------------------------------------------------------------------------------\r
---\r
--- GHC Interactive support for inspecting arbitrary closures at runtime\r
---\r
--- Pepe Iborra (supported by Google SoC) 2006\r
---\r
------------------------------------------------------------------------------\r
-\r
-module RtClosureInspect(\r
- \r
- cvObtainTerm, -- :: HscEnv -> Bool -> Maybe Type -> HValue -> IO Term\r
-\r
- AddressEnv(..), \r
- DataConEnv,\r
- extendAddressEnvList, \r
- elemAddressEnv, \r
- delFromAddressEnv, \r
- emptyAddressEnv, \r
- lookupAddressEnv, \r
-\r
- ClosureType(..), \r
- getClosureData, \r
- Closure ( tipe, infoTable, ptrs, nonPtrs ), \r
- getClosureType, \r
- isConstr, \r
- isIndirection,\r
- getInfoTablePtr, \r
-\r
- Term(..), \r
- printTerm, \r
- customPrintTerm, \r
- customPrintTermBase,\r
- termType,\r
- foldTerm, \r
- TermFold(..), \r
- idTermFold, \r
- idTermFoldM,\r
- isFullyEvaluated, \r
- isPointed,\r
- isFullyEvaluatedTerm,\r
--- unsafeDeepSeq, \r
- ) where \r
-\r
-#include "HsVersions.h"\r
-\r
-import ByteCodeItbls ( StgInfoTable )\r
-import qualified ByteCodeItbls as BCI( StgInfoTable(..) )\r
-import ByteCodeLink ( HValue )\r
-import HscTypes ( HscEnv )\r
-\r
-import DataCon \r
-import Type \r
-import TcRnMonad ( TcM, initTcPrintErrors, ioToTcRn, recoverM, writeMutVar )\r
-import TcType\r
-import TcMType\r
-import TcUnify\r
-import TcGadt\r
-import TyCon \r
-import Var\r
-import Name \r
-import VarEnv\r
-import OccName\r
-import VarSet\r
-import Unique\r
-import {-#SOURCE#-} TcRnDriver ( tcRnRecoverDataCon )\r
-\r
-import TysPrim \r
-import PrelNames\r
-import TysWiredIn\r
-\r
-import Constants ( wORD_SIZE )\r
-import Outputable\r
-import Maybes\r
-import Panic\r
-import FiniteMap\r
-\r
-import GHC.Arr ( Array(..) )\r
-import GHC.Ptr ( Ptr(..), castPtr )\r
-import GHC.Exts \r
-import GHC.Int ( Int32(..), Int64(..) )\r
-import GHC.Word ( Word32(..), Word64(..) )\r
-\r
-import Control.Monad\r
-import Data.Maybe\r
-import Data.Array.Base\r
-import Data.List ( partition )\r
-import Foreign.Storable\r
-\r
----------------------------------------------\r
--- * A representation of semi evaluated Terms\r
----------------------------------------------\r
-{-\r
- A few examples in this representation:\r
-\r
- > Just 10 = Term Data.Maybe Data.Maybe.Just (Just 10) [Term Int I# (10) "10"]\r
-\r
- > (('a',_,_),_,('b',_,_)) = \r
- Term ((Char,b,c),d,(Char,e,f)) (,,) (('a',_,_),_,('b',_,_))\r
- [ Term (Char, b, c) (,,) ('a',_,_) [Term Char C# "a", Thunk, Thunk]\r
- , Thunk\r
- , Term (Char, e, f) (,,) ('b',_,_) [Term Char C# "b", Thunk, Thunk]]\r
--}\r
-\r
-data Term = Term { ty :: Type \r
- , dc :: DataCon \r
- , val :: HValue \r
- , subTerms :: [Term] }\r
-\r
- | Prim { ty :: Type\r
- , value :: String }\r
-\r
- | Suspension { ctype :: ClosureType\r
- , mb_ty :: Maybe Type\r
- , val :: HValue\r
- , bound_to :: Maybe Name -- Useful for printing\r
- }\r
-\r
-isTerm Term{} = True\r
-isTerm _ = False\r
-isSuspension Suspension{} = True\r
-isSuspension _ = False\r
-isPrim Prim{} = True\r
-isPrim _ = False\r
-\r
-termType t@(Suspension {}) = mb_ty t\r
-termType t = Just$ ty t\r
-\r
-instance Outputable (Term) where\r
- ppr = head . customPrintTerm customPrintTermBase\r
-\r
--------------------------------------------------------------------------\r
--- Runtime Closure Datatype and functions for retrieving closure related stuff\r
--------------------------------------------------------------------------\r
-data ClosureType = Constr \r
- | Fun \r
- | Thunk Int \r
- | ThunkSelector\r
- | Blackhole \r
- | AP \r
- | PAP \r
- | Indirection Int \r
- | Other Int\r
- deriving (Show, Eq)\r
-\r
-data Closure = Closure { tipe :: ClosureType \r
- , infoTable :: StgInfoTable\r
- , ptrs :: Array Int HValue\r
- -- What would be the type here? HValue is ok? Should I build a Ptr?\r
- , nonPtrs :: ByteArray# \r
- }\r
-\r
-instance Outputable ClosureType where\r
- ppr = text . show \r
-\r
-getInfoTablePtr :: a -> Ptr StgInfoTable\r
-getInfoTablePtr x = \r
- case infoPtr# x of\r
- itbl_ptr -> castPtr ( Ptr itbl_ptr )\r
-\r
-getClosureType :: a -> IO ClosureType\r
-getClosureType = liftM (readCType . BCI.tipe ) . peek . getInfoTablePtr\r
-\r
-#include "../includes/ClosureTypes.h"\r
-\r
-aP_CODE = AP\r
-pAP_CODE = PAP\r
-#undef AP\r
-#undef PAP\r
-\r
-getClosureData :: a -> IO Closure\r
-getClosureData a = do\r
- itbl <- peek (getInfoTablePtr a)\r
- let tipe = readCType (BCI.tipe itbl)\r
- case closurePayload# a of \r
- (# ptrs, nptrs #) -> \r
- let elems = BCI.ptrs itbl \r
- ptrsList = Array 0 (fromIntegral$ elems) ptrs\r
- in ptrsList `seq` return (Closure tipe itbl ptrsList nptrs)\r
-\r
-readCType :: Integral a => a -> ClosureType\r
-readCType i\r
- | i >= CONSTR && i <= CONSTR_NOCAF_STATIC = Constr\r
- | i >= FUN && i <= FUN_STATIC = Fun\r
- | i >= THUNK && i < THUNK_SELECTOR = Thunk (fromIntegral i)\r
- | i == THUNK_SELECTOR = ThunkSelector\r
- | i == BLACKHOLE = Blackhole\r
- | i >= IND && i <= IND_STATIC = Indirection (fromIntegral i)\r
- | fromIntegral i == aP_CODE = AP\r
- | fromIntegral i == pAP_CODE = PAP\r
- | otherwise = Other (fromIntegral i)\r
-\r
-isConstr, isIndirection :: ClosureType -> Bool\r
-isConstr Constr = True\r
-isConstr _ = False\r
-\r
-isIndirection (Indirection _) = True\r
---isIndirection ThunkSelector = True\r
-isIndirection _ = False\r
-\r
-isFullyEvaluated :: a -> IO Bool\r
-isFullyEvaluated a = do \r
- closure <- getClosureData a \r
- case tipe closure of\r
- Constr -> do are_subs_evaluated <- amapM isFullyEvaluated (ptrs closure)\r
- return$ and are_subs_evaluated\r
- otherwise -> return False\r
- where amapM f = sequence . amap' f\r
-\r
-amap' f (Array i0 i arr#) = map (\(I# i#) -> case indexArray# arr# i# of\r
- (# e #) -> f e)\r
- [0 .. i - i0]\r
-\r
--- TODO: Fix it. Probably the otherwise case is failing, trace/debug it\r
-{-\r
-unsafeDeepSeq :: a -> b -> b\r
-unsafeDeepSeq = unsafeDeepSeq1 2\r
- where unsafeDeepSeq1 0 a b = seq a $! b\r
- unsafeDeepSeq1 i a b -- 1st case avoids infinite loops for non reducible thunks\r
- | not (isConstr tipe) = seq a $! unsafeDeepSeq1 (i-1) a b \r
- -- | unsafePerformIO (isFullyEvaluated a) = b\r
- | otherwise = case unsafePerformIO (getClosureData a) of\r
- closure -> foldl' (flip unsafeDeepSeq) b (ptrs closure)\r
- where tipe = unsafePerformIO (getClosureType a)\r
--}\r
-isPointed :: Type -> Bool\r
-isPointed t | Just (t, _) <- splitTyConApp_maybe t = not$ isUnliftedTypeKind (tyConKind t)\r
-isPointed _ = True\r
-\r
-#define MKDECODER(offset,cons,builder) (offset, show$ cons (builder addr 0#))\r
-\r
-extractUnboxed :: [Type] -> ByteArray# -> [String]\r
-extractUnboxed tt ba = helper tt (byteArrayContents# ba)\r
- where helper :: [Type] -> Addr# -> [String]\r
- helper (t:tt) addr \r
- | Just ( tycon,_) <- splitTyConApp_maybe t \r
- = let (offset, txt) = decode tycon addr\r
- (I# word_offset) = offset*wORD_SIZE\r
- in txt : helper tt (plusAddr# addr word_offset)\r
- | otherwise \r
- = -- ["extractUnboxed.helper: Urk. I got a " ++ showSDoc (ppr t)]\r
- panic$ "extractUnboxed.helper: Urk. I got a " ++ showSDoc (ppr t)\r
- helper [] addr = []\r
- decode :: TyCon -> Addr# -> (Int, String)\r
- decode t addr \r
- | t == charPrimTyCon = MKDECODER(1,C#,indexCharOffAddr#)\r
- | t == intPrimTyCon = MKDECODER(1,I#,indexIntOffAddr#)\r
- | t == wordPrimTyCon = MKDECODER(1,W#,indexWordOffAddr#)\r
- | t == floatPrimTyCon = MKDECODER(1,F#,indexFloatOffAddr#)\r
- | t == doublePrimTyCon = MKDECODER(2,D#,indexDoubleOffAddr#)\r
- | t == int32PrimTyCon = MKDECODER(1,I32#,indexInt32OffAddr#)\r
- | t == word32PrimTyCon = MKDECODER(1,W32#,indexWord32OffAddr#)\r
- | t == int64PrimTyCon = MKDECODER(2,I64#,indexInt64OffAddr#)\r
- | t == word64PrimTyCon = MKDECODER(2,W64#,indexWord64OffAddr#)\r
- | t == addrPrimTyCon = MKDECODER(1,I#,(\x off-> addr2Int# (indexAddrOffAddr# x off))) --OPT Improve the presentation of addresses\r
- | t == stablePtrPrimTyCon = (1, "<stablePtr>")\r
- | t == stableNamePrimTyCon = (1, "<stableName>")\r
- | t == statePrimTyCon = (1, "<statethread>")\r
- | t == realWorldTyCon = (1, "<realworld>")\r
- | t == threadIdPrimTyCon = (1, "<ThreadId>")\r
- | t == weakPrimTyCon = (1, "<Weak>")\r
- | t == arrayPrimTyCon = (1,"<array>")\r
- | t == byteArrayPrimTyCon = (1,"<bytearray>")\r
- | t == mutableArrayPrimTyCon = (1, "<mutableArray>")\r
- | t == mutableByteArrayPrimTyCon = (1, "<mutableByteArray>")\r
- | t == mutVarPrimTyCon= (1, "<mutVar>")\r
- | t == mVarPrimTyCon = (1, "<mVar>")\r
- | t == tVarPrimTyCon = (1, "<tVar>")\r
- | otherwise = (1, showSDoc (char '<' <> ppr t <> char '>')) \r
- -- We cannot know the right offset in the otherwise case, so 1 is just a wild dangerous guess!\r
- -- TODO: Improve the offset handling in decode (make it machine dependant)\r
-\r
------------------------------------\r
--- Boilerplate Fold code for Term\r
------------------------------------\r
-\r
-data TermFold a = TermFold { fTerm :: Type -> DataCon -> HValue -> [a] -> a\r
- , fPrim :: Type -> String -> a\r
- , fSuspension :: ClosureType -> Maybe Type -> HValue -> Maybe Name -> a\r
- }\r
-\r
-foldTerm :: TermFold a -> Term -> a\r
-foldTerm tf (Term ty dc v tt) = fTerm tf ty dc v (map (foldTerm tf) tt)\r
-foldTerm tf (Prim ty v ) = fPrim tf ty v\r
-foldTerm tf (Suspension ct ty v b) = fSuspension tf ct ty v b\r
-\r
-idTermFold :: TermFold Term\r
-idTermFold = TermFold {\r
- fTerm = Term,\r
- fPrim = Prim,\r
- fSuspension = Suspension\r
- }\r
-idTermFoldM :: Monad m => TermFold (m Term)\r
-idTermFoldM = TermFold {\r
- fTerm = \ty dc v tt -> sequence tt >>= return . Term ty dc v,\r
- fPrim = (return.). Prim,\r
- fSuspension = (((return.).).). Suspension\r
- }\r
-\r
-----------------------------------\r
--- Pretty printing of terms\r
-----------------------------------\r
-\r
-parensCond True = parens\r
-parensCond False = id\r
-app_prec::Int\r
-app_prec = 10\r
-\r
-printTerm :: Term -> SDoc\r
-printTerm Prim{value=value} = text value \r
-printTerm t@Term{} = printTerm1 0 t \r
-printTerm Suspension{bound_to=Nothing} = char '_' -- <> ppr ct <> char '_'\r
-printTerm Suspension{mb_ty=Just ty, bound_to=Just n} =\r
- parens$ ppr n <> text "::" <> ppr ty \r
-\r
-printTerm1 p Term{dc=dc, subTerms=tt} \r
-{- | dataConIsInfix dc, (t1:t2:tt') <- tt \r
- = parens (printTerm1 True t1 <+> ppr dc <+> printTerm1 True ppr t2) \r
- <+> hsep (map (printTerm1 True) tt) \r
--}\r
- | null tt = ppr dc\r
- | otherwise = parensCond (p > app_prec) \r
- (ppr dc <+> sep (map (printTerm1 (app_prec+1)) tt))\r
-\r
- where fixity = undefined \r
-\r
-printTerm1 _ t = printTerm t\r
-\r
-customPrintTerm :: Monad m => ((Int->Term->m SDoc)->[Term->m (Maybe SDoc)]) -> Term -> m SDoc\r
-customPrintTerm custom = let \r
--- go :: Monad m => Int -> Term -> m SDoc\r
- go prec t@Term{subTerms=tt, dc=dc} = do\r
- mb_customDocs <- sequence$ sequence (custom go) t -- Inner sequence is List monad\r
- case msum mb_customDocs of -- msum is in Maybe monad\r
- Just doc -> return$ parensCond (prec>app_prec+1) doc\r
--- | dataConIsInfix dc, (t1:t2:tt') <- tt =\r
- Nothing -> do pprSubterms <- mapM (go (app_prec+1)) tt\r
- return$ parensCond (prec>app_prec+1) \r
- (ppr dc <+> sep pprSubterms)\r
- go _ t = return$ printTerm t\r
- in go 0 \r
- where fixity = undefined \r
-\r
-customPrintTermBase :: Monad m => (Int->Term-> m SDoc)->[Term->m (Maybe SDoc)]\r
-customPrintTermBase showP =\r
- [ \r
- test isTupleDC (liftM (parens . cat . punctuate comma) . mapM (showP 0) . subTerms)\r
- , test (isDC consDataCon) (\Term{subTerms=[h,t]} -> doList h t)\r
- , test (isDC intDataCon) (coerceShow$ \(a::Int)->a)\r
- , test (isDC charDataCon) (coerceShow$ \(a::Char)->a)\r
--- , test (isDC wordDataCon) (coerceShow$ \(a::Word)->a)\r
- , test (isDC floatDataCon) (coerceShow$ \(a::Float)->a)\r
- , test (isDC doubleDataCon) (coerceShow$ \(a::Double)->a)\r
- , test isIntegerDC (coerceShow$ \(a::Integer)->a)\r
- ] \r
- where test pred f t = if pred t then liftM Just (f t) else return Nothing\r
- isIntegerDC Term{dc=dc} = \r
- dataConName dc `elem` [ smallIntegerDataConName\r
- , largeIntegerDataConName] \r
- isTupleDC Term{dc=dc} = dc `elem` snd (unzip (elems boxedTupleArr))\r
- isDC a_dc Term{dc=dc} = a_dc == dc\r
- coerceShow f Term{val=val} = return . text . show . f . unsafeCoerce# $ val\r
- --TODO pprinting of list terms is not lazy\r
- doList h t = do\r
- let elems = h : getListTerms t\r
- isConsLast = isSuspension (last elems) && \r
- (mb_ty$ last elems) /= (termType h)\r
- init <- mapM (showP 0) (init elems) \r
- last0 <- showP 0 (last elems)\r
- let last = case length elems of \r
- 1 -> last0 \r
- _ | isConsLast -> text " | " <> last0\r
- _ -> comma <> last0\r
- return$ brackets (cat (punctuate comma init ++ [last]))\r
-\r
- where Just a /= Just b = not (a `coreEqType` b)\r
- _ /= _ = True\r
- getListTerms Term{subTerms=[h,t]} = h : getListTerms t\r
- getListTerms t@Term{subTerms=[]} = []\r
- getListTerms t@Suspension{} = [t]\r
- getListTerms t = pprPanic "getListTerms" (ppr t)\r
-\r
-isFullyEvaluatedTerm :: Term -> Bool\r
-isFullyEvaluatedTerm Term {subTerms=tt} = all isFullyEvaluatedTerm tt\r
-isFullyEvaluatedTerm Suspension {} = False\r
-isFullyEvaluatedTerm Prim {} = True\r
-\r
-\r
------------------------------------\r
--- Type Reconstruction\r
------------------------------------\r
-\r
--- The Type Reconstruction monad\r
-type TR a = TcM a\r
-\r
-runTR :: HscEnv -> TR Term -> IO Term\r
-runTR hsc_env c = do \r
- mb_term <- initTcPrintErrors hsc_env iNTERACTIVE (c >>= zonkTerm)\r
- case mb_term of \r
- Nothing -> panic "Can't unify"\r
- Just term -> return term\r
-\r
-trIO :: IO a -> TR a \r
-trIO = liftTcM . ioToTcRn\r
-\r
-addConstraint :: TcType -> TcType -> TR ()\r
-addConstraint t1 t2 = congruenceNewtypes t1 t2 >> unifyType t1 t2\r
-\r
--- A parallel fold over a Type value, replacing\r
--- in the right side reptypes for newtypes as found in the lhs\r
--- Sadly it doesn't cover all the possibilities. It does not always manage\r
--- to recover the highest level type. See test print016 for an example\r
-congruenceNewtypes :: TcType -> TcType -> TcM TcType\r
-congruenceNewtypes lhs rhs\r
--- | pprTrace "Congruence" (ppr lhs $$ ppr rhs) False = undefined\r
- -- We have a tctyvar at the other side\r
- | Just tv <- getTyVar_maybe rhs \r
--- , trace "congruence, entering tyvar" True\r
- = recoverM (return rhs) $ do \r
- Indirect ty_v <- readMetaTyVar tv\r
- newtyped_tytv <- congruenceNewtypes lhs ty_v\r
- writeMutVar (metaTvRef tv) (Indirect newtyped_tytv)\r
- return newtyped_tytv\r
--- We have a function type: go on inductively\r
- | Just (r1,r2) <- splitFunTy_maybe rhs\r
- , Just (l1,l2) <- splitFunTy_maybe lhs\r
- = liftM2 mkFunTy ( congruenceNewtypes l1 r1)\r
- (congruenceNewtypes l2 r2)\r
--- There is a newtype at the top level tycon and we can manage it\r
- | Just (tycon, args) <- splitNewTyConApp_maybe lhs\r
- , isNewTyCon tycon\r
- , (tvs, realtipe) <- newTyConRep tycon\r
- = case tcUnifyTys (const BindMe) [realtipe] [rhs] of\r
- Just subst -> \r
- let tvs' = substTys subst (map mkTyVarTy tvs) in\r
- liftM (mkTyConApp tycon) (zipWithM congruenceNewtypes args tvs')\r
- otherwise -> panic "congruenceNewtypes: Can't unify a newtype"\r
- \r
--- We have a TyconApp: go on inductively\r
- | Just (tycon, args) <- splitNewTyConApp_maybe lhs\r
- , Just (tycon_v, args_v) <- splitNewTyConApp_maybe rhs\r
- = liftM (mkTyConApp tycon_v) (zipWithM congruenceNewtypes args args_v)\r
-\r
- | otherwise = return rhs\r
-\r
-\r
-newVar :: Kind -> TR TcTyVar\r
-newVar = liftTcM . newFlexiTyVar\r
-\r
-liftTcM = id\r
-\r
-instScheme :: Type -> TR TcType\r
-instScheme ty = liftTcM$ liftM trd (tcInstType (liftM fst3 . tcInstTyVars) ty)\r
- where fst3 (x,y,z) = x\r
- trd (x,y,z) = z\r
-\r
-cvObtainTerm :: HscEnv -> Bool -> Maybe Type -> HValue -> IO Term\r
-cvObtainTerm hsc_env force mb_ty a = \r
- -- Obtain the term and tidy the type before returning it\r
- cvObtainTerm1 hsc_env force mb_ty a >>= return . tidyTypes \r
- where \r
- tidyTypes = foldTerm idTermFold {\r
- fTerm = \ty dc hval tt -> Term (tidy ty) dc hval tt,\r
- fSuspension = \ct mb_ty hval n -> \r
- Suspension ct (fmap tidy mb_ty) hval n\r
- }\r
- tidy ty = tidyType (emptyTidyOccEnv, tidyVarEnv ty) ty \r
- tidyVarEnv ty = \r
- mkVarEnv$ [ (v, setTyVarName v (tyVarName tv))\r
- | (tv,v) <- zip alphaTyVars vars]\r
- where vars = varSetElems$ tyVarsOfType ty\r
-\r
-cvObtainTerm1 :: HscEnv -> Bool -> Maybe Type -> HValue -> IO Term\r
-cvObtainTerm1 hsc_env force mb_ty hval\r
- | Nothing <- mb_ty = runTR hsc_env . go argTypeKind $ hval\r
- | Just ty <- mb_ty = runTR hsc_env $ do\r
- term <- go argTypeKind hval\r
- ty' <- instScheme ty\r
- addConstraint ty' (fromMaybe (error "by definition") \r
- (termType term)) \r
- return term\r
- where \r
- go k a = do \r
- ctype <- trIO$ getClosureType a\r
- case ctype of\r
--- Thunks we may want to force\r
- Thunk _ | force -> seq a $ go k a\r
--- We always follow indirections \r
- _ | isIndirection ctype \r
- -> do\r
- clos <- trIO$ getClosureData a\r
--- dflags <- getSessionDynFlags session\r
--- debugTraceMsg dflags 2 (text "Following an indirection")\r
- go k $! (ptrs clos ! 0)\r
- -- The interesting case\r
- Constr -> do\r
- m_dc <- trIO$ tcRnRecoverDataCon hsc_env a\r
- case m_dc of\r
- Nothing -> panic "Can't find the DataCon for a term"\r
- Just dc -> do \r
- clos <- trIO$ getClosureData a\r
- let extra_args = length(dataConRepArgTys dc) - length(dataConOrigArgTys dc)\r
- subTtypes = drop extra_args (dataConRepArgTys dc)\r
- (subTtypesP, subTtypesNP) = partition isPointed subTtypes\r
- \r
- subTermsP <- mapM (\i->extractSubterm i (ptrs clos)\r
- (subTtypesP!!(i-extra_args)))\r
- [extra_args..extra_args + length subTtypesP - 1]\r
- let unboxeds = extractUnboxed subTtypesNP (nonPtrs clos)\r
- subTermsNP = map (uncurry Prim) (zip subTtypesNP unboxeds) \r
- subTerms = reOrderTerms subTermsP subTermsNP subTtypes\r
- resType <- liftM mkTyVarTy (newVar k)\r
- baseType <- instScheme (dataConRepType dc)\r
- let myType = mkFunTys (map (fromMaybe undefined . termType) \r
- subTerms) \r
- resType\r
- addConstraint baseType myType\r
- return (Term resType dc a subTerms)\r
--- The otherwise case: can be a Thunk,AP,PAP,etc.\r
- otherwise -> do\r
- x <- liftM mkTyVarTy (newVar k)\r
- return (Suspension ctype (Just x) a Nothing)\r
-\r
--- Access the array of pointers and recurse down. Needs to be done with\r
--- care of no introducing a thunk! or go will fail to do its job \r
- extractSubterm (I# i#) ptrs ty = case ptrs of \r
- (Array _ _ ptrs#) -> case indexArray# ptrs# i# of \r
- (# e #) -> go (typeKind ty) e\r
-\r
--- This is used to put together pointed and nonpointed subterms in the \r
--- correct order.\r
- reOrderTerms _ _ [] = []\r
- reOrderTerms pointed unpointed (ty:tys) \r
- | isPointed ty = head pointed : reOrderTerms (tail pointed) unpointed tys\r
- | otherwise = head unpointed : reOrderTerms pointed (tail unpointed) tys\r
-\r
-zonkTerm :: Term -> TcM Term\r
-zonkTerm = foldTerm idTermFoldM {\r
- fTerm = \ty dc v tt -> sequence tt >>= \tt ->\r
- zonkTcType ty >>= \ty' ->\r
- return (Term ty' dc v tt)\r
- ,fSuspension = \ct ty v b -> fmapMMaybe zonkTcType ty >>= \ty ->\r
- return (Suspension ct ty v b)} \r
-\r
-{-\r
-Example of Type Reconstruction\r
---------------------------------\r
-Suppose we have an existential type such as\r
-\r
-data Opaque = forall a. Opaque a\r
-\r
-And we have a term built as:\r
-\r
-t = Opaque (map Just [[1,1],[2,2]])\r
-\r
-The type of t as far as the typechecker goes is t :: Opaque\r
-If we seq the head of t, we obtain:\r
-\r
-t - O (_1::a) \r
-\r
-seq _1 ()\r
-\r
-t - O ( (_3::b) : (_4::[b]) ) \r
-\r
-seq _3 ()\r
-\r
-t - O ( (Just (_5::c)) : (_4::[b]) ) \r
-\r
-At this point, we know that b = (Maybe c)\r
-\r
-seq _5 ()\r
-\r
-t - O ( (Just ((_6::d) : (_7::[d]) )) : (_4::[b]) )\r
-\r
-At this point, we know that c = [d]\r
-\r
-seq _6 ()\r
-\r
-t - O ( (Just (1 : (_7::[d]) )) : (_4::[b]) )\r
-\r
-At this point, we know that d = Integer\r
-\r
-The fully reconstructed expressions, with propagation, would be:\r
-\r
-t - O ( (Just (_5::c)) : (_4::[Maybe c]) ) \r
-t - O ( (Just ((_6::d) : (_7::[d]) )) : (_4::[Maybe [d]]) )\r
-t - O ( (Just (1 : (_7::[Integer]) )) : (_4::[Maybe [Integer]]) )\r
-\r
-\r
-For reference, the type of the thing inside the opaque is \r
-map Just [[1,1],[2,2]] :: [Maybe [Integer]]\r
-\r
-NOTE: (Num t) contexts have been manually replaced by Integer for clarity\r
--}\r
-\r
---------------------------------------------------------------------\r
--- The DataConEnv is used to store the addresses of datacons loaded\r
--- via the dynamic linker\r
---------------------------------------------------------------------\r
-\r
-type DataConEnv = AddressEnv StgInfoTable\r
-\r
--- Note that this AddressEnv and DataConEnv I wrote trying to follow \r
--- conventions in ghc, but probably they make not much sense.\r
-\r
-newtype AddressEnv a = AE {aenv:: FiniteMap (Ptr a) Name}\r
- deriving (Outputable)\r
-\r
-emptyAddressEnv = AE emptyFM\r
-\r
-extendAddressEnvList :: AddressEnv a -> [(Ptr a, Name)] -> AddressEnv a\r
-elemAddressEnv :: Ptr a -> AddressEnv a -> Bool\r
-delFromAddressEnv :: AddressEnv a -> Ptr a -> AddressEnv a\r
-nullAddressEnv :: AddressEnv a -> Bool\r
-lookupAddressEnv :: AddressEnv a -> Ptr a -> Maybe Name\r
-\r
-extendAddressEnvList (AE env) = AE . addListToFM env \r
-elemAddressEnv ptr (AE env) = ptr `elemFM` env\r
-delFromAddressEnv (AE env) = AE . delFromFM env\r
-nullAddressEnv = isEmptyFM . aenv\r
-lookupAddressEnv (AE env) = lookupFM env\r
-\r
-\r
-instance Outputable (Ptr a) where\r
- ppr = text . show
\ No newline at end of file
+-----------------------------------------------------------------------------
+--
+-- GHC Interactive support for inspecting arbitrary closures at runtime
+--
+-- Pepe Iborra (supported by Google SoC) 2006
+--
+-----------------------------------------------------------------------------
+
+module RtClosureInspect(
+ cvObtainTerm, -- :: HscEnv -> Int -> Bool -> Maybe Type -> HValue -> IO Term
+ cvReconstructType,
+ improveRTTIType,
+
+ Term(..),
+ isTerm, isSuspension, isPrim, isFun, isFunLike, isNewtypeWrap,
+ isFullyEvaluated, isFullyEvaluatedTerm,
+ termType, mapTermType, termTyVars,
+ foldTerm, TermFold(..), foldTermM, TermFoldM(..), idTermFold,
+ pprTerm, cPprTerm, cPprTermBase, CustomTermPrinter,
+
+-- unsafeDeepSeq,
+
+ Closure(..), getClosureData, ClosureType(..), isConstr, isIndirection
+ ) where
+
+#include "HsVersions.h"
+
+import ByteCodeItbls ( StgInfoTable )
+import qualified ByteCodeItbls as BCI( StgInfoTable(..) )
+import HscTypes
+import Linker
+
+import DataCon
+import Type
+import qualified Unify as U
+import TypeRep -- I know I know, this is cheating
+import Var
+import TcRnMonad
+import TcType
+import TcMType
+import TcUnify
+import TcEnv
+
+import TyCon
+import Name
+import VarEnv
+import Util
+import ListSetOps
+import VarSet
+import TysPrim
+import PrelNames
+import TysWiredIn
+import DynFlags
+import Outputable
+import FastString
+-- import Panic
+
+import Constants ( wORD_SIZE )
+
+import GHC.Arr ( Array(..) )
+import GHC.Exts
+import GHC.IO ( IO(..) )
+
+import Control.Monad
+import Data.Maybe
+import Data.Array.Base
+import Data.Ix
+import Data.List
+import qualified Data.Sequence as Seq
+import Data.Monoid
+import Data.Sequence (viewl, ViewL(..))
+import Foreign hiding (unsafePerformIO)
+import System.IO.Unsafe
+
+---------------------------------------------
+-- * A representation of semi evaluated Terms
+---------------------------------------------
+
+data Term = Term { ty :: RttiType
+ , dc :: Either String DataCon
+ -- Carries a text representation if the datacon is
+ -- not exported by the .hi file, which is the case
+ -- for private constructors in -O0 compiled libraries
+ , val :: HValue
+ , subTerms :: [Term] }
+
+ | Prim { ty :: RttiType
+ , value :: [Word] }
+
+ | Suspension { ctype :: ClosureType
+ , ty :: RttiType
+ , val :: HValue
+ , bound_to :: Maybe Name -- Useful for printing
+ }
+ | NewtypeWrap{ -- At runtime there are no newtypes, and hence no
+ -- newtype constructors. A NewtypeWrap is just a
+ -- made-up tag saying "heads up, there used to be
+ -- a newtype constructor here".
+ ty :: RttiType
+ , dc :: Either String DataCon
+ , wrapped_term :: Term }
+ | RefWrap { -- The contents of a reference
+ ty :: RttiType
+ , wrapped_term :: Term }
+
+isTerm, isSuspension, isPrim, isFun, isFunLike, isNewtypeWrap :: Term -> Bool
+isTerm Term{} = True
+isTerm _ = False
+isSuspension Suspension{} = True
+isSuspension _ = False
+isPrim Prim{} = True
+isPrim _ = False
+isNewtypeWrap NewtypeWrap{} = True
+isNewtypeWrap _ = False
+
+isFun Suspension{ctype=Fun} = True
+isFun _ = False
+
+isFunLike s@Suspension{ty=ty} = isFun s || isFunTy ty
+isFunLike _ = False
+
+termType :: Term -> RttiType
+termType t = ty t
+
+isFullyEvaluatedTerm :: Term -> Bool
+isFullyEvaluatedTerm Term {subTerms=tt} = all isFullyEvaluatedTerm tt
+isFullyEvaluatedTerm Prim {} = True
+isFullyEvaluatedTerm NewtypeWrap{wrapped_term=t} = isFullyEvaluatedTerm t
+isFullyEvaluatedTerm RefWrap{wrapped_term=t} = isFullyEvaluatedTerm t
+isFullyEvaluatedTerm _ = False
+
+instance Outputable (Term) where
+ ppr t | Just doc <- cPprTerm cPprTermBase t = doc
+ | otherwise = panic "Outputable Term instance"
+
+-------------------------------------------------------------------------
+-- Runtime Closure Datatype and functions for retrieving closure related stuff
+-------------------------------------------------------------------------
+data ClosureType = Constr
+ | Fun
+ | Thunk Int
+ | ThunkSelector
+ | Blackhole
+ | AP
+ | PAP
+ | Indirection Int
+ | MutVar Int
+ | MVar Int
+ | Other Int
+ deriving (Show, Eq)
+
+data Closure = Closure { tipe :: ClosureType
+ , infoPtr :: Ptr ()
+ , infoTable :: StgInfoTable
+ , ptrs :: Array Int HValue
+ , nonPtrs :: [Word]
+ }
+
+instance Outputable ClosureType where
+ ppr = text . show
+
+#include "../includes/rts/storage/ClosureTypes.h"
+
+aP_CODE, pAP_CODE :: Int
+aP_CODE = AP
+pAP_CODE = PAP
+#undef AP
+#undef PAP
+
+getClosureData :: a -> IO Closure
+getClosureData a =
+ case unpackClosure# a of
+ (# iptr, ptrs, nptrs #) -> do
+ let iptr'
+ | ghciTablesNextToCode =
+ Ptr iptr
+ | otherwise =
+ -- the info pointer we get back from unpackClosure#
+ -- is to the beginning of the standard info table,
+ -- but the Storable instance for info tables takes
+ -- into account the extra entry pointer when
+ -- !ghciTablesNextToCode, so we must adjust here:
+ Ptr iptr `plusPtr` negate wORD_SIZE
+ itbl <- peek iptr'
+ let tipe = readCType (BCI.tipe itbl)
+ elems = fromIntegral (BCI.ptrs itbl)
+ ptrsList = Array 0 (elems - 1) elems ptrs
+ nptrs_data = [W# (indexWordArray# nptrs i)
+ | I# i <- [0.. fromIntegral (BCI.nptrs itbl)] ]
+ ASSERT(elems >= 0) return ()
+ ptrsList `seq`
+ return (Closure tipe (Ptr iptr) itbl ptrsList nptrs_data)
+
+readCType :: Integral a => a -> ClosureType
+readCType i
+ | i >= CONSTR && i <= CONSTR_NOCAF_STATIC = Constr
+ | i >= FUN && i <= FUN_STATIC = Fun
+ | i >= THUNK && i < THUNK_SELECTOR = Thunk i'
+ | i == THUNK_SELECTOR = ThunkSelector
+ | i == BLACKHOLE = Blackhole
+ | i >= IND && i <= IND_STATIC = Indirection i'
+ | i' == aP_CODE = AP
+ | i == AP_STACK = AP
+ | i' == pAP_CODE = PAP
+ | i == MUT_VAR_CLEAN || i == MUT_VAR_DIRTY= MutVar i'
+ | i == MVAR_CLEAN || i == MVAR_DIRTY = MVar i'
+ | otherwise = Other i'
+ where i' = fromIntegral i
+
+isConstr, isIndirection, isThunk :: ClosureType -> Bool
+isConstr Constr = True
+isConstr _ = False
+
+isIndirection (Indirection _) = True
+isIndirection _ = False
+
+isThunk (Thunk _) = True
+isThunk ThunkSelector = True
+isThunk AP = True
+isThunk _ = False
+
+isFullyEvaluated :: a -> IO Bool
+isFullyEvaluated a = do
+ closure <- getClosureData a
+ case tipe closure of
+ Constr -> do are_subs_evaluated <- amapM isFullyEvaluated (ptrs closure)
+ return$ and are_subs_evaluated
+ _ -> return False
+ where amapM f = sequence . amap' f
+
+-- TODO: Fix it. Probably the otherwise case is failing, trace/debug it
+{-
+unsafeDeepSeq :: a -> b -> b
+unsafeDeepSeq = unsafeDeepSeq1 2
+ where unsafeDeepSeq1 0 a b = seq a $! b
+ unsafeDeepSeq1 i a b -- 1st case avoids infinite loops for non reducible thunks
+ | not (isConstr tipe) = seq a $! unsafeDeepSeq1 (i-1) a b
+ -- | unsafePerformIO (isFullyEvaluated a) = b
+ | otherwise = case unsafePerformIO (getClosureData a) of
+ closure -> foldl' (flip unsafeDeepSeq) b (ptrs closure)
+ where tipe = unsafePerformIO (getClosureType a)
+-}
+
+-----------------------------------
+-- * Traversals for Terms
+-----------------------------------
+type TermProcessor a b = RttiType -> Either String DataCon -> HValue -> [a] -> b
+
+data TermFold a = TermFold { fTerm :: TermProcessor a a
+ , fPrim :: RttiType -> [Word] -> a
+ , fSuspension :: ClosureType -> RttiType -> HValue
+ -> Maybe Name -> a
+ , fNewtypeWrap :: RttiType -> Either String DataCon
+ -> a -> a
+ , fRefWrap :: RttiType -> a -> a
+ }
+
+
+data TermFoldM m a =
+ TermFoldM {fTermM :: TermProcessor a (m a)
+ , fPrimM :: RttiType -> [Word] -> m a
+ , fSuspensionM :: ClosureType -> RttiType -> HValue
+ -> Maybe Name -> m a
+ , fNewtypeWrapM :: RttiType -> Either String DataCon
+ -> a -> m a
+ , fRefWrapM :: RttiType -> a -> m a
+ }
+
+foldTerm :: TermFold a -> Term -> a
+foldTerm tf (Term ty dc v tt) = fTerm tf ty dc v (map (foldTerm tf) tt)
+foldTerm tf (Prim ty v ) = fPrim tf ty v
+foldTerm tf (Suspension ct ty v b) = fSuspension tf ct ty v b
+foldTerm tf (NewtypeWrap ty dc t) = fNewtypeWrap tf ty dc (foldTerm tf t)
+foldTerm tf (RefWrap ty t) = fRefWrap tf ty (foldTerm tf t)
+
+
+foldTermM :: Monad m => TermFoldM m a -> Term -> m a
+foldTermM tf (Term ty dc v tt) = mapM (foldTermM tf) tt >>= fTermM tf ty dc v
+foldTermM tf (Prim ty v ) = fPrimM tf ty v
+foldTermM tf (Suspension ct ty v b) = fSuspensionM tf ct ty v b
+foldTermM tf (NewtypeWrap ty dc t) = foldTermM tf t >>= fNewtypeWrapM tf ty dc
+foldTermM tf (RefWrap ty t) = foldTermM tf t >>= fRefWrapM tf ty
+
+idTermFold :: TermFold Term
+idTermFold = TermFold {
+ fTerm = Term,
+ fPrim = Prim,
+ fSuspension = Suspension,
+ fNewtypeWrap = NewtypeWrap,
+ fRefWrap = RefWrap
+ }
+
+mapTermType :: (RttiType -> Type) -> Term -> Term
+mapTermType f = foldTerm idTermFold {
+ fTerm = \ty dc hval tt -> Term (f ty) dc hval tt,
+ fSuspension = \ct ty hval n ->
+ Suspension ct (f ty) hval n,
+ fNewtypeWrap= \ty dc t -> NewtypeWrap (f ty) dc t,
+ fRefWrap = \ty t -> RefWrap (f ty) t}
+
+mapTermTypeM :: Monad m => (RttiType -> m Type) -> Term -> m Term
+mapTermTypeM f = foldTermM TermFoldM {
+ fTermM = \ty dc hval tt -> f ty >>= \ty' -> return $ Term ty' dc hval tt,
+ fPrimM = (return.) . Prim,
+ fSuspensionM = \ct ty hval n ->
+ f ty >>= \ty' -> return $ Suspension ct ty' hval n,
+ fNewtypeWrapM= \ty dc t -> f ty >>= \ty' -> return $ NewtypeWrap ty' dc t,
+ fRefWrapM = \ty t -> f ty >>= \ty' -> return $ RefWrap ty' t}
+
+termTyVars :: Term -> TyVarSet
+termTyVars = foldTerm TermFold {
+ fTerm = \ty _ _ tt ->
+ tyVarsOfType ty `plusVarEnv` concatVarEnv tt,
+ fSuspension = \_ ty _ _ -> tyVarsOfType ty,
+ fPrim = \ _ _ -> emptyVarEnv,
+ fNewtypeWrap= \ty _ t -> tyVarsOfType ty `plusVarEnv` t,
+ fRefWrap = \ty t -> tyVarsOfType ty `plusVarEnv` t}
+ where concatVarEnv = foldr plusVarEnv emptyVarEnv
+
+----------------------------------
+-- Pretty printing of terms
+----------------------------------
+
+type Precedence = Int
+type TermPrinter = Precedence -> Term -> SDoc
+type TermPrinterM m = Precedence -> Term -> m SDoc
+
+app_prec,cons_prec, max_prec ::Int
+max_prec = 10
+app_prec = max_prec
+cons_prec = 5 -- TODO Extract this info from GHC itself
+
+pprTerm :: TermPrinter -> TermPrinter
+pprTerm y p t | Just doc <- pprTermM (\p -> Just . y p) p t = doc
+pprTerm _ _ _ = panic "pprTerm"
+
+pprTermM, ppr_termM, pprNewtypeWrap :: Monad m => TermPrinterM m -> TermPrinterM m
+pprTermM y p t = pprDeeper `liftM` ppr_termM y p t
+
+ppr_termM y p Term{dc=Left dc_tag, subTerms=tt} = do
+ tt_docs <- mapM (y app_prec) tt
+ return$ cparen (not(null tt) && p >= app_prec) (text dc_tag <+> pprDeeperList fsep tt_docs)
+
+ppr_termM y p Term{dc=Right dc, subTerms=tt}
+{- | dataConIsInfix dc, (t1:t2:tt') <- tt --TODO fixity
+ = parens (ppr_term1 True t1 <+> ppr dc <+> ppr_term1 True ppr t2)
+ <+> hsep (map (ppr_term1 True) tt)
+-} -- TODO Printing infix constructors properly
+ | null tt = return$ ppr dc
+ | otherwise = do
+ tt_docs <- mapM (y app_prec) tt
+ return$ cparen (p >= app_prec) (ppr dc <+> pprDeeperList fsep tt_docs)
+
+ppr_termM y p t@NewtypeWrap{} = pprNewtypeWrap y p t
+ppr_termM y p RefWrap{wrapped_term=t} = do
+ contents <- y app_prec t
+ return$ cparen (p >= app_prec) (text "GHC.Prim.MutVar#" <+> contents)
+ -- The constructor name is wired in here ^^^ for the sake of simplicity.
+ -- I don't think mutvars are going to change in a near future.
+ -- In any case this is solely a presentation matter: MutVar# is
+ -- a datatype with no constructors, implemented by the RTS
+ -- (hence there is no way to obtain a datacon and print it).
+ppr_termM _ _ t = ppr_termM1 t
+
+
+ppr_termM1 :: Monad m => Term -> m SDoc
+ppr_termM1 Prim{value=words, ty=ty} =
+ return$ text$ repPrim (tyConAppTyCon ty) words
+ppr_termM1 Suspension{ty=ty, bound_to=Nothing} =
+ return (char '_' <+> ifPprDebug (text "::" <> ppr ty))
+ppr_termM1 Suspension{ty=ty, bound_to=Just n}
+-- | Just _ <- splitFunTy_maybe ty = return$ ptext (sLit("<function>")
+ | otherwise = return$ parens$ ppr n <> text "::" <> ppr ty
+ppr_termM1 Term{} = panic "ppr_termM1 - Term"
+ppr_termM1 RefWrap{} = panic "ppr_termM1 - RefWrap"
+ppr_termM1 NewtypeWrap{} = panic "ppr_termM1 - NewtypeWrap"
+
+pprNewtypeWrap y p NewtypeWrap{ty=ty, wrapped_term=t}
+ | Just (tc,_) <- tcSplitTyConApp_maybe ty
+ , ASSERT(isNewTyCon tc) True
+ , Just new_dc <- tyConSingleDataCon_maybe tc = do
+ real_term <- y max_prec t
+ return $ cparen (p >= app_prec) (ppr new_dc <+> real_term)
+pprNewtypeWrap _ _ _ = panic "pprNewtypeWrap"
+
+-------------------------------------------------------
+-- Custom Term Pretty Printers
+-------------------------------------------------------
+
+-- We can want to customize the representation of a
+-- term depending on its type.
+-- However, note that custom printers have to work with
+-- type representations, instead of directly with types.
+-- We cannot use type classes here, unless we employ some
+-- typerep trickery (e.g. Weirich's RepLib tricks),
+-- which I didn't. Therefore, this code replicates a lot
+-- of what type classes provide for free.
+
+type CustomTermPrinter m = TermPrinterM m
+ -> [Precedence -> Term -> (m (Maybe SDoc))]
+
+-- | Takes a list of custom printers with a explicit recursion knot and a term,
+-- and returns the output of the first succesful printer, or the default printer
+cPprTerm :: Monad m => CustomTermPrinter m -> Term -> m SDoc
+cPprTerm printers_ = go 0 where
+ printers = printers_ go
+ go prec t = do
+ let default_ = Just `liftM` pprTermM go prec t
+ mb_customDocs = [pp prec t | pp <- printers] ++ [default_]
+ Just doc <- firstJustM mb_customDocs
+ return$ cparen (prec>app_prec+1) doc
+
+ firstJustM (mb:mbs) = mb >>= maybe (firstJustM mbs) (return . Just)
+ firstJustM [] = return Nothing
+
+-- Default set of custom printers. Note that the recursion knot is explicit
+cPprTermBase :: Monad m => CustomTermPrinter m
+cPprTermBase y =
+ [ ifTerm (isTupleTy.ty) (\_p -> liftM (parens . hcat . punctuate comma)
+ . mapM (y (-1))
+ . subTerms)
+ , ifTerm (\t -> isTyCon listTyCon (ty t) && subTerms t `lengthIs` 2)
+ (\ p t -> doList p t)
+ , ifTerm (isTyCon intTyCon . ty) (coerceShow$ \(a::Int)->a)
+ , ifTerm (isTyCon charTyCon . ty) (coerceShow$ \(a::Char)->a)
+ , ifTerm (isTyCon floatTyCon . ty) (coerceShow$ \(a::Float)->a)
+ , ifTerm (isTyCon doubleTyCon . ty) (coerceShow$ \(a::Double)->a)
+ , ifTerm (isIntegerTy . ty) (coerceShow$ \(a::Integer)->a)
+ ]
+ where ifTerm pred f prec t@Term{}
+ | pred t = Just `liftM` f prec t
+ ifTerm _ _ _ _ = return Nothing
+
+ isTupleTy ty = fromMaybe False $ do
+ (tc,_) <- tcSplitTyConApp_maybe ty
+ return (isBoxedTupleTyCon tc)
+
+ isTyCon a_tc ty = fromMaybe False $ do
+ (tc,_) <- tcSplitTyConApp_maybe ty
+ return (a_tc == tc)
+
+ isIntegerTy ty = fromMaybe False $ do
+ (tc,_) <- tcSplitTyConApp_maybe ty
+ return (tyConName tc == integerTyConName)
+
+ coerceShow f _p = return . text . show . f . unsafeCoerce# . val
+
+ --Note pprinting of list terms is not lazy
+ doList p (Term{subTerms=[h,t]}) = do
+ let elems = h : getListTerms t
+ isConsLast = not(termType(last elems) `coreEqType` termType h)
+ print_elems <- mapM (y cons_prec) elems
+ return$ if isConsLast
+ then cparen (p >= cons_prec)
+ . pprDeeperList fsep
+ . punctuate (space<>colon)
+ $ print_elems
+ else brackets (pprDeeperList fcat$
+ punctuate comma print_elems)
+
+ where getListTerms Term{subTerms=[h,t]} = h : getListTerms t
+ getListTerms Term{subTerms=[]} = []
+ getListTerms t@Suspension{} = [t]
+ getListTerms t = pprPanic "getListTerms" (ppr t)
+ doList _ _ = panic "doList"
+
+
+repPrim :: TyCon -> [Word] -> String
+repPrim t = rep where
+ rep x
+ | t == charPrimTyCon = show (build x :: Char)
+ | t == intPrimTyCon = show (build x :: Int)
+ | t == wordPrimTyCon = show (build x :: Word)
+ | t == floatPrimTyCon = show (build x :: Float)
+ | t == doublePrimTyCon = show (build x :: Double)
+ | t == int32PrimTyCon = show (build x :: Int32)
+ | t == word32PrimTyCon = show (build x :: Word32)
+ | t == int64PrimTyCon = show (build x :: Int64)
+ | t == word64PrimTyCon = show (build x :: Word64)
+ | t == addrPrimTyCon = show (nullPtr `plusPtr` build x)
+ | t == stablePtrPrimTyCon = "<stablePtr>"
+ | t == stableNamePrimTyCon = "<stableName>"
+ | t == statePrimTyCon = "<statethread>"
+ | t == realWorldTyCon = "<realworld>"
+ | t == threadIdPrimTyCon = "<ThreadId>"
+ | t == weakPrimTyCon = "<Weak>"
+ | t == arrayPrimTyCon = "<array>"
+ | t == byteArrayPrimTyCon = "<bytearray>"
+ | t == mutableArrayPrimTyCon = "<mutableArray>"
+ | t == mutableByteArrayPrimTyCon = "<mutableByteArray>"
+ | t == mutVarPrimTyCon= "<mutVar>"
+ | t == mVarPrimTyCon = "<mVar>"
+ | t == tVarPrimTyCon = "<tVar>"
+ | otherwise = showSDoc (char '<' <> ppr t <> char '>')
+ where build ww = unsafePerformIO $ withArray ww (peek . castPtr)
+-- This ^^^ relies on the representation of Haskell heap values being
+-- the same as in a C array.
+
+-----------------------------------
+-- Type Reconstruction
+-----------------------------------
+{-
+Type Reconstruction is type inference done on heap closures.
+The algorithm walks the heap generating a set of equations, which
+are solved with syntactic unification.
+A type reconstruction equation looks like:
+
+ <datacon reptype> = <actual heap contents>
+
+The full equation set is generated by traversing all the subterms, starting
+from a given term.
+
+The only difficult part is that newtypes are only found in the lhs of equations.
+Right hand sides are missing them. We can either (a) drop them from the lhs, or
+(b) reconstruct them in the rhs when possible.
+
+The function congruenceNewtypes takes a shot at (b)
+-}
+
+
+-- A (non-mutable) tau type containing
+-- existentially quantified tyvars.
+-- (since GHC type language currently does not support
+-- existentials, we leave these variables unquantified)
+type RttiType = Type
+
+-- An incomplete type as stored in GHCi:
+-- no polymorphism: no quantifiers & all tyvars are skolem.
+type GhciType = Type
+
+
+-- The Type Reconstruction monad
+--------------------------------
+type TR a = TcM a
+
+runTR :: HscEnv -> TR a -> IO a
+runTR hsc_env thing = do
+ mb_val <- runTR_maybe hsc_env thing
+ case mb_val of
+ Nothing -> error "unable to :print the term"
+ Just x -> return x
+
+runTR_maybe :: HscEnv -> TR a -> IO (Maybe a)
+runTR_maybe hsc_env = fmap snd . initTc hsc_env HsSrcFile False iNTERACTIVE
+
+traceTR :: SDoc -> TR ()
+traceTR = liftTcM . traceOptTcRn Opt_D_dump_rtti
+
+
+-- Semantically different to recoverM in TcRnMonad
+-- recoverM retains the errors in the first action,
+-- whereas recoverTc here does not
+recoverTR :: TR a -> TR a -> TR a
+recoverTR recover thing = do
+ (_,mb_res) <- tryTcErrs thing
+ case mb_res of
+ Nothing -> recover
+ Just res -> return res
+
+trIO :: IO a -> TR a
+trIO = liftTcM . liftIO
+
+liftTcM :: TcM a -> TR a
+liftTcM = id
+
+newVar :: Kind -> TR TcType
+newVar = liftTcM . newFlexiTyVarTy
+
+type RttiInstantiation = [(TcTyVar, TyVar)]
+ -- Associates the typechecker-world meta type variables
+ -- (which are mutable and may be refined), to their
+ -- debugger-world RuntimeUnk counterparts.
+ -- If the TcTyVar has not been refined by the runtime type
+ -- elaboration, then we want to turn it back into the
+ -- original RuntimeUnk
+
+-- | Returns the instantiated type scheme ty', and the
+-- mapping from new (instantiated) -to- old (skolem) type variables
+instScheme :: QuantifiedType -> TR (TcType, RttiInstantiation)
+instScheme (tvs, ty)
+ = liftTcM $ do { (tvs', _, subst) <- tcInstTyVars tvs
+ ; let rtti_inst = [(tv',tv) | (tv',tv) <- tvs' `zip` tvs]
+ ; return (substTy subst ty, rtti_inst) }
+
+applyRevSubst :: RttiInstantiation -> TR ()
+-- Apply the *reverse* substitution in-place to any un-filled-in
+-- meta tyvars. This recovers the original debugger-world variable
+-- unless it has been refined by new information from the heap
+applyRevSubst pairs = liftTcM (mapM_ do_pair pairs)
+ where
+ do_pair (tc_tv, rtti_tv)
+ = do { tc_ty <- zonkTcTyVar tc_tv
+ ; case tcGetTyVar_maybe tc_ty of
+ Just tv | isMetaTyVar tv -> writeMetaTyVar tv (mkTyVarTy rtti_tv)
+ _ -> return () }
+
+-- Adds a constraint of the form t1 == t2
+-- t1 is expected to come from walking the heap
+-- t2 is expected to come from a datacon signature
+-- Before unification, congruenceNewtypes needs to
+-- do its magic.
+addConstraint :: TcType -> TcType -> TR ()
+addConstraint actual expected = do
+ traceTR (text "add constraint:" <+> fsep [ppr actual, equals, ppr expected])
+ recoverTR (traceTR $ fsep [text "Failed to unify", ppr actual,
+ text "with", ppr expected]) $
+ do { (ty1, ty2) <- congruenceNewtypes actual expected
+ ; _ <- captureConstraints $ unifyType ty1 ty2
+ ; return () }
+ -- TOMDO: what about the coercion?
+ -- we should consider family instances
+
+
+-- Type & Term reconstruction
+------------------------------
+cvObtainTerm :: HscEnv -> Int -> Bool -> RttiType -> HValue -> IO Term
+cvObtainTerm hsc_env max_depth force old_ty hval = runTR hsc_env $ do
+ -- we quantify existential tyvars as universal,
+ -- as this is needed to be able to manipulate
+ -- them properly
+ let quant_old_ty@(old_tvs, old_tau) = quantifyType old_ty
+ sigma_old_ty = mkForAllTys old_tvs old_tau
+ traceTR (text "Term reconstruction started with initial type " <> ppr old_ty)
+ term <-
+ if null old_tvs
+ then do
+ term <- go max_depth sigma_old_ty sigma_old_ty hval
+ term' <- zonkTerm term
+ return $ fixFunDictionaries $ expandNewtypes term'
+ else do
+ (old_ty', rev_subst) <- instScheme quant_old_ty
+ my_ty <- newVar argTypeKind
+ when (check1 quant_old_ty) (traceTR (text "check1 passed") >>
+ addConstraint my_ty old_ty')
+ term <- go max_depth my_ty sigma_old_ty hval
+ new_ty <- zonkTcType (termType term)
+ if isMonomorphic new_ty || check2 (quantifyType new_ty) quant_old_ty
+ then do
+ traceTR (text "check2 passed")
+ addConstraint new_ty old_ty'
+ applyRevSubst rev_subst
+ zterm' <- zonkTerm term
+ return ((fixFunDictionaries . expandNewtypes) zterm')
+ else do
+ traceTR (text "check2 failed" <+> parens
+ (ppr term <+> text "::" <+> ppr new_ty))
+ -- we have unsound types. Replace constructor types in
+ -- subterms with tyvars
+ zterm' <- mapTermTypeM
+ (\ty -> case tcSplitTyConApp_maybe ty of
+ Just (tc, _:_) | tc /= funTyCon
+ -> newVar argTypeKind
+ _ -> return ty)
+ term
+ zonkTerm zterm'
+ traceTR (text "Term reconstruction completed." $$
+ text "Term obtained: " <> ppr term $$
+ text "Type obtained: " <> ppr (termType term))
+ return term
+ where
+ go :: Int -> Type -> Type -> HValue -> TcM Term
+ go max_depth _ _ _ | seq max_depth False = undefined
+ go 0 my_ty _old_ty a = do
+ traceTR (text "Gave up reconstructing a term after" <>
+ int max_depth <> text " steps")
+ clos <- trIO $ getClosureData a
+ return (Suspension (tipe clos) my_ty a Nothing)
+ go max_depth my_ty old_ty a = do
+ let monomorphic = not(isTyVarTy my_ty)
+ -- This ^^^ is a convention. The ancestor tests for
+ -- monomorphism and passes a type instead of a tv
+ clos <- trIO $ getClosureData a
+ case tipe clos of
+-- Thunks we may want to force
+ t | isThunk t && force -> traceTR (text "Forcing a " <> text (show t)) >>
+ seq a (go (pred max_depth) my_ty old_ty a)
+-- Blackholes are indirections iff the payload is not TSO or BLOCKING_QUEUE. So we
+-- treat them like indirections; if the payload is TSO or BLOCKING_QUEUE, we'll end up
+-- showing '_' which is what we want.
+ Blackhole -> do traceTR (text "Following a BLACKHOLE")
+ appArr (go max_depth my_ty old_ty) (ptrs clos) 0
+-- We always follow indirections
+ Indirection i -> do traceTR (text "Following an indirection" <> parens (int i) )
+ go max_depth my_ty old_ty $! (ptrs clos ! 0)
+-- We also follow references
+ MutVar _ | Just (tycon,[world,contents_ty]) <- tcSplitTyConApp_maybe old_ty
+ -> do
+ -- Deal with the MutVar# primitive
+ -- It does not have a constructor at all,
+ -- so we simulate the following one
+ -- MutVar# :: contents_ty -> MutVar# s contents_ty
+ traceTR (text "Following a MutVar")
+ contents_tv <- newVar liftedTypeKind
+ contents <- trIO$ IO$ \w -> readMutVar# (unsafeCoerce# a) w
+ ASSERT(isUnliftedTypeKind $ typeKind my_ty) return ()
+ (mutvar_ty,_) <- instScheme $ quantifyType $ mkFunTy
+ contents_ty (mkTyConApp tycon [world,contents_ty])
+ addConstraint (mkFunTy contents_tv my_ty) mutvar_ty
+ x <- go (pred max_depth) contents_tv contents_ty contents
+ return (RefWrap my_ty x)
+
+ -- The interesting case
+ Constr -> do
+ traceTR (text "entering a constructor " <>
+ if monomorphic
+ then parens (text "already monomorphic: " <> ppr my_ty)
+ else Outputable.empty)
+ Right dcname <- dataConInfoPtrToName (infoPtr clos)
+ (_,mb_dc) <- tryTcErrs (tcLookupDataCon dcname)
+ case mb_dc of
+ Nothing -> do -- This can happen for private constructors compiled -O0
+ -- where the .hi descriptor does not export them
+ -- In such case, we return a best approximation:
+ -- ignore the unpointed args, and recover the pointeds
+ -- This preserves laziness, and should be safe.
+ let tag = showSDoc (ppr dcname)
+ vars <- replicateM (length$ elems$ ptrs clos)
+ (newVar (liftedTypeKind))
+ subTerms <- sequence [appArr (go (pred max_depth) tv tv) (ptrs clos) i
+ | (i, tv) <- zip [0..] vars]
+ return (Term my_ty (Left ('<' : tag ++ ">")) a subTerms)
+ Just dc -> do
+ let subTtypes = matchSubTypes dc old_ty
+ subTermTvs <- mapMif (not . isMonomorphic)
+ (\t -> newVar (typeKind t))
+ subTtypes
+ let (subTermsP, subTermsNP) = partition (\(ty,_) -> isLifted ty
+ || isRefType ty)
+ (zip subTtypes subTermTvs)
+ (subTtypesP, subTermTvsP ) = unzip subTermsP
+ (subTtypesNP, _subTermTvsNP) = unzip subTermsNP
+
+ -- When we already have all the information, avoid solving
+ -- unnecessary constraints. Propagation of type information
+ -- to subterms is already being done via matching.
+ when (not monomorphic) $ do
+ let myType = mkFunTys subTermTvs my_ty
+ (signatureType,_) <- instScheme (mydataConType dc)
+ -- It is vital for newtype reconstruction that the unification step
+ -- is done right here, _before_ the subterms are RTTI reconstructed
+ addConstraint myType signatureType
+ subTermsP <- sequence
+ [ appArr (go (pred max_depth) tv t) (ptrs clos) i
+ | (i,tv,t) <- zip3 [0..] subTermTvsP subTtypesP]
+ let unboxeds = extractUnboxed subTtypesNP clos
+ subTermsNP = map (uncurry Prim) (zip subTtypesNP unboxeds)
+ subTerms = reOrderTerms subTermsP subTermsNP subTtypes
+ return (Term my_ty (Right dc) a subTerms)
+-- The otherwise case: can be a Thunk,AP,PAP,etc.
+ tipe_clos ->
+ return (Suspension tipe_clos my_ty a Nothing)
+
+ matchSubTypes dc ty
+ | ty' <- repType ty -- look through newtypes
+ , Just (tc,ty_args) <- tcSplitTyConApp_maybe ty'
+ , dc `elem` tyConDataCons tc
+ -- It is necessary to check that dc is actually a constructor for tycon tc,
+ -- because it may be the case that tc is a recursive newtype and tcSplitTyConApp
+ -- has not removed it. In that case, we happily give up and don't match
+ = myDataConInstArgTys dc ty_args
+ | otherwise = dataConRepArgTys dc
+
+ -- put together pointed and nonpointed subterms in the
+ -- correct order.
+ reOrderTerms _ _ [] = []
+ reOrderTerms pointed unpointed (ty:tys)
+ | isLifted ty || isRefType ty
+ = ASSERT2(not(null pointed)
+ , ptext (sLit "reOrderTerms") $$
+ (ppr pointed $$ ppr unpointed))
+ let (t:tt) = pointed in t : reOrderTerms tt unpointed tys
+ | otherwise = ASSERT2(not(null unpointed)
+ , ptext (sLit "reOrderTerms") $$
+ (ppr pointed $$ ppr unpointed))
+ let (t:tt) = unpointed in t : reOrderTerms pointed tt tys
+
+ -- insert NewtypeWraps around newtypes
+ expandNewtypes = foldTerm idTermFold { fTerm = worker } where
+ worker ty dc hval tt
+ | Just (tc, args) <- tcSplitTyConApp_maybe ty
+ , isNewTyCon tc
+ , wrapped_type <- newTyConInstRhs tc args
+ , Just dc' <- tyConSingleDataCon_maybe tc
+ , t' <- worker wrapped_type dc hval tt
+ = NewtypeWrap ty (Right dc') t'
+ | otherwise = Term ty dc hval tt
+
+
+ -- Avoid returning types where predicates have been expanded to dictionaries.
+ fixFunDictionaries = foldTerm idTermFold {fSuspension = worker} where
+ worker ct ty hval n | isFunTy ty = Suspension ct (dictsView ty) hval n
+ | otherwise = Suspension ct ty hval n
+
+
+-- Fast, breadth-first Type reconstruction
+------------------------------------------
+cvReconstructType :: HscEnv -> Int -> GhciType -> HValue -> IO (Maybe Type)
+cvReconstructType hsc_env max_depth old_ty hval = runTR_maybe hsc_env $ do
+ traceTR (text "RTTI started with initial type " <> ppr old_ty)
+ let sigma_old_ty@(old_tvs, _) = quantifyType old_ty
+ new_ty <-
+ if null old_tvs
+ then return old_ty
+ else do
+ (old_ty', rev_subst) <- instScheme sigma_old_ty
+ my_ty <- newVar argTypeKind
+ when (check1 sigma_old_ty) (traceTR (text "check1 passed") >>
+ addConstraint my_ty old_ty')
+ search (isMonomorphic `fmap` zonkTcType my_ty)
+ (\(ty,a) -> go ty a)
+ (Seq.singleton (my_ty, hval))
+ max_depth
+ new_ty <- zonkTcType my_ty
+ if isMonomorphic new_ty || check2 (quantifyType new_ty) sigma_old_ty
+ then do
+ traceTR (text "check2 passed" <+> ppr old_ty $$ ppr new_ty)
+ addConstraint my_ty old_ty'
+ applyRevSubst rev_subst
+ zonkRttiType new_ty
+ else traceTR (text "check2 failed" <+> parens (ppr new_ty)) >>
+ return old_ty
+ traceTR (text "RTTI completed. Type obtained:" <+> ppr new_ty)
+ return new_ty
+ where
+-- search :: m Bool -> ([a] -> [a] -> [a]) -> [a] -> m ()
+ search _ _ _ 0 = traceTR (text "Failed to reconstruct a type after " <>
+ int max_depth <> text " steps")
+ search stop expand l d =
+ case viewl l of
+ EmptyL -> return ()
+ x :< xx -> unlessM stop $ do
+ new <- expand x
+ search stop expand (xx `mappend` Seq.fromList new) $! (pred d)
+
+ -- returns unification tasks,since we are going to want a breadth-first search
+ go :: Type -> HValue -> TR [(Type, HValue)]
+ go my_ty a = do
+ clos <- trIO $ getClosureData a
+ case tipe clos of
+ Blackhole -> appArr (go my_ty) (ptrs clos) 0 -- carefully, don't eval the TSO
+ Indirection _ -> go my_ty $! (ptrs clos ! 0)
+ MutVar _ -> do
+ contents <- trIO$ IO$ \w -> readMutVar# (unsafeCoerce# a) w
+ tv' <- newVar liftedTypeKind
+ world <- newVar liftedTypeKind
+ addConstraint my_ty (mkTyConApp mutVarPrimTyCon [world,tv'])
+ return [(tv', contents)]
+ Constr -> do
+ Right dcname <- dataConInfoPtrToName (infoPtr clos)
+ (_,mb_dc) <- tryTcErrs (tcLookupDataCon dcname)
+ case mb_dc of
+ Nothing-> do
+ -- TODO: Check this case
+ forM [0..length (elems $ ptrs clos)] $ \i -> do
+ tv <- newVar liftedTypeKind
+ return$ appArr (\e->(tv,e)) (ptrs clos) i
+
+ Just dc -> do
+ subTtypes <- mapMif (not . isMonomorphic)
+ (\t -> newVar (typeKind t))
+ (dataConRepArgTys dc)
+
+ -- It is vital for newtype reconstruction that the unification step
+ -- is done right here, _before_ the subterms are RTTI reconstructed
+ let myType = mkFunTys subTtypes my_ty
+ (signatureType,_) <- instScheme (mydataConType dc)
+ addConstraint myType signatureType
+ return $ [ appArr (\e->(t,e)) (ptrs clos) i
+ | (i,t) <- zip [0..] (filter (isLifted |.| isRefType) subTtypes)]
+ _ -> return []
+
+-- Compute the difference between a base type and the type found by RTTI
+-- improveType <base_type> <rtti_type>
+-- The types can contain skolem type variables, which need to be treated as normal vars.
+-- In particular, we want them to unify with things.
+improveRTTIType :: HscEnv -> RttiType -> RttiType -> Maybe TvSubst
+improveRTTIType _ base_ty new_ty
+ = U.tcUnifyTys (const U.BindMe) [base_ty] [new_ty]
+
+myDataConInstArgTys :: DataCon -> [Type] -> [Type]
+myDataConInstArgTys dc args
+ | null (dataConExTyVars dc) && null (dataConEqTheta dc) = dataConInstArgTys dc args
+ | otherwise = dataConRepArgTys dc
+
+mydataConType :: DataCon -> QuantifiedType
+-- ^ Custom version of DataCon.dataConUserType where we
+-- - remove the equality constraints
+-- - use the representation types for arguments, including dictionaries
+-- - keep the original result type
+mydataConType dc
+ = ( (univ_tvs `minusList` map fst eq_spec) ++ ex_tvs
+ , mkFunTys arg_tys res_ty )
+ where univ_tvs = dataConUnivTyVars dc
+ ex_tvs = dataConExTyVars dc
+ eq_spec = dataConEqSpec dc
+ arg_tys = [case a of
+ PredTy p -> predTypeRep p
+ _ -> a
+ | a <- dataConRepArgTys dc]
+ res_ty = dataConOrigResTy dc
+
+isRefType :: Type -> Bool
+isRefType ty
+ | Just (tc, _) <- tcSplitTyConApp_maybe ty' = isRefTyCon tc
+ | otherwise = False
+ where ty'= repType ty
+
+isRefTyCon :: TyCon -> Bool
+isRefTyCon tc = tc `elem` [mutVarPrimTyCon, mVarPrimTyCon, tVarPrimTyCon]
+
+-- Soundness checks
+--------------------
+{-
+This is not formalized anywhere, so hold to your seats!
+RTTI in the presence of newtypes can be a tricky and unsound business.
+
+Example:
+~~~~~~~~~
+Suppose we are doing RTTI for a partially evaluated
+closure t, the real type of which is t :: MkT Int, for
+
+ newtype MkT a = MkT [Maybe a]
+
+The table below shows the results of RTTI and the improvement
+calculated for different combinations of evaluatedness and :type t.
+Regard the two first columns as input and the next two as output.
+
+ # | t | :type t | rtti(t) | improv. | result
+ ------------------------------------------------------------
+ 1 | _ | t b | a | none | OK
+ 2 | _ | MkT b | a | none | OK
+ 3 | _ | t Int | a | none | OK
+
+ If t is not evaluated at *all*, we are safe.
+
+ 4 | (_ : _) | t b | [a] | t = [] | UNSOUND
+ 5 | (_ : _) | MkT b | MkT a | none | OK (compensating for the missing newtype)
+ 6 | (_ : _) | t Int | [Int] | t = [] | UNSOUND
+
+ If a is a minimal whnf, we run into trouble. Note that
+ row 5 above does newtype enrichment on the ty_rtty parameter.
+
+ 7 | (Just _:_)| t b |[Maybe a] | t = [], | UNSOUND
+ | | | b = Maybe a|
+
+ 8 | (Just _:_)| MkT b | MkT a | none | OK
+ 9 | (Just _:_)| t Int | FAIL | none | OK
+
+ And if t is any more evaluated than whnf, we are still in trouble.
+ Because constraints are solved in top-down order, when we reach the
+ Maybe subterm what we got is already unsound. This explains why the
+ row 9 fails to complete.
+
+ 10 | (Just _:_)| t Int | [Maybe a] | FAIL | OK
+ 11 | (Just 1:_)| t Int | [Maybe Int] | FAIL | OK
+
+ We can undo the failure in row 9 by leaving out the constraint
+ coming from the type signature of t (i.e., the 2nd column).
+ Note that this type information is still used
+ to calculate the improvement. But we fail
+ when trying to calculate the improvement, as there is no unifier for
+ t Int = [Maybe a] or t Int = [Maybe Int].
+
+
+ Another set of examples with t :: [MkT (Maybe Int)] \equiv [[Maybe (Maybe Int)]]
+
+ # | t | :type t | rtti(t) | improvement | result
+ ---------------------------------------------------------------------
+ 1 |(Just _:_) | [t (Maybe a)] | [[Maybe b]] | t = [] |
+ | | | | b = Maybe a |
+
+The checks:
+~~~~~~~~~~~
+Consider a function obtainType that takes a value and a type and produces
+the Term representation and a substitution (the improvement).
+Assume an auxiliar rtti' function which does the actual job if recovering
+the type, but which may produce a false type.
+
+In pseudocode:
+
+ rtti' :: a -> IO Type -- Does not use the static type information
+
+ obtainType :: a -> Type -> IO (Maybe (Term, Improvement))
+ obtainType v old_ty = do
+ rtti_ty <- rtti' v
+ if monomorphic rtti_ty || (check rtti_ty old_ty)
+ then ...
+ else return Nothing
+ where check rtti_ty old_ty = check1 rtti_ty &&
+ check2 rtti_ty old_ty
+
+ check1 :: Type -> Bool
+ check2 :: Type -> Type -> Bool
+
+Now, if rtti' returns a monomorphic type, we are safe.
+If that is not the case, then we consider two conditions.
+
+
+1. To prevent the class of unsoundness displayed by
+ rows 4 and 7 in the example: no higher kind tyvars
+ accepted.
+
+ check1 (t a) = NO
+ check1 (t Int) = NO
+ check1 ([] a) = YES
+
+2. To prevent the class of unsoundness shown by row 6,
+ the rtti type should be structurally more
+ defined than the old type we are comparing it to.
+ check2 :: NewType -> OldType -> Bool
+ check2 a _ = True
+ check2 [a] a = True
+ check2 [a] (t Int) = False
+ check2 [a] (t a) = False -- By check1 we never reach this equation
+ check2 [Int] a = True
+ check2 [Int] (t Int) = True
+ check2 [Maybe a] (t Int) = False
+ check2 [Maybe Int] (t Int) = True
+ check2 (Maybe [a]) (m [Int]) = False
+ check2 (Maybe [Int]) (m [Int]) = True
+
+-}
+
+check1 :: QuantifiedType -> Bool
+check1 (tvs, _) = not $ any isHigherKind (map tyVarKind tvs)
+ where
+ isHigherKind = not . null . fst . splitKindFunTys
+
+check2 :: QuantifiedType -> QuantifiedType -> Bool
+check2 (_, rtti_ty) (_, old_ty)
+ | Just (_, rttis) <- tcSplitTyConApp_maybe rtti_ty
+ = case () of
+ _ | Just (_,olds) <- tcSplitTyConApp_maybe old_ty
+ -> and$ zipWith check2 (map quantifyType rttis) (map quantifyType olds)
+ _ | Just _ <- splitAppTy_maybe old_ty
+ -> isMonomorphicOnNonPhantomArgs rtti_ty
+ _ -> True
+ | otherwise = True
+
+-- Dealing with newtypes
+--------------------------
+{-
+ congruenceNewtypes does a parallel fold over two Type values,
+ compensating for missing newtypes on both sides.
+ This is necessary because newtypes are not present
+ in runtime, but sometimes there is evidence available.
+ Evidence can come from DataCon signatures or
+ from compile-time type inference.
+ What we are doing here is an approximation
+ of unification modulo a set of equations derived
+ from newtype definitions. These equations should be the
+ same as the equality coercions generated for newtypes
+ in System Fc. The idea is to perform a sort of rewriting,
+ taking those equations as rules, before launching unification.
+
+ The caller must ensure the following.
+ The 1st type (lhs) comes from the heap structure of ptrs,nptrs.
+ The 2nd type (rhs) comes from a DataCon type signature.
+ Rewriting (i.e. adding/removing a newtype wrapper) can happen
+ in both types, but in the rhs it is restricted to the result type.
+
+ Note that it is very tricky to make this 'rewriting'
+ work with the unification implemented by TcM, where
+ substitutions are operationally inlined. The order in which
+ constraints are unified is vital as we cannot modify
+ anything that has been touched by a previous unification step.
+Therefore, congruenceNewtypes is sound only if the types
+recovered by the RTTI mechanism are unified Top-Down.
+-}
+congruenceNewtypes :: TcType -> TcType -> TR (TcType,TcType)
+congruenceNewtypes lhs rhs = go lhs rhs >>= \rhs' -> return (lhs,rhs')
+ where
+ go l r
+ -- TyVar lhs inductive case
+ | Just tv <- getTyVar_maybe l
+ , isTcTyVar tv
+ , isMetaTyVar tv
+ = recoverTR (return r) $ do
+ Indirect ty_v <- readMetaTyVar tv
+ traceTR $ fsep [text "(congruence) Following indirect tyvar:",
+ ppr tv, equals, ppr ty_v]
+ go ty_v r
+-- FunTy inductive case
+ | Just (l1,l2) <- splitFunTy_maybe l
+ , Just (r1,r2) <- splitFunTy_maybe r
+ = do r2' <- go l2 r2
+ r1' <- go l1 r1
+ return (mkFunTy r1' r2')
+-- TyconApp Inductive case; this is the interesting bit.
+ | Just (tycon_l, _) <- tcSplitTyConApp_maybe lhs
+ , Just (tycon_r, _) <- tcSplitTyConApp_maybe rhs
+ , tycon_l /= tycon_r
+ = upgrade tycon_l r
+
+ | otherwise = return r
+
+ where upgrade :: TyCon -> Type -> TR Type
+ upgrade new_tycon ty
+ | not (isNewTyCon new_tycon) = do
+ traceTR (text "(Upgrade) Not matching newtype evidence: " <>
+ ppr new_tycon <> text " for " <> ppr ty)
+ return ty
+ | otherwise = do
+ traceTR (text "(Upgrade) upgraded " <> ppr ty <>
+ text " in presence of newtype evidence " <> ppr new_tycon)
+ vars <- mapM (newVar . tyVarKind) (tyConTyVars new_tycon)
+ let ty' = mkTyConApp new_tycon vars
+ _ <- liftTcM (unifyType ty (repType ty'))
+ -- assumes that reptype doesn't ^^^^ touch tyconApp args
+ return ty'
+
+
+zonkTerm :: Term -> TcM Term
+zonkTerm = foldTermM (TermFoldM
+ { fTermM = \ty dc v tt -> zonkRttiType ty >>= \ty' ->
+ return (Term ty' dc v tt)
+ , fSuspensionM = \ct ty v b -> zonkRttiType ty >>= \ty ->
+ return (Suspension ct ty v b)
+ , fNewtypeWrapM = \ty dc t -> zonkRttiType ty >>= \ty' ->
+ return$ NewtypeWrap ty' dc t
+ , fRefWrapM = \ty t -> return RefWrap `ap`
+ zonkRttiType ty `ap` return t
+ , fPrimM = (return.) . Prim })
+
+zonkRttiType :: TcType -> TcM Type
+-- Zonk the type, replacing any unbound Meta tyvars
+-- by skolems, safely out of Meta-tyvar-land
+zonkRttiType = zonkType (mkZonkTcTyVar zonk_unbound_meta)
+ where
+ zonk_unbound_meta tv
+ = ASSERT( isTcTyVar tv )
+ do { tv' <- skolemiseUnboundMetaTyVar tv RuntimeUnk
+ -- This is where RuntimeUnks are born:
+ -- otherwise-unconstrained unification variables are
+ -- turned into RuntimeUnks as they leave the
+ -- typechecker's monad
+ ; return (mkTyVarTy tv') }
+
+--------------------------------------------------------------------------------
+-- Restore Class predicates out of a representation type
+dictsView :: Type -> Type
+-- dictsView ty = ty
+dictsView (FunTy (TyConApp tc_dict args) ty)
+ | Just c <- tyConClass_maybe tc_dict
+ = FunTy (PredTy (ClassP c args)) (dictsView ty)
+dictsView ty
+ | Just (tc_fun, [TyConApp tc_dict args, ty2]) <- tcSplitTyConApp_maybe ty
+ , Just c <- tyConClass_maybe tc_dict
+ = mkTyConApp tc_fun [PredTy (ClassP c args), dictsView ty2]
+dictsView ty = ty
+
+
+-- Use only for RTTI types
+isMonomorphic :: RttiType -> Bool
+isMonomorphic ty = noExistentials && noUniversals
+ where (tvs, _, ty') = tcSplitSigmaTy ty
+ noExistentials = isEmptyVarSet (tyVarsOfType ty')
+ noUniversals = null tvs
+
+-- Use only for RTTI types
+isMonomorphicOnNonPhantomArgs :: RttiType -> Bool
+isMonomorphicOnNonPhantomArgs ty
+ | Just (tc, all_args) <- tcSplitTyConApp_maybe (repType ty)
+ , phantom_vars <- tyConPhantomTyVars tc
+ , concrete_args <- [ arg | (tyv,arg) <- tyConTyVars tc `zip` all_args
+ , tyv `notElem` phantom_vars]
+ = all isMonomorphicOnNonPhantomArgs concrete_args
+ | Just (ty1, ty2) <- splitFunTy_maybe ty
+ = all isMonomorphicOnNonPhantomArgs [ty1,ty2]
+ | otherwise = isMonomorphic ty
+
+tyConPhantomTyVars :: TyCon -> [TyVar]
+tyConPhantomTyVars tc
+ | isAlgTyCon tc
+ , Just dcs <- tyConDataCons_maybe tc
+ , dc_vars <- concatMap dataConUnivTyVars dcs
+ = tyConTyVars tc \\ dc_vars
+tyConPhantomTyVars _ = []
+
+type QuantifiedType = ([TyVar], Type) -- Make the free type variables explicit
+
+quantifyType :: Type -> QuantifiedType
+-- Generalize the type: find all free tyvars and wrap in the appropiate ForAll.
+quantifyType ty = (varSetElems (tyVarsOfType ty), ty)
+
+mapMif :: Monad m => (a -> Bool) -> (a -> m a) -> [a] -> m [a]
+mapMif pred f xx = sequence $ mapMif_ pred f xx
+ where
+ mapMif_ _ _ [] = []
+ mapMif_ pred f (x:xx) = (if pred x then f x else return x) : mapMif_ pred f xx
+
+unlessM :: Monad m => m Bool -> m () -> m ()
+unlessM condM acc = condM >>= \c -> unless c acc
+
+
+-- Strict application of f at index i
+appArr :: Ix i => (e -> a) -> Array i e -> Int -> a
+appArr f a@(Array _ _ _ ptrs#) i@(I# i#)
+ = ASSERT2 (i < length(elems a), ppr(length$ elems a, i))
+ case indexArray# ptrs# i# of
+ (# e #) -> f e
+
+amap' :: (t -> b) -> Array Int t -> [b]
+amap' f (Array i0 i _ arr#) = map g [0 .. i - i0]
+ where g (I# i#) = case indexArray# arr# i# of
+ (# e #) -> f e
+
+
+isLifted :: Type -> Bool
+isLifted = not . isUnLiftedType
+
+extractUnboxed :: [Type] -> Closure -> [[Word]]
+extractUnboxed tt clos = go tt (nonPtrs clos)
+ where sizeofType t
+ | Just (tycon,_) <- tcSplitTyConApp_maybe t
+ = ASSERT (isPrimTyCon tycon) sizeofTyCon tycon
+ | otherwise = pprPanic "Expected a TcTyCon" (ppr t)
+ go [] _ = []
+ go (t:tt) xx
+ | (x, rest) <- splitAt (sizeofType t) xx
+ = x : go tt rest
+
+sizeofTyCon :: TyCon -> Int -- in *words*
+sizeofTyCon = primRepSizeW . tyConPrimRep
+
+
+(|.|) :: (a -> Bool) -> (a -> Bool) -> a -> Bool
+(f |.| g) x = f x || g x
projects / ghc-hetmet.git / blobdiff