Revert "Warn if TH and Mac and static binary (haskell#2470)"

This reverts commit 807cb8f.

Author: jneira

docs/troubleshooting.md

@@ -63,13 +63,15 @@ Often this means that the client is configured to run the wrong binary, or the c
 
 The easiest way to check whether the server is running is to use an OS process monitor to see if there is a `haskell-language-server` process running.
 
-### Checking whether the client is connecting to the server
+### Problems with Template Haskell
 
-If the server is running, you should see some kind of indicator in your client.
-In some clients (e.g. `coc`) you may need to run a command to query the client's beliefs about the server state.
-If the client doesn't seem to be connected despite the server running, this may indicate a bug in the client or HLS.
+Due to how Template Haskell code is evaluated at compile time and some limitations in the interaction between HLS and GHC, the loading of modules using TH can be problematic.
 
-### Checking whether the project is being built correctly by HLS
+The errors thrown are usually related to linking and usually make HLS crash: `Segmentation fault`, `GHC runtime linker: fatal error`, etc
+
+A workaround which has helped in some cases is to compile HLS from source with the ghc option `-dynamic` enabled, as in the previous issue.
+
+We have a [dedicated label](https://github.com/haskell/haskell-language-server/issues?q=is%3Aissue+is%3Aopen+label%3A%22type%3A+template+haskell+related%22) in the issue tracker and an [general issue](https://github.com/haskell/haskell-language-server/issues/1431) tracking support for TH.
 
 HLS needs to build the project correctly, with the correct flags, and if it does not do so then very little is likely to work.
 A typical symptom of this going wrong is "incorrect" compilation errors being sent to the client.

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

@@ -57,8 +57,7 @@ module Development.IDE.Core.Rules(
     getParsedModuleDefinition,
     typeCheckRuleDefinition,
     GhcSessionDepsConfig(..),
-    Log(..),
-    DisplayTHWarning(..),
+    Log(..)
     ) where
 
 #if !MIN_VERSION_ghc(8,8,0)
@@ -136,7 +135,7 @@ import qualified GHC.LanguageExtensions                       as LangExt
 import qualified HieDb
 import           Ide.Plugin.Config
 import qualified Language.LSP.Server                          as LSP
-import           Language.LSP.Types                           (SMethod (SCustomMethod, SWindowShowMessage), ShowMessageParams (ShowMessageParams), MessageType (MtInfo))
+import           Language.LSP.Types                           (SMethod (SCustomMethod))
 import           Language.LSP.VFS
 import           System.Directory                             (makeAbsolute)
 import           Data.Default                                 (def, Default)
@@ -149,15 +148,12 @@ import           Ide.PluginUtils                              (configForPlugin)
 import           Ide.Types                                    (DynFlagsModifications (dynFlagsModifyGlobal, dynFlagsModifyParser),
                                                                PluginId)
 import Control.Concurrent.STM.Stats (atomically)
-import Language.LSP.Server (LspT)
-import System.Info.Extra (isWindows)
-import HIE.Bios.Ghc.Gap (hostIsDynamic)
 import Development.IDE.Types.Logger (Recorder, logWith, cmapWithPrio, WithPriority, Pretty (pretty), (<+>), nest, vcat)
 import qualified Development.IDE.Core.Shake as Shake
 import qualified Development.IDE.GHC.ExactPrint as ExactPrint hiding (LogShake)
 import qualified Development.IDE.Types.Logger as Logger
 
-data Log 
+data Log
   = LogShake Shake.Log
   | LogReindexingHieFile !NormalizedFilePath
   | LogLoadingHieFile !NormalizedFilePath
@@ -182,9 +178,6 @@ instance Pretty Log where
       "SUCCEEDED LOADING HIE FILE FOR" <+> pretty path
     LogExactPrint log -> pretty log
 
-templateHaskellInstructions :: T.Text
-templateHaskellInstructions = "https://haskell-language-server.readthedocs.io/en/latest/troubleshooting.html#static-binaries"
-
 -- | This is useful for rules to convert rules that can only produce errors or
 -- a result into the more general IdeResult type that supports producing
 -- warnings while also producing a result.
@@ -852,27 +845,8 @@ isHiFileStableRule recorder = defineEarlyCutoff (cmapWithPrio LogShake recorder)
       summarize SourceUnmodified          = BS.singleton 2
       summarize SourceUnmodifiedAndStable = BS.singleton 3
 
-displayTHWarning :: LspT c IO ()
-displayTHWarning
-  | not isWindows && not hostIsDynamic = do
-      LSP.sendNotification SWindowShowMessage $
-        ShowMessageParams MtInfo $ T.unwords
-          [ "This HLS binary does not support Template Haskell."
-          , "Follow the [instructions](" <> templateHaskellInstructions <> ")"
-          , "to build an HLS binary with support for Template Haskell."
-          ]
-  | otherwise = return ()
-
-newtype DisplayTHWarning = DisplayTHWarning (IO ())
-instance IsIdeGlobal DisplayTHWarning
-
 getModSummaryRule :: Recorder (WithPriority Log) -> Rules ()
 getModSummaryRule recorder = do
-    menv <- lspEnv <$> getShakeExtrasRules
-    forM_ menv $ \env -> do
-        displayItOnce <- liftIO $ once $ LSP.runLspT env displayTHWarning
-        addIdeGlobal (DisplayTHWarning displayItOnce)
-
     defineEarlyCutoff (cmapWithPrio LogShake recorder) $ Rule $ \GetModSummary f -> do
         session' <- hscEnv <$> use_ GhcSession f
         modify_dflags <- getModifyDynFlags dynFlagsModifyGlobal
@@ -883,10 +857,6 @@ getModSummaryRule recorder = do
                 getModSummaryFromImports session fp modTime (textToStringBuffer <$> mFileContent)
         case modS of
             Right res -> do
-                -- Check for Template Haskell
-                when (uses_th_qq $ msrModSummary res) $ do
-                    DisplayTHWarning act <- getIdeGlobalAction
-                    liftIO act
                 bufFingerPrint <- liftIO $
                     fingerprintFromStringBuffer $ fromJust $ ms_hspp_buf $ msrModSummary res
                 let fingerPrint = Util.fingerprintFingerprints
@@ -1082,6 +1052,9 @@ needsCompilationRule file = do
 
   pure (Just $ encodeLinkableType res, Just res)
   where
+    uses_th_qq (ms_hspp_opts -> dflags) =
+      xopt LangExt.TemplateHaskell dflags || xopt LangExt.QuasiQuotes dflags
+
     computeLinkableType :: ModSummary -> [Maybe ModSummary] -> [Maybe LinkableType] -> Maybe LinkableType
     computeLinkableType this deps xs
       | Just ObjectLinkable `elem` xs     = Just ObjectLinkable -- If any dependent needs object code, so do we
@@ -1091,10 +1064,6 @@ needsCompilationRule file = do
       where
         this_type = computeLinkableTypeForDynFlags (ms_hspp_opts this)
 
-uses_th_qq :: ModSummary -> Bool
-uses_th_qq (ms_hspp_opts -> dflags) =
-      xopt LangExt.TemplateHaskell dflags || xopt LangExt.QuasiQuotes dflags
-
 -- | How should we compile this module?
 -- (assuming we do in fact need to compile it).
 -- Depends on whether it uses unboxed tuples or sums