-
+%
+% (c) The University of Glasgow 2006
% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[TcType]{Types used in the typechecker}
newtypes, and predicates are meaningful.
* look through usage types
-The "tc" prefix is for "typechechecker", because the type checker
+The "tc" prefix is for "TypeChecker", because the type checker
is the principal client.
\begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+-- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
module TcType (
--------------------------------
-- Types
UserTypeCtxt(..), pprUserTypeCtxt,
TcTyVarDetails(..), BoxInfo(..), pprTcTyVarDetails,
MetaDetails(Flexi, Indirect), SkolemInfo(..), pprSkolTvBinding, pprSkolInfo,
- isImmutableTyVar, isSkolemTyVar, isMetaTyVar, isBoxyTyVar, isSigTyVar, isExistentialTyVar,
+ isImmutableTyVar, isSkolemTyVar, isMetaTyVar, isBoxyTyVar,
+ isSigTyVar, isExistentialTyVar, isTyConableTyVar,
metaTvRef,
isFlexi, isIndirect,
tcSplitFunTy_maybe, tcSplitFunTys, tcFunArgTy, tcFunResultTy, tcSplitFunTysN,
tcSplitTyConApp, tcSplitTyConApp_maybe, tcTyConAppTyCon, tcTyConAppArgs,
tcSplitAppTy_maybe, tcSplitAppTy, tcSplitAppTys, repSplitAppTy_maybe,
- tcValidInstHeadTy, tcGetTyVar_maybe, tcGetTyVar,
+ tcInstHeadTyNotSynonym, tcInstHeadTyAppAllTyVars,
+ tcGetTyVar_maybe, tcGetTyVar,
tcSplitSigmaTy, tcMultiSplitSigmaTy,
---------------------------------
eqKind,
isSigmaTy, isOverloadedTy, isRigidTy, isBoxyTy,
isDoubleTy, isFloatTy, isIntTy, isStringTy,
- isIntegerTy, isBoolTy, isUnitTy,
+ isIntegerTy, isBoolTy, isUnitTy, isCharTy,
isTauTy, isTauTyCon, tcIsTyVarTy, tcIsForAllTy,
+ isOpenSynTyConApp,
---------------------------------
-- Misc type manipulators
- deNoteType, classesOfTheta,
+ deNoteType,
tyClsNamesOfType, tyClsNamesOfDFunHead,
getDFunTyKey,
isClassPred, isTyVarClassPred, isEqPred,
mkDictTy, tcSplitPredTy_maybe,
isPredTy, isDictTy, tcSplitDFunTy, tcSplitDFunHead, predTyUnique,
- mkClassPred, isInheritablePred, isLinearPred, isIPPred, mkPredName,
- dataConsStupidTheta, isRefineableTy,
+ mkClassPred, isInheritablePred, isIPPred,
+ dataConsStupidTheta, isRefineableTy, isRefineablePred,
---------------------------------
-- Foreign import and export
mkOpenTvSubst, zipOpenTvSubst, zipTopTvSubst, mkTopTvSubst, notElemTvSubst,
getTvSubstEnv, setTvSubstEnv, getTvInScope, extendTvInScope, lookupTyVar,
extendTvSubst, extendTvSubstList, isInScope, mkTvSubst, zipTyEnv,
- substTy, substTys, substTyWith, substTheta, substTyVar, substTyVarBndr,
+ substTy, substTys, substTyWith, substTheta, substTyVar, substTyVars, substTyVarBndr,
isUnLiftedType, -- Source types are always lifted
isUnboxedTupleType, -- Ditto
tcTyVarsOfType, tcTyVarsOfTypes, exactTyVarsOfType, exactTyVarsOfTypes,
pprKind, pprParendKind,
- pprType, pprParendType, pprTyThingCategory,
+ pprType, pprParendType, pprTypeApp, pprTyThingCategory,
pprPred, pprTheta, pprThetaArrow, pprClassPred
) where
#include "HsVersions.h"
-- friends:
-import TypeRep ( Type(..), funTyCon, Kind ) -- friend
-
-import Type ( -- Re-exports
- tyVarsOfType, tyVarsOfTypes, tyVarsOfPred,
- tyVarsOfTheta, Kind, PredType(..), KindVar,
- ThetaType, isUnliftedTypeKind, unliftedTypeKind,
- argTypeKind,
- liftedTypeKind, openTypeKind, mkArrowKind,
- tySuperKind, isLiftedTypeKind,
- mkArrowKinds, mkForAllTy, mkForAllTys,
- defaultKind, isSubArgTypeKind, isSubOpenTypeKind,
- mkFunTy, mkFunTys, zipFunTys,
- mkTyConApp, mkAppTy,
- mkAppTys, applyTy, applyTys,
- mkTyVarTy, mkTyVarTys, mkTyConTy, mkPredTy,
- mkPredTys, isUnLiftedType,
- isUnboxedTupleType, isPrimitiveType,
- splitTyConApp_maybe,
- tidyTopType, tidyType, tidyPred, tidyTypes,
- tidyFreeTyVars, tidyOpenType, tidyOpenTypes,
- tidyTyVarBndr, tidyOpenTyVar,
- tidyOpenTyVars, tidyKind,
- isSubKind, tcView,
-
- tcEqType, tcEqTypes, tcCmpType, tcCmpTypes,
- tcEqPred, tcCmpPred, tcEqTypeX, eqKind,
-
- TvSubst(..),
- TvSubstEnv, emptyTvSubst, mkTvSubst, zipTyEnv,
- mkOpenTvSubst, zipOpenTvSubst, zipTopTvSubst, mkTopTvSubst,
- getTvSubstEnv, setTvSubstEnv, getTvInScope, extendTvInScope,
- extendTvSubst, extendTvSubstList, isInScope, notElemTvSubst,
- substTy, substTys, substTyWith, substTheta,
- substTyVar, substTyVarBndr, substPred, lookupTyVar,
-
- typeKind, repType, coreView, repSplitAppTy_maybe,
- pprKind, pprParendKind,
- pprType, pprParendType, pprTyThingCategory,
- pprPred, pprTheta, pprThetaArrow, pprClassPred
- )
-import TyCon ( TyCon, isUnLiftedTyCon, isSynTyCon, isOpenTyCon,
- synTyConDefn, tyConUnique )
-import DataCon ( DataCon, dataConStupidTheta, dataConResTys )
-import Class ( Class )
-import Var ( TyVar, Id, isCoVar, isTcTyVar, mkTcTyVar, tyVarName, tyVarKind, tcTyVarDetails )
-import ForeignCall ( Safety, DNType(..) )
-import Unify ( tcMatchTys )
+import TypeRep
+import DataCon
+import Class
+import Var
+import ForeignCall
+import Unify
import VarSet
+import Type
+import Coercion
+import TyCon
-- others:
-import DynFlags ( DynFlags, DynFlag( Opt_GlasgowExts ), dopt )
-import Name ( Name, NamedThing(..), mkInternalName, getSrcLoc, mkSystemName )
+import DynFlags
+import CoreSyn
+import Name
import NameSet
-import VarEnv ( TidyEnv )
-import OccName ( OccName, mkDictOcc, mkOccName, tvName )
-import PrelNames -- Lots (e.g. in isFFIArgumentTy)
-import TysWiredIn ( unitTyCon, charTyCon, listTyCon )
-import BasicTypes ( IPName(..), Arity, ipNameName )
-import SrcLoc ( SrcLoc, SrcSpan )
-import Util ( equalLength )
-import Maybes ( maybeToBool, expectJust, mapCatMaybes )
-import ListSetOps ( hasNoDups )
-import List ( nubBy )
+import VarEnv
+import OccName
+import PrelNames
+import TysWiredIn
+import BasicTypes
+import Util
+import Maybes
+import ListSetOps
import Outputable
-import DATA_IOREF
-\end{code}
+import Data.List
+import Data.IORef
+\end{code}
%************************************************************************
%* *
-- b2 is another (currently empty) box.
data MetaDetails
- = Flexi -- Flexi type variables unify to become
- -- Indirects.
+ = Flexi -- Flexi type variables unify to become
+ -- Indirects.
- | Indirect TcType -- INVARIANT:
- -- For a BoxTv, this type must be non-boxy
- -- For a TauTv, this type must be a tau-type
+ | Indirect TcType -- INVARIANT:
+ -- For a BoxTv, this type must be non-boxy
+ -- For a TauTv, this type must be a tau-type
+-- Generally speaking, SkolemInfo should not contain location info
+-- that is contained in the Name of the tyvar with this SkolemInfo
data SkolemInfo
= SigSkol UserTypeCtxt -- A skolem that is created by instantiating
-- a programmer-supplied type signature
-- The rest are for non-scoped skolems
| ClsSkol Class -- Bound at a class decl
- | InstSkol Id -- Bound at an instance decl
+ | InstSkol -- Bound at an instance decl
+ | FamInstSkol -- Bound at a family instance decl
| PatSkol DataCon -- An existential type variable bound by a pattern for
- SrcSpan -- a data constructor with an existential type. E.g.
+ -- a data constructor with an existential type. E.g.
-- data T = forall a. Eq a => MkT a
-- f (MkT x) = ...
-- The pattern MkT x will allocate an existential type
-- variable for 'a'.
- | ArrowSkol SrcSpan -- An arrow form (see TcArrows)
+ | ArrowSkol -- An arrow form (see TcArrows)
+ | RuleSkol RuleName -- The LHS of a RULE
| GenSkol [TcTyVar] -- Bound when doing a subsumption check for
TcType -- (forall tvs. ty)
- SrcSpan
+
+ | RuntimeUnkSkol -- a type variable used to represent an unknown
+ -- runtime type (used in the GHCi debugger)
| UnkSkol -- Unhelpful info (until I improve it)
-------------------------------------
-- UserTypeCtxt describes the places where a
-- programmer-written type signature can occur
+-- Like SkolemInfo, no location info
data UserTypeCtxt
= FunSigCtxt Name -- Function type signature
-- Also used for types in SPECIALISE pragmas
| ResSigCtxt -- Result type sig
-- f x :: t = ....
| ForSigCtxt Name -- Foreign inport or export signature
- | RuleSigCtxt Name -- Signature on a forall'd variable in a RULE
| DefaultDeclCtxt -- Types in a default declaration
| SpecInstCtxt -- SPECIALISE instance pragma
kindVarRef :: KindVar -> IORef MetaDetails
kindVarRef tc =
+ ASSERT ( isTcTyVar tc )
case tcTyVarDetails tc of
MetaTv TauTv ref -> ref
other -> pprPanic "kindVarRef" (ppr tc)
-- They may be jiggled by tidying
kind_var_occ = mkOccName tvName "k"
\end{code}
-\end{code}
%************************************************************************
%* *
pprUserTypeCtxt BindPatSigCtxt = ptext SLIT("a pattern type signature")
pprUserTypeCtxt ResSigCtxt = ptext SLIT("a result type signature")
pprUserTypeCtxt (ForSigCtxt n) = ptext SLIT("the foreign declaration for") <+> quotes (ppr n)
-pprUserTypeCtxt (RuleSigCtxt n) = ptext SLIT("the type signature for") <+> quotes (ppr n)
pprUserTypeCtxt DefaultDeclCtxt = ptext SLIT("a type in a `default' declaration")
pprUserTypeCtxt SpecInstCtxt = ptext SLIT("a SPECIALISE instance pragma")
(env1, info') = tidy_skol_info env info
info -> (env, info)
- tidy_skol_info env (GenSkol tvs ty loc) = (env2, GenSkol tvs1 ty1 loc)
+ tidy_skol_info env (GenSkol tvs ty) = (env2, GenSkol tvs1 ty1)
where
(env1, tvs1) = tidyOpenTyVars env tvs
(env2, ty1) = tidyOpenType env1 ty
-- Print info about the binding of a skolem tyvar,
-- or nothing if we don't have anything useful to say
pprSkolTvBinding tv
- = ppr_details (tcTyVarDetails tv)
+ = ASSERT ( isTcTyVar tv )
+ quotes (ppr tv) <+> ppr_details (tcTyVarDetails tv)
where
- ppr_details (MetaTv TauTv _) = quotes (ppr tv) <+> ptext SLIT("is a meta type variable")
- ppr_details (MetaTv BoxTv _) = quotes (ppr tv) <+> ptext SLIT("is a boxy type variable")
+ ppr_details (MetaTv TauTv _) = ptext SLIT("is a meta type variable")
+ ppr_details (MetaTv BoxTv _) = ptext SLIT("is a boxy type variable")
ppr_details (MetaTv (SigTv info) _) = ppr_skol info
ppr_details (SkolemTv info) = ppr_skol info
- ppr_skol UnkSkol = empty -- Unhelpful; omit
- ppr_skol (SigSkol ctxt) = sep [quotes (ppr tv) <+> ptext SLIT("is bound by") <+> pprUserTypeCtxt ctxt,
- nest 2 (ptext SLIT("at") <+> ppr (getSrcLoc tv))]
- ppr_skol info = quotes (ppr tv) <+> pprSkolInfo info
+ ppr_skol UnkSkol = empty -- Unhelpful; omit
+ ppr_skol RuntimeUnkSkol = ptext SLIT("is an unknown runtime type")
+ ppr_skol info = sep [ptext SLIT("is a rigid type variable bound by"),
+ sep [pprSkolInfo info,
+ nest 2 (ptext SLIT("at") <+> ppr (getSrcLoc tv))]]
pprSkolInfo :: SkolemInfo -> SDoc
-pprSkolInfo (SigSkol ctxt) = ptext SLIT("is bound by") <+> pprUserTypeCtxt ctxt
-pprSkolInfo (ClsSkol cls) = ptext SLIT("is bound by the class declaration for") <+> quotes (ppr cls)
-pprSkolInfo (InstSkol df) = ptext SLIT("is bound by the instance declaration at") <+> ppr (getSrcLoc df)
-pprSkolInfo (ArrowSkol loc) = ptext SLIT("is bound by the arrow form at") <+> ppr loc
-pprSkolInfo (PatSkol dc loc) = sep [ptext SLIT("is bound by the pattern for") <+> quotes (ppr dc),
- nest 2 (ptext SLIT("at") <+> ppr loc)]
-pprSkolInfo (GenSkol tvs ty loc) = sep [sep [ptext SLIT("is bound by the polymorphic type"),
- nest 2 (quotes (ppr (mkForAllTys tvs ty)))],
- nest 2 (ptext SLIT("at") <+> ppr loc)]
--- UnkSkol, SigSkol
+pprSkolInfo (SigSkol ctxt) = pprUserTypeCtxt ctxt
+pprSkolInfo (ClsSkol cls) = ptext SLIT("the class declaration for") <+> quotes (ppr cls)
+pprSkolInfo InstSkol = ptext SLIT("the instance declaration")
+pprSkolInfo FamInstSkol = ptext SLIT("the family instance declaration")
+pprSkolInfo (RuleSkol name) = ptext SLIT("the RULE") <+> doubleQuotes (ftext name)
+pprSkolInfo ArrowSkol = ptext SLIT("the arrow form")
+pprSkolInfo (PatSkol dc) = sep [ptext SLIT("the constructor") <+> quotes (ppr dc)]
+pprSkolInfo (GenSkol tvs ty) = sep [ptext SLIT("the polymorphic type"),
+ nest 2 (quotes (ppr (mkForAllTys tvs ty)))]
+
+-- UnkSkol
-- For type variables the others are dealt with by pprSkolTvBinding.
-- For Insts, these cases should not happen
pprSkolInfo UnkSkol = panic "UnkSkol"
+pprSkolInfo RuntimeUnkSkol = panic "RuntimeUnkSkol"
instance Outputable MetaDetails where
- ppr Flexi = ptext SLIT("Flexi")
+ ppr Flexi = ptext SLIT("Flexi")
ppr (Indirect ty) = ptext SLIT("Indirect") <+> ppr ty
\end{code}
%************************************************************************
\begin{code}
-isImmutableTyVar, isSkolemTyVar, isExistentialTyVar, isBoxyTyVar, isMetaTyVar :: TyVar -> Bool
+isImmutableTyVar :: TyVar -> Bool
+
isImmutableTyVar tv
| isTcTyVar tv = isSkolemTyVar tv
| otherwise = True
+isTyConableTyVar, isSkolemTyVar, isExistentialTyVar,
+ isBoxyTyVar, isMetaTyVar :: TcTyVar -> Bool
+
+isTyConableTyVar tv
+ -- True of a meta-type variable that can be filled in
+ -- with a type constructor application; in particular,
+ -- not a SigTv
+ = ASSERT( isTcTyVar tv)
+ case tcTyVarDetails tv of
+ MetaTv BoxTv _ -> True
+ MetaTv TauTv _ -> True
+ MetaTv (SigTv {}) _ -> False
+ SkolemTv {} -> False
+
isSkolemTyVar tv
= ASSERT( isTcTyVar tv )
case tcTyVarDetails tv of
isExistentialTyVar tv -- Existential type variable, bound by a pattern
= ASSERT( isTcTyVar tv )
case tcTyVarDetails tv of
- SkolemTv (PatSkol _ _) -> True
- other -> False
+ SkolemTv (PatSkol {}) -> True
+ other -> False
isMetaTyVar tv
= ASSERT2( isTcTyVar tv, ppr tv )
metaTvRef :: TyVar -> IORef MetaDetails
metaTvRef tv
- = ASSERT( isTcTyVar tv )
+ = ASSERT2( isTcTyVar tv, ppr tv )
case tcTyVarDetails tv of
MetaTv _ ref -> ref
other -> pprPanic "metaTvRef" (ppr tv)
isFlexi, isIndirect :: MetaDetails -> Bool
-isFlexi Flexi = True
-isFlexi other = False
+isFlexi Flexi = True
+isFlexi other = False
isIndirect (Indirect _) = True
isIndirect other = False
mkSigmaTy tyvars theta tau = mkForAllTys tyvars (mkPhiTy theta tau)
mkPhiTy :: [PredType] -> Type -> Type
-mkPhiTy theta ty = foldr (\p r -> FunTy (mkPredTy p) r) ty theta
+mkPhiTy theta ty = foldr (\p r -> mkFunTy (mkPredTy p) r) ty theta
\end{code}
@isTauTy@ tests for nested for-alls. It should not be called on a boxy type.
isTauTyCon :: TyCon -> Bool
-- Returns False for type synonyms whose expansion is a polytype
isTauTyCon tc
- | isSynTyCon tc && not (isOpenTyCon tc) = isTauTy (snd (synTyConDefn tc))
- | otherwise = True
+ | isClosedSynTyCon tc = isTauTy (snd (synTyConDefn tc))
+ | otherwise = True
---------------
isBoxyTy :: TcType -> Bool
isRigidTy :: TcType -> Bool
-- A type is rigid if it has no meta type variables in it
-isRigidTy ty = all isSkolemTyVar (varSetElems (tcTyVarsOfType ty))
+isRigidTy ty = all isImmutableTyVar (varSetElems (tcTyVarsOfType ty))
-isRefineableTy :: TcType -> Bool
+isRefineableTy :: TcType -> (Bool,Bool)
-- A type should have type refinements applied to it if it has
-- free type variables, and they are all rigid
-isRefineableTy ty = not (null tc_tvs) && all isSkolemTyVar tc_tvs
+isRefineableTy ty = (null tc_tvs, all isImmutableTyVar tc_tvs)
where
tc_tvs = varSetElems (tcTyVarsOfType ty)
+isRefineablePred :: TcPredType -> Bool
+isRefineablePred pred = not (null tc_tvs) && all isImmutableTyVar tc_tvs
+ where
+ tc_tvs = varSetElems (tcTyVarsOfPred pred)
+
---------------
getDFunTyKey :: Type -> OccName -- Get some string from a type, to be used to
-- construct a dictionary function name
-----------------------
tcTyConAppTyCon :: Type -> TyCon
-tcTyConAppTyCon ty = fst (tcSplitTyConApp ty)
+tcTyConAppTyCon ty = case tcSplitTyConApp_maybe ty of
+ Just (tc, _) -> tc
+ Nothing -> pprPanic "tcTyConAppTyCon" (pprType ty)
tcTyConAppArgs :: Type -> [Type]
-tcTyConAppArgs ty = snd (tcSplitTyConApp ty)
+tcTyConAppArgs ty = case tcSplitTyConApp_maybe ty of
+ Just (_, args) -> args
+ Nothing -> pprPanic "tcTyConAppArgs" (pprType ty)
tcSplitTyConApp :: Type -> (TyCon, [Type])
tcSplitTyConApp ty = case tcSplitTyConApp_maybe ty of
(args,res') = tcSplitFunTys res
tcSplitFunTy_maybe :: Type -> Maybe (Type, Type)
-tcSplitFunTy_maybe ty | Just ty' <- tcView ty = tcSplitFunTy_maybe ty'
-tcSplitFunTy_maybe (FunTy arg res) = Just (arg, res)
-tcSplitFunTy_maybe other = Nothing
+tcSplitFunTy_maybe ty | Just ty' <- tcView ty = tcSplitFunTy_maybe ty'
+tcSplitFunTy_maybe (FunTy arg res) | not (isPredTy arg) = Just (arg, res)
+tcSplitFunTy_maybe other = Nothing
+ -- Note the (not (isPredTy arg)) guard
+ -- Consider (?x::Int) => Bool
+ -- We don't want to treat this as a function type!
+ -- A concrete example is test tc230:
+ -- f :: () -> (?p :: ()) => () -> ()
+ --
+ -- g = f () ()
tcSplitFunTysN
:: TcRhoType
Just (ClassP clas tys) -> (clas, tys)
other -> panic "tcSplitDFunHead"
-tcValidInstHeadTy :: Type -> Bool
+tcInstHeadTyNotSynonym :: Type -> Bool
-- Used in Haskell-98 mode, for the argument types of an instance head
-- These must not be type synonyms, but everywhere else type synonyms
-- are transparent, so we need a special function here
-tcValidInstHeadTy ty
+tcInstHeadTyNotSynonym ty
= case ty of
- NoteTy _ ty -> tcValidInstHeadTy ty
- TyConApp tc tys -> not (isSynTyCon tc) && ok tys
+ NoteTy _ ty -> tcInstHeadTyNotSynonym ty
+ TyConApp tc tys -> not (isSynTyCon tc)
+ _ -> True
+
+tcInstHeadTyAppAllTyVars :: Type -> Bool
+-- Used in Haskell-98 mode, for the argument types of an instance head
+-- These must be a constructor applied to type variable arguments
+tcInstHeadTyAppAllTyVars ty
+ = case ty of
+ NoteTy _ ty -> tcInstHeadTyAppAllTyVars ty
+ TyConApp _ tys -> ok tys
FunTy arg res -> ok [arg, res]
other -> False
where
predTyUnique :: PredType -> Unique
predTyUnique (IParam n _) = getUnique (ipNameName n)
predTyUnique (ClassP clas tys) = getUnique clas
-
-mkPredName :: Unique -> SrcLoc -> PredType -> Name
-mkPredName uniq loc (ClassP cls tys) = mkInternalName uniq (mkDictOcc (getOccName cls)) loc
-mkPredName uniq loc (IParam ip ty) = mkInternalName uniq (getOccName (ipNameName ip)) loc
+predTyUnique (EqPred a b) = pprPanic "predTyUnique" (ppr (EqPred a b))
\end{code}
getClassPredTys (ClassP clas tys) = (clas, tys)
getClassPredTys other = panic "getClassPredTys"
-isEqPred :: PredType -> Bool
-isEqPred (EqPred {}) = True
-isEqPred _ = False
-
mkDictTy :: Class -> [Type] -> Type
mkDictTy clas tys = mkPredTy (ClassP clas tys)
-- but it doesn't need to be quantified over the Num a dictionary
-- which can be free in g's rhs, and shared by both calls to g
isInheritablePred (ClassP _ _) = True
-isInheritablePred other = False
-
-isLinearPred :: TcPredType -> Bool
-isLinearPred (IParam (Linear n) _) = True
-isLinearPred other = False
+isInheritablePred (EqPred _ _) = True
+isInheritablePred other = False
\end{code}
--------------------- Equality predicates ---------------------------------
= nubBy tcEqPred all_preds
where
all_preds = dataConStupidTheta con1 ++ other_stupids
- res_tys1 = dataConResTys con1
- tvs1 = tyVarsOfTypes res_tys1
+ res_ty1 = dataConOrigResTy con1
other_stupids = [ substPred subst pred
| con <- cons
- , let Just subst = tcMatchTys tvs1 res_tys1 (dataConResTys con)
+ , let (tvs, _, _, res_ty) = dataConSig con
+ Just subst = tcMatchTy (mkVarSet tvs) res_ty res_ty1
, pred <- dataConStupidTheta con ]
dataConsStupidTheta [] = panic "dataConsStupidTheta"
\end{code}
isIntTy = is_tc intTyConKey
isBoolTy = is_tc boolTyConKey
isUnitTy = is_tc unitTyConKey
+isCharTy = is_tc charTyConKey
+
+isStringTy ty
+ = case tcSplitTyConApp_maybe ty of
+ Just (tc, [arg_ty]) -> tc == listTyCon && isCharTy arg_ty
+ other -> False
is_tc :: Unique -> Type -> Bool
-- Newtypes are opaque to this
Nothing -> False
\end{code}
+\begin{code}
+-- NB: Currently used in places where we have already expanded type synonyms;
+-- hence no 'coreView'. This could, however, be changed without breaking
+-- any code.
+isOpenSynTyConApp :: TcTauType -> Bool
+isOpenSynTyConApp (TyConApp tc _) = isOpenSynTyCon tc
+isOpenSynTyConApp _other = False
+\end{code}
+
%************************************************************************
%* *
go (AppTy fun arg) = go fun `unionVarSet` go arg
go (ForAllTy tyvar ty) = delVarSet (go ty) tyvar
`unionVarSet` go_tv tyvar
+ go (NoteTy _ _) = panic "exactTyVarsOfType" -- Handled by tcView
go_pred (IParam _ ty) = go ty
go_pred (ClassP _ tys) = exactTyVarsOfTypes tys
tyClsNamesOfDFunHead dfun_ty
= case tcSplitSigmaTy dfun_ty of
(tvs,_,head_ty) -> tyClsNamesOfType head_ty
-
-classesOfTheta :: ThetaType -> [Class]
--- Looks just for ClassP things; maybe it should check
-classesOfTheta preds = [ c | ClassP c _ <- preds ]
\end{code}
being the )
\begin{code}
-tcSplitIOType_maybe :: Type -> Maybe (TyCon, Type)
--- (isIOType t) returns (Just (IO,t')) if t is of the form (IO t'), or
--- some newtype wrapping thereof
+tcSplitIOType_maybe :: Type -> Maybe (TyCon, Type, CoercionI)
+-- (isIOType t) returns Just (IO,t',co)
+-- if co : t ~ IO t'
-- returns Nothing otherwise
tcSplitIOType_maybe ty
- | Just (io_tycon, [io_res_ty]) <- tcSplitTyConApp_maybe ty,
+ = case tcSplitTyConApp_maybe ty of
-- This split absolutely has to be a tcSplit, because we must
-- see the IO type; and it's a newtype which is transparent to splitTyConApp.
- io_tycon `hasKey` ioTyConKey
- = Just (io_tycon, io_res_ty)
- | Just ty' <- coreView ty -- Look through non-recursive newtypes
- = tcSplitIOType_maybe ty'
+ Just (io_tycon, [io_res_ty])
+ | io_tycon `hasKey` ioTyConKey
+ -> Just (io_tycon, io_res_ty, IdCo)
- | otherwise
- = Nothing
+ Just (tc, tys)
+ | not (isRecursiveTyCon tc)
+ , Just (ty, co1) <- instNewTyCon_maybe tc tys
+ -- Newtypes that require a coercion are ok
+ -> case tcSplitIOType_maybe ty of
+ Nothing -> Nothing
+ Just (tc, ty', co2) -> Just (tc, ty', co1 `mkTransCoI` co2)
+
+ other -> Nothing
isFFITy :: Type -> Bool
-- True for any TyCon that can possibly be an arg or result of an FFI call
isFFIDotnetTy dflags ty
= checkRepTyCon (\ tc -> (legalFIResultTyCon dflags tc ||
isFFIDotnetObjTy ty || isStringTy ty)) ty
+ -- NB: isStringTy used to look through newtypes, but
+ -- it no longer does so. May need to adjust isFFIDotNetTy
+ -- if we do want to look through newtypes.
--- Support String as an argument or result from a .NET FFI call.
-isStringTy ty =
- case tcSplitTyConApp_maybe (repType ty) of
- Just (tc, [arg_ty])
- | tc == listTyCon ->
- case tcSplitTyConApp_maybe (repType arg_ty) of
- Just (cc,[]) -> cc == charTyCon
- _ -> False
- _ -> False
-
--- Support String as an argument or result from a .NET FFI call.
-isFFIDotnetObjTy ty =
- let
+isFFIDotnetObjTy ty
+ = checkRepTyCon check_tc t_ty
+ where
(_, t_ty) = tcSplitForAllTys ty
- in
- case tcSplitTyConApp_maybe (repType t_ty) of
- Just (tc, [arg_ty]) | getName tc == objectTyConName -> True
- _ -> False
+ check_tc tc = getName tc == objectTyConName
toDNType :: Type -> DNType
toDNType ty
= isUnLiftedTyCon tc || boxedMarshalableTyCon tc || tc == unitTyCon
marshalableTyCon dflags tc
- = (dopt Opt_GlasgowExts dflags && isUnLiftedTyCon tc)
+ = (dopt Opt_UnliftedFFITypes dflags
+ && isUnLiftedTyCon tc
+ && case tyConPrimRep tc of -- Note [Marshalling VoidRep]
+ VoidRep -> False
+ other -> True)
|| boxedMarshalableTyCon tc
boxedMarshalableTyCon tc
, boolTyConKey
]
\end{code}
+
+Note [Marshalling VoidRep]
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+We don't treat State# (whose PrimRep is VoidRep) as marshalable.
+In turn that means you can't write
+ foreign import foo :: Int -> State# RealWorld
+
+Reason: the back end falls over with panic "primRepHint:VoidRep";
+ and there is no compelling reason to permit it
projects / ghc-hetmet.git / blobdiff