X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcDeriv.lhs;h=30e57ff593fb18804df1f595d647758cb635b9ad;hb=d2f11ea842a25bebd51d6c0c730a756c1d987e25;hp=8fa8c0b3fa45c3b60535b51a5e3dd5d4fc5c9ea1;hpb=d2ce0f52d42edf32bb9f13796e6ba6edba8bd516;p=ghc-hetmet.git diff --git a/compiler/typecheck/TcDeriv.lhs b/compiler/typecheck/TcDeriv.lhs index 8fa8c0b..30e57ff 100644 --- a/compiler/typecheck/TcDeriv.lhs +++ b/compiler/typecheck/TcDeriv.lhs @@ -352,10 +352,8 @@ renameDeriv is_boot gen_binds insts rm_dups [] $ concat deriv_aux_binds aux_val_binds = ValBindsIn (listToBag aux_binds) aux_sigs ; rn_aux_lhs <- rnTopBindsLHS emptyFsEnv aux_val_binds - ; let aux_names = collectHsValBinders rn_aux_lhs - - ; bindLocalNames aux_names $ - do { (rn_aux, dus_aux) <- rnTopBindsRHS (mkNameSet aux_names) rn_aux_lhs + ; bindLocalNames (collectHsValBinders rn_aux_lhs) $ + do { (rn_aux, dus_aux) <- rnTopBindsRHS rn_aux_lhs ; (rn_inst_infos, fvs_insts) <- mapAndUnzipM rn_inst_info inst_infos ; return (rn_inst_infos, rn_aux `plusHsValBinds` rn_gen, dus_gen `plusDU` dus_aux `plusDU` usesOnly (plusFVs fvs_insts)) } } @@ -597,32 +595,46 @@ mkEqnHelp :: CtOrigin -> [TyVar] -> Class -> [Type] -> Type mkEqnHelp orig tvs cls cls_tys tc_app mtheta | Just (tycon, tc_args) <- tcSplitTyConApp_maybe tc_app , isAlgTyCon tycon -- Check for functions, primitive types etc - = do { (rep_tc, rep_tc_args) <- tcLookupDataFamInst tycon tc_args - -- Be careful to test rep_tc here: in the case of families, - -- we want to check the instance tycon, not the family tycon - - -- For standalone deriving (mtheta /= Nothing), - -- check that all the data constructors are in scope. - -- No need for this when deriving Typeable, becuase we don't need - -- the constructors for that. - ; rdr_env <- getGlobalRdrEnv - ; let hidden_data_cons = isAbstractTyCon rep_tc || any not_in_scope (tyConDataCons rep_tc) - not_in_scope dc = null (lookupGRE_Name rdr_env (dataConName dc)) - ; checkTc (isNothing mtheta || - not hidden_data_cons || - className cls `elem` typeableClassNames) - (derivingHiddenErr tycon) - - ; dflags <- getDOpts - ; if isDataTyCon rep_tc then - mkDataTypeEqn orig dflags tvs cls cls_tys - tycon tc_args rep_tc rep_tc_args mtheta - else - mkNewTypeEqn orig dflags tvs cls cls_tys - tycon tc_args rep_tc rep_tc_args mtheta } + = mk_alg_eqn tycon tc_args | otherwise = failWithTc (derivingThingErr False cls cls_tys tc_app (ptext (sLit "The last argument of the instance must be a data or newtype application"))) + + where + bale_out msg = failWithTc (derivingThingErr False cls cls_tys tc_app msg) + + mk_alg_eqn tycon tc_args + | className cls `elem` typeableClassNames + = do { dflags <- getDOpts + ; case checkTypeableConditions (dflags, tycon) of + Just err -> bale_out err + Nothing -> mk_typeable_eqn orig tvs cls tycon tc_args mtheta } + + | isDataFamilyTyCon tycon + , length tc_args /= tyConArity tycon + = bale_out (ptext (sLit "Unsaturated data family application")) + + | otherwise + = do { (rep_tc, rep_tc_args) <- tcLookupDataFamInst tycon tc_args + -- Be careful to test rep_tc here: in the case of families, + -- we want to check the instance tycon, not the family tycon + + -- For standalone deriving (mtheta /= Nothing), + -- check that all the data constructors are in scope. + ; rdr_env <- getGlobalRdrEnv + ; let hidden_data_cons = isAbstractTyCon rep_tc || + any not_in_scope (tyConDataCons rep_tc) + not_in_scope dc = null (lookupGRE_Name rdr_env (dataConName dc)) + ; unless (isNothing mtheta || not hidden_data_cons) + (bale_out (derivingHiddenErr tycon)) + + ; dflags <- getDOpts + ; if isDataTyCon rep_tc then + mkDataTypeEqn orig dflags tvs cls cls_tys + tycon tc_args rep_tc rep_tc_args mtheta + else + mkNewTypeEqn orig dflags tvs cls cls_tys + tycon tc_args rep_tc rep_tc_args mtheta } \end{code} @@ -657,15 +669,10 @@ mkDataTypeEqn orig dflags tvs cls cls_tys go_for_it = mk_data_eqn orig tvs cls tycon tc_args rep_tc rep_tc_args mtheta bale_out msg = failWithTc (derivingThingErr False cls cls_tys (mkTyConApp tycon tc_args) msg) -mk_data_eqn, mk_typeable_eqn - :: CtOrigin -> [TyVar] -> Class - -> TyCon -> [TcType] -> TyCon -> [TcType] -> DerivContext - -> TcM EarlyDerivSpec +mk_data_eqn :: CtOrigin -> [TyVar] -> Class + -> TyCon -> [TcType] -> TyCon -> [TcType] -> DerivContext + -> TcM EarlyDerivSpec mk_data_eqn orig tvs cls tycon tc_args rep_tc rep_tc_args mtheta - | getName cls `elem` typeableClassNames - = mk_typeable_eqn orig tvs cls tycon tc_args rep_tc rep_tc_args mtheta - - | otherwise = do { dfun_name <- new_dfun_name cls tycon ; loc <- getSrcSpanM ; let inst_tys = [mkTyConApp tycon tc_args] @@ -680,7 +687,11 @@ mk_data_eqn orig tvs cls tycon tc_args rep_tc rep_tc_args mtheta ; return (if isJust mtheta then Right spec -- Specified context else Left spec) } -- Infer context -mk_typeable_eqn orig tvs cls tycon tc_args rep_tc rep_tc_args mtheta +---------------------- +mk_typeable_eqn :: CtOrigin -> [TyVar] -> Class + -> TyCon -> [TcType] -> DerivContext + -> TcM EarlyDerivSpec +mk_typeable_eqn orig tvs cls tycon tc_args mtheta -- The Typeable class is special in several ways -- data T a b = ... deriving( Typeable ) -- gives @@ -694,7 +705,7 @@ mk_typeable_eqn orig tvs cls tycon tc_args rep_tc rep_tc_args mtheta = do { checkTc (cls `hasKey` typeableClassKey) (ptext (sLit "Use deriving( Typeable ) on a data type declaration")) ; real_cls <- tcLookupClass (typeableClassNames !! tyConArity tycon) - ; mk_typeable_eqn orig tvs real_cls tycon [] rep_tc [] (Just []) } + ; mk_typeable_eqn orig tvs real_cls tycon [] (Just []) } | otherwise -- standaone deriving = do { checkTc (null tc_args) @@ -705,10 +716,10 @@ mk_typeable_eqn orig tvs cls tycon tc_args rep_tc rep_tc_args mtheta ; return (Right $ DS { ds_loc = loc, ds_orig = orig, ds_name = dfun_name, ds_tvs = [] , ds_cls = cls, ds_tys = [mkTyConApp tycon []] - , ds_tc = rep_tc, ds_tc_args = rep_tc_args + , ds_tc = tycon, ds_tc_args = [] , ds_theta = mtheta `orElse` [], ds_newtype = False }) } - +---------------------- inferConstraints :: [TyVar] -> Class -> [TcType] -> TyCon -> [TcType] -> ThetaType -- Generate a sufficiently large set of constraints that typechecking the -- generated method definitions should succeed. This set will be simplified @@ -794,6 +805,9 @@ checkSideConditions dflags mtheta cls cls_tys rep_tc where ty_args_why = quotes (ppr (mkClassPred cls cls_tys)) <+> ptext (sLit "is not a class") +checkTypeableConditions :: Condition +checkTypeableConditions = checkFlag Opt_DeriveDataTypeable `andCond` cond_typeableOK + nonStdErr :: Class -> SDoc nonStdErr cls = quotes (ppr cls) <+> ptext (sLit "is not a derivable class") @@ -814,7 +828,6 @@ sideConditions mtheta cls cond_functorOK False) -- Functor/Fold/Trav works ok for rank-n types | cls_key == traversableClassKey = Just (checkFlag Opt_DeriveTraversable `andCond` cond_functorOK False) - | getName cls `elem` typeableClassNames = Just (checkFlag Opt_DeriveDataTypeable `andCond` cond_typeableOK) | otherwise = Nothing where cls_key = getUnique cls @@ -830,11 +843,11 @@ type Condition = (DynFlags, TyCon) -> Maybe SDoc orCond :: Condition -> Condition -> Condition orCond c1 c2 tc = case c1 tc of - Nothing -> Nothing -- c1 succeeds - Just x -> case c2 tc of -- c1 fails + Nothing -> Nothing -- c1 succeeds + Just x -> case c2 tc of -- c1 fails Nothing -> Nothing Just y -> Just (x $$ ptext (sLit " and") $$ y) - -- Both fail + -- Both fail andCond :: Condition -> Condition -> Condition andCond c1 c2 tc = case c1 tc of @@ -845,16 +858,14 @@ cond_stdOK :: DerivContext -> Condition cond_stdOK (Just _) _ = Nothing -- Don't check these conservative conditions for -- standalone deriving; just generate the code + -- and let the typechecker handle the result cond_stdOK Nothing (_, rep_tc) - | null data_cons = Just (no_cons_why $$ suggestion) + | null data_cons = Just (no_cons_why rep_tc $$ suggestion) | not (null con_whys) = Just (vcat con_whys $$ suggestion) | otherwise = Nothing where suggestion = ptext (sLit "Possible fix: use a standalone deriving declaration instead") data_cons = tyConDataCons rep_tc - no_cons_why = quotes (pprSourceTyCon rep_tc) <+> - ptext (sLit "has no data constructors") - con_whys = mapCatMaybes check_con data_cons check_con :: DataCon -> Maybe SDoc @@ -863,6 +874,10 @@ cond_stdOK Nothing (_, rep_tc) , all isTauTy (dataConOrigArgTys con) = Nothing | otherwise = Just (badCon con (ptext (sLit "does not have a Haskell-98 type"))) +no_cons_why :: TyCon -> SDoc +no_cons_why rep_tc = quotes (pprSourceTyCon rep_tc) <+> + ptext (sLit "has no data constructors") + cond_enumOrProduct :: Condition cond_enumOrProduct = cond_isEnumeration `orCond` (cond_isProduct `andCond` cond_noUnliftedArgs) @@ -880,11 +895,13 @@ cond_noUnliftedArgs (_, tc) cond_isEnumeration :: Condition cond_isEnumeration (_, rep_tc) - | isEnumerationTyCon rep_tc = Nothing - | otherwise = Just why + | isEnumerationTyCon rep_tc = Nothing + | otherwise = Just why where - why = quotes (pprSourceTyCon rep_tc) <+> - ptext (sLit "has non-nullary constructors") + why = sep [ quotes (pprSourceTyCon rep_tc) <+> + ptext (sLit "is not an enumeration type") + , nest 2 $ ptext (sLit "(an enumeration consists of one or more nullary constructors)") ] + -- See Note [Enumeration types] in TyCon cond_isProduct :: Condition cond_isProduct (_, rep_tc) @@ -892,26 +909,22 @@ cond_isProduct (_, rep_tc) | otherwise = Just why where why = quotes (pprSourceTyCon rep_tc) <+> - ptext (sLit "has more than one constructor") + ptext (sLit "does not have precisely one constructor") cond_typeableOK :: Condition -- OK for Typeable class -- Currently: (a) args all of kind * -- (b) 7 or fewer args -cond_typeableOK (_, rep_tc) - | tyConArity rep_tc > 7 = Just too_many - | not (all (isSubArgTypeKind . tyVarKind) (tyConTyVars rep_tc)) - = Just bad_kind - | isFamInstTyCon rep_tc = Just fam_inst -- no Typable for family insts - | otherwise = Nothing +cond_typeableOK (_, tc) + | tyConArity tc > 7 = Just too_many + | not (all (isSubArgTypeKind . tyVarKind) (tyConTyVars tc)) + = Just bad_kind + | otherwise = Nothing where - too_many = quotes (pprSourceTyCon rep_tc) <+> + too_many = quotes (pprSourceTyCon tc) <+> ptext (sLit "has too many arguments") - bad_kind = quotes (pprSourceTyCon rep_tc) <+> + bad_kind = quotes (pprSourceTyCon tc) <+> ptext (sLit "has arguments of kind other than `*'") - fam_inst = quotes (pprSourceTyCon rep_tc) <+> - ptext (sLit "is a type family") - functorLikeClassKeys :: [Unique] functorLikeClassKeys = [functorClassKey, foldableClassKey, traversableClassKey] @@ -923,10 +936,7 @@ cond_functorOK :: Bool -> Condition -- (c) don't use argument in the wrong place, e.g. data T a = T (X a a) -- (d) optionally: don't use function types -- (e) no "stupid context" on data type -cond_functorOK allowFunctions (dflags, rep_tc) - | not (dopt Opt_DeriveFunctor dflags) - = Just (ptext (sLit "You need -XDeriveFunctor to derive an instance for this class")) - +cond_functorOK allowFunctions (_, rep_tc) | null tc_tvs = Just (ptext (sLit "Data type") <+> quotes (ppr rep_tc) <+> ptext (sLit "has no parameters")) @@ -967,7 +977,7 @@ cond_functorOK allowFunctions (dflags, rep_tc) checkFlag :: ExtensionFlag -> Condition checkFlag flag (dflags, _) - | dopt flag dflags = Nothing + | xopt flag dflags = Nothing | otherwise = Just why where why = ptext (sLit "You need -X") <> text flag_str @@ -1070,7 +1080,7 @@ mkNewTypeEqn orig dflags tvs | can_derive_via_isomorphism -> bale_out (non_std $$ suggest_nd) -- Try newtype deriving! | otherwise -> bale_out non_std where - newtype_deriving = dopt Opt_GeneralizedNewtypeDeriving dflags + newtype_deriving = xopt Opt_GeneralizedNewtypeDeriving dflags go_for_it = mk_data_eqn orig tvs cls tycon tc_args rep_tycon rep_tc_args mtheta bale_out msg = failWithTc (derivingThingErr newtype_deriving cls cls_tys inst_ty msg)