Fix core file location in GetLinkable (haskell#4347)

Fix haskell#4145
The error case is demonstrated in haskell#4145 (comment)

Include ModLocation in the ModSummaryResult fingerprint.
Instead of getting the core file location from GetModSummary, get it from the result of GetModIface directly since that is the actual location the core file written to.

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

@@ -94,7 +94,7 @@ import           Development.IDE.Types.Location
 import           Development.IDE.Types.Options
 import           GHC                                    (ForeignHValue,
                                                          GetDocsFailure (..),
-                                                         parsedSource)
+                                                         parsedSource, ModLocation (..))
 import qualified GHC.LanguageExtensions                 as LangExt
 import           GHC.Serialized
 import           HieDb                                  hiding (withHieDb)
@@ -1021,8 +1021,17 @@ getModSummaryFromImports env fp _modTime mContents = do
             return $! Util.fingerprintFingerprints $
                     [ Util.fingerprintString fp
                     , fingerPrintImports
+                    , modLocationFingerprint ms_location
                     ] ++ map Util.fingerprintString opts
 
+        modLocationFingerprint :: ModLocation -> Util.Fingerprint
+        modLocationFingerprint ModLocation{..} = Util.fingerprintFingerprints $
+            Util.fingerprintString <$> [ fromMaybe "" ml_hs_file
+                                         , ml_hi_file
+                                         , ml_dyn_hi_file
+                                         , ml_obj_file
+                                         , ml_dyn_obj_file
+                                         , ml_hie_file]
 
 -- | Parse only the module header
 parseHeader

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

@@ -1039,10 +1039,9 @@ usePropertyByPathAction path plId p = do
 getLinkableRule :: Recorder (WithPriority Log) -> Rules ()
 getLinkableRule recorder =
   defineEarlyCutoff (cmapWithPrio LogShake recorder) $ Rule $ \GetLinkable f -> do
-    ModSummaryResult{msrModSummary = ms} <- use_ GetModSummary f
-    HiFileResult{hirModIface, hirModDetails, hirCoreFp} <- use_ GetModIface f
-    let obj_file  = ml_obj_file (ms_location ms)
-        core_file = ml_core_file (ms_location ms)
+    HiFileResult{hirModSummary, hirModIface, hirModDetails, hirCoreFp} <- use_ GetModIface f
+    let obj_file  = ml_obj_file (ms_location hirModSummary)
+        core_file = ml_core_file (ms_location hirModSummary)
     case hirCoreFp of
       Nothing -> error $ "called GetLinkable for a file without a linkable: " ++ show f
       Just (bin_core, fileHash) -> do
@@ -1055,7 +1054,7 @@ getLinkableRule recorder =
         core_t <- liftIO $ getModTime core_file
         (warns, hmi) <- case linkableType of
           -- Bytecode needs to be regenerated from the core file
-          BCOLinkable -> liftIO $ coreFileToLinkable linkableType (hscEnv session) ms hirModIface hirModDetails bin_core (posixSecondsToUTCTime core_t)
+          BCOLinkable -> liftIO $ coreFileToLinkable linkableType (hscEnv session) hirModSummary hirModIface hirModDetails bin_core (posixSecondsToUTCTime core_t)
           -- Object code can be read from the disk
           ObjectLinkable -> do
             -- object file is up to date if it is newer than the core file
@@ -1068,8 +1067,8 @@ getLinkableRule recorder =
               else pure Nothing
             case mobj_time of
               Just obj_t
-                | obj_t >= core_t -> pure ([], Just $ HomeModInfo hirModIface hirModDetails (justObjects $ LM (posixSecondsToUTCTime obj_t) (ms_mod ms) [DotO obj_file]))
-              _ -> liftIO $ coreFileToLinkable linkableType (hscEnv session) ms hirModIface hirModDetails bin_core (error "object doesn't have time")
+                | obj_t >= core_t -> pure ([], Just $ HomeModInfo hirModIface hirModDetails (justObjects $ LM (posixSecondsToUTCTime obj_t) (ms_mod hirModSummary) [DotO obj_file]))
+              _ -> liftIO $ coreFileToLinkable linkableType (hscEnv session) hirModSummary hirModIface hirModDetails bin_core (error "object doesn't have time")
         -- Record the linkable so we know not to unload it, and unload old versions
         whenJust ((homeModInfoByteCode =<< hmi) <|> (homeModInfoObject =<< hmi)) $ \(LM time mod _) -> do
             compiledLinkables <- getCompiledLinkables <$> getIdeGlobalAction