X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fmain%2FInteractiveEval.hs;h=c80f2933f793167f9d34738b8dd906878c3717eb;hp=f7e910135eb12851df2dac875378135e90365fe4;hb=ede84b2aad85b55c616d91e8863f8c8ce8bc17a9;hpb=54fd57cdd7c974f81dee81e8edc53e78de82db04

diff --git a/compiler/main/InteractiveEval.hs b/compiler/main/InteractiveEval.hs
index f7e9101..c80f293 100644
--- a/compiler/main/InteractiveEval.hs
+++ b/compiler/main/InteractiveEval.hs
@@ -268,10 +268,18 @@ foreign import ccall "&rts_breakpoint_io_action"
 sandboxIO :: MVar Status -> IO [HValue] -> IO Status
 sandboxIO statusMVar thing = 
   withInterruptsSentTo 
-        (forkIO (do res <- Exception.try thing
+        (forkIO (do res <- Exception.try (rethrow thing)
                     putMVar statusMVar (Complete res)))
         (takeMVar statusMVar)
 
+-- | this just re-throws any exceptions received.  The point of this
+-- is that if -fbreak-on-excepsions is on, we only get a chance to break
+-- for synchronous exceptions, and this turns an async exception into
+-- a sync exception, so for instance a ^C exception will break right here
+-- unless it is caught elsewhere.
+rethrow :: IO a -> IO a
+rethrow io = Exception.catch io Exception.throwIO
+
 withInterruptsSentTo :: IO ThreadId -> IO r -> IO r
 withInterruptsSentTo io get_result = do
   ts <- takeMVar interruptTargetThread