X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fmain%2FInteractiveEval.hs;h=1f3686186b28f4ee09131058b710cdc7c3da6bb1;hp=b53e015da7c60109fb2bdc23148d69d240ce4791;hb=27ebe4c5edb356cec5c9b12f357404ae998bc905;hpb=efb02b428941021771c9b9b955bba3ec0214dbaf diff --git a/compiler/main/InteractiveEval.hs b/compiler/main/InteractiveEval.hs index b53e015..1f36861 100644 --- a/compiler/main/InteractiveEval.hs +++ b/compiler/main/InteractiveEval.hs @@ -70,6 +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 @@ -84,11 +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 @@ -102,7 +103,9 @@ 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. + 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. @@ -135,28 +138,6 @@ getHistorySpan s hist = withSession s $ \hsc_env -> do Just hmi -> return (modBreaks_locs (md_modBreaks (hm_details hmi)) ! num) _ -> panic "getHistorySpan" -{- - [Main.hs:42:(1,0)-(3,52)] *Main> :history 2 - Foo.hs:1:3-5 - Bar.hs:5:23-48 - [Main.hs:42:(1,0)-(3,52)] *Main> :back - Logged breakpoint at Foo.hs:1:3-5 - x :: Int - y :: a - _result :: [Char] - [-1: Foo.hs:1:3-5] *Main> :back - Logged breakpoint at Bar.hs:5:23-48 - z :: a - _result :: Float - [-2: Bar.hs:5:23-48] *Main> :forward - Logged breakpoint at Foo.hs:1:3-5 - x :: Int - y :: a - _result :: [Char] - [-1: Foo.hs:1:3-5] *Main> :cont - .. continues --} - -- | Run a statement in the current interactive context. Statement -- may bind multple values. runStmt :: Session -> String -> SingleStep -> IO RunResult @@ -178,13 +159,7 @@ 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 @@ -207,17 +182,20 @@ 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 - (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env apStack info + let mb_info | is_exception = Nothing + | otherwise = Just info + (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env + 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) @@ -238,7 +216,7 @@ traceRunStatus expr ref bindings final_ids 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) -> do + (Break is_exception apStack info tid) | not is_exception -> do b <- isBreakEnabled hsc_env info if b then handle_normally @@ -247,8 +225,8 @@ traceRunStatus expr ref bindings final_ids -- probably better make history strict here, otherwise -- our BoundedList will be pointless. evaluate history' - setStepFlag - status <- withBreakAction breakMVar statusMVar $ do + status <- withBreakAction True (hsc_dflags hsc_env) + breakMVar statusMVar $ do withInterruptsSentTo (do putMVar breakMVar () -- awaken the stopped thread return tid) @@ -273,11 +251,15 @@ isBreakEnabled hsc_env inf = return False -foreign import ccall "rts_setStepFlag" setStepFlag :: IO () +foreign import ccall "&rts_stop_next_breakpoint" stepFlag :: Ptr CInt +foreign import ccall "&rts_stop_on_exception" exceptionFlag :: Ptr CInt + +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 @@ -286,10 +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 @@ -297,25 +295,38 @@ 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" + +noBreakAction False info apStack = putStrLn "*** Ignoring breakpoint" +noBreakAction True info apStack = return () -- exception: just continue resume :: Session -> SingleStep -> IO RunResult resume (Session ref) step @@ -346,7 +357,8 @@ resume (Session ref) step case r of Resume expr tid breakMVar statusMVar bindings final_ids apStack info _ _ _ -> do - withBreakAction breakMVar statusMVar $ do + withBreakAction (isStep step) (hsc_dflags hsc_env) + breakMVar statusMVar $ do status <- withInterruptsSentTo (do putMVar breakMVar () -- this awakens the stopped thread... @@ -377,15 +389,15 @@ moveHist fn (Session ref) = do history = resumeHistory r new_ix = fn ix -- - when (new_ix >= length history) $ + 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 info = do + update_ic apStack mb_info = do (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env - apStack info + apStack mb_info let ic = hsc_IC hsc_env1 r' = r { resumeHistoryIx = new_ix } ic' = ic { ic_resume = r':rs } @@ -400,11 +412,11 @@ moveHist fn (Session ref) = do if new_ix == 0 then case r of Resume { resumeApStack = apStack, - resumeBreakInfo = info } -> - update_ic apStack info + resumeBreakInfo = mb_info } -> + update_ic apStack mb_info else case history !! (new_ix - 1) of History apStack info -> - update_ic apStack info + update_ic apStack (Just info) -- ----------------------------------------------------------------------------- -- After stopping at a breakpoint, add free variables to the environment @@ -412,9 +424,34 @@ moveHist fn (Session ref) = do bindLocalsAtBreakpoint :: HscEnv -> HValue - -> BreakInfo + -> Maybe BreakInfo -> IO (HscEnv, [Name], SrcSpan) -bindLocalsAtBreakpoint hsc_env apStack info = 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) @@ -451,8 +488,9 @@ bindLocalsAtBreakpoint hsc_env apStack info = do -- _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 @@ -478,7 +516,7 @@ bindLocalsAtBreakpoint hsc_env apStack info = do 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 = idType id new_id = Id.mkGlobalId VanillaGlobal name ty (idInfo id) @@ -522,8 +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 @@ -532,11 +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 @@ -593,7 +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 @@ -768,11 +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 */