Skip parsing without haddock for above GHC9.0

Author: yoshitsugu

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

@@ -218,6 +218,11 @@ getParsedModuleRule =
         mainParse = getParsedModuleDefinition hsc opt file ms
         reset_ms pm = pm { pm_mod_summary = ms' }
 
+#if MIN_VERSION_ghc(9,0,1)
+    -- We no longer need to parse again if GHC version is above 9.0
+    -- https://github.com/haskell/haskell-language-server/issues/1892
+    res@(_,pmod) <- liftIO $ (fmap.fmap.fmap) reset_ms mainParse
+#else
     -- Parse again (if necessary) to capture Haddock parse errors
     res@(_,pmod) <- if gopt Opt_Haddock dflags
         then
@@ -245,6 +250,7 @@ getParsedModuleRule =
               -- This seems to be the correct behaviour because the Haddock flag is added
               -- by us and not the user, so our IDE shouldn't stop working because of it.
               _ -> pure (diagsM, res)
+#endif
     -- Add dependencies on included files
     _ <- uses GetModificationTime $ map toNormalizedFilePath' (maybe [] pm_extra_src_files pmod)
     pure res
@@ -892,12 +898,17 @@ regenerateHiFile sess f ms compNeeded = do
 
     -- Embed haddocks in the interface file
     (diags, mb_pm) <- liftIO $ getParsedModuleDefinition hsc opt f (withOptHaddock ms)
+#if MIN_VERSION_ghc(9,0,1)
+    -- We no longer need to parse again if GHC version is above 9.0
+    -- https://github.com/haskell/haskell-language-server/issues/1892
+#else
     (diags, mb_pm) <- case mb_pm of
         Just _ -> return (diags, mb_pm)
         Nothing -> do
             -- if parsing fails, try parsing again with Haddock turned off
             (diagsNoHaddock, mb_pm) <- liftIO $ getParsedModuleDefinition hsc opt f ms
             return (mergeParseErrorsHaddock diagsNoHaddock diags, mb_pm)
+#endif
     case mb_pm of
         Nothing -> return (diags, Nothing)
         Just pm -> do