X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyDecls.lhs;h=f525f4e62357fd151b7257c93ba3c1df516a4423;hb=a2415187cc4dd695de8e477a99b2b971390d14fa;hp=0392d34cda72d84772d508ef12791d15eb4d936e;hpb=4a91d102be99778efcab80211ca5de3f2cf6619a;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcTyDecls.lhs b/ghc/compiler/typecheck/TcTyDecls.lhs index 0392d34..f525f4e 100644 --- a/ghc/compiler/typecheck/TcTyDecls.lhs +++ b/ghc/compiler/typecheck/TcTyDecls.lhs @@ -4,52 +4,38 @@ \section[TcTyDecls]{Typecheck type declarations} \begin{code} -module TcTyDecls ( - tcTyDecl1, - kcConDetails, - mkImplicitDataBinds, mkNewTyConRep - ) where +module TcTyDecls ( tcTyDecl, checkValidTyCon, kcConDetails ) where #include "HsVersions.h" -import HsSyn ( MonoBinds(..), - TyClDecl(..), ConDecl(..), ConDetails(..), BangType(..), - getBangType +import HsSyn ( TyClDecl(..), ConDecl(..), ConDetails(..), + getBangType, getBangStrictness, conDetailsTys ) import RnHsSyn ( RenamedTyClDecl, RenamedConDecl, RenamedContext ) -import TcHsSyn ( TcMonoBinds, idsToMonoBinds ) import BasicTypes ( NewOrData(..) ) -import TcMonoType ( tcHsType, tcHsSigType, tcHsBoxedSigType, tcHsTyVars, tcClassContext, - kcHsContext, kcHsSigType +import TcMonoType ( tcHsTyVars, tcHsTheta, tcHsType, + kcHsContext, kcHsSigType, kcHsLiftedSigType ) import TcEnv ( tcExtendTyVarEnv, - tcLookupTyCon, tcLookupClass, tcLookupGlobalId, - TyThing(..), TyThingDetails(..) + tcLookupTyCon, tcLookupRecId, + TyThingDetails(..), RecTcEnv ) +import TcType ( tcEqType, tyVarsOfTypes, tyVarsOfPred, ThetaType ) +import TcMType ( checkValidType, UserTypeCtxt(..), checkValidTheta, SourceTyCtxt(..) ) import TcMonad -import Class ( ClassContext ) -import DataCon ( DataCon, mkDataCon, - dataConFieldLabels, dataConId, dataConWrapId, - markedStrict, notMarkedStrict, markedUnboxed, dataConRepType - ) +import DataCon ( DataCon, mkDataCon, dataConFieldLabels, dataConWrapId, dataConName ) import MkId ( mkDataConId, mkDataConWrapId, mkRecordSelId ) import FieldLabel -import Var ( Id, TyVar ) -import Name ( Name, isLocallyDefined, NamedThing(..) ) +import Var ( TyVar, idType ) +import Name ( Name, NamedThing(..) ) import Outputable -import TyCon ( TyCon, isSynTyCon, isNewTyCon, - tyConDataConsIfAvailable, tyConTyVars, tyConGenIds - ) -import Type ( tyVarsOfTypes, splitFunTy, applyTys, - mkTyConApp, mkTyVarTys, mkForAllTys, - splitAlgTyConApp_maybe, Type - ) -import TysWiredIn ( unitTy ) +import TyCon ( TyCon, tyConName, tyConTheta, getSynTyConDefn, tyConTyVars, tyConDataCons, isSynTyCon ) import VarSet ( intersectVarSet, isEmptyVarSet ) import PrelNames ( unpackCStringName, unpackCStringUtf8Name ) import ListSetOps ( equivClasses ) +import List ( nubBy ) \end{code} %************************************************************************ @@ -59,65 +45,97 @@ import ListSetOps ( equivClasses ) %************************************************************************ \begin{code} -tcTyDecl1 :: RenamedTyClDecl -> TcM (Name, TyThingDetails) -tcTyDecl1 (TySynonym tycon_name tyvar_names rhs src_loc) +tcTyDecl :: RecTcEnv -> RenamedTyClDecl -> TcM (Name, TyThingDetails) +tcTyDecl unf_env (TySynonym {tcdName = tycon_name, tcdSynRhs = rhs}) = tcLookupTyCon tycon_name `thenNF_Tc` \ tycon -> tcExtendTyVarEnv (tyConTyVars tycon) $ tcHsType rhs `thenTc` \ rhs_ty -> - -- Note tcHsType not tcHsSigType; we allow type synonyms - -- that aren't types; e.g. type List = [] - -- - -- If the RHS mentions tyvars that aren't in scope, we'll - -- quantify over them: - -- e.g. type T = a->a - -- will become type T = forall a. a->a - -- - -- With gla-exts that's right, but for H98 we should complain. - -- We can now do that here without falling into - -- a black hole, we still do it in rnDecl (TySynonym case) - returnTc (tycon_name, SynTyDetails rhs_ty) -tcTyDecl1 (TyData new_or_data context tycon_name _ con_decls _ derivings src_loc name1 name2) +tcTyDecl unf_env (TyData {tcdND = new_or_data, tcdCtxt = context, + tcdName = tycon_name, tcdCons = con_decls}) = tcLookupTyCon tycon_name `thenNF_Tc` \ tycon -> let tyvars = tyConTyVars tycon in tcExtendTyVarEnv tyvars $ - - -- Typecheck the pieces - tcClassContext context `thenTc` \ ctxt -> - tc_derivs derivings `thenTc` \ derived_classes -> + tcHsTheta context `thenTc` \ ctxt -> mapTc (tcConDecl new_or_data tycon tyvars ctxt) con_decls `thenTc` \ data_cons -> + let + sel_ids = mkRecordSelectors unf_env tycon data_cons + in + returnTc (tycon_name, DataTyDetails ctxt data_cons sel_ids) + +tcTyDecl unf_env (ForeignType {tcdName = tycon_name}) + = returnTc (tycon_name, ForeignTyDetails) - returnTc (tycon_name, DataTyDetails ctxt data_cons derived_classes) + +mkRecordSelectors unf_env tycon data_cons + = -- We'll check later that fields with the same name + -- from different constructors have the same type. + [ mkRecordSelId tycon field unpack_id unpackUtf8_id + | field <- nubBy eq_name fields ] where - tc_derivs Nothing = returnTc [] - tc_derivs (Just ds) = mapTc tcLookupClass ds + fields = [ field | con <- data_cons, field <- dataConFieldLabels con ] + eq_name field1 field2 = fieldLabelName field1 == fieldLabelName field2 + + unpack_id = tcLookupRecId unf_env unpackCStringName + unpackUtf8_id = tcLookupRecId unf_env unpackCStringUtf8Name \end{code} + +%************************************************************************ +%* * +\subsection{Validity check} +%* * +%************************************************************************ + +checkValidTyCon is called once the mutually-recursive knot has been +tied, so we can look at things freely. + \begin{code} -mkNewTyConRep :: TyCon -> Type --- Find the representation type for this newtype TyCon --- The trick is to to deal correctly with recursive newtypes --- such as newtype T = MkT T +checkValidTyCon :: TyCon -> TcM () +checkValidTyCon tc + | isSynTyCon tc = checkValidType (TySynCtxt name) syn_rhs + | otherwise + = -- Check the context on the data decl + checkValidTheta (DataTyCtxt name) (tyConTheta tc) `thenTc_` + + -- Check arg types of data constructors + mapTc_ check_data_con data_cons `thenTc_` + + -- Check that fields with the same name share a type + mapTc_ check_fields groups -mkNewTyConRep tc - = mkForAllTys tvs (loop [] (mkTyConApp tc (mkTyVarTys tvs))) where - tvs = tyConTyVars tc - loop tcs ty = case splitAlgTyConApp_maybe ty of { - Nothing -> ty ; - Just (tc, tys, data_cons) | not (isNewTyCon tc) -> ty - | tc `elem` tcs -> unitTy - | otherwise -> - - case splitFunTy (applyTys (dataConRepType (head data_cons)) tys) of - (rep_ty, _) -> loop (tc:tcs) rep_ty - } + name = tyConName tc + (_, syn_rhs) = getSynTyConDefn tc + data_cons = tyConDataCons tc + + fields = [field | con <- data_cons, field <- dataConFieldLabels con] + groups = equivClasses cmp_name fields + cmp_name field1 field2 = fieldLabelName field1 `compare` fieldLabelName field2 + + check_data_con con = checkValidType (ConArgCtxt (dataConName con)) + (idType (dataConWrapId con)) + -- This checks the argument types and + -- the existential context (if any) + + check_fields fields@(first_field_label : other_fields) + -- These fields all have the same name, but are from + -- different constructors in the data type + = -- Check that all the fields in the group have the same type + -- NB: this check assumes that all the constructors of a given + -- data type use the same type variables + checkTc (all (tcEqType field_ty) other_tys) (fieldTypeMisMatch field_name) + where + field_ty = fieldLabelType first_field_label + field_name = fieldLabelName first_field_label + other_tys = map fieldLabelType other_fields \end{code} + %************************************************************************ %* * \subsection{Kind and type check constructors} @@ -125,43 +143,31 @@ mkNewTyConRep tc %************************************************************************ \begin{code} -kcConDetails :: RenamedContext -> ConDetails Name -> TcM () -kcConDetails ex_ctxt details +kcConDetails :: NewOrData -> RenamedContext -> ConDetails Name -> TcM () +kcConDetails new_or_data ex_ctxt details = kcHsContext ex_ctxt `thenTc_` - kc_con_details details + mapTc_ kc_sig_type (conDetailsTys details) where - kc_con_details (VanillaCon btys) = mapTc_ kc_bty btys - kc_con_details (InfixCon bty1 bty2) = mapTc_ kc_bty [bty1,bty2] - kc_con_details (RecCon flds) = mapTc_ kc_field flds - - kc_field (_, bty) = kc_bty bty - - kc_bty bty = kcHsSigType (getBangType bty) + kc_sig_type = case new_or_data of + DataType -> kcHsSigType + NewType -> kcHsLiftedSigType + -- Can't allow an unlifted type here, because we're effectively + -- going to remove the constructor while coercing it to a lifted type. -tcConDecl :: NewOrData -> TyCon -> [TyVar] -> ClassContext -> RenamedConDecl -> TcM DataCon +tcConDecl :: NewOrData -> TyCon -> [TyVar] -> ThetaType -> RenamedConDecl -> TcM DataCon tcConDecl new_or_data tycon tyvars ctxt (ConDecl name wkr_name ex_tvs ex_ctxt details src_loc) - = tcAddSrcLoc src_loc $ - tcHsTyVars ex_tvs (kcConDetails ex_ctxt details) $ \ ex_tyvars -> - tcClassContext ex_ctxt `thenTc` \ ex_theta -> + = tcAddSrcLoc src_loc $ + tcHsTyVars ex_tvs (kcConDetails new_or_data ex_ctxt details) $ \ ex_tyvars -> + tcHsTheta ex_ctxt `thenTc` \ ex_theta -> case details of VanillaCon btys -> tc_datacon ex_tyvars ex_theta btys InfixCon bty1 bty2 -> tc_datacon ex_tyvars ex_theta [bty1,bty2] RecCon fields -> tc_rec_con ex_tyvars ex_theta fields where - tc_sig_type = case new_or_data of - DataType -> tcHsSigType - NewType -> tcHsBoxedSigType - -- Can't allow an unboxed type here, because we're effectively - -- going to remove the constructor while coercing it to a boxed type. - tc_datacon ex_tyvars ex_theta btys - = let - arg_stricts = map getBangStrictness btys - tys = map getBangType btys - in - mapTc tc_sig_type tys `thenTc` \ arg_tys -> - mk_data_con ex_tyvars ex_theta arg_stricts arg_tys [] + = mapTc tcHsType (map getBangType btys) `thenTc` \ arg_tys -> + mk_data_con ex_tyvars ex_theta (map getBangStrictness btys) arg_tys [] tc_rec_con ex_tyvars ex_theta fields = checkTc (null ex_tyvars) (exRecConErr name) `thenTc_` @@ -169,15 +175,15 @@ tcConDecl new_or_data tycon tyvars ctxt (ConDecl name wkr_name ex_tvs ex_ctxt de let field_labels = concat field_labels_s arg_stricts = [str | (ns, bty) <- fields, - let str = getBangStrictness bty, - n <- ns -- One for each. E.g x,y,z :: !Int + let str = getBangStrictness bty, + n <- ns -- One for each. E.g x,y,z :: !Int ] in mk_data_con ex_tyvars ex_theta arg_stricts (map fieldLabelType field_labels) field_labels tc_field ((field_label_names, bty), tag) - = tc_sig_type (getBangType bty) `thenTc` \ field_ty -> + = tcHsType (getBangType bty) `thenTc` \ field_ty -> returnTc [mkFieldLabel (getName name) tycon field_ty tag | name <- field_label_names] mk_data_con ex_tyvars ex_theta arg_stricts arg_tys fields @@ -199,85 +205,21 @@ thinContext arg_tys ctxt = filter in_arg_tys ctxt where arg_tyvars = tyVarsOfTypes arg_tys - in_arg_tys (clas,tys) = not $ isEmptyVarSet $ - tyVarsOfTypes tys `intersectVarSet` arg_tyvars - -getBangStrictness (Banged _) = markedStrict -getBangStrictness (Unbanged _) = notMarkedStrict -getBangStrictness (Unpacked _) = markedUnboxed + in_arg_tys pred = not $ isEmptyVarSet $ + tyVarsOfPred pred `intersectVarSet` arg_tyvars \end{code} - %************************************************************************ %* * -\subsection{Generating constructor/selector bindings for data declarations} +\subsection{Errors and contexts} %* * %************************************************************************ -\begin{code} -mkImplicitDataBinds :: [TyCon] -> TcM ([Id], TcMonoBinds) -mkImplicitDataBinds [] = returnTc ([], EmptyMonoBinds) -mkImplicitDataBinds (tycon : tycons) - | isSynTyCon tycon = mkImplicitDataBinds tycons - | otherwise = mkImplicitDataBinds_one tycon `thenTc` \ (ids1, b1) -> - mkImplicitDataBinds tycons `thenTc` \ (ids2, b2) -> - returnTc (ids1++ids2, b1 `AndMonoBinds` b2) - -mkImplicitDataBinds_one tycon - = mapTc (mkRecordSelector tycon) groups `thenTc` \ sel_ids -> - let - unf_ids = sel_ids ++ data_con_wrapper_ids ++ gen_ids - all_ids = map dataConId data_cons ++ unf_ids - - -- For the locally-defined things - -- we need to turn the unfoldings inside the selector Ids into bindings, - -- and build bindigns for the constructor wrappers - binds | isLocallyDefined tycon = idsToMonoBinds unf_ids - | otherwise = EmptyMonoBinds - in - returnTc (all_ids, binds) - where - data_cons = tyConDataConsIfAvailable tycon - -- Abstract types mean we don't bring the - -- data cons into scope, which should be fine - gen_ids = tyConGenIds tycon - data_con_wrapper_ids = map dataConWrapId data_cons - - fields = [ (con, field) | con <- data_cons, - field <- dataConFieldLabels con - ] - - -- groups is list of fields that share a common name - groups = equivClasses cmp_name fields - cmp_name (_, field1) (_, field2) - = fieldLabelName field1 `compare` fieldLabelName field2 -\end{code} - -\begin{code} -mkRecordSelector tycon fields@((first_con, first_field_label) : other_fields) - -- These fields all have the same name, but are from - -- different constructors in the data type - -- Check that all the fields in the group have the same type - -- This check assumes that all the constructors of a given - -- data type use the same type variables - = checkTc (all (== field_ty) other_tys) - (fieldTypeMisMatch field_name) `thenTc_` - tcLookupGlobalId unpackCStringName `thenTc` \ unpack_id -> - tcLookupGlobalId unpackCStringUtf8Name `thenTc` \ unpackUtf8_id -> - returnTc (mkRecordSelId tycon first_field_label unpack_id unpackUtf8_id) - where - field_ty = fieldLabelType first_field_label - field_name = fieldLabelName first_field_label - other_tys = [fieldLabelType fl | (_, fl) <- other_fields] -\end{code} - -Errors and contexts -~~~~~~~~~~~~~~~~~~~ \begin{code} fieldTypeMisMatch field_name - = sep [ptext SLIT("Declared types differ for field"), quotes (ppr field_name)] + = sep [ptext SLIT("Different constructors give different types for field"), quotes (ppr field_name)] exRecConErr name = ptext SLIT("Can't combine named fields with locally-quantified type variables")