Compatibility with fbghc (#892)

* Compatibility with fbghc

Rather than forking ghcide, we use conditional compilation to build with https://github.com/facebook/fbghc hopefully only until certain changes have been upstreamed.

* Reexport DynFlags from Compat.GHC

* Add a link to the fbghc repo

session-loader/Development/IDE/Session.hs

@@ -59,7 +59,6 @@ import System.Info
 import System.IO
 
 import GHCi
-import DynFlags
 import HscTypes (ic_dflags, hsc_IC, hsc_dflags, hsc_NC)
 import Linker
 import Module

src/Development/IDE/Core/Preprocessor.hs

@@ -15,7 +15,6 @@ import Data.List.Extra
 import System.FilePath
 import System.IO.Extra
 import Data.Char
-import DynFlags
 import qualified HeaderInfo as Hdr
 import Development.IDE.Types.Diagnostics
 import Development.IDE.Types.Location

src/Development/IDE/Core/Rules.hs

@@ -69,7 +69,6 @@ import           Language.Haskell.LSP.Types (DocumentHighlight (..))
 
 import qualified GHC.LanguageExtensions as LangExt
 import HscTypes hiding (TargetModule, TargetFile)
-import DynFlags (gopt_set, xopt)
 import GHC.Generics(Generic)
 
 import qualified Development.IDE.Spans.AtPoint as AtPoint

src/Development/IDE/GHC/CPP.hs

@@ -26,7 +26,6 @@ import Development.IDE.GHC.Compat
 import Packages
 import SysTools
 import Module
-import DynFlags
 import Panic
 import FileCleanup
 #if MIN_GHC_API_VERSION(8,8,2)

src/Development/IDE/GHC/Compat.hs

@@ -28,8 +28,6 @@ module Development.IDE.GHC.Compat(
     addBootSuffixLocnOut,
 #endif
     hPutStringBuffer,
-    includePathsGlobal,
-    includePathsQuote,
     addIncludePathsQuote,
     getModuleHash,
     getPackageName,
@@ -37,6 +35,7 @@ module Development.IDE.GHC.Compat(
     GHC.ModLocation,
     Module.addBootSuffix,
     pattern ModLocation,
+    pattern ExposePackage,
     HasSrcSpan,
     getLoc,
     upNameCache,
@@ -54,6 +53,7 @@ module Development.IDE.GHC.Compat(
 #endif
 
     module GHC,
+    module DynFlags,
     initializePlugins,
     applyPluginsParsedResultAction,
     module Compat.HieTypes,
@@ -66,7 +66,8 @@ import LinkerTypes
 #endif
 
 import StringBuffer
-import DynFlags
+import qualified DynFlags
+import DynFlags hiding (ExposePackage)
 import Fingerprint (Fingerprint)
 import qualified Module
 import Packages
@@ -274,3 +275,11 @@ applyPluginsParsedResultAction env dflags ms hpm_annotations parsed = do
   fmap hpm_module $
     runHsc env $ withPlugins dflags applyPluginAction
       (HsParsedModule parsed [] hpm_annotations)
+
+pattern ExposePackage :: String -> PackageArg -> ModRenaming -> PackageFlag
+-- https://github.com/facebook/fbghc
+#ifdef __FACEBOOK_HASKELL__
+pattern ExposePackage s a mr <- DynFlags.ExposePackage s a _ mr
+#else
+pattern ExposePackage s a mr = DynFlags.ExposePackage s a mr
+#endif

src/Development/IDE/GHC/Util.hs

@@ -68,7 +68,6 @@ import Outputable (showSDocUnsafe, ppr, showSDoc, Outputable)
 import Packages (getPackageConfigMap, lookupPackage')
 import SrcLoc (mkRealSrcLoc)
 import FastString (mkFastString)
-import DynFlags (emptyFilesToClean, unsafeGlobalDynFlags)
 import Module (moduleNameSlashes, InstalledUnitId)
 import OccName (parenSymOcc)
 import RdrName (nameRdrName, rdrNameOcc)

src/Development/IDE/Plugin/CodeAction.hs

@@ -54,7 +54,6 @@ import HscTypes
 import Parser
 import Text.Regex.TDFA (mrAfter, (=~), (=~~))
 import Outputable (ppr, showSDocUnsafe)
-import DynFlags (xFlags, FlagSpec(..))
 import GHC.LanguageExtensions.Type (Extension)
 import Data.Function
 import Control.Arrow ((>>>))

src/Development/IDE/Plugin/Completions/Logic.hs

@@ -23,7 +23,6 @@ import Name
 import RdrName
 import Type
 import Packages
-import DynFlags
 #if MIN_GHC_API_VERSION(8,10,0)
 import Predicate (isDictTy)
 import GHC.Platform
@@ -474,9 +473,9 @@ getCompletions ideOpts CC { allModNamesAsNS, unqualCompls, qualCompls, importabl
 -- The supported languages and extensions
 languagesAndExts :: [T.Text]
 #if MIN_GHC_API_VERSION(8,10,0)
-languagesAndExts = map T.pack $ DynFlags.supportedLanguagesAndExtensions ( PlatformMini ArchUnknown OSUnknown )
+languagesAndExts = map T.pack $ GHC.supportedLanguagesAndExtensions ( PlatformMini ArchUnknown OSUnknown )
 #else
-languagesAndExts = map T.pack DynFlags.supportedLanguagesAndExtensions
+languagesAndExts = map T.pack GHC.supportedLanguagesAndExtensions
 #endif
 
 -- ---------------------------------------------------------------------

src/Development/IDE/Spans/Common.hs

@@ -26,7 +26,6 @@ import GHC.Generics
 
 import GHC
 import Outputable hiding ((<>))
-import DynFlags
 import ConLike
 import DataCon
 import Var
@@ -34,6 +33,7 @@ import NameEnv
 
 import qualified Documentation.Haddock.Parser as H
 import qualified Documentation.Haddock.Types as H
+import Development.IDE.GHC.Compat
 import Development.IDE.GHC.Orphans ()
 
 type DocMap = NameEnv SpanDoc