isImmutableTyVar, isSkolemTyVar, isMetaTyVar, isBoxyTyVar,
isSigTyVar, isExistentialTyVar, isTyConableTyVar,
metaTvRef,
- isFlexi, isIndirect,
+ isFlexi, isIndirect, isRuntimeUnk, isUnk,
--------------------------------
-- Builders
-- Splitters
-- These are important because they do not look through newtypes
tcView,
- tcSplitForAllTys, tcSplitPhiTy,
+ tcSplitForAllTys, tcSplitPhiTy, tcSplitPredFunTy_maybe,
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,
---------------------------------
tcEqType, tcEqTypes, tcEqPred, tcCmpType, tcCmpTypes, tcCmpPred, tcEqTypeX,
eqKind,
isSigmaTy, isOverloadedTy, isRigidTy, isBoxyTy,
- isDoubleTy, isFloatTy, isIntTy, isStringTy,
+ isDoubleTy, isFloatTy, isIntTy, isWordTy, isStringTy,
isIntegerTy, isBoolTy, isUnitTy, isCharTy,
isTauTy, isTauTyCon, tcIsTyVarTy, tcIsForAllTy,
+ isOpenSynTyConApp,
---------------------------------
-- Misc type manipulators
getClassPredTys_maybe, getClassPredTys,
isClassPred, isTyVarClassPred, isEqPred,
mkDictTy, tcSplitPredTy_maybe,
- isPredTy, isDictTy, tcSplitDFunTy, tcSplitDFunHead, predTyUnique,
+ isPredTy, isDictTy, isDictLikeTy,
+ tcSplitDFunTy, tcSplitDFunHead, predTyUnique,
mkClassPred, isInheritablePred, isIPPred,
- dataConsStupidTheta, isRefineableTy, isRefineablePred,
+ isRefineableTy, isRefineablePred,
---------------------------------
-- Foreign import and export
isFFIExternalTy, -- :: Type -> Bool
isFFIDynArgumentTy, -- :: Type -> Bool
isFFIDynResultTy, -- :: Type -> Bool
+ isFFIPrimArgumentTy, -- :: DynFlags -> Type -> Bool
+ isFFIPrimResultTy, -- :: DynFlags -> Type -> Bool
isFFILabelTy, -- :: Type -> Bool
isFFIDotnetTy, -- :: DynFlags -> Type -> Bool
isFFIDotnetObjTy, -- :: Type -> Bool
isFFITy, -- :: Type -> Bool
+ isFunPtrTy, -- :: Type -> Bool
tcSplitIOType_maybe, -- :: Type -> Maybe Type
- toDNType, -- :: Type -> DNType
--------------------------------
-- Rexported from Type
unliftedTypeKind, liftedTypeKind, argTypeKind,
openTypeKind, mkArrowKind, mkArrowKinds,
isLiftedTypeKind, isUnliftedTypeKind, isSubOpenTypeKind,
- isSubArgTypeKind, isSubKind, defaultKind,
+ isSubArgTypeKind, isSubKind, splitKindFunTys, defaultKind,
kindVarRef, mkKindVar,
Type, PredType(..), ThetaType,
typeKind, tidyKind,
tyVarsOfType, tyVarsOfTypes, tyVarsOfPred, tyVarsOfTheta,
- tcTyVarsOfType, tcTyVarsOfTypes, exactTyVarsOfType, exactTyVarsOfTypes,
+ tcTyVarsOfType, tcTyVarsOfTypes, tcTyVarsOfPred, exactTyVarsOfType,
+ exactTyVarsOfTypes,
pprKind, pprParendKind,
pprType, pprParendType, pprTypeApp, pprTyThingCategory,
import Class
import Var
import ForeignCall
-import Unify
import VarSet
import Type
+import Coercion
import TyCon
-- others:
import DynFlags
-import CoreSyn
import Name
import NameSet
import VarEnv
-import OccName
import PrelNames
import TysWiredIn
import BasicTypes
import Maybes
import ListSetOps
import Outputable
+import FastString
-import Data.List
import Data.IORef
\end{code}
-
%************************************************************************
%* *
\subsection{Types}
-- 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
| ForSigCtxt Name -- Foreign inport or export signature
| DefaultDeclCtxt -- Types in a default declaration
| SpecInstCtxt -- SPECIALISE instance pragma
+ | ThBrackCtxt -- Template Haskell type brackets [t| ... |]
-- Notes re TySynCtxt
-- We allow type synonyms that aren't types; e.g. type List = []
ASSERT ( isTcTyVar tc )
case tcTyVarDetails tc of
MetaTv TauTv ref -> ref
- other -> pprPanic "kindVarRef" (ppr tc)
+ _ -> pprPanic "kindVarRef" (ppr tc)
mkKindVar :: Unique -> IORef MetaDetails -> KindVar
mkKindVar u r
-- They may be jiggled by tidying
kind_var_occ = mkOccName tvName "k"
\end{code}
-\end{code}
%************************************************************************
%* *
\begin{code}
pprTcTyVarDetails :: TcTyVarDetails -> SDoc
-- For debugging
-pprTcTyVarDetails (SkolemTv _) = ptext SLIT("sk")
-pprTcTyVarDetails (MetaTv BoxTv _) = ptext SLIT("box")
-pprTcTyVarDetails (MetaTv TauTv _) = ptext SLIT("tau")
-pprTcTyVarDetails (MetaTv (SigTv _) _) = ptext SLIT("sig")
+pprTcTyVarDetails (SkolemTv _) = ptext (sLit "sk")
+pprTcTyVarDetails (MetaTv BoxTv _) = ptext (sLit "box")
+pprTcTyVarDetails (MetaTv TauTv _) = ptext (sLit "tau")
+pprTcTyVarDetails (MetaTv (SigTv _) _) = ptext (sLit "sig")
pprUserTypeCtxt :: UserTypeCtxt -> SDoc
-pprUserTypeCtxt (FunSigCtxt n) = ptext SLIT("the type signature for") <+> quotes (ppr n)
-pprUserTypeCtxt ExprSigCtxt = ptext SLIT("an expression type signature")
-pprUserTypeCtxt (ConArgCtxt c) = ptext SLIT("the type of the constructor") <+> quotes (ppr c)
-pprUserTypeCtxt (TySynCtxt c) = ptext SLIT("the RHS of the type synonym") <+> quotes (ppr c)
-pprUserTypeCtxt GenPatCtxt = ptext SLIT("the type pattern of a generic definition")
-pprUserTypeCtxt LamPatSigCtxt = ptext SLIT("a pattern type signature")
-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 DefaultDeclCtxt = ptext SLIT("a type in a `default' declaration")
-pprUserTypeCtxt SpecInstCtxt = ptext SLIT("a SPECIALISE instance pragma")
+pprUserTypeCtxt (FunSigCtxt n) = ptext (sLit "the type signature for") <+> quotes (ppr n)
+pprUserTypeCtxt ExprSigCtxt = ptext (sLit "an expression type signature")
+pprUserTypeCtxt (ConArgCtxt c) = ptext (sLit "the type of the constructor") <+> quotes (ppr c)
+pprUserTypeCtxt (TySynCtxt c) = ptext (sLit "the RHS of the type synonym") <+> quotes (ppr c)
+pprUserTypeCtxt GenPatCtxt = ptext (sLit "the type pattern of a generic definition")
+pprUserTypeCtxt ThBrackCtxt = ptext (sLit "a Template Haskell quotation [t|...|]")
+pprUserTypeCtxt LamPatSigCtxt = ptext (sLit "a pattern type signature")
+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 DefaultDeclCtxt = ptext (sLit "a type in a `default' declaration")
+pprUserTypeCtxt SpecInstCtxt = ptext (sLit "a SPECIALISE instance pragma")
--------------------------------
tidySkolemTyVar :: TidyEnv -> TcTyVar -> (TidyEnv, TcTyVar)
-- Tidy the type inside a GenSkol, preparatory to printing it
tidySkolemTyVar env tv
- = ASSERT( isSkolemTyVar tv || isSigTyVar tv )
+ = ASSERT( isTcTyVar tv && (isSkolemTyVar tv || isSigTyVar tv ) )
(env1, mkTcTyVar (tyVarName tv) (tyVarKind tv) info1)
where
(env1, info1) = case tcTyVarDetails tv of
= ASSERT ( isTcTyVar tv )
quotes (ppr tv) <+> ppr_details (tcTyVarDetails tv)
where
- 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 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 RuntimeUnkSkol = ptext SLIT("is an unknown runtime type")
- ppr_skol info = ptext SLIT("is a rigid type variable bound by")
- <+> sep [pprSkolInfo info,
- nest 2 (ptext SLIT("at") <+> ppr (getSrcLoc tv))]
+ ppr_skol UnkSkol = ptext (sLit "is an unknown type variable") -- Unhelpful
+ 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) = 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"),
+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
pprSkolInfo RuntimeUnkSkol = panic "RuntimeUnkSkol"
instance Outputable MetaDetails where
- ppr Flexi = ptext SLIT("Flexi")
- ppr (Indirect ty) = ptext SLIT("Indirect") <+> ppr ty
+ ppr Flexi = ptext (sLit "Flexi")
+ ppr (Indirect ty) = ptext (sLit "Indirect") <+> ppr ty
\end{code}
isBoxyTyVar, isMetaTyVar :: TcTyVar -> Bool
isTyConableTyVar tv
- -- True of a meta-type variable tha can be filled in
+ -- True of a meta-type variable that can be filled in
-- with a type constructor application; in particular,
-- not a SigTv
= ASSERT( isTcTyVar tv)
SkolemTv {} -> False
isSkolemTyVar tv
- = ASSERT( isTcTyVar tv )
+ = ASSERT2( isTcTyVar tv, ppr tv )
case tcTyVarDetails tv of
SkolemTv _ -> True
MetaTv _ _ -> False
= ASSERT( isTcTyVar tv )
case tcTyVarDetails tv of
SkolemTv (PatSkol {}) -> True
- other -> False
+ _ -> False
isMetaTyVar tv
= ASSERT2( isTcTyVar tv, ppr tv )
case tcTyVarDetails tv of
MetaTv _ _ -> True
- other -> False
+ _ -> False
isBoxyTyVar tv
= ASSERT( isTcTyVar tv )
case tcTyVarDetails tv of
MetaTv BoxTv _ -> True
- other -> False
+ _ -> False
+isSigTyVar :: Var -> Bool
isSigTyVar tv
= ASSERT( isTcTyVar tv )
case tcTyVarDetails tv of
MetaTv (SigTv _) _ -> True
- other -> False
+ _ -> False
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)
+ _ -> pprPanic "metaTvRef" (ppr tv)
isFlexi, isIndirect :: MetaDetails -> Bool
isFlexi Flexi = True
-isFlexi other = False
+isFlexi _ = False
isIndirect (Indirect _) = True
-isIndirect other = False
+isIndirect _ = False
+
+isRuntimeUnk :: TyVar -> Bool
+isRuntimeUnk x | isTcTyVar x
+ , SkolemTv RuntimeUnkSkol <- tcTyVarDetails x = True
+ | otherwise = False
+
+isUnk :: TyVar -> Bool
+isUnk x | isTcTyVar x
+ , SkolemTv UnkSkol <- tcTyVarDetails x = True
+ | otherwise = False
\end{code}
isTauTy (TyConApp tc tys) = all isTauTy tys && isTauTyCon tc
isTauTy (AppTy a b) = isTauTy a && isTauTy b
isTauTy (FunTy a b) = isTauTy a && isTauTy b
-isTauTy (PredTy p) = True -- Don't look through source types
-isTauTy other = False
+isTauTy (PredTy _) = True -- Don't look through source types
+isTauTy _ = False
isTauTyCon :: TyCon -> Bool
-- A type is rigid if it has no meta type variables in it
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 isImmutableTyVar tc_tvs
+isRefineableTy ty = (null tc_tvs, all isImmutableTyVar tc_tvs)
where
tc_tvs = varSetElems (tcTyVarsOfType ty)
getDFunTyKey (TyVarTy tv) = getOccName tv
getDFunTyKey (TyConApp tc _) = getOccName tc
getDFunTyKey (AppTy fun _) = getDFunTyKey fun
-getDFunTyKey (FunTy arg _) = getOccName funTyCon
+getDFunTyKey (FunTy _ _) = getOccName funTyCon
getDFunTyKey (ForAllTy _ t) = getDFunTyKey t
getDFunTyKey ty = pprPanic "getDFunTyKey" (pprType ty)
-- PredTy shouldn't happen
These tcSplit functions are like their non-Tc analogues, but
a) they do not look through newtypes
b) they do not look through PredTys
- c) [future] they ignore usage-type annotations
However, they are non-monadic and do not follow through mutable type
variables. It's up to you to make sure this doesn't matter.
tcSplitForAllTys ty = split ty ty []
where
split orig_ty ty tvs | Just ty' <- tcView ty = split orig_ty ty' tvs
- split orig_ty (ForAllTy tv ty) tvs
+ split _ (ForAllTy tv ty) tvs
| not (isCoVar tv) = split ty ty (tv:tvs)
- split orig_ty t tvs = (reverse tvs, orig_ty)
+ split orig_ty _ tvs = (reverse tvs, orig_ty)
+tcIsForAllTy :: Type -> Bool
tcIsForAllTy ty | Just ty' <- tcView ty = tcIsForAllTy ty'
-tcIsForAllTy (ForAllTy tv ty) = not (isCoVar tv)
-tcIsForAllTy t = False
+tcIsForAllTy (ForAllTy tv _) = not (isCoVar tv)
+tcIsForAllTy _ = False
+
+tcSplitPredFunTy_maybe :: Type -> Maybe (PredType, Type)
+-- Split off the first predicate argument from a type
+tcSplitPredFunTy_maybe ty | Just ty' <- tcView ty = tcSplitPredFunTy_maybe ty'
+tcSplitPredFunTy_maybe (ForAllTy tv ty)
+ | isCoVar tv = Just (coVarPred tv, ty)
+tcSplitPredFunTy_maybe (FunTy arg res)
+ | Just p <- tcSplitPredTy_maybe arg = Just (p, res)
+tcSplitPredFunTy_maybe _
+ = Nothing
tcSplitPhiTy :: Type -> (ThetaType, Type)
-tcSplitPhiTy ty = split ty ty []
- where
- split orig_ty ty tvs | Just ty' <- tcView ty = split orig_ty ty' tvs
-
- split orig_ty (ForAllTy tv ty) ts
- | isCoVar tv = split ty ty (eq_pred:ts)
- where
- PredTy eq_pred = tyVarKind tv
- split orig_ty (FunTy arg res) ts
- | Just p <- tcSplitPredTy_maybe arg = split res res (p:ts)
- split orig_ty ty ts = (reverse ts, orig_ty)
+tcSplitPhiTy ty
+ = split ty []
+ where
+ split ty ts
+ = case tcSplitPredFunTy_maybe ty of
+ Just (pred, ty) -> split ty (pred:ts)
+ Nothing -> (reverse ts, ty)
tcSplitSigmaTy :: Type -> ([TyVar], ThetaType, Type)
tcSplitSigmaTy ty = case tcSplitForAllTys ty of
tcMultiSplitSigmaTy sigma
= case (tcSplitSigmaTy sigma) of
- ([],[],ty) -> ([], sigma)
+ ([], [], _) -> ([], sigma)
(tvs, theta, ty) -> case tcMultiSplitSigmaTy ty of
(pairs, rest) -> ((tvs,theta):pairs, rest)
-- Newtypes are opaque, so they may be split
-- However, predicates are not treated
-- as tycon applications by the type checker
-tcSplitTyConApp_maybe other = Nothing
+tcSplitTyConApp_maybe _ = Nothing
-----------------------
tcSplitFunTys :: Type -> ([Type], Type)
tcSplitFunTy_maybe :: Type -> Maybe (Type, Type)
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
+tcSplitFunTy_maybe _ = Nothing
-- Note the (not (isPredTy arg)) guard
-- Consider (?x::Int) => Bool
-- We don't want to treat this as a function type!
| otherwise
= ([], ty)
+tcSplitFunTy :: Type -> (Type, Type)
tcSplitFunTy ty = expectJust "tcSplitFunTy" (tcSplitFunTy_maybe ty)
+
+tcFunArgTy :: Type -> Type
tcFunArgTy ty = fst (tcSplitFunTy ty)
+
+tcFunResultTy :: Type -> Type
tcFunResultTy ty = snd (tcSplitFunTy ty)
-----------------------
-----------------------
tcGetTyVar_maybe :: Type -> Maybe TyVar
tcGetTyVar_maybe ty | Just ty' <- tcView ty = tcGetTyVar_maybe ty'
-tcGetTyVar_maybe (TyVarTy tv) = Just tv
-tcGetTyVar_maybe other = Nothing
+tcGetTyVar_maybe (TyVarTy tv) = Just tv
+tcGetTyVar_maybe _ = Nothing
tcGetTyVar :: String -> Type -> TyVar
tcGetTyVar msg ty = expectJust msg (tcGetTyVar_maybe ty)
tcIsTyVarTy ty = maybeToBool (tcGetTyVar_maybe ty)
-----------------------
-tcSplitDFunTy :: Type -> ([TyVar], [PredType], Class, [Type])
+tcSplitDFunTy :: Type -> ([TyVar], Class, [Type])
-- Split the type of a dictionary function
+-- We don't use tcSplitSigmaTy, because a DFun may (with NDP)
+-- have non-Pred arguments, such as
+-- df :: forall m. (forall b. Eq b => Eq (m b)) -> C m
tcSplitDFunTy ty
- = case tcSplitSigmaTy ty of { (tvs, theta, tau) ->
- case tcSplitDFunHead tau of { (clas, tys) ->
- (tvs, theta, clas, tys) }}
+ = case tcSplitForAllTys ty of { (tvs, rho) ->
+ case tcSplitDFunHead (drop_pred_tys rho) of { (clas, tys) ->
+ (tvs, clas, tys) }}
+ where
+ -- Discard the context of the dfun. This can be a mix of
+ -- coercion and class constraints; or (in the general NDP case)
+ -- some other function argument
+ drop_pred_tys ty | Just ty' <- tcView ty = drop_pred_tys ty'
+ drop_pred_tys (ForAllTy tv ty) = ASSERT( isCoVar tv ) drop_pred_tys ty
+ drop_pred_tys (FunTy _ ty) = drop_pred_tys ty
+ drop_pred_tys ty = ty
tcSplitDFunHead :: Type -> (Class, [Type])
tcSplitDFunHead tau
= case tcSplitPredTy_maybe tau of
Just (ClassP clas tys) -> (clas, tys)
- other -> panic "tcSplitDFunHead"
+ _ -> pprPanic "tcSplitDFunHead" (ppr tau)
-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
+ TyConApp tc _ -> 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 -> tcValidInstHeadTy ty
- TyConApp tc tys -> not (isSynTyCon tc) && ok tys
+ TyConApp _ tys -> ok tys
FunTy arg res -> ok [arg, res]
- other -> False
+ _ -> False
where
-- Check that all the types are type variables,
-- and that each is distinct
where
tvs = mapCatMaybes get_tv tys
- get_tv (NoteTy _ ty) = get_tv ty -- Again, do not look
get_tv (TyVarTy tv) = Just tv -- through synonyms
- get_tv other = Nothing
+ get_tv _ = Nothing
\end{code}
-- Returns Just for predicates only
tcSplitPredTy_maybe ty | Just ty' <- tcView ty = tcSplitPredTy_maybe ty'
tcSplitPredTy_maybe (PredTy p) = Just p
-tcSplitPredTy_maybe other = Nothing
-
+tcSplitPredTy_maybe _ = Nothing
+
predTyUnique :: PredType -> Unique
-predTyUnique (IParam n _) = getUnique (ipNameName n)
-predTyUnique (ClassP clas tys) = getUnique clas
+predTyUnique (IParam n _) = getUnique (ipNameName n)
+predTyUnique (ClassP clas _) = getUnique clas
+predTyUnique (EqPred a b) = pprPanic "predTyUnique" (ppr (EqPred a b))
\end{code}
--------------------- Dictionary types ---------------------------------
\begin{code}
+mkClassPred :: Class -> [Type] -> PredType
mkClassPred clas tys = ClassP clas tys
isClassPred :: PredType -> Bool
-isClassPred (ClassP clas tys) = True
-isClassPred other = False
+isClassPred (ClassP _ _) = True
+isClassPred _ = False
-isTyVarClassPred (ClassP clas tys) = all tcIsTyVarTy tys
-isTyVarClassPred other = False
+isTyVarClassPred :: PredType -> Bool
+isTyVarClassPred (ClassP _ tys) = all tcIsTyVarTy tys
+isTyVarClassPred _ = False
getClassPredTys_maybe :: PredType -> Maybe (Class, [Type])
getClassPredTys_maybe (ClassP clas tys) = Just (clas, tys)
-getClassPredTys_maybe _ = Nothing
+getClassPredTys_maybe _ = Nothing
getClassPredTys :: PredType -> (Class, [Type])
getClassPredTys (ClassP clas tys) = (clas, tys)
-getClassPredTys other = panic "getClassPredTys"
+getClassPredTys _ = panic "getClassPredTys"
mkDictTy :: Class -> [Type] -> Type
mkDictTy clas tys = mkPredTy (ClassP clas tys)
isDictTy :: Type -> Bool
isDictTy ty | Just ty' <- tcView ty = isDictTy ty'
isDictTy (PredTy p) = isClassPred p
-isDictTy other = False
+isDictTy _ = False
+
+isDictLikeTy :: Type -> Bool
+-- Note [Dictionary-like types]
+isDictLikeTy ty | Just ty' <- tcView ty = isDictTy ty'
+isDictLikeTy (PredTy p) = isClassPred p
+isDictLikeTy (TyConApp tc tys)
+ | isTupleTyCon tc = all isDictLikeTy tys
+isDictLikeTy _ = False
\end{code}
+Note [Dictionary-like types]
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Being "dictionary-like" means either a dictionary type or a tuple thereof.
+In GHC 6.10 we build implication constraints which construct such tuples,
+and if we land up with a binding
+ t :: (C [a], Eq [a])
+ t = blah
+then we want to treat t as cheap under "-fdicts-cheap" for example.
+(Implication constraints are normally inlined, but sadly not if the
+occurrence is itself inside an INLINE function! Until we revise the
+handling of implication constraints, that is.) This turned out to
+be important in getting good arities in DPH code. Example:
+
+ class C a
+ class D a where { foo :: a -> a }
+ instance C a => D (Maybe a) where { foo x = x }
+
+ bar :: (C a, C b) => a -> b -> (Maybe a, Maybe b)
+ {-# INLINE bar #-}
+ bar x y = (foo (Just x), foo (Just y))
+
+Then 'bar' should jolly well have arity 4 (two dicts, two args), but
+we ended up with something like
+ bar = __inline_me__ (\d1,d2. let t :: (D (Maybe a), D (Maybe b)) = ...
+ in \x,y. <blah>)
+
+This is all a bit ad-hoc; eg it relies on knowing that implication
+constraints build tuples.
+
--------------------- Implicit parameters ---------------------------------
\begin{code}
isIPPred :: PredType -> Bool
isIPPred (IParam _ _) = True
-isIPPred other = False
+isIPPred _ = False
isInheritablePred :: PredType -> Bool
-- Can be inherited by a context. For example, consider
-- which can be free in g's rhs, and shared by both calls to g
isInheritablePred (ClassP _ _) = True
isInheritablePred (EqPred _ _) = True
-isInheritablePred other = False
+isInheritablePred _ = False
\end{code}
--------------------- Equality predicates ---------------------------------
| (tv,ty) <- eq_spec]
\end{code}
---------------------- The stupid theta (sigh) ---------------------------------
-
-\begin{code}
-dataConsStupidTheta :: [DataCon] -> ThetaType
--- Union the stupid thetas from all the specified constructors (non-empty)
--- All the constructors should have the same result type, modulo alpha conversion
--- The resulting ThetaType uses type variables from the *first* constructor in the list
---
--- It's here because it's used in MkId.mkRecordSelId, and in TcExpr
-dataConsStupidTheta (con1:cons)
- = nubBy tcEqPred all_preds
- where
- all_preds = dataConStupidTheta con1 ++ other_stupids
- res_ty1 = dataConOrigResTy con1
- other_stupids = [ substPred subst pred
- | con <- cons
- , let (tvs, _, _, res_ty) = dataConSig con
- Just subst = tcMatchTy (mkVarSet tvs) res_ty res_ty1
- , pred <- dataConStupidTheta con ]
-dataConsStupidTheta [] = panic "dataConsStupidTheta"
-\end{code}
-
%************************************************************************
%* *
\begin{code}
isSigmaTy :: Type -> Bool
isSigmaTy ty | Just ty' <- tcView ty = isSigmaTy ty'
-isSigmaTy (ForAllTy tyvar ty) = True
-isSigmaTy (FunTy a b) = isPredTy a
-isSigmaTy _ = False
+isSigmaTy (ForAllTy _ _) = True
+isSigmaTy (FunTy a _) = isPredTy a
+isSigmaTy _ = False
isOverloadedTy :: Type -> Bool
+-- Yes for a type of a function that might require evidence-passing
+-- Used only by bindInstsOfLocalFuns/Pats
+-- NB: be sure to check for type with an equality predicate; hence isCoVar
isOverloadedTy ty | Just ty' <- tcView ty = isOverloadedTy ty'
-isOverloadedTy (ForAllTy tyvar ty) = isOverloadedTy ty
-isOverloadedTy (FunTy a b) = isPredTy a
-isOverloadedTy _ = False
+isOverloadedTy (ForAllTy tv ty) = isCoVar tv || isOverloadedTy ty
+isOverloadedTy (FunTy a _) = isPredTy a
+isOverloadedTy _ = False
isPredTy :: Type -> Bool -- Belongs in TcType because it does
-- not look through newtypes, or predtypes (of course)
isPredTy ty | Just ty' <- tcView ty = isPredTy ty'
-isPredTy (PredTy sty) = True
-isPredTy _ = False
+isPredTy (PredTy _) = True
+isPredTy _ = False
\end{code}
\begin{code}
+isFloatTy, isDoubleTy, isIntegerTy, isIntTy, isWordTy, isBoolTy,
+ isUnitTy, isCharTy :: Type -> Bool
isFloatTy = is_tc floatTyConKey
isDoubleTy = is_tc doubleTyConKey
isIntegerTy = is_tc integerTyConKey
isIntTy = is_tc intTyConKey
+isWordTy = is_tc wordTyConKey
isBoolTy = is_tc boolTyConKey
isUnitTy = is_tc unitTyConKey
isCharTy = is_tc charTyConKey
+isStringTy :: Type -> Bool
isStringTy ty
= case tcSplitTyConApp_maybe ty of
Just (tc, [arg_ty]) -> tc == listTyCon && isCharTy arg_ty
- other -> False
+ _ -> 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 tys) = isOpenSynTyCon tc &&
+ length tys == tyConArity tc
+isOpenSynTyConApp _other = False
+\end{code}
+
%************************************************************************
%* *
-- (Types.tyVarsOfTypes finds all free TyVars)
tcTyVarsOfType (TyVarTy tv) = if isTcTyVar tv then unitVarSet tv
else emptyVarSet
-tcTyVarsOfType (TyConApp tycon tys) = tcTyVarsOfTypes tys
-tcTyVarsOfType (NoteTy _ ty) = tcTyVarsOfType ty
+tcTyVarsOfType (TyConApp _ tys) = tcTyVarsOfTypes tys
tcTyVarsOfType (PredTy sty) = tcTyVarsOfPred sty
tcTyVarsOfType (FunTy arg res) = tcTyVarsOfType arg `unionVarSet` tcTyVarsOfType res
tcTyVarsOfType (AppTy fun arg) = tcTyVarsOfType fun `unionVarSet` tcTyVarsOfType arg
which type variables are mentioned in a type. It's also used in the
smart-app checking code --- see TcExpr.tcIdApp
+On the other hand, consider a *top-level* definition
+ f = (\x -> x) :: T a -> T a
+If we don't abstract over 'a' it'll get fixed to GHC.Prim.Any, and then
+if we have an application like (f "x") we get a confusing error message
+involving Any. So the conclusion is this: when generalising
+ - at top level use tyVarsOfType
+ - in nested bindings use exactTyVarsOfType
+See Trac #1813 for example.
+
\begin{code}
exactTyVarsOfType :: TcType -> TyVarSet
-- Find the free type variables (of any kind)
where
go ty | Just ty' <- tcView ty = go ty' -- This is the key line
go (TyVarTy tv) = unitVarSet tv
- go (TyConApp tycon tys) = exactTyVarsOfTypes tys
+ go (TyConApp _ tys) = exactTyVarsOfTypes tys
go (PredTy ty) = go_pred ty
go (FunTy arg res) = go arg `unionVarSet` go res
go (AppTy fun arg) = go fun `unionVarSet` go arg
\begin{code}
tyClsNamesOfType :: Type -> NameSet
-tyClsNamesOfType (TyVarTy tv) = emptyNameSet
+tyClsNamesOfType (TyVarTy _) = emptyNameSet
tyClsNamesOfType (TyConApp tycon tys) = unitNameSet (getName tycon) `unionNameSets` tyClsNamesOfTypes tys
-tyClsNamesOfType (NoteTy _ ty2) = tyClsNamesOfType ty2
-tyClsNamesOfType (PredTy (IParam n ty)) = tyClsNamesOfType ty
+tyClsNamesOfType (PredTy (IParam _ ty)) = tyClsNamesOfType ty
tyClsNamesOfType (PredTy (ClassP cl tys)) = unitNameSet (getName cl) `unionNameSets` tyClsNamesOfTypes tys
tyClsNamesOfType (PredTy (EqPred ty1 ty2)) = tyClsNamesOfType ty1 `unionNameSets` tyClsNamesOfType ty2
tyClsNamesOfType (FunTy arg res) = tyClsNamesOfType arg `unionNameSets` tyClsNamesOfType res
tyClsNamesOfType (AppTy fun arg) = tyClsNamesOfType fun `unionNameSets` tyClsNamesOfType arg
-tyClsNamesOfType (ForAllTy tyvar ty) = tyClsNamesOfType ty
+tyClsNamesOfType (ForAllTy _ ty) = tyClsNamesOfType ty
+tyClsNamesOfTypes :: [Type] -> NameSet
tyClsNamesOfTypes tys = foldr (unionNameSets . tyClsNamesOfType) emptyNameSet tys
tyClsNamesOfDFunHead :: Type -> NameSet
-- even if Foo *is* locally defined
tyClsNamesOfDFunHead dfun_ty
= case tcSplitSigmaTy dfun_ty of
- (tvs,_,head_ty) -> tyClsNamesOfType head_ty
+ (_, _, head_ty) -> tyClsNamesOfType head_ty
\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)
+
+ _ -> Nothing
isFFITy :: Type -> Bool
-- True for any TyCon that can possibly be an arg or result of an FFI call
-- or a newtype of either.
isFFILabelTy = checkRepTyConKey [ptrTyConKey, funPtrTyConKey]
+isFFIPrimArgumentTy :: DynFlags -> Type -> Bool
+-- Checks for valid argument type for a 'foreign import prim'
+-- Currently they must all be simple unlifted types.
+isFFIPrimArgumentTy dflags ty
+ = checkRepTyCon (legalFIPrimArgTyCon dflags) ty
+
+isFFIPrimResultTy :: DynFlags -> Type -> Bool
+-- Checks for valid result type for a 'foreign import prim'
+-- Currently it must be an unlifted type, including unboxed tuples.
+isFFIPrimResultTy dflags ty
+ = checkRepTyCon (legalFIPrimResultTyCon dflags) ty
+
isFFIDotnetTy :: DynFlags -> Type -> Bool
isFFIDotnetTy dflags ty
= checkRepTyCon (\ tc -> (legalFIResultTyCon dflags tc ||
-- it no longer does so. May need to adjust isFFIDotNetTy
-- if we do want to look through newtypes.
-isFFIDotnetObjTy ty =
- let
+isFFIDotnetObjTy :: Type -> Bool
+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
-
-toDNType :: Type -> DNType
-toDNType ty
- | isStringTy ty = DNString
- | isFFIDotnetObjTy ty = DNObject
- | Just (tc,argTys) <- tcSplitTyConApp_maybe ty
- = case lookup (getUnique tc) dn_assoc of
- Just x -> x
- Nothing
- | tc `hasKey` ioTyConKey -> toDNType (head argTys)
- | otherwise -> pprPanic ("toDNType: unsupported .NET type")
- (pprType ty <+> parens (hcat (map pprType argTys)) <+> ppr tc)
- | otherwise = panic "toDNType" -- Is this right?
- where
- dn_assoc :: [ (Unique, DNType) ]
- dn_assoc = [ (unitTyConKey, DNUnit)
- , (intTyConKey, DNInt)
- , (int8TyConKey, DNInt8)
- , (int16TyConKey, DNInt16)
- , (int32TyConKey, DNInt32)
- , (int64TyConKey, DNInt64)
- , (wordTyConKey, DNInt)
- , (word8TyConKey, DNWord8)
- , (word16TyConKey, DNWord16)
- , (word32TyConKey, DNWord32)
- , (word64TyConKey, DNWord64)
- , (floatTyConKey, DNFloat)
- , (doubleTyConKey, DNDouble)
- , (ptrTyConKey, DNPtr)
- , (funPtrTyConKey, DNPtr)
- , (charTyConKey, DNChar)
- , (boolTyConKey, DNBool)
- ]
+ check_tc tc = getName tc == objectTyConName
+
+isFunPtrTy :: Type -> Bool
+isFunPtrTy = checkRepTyConKey [funPtrTyConKey]
checkRepTyCon :: (TyCon -> Bool) -> Type -> Bool
- -- Look through newtypes
- -- Non-recursive ones are transparent to splitTyConApp,
- -- but recursive ones aren't. Manuel had:
- -- newtype T = MkT (Ptr T)
- -- and wanted it to work...
-checkRepTyCon check_tc ty
- | Just (tc,_) <- splitTyConApp_maybe (repType ty) = check_tc tc
- | otherwise = False
+-- Look through newtypes, but *not* foralls
+-- Should work even for recursive newtypes
+-- eg Manuel had: newtype T = MkT (Ptr T)
+checkRepTyCon check_tc ty
+ = go [] ty
+ where
+ go rec_nts ty
+ | Just (tc,tys) <- splitTyConApp_maybe ty
+ = case carefullySplitNewType_maybe rec_nts tc tys of
+ Just (rec_nts', ty') -> go rec_nts' ty'
+ Nothing -> check_tc tc
+ | otherwise
+ = False
checkRepTyConKey :: [Unique] -> Type -> Bool
-- Like checkRepTyCon, but just looks at the TyCon key
legalOutgoingTyCon :: DynFlags -> Safety -> TyCon -> Bool
-- Checks validity of types going from Haskell -> external world
-legalOutgoingTyCon dflags safety tc
+legalOutgoingTyCon dflags _ tc
= marshalableTyCon dflags tc
legalFFITyCon :: TyCon -> Bool
legalFFITyCon tc
= isUnLiftedTyCon tc || boxedMarshalableTyCon tc || tc == unitTyCon
+marshalableTyCon :: DynFlags -> TyCon -> Bool
marshalableTyCon dflags tc
- = (dopt Opt_GlasgowExts dflags && isUnLiftedTyCon tc)
+ = (dopt Opt_UnliftedFFITypes dflags
+ && isUnLiftedTyCon tc
+ && not (isUnboxedTupleTyCon tc)
+ && case tyConPrimRep tc of -- Note [Marshalling VoidRep]
+ VoidRep -> False
+ _ -> True)
|| boxedMarshalableTyCon tc
+boxedMarshalableTyCon :: TyCon -> Bool
boxedMarshalableTyCon tc
= getUnique tc `elem` [ intTyConKey, int8TyConKey, int16TyConKey
, int32TyConKey, int64TyConKey
, stablePtrTyConKey
, boolTyConKey
]
+
+legalFIPrimArgTyCon :: DynFlags -> TyCon -> Bool
+-- Check args of 'foreign import prim', only allow simple unlifted types.
+-- Strictly speaking it is unnecessary to ban unboxed tuples here since
+-- currently they're of the wrong kind to use in function args anyway.
+legalFIPrimArgTyCon dflags tc
+ = dopt Opt_UnliftedFFITypes dflags
+ && isUnLiftedTyCon tc
+ && not (isUnboxedTupleTyCon tc)
+
+legalFIPrimResultTyCon :: DynFlags -> TyCon -> Bool
+-- Check result type of 'foreign import prim'. Allow simple unlifted
+-- types and also unboxed tuple result types '... -> (# , , #)'
+legalFIPrimResultTyCon dflags tc
+ = dopt Opt_UnliftedFFITypes dflags
+ && isUnLiftedTyCon tc
+ && (isUnboxedTupleTyCon tc
+ || case tyConPrimRep tc of -- Note [Marshalling VoidRep]
+ VoidRep -> False
+ _ -> True)
\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