1 -----------------------------------------------------------------------------
3 -- GHC Interactive support for inspecting arbitrary closures at runtime
5 -- Pepe Iborra (supported by Google SoC) 2006
7 -----------------------------------------------------------------------------
9 module RtClosureInspect(
11 cvObtainTerm, -- :: HscEnv -> Bool -> Maybe Type -> HValue -> IO Term
22 getClosureData, -- :: a -> IO Closure
23 Closure ( tipe, infoTable, ptrs, nonPtrs ),
24 getClosureType, -- :: a -> IO ClosureType
25 isConstr, -- :: ClosureType -> Bool
26 isIndirection, -- :: ClosureType -> Bool
27 getInfoTablePtr, -- :: a -> Ptr StgInfoTable
44 #include "HsVersions.h"
46 import ByteCodeItbls ( StgInfoTable )
47 import qualified ByteCodeItbls as BCI( StgInfoTable(..) )
48 import ByteCodeLink ( HValue )
49 import HscTypes ( HscEnv )
53 import TcRnMonad ( TcM, initTcPrintErrors, ioToTcRn, recoverM, writeMutVar )
64 import {-#SOURCE#-} TcRnDriver ( tcRnRecoverDataCon )
70 import Constants ( wORD_SIZE )
76 import GHC.Arr ( Array(..) )
77 import GHC.Ptr ( Ptr(..), castPtr )
79 import GHC.Int ( Int32(..), Int64(..) )
80 import GHC.Word ( Word32(..), Word64(..) )
84 import Data.Array.Base
85 import Data.List ( partition )
86 import Foreign.Storable
88 ---------------------------------------------
89 -- * A representation of semi evaluated Terms
90 ---------------------------------------------
92 A few examples in this representation:
94 > Just 10 = Term Data.Maybe Data.Maybe.Just (Just 10) [Term Int I# (10) "10"]
96 > (('a',_,_),_,('b',_,_)) =
97 Term ((Char,b,c),d,(Char,e,f)) (,,) (('a',_,_),_,('b',_,_))
98 [ Term (Char, b, c) (,,) ('a',_,_) [Term Char C# "a", Thunk, Thunk]
100 , Term (Char, e, f) (,,) ('b',_,_) [Term Char C# "b", Thunk, Thunk]]
103 data Term = Term { ty :: Type
106 , subTerms :: [Term] }
111 | Suspension { ctype :: ClosureType
112 , mb_ty :: Maybe Type
114 , bound_to :: Maybe Name -- Useful for printing
119 isSuspension Suspension{} = True
120 isSuspension _ = False
124 termType t@(Suspension {}) = mb_ty t
125 termType t = Just$ ty t
127 isFullyEvaluatedTerm :: Term -> Bool
128 isFullyEvaluatedTerm Term {subTerms=tt} = all isFullyEvaluatedTerm tt
129 isFullyEvaluatedTerm Suspension {} = False
130 isFullyEvaluatedTerm Prim {} = True
132 instance Outputable (Term) where
133 ppr = head . customPrintTerm customPrintTermBase
135 -------------------------------------------------------------------------
136 -- Runtime Closure Datatype and functions for retrieving closure related stuff
137 -------------------------------------------------------------------------
138 data ClosureType = Constr
149 data Closure = Closure { tipe :: ClosureType
150 , infoTable :: StgInfoTable
151 , ptrs :: Array Int HValue
152 -- What would be the type here? HValue is ok? Should I build a Ptr?
153 , nonPtrs :: ByteArray#
156 instance Outputable ClosureType where
159 getInfoTablePtr :: a -> Ptr StgInfoTable
162 itbl_ptr -> castPtr ( Ptr itbl_ptr )
164 getClosureType :: a -> IO ClosureType
165 getClosureType = liftM (readCType . BCI.tipe ) . peek . getInfoTablePtr
167 #include "../includes/ClosureTypes.h"
174 getClosureData :: a -> IO Closure
175 getClosureData a = do
176 itbl <- peek (getInfoTablePtr a)
177 let tipe = readCType (BCI.tipe itbl)
178 case closurePayload# a of
180 let elems = BCI.ptrs itbl
181 ptrsList = Array 0 (fromIntegral$ elems) ptrs
182 in ptrsList `seq` return (Closure tipe itbl ptrsList nptrs)
184 readCType :: Integral a => a -> ClosureType
186 | i >= CONSTR && i <= CONSTR_NOCAF_STATIC = Constr
187 | i >= FUN && i <= FUN_STATIC = Fun
188 | i >= THUNK && i < THUNK_SELECTOR = Thunk (fromIntegral i)
189 | i == THUNK_SELECTOR = ThunkSelector
190 | i == BLACKHOLE = Blackhole
191 | i >= IND && i <= IND_STATIC = Indirection (fromIntegral i)
192 | fromIntegral i == aP_CODE = AP
193 | fromIntegral i == pAP_CODE = PAP
194 | otherwise = Other (fromIntegral i)
196 isConstr, isIndirection :: ClosureType -> Bool
197 isConstr Constr = True
200 isIndirection (Indirection _) = True
201 --isIndirection ThunkSelector = True
202 isIndirection _ = False
204 isFullyEvaluated :: a -> IO Bool
205 isFullyEvaluated a = do
206 closure <- getClosureData a
208 Constr -> do are_subs_evaluated <- amapM isFullyEvaluated (ptrs closure)
209 return$ and are_subs_evaluated
210 otherwise -> return False
211 where amapM f = sequence . amap' f
213 amap' f (Array i0 i arr#) = map (\(I# i#) -> case indexArray# arr# i# of
217 -- TODO: Fix it. Probably the otherwise case is failing, trace/debug it
219 unsafeDeepSeq :: a -> b -> b
220 unsafeDeepSeq = unsafeDeepSeq1 2
221 where unsafeDeepSeq1 0 a b = seq a $! b
222 unsafeDeepSeq1 i a b -- 1st case avoids infinite loops for non reducible thunks
223 | not (isConstr tipe) = seq a $! unsafeDeepSeq1 (i-1) a b
224 -- | unsafePerformIO (isFullyEvaluated a) = b
225 | otherwise = case unsafePerformIO (getClosureData a) of
226 closure -> foldl' (flip unsafeDeepSeq) b (ptrs closure)
227 where tipe = unsafePerformIO (getClosureType a)
229 isPointed :: Type -> Bool
230 isPointed t | Just (t, _) <- splitTyConApp_maybe t = not$ isUnliftedTypeKind (tyConKind t)
233 #define MKDECODER(offset,cons,builder) (offset, show$ cons (builder addr 0#))
235 extractUnboxed :: [Type] -> ByteArray# -> [String]
236 extractUnboxed tt ba = helper tt (byteArrayContents# ba)
237 where helper :: [Type] -> Addr# -> [String]
239 | Just ( tycon,_) <- splitTyConApp_maybe t
240 = let (offset, txt) = decode tycon addr
241 (I# word_offset) = offset*wORD_SIZE
242 in txt : helper tt (plusAddr# addr word_offset)
244 = -- ["extractUnboxed.helper: Urk. I got a " ++ showSDoc (ppr t)]
245 panic$ "extractUnboxed.helper: Urk. I got a " ++ showSDoc (ppr t)
247 decode :: TyCon -> Addr# -> (Int, String)
249 | t == charPrimTyCon = MKDECODER(1,C#,indexCharOffAddr#)
250 | t == intPrimTyCon = MKDECODER(1,I#,indexIntOffAddr#)
251 | t == wordPrimTyCon = MKDECODER(1,W#,indexWordOffAddr#)
252 | t == floatPrimTyCon = MKDECODER(1,F#,indexFloatOffAddr#)
253 | t == doublePrimTyCon = MKDECODER(2,D#,indexDoubleOffAddr#)
254 | t == int32PrimTyCon = MKDECODER(1,I32#,indexInt32OffAddr#)
255 | t == word32PrimTyCon = MKDECODER(1,W32#,indexWord32OffAddr#)
256 | t == int64PrimTyCon = MKDECODER(2,I64#,indexInt64OffAddr#)
257 | t == word64PrimTyCon = MKDECODER(2,W64#,indexWord64OffAddr#)
258 | t == addrPrimTyCon = MKDECODER(1,I#,(\x off-> addr2Int# (indexAddrOffAddr# x off))) --OPT Improve the presentation of addresses
259 | t == stablePtrPrimTyCon = (1, "<stablePtr>")
260 | t == stableNamePrimTyCon = (1, "<stableName>")
261 | t == statePrimTyCon = (1, "<statethread>")
262 | t == realWorldTyCon = (1, "<realworld>")
263 | t == threadIdPrimTyCon = (1, "<ThreadId>")
264 | t == weakPrimTyCon = (1, "<Weak>")
265 | t == arrayPrimTyCon = (1,"<array>")
266 | t == byteArrayPrimTyCon = (1,"<bytearray>")
267 | t == mutableArrayPrimTyCon = (1, "<mutableArray>")
268 | t == mutableByteArrayPrimTyCon = (1, "<mutableByteArray>")
269 | t == mutVarPrimTyCon= (1, "<mutVar>")
270 | t == mVarPrimTyCon = (1, "<mVar>")
271 | t == tVarPrimTyCon = (1, "<tVar>")
272 | otherwise = (1, showSDoc (char '<' <> ppr t <> char '>'))
273 -- We cannot know the right offset in the otherwise case, so 1 is just a wild dangerous guess!
274 -- TODO: Improve the offset handling in decode (make it machine dependant)
276 -----------------------------------
277 -- * Traversals for Terms
278 -----------------------------------
280 data TermFold a = TermFold { fTerm :: Type -> DataCon -> HValue -> [a] -> a
281 , fPrim :: Type -> String -> a
282 , fSuspension :: ClosureType -> Maybe Type -> HValue -> Maybe Name -> a
285 foldTerm :: TermFold a -> Term -> a
286 foldTerm tf (Term ty dc v tt) = fTerm tf ty dc v (map (foldTerm tf) tt)
287 foldTerm tf (Prim ty v ) = fPrim tf ty v
288 foldTerm tf (Suspension ct ty v b) = fSuspension tf ct ty v b
290 idTermFold :: TermFold Term
291 idTermFold = TermFold {
294 fSuspension = Suspension
296 idTermFoldM :: Monad m => TermFold (m Term)
297 idTermFoldM = TermFold {
298 fTerm = \ty dc v tt -> sequence tt >>= return . Term ty dc v,
299 fPrim = (return.). Prim,
300 fSuspension = (((return.).).). Suspension
303 ----------------------------------
304 -- Pretty printing of terms
305 ----------------------------------
307 parensCond True = parens
308 parensCond False = id
312 printTerm :: Term -> SDoc
313 printTerm Prim{value=value} = text value
314 printTerm t@Term{} = printTerm1 0 t
315 printTerm Suspension{bound_to=Nothing} = char '_' -- <> ppr ct <> char '_'
316 printTerm Suspension{mb_ty=Just ty, bound_to=Just n} =
317 parens$ ppr n <> text "::" <> ppr ty
319 printTerm1 p Term{dc=dc, subTerms=tt}
320 {- | dataConIsInfix dc, (t1:t2:tt') <- tt
321 = parens (printTerm1 True t1 <+> ppr dc <+> printTerm1 True ppr t2)
322 <+> hsep (map (printTerm1 True) tt)
325 | otherwise = parensCond (p > app_prec)
326 (ppr dc <+> sep (map (printTerm1 (app_prec+1)) tt))
328 where fixity = undefined
330 printTerm1 _ t = printTerm t
332 customPrintTerm :: Monad m => ((Int->Term->m SDoc)->[Term->m (Maybe SDoc)]) -> Term -> m SDoc
333 customPrintTerm custom = let
334 -- go :: Monad m => Int -> Term -> m SDoc
335 go prec t@Term{subTerms=tt, dc=dc} = do
336 mb_customDocs <- sequence$ sequence (custom go) t -- Inner sequence is List monad
337 case msum mb_customDocs of -- msum is in Maybe monad
338 Just doc -> return$ parensCond (prec>app_prec+1) doc
339 -- | dataConIsInfix dc, (t1:t2:tt') <- tt =
340 Nothing -> do pprSubterms <- mapM (go (app_prec+1)) tt
341 return$ parensCond (prec>app_prec+1)
342 (ppr dc <+> sep pprSubterms)
343 go _ t = return$ printTerm t
345 where fixity = undefined
347 customPrintTermBase :: Monad m => (Int->Term-> m SDoc)->[Term->m (Maybe SDoc)]
348 customPrintTermBase showP =
350 test isTupleDC (liftM (parens . hcat . punctuate comma) . mapM (showP 0) . subTerms)
351 , test (isDC consDataCon) (\Term{subTerms=[h,t]} -> doList h t)
352 , test (isDC intDataCon) (coerceShow$ \(a::Int)->a)
353 , test (isDC charDataCon) (coerceShow$ \(a::Char)->a)
354 -- , test (isDC wordDataCon) (coerceShow$ \(a::Word)->a)
355 , test (isDC floatDataCon) (coerceShow$ \(a::Float)->a)
356 , test (isDC doubleDataCon) (coerceShow$ \(a::Double)->a)
357 , test isIntegerDC (coerceShow$ \(a::Integer)->a)
359 where test pred f t = if pred t then liftM Just (f t) else return Nothing
360 isIntegerDC Term{dc=dc} =
361 dataConName dc `elem` [ smallIntegerDataConName
362 , largeIntegerDataConName]
363 isTupleDC Term{dc=dc} = dc `elem` snd (unzip (elems boxedTupleArr))
364 isDC a_dc Term{dc=dc} = a_dc == dc
365 coerceShow f = return . text . show . f . unsafeCoerce# . val
366 --TODO pprinting of list terms is not lazy
368 let elems = h : getListTerms t
369 isConsLast = isSuspension (last elems) &&
370 (mb_ty$ last elems) /= (termType h)
371 init <- mapM (showP 0) (init elems)
372 last0 <- showP 0 (last elems)
373 let last = case length elems of
375 _ | isConsLast -> text " | " <> last0
377 return$ brackets (hcat (punctuate comma init ++ [last]))
379 where Just a /= Just b = not (a `coreEqType` b)
381 getListTerms Term{subTerms=[h,t]} = h : getListTerms t
382 getListTerms t@Term{subTerms=[]} = []
383 getListTerms t@Suspension{} = [t]
384 getListTerms t = pprPanic "getListTerms" (ppr t)
386 -----------------------------------
387 -- Type Reconstruction
388 -----------------------------------
390 -- The Type Reconstruction monad
393 runTR :: HscEnv -> TR Term -> IO Term
395 mb_term <- initTcPrintErrors hsc_env iNTERACTIVE (c >>= zonkTerm)
397 Nothing -> panic "Can't unify"
398 Just term -> return term
401 trIO = liftTcM . ioToTcRn
403 addConstraint :: TcType -> TcType -> TR ()
404 addConstraint t1 t2 = congruenceNewtypes t1 t2 >>= uncurry unifyType
407 A parallel fold over two Type values,
408 compensating for missing newtypes on both sides.
409 This is necessary because newtypes are not present
410 in runtime, but since sometimes there is evidence
411 available we do our best to reconstruct them.
412 Evidence can come from DataCon signatures or
413 from compile-time type inference.
414 I am using the words congruence and rewriting
415 because what we are doing here is an approximation
416 of unification modulo a set of equations, which would
417 come from newtype definitions. These should be the
418 equality coercions seen in System Fc. Rewriting
419 is performed, taking those equations as rules,
420 before launching unification.
422 It doesn't make sense to rewrite everywhere,
423 or we would end up with all newtypes. So we rewrite
424 only in presence of evidence.
425 The lhs comes from the heap structure of ptrs,nptrs.
426 The rhs comes from a DataCon type signature.
427 Rewriting in the rhs is restricted to the result type.
429 Note that it is very tricky to make this 'rewriting'
430 work with the unification implemented by TcM, where
431 substitutions are 'inlined'. The order in which
432 constraints are unified is vital for this (or I am
435 congruenceNewtypes :: TcType -> TcType -> TcM (TcType,TcType)
436 congruenceNewtypes = go True
438 go rewriteRHS lhs rhs
439 -- TyVar lhs inductive case
440 | Just tv <- getTyVar_maybe lhs
441 = recoverM (return (lhs,rhs)) $ do
442 Indirect ty_v <- readMetaTyVar tv
443 (lhs', rhs') <- go rewriteRHS ty_v rhs
444 writeMutVar (metaTvRef tv) (Indirect lhs')
446 -- TyVar rhs inductive case
447 | Just tv <- getTyVar_maybe rhs
448 = recoverM (return (lhs,rhs)) $ do
449 Indirect ty_v <- readMetaTyVar tv
450 (lhs', rhs') <- go rewriteRHS lhs ty_v
451 writeMutVar (metaTvRef tv) (Indirect rhs')
453 -- FunTy inductive case
454 | Just (l1,l2) <- splitFunTy_maybe lhs
455 , Just (r1,r2) <- splitFunTy_maybe rhs
456 = do (l2',r2') <- go True l2 r2
457 (l1',r1') <- go False l1 r1
458 return (mkFunTy l1' l2', mkFunTy r1' r2')
459 -- TyconApp Inductive case; this is the interesting bit.
460 | Just (tycon_l, args_l) <- splitNewTyConApp_maybe lhs
461 , Just (tycon_r, args_r) <- splitNewTyConApp_maybe rhs = do
463 let (tycon_l',args_l') = if isNewTyCon tycon_r && not(isNewTyCon tycon_l)
464 then (tycon_r, rewrite tycon_r lhs)
465 else (tycon_l, args_l)
466 (tycon_r',args_r') = if rewriteRHS && isNewTyCon tycon_l && not(isNewTyCon tycon_r)
467 then (tycon_l, rewrite tycon_l rhs)
468 else (tycon_r, args_r)
469 (args_l'', args_r'') <- unzip `liftM` zipWithM (go rewriteRHS) args_l' args_r'
470 return (mkTyConApp tycon_l' args_l'', mkTyConApp tycon_r' args_r'')
472 | otherwise = return (lhs,rhs)
474 where rewrite newtyped_tc lame_tipe
475 | (tvs, tipe) <- newTyConRep newtyped_tc
476 = case tcUnifyTys (const BindMe) [tipe] [lame_tipe] of
477 Just subst -> substTys subst (map mkTyVarTy tvs)
478 otherwise -> panic "congruenceNewtypes: Can't unify a newtype"
480 newVar :: Kind -> TR TcTyVar
481 newVar = liftTcM . newFlexiTyVar
485 instScheme :: Type -> TR TcType
486 instScheme ty = liftTcM$ liftM trd (tcInstType (liftM fst3 . tcInstTyVars) ty)
487 where fst3 (x,y,z) = x
490 cvObtainTerm :: HscEnv -> Bool -> Maybe Type -> HValue -> IO Term
491 cvObtainTerm hsc_env force mb_ty a =
492 -- Obtain the term and tidy the type before returning it
493 cvObtainTerm1 hsc_env force mb_ty a >>= return . tidyTypes
495 tidyTypes = foldTerm idTermFold {
496 fTerm = \ty dc hval tt -> Term (tidy ty) dc hval tt,
497 fSuspension = \ct mb_ty hval n ->
498 Suspension ct (fmap tidy mb_ty) hval n
500 tidy ty = tidyType (emptyTidyOccEnv, tidyVarEnv ty) ty
503 mkVarEnv$ [ (v, setTyVarName v (tyVarName tv))
504 | (tv,v) <- zip alphaTyVars vars]
505 where vars = varSetElems$ tyVarsOfType ty
507 cvObtainTerm1 :: HscEnv -> Bool -> Maybe Type -> HValue -> IO Term
508 cvObtainTerm1 hsc_env force mb_ty hval = runTR hsc_env $ do
509 tv <- liftM mkTyVarTy (newVar argTypeKind)
510 when (isJust mb_ty) $
511 instScheme (sigmaType$ fromJust mb_ty) >>= addConstraint tv
515 ctype <- trIO$ getClosureType a
517 -- Thunks we may want to force
518 Thunk _ | force -> seq a $ go tv a
519 -- We always follow indirections
520 _ | isIndirection ctype -> do
521 clos <- trIO$ getClosureData a
522 (go tv $! (ptrs clos ! 0))
523 -- The interesting case
525 m_dc <- trIO$ tcRnRecoverDataCon hsc_env a
527 Nothing -> panic "Can't find the DataCon for a term"
529 clos <- trIO$ getClosureData a
530 let extra_args = length(dataConRepArgTys dc) - length(dataConOrigArgTys dc)
531 subTtypes = drop extra_args (dataConRepArgTys dc)
532 (subTtypesP, subTtypesNP) = partition isPointed subTtypes
533 n_subtermsP= length subTtypesP
534 subTermTvs <- mapM (liftM mkTyVarTy . newVar ) (map typeKind subTtypesP)
535 baseType <- instScheme (dataConRepType dc)
536 let myType = mkFunTys (reOrderTerms subTermTvs subTtypesNP subTtypes) tv
537 addConstraint myType baseType
538 subTermsP <- sequence [ extractSubterm i tv (ptrs clos)
539 | (i,tv) <- zip [extra_args..extra_args + n_subtermsP - 1]
541 let unboxeds = extractUnboxed subTtypesNP (nonPtrs clos)
542 subTermsNP = map (uncurry Prim) (zip subTtypesNP unboxeds)
543 subTerms = reOrderTerms subTermsP subTermsNP subTtypes
544 return (Term tv dc a subTerms)
545 -- The otherwise case: can be a Thunk,AP,PAP,etc.
547 return (Suspension ctype (Just tv) a Nothing)
549 -- Access the array of pointers and recurse down. Needs to be done with
550 -- care of no introducing a thunk! or go will fail to do its job
551 extractSubterm (I# i#) tv ptrs = case ptrs of
552 (Array _ _ ptrs#) -> case indexArray# ptrs# i# of
555 -- This is used to put together pointed and nonpointed subterms in the
557 reOrderTerms _ _ [] = []
558 reOrderTerms pointed unpointed (ty:tys)
559 | isPointed ty = head pointed : reOrderTerms (tail pointed) unpointed tys
560 | otherwise = head unpointed : reOrderTerms pointed (tail unpointed) tys
562 zonkTerm :: Term -> TcM Term
563 zonkTerm = foldTerm idTermFoldM {
564 fTerm = \ty dc v tt -> sequence tt >>= \tt ->
565 zonkTcType ty >>= \ty' ->
566 return (Term ty' dc v tt)
567 ,fSuspension = \ct ty v b -> fmapMMaybe zonkTcType ty >>= \ty ->
568 return (Suspension ct ty v b)}
571 -- Is this defined elsewhere?
572 -- Generalize the type: find all free tyvars and wrap in the appropiate ForAll.
573 sigmaType ty = mkForAllTys (varSetElems$ tyVarsOfType (dropForAlls ty)) ty
576 Example of Type Reconstruction
577 --------------------------------
578 Suppose we have an existential type such as
580 data Opaque = forall a. Opaque a
582 And we have a term built as:
584 t = Opaque (map Just [[1,1],[2,2]])
586 The type of t as far as the typechecker goes is t :: Opaque
587 If we seq the head of t, we obtain:
593 t - O ( (_3::b) : (_4::[b]) )
597 t - O ( (Just (_5::c)) : (_4::[b]) )
599 At this point, we know that b = (Maybe c)
603 t - O ( (Just ((_6::d) : (_7::[d]) )) : (_4::[b]) )
605 At this point, we know that c = [d]
609 t - O ( (Just (1 : (_7::[d]) )) : (_4::[b]) )
611 At this point, we know that d = Integer
613 The fully reconstructed expressions, with propagation, would be:
615 t - O ( (Just (_5::c)) : (_4::[Maybe c]) )
616 t - O ( (Just ((_6::d) : (_7::[d]) )) : (_4::[Maybe [d]]) )
617 t - O ( (Just (1 : (_7::[Integer]) )) : (_4::[Maybe [Integer]]) )
620 For reference, the type of the thing inside the opaque is
621 map Just [[1,1],[2,2]] :: [Maybe [Integer]]
623 NOTE: (Num t) contexts have been manually replaced by Integer for clarity
626 --------------------------------------------------------------------
627 -- The DataConEnv is used to store the addresses of datacons loaded
628 -- via the dynamic linker
629 --------------------------------------------------------------------
631 type DataConEnv = AddressEnv StgInfoTable
633 -- Note that this AddressEnv and DataConEnv I wrote trying to follow
634 -- conventions in ghc, but probably they make not much sense.
636 newtype AddressEnv a = AE {aenv:: FiniteMap (Ptr a) Name}
637 deriving (Outputable)
639 emptyAddressEnv = AE emptyFM
641 extendAddressEnvList :: AddressEnv a -> [(Ptr a, Name)] -> AddressEnv a
642 elemAddressEnv :: Ptr a -> AddressEnv a -> Bool
643 delFromAddressEnv :: AddressEnv a -> Ptr a -> AddressEnv a
644 nullAddressEnv :: AddressEnv a -> Bool
645 lookupAddressEnv :: AddressEnv a -> Ptr a -> Maybe Name
647 extendAddressEnvList (AE env) = AE . addListToFM env
648 elemAddressEnv ptr (AE env) = ptr `elemFM` env
649 delFromAddressEnv (AE env) = AE . delFromFM env
650 nullAddressEnv = isEmptyFM . aenv
651 lookupAddressEnv (AE env) = lookupFM env
654 instance Outputable (Ptr a) where