X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcDeriv.lhs;h=259dd945575e93c636d51bad226f25ce191548a9;hb=ea659be5faea43df1b2c113d2f22947dff23367e;hp=572fcb99aa1ab51ab805e3f0ba3fab4f09e67200;hpb=9d4c03805bafb6b1e1d47306b6a6c591c998e517;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcDeriv.lhs b/ghc/compiler/typecheck/TcDeriv.lhs index 572fcb9..259dd94 100644 --- a/ghc/compiler/typecheck/TcDeriv.lhs +++ b/ghc/compiler/typecheck/TcDeriv.lhs @@ -1,68 +1,56 @@ % -% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996 +% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % \section[TcDeriv]{Deriving} Handles @deriving@ clauses on @data@ declarations. \begin{code} -#include "HsVersions.h" - module TcDeriv ( tcDeriving ) where -IMP_Ubiq() +#include "HsVersions.h" -import HsSyn ( FixityDecl, Sig, HsBinds(..), Bind(..), MonoBinds(..), - GRHSsAndBinds, Match, HsExpr, HsLit, InPat, - ArithSeqInfo, Fake, MonoType ) -import HsPragmas ( InstancePragmas(..) ) -import RnHsSyn ( mkRnName, RnName(..), SYN_IE(RenamedHsBinds), RenamedFixityDecl(..) ) -import TcHsSyn ( TcIdOcc ) +import HsSyn ( HsBinds(..), MonoBinds(..), TyClDecl(..), + collectLocatedMonoBinders ) +import RdrHsSyn ( RdrNameMonoBinds ) +import RnHsSyn ( RenamedHsBinds, RenamedMonoBinds, RenamedTyClDecl ) +import CmdLineOpts ( DynFlag(..), DynFlags ) import TcMonad -import Inst ( SYN_IE(InstanceMapper) ) -import TcEnv ( getEnv_TyCons, tcLookupClassByKey ) -import TcKind ( TcKind ) +import TcEnv ( TcEnv, tcSetInstEnv, newDFunName, InstInfo(..), pprInstInfo, + tcLookupClass, tcLookupTyCon + ) import TcGenDeriv -- Deriv stuff -import TcInstUtil ( InstInfo(..), mkInstanceRelatedIds, buildInstanceEnvs ) +import InstEnv ( InstEnv, simpleDFunClassTyCon, extendInstEnv ) import TcSimplify ( tcSimplifyThetas ) -import RnMonad -import RnUtils ( SYN_IE(RnEnv), extendGlobalRnEnv ) -import RnBinds ( rnMethodBinds, rnTopBinds ) - -import Bag ( emptyBag{-ToDo:rm-}, Bag, isEmptyBag, unionBags, listToBag ) -import Class ( classKey, needsDataDeclCtxtClassKeys, GenClass ) -import ErrUtils ( pprBagOfErrors, addErrLoc, SYN_IE(Error) ) -import Id ( dataConArgTys, isNullaryDataCon, mkDictFunId ) -import Maybes ( maybeToBool ) -import Name ( isLocallyDefined, getSrcLoc, - mkTopLevName, origName, mkImplicitName, ExportFlag(..), - RdrName(..), Name{--O only-} - ) -import Outputable ( Outputable(..){-instances e.g., (,)-} ) -import PprType ( GenType, GenTyVar, GenClass, TyCon ) -import PprStyle ( PprStyle(..) ) -import Pretty ( ppAbove, ppAboves, ppCat, ppBesides, ppStr, ppHang, SYN_IE(Pretty) ) -import Pretty--ToDo:rm -import FiniteMap--ToDo:rm -import SrcLoc ( mkGeneratedSrcLoc, SrcLoc ) -import TyCon ( tyConTyVars, tyConDataCons, tyConDerivings, - tyConTheta, maybeTyConSingleCon, - isEnumerationTyCon, isDataTyCon, TyCon - ) -import Type ( GenType(..), SYN_IE(TauType), mkTyVarTys, applyTyCon, - mkSigmaTy, mkDictTy, isPrimType, instantiateTy, - getAppDataTyCon, getAppTyCon - ) -import TysPrim ( voidTy ) -import TyVar ( GenTyVar ) -import UniqFM ( emptyUFM ) -import Unique -- Keys stuff -import Util ( zipWithEqual, zipEqual, sortLt, removeDups, assoc, - thenCmp, cmpList, panic, pprPanic, pprPanic#, - assertPanic, pprTrace{-ToDo:rm-} +import RnBinds ( rnMethodBinds, rnTopMonoBinds ) +import RnEnv ( bindLocatedLocalsRn ) +import RnMonad ( renameDerivedCode, thenRn, mapRn, returnRn ) +import HscTypes ( DFunId, PersistentRenamerState ) + +import BasicTypes ( Fixity ) +import Class ( classKey, Class ) +import ErrUtils ( dumpIfSet_dyn, Message ) +import MkId ( mkDictFunId ) +import DataCon ( dataConArgTys, isNullaryDataCon, isExistentialDataCon ) +import PrelInfo ( needsDataDeclCtxtClassKeys ) +import Maybes ( maybeToBool, catMaybes ) +import Module ( Module ) +import Name ( Name, getSrcLoc ) +import RdrName ( RdrName ) + +import TyCon ( tyConTyVars, tyConDataCons, + tyConTheta, maybeTyConSingleCon, isDataTyCon, + isEnumerationTyCon, TyCon ) +import Type ( TauType, PredType(..), mkTyVarTys, mkTyConApp, isUnboxedType ) +import Var ( TyVar ) +import PrelNames +import Util ( zipWithEqual, sortLt ) +import ListSetOps ( removeDups, assoc ) +import Outputable +import List ( nub ) \end{code} %************************************************************************ @@ -150,12 +138,12 @@ this by simplifying the RHS to a form in which So, here are the synonyms for the ``equation'' structures: \begin{code} -type DerivEqn = (Class, TyCon, [TyVar], DerivRhs) - -- The tyvars bind all the variables in the RHS - -- NEW: it's convenient to re-use InstInfo - -- We'll "panic" out some fields... +type DerivEqn = (Name, Class, TyCon, [TyVar], DerivRhs) + -- The Name is the name for the DFun we'll build + -- The tyvars bind all the variables in the RHS -type DerivRhs = [(Class, TauType)] -- Same as a ThetaType! +type DerivRhs = [(Class, [TauType])] -- Same as a ThetaType! + --[PredType] -- ... | Class Class [Type==TauType] type DerivSoln = DerivRhs \end{code} @@ -192,25 +180,28 @@ context to the instance decl. The "offending classes" are %************************************************************************ \begin{code} -tcDeriving :: Module -- name of module under scrutiny - -> RnEnv -- for "renaming" bits of generated code - -> Bag InstInfo -- What we already know about instances - -> [RenamedFixityDecl] -- Fixity info; used by Read and Show - -> TcM s (Bag InstInfo, -- The generated "instance decls". - RenamedHsBinds, -- Extra generated bindings - PprStyle -> Pretty) -- Printable derived instance decls; - -- for debugging via -ddump-derivings. - -tcDeriving modname rn_env inst_decl_infos_in fixities - = -- Fish the "deriving"-related information out of the TcEnv +tcDeriving :: PersistentRenamerState + -> Module -- name of module under scrutiny + -> InstEnv -- What we already know about instances + -> (Name -> Maybe Fixity) -- used in deriving Show and Read + -> [RenamedTyClDecl] -- All type constructors + -> TcM ([InstInfo], -- The generated "instance decls". + RenamedHsBinds) -- Extra generated bindings + +tcDeriving prs mod inst_env_in get_fixity tycl_decls + = recoverTc (returnTc ([], EmptyBinds)) $ + + -- Fish the "deriving"-related information out of the TcEnv -- and make the necessary "equations". - makeDerivEqns `thenTc` \ eqns -> + makeDerivEqns mod tycl_decls `thenTc` \ eqns -> + if null eqns then + returnTc ([], EmptyBinds) + else -- Take the equation list and solve it, to deliver a list of -- solutions, a.k.a. the contexts for the instance decls -- required for the corresponding equations. - solveDerivEqns inst_decl_infos_in eqns - `thenTc` \ new_inst_infos -> + solveDerivEqns inst_env_in eqns `thenTc` \ new_dfuns -> -- Now augment the InstInfos, adding in the rather boring -- actual-code-to-do-the-methods binds. We may also need to @@ -218,29 +209,48 @@ tcDeriving modname rn_env inst_decl_infos_in fixities -- "con2tag" and/or "tag2con" functions. We do these -- separately. - gen_taggery_Names new_inst_infos `thenTc` \ nm_alist_etc -> - gen_tag_n_con_binds rn_env nm_alist_etc - `thenTc` \ (extra_binds, deriver_rn_env) -> + gen_taggery_Names new_dfuns `thenTc` \ nm_alist_etc -> - mapTc (gen_inst_info modname fixities deriver_rn_env) new_inst_infos - `thenTc` \ really_new_inst_infos -> + tcGetEnv `thenNF_Tc` \ env -> + getDOptsTc `thenTc` \ dflags -> let - ddump_deriv = ddump_deriving really_new_inst_infos extra_binds + 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 get_fixity) new_dfuns + mbinders = collectLocatedMonoBinders extra_mbinds + + -- Rename to get RenamedBinds. + -- The only tricky bit is that the extra_binds must scope over the + -- method bindings for the instances. + (rn_method_binds_s, rn_extra_binds) + = renameDerivedCode dflags mod prs ( + bindLocatedLocalsRn (ptext (SLIT("deriving"))) mbinders $ \ _ -> + 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) + ) + + new_inst_infos = zipWith gen_inst_info new_dfuns rn_method_binds_s in - --pprTrace "derived:\n" (ddump_deriv PprDebug) $ - returnTc (listToBag really_new_inst_infos, - extra_binds, - ddump_deriv) - where - ddump_deriving :: [InstInfo] -> RenamedHsBinds -> (PprStyle -> Pretty) + ioToTc (dumpIfSet_dyn dflags Opt_D_dump_deriv "Derived instances" + (ddump_deriving new_inst_infos rn_extra_binds)) `thenTc_` - ddump_deriving inst_infos extra_binds sty - = ppAboves ((map pp_info inst_infos) ++ [ppr sty extra_binds]) + returnTc (new_inst_infos, rn_extra_binds) + where + ddump_deriving :: [InstInfo] -> RenamedHsBinds -> SDoc + ddump_deriving inst_infos extra_binds + = vcat (map pprInstInfo inst_infos) $$ ppr extra_binds where - pp_info (InstInfo clas tvs ty inst_decl_theta _ _ _ mbinds _ _ _ _) - = ppAbove (ppr sty (mkSigmaTy tvs inst_decl_theta (mkDictTy clas ty))) - (ppr sty mbinds) + + -- Make a Real dfun instead of the dummy one we have so far + gen_inst_info :: DFunId -> RenamedMonoBinds -> InstInfo + gen_inst_info dfun binds + = InstInfo { iLocal = True, iDFunId = dfun, + iBinds = binds, iPrags = [] } + + rn_meths meths = rnMethodBinds [] meths `thenRn` \ (meths', _) -> returnRn meths' + -- Ignore the free vars returned \end{code} @@ -266,103 +276,75 @@ or} has just one data constructor (e.g., tuples). all those. \begin{code} -makeDerivEqns :: TcM s [DerivEqn] +makeDerivEqns :: Module -> [RenamedTyClDecl] -> TcM [DerivEqn] -makeDerivEqns - = tcGetEnv `thenNF_Tc` \ env -> - tcLookupClassByKey evalClassKey `thenNF_Tc` \ eval_clas -> - let - tycons = filter isDataTyCon (getEnv_TyCons env) - -- ToDo: what about newtypes??? - think_about_deriving = need_deriving eval_clas tycons - in - mapTc chk_out think_about_deriving `thenTc_` - let - (derive_these, _) = removeDups cmp_deriv think_about_deriving - eqns = map mk_eqn derive_these - in - returnTc eqns +makeDerivEqns this_mod tycl_decls + = mapTc mk_eqn derive_these `thenTc` \ maybe_eqns -> + returnTc (catMaybes maybe_eqns) where ------------------------------------------------------------------ - need_deriving :: Class -> [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 - ) - [] - tycons_to_consider + derive_these :: [(Name, Name)] + -- Find the (Class,TyCon) pairs that must be `derived' + -- NB: only source-language decls have deriving, no imported ones do + derive_these = [ (clas,tycon) + | TyData _ _ tycon _ _ _ (Just classes) _ _ _ <- tycl_decls, + clas <- nub classes ] ------------------------------------------------------------------ - 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) + mk_eqn :: (Name, Name) -> NF_TcM (Maybe DerivEqn) + -- we swizzle the tyvars and datacons out of the tycon + -- to make the rest of the equation - chk_clas clas_uniq clas_str cond - = if (clas_uniq == clas_key) - then checkTc cond (derivingThingErr clas_str tycon) - else returnTc () - in - -- Are things OK for deriving Enum (if appropriate)? - chk_clas enumClassKey "Enum" is_enumeration `thenTc_` + mk_eqn (clas_name, tycon_name) + = tcLookupClass clas_name `thenNF_Tc` \ clas -> + tcLookupTyCon tycon_name `thenNF_Tc` \ tycon -> + let + clas_key = classKey clas + tyvars = tyConTyVars tycon + tyvar_tys = mkTyVarTys tyvars + ty = mkTyConApp tycon tyvar_tys + data_cons = tyConDataCons tycon + locn = getSrcLoc tycon + constraints = extra_constraints ++ concat (map mk_constraints data_cons) + + -- "extra_constraints": see notes above about contexts on data decls + extra_constraints + | offensive_class = tyConTheta tycon + | otherwise = [] - -- Are things OK for deriving Bounded (if appropriate)? - chk_clas boundedClassKey "Bounded" - (is_enumeration || is_single_con) `thenTc_` + offensive_class = clas_key `elem` needsDataDeclCtxtClassKeys + + mk_constraints data_con + = [ (clas, [arg_ty]) + | arg_ty <- dataConArgTys data_con tyvar_tys, + not (isUnboxedType arg_ty) -- No constraints for unboxed types? + ] + in + case chk_out clas tycon of + Just err -> addErrTc err `thenNF_Tc_` + returnNF_Tc Nothing + Nothing -> newDFunName this_mod clas [ty] locn `thenNF_Tc` \ dfun_name -> + returnNF_Tc (Just (dfun_name, clas, tycon, tyvars, constraints)) - -- Are things OK for deriving Ix (if appropriate)? - chk_clas ixClassKey "Ix.Ix" (is_enumeration || is_single_con) - ------------------------------------------------------------------ - cmp_deriv :: (Class, TyCon) -> (Class, TyCon) -> TAG_ - cmp_deriv (c1, t1) (c2, t2) - = (c1 `cmp` c2) `thenCmp` (t1 `cmp` t2) ------------------------------------------------------------------ - mk_eqn :: (Class, TyCon) -> 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) - 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) + 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 - -- "extra_constraints": see notes above about contexts on data decls - extra_constraints - | offensive_class = tyConTheta tycon - | otherwise = [] - where - offensive_class = clas_key `elem` needsDataDeclCtxtClassKeys + 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") - mk_constraints data_con - = [ (clas, arg_ty) - | arg_ty <- instd_arg_tys, - not (isPrimType arg_ty) -- No constraints for primitive types - ] - where - instd_arg_tys = dataConArgTys data_con tyvar_tys + bog_out why = Just (derivingThingErr clas tycon why) \end{code} %************************************************************************ @@ -386,12 +368,12 @@ ordered by sorting on type varible, tv, (major key) and then class, k, \end{itemize} \begin{code} -solveDerivEqns :: Bag InstInfo +solveDerivEqns :: InstEnv -> [DerivEqn] - -> TcM s [InstInfo] -- Solns in same order as eqns. - -- This bunch is Absolutely minimal... + -> TcM [DFunId] -- Solns in same order as eqns. + -- This bunch is Absolutely minimal... -solveDerivEqns inst_decl_infos_in orig_eqns +solveDerivEqns inst_env_in orig_eqns = iterateDeriv initial_solutions where -- The initial solutions for the equations claim that each @@ -400,96 +382,63 @@ solveDerivEqns inst_decl_infos_in orig_eqns initial_solutions :: [DerivSoln] initial_solutions = [ [] | _ <- orig_eqns ] + ------------------------------------------------------------------ -- iterateDeriv calculates the next batch of solutions, -- compares it with the current one; finishes if they are the -- same, otherwise recurses with the new solutions. - - iterateDeriv :: [DerivSoln] ->TcM s [InstInfo] - + -- It fails if any iteration fails + iterateDeriv :: [DerivSoln] ->TcM [DFunId] iterateDeriv current_solns + = checkNoErrsTc (iterateOnce current_solns) + `thenTc` \ (new_dfuns, new_solns) -> + if (current_solns == new_solns) then + returnTc new_dfuns + else + iterateDeriv new_solns + + ------------------------------------------------------------------ + iterateOnce current_solns = -- Extend the inst info from the explicit instance decls -- with the current set of solutions, giving a - - add_solns inst_decl_infos_in orig_eqns current_solns - `thenTc` \ (new_inst_infos, inst_mapper) -> - let - class_to_inst_env cls = fst (inst_mapper cls) - in + getDOptsTc `thenTc` \ dflags -> + let (new_dfuns, inst_env) = + add_solns dflags inst_env_in orig_eqns current_solns + in -- Simplify each RHS - - listTc [ tcSimplifyThetas class_to_inst_env [{-Nothing "given"-}] deriv_rhs - | (_,_,_,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 - = [ sortLt lt_rhs next_soln | next_soln <- next_solns ] in - - if (current_solns `eq_solns` canonicalised_next_solns) then - returnTc new_inst_infos - else - iterateDeriv canonicalised_next_solns - - where - ------------------------------------------------------------------ - lt_rhs r1 r2 = case cmp_rhs r1 r2 of { LT_ -> True; _ -> False } - eq_solns s1 s2 = case cmp_solns s1 s2 of { EQ_ -> True; _ -> False } - cmp_solns s1 s2 = cmpList (cmpList cmp_rhs) s1 s2 - cmp_rhs (c1, TyVarTy tv1) (c2, TyVarTy tv2) - = (tv1 `cmp` tv2) `thenCmp` (c1 `cmp` c2) -#ifdef DEBUG - cmp_rhs other_1 other_2 - = pprPanic# "tcDeriv:cmp_rhs:" (ppCat [ppr PprDebug other_1, ppr PprDebug other_2]) -#endif - + let canonicalised_next_solns = [ sortLt (<) next_soln | next_soln <- next_solns ] + in + returnTc (new_dfuns, canonicalised_next_solns) \end{code} \begin{code} -add_solns :: Bag InstInfo -- The global, non-derived ones +add_solns :: DynFlags + -> InstEnv -- The global, non-derived ones -> [DerivEqn] -> [DerivSoln] - -> TcM s ([InstInfo], -- The new, derived ones - InstanceMapper) + -> ([DFunId], 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 - = buildInstanceEnvs all_inst_infos `thenTc` \ inst_mapper -> - returnTc (new_inst_infos, inst_mapper) - where - new_inst_infos = zipWithEqual "add_solns" mk_deriv_inst_info eqns solns - - all_inst_infos = inst_infos_in `unionBags` listToBag new_inst_infos +add_solns dflags inst_env_in eqns solns + = (new_dfuns, inst_env) + where + new_dfuns = zipWithEqual "add_solns" mk_deriv_dfun eqns solns + (inst_env, _) = extendInstEnv dflags inst_env_in new_dfuns + -- Ignore the errors about duplicate instances. + -- We don't want repeated error messages + -- They'll appear later, when we do the top-level extendInstEnvs - mk_deriv_inst_info (clas, tycon, tyvars, _) theta - = InstInfo clas tyvars (applyTyCon tycon (mkTyVarTys tyvars)) - theta - (my_panic "dfun_theta") + mk_deriv_dfun (dfun_name, clas, tycon, tyvars, _) theta + = mkDictFunId dfun_name clas tyvars [mkTyConApp tycon (mkTyVarTys tyvars)] + (map pair2PredType theta) - dummy_dfun_id - - (my_panic "const_meth_ids") - (my_panic "binds") (my_panic "from_here") - (my_panic "modname") mkGeneratedSrcLoc - (my_panic "upragmas") - where - dummy_dfun_id - = mkDictFunId bottom bottom bottom dummy_dfun_ty - bottom bottom bottom bottom - where - bottom = panic "dummy_dfun_id" - - 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, - -- but that'll be added after the equations are solved. For now, - -- it's enough just to make a dummy dfun with the simple theta part. - -- - -- The part after the theta is dummied here as voidTy; actually it's - -- (C (T a b)), but it doesn't seem worth constructing it. - -- We can't leave it as a panic because to get the theta part we - -- have to run down the type! - - my_panic str = pprPanic ("add_soln:"++str) (ppCat [ppChar ':', ppr PprDebug clas, ppr PprDebug tycon]) + pair2PredType (clas, tautypes) = Class clas tautypes \end{code} %************************************************************************ @@ -555,142 +504,41 @@ the renamer. What a great hack! \end{itemize} \begin{code} -gen_inst_info :: Module -- Module name - -> [RenamedFixityDecl] -- all known fixities; - -- may be needed for Text - -> RnEnv -- lookup stuff for names we may use - -> InstInfo -- the main stuff to work on - -> TcM s InstInfo -- the gen'd (filled-in) "instance decl" - -gen_inst_info modname fixities deriver_rn_env - (InstInfo clas tyvars ty inst_decl_theta _ _ _ _ _ _ locn _) - = - -- Generate the various instance-related Ids - mkInstanceRelatedIds - True {-from_here-} locn modname - NoInstancePragmas - clas tyvars ty - inst_decl_theta - [{-no user pragmas-}] - `thenTc` \ (dfun_id, dfun_theta, const_meth_ids) -> - - -- Generate the bindings for the new instance declaration, - -- rename it, and check for errors - let - (tycon,_,_) = --pprTrace "gen_inst_info:ty" (ppCat[ppr PprDebug clas, ppr PprDebug ty]) $ - getAppDataTyCon ty - - proto_mbinds - = assoc "gen_inst_info: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 fixities) - ,(readClassKey, gen_Read_binds fixities) - ,(ixClassKey, gen_Ix_binds) - ] - clas_key $ tycon - in -{- - let - ((qual, unqual, tc_qual, tc_unqual), stack) = deriver_rn_env - in - pprTrace "gen_inst:qual:" (ppCat [ppBesides[ppPStr m,ppChar '.',ppPStr n] | (n,m) <- keysFM qual]) $ - pprTrace "gen_inst:unqual:" (ppCat (map ppPStr (keysFM unqual))) $ - pprTrace "gen_inst:tc_qual:" (ppCat [ppBesides[ppPStr m,ppChar '.',ppPStr n] | (n,m) <- keysFM tc_qual]) $ - pprTrace "gen_inst:tc_unqual:" (ppCat (map ppPStr (keysFM tc_unqual))) $ --} - -- pprTrace "derived binds:" (ppr PprDebug proto_mbinds) $ - - rnMtoTcM deriver_rn_env ( - setExtraRn emptyUFM{-no fixities-} $ - rnMethodBinds clas_Name proto_mbinds - ) `thenNF_Tc` \ (mbinds, errs) -> - - if not (isEmptyBag errs) then - pprPanic "gen_inst_info:renamer errs!\n" - (ppAbove (pprBagOfErrors PprDebug errs) (ppr PprDebug proto_mbinds)) - else - -- All done - let - from_here = isLocallyDefined tycon -- If so, then from here - in - returnTc (InstInfo clas tyvars ty inst_decl_theta - dfun_theta dfun_id const_meth_ids - (if from_here then mbinds else EmptyMonoBinds) - from_here modname locn []) +-- Generate the method bindings for the required instance +-- (paired with class name, as we need that when generating dict +-- names.) +gen_bind :: (Name -> Maybe Fixity) -> DFunId -> RdrNameMonoBinds +gen_bind get_fixity dfun + | clas `hasKey` showClassKey = gen_Show_binds get_fixity tycon + | clas `hasKey` readClassKey = gen_Read_binds get_fixity tycon + | otherwise + = assoc "gen_bind:bad derived class" + [(eqClassKey, gen_Eq_binds) + ,(ordClassKey, gen_Ord_binds) + ,(enumClassKey, gen_Enum_binds) + ,(boundedClassKey, gen_Bounded_binds) + ,(ixClassKey, gen_Ix_binds) + ] + (classKey clas) + tycon where - clas_key = classKey clas - clas_Name = RnImplicitClass (mkImplicitName clas_key (origName "gen_inst_info" clas)) + (clas, tycon) = simpleDFunClassTyCon dfun \end{code} + %************************************************************************ %* * -\subsection[TcGenDeriv-con2tag-tag2con]{Generating extra binds (@con2tag@ and @tag2con@)} +\subsection[TcDeriv-taggery-Names]{What con2tag/tag2con functions are available?} %* * %************************************************************************ + data Foo ... = ... con2tag_Foo :: Foo ... -> Int# tag2con_Foo :: Int -> Foo ... -- easier if Int, not Int# maxtag_Foo :: Int -- ditto (NB: not unboxed) -\begin{code} -gen_tag_n_con_binds :: RnEnv - -> [(RdrName, TyCon, TagThingWanted)] - -> TcM s (RenamedHsBinds, - RnEnv) -- input one with any new names added - -gen_tag_n_con_binds rn_env nm_alist_etc - = - let - -- We have the renamer's final "name funs" in our hands - -- (they were passed in). So we can handle ProtoNames - -- that refer to anything "out there". But our generated - -- code may also mention "con2tag" (etc.). So we need - -- to augment to "name funs" to include those. - - names_to_add = [ pn | (pn,_,_) <- nm_alist_etc ] - in - tcGetUniques (length names_to_add) `thenNF_Tc` \ uniqs -> - let - pairs_to_add = [ case pn of { Qual pnm pnn -> - (pn, mkRnName (mkTopLevName u (OrigName pnm pnn) mkGeneratedSrcLoc ExportAll [])) } - | (pn,u) <- zipEqual "gen_tag..." names_to_add uniqs ] - - deriver_rn_env - = if null names_to_add - then rn_env else added_rn_env - - (added_rn_env, errs_bag) - = extendGlobalRnEnv rn_env pairs_to_add [{-no tycons-}] - - ---------------- - proto_mbind_list = map gen_tag_n_con_monobind nm_alist_etc - proto_mbinds = foldr AndMonoBinds EmptyMonoBinds proto_mbind_list - in - ASSERT(isEmptyBag errs_bag) - - rnMtoTcM deriver_rn_env ( - setExtraRn emptyUFM{-no fixities-} $ - rnTopBinds (SingleBind (RecBind proto_mbinds)) - ) `thenNF_Tc` \ (binds, errs) -> - - if not (isEmptyBag errs) then - pprPanic "gen_tag_n_con_binds:renamer errs!\n" - (ppAbove (pprBagOfErrors PprDebug errs) (ppr PprDebug binds)) - else - returnTc (binds, deriver_rn_env) -\end{code} - -%************************************************************************ -%* * -\subsection[TcDeriv-taggery-Names]{What con2tag/tag2con functions are available?} -%* * -%************************************************************************ We have a @con2tag@ function for a tycon if: \begin{itemize} @@ -711,45 +559,43 @@ We're deriving @Enum@, or @Ix@ (enum type only???) If we have a @tag2con@ function, we also generate a @maxtag@ constant. \begin{code} -gen_taggery_Names :: [InstInfo] - -> TcM s [(RdrName, -- for an assoc list - TyCon, -- related tycon - TagThingWanted)] - -gen_taggery_Names inst_infos - = --pprTrace "gen_taggery:\n" (ppAboves [ppCat [ppr PprDebug c, ppr PprDebug t] | (c,t) <- all_CTs]) $ - foldlTc do_con2tag [] tycons_of_interest `thenTc` \ names_so_far -> +gen_taggery_Names :: [DFunId] + -> TcM [(RdrName, -- for an assoc list + TyCon, -- related tycon + TagThingWanted)] + +gen_taggery_Names dfuns + = foldlTc do_con2tag [] tycons_of_interest `thenTc` \ names_so_far -> foldlTc do_tag2con names_so_far tycons_of_interest where - all_CTs = [ mk_CT c ty | (InstInfo c _ ty _ _ _ _ _ _ _ _ _) <- inst_infos ] - - mk_CT c ty = (c, fst (getAppTyCon ty)) - - all_tycons = map snd all_CTs - (tycons_of_interest, _) = removeDups cmp all_tycons + all_CTs = map simpleDFunClassTyCon dfuns + all_tycons = map snd all_CTs + (tycons_of_interest, _) = removeDups compare all_tycons do_con2tag acc_Names tycon - = if (we_are_deriving eqClassKey tycon + | isDataTyCon tycon && + ((we_are_deriving eqClassKey tycon && any isNullaryDataCon (tyConDataCons tycon)) - || (we_are_deriving ordClassKey tycon + || (we_are_deriving ordClassKey tycon && not (maybeToBool (maybeTyConSingleCon tycon))) - || (we_are_deriving enumClassKey tycon) - || (we_are_deriving ixClassKey tycon) - then - returnTc ((con2tag_PN tycon, tycon, GenCon2Tag) + || (we_are_deriving enumClassKey tycon) + || (we_are_deriving ixClassKey tycon)) + + = returnTc ((con2tag_RDR tycon, tycon, GenCon2Tag) : acc_Names) - else - returnTc acc_Names + | otherwise + = returnTc acc_Names do_tag2con acc_Names tycon - = if (we_are_deriving enumClassKey tycon) - || (we_are_deriving ixClassKey tycon) - then - returnTc ( (tag2con_PN tycon, tycon, GenTag2Con) - : (maxtag_PN 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 @@ -758,13 +604,20 @@ gen_taggery_Names inst_infos is_in_eqns clas_key tycon ((c,t):cts) = (clas_key == classKey c && tycon == t) || is_in_eqns clas_key tycon cts - \end{code} \begin{code} -derivingThingErr :: String -> TyCon -> Error +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)] + +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)")] -derivingThingErr thing tycon sty - = ppHang (ppCat [ppStr "Can't make a derived instance of", ppStr thing]) - 4 (ppBesides [ppStr "for the type `", ppr sty tycon, ppStr "'"]) +derivCtxt tycon + = ptext SLIT("When deriving classes for") <+> quotes (ppr tycon) \end{code}