X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyClsDecls.lhs;h=95166861ec668c6e0a09546ffc9f5e52a645de73;hb=6a4854eaa266d994ebd0d471614a52b43dd329d9;hp=5acb6a07c5555b28b7ae90ea3242d523aacb6fd9;hpb=f714e6b642fd614a9971717045ae47c3d871275e;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcTyClsDecls.lhs b/ghc/compiler/typecheck/TcTyClsDecls.lhs index 5acb6a0..9516686 100644 --- a/ghc/compiler/typecheck/TcTyClsDecls.lhs +++ b/ghc/compiler/typecheck/TcTyClsDecls.lhs @@ -11,13 +11,15 @@ module TcTyClsDecls ( #include "HsVersions.h" import HsSyn ( TyClDecl(..), HsConDetails(..), HsTyVarBndr(..), - ConDecl(..), Sig(..), BangType(..), HsBang(..), - tyClDeclTyVars, getBangType, getBangStrictness, isSynDecl, - LTyClDecl, tcdName, LHsTyVarBndr + ConDecl(..), Sig(..), , NewOrData(..), + tyClDeclTyVars, isSynDecl, LConDecl, + LTyClDecl, tcdName, LHsTyVarBndr, LHsContext ) -import BasicTypes ( RecFlag(..), NewOrData(..), StrictnessMark(..) ) +import HsTypes ( HsBang(..), getBangStrictness ) +import BasicTypes ( RecFlag(..), StrictnessMark(..) ) import HscTypes ( implicitTyThings ) -import BuildTyCl ( buildClass, buildAlgTyCon, buildSynTyCon, buildDataCon ) +import BuildTyCl ( buildClass, buildAlgTyCon, buildSynTyCon, buildDataCon, + mkDataTyConRhs, mkNewTyConRhs ) import TcRnMonad import TcEnv ( TcTyThing(..), TyThing(..), tcLookupLocated, tcLookupLocatedGlobal, @@ -25,27 +27,29 @@ import TcEnv ( TcTyThing(..), TyThing(..), tcExtendRecEnv, tcLookupTyVar ) import TcTyDecls ( calcTyConArgVrcs, calcRecFlags, calcClassCycles, calcSynCycles ) import TcClassDcl ( tcClassSigs, tcAddDeclCtxt ) -import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsSigType, kcHsType, - kcHsContext, tcTyVarBndrs, tcHsKindedType, tcHsKindedContext ) +import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsType, + kcHsContext, tcTyVarBndrs, tcHsKindedType, tcHsKindedContext, + kcHsSigType, tcHsBangType, tcLHsConSig ) import TcMType ( newKindVar, checkValidTheta, checkValidType, checkFreeness, UserTypeCtxt(..), SourceTyCtxt(..) ) import TcUnify ( unifyKind ) -import TcType ( TcKind, ThetaType, TcType, tyVarsOfType, - mkArrowKind, liftedTypeKind, +import TcType ( TcKind, ThetaType, TcType, tyVarsOfType, + mkArrowKind, liftedTypeKind, mkTyVarTys, tcEqTypes, tcSplitSigmaTy, tcEqType ) import Type ( splitTyConApp_maybe, pprThetaArrow, pprParendType ) -import FieldLabel ( fieldLabelName, fieldLabelType ) import Generics ( validGenericMethodType, canDoGenerics ) import Class ( Class, className, classTyCon, DefMeth(..), classBigSig, classTyVars ) -import TyCon ( TyCon, ArgVrcs, DataConDetails(..), +import TyCon ( TyCon, ArgVrcs, tyConDataCons, mkForeignTyCon, isProductTyCon, isRecursiveTyCon, - tyConTheta, getSynTyConDefn, tyConDataCons, isSynTyCon, tyConName ) -import DataCon ( DataCon, dataConWrapId, dataConName, dataConSig, dataConFieldLabels ) + tyConStupidTheta, getSynTyConDefn, tyConDataCons, isSynTyCon, tyConName ) +import DataCon ( DataCon, dataConWrapId, dataConName, dataConSig, + dataConFieldLabels, dataConOrigArgTys, dataConTyCon ) +import Type ( zipTopTvSubst, substTys ) import Var ( TyVar, idType, idName ) import VarSet ( elemVarSet ) import Name ( Name ) import Outputable -import Util ( zipLazy, isSingleton, notNull ) +import Util ( zipLazy, isSingleton, notNull, sortLe ) import List ( partition ) import SrcLoc ( Located(..), unLoc, getLoc ) import ListSetOps ( equivClasses ) @@ -104,14 +108,15 @@ The knot-tying parameters: @rec_details_list@ is an alist mapping @Name@s to @TyThing@s. @rec_vrcs@ is a finite map from @Name@s to @ArgVrcs@s. \begin{code} -tcTyAndClassDecls :: [LTyClDecl Name] +tcTyAndClassDecls :: [Name] -> [LTyClDecl Name] -> TcM TcGblEnv -- Input env extended by types and classes -- and their implicit Ids,DataCons -tcTyAndClassDecls decls +tcTyAndClassDecls boot_names decls = do { -- First check for cyclic type synonysm or classes -- See notes with checkCycleErrs checkCycleErrs decls - + ; mod <- getModule + ; traceTc (text "tcTyAndCl" <+> ppr mod <+> ppr boot_names) ; (syn_tycons, alg_tyclss) <- fixM (\ ~(rec_syn_tycons, rec_alg_tyclss) -> do { let { -- Calculate variances and rec-flag ; (syn_decls, alg_decls) = partition (isSynDecl . unLoc) decls } @@ -129,7 +134,7 @@ tcTyAndClassDecls decls { (kc_syn_decls, kc_alg_decls) <- kcTyClDecls syn_decls alg_decls ; let { calc_vrcs = calcTyConArgVrcs (rec_syn_tycons ++ rec_alg_tyclss) - ; calc_rec = calcRecFlags rec_alg_tyclss + ; calc_rec = calcRecFlags boot_names rec_alg_tyclss ; tc_decl = addLocM (tcTyClDecl calc_vrcs calc_rec) } -- Type-check the type synonyms, and extend the envt ; syn_tycons <- tcSynDecls calc_vrcs kc_syn_decls @@ -273,6 +278,9 @@ kcTyClDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdCons = cons}) do { ex_ctxt' <- kcHsContext ex_ctxt ; details' <- kc_con_details details ; return (ConDecl name ex_tvs' ex_ctxt' details')} + kc_con_decl (GadtDecl name ty) + = do { ty' <- kcHsSigType ty + ; return (GadtDecl name ty') } kc_con_details (PrefixCon btys) = do { btys' <- mappM kc_larg_ty btys ; return (PrefixCon btys') } @@ -283,14 +291,12 @@ kcTyClDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdCons = cons}) kc_field (fld, bty) = do { bty' <- kc_larg_ty bty ; return (fld, bty') } - kc_larg_ty = wrapLocM kc_arg_ty - - kc_arg_ty (BangType str ty) = do { ty' <- kc_arg_ty_body ty; return (BangType str ty') } - kc_arg_ty_body = case new_or_data of - DataType -> kcHsSigType - NewType -> kcHsLiftedSigType - -- Can't allow an unlifted type for newtypes, because we're effectively - -- going to remove the constructor while coercing it to a lifted type. + kc_larg_ty bty = case new_or_data of + DataType -> kcHsSigType bty + NewType -> kcHsLiftedSigType bty + -- Can't allow an unlifted type for newtypes, because we're effectively + -- going to remove the constructor while coercing it to a lifted type. + -- And newtypes can't be bang'd kcTyClDecl decl@(ClassDecl {tcdCtxt = ctxt, tcdSigs = sigs}) = kcTyClDeclBody decl $ \ tvs' -> @@ -317,8 +323,14 @@ kcTyClDeclBody decl thing_inside do { tc_ty_thing <- tcLookupLocated (tcdLName decl) ; let tc_kind = case tc_ty_thing of { AThing k -> k } ; unifyKind tc_kind (foldr (mkArrowKind . kindedTyVarKind) - liftedTypeKind kinded_tvs) + (result_kind decl) + kinded_tvs) ; thing_inside kinded_tvs } + where + result_kind (TyData { tcdKindSig = Just kind }) = kind + result_kind other = liftedTypeKind + -- On GADT-style declarations we allow a kind signature + -- data T :: *->* where { ... } kindedTyVarKind (L _ (KindedTyVar _ k)) = k \end{code} @@ -356,19 +368,29 @@ tcTyClDecl1 calc_vrcs calc_isrec (TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdTyVars = tvs, tcdLName = L _ tc_name, tcdCons = cons}) = tcTyVarBndrs tvs $ \ tvs' -> do - { ctxt' <- tcHsKindedContext ctxt + { stupid_theta <- tcStupidTheta ctxt cons ; want_generic <- doptM Opt_Generics ; tycon <- fixM (\ tycon -> do - { cons' <- mappM (addLocM (tcConDecl new_or_data tycon tvs' ctxt')) cons - ; buildAlgTyCon new_or_data tc_name tvs' ctxt' - (DataCons cons') arg_vrcs is_rec - (want_generic && canDoGenerics cons') + { unbox_strict <- doptM Opt_UnboxStrictFields + ; gla_exts <- doptM Opt_GlasgowExts + ; checkTc (gla_exts || h98_syntax) (badGadtDecl tc_name) + + ; data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data tycon tvs')) cons + ; let tc_rhs = case new_or_data of + DataType -> mkDataTyConRhs stupid_theta data_cons + NewType -> ASSERT( isSingleton data_cons ) + mkNewTyConRhs tycon (head data_cons) + ; buildAlgTyCon tc_name tvs' tc_rhs arg_vrcs is_rec + (want_generic && canDoGenerics data_cons) }) ; return (ATyCon tycon) } where arg_vrcs = calc_vrcs tc_name is_rec = calc_isrec tc_name + h98_syntax = case cons of -- All constructors have same shape + L _ (GadtDecl {}) : _ -> False + other -> True tcTyClDecl1 calc_vrcs calc_isrec (ClassDecl {tcdLName = L _ class_name, tcdTyVars = tvs, @@ -400,37 +422,87 @@ tcTyClDecl1 calc_vrcs calc_isrec = returnM (ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0 [])) ----------------------------------- -tcConDecl :: NewOrData -> TyCon -> [TyVar] -> ThetaType +tcConDecl :: Bool -- True <=> -funbox-strict_fields + -> NewOrData -> TyCon -> [TyVar] -> ConDecl Name -> TcM DataCon -tcConDecl new_or_data tycon tyvars ctxt - (ConDecl name ex_tvs ex_ctxt details) +tcConDecl unbox_strict NewType tycon tc_tvs -- Newtypes + (ConDecl name ex_tvs ex_ctxt details) + = ASSERT( null ex_tvs && null (unLoc ex_ctxt) ) + do { let tc_datacon field_lbls arg_ty + = do { arg_ty' <- tcHsKindedType arg_ty -- No bang on newtype + ; buildDataCon (unLoc name) False {- Prefix -} + True {- Vanilla -} [NotMarkedStrict] + (map unLoc field_lbls) + tc_tvs [] [arg_ty'] + tycon (mkTyVarTys tc_tvs) } + ; case details of + PrefixCon [arg_ty] -> tc_datacon [] arg_ty + RecCon [(field_lbl, arg_ty)] -> tc_datacon [field_lbl] arg_ty } + +tcConDecl unbox_strict DataType tycon tc_tvs -- Ordinary data types + (ConDecl name ex_tvs ex_ctxt details) = tcTyVarBndrs ex_tvs $ \ ex_tvs' -> do { ex_ctxt' <- tcHsKindedContext ex_ctxt - ; unbox_strict <- doptM Opt_UnboxStrictFields ; let - tc_datacon field_lbls btys - = do { let { ubtys = map unLoc btys } - ; arg_tys <- mappM (tcHsKindedType . getBangType) ubtys - ; buildDataCon (unLoc name) - (argStrictness unbox_strict tycon ubtys arg_tys) + is_vanilla = null ex_tvs && null (unLoc ex_ctxt) + -- Vanilla iff no ex_tvs and no context + + tc_datacon is_infix field_lbls btys + = do { let { bangs = map getBangStrictness btys } + ; arg_tys <- mappM tcHsBangType btys + ; buildDataCon (unLoc name) is_infix is_vanilla + (argStrictness unbox_strict tycon bangs arg_tys) (map unLoc field_lbls) - tyvars ctxt ex_tvs' ex_ctxt' - arg_tys tycon } + (tc_tvs ++ ex_tvs') + ex_ctxt' + arg_tys + tycon (mkTyVarTys tc_tvs) } ; case details of - PrefixCon btys -> tc_datacon [] btys - InfixCon bty1 bty2 -> tc_datacon [] [bty1,bty2] - RecCon fields -> do { checkTc (null ex_tvs') (exRecConErr name) + PrefixCon btys -> tc_datacon False [] btys + InfixCon bty1 bty2 -> tc_datacon True [] [bty1,bty2] + RecCon fields -> do { checkTc is_vanilla (exRecConErr name) ; let { (field_names, btys) = unzip fields } - ; tc_datacon field_names btys } } - + ; tc_datacon False field_names btys } } + +tcConDecl unbox_strict DataType tycon tc_tvs -- GADTs + decl@(GadtDecl name con_ty) + = do { traceTc (text "tcConDecl" <+> ppr name) + ; (tvs, theta, bangs, arg_tys, tc, res_tys) <- tcLHsConSig con_ty + + ; traceTc (text "tcConDecl1" <+> ppr name) + ; let -- Now dis-assemble the type, and check its form + is_vanilla = null theta && mkTyVarTys tvs `tcEqTypes` res_tys + + -- Vanilla datacons guarantee to use the same + -- type variables as the parent tycon + (tvs', arg_tys', res_tys') + | is_vanilla = (tc_tvs, substTys subst arg_tys, substTys subst res_tys) + | otherwise = (tvs, arg_tys, res_tys) + subst = zipTopTvSubst tvs (mkTyVarTys tc_tvs) + + ; traceTc (text "tcConDecl3" <+> ppr name) + ; buildDataCon (unLoc name) False {- Not infix -} is_vanilla + (argStrictness unbox_strict tycon bangs arg_tys) + [{- No field labels -}] + tvs' theta arg_tys' tycon res_tys' } + +------------------- +tcStupidTheta :: LHsContext Name -> [LConDecl Name] -> TcM (Maybe ThetaType) +-- For GADTs we don't allow a context on the data declaration +-- whereas for standard Haskell style data declarations, we do +tcStupidTheta ctxt (L _ (ConDecl _ _ _ _) : _) + = do { theta <- tcHsKindedContext ctxt; return (Just theta) } +tcStupidTheta ctxt other -- Includes an empty constructor list + = ASSERT( null (unLoc ctxt) ) return Nothing + +------------------- argStrictness :: Bool -- True <=> -funbox-strict_fields - -> TyCon -> [BangType Name] + -> TyCon -> [HsBang] -> [TcType] -> [StrictnessMark] -argStrictness unbox_strict tycon btys arg_tys - = zipWith (chooseBoxingStrategy unbox_strict tycon) - arg_tys - (map getBangStrictness btys ++ repeat HsNoBang) +argStrictness unbox_strict tycon bangs arg_tys + = ASSERT( length bangs == length arg_tys ) + zipWith (chooseBoxingStrategy unbox_strict tycon) arg_tys bangs -- We attempt to unbox/unpack a strict field when either: -- (i) The field is marked '!!', or @@ -491,10 +563,10 @@ checkValidTyCon tc = checkValidType syn_ctxt syn_rhs | otherwise = -- Check the context on the data decl - checkValidTheta (DataTyCtxt name) (tyConTheta tc) `thenM_` + checkValidTheta (DataTyCtxt name) (tyConStupidTheta tc) `thenM_` -- Check arg types of data constructors - mappM_ checkValidDataCon data_cons `thenM_` + mappM_ (checkValidDataCon tc) data_cons `thenM_` -- Check that fields with the same name share a type mappM_ check_fields groups @@ -505,33 +577,36 @@ checkValidTyCon 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 + groups = equivClasses cmp_fld (concatMap get_fields data_cons) + cmp_fld (f1,_) (f2,_) = f1 `compare` f2 + get_fields con = dataConFieldLabels con `zip` dataConOrigArgTys con + -- dataConFieldLabels may return the empty list, which is fine - check_fields fields@(first_field_label : other_fields) + check_fields fields@((first_field_label, field_ty) : 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 + checkTc (all (tcEqType field_ty . snd) other_fields) + (fieldTypeMisMatch first_field_label) ------------------------------- -checkValidDataCon :: DataCon -> TcM () -checkValidDataCon con - = addErrCtxt (dataConCtxt con) ( - checkValidType ctxt (idType (dataConWrapId con)) `thenM_` +checkValidDataCon :: TyCon -> DataCon -> TcM () +checkValidDataCon tc con + = addErrCtxt (dataConCtxt con) $ + do { checkTc (dataConTyCon con == tc) (badDataConTyCon con) + ; checkValidType ctxt (idType (dataConWrapId con)) } + -- This checks the argument types and -- ambiguity of the existential context (if any) - checkFreeness ex_tvs ex_theta) + -- + -- Note [Sept 04] Now that tvs is all the tvs, this + -- test doesn't actually check anything +-- ; checkFreeness tvs ex_theta } where ctxt = ConArgCtxt (dataConName con) - (_, _, ex_tvs, ex_theta, _, _) = dataConSig con + (tvs, ex_theta, _, _, _) = dataConSig con ------------------------------- @@ -575,7 +650,7 @@ checkValidClass cls -- Check that for a generic method, the type of -- the method is sufficiently simple - ; checkTc (dm /= GenDefMeth || validGenericMethodType op_ty) + ; checkTc (dm /= GenDefMeth || validGenericMethodType tau) (badGenericMethodType op_name op_ty) } where @@ -592,7 +667,7 @@ fieldTypeMisMatch field_name dataConCtxt con = sep [ptext SLIT("When checking the data constructor:"), nest 2 (ex_part <+> pprThetaArrow ex_theta <+> ppr con <+> arg_part)] where - (_, _, ex_tvs, ex_theta, arg_tys, _) = dataConSig con + (ex_tvs, ex_theta, arg_tys, _, _) = dataConSig con ex_part | null ex_tvs = empty | otherwise = ptext SLIT("forall") <+> hsep (map ppr ex_tvs) <> dot -- The 'ex_theta' part could be non-empty, if the user (bogusly) wrote @@ -627,24 +702,39 @@ genericMultiParamErr clas badGenericMethodType op op_ty = hang (ptext SLIT("Generic method type is too complex")) 4 (vcat [ppr op <+> dcolon <+> ppr op_ty, - ptext SLIT("You can only use type variables, arrows, and tuples")]) + ptext SLIT("You can only use type variables, arrows, lists, and tuples")]) recSynErr syn_decls - = addSrcSpan (getLoc (head syn_decls)) $ + = setSrcSpan (getLoc (head sorted_decls)) $ addErr (sep [ptext SLIT("Cycle in type synonym declarations:"), - nest 2 (vcat (map ppr_decl syn_decls))]) + nest 2 (vcat (map ppr_decl sorted_decls))]) where + sorted_decls = sortLocated syn_decls ppr_decl (L loc decl) = ppr loc <> colon <+> ppr decl recClsErr cls_decls - = addSrcSpan (getLoc (head cls_decls)) $ + = setSrcSpan (getLoc (head sorted_decls)) $ addErr (sep [ptext SLIT("Cycle in class declarations (via superclasses):"), - nest 2 (vcat (map ppr_decl cls_decls))]) + nest 2 (vcat (map ppr_decl sorted_decls))]) where + sorted_decls = sortLocated cls_decls ppr_decl (L loc decl) = ppr loc <> colon <+> ppr (decl { tcdSigs = [] }) +sortLocated :: [Located a] -> [Located a] +sortLocated things = sortLe le things + where + le (L l1 _) (L l2 _) = l1 <= l2 + exRecConErr name - = ptext SLIT("Can't combine named fields with locally-quantified type variables") + = ptext SLIT("Can't combine named fields with locally-quantified type variables or context") $$ (ptext SLIT("In the declaration of data constructor") <+> ppr name) + +badDataConTyCon data_con + = hang (ptext SLIT("Data constructor does not return its parent type:")) + 2 (ppr data_con) + +badGadtDecl tc_name + = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+> quotes (ppr tc_name) + , nest 2 (parens $ ptext SLIT("Use -fglasgow-exts to allow GADTs")) ] \end{code}