X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcTyClsDecls.lhs;h=95166861ec668c6e0a09546ffc9f5e52a645de73;hb=6a4854eaa266d994ebd0d471614a52b43dd329d9;hp=a2849dee09bb036f51b135ccea7bc589f17ad647;hpb=1c9f0be145ee4153d9dc88ad8afd784912a6b271;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcTyClsDecls.lhs b/ghc/compiler/typecheck/TcTyClsDecls.lhs index a2849de..9516686 100644 --- a/ghc/compiler/typecheck/TcTyClsDecls.lhs +++ b/ghc/compiler/typecheck/TcTyClsDecls.lhs @@ -11,41 +11,49 @@ module TcTyClsDecls ( #include "HsVersions.h" import HsSyn ( TyClDecl(..), HsConDetails(..), HsTyVarBndr(..), - ConDecl(..), Sig(..), BangType(..), HsBang(..), - tyClDeclTyVars, getBangType, getBangStrictness + ConDecl(..), Sig(..), , NewOrData(..), + tyClDeclTyVars, isSynDecl, LConDecl, + LTyClDecl, tcdName, LHsTyVarBndr, LHsContext ) -import RnHsSyn ( RenamedTyClDecl, RenamedConDecl ) -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(..), - tcLookup, tcLookupGlobal, tcExtendGlobalEnv, + tcLookupLocated, tcLookupLocatedGlobal, + tcExtendGlobalEnv, tcExtendKindEnv, tcExtendRecEnv, tcLookupTyVar ) -import TcTyDecls ( calcTyConArgVrcs, calcRecFlags, calcCycleErrs ) +import TcTyDecls ( calcTyConArgVrcs, calcRecFlags, calcClassCycles, calcSynCycles ) import TcClassDcl ( tcClassSigs, tcAddDeclCtxt ) -import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsSigType, kcCheckHsType, - 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, - mkArrowKind, liftedTypeKind, +import TcType ( TcKind, ThetaType, TcType, tyVarsOfType, + mkArrowKind, liftedTypeKind, mkTyVarTys, tcEqTypes, tcSplitSigmaTy, tcEqType ) -import Type ( splitTyConApp_maybe ) -import PprType ( pprThetaArrow, pprParendType ) -import FieldLabel ( fieldLabelName, fieldLabelType ) +import Type ( splitTyConApp_maybe, pprThetaArrow, pprParendType ) import Generics ( validGenericMethodType, canDoGenerics ) -import Class ( Class, className, classTyCon, DefMeth(..), classBigSig ) -import TyCon ( TyCon, ArgVrcs, DataConDetails(..), +import Class ( Class, className, classTyCon, DefMeth(..), classBigSig, classTyVars ) +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 Name ( Name, getSrcLoc ) +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 ) +import Digraph ( SCC(..) ) import CmdLineOpts ( DynFlag( Opt_GlasgowExts, Opt_Generics, Opt_UnboxStrictFields ) ) \end{code} @@ -100,58 +108,60 @@ 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 :: [RenamedTyClDecl] +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 - - ; tyclss <- fixM (\ rec_tyclss -> - do { lcl_things <- mappM getInitialKind decls - -- Extend the local env with kinds, and - -- the global env with the knot-tied results - ; let { gbl_things = mkGlobalThings decls rec_tyclss } - ; tcExtendRecEnv gbl_things lcl_things $ do - - -- The local type environment is populated with - -- {"T" -> ARecTyCon k, ...} - -- and the global type envt with - -- {"T" -> ATyCon T, ...} - -- where k is T's (unzonked) kind - -- T is the loop-tied TyCon itself - -- We must populate the environment with the loop-tied T's right - -- away, because the kind checker may "fault in" some type - -- constructors that recursively mention T - - -- Kind-check the declarations, returning kind-annotated decls - { kc_decls <- mappM kcTyClDecl decls - - -- Calculate variances and rec-flag - ; let { calc_vrcs = calcTyConArgVrcs rec_tyclss - ; calc_rec = calcRecFlags rec_tyclss } - - ; mappM (tcTyClDecl calc_vrcs calc_rec) kc_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 } + + -- Extend the global env with the knot-tied results + -- for data types and classes + -- + -- We must populate the environment with the loop-tied T's right + -- away, because the kind checker may "fault in" some type + -- constructors that recursively mention T + ; let { gbl_things = mkGlobalThings alg_decls rec_alg_tyclss } + ; tcExtendRecEnv gbl_things $ do + + -- Kind-check the declarations + { (kc_syn_decls, kc_alg_decls) <- kcTyClDecls syn_decls alg_decls + + ; let { calc_vrcs = calcTyConArgVrcs (rec_syn_tycons ++ 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 + ; tcExtendGlobalEnv syn_tycons $ do + + -- Type-check the data types and classes + { alg_tyclss <- mappM tc_decl kc_alg_decls + ; return (syn_tycons, alg_tyclss) + }}}) -- Finished with knot-tying now -- Extend the environment with the finished things - ; tcExtendGlobalEnv tyclss $ do + ; tcExtendGlobalEnv (syn_tycons ++ alg_tyclss) $ do -- Perform the validity check { traceTc (text "ready for validity check") - ; mappM_ checkValidTyCl decls + ; mappM_ (addLocM checkValidTyCl) decls ; traceTc (text "done") -- Add the implicit things; -- we want them in the environment because -- they may be mentioned in interface files - ; let { implicit_things = concatMap implicitTyThings tyclss } - ; traceTc ((text "Adding" <+> ppr tyclss) $$ (text "and" <+> ppr implicit_things)) + ; let { implicit_things = concatMap implicitTyThings alg_tyclss } + ; traceTc ((text "Adding" <+> ppr alg_tyclss) $$ (text "and" <+> ppr implicit_things)) ; tcExtendGlobalEnv implicit_things getGblEnv }} -mkGlobalThings :: [RenamedTyClDecl] -- The decls +mkGlobalThings :: [LTyClDecl Name] -- The decls -> [TyThing] -- Knot-tied, in 1-1 correspondence with the decls -> [(Name,TyThing)] -- Driven by the Decls, and treating the TyThings lazily @@ -159,8 +169,10 @@ mkGlobalThings :: [RenamedTyClDecl] -- The decls mkGlobalThings decls things = map mk_thing (decls `zipLazy` things) where - mk_thing (ClassDecl {tcdName = name}, ~(AClass cl)) = (name, AClass cl) - mk_thing (decl, ~(ATyCon tc)) = (tcdName decl, ATyCon tc) + mk_thing (L _ (ClassDecl {tcdLName = L _ name}), ~(AClass cl)) + = (name, AClass cl) + mk_thing (L _ decl, ~(ATyCon tc)) + = (tcdName decl, ATyCon tc) \end{code} @@ -183,95 +195,144 @@ Here, the kind of the locally-polymorphic type variable "b" depends on *all the uses of class D*. For example, the use of Monad c in bop's type signature means that D must have kind Type->Type. -\begin{code} ------------------------------------------------------------------------- -getInitialKind :: TyClDecl Name -> TcM (Name, TcTyThing) - --- Note the lazy pattern match on the ATyCon etc --- Exactly the same reason as the zipLay above - -getInitialKind (TyData {tcdName = name}) - = newKindVar `thenM` \ kind -> - returnM (name, ARecTyCon kind) - -getInitialKind (TySynonym {tcdName = name}) - = newKindVar `thenM` \ kind -> - returnM (name, ARecTyCon kind) - -getInitialKind (ClassDecl {tcdName = name}) - = newKindVar `thenM` \ kind -> - returnM (name, ARecClass kind) +However type synonyms work differently. They can have kinds which don't +just involve (->) and *: + type R = Int# -- Kind # + type S a = Array# a -- Kind * -> # + type T a b = (# a,b #) -- Kind * -> * -> (# a,b #) +So we must infer their kinds from their right-hand sides *first* and then +use them, whereas for the mutually recursive data types D we bring into +scope kind bindings D -> k, where k is a kind variable, and do inference. +\begin{code} +kcTyClDecls syn_decls alg_decls + = do { -- First extend the kind env with each data + -- type and class, mapping them to a type variable + alg_kinds <- mappM getInitialKind alg_decls + ; tcExtendKindEnv alg_kinds $ do + + -- Now kind-check the type synonyms, in dependency order + -- We do these differently to data type and classes, + -- because a type synonym can be an unboxed type + -- type Foo = Int# + -- and a kind variable can't unify with UnboxedTypeKind + -- So we infer their kinds in dependency order + { (kc_syn_decls, syn_kinds) <- kcSynDecls (calcSynCycles syn_decls) + ; tcExtendKindEnv syn_kinds $ do + + -- Now kind-check the data type and class declarations, + -- returning kind-annotated decls + { kc_alg_decls <- mappM (wrapLocM kcTyClDecl) alg_decls + + ; return (kc_syn_decls, kc_alg_decls) }}} ------------------------------------------------------------------------ -kcTyClDecl :: RenamedTyClDecl -> TcM RenamedTyClDecl +getInitialKind :: LTyClDecl Name -> TcM (Name, TcKind) + +getInitialKind decl + = newKindVar `thenM` \ kind -> + returnM (unLoc (tcdLName (unLoc decl)), kind) + +---------------- +kcSynDecls :: [SCC (LTyClDecl Name)] + -> TcM ([LTyClDecl Name], -- Kind-annotated decls + [(Name,TcKind)]) -- Kind bindings +kcSynDecls [] + = return ([], []) +kcSynDecls (group : groups) + = do { (decl, nk) <- kcSynDecl group + ; (decls, nks) <- tcExtendKindEnv [nk] (kcSynDecls groups) + ; return (decl:decls, nk:nks) } + +---------------- +kcSynDecl :: SCC (LTyClDecl Name) + -> TcM (LTyClDecl Name, -- Kind-annotated decls + (Name,TcKind)) -- Kind bindings +kcSynDecl (AcyclicSCC ldecl@(L loc decl)) + = tcAddDeclCtxt decl $ + kcHsTyVars (tcdTyVars decl) (\ k_tvs -> + do { traceTc (text "kcd1" <+> ppr (unLoc (tcdLName decl)) <+> brackets (ppr (tcdTyVars decl)) + <+> brackets (ppr k_tvs)) + ; (k_rhs, rhs_kind) <- kcHsType (tcdSynRhs decl) + ; traceTc (text "kcd2" <+> ppr (unLoc (tcdLName decl))) + ; let tc_kind = foldr (mkArrowKind . kindedTyVarKind) rhs_kind k_tvs + ; return (L loc (decl { tcdTyVars = k_tvs, tcdSynRhs = k_rhs }), + (unLoc (tcdLName decl), tc_kind)) }) + +kcSynDecl (CyclicSCC decls) + = do { recSynErr decls; failM } -- Fail here to avoid error cascade + -- of out-of-scope tycons -kcTyClDecl decl@(TySynonym {tcdSynRhs = rhs}) - = do { res_kind <- newKindVar - ; kcTyClDeclBody decl res_kind $ \ tvs' -> - do { rhs' <- kcCheckHsType rhs res_kind - ; return (decl {tcdTyVars = tvs', tcdSynRhs = rhs'}) } } +------------------------------------------------------------------------ +kcTyClDecl :: TyClDecl Name -> TcM (TyClDecl Name) + -- Not used for type synonyms (see kcSynDecl) kcTyClDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdCons = cons}) - = kcTyClDeclBody decl liftedTypeKind $ \ tvs' -> + = kcTyClDeclBody decl $ \ tvs' -> do { ctxt' <- kcHsContext ctxt - ; cons' <- mappM kc_con_decl cons + ; cons' <- mappM (wrapLocM kc_con_decl) cons ; return (decl {tcdTyVars = tvs', tcdCtxt = ctxt', tcdCons = cons'}) } where - kc_con_decl (ConDecl name ex_tvs ex_ctxt details loc) + kc_con_decl (ConDecl name ex_tvs ex_ctxt details) = kcHsTyVars ex_tvs $ \ ex_tvs' -> do { ex_ctxt' <- kcHsContext ex_ctxt ; details' <- kc_con_details details - ; return (ConDecl name ex_tvs' ex_ctxt' details' loc)} + ; 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_arg_ty btys ; return (PrefixCon btys') } + = do { btys' <- mappM kc_larg_ty btys ; return (PrefixCon btys') } kc_con_details (InfixCon bty1 bty2) - = do { bty1' <- kc_arg_ty bty1; bty2' <- kc_arg_ty bty2; return (InfixCon bty1' bty2') } + = do { bty1' <- kc_larg_ty bty1; bty2' <- kc_larg_ty bty2; return (InfixCon bty1' bty2') } kc_con_details (RecCon fields) = do { fields' <- mappM kc_field fields; return (RecCon fields') } - kc_field (fld, bty) = do { bty' <- kc_arg_ty bty ; return (fld, bty') } + kc_field (fld, bty) = do { bty' <- kc_larg_ty bty ; return (fld, bty') } - 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 liftedTypeKind $ \ tvs' -> + = kcTyClDeclBody decl $ \ tvs' -> do { ctxt' <- kcHsContext ctxt - ; sigs' <- mappM kc_sig sigs + ; sigs' <- mappM (wrapLocM kc_sig) sigs ; return (decl {tcdTyVars = tvs', tcdCtxt = ctxt', tcdSigs = sigs'}) } where - kc_sig (Sig nm op_ty loc) = do { op_ty' <- kcHsLiftedSigType op_ty - ; return (Sig nm op_ty' loc) } + kc_sig (Sig nm op_ty) = do { op_ty' <- kcHsLiftedSigType op_ty + ; return (Sig nm op_ty') } kc_sig other_sig = return other_sig -kcTyClDecl decl@(ForeignType {}) +kcTyClDecl decl@(ForeignType {}) = return decl -kcTyClDeclBody :: RenamedTyClDecl -> TcKind - -> ([HsTyVarBndr Name] -> TcM a) +kcTyClDeclBody :: TyClDecl Name + -> ([LHsTyVarBndr Name] -> TcM a) -> TcM a -- Extend the env with bindings for the tyvars, taken from -- the kind of the tycon/class. Give it to the thing inside, and -- check the result kind matches -kcTyClDeclBody decl res_kind thing_inside +kcTyClDeclBody decl thing_inside = tcAddDeclCtxt decl $ kcHsTyVars (tyClDeclTyVars decl) $ \ kinded_tvs -> - do { tc_ty_thing <- tcLookup (tcdName decl) - ; let { tc_kind = case tc_ty_thing of - ARecClass k -> k - ARecTyCon k -> k - } + do { tc_ty_thing <- tcLookupLocated (tcdLName decl) + ; let tc_kind = case tc_ty_thing of { AThing k -> k } ; unifyKind tc_kind (foldr (mkArrowKind . kindedTyVarKind) - res_kind 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 (KindedTyVar _ k) = k +kindedTyVarKind (L _ (KindedTyVar _ k)) = k \end{code} @@ -282,45 +343,62 @@ kindedTyVarKind (KindedTyVar _ k) = k %************************************************************************ \begin{code} +tcSynDecls :: (Name -> ArgVrcs) -> [LTyClDecl Name] -> TcM [TyThing] +tcSynDecls calc_vrcs [] = return [] +tcSynDecls calc_vrcs (decl : decls) + = do { syn_tc <- addLocM (tcSynDecl calc_vrcs) decl + ; syn_tcs <- tcExtendGlobalEnv [syn_tc] (tcSynDecls calc_vrcs decls) + ; return (syn_tc : syn_tcs) } + +tcSynDecl calc_vrcs + (TySynonym {tcdLName = L _ tc_name, tcdTyVars = tvs, tcdSynRhs = rhs_ty}) + = tcTyVarBndrs tvs $ \ tvs' -> do + { traceTc (text "tcd1" <+> ppr tc_name) + ; rhs_ty' <- tcHsKindedType rhs_ty + ; return (ATyCon (buildSynTyCon tc_name tvs' rhs_ty' (calc_vrcs tc_name))) } + +-------------------- tcTyClDecl :: (Name -> ArgVrcs) -> (Name -> RecFlag) - -> RenamedTyClDecl -> TcM TyThing + -> TyClDecl Name -> TcM TyThing tcTyClDecl calc_vrcs calc_isrec decl = tcAddDeclCtxt decl (tcTyClDecl1 calc_vrcs calc_isrec decl) tcTyClDecl1 calc_vrcs calc_isrec - (TySynonym {tcdName = tc_name, tcdTyVars = tvs, tcdSynRhs = rhs_ty}) - = tcTyVarBndrs tvs $ \ tvs' -> do - { rhs_ty' <- tcHsKindedType rhs_ty - ; return (ATyCon (buildSynTyCon tc_name tvs' rhs_ty' arg_vrcs)) } - where - arg_vrcs = calc_vrcs tc_name - -tcTyClDecl1 calc_vrcs calc_isrec (TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdTyVars = tvs, - tcdName = tc_name, tcdCons = cons}) + 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 (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 {tcdName = class_name, tcdTyVars = tvs, + (ClassDecl {tcdLName = L _ class_name, tcdTyVars = tvs, tcdCtxt = ctxt, tcdMeths = meths, tcdFDs = fundeps, tcdSigs = sigs} ) = tcTyVarBndrs tvs $ \ tvs' -> do { ctxt' <- tcHsKindedContext ctxt - ; fds' <- mappM tc_fundep fundeps + ; fds' <- mappM (addLocM tc_fundep) fundeps ; sig_stuff <- tcClassSigs class_name sigs meths ; clas <- fixM (\ clas -> let -- This little knot is just so we can get @@ -340,41 +418,91 @@ tcTyClDecl1 calc_vrcs calc_isrec tcTyClDecl1 calc_vrcs calc_isrec - (ForeignType {tcdName = tc_name, tcdExtName = tc_ext_name}) + (ForeignType {tcdLName = L _ tc_name, tcdExtName = tc_ext_name}) = returnM (ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0 [])) ----------------------------------- -tcConDecl :: NewOrData -> TyCon -> [TyVar] -> ThetaType - -> RenamedConDecl -> TcM DataCon - -tcConDecl new_or_data tycon tyvars ctxt - (ConDecl name ex_tvs ex_ctxt details src_loc) - = addSrcLoc src_loc $ - tcTyVarBndrs ex_tvs $ \ ex_tvs' -> do +tcConDecl :: Bool -- True <=> -funbox-strict_fields + -> NewOrData -> TyCon -> [TyVar] + -> ConDecl Name -> TcM DataCon + +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 { arg_tys <- mappM (tcHsKindedType . getBangType) btys - ; buildDataCon name - (argStrictness unbox_strict tycon btys arg_tys) - field_lbls - tyvars ctxt ex_tvs' ex_ctxt' - arg_tys tycon } + 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) + (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 @@ -404,24 +532,23 @@ Validity checking is done once the mutually-recursive knot has been tied, so we can look at things freely. \begin{code} -checkCycleErrs :: [TyClDecl Name] -> TcM () +checkCycleErrs :: [LTyClDecl Name] -> TcM () checkCycleErrs tyclss - | null syn_cycles && null cls_cycles + | null cls_cycles = return () | otherwise - = do { mappM_ recSynErr syn_cycles - ; mappM_ recClsErr cls_cycles + = do { mappM_ recClsErr cls_cycles ; failM } -- Give up now, because later checkValidTyCl -- will loop if the synonym is recursive where - (syn_cycles, cls_cycles) = calcCycleErrs tyclss + cls_cycles = calcClassCycles tyclss -checkValidTyCl :: RenamedTyClDecl -> TcM () +checkValidTyCl :: TyClDecl Name -> TcM () -- We do the validity check over declarations, rather than TyThings -- only so that we can add a nice context with tcAddDeclCtxt checkValidTyCl decl = tcAddDeclCtxt decl $ - do { thing <- tcLookupGlobal (tcdName decl) + do { thing <- tcLookupLocatedGlobal (tcdLName decl) ; traceTc (text "Validity of" <+> ppr thing) ; case thing of ATyCon tc -> checkValidTyCon tc @@ -436,10 +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 @@ -450,33 +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 ------------------------------- @@ -506,18 +636,23 @@ checkValidClass cls no_generics = null [() | (_, GenDefMeth) <- op_stuff] check_op (sel_id, dm) - = addErrCtxt (classOpCtxt sel_id) ( - checkValidTheta SigmaCtxt (tail theta) `thenM_` + = addErrCtxt (classOpCtxt sel_id tau) $ do + { checkValidTheta SigmaCtxt (tail theta) -- The 'tail' removes the initial (C a) from the -- class itself, leaving just the method type - checkValidType (FunSigCtxt op_name) tau `thenM_` + ; checkValidType (FunSigCtxt op_name) tau + + -- Check that the type mentions at least one of + -- the class type variables + ; checkTc (any (`elemVarSet` tyVarsOfType tau) tyvars) + (noClassTyVarErr cls sel_id) -- 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 op_name = idName sel_id op_ty = idType sel_id @@ -532,7 +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 @@ -545,8 +680,8 @@ dataConCtxt con = sep [ptext SLIT("When checking the data constructor:"), [ ppr n <+> dcolon <+> ppr ty | (n,ty) <- fields `zip` arg_tys])) -classOpCtxt sel_id = sep [ptext SLIT("When checking the class method:"), - nest 2 (ppr sel_id <+> dcolon <+> ppr (idType sel_id))] +classOpCtxt sel_id tau = sep [ptext SLIT("When checking the class method:"), + nest 2 (ppr sel_id <+> dcolon <+> ppr tau)] nullaryClassErr cls = ptext SLIT("No parameters for class") <+> quotes (ppr cls) @@ -555,6 +690,11 @@ classArityErr cls = vcat [ptext SLIT("Too many parameters for class") <+> quotes (ppr cls), parens (ptext SLIT("Use -fglasgow-exts to allow multi-parameter classes"))] +noClassTyVarErr clas op + = sep [ptext SLIT("The class method") <+> quotes (ppr op), + ptext SLIT("mentions none of the type variables of the class") <+> + ppr clas <+> hsep (map ppr (classTyVars clas))] + genericMultiParamErr clas = ptext SLIT("The multi-parameter class") <+> quotes (ppr clas) <+> ptext SLIT("cannot have generic methods") @@ -562,24 +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 tcs - = addSrcLoc (getSrcLoc (head tcs)) $ +recSynErr syn_decls + = setSrcSpan (getLoc (head sorted_decls)) $ addErr (sep [ptext SLIT("Cycle in type synonym declarations:"), - nest 2 (vcat (map ppr_thing tcs))]) + 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 clss - = addSrcLoc (getSrcLoc (head clss)) $ +recClsErr cls_decls + = setSrcSpan (getLoc (head sorted_decls)) $ addErr (sep [ptext SLIT("Cycle in class declarations (via superclasses):"), - nest 2 (vcat (map ppr_thing clss))]) - -ppr_thing :: Name -> SDoc -ppr_thing n = ppr n <+> parens (ppr (getSrcLoc n)) + 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}