Do some recompilation avoidance in GHC.loadModule

[ghc-hetmet.git] / compiler / main / HscMain.lhs

diff --git a/compiler/main/HscMain.lhs b/compiler/main/HscMain.lhs
index 9f91b4d..d5ad093 100644 (file)
--- a/compiler/main/HscMain.lhs
+++ b/compiler/main/HscMain.lhs
@@ -24,6 +24,7 @@ module HscMain
     , hscCompileBatch       -- :: Compiler (HscStatus, ModIface, ModDetails)
     , hscCompileNothing     -- :: Compiler (HscStatus, ModIface, ModDetails)
     , hscCompileInteractive -- :: Compiler (InteractiveStatus, ModIface, ModDetails)
+    , hscCheckRecompBackend
     , HscStatus' (..)
     , InteractiveStatus, HscStatus
 
@@ -382,6 +383,22 @@ genericHscCompile compiler hscMessage
            -> do hscMessage mb_mod_index True mod_summary
                  hscRecompile compiler mod_summary mb_old_hash
 
+hscCheckRecompBackend :: HsCompiler a -> TcGblEnv -> Compiler a
+hscCheckRecompBackend compiler tc_result 
+                   hsc_env mod_summary source_unchanged mb_old_iface _m_of_n =
+   withTempSession (\_ -> hsc_env) $ do
+     (recomp_reqd, mb_checked_iface)
+         <- {-# SCC "checkOldIface" #-}
+            liftIO $ checkOldIface hsc_env mod_summary
+                                   source_unchanged mb_old_iface
+
+     let mb_old_hash = fmap mi_iface_hash mb_checked_iface
+     case mb_checked_iface of
+       Just iface | not recomp_reqd
+           -> hscNoRecomp compiler iface{ mi_globals = Just (tcg_rdr_env tc_result) }
+       _otherwise
+           -> hscBackend compiler tc_result mod_summary mb_old_hash
+
 genericHscRecompile :: GhcMonad m =>
                        HsCompiler a
                     -> ModSummary -> Maybe Fingerprint