#2973: we should virtualise the CWD inside the GHC API, not in the client

[ghc-hetmet.git] / compiler / main / InteractiveEval.hs

diff --git a/compiler/main/InteractiveEval.hs b/compiler/main/InteractiveEval.hs
index 510d876..36e6f7c 100644 (file)
--- a/compiler/main/InteractiveEval.hs
+++ b/compiler/main/InteractiveEval.hs
@@ -71,6 +71,7 @@ import Outputable
 import FastString
 import MonadUtils
 
+import System.Directory
 import Data.Dynamic
 import Data.List (find)
 import Control.Monad
@@ -212,6 +213,7 @@ runStmt expr step =
         clearWarnings
 
         status <-
+          withVirtualCWD $
             withBreakAction (isStep step) dflags' breakMVar statusMVar $ do
                 let thing_to_run = unsafeCoerce# hval :: IO [HValue]
                 liftIO $ sandboxIO dflags' statusMVar thing_to_run
@@ -227,6 +229,28 @@ runStmt expr step =
               handleRunStatus expr bindings ids
                                breakMVar statusMVar status emptyHistory
 
+withVirtualCWD :: GhcMonad m => m a -> m a
+withVirtualCWD m = do
+  hsc_env <- getSession
+  let ic = hsc_IC hsc_env
+
+  let set_cwd = do
+        dir <- liftIO $ getCurrentDirectory
+        case ic_cwd ic of 
+           Just dir -> liftIO $ setCurrentDirectory dir
+           Nothing  -> return ()
+        return dir
+
+      reset_cwd orig_dir = do
+        virt_dir <- liftIO $ getCurrentDirectory
+        hsc_env <- getSession
+        let old_IC = hsc_IC hsc_env
+        setSession hsc_env{  hsc_IC = old_IC{ ic_cwd = Just virt_dir } }
+        liftIO $ setCurrentDirectory orig_dir
+
+  gbracket set_cwd reset_cwd $ \_ -> m
+
+
 emptyHistory :: BoundedList History
 emptyHistory = nilBL 50 -- keep a log of length 50
 
@@ -436,6 +460,7 @@ resume step
         case r of 
           Resume expr tid breakMVar statusMVar bindings 
               final_ids apStack info _ hist _ -> do
+               withVirtualCWD $ do
                 withBreakAction (isStep step) (hsc_dflags hsc_env) 
                                         breakMVar statusMVar $ do
                 status <- liftIO $ withInterruptsSentTo tid $ do