Customize the unitId used for the internal component

Author: pepeiborra

ghcide/session-loader/Development/IDE/Session.hs

@@ -222,6 +222,7 @@ loadSessionWithOptions SessionLoadingOptions{..} dir = do
               , optCheckProject = getCheckProject
               , optCustomDynFlags
               , optExtensions
+              , optFakeUid
               } <- getIdeOptions
 
         -- populate the knownTargetsVar with all the
@@ -274,7 +275,7 @@ loadSessionWithOptions SessionLoadingOptions{..} dir = do
               new_deps' <- forM new_deps $ \RawComponentInfo{..} -> do
                   -- Remove all inplace dependencies from package flags for
                   -- components in this HscEnv
-                  let (df2, uids) = removeInplacePackages inplace rawComponentDynFlags
+                  let (df2, uids) = removeInplacePackages optFakeUid inplace rawComponentDynFlags
                   let prefix = show rawComponentUnitId
                   -- See Note [Avoiding bad interface files]
                   let hscComponents = sort $ map show uids
@@ -713,12 +714,15 @@ getDependencyInfo fs = Map.fromList <$> mapM do_one fs
 -- There are several places in GHC (for example the call to hptInstances in
 -- tcRnImports) which assume that all modules in the HPT have the same unit
 -- ID. Therefore we create a fake one and give them all the same unit id.
-removeInplacePackages :: [InstalledUnitId] -> DynFlags -> (DynFlags, [InstalledUnitId])
-removeInplacePackages us df = (df { packageFlags = ps
+removeInplacePackages
+    :: InstalledUnitId     -- ^ fake uid to use for our internal component
+    -> [InstalledUnitId]
+    -> DynFlags
+    -> (DynFlags, [InstalledUnitId])
+removeInplacePackages fake_uid us df = (df { packageFlags = ps
                                   , thisInstalledUnitId = fake_uid }, uids)
   where
     (uids, ps) = partitionEithers (map go (packageFlags df))
-    fake_uid = toInstalledUnitId (stringToUnitId "fake_uid")
     go p@(ExposePackage _ (UnitIdArg u) _) = if toInstalledUnitId u `elem` us
                                                   then Left (toInstalledUnitId u)
                                                   else Right p

ghcide/src/Development/IDE/Types/Options.hs

@@ -84,6 +84,7 @@ data IdeOptions = IdeOptions
     -- ^ Will be called right after setting up a new cradle,
     --   allowing to customize the Ghc options used
   , optShakeOptions :: ShakeOptions
+  , optFakeUid :: InstalledUnitId
   }
 
 optShakeFiles :: IdeOptions -> Maybe FilePath
@@ -136,6 +137,7 @@ defaultIdeOptions session = IdeOptions
     ,optCheckParents = pure CheckOnSaveAndClose
     ,optHaddockParse = HaddockParse
     ,optCustomDynFlags = id
+    ,optFakeUid = toInstalledUnitId (stringToUnitId "fake_uid")
     }