Server.Internal
   , module Servant.Server.Internal.BasicAuth
@@ -256,7 +254,7 @@ methodRouter splitHeaders method proxy status action = leafRouter route'
                       let bdy = if allowedMethodHead method request then "" else body
                       in Route $ responseLBS status ((hContentType, cs contentT) : headers) bdy
 
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
          ( AllCTRender ctypes a, ReflectMethod method, KnownNat status
          ) => HasServer (Verb method status ctypes a) context where
 
@@ -267,7 +265,7 @@ instance OVERLAPPABLE_
     where method = reflectMethod (Proxy :: Proxy method)
           status = toEnum . fromInteger $ natVal (Proxy :: Proxy status)
 
-instance OVERLAPPING_
+instance {-# OVERLAPPING #-}
          ( AllCTRender ctypes a, ReflectMethod method, KnownNat status
          , GetHeaders (Headers h a)
          ) => HasServer (Verb method status ctypes (Headers h a)) context where
@@ -280,7 +278,7 @@ instance OVERLAPPING_
           status = toEnum . fromInteger $ natVal (Proxy :: Proxy status)
 
 
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
          ( MimeRender ctype a, ReflectMethod method, KnownNat status,
            FramingRender framing ctype, ToStreamGenerator b a
          ) => HasServer (Stream method status framing ctype b) context where
@@ -292,7 +290,7 @@ instance OVERLAPPABLE_
       where method = reflectMethod (Proxy :: Proxy method)
             status = toEnum . fromInteger $ natVal (Proxy :: Proxy status)
 
-instance OVERLAPPING_
+instance {-# OVERLAPPING #-}
          ( MimeRender ctype a, ReflectMethod method, KnownNat status,
            FramingRender framing ctype, ToStreamGenerator b a,
            GetHeaders (Headers h b)

servant-server/src/Servant/Server/Internal/Context.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP                        #-}
 {-# LANGUAGE DataKinds                  #-}
 {-# LANGUAGE FlexibleContexts           #-}
 {-# LANGUAGE FlexibleInstances          #-}
@@ -8,8 +7,6 @@
 {-# LANGUAGE ScopedTypeVariables        #-}
 {-# LANGUAGE TypeOperators              #-}
 
-#include "overlapping-compat.h"
-
 module Servant.Server.Internal.Context where
 
 import           Data.Proxy
@@ -64,11 +61,11 @@ instance (Eq a, Eq (Context as)) => Eq (Context (a ': as)) where
 class HasContextEntry (context :: [*]) (val :: *) where
     getContextEntry :: Context context -> val
 
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
          HasContextEntry xs val => HasContextEntry (notIt ': xs) val where
     getContextEntry (_ :. xs) = getContextEntry xs
 
-instance OVERLAPPING_
+instance {-# OVERLAPPING #-}
          HasContextEntry (val ': xs) val where
     getContextEntry (x :. _) = x
 

servant-server/src/Servant/Server/StaticFiles.hs

@@ -24,10 +24,6 @@ import           Servant.Server
                  (ServerT, Tagged (..))
 import           System.FilePath
                  (addTrailingPathSeparator)
-#if !MIN_VERSION_wai_app_static(3,1,0)
-import           Filesystem.Path.CurrentOS
-                 (decodeString)
-#endif
 import           WaiAppStatic.Storage.Filesystem
                  (ETagLookup)
 
@@ -84,9 +80,4 @@ serveDirectory = serveDirectoryFileServer
 {-# DEPRECATED serveDirectory "Use serveDirectoryFileServer instead" #-}
 
 fixPath :: FilePath -> FilePath
-fixPath =
+fixPath = addTrailingPathSeparator
-#if MIN_VERSION_wai_app_static(3,1,0)
-    addTrailingPathSeparator
-#else
-    decodeString . addTrailingPathSeparator
-#endif

servant-server/test/Servant/ServerSpec.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP                  #-}
 {-# LANGUAGE DataKinds            #-}
 {-# LANGUAGE DeriveGeneric        #-}
 {-# LANGUAGE FlexibleContexts     #-}
@@ -9,11 +8,7 @@
 {-# LANGUAGE TypeFamilies         #-}
 {-# LANGUAGE TypeOperators        #-}
 {-# LANGUAGE TypeSynonymInstances #-}
-#if __GLASGOW_HASKELL__ >= 800
 {-# OPTIONS_GHC -freduction-depth=100 #-}
-#else
-{-# OPTIONS_GHC -fcontext-stack=100 #-}
-#endif
 
 module Servant.ServerSpec where
 

servant/Setup.hs

@@ -1,4 +1,3 @@
-\begin{code}
 {-# LANGUAGE CPP #-}
 {-# OPTIONS_GHC -Wall #-}
 module Main (main) where
@@ -16,6 +15,11 @@ main = defaultMainWithDoctests "doctests"
 #else
 
 #ifdef MIN_VERSION_Cabal
+-- If the macro is defined, we have new cabal-install,
+-- but for some reason we don't have cabal-doctest in package-db
+--
+-- Probably we are running cabal sdist, when otherwise using new-build
+-- workflow
 #warning You are configuring this package without cabal-doctest installed. \
          The doctests test-suite will not work as a result. \
          To fix this, install cabal-doctest before configuring.
@@ -27,5 +31,3 @@ main :: IO ()
 main = defaultMain
 
 #endif
-
-\end{code}

servant/include/overlapping-compat.h

@@ -1,8 +0,0 @@
-#if __GLASGOW_HASKELL__ >= 710
-#define OVERLAPPABLE_ {-# OVERLAPPABLE #-}
-#define OVERLAPPING_  {-# OVERLAPPING #-}
-#else
-{-# LANGUAGE OverlappingInstances #-}
-#define OVERLAPPABLE_
-#define OVERLAPPING_
-#endif

servant/servant.cabal

@@ -22,7 +22,6 @@ tested-with:
   GHC==8.2.2
   GHC==8.4.3
 extra-source-files:
-  include/*.h
   CHANGELOG.md
 source-repository head
   type: git
@@ -120,10 +119,7 @@ library
                   , TypeOperators
                   , TypeSynonymInstances
                   , UndecidableInstances
-  ghc-options: -Wall
+  ghc-options: -Wall -Wno-redundant-constraints
-  if impl(ghc >= 8.0)
-    ghc-options: -Wno-redundant-constraints
-  include-dirs: include
 
 test-suite spec
   type: exitcode-stdio-1.0
@@ -146,10 +142,6 @@ test-suite spec
     , string-conversions
     , text
 
-  if !impl(ghc >= 8.0)
-    build-depends:
-      semigroups
-
   -- Additonal dependencies
   build-depends:
       aeson-compat         >= 0.3.8   && < 0.4
@@ -177,6 +169,5 @@ test-suite doctests
   ghc-options: -Wall -threaded
   if impl(ghc >= 8.2)
     x-doctest-options: -fdiagnostics-color=never
-  include-dirs: include
   x-doctest-source-dirs: test
   x-doctest-modules: Servant.LinksSpec

servant/src/Servant/API/ContentTypes.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP                   #-}
 {-# LANGUAGE ConstraintKinds       #-}
 {-# LANGUAGE DataKinds             #-}
 {-# LANGUAGE DeriveDataTypeable    #-}
@@ -14,8 +13,6 @@
 {-# LANGUAGE UndecidableInstances  #-}
 {-# OPTIONS_HADDOCK not-home       #-}
 
-#include "overlapping-compat.h"
-
 -- | A collection of basic Content-Types (also known as Internet Media
 -- Types, or MIME types). Additionally, this module provides classes that
 -- encapsulate how to serialize or deserialize values to or from
@@ -98,16 +95,13 @@ import qualified Data.Text.Lazy.Encoding          as TextL
 import           Data.Typeable
 import           GHC.Generics
                  (Generic)
+import qualified GHC.TypeLits                     as TL
 import qualified Network.HTTP.Media               as M
 import           Prelude ()
 import           Prelude.Compat
 import           Web.FormUrlEncoded
                  (FromForm, ToForm, urlDecodeAsForm, urlEncodeAsForm)
 
-#if MIN_VERSION_base(4,9,0)
-import qualified GHC.TypeLits                     as TL
-#endif
-
 -- * Provided content types
 data JSON deriving Typeable
 data PlainText deriving Typeable
@@ -185,18 +179,16 @@ class (AllMime list) => AllCTRender (list :: [*]) a where
     -- mimetype).
     handleAcceptH :: Proxy list -> AcceptHeader -> a -> Maybe (ByteString, ByteString)
 
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
          (Accept ct, AllMime cts, AllMimeRender (ct ': cts) a) => AllCTRender (ct ': cts) a where
     handleAcceptH _ (AcceptHeader accept) val = M.mapAcceptMedia lkup accept
       where pctyps = Proxy :: Proxy (ct ': cts)
             amrs = allMimeRender pctyps val
             lkup = fmap (\(a,b) -> (a, (fromStrict $ M.renderHeader a, b))) amrs
 
-#if MIN_VERSION_base(4,9,0)
 instance TL.TypeError ('TL.Text "No instance for (), use NoContent instead.")
   => AllCTRender '[] () where
   handleAcceptH _ _ _ = error "unreachable"
-#endif
 
 --------------------------------------------------------------------------
 -- * Unrender
@@ -277,13 +269,13 @@ class (AllMime list) => AllMimeRender (list :: [*]) a where
                   -> a                              -- value to serialize
                   -> [(M.MediaType, ByteString)]    -- content-types/response pairs
 
-instance OVERLAPPABLE_ ( MimeRender ctyp a ) => AllMimeRender '[ctyp] a where
+instance {-# OVERLAPPABLE #-} ( MimeRender ctyp a ) => AllMimeRender '[ctyp] a where
     allMimeRender _ a = map (, bs) $ NE.toList $ contentTypes pctyp
       where
         bs    = mimeRender pctyp a
         pctyp = Proxy :: Proxy ctyp
 
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
          ( MimeRender ctyp a
          , AllMimeRender (ctyp' ': ctyps) a
          ) => AllMimeRender (ctyp ': ctyp' ': ctyps) a where
@@ -299,12 +291,12 @@ instance OVERLAPPABLE_
 -- Ideally we would like to declare a 'MimeRender a NoContent' instance, and
 -- then this would be taken care of. However there is no more specific instance
 -- between that and 'MimeRender JSON a', so we do this instead
-instance OVERLAPPING_ ( Accept ctyp ) => AllMimeRender '[ctyp] NoContent where
+instance {-# OVERLAPPING #-} ( Accept ctyp ) => AllMimeRender '[ctyp] NoContent where
     allMimeRender _ _ = map (, "") $ NE.toList $ contentTypes pctyp
       where
         pctyp = Proxy :: Proxy ctyp
 
-instance OVERLAPPING_
+instance {-# OVERLAPPING #-}
          ( AllMime (ctyp ': ctyp' ': ctyps)
          ) => AllMimeRender (ctyp ': ctyp' ': ctyps) NoContent where
     allMimeRender p _ = zip (allMime p) (repeat "")
@@ -334,14 +326,14 @@ instance ( MimeUnrender ctyp a
 -- * MimeRender Instances
 
 -- | `encode`
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
          ToJSON a => MimeRender JSON a where
     mimeRender _ = encode
 
 -- | @urlEncodeAsForm@
 -- Note that the @mimeUnrender p (mimeRender p x) == Right x@ law only
 -- holds if every element of x is non-null (i.e., not @("", "")@)
-instance OVERLAPPABLE_
+instance {-# OVERLAPPABLE #-}
          ToForm a => MimeRender FormUrlEncoded a where
     mimeRender _ = urlEncodeAsForm
 

servant/src/Servant/API/ResponseHeaders.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP                    #-}
 {-# LANGUAGE DataKinds              #-}
 {-# LANGUAGE DeriveDataTypeable     #-}
 {-# LANGUAGE DeriveFunctor          #-}
@@ -15,7 +14,6 @@
 {-# LANGUAGE UndecidableInstances   #-}
 {-# OPTIONS_HADDOCK not-home        #-}
 
-#include "overlapping-compat.h"
 -- | This module provides facilities for adding headers to a response.
 --
 -- >>> let headerVal = addHeader "some-url" 5 :: Headers '[Header "Location" String] Int
@@ -80,10 +78,10 @@ class BuildHeadersTo hs where
     -- the values are interspersed with commas before deserialization (see
     -- <http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2 RFC2616 Sec 4.2>)
 
-instance OVERLAPPING_ BuildHeadersTo '[] where
+instance {-# OVERLAPPING #-} BuildHeadersTo '[] where
     buildHeadersTo _ = HNil
 
-instance OVERLAPPABLE_ ( FromHttpApiData v, BuildHeadersTo xs, KnownSymbol h )
+instance {-# OVERLAPPABLE #-} ( FromHttpApiData v, BuildHeadersTo xs, KnownSymbol h )
          => BuildHeadersTo (Header h v ': xs) where
     buildHeadersTo headers =
       let wantedHeader = CI.mk . pack $ symbolVal (Proxy :: Proxy h)
@@ -144,11 +142,11 @@ class AddHeader h v orig new
   addOptionalHeader :: ResponseHeader h v -> orig -> new  -- ^ N.B.: The same header can't be added multiple times
 
 
-instance OVERLAPPING_ ( KnownSymbol h, ToHttpApiData v )
+instance {-# OVERLAPPING #-} ( KnownSymbol h, ToHttpApiData v )
          => AddHeader h v (Headers (fst ': rest)  a) (Headers (Header h v  ': fst ': rest) a) where
     addOptionalHeader hdr (Headers resp heads) = Headers resp (HCons hdr heads)
 
-instance OVERLAPPABLE_ ( KnownSymbol h, ToHttpApiData v
+instance {-# OVERLAPPABLE #-} ( KnownSymbol h, ToHttpApiData v
                        , new ~ (Headers '[Header h v] a) )
          => AddHeader h v a new where
     addOptionalHeader hdr resp = Headers resp (HCons hdr HNil)

servant/src/Servant/API/TypeLevel.hs

@@ -41,9 +41,6 @@ module Servant.API.TypeLevel (
     -- ** Logic
     Or,
     And,
-    -- * Custom type errors
-    -- | Before @base-4.9.0.0@ we use non-exported 'ElemNotFoundIn' class,
-    -- which cannot be instantiated.
     ) where
 
 
@@ -63,10 +60,8 @@ import           Servant.API.Sub
                  (type (:>))
 import           Servant.API.Verbs
                  (Verb)
-#if MIN_VERSION_base(4,9,0)
 import           GHC.TypeLits
                  (ErrorMessage (..), TypeError)
-#endif
 
 
 
@@ -222,14 +217,10 @@ type Elem e es = ElemGo e es es
 type family ElemGo e es orig :: Constraint where
   ElemGo x (x ': xs) orig = ()
   ElemGo y (x ': xs) orig = ElemGo y xs orig
-#if MIN_VERSION_base(4,9,0)
   -- Note [Custom Errors]
   ElemGo x '[] orig       = TypeError ('ShowType x
                                  ':<>: 'Text " expected in list "
                                  ':<>: 'ShowType orig)
-#else
-  ElemGo x '[] orig       = ElemNotFoundIn x orig
-#endif
 
 -- ** Logic
 
@@ -244,12 +235,6 @@ type family Or (a :: Constraint) (b :: Constraint) :: Constraint where
 type family And (a :: Constraint) (b :: Constraint) :: Constraint where
   And () ()     = ()
 
--- * Custom type errors
-
-#if !MIN_VERSION_base(4,9,0)
-class ElemNotFoundIn val list
-#endif
-
 {- Note [Custom Errors]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 We might try to factor these our more cleanly, but the type synonyms and type

servant/test/Servant/API/ContentTypesSpec.hs

@@ -1,4 +1,3 @@
-{-# LANGUAGE CPP                   #-}
 {-# LANGUAGE DataKinds             #-}
 {-# LANGUAGE DeriveGeneric         #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
@@ -195,7 +194,6 @@ spec = describe "Servant.API.ContentTypes" $ do
                 handleCTypeH (Proxy :: Proxy '[JSONorText]) "image/jpeg"
                     "foobar" `shouldBe` (Nothing :: Maybe (Either String Int))
 
-#if MIN_VERSION_aeson(0,9,0)
     -- aeson >= 0.9 decodes top-level strings
     describe "eitherDecodeLenient" $ do
 
@@ -204,7 +202,6 @@ spec = describe "Servant.API.ContentTypes" $ do
             -- The Left messages differ, so convert to Maybe
             property $ \x -> toMaybe (eitherDecodeLenient x)
                 `shouldBe` (decode x :: Maybe String)
-#endif
 
 
 data SomeData = SomeData { record1 :: String, record2 :: Int }

servant/test/Servant/LinksSpec.hs

@@ -1,12 +1,8 @@
-{-# LANGUAGE CPP                 #-}
 {-# LANGUAGE ConstraintKinds     #-}
 {-# LANGUAGE DataKinds           #-}
 {-# LANGUAGE PolyKinds           #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeOperators       #-}
-#if __GLASGOW_HASKELL__ < 709
-{-# OPTIONS_GHC -fcontext-stack=41 #-}
-#endif
 module Servant.LinksSpec where
 
 import           Data.Proxy