X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyDecls.lhs;h=8c1b9da7e758d780305c0ad3a6aa3bc5b130aead;hb=97958a3981cf8eb79e93ed644ae45d6e272a8b74;hp=8c03384c5ad30d3b78c2fca7a3184b29e1eb67ee;hpb=f9120c200bcf613b58d742802172fb4c08171f0d;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcTyDecls.lhs b/ghc/compiler/typecheck/TcTyDecls.lhs index 8c03384..8c1b9da 100644 --- a/ghc/compiler/typecheck/TcTyDecls.lhs +++ b/ghc/compiler/typecheck/TcTyDecls.lhs @@ -1,313 +1,194 @@ % -% (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, - tcRecordSelectors - ) where - -import Ubiq{-uitous-} +module TcTyDecls ( tcTyDecl, kcConDetails, tcMkDataCon ) where -import HsSyn ( TyDecl(..), ConDecl(..), BangType(..), HsExpr(..), - Match(..), GRHSsAndBinds(..), GRHS(..), OutPat(..), - HsBinds(..), HsLit, Stmt, Qual, ArithSeqInfo, PolyType, - Bind(..), MonoBinds(..), Sig, - MonoType ) -import RnHsSyn ( RenamedTyDecl(..), RenamedConDecl(..), - RnName{-instance Outputable-} - ) -import TcHsSyn ( TcHsBinds(..), TcIdOcc(..), mkHsTyLam ) +#include "HsVersions.h" -import TcMonoType ( tcMonoTypeKind, tcMonoType, tcContext ) -import TcType ( tcInstTyVars, tcInstType ) -import TcEnv ( tcLookupTyCon, tcLookupTyVar, tcLookupClass, - newLocalId +import HsSyn ( TyClDecl(..), ConDecl(..), HsConDetails(..), BangType, + getBangType, getBangStrictness, conDetailsTys ) -import TcMonad -import TcKind ( TcKind, unifyKind, mkTcArrowKind, mkTcTypeKind ) +import RnHsSyn ( RenamedTyClDecl, RenamedConDecl, RenamedContext ) +import BasicTypes ( NewOrData(..), StrictnessMark ) -import Id ( mkDataCon, dataConSig, mkRecordSelId, - dataConFieldLabels, StrictnessMark(..) +import TcMonoType ( tcHsTyVars, tcHsTheta, tcHsType, + kcHsContext, kcHsSigType, kcHsLiftedSigType ) -import FieldLabel -import Kind ( Kind, mkArrowKind, mkBoxedTypeKind ) -import SpecEnv ( SpecEnv(..), nullSpecEnv ) -import Name ( Name{-instance Ord3-} ) -import Pretty -import TyCon ( TyCon, NewOrData(..), mkSynTyCon, mkDataTyCon, tyConDataCons ) -import Type ( getTypeKind, getTyVar, tyVarsOfTypes, eqTy, applyTyCon, - mkForAllTys, mkFunTy ) -import TyVar ( getTyVarKind, elementOfTyVarSet ) -import UniqSet ( emptyUniqSet, mkUniqSet, uniqSetToList, unionManyUniqSets, UniqSet(..) ) -import Util ( panic, equivClasses ) +import TcEnv ( tcExtendTyVarEnv, tcLookupTyCon, TyThingDetails(..) ) +import TcType ( Type, tyVarsOfTypes, tyVarsOfPred, ThetaType ) +import RnEnv ( lookupSysName ) +import TcRnMonad + +import DataCon ( DataCon, mkDataCon, dataConFieldLabels ) +import FieldLabel ( FieldLabel, fieldLabelName, fieldLabelType, allFieldLabelTags, mkFieldLabel ) +import MkId ( mkDataConWorkId, mkDataConWrapId, mkRecordSelId ) +import Var ( TyVar ) +import Name ( Name ) +import OccName ( mkDataConWrapperOcc, mkDataConWorkerOcc, + mkGenOcc1, mkGenOcc2, setOccNameSpace ) +import Outputable +import TyCon ( TyCon, DataConDetails(..), visibleDataCons, + tyConTyVars, tyConName ) +import VarSet ( intersectVarSet, isEmptyVarSet ) +import Generics ( mkTyConGenInfo ) +import CmdLineOpts ( DynFlag(..) ) +import List ( nubBy ) \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_` +tcTyDecl :: RenamedTyClDecl -> TcM (Name, TyThingDetails) +tcTyDecl (TySynonym {tcdName = tycon_name, tcdSynRhs = rhs}) + = tcLookupTyCon tycon_name `thenM` \ tycon -> + tcExtendTyVarEnv (tyConTyVars tycon) $ + tcHsType rhs `thenM` \ rhs_ty -> + returnM (tycon_name, SynTyDetails rhs_ty) + +tcTyDecl (TyData {tcdND = new_or_data, tcdCtxt = context, + tcdName = tycon_name, tcdCons = con_decls, + tcdGeneric = generic}) + = tcLookupTyCon tycon_name `thenM` \ tycon -> let - -- Getting the TyCon's kind is a bit of a nuisance. We can't use the tycon_kind, - -- because that's a TcKind and may not yet be fully unified with other kinds. - -- We could have augmented the tycon environment with a knot-tied kind, - -- but the simplest thing to do seems to be to get the Kind by (lazily) - -- looking at the tyvars and rhs_ty. - result_kind, final_tycon_kind :: Kind -- NB not TcKind! - result_kind = getTypeKind rhs_ty - final_tycon_kind = foldr (mkArrowKind . getTyVarKind) result_kind rec_tyvars - - -- Construct the tycon - tycon = mkSynTyCon (getName tycon_name) - final_tycon_kind - (length tyvar_names) - rec_tyvars - rhs_ty + tyvars = tyConTyVars tycon in - returnTc tycon -\end{code} - -Algebraic data and newtype decls -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -\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 - -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 - - -tcTyDataOrNew data_or_new context tycon_name tyvar_names con_decls derivings pragmas src_loc - = tcAddSrcLoc src_loc $ - tcAddErrCtxt (tyDataCtxt tycon_name) $ - - -- 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 -> - - -- Typecheck the context - tcContext context `thenTc` \ ctxt -> - - -- 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 -> + tcExtendTyVarEnv tyvars $ + tcHsTheta context `thenM` \ ctxt -> + tcConDecls new_or_data tycon tyvars ctxt con_decls `thenM` \ data_cons -> let - -- Construct the tycon - final_tycon_kind :: Kind -- NB not TcKind! - final_tycon_kind = foldr (mkArrowKind . getTyVarKind) mkBoxedTypeKind rec_tyvars - - tycon = mkDataTyCon (getName tycon_name) - final_tycon_kind - rec_tyvars - ctxt - con_ids - derived_classes - data_or_new + sel_ids = mkRecordSelectors tycon data_cons in - returnTc tycon + tcGenericInfo tycon generic `thenM` \ gen_info -> + returnM (tycon_name, DataTyDetails ctxt data_cons sel_ids gen_info) -tc_derivs Nothing = returnNF_Tc [] -tc_derivs (Just ds) = mapNF_Tc tc_deriv ds - -tc_deriv name - = tcLookupClass name `thenNF_Tc` \ (_, clas) -> - returnNF_Tc clas -\end{code} +tcTyDecl (ForeignType {tcdName = tycon_name}) + = returnM (tycon_name, ForeignTyDetails) -Generating selector bindings for record delarations -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -\begin{code} -tcRecordSelectors :: TyCon -> TcM s ([Id], TcHsBinds s) -tcRecordSelectors tycon - = mapAndUnzipTc (tcRecordSelector tycon) groups `thenTc` \ (ids, binds) -> - returnTc (ids, SingleBind (NonRecBind (foldr AndMonoBinds EmptyMonoBinds binds))) +tcGenericInfo tycon generics -- Source code decl: consult the flag + = do_we_want generics `thenM` \ want_generics -> + if want_generics then + mapM (lookupSysName (tyConName tycon)) + [mkGenOcc1, mkGenOcc2] `thenM` \ gen_sys_names -> + returnM (mkTyConGenInfo tycon gen_sys_names) + else + returnM Nothing where - data_cons = tyConDataCons tycon - 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 `cmp` fieldLabelName field2 + do_we_want (Just g) = returnM g -- Interface file decl + -- so look at decl + do_we_want Nothing = doptM Opt_Generics -- Source code decl + -- so look at flag + +mkRecordSelectors tycon data_cons + = -- We'll check later that fields with the same name + -- from different constructors have the same type. + [ mkRecordSelId tycon field + | field <- nubBy eq_name fields ] + where + fields = [ field | con <- visibleDataCons data_cons, + field <- dataConFieldLabels con ] + eq_name field1 field2 = fieldLabelName field1 == fieldLabelName field2 \end{code} -We're going to build a record selector that looks like this: - - data T a b c = T1 { op :: a, ...} - | T2 { op :: a, ...} - | T3 - sel :: forall a b c. T a b c -> a - sel = /\ a b c -> \ T1 { sel = x } -> x - T2 { sel = 2 } -> x - -Note that the selector Id itself is used as the field -label; it has to be an Id, you see! +%************************************************************************ +%* * +\subsection{Kind and type check constructors} +%* * +%************************************************************************ \begin{code} -tcRecordSelector tycon fields@((first_con, first_field_label) : other_fields) - = panic "tcRecordSelector: don't typecheck" -{- - = let - field_ty = fieldLabelType first_field_label - field_name = fieldLabelName first_field_label - other_tys = [fieldLabelType fl | (_, fl) <- fields] - (tyvars, _, _, _) = dataConSig first_con - -- tyvars of first_con may be free in first_ty - in - - -- 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 (eqTy field_ty) other_tys) - (fieldTypeMisMatch field_name) `thenTc_` +kcConDetails :: NewOrData -> RenamedContext + -> HsConDetails Name (BangType Name) -> TcM () +kcConDetails new_or_data ex_ctxt details + = kcHsContext ex_ctxt `thenM_` + mappM_ 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. + + +tcConDecls :: NewOrData -> TyCon -> [TyVar] -> ThetaType + -> DataConDetails RenamedConDecl -> TcM (DataConDetails DataCon) + +tcConDecls new_or_data tycon tyvars ctxt con_decls + = case con_decls of + Unknown -> returnM Unknown + HasCons n -> returnM (HasCons n) + DataCons cs -> mappM tc_con_decl cs `thenM` \ data_cons -> + returnM (DataCons data_cons) + where + tc_con_decl (ConDecl name ex_tvs ex_ctxt details src_loc) + = addSrcLoc src_loc $ + tcHsTyVars ex_tvs (kcConDetails new_or_data ex_ctxt details) $ \ ex_tyvars -> + tcHsTheta ex_ctxt `thenM` \ ex_theta -> + case details of + PrefixCon 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 + = mappM tcHsType (map getBangType btys) `thenM` \ arg_tys -> + tcMkDataCon name + (map getBangStrictness btys) + [{- No field labels -}] + tyvars ctxt ex_tyvars ex_theta + arg_tys tycon - -- Create an Id for the field itself - tcInstTyVars tyvars `thenNF_Tc` \ (tyvars', tyvar_tys, tenv) -> - tcInstType tenv field_ty `thenNF_Tc` \ field_ty' -> - let - data_ty' = applyTyCon tycon tyvar_tys - in - newLocalId SLIT("x") field_ty' `thenNF_Tc` \ field_id -> - newLocalId SLIT("r") data_ty' `thenNF_Tc` \ record_id -> - - -- Now build the selector - let - tycon_src_loc = getSrcLoc tycon - - selector_ty = mkForAllTys tyvars' $ - mkFunTy data_ty' $ - field_ty' - - selector_id = mkRecordSelId first_field_label selector_ty - - -- HsSyn is dreadfully verbose for defining the selector! - selector_rhs = mkHsTyLam tyvars' $ - HsLam $ - PatMatch (VarPat record_id) $ - GRHSMatch $ - GRHSsAndBindsOut [OtherwiseGRHS selector_body tycon_src_loc] - EmptyBinds field_ty' - - selector_body = HsCase (HsVar record_id) (map mk_match fields) tycon_src_loc - - mk_match (con_id, field_label) - = PatMatch (RecPat con_id data_ty' [(selector_id, VarPat field_id, False)]) $ - GRHSMatch $ - GRHSsAndBindsOut [OtherwiseGRHS (HsVar field_id) - (getSrcLoc (fieldLabelName field_label))] - EmptyBinds - field_ty' - in - returnTc (selector_id, VarMonoBind selector_id selector_rhs) --} -\end{code} - -Constructors -~~~~~~~~~~~~ -\begin{code} -tcConDecl :: TyCon -> [TyVar] -> [(Class,Type)] -> RenamedConDecl -> TcM s Id - -tcConDecl tycon tyvars ctxt (ConDecl name btys src_loc) - = tcDataCon tycon tyvars ctxt name btys src_loc - -tcConDecl tycon tyvars ctxt (ConOpDecl bty1 op bty2 src_loc) - = tcDataCon tycon tyvars ctxt op [bty1,bty2] src_loc - -tcConDecl tycon tyvars ctxt (NewConDecl name ty src_loc) - = tcAddSrcLoc src_loc $ - tcMonoType ty `thenTc` \ arg_ty -> - let - data_con = mkDataCon (getName name) - [NotMarkedStrict] - [{- No labelled fields -}] - tyvars - ctxt - [arg_ty] - tycon - -- nullSpecEnv - in - returnTc data_con - -tcConDecl tycon tyvars ctxt (RecConDecl name fields src_loc) - = tcAddSrcLoc src_loc $ - mapTc tcField fields `thenTc` \ field_label_infos_s -> - let - field_label_infos = concat field_label_infos_s - stricts = [strict | (_, _, strict) <- field_label_infos] - arg_tys = [ty | (_, ty, _) <- field_label_infos] - - field_labels = [ mkFieldLabel (getName name) ty tag - | ((name, ty, _), tag) <- field_label_infos `zip` allFieldLabelTags - ] - - data_con = mkDataCon (getName name) - stricts - field_labels - tyvars - (thinContext arg_tys ctxt) - arg_tys - tycon - -- nullSpecEnv - in - returnTc data_con - -tcField (field_label_names, bty) - = tcMonoType (get_ty bty) `thenTc` \ field_ty -> - returnTc [(name, field_ty, get_strictness bty) | name <- field_label_names] - -tcDataCon tycon tyvars ctxt name btys src_loc - = tcAddSrcLoc src_loc $ - let - stricts = map get_strictness btys - tys = map get_ty btys - in - mapTc tcMonoType tys `thenTc` \ arg_tys -> + tc_rec_con ex_tyvars ex_theta fields + = checkTc (null ex_tyvars) (exRecConErr name) `thenM_` + mappM tc_field (fields `zip` allFieldLabelTags) `thenM` \ field_labels -> + let + arg_stricts = [getBangStrictness bty | (n, bty) <- fields] + arg_tys = map fieldLabelType field_labels + in + tcMkDataCon name arg_stricts field_labels + tyvars ctxt ex_tyvars ex_theta + arg_tys tycon + + tc_field ((field_label_name, bty), tag) + = tcHsType (getBangType bty) `thenM` \ field_ty -> + returnM (mkFieldLabel field_label_name tycon field_ty tag) + +tcMkDataCon :: Name + -> [StrictnessMark] -> [FieldLabel] + -> [TyVar] -> ThetaType + -> [TyVar] -> ThetaType + -> [Type] -> TyCon + -> TcM DataCon +-- A wrapper for DataCon.mkDataCon that +-- a) makes the worker Id +-- b) makes the wrapper Id if necessary, including +-- allocating its unique (hence monadic) +tcMkDataCon src_name arg_stricts fields + tyvars ctxt ex_tyvars ex_theta + arg_tys tycon + = lookupSysName src_name mkDataConWrapperOcc `thenM` \ wrap_name -> + lookupSysName src_name mkDataConWorkerOcc `thenM` \ work_name -> + -- This last one takes the name of the data constructor in the source + -- code, which (for Haskell source anyway) will be in the SrcDataName name + -- space, and makes it into a "real data constructor name" let - data_con = mkDataCon (getName name) - stricts - [{- No field labels -}] - tyvars - (thinContext arg_tys ctxt) - arg_tys - tycon - -- nullSpecEnv + data_con = mkDataCon src_name arg_stricts fields + tyvars (thinContext arg_tys ctxt) + ex_tyvars ex_theta + arg_tys tycon + data_con_work_id data_con_wrap_id + data_con_work_id = mkDataConWorkId work_name data_con + data_con_wrap_id = mkDataConWrapId wrap_name data_con in - returnTc data_con + returnM data_con -- The context for a data constructor should be limited to -- the type variables mentioned in the arg_tys @@ -315,29 +196,21 @@ thinContext arg_tys ctxt = filter in_arg_tys ctxt where arg_tyvars = tyVarsOfTypes arg_tys - in_arg_tys (clas,ty) = getTyVar "tcDataCon" ty `elementOfTyVarSet` arg_tyvars - -get_strictness (Banged ty) = MarkedStrict -get_strictness (Unbanged ty) = NotMarkedStrict - -get_ty (Banged ty) = ty -get_ty (Unbanged ty) = ty + in_arg_tys pred = not $ isEmptyVarSet $ + tyVarsOfPred pred `intersectVarSet` arg_tyvars \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] -tyNewCtxt tycon_name sty - = ppCat [ppStr "In the newtype declaration for", ppr sty tycon_name] - -fieldTypeMisMatch field_name sty - = ppSep [ppStr "Declared types differ for field", ppr sty field_name] +\begin{code} +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}