X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcDeriv.lhs;h=8ffabd0bf9b6936701aa6c750b91762d3df2031b;hb=1bba522f5ec82c43abd2ba4e84127b9c915dd020;hp=6c45ca93779588358ff0a7d4cf94dad036191699;hpb=e0eaaf09894f74939166568573b36cb5bdafcfc7;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcDeriv.lhs b/ghc/compiler/typecheck/TcDeriv.lhs index 6c45ca9..8ffabd0 100644 --- a/ghc/compiler/typecheck/TcDeriv.lhs +++ b/ghc/compiler/typecheck/TcDeriv.lhs @@ -1,5 +1,5 @@ % -% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996 +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[TcDeriv]{Deriving} @@ -11,44 +11,44 @@ module TcDeriv ( tcDeriving ) where #include "HsVersions.h" import HsSyn ( HsBinds(..), MonoBinds(..), collectMonoBinders ) -import RdrHsSyn ( RdrName, RdrNameMonoBinds ) -import RnHsSyn ( RenamedHsBinds, RenamedMonoBinds ) +import RdrHsSyn ( RdrNameMonoBinds ) +import RnHsSyn ( RenamedHsBinds ) +import CmdLineOpts ( opt_D_dump_deriv ) import TcMonad -import Inst ( InstanceMapper ) -import TcEnv ( getEnv_TyCons, tcLookupClassByKey ) -import TcKind ( TcKind ) +import TcEnv ( InstEnv, getEnvTyCons, tcSetInstEnv, newDFunName ) import TcGenDeriv -- Deriv stuff -import TcInstUtil ( InstInfo(..), mkInstanceRelatedIds, buildInstanceEnvs ) +import TcInstUtil ( InstInfo(..), buildInstanceEnv ) import TcSimplify ( tcSimplifyThetas ) import RnBinds ( rnMethodBinds, rnTopMonoBinds ) -import RnEnv ( newDfunName, bindLocatedLocalsRn ) -import RnMonad ( RnM, RnDown, SDown, RnNameSupply, +import RnEnv ( bindLocatedLocalsRn ) +import RnMonad ( RnNameSupply, renameSourceCode, thenRn, mapRn, returnRn ) import Bag ( Bag, emptyBag, unionBags, listToBag ) import Class ( classKey, Class ) -import ErrUtils ( ErrMsg ) +import ErrUtils ( dumpIfSet, Message ) import MkId ( mkDictFunId ) -import Id ( dataConArgTys, isNullaryDataCon ) +import Id ( mkVanillaId ) +import DataCon ( dataConArgTys, isNullaryDataCon, isExistentialDataCon ) import PrelInfo ( needsDataDeclCtxtClassKeys ) -import Maybes ( maybeToBool ) -import Name ( isLocallyDefined, getSrcLoc, Provenance, - Name{--O only-}, Module, NamedThing(..), - OccName, nameOccName - ) -import SrcLoc ( mkGeneratedSrcLoc, SrcLoc ) +import Maybes ( maybeToBool, catMaybes ) +import Module ( Module ) +import Name ( isLocallyDefined, getSrcLoc, NamedThing(..) ) +import RdrName ( RdrName ) +import RnMonad ( FixityEnv ) + import TyCon ( tyConTyVars, tyConDataCons, tyConDerivings, tyConTheta, maybeTyConSingleCon, isDataTyCon, isEnumerationTyCon, isAlgTyCon, TyCon ) -import Type ( GenType(..), TauType, mkTyVarTys, mkTyConApp, +import Type ( TauType, mkTyVarTys, mkTyConApp, mkSigmaTy, mkDictTy, isUnboxedType, - splitAlgTyConApp + splitAlgTyConApp, classesToPreds ) -import TysPrim ( voidTy ) -import TyVar ( GenTyVar, TyVar ) +import TysWiredIn ( voidTy ) +import Var ( TyVar ) import Unique -- Keys stuff import Bag ( bagToList ) import Util ( zipWithEqual, sortLt, removeDups, assoc, thenCmp ) @@ -183,21 +183,20 @@ context to the instance decl. The "offending classes" are \begin{code} tcDeriving :: Module -- name of module under scrutiny + -> FixityEnv -- for the deriving code (Show/Read.) -> RnNameSupply -- for "renaming" bits of generated code -> Bag InstInfo -- What we already know about instances -> TcM s (Bag InstInfo, -- The generated "instance decls". - RenamedHsBinds, -- Extra generated bindings - SDoc) -- Printable derived instance decls; - -- for debugging via -ddump-derivings. + RenamedHsBinds) -- Extra generated bindings -tcDeriving modname rn_name_supply inst_decl_infos_in - = recoverTc (returnTc (emptyBag, EmptyBinds, empty)) $ +tcDeriving mod fixs rn_name_supply inst_decl_infos_in + = recoverTc (returnTc (emptyBag, EmptyBinds)) $ -- Fish the "deriving"-related information out of the TcEnv -- and make the necessary "equations". makeDerivEqns `thenTc` \ eqns -> if null eqns then - returnTc (emptyBag, EmptyBinds, text "No derivings") + returnTc (emptyBag, EmptyBinds) else -- Take the equation list and solve it, to deliver a list of @@ -217,44 +216,48 @@ tcDeriving modname rn_name_supply inst_decl_infos_in let extra_mbind_list = map gen_tag_n_con_monobind nm_alist_etc extra_mbinds = foldr AndMonoBinds EmptyMonoBinds extra_mbind_list - method_binds_s = map gen_bind new_inst_infos + method_binds_s = map (gen_bind fixs) new_inst_infos mbinders = bagToList (collectMonoBinders extra_mbinds) -- Rename to get RenamedBinds. -- The only tricky bit is that the extra_binds must scope over the -- method bindings for the instances. - (dfun_names_w_method_binds, rn_extra_binds) - = renameSourceCode modname rn_name_supply ( + (rn_method_binds_s, rn_extra_binds) + = renameSourceCode mod rn_name_supply ( bindLocatedLocalsRn (ptext (SLIT("deriving"))) mbinders $ \ _ -> - rnTopMonoBinds extra_mbinds [] `thenRn` \ rn_extra_binds -> - mapRn rn_one method_binds_s `thenRn` \ dfun_names_w_method_binds -> - returnRn (dfun_names_w_method_binds, rn_extra_binds) + rnTopMonoBinds extra_mbinds [] `thenRn` \ (rn_extra_binds, _) -> + mapRn rn_meths method_binds_s `thenRn` \ rn_method_binds_s -> + returnRn (rn_method_binds_s, rn_extra_binds) ) - rn_one (cl_nm, tycon_nm, meth_binds) - = newDfunName cl_nm tycon_nm - Nothing mkGeneratedSrcLoc `thenRn` \ dfun_name -> - rnMethodBinds meth_binds `thenRn` \ rn_meth_binds -> - returnRn (dfun_name, rn_meth_binds) - - really_new_inst_infos = map (gen_inst_info modname) - (new_inst_infos `zip` dfun_names_w_method_binds) - - ddump_deriv = ddump_deriving really_new_inst_infos rn_extra_binds in - --pprTrace "derived:\n" (ddump_deriv) $ + mapNF_Tc gen_inst_info (new_inst_infos `zip` rn_method_binds_s) `thenNF_Tc` \ really_new_inst_infos -> + + ioToTc (dumpIfSet opt_D_dump_deriv "Derived instances" + (ddump_deriving really_new_inst_infos rn_extra_binds)) `thenTc_` - returnTc (listToBag really_new_inst_infos, - rn_extra_binds, - ddump_deriv) + returnTc (listToBag really_new_inst_infos, rn_extra_binds) where ddump_deriving :: [InstInfo] -> RenamedHsBinds -> SDoc - ddump_deriving inst_infos extra_binds - = vcat ((map pp_info inst_infos) ++ [ppr extra_binds]) + = vcat (map pp_info inst_infos) $$ ppr extra_binds where - pp_info (InstInfo clas tvs [ty] inst_decl_theta _ _ mbinds _ _) - = ($$) (ppr (mkSigmaTy tvs inst_decl_theta (mkDictTy clas [ty]))) - (ppr mbinds) + pp_info (InstInfo clas tvs [ty] inst_decl_theta _ mbinds _ _) + = ppr (mkSigmaTy tvs inst_decl_theta' (mkDictTy clas [ty])) + $$ + ppr mbinds + where inst_decl_theta' = classesToPreds inst_decl_theta + + -- Paste the dfun id and method binds into the InstInfo + gen_inst_info (InstInfo clas tyvars tys@(ty:_) inst_decl_theta _ _ locn _, meth_binds) + = newDFunName mod clas tys locn `thenNF_Tc` \ dfun_name -> + let + dfun_id = mkDictFunId dfun_name clas tyvars tys inst_decl_theta + in + returnNF_Tc (InstInfo clas tyvars tys inst_decl_theta + dfun_id meth_binds locn []) + + rn_meths meths = rnMethodBinds meths `thenRn` \ (meths', _) -> returnRn meths' + -- Ignore the free vars returned \end{code} @@ -286,89 +289,47 @@ makeDerivEqns = tcGetEnv `thenNF_Tc` \ env -> let local_data_tycons = filter (\tc -> isLocallyDefined tc && isAlgTyCon tc) - (getEnv_TyCons env) + (getEnvTyCons env) + + think_about_deriving = need_deriving local_data_tycons + (derive_these, _) = removeDups cmp_deriv think_about_deriving in if null local_data_tycons then - -- Bale out now; evalClass may not be loaded if there aren't any - returnTc [] + returnTc [] -- Bale out now else - tcLookupClassByKey evalClassKey `thenNF_Tc` \ eval_clas -> - let - think_about_deriving = need_deriving eval_clas local_data_tycons - (derive_these, _) = removeDups cmp_deriv think_about_deriving - eqns = map mk_eqn derive_these - in - mapTc chk_out think_about_deriving `thenTc_` - returnTc eqns + mapTc mk_eqn derive_these `thenTc` \ maybe_eqns -> + returnTc (catMaybes maybe_eqns) where ------------------------------------------------------------------ - need_deriving :: Class -> [TyCon] -> [(Class, TyCon)] + need_deriving :: [TyCon] -> [(Class, TyCon)] -- find the tycons that have `deriving' clauses; - -- we handle the "every datatype in Eval" by - -- doing a dummy "deriving" for it. - - need_deriving eval_clas tycons_to_consider - = foldr ( \ tycon acc -> - let - acc_plus = if isLocallyDefined tycon - then (eval_clas, tycon) : acc - else acc - in - case (tyConDerivings tycon) of - [] -> acc_plus - cs -> [ (clas,tycon) | clas <- cs ] ++ acc_plus - ) + + need_deriving tycons_to_consider + = foldr (\ tycon acc -> [(clas,tycon) | clas <- tyConDerivings tycon] ++ acc) [] tycons_to_consider ------------------------------------------------------------------ - chk_out :: (Class, TyCon) -> TcM s () - chk_out this_one@(clas, tycon) - = let - clas_key = classKey clas - - is_enumeration = isEnumerationTyCon tycon - is_single_con = maybeToBool (maybeTyConSingleCon tycon) - - single_nullary_why = SLIT("one constructor data type or type with all nullary constructors expected") - nullary_why = SLIT("data type with all nullary constructors expected") - - chk_clas clas_uniq clas_str clas_why cond - = if (clas_uniq == clas_key) - then checkTc cond (derivingThingErr clas_str clas_why tycon) - else returnTc () - in - -- Are things OK for deriving Enum (if appropriate)? - chk_clas enumClassKey (SLIT("Enum")) nullary_why is_enumeration `thenTc_` - - -- Are things OK for deriving Bounded (if appropriate)? - chk_clas boundedClassKey (SLIT("Bounded")) single_nullary_why - (is_enumeration || is_single_con) `thenTc_` - - -- Are things OK for deriving Ix (if appropriate)? - chk_clas ixClassKey (SLIT("Ix.Ix")) single_nullary_why - (is_enumeration || is_single_con) - - ------------------------------------------------------------------ cmp_deriv :: (Class, TyCon) -> (Class, TyCon) -> Ordering cmp_deriv (c1, t1) (c2, t2) = (c1 `compare` c2) `thenCmp` (t1 `compare` t2) ------------------------------------------------------------------ - mk_eqn :: (Class, TyCon) -> DerivEqn + mk_eqn :: (Class, TyCon) -> NF_TcM s (Maybe DerivEqn) -- we swizzle the tyvars and datacons out of the tycon -- to make the rest of the equation mk_eqn (clas, tycon) - = (clas, tycon, tyvars, if_not_Eval constraints) + = case chk_out clas tycon of + Just err -> addErrTc err `thenNF_Tc_` + returnNF_Tc Nothing + Nothing -> returnNF_Tc (Just (clas, tycon, tyvars, constraints)) where clas_key = classKey clas tyvars = tyConTyVars tycon -- ToDo: Do we need new tyvars ??? tyvar_tys = mkTyVarTys tyvars data_cons = tyConDataCons tycon - if_not_Eval cs = if clas_key == evalClassKey then [] else cs - constraints = extra_constraints ++ concat (map mk_constraints data_cons) -- "extra_constraints": see notes above about contexts on data decls @@ -385,6 +346,24 @@ makeDerivEqns ] where instd_arg_tys = dataConArgTys data_con tyvar_tys + + ------------------------------------------------------------------ + chk_out :: Class -> TyCon -> Maybe Message + chk_out clas tycon + | clas `hasKey` enumClassKey && not is_enumeration = bog_out nullary_why + | clas `hasKey` boundedClassKey && not is_enumeration_or_single = bog_out single_nullary_why + | clas `hasKey` ixClassKey && not is_enumeration_or_single = bog_out single_nullary_why + | any isExistentialDataCon (tyConDataCons tycon) = Just (existentialErr clas tycon) + | otherwise = Nothing + where + is_enumeration = isEnumerationTyCon tycon + is_single_con = maybeToBool (maybeTyConSingleCon tycon) + is_enumeration_or_single = is_enumeration || is_single_con + + single_nullary_why = SLIT("one constructor data type or type with all nullary constructors expected") + nullary_why = SLIT("data type with all nullary constructors expected") + + bog_out why = Just (derivingThingErr clas tycon why) \end{code} %************************************************************************ @@ -441,15 +420,15 @@ solveDerivEqns inst_decl_infos_in orig_eqns -- with the current set of solutions, giving a add_solns inst_decl_infos_in orig_eqns current_solns - `thenNF_Tc` \ (new_inst_infos, inst_mapper) -> - let - class_to_inst_env cls = inst_mapper cls - in + `thenNF_Tc` \ (new_inst_infos, inst_env) -> + -- Simplify each RHS - listTc [ tcAddErrCtxt (derivCtxt tc) $ - tcSimplifyThetas class_to_inst_env deriv_rhs - | (_,tc,_,deriv_rhs) <- orig_eqns ] `thenTc` \ next_solns -> + tcSetInstEnv inst_env ( + listTc [ tcAddErrCtxt (derivCtxt tc) $ + tcSimplifyThetas deriv_rhs + | (_,tc,_,deriv_rhs) <- orig_eqns ] + ) `thenTc` \ next_solns -> -- Canonicalise the solutions, so they compare nicely let canonicalised_next_solns @@ -462,18 +441,18 @@ solveDerivEqns inst_decl_infos_in orig_eqns add_solns :: Bag InstInfo -- The global, non-derived ones -> [DerivEqn] -> [DerivSoln] -> NF_TcM s ([InstInfo], -- The new, derived ones - InstanceMapper) + InstEnv) -- the eqns and solns move "in lockstep"; we have the eqns -- because we need the LHS info for addClassInstance. add_solns inst_infos_in eqns solns - = discardErrsTc (buildInstanceEnvs all_inst_infos) `thenNF_Tc` \ inst_mapper -> + = discardErrsTc (buildInstanceEnv all_inst_infos) `thenNF_Tc` \ inst_env -> -- We do the discard-errs so that we don't get repeated error messages -- about duplicate instances. - -- They'll appear later, when we do the top-level buildInstanceEnvs. + -- They'll appear later, when we do the top-level buildInstanceEnv. - returnNF_Tc (new_inst_infos, inst_mapper) + returnNF_Tc (new_inst_infos, inst_env) where new_inst_infos = zipWithEqual "add_solns" mk_deriv_inst_info eqns solns @@ -482,20 +461,16 @@ add_solns inst_infos_in eqns solns mk_deriv_inst_info (clas, tycon, tyvars, _) theta = InstInfo clas tyvars [mkTyConApp tycon (mkTyVarTys tyvars)] theta - (my_panic "dfun_theta") - dummy_dfun_id - (my_panic "binds") (getSrcLoc tycon) (my_panic "upragmas") where dummy_dfun_id - = mkDictFunId (getName tycon) dummy_dfun_ty bottom bottom + = mkVanillaId (getName tycon) dummy_dfun_ty -- The name is getSrcLoc'd in an error message - where - bottom = panic "dummy_dfun_id" - dummy_dfun_ty = mkSigmaTy tyvars theta voidTy + theta' = classesToPreds theta + dummy_dfun_ty = mkSigmaTy tyvars theta' voidTy -- All we need from the dfun is its "theta" part, used during -- equation simplification (tcSimplifyThetas). The final -- dfun_id will have the superclass dictionaries as arguments too, @@ -576,51 +551,24 @@ the renamer. What a great hack! -- Generate the method bindings for the required instance -- (paired with class name, as we need that when generating dict -- names.) -gen_bind :: InstInfo -> ({-class-}OccName, {-tyCon-}OccName, RdrNameMonoBinds) -gen_bind (InstInfo clas _ [ty] _ _ _ _ _ _) - | not from_here - = (clas_nm, tycon_nm, EmptyMonoBinds) +gen_bind :: FixityEnv -> InstInfo -> RdrNameMonoBinds +gen_bind fixities (InstInfo clas _ [ty] _ _ _ _ _) + | not from_here = EmptyMonoBinds + | clas `hasKey` showClassKey = gen_Show_binds fixities tycon + | clas `hasKey` readClassKey = gen_Read_binds fixities tycon | otherwise - = (clas_nm, tycon_nm, - assoc "gen_bind:bad derived class" + = assoc "gen_bind:bad derived class" [(eqClassKey, gen_Eq_binds) ,(ordClassKey, gen_Ord_binds) ,(enumClassKey, gen_Enum_binds) - ,(evalClassKey, gen_Eval_binds) ,(boundedClassKey, gen_Bounded_binds) - ,(showClassKey, gen_Show_binds) - ,(readClassKey, gen_Read_binds) ,(ixClassKey, gen_Ix_binds) ] - (classKey clas) - tycon) + (classKey clas) + tycon where - clas_nm = nameOccName (getName clas) - tycon_nm = nameOccName (getName tycon) from_here = isLocallyDefined tycon (tycon,_,_) = splitAlgTyConApp ty - - -gen_inst_info :: Module -- Module name - -> (InstInfo, (Name, RenamedMonoBinds)) -- the main stuff to work on - -> InstInfo -- the gen'd (filled-in) "instance decl" - -gen_inst_info modname - (InstInfo clas tyvars tys@(ty:_) inst_decl_theta _ _ _ locn _, (dfun_name, meth_binds)) - = - -- Generate the various instance-related Ids - InstInfo clas tyvars tys inst_decl_theta - dfun_theta dfun_id - meth_binds - locn [] - where - (dfun_id, dfun_theta) = mkInstanceRelatedIds - dfun_name - clas tyvars tys - inst_decl_theta - - from_here = isLocallyDefined tycon - (tycon,_,_) = splitAlgTyConApp ty \end{code} @@ -667,7 +615,7 @@ gen_taggery_Names inst_infos foldlTc do_con2tag [] tycons_of_interest `thenTc` \ names_so_far -> foldlTc do_tag2con names_so_far tycons_of_interest where - all_CTs = [ (c, get_tycon ty) | (InstInfo c _ [ty] _ _ _ _ _ _) <- inst_infos ] + all_CTs = [ (c, get_tycon ty) | (InstInfo c _ [ty] _ _ _ _ _) <- inst_infos ] get_tycon ty = case splitAlgTyConApp ty of { (tc, _, _) -> tc } @@ -676,12 +624,12 @@ gen_taggery_Names inst_infos do_con2tag acc_Names tycon | isDataTyCon tycon && - (we_are_deriving eqClassKey tycon + ((we_are_deriving eqClassKey tycon && any isNullaryDataCon (tyConDataCons tycon)) || (we_are_deriving ordClassKey tycon && not (maybeToBool (maybeTyConSingleCon tycon))) || (we_are_deriving enumClassKey tycon) - || (we_are_deriving ixClassKey tycon) + || (we_are_deriving ixClassKey tycon)) = returnTc ((con2tag_RDR tycon, tycon, GenCon2Tag) : acc_Names) @@ -689,14 +637,15 @@ gen_taggery_Names inst_infos = returnTc acc_Names do_tag2con acc_Names tycon - = if (we_are_deriving enumClassKey tycon) - || (we_are_deriving ixClassKey tycon) - then - returnTc ( (tag2con_RDR tycon, tycon, GenTag2Con) - : (maxtag_RDR tycon, tycon, GenMaxTag) - : acc_Names) - else - returnTc acc_Names + | isDataTyCon tycon && + (we_are_deriving enumClassKey tycon || + we_are_deriving ixClassKey tycon + && isEnumerationTyCon tycon) + = returnTc ( (tag2con_RDR tycon, tycon, GenTag2Con) + : (maxtag_RDR tycon, tycon, GenMaxTag) + : acc_Names) + | otherwise + = returnTc acc_Names we_are_deriving clas_key tycon = is_in_eqns clas_key tycon all_CTs @@ -709,12 +658,16 @@ gen_taggery_Names inst_infos \end{code} \begin{code} -derivingThingErr :: FAST_STRING -> FAST_STRING -> TyCon -> ErrMsg +derivingThingErr :: Class -> TyCon -> FAST_STRING -> Message + +derivingThingErr clas tycon why + = sep [hsep [ptext SLIT("Can't make a derived instance of"), quotes (ppr clas)], + hsep [ptext SLIT("for the type"), quotes (ppr tycon)], + parens (ptext why)] -derivingThingErr thing why tycon - = hang (hsep [ptext SLIT("Can't make a derived instance of"), ptext thing]) - 0 (hang (hsep [ptext SLIT("for the type"), quotes (ppr tycon)]) - 0 (parens (ptext why))) +existentialErr clas tycon + = sep [ptext SLIT("Can't derive any instances for type") <+> quotes (ppr tycon), + ptext SLIT("because it has existentially-quantified constructor(s)")] derivCtxt tycon = ptext SLIT("When deriving classes for") <+> quotes (ppr tycon)