isModuleInterpreted,
compileExpr, dynCompileExpr,
lookupName,
- obtainTerm, obtainTerm1
+ obtainTerm, obtainTerm1, reconstructType,
+ skolemiseSubst, skolemiseTy
#endif
) where
import Data.Dynamic
import Control.Monad
import Foreign
+import Foreign.C
import GHC.Exts
import Data.Array
import Control.Exception as Exception
= 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
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.
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
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)
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)
final_ids emptyVarSet
-- the bound Ids never have any free TyVars
final_names = map idName final_ids
- writeIORef ref hsc_env{hsc_IC=final_ic}
Linker.extendLinkEnv (zip final_names hvals)
+ hsc_env' <- rttiEnvironment hsc_env{hsc_IC=final_ic}
+ writeIORef ref hsc_env'
return (RunOk final_names)
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
-- 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)
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
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
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
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...
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 }
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
-
+result_fs = FSLIT("_result")
+
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("<exception thrown>")
+ --
+ 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)
-- 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 ]
+ let (filtered_hvs, filtered_ids) =
+ unzip [ (hv, id) | (id, Just hv) <- 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"
-- 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
+ let result_name = mkInternalName (getUnique result_fs)
+ (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
(id_tys, tyvarss) = mapAndUnzip (skolemiseTy.idType) all_ids
(_,tidy_tys) = tidyOpenTypes emptyTidyEnv id_tys
new_tyvars = unionVarSets tyvarss
- final_ids = zipWith setIdType all_ids tidy_tys
-
- let ictxt0 = hsc_IC hsc_env
- ictxt1 = extendInteractiveContext ictxt0 final_ids new_tyvars
-
+ let final_ids = zipWith setIdType all_ids tidy_tys
+ ictxt0 = hsc_IC hsc_env
+ ictxt1 = extendInteractiveContext ictxt0 final_ids new_tyvars
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)
+ hsc_env1 <- rttiEnvironment hsc_env{ hsc_IC = ictxt1 }
+ return (hsc_env1, 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 = idType id
new_id = Id.mkGlobalId VanillaGlobal name ty (idInfo id)
return new_id
+rttiEnvironment :: HscEnv -> IO HscEnv
+rttiEnvironment hsc_env@HscEnv{hsc_IC=ic} = do
+ let InteractiveContext{ic_tmp_ids=tmp_ids, ic_tyvars = tyvars} = ic
+ incompletelyTypedIds =
+ [id | id <- tmp_ids
+ , not $ null [v | v <- varSetElems$ tyVarsOfType (idType id)
+ , isSkolemTyVar v]
+ , (occNameFS.nameOccName.idName) id /= result_fs]
+ tys <- reconstructType hsc_env False `mapM` incompletelyTypedIds
+ -- map termType `fmap` (obtainTerm hsc_env False `mapM` incompletelyTypedIds)
+
+ let substs = [computeRTTIsubst ty ty'
+ | (ty, Just ty') <- zip (map idType incompletelyTypedIds) tys]
+ ic' = foldr (flip substInteractiveContext) ic
+ (map skolemiseSubst $ catMaybes substs)
+ return hsc_env{hsc_IC=ic'}
+
+skolemiseSubst subst = subst `setTvSubstEnv`
+ mapVarEnv (fst.skolemiseTy) (getTvSubstEnv subst)
+
skolemiseTy :: Type -> (Type, TyVarSet)
skolemiseTy ty = (substTy subst ty, mkVarSet new_tyvars)
where env = mkVarEnv (zip tyvars new_tyvar_tys)
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
_not_a_home_module -> return False
-- | Looks up an identifier in the current interactive context (for :info)
+-- Filter the instances by the ones whose tycons (or clases resp)
+-- are in scope (qualified or otherwise). Otherwise we list a whole lot too many!
+-- The exact choice of which ones to show, and which to hide, is a judgement call.
+-- (see Trac #1581)
getInfo :: Session -> Name -> IO (Maybe (TyThing,Fixity,[Instance]))
-getInfo s name = withSession s $ \hsc_env -> tcRnGetInfo hsc_env name
+getInfo s name
+ = withSession s $ \hsc_env ->
+ do { mb_stuff <- tcRnGetInfo hsc_env name
+ ; case mb_stuff of
+ Nothing -> return Nothing
+ Just (thing, fixity, ispecs) -> do
+ { let rdr_env = ic_rn_gbl_env (hsc_IC hsc_env)
+ ; return (Just (thing, fixity, filter (plausible rdr_env) ispecs)) } }
+ where
+ plausible rdr_env ispec -- Dfun involving only names that are in ic_rn_glb_env
+ = all ok $ nameSetToList $ tyClsNamesOfType $ idType $ instanceDFunId ispec
+ where -- A name is ok if it's in the rdr_env,
+ -- whether qualified or not
+ ok n | n == name = True -- The one we looked for in the first place!
+ | isBuiltInSyntax n = True
+ | isExternalName n = any ((== n) . gre_name)
+ (lookupGRE_Name rdr_env n)
+ | otherwise = True
-- | Returns all names in scope in the current interactive context
getNamesInScope :: Session -> IO [Name]
where
obj_linkable = isObjectLinkable (expectJust "showModule" (hm_linkable mod_info))
-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)
+----------------------------------------------------------------------------
+-- RTTI primitives
-obtainTerm :: Session -> Bool -> Id -> IO Term
-obtainTerm sess force id = withSession sess $ \hsc_env -> do
+obtainTerm1 :: HscEnv -> Bool -> Maybe Type -> a -> IO Term
+obtainTerm1 hsc_env force mb_ty x =
+ cvObtainTerm hsc_env force mb_ty (unsafeCoerce# x)
+
+obtainTerm :: HscEnv -> Bool -> Id -> IO Term
+obtainTerm hsc_env force id = do
hv <- Linker.getHValue hsc_env (varName id)
cvObtainTerm hsc_env force (Just$ idType id) hv
+-- Uses RTTI to reconstruct the type of an Id, making it less polymorphic
+reconstructType :: HscEnv -> Bool -> Id -> IO (Maybe Type)
+reconstructType hsc_env force id = do
+ hv <- Linker.getHValue hsc_env (varName id)
+ cvReconstructType hsc_env force (Just$ idType id) hv
#endif /* GHCI */