1 -- -----------------------------------------------------------------------------
3 -- (c) The University of Glasgow, 2005-2007
5 -- Running statements interactively
7 -- -----------------------------------------------------------------------------
10 -- The above warning supression flag is a temporary kludge.
11 -- While working on this module you are encouraged to remove it and fix
12 -- any warnings in the module. See
13 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
16 module InteractiveEval (
18 RunResult(..), Status(..), Resume(..), History(..),
19 runStmt, SingleStep(..),
26 setContext, getContext,
27 nameSetToGlobalRdrEnv,
37 compileExpr, dynCompileExpr,
39 Term(..), obtainTerm, obtainTerm1, obtainTermB, reconstructType,
40 skolemiseSubst, skolemiseTy
46 #include "HsVersions.h"
48 import HscMain hiding (compileExpr)
51 import Type hiding (typeKind)
52 import TcType hiding (typeKind)
54 import Var hiding (setIdType)
57 import Name hiding ( varName )
74 import RtClosureInspect
80 import Data.List (find)
86 import Control.Exception as Exception
87 import Control.Concurrent
88 import Data.List (sortBy)
90 import Foreign.StablePtr
92 -- -----------------------------------------------------------------------------
93 -- running a statement interactively
96 = RunOk [Name] -- ^ names bound by this evaluation
97 | RunFailed -- ^ statement failed compilation
98 | RunException Exception -- ^ statement raised an exception
99 | RunBreak ThreadId [Name] (Maybe BreakInfo)
102 = Break Bool HValue BreakInfo ThreadId
103 -- ^ the computation hit a breakpoint (Bool <=> was an exception)
104 | Complete (Either Exception [HValue])
105 -- ^ the computation completed with either an exception or a value
109 resumeStmt :: String, -- the original statement
110 resumeThreadId :: ThreadId, -- thread running the computation
111 resumeBreakMVar :: MVar (),
112 resumeStatMVar :: MVar Status,
113 resumeBindings :: ([Id], TyVarSet),
114 resumeFinalIds :: [Id], -- [Id] to bind on completion
115 resumeApStack :: HValue, -- The object from which we can get
116 -- value of the free variables.
117 resumeBreakInfo :: Maybe BreakInfo,
118 -- the breakpoint we stopped at
119 -- (Nothing <=> exception)
120 resumeSpan :: SrcSpan, -- just a cache, otherwise it's a pain
121 -- to fetch the ModDetails & ModBreaks
123 resumeHistory :: [History],
124 resumeHistoryIx :: Int -- 0 <==> at the top of the history
127 getResumeContext :: Session -> IO [Resume]
128 getResumeContext s = withSession s (return . ic_resume . hsc_IC)
135 isStep RunToCompletion = False
140 historyApStack :: HValue,
141 historyBreakInfo :: BreakInfo,
142 historyEnclosingDecl :: Id
143 -- ^^ A cache of the enclosing top level declaration, for convenience
146 mkHistory :: HscEnv -> HValue -> BreakInfo -> History
147 mkHistory hsc_env hval bi = let
148 h = History hval bi decl
149 decl = findEnclosingDecl hsc_env (getHistoryModule h)
150 (getHistorySpan hsc_env h)
153 getHistoryModule :: History -> Module
154 getHistoryModule = breakInfo_module . historyBreakInfo
156 getHistorySpan :: HscEnv -> History -> SrcSpan
157 getHistorySpan hsc_env hist =
158 let inf = historyBreakInfo hist
159 num = breakInfo_number inf
160 in case lookupUFM (hsc_HPT hsc_env) (moduleName (breakInfo_module inf)) of
161 Just hmi -> modBreaks_locs (md_modBreaks (hm_details hmi)) ! num
162 _ -> panic "getHistorySpan"
164 {- | Finds the enclosing top level function name -}
165 -- ToDo: a better way to do this would be to keep hold of the decl_path computed
166 -- by the coverage pass, which gives the list of lexically-enclosing bindings
168 findEnclosingDecl :: HscEnv -> Module -> SrcSpan -> Id
169 findEnclosingDecl hsc_env mod span =
170 case lookupUFM (hsc_HPT hsc_env) (moduleName mod) of
171 Nothing -> panic "findEnclosingDecl"
173 globals = typeEnvIds (md_types (hm_details hmi))
175 find (\id -> let n = idName id in
176 nameSrcSpan n < span && isExternalName n)
177 (reverse$ sortBy (compare `on` (nameSrcSpan.idName))
181 -- | Run a statement in the current interactive context. Statement
182 -- may bind multple values.
183 runStmt :: Session -> String -> SingleStep -> IO RunResult
184 runStmt (Session ref) expr step
186 hsc_env <- readIORef ref
188 breakMVar <- newEmptyMVar -- wait on this when we hit a breakpoint
189 statusMVar <- newEmptyMVar -- wait on this when a computation is running
191 -- Turn off -fwarn-unused-bindings when running a statement, to hide
192 -- warnings about the implicit bindings we introduce.
193 let dflags' = dopt_unset (hsc_dflags hsc_env) Opt_WarnUnusedBinds
194 hsc_env' = hsc_env{ hsc_dflags = dflags' }
196 maybe_stuff <- hscStmt hsc_env' expr
199 Nothing -> return RunFailed
200 Just (ids, hval) -> do
202 withBreakAction (isStep step) dflags' breakMVar statusMVar $ do
204 let thing_to_run = unsafeCoerce# hval :: IO [HValue]
205 status <- sandboxIO statusMVar thing_to_run
207 let ic = hsc_IC hsc_env
208 bindings = (ic_tmp_ids ic, ic_tyvars ic)
212 traceRunStatus expr ref bindings ids
213 breakMVar statusMVar status emptyHistory
215 handleRunStatus expr ref bindings ids
216 breakMVar statusMVar status emptyHistory
219 emptyHistory = nilBL 50 -- keep a log of length 50
221 handleRunStatus expr ref bindings final_ids breakMVar statusMVar status
224 -- did we hit a breakpoint or did we complete?
225 (Break is_exception apStack info tid) -> do
226 hsc_env <- readIORef ref
227 let mb_info | is_exception = Nothing
228 | otherwise = Just info
229 (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env
232 resume = Resume expr tid breakMVar statusMVar
233 bindings final_ids apStack mb_info span
235 hsc_env2 = pushResume hsc_env1 resume
237 writeIORef ref hsc_env2
238 return (RunBreak tid names mb_info)
239 (Complete either_hvals) ->
241 Left e -> return (RunException e)
243 hsc_env <- readIORef ref
244 let final_ic = extendInteractiveContext (hsc_IC hsc_env)
245 final_ids emptyVarSet
246 -- the bound Ids never have any free TyVars
247 final_names = map idName final_ids
248 Linker.extendLinkEnv (zip final_names hvals)
249 hsc_env' <- rttiEnvironment hsc_env{hsc_IC=final_ic}
250 writeIORef ref hsc_env'
251 return (RunOk final_names)
254 traceRunStatus expr ref bindings final_ids
255 breakMVar statusMVar status history = do
256 hsc_env <- readIORef ref
258 -- when tracing, if we hit a breakpoint that is not explicitly
259 -- enabled, then we just log the event in the history and continue.
260 (Break is_exception apStack info tid) | not is_exception -> do
261 b <- isBreakEnabled hsc_env info
265 let history' = mkHistory hsc_env apStack info `consBL` history
266 -- probably better make history strict here, otherwise
267 -- our BoundedList will be pointless.
269 status <- withBreakAction True (hsc_dflags hsc_env)
270 breakMVar statusMVar $ do
272 (do putMVar breakMVar () -- awaken the stopped thread
274 (takeMVar statusMVar) -- and wait for the result
275 traceRunStatus expr ref bindings final_ids
276 breakMVar statusMVar status history'
280 handle_normally = handleRunStatus expr ref bindings final_ids
281 breakMVar statusMVar status history
284 isBreakEnabled :: HscEnv -> BreakInfo -> IO Bool
285 isBreakEnabled hsc_env inf =
286 case lookupUFM (hsc_HPT hsc_env) (moduleName (breakInfo_module inf)) of
288 w <- getBreak (modBreaks_flags (md_modBreaks (hm_details hmi)))
289 (breakInfo_number inf)
290 case w of Just n -> return (n /= 0); _other -> return False
295 foreign import ccall "&rts_stop_next_breakpoint" stepFlag :: Ptr CInt
296 foreign import ccall "&rts_stop_on_exception" exceptionFlag :: Ptr CInt
298 setStepFlag = poke stepFlag 1
299 resetStepFlag = poke stepFlag 0
301 -- this points to the IO action that is executed when a breakpoint is hit
302 foreign import ccall "&rts_breakpoint_io_action"
303 breakPointIOAction :: Ptr (StablePtr (Bool -> BreakInfo -> HValue -> IO ()))
305 -- When running a computation, we redirect ^C exceptions to the running
306 -- thread. ToDo: we might want a way to continue even if the target
307 -- thread doesn't die when it receives the exception... "this thread
308 -- is not responding".
309 sandboxIO :: MVar Status -> IO [HValue] -> IO Status
310 sandboxIO statusMVar thing =
312 (forkIO (do res <- Exception.try (rethrow thing)
313 putMVar statusMVar (Complete res)))
314 (takeMVar statusMVar)
316 -- We want to turn ^C into a break when -fbreak-on-exception is on,
317 -- but it's an async exception and we only break for sync exceptions.
318 -- Idea: if we catch and re-throw it, then the re-throw will trigger
319 -- a break. Great - but we don't want to re-throw all exceptions, because
320 -- then we'll get a double break for ordinary sync exceptions (you'd have
321 -- to :continue twice, which looks strange). So if the exception is
322 -- not "Interrupted", we unset the exception flag before throwing.
324 rethrow :: IO a -> IO a
325 rethrow io = Exception.catch io $ \e -> -- NB. not catchDyn
327 DynException d | Just Interrupted <- fromDynamic d
328 -> Exception.throwIO e
329 _ -> do poke exceptionFlag 0; Exception.throwIO e
332 withInterruptsSentTo :: IO ThreadId -> IO r -> IO r
333 withInterruptsSentTo io get_result = do
334 ts <- takeMVar interruptTargetThread
336 putMVar interruptTargetThread (child:ts)
337 get_result `finally` modifyMVar_ interruptTargetThread (return.tail)
339 -- This function sets up the interpreter for catching breakpoints, and
340 -- resets everything when the computation has stopped running. This
341 -- is a not-very-good way to ensure that only the interactive
342 -- evaluation should generate breakpoints.
343 withBreakAction step dflags breakMVar statusMVar io
344 = bracket setBreakAction resetBreakAction (\_ -> io)
347 stablePtr <- newStablePtr onBreak
348 poke breakPointIOAction stablePtr
349 when (dopt Opt_BreakOnException dflags) $ poke exceptionFlag 1
350 when step $ setStepFlag
352 -- Breaking on exceptions is not enabled by default, since it
353 -- might be a bit surprising. The exception flag is turned off
354 -- as soon as it is hit, or in resetBreakAction below.
356 onBreak is_exception info apStack = do
358 putMVar statusMVar (Break is_exception apStack info tid)
361 resetBreakAction stablePtr = do
362 poke breakPointIOAction noBreakStablePtr
365 freeStablePtr stablePtr
367 noBreakStablePtr = unsafePerformIO $ newStablePtr noBreakAction
369 noBreakAction False info apStack = putStrLn "*** Ignoring breakpoint"
370 noBreakAction True info apStack = return () -- exception: just continue
372 resume :: Session -> SingleStep -> IO RunResult
373 resume (Session ref) step
375 hsc_env <- readIORef ref
376 let ic = hsc_IC hsc_env
377 resume = ic_resume ic
380 [] -> throwDyn (ProgramError "not stopped at a breakpoint")
382 -- unbind the temporary locals by restoring the TypeEnv from
383 -- before the breakpoint, and drop this Resume from the
384 -- InteractiveContext.
385 let (resume_tmp_ids, resume_tyvars) = resumeBindings r
386 ic' = ic { ic_tmp_ids = resume_tmp_ids,
387 ic_tyvars = resume_tyvars,
389 writeIORef ref hsc_env{ hsc_IC = ic' }
391 -- remove any bindings created since the breakpoint from the
392 -- linker's environment
393 let new_names = map idName (filter (`notElem` resume_tmp_ids)
395 Linker.deleteFromLinkEnv new_names
397 when (isStep step) $ setStepFlag
399 Resume expr tid breakMVar statusMVar bindings
400 final_ids apStack info _ hist _ -> do
401 withBreakAction (isStep step) (hsc_dflags hsc_env)
402 breakMVar statusMVar $ do
403 status <- withInterruptsSentTo
404 (do putMVar breakMVar ()
405 -- this awakens the stopped thread...
407 (takeMVar statusMVar)
408 -- and wait for the result
411 Nothing -> fromListBL 50 hist
412 Just i -> mkHistory hsc_env apStack i `consBL`
416 traceRunStatus expr ref bindings final_ids
417 breakMVar statusMVar status hist'
419 handleRunStatus expr ref bindings final_ids
420 breakMVar statusMVar status hist'
423 back :: Session -> IO ([Name], Int, SrcSpan)
426 forward :: Session -> IO ([Name], Int, SrcSpan)
427 forward = moveHist (subtract 1)
429 moveHist fn (Session ref) = do
430 hsc_env <- readIORef ref
431 case ic_resume (hsc_IC hsc_env) of
432 [] -> throwDyn (ProgramError "not stopped at a breakpoint")
434 let ix = resumeHistoryIx r
435 history = resumeHistory r
438 when (new_ix > length history) $
439 throwDyn (ProgramError "no more logged breakpoints")
441 throwDyn (ProgramError "already at the beginning of the history")
444 update_ic apStack mb_info = do
445 (hsc_env1, names, span) <- bindLocalsAtBreakpoint hsc_env
447 let ic = hsc_IC hsc_env1
448 r' = r { resumeHistoryIx = new_ix }
449 ic' = ic { ic_resume = r':rs }
451 writeIORef ref hsc_env1{ hsc_IC = ic' }
453 return (names, new_ix, span)
455 -- careful: we want apStack to be the AP_STACK itself, not a thunk
456 -- around it, hence the cases are carefully constructed below to
457 -- make this the case. ToDo: this is v. fragile, do something better.
460 Resume { resumeApStack = apStack,
461 resumeBreakInfo = mb_info } ->
462 update_ic apStack mb_info
463 else case history !! (new_ix - 1) of
464 History apStack info _ ->
465 update_ic apStack (Just info)
467 -- -----------------------------------------------------------------------------
468 -- After stopping at a breakpoint, add free variables to the environment
469 result_fs = FSLIT("_result")
471 bindLocalsAtBreakpoint
475 -> IO (HscEnv, [Name], SrcSpan)
477 -- Nothing case: we stopped when an exception was raised, not at a
478 -- breakpoint. We have no location information or local variables to
479 -- bind, all we can do is bind a local variable to the exception
481 bindLocalsAtBreakpoint hsc_env apStack Nothing = do
482 let exn_fs = FSLIT("_exception")
483 exn_name = mkInternalName (getUnique exn_fs) (mkVarOccFS exn_fs) span
485 e_name = mkInternalName (getUnique e_fs) (mkTyVarOcc e_fs) span
486 e_tyvar = mkTcTyVar e_name liftedTypeKind (SkolemTv RuntimeUnkSkol)
487 exn_id = Id.mkGlobalId VanillaGlobal exn_name (mkTyVarTy e_tyvar)
489 new_tyvars = unitVarSet e_tyvar
491 ictxt0 = hsc_IC hsc_env
492 ictxt1 = extendInteractiveContext ictxt0 [exn_id] new_tyvars
494 span = mkGeneralSrcSpan FSLIT("<exception thrown>")
496 Linker.extendLinkEnv [(exn_name, unsafeCoerce# apStack)]
497 return (hsc_env{ hsc_IC = ictxt1 }, [exn_name], span)
499 -- Just case: we stopped at a breakpoint, we have information about the location
500 -- of the breakpoint and the free variables of the expression.
501 bindLocalsAtBreakpoint hsc_env apStack (Just info) = do
504 mod_name = moduleName (breakInfo_module info)
505 mod_details = fmap hm_details (lookupUFM (hsc_HPT hsc_env) mod_name)
506 breaks = md_modBreaks (expectJust "handlRunStatus" mod_details)
507 index = breakInfo_number info
508 vars = breakInfo_vars info
509 result_ty = breakInfo_resty info
510 occs = modBreaks_vars breaks ! index
511 span = modBreaks_locs breaks ! index
513 -- filter out any unboxed ids; we can't bind these at the prompt
514 let pointers = filter (\(id,_) -> isPointer id) vars
515 isPointer id | PtrRep <- idPrimRep id = True
518 let (ids, offsets) = unzip pointers
520 -- It might be that getIdValFromApStack fails, because the AP_STACK
521 -- has been accidentally evaluated, or something else has gone wrong.
522 -- So that we don't fall over in a heap when this happens, just don't
523 -- bind any free variables instead, and we emit a warning.
524 mb_hValues <- mapM (getIdValFromApStack apStack) offsets
525 let filtered_ids = [ id | (id, Just hv) <- zip ids mb_hValues ]
526 when (any isNothing mb_hValues) $
527 debugTraceMsg (hsc_dflags hsc_env) 1 $
528 text "Warning: _result has been evaluated, some bindings have been lost"
530 new_ids <- zipWithM mkNewId occs filtered_ids
531 let names = map idName new_ids
533 -- make an Id for _result. We use the Unique of the FastString "_result";
534 -- we don't care about uniqueness here, because there will only be one
535 -- _result in scope at any time.
536 let result_name = mkInternalName (getUnique result_fs)
537 (mkVarOccFS result_fs) span
538 result_id = Id.mkGlobalId VanillaGlobal result_name result_ty
541 -- for each Id we're about to bind in the local envt:
542 -- - skolemise the type variables in its type, so they can't
543 -- be randomly unified with other types. These type variables
544 -- can only be resolved by type reconstruction in RtClosureInspect
545 -- - tidy the type variables
546 -- - globalise the Id (Ids are supposed to be Global, apparently).
548 let all_ids | isPointer result_id = result_id : new_ids
549 | otherwise = new_ids
550 (id_tys, tyvarss) = mapAndUnzip (skolemiseTy.idType) all_ids
551 (_,tidy_tys) = tidyOpenTypes emptyTidyEnv id_tys
552 new_tyvars = unionVarSets tyvarss
553 let final_ids = zipWith setIdType all_ids tidy_tys
554 ictxt0 = hsc_IC hsc_env
555 ictxt1 = extendInteractiveContext ictxt0 final_ids new_tyvars
556 Linker.extendLinkEnv [ (name,hval) | (name, Just hval) <- zip names mb_hValues ]
557 Linker.extendLinkEnv [(result_name, unsafeCoerce# apStack)]
558 hsc_env1 <- rttiEnvironment hsc_env{ hsc_IC = ictxt1 }
559 return (hsc_env1, result_name:names, span)
561 mkNewId :: OccName -> Id -> IO Id
563 let uniq = idUnique id
564 loc = nameSrcSpan (idName id)
565 name = mkInternalName uniq occ loc
567 new_id = Id.mkGlobalId VanillaGlobal name ty (idInfo id)
570 rttiEnvironment :: HscEnv -> IO HscEnv
571 rttiEnvironment hsc_env@HscEnv{hsc_IC=ic} = do
572 let InteractiveContext{ic_tmp_ids=tmp_ids} = ic
573 incompletelyTypedIds =
575 , not $ null [v | v <- varSetElems$ tyVarsOfType (idType id)
577 , (occNameFS.nameOccName.idName) id /= result_fs]
578 tys <- reconstructType hsc_env False `mapM` incompletelyTypedIds
579 -- map termType `fmap` (obtainTerm hsc_env False `mapM` incompletelyTypedIds)
581 let substs = [computeRTTIsubst ty ty'
582 | (ty, Just ty') <- zip (map idType incompletelyTypedIds) tys]
583 ic' = foldr (flip substInteractiveContext) ic
584 (map skolemiseSubst $ catMaybes substs)
585 return hsc_env{hsc_IC=ic'}
587 skolemiseSubst subst = subst `setTvSubstEnv`
588 mapVarEnv (fst.skolemiseTy) (getTvSubstEnv subst)
590 skolemiseTy :: Type -> (Type, TyVarSet)
591 skolemiseTy ty = (substTy subst ty, mkVarSet new_tyvars)
592 where env = mkVarEnv (zip tyvars new_tyvar_tys)
593 subst = mkTvSubst emptyInScopeSet env
594 tyvars = varSetElems (tyVarsOfType ty)
595 new_tyvars = map skolemiseTyVar tyvars
596 new_tyvar_tys = map mkTyVarTy new_tyvars
598 skolemiseTyVar :: TyVar -> TyVar
599 skolemiseTyVar tyvar = mkTcTyVar (tyVarName tyvar) (tyVarKind tyvar)
600 (SkolemTv RuntimeUnkSkol)
602 getIdValFromApStack :: HValue -> Int -> IO (Maybe HValue)
603 getIdValFromApStack apStack (I# stackDepth) = do
604 case getApStackVal# apStack (stackDepth +# 1#) of
605 -- The +1 is magic! I don't know where it comes
606 -- from, but this makes things line up. --SDM
609 0# -> return Nothing -- AP_STACK not found
610 _ -> return (Just (unsafeCoerce# result))
612 pushResume :: HscEnv -> Resume -> HscEnv
613 pushResume hsc_env resume = hsc_env { hsc_IC = ictxt1 }
615 ictxt0 = hsc_IC hsc_env
616 ictxt1 = ictxt0 { ic_resume = resume : ic_resume ictxt0 }
618 -- -----------------------------------------------------------------------------
619 -- Abandoning a resume context
621 abandon :: Session -> IO Bool
622 abandon (Session ref) = do
623 hsc_env <- readIORef ref
624 let ic = hsc_IC hsc_env
625 resume = ic_resume ic
629 writeIORef ref hsc_env{ hsc_IC = ic { ic_resume = rs } }
633 abandonAll :: Session -> IO Bool
634 abandonAll (Session ref) = do
635 hsc_env <- readIORef ref
636 let ic = hsc_IC hsc_env
637 resume = ic_resume ic
641 writeIORef ref hsc_env{ hsc_IC = ic { ic_resume = [] } }
645 -- when abandoning a computation we have to
646 -- (a) kill the thread with an async exception, so that the
647 -- computation itself is stopped, and
648 -- (b) fill in the MVar. This step is necessary because any
649 -- thunks that were under evaluation will now be updated
650 -- with the partial computation, which still ends in takeMVar,
651 -- so any attempt to evaluate one of these thunks will block
652 -- unless we fill in the MVar.
653 -- See test break010.
654 abandon_ :: Resume -> IO ()
656 killThread (resumeThreadId r)
657 putMVar (resumeBreakMVar r) ()
659 -- -----------------------------------------------------------------------------
660 -- Bounded list, optimised for repeated cons
662 data BoundedList a = BL
663 {-# UNPACK #-} !Int -- length
664 {-# UNPACK #-} !Int -- bound
666 [a] -- right, list is (left ++ reverse right)
668 nilBL :: Int -> BoundedList a
669 nilBL bound = BL 0 bound [] []
671 consBL a (BL len bound left right)
672 | len < bound = BL (len+1) bound (a:left) right
673 | null right = BL len bound [a] $! tail (reverse left)
674 | otherwise = BL len bound (a:left) $! tail right
676 toListBL (BL _ _ left right) = left ++ reverse right
678 fromListBL bound l = BL (length l) bound l []
680 -- lenBL (BL len _ _ _) = len
682 -- -----------------------------------------------------------------------------
683 -- | Set the interactive evaluation context.
685 -- Setting the context doesn't throw away any bindings; the bindings
686 -- we've built up in the InteractiveContext simply move to the new
687 -- module. They always shadow anything in scope in the current context.
688 setContext :: Session
689 -> [Module] -- entire top level scope of these modules
690 -> [Module] -- exports only of these modules
692 setContext sess@(Session ref) toplev_mods export_mods = do
693 hsc_env <- readIORef ref
694 let old_ic = hsc_IC hsc_env
695 hpt = hsc_HPT hsc_env
697 export_env <- mkExportEnv hsc_env export_mods
698 toplev_envs <- mapM (mkTopLevEnv hpt) toplev_mods
699 let all_env = foldr plusGlobalRdrEnv export_env toplev_envs
700 writeIORef ref hsc_env{ hsc_IC = old_ic { ic_toplev_scope = toplev_mods,
701 ic_exports = export_mods,
702 ic_rn_gbl_env = all_env }}
704 -- Make a GlobalRdrEnv based on the exports of the modules only.
705 mkExportEnv :: HscEnv -> [Module] -> IO GlobalRdrEnv
706 mkExportEnv hsc_env mods = do
707 stuff <- mapM (getModuleExports hsc_env) mods
709 (_msgs, mb_name_sets) = unzip stuff
710 gres = [ nameSetToGlobalRdrEnv (availsToNameSet avails) (moduleName mod)
711 | (Just avails, mod) <- zip mb_name_sets mods ]
713 return $! foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres
715 nameSetToGlobalRdrEnv :: NameSet -> ModuleName -> GlobalRdrEnv
716 nameSetToGlobalRdrEnv names mod =
717 mkGlobalRdrEnv [ GRE { gre_name = name, gre_par = NoParent, gre_prov = vanillaProv mod }
718 | name <- nameSetToList names ]
720 vanillaProv :: ModuleName -> Provenance
721 -- We're building a GlobalRdrEnv as if the user imported
722 -- all the specified modules into the global interactive module
723 vanillaProv mod_name = Imported [ImpSpec { is_decl = decl, is_item = ImpAll}]
725 decl = ImpDeclSpec { is_mod = mod_name, is_as = mod_name,
727 is_dloc = srcLocSpan interactiveSrcLoc }
729 mkTopLevEnv :: HomePackageTable -> Module -> IO GlobalRdrEnv
731 = case lookupUFM hpt (moduleName modl) of
732 Nothing -> throwDyn (ProgramError ("mkTopLevEnv: not a home module " ++
733 showSDoc (ppr modl)))
735 case mi_globals (hm_iface details) of
737 throwDyn (ProgramError ("mkTopLevEnv: not interpreted "
738 ++ showSDoc (ppr modl)))
739 Just env -> return env
741 -- | Get the interactive evaluation context, consisting of a pair of the
742 -- set of modules from which we take the full top-level scope, and the set
743 -- of modules from which we take just the exports respectively.
744 getContext :: Session -> IO ([Module],[Module])
745 getContext s = withSession s (\HscEnv{ hsc_IC=ic } ->
746 return (ic_toplev_scope ic, ic_exports ic))
748 -- | Returns 'True' if the specified module is interpreted, and hence has
749 -- its full top-level scope available.
750 moduleIsInterpreted :: Session -> Module -> IO Bool
751 moduleIsInterpreted s modl = withSession s $ \h ->
752 if modulePackageId modl /= thisPackage (hsc_dflags h)
754 else case lookupUFM (hsc_HPT h) (moduleName modl) of
755 Just details -> return (isJust (mi_globals (hm_iface details)))
756 _not_a_home_module -> return False
758 -- | Looks up an identifier in the current interactive context (for :info)
759 -- Filter the instances by the ones whose tycons (or clases resp)
760 -- are in scope (qualified or otherwise). Otherwise we list a whole lot too many!
761 -- The exact choice of which ones to show, and which to hide, is a judgement call.
763 getInfo :: Session -> Name -> IO (Maybe (TyThing,Fixity,[Instance]))
765 = withSession s $ \hsc_env ->
766 do { mb_stuff <- tcRnGetInfo hsc_env name
768 Nothing -> return Nothing
769 Just (thing, fixity, ispecs) -> do
770 { let rdr_env = ic_rn_gbl_env (hsc_IC hsc_env)
771 ; return (Just (thing, fixity, filter (plausible rdr_env) ispecs)) } }
773 plausible rdr_env ispec -- Dfun involving only names that are in ic_rn_glb_env
774 = all ok $ nameSetToList $ tyClsNamesOfType $ idType $ instanceDFunId ispec
775 where -- A name is ok if it's in the rdr_env,
776 -- whether qualified or not
777 ok n | n == name = True -- The one we looked for in the first place!
778 | isBuiltInSyntax n = True
779 | isExternalName n = any ((== n) . gre_name)
780 (lookupGRE_Name rdr_env n)
783 -- | Returns all names in scope in the current interactive context
784 getNamesInScope :: Session -> IO [Name]
785 getNamesInScope s = withSession s $ \hsc_env -> do
786 return (map gre_name (globalRdrEnvElts (ic_rn_gbl_env (hsc_IC hsc_env))))
788 getRdrNamesInScope :: Session -> IO [RdrName]
789 getRdrNamesInScope s = withSession s $ \hsc_env -> do
792 gbl_rdrenv = ic_rn_gbl_env ic
794 gbl_names = concat (map greToRdrNames (globalRdrEnvElts gbl_rdrenv))
795 lcl_names = map (mkRdrUnqual.nameOccName.idName) ids
797 return (gbl_names ++ lcl_names)
800 -- ToDo: move to RdrName
801 greToRdrNames :: GlobalRdrElt -> [RdrName]
802 greToRdrNames GRE{ gre_name = name, gre_prov = prov }
805 Imported specs -> concat (map do_spec (map is_decl specs))
807 occ = nameOccName name
810 | is_qual decl_spec = [qual]
811 | otherwise = [unqual,qual]
812 where qual = Qual (is_as decl_spec) occ
814 -- | Parses a string as an identifier, and returns the list of 'Name's that
815 -- the identifier can refer to in the current interactive context.
816 parseName :: Session -> String -> IO [Name]
817 parseName s str = withSession s $ \hsc_env -> do
818 maybe_rdr_name <- hscParseIdentifier (hsc_dflags hsc_env) str
819 case maybe_rdr_name of
821 Just (L _ rdr_name) -> do
822 mb_names <- tcRnLookupRdrName hsc_env rdr_name
826 -- ToDo: should return error messages
828 -- | Returns the 'TyThing' for a 'Name'. The 'Name' may refer to any
829 -- entity known to GHC, including 'Name's defined using 'runStmt'.
830 lookupName :: Session -> Name -> IO (Maybe TyThing)
831 lookupName s name = withSession s $ \hsc_env -> tcRnLookupName hsc_env name
833 -- -----------------------------------------------------------------------------
834 -- Getting the type of an expression
836 -- | Get the type of an expression
837 exprType :: Session -> String -> IO (Maybe Type)
838 exprType s expr = withSession s $ \hsc_env -> do
839 maybe_stuff <- hscTcExpr hsc_env expr
841 Nothing -> return Nothing
842 Just ty -> return (Just tidy_ty)
844 tidy_ty = tidyType emptyTidyEnv ty
846 -- -----------------------------------------------------------------------------
847 -- Getting the kind of a type
849 -- | Get the kind of a type
850 typeKind :: Session -> String -> IO (Maybe Kind)
851 typeKind s str = withSession s $ \hsc_env -> do
852 maybe_stuff <- hscKcType hsc_env str
854 Nothing -> return Nothing
855 Just kind -> return (Just kind)
857 -----------------------------------------------------------------------------
858 -- cmCompileExpr: compile an expression and deliver an HValue
860 compileExpr :: Session -> String -> IO (Maybe HValue)
861 compileExpr s expr = withSession s $ \hsc_env -> do
862 maybe_stuff <- hscStmt hsc_env ("let __cmCompileExpr = "++expr)
864 Nothing -> return Nothing
865 Just (ids, hval) -> do
867 hvals <- (unsafeCoerce# hval) :: IO [HValue]
870 ([n],[hv]) -> return (Just hv)
871 _ -> panic "compileExpr"
873 -- -----------------------------------------------------------------------------
874 -- Compile an expression into a dynamic
876 dynCompileExpr :: Session -> String -> IO (Maybe Dynamic)
877 dynCompileExpr ses expr = do
878 (full,exports) <- getContext ses
879 setContext ses full $
881 (stringToPackageId "base") (mkModuleName "Data.Dynamic")
883 let stmt = "let __dynCompileExpr = Data.Dynamic.toDyn (" ++ expr ++ ")"
884 res <- withSession ses (flip hscStmt stmt)
885 setContext ses full exports
887 Nothing -> return Nothing
888 Just (ids, hvals) -> do
889 vals <- (unsafeCoerce# hvals :: IO [Dynamic])
891 (_:[], v:[]) -> return (Just v)
892 _ -> panic "dynCompileExpr"
894 -----------------------------------------------------------------------------
895 -- show a module and it's source/object filenames
897 showModule :: Session -> ModSummary -> IO String
898 showModule s mod_summary = withSession s $ \hsc_env ->
899 isModuleInterpreted s mod_summary >>= \interpreted ->
900 return (showModMsg (hscTarget(hsc_dflags hsc_env)) interpreted mod_summary)
902 isModuleInterpreted :: Session -> ModSummary -> IO Bool
903 isModuleInterpreted s mod_summary = withSession s $ \hsc_env ->
904 case lookupUFM (hsc_HPT hsc_env) (ms_mod_name mod_summary) of
905 Nothing -> panic "missing linkable"
906 Just mod_info -> return (not obj_linkable)
908 obj_linkable = isObjectLinkable (expectJust "showModule" (hm_linkable mod_info))
910 ----------------------------------------------------------------------------
913 obtainTerm1 :: HscEnv -> Bool -> Maybe Type -> a -> IO Term
914 obtainTerm1 hsc_env force mb_ty x =
915 cvObtainTerm hsc_env maxBound force mb_ty (unsafeCoerce# x)
917 obtainTermB :: HscEnv -> Int -> Bool -> Id -> IO Term
918 obtainTermB hsc_env bound force id = do
919 hv <- Linker.getHValue hsc_env (varName id)
920 cvObtainTerm hsc_env bound force (Just$ idType id) hv
922 obtainTerm :: HscEnv -> Bool -> Id -> IO Term
923 obtainTerm hsc_env force id = do
924 hv <- Linker.getHValue hsc_env (varName id)
925 cvObtainTerm hsc_env maxBound force (Just$ idType id) hv
927 -- Uses RTTI to reconstruct the type of an Id, making it less polymorphic
928 reconstructType :: HscEnv -> Bool -> Id -> IO (Maybe Type)
929 reconstructType hsc_env force id = do
930 hv <- Linker.getHValue hsc_env (varName id)
931 cvReconstructType hsc_env force (Just$ idType id) hv