X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fghci%2FLinker.lhs;h=d44b22a496bc01297180ff93eaaeadc3b89b2d11;hb=c1681a73fa4ca4cf8758264ae387ac09a9e900d8;hp=fe009c2fefba77ed3ee38ec3950401c281182fca;hpb=37f22a833c33c3ab504778fd91a39d8d48fa3766;p=ghc-hetmet.git

diff --git a/compiler/ghci/Linker.lhs b/compiler/ghci/Linker.lhs
index fe009c2..d44b22a 100644
--- a/compiler/ghci/Linker.lhs
+++ b/compiler/ghci/Linker.lhs
@@ -161,7 +161,7 @@ deleteFromLinkEnv to_remove
 --   We use this string to lookup the interpreter's internal representation of the name
 --   using the lookupOrig.    
 
-dataConInfoPtrToName :: Ptr () -> TcM Name
+dataConInfoPtrToName :: Ptr () -> TcM (Either String Name)
 dataConInfoPtrToName x = do 
    theString <- ioToTcRn $ do
       let ptr = castPtr x :: Ptr StgInfoTable
@@ -173,7 +173,8 @@ dataConInfoPtrToName x = do
        occFS = mkFastStringByteList occ
        occName = mkOccNameFS OccName.dataName occFS
        modName = mkModule (fsToPackageId pkgFS) (mkModuleNameFS modFS) 
-   lookupOrig modName occName
+   return (Left$ showSDoc$ ppr modName <> dot <> ppr occName ) 
+    `recoverM` (Right `fmap` lookupOrig modName occName)
 
    where
 
@@ -278,17 +279,31 @@ linkDependencies hsc_env span needed_mods = do
    linkModules dflags lnks
 
 
+-- | Temporarily extend the linker state.
+
 withExtendedLinkEnv :: [(Name,HValue)] -> IO a -> IO a
 withExtendedLinkEnv new_env action
     = bracket set_new_env
               reset_old_env
               (const action)
-    where set_new_env = do pls <- readIORef v_PersistentLinkerState
-                           let new_closure_env = extendClosureEnv (closure_env pls) new_env
-                               new_pls = pls { closure_env = new_closure_env }
-                           writeIORef v_PersistentLinkerState new_pls
-                           return (closure_env pls)
-          reset_old_env env = modifyIORef v_PersistentLinkerState (\pls -> pls{ closure_env = env })
+    where set_new_env = do 
+            pls <- readIORef v_PersistentLinkerState
+            let new_closure_env = extendClosureEnv (closure_env pls) new_env
+                new_pls = pls { closure_env = new_closure_env }
+            writeIORef v_PersistentLinkerState new_pls
+            return (closure_env pls)
+
+        -- Remember that the linker state might be side-effected
+        -- during the execution of the IO action, and we don't want to
+        -- lose those changes (we might have linked a new module or
+        -- package), so the reset action only removes the names we
+        -- added earlier.
+          reset_old_env env = do
+            modifyIORef v_PersistentLinkerState $ \pls ->
+                let cur = closure_env pls
+                    new = delListFromNameEnv cur (map fst new_env)
+                in
+                pls{ closure_env = new }
 
 -- filterNameMap removes from the environment all entries except 
 -- 	those for a given set of modules;