1 -- -----------------------------------------------------------------------------
3 -- (c) The University of Glasgow, 2005-2007
5 -- Running statements interactively
7 -- -----------------------------------------------------------------------------
9 module InteractiveEval (
11 RunResult(..), Status(..), Resume(..), History(..),
12 runStmt, SingleStep(..),
19 setContext, getContext,
20 nameSetToGlobalRdrEnv,
30 compileExpr, dynCompileExpr,
32 Term(..), obtainTerm, obtainTerm1, obtainTermB, reconstructType,
33 skolemiseSubst, skolemiseTy
39 #include "HsVersions.h"
41 import HscMain hiding (compileExpr)
44 import Type hiding (typeKind)
45 import TcType hiding (typeKind)
47 import Var hiding (setIdType)
50 import Name hiding ( varName )
67 import RtClosureInspect
73 import Data.List (find)
79 import Control.Exception as Exception
80 import Control.Concurrent
81 import Data.List (sortBy)
83 import Foreign.StablePtr
85 -- -----------------------------------------------------------------------------
86 -- running a statement interactively
89 = RunOk [Name] -- ^ names bound by this evaluation
90 | RunFailed -- ^ statement failed compilation
91 | RunException Exception -- ^ statement raised an exception
92 | RunBreak ThreadId [Name] (Maybe BreakInfo)
95 = Break Bool HValue BreakInfo ThreadId
96 -- ^ the computation hit a breakpoint (Bool <=> was an exception)
97 | Complete (Either Exception [HValue])
98 -- ^ the computation completed with either an exception or a value
102 resumeStmt :: String, -- the original statement
103 resumeThreadId :: ThreadId, -- thread running the computation
104 resumeBreakMVar :: MVar (),
105 resumeStatMVar :: MVar Status,
106 resumeBindings :: ([Id], TyVarSet),
107 resumeFinalIds :: [Id], -- [Id] to bind on completion
108 resumeApStack :: HValue, -- The object from which we can get
109 -- value of the free variables.
110 resumeBreakInfo :: Maybe BreakInfo,
111 -- the breakpoint we stopped at
112 -- (Nothing <=> exception)
113 resumeSpan :: SrcSpan, -- just a cache, otherwise it's a pain
114 -- to fetch the ModDetails & ModBreaks
116 resumeHistory :: [History],
117 resumeHistoryIx :: Int -- 0 <==> at the top of the history
120 getResumeContext :: Session -> IO [Resume]
121 getResumeContext s = withSession s (return . ic_resume . hsc_IC)
128 isStep RunToCompletion = False
133 historyApStack :: HValue,
134 historyBreakInfo :: BreakInfo,
135 historyEnclosingDecl :: Id
136 -- ^^ A cache of the enclosing top level declaration, for convenience
139 mkHistory :: HscEnv -> HValue -> BreakInfo -> History
140 mkHistory hsc_env hval bi = let
141 h = History hval bi decl
142 decl = findEnclosingDecl hsc_env (getHistoryModule h)
143 (getHistorySpan hsc_env h)
146 getHistoryModule :: History -> Module
147 getHistoryModule = breakInfo_module . historyBreakInfo
149 getHistorySpan :: HscEnv -> History -> SrcSpan
150 getHistorySpan hsc_env hist =
151 let inf = historyBreakInfo hist
152 num = breakInfo_number inf
153 in case lookupUFM (hsc_HPT hsc_env) (moduleName (breakInfo_module inf)) of
154 Just hmi -> modBreaks_locs (md_modBreaks (hm_details hmi)) ! num
155 _ -> panic "getHistorySpan"
157 -- | Finds the enclosing top level function name
158 findEnclosingDecl :: HscEnv -> Module -> SrcSpan -> Id
159 findEnclosingDecl hsc_env mod span =
160 case lookupUFM (hsc_HPT hsc_env) (moduleName mod) of
161 Nothing -> panic "findEnclosingDecl"
163 globals = typeEnvIds (md_types (hm_details hmi))
165 find (\id -> let n = idName id in
166 nameSrcSpan n < span && isExternalName n)
167 (reverse$ sortBy (compare `on` (nameSrcSpan.idName))
171 -- | Find the Module corresponding to a FilePath
172 findModuleFromFile :: HscEnv -> FilePath -> Maybe Module
173 findModuleFromFile hsc_env fp =
174 listToMaybe $ [ms_mod ms | ms <- hsc_mod_graph hsc_env
175 , ml_hs_file(ms_location ms) == Just (read fp)]
178 -- | Run a statement in the current interactive context. Statement
179 -- may bind multple values.
180 runStmt :: Session -> String -> SingleStep -> IO RunResult
181 runStmt (Session ref) expr step
183 hsc_env <- readIORef ref
185 breakMVar <- newEmptyMVar -- wait on this when we hit a breakpoint
186 statusMVar <- newEmptyMVar -- wait on this when a computation is running
188 -- Turn off -fwarn-unused-bindings when running a statement, to hide
189 -- warnings about the implicit bindings we introduce.
190 let dflags' = dopt_unset (hsc_dflags hsc_env) Opt_WarnUnusedBinds
191 hsc_env' = hsc_env{ hsc_dflags = dflags' }
193 maybe_stuff <- hscStmt hsc_env' expr
196 Nothing -> return RunFailed
197 Just (ids, hval) -> do
199 withBreakAction (isStep step) dflags' breakMVar statusMVar $ do
201 let thing_to_run = unsafeCoerce# hval :: IO [HValue]
202 status <- sandboxIO statusMVar thing_to_run
204 let ic = hsc_IC hsc_env
205 bindings = (ic_tmp_ids ic, ic_tyvars ic)
209 traceRunStatus expr ref bindings ids
210 breakMVar statusMVar status emptyHistory
212 handleRunStatus expr ref bindings ids
213 breakMVar statusMVar status emptyHistory
216 emptyHistory = nilBL 50 -- keep a log of length 50
218 handleRunStatus expr ref bindings final_ids breakMVar statusMVar status
221 -- did we hit a breakpoint or did we complete?
222 (Break is_exception apStack info tid) -> do
223 hsc_env <- readIORef ref
224 let mb_info | is_exception = Nothing
225 | otherwise = Just info
226 (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env
229 resume = Resume expr tid breakMVar statusMVar
230 bindings final_ids apStack mb_info span
232 hsc_env2 = pushResume hsc_env1 resume
234 writeIORef ref hsc_env2
235 return (RunBreak tid names mb_info)
236 (Complete either_hvals) ->
238 Left e -> return (RunException e)
240 hsc_env <- readIORef ref
241 let final_ic = extendInteractiveContext (hsc_IC hsc_env)
242 final_ids emptyVarSet
243 -- the bound Ids never have any free TyVars
244 final_names = map idName final_ids
245 Linker.extendLinkEnv (zip final_names hvals)
246 hsc_env' <- rttiEnvironment hsc_env{hsc_IC=final_ic}
247 writeIORef ref hsc_env'
248 return (RunOk final_names)
251 traceRunStatus expr ref bindings final_ids
252 breakMVar statusMVar status history = do
253 hsc_env <- readIORef ref
255 -- when tracing, if we hit a breakpoint that is not explicitly
256 -- enabled, then we just log the event in the history and continue.
257 (Break is_exception apStack info tid) | not is_exception -> do
258 b <- isBreakEnabled hsc_env info
262 let history' = mkHistory hsc_env apStack info `consBL` history
263 -- probably better make history strict here, otherwise
264 -- our BoundedList will be pointless.
266 status <- withBreakAction True (hsc_dflags hsc_env)
267 breakMVar statusMVar $ do
269 (do putMVar breakMVar () -- awaken the stopped thread
271 (takeMVar statusMVar) -- and wait for the result
272 traceRunStatus expr ref bindings final_ids
273 breakMVar statusMVar status history'
277 handle_normally = handleRunStatus expr ref bindings final_ids
278 breakMVar statusMVar status history
281 isBreakEnabled :: HscEnv -> BreakInfo -> IO Bool
282 isBreakEnabled hsc_env inf =
283 case lookupUFM (hsc_HPT hsc_env) (moduleName (breakInfo_module inf)) of
285 w <- getBreak (modBreaks_flags (md_modBreaks (hm_details hmi)))
286 (breakInfo_number inf)
287 case w of Just n -> return (n /= 0); _other -> return False
292 foreign import ccall "&rts_stop_next_breakpoint" stepFlag :: Ptr CInt
293 foreign import ccall "&rts_stop_on_exception" exceptionFlag :: Ptr CInt
295 setStepFlag = poke stepFlag 1
296 resetStepFlag = poke stepFlag 0
298 -- this points to the IO action that is executed when a breakpoint is hit
299 foreign import ccall "&rts_breakpoint_io_action"
300 breakPointIOAction :: Ptr (StablePtr (Bool -> BreakInfo -> HValue -> IO ()))
302 -- When running a computation, we redirect ^C exceptions to the running
303 -- thread. ToDo: we might want a way to continue even if the target
304 -- thread doesn't die when it receives the exception... "this thread
305 -- is not responding".
306 sandboxIO :: MVar Status -> IO [HValue] -> IO Status
307 sandboxIO statusMVar thing =
309 (forkIO (do res <- Exception.try (rethrow thing)
310 putMVar statusMVar (Complete res)))
311 (takeMVar statusMVar)
313 -- We want to turn ^C into a break when -fbreak-on-exception is on,
314 -- but it's an async exception and we only break for sync exceptions.
315 -- Idea: if we catch and re-throw it, then the re-throw will trigger
316 -- a break. Great - but we don't want to re-throw all exceptions, because
317 -- then we'll get a double break for ordinary sync exceptions (you'd have
318 -- to :continue twice, which looks strange). So if the exception is
319 -- not "Interrupted", we unset the exception flag before throwing.
321 rethrow :: IO a -> IO a
322 rethrow io = Exception.catch io $ \e -> -- NB. not catchDyn
324 DynException d | Just Interrupted <- fromDynamic d
325 -> Exception.throwIO e
326 _ -> do poke exceptionFlag 0; Exception.throwIO e
329 withInterruptsSentTo :: IO ThreadId -> IO r -> IO r
330 withInterruptsSentTo io get_result = do
331 ts <- takeMVar interruptTargetThread
333 putMVar interruptTargetThread (child:ts)
334 get_result `finally` modifyMVar_ interruptTargetThread (return.tail)
336 -- This function sets up the interpreter for catching breakpoints, and
337 -- resets everything when the computation has stopped running. This
338 -- is a not-very-good way to ensure that only the interactive
339 -- evaluation should generate breakpoints.
340 withBreakAction step dflags breakMVar statusMVar io
341 = bracket setBreakAction resetBreakAction (\_ -> io)
344 stablePtr <- newStablePtr onBreak
345 poke breakPointIOAction stablePtr
346 when (dopt Opt_BreakOnException dflags) $ poke exceptionFlag 1
347 when step $ setStepFlag
349 -- Breaking on exceptions is not enabled by default, since it
350 -- might be a bit surprising. The exception flag is turned off
351 -- as soon as it is hit, or in resetBreakAction below.
353 onBreak is_exception info apStack = do
355 putMVar statusMVar (Break is_exception apStack info tid)
358 resetBreakAction stablePtr = do
359 poke breakPointIOAction noBreakStablePtr
362 freeStablePtr stablePtr
364 noBreakStablePtr = unsafePerformIO $ newStablePtr noBreakAction
366 noBreakAction False info apStack = putStrLn "*** Ignoring breakpoint"
367 noBreakAction True info apStack = return () -- exception: just continue
369 resume :: Session -> SingleStep -> IO RunResult
370 resume (Session ref) step
372 hsc_env <- readIORef ref
373 let ic = hsc_IC hsc_env
374 resume = ic_resume ic
377 [] -> throwDyn (ProgramError "not stopped at a breakpoint")
379 -- unbind the temporary locals by restoring the TypeEnv from
380 -- before the breakpoint, and drop this Resume from the
381 -- InteractiveContext.
382 let (resume_tmp_ids, resume_tyvars) = resumeBindings r
383 ic' = ic { ic_tmp_ids = resume_tmp_ids,
384 ic_tyvars = resume_tyvars,
386 writeIORef ref hsc_env{ hsc_IC = ic' }
388 -- remove any bindings created since the breakpoint from the
389 -- linker's environment
390 let new_names = map idName (filter (`notElem` resume_tmp_ids)
392 Linker.deleteFromLinkEnv new_names
394 when (isStep step) $ setStepFlag
396 Resume expr tid breakMVar statusMVar bindings
397 final_ids apStack info _ hist _ -> do
398 withBreakAction (isStep step) (hsc_dflags hsc_env)
399 breakMVar statusMVar $ do
400 status <- withInterruptsSentTo
401 (do putMVar breakMVar ()
402 -- this awakens the stopped thread...
404 (takeMVar statusMVar)
405 -- and wait for the result
408 Nothing -> fromListBL 50 hist
409 Just i -> mkHistory hsc_env apStack i `consBL`
413 traceRunStatus expr ref bindings final_ids
414 breakMVar statusMVar status hist'
416 handleRunStatus expr ref bindings final_ids
417 breakMVar statusMVar status hist'
420 back :: Session -> IO ([Name], Int, SrcSpan)
423 forward :: Session -> IO ([Name], Int, SrcSpan)
424 forward = moveHist (subtract 1)
426 moveHist fn (Session ref) = do
427 hsc_env <- readIORef ref
428 case ic_resume (hsc_IC hsc_env) of
429 [] -> throwDyn (ProgramError "not stopped at a breakpoint")
431 let ix = resumeHistoryIx r
432 history = resumeHistory r
435 when (new_ix > length history) $
436 throwDyn (ProgramError "no more logged breakpoints")
438 throwDyn (ProgramError "already at the beginning of the history")
441 update_ic apStack mb_info = do
442 (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env
444 let ic = hsc_IC hsc_env1
445 r' = r { resumeHistoryIx = new_ix }
446 ic' = ic { ic_resume = r':rs }
448 writeIORef ref hsc_env1{ hsc_IC = ic' }
450 return (names, new_ix, span)
452 -- careful: we want apStack to be the AP_STACK itself, not a thunk
453 -- around it, hence the cases are carefully constructed below to
454 -- make this the case. ToDo: this is v. fragile, do something better.
457 Resume { resumeApStack = apStack,
458 resumeBreakInfo = mb_info } ->
459 update_ic apStack mb_info
460 else case history !! (new_ix - 1) of
461 History apStack info _ ->
462 update_ic apStack (Just info)
464 -- -----------------------------------------------------------------------------
465 -- After stopping at a breakpoint, add free variables to the environment
466 result_fs = FSLIT("_result")
468 bindLocalsAtBreakpoint
472 -> IO (HscEnv, [Name], SrcSpan)
474 -- Nothing case: we stopped when an exception was raised, not at a
475 -- breakpoint. We have no location information or local variables to
476 -- bind, all we can do is bind a local variable to the exception
478 bindLocalsAtBreakpoint hsc_env apStack Nothing = do
479 let exn_fs = FSLIT("_exception")
480 exn_name = mkInternalName (getUnique exn_fs) (mkVarOccFS exn_fs) span
482 e_name = mkInternalName (getUnique e_fs) (mkTyVarOcc e_fs) span
483 e_tyvar = mkTcTyVar e_name liftedTypeKind (SkolemTv RuntimeUnkSkol)
484 exn_id = Id.mkGlobalId VanillaGlobal exn_name (mkTyVarTy e_tyvar)
486 new_tyvars = unitVarSet e_tyvar
488 ictxt0 = hsc_IC hsc_env
489 ictxt1 = extendInteractiveContext ictxt0 [exn_id] new_tyvars
491 span = mkGeneralSrcSpan FSLIT("<exception thrown>")
493 Linker.extendLinkEnv [(exn_name, unsafeCoerce# apStack)]
494 return (hsc_env{ hsc_IC = ictxt1 }, [exn_name], span)
496 -- Just case: we stopped at a breakpoint, we have information about the location
497 -- of the breakpoint and the free variables of the expression.
498 bindLocalsAtBreakpoint hsc_env apStack (Just info) = do
501 mod_name = moduleName (breakInfo_module info)
502 mod_details = fmap hm_details (lookupUFM (hsc_HPT hsc_env) mod_name)
503 breaks = md_modBreaks (expectJust "handlRunStatus" mod_details)
504 index = breakInfo_number info
505 vars = breakInfo_vars info
506 result_ty = breakInfo_resty info
507 occs = modBreaks_vars breaks ! index
508 span = modBreaks_locs breaks ! index
510 -- filter out any unboxed ids; we can't bind these at the prompt
511 let pointers = filter (\(id,_) -> isPointer id) vars
512 isPointer id | PtrRep <- idPrimRep id = True
515 let (ids, offsets) = unzip pointers
517 -- It might be that getIdValFromApStack fails, because the AP_STACK
518 -- has been accidentally evaluated, or something else has gone wrong.
519 -- So that we don't fall over in a heap when this happens, just don't
520 -- bind any free variables instead, and we emit a warning.
521 mb_hValues <- mapM (getIdValFromApStack apStack) offsets
522 let (filtered_hvs, filtered_ids) =
523 unzip [ (hv, id) | (id, Just hv) <- zip ids mb_hValues ]
524 when (any isNothing mb_hValues) $
525 debugTraceMsg (hsc_dflags hsc_env) 1 $
526 text "Warning: _result has been evaluated, some bindings have been lost"
528 new_ids <- zipWithM mkNewId occs filtered_ids
529 let names = map idName new_ids
531 -- make an Id for _result. We use the Unique of the FastString "_result";
532 -- we don't care about uniqueness here, because there will only be one
533 -- _result in scope at any time.
534 let result_name = mkInternalName (getUnique result_fs)
535 (mkVarOccFS result_fs) span
536 result_id = Id.mkGlobalId VanillaGlobal result_name result_ty
539 -- for each Id we're about to bind in the local envt:
540 -- - skolemise the type variables in its type, so they can't
541 -- be randomly unified with other types. These type variables
542 -- can only be resolved by type reconstruction in RtClosureInspect
543 -- - tidy the type variables
544 -- - globalise the Id (Ids are supposed to be Global, apparently).
546 let all_ids | isPointer result_id = result_id : new_ids
547 | otherwise = new_ids
548 (id_tys, tyvarss) = mapAndUnzip (skolemiseTy.idType) all_ids
549 (_,tidy_tys) = tidyOpenTypes emptyTidyEnv id_tys
550 new_tyvars = unionVarSets tyvarss
551 let final_ids = zipWith setIdType all_ids tidy_tys
552 ictxt0 = hsc_IC hsc_env
553 ictxt1 = extendInteractiveContext ictxt0 final_ids new_tyvars
554 Linker.extendLinkEnv [ (name,hval) | (name, Just hval) <- zip names mb_hValues ]
555 Linker.extendLinkEnv [(result_name, unsafeCoerce# apStack)]
556 hsc_env1 <- rttiEnvironment hsc_env{ hsc_IC = ictxt1 }
557 return (hsc_env1, result_name:names, span)
559 mkNewId :: OccName -> Id -> IO Id
561 let uniq = idUnique id
562 loc = nameSrcSpan (idName id)
563 name = mkInternalName uniq occ loc
565 new_id = Id.mkGlobalId VanillaGlobal name ty (idInfo id)
568 rttiEnvironment :: HscEnv -> IO HscEnv
569 rttiEnvironment hsc_env@HscEnv{hsc_IC=ic} = do
570 let InteractiveContext{ic_tmp_ids=tmp_ids, ic_tyvars = tyvars} = ic
571 incompletelyTypedIds =
573 , not $ null [v | v <- varSetElems$ tyVarsOfType (idType id)
575 , (occNameFS.nameOccName.idName) id /= result_fs]
576 tys <- reconstructType hsc_env False `mapM` incompletelyTypedIds
577 -- map termType `fmap` (obtainTerm hsc_env False `mapM` incompletelyTypedIds)
579 let substs = [computeRTTIsubst ty ty'
580 | (ty, Just ty') <- zip (map idType incompletelyTypedIds) tys]
581 ic' = foldr (flip substInteractiveContext) ic
582 (map skolemiseSubst $ catMaybes substs)
583 return hsc_env{hsc_IC=ic'}
585 skolemiseSubst subst = subst `setTvSubstEnv`
586 mapVarEnv (fst.skolemiseTy) (getTvSubstEnv subst)
588 skolemiseTy :: Type -> (Type, TyVarSet)
589 skolemiseTy ty = (substTy subst ty, mkVarSet new_tyvars)
590 where env = mkVarEnv (zip tyvars new_tyvar_tys)
591 subst = mkTvSubst emptyInScopeSet env
592 tyvars = varSetElems (tyVarsOfType ty)
593 new_tyvars = map skolemiseTyVar tyvars
594 new_tyvar_tys = map mkTyVarTy new_tyvars
596 skolemiseTyVar :: TyVar -> TyVar
597 skolemiseTyVar tyvar = mkTcTyVar (tyVarName tyvar) (tyVarKind tyvar)
598 (SkolemTv RuntimeUnkSkol)
600 getIdValFromApStack :: HValue -> Int -> IO (Maybe HValue)
601 getIdValFromApStack apStack (I# stackDepth) = do
602 case getApStackVal# apStack (stackDepth +# 1#) of
603 -- The +1 is magic! I don't know where it comes
604 -- from, but this makes things line up. --SDM
607 0# -> return Nothing -- AP_STACK not found
608 _ -> return (Just (unsafeCoerce# result))
610 pushResume :: HscEnv -> Resume -> HscEnv
611 pushResume hsc_env resume = hsc_env { hsc_IC = ictxt1 }
613 ictxt0 = hsc_IC hsc_env
614 ictxt1 = ictxt0 { ic_resume = resume : ic_resume ictxt0 }
616 -- -----------------------------------------------------------------------------
617 -- Abandoning a resume context
619 abandon :: Session -> IO Bool
620 abandon (Session ref) = do
621 hsc_env <- readIORef ref
622 let ic = hsc_IC hsc_env
623 resume = ic_resume ic
627 writeIORef ref hsc_env{ hsc_IC = ic { ic_resume = rs } }
631 abandonAll :: Session -> IO Bool
632 abandonAll (Session ref) = do
633 hsc_env <- readIORef ref
634 let ic = hsc_IC hsc_env
635 resume = ic_resume ic
639 writeIORef ref hsc_env{ hsc_IC = ic { ic_resume = [] } }
643 -- when abandoning a computation we have to
644 -- (a) kill the thread with an async exception, so that the
645 -- computation itself is stopped, and
646 -- (b) fill in the MVar. This step is necessary because any
647 -- thunks that were under evaluation will now be updated
648 -- with the partial computation, which still ends in takeMVar,
649 -- so any attempt to evaluate one of these thunks will block
650 -- unless we fill in the MVar.
651 -- See test break010.
652 abandon_ :: Resume -> IO ()
654 killThread (resumeThreadId r)
655 putMVar (resumeBreakMVar r) ()
657 -- -----------------------------------------------------------------------------
658 -- Bounded list, optimised for repeated cons
660 data BoundedList a = BL
661 {-# UNPACK #-} !Int -- length
662 {-# UNPACK #-} !Int -- bound
664 [a] -- right, list is (left ++ reverse right)
666 nilBL :: Int -> BoundedList a
667 nilBL bound = BL 0 bound [] []
669 consBL a (BL len bound left right)
670 | len < bound = BL (len+1) bound (a:left) right
671 | null right = BL len bound [a] $! tail (reverse left)
672 | otherwise = BL len bound (a:left) $! tail right
674 toListBL (BL _ _ left right) = left ++ reverse right
676 fromListBL bound l = BL (length l) bound l []
678 -- lenBL (BL len _ _ _) = len
680 -- -----------------------------------------------------------------------------
681 -- | Set the interactive evaluation context.
683 -- Setting the context doesn't throw away any bindings; the bindings
684 -- we've built up in the InteractiveContext simply move to the new
685 -- module. They always shadow anything in scope in the current context.
686 setContext :: Session
687 -> [Module] -- entire top level scope of these modules
688 -> [Module] -- exports only of these modules
690 setContext sess@(Session ref) toplev_mods export_mods = do
691 hsc_env <- readIORef ref
692 let old_ic = hsc_IC hsc_env
693 hpt = hsc_HPT hsc_env
695 export_env <- mkExportEnv hsc_env export_mods
696 toplev_envs <- mapM (mkTopLevEnv hpt) toplev_mods
697 let all_env = foldr plusGlobalRdrEnv export_env toplev_envs
698 writeIORef ref hsc_env{ hsc_IC = old_ic { ic_toplev_scope = toplev_mods,
699 ic_exports = export_mods,
700 ic_rn_gbl_env = all_env }}
702 -- Make a GlobalRdrEnv based on the exports of the modules only.
703 mkExportEnv :: HscEnv -> [Module] -> IO GlobalRdrEnv
704 mkExportEnv hsc_env mods = do
705 stuff <- mapM (getModuleExports hsc_env) mods
707 (_msgs, mb_name_sets) = unzip stuff
708 gres = [ nameSetToGlobalRdrEnv (availsToNameSet avails) (moduleName mod)
709 | (Just avails, mod) <- zip mb_name_sets mods ]
711 return $! foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres
713 nameSetToGlobalRdrEnv :: NameSet -> ModuleName -> GlobalRdrEnv
714 nameSetToGlobalRdrEnv names mod =
715 mkGlobalRdrEnv [ GRE { gre_name = name, gre_par = NoParent, gre_prov = vanillaProv mod }
716 | name <- nameSetToList names ]
718 vanillaProv :: ModuleName -> Provenance
719 -- We're building a GlobalRdrEnv as if the user imported
720 -- all the specified modules into the global interactive module
721 vanillaProv mod_name = Imported [ImpSpec { is_decl = decl, is_item = ImpAll}]
723 decl = ImpDeclSpec { is_mod = mod_name, is_as = mod_name,
725 is_dloc = srcLocSpan interactiveSrcLoc }
727 mkTopLevEnv :: HomePackageTable -> Module -> IO GlobalRdrEnv
729 = case lookupUFM hpt (moduleName modl) of
730 Nothing -> throwDyn (ProgramError ("mkTopLevEnv: not a home module " ++
731 showSDoc (ppr modl)))
733 case mi_globals (hm_iface details) of
735 throwDyn (ProgramError ("mkTopLevEnv: not interpreted "
736 ++ showSDoc (ppr modl)))
737 Just env -> return env
739 -- | Get the interactive evaluation context, consisting of a pair of the
740 -- set of modules from which we take the full top-level scope, and the set
741 -- of modules from which we take just the exports respectively.
742 getContext :: Session -> IO ([Module],[Module])
743 getContext s = withSession s (\HscEnv{ hsc_IC=ic } ->
744 return (ic_toplev_scope ic, ic_exports ic))
746 -- | Returns 'True' if the specified module is interpreted, and hence has
747 -- its full top-level scope available.
748 moduleIsInterpreted :: Session -> Module -> IO Bool
749 moduleIsInterpreted s modl = withSession s $ \h ->
750 if modulePackageId modl /= thisPackage (hsc_dflags h)
752 else case lookupUFM (hsc_HPT h) (moduleName modl) of
753 Just details -> return (isJust (mi_globals (hm_iface details)))
754 _not_a_home_module -> return False
756 -- | Looks up an identifier in the current interactive context (for :info)
757 -- Filter the instances by the ones whose tycons (or clases resp)
758 -- are in scope (qualified or otherwise). Otherwise we list a whole lot too many!
759 -- The exact choice of which ones to show, and which to hide, is a judgement call.
761 getInfo :: Session -> Name -> IO (Maybe (TyThing,Fixity,[Instance]))
763 = withSession s $ \hsc_env ->
764 do { mb_stuff <- tcRnGetInfo hsc_env name
766 Nothing -> return Nothing
767 Just (thing, fixity, ispecs) -> do
768 { let rdr_env = ic_rn_gbl_env (hsc_IC hsc_env)
769 ; return (Just (thing, fixity, filter (plausible rdr_env) ispecs)) } }
771 plausible rdr_env ispec -- Dfun involving only names that are in ic_rn_glb_env
772 = all ok $ nameSetToList $ tyClsNamesOfType $ idType $ instanceDFunId ispec
773 where -- A name is ok if it's in the rdr_env,
774 -- whether qualified or not
775 ok n | n == name = True -- The one we looked for in the first place!
776 | isBuiltInSyntax n = True
777 | isExternalName n = any ((== n) . gre_name)
778 (lookupGRE_Name rdr_env n)
781 -- | Returns all names in scope in the current interactive context
782 getNamesInScope :: Session -> IO [Name]
783 getNamesInScope s = withSession s $ \hsc_env -> do
784 return (map gre_name (globalRdrEnvElts (ic_rn_gbl_env (hsc_IC hsc_env))))
786 getRdrNamesInScope :: Session -> IO [RdrName]
787 getRdrNamesInScope s = withSession s $ \hsc_env -> do
790 gbl_rdrenv = ic_rn_gbl_env ic
792 gbl_names = concat (map greToRdrNames (globalRdrEnvElts gbl_rdrenv))
793 lcl_names = map (mkRdrUnqual.nameOccName.idName) ids
795 return (gbl_names ++ lcl_names)
798 -- ToDo: move to RdrName
799 greToRdrNames :: GlobalRdrElt -> [RdrName]
800 greToRdrNames GRE{ gre_name = name, gre_prov = prov }
803 Imported specs -> concat (map do_spec (map is_decl specs))
805 occ = nameOccName name
808 | is_qual decl_spec = [qual]
809 | otherwise = [unqual,qual]
810 where qual = Qual (is_as decl_spec) occ
812 -- | Parses a string as an identifier, and returns the list of 'Name's that
813 -- the identifier can refer to in the current interactive context.
814 parseName :: Session -> String -> IO [Name]
815 parseName s str = withSession s $ \hsc_env -> do
816 maybe_rdr_name <- hscParseIdentifier (hsc_dflags hsc_env) str
817 case maybe_rdr_name of
819 Just (L _ rdr_name) -> do
820 mb_names <- tcRnLookupRdrName hsc_env rdr_name
824 -- ToDo: should return error messages
826 -- | Returns the 'TyThing' for a 'Name'. The 'Name' may refer to any
827 -- entity known to GHC, including 'Name's defined using 'runStmt'.
828 lookupName :: Session -> Name -> IO (Maybe TyThing)
829 lookupName s name = withSession s $ \hsc_env -> tcRnLookupName hsc_env name
831 -- -----------------------------------------------------------------------------
832 -- Getting the type of an expression
834 -- | Get the type of an expression
835 exprType :: Session -> String -> IO (Maybe Type)
836 exprType s expr = withSession s $ \hsc_env -> do
837 maybe_stuff <- hscTcExpr hsc_env expr
839 Nothing -> return Nothing
840 Just ty -> return (Just tidy_ty)
842 tidy_ty = tidyType emptyTidyEnv ty
844 -- -----------------------------------------------------------------------------
845 -- Getting the kind of a type
847 -- | Get the kind of a type
848 typeKind :: Session -> String -> IO (Maybe Kind)
849 typeKind s str = withSession s $ \hsc_env -> do
850 maybe_stuff <- hscKcType hsc_env str
852 Nothing -> return Nothing
853 Just kind -> return (Just kind)
855 -----------------------------------------------------------------------------
856 -- cmCompileExpr: compile an expression and deliver an HValue
858 compileExpr :: Session -> String -> IO (Maybe HValue)
859 compileExpr s expr = withSession s $ \hsc_env -> do
860 maybe_stuff <- hscStmt hsc_env ("let __cmCompileExpr = "++expr)
862 Nothing -> return Nothing
863 Just (ids, hval) -> do
865 hvals <- (unsafeCoerce# hval) :: IO [HValue]
868 ([n],[hv]) -> return (Just hv)
869 _ -> panic "compileExpr"
871 -- -----------------------------------------------------------------------------
872 -- Compile an expression into a dynamic
874 dynCompileExpr :: Session -> String -> IO (Maybe Dynamic)
875 dynCompileExpr ses expr = do
876 (full,exports) <- getContext ses
877 setContext ses full $
879 (stringToPackageId "base") (mkModuleName "Data.Dynamic")
881 let stmt = "let __dynCompileExpr = Data.Dynamic.toDyn (" ++ expr ++ ")"
882 res <- withSession ses (flip hscStmt stmt)
883 setContext ses full exports
885 Nothing -> return Nothing
886 Just (ids, hvals) -> do
887 vals <- (unsafeCoerce# hvals :: IO [Dynamic])
889 (_:[], v:[]) -> return (Just v)
890 _ -> panic "dynCompileExpr"
892 -----------------------------------------------------------------------------
893 -- show a module and it's source/object filenames
895 showModule :: Session -> ModSummary -> IO String
896 showModule s mod_summary = withSession s $ \hsc_env ->
897 isModuleInterpreted s mod_summary >>= \interpreted ->
898 return (showModMsg (hscTarget(hsc_dflags hsc_env)) interpreted mod_summary)
900 isModuleInterpreted :: Session -> ModSummary -> IO Bool
901 isModuleInterpreted s mod_summary = withSession s $ \hsc_env ->
902 case lookupUFM (hsc_HPT hsc_env) (ms_mod_name mod_summary) of
903 Nothing -> panic "missing linkable"
904 Just mod_info -> return (not obj_linkable)
906 obj_linkable = isObjectLinkable (expectJust "showModule" (hm_linkable mod_info))
908 ----------------------------------------------------------------------------
911 obtainTerm1 :: HscEnv -> Bool -> Maybe Type -> a -> IO Term
912 obtainTerm1 hsc_env force mb_ty x =
913 cvObtainTerm hsc_env maxBound force mb_ty (unsafeCoerce# x)
915 obtainTermB :: HscEnv -> Int -> Bool -> Id -> IO Term
916 obtainTermB hsc_env bound force id = do
917 hv <- Linker.getHValue hsc_env (varName id)
918 cvObtainTerm hsc_env bound force (Just$ idType id) hv
920 obtainTerm :: HscEnv -> Bool -> Id -> IO Term
921 obtainTerm hsc_env force id = do
922 hv <- Linker.getHValue hsc_env (varName id)
923 cvObtainTerm hsc_env maxBound force (Just$ idType id) hv
925 -- Uses RTTI to reconstruct the type of an Id, making it less polymorphic
926 reconstructType :: HscEnv -> Bool -> Id -> IO (Maybe Type)
927 reconstructType hsc_env force id = do
928 hv <- Linker.getHValue hsc_env (varName id)
929 cvReconstructType hsc_env force (Just$ idType id) hv