X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyDecls.lhs;h=bde665527a38cb7682abcf8eed73238b575dd50c;hb=da47a29433290180fd15e39a13ab3bdfacaeea1b;hp=83a4c96732fdc6e93592cf0ec6617d3e272ff21e;hpb=6c381e873e222417d9a67aeec77b9555eca7b7a8;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcTyDecls.lhs b/ghc/compiler/typecheck/TcTyDecls.lhs index 83a4c96..bde6655 100644 --- a/ghc/compiler/typecheck/TcTyDecls.lhs +++ b/ghc/compiler/typecheck/TcTyDecls.lhs @@ -1,211 +1,251 @@ % -% (c) The AQUA Project, Glasgow University, 1996 +% (c) The AQUA Project, Glasgow University, 1996-1998 % \section[TcTyDecls]{Typecheck type declarations} \begin{code} -#include "HsVersions.h" - module TcTyDecls ( - tcTyDecl, - tcConDecl + tcTyDecl1, kcConDetails, mkNewTyConRep ) where -import Ubiq{-uitous-} - -import HsSyn ( TyDecl(..), ConDecl(..), BangType(..), MonoType ) -import RnHsSyn ( RenamedTyDecl(..), RenamedConDecl(..) ) +#include "HsVersions.h" -import TcMonoType ( tcMonoTypeKind, tcMonoType, tcContext ) -import TcEnv ( tcLookupTyCon, tcLookupTyVar, tcLookupClass ) +import HsSyn ( TyClDecl(..), ConDecl(..), ConDetails(..), BangType(..), + getBangType, conDetailsTys + ) +import RnHsSyn ( RenamedTyClDecl, RenamedConDecl, RenamedContext ) +import BasicTypes ( NewOrData(..), RecFlag, isRec ) + +import TcMonoType ( tcHsRecType, tcHsTyVars, tcRecTheta, + kcHsContext, kcHsSigType, kcHsLiftedSigType + ) +import TcEnv ( tcExtendTyVarEnv, + tcLookupTyCon, tcLookupRecId, + TyThingDetails(..), RecTcEnv + ) import TcMonad -import TcKind ( TcKind, unifyKind, mkTcArrowKind, mkTcTypeKind ) - -import Id ( mkDataCon, StrictnessMark(..) ) -import Kind ( Kind, mkArrowKind, mkBoxedTypeKind ) -import SpecEnv ( SpecEnv(..), nullSpecEnv ) -import Name ( getNameFullName, Name(..) ) -import Pretty -import TyCon ( TyCon, ConsVisible(..), NewOrData(..), mkSynTyCon, mkDataTyCon ) -import Type ( getTypeKind ) -import TyVar ( getTyVarKind ) -import Util ( panic ) +import DataCon ( DataCon, mkDataCon, dataConFieldLabels, markedStrict, + notMarkedStrict, markedUnboxed, dataConRepType + ) +import MkId ( mkDataConId, mkDataConWrapId, mkRecordSelId ) +import FieldLabel +import Var ( TyVar ) +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 VarSet ( intersectVarSet, isEmptyVarSet ) +import PrelNames ( unpackCStringName, unpackCStringUtf8Name ) +import ListSetOps ( equivClasses ) \end{code} -\begin{code} -tcTyDecl :: RenamedTyDecl -> TcM s TyCon -\end{code} - -Type synonym decls -~~~~~~~~~~~~~~~~~~ +%************************************************************************ +%* * +\subsection{Type checking} +%* * +%************************************************************************ \begin{code} -tcTyDecl (TySynonym tycon_name tyvar_names rhs src_loc) - = tcAddSrcLoc src_loc $ - tcAddErrCtxt (tySynCtxt tycon_name) $ - - -- Look up the pieces - tcLookupTyCon tycon_name `thenNF_Tc` \ (tycon_kind, rec_tycon) -> - mapAndUnzipNF_Tc tcLookupTyVar tyvar_names `thenNF_Tc` \ (tyvar_kinds, rec_tyvars) -> - - -- Look at the rhs - tcMonoTypeKind rhs `thenTc` \ (rhs_kind, rhs_ty) -> - - -- Unify tycon kind with (k1->...->kn->rhs) - unifyKind tycon_kind - (foldr mkTcArrowKind rhs_kind tyvar_kinds) - `thenTc_` +tcTyDecl1 :: RecFlag -> RecTcEnv -> RenamedTyClDecl -> TcM (Name, TyThingDetails) +tcTyDecl1 is_rec 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) + + returnTc (tycon_name, SynTyDetails rhs_ty) + +tcTyDecl1 is_rec unf_env (TyData {tcdND = new_or_data, tcdCtxt = context, + tcdName = tycon_name, tcdCons = con_decls}) + = tcLookupTyCon tycon_name `thenNF_Tc` \ tycon -> let - -- Construct the tycon - result_kind, final_tycon_kind :: Kind -- NB not TcKind! - result_kind = getTypeKind rhs_ty - final_tycon_kind = foldr (mkArrowKind . getTyVarKind) result_kind rec_tyvars - - tycon = mkSynTyCon (getItsUnique tycon_name) - (getNameFullName tycon_name) - final_tycon_kind - (length tyvar_names) - rec_tyvars - rhs_ty + tyvars = tyConTyVars tycon in - returnTc tycon -\end{code} + tcExtendTyVarEnv tyvars $ -Algebraic data and newtype decls -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + -- 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 -> + returnTc (tycon_name, DataTyDetails ctxt data_cons sel_ids) +\end{code} \begin{code} -tcTyDecl (TyData context tycon_name tyvar_names con_decls derivings pragmas src_loc) - = tcTyDataOrNew DataType context tycon_name tyvar_names con_decls derivings pragmas src_loc +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 -tcTyDecl (TyNew context tycon_name tyvar_names con_decl derivings pragmas src_loc) - = tcTyDataOrNew NewType context tycon_name tyvar_names con_decl derivings pragmas src_loc +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 + } +\end{code} -tcTyDataOrNew data_or_new context tycon_name tyvar_names con_decls derivings pragmas src_loc - = tcAddSrcLoc src_loc $ - tcAddErrCtxt (tyDataCtxt tycon_name) $ +%************************************************************************ +%* * +\subsection{Kind and type check constructors} +%* * +%************************************************************************ - -- Lookup the pieces - tcLookupTyCon tycon_name `thenNF_Tc` \ (tycon_kind, rec_tycon) -> - mapAndUnzipNF_Tc tcLookupTyVar tyvar_names `thenNF_Tc` \ (tyvar_kinds, rec_tyvars) -> - tc_derivs derivings `thenNF_Tc` \ derived_classes -> +\begin{code} +kcConDetails :: NewOrData -> RenamedContext -> ConDetails Name -> TcM () +kcConDetails new_or_data ex_ctxt details + = kcHsContext ex_ctxt `thenTc_` + mapTc_ kc_sig_type (conDetailsTys details) + where + 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 :: 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) + = tcAddSrcLoc src_loc $ + tcHsTyVars ex_tvs (kcConDetails new_or_data ex_ctxt details) $ \ ex_tyvars -> + tcRecTheta is_rec 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 [] + + tc_rec_con ex_tyvars ex_theta fields + = checkTc (null ex_tyvars) (exRecConErr name) `thenTc_` + mapTc tc_field (fields `zip` allFieldLabelTags) `thenTc` \ field_labels_s -> + 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 + ] + 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 -> + returnTc [mkFieldLabel (getName name) tycon field_ty tag | name <- field_label_names] + + mk_data_con ex_tyvars ex_theta arg_stricts arg_tys fields + = let + data_con = mkDataCon name arg_stricts fields + tyvars (thinContext arg_tys ctxt) + ex_tyvars ex_theta + arg_tys + tycon data_con_id data_con_wrap_id - -- Typecheck the context - tcContext context `thenTc` \ ctxt -> + data_con_id = mkDataConId wkr_name data_con + data_con_wrap_id = mkDataConWrapId data_con + in + returnNF_Tc data_con - -- Unify tycon kind with (k1->...->kn->Type) - unifyKind tycon_kind - (foldr mkTcArrowKind mkTcTypeKind tyvar_kinds) - `thenTc_` - -- Walk the condecls - mapTc (tcConDecl rec_tycon rec_tyvars ctxt) con_decls - `thenTc` \ con_ids -> - let - -- Construct the tycon - final_tycon_kind :: Kind -- NB not TcKind! - final_tycon_kind = foldr (mkArrowKind . getTyVarKind) mkBoxedTypeKind rec_tyvars - - tycon = mkDataTyCon (getItsUnique tycon_name) - final_tycon_kind - (getNameFullName tycon_name) - rec_tyvars - ctxt - con_ids - derived_classes - ConsVisible -- For now; if constrs are from pragma we are *abstract* - data_or_new - in - returnTc tycon +-- The context for a data constructor should be limited to +-- the type variables mentioned in the arg_tys +thinContext arg_tys ctxt + = filter in_arg_tys ctxt where - tc_derivs Nothing = returnNF_Tc [] - tc_derivs (Just ds) = mapNF_Tc tc_deriv ds + arg_tyvars = tyVarsOfTypes arg_tys + in_arg_tys pred = not $ isEmptyVarSet $ + tyVarsOfPred pred `intersectVarSet` arg_tyvars - tc_deriv name - = tcLookupClass name `thenNF_Tc` \ (_, clas) -> - returnNF_Tc clas +getBangStrictness (Banged _) = markedStrict +getBangStrictness (Unbanged _) = notMarkedStrict +getBangStrictness (Unpacked _) = markedUnboxed \end{code} -Constructors -~~~~~~~~~~~~ -\begin{code} -tcConDecl :: TyCon -> [TyVar] -> [(Class,Type)] -> RenamedConDecl -> TcM s Id +%************************************************************************ +%* * +\subsection{Record selectors} +%* * +%************************************************************************ -tcConDecl tycon tyvars ctxt (ConDecl name btys src_loc) - = tcAddSrcLoc src_loc $ - let - (stricts, tys) = sep_bangs btys - in - mapTc tcMonoType tys `thenTc` \ arg_tys -> - let - data_con = mkDataCon (getItsUnique name) - (getNameFullName name) - stricts - tyvars - [] -- ToDo: ctxt; limited to tyvars in arg_tys - arg_tys - tycon - -- nullSpecEnv - in - returnTc data_con - -tcConDecl tycon tyvars ctxt (ConOpDecl bty1 op bty2 src_loc) - = tcAddSrcLoc src_loc $ - let - (stricts, tys) = sep_bangs [bty1, bty2] - in - mapTc tcMonoType tys `thenTc` \ arg_tys -> - let - data_con = mkDataCon (getItsUnique op) - (getNameFullName op) - stricts - tyvars - [] -- ToDo: ctxt - arg_tys - tycon - -- nullSpecEnv - in - returnTc data_con - -tcConDecl tycon tyvars ctxt (NewConDecl name ty src_loc) - = tcAddSrcLoc src_loc $ - tcMonoType ty `thenTc` \ arg_ty -> - let - data_con = mkDataCon (getItsUnique name) - (getNameFullName name) - [NotMarkedStrict] - tyvars - [] -- ToDo: ctxt - [arg_ty] - tycon - -- nullSpecEnv - in - returnTc data_con - -tcConDecl tycon tyvars ctxt (RecConDecl con fields src_loc) - = panic "tcConDecls:RecConDecl" +\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} -sep_bangs btys - = unzip (map sep_bang btys) - where - sep_bang (Banged ty) = (MarkedStrict, ty) - sep_bang (Unbanged ty) = (NotMarkedStrict, ty) -\end{code} +%************************************************************************ +%* * +\subsection{Errors and contexts} +%* * +%************************************************************************ -Errors and contexts -~~~~~~~~~~~~~~~~~~~ \begin{code} -tySynCtxt tycon_name sty - = ppCat [ppStr "In the type declaration for", ppr sty tycon_name] - -tyDataCtxt tycon_name sty - = ppCat [ppStr "In the data declaration for", ppr sty tycon_name] +fieldTypeMisMatch field_name + = sep [ptext SLIT("Different constructors give different types for field"), quotes (ppr field_name)] -tyNewCtxt tycon_name sty - = ppCat [ppStr "In the newtype declaration for", ppr sty tycon_name] +exRecConErr name + = ptext SLIT("Can't combine named fields with locally-quantified type variables") + $$ + (ptext SLIT("In the declaration of data constructor") <+> ppr name) \end{code}