X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcInstDcls.lhs;h=d59e0d5ba3e0804157f61cc4c87cecb5b5fc5343;hb=e47dd5d2e5e6dadec89fd0c36d53a14e686dcbfa;hp=85d60717917ef96a37b9a1dd88a6bf0357baf0f3;hpb=2c8f04b5b883db74f449dfc8c224929fe28b027d;p=ghc-hetmet.git diff --git a/ghc/compiler/typecheck/TcInstDcls.lhs b/ghc/compiler/typecheck/TcInstDcls.lhs index 85d6071..d59e0d5 100644 --- a/ghc/compiler/typecheck/TcInstDcls.lhs +++ b/ghc/compiler/typecheck/TcInstDcls.lhs @@ -13,16 +13,17 @@ module TcInstDcls ( import HsSyn ( HsDecl(..), InstDecl(..), HsBinds(..), MonoBinds(..), GRHSsAndBinds(..), GRHS(..), - HsExpr(..), InPat(..), HsLit(..), + HsExpr(..), InPat(..), HsLit(..), Sig(..), unguardedRHS, collectMonoBinders, andMonoBinds ) +import HsBinds ( sigsForMe ) import RnHsSyn ( RenamedHsBinds, RenamedMonoBinds, RenamedInstDecl, RenamedHsExpr, RenamedSig, RenamedHsDecl ) import TcHsSyn ( TcMonoBinds, TcIdOcc(..), TcIdBndr, - maybeBoxedPrimType + maybeBoxedPrimType, tcIdType ) import TcBinds ( tcPragmaSigs ) @@ -46,13 +47,13 @@ import Bag ( emptyBag, unitBag, unionBags, unionManyBags, ) import CmdLineOpts ( opt_GlasgowExts, opt_WarnMissingMethods ) import Class ( classBigSig, Class ) -import Id ( isNullaryDataCon, dataConArgTys, Id ) +import Id ( isNullaryDataCon, dataConArgTys, replaceIdInfo, idName, Id ) import Maybes ( maybeToBool, seqMaybe, catMaybes ) import Name ( nameOccName, mkLocalName, isLocallyDefined, Module, NamedThing(..) ) -import PrelVals ( nO_METHOD_BINDING_ERROR_ID ) +import PrelVals ( nO_METHOD_BINDING_ERROR_ID, eRROR_ID ) import PprType ( pprParendType, pprConstraint ) import SrcLoc ( SrcLoc, noSrcLoc ) import TyCon ( isSynTyCon, isDataTyCon, tyConDerivings ) @@ -329,7 +330,6 @@ tcInstDecl2 (InstInfo clas inst_tyvars inst_tys tcInstTheta tenv inst_decl_theta `thenNF_Tc` \ inst_decl_theta' -> -- Instantiate the super-class context with inst_tys - tcInstTheta (zipTyVarEnv class_tyvars inst_tys') sc_theta `thenNF_Tc` \ sc_theta' -> -- Create dictionary Ids from the specified instance contexts. @@ -338,10 +338,6 @@ tcInstDecl2 (InstInfo clas inst_tyvars inst_tys newDicts origin inst_decl_theta' `thenNF_Tc` \ (inst_decl_dicts, _) -> newDicts origin [(clas,inst_tys')] `thenNF_Tc` \ (this_dict, [this_dict_id]) -> - -- Now process any INLINE or SPECIALIZE pragmas for the methods - -- ...[NB May 97; all ignored except INLINE] - tcPragmaSigs uprags `thenTc` \ (prag_fn, spec_binds, spec_lie) -> - -- Check that all the method bindings come from this class let check_from_this_class (bndr, loc) @@ -356,10 +352,18 @@ tcInstDecl2 (InstInfo clas inst_tyvars inst_tys tcExtendGlobalValEnv (catMaybes defm_ids) ( -- Default-method Ids may be mentioned in synthesised RHSs - mapAndUnzip3Tc (tcInstMethodBind clas inst_tys' inst_tyvars' monobinds) + mapAndUnzip3Tc (tcInstMethodBind clas inst_tys' inst_tyvars' monobinds uprags) (op_sel_ids `zip` defm_ids) ) `thenTc` \ (method_binds_s, insts_needed_s, meth_lies_w_ids) -> + -- Deal with SPECIALISE instance pragmas + let + dfun_prags = [Sig (idName dfun_id) ty loc | SpecInstSig ty loc <- uprags] + in + tcExtendGlobalValEnv [dfun_id] ( + tcPragmaSigs dfun_prags + ) `thenTc` \ (prag_info_fn, prag_binds, prag_lie) -> + -- Check the overloading constraints of the methods and superclasses mapNF_Tc zonkSigTyVar inst_tyvars' `thenNF_Tc` \ zonked_inst_tyvars -> @@ -409,33 +413,51 @@ tcInstDecl2 (InstInfo clas inst_tyvars inst_tys inst_tyvars_set dfun_arg_dicts -- NB! Don't include this_dict here, else the sc_dicts -- get bound by just selecting from this_dict!! - (sc_dicts `plusLIE` methods_lie) + (sc_dicts `plusLIE` methods_lie `plusLIE` prag_lie) ) `thenTc` \ (const_lie, lie_binds) -> -- Create the result bindings let - dict_constr = classDataCon clas - - con_app = foldl HsApp (TyApp (HsVar (RealId dict_constr)) inst_tys') - (map HsVar (sc_dict_ids ++ meth_ids)) + dict_constr = classDataCon clas + scs_and_meths = sc_dict_ids ++ meth_ids + + dict_rhs + | null scs_and_meths + = -- Blatant special case for CCallable, CReturnable + -- If the dictionary is empty then we should never + -- select anything from it, so we make its RHS just + -- emit an error message. This in turn means that we don't + -- mention the constructor, which doesn't exist for CCallable, CReturnable + -- Hardly beautiful, but only three extra lines. + HsApp (TyApp (HsVar (RealId eRROR_ID)) [tcIdType this_dict_id]) + (HsLitOut (HsString msg) stringTy) + + | otherwise -- The common case + = foldl HsApp (TyApp (HsVar (RealId dict_constr)) inst_tys') + (map HsVar (sc_dict_ids ++ meth_ids)) -- We don't produce a binding for the dict_constr; instead we -- rely on the simplifier to unfold this saturated application + where + msg = _PK_ ("Compiler error: bad dictionary " ++ showSDoc (ppr clas)) - dict_bind = VarMonoBind this_dict_id con_app + dict_bind = VarMonoBind this_dict_id dict_rhs method_binds = andMonoBinds method_binds_s + final_dfun_id = replaceIdInfo dfun_id (prag_info_fn (idName dfun_id)) + -- Pretty truesome main_bind = AbsBinds zonked_inst_tyvars dfun_arg_dicts_ids - [(inst_tyvars', RealId dfun_id, this_dict_id)] + [(inst_tyvars', RealId final_dfun_id, this_dict_id)] (lie_binds `AndMonoBinds` method_binds `AndMonoBinds` + prag_binds `AndMonoBinds` dict_bind) in - returnTc (const_lie `plusLIE` spec_lie, - main_bind `AndMonoBinds` spec_binds) + returnTc (const_lie, + main_bind `AndMonoBinds` prag_binds) \end{code} @@ -451,30 +473,33 @@ tcInstMethodBind -> [TcType s] -- Instance types -> [TcTyVar s] -- and their free (sig) tyvars -> RenamedMonoBinds -- Method binding + -> [RenamedSig] -- Pragmas -> (Id, Maybe Id) -- Selector id and default-method id -> TcM s (TcMonoBinds s, LIE s, (LIE s, TcIdOcc s)) -tcInstMethodBind clas inst_tys inst_tyvars meth_binds (sel_id, maybe_dm_id) +tcInstMethodBind clas inst_tys inst_tyvars meth_binds prags (sel_id, maybe_dm_id) = tcGetSrcLoc `thenNF_Tc` \ loc -> tcGetUnique `thenNF_Tc` \ uniq -> let - meth_occ = getOccName sel_id + sel_name = idName sel_id + meth_occ = getOccName sel_name default_meth_name = mkLocalName uniq meth_occ loc maybe_meth_bind = find meth_occ meth_binds the_meth_bind = case maybe_meth_bind of Just stuff -> stuff Nothing -> mk_default_bind default_meth_name loc + meth_prags = sigsForMe (== sel_name) prags in -- Warn if no method binding, only if -fwarn-missing-methods - warnTc (opt_WarnMissingMethods && + warnTc (opt_WarnMissingMethods && not (maybeToBool maybe_meth_bind) && not (maybeToBool maybe_dm_id)) (omittedMethodWarn sel_id clas) `thenNF_Tc_` -- Typecheck the method binding - tcMethodBind clas origin inst_tys inst_tyvars sel_id the_meth_bind + tcMethodBind clas origin inst_tys inst_tyvars sel_id the_meth_bind meth_prags where origin = InstanceDeclOrigin -- Poor @@ -503,150 +528,16 @@ tcInstMethodBind clas inst_tys inst_tyvars meth_binds (sel_id, maybe_dm_id) (HsLit (HsString (_PK_ (error_msg loc)))) error_msg loc = showSDoc (hcat [ppr loc, text "|", ppr sel_id ]) - \end{code} %************************************************************************ %* * -\subsection{Type-checking specialise instance pragmas} +\subsection{Checking for a decent instance type} %* * %************************************************************************ -\begin{code} -{- LATER -tcSpecInstSigs :: E -> CE -> TCE - -> Bag InstInfo -- inst decls seen (declared and derived) - -> [RenamedSpecInstSig] -- specialise instance upragmas - -> TcM (Bag InstInfo) -- new, overlapped, inst decls - -tcSpecInstSigs e ce tce inst_infos [] - = returnTc emptyBag - -tcSpecInstSigs e ce tce inst_infos sigs - = buildInstanceEnvs inst_infos `thenTc` \ inst_mapper -> - tc_inst_spec_sigs inst_mapper sigs `thenNF_Tc` \ spec_inst_infos -> - returnTc spec_inst_infos - where - tc_inst_spec_sigs inst_mapper [] - = returnNF_Tc emptyBag - tc_inst_spec_sigs inst_mapper (sig:sigs) - = tcSpecInstSig e ce tce inst_infos inst_mapper sig `thenNF_Tc` \ info_sig -> - tc_inst_spec_sigs inst_mapper sigs `thenNF_Tc` \ info_sigs -> - returnNF_Tc (info_sig `unionBags` info_sigs) - -tcSpecInstSig :: E -> CE -> TCE - -> Bag InstInfo - -> InstanceMapper - -> RenamedSpecInstSig - -> NF_TcM (Bag InstInfo) - -tcSpecInstSig e ce tce inst_infos inst_mapper (SpecInstSig class_name ty src_loc) - = recoverTc emptyBag ( - tcAddSrcLoc src_loc ( - let - clas = lookupCE ce class_name -- Renamer ensures this can't fail - - -- Make some new type variables, named as in the specialised instance type - ty_names = extractHsTyNames ???is_tyvarish_name??? ty - (tmpl_e,inst_tmpls,inst_tmpl_tys) = mkTVE ty_names - in - babyTcMtoTcM (tcInstanceType ce tce tmpl_e True src_loc ty) - `thenTc` \ inst_ty -> - let - maybe_tycon = case splitAlgTyConApp_maybe inst_ty of - Just (tc,_,_) -> Just tc - Nothing -> Nothing - - maybe_unspec_inst = lookup_unspec_inst clas maybe_tycon inst_infos - in - -- Check that we have a local instance declaration to specialise - checkMaybeTc maybe_unspec_inst - (specInstUnspecInstNotFoundErr clas inst_ty src_loc) `thenTc_` - - -- Create tvs to substitute for tmpls while simplifying the context - copyTyVars inst_tmpls `thenNF_Tc` \ (tv_e, inst_tvs, inst_tv_tys) -> - let - Just (InstInfo _ unspec_tyvars unspec_inst_ty unspec_theta - _ _ binds _ uprag) = maybe_unspec_inst - - subst = case matchTy unspec_inst_ty inst_ty of - Just subst -> subst - Nothing -> panic "tcSpecInstSig:matchTy" - - subst_theta = instantiateThetaTy subst unspec_theta - subst_tv_theta = instantiateThetaTy tv_e subst_theta - - mk_spec_origin clas ty - = InstanceSpecOrigin inst_mapper clas ty src_loc - -- I'm VERY SUSPICIOUS ABOUT THIS - -- the inst-mapper is in a knot at this point so it's no good - -- looking at it in tcSimplify... - in - tcSimplifyThetas mk_spec_origin subst_tv_theta - `thenTc` \ simpl_tv_theta -> - let - simpl_theta = [ (clas, tv_to_tmpl tv) | (clas, tv) <- simpl_tv_theta ] - - tv_tmpl_map = zipEqual "tcSpecInstSig" inst_tv_tys inst_tmpl_tys - tv_to_tmpl tv = assoc "tcSpecInstSig" tv_tmpl_map tv - in - mkInstanceRelatedIds clas inst_tmpls inst_ty simpl_theta uprag - `thenNF_Tc` \ (dfun_id, dfun_theta, const_meth_ids) -> - - getSwitchCheckerTc `thenNF_Tc` \ sw_chkr -> - (if sw_chkr SpecialiseTrace then - pprTrace "Specialised Instance: " - (vcat [hsep [if null simpl_theta then empty else ppr simpl_theta, - if null simpl_theta then empty else ptext SLIT("=>"), - ppr clas, - pprParendType inst_ty], - hsep [ptext SLIT(" derived from:"), - if null unspec_theta then empty else ppr unspec_theta, - if null unspec_theta then empty else ptext SLIT("=>"), - ppr clas, - pprParendType unspec_inst_ty]]) - else id) ( - - returnTc (unitBag (InstInfo clas inst_tmpls inst_ty simpl_theta - dfun_theta dfun_id - binds src_loc uprag)) - ))) - - -lookup_unspec_inst clas maybe_tycon inst_infos - = case filter (match_info match_inst_ty) (bagToList inst_infos) of - [] -> Nothing - (info:_) -> Just info - where - match_info match_ty (InstInfo inst_clas _ inst_ty _ _ _ _ _ from_here _ _ _) - = from_here && clas == inst_clas && - match_ty inst_ty && is_plain_instance inst_ty - - match_inst_ty = case maybe_tycon of - Just tycon -> match_tycon tycon - Nothing -> match_fun - - match_tycon tycon inst_ty = case (splitAlgTyConApp_maybe inst_ty) of - Just (inst_tc,_,_) -> tycon == inst_tc - Nothing -> False - - match_fun inst_ty = isFunType inst_ty - - -is_plain_instance inst_ty - = case (splitAlgTyConApp_maybe inst_ty) of - Just (_,tys,_) -> all isTyVarTemplateTy tys - Nothing -> case maybeUnpackFunTy inst_ty of - Just (arg, res) -> isTyVarTemplateTy arg && isTyVarTemplateTy res - Nothing -> error "TcInstDecls:is_plain_instance" --} -\end{code} - - -Checking for a decent instance type -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @scrutiniseInstanceType@ checks the type {\em and} its syntactic constraints: it must normally look like: @instance Foo (Tycon a b c ...) ...@