From 786932468faac49aafe20b65eabc8bdf465fbc9d Mon Sep 17 00:00:00 2001 From: "simonpj@microsoft.com" Date: Tue, 25 May 2010 11:39:10 +0000 Subject: [PATCH] Refactor (again) the handling of default methods This patch fixes Trac #4056, by a) tidying up the treatment of default method names b) removing the 'module' argument to newTopSrcBinder The details aren't that interesting, but the result is much tidier. The original bug was a 'nameModule' panic, caused by trying to find the module of a top-level name. But TH quotes generate Internal top-level names that don't have a module, and that is generally a good thing. Fixing that in turn led to the default-method refactoring, which also makes the Name for a default method be handled in the same way as other derived names, generated in BuildTyCl via a call newImplicitBinder. Hurrah. --- compiler/basicTypes/BasicTypes.lhs | 28 +++++++++++- compiler/basicTypes/RdrName.lhs | 9 ---- compiler/iface/BinIface.hs | 15 +++---- compiler/iface/BuildTyCl.lhs | 37 ++++++++++------ compiler/iface/IfaceSyn.lhs | 2 +- compiler/iface/MkIface.lhs | 6 ++- compiler/rename/RnBinds.lhs | 3 +- compiler/rename/RnEnv.lhs | 15 ++++--- compiler/rename/RnNames.lhs | 9 ++-- compiler/rename/RnPat.lhs | 19 ++++---- compiler/typecheck/TcClassDcl.lhs | 86 +++++++++++++++--------------------- compiler/typecheck/TcInstDcls.lhs | 6 +-- compiler/typecheck/TcSplice.lhs | 11 ++++- compiler/types/Class.lhs | 6 +-- 14 files changed, 136 insertions(+), 116 deletions(-) diff --git a/compiler/basicTypes/BasicTypes.lhs b/compiler/basicTypes/BasicTypes.lhs index d4863dd..022a8fc 100644 --- a/compiler/basicTypes/BasicTypes.lhs +++ b/compiler/basicTypes/BasicTypes.lhs @@ -21,7 +21,7 @@ module BasicTypes( Arity, - FunctionOrData(..), + FunctionOrData(..), WarningTxt(..), @@ -57,6 +57,8 @@ module BasicTypes( HsBang(..), isBanged, isMarkedUnboxed, StrictnessMark(..), isMarkedStrict, + DefMethSpec(..), + CompilerPhase, Activation(..), isActive, isNeverActive, isAlwaysActive, isEarlyActive, RuleMatchInfo(..), isConLike, isFunLike, @@ -522,7 +524,7 @@ instance Show OccInfo where %************************************************************************ %* * -\subsection{Strictness indication} + Strictness indication %* * %************************************************************************ @@ -575,6 +577,28 @@ isMarkedStrict _ = True -- All others are strict %************************************************************************ %* * + Default method specfication +%* * +%************************************************************************ + +The DefMethSpec enumeration just indicates what sort of default method +is used for a class. It is generated from source code, and present in +interface files; it is converted to Class.DefMeth before begin put in a +Class object. + +\begin{code} +data DefMethSpec = NoDM -- No default method + | VanillaDM -- Default method given with polymorphic code + | GenericDM -- Default method given with generic code + +instance Outputable DefMethSpec where + ppr NoDM = empty + ppr VanillaDM = ptext (sLit "{- Has default method -}") + ppr GenericDM = ptext (sLit "{- Has generic default method -}") +\end{code} + +%************************************************************************ +%* * \subsection{Success flag} %* * %************************************************************************ diff --git a/compiler/basicTypes/RdrName.lhs b/compiler/basicTypes/RdrName.lhs index 69b791f..6db15bc 100644 --- a/compiler/basicTypes/RdrName.lhs +++ b/compiler/basicTypes/RdrName.lhs @@ -30,7 +30,6 @@ module RdrName ( mkRdrUnqual, mkRdrQual, mkUnqual, mkVarUnqual, mkQual, mkOrig, nameRdrName, getRdrName, - mkDerivedRdrName, -- ** Destruction rdrNameOcc, rdrNameSpace, setRdrNameSpace, @@ -164,14 +163,6 @@ mkOrig :: Module -> OccName -> RdrName mkOrig mod occ = Orig mod occ --------------- --- | Produce an original 'RdrName' whose module that of a parent 'Name' but its 'OccName' --- is derived from that of it's parent using the supplied function -mkDerivedRdrName :: Name -> (OccName -> OccName) -> RdrName -mkDerivedRdrName parent mk_occ - = ASSERT2( isExternalName parent, ppr parent ) - mkOrig (nameModule parent) (mk_occ (nameOccName parent)) - ---------------- -- These two are used when parsing source files -- They do encode the module and occurrence names mkUnqual :: NameSpace -> FastString -> RdrName diff --git a/compiler/iface/BinIface.hs b/compiler/iface/BinIface.hs index e608421..4d3f619 100644 --- a/compiler/iface/BinIface.hs +++ b/compiler/iface/BinIface.hs @@ -23,7 +23,6 @@ import IfaceSyn import Module import Name import VarEnv -import Class import DynFlags import UniqFM import UniqSupply @@ -655,16 +654,16 @@ instance Binary RecFlag where 0 -> do return Recursive _ -> do return NonRecursive -instance Binary DefMeth where - put_ bh NoDefMeth = putByte bh 0 - put_ bh DefMeth = putByte bh 1 - put_ bh GenDefMeth = putByte bh 2 +instance Binary DefMethSpec where + put_ bh NoDM = putByte bh 0 + put_ bh VanillaDM = putByte bh 1 + put_ bh GenericDM = putByte bh 2 get bh = do h <- getByte bh case h of - 0 -> return NoDefMeth - 1 -> return DefMeth - _ -> return GenDefMeth + 0 -> return NoDM + 1 -> return VanillaDM + _ -> return GenericDM instance Binary FixityDirection where put_ bh InfixL = do diff --git a/compiler/iface/BuildTyCl.lhs b/compiler/iface/BuildTyCl.lhs index 738a5e3..4c570a0 100644 --- a/compiler/iface/BuildTyCl.lhs +++ b/compiler/iface/BuildTyCl.lhs @@ -6,7 +6,7 @@ \begin{code} module BuildTyCl ( buildSynTyCon, buildAlgTyCon, buildDataCon, - buildClass, + TcMethInfo, buildClass, mkAbstractTyConRhs, mkOpenDataTyConRhs, mkNewTyConRhs, mkDataTyConRhs, setAssocFamilyPermutation ) where @@ -246,14 +246,17 @@ mkDataConStupidTheta tycon arg_tys univ_tvs ------------------------------------------------------ \begin{code} +type TcMethInfo = (Name, DefMethSpec, Type) -- A temporary intermediate, to communicate + -- between tcClassSigs and buildClass + buildClass :: Bool -- True <=> do not include unfoldings -- on dict selectors -- Used when importing a class without -O -> Name -> [TyVar] -> ThetaType - -> [FunDep TyVar] -- Functional dependencies - -> [TyThing] -- Associated types - -> [(Name, DefMeth, Type)] -- Method info - -> RecFlag -- Info for type constructor + -> [FunDep TyVar] -- Functional dependencies + -> [TyThing] -- Associated types + -> [TcMethInfo] -- Method info + -> RecFlag -- Info for type constructor -> TcRnIf m n Class buildClass no_unf class_name tvs sc_theta fds ats sig_stuff tc_isrec @@ -266,11 +269,7 @@ buildClass no_unf class_name tvs sc_theta fds ats sig_stuff tc_isrec ; fixM (\ rec_clas -> do { -- Only name generation inside loop - let { rec_tycon = classTyCon rec_clas - ; op_tys = [ty | (_,_,ty) <- sig_stuff] - ; op_names = [op | (op,_,_) <- sig_stuff] - ; op_items = [ (mkDictSelId no_unf op_name rec_clas, dm_info) - | (op_name, dm_info, _) <- sig_stuff ] } + ; op_items <- mapM (mk_op_item rec_clas) sig_stuff -- Build the selector id and default method id ; let n_value_preds = count (not . isEqPred) sc_theta @@ -301,9 +300,12 @@ buildClass no_unf class_name tvs sc_theta fds ats sig_stuff tc_isrec -- as ordinary arguments. That means that in the case of -- class C a => D a -- we don't get a newtype with no arguments! - args = sc_sel_names ++ op_names - arg_tys = map mkPredTy sc_theta ++ op_tys - + args = sc_sel_names ++ op_names + arg_tys = map mkPredTy sc_theta ++ op_tys + op_tys = [ty | (_,_,ty) <- sig_stuff] + op_names = [op | (op,_,_) <- sig_stuff] + rec_tycon = classTyCon rec_clas + ; dict_con <- buildDataCon datacon_name False -- Not declared infix (map (const HsNoBang) args) @@ -339,6 +341,15 @@ buildClass no_unf class_name tvs sc_theta fds ats sig_stuff tc_isrec ; traceIf (text "buildClass" <+> ppr tycon) ; return result })} + where + mk_op_item :: Class -> TcMethInfo -> TcRnIf n m ClassOpItem + mk_op_item rec_clas (op_name, dm_spec, _) + = do { dm_info <- case dm_spec of + NoDM -> return NoDefMeth + GenericDM -> return GenDefMeth + VanillaDM -> do { dm_name <- newImplicitBinder op_name mkDefaultMethodOcc + ; return (DefMeth dm_name) } + ; return (mkDictSelId no_unf op_name rec_clas, dm_info) } \end{code} Note [Class newtypes and equality predicates] diff --git a/compiler/iface/IfaceSyn.lhs b/compiler/iface/IfaceSyn.lhs index 44dd34a..282752b 100644 --- a/compiler/iface/IfaceSyn.lhs +++ b/compiler/iface/IfaceSyn.lhs @@ -105,7 +105,7 @@ data IfaceDecl -- beyond .NET ifExtName :: Maybe FastString } -data IfaceClassOp = IfaceClassOp OccName DefMeth IfaceType +data IfaceClassOp = IfaceClassOp OccName DefMethSpec IfaceType -- Nothing => no default method -- Just False => ordinary polymorphic default method -- Just True => generic default method diff --git a/compiler/iface/MkIface.lhs b/compiler/iface/MkIface.lhs index 8849b1e..07b1268 100644 --- a/compiler/iface/MkIface.lhs +++ b/compiler/iface/MkIface.lhs @@ -1333,7 +1333,7 @@ tyThingToIfaceDecl (AClass clas) toIfaceClassOp (sel_id, def_meth) = ASSERT(sel_tyvars == clas_tyvars) - IfaceClassOp (getOccName sel_id) def_meth (toIfaceType op_ty) + IfaceClassOp (getOccName sel_id) (toDmSpec def_meth) (toIfaceType op_ty) where -- Be careful when splitting the type, because of things -- like class Foo a where @@ -1343,6 +1343,10 @@ tyThingToIfaceDecl (AClass clas) (sel_tyvars, rho_ty) = splitForAllTys (idType sel_id) op_ty = funResultTy rho_ty + toDmSpec NoDefMeth = NoDM + toDmSpec GenDefMeth = GenericDM + toDmSpec (DefMeth _) = VanillaDM + toIfaceFD (tvs1, tvs2) = (map getFS tvs1, map getFS tvs2) tyThingToIfaceDecl (ATyCon tycon) diff --git a/compiler/rename/RnBinds.lhs b/compiler/rename/RnBinds.lhs index 8749711..ee45f61 100644 --- a/compiler/rename/RnBinds.lhs +++ b/compiler/rename/RnBinds.lhs @@ -158,8 +158,7 @@ rnTopBindsLHS :: MiniFixityEnv -> HsValBinds RdrName -> RnM (HsValBindsLR Name RdrName) rnTopBindsLHS fix_env binds - = do { mod <- getModule - ; rnValBindsLHSFromDoc (topRecNameMaker mod fix_env) binds } + = rnValBindsLHSFromDoc (topRecNameMaker fix_env) binds rnTopBindsRHS :: NameSet -- Names bound by these binds -> HsValBindsLR Name RdrName diff --git a/compiler/rename/RnEnv.lhs b/compiler/rename/RnEnv.lhs index 1a05139..c2b7a7b 100644 --- a/compiler/rename/RnEnv.lhs +++ b/compiler/rename/RnEnv.lhs @@ -51,7 +51,7 @@ import NameEnv import UniqFM import DataCon ( dataConFieldLabels ) import OccName -import Module ( Module, ModuleName ) +import Module ( ModuleName ) import PrelNames ( mkUnboundName, rOOT_MAIN, iNTERACTIVE, consDataConKey, forall_tv_RDR ) import Unique @@ -82,8 +82,8 @@ thenM = (>>=) %********************************************************* \begin{code} -newTopSrcBinder :: Module -> Located RdrName -> RnM Name -newTopSrcBinder this_mod (L loc rdr_name) +newTopSrcBinder :: Located RdrName -> RnM Name +newTopSrcBinder (L loc rdr_name) | Just name <- isExact_maybe rdr_name = -- This is here to catch -- (a) Exact-name binders created by Template Haskell @@ -95,13 +95,15 @@ newTopSrcBinder this_mod (L loc rdr_name) -- data T = (,) Int Int -- unless we are in GHC.Tup ASSERT2( isExternalName name, ppr name ) - do { unless (this_mod == nameModule name) + do { this_mod <- getModule + ; unless (this_mod == nameModule name) (addErrAt loc (badOrigBinding rdr_name)) ; return name } | Just (rdr_mod, rdr_occ) <- isOrig_maybe rdr_name - = do { unless (rdr_mod == this_mod || rdr_mod == rOOT_MAIN) + = do { this_mod <- getModule + ; unless (rdr_mod == this_mod || rdr_mod == rOOT_MAIN) (addErrAt loc (badOrigBinding rdr_name)) -- When reading External Core we get Orig names as binders, -- but they should agree with the module gotten from the monad @@ -137,7 +139,8 @@ newTopSrcBinder this_mod (L loc rdr_name) ; return (mkInternalName uniq (rdrNameOcc rdr_name) loc) } else -- Normal case - newGlobalBinder this_mod (rdrNameOcc rdr_name) loc } + do { this_mod <- getModule + ; newGlobalBinder this_mod (rdrNameOcc rdr_name) loc } } \end{code} %********************************************************* diff --git a/compiler/rename/RnNames.lhs b/compiler/rename/RnNames.lhs index 2c0a45b..9fcfd28 100644 --- a/compiler/rename/RnNames.lhs +++ b/compiler/rename/RnNames.lhs @@ -410,7 +410,6 @@ get_local_binders gbl_env (HsGroup {hs_valds = ValBindsIn _ val_sigs, ; val_names <- mapM new_simple val_bndrs ; return (val_names ++ tc_names ++ ti_names) } where - mod = tcg_mod gbl_env is_hs_boot = isHsBoot (tcg_src gbl_env) ; for_hs_bndrs :: [Located RdrName] @@ -424,19 +423,19 @@ get_local_binders gbl_env (HsGroup {hs_valds = ValBindsIn _ val_sigs, new_simple :: Located RdrName -> RnM (GenAvailInfo Name) new_simple rdr_name = do - nm <- newTopSrcBinder mod rdr_name + nm <- newTopSrcBinder rdr_name return (Avail nm) new_tc tc_decl -- NOT for type/data instances - = do { main_name <- newTopSrcBinder mod main_rdr - ; sub_names <- mapM (newTopSrcBinder mod) sub_rdrs + = do { main_name <- newTopSrcBinder main_rdr + ; sub_names <- mapM newTopSrcBinder sub_rdrs ; return (AvailTC main_name (main_name : sub_names)) } where (main_rdr : sub_rdrs) = hsTyClDeclBinders tc_decl new_ti tc_name_env ti_decl -- ONLY for type/data instances = do { main_name <- lookupFamInstDeclBndr tc_name_env main_rdr - ; sub_names <- mapM (newTopSrcBinder mod) sub_rdrs + ; sub_names <- mapM newTopSrcBinder sub_rdrs ; return (AvailTC main_name sub_names) } -- main_name is not bound here! where diff --git a/compiler/rename/RnPat.lhs b/compiler/rename/RnPat.lhs index 58c2c34..fffd80f 100644 --- a/compiler/rename/RnPat.lhs +++ b/compiler/rename/RnPat.lhs @@ -45,8 +45,8 @@ import PrelNames import Constants ( mAX_TUPLE_SIZE ) import Name import NameSet -import Module import RdrName +import BasicTypes import ListSetOps ( removeDups, minusList ) import Outputable import SrcLoc @@ -135,15 +135,14 @@ data NameMaker | LetMk -- Let bindings, incl top level -- Do *not* check for unused bindings - (Maybe Module) -- Just m => top level of module m - -- Nothing => not top level + TopLevelFlag MiniFixityEnv -topRecNameMaker :: Module -> MiniFixityEnv -> NameMaker -topRecNameMaker mod fix_env = LetMk (Just mod) fix_env +topRecNameMaker :: MiniFixityEnv -> NameMaker +topRecNameMaker fix_env = LetMk TopLevel fix_env localRecNameMaker :: MiniFixityEnv -> NameMaker -localRecNameMaker fix_env = LetMk Nothing fix_env +localRecNameMaker fix_env = LetMk NotTopLevel fix_env matchNameMaker :: HsMatchContext a -> NameMaker matchNameMaker ctxt = LamMk report_unused @@ -162,11 +161,11 @@ newName (LamMk report_unused) rdr_name ; when report_unused $ warnUnusedMatches [name] fvs ; return (res, name `delFV` fvs) }) -newName (LetMk mb_top fix_env) rdr_name +newName (LetMk is_top fix_env) rdr_name = CpsRn (\ thing_inside -> - do { name <- case mb_top of - Nothing -> newLocalBndrRn rdr_name - Just mod -> newTopSrcBinder mod rdr_name + do { name <- case is_top of + NotTopLevel -> newLocalBndrRn rdr_name + TopLevel -> newTopSrcBinder rdr_name ; bindLocalName name $ -- Do *not* use bindLocalNameFV here -- See Note [View pattern usage] addLocalFixities fix_env [name] $ diff --git a/compiler/typecheck/TcClassDcl.lhs b/compiler/typecheck/TcClassDcl.lhs index 0fb82cb..2f7f6bc 100644 --- a/compiler/typecheck/TcClassDcl.lhs +++ b/compiler/typecheck/TcClassDcl.lhs @@ -8,7 +8,7 @@ Typechecking class declarations \begin{code} module TcClassDcl ( tcClassSigs, tcClassDecl2, findMethodBind, instantiateMethod, tcInstanceMethodBody, - mkGenericDefMethBind, getGenericInstances, mkDefMethRdrName, + mkGenericDefMethBind, getGenericInstances, tcAddDeclCtxt, badMethodErr, badATErr, omittedATWarn ) where @@ -17,7 +17,6 @@ module TcClassDcl ( tcClassSigs, tcClassDecl2, import HsSyn import RnHsSyn import RnExpr -import RnEnv import Inst import InstEnv import TcEnv @@ -27,6 +26,7 @@ import TcHsType import TcMType import TcType import TcRnMonad +import BuildTyCl( TcMethInfo ) import Generics import Class import TyCon @@ -36,7 +36,6 @@ import Name import Var import NameEnv import NameSet -import RdrName import Outputable import PrelNames import DynFlags @@ -99,54 +98,44 @@ tcClassSigs :: Name -- Name of the class -> LHsBinds Name -> TcM [TcMethInfo] -type TcMethInfo = (Name, DefMeth, Type) -- A temporary intermediate, to communicate - -- between tcClassSigs and buildClass tcClassSigs clas sigs def_methods - = do { dm_env <- checkDefaultBinds clas op_names def_methods - ; mapM (tcClassSig dm_env) op_sigs } + = do { dm_env <- mapM (addLocM (checkDefaultBind clas op_names)) + (bagToList def_methods) + ; mapM (tcClassSig (mkNameEnv dm_env)) op_sigs } where op_sigs = [sig | sig@(L _ (TypeSig _ _)) <- sigs] op_names = [n | (L _ (TypeSig (L _ n) _)) <- op_sigs] - -checkDefaultBinds :: Name -> [Name] -> LHsBinds Name -> TcM (NameEnv Bool) +checkDefaultBind :: Name -> [Name] -> HsBindLR Name Name -> TcM (Name, DefMethSpec) -- Check default bindings -- a) must be for a class op for this class -- b) must be all generic or all non-generic - -- and return a mapping from class-op to Bool - -- where True <=> it's a generic default method -checkDefaultBinds clas ops binds - = do dm_infos <- mapM (addLocM (checkDefaultBind clas ops)) (bagToList binds) - return (mkNameEnv dm_infos) - -checkDefaultBind :: Name -> [Name] -> HsBindLR Name Name -> TcM (Name, Bool) checkDefaultBind clas ops (FunBind {fun_id = L _ op, fun_matches = MatchGroup matches _ }) = do { -- Check that the op is from this class - checkTc (op `elem` ops) (badMethodErr clas op) + checkTc (op `elem` ops) (badMethodErr clas op) -- Check that all the defns ar generic, or none are - ; checkTc (all_generic || none_generic) (mixedGenericErr op) - - ; return (op, all_generic) + ; case (none_generic, all_generic) of + (True, _) -> return (op, VanillaDM) + (_, True) -> return (op, GenericDM) + _ -> failWith (mixedGenericErr op) } where n_generic = count (isJust . maybeGenericMatch) matches none_generic = n_generic == 0 all_generic = matches `lengthIs` n_generic + checkDefaultBind _ _ b = pprPanic "checkDefaultBind" (ppr b) -tcClassSig :: NameEnv Bool -- Info about default methods; +tcClassSig :: NameEnv DefMethSpec -- Info about default methods; -> LSig Name -> TcM TcMethInfo tcClassSig dm_env (L loc (TypeSig (L _ op_name) op_hs_ty)) = setSrcSpan loc $ do { op_ty <- tcHsKindedType op_hs_ty -- Class tyvars already in scope - ; let dm = case lookupNameEnv dm_env op_name of - Nothing -> NoDefMeth - Just False -> DefMeth - Just True -> GenDefMeth + ; let dm = lookupNameEnv dm_env op_name `orElse` NoDM ; return (op_name, dm, op_ty) } tcClassSig _ s = pprPanic "tcClassSig" (ppr s) \end{code} @@ -189,32 +178,32 @@ tcClassDecl2 (L loc (ClassDecl {tcdLName = class_name, tcdSigs = sigs, ; let tc_dm = tcDefMeth clas clas_tyvars this_dict default_binds sig_fn prag_fn - -- tc_dm is called only for a sel_id - -- that has a binding in default_binds - - dm_sel_ids = [sel_id | (sel_id, DefMeth) <- op_items] - -- Generate code for polymorphic default methods only (hence DefMeth) - -- (Generic default methods have turned into instance decls by now.) - -- This is incompatible with Hugs, which expects a polymorphic - -- default method for every class op, regardless of whether or not - -- the programmer supplied an explicit default decl for the class. - -- (If necessary we can fix that, but we don't have a convenient Id to hand.) - ; (dm_ids, defm_binds) <- tcExtendTyVarEnv clas_tyvars $ - mapAndUnzipM tc_dm dm_sel_ids + ; dm_stuff <- tcExtendTyVarEnv clas_tyvars $ + mapM tc_dm op_items + ; let (dm_ids, defm_binds) = unzip (catMaybes dm_stuff) ; return (dm_ids, listToBag defm_binds) } tcClassDecl2 d = pprPanic "tcClassDecl2" (ppr d) tcDefMeth :: Class -> [TyVar] -> Inst -> LHsBinds Name - -> TcSigFun -> TcPragFun -> Id - -> TcM (Id, LHsBind Id) -tcDefMeth clas tyvars this_dict binds_in sig_fn prag_fn sel_id - = do { let sel_name = idName sel_id - ; dm_name <- lookupTopBndrRn (mkDefMethRdrName sel_name) - ; local_dm_name <- newLocalName sel_name - -- Base the local_dm_name on the selector name, becuase + -> TcSigFun -> TcPragFun -> ClassOpItem + -> TcM (Maybe (Id, LHsBind Id)) +-- Generate code for polymorphic default methods only (hence DefMeth) +-- (Generic default methods have turned into instance decls by now.) +-- This is incompatible with Hugs, which expects a polymorphic +-- default method for every class op, regardless of whether or not +-- the programmer supplied an explicit default decl for the class. +-- (If necessary we can fix that, but we don't have a convenient Id to hand.) +tcDefMeth clas tyvars this_dict binds_in sig_fn prag_fn (sel_id, dm_info) + = case dm_info of + NoDefMeth -> return Nothing + GenDefMeth -> return Nothing + DefMeth dm_name -> do + { let sel_name = idName sel_id + ; local_dm_name <- newLocalName sel_name + -- Base the local_dm_name on the selector name, because -- type errors from tcInstanceMethodBody come from here -- See Note [Silly default-method bind] @@ -222,8 +211,7 @@ tcDefMeth clas tyvars this_dict binds_in sig_fn prag_fn sel_id ; let meth_bind = findMethodBind sel_name local_dm_name binds_in `orElse` pprPanic "tcDefMeth" (ppr sel_id) - -- We only call tcDefMeth on selectors for which - -- there is a binding in binds_in + -- dm_info = DefMeth dm_name only if there is a binding in binds_in dm_sig_fn _ = sig_fn sel_name dm_ty = idType sel_id @@ -238,7 +226,8 @@ tcDefMeth clas tyvars this_dict binds_in sig_fn prag_fn sel_id (ptext (sLit "Ignoring SPECIALISE pragmas on default method") <+> quotes (ppr sel_name)) - ; tcInstanceMethodBody (instLoc this_dict) + ; liftM Just $ + tcInstanceMethodBody (instLoc this_dict) tyvars [this_dict] ([], emptyBag) dm_id_w_inline local_dm_id @@ -282,9 +271,6 @@ tcInstanceMethodBody inst_loc tyvars dfun_dicts \end{code} \begin{code} -mkDefMethRdrName :: Name -> RdrName -mkDefMethRdrName sel_name = mkDerivedRdrName sel_name mkDefaultMethodOcc - instantiateMethod :: Class -> Id -> [TcType] -> TcType -- Take a class operation, say -- op :: forall ab. C a => forall c. Ix c => (b,c) -> a diff --git a/compiler/typecheck/TcInstDcls.lhs b/compiler/typecheck/TcInstDcls.lhs index 1bc7099..55fc342 100644 --- a/compiler/typecheck/TcInstDcls.lhs +++ b/compiler/typecheck/TcInstDcls.lhs @@ -21,7 +21,6 @@ import FamInst import FamInstEnv import TcDeriv import TcEnv -import RnEnv ( lookupGlobalOccRn ) import RnSource ( addTcgDUs ) import TcHsType import TcUnify @@ -1026,7 +1025,7 @@ tcInstanceMethod loc standalone_deriv clas tyvars dfun_dicts inst_tys = do { meth_bind <- mkGenericDefMethBind clas inst_tys sel_id local_meth_name ; tc_body meth_bind } - tc_default DefMeth -- An polymorphic default method + tc_default (DefMeth dm_name) -- An polymorphic default method = do { -- Build the typechecked version directly, -- without calling typecheck_method; -- see Note [Default methods in instances] @@ -1034,8 +1033,7 @@ tcInstanceMethod loc standalone_deriv clas tyvars dfun_dicts inst_tys -- in $dm inst_tys this -- The 'let' is necessary only because HsSyn doesn't allow -- you to apply a function to a dictionary *expression*. - dm_name <- lookupGlobalOccRn (mkDefMethRdrName sel_name) - -- Might not be imported, but will be an OrigName + ; dm_id <- tcLookupId dm_name ; let dm_inline_prag = idInlinePragma dm_id rhs = HsWrap (WpApp (instToId this_dict) <.> mkWpTyApps inst_tys) $ diff --git a/compiler/typecheck/TcSplice.lhs b/compiler/typecheck/TcSplice.lhs index bafddf8..abba313 100644 --- a/compiler/typecheck/TcSplice.lhs +++ b/compiler/typecheck/TcSplice.lhs @@ -338,9 +338,12 @@ tcBracket brack res_ty -- it again when we actually use it. ; pending_splices <- newMutVar [] ; lie_var <- getLIEVar + ; let brack_stage = Brack cur_stage pending_splices lie_var + + ; (meta_ty, lie) <- setStage brack_stage $ + getLIE $ + tc_bracket cur_stage brack - ; (meta_ty, lie) <- setStage (Brack cur_stage pending_splices lie_var) - (getLIE (tc_bracket cur_stage brack)) ; tcSimplifyBracket lie -- Make the expected type have the right shape @@ -381,6 +384,10 @@ tc_bracket _ (DecBrG decls) = do { _ <- tcTopSrcDecls emptyModDetails decls -- Typecheck the declarations, dicarding the result -- We'll get all that stuff later, when we splice it in + + -- Top-level declarations in the bracket get unqualified names + -- See Note [Top-level Names in Template Haskell decl quotes] in RnNames + ; tcMetaTy decsQTyConName } -- Result type is Q [Dec] tc_bracket _ (PatBr pat) diff --git a/compiler/types/Class.lhs b/compiler/types/Class.lhs index 5e8a4d4..27ec5c1 100644 --- a/compiler/types/Class.lhs +++ b/compiler/types/Class.lhs @@ -71,7 +71,7 @@ type ClassOpItem = (Id, DefMeth) -- Default-method info data DefMeth = NoDefMeth -- No default method - | DefMeth -- A polymorphic default method + | DefMeth Name -- A polymorphic default method | GenDefMeth -- A generic default method deriving Eq \end{code} @@ -173,8 +173,8 @@ instance Show Class where showsPrec p c = showsPrecSDoc p (ppr c) instance Outputable DefMeth where - ppr DefMeth = text "{- has default method -}" - ppr GenDefMeth = text "{- has generic method -}" + ppr (DefMeth n) = ptext (sLit "Default method") <+> ppr n + ppr GenDefMeth = ptext (sLit "Generic default method") ppr NoDefMeth = empty -- No default method pprFundeps :: Outputable a => [FunDep a] -> SDoc -- 1.7.10.4