X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyDecls.lhs;h=f525f4e62357fd151b7257c93ba3c1df516a4423;hb=979947f545d70c63edb7ca96f6e47008ac90e3bf;hp=a0a00b040a7e532b50eb109ab7cfbf098c695a48;hpb=b4775e5e760111e2d71fba3c44882dce390edfb2;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcTyDecls.lhs b/ghc/compiler/typecheck/TcTyDecls.lhs index a0a00b0..f525f4e 100644 --- a/ghc/compiler/typecheck/TcTyDecls.lhs +++ b/ghc/compiler/typecheck/TcTyDecls.lhs @@ -4,42 +4,38 @@ \section[TcTyDecls]{Typecheck type declarations} \begin{code} -module TcTyDecls ( - tcTyDecl1, kcConDetails, mkNewTyConRep - ) where +module TcTyDecls ( tcTyDecl, checkValidTyCon, kcConDetails ) where #include "HsVersions.h" -import HsSyn ( TyClDecl(..), ConDecl(..), ConDetails(..), BangType(..), +import HsSyn ( TyClDecl(..), ConDecl(..), ConDetails(..), getBangType, getBangStrictness, conDetailsTys ) import RnHsSyn ( RenamedTyClDecl, RenamedConDecl, RenamedContext ) -import BasicTypes ( NewOrData(..), RecFlag, isRec ) +import BasicTypes ( NewOrData(..) ) -import TcMonoType ( tcHsRecType, tcHsTyVars, tcRecTheta, +import TcMonoType ( tcHsTyVars, tcHsTheta, tcHsType, kcHsContext, kcHsSigType, kcHsLiftedSigType ) import TcEnv ( tcExtendTyVarEnv, tcLookupTyCon, tcLookupRecId, TyThingDetails(..), RecTcEnv ) +import TcType ( tcEqType, tyVarsOfTypes, tyVarsOfPred, ThetaType ) +import TcMType ( checkValidType, UserTypeCtxt(..), checkValidTheta, SourceTyCtxt(..) ) import TcMonad -import DataCon ( DataCon, mkDataCon, dataConFieldLabels, dataConRepType ) +import DataCon ( DataCon, mkDataCon, dataConFieldLabels, dataConWrapId, dataConName ) import MkId ( mkDataConId, mkDataConWrapId, mkRecordSelId ) import FieldLabel -import Var ( TyVar ) +import Var ( TyVar, idType ) import Name ( Name, NamedThing(..) ) import Outputable -import TyCon ( TyCon, isNewTyCon, tyConTyVars ) -import Type ( tyVarsOfTypes, tyVarsOfPred, splitFunTy, applyTys, - mkTyConApp, mkTyVarTys, mkForAllTys, - splitAlgTyConApp_maybe, Type, ThetaType - ) -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} %************************************************************************ @@ -49,62 +45,97 @@ import ListSetOps ( equivClasses ) %************************************************************************ \begin{code} -tcTyDecl1 :: RecFlag -> RecTcEnv -> RenamedTyClDecl -> TcM (Name, TyThingDetails) -tcTyDecl1 is_rec unf_env (TySynonym {tcdName = tycon_name, tcdSynRhs = rhs}) +tcTyDecl :: RecTcEnv -> RenamedTyClDecl -> TcM (Name, TyThingDetails) +tcTyDecl unf_env (TySynonym {tcdName = tycon_name, tcdSynRhs = rhs}) = tcLookupTyCon tycon_name `thenNF_Tc` \ tycon -> tcExtendTyVarEnv (tyConTyVars tycon) $ - tcHsRecType is_rec rhs `thenTc` \ rhs_ty -> - -- Note tcHsRecType not tcHsRecSigType; 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) - + tcHsType rhs `thenTc` \ rhs_ty -> returnTc (tycon_name, SynTyDetails rhs_ty) -tcTyDecl1 is_rec unf_env (TyData {tcdND = new_or_data, tcdCtxt = context, +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 - tcRecTheta is_rec context `thenTc` \ ctxt -> - mapTc (tcConDecl is_rec new_or_data tycon tyvars ctxt) con_decls `thenTc` \ data_cons -> - tcRecordSelectors is_rec unf_env tycon data_cons `thenTc` \ sel_ids -> + 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) + + +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 + 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} @@ -124,24 +155,19 @@ kcConDetails new_or_data ex_ctxt details -- going to remove the constructor while coercing it to a lifted type. -tcConDecl :: RecFlag -> NewOrData -> TyCon -> [TyVar] -> ThetaType -> RenamedConDecl -> TcM DataCon - -tcConDecl is_rec new_or_data tycon tyvars ctxt (ConDecl name wkr_name ex_tvs ex_ctxt details src_loc) +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 new_or_data ex_ctxt details) $ \ ex_tyvars -> - tcRecTheta is_rec ex_ctxt `thenTc` \ ex_theta -> + 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_datacon ex_tyvars ex_theta btys - = let - arg_stricts = map getBangStrictness btys - tys = map getBangType btys - in - mapTc (tcHsRecType is_rec) 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_` @@ -150,14 +176,14 @@ tcConDecl is_rec new_or_data tycon tyvars ctxt (ConDecl name wkr_name ex_tvs ex_ 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 + 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) - = tcHsRecType is_rec (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 @@ -186,49 +212,6 @@ thinContext arg_tys ctxt %************************************************************************ %* * -\subsection{Record selectors} -%* * -%************************************************************************ - -\begin{code} -tcRecordSelectors is_rec unf_env tycon data_cons - -- Omit the check that the fields have consistent types if - -- the group is recursive; TcTyClsDecls.tcGroup will repeat - -- with NonRecursive once we have tied the knot - | isRec is_rec = returnTc sel_ids - | otherwise = mapTc check groups `thenTc_` - returnTc sel_ids - where - fields = [ 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 - - sel_ids = [ mkRecordSelId tycon field unpack_id unpackUtf8_id - | (field : _) <- groups ] - - check 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 (== 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 - - unpack_id = tcLookupRecId unf_env unpackCStringName - unpackUtf8_id = tcLookupRecId unf_env unpackCStringUtf8Name -\end{code} - - - -%************************************************************************ -%* * \subsection{Errors and contexts} %* * %************************************************************************