X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FbasicTypes%2FMkId.lhs;h=1c25d8125ee982542bb27d15553eb31691bef1c3;hp=8f71aabf065113789db7d6e5d25f4cce928a53fd;hb=6fcf90065dc4e75b7dc6bbf238a9891a71ae5a86;hpb=0119bfdc7ae348c0f45b591391d1b68bc6bd8cc8 diff --git a/compiler/basicTypes/MkId.lhs b/compiler/basicTypes/MkId.lhs index 8f71aab..1c25d81 100644 --- a/compiler/basicTypes/MkId.lhs +++ b/compiler/basicTypes/MkId.lhs @@ -20,12 +20,13 @@ module MkId ( mkRecordSelId, mkPrimOpId, mkFCallId, - mkReboxingAlt, mkNewTypeBody, + mkReboxingAlt, wrapNewTypeBody, unwrapNewTypeBody, + mkUnpackCase, mkProductBox, -- And some particular Ids; see below for why they are wired in wiredInIds, ghcPrimIds, unsafeCoerceId, realWorldPrimId, voidArgId, nullAddrId, seqId, - lazyId, lazyIdUnfolding, lazyIdKey, + lazyId, lazyIdUnfolding, lazyIdKey, mkRuntimeErrorApp, rEC_CON_ERROR_ID, iRREFUT_PAT_ERROR_ID, rUNTIME_ERROR_ID, @@ -45,7 +46,9 @@ import TysPrim ( openAlphaTyVars, alphaTyVar, alphaTy, ) import TysWiredIn ( charTy, mkListTy ) import PrelRules ( primOpRules ) -import Type ( TyThing(..), mkForAllTy, tyVarsOfTypes ) +import Type ( TyThing(..), mkForAllTy, tyVarsOfTypes, newTyConInstRhs, coreEqType ) +import Coercion ( mkSymCoercion, mkUnsafeCoercion, + splitNewTypeRepCo_maybe ) import TcType ( Type, ThetaType, mkDictTy, mkPredTys, mkPredTy, mkTyConApp, mkTyVarTys, mkClassPred, mkFunTys, mkFunTy, mkSigmaTy, tcSplitSigmaTy, @@ -56,24 +59,25 @@ import CoreUtils ( exprType ) import CoreUnfold ( mkTopUnfolding, mkCompulsoryUnfolding ) import Literal ( nullAddrLit, mkStringLit ) import TyCon ( TyCon, isNewTyCon, tyConDataCons, FieldLabel, - tyConStupidTheta, isProductTyCon, isDataTyCon, isRecursiveTyCon ) + tyConStupidTheta, isProductTyCon, isDataTyCon, isRecursiveTyCon, + newTyConCo, tyConArity ) import Class ( Class, classTyCon, classSelIds ) -import Var ( Id, TyVar, Var ) +import Var ( Id, TyVar, Var, setIdType ) import VarSet ( isEmptyVarSet, subVarSet, varSetElems ) import Name ( mkFCallName, mkWiredInName, Name, BuiltInSyntax(..) ) import OccName ( mkOccNameFS, varName ) import PrimOp ( PrimOp, primOpSig, primOpOcc, primOpTag ) import ForeignCall ( ForeignCall ) -import DataCon ( DataCon, DataConIds(..), dataConTyVars, +import DataCon ( DataCon, DataConIds(..), dataConTyCon, dataConUnivTyVars, dataConFieldLabels, dataConRepArity, dataConResTys, dataConRepArgTys, dataConRepType, dataConSig, dataConStrictMarks, dataConExStricts, splitProductType, isVanillaDataCon, dataConFieldType, - dataConInstOrigArgTys + dataConInstOrigArgTys, deepSplitProductType ) import Id ( idType, mkGlobalId, mkVanillaGlobal, mkSysLocal, mkTemplateLocals, mkTemplateLocalsNum, mkExportedLocalId, - mkTemplateLocal, idName + mkTemplateLocal, idName, mkWildId ) import IdInfo ( IdInfo, noCafIdInfo, setUnfoldingInfo, setArityInfo, setSpecInfo, setCafInfo, @@ -184,8 +188,6 @@ Notice that \begin{code} mkDataConIds :: Name -> Name -> DataCon -> DataConIds - -- Makes the *worker* for the data constructor; that is, the function - -- that takes the reprsentation arguments and builds the constructor. mkDataConIds wrap_name wkr_name data_con | isNewTyCon tycon = NewDC nt_wrap_id @@ -196,18 +198,23 @@ mkDataConIds wrap_name wkr_name data_con | otherwise -- Algebraic, no wrapper = AlgDC Nothing wrk_id where - (tyvars, theta, orig_arg_tys, tycon, res_tys) = dataConSig data_con + (tvs, theta, orig_arg_tys) = dataConSig data_con + tycon = dataConTyCon data_con dict_tys = mkPredTys theta all_arg_tys = dict_tys ++ orig_arg_tys - result_ty = mkTyConApp tycon res_tys + tycon_args = dataConUnivTyVars data_con + result_ty_args = (mkTyVarTys tycon_args) + result_ty = mkTyConApp tycon result_ty_args - wrap_ty = mkForAllTys tyvars (mkFunTys all_arg_tys result_ty) + wrap_ty = mkForAllTys tvs (mkFunTys all_arg_tys result_ty) -- We used to include the stupid theta in the wrapper's args -- but now we don't. Instead the type checker just injects these -- extra constraints where necessary. ----------- Worker (algebraic data types only) -------------- + -- The *worker* for the data constructor is the function that + -- takes the representation arguments and builds the constructor. wrk_id = mkGlobalId (DataConWorkId data_con) wkr_name (dataConRepType data_con) wkr_info @@ -253,8 +260,9 @@ mkDataConIds wrap_name wkr_name data_con -- No existentials on a newtype, but it can have a context -- e.g. newtype Eq a => T a = MkT (...) mkCompulsoryUnfolding $ - mkLams tyvars $ Lam id_arg1 $ - mkNewTypeBody tycon result_ty (Var id_arg1) + mkLams tvs $ Lam id_arg1 $ + wrapNewTypeBody tycon result_ty_args + (Var id_arg1) id_arg1 = mkTemplateLocal 1 (head orig_arg_tys) @@ -282,14 +290,14 @@ mkDataConIds wrap_name wkr_name data_con -- we want to see that w is strict in its two arguments alg_unf = mkTopUnfolding $ Note InlineMe $ - mkLams tyvars $ + mkLams tvs $ mkLams dict_args $ mkLams id_args $ foldr mk_case con_app (zip (dict_args ++ id_args) all_strict_marks) i3 [] con_app i rep_ids = mkApps (Var wrk_id) - (map varToCoreExpr (tyvars ++ reverse rep_ids)) + (map varToCoreExpr (tvs ++ reverse rep_ids)) (dict_args,i2) = mkLocals 1 dict_tys (id_args,i3) = mkLocals i2 orig_arg_tys @@ -310,14 +318,9 @@ mkDataConIds wrap_name wkr_name data_con Case (Var arg) arg result_ty [(DEFAULT,[], body i (arg:rep_args))] MarkedUnboxed - -> case splitProductType "do_unbox" (idType arg) of - (tycon, tycon_args, con, tys) -> - Case (Var arg) arg result_ty - [(DataAlt con, - con_args, - body i' (reverse con_args ++ rep_args))] - where - (con_args, i') = mkLocals i tys + -> unboxProduct i (Var arg) (idType arg) the_body result_ty + where + the_body i con_args = body i (reverse con_args ++ rep_args) mAX_CPR_SIZE :: Arity mAX_CPR_SIZE = 10 @@ -391,11 +394,13 @@ We obviously can't define Nevertheless we *do* put a RecordSelId into the type environment so that if the user tries to use 'x' as a selector we can bleat helpfully, rather than saying unhelpfully that 'x' is not in scope. -Hence the sel_naughty flag, to identify record selcectors that don't really exist. +Hence the sel_naughty flag, to identify record selectors that don't really exist. In general, a field is naughty if its type mentions a type variable that isn't in the result type of the constructor. +Note [GADT record selectors] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For GADTs, we require that all constructors with a common field 'f' have the same result type (modulo alpha conversion). [Checked in TcTyClsDecls.checkValidTyCon] E.g. @@ -424,7 +429,7 @@ mkRecordSelId tycon field_label | is_naughty = naughty_id | otherwise = sel_id where - is_naughty = not (tyVarsOfType field_ty `subVarSet` tyvar_set) + is_naughty = not (tyVarsOfType field_ty `subVarSet` res_tv_set) sel_id_details = RecordSelId tycon field_label is_naughty -- Escapist case here for naughty construcotrs @@ -440,8 +445,8 @@ mkRecordSelId tycon field_label con1 = head data_cons_w_field res_tys = dataConResTys con1 - tyvar_set = tyVarsOfTypes res_tys - tyvars = varSetElems tyvar_set + res_tv_set = tyVarsOfTypes res_tys + res_tvs = varSetElems res_tv_set data_ty = mkTyConApp tycon res_tys field_ty = dataConFieldType con1 field_label @@ -475,7 +480,7 @@ mkRecordSelId tycon field_label -- op (R op) = op selector_ty :: Type - selector_ty = mkForAllTys tyvars $ mkForAllTys field_tyvars $ + selector_ty = mkForAllTys res_tvs $ mkForAllTys field_tyvars $ mkFunTys stupid_dict_tys $ mkFunTys field_dict_tys $ mkFunTy data_ty field_tau @@ -515,12 +520,14 @@ mkRecordSelId tycon field_label caf_info | no_default = NoCafRefs | otherwise = MayHaveCafRefs - sel_rhs = mkLams tyvars $ mkLams field_tyvars $ + sel_rhs = mkLams res_tvs $ mkLams field_tyvars $ mkLams stupid_dict_ids $ mkLams field_dict_ids $ - Lam data_id $ sel_body + Lam data_id $ mk_result sel_body - sel_body | isNewTyCon tycon = mk_result (mkNewTypeBody tycon field_ty (Var data_id)) - | otherwise = Case (Var data_id) data_id field_tau (default_alt ++ the_alts) + -- NB: A newtype always has a vanilla DataCon; no existentials etc + -- res_tys will simply be the dataConUnivTyVars + sel_body | isNewTyCon tycon = unwrapNewTypeBody tycon res_tys (Var data_id) + | otherwise = Case (Var data_id) data_id field_ty (default_alt ++ the_alts) mk_result poly_result = mkVarApps (mkVarApps poly_result field_tyvars) field_dict_ids -- We pull the field lambdas to the top, so we need to @@ -533,18 +540,17 @@ mkRecordSelId tycon field_label mk_alt data_con = -- In the non-vanilla case, the pattern must bind type variables and -- the context stuff; hence the arg_prefix binding below - mkReboxingAlt uniqs data_con (arg_prefix ++ arg_ids) - (mk_result (Var the_arg_id)) + mkReboxingAlt uniqs data_con (arg_prefix ++ arg_ids) (Var the_arg_id) where (arg_prefix, arg_ids) | isVanillaDataCon data_con -- Instantiate from commmon base = ([], mkTemplateLocalsNum arg_base (dataConInstOrigArgTys data_con res_tys)) | otherwise -- The case pattern binds type variables, which are used -- in the types of the arguments of the pattern - = (dc_tyvars ++ mkTemplateLocalsNum arg_base (mkPredTys dc_theta), + = (dc_tvs ++ mkTemplateLocalsNum arg_base (mkPredTys dc_theta), mkTemplateLocalsNum arg_base' dc_arg_tys) - (dc_tyvars, dc_theta, dc_arg_tys, _, _) = dataConSig data_con + (dc_tvs, dc_theta, dc_arg_tys) = dataConSig data_con arg_base' = arg_base + length dc_theta unpack_base = arg_base' + length dc_arg_tys @@ -554,7 +560,81 @@ mkRecordSelId tycon field_label field_lbls = dataConFieldLabels data_con error_expr = mkRuntimeErrorApp rEC_SEL_ERROR_ID field_tau full_msg - full_msg = showSDoc (sep [text "No match in record selector", ppr sel_id]) + full_msg = showSDoc (sep [text "No match in record selector", ppr sel_id]) + +-- unbox a product type... +-- we will recurse into newtypes, casting along the way, and unbox at the +-- first product data constructor we find. e.g. +-- +-- data PairInt = PairInt Int Int +-- newtype S = MkS PairInt +-- newtype T = MkT S +-- +-- If we have e = MkT (MkS (PairInt 0 1)) and some body expecting a list of +-- ids, we get (modulo int passing) +-- +-- case (e `cast` (sym CoT)) `cast` (sym CoS) of +-- PairInt a b -> body [a,b] +-- +-- The Ints passed around are just for creating fresh locals +unboxProduct :: Int -> CoreExpr -> Type -> (Int -> [Id] -> CoreExpr) -> Type -> CoreExpr +unboxProduct i arg arg_ty body res_ty + = result + where + result = mkUnpackCase the_id arg arg_ty con_args boxing_con rhs + (tycon, tycon_args, boxing_con, tys) = deepSplitProductType "unboxProduct" arg_ty + ([the_id], i') = mkLocals i [arg_ty] + (con_args, i'') = mkLocals i' tys + rhs = body i'' con_args + +mkUnpackCase :: Id -> CoreExpr -> Type -> [Id] -> DataCon -> CoreExpr -> CoreExpr +-- (mkUnpackCase x e args Con body) +-- returns +-- case (e `cast` ...) of bndr { Con args -> body } +-- +-- the type of the bndr passed in is irrelevent +mkUnpackCase bndr arg arg_ty unpk_args boxing_con body + = Case cast_arg (setIdType bndr bndr_ty) (exprType body) [(DataAlt boxing_con, unpk_args, body)] + where + (cast_arg, bndr_ty) = go (idType bndr) arg + go ty arg + | res@(tycon, tycon_args, _, _) <- splitProductType "mkUnpackCase" ty + , isNewTyCon tycon && not (isRecursiveTyCon tycon) + = go (newTyConInstRhs tycon tycon_args) + (unwrapNewTypeBody tycon tycon_args arg) + | otherwise = (arg, ty) + +-- ...and the dual +reboxProduct :: [Unique] -- uniques to create new local binders + -> Type -- type of product to box + -> ([Unique], -- remaining uniques + CoreExpr, -- boxed product + [Id]) -- Ids being boxed into product +reboxProduct us ty + = let + (tycon, tycon_args, pack_con, con_arg_tys) = deepSplitProductType "reboxProduct" ty + + us' = dropList con_arg_tys us + + arg_ids = zipWith (mkSysLocal FSLIT("rb")) us con_arg_tys + + bind_rhs = mkProductBox arg_ids ty + + in + (us', bind_rhs, arg_ids) + +mkProductBox :: [Id] -> Type -> CoreExpr +mkProductBox arg_ids ty + = result_expr + where + (tycon, tycon_args, pack_con, con_arg_tys) = splitProductType "mkProductBox" ty + + result_expr + | isNewTyCon tycon && not (isRecursiveTyCon tycon) + = wrap (mkProductBox arg_ids (newTyConInstRhs tycon tycon_args)) + | otherwise = mkConApp pack_con (map Type tycon_args ++ map Var arg_ids) + + wrap expr = wrapNewTypeBody tycon tycon_args expr -- (mkReboxingAlt us con xs rhs) basically constructs the case @@ -601,16 +681,11 @@ mkReboxingAlt us con args rhs -- Term variable case go (arg:args) (str:stricts) us | isMarkedUnboxed str - = let - (_, tycon_args, pack_con, con_arg_tys) - = splitProductType "mkReboxingAlt" (idType arg) - - unpacked_args = zipWith (mkSysLocal FSLIT("rb")) us con_arg_tys - (binds, args') = go args stricts (dropList con_arg_tys us) - con_app = mkConApp pack_con (map Type tycon_args ++ map Var unpacked_args) - in - (NonRec arg con_app : binds, unpacked_args ++ args') - + = + let (binds, unpacked_args') = go args stricts us' + (us', bind_rhs, unpacked_args) = reboxProduct us (idType arg) + in + (NonRec arg bind_rhs : binds, unpacked_args ++ unpacked_args') | otherwise = let (binds, args') = go args stricts us in (binds, arg:args') @@ -672,26 +747,46 @@ mkDictSelId name clas tycon = classTyCon clas [data_con] = tyConDataCons tycon - tyvars = dataConTyVars data_con - arg_tys = dataConRepArgTys data_con + tyvars = dataConUnivTyVars data_con + arg_tys = ASSERT( isVanillaDataCon data_con ) dataConRepArgTys data_con the_arg_id = assoc "MkId.mkDictSelId" (map idName (classSelIds clas) `zip` arg_ids) name pred = mkClassPred clas (mkTyVarTys tyvars) (dict_id:arg_ids) = mkTemplateLocals (mkPredTy pred : arg_tys) - rhs | isNewTyCon tycon = mkLams tyvars $ Lam dict_id $ - mkNewTypeBody tycon (head arg_tys) (Var dict_id) - | otherwise = mkLams tyvars $ Lam dict_id $ - Case (Var dict_id) dict_id (idType the_arg_id) - [(DataAlt data_con, arg_ids, Var the_arg_id)] - -mkNewTypeBody tycon result_ty result_expr - -- Adds a coerce where necessary - -- Used for both wrapping and unwrapping - | isRecursiveTyCon tycon -- Recursive case; use a coerce - = Note (Coerce result_ty (exprType result_expr)) result_expr - | otherwise -- Normal case + rhs = mkLams tyvars (Lam dict_id rhs_body) + rhs_body | isNewTyCon tycon = unwrapNewTypeBody tycon (map mkTyVarTy tyvars) (Var dict_id) + | otherwise = Case (Var dict_id) dict_id (idType the_arg_id) + [(DataAlt data_con, arg_ids, Var the_arg_id)] + +wrapNewTypeBody :: TyCon -> [Type] -> CoreExpr -> CoreExpr +-- The wrapper for the data constructor for a newtype looks like this: +-- newtype T a = MkT (a,Int) +-- MkT :: forall a. (a,Int) -> T a +-- MkT = /\a. \(x:(a,Int)). x `cast` CoT a +-- where CoT is the coercion TyCon assoicated with the newtype +-- +-- The call (wrapNewTypeBody T [a] e) returns the +-- body of the wrapper, namely +-- e `cast` CoT [a] +-- +-- If a coercion constructor is prodivided in the newtype, then we use +-- it, otherwise the wrap/unwrap are both no-ops +-- +wrapNewTypeBody tycon args result_expr + | Just co_con <- newTyConCo tycon + = Cast result_expr (mkTyConApp co_con args) + | otherwise = result_expr + +unwrapNewTypeBody :: TyCon -> [Type] -> CoreExpr -> CoreExpr +unwrapNewTypeBody tycon args result_expr + | Just co_con <- newTyConCo tycon + = Cast result_expr (mkSymCoercion (mkTyConApp co_con args)) + | otherwise + = result_expr + + \end{code} @@ -882,7 +977,8 @@ unsafeCoerceId (mkFunTy openAlphaTy openBetaTy) [x] = mkTemplateLocals [openAlphaTy] rhs = mkLams [openAlphaTyVar,openBetaTyVar,x] $ - Note (Coerce openBetaTy openAlphaTy) (Var x) +-- Note (Coerce openBetaTy openAlphaTy) (Var x) + Cast (Var x) (mkUnsafeCoercion openAlphaTy openBetaTy) -- nullAddr# :: Addr# -- The reason is is here is because we don't provide