diff options
Diffstat (limited to 'compiler/ghci/RtClosureInspect.hs')
| -rw-r--r-- | compiler/ghci/RtClosureInspect.hs | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/compiler/ghci/RtClosureInspect.hs b/compiler/ghci/RtClosureInspect.hs index 18feeb523f..167ea1b6ac 100644 --- a/compiler/ghci/RtClosureInspect.hs +++ b/compiler/ghci/RtClosureInspect.hs @@ -692,12 +692,24 @@ cvObtainTerm hsc_env max_depth force old_ty hval = runTR hsc_env $ do traceTR (text "Forcing a " <> text (show (fmap (const ()) t))) liftIO $ GHCi.seqHValue hsc_env a go (pred max_depth) my_ty old_ty a --- Blackholes are indirections iff the payload is not TSO or BLOCKING_QUEUE. So we --- treat them like indirections; if the payload is TSO or BLOCKING_QUEUE, we'll end up --- showing '_' which is what we want. +-- Blackholes are indirections iff the payload is not TSO or BLOCKING_QUEUE. If +-- the indirection is a TSO or BLOCKING_QUEUE, we return the BLACKHOLE itself as +-- the suspension so that entering it in GHCi will enter the BLACKHOLE instead +-- of entering the TSO or BLOCKING_QUEUE (which leads to runtime panic). BlackholeClosure{indirectee=ind} -> do traceTR (text "Following a BLACKHOLE") - go max_depth my_ty old_ty ind + ind_clos <- trIO (GHCi.getClosure hsc_env ind) + let return_bh_value = return (Suspension BLACKHOLE my_ty a Nothing) + case ind_clos of + -- TSO and BLOCKING_QUEUE cases + BlockingQueueClosure{} -> return_bh_value + OtherClosure info _ _ + | tipe info == TSO -> return_bh_value + UnsupportedClosure info + | tipe info == TSO -> return_bh_value + -- Otherwise follow the indirectee + -- (NOTE: This code will break if we support TSO in ghc-heap one day) + _ -> go max_depth my_ty old_ty ind -- We always follow indirections IndClosure{indirectee=ind} -> do traceTR (text "Following an indirection" ) |