X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FbasicTypes%2FMkId.lhs;h=11dcc395b6e5a3c4e9e6bbaa294237dcdeac1e86;hb=caac75c6a454396dadff0323162ed14adb4893cd;hp=411c9941e8d5b4bfeb06bb1e611c66e71040fefa;hpb=db1ec79d634e2c502261bfdeb4f2bf3398a61928;p=ghc-hetmet.git diff --git a/ghc/compiler/basicTypes/MkId.lhs b/ghc/compiler/basicTypes/MkId.lhs index 411c994..11dcc39 100644 --- a/ghc/compiler/basicTypes/MkId.lhs +++ b/ghc/compiler/basicTypes/MkId.lhs @@ -13,90 +13,88 @@ have a standard form, namely: \begin{code} module MkId ( - mkSpecPragmaId, mkWorkerId, - mkDictFunId, mkDefaultMethodId, mkDictSelId, mkDataConId, mkDataConWrapId, - mkRecordSelId, - mkPrimOpId, mkCCallOpId, + mkRecordSelId, rebuildConArgs, + mkPrimOpId, mkFCallId, -- And some particular Ids; see below for why they are wired in - wiredInIds, - unsafeCoerceId, realWorldPrimId, - eRROR_ID, rEC_SEL_ERROR_ID, pAT_ERROR_ID, rEC_CON_ERROR_ID, - rEC_UPD_ERROR_ID, iRREFUT_PAT_ERROR_ID, nON_EXHAUSTIVE_GUARDS_ERROR_ID, - nO_METHOD_BINDING_ERROR_ID, aBSENT_ERROR_ID, pAR_ERROR_ID + wiredInIds, ghcPrimIds, + unsafeCoerceId, realWorldPrimId, voidArgId, nullAddrId, + eRROR_ID, eRROR_CSTRING_ID, rEC_SEL_ERROR_ID, pAT_ERROR_ID, + rEC_CON_ERROR_ID, rEC_UPD_ERROR_ID, iRREFUT_PAT_ERROR_ID, + nON_EXHAUSTIVE_GUARDS_ERROR_ID, nO_METHOD_BINDING_ERROR_ID, + aBSENT_ERROR_ID, pAR_ERROR_ID ) where #include "HsVersions.h" -import TysPrim ( openAlphaTyVars, alphaTyVar, alphaTy, - intPrimTy, realWorldStatePrimTy +import BasicTypes ( Arity, StrictnessMark(..), isMarkedUnboxed, isMarkedStrict ) +import TysPrim ( openAlphaTyVars, alphaTyVar, alphaTy, betaTyVar, betaTy, + intPrimTy, realWorldStatePrimTy, addrPrimTy ) -import TysWiredIn ( boolTy, charTy, mkListTy ) -import PrelMods ( pREL_ERR, pREL_GHC ) -import PrelRules ( primOpRule ) +import TysWiredIn ( charTy, mkListTy ) +import PrelRules ( primOpRules ) import Rules ( addRule ) -import Type ( Type, ClassContext, mkDictTy, mkDictTys, mkTyConApp, mkTyVarTys, - mkFunTys, mkFunTy, mkSigmaTy, classesToPreds, - isUnLiftedType, mkForAllTys, mkTyVarTy, tyVarsOfType, tyVarsOfTypes, - splitSigmaTy, splitFunTy_maybe, - splitFunTys, splitForAllTys, unUsgTy, - mkUsgTy, UsageAnn(..) +import TcType ( Type, ThetaType, mkDictTy, mkPredTys, mkTyConApp, + mkTyVarTys, mkClassPred, tcEqPred, + mkFunTys, mkFunTy, mkSigmaTy, tcSplitSigmaTy, + isUnLiftedType, mkForAllTys, mkTyVarTy, tyVarsOfType, + tcSplitFunTys, tcSplitForAllTys, mkPredTy ) -import PprType ( pprParendType ) import Module ( Module ) -import CoreUtils ( exprType, mkInlineMe ) +import CoreUtils ( exprType ) import CoreUnfold ( mkTopUnfolding, mkCompulsoryUnfolding, mkOtherCon ) -import Subst ( mkTopTyVarSubst, substClasses ) -import TyCon ( TyCon, isNewTyCon, tyConTyVars, tyConDataCons, isDataTyCon, - tyConTheta, isProductTyCon, isUnboxedTupleTyCon ) -import Class ( Class, classBigSig, classTyCon, classTyVars, classSelIds ) +import Literal ( Literal(..), nullAddrLit ) +import TyCon ( TyCon, isNewTyCon, tyConTyVars, tyConDataCons, + tyConTheta, isProductTyCon, isDataTyCon, isRecursiveTyCon ) +import Class ( Class, classTyCon, classTyVars, classSelIds ) import Var ( Id, TyVar ) import VarSet ( isEmptyVarSet ) -import Name ( mkDerivedName, mkWiredInIdName, mkLocalName, - mkWorkerOcc, mkSuperDictSelOcc, mkCCallName, - Name, NamedThing(..), - ) -import OccName ( mkSrcVarOcc ) -import PrimOp ( PrimOp(DataToTagOp, CCallOp), - primOpSig, mkPrimOpIdName, - CCall, pprCCallOp - ) -import Demand ( wwStrict, wwPrim ) -import DataCon ( DataCon, StrictnessMark(..), +import Name ( mkWiredInName, mkFCallName, Name ) +import OccName ( mkVarOcc ) +import PrimOp ( PrimOp(DataToTagOp), primOpSig, mkPrimOpIdName ) +import ForeignCall ( ForeignCall ) +import DataCon ( DataCon, dataConFieldLabels, dataConRepArity, dataConTyCon, - dataConArgTys, dataConRepType, dataConRepStrictness, + dataConArgTys, dataConRepType, + dataConInstOrigArgTys, dataConName, dataConTheta, - dataConSig, dataConStrictMarks, dataConId + dataConSig, dataConStrictMarks, dataConId, + splitProductType ) -import Id ( idType, mkId, - mkVanillaId, mkTemplateLocals, - mkTemplateLocal, setInlinePragma, idCprInfo +import Id ( idType, mkGlobalId, mkVanillaGlobal, mkSysLocal, + mkTemplateLocals, mkTemplateLocalsNum, + mkTemplateLocal, idNewStrictness, idName ) -import IdInfo ( IdInfo, vanillaIdInfo, mkIdInfo, - exactArity, setUnfoldingInfo, setCafInfo, setCprInfo, - setArityInfo, setInlinePragInfo, setSpecInfo, - mkStrictnessInfo, setStrictnessInfo, - IdFlavour(..), InlinePragInfo(..), CafInfo(..), StrictnessInfo(..), CprInfo(..) +import IdInfo ( IdInfo, noCafNoTyGenIdInfo, + setUnfoldingInfo, + setArityInfo, setSpecInfo, setCafInfo, + setAllStrictnessInfo, + GlobalIdDetails(..), CafInfo(..) ) -import FieldLabel ( FieldLabel, FieldLabelTag, mkFieldLabel, fieldLabelName, +import NewDemand ( mkStrictSig, strictSigResInfo, DmdResult(..), + mkTopDmdType, topDmd, evalDmd, lazyDmd, + Demand(..), Demands(..) ) +import FieldLabel ( mkFieldLabel, fieldLabelName, firstFieldLabelTag, allFieldLabelTags, fieldLabelType ) +import DmdAnal ( dmdAnalTopRhs ) import CoreSyn +import Unique ( mkBuiltinUnique ) import Maybes -import BasicTypes ( Arity ) -import Unique +import PrelNames import Maybe ( isJust ) +import Util ( dropList, isSingleton ) import Outputable -import Util ( assoc ) -import List ( nub ) +import ListSetOps ( assoc, assocMaybe ) +import UnicodeUtil ( stringToUtf8 ) +import Char ( ord ) \end{code} - %************************************************************************ %* * \subsection{Wired in Ids} @@ -110,46 +108,36 @@ wiredInIds -- is 'open'; that is can be unified with an unboxed type -- -- [The interface file format now carry such information, but there's - -- no way yet of expressing at the definition site for these error-reporting - -- functions that they have an 'open' result type. -- sof 1/99] - - aBSENT_ERROR_ID - , eRROR_ID - , iRREFUT_PAT_ERROR_ID - , nON_EXHAUSTIVE_GUARDS_ERROR_ID - , nO_METHOD_BINDING_ERROR_ID - , pAR_ERROR_ID - , pAT_ERROR_ID - , rEC_CON_ERROR_ID - , rEC_UPD_ERROR_ID - - -- These two can't be defined in Haskell - , realWorldPrimId - , unsafeCoerceId - , getTagId + -- no way yet of expressing at the definition site for these + -- error-reporting functions that they have an 'open' + -- result type. -- sof 1/99] + + aBSENT_ERROR_ID, + eRROR_ID, + eRROR_CSTRING_ID, + iRREFUT_PAT_ERROR_ID, + nON_EXHAUSTIVE_GUARDS_ERROR_ID, + nO_METHOD_BINDING_ERROR_ID, + pAR_ERROR_ID, + pAT_ERROR_ID, + rEC_CON_ERROR_ID, + rEC_UPD_ERROR_ID + ] ++ ghcPrimIds + +-- These Ids are exported from GHC.Prim +ghcPrimIds + = [ -- These can't be defined in Haskell, but they have + -- perfectly reasonable unfoldings in Core + realWorldPrimId, + unsafeCoerceId, + nullAddrId, + getTagId, + seqId ] \end{code} %************************************************************************ %* * -\subsection{Easy ones} -%* * -%************************************************************************ - -\begin{code} -mkSpecPragmaId occ uniq ty loc - = mkId (mkLocalName uniq occ loc) ty (mkIdInfo SpecPragmaId) - -- Maybe a SysLocal? But then we'd lose the location - -mkDefaultMethodId dm_name rec_c ty - = mkVanillaId dm_name ty - -mkWorkerId uniq unwrkr ty - = mkVanillaId (mkDerivedName mkWorkerOcc (getName unwrkr) uniq) ty -\end{code} - -%************************************************************************ -%* * \subsection{Data constructors} %* * %************************************************************************ @@ -159,31 +147,50 @@ mkDataConId :: Name -> DataCon -> Id -- Makes the *worker* for the data constructor; that is, the function -- that takes the reprsentation arguments and builds the constructor. mkDataConId work_name data_con - = mkId work_name (dataConRepType data_con) info + = mkGlobalId (DataConId data_con) work_name (dataConRepType data_con) info where - info = mkIdInfo (DataConId data_con) - `setArityInfo` exactArity arity - `setStrictnessInfo` strict_info - `setCprInfo` cpr_info - - arity = dataConRepArity data_con - - strict_info = StrictnessInfo (dataConRepStrictness data_con) False - + info = noCafNoTyGenIdInfo + `setArityInfo` arity + `setAllStrictnessInfo` Just strict_sig + + arity = dataConRepArity data_con + + strict_sig = mkStrictSig (mkTopDmdType (replicate arity topDmd) cpr_info) + -- Notice that we do *not* say the worker is strict + -- even if the data constructor is declared strict + -- e.g. data T = MkT !(Int,Int) + -- Why? Because the *wrapper* is strict (and its unfolding has case + -- expresssions that do the evals) but the *worker* itself is not. + -- If we pretend it is strict then when we see + -- case x of y -> $wMkT y + -- the simplifier thinks that y is "sure to be evaluated" (because + -- $wMkT is strict) and drops the case. No, $wMkT is not strict. + -- + -- When the simplifer sees a pattern + -- case e of MkT x -> ... + -- it uses the dataConRepStrictness of MkT to mark x as evaluated; + -- but that's fine... dataConRepStrictness comes from the data con + -- not from the worker Id. + + tycon = dataConTyCon data_con cpr_info | isProductTyCon tycon && - not (isUnboxedTupleTyCon tycon) && - arity > 0 = ReturnsCPR - | otherwise = NoCPRInfo - where - tycon = dataConTyCon data_con - -- Newtypes don't have a worker at all - -- - -- If we are a product with 0 args we must be void(like) - -- We can't create an unboxed tuple with 0 args for this - -- and since Void has only one, constant value it should - -- just mean returning a pointer to a pre-existing cell. - -- So we won't really gain from doing anything fancy - -- and we treat this case as Top. + isDataTyCon tycon && + arity > 0 && + arity <= mAX_CPR_SIZE = RetCPR + | otherwise = TopRes + -- RetCPR is only true for products that are real data types; + -- that is, not unboxed tuples or [non-recursive] newtypes + +mAX_CPR_SIZE :: Arity +mAX_CPR_SIZE = 10 +-- We do not treat very big tuples as CPR-ish: +-- a) for a start we get into trouble because there aren't +-- "enough" unboxed tuple types (a tiresome restriction, +-- but hard to fix), +-- b) more importantly, big unboxed tuples get returned mainly +-- on the stack, and are often then allocated in the heap +-- by the caller. So doing CPR for them may in fact make +-- things worse. \end{code} The wrapper for a constructor is an ordinary top-level binding that evaluates @@ -225,57 +232,64 @@ Notice that \begin{code} mkDataConWrapId data_con - = wrap_id + = mkGlobalId (DataConWrapId data_con) (dataConName data_con) wrap_ty info where - wrap_id = mkId (dataConName data_con) wrap_ty info work_id = dataConId data_con - info = mkIdInfo (DataConWrapId data_con) - `setUnfoldingInfo` mkTopUnfolding (mkInlineMe wrap_rhs) - `setCprInfo` cpr_info - -- The Cpr info can be important inside INLINE rhss, where the - -- wrapper constructor isn't inlined - `setArityInfo` exactArity arity + info = noCafNoTyGenIdInfo + `setUnfoldingInfo` wrap_unf + -- The NoCaf-ness is set by noCafNoTyGenIdInfo + `setArityInfo` arity -- It's important to specify the arity, so that partial -- applications are treated as values - `setCafInfo` NoCafRefs - -- The wrapper Id ends up in STG code as an argument, - -- sometimes before its definition, so we want to - -- signal that it has no CAFs - - wrap_ty = mkForAllTys all_tyvars $ - mkFunTys all_arg_tys - result_ty - - cpr_info = idCprInfo work_id - - wrap_rhs | isNewTyCon tycon - = ASSERT( null ex_tyvars && null ex_dict_args && length orig_arg_tys == 1 ) - -- No existentials on a newtype, but it can have a contex + `setAllStrictnessInfo` Just wrap_sig + + wrap_ty = mkForAllTys all_tyvars (mkFunTys all_arg_tys result_ty) + + wrap_sig = mkStrictSig (mkTopDmdType arg_dmds res_info) + res_info = strictSigResInfo (idNewStrictness work_id) + arg_dmds = [Abs | d <- dict_args] ++ map mk_dmd strict_marks + mk_dmd str | isMarkedStrict str = evalDmd + | otherwise = lazyDmd + -- The Cpr info can be important inside INLINE rhss, where the + -- wrapper constructor isn't inlined. + -- And the argument strictness can be important too; we + -- may not inline a contructor when it is partially applied. + -- For example: + -- data W = C !Int !Int !Int + -- ...(let w = C x in ...(w p q)...)... + -- we want to see that w is strict in its two arguments + + wrap_unf | isNewTyCon tycon + = ASSERT( null ex_tyvars && null ex_dict_args && isSingleton orig_arg_tys ) + -- No existentials on a newtype, but it can have a context -- e.g. newtype Eq a => T a = MkT (...) - - mkLams tyvars $ mkLams dict_args $ Lam id_arg1 $ - Note (Coerce result_ty (head orig_arg_tys)) (Var id_arg1) - -{- I nuked this because map (:) xs would create a - new local lambda for the (:) in core-to-stg. - There isn't a defn for the worker! - - | null dict_args && all not_marked_strict strict_marks - = Var work_id -- The common case. Not only is this efficient, - -- but it also ensures that the wrapper is replaced - -- by the worker even when there are no args. - -- f (:) x - -- becomes - -- f $w: x - -- This is really important in rule matching, - -- which is a bit sad. (We could match on the wrappers, - -- but that makes it less likely that rules will match - -- when we bring bits of unfoldings together --} + mkTopUnfolding $ Note InlineMe $ + mkLams tyvars $ mkLams dict_args $ Lam id_arg1 $ + mkNewTypeBody tycon result_ty (Var id_arg1) + + | null dict_args && not (any isMarkedStrict strict_marks) + = mkCompulsoryUnfolding (Var work_id) + -- The common case. Not only is this efficient, + -- but it also ensures that the wrapper is replaced + -- by the worker even when there are no args. + -- f (:) x + -- becomes + -- f $w: x + -- This is really important in rule matching, + -- (We could match on the wrappers, + -- but that makes it less likely that rules will match + -- when we bring bits of unfoldings together.) + -- + -- NB: because of this special case, (map (:) ys) turns into + -- (map $w: ys). The top-level defn for (:) is never used. + -- This is somewhat of a bore, but I'm currently leaving it + -- as is, so that there still is a top level curried (:) for + -- the interpreter to call. | otherwise - = mkLams all_tyvars $ mkLams dict_args $ + = mkTopUnfolding $ Note InlineMe $ + mkLams all_tyvars $ mkLams dict_args $ mkLams ex_dict_args $ mkLams id_args $ foldr mk_case con_app (zip (ex_dict_args++id_args) strict_marks) i3 [] @@ -286,8 +300,8 @@ mkDataConWrapId data_con (tyvars, theta, ex_tyvars, ex_theta, orig_arg_tys, tycon) = dataConSig data_con all_tyvars = tyvars ++ ex_tyvars - dict_tys = mkDictTys theta - ex_dict_tys = mkDictTys ex_theta + dict_tys = mkPredTys theta + ex_dict_tys = mkPredTys ex_theta all_arg_tys = dict_tys ++ ex_dict_tys ++ orig_arg_tys result_ty = mkTyConApp tycon (mkTyVarTys tyvars) @@ -302,15 +316,12 @@ mkDataConWrapId data_con (id_arg1:_) = id_args -- Used for newtype only strict_marks = dataConStrictMarks data_con - not_marked_strict NotMarkedStrict = True - not_marked_strict other = False - mk_case - :: (Id, StrictnessMark) -- arg, strictness - -> (Int -> [Id] -> CoreExpr) -- body - -> Int -- next rep arg id - -> [Id] -- rep args so far + :: (Id, StrictnessMark) -- Arg, strictness + -> (Int -> [Id] -> CoreExpr) -- Body + -> Int -- Next rep arg id + -> [Id] -- Rep args so far, reversed -> CoreExpr mk_case (arg,strict) body i rep_args = case strict of @@ -320,11 +331,13 @@ mkDataConWrapId data_con | otherwise -> Case (Var arg) arg [(DEFAULT,[], body i (arg:rep_args))] - MarkedUnboxed con tys -> - Case (Var arg) arg [(DataAlt con, con_args, - body i' (reverse con_args++rep_args))] - where n_tys = length tys - (con_args,i') = mkLocals i tys + MarkedUnboxed + -> case splitProductType "do_unbox" (idType arg) of + (tycon, tycon_args, con, tys) -> + Case (Var arg) arg [(DataAlt con, con_args, + body i' (reverse con_args ++ rep_args))] + where + (con_args, i') = mkLocals i tys \end{code} @@ -373,77 +386,180 @@ Similarly for newtypes unN = /\a -> \n:N -> coerce (a->a) n \begin{code} -mkRecordSelId tycon field_label - -- Assumes that all fields with the same field label - -- have the same type +mkRecordSelId tycon field_label unpack_id unpackUtf8_id + -- Assumes that all fields with the same field label have the same type + -- + -- Annoyingly, we have to pass in the unpackCString# Id, because + -- we can't conjure it up out of thin air = sel_id where - sel_id = mkId (fieldLabelName field_label) selector_ty info - + sel_id = mkGlobalId (RecordSelId field_label) (fieldLabelName field_label) selector_ty info field_ty = fieldLabelType field_label - field_name = fieldLabelName field_label data_cons = tyConDataCons tycon tyvars = tyConTyVars tycon -- These scope over the types in -- the FieldLabels of constructors of this type - tycon_theta = tyConTheta tycon -- The context on the data decl - -- eg data (Eq a, Ord b) => T a b = ... - (field_tyvars,field_tau) = splitForAllTys field_ty - data_ty = mkTyConApp tycon tyvar_tys tyvar_tys = mkTyVarTys tyvars + tycon_theta = tyConTheta tycon -- The context on the data decl + -- eg data (Eq a, Ord b) => T a b = ... + dict_tys = [mkPredTy pred | pred <- tycon_theta, + needed_dict pred] + needed_dict pred = or [ tcEqPred pred p + | (DataAlt dc, _, _) <- the_alts, p <- dataConTheta dc] + n_dict_tys = length dict_tys + + (field_tyvars,field_theta,field_tau) = tcSplitSigmaTy field_ty + field_dict_tys = map mkPredTy field_theta + n_field_dict_tys = length field_dict_tys + -- If the field has a universally quantified type we have to + -- be a bit careful. Suppose we have + -- data R = R { op :: forall a. Foo a => a -> a } + -- Then we can't give op the type + -- op :: R -> forall a. Foo a => a -> a + -- because the typechecker doesn't understand foralls to the + -- right of an arrow. The "right" type to give it is + -- op :: forall a. Foo a => R -> a -> a + -- But then we must generate the right unfolding too: + -- op = /\a -> \dfoo -> \ r -> + -- case r of + -- R op -> op a dfoo + -- Note that this is exactly the type we'd infer from a user defn + -- op (R op) = op + -- Very tiresomely, the selectors are (unnecessarily!) overloaded over -- just the dictionaries in the types of the constructors that contain -- the relevant field. Urgh. -- NB: this code relies on the fact that DataCons are quantified over -- the identical type variables as their parent TyCon - dict_tys = [mkDictTy cls tys | (cls, tys) <- tycon_theta, needed_dict (cls, tys)] - needed_dict pred = or [ pred `elem` (dataConTheta dc) - | (DataAlt dc, _, _) <- the_alts] selector_ty :: Type selector_ty = mkForAllTys tyvars $ mkForAllTys field_tyvars $ - mkFunTys dict_tys $ mkFunTy data_ty field_tau + mkFunTys dict_tys $ mkFunTys field_dict_tys $ + mkFunTy data_ty field_tau - info = mkIdInfo (RecordSelId field_label) - `setArityInfo` exactArity 1 - `setUnfoldingInfo` unfolding - `setCafInfo` NoCafRefs - -- ToDo: consider adding further IdInfo - - unfolding = mkTopUnfolding sel_rhs + arity = 1 + n_dict_tys + n_field_dict_tys + + (strict_sig, rhs_w_str) = dmdAnalTopRhs sel_rhs + -- Use the demand analyser to work out strictness. + -- With all this unpackery it's not easy! + + info = noCafNoTyGenIdInfo + `setCafInfo` caf_info + `setArityInfo` arity + `setUnfoldingInfo` mkTopUnfolding rhs_w_str + `setAllStrictnessInfo` Just strict_sig + + -- Allocate Ids. We do it a funny way round because field_dict_tys is + -- almost always empty. Also note that we use length_tycon_theta + -- rather than n_dict_tys, because the latter gives an infinite loop: + -- n_dict tys depends on the_alts, which depens on arg_ids, which depends + -- on arity, which depends on n_dict tys. Sigh! Mega sigh! + field_dict_base = length tycon_theta + 1 + dict_id_base = field_dict_base + n_field_dict_tys + field_base = dict_id_base + 1 + dict_ids = mkTemplateLocalsNum 1 dict_tys + field_dict_ids = mkTemplateLocalsNum field_dict_base field_dict_tys + data_id = mkTemplateLocal dict_id_base data_ty - - (data_id:dict_ids) = mkTemplateLocals (data_ty:dict_tys) alts = map mk_maybe_alt data_cons the_alts = catMaybes alts - default_alt | all isJust alts = [] -- No default needed - | otherwise = [(DEFAULT, [], error_expr)] - sel_rhs | isNewTyCon tycon = new_sel_rhs - | otherwise = data_sel_rhs + no_default = all isJust alts -- No default needed + default_alt | no_default = [] + | otherwise = [(DEFAULT, [], error_expr)] + + -- the default branch may have CAF refs, because it calls recSelError etc. + caf_info | no_default = NoCafRefs + | otherwise = MayHaveCafRefs + + sel_rhs = mkLams tyvars $ mkLams field_tyvars $ + mkLams dict_ids $ mkLams field_dict_ids $ + Lam data_id $ sel_body - data_sel_rhs = mkLams tyvars $ mkLams field_tyvars $ - mkLams dict_ids $ Lam data_id $ - Case (Var data_id) data_id (the_alts ++ default_alt) + sel_body | isNewTyCon tycon = mkNewTypeBody tycon field_tau (mk_result data_id) + | otherwise = Case (Var data_id) data_id (default_alt ++ the_alts) - new_sel_rhs = mkLams tyvars $ mkLams field_tyvars $ Lam data_id $ - Note (Coerce (unUsgTy field_tau) (unUsgTy data_ty)) (Var data_id) + mk_result result_id = mkVarApps (mkVarApps (Var result_id) field_tyvars) field_dict_ids + -- We pull the field lambdas to the top, so we need to + -- apply them in the body. For example: + -- data T = MkT { foo :: forall a. a->a } + -- + -- foo :: forall a. T -> a -> a + -- foo = /\a. \t:T. case t of { MkT f -> f a } mk_maybe_alt data_con = case maybe_the_arg_id of Nothing -> Nothing - Just the_arg_id -> Just (DataAlt data_con, arg_ids, - mkVarApps (Var the_arg_id) field_tyvars) - where - arg_ids = mkTemplateLocals (dataConArgTys data_con tyvar_tys) - -- The first one will shadow data_id, but who cares - field_lbls = dataConFieldLabels data_con - maybe_the_arg_id = assocMaybe (field_lbls `zip` arg_ids) field_label - - error_expr = mkApps (Var rEC_SEL_ERROR_ID) [Type (unUsgTy field_tau), mkStringLit full_msg] - -- preserves invariant that type args are *not* usage-annotated on top. KSW 1999-04. + Just the_arg_id -> Just (DataAlt data_con, real_args, mkLets binds body) + where + body = mk_result the_arg_id + strict_marks = dataConStrictMarks data_con + (binds, real_args) = rebuildConArgs arg_ids strict_marks + (map mkBuiltinUnique [unpack_base..]) + where + arg_ids = mkTemplateLocalsNum field_base (dataConInstOrigArgTys data_con tyvar_tys) + + unpack_base = field_base + length arg_ids + + -- arity+1 avoids all shadowing + maybe_the_arg_id = assocMaybe (field_lbls `zip` arg_ids) field_label + field_lbls = dataConFieldLabels data_con + + error_expr = mkApps (Var rEC_SEL_ERROR_ID) [Type field_tau, err_string] + err_string + | all safeChar full_msg + = App (Var unpack_id) (Lit (MachStr (_PK_ full_msg))) + | otherwise + = App (Var unpackUtf8_id) (Lit (MachStr (_PK_ (stringToUtf8 (map ord full_msg))))) + where + safeChar c = c >= '\1' && c <= '\xFF' + -- TODO: Putting this Unicode stuff here is ugly. Find a better + -- generic place to make string literals. This logic is repeated + -- in DsUtils. full_msg = showSDoc (sep [text "No match in record selector", ppr sel_id]) + + +-- This rather ugly function converts the unpacked data con +-- arguments back into their packed form. + +rebuildConArgs + :: [Id] -- Source-level args + -> [StrictnessMark] -- Strictness annotations (per-arg) + -> [Unique] -- Uniques for the new Ids + -> ([CoreBind], [Id]) -- A binding for each source-level arg, plus + -- a list of the representation-level arguments +-- e.g. data T = MkT Int !Int +-- +-- rebuild [x::Int, y::Int] [Not, Unbox] +-- = ([ y = I# t ], [x,t]) + +rebuildConArgs [] stricts us = ([], []) + +-- Type variable case +rebuildConArgs (arg:args) stricts us + | isTyVar arg + = let (binds, args') = rebuildConArgs args stricts us + in (binds, arg:args') + +-- Term variable case +rebuildConArgs (arg:args) (str:stricts) us + | isMarkedUnboxed str + = let + arg_ty = idType arg + + (_, tycon_args, pack_con, con_arg_tys) + = splitProductType "rebuildConArgs" arg_ty + + unpacked_args = zipWith (mkSysLocal FSLIT("rb")) us con_arg_tys + (binds, args') = rebuildConArgs 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') + + | otherwise + = let (binds, args') = rebuildConArgs args stricts us + in (binds, arg:args') \end{code} @@ -459,23 +575,36 @@ there's nothing to do. ToDo: unify with mkRecordSelId. \begin{code} +mkDictSelId :: Name -> Class -> Id mkDictSelId name clas - = sel_id + = mkGlobalId (RecordSelId field_lbl) name sel_ty info where - ty = exprType rhs - sel_id = mkId name ty info - field_lbl = mkFieldLabel name ty tag - tag = assoc "MkId.mkDictSelId" (classSelIds clas `zip` allFieldLabelTags) sel_id - - info = mkIdInfo (RecordSelId field_lbl) - `setArityInfo` exactArity 1 - `setUnfoldingInfo` unfolding - `setCafInfo` NoCafRefs - + sel_ty = mkForAllTys tyvars (mkFunTy (idType dict_id) (idType the_arg_id)) + -- We can't just say (exprType rhs), because that would give a type + -- C a -> C a + -- for a single-op class (after all, the selector is the identity) + -- But it's type must expose the representation of the dictionary + -- to gat (say) C a -> (a -> a) + + field_lbl = mkFieldLabel name tycon sel_ty tag + tag = assoc "MkId.mkDictSelId" (map idName (classSelIds clas) `zip` allFieldLabelTags) name + + info = noCafNoTyGenIdInfo + `setArityInfo` 1 + `setUnfoldingInfo` mkTopUnfolding rhs + `setAllStrictnessInfo` Just strict_sig + -- We no longer use 'must-inline' on record selectors. They'll -- inline like crazy if they scrutinise a constructor - unfolding = mkTopUnfolding rhs + -- The strictness signature is of the form U(AAAVAAAA) -> T + -- where the V depends on which item we are selecting + -- It's worth giving one, so that absence info etc is generated + -- even if the selector isn't inlined + strict_sig = mkStrictSig (mkTopDmdType [arg_dmd] TopRes) + arg_dmd | isNewTyCon tycon = evalDmd + | otherwise = Eval (Prod [ if the_arg_id == id then evalDmd else Abs + | id <- arg_ids ]) tyvars = classTyVars clas @@ -485,14 +614,22 @@ mkDictSelId name clas arg_tys = dataConArgTys data_con tyvar_tys the_arg_id = arg_ids !! (tag - firstFieldLabelTag) - dict_ty = mkDictTy clas tyvar_tys - (dict_id:arg_ids) = mkTemplateLocals (dict_ty : arg_tys) + pred = mkClassPred clas tyvar_tys + (dict_id:arg_ids) = mkTemplateLocals (mkPredTy pred : arg_tys) - rhs | isNewTyCon tycon = mkLams tyvars $ Lam dict_id $ - Note (Coerce (head arg_tys) dict_ty) (Var dict_id) + 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 [(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 + = result_expr \end{code} @@ -507,17 +644,17 @@ mkPrimOpId :: PrimOp -> Id mkPrimOpId prim_op = id where - (tyvars,arg_tys,res_ty, arity, strict_info) = primOpSig prim_op + (tyvars,arg_tys,res_ty, arity, strict_sig) = primOpSig prim_op ty = mkForAllTys tyvars (mkFunTys arg_tys res_ty) - name = mkPrimOpIdName prim_op id - id = mkId name ty info + name = mkPrimOpIdName prim_op + id = mkGlobalId (PrimOpId prim_op) name ty info - info = mkIdInfo (PrimOpId prim_op) + info = noCafNoTyGenIdInfo `setSpecInfo` rules - `setArityInfo` exactArity arity - `setStrictnessInfo` strict_info + `setArityInfo` arity + `setAllStrictnessInfo` Just strict_sig - rules = addRule id emptyCoreRules (primOpRule prim_op) + rules = foldl (addRule id) emptyCoreRules (primOpRules prim_op) -- For each ccall we manufacture a separate CCallOpId, giving it @@ -529,57 +666,84 @@ mkPrimOpId prim_op -- details of the ccall, type and all. This means that the interface -- file reader can reconstruct a suitable Id -mkCCallOpId :: Unique -> CCall -> Type -> Id -mkCCallOpId uniq ccall ty +mkFCallId :: Unique -> ForeignCall -> Type -> Id +mkFCallId uniq fcall ty = ASSERT( isEmptyVarSet (tyVarsOfType ty) ) -- A CCallOpId should have no free type variables; -- when doing substitutions won't substitute over it - mkId name ty info + mkGlobalId (FCallId fcall) name ty info where - occ_str = showSDocIface (braces (pprCCallOp ccall <+> ppr ty)) + occ_str = showSDocIface (braces (ppr fcall <+> ppr ty)) -- The "occurrence name" of a ccall is the full info about the -- ccall; it is encoded, but may have embedded spaces etc! - name = mkCCallName uniq occ_str - prim_op = CCallOp ccall + name = mkFCallName uniq occ_str - info = mkIdInfo (PrimOpId prim_op) - `setArityInfo` exactArity arity - `setStrictnessInfo` strict_info + info = noCafNoTyGenIdInfo + `setArityInfo` arity + `setAllStrictnessInfo` Just strict_sig - (_, tau) = splitForAllTys ty - (arg_tys, _) = splitFunTys tau + (_, tau) = tcSplitForAllTys ty + (arg_tys, _) = tcSplitFunTys tau arity = length arg_tys - strict_info = mkStrictnessInfo (take arity (repeat wwPrim), False) + strict_sig = mkStrictSig (mkTopDmdType (replicate arity evalDmd) TopRes) \end{code} %************************************************************************ %* * -\subsection{DictFuns} +\subsection{DictFuns and default methods} %* * %************************************************************************ +Important notes about dict funs and default methods +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Dict funs and default methods are *not* ImplicitIds. Their definition +involves user-written code, so we can't figure out their strictness etc +based on fixed info, as we can for constructors and record selectors (say). + +We build them as GlobalIds, but when in the module where they are +bound, we turn the Id at the *binding site* into an exported LocalId. +This ensures that they are taken to account by free-variable finding +and dependency analysis (e.g. CoreFVs.exprFreeVars). The simplifier +will propagate the LocalId to all occurrence sites. + +Why shouldn't they be bound as GlobalIds? Because, in particular, if +they are globals, the specialiser floats dict uses above their defns, +which prevents good simplifications happening. Also the strictness +analyser treats a occurrence of a GlobalId as imported and assumes it +contains strictness in its IdInfo, which isn't true if the thing is +bound in the same module as the occurrence. + +It's OK for dfuns to be LocalIds, because we form the instance-env to +pass on to the next module (md_insts) in CoreTidy, afer tidying +and globalising the top-level Ids. + +BUT make sure they are *exported* LocalIds (setIdLocalExported) so +that they aren't discarded by the occurrence analyser. + \begin{code} +mkDefaultMethodId dm_name ty = mkVanillaGlobal dm_name ty noCafNoTyGenIdInfo + mkDictFunId :: Name -- Name to use for the dict fun; -> Class -> [TyVar] -> [Type] - -> ClassContext + -> ThetaType -> Id -mkDictFunId dfun_name clas inst_tyvars inst_tys inst_decl_theta - = mkVanillaId dfun_name dfun_ty +mkDictFunId dfun_name clas inst_tyvars inst_tys dfun_theta + = mkVanillaGlobal dfun_name dfun_ty noCafNoTyGenIdInfo where - (class_tyvars, sc_theta, _, _) = classBigSig clas - sc_theta' = substClasses (mkTopTyVarSubst class_tyvars inst_tys) sc_theta - - dfun_theta = classesToPreds inst_decl_theta + dfun_ty = mkSigmaTy inst_tyvars dfun_theta (mkDictTy clas inst_tys) {- 1 dec 99: disable the Mark Jones optimisation for the sake of compatibility with Hugs. See `types/InstEnv' for a discussion related to this. + (class_tyvars, sc_theta, _, _) = classBigSig clas + not_const (clas, tys) = not (isEmptyVarSet (tyVarsOfTypes tys)) + sc_theta' = substClasses (mkTopTyVarSubst class_tyvars inst_tys) sc_theta dfun_theta = case inst_decl_theta of [] -> [] -- If inst_decl_theta is empty, then we don't -- want to have any dict arguments, so that we can @@ -600,9 +764,6 @@ mkDictFunId dfun_name clas inst_tyvars inst_tys inst_decl_theta -- instance Wob b => Baz T b where.. -- Now sc_theta' has Foo T -} - dfun_ty = mkSigmaTy inst_tyvars dfun_theta (mkDictTy clas inst_tys) - - not_const (clas, tys) = not (isEmptyVarSet (tyVarsOfTypes tys)) \end{code} @@ -612,7 +773,12 @@ mkDictFunId dfun_name clas inst_tyvars inst_tys inst_decl_theta %* * %************************************************************************ -These two can't be defined in Haskell. +These Ids can't be defined in Haskell. They could be defined in +unfoldings in PrelGHC.hi-boot, but we'd have to ensure that they +were definitely, definitely inlined, because there is no curried +identifier for them. That's what mkCompulsoryUnfolding does. +If we had a way to get a compulsory unfolding from an interface file, +we could do that, but we don't right now. unsafeCoerce# isn't so much a PrimOp as a phantom identifier, that just gets expanded into a type coercion wherever it occurs. Hence we @@ -623,11 +789,11 @@ they can unify with both unlifted and lifted types. Hence we provide another gun with which to shoot yourself in the foot. \begin{code} +-- unsafeCoerce# :: forall a b. a -> b unsafeCoerceId - = pcMiscPrelId unsafeCoerceIdKey pREL_GHC SLIT("unsafeCoerce#") ty info + = pcMiscPrelId unsafeCoerceIdKey gHC_PRIM FSLIT("unsafeCoerce#") ty info where - info = vanillaIdInfo - `setUnfoldingInfo` mkCompulsoryUnfolding rhs + info = noCafNoTyGenIdInfo `setUnfoldingInfo` mkCompulsoryUnfolding rhs ty = mkForAllTys [openAlphaTyVar,openBetaTyVar] @@ -635,18 +801,36 @@ unsafeCoerceId [x] = mkTemplateLocals [openAlphaTy] rhs = mkLams [openAlphaTyVar,openBetaTyVar,x] $ Note (Coerce openBetaTy openAlphaTy) (Var x) -\end{code} +-- nullAddr# :: Addr# +-- The reason is is here is because we don't provide +-- a way to write this literal in Haskell. +nullAddrId + = pcMiscPrelId nullAddrIdKey gHC_PRIM FSLIT("nullAddr#") addrPrimTy info + where + info = noCafNoTyGenIdInfo `setUnfoldingInfo` + mkCompulsoryUnfolding (Lit nullAddrLit) + +seqId + = pcMiscPrelId seqIdKey gHC_PRIM FSLIT("seq") ty info + where + info = noCafNoTyGenIdInfo `setUnfoldingInfo` mkCompulsoryUnfolding rhs + + + ty = mkForAllTys [alphaTyVar,betaTyVar] + (mkFunTy alphaTy (mkFunTy betaTy betaTy)) + [x,y] = mkTemplateLocals [alphaTy, betaTy] + rhs = mkLams [alphaTyVar,betaTyVar,x,y] (Case (Var x) x [(DEFAULT, [], Var y)]) +\end{code} @getTag#@ is another function which can't be defined in Haskell. It needs to evaluate its argument and call the dataToTag# primitive. \begin{code} getTagId - = pcMiscPrelId getTagIdKey pREL_GHC SLIT("getTag#") ty info + = pcMiscPrelId getTagIdKey gHC_PRIM FSLIT("getTag#") ty info where - info = vanillaIdInfo - `setUnfoldingInfo` mkCompulsoryUnfolding rhs + info = noCafNoTyGenIdInfo `setUnfoldingInfo` mkCompulsoryUnfolding rhs -- We don't provide a defn for this; you must inline it ty = mkForAllTys [alphaTyVar] (mkFunTy alphaTy intPrimTy) @@ -660,15 +844,25 @@ dataToTagId = mkPrimOpId DataToTagOp @realWorld#@ used to be a magic literal, \tr{void#}. If things get nasty as-is, change it back to a literal (@Literal@). +voidArgId is a Local Id used simply as an argument in functions +where we just want an arg to avoid having a thunk of unlifted type. +E.g. + x = \ void :: State# RealWorld -> (# p, q #) + +This comes up in strictness analysis + \begin{code} realWorldPrimId -- :: State# RealWorld - = pcMiscPrelId realWorldPrimIdKey pREL_GHC SLIT("realWorld#") + = pcMiscPrelId realWorldPrimIdKey gHC_PRIM FSLIT("realWorld#") realWorldStatePrimTy - (noCafIdInfo `setUnfoldingInfo` mkOtherCon []) + (noCafNoTyGenIdInfo `setUnfoldingInfo` mkOtherCon []) -- The mkOtherCon makes it look that realWorld# is evaluated -- which in turn makes Simplify.interestingArg return True, -- which in turn makes INLINE things applied to realWorld# likely -- to be inlined + +voidArgId -- :: State# RealWorld + = mkSysLocal FSLIT("void") voidArgIdKey realWorldStatePrimTy \end{code} @@ -695,30 +889,32 @@ templates, but we don't ever expect to generate code for it. \begin{code} eRROR_ID - = pc_bottoming_Id errorIdKey pREL_ERR SLIT("error") errorTy -rEC_SEL_ERROR_ID - = generic_ERROR_ID recSelErrIdKey SLIT("patError") + = pc_bottoming_Id errorIdKey pREL_ERR FSLIT("error") errorTy +eRROR_CSTRING_ID + = pc_bottoming_Id errorCStringIdKey pREL_ERR FSLIT("errorCString") + (mkSigmaTy [openAlphaTyVar] [] (mkFunTy addrPrimTy openAlphaTy)) pAT_ERROR_ID - = generic_ERROR_ID patErrorIdKey SLIT("patError") + = generic_ERROR_ID patErrorIdKey FSLIT("patError") +rEC_SEL_ERROR_ID + = generic_ERROR_ID recSelErrIdKey FSLIT("recSelError") rEC_CON_ERROR_ID - = generic_ERROR_ID recConErrorIdKey SLIT("recConError") + = generic_ERROR_ID recConErrorIdKey FSLIT("recConError") rEC_UPD_ERROR_ID - = generic_ERROR_ID recUpdErrorIdKey SLIT("recUpdError") + = generic_ERROR_ID recUpdErrorIdKey FSLIT("recUpdError") iRREFUT_PAT_ERROR_ID - = generic_ERROR_ID irrefutPatErrorIdKey SLIT("irrefutPatError") + = generic_ERROR_ID irrefutPatErrorIdKey FSLIT("irrefutPatError") nON_EXHAUSTIVE_GUARDS_ERROR_ID - = generic_ERROR_ID nonExhaustiveGuardsErrorIdKey SLIT("nonExhaustiveGuardsError") + = generic_ERROR_ID nonExhaustiveGuardsErrorIdKey FSLIT("nonExhaustiveGuardsError") nO_METHOD_BINDING_ERROR_ID - = generic_ERROR_ID noMethodBindingErrorIdKey SLIT("noMethodBindingError") + = generic_ERROR_ID noMethodBindingErrorIdKey FSLIT("noMethodBindingError") aBSENT_ERROR_ID - = pc_bottoming_Id absentErrorIdKey pREL_ERR SLIT("absentErr") + = pc_bottoming_Id absentErrorIdKey pREL_ERR FSLIT("absentErr") (mkSigmaTy [openAlphaTyVar] [] openAlphaTy) pAR_ERROR_ID - = pcMiscPrelId parErrorIdKey pREL_ERR SLIT("parError") - (mkSigmaTy [openAlphaTyVar] [] openAlphaTy) noCafIdInfo - + = pcMiscPrelId parErrorIdKey pREL_ERR FSLIT("parError") + (mkSigmaTy [openAlphaTyVar] [] openAlphaTy) noCafNoTyGenIdInfo \end{code} @@ -732,8 +928,8 @@ pAR_ERROR_ID pcMiscPrelId :: Unique{-IdKey-} -> Module -> FAST_STRING -> Type -> IdInfo -> Id pcMiscPrelId key mod str ty info = let - name = mkWiredInIdName key mod (mkSrcVarOcc str) imp - imp = mkId name ty info -- the usual case... + name = mkWiredInName mod (mkVarOcc str) key + imp = mkVanillaGlobal name ty info -- the usual case... in imp -- We lie and say the thing is imported; otherwise, we get into @@ -745,24 +941,19 @@ pcMiscPrelId key mod str ty info pc_bottoming_Id key mod name ty = pcMiscPrelId key mod name ty bottoming_info where - bottoming_info = noCafIdInfo - `setStrictnessInfo` mkStrictnessInfo ([wwStrict], True) - + strict_sig = mkStrictSig (mkTopDmdType [evalDmd] BotRes) + bottoming_info = noCafNoTyGenIdInfo `setAllStrictnessInfo` Just strict_sig -- these "bottom" out, no matter what their arguments generic_ERROR_ID u n = pc_bottoming_Id u pREL_ERR n errorTy --- Very useful... -noCafIdInfo = vanillaIdInfo `setCafInfo` NoCafRefs - (openAlphaTyVar:openBetaTyVar:_) = openAlphaTyVars openAlphaTy = mkTyVarTy openAlphaTyVar openBetaTy = mkTyVarTy openBetaTyVar errorTy :: Type -errorTy = mkUsgTy UsMany $ - mkSigmaTy [openAlphaTyVar] [] (mkFunTys [mkUsgTy UsOnce (mkListTy charTy)] - (mkUsgTy UsMany openAlphaTy)) +errorTy = mkSigmaTy [openAlphaTyVar] [] (mkFunTys [mkListTy charTy] + openAlphaTy) -- Notice the openAlphaTyVar. It says that "error" can be applied -- to unboxed as well as boxed types. This is OK because it never -- returns, so the return type is irrelevant.