X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcExpr.lhs;h=e2f1d0cd5ea2ba4fbacde26712fe6ba18e87d805;hp=0da370bd4e31ede37ddafeaccf561491e2f89e11;hb=9da4639011348fb6c318e3cba4b08622f811d9c4;hpb=8c839b096be9a3fd44f4f681ed7f14fd95fe8ff9 diff --git a/compiler/typecheck/TcExpr.lhs b/compiler/typecheck/TcExpr.lhs index 0da370b..e2f1d0c 100644 --- a/compiler/typecheck/TcExpr.lhs +++ b/compiler/typecheck/TcExpr.lhs @@ -12,7 +12,7 @@ module TcExpr ( tcPolyExpr, tcPolyExprNC, #ifdef GHCI /* Only if bootstrapped */ import {-# SOURCE #-} TcSplice( tcSpliceExpr, tcBracket ) import HsSyn ( nlHsVar ) -import Id ( Id ) +import Id ( Id, idName ) import Name ( isExternalName ) import TcType ( isTauTy ) import TcEnv ( checkWellStaged ) @@ -21,39 +21,47 @@ import qualified DsMeta #endif import HsSyn ( HsExpr(..), LHsExpr, ArithSeqInfo(..), recBindFields, - HsMatchContext(..), HsRecordBinds, - mkHsCoerce, mkHsApp, mkHsDictApp, mkHsTyApp ) + HsMatchContext(..), HsRecordBinds, mkHsWrap, hsExplicitTvs, + mkHsApp, mkLHsWrap ) import TcHsSyn ( hsLitType ) import TcRnMonad import TcUnify ( tcInfer, tcSubExp, tcFunResTy, tcGen, boxyUnify, subFunTys, zapToMonotype, stripBoxyType, boxySplitListTy, boxySplitTyConApp, wrapFunResCoercion, preSubType, unBox ) import BasicTypes ( Arity, isMarkedStrict ) -import Inst ( newMethodFromName, newIPDict, instToId, - newDicts, newMethodWithGivenTy, tcInstStupidTheta ) +import Inst ( newMethodFromName, newIPDict, instCall, + newMethodWithGivenTy, instStupidTheta ) import TcBinds ( tcLocalBinds ) -import TcEnv ( tcLookup, tcLookupId, tcLookupDataCon, tcLookupField ) +import TcEnv ( tcLookup, tcLookupDataCon, tcLookupField, tcExtendTyVarEnv2 ) import TcArrows ( tcProc ) -import TcMatches ( tcMatchesCase, tcMatchLambda, tcDoStmts, TcMatchCtxt(..) ) +import TcMatches ( tcMatchesCase, tcMatchLambda, tcDoStmts, tcBody, + TcMatchCtxt(..) ) import TcHsType ( tcHsSigType, UserTypeCtxt(..) ) -import TcPat ( tcOverloadedLit, badFieldCon ) -import TcMType ( tcInstTyVars, newFlexiTyVarTy, newBoxyTyVars, readFilledBox, zonkTcTypes ) -import TcType ( TcType, TcSigmaType, TcRhoType, +import TcPat ( tcOverloadedLit, addDataConStupidTheta, badFieldCon ) +import TcMType ( tcInstTyVars, newFlexiTyVarTy, newBoxyTyVars, + readFilledBox, zonkTcTypes ) +import TcType ( TcType, TcSigmaType, TcRhoType, TvSubst, BoxySigmaType, BoxyRhoType, ThetaType, mkTyVarTys, mkFunTys, - tcMultiSplitSigmaTy, tcSplitFunTysN, tcSplitTyConApp_maybe, - isSigmaTy, mkFunTy, mkTyConApp, isLinearPred, + tcMultiSplitSigmaTy, tcSplitFunTysN, + tcSplitTyConApp_maybe, + isSigmaTy, mkFunTy, mkTyConApp, exactTyVarsOfType, exactTyVarsOfTypes, zipTopTvSubst, zipOpenTvSubst, substTys, substTyVar ) -import Kind ( argTypeKind ) - -import Id ( Id, idType, idName, recordSelectorFieldLabel, - isRecordSelector, isNaughtyRecordSelector, isDataConId_maybe ) -import DataCon ( DataCon, dataConFieldLabels, dataConStrictMarks, dataConSourceArity, - dataConWrapId, isVanillaDataCon, dataConTyVars, dataConOrigArgTys ) +import {- Kind parts of -} + Type ( argTypeKind ) + +import Id ( idType, recordSelectorFieldLabel, + isRecordSelector, isNaughtyRecordSelector, + isDataConId_maybe ) +import DataCon ( DataCon, dataConFieldLabels, dataConStrictMarks, + dataConSourceArity, + dataConWrapId, isVanillaDataCon, dataConUnivTyVars, + dataConOrigArgTys ) import Name ( Name ) -import TyCon ( FieldLabel, tyConStupidTheta, tyConDataCons, isEnumerationTyCon ) +import TyCon ( FieldLabel, tyConStupidTheta, tyConDataCons, + isEnumerationTyCon ) import Type ( substTheta, substTy ) import Var ( TyVar, tyVarKind ) import VarSet ( emptyVarSet, elemVarSet, unionVarSet ) @@ -68,7 +76,7 @@ import PrimOp ( tagToEnumKey ) import DynFlags import StaticFlags ( opt_NoMethodSharing ) import HscTypes ( TyThing(..) ) -import SrcLoc ( Located(..), unLoc, noLoc, getLoc ) +import SrcLoc ( Located(..), unLoc ) import Util import ListSetOps ( assocMaybe ) import Maybes ( catMaybes ) @@ -103,10 +111,10 @@ tcPolyExpr expr res_ty tcPolyExprNC expr res_ty | isSigmaTy res_ty - = do { (gen_fn, expr') <- tcGen res_ty emptyVarSet (tcPolyExprNC expr) + = do { (gen_fn, expr') <- tcGen res_ty emptyVarSet (\_ -> tcPolyExprNC expr) -- Note the recursive call to tcPolyExpr, because the -- type may have multiple layers of for-alls - ; return (L (getLoc expr') (mkHsCoerce gen_fn (unLoc expr'))) } + ; return (mkLHsWrap gen_fn expr') } | otherwise = tcMonoExpr expr res_ty @@ -182,7 +190,7 @@ tcExpr (HsIPVar ip) res_ty ; co_fn <- tcSubExp ip_ty res_ty ; (ip', inst) <- newIPDict (IPOccOrigin ip) ip ip_ty ; extendLIE inst - ; return (mkHsCoerce co_fn (HsIPVar ip')) } + ; return (mkHsWrap co_fn (HsIPVar ip')) } tcExpr (HsApp e1 e2) res_ty = go e1 [e2] @@ -196,13 +204,18 @@ tcExpr (HsApp e1 e2) res_ty tcExpr (HsLam match) res_ty = do { (co_fn, match') <- tcMatchLambda match res_ty - ; return (mkHsCoerce co_fn (HsLam match')) } + ; return (mkHsWrap co_fn (HsLam match')) } tcExpr in_expr@(ExprWithTySig expr sig_ty) res_ty = do { sig_tc_ty <- tcHsSigType ExprSigCtxt sig_ty - ; expr' <- tcPolyExpr expr sig_tc_ty + + -- Remember to extend the lexical type-variable environment + ; (gen_fn, expr') <- tcGen sig_tc_ty emptyVarSet (\ skol_tvs res_ty -> + tcExtendTyVarEnv2 (hsExplicitTvs sig_ty `zip` mkTyVarTys skol_tvs) $ + tcPolyExprNC expr res_ty) + ; co_fn <- tcSubExp sig_tc_ty res_ty - ; return (mkHsCoerce co_fn (ExprWithTySigOut expr' sig_ty)) } + ; return (mkHsWrap co_fn (ExprWithTySigOut (mkLHsWrap gen_fn expr') sig_ty)) } tcExpr (HsType ty) res_ty = failWithTc (text "Can't handle type argument:" <+> ppr ty) @@ -248,7 +261,7 @@ tcExpr in_expr@(SectionL arg1 lop@(L loc op)) res_ty tcExpr in_expr@(SectionR lop@(L loc op) arg2) res_ty = do { (co_fn, (op', arg2')) <- subFunTys doc 1 res_ty $ \ [arg1_ty'] res_ty' -> tcApp op 2 (tc_args arg1_ty') res_ty' - ; return (mkHsCoerce co_fn (SectionR (L loc op') arg2')) } + ; return (mkHsWrap co_fn (SectionR (L loc op') arg2')) } where doc = ptext SLIT("The section") <+> quotes (ppr in_expr) <+> ptext SLIT("takes one argument") @@ -282,7 +295,7 @@ tcExpr (HsCase scrut matches) exp_ty ; return (HsCase scrut' matches') } where match_ctxt = MC { mc_what = CaseAlt, - mc_body = tcPolyExpr } + mc_body = tcBody } tcExpr (HsIf pred b1 b2) res_ty = do { pred' <- addErrCtxt (predCtxt pred) $ @@ -440,7 +453,7 @@ tcExpr expr@(RecordUpd record_expr rbinds _ _) res_ty -- A constructor is only relevant to this process if -- it contains *all* the fields that are being updated con1 = head relevant_cons -- A representative constructor - con1_tyvars = dataConTyVars con1 + con1_tyvars = dataConUnivTyVars con1 con1_flds = dataConFieldLabels con1 con1_arg_tys = dataConOrigArgTys con1 common_tyvars = exactTyVarsOfTypes [ty | (fld,ty) <- con1_flds `zip` con1_arg_tys @@ -481,17 +494,14 @@ tcExpr expr@(RecordUpd record_expr rbinds _ _) res_ty -- dictionaries for the data type context, since we are going to -- do pattern matching over the data cons. -- - -- What dictionaries do we need? - -- We just take the context of the first data constructor - -- This isn't right, but I just can't bear to union up all the relevant ones + -- What dictionaries do we need? The tyConStupidTheta tells us. let theta' = substTheta inst_env (tyConStupidTheta tycon) in - newDicts RecordUpdOrigin theta' `thenM` \ dicts -> - extendLIEs dicts `thenM_` + instStupidTheta RecordUpdOrigin theta' `thenM_` -- Phew! - returnM (mkHsCoerce co_fn (RecordUpd record_expr' rbinds' record_ty result_record_ty)) + returnM (mkHsWrap co_fn (RecordUpd record_expr' rbinds' record_ty result_record_ty)) \end{code} @@ -633,10 +643,11 @@ tcIdApp :: Name -- Function -- Then fres <= bx_(k+1) -> ... -> bx_n -> res_ty tcIdApp fun_name n_args arg_checker res_ty - = do { fun_id <- lookupFun (OccurrenceOf fun_name) fun_name + = do { let orig = OccurrenceOf fun_name + ; (fun, fun_ty) <- lookupFun orig fun_name -- Split up the function type - ; let (tv_theta_prs, rho) = tcMultiSplitSigmaTy (idType fun_id) + ; let (tv_theta_prs, rho) = tcMultiSplitSigmaTy fun_ty (fun_arg_tys, fun_res_ty) = tcSplitFunTysN rho n_args qtvs = concatMap fst tv_theta_prs -- Quantified tyvars @@ -678,9 +689,9 @@ tcIdApp fun_name n_args arg_checker res_ty -- And pack up the results -- By applying the coercion just to the *function* we can make -- tcFun work nicely for OpApp and Sections too - ; fun' <- instFun fun_id qtvs qtys'' tv_theta_prs + ; fun' <- instFun orig fun res_subst tv_theta_prs ; co_fn' <- wrapFunResCoercion fun_arg_tys' co_fn - ; return (mkHsCoerce co_fn' fun', args') } + ; return (mkHsWrap co_fn' fun', args') } \end{code} Note [Silly type synonyms in smart-app] @@ -707,10 +718,10 @@ tcId :: InstOrigin -> TcM (HsExpr TcId) tcId orig fun_name res_ty = do { traceTc (text "tcId" <+> ppr fun_name <+> ppr res_ty) - ; fun_id <- lookupFun orig fun_name + ; (fun, fun_ty) <- lookupFun orig fun_name -- Split up the function type - ; let (tv_theta_prs, fun_tau) = tcMultiSplitSigmaTy (idType fun_id) + ; let (tv_theta_prs, fun_tau) = tcMultiSplitSigmaTy fun_ty qtvs = concatMap fst tv_theta_prs -- Quantified tyvars tau_qtvs = exactTyVarsOfType fun_tau -- Mentioned in the tau part ; qtv_tys <- preSubType qtvs tau_qtvs fun_tau res_ty @@ -722,8 +733,8 @@ tcId orig fun_name res_ty ; co_fn <- tcFunResTy fun_name fun_tau' res_ty -- And pack up the results - ; fun' <- instFun fun_id qtvs qtv_tys tv_theta_prs - ; return (mkHsCoerce co_fn fun') } + ; fun' <- instFun orig fun res_subst tv_theta_prs + ; return (mkHsWrap co_fn fun') } -- Note [Push result type in] -- @@ -756,63 +767,43 @@ tcSyntaxOp orig (HsVar op) ty = tcId orig op ty tcSyntaxOp orig other ty = pprPanic "tcSyntaxOp" (ppr other) --------------------------- -instFun :: TcId - -> [TyVar] -> [TcType] -- Quantified type variables and - -- their instantiating types - -> [([TyVar], ThetaType)] -- Stuff to instantiate +instFun :: InstOrigin + -> HsExpr TcId + -> TvSubst -- The instantiating substitution + -> [([TyVar], ThetaType)] -- Stuff to instantiate -> TcM (HsExpr TcId) -instFun fun_id qtvs qtv_tys [] - = return (HsVar fun_id) -- Common short cut -instFun fun_id qtvs qtv_tys tv_theta_prs - = do { -- Horrid check for tagToEnum; see Note [tagToEnum#] - checkBadTagToEnumCall fun_id qtv_tys +instFun orig fun subst [] + = return fun -- Common short cut - ; let subst = zipOpenTvSubst qtvs qtv_tys - ty_theta_prs' = map subst_pr tv_theta_prs - subst_pr (tvs, theta) = (map (substTyVar subst) tvs, - substTheta subst theta) +instFun orig fun subst tv_theta_prs + = do { let ty_theta_prs' = map subst_pr tv_theta_prs - -- The ty_theta_prs' is always non-empty - ((tys1',theta1') : further_prs') = ty_theta_prs' - - -- First, chuck in the constraints from - -- the "stupid theta" of a data constructor (sigh) - ; case isDataConId_maybe fun_id of - Just con -> tcInstStupidTheta con tys1' - Nothing -> return () - - ; if want_method_inst theta1' - then do { meth_id <- newMethodWithGivenTy orig fun_id tys1' - -- See Note [Multiple instantiation] - ; go (HsVar meth_id) further_prs' } - else go (HsVar fun_id) ty_theta_prs' - } + -- Make two ad-hoc checks + ; doStupidChecks fun ty_theta_prs' + + -- Now do normal instantiation + ; go True fun ty_theta_prs' } where - orig = OccurrenceOf (idName fun_id) + subst_pr (tvs, theta) + = (map (substTyVar subst) tvs, substTheta subst theta) + + go _ fun [] = return fun - go fun [] = return fun + go True (HsVar fun_id) ((tys,theta) : prs) + | want_method_inst theta + = do { meth_id <- newMethodWithGivenTy orig fun_id tys + ; go False (HsVar meth_id) prs } + -- Go round with 'False' to prevent further use + -- of newMethod: see Note [Multiple instantiation] - go fun ((tys, theta) : prs) - = do { dicts <- newDicts orig theta - ; extendLIEs dicts - ; let the_app = unLoc $ mkHsDictApp (mkHsTyApp (noLoc fun) tys) - (map instToId dicts) - ; go the_app prs } + go _ fun ((tys, theta) : prs) + = do { co_fn <- instCall orig tys theta + ; go False (HsWrap co_fn fun) prs } - -- Hack Alert (want_method_inst)! -- See Note [No method sharing] - -- If f :: (%x :: T) => Int -> Int - -- Then if we have two separate calls, (f 3, f 4), we cannot - -- make a method constraint that then gets shared, thus: - -- let m = f %x in (m 3, m 4) - -- because that loses the linearity of the constraint. - -- The simplest thing to do is never to construct a method constraint - -- in the first place that has a linear implicit parameter in it. - want_method_inst theta = not (null theta) -- Overloaded - && not (any isLinearPred theta) -- Not linear + want_method_inst theta = not (null theta) -- Overloaded && not opt_NoMethodSharing - -- See Note [No method sharing] below \end{code} Note [Multiple instantiation] @@ -895,20 +886,32 @@ Here's are two cases that should fail \begin{code} -checkBadTagToEnumCall :: Id -> [TcType] -> TcM () -checkBadTagToEnumCall fun_id tys - | fun_id `hasKey` tagToEnumKey +doStupidChecks :: HsExpr TcId + -> [([TcType], ThetaType)] + -> TcM () +-- Check two tiresome and ad-hoc cases +-- (a) the "stupid theta" for a data con; add the constraints +-- from the "stupid theta" of a data constructor (sigh) +-- (b) deal with the tagToEnum# problem: see Note [tagToEnum#] + +doStupidChecks (HsVar fun_id) ((tys,_):_) + | Just con <- isDataConId_maybe fun_id -- (a) + = addDataConStupidTheta con tys + + | fun_id `hasKey` tagToEnumKey -- (b) = do { tys' <- zonkTcTypes tys ; checkTc (ok tys') (tagToEnumError tys') } - | otherwise -- Vastly common case - = return () where ok [] = False ok (ty:tys) = case tcSplitTyConApp_maybe ty of Just (tc,_) -> isEnumerationTyCon tc Nothing -> False +doStupidChecks fun tv_theta_prs + = return () -- The common case + + tagToEnumError tys = hang (ptext SLIT("Bad call to tagToEnum#") <+> at_type) 2 (vcat [ptext SLIT("Specify the type by giving a type signature"), @@ -925,40 +928,47 @@ tagToEnumError tys %************************************************************************ \begin{code} -lookupFun :: InstOrigin -> Name -> TcM TcId +lookupFun :: InstOrigin -> Name -> TcM (HsExpr TcId, TcType) lookupFun orig id_name = do { thing <- tcLookup id_name ; case thing of - AGlobal (ADataCon con) -> return (dataConWrapId con) + AGlobal (ADataCon con) -> return (HsVar wrap_id, idType wrap_id) + where + wrap_id = dataConWrapId con AGlobal (AnId id) | isNaughtyRecordSelector id -> failWithTc (naughtyRecordSel id) - | otherwise -> return id + | otherwise -> return (HsVar id, idType id) -- A global cannot possibly be ill-staged -- nor does it need the 'lifting' treatment -#ifndef GHCI - ATcId id th_level _ -> return id -- Non-TH case -#else - ATcId id th_level _ -> do { use_stage <- getStage -- TH case - ; thLocalId orig id_name id th_level use_stage } -#endif + ATcId { tct_id = id, tct_type = ty, tct_co = mb_co, tct_level = lvl } + -> do { thLocalId orig id ty lvl + ; case mb_co of + Nothing -> return (HsVar id, ty) -- Wobbly, or no free vars + Just co -> return (mkHsWrap co (HsVar id), ty) } other -> failWithTc (ppr other <+> ptext SLIT("used where a value identifer was expected")) } -#ifdef GHCI /* GHCI and TH is on */ +#ifndef GHCI /* GHCI and TH is off */ -------------------------------------- -- thLocalId : Check for cross-stage lifting -thLocalId orig id_name id th_bind_lvl (Brack use_lvl ps_var lie_var) - | use_lvl > th_bind_lvl - = thBrackId orig id_name id ps_var lie_var -thLocalId orig id_name id th_bind_lvl use_stage - = do { checkWellStaged (quotes (ppr id)) th_bind_lvl use_stage - ; return id } +thLocalId orig id id_ty th_bind_lvl + = return () + +#else /* GHCI and TH is on */ +thLocalId orig id id_ty th_bind_lvl + = do { use_stage <- getStage -- TH case + ; case use_stage of + Brack use_lvl ps_var lie_var | use_lvl > th_bind_lvl + -> thBrackId orig id ps_var lie_var + other -> do { checkWellStaged (quotes (ppr id)) th_bind_lvl use_stage + ; return id } + } -------------------------------------- -thBrackId orig id_name id ps_var lie_var +thBrackId orig id ps_var lie_var | isExternalName id_name = -- Top-level identifiers in this module, -- (which have External Names) @@ -1005,6 +1015,8 @@ thBrackId orig id_name id ps_var lie_var ; writeMutVar ps_var ((id_name, nlHsApp (nlHsVar lift) (nlHsVar id)) : ps) ; return id } } + where + id_name = idName id #endif /* GHCI */ \end{code} @@ -1048,7 +1060,7 @@ tcRecordBinds data_con arg_tys rbinds | Just field_ty <- assocMaybe flds_w_tys field_lbl = addErrCtxt (fieldCtxt field_lbl) $ do { rhs' <- tcPolyExprNC rhs field_ty - ; sel_id <- tcLookupId field_lbl + ; sel_id <- tcLookupField field_lbl ; ASSERT( isRecordSelector sel_id ) return (Just (L loc sel_id, rhs')) } | otherwise