-----------------------------------------------------------------------------
module RtClosureInspect(
-
cvObtainTerm, -- :: HscEnv -> Int -> Bool -> Maybe Type -> HValue -> IO Term
-
- Term(..),
- isTerm,
- isSuspension,
- isPrim,
- isNewtypeWrap,
- pprTerm,
- cPprTerm,
- cPprTermBase,
- CustomTermPrinter,
- termType,
- foldTerm,
- TermFold(..),
- idTermFold,
- idTermFoldM,
- isFullyEvaluated,
- isPointed,
- isFullyEvaluatedTerm,
- mapTermType,
- termTyVars,
--- unsafeDeepSeq,
cvReconstructType,
improveRTTIType,
- sigmaType,
- Closure(..),
- getClosureData,
- ClosureType(..),
- isConstr,
- isIndirection
- ) where
+
+ 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,
+
+ sigmaType
+ ) where
#include "HsVersions.h"
import ByteCodeItbls ( StgInfoTable )
import qualified ByteCodeItbls as BCI( StgInfoTable(..) )
-import HscTypes ( HscEnv )
+import HscTypes
import Linker
import DataCon
import Type
+import TypeRep -- I know I know, this is cheating
import Var
import TcRnMonad
import TcType
import TcMType
import TcUnify
import TcEnv
-import DriverPhases
+
import TyCon
import Name
import VarEnv
import Util
import VarSet
-
import TysPrim
import PrelNames
import TysWiredIn
-
+import DynFlags
import Outputable
import FastString
import Panic
import Data.Maybe
import Data.Array.Base
import Data.Ix
-import Data.List ( partition )
+import Data.List
import qualified Data.Sequence as Seq
import Data.Monoid
import Data.Sequence hiding (null, length, index, take, drop, splitAt, reverse)
---------------------------------------------
-- * A representation of semi evaluated Terms
---------------------------------------------
-{-
-
--}
-data Term = Term { ty :: Type
+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
, val :: HValue
, subTerms :: [Term] }
- | Prim { ty :: Type
+ | Prim { ty :: RttiType
, value :: [Word] }
| Suspension { ctype :: ClosureType
- , ty :: Type
+ , ty :: RttiType
, val :: HValue
, bound_to :: Maybe Name -- Useful for printing
}
- | NewtypeWrap{ ty :: Type
+ | 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 { ty :: Type
+ | RefWrap { -- The contents of a reference
+ ty :: RttiType
, wrapped_term :: Term }
-isTerm, isSuspension, isPrim, isNewtypeWrap :: Term -> Bool
+isTerm, isSuspension, isPrim, isFun, isFunLike, isNewtypeWrap :: Term -> Bool
isTerm Term{} = True
isTerm _ = False
isSuspension Suspension{} = True
isNewtypeWrap NewtypeWrap{} = True
isNewtypeWrap _ = False
-termType :: Term -> Type
+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
| PAP
| Indirection Int
| MutVar Int
+ | MVar Int
| Other Int
deriving (Show, Eq)
| i' == aP_CODE = AP
| i == AP_STACK = AP
| i' == pAP_CODE = PAP
- | i == MUT_VAR_CLEAN || i == MUT_VAR_DIRTY = MutVar i'
+ | 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
_ -> return False
where amapM f = sequence . amap' f
-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
-
-- TODO: Fix it. Probably the otherwise case is failing, trace/debug it
{-
unsafeDeepSeq :: a -> b -> b
closure -> foldl' (flip unsafeDeepSeq) b (ptrs closure)
where tipe = unsafePerformIO (getClosureType a)
-}
-isPointed :: Type -> Bool
-isPointed t | Just (t, _) <- splitTyConApp_maybe t
- = not$ isUnliftedTypeKind (tyConKind t)
-isPointed _ = True
-
-extractUnboxed :: [Type] -> Closure -> [[Word]]
-extractUnboxed tt clos = go tt (nonPtrs clos)
- where sizeofType t
- | Just (tycon,_) <- splitTyConApp_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
-----------------------------------
-- * Traversals for Terms
-----------------------------------
-type TermProcessor a b = Type -> Either String DataCon -> HValue -> [a] -> b
+type TermProcessor a b = RttiType -> Either String DataCon -> HValue -> [a] -> b
data TermFold a = TermFold { fTerm :: TermProcessor a a
- , fPrim :: Type -> [Word] -> a
- , fSuspension :: ClosureType -> Type -> HValue
+ , fPrim :: RttiType -> [Word] -> a
+ , fSuspension :: ClosureType -> RttiType -> HValue
-> Maybe Name -> a
- , fNewtypeWrap :: Type -> Either String DataCon
+ , fNewtypeWrap :: RttiType -> Either String DataCon
-> a -> a
- , fRefWrap :: Type -> 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 (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,
fNewtypeWrap = NewtypeWrap,
fRefWrap = RefWrap
}
-idTermFoldM :: Monad m => TermFold (m Term)
-idTermFoldM = TermFold {
- fTerm = \ty dc v tt -> sequence tt >>= return . Term ty dc v,
- fPrim = (return.). Prim,
- fSuspension = (((return.).).). Suspension,
- fNewtypeWrap= \ty dc t -> NewtypeWrap ty dc `liftM` t,
- fRefWrap = \ty t -> RefWrap ty `liftM` t
- }
-mapTermType :: (Type -> Type) -> Term -> Term
+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 ->
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 ->
ppr_termM1 :: Monad m => Term -> m SDoc
ppr_termM1 Prim{value=words, ty=ty} =
return$ text$ repPrim (tyConAppTyCon ty) words
-ppr_termM1 Suspension{bound_to=Nothing} = return$ char '_'
+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>")
+-- | 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"
ifTerm _ _ _ _ = return Nothing
isIntegerTy ty = fromMaybe False $ do
- (tc,_) <- splitTyConApp_maybe ty
+ (tc,_) <- tcSplitTyConApp_maybe ty
return (tyConName tc == integerTyConName)
isTupleTy ty = fromMaybe False $ do
- (tc,_) <- splitTyConApp_maybe ty
+ (tc,_) <- tcSplitTyConApp_maybe ty
return (isBoxedTupleTyCon tc)
isTyCon a_tc ty = fromMaybe False $ do
- (tc,_) <- splitTyConApp_maybe ty
+ (tc,_) <- tcSplitTyConApp_maybe ty
return (a_tc == tc)
coerceShow f _p = return . text . show . f . unsafeCoerce# . val
-- The Type Reconstruction monad
type TR a = TcM a
+-- 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
+{-
runTR :: HscEnv -> TR a -> IO a
-runTR hsc_env c = do
+runTR hsc_env c = do
mb_term <- runTR_maybe hsc_env c
case mb_term of
- Nothing -> panic "Can't unify"
+ Nothing -> panic "RTTI: Failed to reconstruct a term"
+ Just x -> return x
+-}
+
+runTR :: HscEnv -> TR a -> IO a
+runTR hsc_env thing = do
+ mb_val <- runTR_maybe hsc_env thing
+ case mb_val of
+ Nothing -> error "RTTI error: probably due to :forcing an undefined"
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 . traceTc
+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 = id
newVar :: Kind -> TR TcType
-newVar = liftTcM . fmap mkTyVarTy . newBoxyTyVar
+newVar = liftTcM . liftM mkTyVarTy . newBoxyTyVar
-- | Returns the instantiated type scheme ty', and the substitution sigma
-- such that sigma(ty') = ty
instScheme :: Type -> TR (TcType, TvSubst)
-instScheme ty | (tvs, _rho) <- tcSplitForAllTys ty = liftTcM$ do
- (tvs',_theta,ty') <- tcInstType (mapM tcInstTyVar) ty
+instScheme ty = liftTcM$ do
+ (tvs, _, _) <- tcInstType return ty
+ (tvs',_,ty') <- tcInstType (mapM tcInstTyVar) ty
return (ty', zipTopTvSubst tvs' (mkTyVarTys tvs))
-- Adds a constraint of the form t1 == t2
-- Before unification, congruenceNewtypes needs to
-- do its magic.
addConstraint :: TcType -> TcType -> TR ()
-addConstraint t1 t2 = congruenceNewtypes t1 t2 >>= uncurry boxyUnify
- >> return () -- TOMDO: what about the coercion?
- -- we should consider family instances
+addConstraint actual expected = do
+ traceTR $ fsep [text "add constraint:", ppr actual, equals, ppr expected]
+ recoverTR (traceTR $ fsep [text "Failed to unify", ppr actual,
+ text "with", ppr expected])
+ (congruenceNewtypes actual expected >>=
+ uncurry boxyUnify >> return ())
+ -- TOMDO: what about the coercion?
+ -- we should consider family instances
-- Type & Term reconstruction
-cvObtainTerm :: HscEnv -> Int -> Bool -> Maybe Type -> HValue -> IO Term
-cvObtainTerm hsc_env bound force mb_ty hval = runTR hsc_env $ do
- tv <- newVar argTypeKind
- case mb_ty of
- Nothing -> go bound tv tv hval
- >>= zonkTerm
- >>= return . expandNewtypes
- Just ty | isMonomorphic ty -> go bound ty ty hval
- >>= zonkTerm
- >>= return . expandNewtypes
- Just ty -> do
- (ty',rev_subst) <- instScheme (sigmaType ty)
- addConstraint tv ty'
- term <- go bound tv tv hval >>= zonkTerm
- --restore original Tyvars
- return$ expandNewtypes $ mapTermType (substTy rev_subst) term
+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 sigma_old_ty = sigmaType old_ty
+ traceTR (text "Term reconstruction started with initial type " <> ppr old_ty)
+ term <-
+ if isMonomorphic sigma_old_ty
+ then do
+ new_ty <- go max_depth sigma_old_ty sigma_old_ty hval >>= zonkTerm
+ return $ fixFunDictionaries $ expandNewtypes new_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')
+ term <- go max_depth my_ty sigma_old_ty hval
+ zterm <- zonkTerm term
+ let new_ty = termType zterm
+ if isMonomorphic new_ty || check2 (sigmaType new_ty) sigma_old_ty
+ then do
+ traceTR (text "check2 passed")
+ addConstraint (termType term) old_ty'
+ zterm' <- zonkTerm term
+ return ((fixFunDictionaries . expandNewtypes . mapTermType (substTy rev_subst)) zterm')
+ else do
+ traceTR (text "check2 failed" <+> parens
+ (ppr zterm <+> 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)
+ zterm
+ zonkTerm zterm'
+ traceTR (text "Term reconstruction completed. Term obtained: " <> ppr term)
+ return term
where
- go bound _ _ _ | seq bound False = undefined
- go 0 tv _ty a = do
+ go :: Int -> Type -> Type -> HValue -> TcM Term
+ go max_depth _ _ _ | seq max_depth False = undefined
+ go 0 my_ty _old_ty a = do
clos <- trIO $ getClosureData a
- return (Suspension (tipe clos) tv a Nothing)
- go bound tv ty a = do
- let monomorphic = not(isTyVarTy tv)
+ 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
-- NB. this won't attempt to force a BLACKHOLE. Even with :force, we never
-- force blackholes, because it would almost certainly result in deadlock,
-- and showing the '_' is more useful.
- t | isThunk t && force -> seq a $ go (pred bound) tv ty a
--- We always follow indirections
- Indirection _ -> go bound tv ty $! (ptrs clos ! 0)
+ t | isThunk t && force -> traceTR (text "Forcing a " <> text (show t)) >>
+ seq a (go (pred max_depth) my_ty old_ty a)
+-- We always follow indirections
+ Indirection i -> do traceTR (text "Following an indirection" <> parens (int i) )
+ go max_depth my_ty old_ty $! (ptrs clos ! 0)
-- We also follow references
- MutVar _ | Just (tycon,[world,ty_contents]) <- splitTyConApp_maybe ty
- -- , tycon == mutVarPrimTyCon
+ MutVar _ | Just (tycon,[world,contents_ty]) <- tcSplitTyConApp_maybe old_ty
-> do
+ -- Deal with the MutVar# primitive
+ -- It does not have a constructor at all,
+ -- so we simulate the following one
+ -- MutVar# :: contents_ty -> MutVar# s contents_ty
+ traceTR (text "Following a MutVar")
+ contents_tv <- newVar liftedTypeKind
contents <- trIO$ IO$ \w -> readMutVar# (unsafeCoerce# a) w
- tv' <- newVar liftedTypeKind
- addConstraint tv (mkTyConApp tycon [world,tv'])
- x <- go bound tv' ty_contents contents
- return (RefWrap ty x)
+ ASSERT(isUnliftedTypeKind $ typeKind my_ty) return ()
+ (mutvar_ty,_) <- instScheme $ sigmaType $ 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")
Right dcname <- dataConInfoPtrToName (infoPtr clos)
(_,mb_dc) <- tryTcErrs (tcLookupDataCon dcname)
case mb_dc of
let tag = showSDoc (ppr dcname)
vars <- replicateM (length$ elems$ ptrs clos)
(newVar (liftedTypeKind))
- subTerms <- sequence [appArr (go (pred bound) tv tv) (ptrs clos) i
+ subTerms <- sequence [appArr (go (pred max_depth) tv tv) (ptrs clos) i
| (i, tv) <- zip [0..] vars]
- return (Term tv (Left ('<' : tag ++ ">")) a subTerms)
- Just dc -> do
- let extra_args = length(dataConRepArgTys dc) -
- length(dataConOrigArgTys dc)
- subTtypes = matchSubTypes dc ty
- (subTtypesP, subTtypesNP) = partition isPointed subTtypes
- subTermTvs <- sequence
- [ if isMonomorphic t then return t
- else (newVar k)
- | (t,k) <- zip subTtypesP (map typeKind subTtypesP)]
+ return (Term my_ty (Left ('<' : tag ++ ">")) a subTerms)
+ Just dc -> do
+ let subTtypes = matchSubTypes dc old_ty
+ (subTtypesP, subTtypesNP) = partition (isLifted |.| isRefType) subTtypes
+ subTermTvs <- mapMif (not . isMonomorphic)
+ (\t -> newVar (typeKind t))
+ subTtypes
-- It is vital for newtype reconstruction that the unification step
- -- is done right here, _before_ the subterms are RTTI reconstructed
+ -- is done right here, _before_ the subterms are RTTI reconstructed
when (not monomorphic) $ do
- let myType = mkFunTys (reOrderTerms subTermTvs
- subTtypesNP
- subTtypes)
- tv
- (signatureType,_) <- instScheme(dataConRepType dc)
- addConstraint myType signatureType
- subTermsP <- sequence $ drop extra_args
- -- \^^^ all extra arguments are pointed
- [ appArr (go (pred bound) tv t) (ptrs clos) i
+
+ -- When we already have all the information, avoid solving
+ -- unnecessary constraints. Propagation of type information
+ -- to subterms is already being done via matching.
+ let myType = mkFunTys subTermTvs my_ty
+ (signatureType,_) <- instScheme (rttiView $ dataConUserType dc)
+ addConstraint myType signatureType
+ subTermsP <- sequence
+ [ appArr (go (pred max_depth) tv t) (ptrs clos) i
| (i,tv,t) <- zip3 [0..] subTermTvs subTtypesP]
let unboxeds = extractUnboxed subTtypesNP clos
subTermsNP = map (uncurry Prim) (zip subTtypesNP unboxeds)
- subTerms = reOrderTerms subTermsP subTermsNP
- (drop extra_args subTtypes)
- return (Term tv (Right dc) a subTerms)
+ 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 tv a Nothing)
+ return (Suspension tipe_clos my_ty a Nothing)
matchSubTypes dc ty
- | Just (_,ty_args) <- splitTyConApp_maybe (repType ty)
--- assumption: ^^^ looks through newtypes
- , isVanillaDataCon dc --TODO non-vanilla case
- = dataConInstArgTys dc ty_args
+ | 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
--- This is used to put together pointed and nonpointed subterms in the
--- correct order.
+ -- put together pointed and nonpointed subterms in the
+ -- correct order.
reOrderTerms _ _ [] = []
reOrderTerms pointed unpointed (ty:tys)
- | isPointed ty = ASSERT2(not(null pointed)
+ | 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") $$
+ , ptext (sLit "Reorderterms") $$
(ppr pointed $$ ppr unpointed))
let (t:tt) = unpointed in t : reOrderTerms pointed tt tys
-
- expandNewtypes t@Term{ ty=ty, subTerms=tt }
- | Just (tc, args) <- tcSplitTyConApp_maybe ty
- , isNewTyCon tc
- , wrapped_type <- newTyConInstRhs tc args
- , Just dc <- tyConSingleDataCon_maybe tc
- , t' <- expandNewtypes t{ ty = wrapped_type
- , subTerms = map expandNewtypes tt }
- = NewtypeWrap ty (Right dc) t'
- | otherwise = t{ subTerms = map expandNewtypes tt }
+ -- 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
+
- expandNewtypes t = t
+ -- 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 -> Maybe Type -> HValue -> IO (Maybe Type)
-cvReconstructType hsc_env max_depth mb_ty hval = runTR_maybe hsc_env $ do
- tv <- newVar argTypeKind
- case mb_ty of
- Nothing -> do search (isMonomorphic `fmap` zonkTcType tv)
- (uncurry go)
- (Seq.singleton (tv, hval))
- max_depth
- zonkTcType tv -- TODO untested!
- Just ty | isMonomorphic ty -> return ty
- Just ty -> do
- (ty',rev_subst) <- instScheme (sigmaType ty)
- addConstraint tv ty'
- search (isMonomorphic `fmap` zonkTcType tv)
- (\(ty,a) -> go ty a)
- (Seq.singleton (tv, hval))
- max_depth
- substTy rev_subst `fmap` zonkTcType tv
- where
+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 = sigmaType old_ty
+ new_ty <-
+ if isMonomorphic sigma_old_ty
+ 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 (sigmaType new_ty) sigma_old_ty
+ then do
+ traceTR (text "check2 passed")
+ addConstraint my_ty old_ty'
+ new_ty' <- zonkTcType my_ty
+ return (substTy rev_subst 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")
-- returns unification tasks,since we are going to want a breadth-first search
go :: Type -> HValue -> TR [(Type, HValue)]
- go tv a = do
+ go my_ty a = do
clos <- trIO $ getClosureData a
case tipe clos of
- Indirection _ -> go tv $! (ptrs clos ! 0)
+ Indirection _ -> go my_ty $! (ptrs clos ! 0)
MutVar _ -> do
contents <- trIO$ IO$ \w -> readMutVar# (unsafeCoerce# a) w
tv' <- newVar liftedTypeKind
world <- newVar liftedTypeKind
- addConstraint tv (mkTyConApp mutVarPrimTyCon [world,tv'])
--- x <- go tv' ty_contents contents
+ addConstraint my_ty (mkTyConApp mutVarPrimTyCon [world,tv'])
return [(tv', contents)]
Constr -> do
Right dcname <- dataConInfoPtrToName (infoPtr clos)
return$ appArr (\e->(tv,e)) (ptrs clos) i
Just dc -> do
- let extra_args = length(dataConRepArgTys dc) -
- length(dataConOrigArgTys dc)
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 tv
- (signatureType,_) <- instScheme(dataConRepType dc)
+ let myType = mkFunTys subTtypes my_ty
+ (signatureType,_) <- instScheme(rttiView $ dataConUserType dc)
addConstraint myType signatureType
return $ [ appArr (\e->(t,e)) (ptrs clos) i
- | (i,t) <- drop extra_args $
- zip [0..] (filter isPointed subTtypes)]
+ | (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 -> Type -> Type -> IO (Maybe TvSubst)
-improveRTTIType hsc_env ty rtti_ty = runTR_maybe hsc_env $ do
- let (_,ty0) = splitForAllTys ty
- ty_tvs = varSetElems $ tyVarsOfType ty0
- let (_,rtti_ty0)= splitForAllTys rtti_ty
- rtti_tvs = varSetElems $ tyVarsOfType rtti_ty0
- (ty_tvs',_,ty')<- tcInstType (mapM tcInstTyVar) (mkSigmaTy ty_tvs [] ty0)
- (_,_,rtti_ty') <- tcInstType (mapM tcInstTyVar) (mkSigmaTy rtti_tvs [] rtti_ty0)
+improveRTTIType :: HscEnv -> RttiType -> RttiType -> IO (Maybe TvSubst)
+improveRTTIType hsc_env _ty rtti_ty = runTR_maybe hsc_env $ do
+ traceTR $ fsep [text "improveRttiType", ppr _ty, ppr rtti_ty]
+ (ty_tvs, _, _) <- tcInstType return ty
+ (ty_tvs', _, ty') <- tcInstType (mapM tcInstTyVar) ty
+ (_, _, rtti_ty') <- tcInstType (mapM tcInstTyVar) (sigmaType rtti_ty)
boxyUnify rtti_ty' ty'
- tvs1_contents <- zonkTcTyVars ty_tvs'
- let subst = uncurry zipTopTvSubst
- (unzip [(tv,ty) | tv <- ty_tvs, ty <- tvs1_contents
- , getTyVar_maybe ty /= Just tv
- , not(isTyVarTy ty)])
--- liftIO $ hPutStrLn stderr $ showSDocDebug $ text "unify " <+> sep [ppr ty, ppr rtti_ty, equals, ppr subst ]
+ tvs1_contents <- zonkTcTyVars ty_tvs'
+ let subst = (uncurry zipTopTvSubst . unzip)
+ [(tv,ty) | (tv,ty) <- zip ty_tvs tvs1_contents
+ , getTyVar_maybe ty /= Just tv
+ --, not(isTyVarTy ty)
+ ]
return subst
+ where ty = sigmaType _ty
+
+myDataConInstArgTys :: DataCon -> [Type] -> [Type]
+myDataConInstArgTys dc args
+ | null (dataConExTyVars dc) && null (dataConEqTheta dc) = dataConInstArgTys dc args
+ | otherwise = dataConRepArgTys 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 :: OldType -> NewTy pe -> 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 :: Type -> Bool
+check1 ty | (tvs, _, _) <- tcSplitSigmaTy ty = not $ any isHigherKind (map tyVarKind tvs)
+ where
+ isHigherKind = not . null . fst . splitKindFunTys
+
+check2 :: Type -> Type -> Bool
+check2 sigma_rtti_ty sigma_old_ty
+ | Just (_, rttis) <- tcSplitTyConApp_maybe rtti_ty
+ = case () of
+ _ | Just (_,olds) <- tcSplitTyConApp_maybe old_ty
+ -> and$ zipWith check2 rttis olds
+ _ | Just _ <- splitAppTy_maybe old_ty
+ -> isMonomorphicOnNonPhantomArgs rtti_ty
+ _ -> True
+ | otherwise = True
+ where (_, _ , rtti_ty) = tcSplitSigmaTy sigma_rtti_ty
+ (_, _ , old_ty) = tcSplitSigmaTy sigma_old_ty
+
-- Dealing with newtypes
+--------------------------
{-
congruenceNewtypes does a parallel fold over two Type values,
compensating for missing newtypes on both sides.
recovered by the RTTI mechanism are unified Top-Down.
-}
congruenceNewtypes :: TcType -> TcType -> TR (TcType,TcType)
-congruenceNewtypes lhs rhs
+congruenceNewtypes lhs rhs = go lhs rhs >>= \rhs' -> return (lhs,rhs')
+ where
+ go l r
-- TyVar lhs inductive case
- | Just tv <- getTyVar_maybe lhs
- = recoverTc (return (lhs,rhs)) $ do
+ | Just tv <- getTyVar_maybe l
+ = recoverTR (return r) $ do
Indirect ty_v <- readMetaTyVar tv
- (_lhs1, rhs1) <- congruenceNewtypes ty_v rhs
- return (lhs, rhs1)
+ 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 lhs
- , Just (r1,r2) <- splitFunTy_maybe rhs
- = do (l2',r2') <- congruenceNewtypes l2 r2
- (l1',r1') <- congruenceNewtypes l1 r1
- return (mkFunTy l1' l2', mkFunTy r1' r2')
+ | 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
- = do rhs' <- upgrade tycon_l rhs
- return (lhs, rhs')
+ = upgrade tycon_l r
- | otherwise = return (lhs,rhs)
+ | otherwise = return r
where upgrade :: TyCon -> Type -> TR Type
upgrade new_tycon ty
- | not (isNewTyCon new_tycon) = return ty
- | otherwise = do
+ | 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'))
+ liftTcM (boxyUnify 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 -> zonkTcType ty >>= \ty' ->
+ return (Term ty' dc v tt)
+ ,fSuspensionM = \ct ty v b -> zonkTcType ty >>= \ty ->
+ return (Suspension ct ty v b)
+ ,fNewtypeWrapM= \ty dc t -> zonkTcType ty >>= \ty' ->
+ return$ NewtypeWrap ty' dc t
+ ,fRefWrapM = \ty t ->
+ return RefWrap `ap` zonkTcType ty `ap` return t
+ ,fPrimM = (return.) . Prim
+ }
+
--------------------------------------------------------------------------------
--- Semantically different to recoverM in TcRnMonad
--- recoverM retains the errors in the first action,
--- whereas recoverTc here does not
-recoverTc :: TcM a -> TcM a -> TcM a
-recoverTc recover thing = do
- (_,mb_res) <- tryTcErrs thing
- case mb_res of
- Nothing -> recover
- Just res -> return res
+-- representation types for thetas
+rttiView :: Type -> Type
+rttiView ty | Just ty' <- coreView ty = rttiView ty'
+rttiView ty
+ | (tvs, theta, tau) <- tcSplitSigmaTy ty
+ = mkForAllTys tvs (mkFunTys [predTypeRep p | p <- theta, isClassPred p] tau)
+
+-- 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 _ = []
+
+-- Is this defined elsewhere?
+-- Generalize the type: find all free tyvars and wrap in the appropiate ForAll.
+sigmaType :: Type -> Type
+sigmaType ty = mkSigmaTy (varSetElems$ tyVarsOfType ty) [] ty
-isMonomorphic :: Type -> Bool
-isMonomorphic ty | (tvs, ty') <- splitForAllTys ty
- = null tvs && (isEmptyVarSet . tyVarsOfType) ty'
mapMif :: Monad m => (a -> Bool) -> (a -> m a) -> [a] -> m [a]
mapMif pred f xx = sequence $ 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#)
- = ASSERT (i < length(elems a))
+ = ASSERT2 (i < length(elems a), ppr(length$ elems a, i))
case indexArray# ptrs# i# of
(# e #) -> f e
-zonkTerm :: Term -> TcM Term
-zonkTerm = foldTerm idTermFoldM {
- fTerm = \ty dc v tt -> sequence tt >>= \tt ->
- zonkTcType ty >>= \ty' ->
- return (Term ty' dc v tt)
- ,fSuspension = \ct ty v b -> zonkTcType ty >>= \ty ->
- return (Suspension ct ty v b)
- ,fNewtypeWrap= \ty dc t ->
- return NewtypeWrap `ap` zonkTcType ty `ap` return dc `ap` t}
+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
--- Is this defined elsewhere?
--- Generalize the type: find all free tyvars and wrap in the appropiate ForAll.
-sigmaType :: Type -> Type
-sigmaType ty = mkSigmaTy (varSetElems$ tyVarsOfType (dropForAlls ty)) [] ty
+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
\ No newline at end of file
projects / ghc-hetmet.git / commitdiff