-----------------------------------------------------------------------------
module RtClosureInspect(
-
cvObtainTerm, -- :: HscEnv -> Int -> Bool -> Maybe Type -> HValue -> IO Term
+ cvReconstructType,
+ improveRTTIType,
Term(..),
- isTerm,
- isSuspension,
- isPrim,
- isNewtypeWrap,
- pprTerm,
- cPprTerm,
- cPprTermBase,
- CustomTermPrinter,
- termType,
- foldTerm,
- TermFold(..),
- idTermFold,
- idTermFoldM,
- isFullyEvaluated,
- isPointed,
- isFullyEvaluatedTerm,
- mapTermType,
- termTyVars,
--- unsafeDeepSeq,
- cvReconstructType,
- unifyRTTI,
- sigmaType,
- Closure(..),
- getClosureData,
- ClosureType(..),
- isConstr,
- isIndirection
- ) where
+ 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 ( HscEnv )
+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 TcGadt
import TcEnv
-import DriverPhases
+
import TyCon
import Name
import VarEnv
import Util
import VarSet
-
import TysPrim
import PrelNames
import TysWiredIn
-
-import Outputable
-import Panic
-
+import DynFlags
+import Outputable as Ppr
+import FastString
+import Constants ( wORD_SIZE )
import GHC.Arr ( Array(..) )
import GHC.Exts
-import GHC.IOBase ( IO(IO) )
+import GHC.IO ( IO(..) )
+import StaticFlags( opt_PprStyle_Debug )
import Control.Monad
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)
-import Foreign
+import Data.Sequence (viewl, ViewL(..))
+import Foreign hiding (unsafePerformIO)
import System.IO.Unsafe
---------------------------------------------
-- * 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)
instance Outputable ClosureType where
ppr = text . show
-#include "../includes/ClosureTypes.h"
+#include "../includes/rts/storage/ClosureTypes.h"
aP_CODE, pAP_CODE :: Int
aP_CODE = AP
getClosureData a =
case unpackClosure# a of
(# iptr, ptrs, nptrs #) -> do
-#ifndef GHCI_TABLES_NEXT_TO_CODE
- -- 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 !tablesNextToCode, so we must adjust here:
- itbl <- peek (Ptr iptr `plusPtr` negate wORD_SIZE)
-#else
- itbl <- peek (Ptr iptr)
-#endif
+ 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)] ]
+ | I# i <- [0.. fromIntegral (BCI.nptrs itbl)-1] ]
ASSERT(elems >= 0) return ()
ptrsList `seq`
return (Closure tipe (Ptr iptr) itbl ptrsList nptrs_data)
| 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 ->
= 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)
+ | null sub_terms_to_show
+ = return (ppr dc)
+ | otherwise
+ = do { tt_docs <- mapM (y app_prec) sub_terms_to_show
+ ; return $ cparen (p >= app_prec) $
+ sep [ppr dc, nest 2 (pprDeeperList fsep tt_docs)] }
+ where
+ sub_terms_to_show -- Don't show the dictionary arguments to
+ -- constructors unless -dppr-debug is on
+ | opt_PprStyle_Debug = tt
+ | otherwise = dropList (dataConTheta dc) tt
ppr_termM y p t@NewtypeWrap{} = pprNewtypeWrap y p t
ppr_termM y p RefWrap{wrapped_term=t} = do
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"
ppr_termM1 NewtypeWrap{} = panic "ppr_termM1 - NewtypeWrap"
-pprNewtypeWrap y p NewtypeWrap{ty=ty, wrapped_term=t}
- | Just (tc,_) <- splitNewTyConApp_maybe ty
+pprNewtypeWrap y p NewtypeWrap{ty=ty, wrapped_term=t}
+ | Just (tc,_) <- tcSplitTyConApp_maybe ty
, ASSERT(isNewTyCon tc) True
- , Just new_dc <- maybeTyConSingleCon tc = do
- real_term <- y max_prec t
- return$ cparen (p >= app_prec) (ppr new_dc <+> real_term)
+ , 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"
-------------------------------------------------------
firstJustM [] = return Nothing
-- Default set of custom printers. Note that the recursion knot is explicit
-cPprTermBase :: Monad m => CustomTermPrinter m
+cPprTermBase :: forall m. 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 Term{subTerms=[h,t]} -> doList p h 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)
+ ppr_list
+ , ifTerm (isTyCon intTyCon . ty) ppr_int
+ , ifTerm (isTyCon charTyCon . ty) ppr_char
+ , ifTerm (isTyCon floatTyCon . ty) ppr_float
+ , ifTerm (isTyCon doubleTyCon . ty) ppr_double
+ , ifTerm (isIntegerTy . ty) ppr_integer
]
- where ifTerm pred f prec t@Term{}
- | pred t = Just `liftM` f prec t
- ifTerm _ _ _ _ = return Nothing
-
- isIntegerTy ty = fromMaybe False $ do
- (tc,_) <- splitTyConApp_maybe ty
- return (tyConName tc == integerTyConName)
-
- isTupleTy ty = fromMaybe False $ do
- (tc,_) <- splitTyConApp_maybe ty
- return (tc `elem` (fst.unzip.elems) boxedTupleArr)
-
- isTyCon a_tc ty = fromMaybe False $ do
- (tc,_) <- splitTyConApp_maybe ty
- return (a_tc == tc)
-
- coerceShow f _p = return . text . show . f . unsafeCoerce# . val
-
- --Note pprinting of list terms is not lazy
- doList p 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)
+ where
+ ifTerm :: (Term -> Bool)
+ -> (Precedence -> Term -> m SDoc)
+ -> Precedence -> Term -> m (Maybe SDoc)
+ 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)
+
+ ppr_int, ppr_char, ppr_float, ppr_double, ppr_integer
+ :: Precedence -> Term -> m SDoc
+ ppr_int _ v = return (Ppr.int (unsafeCoerce# (val v)))
+ ppr_char _ v = return (Ppr.char '\'' <> Ppr.char (unsafeCoerce# (val v)) <> Ppr.char '\'')
+ ppr_float _ v = return (Ppr.float (unsafeCoerce# (val v)))
+ ppr_double _ v = return (Ppr.double (unsafeCoerce# (val v)))
+ ppr_integer _ v = return (Ppr.integer (unsafeCoerce# (val v)))
+
+ --Note pprinting of list terms is not lazy
+ ppr_list :: Precedence -> Term -> m SDoc
+ ppr_list p (Term{subTerms=[h,t]}) = do
+ let elems = h : getListTerms t
+ isConsLast = not(termType(last elems) `eqType` termType h)
+ is_string = all (isCharTy . ty) elems
+
+ print_elems <- mapM (y cons_prec) elems
+ if is_string
+ then return (Ppr.doubleQuotes (Ppr.text (unsafeCoerce# (map val elems))))
+ else if isConsLast
+ then return $ cparen (p >= cons_prec)
+ $ pprDeeperList fsep
+ $ punctuate (space<>colon) print_elems
+ else return $ 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)
+ ppr_list _ _ = panic "doList"
repPrim :: TyCon -> [Word] -> String
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 c = do
- mb_term <- runTR_maybe hsc_env c
- case mb_term of
- Nothing -> panic "Can't unify"
+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
+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 . newFlexiTyVar
-
--- | 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
- return (ty', zipTopTvSubst tvs' (mkTyVarTys tvs))
+newVar = liftTcM . newFlexiTyVarTy
+
+instTyVars :: [TyVar] -> TR ([TcTyVar], [TcType], TvSubst)
+-- Instantiate fresh mutable type variables from some TyVars
+-- This function preserves the print-name, which helps error messages
+instTyVars = liftTcM . tcInstTyVars
+
+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
-- Before unification, congruenceNewtypes needs to
-- do its magic.
addConstraint :: TcType -> TcType -> TR ()
-addConstraint t1 t2 = congruenceNewtypes t1 t2 >>= uncurry unifyType
- >> 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
+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 bound _ _ _ | seq bound False = undefined
- go 0 tv _ty a = do
+
+ go :: Int -> Type -> Type -> HValue -> TcM Term
+ -- [SPJ May 11] I don't understand the difference between my_ty and old_ty
+
+ 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) 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
case tipe clos of
-- Thunks we may want to force
--- 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)
+-- 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 $! (ptrs clos ! 0)
-- We also follow references
- MutVar _ | Just (tycon,[world,ty_contents]) <- splitTyConApp_maybe ty
- -- , tycon == mutVarPrimTyCon
+ MutVar _ | Just (tycon,[world,contents_ty]) <- tcSplitTyConApp_maybe old_ty
-> do
+ -- Deal with the MutVar# primitive
+ -- It does not have a constructor at all,
+ -- so we simulate the following one
+ -- MutVar# :: contents_ty -> MutVar# s contents_ty
+ traceTR (text "Following a MutVar")
+ contents_tv <- newVar liftedTypeKind
contents <- trIO$ 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 $ 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 Ppr.empty)
Right dcname <- dataConInfoPtrToName (infoPtr clos)
(_,mb_dc) <- tryTcErrs (tcLookupDataCon dcname)
case mb_dc of
-- In such case, we return a best approximation:
-- ignore the unpointed args, and recover the pointeds
-- This preserves laziness, and should be safe.
+ traceTR (text "Nothing" <+> ppr dcname)
let tag = showSDoc (ppr dcname)
vars <- replicateM (length$ elems$ ptrs clos)
- (newVar (liftedTypeKind))
- subTerms <- sequence [appArr (go (pred bound) tv tv) (ptrs clos) i
+ (newVar liftedTypeKind)
+ 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)]
- -- It is vital for newtype reconstruction that the unification step
- -- 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
- | (i,tv,t) <- zip3 [0..] subTermTvs subTtypesP]
+ return (Term my_ty (Left ('<' : tag ++ ">")) a subTerms)
+ Just dc -> do
+ traceTR (text "Just" <+> ppr dc)
+ subTtypes <- getDataConArgTys dc my_ty
+ let (subTtypesP, subTtypesNP) = partition isPtrType subTtypes
+ subTermsP <- sequence
+ [ appArr (go (pred max_depth) ty ty) (ptrs clos) i
+ | (i,ty) <- zip [0..] 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)
+ subTermsNP = zipWith Prim 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 tv 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
- | otherwise = dataConRepArgTys dc
+ return (Suspension tipe_clos my_ty a Nothing)
--- 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)
- , ptext SLIT("reOrderTerms") $$
+ | isPtrType ty = ASSERT2(not(null pointed)
+ , ptext (sLit "reOrderTerms") $$
(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) <- splitNewTyConApp_maybe ty
- , isNewTyCon tc
- , wrapped_type <- newTyConInstRhs tc args
- , Just dc <- maybeTyConSingleCon 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@(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")
-- 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
+ traceTR (text "go" <+> ppr my_ty)
clos <- trIO $ getClosureData a
case tipe clos of
- Indirection _ -> go tv $! (ptrs clos ! 0)
+ 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 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)
+ traceTR (text "Constr1" <+> ppr dcname)
(_,mb_dc) <- tryTcErrs (tcLookupDataCon dcname)
case mb_dc of
Nothing-> do
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)
- addConstraint myType signatureType
- return $ [ appArr (\e->(t,e)) (ptrs clos) i
- | (i,t) <- drop extra_args $
- zip [0..] (filter isPointed subTtypes)]
+ arg_tys <- getDataConArgTys dc my_ty
+ traceTR (text "Constr2" <+> ppr dcname <+> ppr arg_tys)
+ return $ [ appArr (\e-> (ty,e)) (ptrs clos) i
+ | (i,ty) <- zip [0..] (filter isPtrType arg_tys)]
_ -> 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]
+
+getDataConArgTys :: DataCon -> Type -> TR [Type]
+-- Given the result type ty of a constructor application (D a b c :: ty)
+-- return the types of the arguments. This is RTTI-land, so 'ty' might
+-- not be fully known. Moreover, the arg types might involve existentials;
+-- if so, make up fresh RTTI type variables for them
+getDataConArgTys dc con_app_ty
+ = do { (_, ex_tys, _) <- instTyVars ex_tvs
+ ; let rep_con_app_ty = repType con_app_ty
+ ; ty_args <- case tcSplitTyConApp_maybe rep_con_app_ty of
+ Just (tc, ty_args) | dataConTyCon dc == tc
+ -> ASSERT( univ_tvs `equalLength` ty_args)
+ return ty_args
+ _ -> do { (_, ty_args, subst) <- instTyVars univ_tvs
+ ; let res_ty = substTy subst (dataConOrigResTy dc)
+ ; addConstraint rep_con_app_ty res_ty
+ ; return ty_args }
+ -- It is necessary to check dataConTyCon dc == 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
+ ; let subst = zipTopTvSubst (univ_tvs ++ ex_tvs) (ty_args ++ ex_tys)
+ ; return (substTys subst (dataConRepArgTys dc)) }
+ where
+ univ_tvs = dataConUnivTyVars dc
+ ex_tvs = dataConExTyVars dc
+
+isPtrType :: Type -> Bool
+isPtrType ty = case typePrimRep ty of
+ PtrRep -> True
+ _ -> False
+
+-- Soundness checks
+--------------------
{-
- This helper computes the difference between a base type t and the
- improved rtti_t computed by RTTI
- The main difference between RTTI types and their normal counterparts
- is that the former are _not_ polymorphic, thus polymorphism must
- be stripped. Syntactically, forall's must be stripped.
- We also remove predicates.
+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
+
-}
-unifyRTTI :: Type -> Type -> TvSubst
-unifyRTTI ty rtti_ty =
- case mb_subst of
- Just subst -> subst
- Nothing -> pprPanic "Failed to compute a RTTI substitution"
- (ppr (ty, rtti_ty))
- -- In addition, we strip newtypes too, since the reconstructed type might
- -- not have recovered them all
- -- TODO stripping newtypes shouldn't be necessary, test
- where mb_subst = tcUnifyTys (const BindMe)
- [rttiView ty]
- [rttiView rtti_ty]
+
+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.
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
+ , isTcTyVar tv
+ , isMetaTyVar tv
+ = 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, _) <- splitNewTyConApp_maybe lhs
- , Just (tycon_r, _) <- splitNewTyConApp_maybe rhs
+ | 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
- vars <- mapM (newVar . tyVarKind) (tyConTyVars new_tycon)
+ | 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, _) <- instTyVars (tyConTyVars new_tycon)
let ty' = mkTyConApp new_tycon vars
- liftTcM (unifyType ty (repType ty'))
+ _ <- liftTcM (unifyType ty (repType ty'))
-- assumes that reptype doesn't ^^^^ touch tyconApp args
return ty'
---------------------------------------------------------------------------------
--- 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
-
-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
+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
- mapMif_ _ _ [] = []
- mapMif_ pred f (x:xx) = (if pred x then f x else return x) : mapMif_ pred f xx
+ 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)
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}
-
-
--- Is this defined elsewhere?
--- Generalize the type: find all free tyvars and wrap in the appropiate ForAll.
-sigmaType :: Type -> Type
-sigmaType ty = mkForAllTys (varSetElems$ tyVarsOfType (dropForAlls ty)) ty
-
+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
+extractUnboxed :: [Type] -> Closure -> [[Word]]
+extractUnboxed tt clos = go tt (nonPtrs clos)
+ where sizeofType t = primRepSizeW (typePrimRep t)
+ go [] _ = []
+ go (t:tt) xx
+ | (x, rest) <- splitAt (sizeofType t) xx
+ = x : go tt rest