X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcTyClsDecls.lhs;h=834bedcc3352b1f8bf5e9f1c22f87d585ec403cf;hb=f8f8449e1e54d0da1d16536070f18709b9e95af4;hp=9137ecee587fce36b4bc17067d681d8dcfb0f1b3;hpb=bb106f283663e9c16a4c72ec9ca57109ae57a0ed;p=ghc-hetmet.git diff --git a/compiler/typecheck/TcTyClsDecls.lhs b/compiler/typecheck/TcTyClsDecls.lhs index 9137ece..834bedc 100644 --- a/compiler/typecheck/TcTyClsDecls.lhs +++ b/compiler/typecheck/TcTyClsDecls.lhs @@ -1,7 +1,9 @@ % +% (c) The University of Glasgow 2006 % (c) The AQUA Project, Glasgow University, 1996-1998 % -\section[TcTyClsDecls]{Typecheck type and class declarations} + +TcTyClsDecls: Typecheck type and class declarations \begin{code} module TcTyClsDecls ( @@ -10,65 +12,39 @@ module TcTyClsDecls ( #include "HsVersions.h" -import HsSyn ( TyClDecl(..), HsConDetails(..), HsTyVarBndr(..), - ConDecl(..), Sig(..), NewOrData(..), ResType(..), - tyClDeclTyVars, isSynDecl, isClassDecl, isIdxTyDecl, - isKindSigDecl, hsConArgs, LTyClDecl, tcdName, - hsTyVarName, LHsTyVarBndr, LHsType - ) -import HsTypes ( HsBang(..), getBangStrictness ) -import BasicTypes ( RecFlag(..), StrictnessMark(..) ) -import HscTypes ( implicitTyThings, ModDetails ) -import BuildTyCl ( buildClass, buildAlgTyCon, buildSynTyCon, buildDataCon, - mkDataTyConRhs, mkNewTyConRhs ) +import HsSyn +import HsTypes +import BasicTypes +import HscTypes +import BuildTyCl import TcRnMonad -import TcEnv ( TyThing(..), - tcLookupLocated, tcLookupLocatedGlobal, - tcExtendGlobalEnv, tcExtendKindEnv, tcExtendKindEnvTvs, - tcExtendRecEnv, tcLookupTyVar, InstInfo ) -import TcTyDecls ( calcRecFlags, calcClassCycles, calcSynCycles ) -import TcClassDcl ( tcClassSigs, tcAddDeclCtxt ) -import TcHsType ( kcHsTyVars, kcHsLiftedSigType, kcHsType, - kcHsContext, tcTyVarBndrs, tcHsKindedType, tcHsKindedContext, - kcHsSigType, tcHsBangType, tcLHsConResTy, - tcDataKindSig, kcCheckHsType ) -import TcMType ( newKindVar, checkValidTheta, checkValidType, - -- checkFreeness, - UserTypeCtxt(..), SourceTyCtxt(..) ) -import TcType ( TcKind, TcType, Type, tyVarsOfType, mkPhiTy, - mkArrowKind, liftedTypeKind, mkTyVarTys, - tcSplitSigmaTy, tcEqTypes, tcGetTyVar_maybe ) -import Type ( PredType(..), splitTyConApp_maybe, mkTyVarTy, - newTyConInstRhs, isLiftedTypeKind, Kind - -- pprParendType, pprThetaArrow - ) -import Generics ( validGenericMethodType, canDoGenerics ) -import Class ( Class, className, classTyCon, DefMeth(..), classBigSig, classTyVars ) -import TyCon ( TyCon, AlgTyConRhs( AbstractTyCon, OpenDataTyCon, - OpenNewTyCon ), - SynTyConRhs( OpenSynTyCon, SynonymTyCon ), - tyConDataCons, mkForeignTyCon, isProductTyCon, - isRecursiveTyCon, isOpenTyCon, - tyConStupidTheta, synTyConRhs, isSynTyCon, tyConName, - isNewTyCon, tyConKind ) -import DataCon ( DataCon, dataConUserType, dataConName, - dataConFieldLabels, dataConTyCon, dataConAllTyVars, - dataConFieldType, dataConResTys ) -import Var ( TyVar, idType, idName ) -import VarSet ( elemVarSet, mkVarSet ) -import Name ( Name, getSrcLoc ) +import TcEnv +import TcTyDecls +import TcClassDcl +import TcHsType +import TcMType +import TcType +import FunDeps +import Type +import Generics +import Class +import TyCon +import DataCon +import Var +import VarSet +import Name +import OccName import Outputable -import Maybe ( isJust, fromJust, isNothing ) -import Maybes ( expectJust ) -import Unify ( tcMatchTys, tcMatchTyX ) -import Util ( zipLazy, isSingleton, notNull, sortLe ) -import List ( partition ) -import SrcLoc ( Located(..), unLoc, getLoc, srcLocSpan ) -import ListSetOps ( equivClasses, minusList ) -import List ( delete ) -import Digraph ( SCC(..) ) -import DynFlags ( DynFlag( Opt_GlasgowExts, Opt_Generics, - Opt_UnboxStrictFields ) ) +import Maybes +import Monad +import Unify +import Util +import SrcLoc +import ListSetOps +import Digraph +import DynFlags + +import Data.List ( partition, elemIndex ) \end{code} @@ -166,30 +142,39 @@ tcTyAndClassDecls boot_details allDecls ; mod <- getModule ; traceTc (text "tcTyAndCl" <+> ppr mod) ; (syn_tycons, alg_tyclss) <- fixM (\ ~(rec_syn_tycons, rec_alg_tyclss) -> - do { let { -- Calculate variances and rec-flag + do { let { -- Seperate ordinary synonyms from all other type and + -- class declarations and add all associated type + -- declarations from type classes. The latter is + -- required so that the temporary environment for the + -- knot includes all associated family declarations. ; (syn_decls, alg_decls) = partition (isSynDecl . unLoc) - decls } + decls + ; alg_at_decls = concatMap addATs alg_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 } + -- 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_at_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_rec = calcRecFlags boot_details rec_alg_tyclss + ; let { -- Calculate rec-flag + ; calc_rec = calcRecFlags boot_details rec_alg_tyclss ; tc_decl = addLocM (tcTyClDecl calc_rec) } + -- Type-check the type synonyms, and extend the envt ; syn_tycons <- tcSynDecls 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) + ; return (syn_tycons, concat alg_tyclss) }}}) -- Finished with knot-tying now -- Extend the environment with the finished things @@ -203,10 +188,22 @@ tcTyAndClassDecls boot_details allDecls -- Add the implicit things; -- we want them in the environment because -- they may be mentioned in interface files + -- NB: All associated types and their implicit things will be added a + -- second time here. This doesn't matter as the definitions are + -- the same. ; let { implicit_things = concatMap implicitTyThings alg_tyclss } - ; traceTc ((text "Adding" <+> ppr alg_tyclss) $$ (text "and" <+> ppr implicit_things)) + ; traceTc ((text "Adding" <+> ppr alg_tyclss) + $$ (text "and" <+> ppr implicit_things)) ; tcExtendGlobalEnv implicit_things getGblEnv }} + where + -- Pull associated types out of class declarations, to tie them into the + -- knot above. + -- NB: We put them in the same place in the list as `tcTyClDecl' will + -- eventually put the matching `TyThing's. That's crucial; otherwise, + -- the two argument lists of `mkGlobalThings' don't match up. + addATs decl@(L _ (ClassDecl {tcdATs = ats})) = decl : ats + addATs decl = [decl] mkGlobalThings :: [LTyClDecl Name] -- The decls -> [TyThing] -- Knot-tied, in 1-1 correspondence with the decls @@ -235,15 +232,15 @@ they share a lot of kinding and type checking code with ordinary algebraic data types (and GADTs). \begin{code} -tcIdxTyInstDecl :: LTyClDecl Name -> TcM (Maybe InstInfo) -- Nothing if error +tcIdxTyInstDecl :: LTyClDecl Name -> TcM (Maybe TyThing) -- Nothing if error tcIdxTyInstDecl (L loc decl) = -- Prime error recovery, set source location - recoverM (returnM Nothing) $ - setSrcSpan loc $ - tcAddDeclCtxt decl $ - do { -- indexed data types require -fglasgow-exts and can't be in an + recoverM (returnM Nothing) $ + setSrcSpan loc $ + tcAddDeclCtxt decl $ + do { -- indexed data types require -findexed-types and can't be in an -- hs-boot file - ; gla_exts <- doptM Opt_GlasgowExts + ; gla_exts <- doptM Opt_IndexedTypes ; is_boot <- tcIsHsBoot -- Are we compiling an hs-boot file? ; checkTc gla_exts $ badIdxTyDecl (tcdLName decl) ; checkTc (not is_boot) $ badBootTyIdxDeclErr @@ -252,11 +249,15 @@ tcIdxTyInstDecl (L loc decl) ; tcIdxTyInstDecl1 decl } -tcIdxTyInstDecl1 :: TyClDecl Name -> TcM (Maybe InstInfo) -- Nothing if error +tcIdxTyInstDecl1 :: TyClDecl Name -> TcM (Maybe TyThing) -- Nothing if error tcIdxTyInstDecl1 (decl@TySynonym {}) - = kcIdxTyPats decl $ \k_tvs k_typats resKind -> - do { -- (1) kind check the right hand side of the type equation + = kcIdxTyPats decl $ \k_tvs k_typats resKind family -> + do { -- check that the family declaration is for a synonym + unless (isSynTyCon family) $ + addErr (wrongKindOfFamily family) + + ; -- (1) kind check the right hand side of the type equation ; k_rhs <- kcCheckHsType (tcdSynRhs decl) resKind -- (2) type check type equation @@ -264,18 +265,22 @@ tcIdxTyInstDecl1 (decl@TySynonym {}) ; t_typats <- mappM tcHsKindedType k_typats ; t_rhs <- tcHsKindedType k_rhs - -- construct type rewrite rule -- !!!of the form: forall t_tvs. (tcdLName decl) t_typats = t_rhs - ; return Nothing -- !!!TODO: need InstInfo for indexed types + ; return Nothing -- !!!TODO: need TyThing for indexed synonym }} -tcIdxTyInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L _ tc_name, +tcIdxTyInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name, tcdCons = cons}) - = kcIdxTyPats decl $ \k_tvs k_typats resKind -> - do { -- (1) kind check the data declaration as usual + = kcIdxTyPats decl $ \k_tvs k_typats resKind family -> + do { -- check that the family declaration is for the right kind + unless (new_or_data == NewType && isNewTyCon family || + new_or_data == DataType && isDataTyCon family) $ + addErr (wrongKindOfFamily family) + + ; -- (1) kind check the data declaration as usual ; k_decl <- kcDataDecl decl k_tvs - ; let k_ctxt = tcdCtxt decl - k_cons = tcdCons decl + ; let k_ctxt = tcdCtxt k_decl + k_cons = tcdCons k_decl -- result kind must be '*' (otherwise, we have too few patterns) ; checkTc (isLiftedTypeKind resKind) $ tooFewParmsErr tc_name @@ -288,24 +293,24 @@ tcIdxTyInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L _ tc_name, ; checkTc h98_syntax (badGadtIdxTyDecl tc_name) -- Check that a newtype has exactly one constructor - ; checkTc (new_or_data == DataType || isSingleton cons) $ - newtypeConError tc_name (length cons) + ; checkTc (new_or_data == DataType || isSingleton k_cons) $ + newtypeConError tc_name (length k_cons) ; t_typats <- mappM tcHsKindedType k_typats ; stupid_theta <- tcHsKindedContext k_ctxt + + ; rep_tc_name <- newFamInstTyConName tc_name (srcSpanStart loc) ; tycon <- fixM (\ tycon -> do { data_cons <- mappM (addLocM (tcConDecl unbox_strict new_or_data - tycon t_tvs)) + tycon t_tvs)) k_cons ; tc_rhs <- case new_or_data of DataType -> return (mkDataTyConRhs data_cons) - NewType -> - ASSERT( isSingleton data_cons ) - mkNewTyConRhs tc_name tycon (head data_cons) - --vvvvvvv !!! need a new derived tc_name here - ; buildAlgTyCon tc_name t_tvs stupid_theta tc_rhs Recursive - False h98_syntax + NewType -> ASSERT( isSingleton data_cons ) + mkNewTyConRhs tc_name tycon (head data_cons) + ; buildAlgTyCon rep_tc_name t_tvs stupid_theta tc_rhs Recursive + False h98_syntax (Just (family, t_typats)) -- We always assume that indexed types are recursive. Why? -- (1) Due to their open nature, we can never be sure that a -- further instance might not introduce a new recursive @@ -314,8 +319,7 @@ tcIdxTyInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L _ tc_name, }) -- construct result - -- !!!twofold: (1) (ATyCon tycon) and (2) an equality axiom - ; return Nothing -- !!!TODO: need InstInfo for indexed types + ; return $ Just (ATyCon tycon) }} where h98_syntax = case cons of -- All constructors have same shape @@ -332,15 +336,13 @@ tcIdxTyInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L _ tc_name, -- check is only required for type functions. -- kcIdxTyPats :: TyClDecl Name - -> ([LHsTyVarBndr Name] -> [LHsType Name] -> Kind -> TcM a) + -> ([LHsTyVarBndr Name] -> [LHsType Name] -> Kind -> TyCon -> TcM a) -- ^^kinded tvs ^^kinded ty pats ^^res kind -> TcM a kcIdxTyPats decl thing_inside = kcHsTyVars (tcdTyVars decl) $ \tvs -> - do { tc_ty_thing <- tcLookupLocated (tcdLName decl) - ; let { tc_kind = case tc_ty_thing of - AGlobal (ATyCon tycon) -> tyConKind tycon - ; (kinds, resKind) = splitKindFunTys tc_kind + do { family <- tcLookupLocatedTyCon (tcdLName decl) + ; let { (kinds, resKind) = splitKindFunTys (tyConKind family) ; hs_typats = fromJust $ tcdTyPats decl } -- we may not have more parameters than the kind indicates @@ -349,8 +351,8 @@ kcIdxTyPats decl thing_inside -- type functions can have a higher-kinded result ; let resultKind = mkArrowKinds (drop (length hs_typats) kinds) resKind - ; typats <- zipWithM kcCheckHsType hs_typats kinds - ; thing_inside tvs typats resultKind + ; typats <- TcRnMonad.zipWithM kcCheckHsType hs_typats kinds + ; thing_inside tvs typats resultKind family } where \end{code} @@ -542,14 +544,15 @@ kcDataDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdCons = cons}) ; cons' <- mappM (wrapLocM kc_con_decl) cons ; return (decl {tcdTyVars = tvs, tcdCtxt = ctxt', tcdCons = cons'}) } where - kc_con_decl (ConDecl name expl ex_tvs ex_ctxt details res) = do + -- doc comments are typechecked to Nothing here + kc_con_decl (ConDecl name expl ex_tvs ex_ctxt details res _) = do kcHsTyVars ex_tvs $ \ex_tvs' -> do ex_ctxt' <- kcHsContext ex_ctxt details' <- kc_con_details details res' <- case res of ResTyH98 -> return ResTyH98 ResTyGADT ty -> do { ty' <- kcHsSigType ty; return (ResTyGADT ty') } - return (ConDecl name expl ex_tvs' ex_ctxt' details' res') + return (ConDecl name expl ex_tvs' ex_ctxt' details' res' Nothing) kc_con_details (PrefixCon btys) = do { btys' <- mappM kc_larg_ty btys ; return (PrefixCon btys') } @@ -558,7 +561,7 @@ kcDataDecl decl@(TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdCons = cons}) kc_con_details (RecCon fields) = do { fields' <- mappM kc_field fields; return (RecCon fields') } - kc_field (fld, bty) = do { bty' <- kc_larg_ty bty ; return (fld, bty') } + kc_field (HsRecField fld bty d) = do { bty' <- kc_larg_ty bty ; return (HsRecField fld bty' d) } kc_larg_ty bty = case new_or_data of DataType -> kcHsSigType bty @@ -591,7 +594,7 @@ tcSynDecl ; return (ATyCon (buildSynTyCon tc_name tvs' (SynonymTyCon rhs_ty'))) } -------------------- -tcTyClDecl :: (Name -> RecFlag) -> TyClDecl Name -> TcM TyThing +tcTyClDecl :: (Name -> RecFlag) -> TyClDecl Name -> TcM [TyThing] tcTyClDecl calc_isrec decl = tcAddDeclCtxt decl (tcTyClDecl1 calc_isrec decl) @@ -600,24 +603,26 @@ tcTyClDecl calc_isrec decl tcTyClDecl1 _calc_isrec (TyFunction {tcdLName = L _ tc_name, tcdTyVars = tvs, tcdKind = kind}) = tcTyVarBndrs tvs $ \ tvs' -> do - { gla_exts <- doptM Opt_GlasgowExts + { traceTc (text "type family: " <+> ppr tc_name) + ; gla_exts <- doptM Opt_IndexedTypes -- Check that we don't use kind signatures without Glasgow extensions ; checkTc gla_exts $ badSigTyDecl tc_name - ; return (ATyCon (buildSynTyCon tc_name tvs' (OpenSynTyCon kind))) + ; return [ATyCon $ buildSynTyCon tc_name tvs' (OpenSynTyCon kind)] } -- kind signature for an indexed data type tcTyClDecl1 _calc_isrec (TyData {tcdND = new_or_data, tcdCtxt = ctxt, tcdTyVars = tvs, - tcdLName = L _ tc_name, tcdKindSig = mb_ksig, tcdCons = []}) + tcdLName = L _ tc_name, tcdKindSig = Just ksig, tcdCons = []}) = tcTyVarBndrs tvs $ \ tvs' -> do - { extra_tvs <- tcDataKindSig mb_ksig + { traceTc (text "data/newtype family: " <+> ppr tc_name) + ; extra_tvs <- tcDataKindSig (Just ksig) ; let final_tvs = tvs' ++ extra_tvs -- we may not need these ; checkTc (null . unLoc $ ctxt) $ badKindSigCtxt tc_name - ; gla_exts <- doptM Opt_GlasgowExts + ; gla_exts <- doptM Opt_IndexedTypes -- Check that we don't use kind signatures without Glasgow extensions ; checkTc gla_exts $ badSigTyDecl tc_name @@ -626,8 +631,8 @@ tcTyClDecl1 _calc_isrec (case new_or_data of DataType -> OpenDataTyCon NewType -> OpenNewTyCon) - Recursive False True - ; return (ATyCon tycon) + Recursive False True Nothing + ; return [ATyCon tycon] } tcTyClDecl1 calc_isrec @@ -673,9 +678,9 @@ tcTyClDecl1 calc_isrec ASSERT( isSingleton data_cons ) mkNewTyConRhs tc_name tycon (head data_cons) ; buildAlgTyCon tc_name final_tvs stupid_theta tc_rhs is_rec - (want_generic && canDoGenerics data_cons) h98_syntax + (want_generic && canDoGenerics data_cons) h98_syntax Nothing }) - ; return (ATyCon tycon) + ; return [ATyCon tycon] } where is_rec = calc_isrec tc_name @@ -690,7 +695,8 @@ tcTyClDecl1 calc_isrec = tcTyVarBndrs tvs $ \ tvs' -> do { ctxt' <- tcHsKindedContext ctxt ; fds' <- mappM (addLocM tc_fundep) fundeps - ; ats' <- mappM (addLocM (tcTyClDecl1 (const Recursive))) ats + ; atss <- mappM (addLocM (tcTyClDecl1 (const Recursive))) ats + ; let ats' = zipWith setTyThingPoss atss (map (tcdTyVars . unLoc) ats) ; sig_stuff <- tcClassSigs class_name sigs meths ; clas <- fixM (\ clas -> let -- This little knot is just so we can get @@ -701,24 +707,42 @@ tcTyClDecl1 calc_isrec in buildClass class_name tvs' ctxt' fds' ats' sig_stuff tc_isrec) - ; return (AClass clas) } + ; return (AClass clas : ats') + -- NB: Order is important due to the call to `mkGlobalThings' when + -- tying the the type and class declaration type checking knot. + } where tc_fundep (tvs1, tvs2) = do { tvs1' <- mappM tcLookupTyVar tvs1 ; ; tvs2' <- mappM tcLookupTyVar tvs2 ; ; return (tvs1', tvs2') } + -- For each AT argument compute the position of the corresponding class + -- parameter in the class head. This will later serve as a permutation + -- vector when checking the validity of instance declarations. + setTyThingPoss [ATyCon tycon] atTyVars = + let classTyVars = hsLTyVarNames tvs + poss = catMaybes + . map (`elemIndex` classTyVars) + . hsLTyVarNames + $ atTyVars + -- There will be no Nothing, as we already passed renaming + in + ATyCon (setTyConArgPoss tycon poss) + setTyThingPoss _ _ = panic "TcTyClsDecls.setTyThingPoss" tcTyClDecl1 calc_isrec (ForeignType {tcdLName = L _ tc_name, tcdExtName = tc_ext_name}) - = returnM (ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0)) + = returnM [ATyCon (mkForeignTyCon tc_name tc_ext_name liftedTypeKind 0)] ----------------------------------- tcConDecl :: Bool -- True <=> -funbox-strict_fields - -> NewOrData -> TyCon -> [TyVar] - -> ConDecl Name -> TcM DataCon + -> NewOrData + -> TyCon -> [TyVar] + -> ConDecl Name + -> TcM DataCon tcConDecl unbox_strict NewType tycon tc_tvs -- Newtypes - (ConDecl name _ ex_tvs ex_ctxt details ResTyH98) + (ConDecl name _ ex_tvs ex_ctxt details ResTyH98 _) = do { let tc_datacon field_lbls arg_ty = do { arg_ty' <- tcHsKindedType arg_ty -- No bang on newtype ; buildDataCon (unLoc name) False {- Prefix -} @@ -733,36 +757,38 @@ tcConDecl unbox_strict NewType tycon tc_tvs -- Newtypes ; checkTc (null ex_tvs && null (unLoc ex_ctxt)) (newtypeExError name) ; case details of - PrefixCon [arg_ty] -> tc_datacon [] arg_ty - RecCon [(field_lbl, arg_ty)] -> tc_datacon [field_lbl] arg_ty - other -> failWithTc (newtypeFieldErr name (length (hsConArgs details))) + PrefixCon [arg_ty] -> tc_datacon [] arg_ty + RecCon [HsRecField field_lbl arg_ty _] -> tc_datacon [field_lbl] arg_ty + other -> + failWithTc (newtypeFieldErr name (length (hsConArgs details))) -- Check that the constructor has exactly one field } tcConDecl unbox_strict DataType tycon tc_tvs -- Data types - (ConDecl name _ tvs ctxt details res_ty) + (ConDecl name _ tvs ctxt details res_ty _) = tcTyVarBndrs tvs $ \ tvs' -> do { ctxt' <- tcHsKindedContext ctxt ; (univ_tvs, ex_tvs, eq_preds, data_tc) <- tcResultType tycon tc_tvs tvs' res_ty ; let + -- Tiresome: tidy the tyvar binders, since tc_tvs and tvs' may have the same OccNames tc_datacon is_infix field_lbls btys = do { let bangs = map getBangStrictness btys ; arg_tys <- mappM tcHsBangType btys ; buildDataCon (unLoc name) is_infix - (argStrictness unbox_strict tycon bangs arg_tys) + (argStrictness unbox_strict bangs arg_tys) (map unLoc field_lbls) univ_tvs ex_tvs eq_preds ctxt' arg_tys data_tc } - -- NB: we put data_tc, the type constructor gotten from the constructor - -- type signature into the data constructor; that way - -- checkValidDataCon can complain if it's wrong. + -- NB: we put data_tc, the type constructor gotten from the + -- constructor type signature into the data constructor; + -- that way checkValidDataCon can complain if it's wrong. ; case details of PrefixCon btys -> tc_datacon False [] btys InfixCon bty1 bty2 -> tc_datacon True [] [bty1,bty2] RecCon fields -> tc_datacon False field_names btys where - (field_names, btys) = unzip fields + (field_names, btys) = unzip [ (n, t) | HsRecField n t _ <- fields ] } @@ -771,7 +797,7 @@ tcResultType :: TyCon -> [TyVar] -- where MkT :: forall a b c. ... -> ResType Name -> TcM ([TyVar], -- Universal - [TyVar], -- Existential + [TyVar], -- Existential (distinct OccNames from univs) [(TyVar,Type)], -- Equality predicates TyCon) -- TyCon given in the ResTy -- We don't check that the TyCon given in the ResTy is @@ -791,8 +817,8 @@ tcResultType _ tc_tvs dc_tvs (ResTyGADT res_ty) -- ([a,z,c], [x,y], [a:=:(x,y), c:=:z], T) = do { (dc_tycon, res_tys) <- tcLHsConResTy res_ty - -- NB: tc_tvs and dc_tvs are distinct - ; let univ_tvs = choose_univs [] tc_tvs res_tys + + ; let univ_tvs = choose_univs [] tidy_tc_tvs res_tys -- Each univ_tv is either a dc_tv or a tc_tv ex_tvs = dc_tvs `minusList` univ_tvs eq_spec = [ (tv, ty) | (tv,ty) <- univ_tvs `zip` res_tys, @@ -809,13 +835,25 @@ tcResultType _ tc_tvs dc_tvs (ResTyGADT res_ty) | otherwise = tc_tv : choose_univs used tc_tvs res_tys -------------------- + -- NB: tc_tvs and dc_tvs are distinct, but + -- we want them to be *visibly* distinct, both for + -- interface files and general confusion. So rename + -- the tc_tvs, since they are not used yet (no + -- consequential renaming needed) + init_occ_env = initTidyOccEnv (map getOccName dc_tvs) + (_, tidy_tc_tvs) = mapAccumL tidy_one init_occ_env tc_tvs + tidy_one env tv = (env', setTyVarName tv (tidyNameOcc name occ')) + where + name = tyVarName tv + (env', occ') = tidyOccName env (getOccName name) + + ------------------- argStrictness :: Bool -- True <=> -funbox-strict_fields - -> TyCon -> [HsBang] + -> [HsBang] -> [TcType] -> [StrictnessMark] -argStrictness unbox_strict tycon bangs arg_tys +argStrictness unbox_strict bangs arg_tys = ASSERT( length bangs == length arg_tys ) - zipWith (chooseBoxingStrategy unbox_strict tycon) arg_tys bangs + zipWith (chooseBoxingStrategy unbox_strict) arg_tys bangs -- We attempt to unbox/unpack a strict field when either: -- (i) The field is marked '!!', or @@ -823,8 +861,8 @@ argStrictness unbox_strict tycon bangs arg_tys -- -- We have turned off unboxing of newtypes because coercions make unboxing -- and reboxing more complicated -chooseBoxingStrategy :: Bool -> TyCon -> TcType -> HsBang -> StrictnessMark -chooseBoxingStrategy unbox_strict_fields tycon arg_ty bang +chooseBoxingStrategy :: Bool -> TcType -> HsBang -> StrictnessMark +chooseBoxingStrategy unbox_strict_fields arg_ty bang = case bang of HsNoBang -> NotMarkedStrict HsStrict | unbox_strict_fields @@ -837,13 +875,21 @@ chooseBoxingStrategy unbox_strict_fields tycon arg_ty bang can_unbox arg_ty = case splitTyConApp_maybe arg_ty of Nothing -> False Just (arg_tycon, tycon_args) -> - not (isRecursiveTyCon tycon) && + not (isRecursiveTyCon arg_tycon) && -- Note [Recusive unboxing] isProductTyCon arg_tycon && (if isNewTyCon arg_tycon then can_unbox (newTyConInstRhs arg_tycon tycon_args) else True) \end{code} +Note [Recursive unboxing] +~~~~~~~~~~~~~~~~~~~~~~~~~ +Be careful not to try to unbox this! + data T = MkT !T Int +But it's the *argument* type that matters. This is fine: + data S = MkS S !Int +because Int is non-recursive. + %************************************************************************ %* * \subsection{Dependency analysis} @@ -998,8 +1044,13 @@ checkValidClass cls ; checkValidType (FunSigCtxt op_name) tau -- Check that the type mentions at least one of - -- the class type variables - ; checkTc (any (`elemVarSet` tyVarsOfType tau) tyvars) + -- the class type variables...or at least one reachable + -- from one of the class variables. Example: tc223 + -- class Error e => Game b mv e | b -> mv e where + -- newBoard :: MonadState b m => m () + -- Here, MonadState has a fundep m->b, so newBoard is fine + ; let grown_tyvars = grow theta (mkVarSet tyvars) + ; checkTc (tyVarsOfType tau `intersectsVarSet` grown_tyvars) (noClassTyVarErr cls sel_id) -- Check that for a generic method, the type of @@ -1105,7 +1156,7 @@ newtypeFieldErr con_name n_flds badSigTyDecl tc_name = vcat [ ptext SLIT("Illegal kind signature") <+> quotes (ppr tc_name) - , nest 2 (parens $ ptext SLIT("Use -fglasgow-exts to allow indexed types")) ] + , nest 2 (parens $ ptext SLIT("Use -findexed-types to allow indexed types")) ] badKindSigCtxt tc_name = vcat [ ptext SLIT("Illegal context in kind signature") <+> @@ -1115,7 +1166,7 @@ badKindSigCtxt tc_name badIdxTyDecl tc_name = vcat [ ptext SLIT("Illegal indexed type instance for") <+> quotes (ppr tc_name) - , nest 2 (parens $ ptext SLIT("Use -fglasgow-exts to allow indexed types")) ] + , nest 2 (parens $ ptext SLIT("Use -findexed-types to allow indexed types")) ] badGadtIdxTyDecl tc_name = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+> @@ -1130,7 +1181,16 @@ tooFewParmsErr tc_name = ptext SLIT("Indexed type instance has too few parameters:") <+> quotes (ppr tc_name) -badBootTyIdxDeclErr = ptext SLIT("Illegal indexed type instance in hs-boot file") +badBootTyIdxDeclErr = + ptext SLIT("Illegal indexed type instance in hs-boot file") + +wrongKindOfFamily family = + ptext SLIT("Wrong category of type instance; declaration was for a") <+> + kindOfFamily + where + kindOfFamily | isSynTyCon family = ptext SLIT("type synonym") + | isDataTyCon family = ptext SLIT("data type") + | isNewTyCon family = ptext SLIT("newtype") emptyConDeclsErr tycon = sep [quotes (ppr tycon) <+> ptext SLIT("has no constructors"),