See if fakeDynFlags is unnecessary (#378)

* See if fakeDynFlags is unnecessary

* Cleanups now fakeDynFlags is gone

* Remove redundant CPP

src/Development/IDE/GHC/Util.hs

@@ -1,16 +1,11 @@
 -- Copyright (c) 2019 The DAML Authors. All rights reserved.
 -- SPDX-License-Identifier: Apache-2.0
 
-{-# OPTIONS_GHC -Wno-missing-fields #-} -- to enable prettyPrint
-{-# LANGUAGE CPP #-}
-#include "ghc-api-version.h"
-
 -- | General utility functions, mostly focused around GHC operations.
 module Development.IDE.GHC.Util(
     -- * HcsEnv and environment
     HscEnvEq, hscEnv, newHscEnvEq,
     modifyDynFlags,
-    fakeDynFlags,
     runGhcEnv,
     -- * GHC wrappers
     prettyPrint,
@@ -25,7 +20,6 @@ module Development.IDE.GHC.Util(
     hDuplicateTo',
     ) where
 
-
 import Control.Concurrent
 import Data.List.Extra
 import Data.Maybe
@@ -47,11 +41,6 @@ import GHC.IO.Encoding
 import GHC.IO.Exception
 import GHC.IO.Handle.Types
 import GHC.IO.Handle.Internals
-#if MIN_GHC_API_VERSION(8,10,0)
-#else
-import Config
-import Platform
-#endif
 import Data.Unique
 import Development.Shake.Classes
 import qualified Data.Text                as T
@@ -94,9 +83,9 @@ textToStringBuffer :: T.Text -> StringBuffer
 textToStringBuffer = stringToStringBuffer . T.unpack
 
 
--- | Pretty print a GHC value using 'fakeDynFlags'.
+-- | Pretty print a GHC value using 'unsafeGlobalDynFlags '.
 prettyPrint :: Outputable a => a -> String
-prettyPrint = showSDoc fakeDynFlags . ppr
+prettyPrint = showSDoc unsafeGlobalDynFlags . ppr
 
 -- | Run a 'Ghc' monad value using an existing 'HscEnv'. Sets up and tears down all the required
 --   pieces, but designed to be more efficient than a standard 'runGhc'.
@@ -110,36 +99,6 @@ runGhcEnv env act = do
         cleanTempFiles dflags
         cleanTempDirs dflags
 
--- | A 'DynFlags' value where most things are undefined. It's sufficient to call pretty printing,
---   but not much else.
-fakeDynFlags :: DynFlags
-#if MIN_GHC_API_VERSION(8,10,0)
-fakeDynFlags = unsafeGlobalDynFlags
-#else
-fakeDynFlags = defaultDynFlags
-                  settings
-                  mempty
-    where
-        settings = Settings
-                   { sTargetPlatform = platform
-                   , sPlatformConstants = platformConstants
-                   , sProgramName = "ghc"
-                   , sProjectVersion = cProjectVersion
-#if MIN_GHC_API_VERSION(8,6,0)
-                   , sOpt_P_fingerprint = fingerprint0
-#endif
-                   }
-        platform = Platform
-          { platformWordSize=8
-          , platformOS=OSUnknown
-          , platformUnregisterised=True
-          }
-        platformConstants = PlatformConstants
-          { pc_DYNAMIC_BY_DEFAULT=False
-          , pc_WORD_SIZE=8
-          }
-#endif
-
 -- | Given a module location, and its parse tree, figure out what is the include directory implied by it.
 --   For example, given the file @\/usr\/\Test\/Foo\/Bar.hs@ with the module name @Foo.Bar@ the directory
 --   @\/usr\/Test@ should be on the include path to find sibling modules.