Use cabal-helper's compilerVersion for GHC version check

Author: DanielG

src/HaskellCodeExplorer/PackageInfo.hs

@@ -148,18 +148,15 @@ createPackageInfo packageDirectoryPath mbDistDirRelativePath sourceCodePreproces
           Right distDir -> return distDir
           Left errorMessage ->
             logErrorN (T.pack errorMessage) >> liftIO exitFailure
-  eitherPackageGhcVersion <- liftIO $ getPackageGhcVersion distDir
-  case eitherPackageGhcVersion of
-    Right packageGhcVersion ->
-      if take 2 (versionBranch packageGhcVersion) == take 2 (versionBranch ghcVersion)
-        then return ()
-        else let message =
-                   "GHC version mismatch. haskell-code-indexer: " ++
-                   showVersion ghcVersion ++
-                   ", package: " ++
-                   showVersion packageGhcVersion
-              in logErrorN (T.pack message) >> liftIO exitFailure
-    Left err -> logErrorN (T.pack err) >> liftIO exitFailure
+  cabalHelperQueryEnv <- liftIO $ mkQueryEnv (ProjLocV1Dir packageDirectoryAbsPath) (DistDirV1 distDir)
+  ("ghc", packageGhcVersion) <- liftIO $ runQuery compilerVersion cabalHelperQueryEnv
+  unless (take 2 (versionBranch packageGhcVersion) == take 2 (versionBranch ghcVersion)) $
+    let message =
+          "GHC version mismatch. haskell-code-indexer: " ++
+          showVersion ghcVersion ++
+          ", package: " ++
+          showVersion packageGhcVersion
+    in logErrorN (T.pack message) >> liftIO exitFailure
   units <- liftIO $ flip runQuery cabalHelperQueryEnv $ allUnits Prelude.id
   let compInfo = concatMap (toList . uiComponents) units
   let (packageName, packageVersion) = uiPackageId (NE.head units)
@@ -266,39 +263,6 @@ createPackageInfo packageDirectoryPath mbDistDirRelativePath sourceCodePreproces
       HCE.ComponentId . T.append "bench-" . T.pack $ name
     chComponentNameToComponentId ChSetupHsName = HCE.ComponentId "setup"
 
--- | Parses the header of setup-config file.
--- The header is generated by Cabal:
--- https://github.com/haskell/cabal/blob/5be57c0d251be40a6263cd996d99703b8de1ed79/Cabal/Distribution/Simple/Configure.hs#L286-L295
-getPackageGhcVersion :: FilePath -> IO (Either String Version)
-getPackageGhcVersion distDir =
-  withFile (distDir </> "setup-config") ReadMode $ \handle -> do
-    header <- BSC.hGetLine handle
-    let parseHeader :: BSC.ByteString -> Maybe BSC.ByteString
-        parseHeader hdr =
-          case BSC.words hdr of
-            ["Saved", "package", "config", "for", _package, "written", "by", _cabal, "using", compiler] ->
-              Just compiler
-            _ -> Nothing
-        parseCompiler :: BSC.ByteString -> Maybe BSC.ByteString
-        parseCompiler compiler =
-          case BSC.split '-' compiler of
-            ["ghc", version] -> Just version
-            _ -> Nothing
-        parseGhcVersion :: BSC.ByteString -> Maybe Version
-        parseGhcVersion version =
-          case filter ((== "") . snd) $
-               readP_to_S parseVersion $ BSC.unpack version of
-            [(ver, "")] -> Just ver
-            _ -> Nothing
-    case parseHeader header >>= parseCompiler >>= parseGhcVersion of
-      Just version -> return $ Right version
-      _ ->
-        return $
-        Left $
-        "Unexpected setup-config header: \"" ++
-        BSC.unpack header ++
-        "\"\nIt may mean that the version of Cabal used to build this package is not supported by haskell-code-indexer yet."
-
 #if MIN_VERSION_GLASGOW_HASKELL(8,6,4,0)
 ghcVersion :: Version
 ghcVersion = makeVersion [8, 6, 4, 0]