X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fmain%2FInteractiveEval.hs;h=1f3686186b28f4ee09131058b710cdc7c3da6bb1;hb=2eb04ca0f8d0ec72b417cddc60672c696b4a3daa;hp=ef9e5afa580a5e9c3557c73b42d3e96e237b84ef;hpb=86bec4298d582ef1d8f0a201d6a81145e1be9498;p=ghc-hetmet.git diff --git a/compiler/main/InteractiveEval.hs b/compiler/main/InteractiveEval.hs index ef9e5af..1f36861 100644 --- a/compiler/main/InteractiveEval.hs +++ b/compiler/main/InteractiveEval.hs @@ -8,11 +8,13 @@ module InteractiveEval ( #ifdef GHCI - RunResult(..), Status(..), Resume(..), - runStmt, stepStmt, -- traceStmt, - resume, stepResume, -- traceResume, + RunResult(..), Status(..), Resume(..), History(..), + runStmt, SingleStep(..), + resume, abandon, abandonAll, getResumeContext, + getHistorySpan, + back, forward, setContext, getContext, nameSetToGlobalRdrEnv, getNamesInScope, @@ -56,8 +58,10 @@ import Module import Panic import UniqFM import Maybes +import ErrUtils import Util import SrcLoc +import BreakArray import RtClosureInspect import Packages import BasicTypes @@ -66,6 +70,7 @@ import Outputable import Data.Dynamic import Control.Monad import Foreign +import Foreign.C import GHC.Exts import Data.Array import Control.Exception as Exception @@ -80,11 +85,11 @@ data RunResult = RunOk [Name] -- ^ names bound by this evaluation | RunFailed -- ^ statement failed compilation | RunException Exception -- ^ statement raised an exception - | RunBreak ThreadId [Name] BreakInfo + | RunBreak ThreadId [Name] (Maybe BreakInfo) data Status - = Break HValue BreakInfo ThreadId - -- ^ the computation hit a breakpoint + = Break Bool HValue BreakInfo ThreadId + -- ^ the computation hit a breakpoint (Bool <=> was an exception) | Complete (Either Exception [HValue]) -- ^ the computation completed with either an exception or a value @@ -98,10 +103,14 @@ data Resume resumeFinalIds :: [Id], -- [Id] to bind on completion resumeApStack :: HValue, -- The object from which we can get -- value of the free variables. - resumeBreakInfo :: BreakInfo, -- the breakpoint we stopped at. - resumeSpan :: SrcSpan -- just a cache, otherwise it's a pain + resumeBreakInfo :: Maybe BreakInfo, + -- the breakpoint we stopped at + -- (Nothing <=> exception) + resumeSpan :: SrcSpan, -- just a cache, otherwise it's a pain -- to fetch the ModDetails & ModBreaks -- to get this. + resumeHistory :: [History], + resumeHistoryIx :: Int -- 0 <==> at the top of the history } getResumeContext :: Session -> IO [Resume] @@ -115,37 +124,24 @@ data SingleStep isStep RunToCompletion = False isStep _ = True --- type History = [HistoryItem] --- --- data HistoryItem = HistoryItem HValue BreakInfo --- --- historyBreakInfo :: HistoryItem -> BreakInfo --- historyBreakInfo (HistoryItem _ bi) = bi --- --- setContextToHistoryItem :: Session -> HistoryItem -> IO () --- setContextToHistoryItem - --- We need to track two InteractiveContexts: --- - the IC before runStmt, which is restored on each resume --- - the IC binding the results of the original statement, which --- will be the IC when runStmt returns with RunOk. +data History + = History { + historyApStack :: HValue, + historyBreakInfo :: BreakInfo + } + +getHistorySpan :: Session -> History -> IO SrcSpan +getHistorySpan s hist = withSession s $ \hsc_env -> do + let inf = historyBreakInfo hist + num = breakInfo_number inf + case lookupUFM (hsc_HPT hsc_env) (moduleName (breakInfo_module inf)) of + Just hmi -> return (modBreaks_locs (md_modBreaks (hm_details hmi)) ! num) + _ -> panic "getHistorySpan" -- | Run a statement in the current interactive context. Statement -- may bind multple values. -runStmt :: Session -> String -> IO RunResult -runStmt session expr = runStmt_ session expr RunToCompletion - --- | Run a statement, stopping at the first breakpoint location encountered --- (regardless of whether the breakpoint is enabled). -stepStmt :: Session -> String -> IO RunResult -stepStmt session expr = runStmt_ session expr SingleStep - --- | Run a statement, logging breakpoints passed, and stopping when either --- an enabled breakpoint is reached, or the statement completes. --- traceStmt :: Session -> String -> IO (RunResult, History) --- traceStmt session expr = runStmt_ session expr RunAndLogSteps - -runStmt_ (Session ref) expr step +runStmt :: Session -> String -> SingleStep -> IO RunResult +runStmt (Session ref) expr step = do hsc_env <- readIORef ref @@ -163,40 +159,43 @@ runStmt_ (Session ref) expr step Nothing -> return RunFailed Just (ids, hval) -> do - when (isStep step) $ setStepFlag - - -- set the onBreakAction to be performed when we hit a - -- breakpoint this is visible in the Byte Code - -- Interpreter, thus it is a global variable, - -- implemented with stable pointers - withBreakAction breakMVar statusMVar $ do + withBreakAction (isStep step) dflags' breakMVar statusMVar $ do let thing_to_run = unsafeCoerce# hval :: IO [HValue] status <- sandboxIO statusMVar thing_to_run let ic = hsc_IC hsc_env bindings = (ic_tmp_ids ic, ic_tyvars ic) - handleRunStatus expr ref bindings ids breakMVar statusMVar status -handleRunStatus expr ref bindings final_ids breakMVar statusMVar status = + case step of + RunAndLogSteps -> + traceRunStatus expr ref bindings ids + breakMVar statusMVar status emptyHistory + _other -> + handleRunStatus expr ref bindings ids + breakMVar statusMVar status emptyHistory + + +emptyHistory = nilBL 50 -- keep a log of length 50 + +handleRunStatus expr ref bindings final_ids breakMVar statusMVar status + history = case status of -- did we hit a breakpoint or did we complete? - (Break apStack info tid) -> do + (Break is_exception apStack info tid) -> do hsc_env <- readIORef ref - let - mod_name = moduleName (breakInfo_module info) - mod_details = fmap hm_details (lookupUFM (hsc_HPT hsc_env) mod_name) - breaks = md_modBreaks (expectJust "handlRunStatus" mod_details) - -- + let mb_info | is_exception = Nothing + | otherwise = Just info (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env - apStack info breaks + apStack mb_info let resume = Resume expr tid breakMVar statusMVar - bindings final_ids apStack info span + bindings final_ids apStack mb_info span + (toListBL history) 0 hsc_env2 = pushResume hsc_env1 resume -- writeIORef ref hsc_env2 - return (RunBreak tid names info) + return (RunBreak tid names mb_info) (Complete either_hvals) -> case either_hvals of Left e -> return (RunException e) @@ -210,34 +209,57 @@ handleRunStatus expr ref bindings final_ids breakMVar statusMVar status = Linker.extendLinkEnv (zip final_names hvals) return (RunOk final_names) -{- -traceRunStatus ref final_ids + +traceRunStatus expr ref bindings final_ids breakMVar statusMVar status history = do hsc_env <- readIORef ref case status of -- when tracing, if we hit a breakpoint that is not explicitly -- enabled, then we just log the event in the history and continue. - (Break apStack info tid) | not (isBreakEnabled hsc_env info) -> do - let history' = consBL (apStack,info) history - withBreakAction breakMVar statusMVar $ do - status <- withInterruptsSentTo - (do putMVar breakMVar () -- this awakens the stopped thread... - return tid) - (takeMVar statusMVar) -- and wait for the result - - traceRunStatus ref final_ids - breakMVar statusMVar status history' + (Break is_exception apStack info tid) | not is_exception -> do + b <- isBreakEnabled hsc_env info + if b + then handle_normally + else do + let history' = consBL (History apStack info) history + -- probably better make history strict here, otherwise + -- our BoundedList will be pointless. + evaluate history' + status <- withBreakAction True (hsc_dflags hsc_env) + breakMVar statusMVar $ do + withInterruptsSentTo + (do putMVar breakMVar () -- awaken the stopped thread + return tid) + (takeMVar statusMVar) -- and wait for the result + traceRunStatus expr ref bindings final_ids + breakMVar statusMVar status history' _other -> - handleRunStatus ref final_ids - breakMVar statusMVar status - --} + handle_normally + where + handle_normally = handleRunStatus expr ref bindings final_ids + breakMVar statusMVar status history + + +isBreakEnabled :: HscEnv -> BreakInfo -> IO Bool +isBreakEnabled hsc_env inf = + case lookupUFM (hsc_HPT hsc_env) (moduleName (breakInfo_module inf)) of + Just hmi -> do + w <- getBreak (modBreaks_flags (md_modBreaks (hm_details hmi))) + (breakInfo_number inf) + case w of Just n -> return (n /= 0); _other -> return False + _ -> + return False + + +foreign import ccall "&rts_stop_next_breakpoint" stepFlag :: Ptr CInt +foreign import ccall "&rts_stop_on_exception" exceptionFlag :: Ptr CInt -foreign import ccall "rts_setStepFlag" setStepFlag :: IO () +setStepFlag = poke stepFlag 1 +resetStepFlag = poke stepFlag 0 -- this points to the IO action that is executed when a breakpoint is hit -foreign import ccall "&breakPointIOAction" - breakPointIOAction :: Ptr (StablePtr (BreakInfo -> HValue -> IO ())) +foreign import ccall "&rts_breakpoint_io_action" + breakPointIOAction :: Ptr (StablePtr (Bool -> BreakInfo -> HValue -> IO ())) -- When running a computation, we redirect ^C exceptions to the running -- thread. ToDo: we might want a way to continue even if the target @@ -246,10 +268,26 @@ foreign import ccall "&breakPointIOAction" 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) +-- We want to turn ^C into a break when -fbreak-on-exception is on, +-- but it's an async exception and we only break for sync exceptions. +-- Idea: if we catch and re-throw it, then the re-throw will trigger +-- a break. Great - but we don't want to re-throw all exceptions, because +-- then we'll get a double break for ordinary sync exceptions (you'd have +-- to :continue twice, which looks strange). So if the exception is +-- not "Interrupted", we unset the exception flag before throwing. +-- +rethrow :: IO a -> IO a +rethrow io = Exception.catch io $ \e -> -- NB. not catchDyn + case e of + DynException d | Just Interrupted <- fromDynamic d + -> Exception.throwIO e + _ -> do poke exceptionFlag 0; Exception.throwIO e + + withInterruptsSentTo :: IO ThreadId -> IO r -> IO r withInterruptsSentTo io get_result = do ts <- takeMVar interruptTargetThread @@ -257,37 +295,41 @@ withInterruptsSentTo io get_result = do putMVar interruptTargetThread (child:ts) get_result `finally` modifyMVar_ interruptTargetThread (return.tail) -withBreakAction breakMVar statusMVar io +-- This function sets up the interpreter for catching breakpoints, and +-- resets everything when the computation has stopped running. This +-- is a not-very-good way to ensure that only the interactive +-- evaluation should generate breakpoints. +withBreakAction step dflags breakMVar statusMVar io = bracket setBreakAction resetBreakAction (\_ -> io) where setBreakAction = do stablePtr <- newStablePtr onBreak poke breakPointIOAction stablePtr + when (dopt Opt_BreakOnException dflags) $ poke exceptionFlag 1 + when step $ setStepFlag return stablePtr + -- Breaking on exceptions is not enabled by default, since it + -- might be a bit surprising. The exception flag is turned off + -- as soon as it is hit, or in resetBreakAction below. - onBreak info apStack = do + onBreak is_exception info apStack = do tid <- myThreadId - putMVar statusMVar (Break apStack info tid) + putMVar statusMVar (Break is_exception apStack info tid) takeMVar breakMVar resetBreakAction stablePtr = do poke breakPointIOAction noBreakStablePtr + poke exceptionFlag 0 + resetStepFlag freeStablePtr stablePtr noBreakStablePtr = unsafePerformIO $ newStablePtr noBreakAction -noBreakAction info apStack = putStrLn "*** Ignoring breakpoint" - -resume :: Session -> IO RunResult -resume session = resume_ session RunToCompletion - -stepResume :: Session -> IO RunResult -stepResume session = resume_ session SingleStep --- traceResume :: Session -> IO RunResult --- traceResume session handle = resume_ session handle RunAndLogSteps +noBreakAction False info apStack = putStrLn "*** Ignoring breakpoint" +noBreakAction True info apStack = return () -- exception: just continue -resume_ :: Session -> SingleStep -> IO RunResult -resume_ (Session ref) step +resume :: Session -> SingleStep -> IO RunResult +resume (Session ref) step = do hsc_env <- readIORef ref let ic = hsc_IC hsc_env @@ -311,20 +353,70 @@ resume_ (Session ref) step (ic_tmp_ids ic)) Linker.deleteFromLinkEnv new_names - when (isStep step) $ setStepFlag case r of Resume expr tid breakMVar statusMVar bindings - final_ids apStack info _ -> do - withBreakAction breakMVar statusMVar $ do + final_ids apStack info _ _ _ -> do + withBreakAction (isStep step) (hsc_dflags hsc_env) + breakMVar statusMVar $ do status <- withInterruptsSentTo (do putMVar breakMVar () -- this awakens the stopped thread... return tid) (takeMVar statusMVar) -- and wait for the result - handleRunStatus expr ref bindings final_ids - breakMVar statusMVar status + case step of + RunAndLogSteps -> + traceRunStatus expr ref bindings final_ids + breakMVar statusMVar status emptyHistory + _other -> + handleRunStatus expr ref bindings final_ids + breakMVar statusMVar status emptyHistory + + +back :: Session -> IO ([Name], Int, SrcSpan) +back = moveHist (+1) + +forward :: Session -> IO ([Name], Int, SrcSpan) +forward = moveHist (subtract 1) + +moveHist fn (Session ref) = do + hsc_env <- readIORef ref + case ic_resume (hsc_IC hsc_env) of + [] -> throwDyn (ProgramError "not stopped at a breakpoint") + (r:rs) -> do + let ix = resumeHistoryIx r + history = resumeHistory r + new_ix = fn ix + -- + when (new_ix > length history) $ + throwDyn (ProgramError "no more logged breakpoints") + when (new_ix < 0) $ + throwDyn (ProgramError "already at the beginning of the history") + + let + update_ic apStack mb_info = do + (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env + apStack mb_info + let ic = hsc_IC hsc_env1 + r' = r { resumeHistoryIx = new_ix } + ic' = ic { ic_resume = r':rs } + + writeIORef ref hsc_env1{ hsc_IC = ic' } + + return (names, new_ix, span) + + -- careful: we want apStack to be the AP_STACK itself, not a thunk + -- around it, hence the cases are carefully constructed below to + -- make this the case. ToDo: this is v. fragile, do something better. + if new_ix == 0 + then case r of + Resume { resumeApStack = apStack, + resumeBreakInfo = mb_info } -> + update_ic apStack mb_info + else case history !! (new_ix - 1) of + History apStack info -> + update_ic apStack (Just info) -- ----------------------------------------------------------------------------- -- After stopping at a breakpoint, add free variables to the environment @@ -332,12 +424,39 @@ resume_ (Session ref) step bindLocalsAtBreakpoint :: HscEnv -> HValue - -> BreakInfo - -> ModBreaks + -> Maybe BreakInfo -> IO (HscEnv, [Name], SrcSpan) -bindLocalsAtBreakpoint hsc_env apStack info breaks = do + +-- Nothing case: we stopped when an exception was raised, not at a +-- breakpoint. We have no location information or local variables to +-- bind, all we can do is bind a local variable to the exception +-- value. +bindLocalsAtBreakpoint hsc_env apStack Nothing = do + let exn_fs = FSLIT("_exception") + exn_name = mkInternalName (getUnique exn_fs) (mkVarOccFS exn_fs) span + e_fs = FSLIT("e") + e_name = mkInternalName (getUnique e_fs) (mkTyVarOcc e_fs) span + e_tyvar = mkTcTyVar e_name liftedTypeKind (SkolemTv RuntimeUnkSkol) + exn_id = Id.mkGlobalId VanillaGlobal exn_name (mkTyVarTy e_tyvar) + vanillaIdInfo + new_tyvars = unitVarSet e_tyvar + + ictxt0 = hsc_IC hsc_env + ictxt1 = extendInteractiveContext ictxt0 [exn_id] new_tyvars + + span = mkGeneralSrcSpan FSLIT("") + -- + Linker.extendLinkEnv [(exn_name, unsafeCoerce# apStack)] + return (hsc_env{ hsc_IC = ictxt1 }, [exn_name], span) + +-- Just case: we stopped at a breakpoint, we have information about the location +-- of the breakpoint and the free variables of the expression. +bindLocalsAtBreakpoint hsc_env apStack (Just info) = do let + mod_name = moduleName (breakInfo_module info) + mod_details = fmap hm_details (lookupUFM (hsc_HPT hsc_env) mod_name) + breaks = md_modBreaks (expectJust "handlRunStatus" mod_details) index = breakInfo_number info vars = breakInfo_vars info result_ty = breakInfo_resty info @@ -350,17 +469,28 @@ bindLocalsAtBreakpoint hsc_env apStack info breaks = do | otherwise = False let (ids, offsets) = unzip pointers - hValues <- mapM (getIdValFromApStack apStack) offsets - new_ids <- zipWithM mkNewId occs ids - let names = map idName ids + + -- It might be that getIdValFromApStack fails, because the AP_STACK + -- has been accidentally evaluated, or something else has gone wrong. + -- So that we don't fall over in a heap when this happens, just don't + -- bind any free variables instead, and we emit a warning. + mb_hValues <- mapM (getIdValFromApStack apStack) offsets + let filtered_ids = [ id | (id, Just _) <- zip ids mb_hValues ] + when (any isNothing mb_hValues) $ + debugTraceMsg (hsc_dflags hsc_env) 1 $ + text "Warning: _result has been evaluated, some bindings have been lost" + + new_ids <- zipWithM mkNewId occs filtered_ids + let names = map idName new_ids -- make an Id for _result. We use the Unique of the FastString "_result"; -- we don't care about uniqueness here, because there will only be one -- _result in scope at any time. let result_fs = FSLIT("_result") result_name = mkInternalName (getUnique result_fs) - (mkVarOccFS result_fs) (srcSpanStart span) - result_id = Id.mkLocalId result_name result_ty + (mkVarOccFS result_fs) span + result_id = Id.mkGlobalId VanillaGlobal result_name result_ty + vanillaIdInfo -- for each Id we're about to bind in the local envt: -- - skolemise the type variables in its type, so they can't @@ -369,27 +499,26 @@ bindLocalsAtBreakpoint hsc_env apStack info breaks = do -- - tidy the type variables -- - globalise the Id (Ids are supposed to be Global, apparently). -- - let all_ids | isPointer result_id = result_id : ids - | otherwise = ids + let all_ids | isPointer result_id = result_id : new_ids + | otherwise = new_ids (id_tys, tyvarss) = mapAndUnzip (skolemiseTy.idType) all_ids (_,tidy_tys) = tidyOpenTypes emptyTidyEnv id_tys new_tyvars = unionVarSets tyvarss - new_ids = zipWith setIdType all_ids tidy_tys - global_ids = map (globaliseId VanillaGlobal) new_ids + final_ids = zipWith setIdType all_ids tidy_tys let ictxt0 = hsc_IC hsc_env - ictxt1 = extendInteractiveContext ictxt0 global_ids new_tyvars + ictxt1 = extendInteractiveContext ictxt0 final_ids new_tyvars - Linker.extendLinkEnv (zip names hValues) + Linker.extendLinkEnv [ (name,hval) | (name, Just hval) <- zip names mb_hValues ] Linker.extendLinkEnv [(result_name, unsafeCoerce# apStack)] return (hsc_env{ hsc_IC = ictxt1 }, result_name:names, span) where mkNewId :: OccName -> Id -> IO Id mkNewId occ id = do let uniq = idUnique id - loc = nameSrcLoc (idName id) + loc = nameSrcSpan (idName id) name = mkInternalName uniq occ loc - ty = tidyTopType (idType id) + ty = idType id new_id = Id.mkGlobalId VanillaGlobal name ty (idInfo id) return new_id @@ -405,19 +534,15 @@ skolemiseTyVar :: TyVar -> TyVar skolemiseTyVar tyvar = mkTcTyVar (tyVarName tyvar) (tyVarKind tyvar) (SkolemTv RuntimeUnkSkol) --- Todo: turn this into a primop, and provide special version(s) for --- unboxed things -foreign import ccall unsafe "rts_getApStackVal" - getApStackVal :: StablePtr a -> Int -> IO (StablePtr b) - -getIdValFromApStack :: a -> Int -> IO HValue -getIdValFromApStack apStack stackDepth = do - apSptr <- newStablePtr apStack - resultSptr <- getApStackVal apSptr (stackDepth - 1) - result <- deRefStablePtr resultSptr - freeStablePtr apSptr - freeStablePtr resultSptr - return (unsafeCoerce# result) +getIdValFromApStack :: HValue -> Int -> IO (Maybe HValue) +getIdValFromApStack apStack (I# stackDepth) = do + case getApStackVal# apStack (stackDepth +# 1#) of + -- The +1 is magic! I don't know where it comes + -- from, but this makes things line up. --SDM + (# ok, result #) -> + case ok of + 0# -> return Nothing -- AP_STACK not found + _ -> return (Just (unsafeCoerce# result)) pushResume :: HscEnv -> Resume -> HscEnv pushResume hsc_env resume = hsc_env { hsc_IC = ictxt1 } @@ -435,8 +560,9 @@ abandon (Session ref) = do resume = ic_resume ic case resume of [] -> return False - _:rs -> do + r:rs -> do writeIORef ref hsc_env{ hsc_IC = ic { ic_resume = rs } } + abandon_ r return True abandonAll :: Session -> IO Bool @@ -445,11 +571,26 @@ abandonAll (Session ref) = do let ic = hsc_IC hsc_env resume = ic_resume ic case resume of - [] -> return False - _:rs -> do + [] -> return False + rs -> do writeIORef ref hsc_env{ hsc_IC = ic { ic_resume = [] } } + mapM_ abandon_ rs return True +-- when abandoning a computation we have to +-- (a) kill the thread with an async exception, so that the +-- computation itself is stopped, and +-- (b) fill in the MVar. This step is necessary because any +-- thunks that were under evaluation will now be updated +-- with the partial computation, which still ends in takeMVar, +-- so any attempt to evaluate one of these thunks will block +-- unless we fill in the MVar. +-- See test break010. +abandon_ :: Resume -> IO () +abandon_ r = do + killThread (resumeThreadId r) + putMVar (resumeBreakMVar r) () + -- ----------------------------------------------------------------------------- -- Bounded list, optimised for repeated cons @@ -459,14 +600,17 @@ data BoundedList a = BL [a] -- left [a] -- right, list is (left ++ reverse right) +nilBL :: Int -> BoundedList a +nilBL bound = BL 0 bound [] [] + consBL a (BL len bound left right) | len < bound = BL (len+1) bound (a:left) right - | null right = BL len bound [] $! tail (reverse left) - | otherwise = BL len bound [] $! tail right + | null right = BL len bound [a] $! tail (reverse left) + | otherwise = BL len bound (a:left) $! tail right toListBL (BL _ _ left right) = left ++ reverse right -lenBL (BL len _ _ _) = len +-- lenBL (BL len _ _ _) = len -- ----------------------------------------------------------------------------- -- | Set the interactive evaluation context. @@ -503,7 +647,7 @@ mkExportEnv hsc_env mods = do nameSetToGlobalRdrEnv :: NameSet -> ModuleName -> GlobalRdrEnv nameSetToGlobalRdrEnv names mod = - mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = vanillaProv mod } + mkGlobalRdrEnv [ GRE { gre_name = name, gre_par = NoParent, gre_prov = vanillaProv mod } | name <- nameSetToList names ] vanillaProv :: ModuleName -> Provenance @@ -678,11 +822,9 @@ isModuleInterpreted s mod_summary = withSession s $ \hsc_env -> obtainTerm1 :: Session -> Bool -> Maybe Type -> a -> IO Term obtainTerm1 sess force mb_ty x = withSession sess $ \hsc_env -> cvObtainTerm hsc_env force mb_ty (unsafeCoerce# x) -obtainTerm :: Session -> Bool -> Id -> IO (Maybe Term) +obtainTerm :: Session -> Bool -> Id -> IO Term obtainTerm sess force id = withSession sess $ \hsc_env -> do - mb_v <- Linker.getHValue (varName id) - case mb_v of - Just v -> fmap Just$ cvObtainTerm hsc_env force (Just$ idType id) v - Nothing -> return Nothing + hv <- Linker.getHValue hsc_env (varName id) + cvObtainTerm hsc_env force (Just$ idType id) hv #endif /* GHCI */