X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcBinds.lhs;h=0db76d14f7898d657f0aaad191777f0c5cb1f338;hb=5de363ca9ebdb7d85e3c353c1cffdf0a1c11128e;hp=368ede48694003858982a0a45c2dbb018d9689f8;hpb=6eff70f0286a307a7266c87358493478b5f54933;p=ghc-hetmet.git diff --git a/compiler/typecheck/TcBinds.lhs b/compiler/typecheck/TcBinds.lhs index 368ede4..0db76d1 100644 --- a/compiler/typecheck/TcBinds.lhs +++ b/compiler/typecheck/TcBinds.lhs @@ -7,7 +7,7 @@ \begin{code} module TcBinds ( tcLocalBinds, tcTopBinds, tcHsBootSigs, tcPolyBinds, - PragFun, tcPrags, mkPragFun, + PragFun, tcSpecPrags, mkPragFun, TcSigInfo(..), SigFun, mkSigFun, badBootDeclErr ) where @@ -43,7 +43,6 @@ import BasicTypes import Outputable import FastString -import Data.List( partition ) import Control.Monad \end{code} @@ -326,41 +325,34 @@ tcPolyBinds top_lvl sig_fn prag_fn rec_group rec_tc bind_list ; let plan = decideGeneralisationPlan dflags top_lvl binder_names bind_list tc_sig_fn ; traceTc "Generalisation plan" (ppr plan) ; (binds, poly_ids) <- case plan of - NoGen -> tcPolyNoGen tc_sig_fn prag_fn rec_group rec_tc bind_list - InferGen mono -> tcPolyInfer top_lvl mono tc_sig_fn prag_fn rec_group rec_tc bind_list - CheckGen sig -> tcPolyCheck sig prag_fn rec_group rec_tc bind_list + NoGen -> tcPolyNoGen tc_sig_fn prag_fn rec_tc bind_list + InferGen mono -> tcPolyInfer top_lvl mono tc_sig_fn prag_fn rec_tc bind_list + CheckGen sig -> tcPolyCheck sig prag_fn rec_tc bind_list -- Check whether strict bindings are ok -- These must be non-recursive etc, and are not generalised -- They desugar to a case expression in the end ; checkStrictBinds top_lvl rec_group bind_list poly_ids - -- Warn about missing signatures - -- Do this only when we we have a type to offer - ; warn_missing_sigs <- doptM Opt_WarnMissingSigs - ; when (isTopLevel top_lvl && warn_missing_sigs) $ - mapM_ missingSigWarn (filter no_sig poly_ids) - ; return (binds, poly_ids) } where - no_sig id = isNothing (sig_fn (idName id)) - binder_names = collectHsBindListBinders bind_list loc = getLoc (head bind_list) -- TODO: location a bit awkward, but the mbinds have been -- dependency analysed and may no longer be adjacent +------------------ tcPolyNoGen :: TcSigFun -> PragFun - -> RecFlag -- Whether the group is really recursive -> RecFlag -- Whether it's recursive after breaking -- dependencies based on type signatures -> [LHsBind Name] -> TcM (LHsBinds TcId, [TcId]) -- No generalisation whatsoever -tcPolyNoGen tc_sig_fn prag_fn rec_group rec_tc bind_list - = do { (binds', mono_infos) <- tcMonoBinds tc_sig_fn True rec_tc bind_list +tcPolyNoGen tc_sig_fn prag_fn rec_tc bind_list + = do { (binds', mono_infos) <- tcMonoBinds tc_sig_fn (LetGblBndr prag_fn) + rec_tc bind_list ; mono_ids' <- mapM tc_mono_info mono_infos ; return (binds', mono_ids') } where @@ -368,16 +360,15 @@ tcPolyNoGen tc_sig_fn prag_fn rec_group rec_tc bind_list = do { mono_ty' <- zonkTcTypeCarefully (idType mono_id) -- Zonk, mainly to expose unboxed types to checkStrictBinds ; let mono_id' = setIdType mono_id mono_ty' - ; (mono_id'', _specs) <- tcPrags rec_group False False - mono_id' (prag_fn name) - ; return mono_id'' } - -- NB: tcPrags generates and error message for + ; _specs <- tcSpecPrags False mono_id' (prag_fn name) + ; return mono_id' } + -- NB: tcPrags generates error messages for -- specialisation pragmas for non-overloaded sigs + -- Indeed that is why we call it here! -- So we can safely ignore _specs ------------------ tcPolyCheck :: TcSigInfo -> PragFun - -> RecFlag -- Whether the group is really recursive -> RecFlag -- Whether it's recursive after breaking -- dependencies based on type signatures -> [LHsBind Name] @@ -387,16 +378,16 @@ tcPolyCheck :: TcSigInfo -> PragFun -- it has a signature, tcPolyCheck sig@(TcSigInfo { sig_id = id, sig_tvs = tvs, sig_scoped = scoped , sig_theta = theta, sig_loc = loc }) - prag_fn rec_group rec_tc bind_list + prag_fn rec_tc bind_list = do { ev_vars <- newEvVars theta ; let skol_info = SigSkol (FunSigCtxt (idName id)) ; (ev_binds, (binds', [mono_info])) <- checkConstraints skol_info emptyVarSet tvs ev_vars $ tcExtendTyVarEnv2 (scoped `zip` mkTyVarTys tvs) $ - tcMonoBinds (\_ -> Just sig) False rec_tc bind_list + tcMonoBinds (\_ -> Just sig) LetLclBndr rec_tc bind_list - ; export <- mkExport rec_group False prag_fn tvs theta mono_info + ; export <- mkExport prag_fn tvs theta mono_info ; let (_, poly_id, _, _) = export abs_bind = L loc $ AbsBinds @@ -405,19 +396,19 @@ tcPolyCheck sig@(TcSigInfo { sig_id = id, sig_tvs = tvs, sig_scoped = scoped , abs_exports = [export], abs_binds = binds' } ; return (unitBag abs_bind, [poly_id]) } +------------------ tcPolyInfer :: TopLevelFlag -> Bool -- True <=> apply the monomorphism restriction -> TcSigFun -> PragFun - -> RecFlag -- Whether the group is really recursive -> RecFlag -- Whether it's recursive after breaking -- dependencies based on type signatures -> [LHsBind Name] -> TcM (LHsBinds TcId, [TcId]) -tcPolyInfer top_lvl mono sig_fn prag_fn rec_group rec_tc bind_list +tcPolyInfer top_lvl mono sig_fn prag_fn rec_tc bind_list = do { ((binds', mono_infos), wanted) <- getConstraints $ - tcMonoBinds sig_fn False rec_tc bind_list + tcMonoBinds sig_fn LetLclBndr rec_tc bind_list ; unifyCtxts [sig | (_, Just sig, _) <- mono_infos] @@ -428,8 +419,7 @@ tcPolyInfer top_lvl mono sig_fn prag_fn rec_group rec_tc bind_list ; (qtvs, givens, ev_binds) <- simplifyInfer mono tau_tvs wanted - ; exports <- mapM (mkExport rec_group (length mono_infos > 1) - prag_fn qtvs (map evVarPred givens)) + ; exports <- mapM (mkExport prag_fn qtvs (map evVarPred givens)) mono_infos ; let poly_ids = [poly_id | (_, poly_id, _, _) <- exports] @@ -445,10 +435,7 @@ tcPolyInfer top_lvl mono sig_fn prag_fn rec_group rec_tc bind_list -------------- -mkExport :: RecFlag - -> Bool -- More than one variable is bound, so we'll desugar to - -- a tuple, so INLINE pragmas won't work - -> PragFun -> [TyVar] -> TcThetaType +mkExport :: PragFun -> [TyVar] -> TcThetaType -> MonoBindInfo -> TcM ([TyVar], Id, Id, TcSpecPrags) -- mkExport generates exports with @@ -462,17 +449,19 @@ mkExport :: RecFlag -- Pre-condition: the inferred_tvs are already zonked -mkExport rec_group multi_bind prag_fn inferred_tvs theta +mkExport prag_fn inferred_tvs theta (poly_name, mb_sig, mono_id) = do { (tvs, poly_id) <- mk_poly_id mb_sig -- poly_id has a zonked type - ; (poly_id', spec_prags) <- tcPrags rec_group multi_bind (notNull theta) - poly_id (prag_fn poly_name) + ; poly_id' <- addInlinePrags poly_id prag_sigs + + ; spec_prags <- tcSpecPrags (notNull theta) poly_id prag_sigs -- tcPrags requires a zonked poly_id ; return (tvs, poly_id', mono_id, SpecPrags spec_prags) } where + prag_sigs = prag_fn poly_name poly_ty = mkSigmaTy inferred_tvs theta (idType mono_id) mk_poly_id Nothing = do { poly_ty' <- zonkTcTypeCarefully poly_ty @@ -512,89 +501,43 @@ lhsBindArity (L _ (FunBind { fun_id = id, fun_matches = ms })) env = extendNameEnv env (unLoc id) (matchGroupArity ms) lhsBindArity _ env = env -- PatBind/VarBind -tcPrags :: RecFlag - -> Bool -- True <=> AbsBinds binds more than one variable - -> Bool -- True <=> function is overloaded - -> Id -> [LSig Name] - -> TcM (Id, [Located TcSpecPrag]) +------------------ +tcSpecPrags :: Bool -- True <=> function is overloaded + -> Id -> [LSig Name] + -> TcM [Located TcSpecPrag] -- Add INLINE and SPECIALSE pragmas -- INLINE prags are added to the (polymorphic) Id directly -- SPECIALISE prags are passed to the desugarer via TcSpecPrags -- Pre-condition: the poly_id is zonked -- Reason: required by tcSubExp -tcPrags _rec_group _multi_bind is_overloaded_id poly_id prag_sigs - = do { poly_id' <- tc_inl inl_sigs - - ; spec_prags <- mapM (wrapLocM (tcSpecPrag poly_id')) spec_sigs - - ; unless (null spec_sigs || is_overloaded_id) warn_discarded_spec - +tcSpecPrags is_overloaded_id poly_id prag_sigs + = do { unless (null spec_sigs || is_overloaded_id) warn_discarded_spec ; unless (null bad_sigs) warn_discarded_sigs - - ; return (poly_id', spec_prags) } + ; mapM (wrapLocM tc_spec) spec_sigs } where - (inl_sigs, other_sigs) = partition isInlineLSig prag_sigs - (spec_sigs, bad_sigs) = partition isSpecLSig other_sigs + spec_sigs = filter isSpecLSig prag_sigs + bad_sigs = filter is_bad_sig prag_sigs + is_bad_sig s = not (isSpecLSig s || isInlineLSig s) + + name = idName poly_id + poly_ty = idType poly_id + sig_ctxt = FunSigCtxt name + origin = SpecPragOrigin name + skol_info = SigSkol sig_ctxt + + tc_spec prag@(SpecSig _ hs_ty inl) + = addErrCtxt (spec_ctxt prag) $ + do { spec_ty <- tcHsSigType sig_ctxt hs_ty + ; wrap <- tcSubType origin skol_info poly_ty spec_ty + ; return (SpecPrag wrap inl) } + tc_spec sig = pprPanic "tcSpecPrag" (ppr sig) warn_discarded_spec = warnPrags poly_id spec_sigs $ ptext (sLit "SPECIALISE pragmas for non-overloaded function") - warn_dup_inline = warnPrags poly_id inl_sigs $ - ptext (sLit "Duplicate INLINE pragmas for") warn_discarded_sigs = warnPrags poly_id bad_sigs $ ptext (sLit "Discarding unexpected pragmas for") - ----------- - tc_inl [] = return poly_id - tc_inl (L loc (InlineSig _ prag) : other_inls) - = do { unless (null other_inls) (setSrcSpan loc warn_dup_inline) - ; return (poly_id `setInlinePragma` prag) } - tc_inl _ = panic "tc_inl" - -{- Earlier we tried to warn about - (a) INLINE for recursive function - (b) INLINE for function that is part of a multi-binder group - Code fragments below. But we want to allow - {-# INLINE f #-} - f x = x : g y - g y = ....f...f.... - even though they are mutually recursive. - So I'm just omitting the warnings for now - - | multi_bind && isInlinePragma prag - = do { setSrcSpan loc $ addWarnTc multi_bind_warn - ; return poly_id } - | otherwise - ; when (isInlinePragma prag && isRec rec_group) - (setSrcSpan loc (addWarnTc rec_inline_warn)) - - rec_inline_warn = ptext (sLit "INLINE pragma for recursive binder") - <+> quotes (ppr poly_id) <+> ptext (sLit "may be discarded") - - multi_bind_warn = hang (ptext (sLit "Discarding INLINE pragma for") <+> quotes (ppr poly_id)) - 2 (ptext (sLit "because it is bound by a pattern, or mutual recursion") ) --} - - -warnPrags :: Id -> [LSig Name] -> SDoc -> TcM () -warnPrags id bad_sigs herald - = addWarnTc (hang (herald <+> quotes (ppr id)) - 2 (ppr_sigs bad_sigs)) - where - ppr_sigs sigs = vcat (map (ppr . getLoc) sigs) - --------------- -tcSpecPrag :: TcId -> Sig Name -> TcM TcSpecPrag -tcSpecPrag poly_id prag@(SpecSig _ hs_ty inl) - = addErrCtxt (spec_ctxt prag) $ - do { let name = idName poly_id - sig_ctxt = FunSigCtxt name - ; spec_ty <- tcHsSigType sig_ctxt hs_ty - ; wrap <- tcSubType (SpecPragOrigin name) (SigSkol sig_ctxt) - (idType poly_id) spec_ty - ; return (SpecPrag wrap inl) } - where spec_ctxt prag = hang (ptext (sLit "In the SPECIALISE pragma")) 2 (ppr prag) -tcSpecPrag _ sig = pprPanic "tcSpecPrag" (ppr sig) -------------- -- If typechecking the binds fails, then return with each @@ -625,8 +568,7 @@ forall_a_a = mkForAllTy openAlphaTyVar (mkTyVarTy openAlphaTyVar) The signatures have been dealt with already. \begin{code} -tcMonoBinds :: TcSigFun - -> Bool -- True <=> no generalisation will be done for this binding +tcMonoBinds :: TcSigFun -> LetBndrSpec -> RecFlag -- Whether the binding is recursive for typechecking purposes -- i.e. the binders are mentioned in their RHSs, and -- we are not resuced by a type signature @@ -647,7 +589,7 @@ tcMonoBinds sig_fn no_gen is_rec setSrcSpan b_loc $ do { ((co_fn, matches'), rhs_ty) <- tcInfer (tcMatchesFun name inf matches) - ; mono_id <- newLetBndr no_gen name rhs_ty + ; mono_id <- newNoSigLetBndr no_gen name rhs_ty ; return (unitBag (L b_loc (FunBind { fun_id = L nm_loc mono_id, fun_infix = inf, fun_matches = matches', bind_fvs = fvs, fun_co_fn = co_fn, fun_tick = Nothing })), @@ -685,7 +627,7 @@ tcMonoBinds sig_fn no_gen _ binds -- it; hence the TcMonoBind data type in which the LHS is done but the RHS isn't data TcMonoBind -- Half completed; LHS done, RHS not done - = TcFunBind MonoBindInfo (Located TcId) Bool (MatchGroup Name) + = TcFunBind MonoBindInfo SrcSpan Bool (MatchGroup Name) | TcPatBind [MonoBindInfo] (LPat TcId) (GRHSs Name) TcSigmaType type MonoBindInfo = (Name, Maybe TcSigInfo, TcId) @@ -695,12 +637,15 @@ type MonoBindInfo = (Name, Maybe TcSigInfo, TcId) getMonoType :: MonoBindInfo -> TcTauType getMonoType (_,_,mono_id) = idType mono_id -tcLhs :: TcSigFun -> Bool -> HsBind Name -> TcM TcMonoBind +tcLhs :: TcSigFun -> LetBndrSpec -> HsBind Name -> TcM TcMonoBind tcLhs sig_fn no_gen (FunBind { fun_id = L nm_loc name, fun_infix = inf, fun_matches = matches }) - = do { mono_id <- newLhsBndr mb_sig no_gen name - ; return (TcFunBind (name, mb_sig, mono_id) (L nm_loc mono_id) inf matches) } - where - mb_sig = sig_fn name + | Just sig <- sig_fn name + = do { mono_id <- newSigLetBndr no_gen name sig + ; return (TcFunBind (name, Just sig, mono_id) nm_loc inf matches) } + | otherwise + = do { mono_ty <- newFlexiTyVarTy argTypeKind + ; mono_id <- newNoSigLetBndr no_gen name mono_ty + ; return (TcFunBind (name, Nothing, mono_id) nm_loc inf matches) } tcLhs sig_fn no_gen (PatBind { pat_lhs = pat, pat_rhs = grhss }) = do { let tc_pat exp_ty = tcLetPat sig_fn no_gen pat exp_ty $ @@ -720,28 +665,17 @@ tcLhs sig_fn no_gen (PatBind { pat_lhs = pat, pat_rhs = grhss }) tcLhs _ _ other_bind = pprPanic "tcLhs" (ppr other_bind) -- AbsBind, VarBind impossible ------------------ -newLhsBndr :: Maybe TcSigInfo -> Bool -> Name -> TcM TcId --- cf TcPat.tcPatBndr (LetPat case) -newLhsBndr (Just sig) no_gen name - | no_gen = return (sig_id sig) - | otherwise = do { mono_name <- newLocalName name - ; return (mkLocalId mono_name (sig_tau sig)) } - -newLhsBndr Nothing no_gen name - = do { mono_ty <- newFlexiTyVarTy argTypeKind - ; newLetBndr no_gen name mono_ty } - ------------------- tcRhs :: TcMonoBind -> TcM (HsBind TcId) -- When we are doing pattern bindings, or multiple function bindings at a time -- we *don't* bring any scoped type variables into scope -- Wny not? They are not completely rigid. -- That's why we have the special case for a single FunBind in tcMonoBinds -tcRhs (TcFunBind (_,_,mono_id) fun' inf matches) +tcRhs (TcFunBind (_,_,mono_id) loc inf matches) = do { (co_fn, matches') <- tcMatchesFun (idName mono_id) inf matches (idType mono_id) - ; return (FunBind { fun_id = fun', fun_infix = inf, fun_matches = matches' + ; return (FunBind { fun_id = L loc mono_id, fun_infix = inf + , fun_matches = matches' , fun_co_fn = co_fn , bind_fvs = placeHolderNames, fun_tick = Nothing }) } @@ -905,8 +839,6 @@ Then we get in fm - - %************************************************************************ %* * Signatures @@ -1082,18 +1014,15 @@ decideGeneralisationPlan dflags top_lvl _bndrs binds sig_fn | Just sig <- one_funbind_with_sig binds = if null (sig_tvs sig) && null (sig_theta sig) then NoGen -- Optimise common case else CheckGen sig - | (dopt Opt_MonoLocalBinds dflags + | (xopt Opt_MonoLocalBinds dflags && isNotTopLevel top_lvl) = NoGen | otherwise = InferGen mono_restriction --- | all no_sig bndrs = InferGen mono_restriction --- | otherwise = NoGen -- A mixture of function --- -- and pattern bindings where - mono_pat_binds = dopt Opt_MonoPatBinds dflags + mono_pat_binds = xopt Opt_MonoPatBinds dflags && any (is_pat_bind . unLoc) binds - mono_restriction = dopt Opt_MonomorphismRestriction dflags + mono_restriction = xopt Opt_MonomorphismRestriction dflags && any (restricted . unLoc) binds no_sig n = isNothing (sig_fn n) @@ -1191,35 +1120,4 @@ sigContextsCtxt sig1 sig2 where id1 = sig_id sig1 id2 = sig_id sig2 - ------------------------------------------------ -{- -badStrictSig :: Bool -> TcSigInfo -> SDoc -badStrictSig unlifted sig - = hang (ptext (sLit "Illegal polymorphic signature in") <+> msg) - 2 (ppr sig) - where - msg | unlifted = ptext (sLit "an unlifted binding") - | otherwise = ptext (sLit "a bang-pattern binding") - -restrictedBindSigErr :: [Name] -> SDoc -restrictedBindSigErr binder_names - = hang (ptext (sLit "Illegal type signature(s)")) - 2 (vcat [ptext (sLit "in a binding group for") <+> pprBinders binder_names, - ptext (sLit "that falls under the monomorphism restriction")]) - -genCtxt :: [Name] -> SDoc -genCtxt binder_names - = ptext (sLit "When generalising the type(s) for") <+> pprBinders binder_names --} - -missingSigWarn :: TcId -> TcM () -missingSigWarn id - = do { env0 <- tcInitTidyEnv - ; let (env1, tidy_ty) = tidyOpenType env0 (idType id) - ; addWarnTcM (env1, mk_msg tidy_ty) } - where - name = idName id - mk_msg ty = vcat [ptext (sLit "Definition but no type signature for") <+> quotes (ppr name), - sep [ptext (sLit "Inferred type:") <+> pprHsVar name <+> dcolon <+> ppr ty]] \end{code}