diff options
Diffstat (limited to 'compiler/rename/RnNames.lhs')
| -rw-r--r-- | compiler/rename/RnNames.lhs | 558 |
1 files changed, 259 insertions, 299 deletions
diff --git a/compiler/rename/RnNames.lhs b/compiler/rename/RnNames.lhs index 29468fd0ba..738a0c4f4f 100644 --- a/compiler/rename/RnNames.lhs +++ b/compiler/rename/RnNames.lhs @@ -28,27 +28,26 @@ import TcRnMonad hiding (LIE) import PrelNames import Module import Name -import NameSet import NameEnv -import OccName ( srcDataName, isTcOcc, pprNonVarNameSpace, +import NameSet +import OccName ( srcDataName, pprNonVarNameSpace, occNameSpace, OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv, extendOccEnv ) import HscTypes ( GenAvailInfo(..), AvailInfo, availNames, availName, HomePackageTable, PackageIfaceTable, mkPrintUnqualified, availsToNameSet, - availsToNameEnv, Deprecs(..), ModIface(..), Dependencies(..), lookupIfaceByModule, ExternalPackageState(..) ) -import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, +import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, Parent(..), GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..), emptyGlobalRdrEnv, plusGlobalRdrEnv, globalRdrEnvElts, - extendGlobalRdrEnv, lookupGlobalRdrEnv, unQualOK, lookupGRE_Name, + extendGlobalRdrEnv, lookupGlobalRdrEnv, lookupGRE_Name, Provenance(..), ImportSpec(..), ImpDeclSpec(..), ImpItemSpec(..), - importSpecLoc, importSpecModule, isLocalGRE, pprNameProvenance ) + importSpecLoc, importSpecModule, isLocalGRE, pprNameProvenance, + unQualSpecOK, qualSpecOK ) import Outputable -import UniqFM import Maybes import SrcLoc ( Located(..), mkGeneralSrcSpan, getLoc, unLoc, noLoc, srcLocSpan, SrcSpan ) @@ -56,8 +55,9 @@ import FiniteMap import ErrUtils import BasicTypes ( DeprecTxt ) import DriverPhases ( isHsBoot ) -import Util ( notNull ) -import Data.List ( nub, partition, concatMap ) +import Util +import ListSetOps +import Data.List ( partition, concatMap ) import IO ( openFile, IOMode(..) ) import Monad ( when ) \end{code} @@ -86,17 +86,9 @@ rnImports imports stuff1 <- mapM (rnImportDecl this_mod) ordinary stuff2 <- mapM (rnImportDecl this_mod) source - let (decls, rdr_env, avails, imp_avails) = combine (stuff1 ++ stuff2) - return (decls, rdr_env, - imp_avails{ imp_parent = availsToNameEnv (nubAvails avails) }) - -- why wait until now to set the imp_parent, rather than - -- setting it in rnImportDecl for each import, and - -- combining them with plusImportAvails? The reason is - -- that we need to combine all the AvailInfos *before* - -- we build the NameEnv, otherwise the NameEnv can - -- end up with inconsistencies, eg. the parent can say - -- C(m1,m2), but the entry for m2 might only say C(m2). - -- The test mod118 illustrates the bug. + let (decls, rdr_env, imp_avails) = combine (stuff1 ++ stuff2) + return (decls, rdr_env, imp_avails) + where -- NB: opt_NoImplicitPrelude is slightly different to import Prelude (); -- because the former doesn't even look at Prelude.hi for instance @@ -111,14 +103,13 @@ rnImports imports = notNull [ () | L _ (ImportDecl mod _ _ _ _) <- imports, unLoc mod == pRELUDE_NAME ] - combine :: [(LImportDecl Name, GlobalRdrEnv, [AvailInfo], ImportAvails)] - -> ([LImportDecl Name], GlobalRdrEnv, [AvailInfo], ImportAvails) - combine = foldr plus ([], emptyGlobalRdrEnv, [], emptyImportAvails) - where plus (decl, gbl_env1, avails1, imp_avails1) - (decls, gbl_env2, avails2, imp_avails2) + combine :: [(LImportDecl Name, GlobalRdrEnv, ImportAvails)] + -> ([LImportDecl Name], GlobalRdrEnv, ImportAvails) + combine = foldr plus ([], emptyGlobalRdrEnv, emptyImportAvails) + where plus (decl, gbl_env1, imp_avails1) + (decls, gbl_env2, imp_avails2) = (decl:decls, gbl_env1 `plusGlobalRdrEnv` gbl_env2, - avails1 ++ avails2, imp_avails1 `plusImportAvails` imp_avails2) preludeImportDecl :: LImportDecl RdrName @@ -136,8 +127,7 @@ preludeImportDecl rnImportDecl :: Module -> LImportDecl RdrName - -> RnM (LImportDecl Name, GlobalRdrEnv, - [AvailInfo], ImportAvails) + -> RnM (LImportDecl Name, GlobalRdrEnv, ImportAvails) rnImportDecl this_mod (L loc (ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details)) @@ -200,7 +190,7 @@ rnImportDecl this_mod (L loc (ImportDecl loc_imp_mod_name want_boot total_avails <- ifaceExportNames filtered_exports -- filter the imports according to the import declaration - (new_imp_details, filtered_avails, gbl_env) <- + (new_imp_details, gbl_env) <- filterImports iface imp_spec imp_details total_avails dflags <- getDOpts @@ -246,17 +236,13 @@ rnImportDecl this_mod (L loc (ImportDecl loc_imp_mod_name want_boot other -> False imports = ImportAvails { - imp_env = unitUFM qual_mod_name filtered_avails, imp_mods = unitModuleEnv imp_mod (imp_mod, import_all, loc), imp_orphs = orphans, imp_finsts = finsts, imp_dep_mods = mkModDeps dependent_mods, - imp_dep_pkgs = dependent_pkgs, - imp_parent = emptyNameEnv + imp_dep_pkgs = dependent_pkgs } - -- in - -- Complain if we import a deprecated module ifOptM Opt_WarnDeprecations ( case deprecs of @@ -267,7 +253,7 @@ rnImportDecl this_mod (L loc (ImportDecl loc_imp_mod_name want_boot let new_imp_decl = L loc (ImportDecl loc_imp_mod_name want_boot qual_only as_mod new_imp_details) - returnM (new_imp_decl, gbl_env, filtered_avails, imports) + returnM (new_imp_decl, gbl_env, imports) ) warnRedundantSourceImport mod_name @@ -296,64 +282,27 @@ importsFromLocalDecls group ; avails <- getLocalDeclBinders gbl_env group - ; implicit_prelude <- doptM Opt_ImplicitPrelude - ; let { - -- Optimisation: filter out names for built-in syntax - -- They just clutter up the environment (esp tuples), and the parser - -- will generate Exact RdrNames for them, so the cluttered - -- envt is no use. To avoid doing this filter all the time, - -- we use -fno-implicit-prelude as a clue that the filter is - -- worth while. Really, it's only useful for GHC.Base and GHC.Tuple. - -- - -- It's worth doing because it makes the environment smaller for - -- every module that imports the Prelude - -- - -- Note: don't filter the gbl_env (hence all_names, not filered_all_names - -- in defn of gres above). Stupid reason: when parsing - -- data type decls, the constructors start as Exact tycon-names, - -- and then get turned into data con names by zapping the name space; - -- but that stops them being Exact, so they get looked up. - -- Ditto in fixity decls; e.g. infix 5 : - -- Sigh. It doesn't matter because it only affects the Data.Tuple really. - -- The important thing is to trim down the exports. - names = concatMap availNames avails; - - filtered_avails - | implicit_prelude = avails - | otherwise = filterAvails (not.isBuiltInSyntax) avails; - - ; this_mod = tcg_mod gbl_env - ; imports = emptyImportAvails { - imp_env = unitUFM (moduleName this_mod) - filtered_avails, - imp_parent = availsToNameEnv avails - } - } - - ; rdr_env' <- extendRdrEnvRn (tcg_rdr_env gbl_env) names + ; rdr_env' <- extendRdrEnvRn (tcg_rdr_env gbl_env) avails ; traceRn (text "local avails: " <> ppr avails) - ; returnM (gbl_env { tcg_rdr_env = rdr_env', - tcg_imports = imports `plusImportAvails` tcg_imports gbl_env }) + ; returnM (gbl_env { tcg_rdr_env = rdr_env' }) } -extendRdrEnvRn :: GlobalRdrEnv -> [Name] -> RnM GlobalRdrEnv +extendRdrEnvRn :: GlobalRdrEnv -> [AvailInfo] -> RnM GlobalRdrEnv -- Add the new locally-bound names one by one, checking for duplicates as -- we do so. Remember that in Template Haskell the duplicates -- might *already be* in the GlobalRdrEnv from higher up the module -extendRdrEnvRn rdr_env names - = foldlM add_local rdr_env names +extendRdrEnvRn rdr_env avails + = foldlM add_local rdr_env (gresFromAvails LocalDef avails) where - add_local rdr_env name - | gres <- lookupGlobalRdrEnv rdr_env (nameOccName name) + add_local rdr_env gre + | gres <- lookupGlobalRdrEnv rdr_env (nameOccName (gre_name gre)) , (dup_gre:_) <- filter isLocalGRE gres -- Check for existing *local* defns - = do { addDupDeclErr (gre_name dup_gre) name + = do { addDupDeclErr (gre_name dup_gre) (gre_name gre) ; return rdr_env } | otherwise - = return (extendGlobalRdrEnv rdr_env new_gre) - where - new_gre = GRE {gre_name = name, gre_prov = LocalDef} + = return (extendGlobalRdrEnv rdr_env gre) \end{code} @getLocalDeclBinders@ returns the names for an @HsDecl@. It's @@ -413,6 +362,8 @@ getLocalDeclBinders gbl_env (HsGroup {hs_valds = ValBindsIn val_decls val_sigs, inst_ats inst_decl = mappM new_tc (instDeclATs (unLoc inst_decl)) + +getLocalDeclBinders _ _ = panic "getLocalDeclBinders" -- ValBindsOut can't happen \end{code} @@ -431,45 +382,33 @@ filterImports :: ModIface -> Maybe (Bool, [LIE RdrName]) -- Import spec; True => hiding -> [AvailInfo] -- What's available -> RnM (Maybe (Bool, [LIE Name]), -- Import spec w/ Names - [AvailInfo], -- What's imported GlobalRdrEnv) -- Same again, but in GRE form filterImports iface decl_spec Nothing all_avails - = return (Nothing, all_avails, mkGenericRdrEnv decl_spec all_avails) + = return (Nothing, mkGlobalRdrEnv (gresFromAvails prov all_avails)) + where + prov = Imported [ImpSpec { is_decl = decl_spec, is_item = ImpAll }] + filterImports iface decl_spec (Just (want_hiding, import_items)) all_avails - = do - -- check for errors, convert RdrNames to Names + = do -- check for errors, convert RdrNames to Names opt_indexedtypes <- doptM Opt_IndexedTypes items1 <- mapM (lookup_lie opt_indexedtypes) import_items - let -- build the AvailInfo corresponding to each import item. - items2 = [ (ie, filterAvailByIE (unLoc ie) av) - | (ie,av) <- concat items1 ] - - -- eliminate duplicates - avails = nubAvails (map snd items2) - - -- the new import spec, with Names instead of RdrNames - imp_spec_out = Just (want_hiding, map fst items2) - - case want_hiding of - True -> - let - keep n = not (n `elemNameSet` availsToNameSet avails) - pruned_avails = filterAvails keep all_avails - in do - traceRn (text "pruned_avails: " <> ppr pruned_avails) - return (imp_spec_out, pruned_avails, - mkGenericRdrEnv decl_spec pruned_avails) - - False -> - let - gres = concat [ mkGlobalRdrEltsFromIE decl_spec lie avail - | (lie, avail) <- items2 ] - in do - traceRn (text "imported avails: " <> ppr avails) - return (imp_spec_out, avails, mkGlobalRdrEnv gres) + let items2 :: [(LIE Name, AvailInfo)] + items2 = concat items1 + -- NB the AvailInfo may have duplicates, and several items + -- for the same parent; e.g N(x) and N(y) + + names = availsToNameSet (map snd items2) + keep n = not (n `elemNameSet` names) + pruned_avails = filterAvails keep all_avails + hiding_prov = Imported [ImpSpec { is_decl = decl_spec, is_item = ImpAll }] + + gres | want_hiding = gresFromAvails hiding_prov pruned_avails + | otherwise = concatMap (gresFromIE decl_spec) items2 + + return (Just (want_hiding, map fst items2), mkGlobalRdrEnv gres) where -- This environment is how we map names mentioned in the import -- list to the actual Name they correspond to, and the family @@ -486,13 +425,13 @@ filterImports iface decl_spec (Just (want_hiding, import_items)) all_avails lookup_lie opt_indexedtypes (L loc ieRdr) = do stuff <- setSrcSpan loc $ - case lookup_ie opt_indexedtypes ieRdr of + case lookup_ie opt_indexedtypes ieRdr of Failed err -> addErr err >> return [] Succeeded a -> return a checkDodgyImport stuff return [ (L loc ie, avail) | (ie,avail) <- stuff ] where - -- warn when importing T(..) if T was exported absgtractly + -- Warn when importing T(..) if T was exported abstractly checkDodgyImport stuff | IEThingAll n <- ieRdr, (_, AvailTC _ [one]):_ <- stuff = ifOptM Opt_WarnDodgyImports (addWarn (dodgyImportWarn n)) @@ -519,7 +458,7 @@ filterImports iface decl_spec (Just (want_hiding, import_items)) all_avails case ie of IEVar n -> do (name,avail) <- lookup_name n - return [(IEVar name, avail)] + return [(IEVar name, trimAvail avail name)] IEThingAll tc -> do (name,avail) <- lookup_name tc @@ -534,10 +473,11 @@ filterImports iface decl_spec (Just (want_hiding, import_items)) all_avails in case catMaybeErr [ tc_name, dc_name ] of [] -> bad_ie - names -> return [ (IEThingAbs n, av) | (n,av) <- names ] + names -> return [ (IEThingAbs n, trimAvail av n) + | (n,av) <- names ] | otherwise -> do (name,avail) <- lookup_name tc - return [(IEThingAbs name, avail)] + return [(IEThingAbs name, AvailTC name [name])] IEThingWith n ns -> do (name,avail) <- lookup_name n @@ -555,7 +495,8 @@ filterImports iface decl_spec (Just (want_hiding, import_items)) all_avails Failed (typeItemErr (head . filter isTyConName $ children ) (text "in import list")) - return [(IEThingWith name children, avail)] + return [(IEThingWith name children, AvailTC name (name:children))] + _otherwise -> bad_ie _other -> Failed illegalImportItemErr @@ -576,22 +517,37 @@ catMaybeErr ms = [ a | Succeeded a <- ms ] -- | make a 'GlobalRdrEnv' where all the elements point to the same -- import declaration (useful for "hiding" imports, or imports with -- no details). -mkGenericRdrEnv decl_spec avails - = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] } - | name <- concatMap availNames avails ] - where - imp_spec = ImpSpec { is_decl = decl_spec, is_item = ImpAll } - - --- | filters an 'AvailInfo' by the given import/export spec. -filterAvailByIE :: IE Name -> AvailInfo -> AvailInfo -filterAvailByIE (IEVar n) a@(Avail _) = a -filterAvailByIE (IEVar n) a@(AvailTC tc subs) = AvailTC tc [n] -filterAvailByIE (IEThingAbs n) a@(AvailTC _ _) = AvailTC n [n] -filterAvailByIE (IEThingAll n) a@(AvailTC tc subs) = a -filterAvailByIE (IEThingWith n ns) a@(AvailTC tc subs) = - AvailTC tc (filter (`elem` (n:ns)) subs) -filterAvailByIE _ _ = panic "filterAvailByIE" +gresFromAvails :: Provenance -> [AvailInfo] -> [GlobalRdrElt] +gresFromAvails prov avails + = concatMap (gresFromAvail (const prov)) avails + +gresFromAvail :: (Name -> Provenance) -> AvailInfo -> [GlobalRdrElt] +gresFromAvail prov_fn avail + = [ GRE {gre_name = n, + gre_par = availParent n avail, + gre_prov = prov_fn n} + | n <- availNames avail ] + +greAvail :: GlobalRdrElt -> AvailInfo +greAvail gre = mkUnitAvail (gre_name gre) (gre_par gre) + +mkUnitAvail :: Name -> Parent -> AvailInfo +mkUnitAvail me (ParentIs p) = AvailTC p [me] +mkUnitAvail me NoParent | isTyConName me = AvailTC me [me] + | otherwise = Avail me + +plusAvail (Avail n1) (Avail n2) = Avail n1 +plusAvail (AvailTC n1 ns1) (AvailTC n2 ns2) = AvailTC n2 (ns1 `unionLists` ns2) +plusAvail a1 a2 = pprPanic "RnEnv.plusAvail" (hsep [ppr a1,ppr a2]) + +availParent :: Name -> AvailInfo -> Parent +availParent n (Avail _) = NoParent +availParent n (AvailTC m ms) | n==m = NoParent + | otherwise = ParentIs m + +trimAvail :: AvailInfo -> Name -> AvailInfo +trimAvail (Avail n) m = Avail n +trimAvail (AvailTC n ns) m = ASSERT( m `elem` ns) AvailTC n [m] -- | filters 'AvailInfo's by the given predicate filterAvails :: (Name -> Bool) -> [AvailInfo] -> [AvailInfo] @@ -607,38 +563,64 @@ filterAvail keep ie rest = let left = filter keep ns in if null left then rest else AvailTC tc left : rest --- | combines 'AvailInfo's from the same family -nubAvails :: [AvailInfo] -> [AvailInfo] -nubAvails avails = nameEnvElts (foldr add emptyNameEnv avails) - where - add avail env = extendNameEnv_C comb_avails env (availName avail) avail - comb_avails (AvailTC tc subs1) (AvailTC _ subs2) - = AvailTC tc (nub (subs1 ++ subs2)) - comb_avails avail _ = avail - -- | Given an import/export spec, construct the appropriate 'GlobalRdrElt's. -mkGlobalRdrEltsFromIE :: ImpDeclSpec -> LIE Name -> AvailInfo -> [GlobalRdrElt] -mkGlobalRdrEltsFromIE decl_spec (L loc ie) avail = - case ie of - IEVar name -> - [mk_explicit_gre name] - IEThingAbs name -> - [mk_explicit_gre name] - IEThingAll name | AvailTC _ subs <- avail -> - mk_explicit_gre name : map mk_implicit_gre subs - IEThingWith name subs -> - mk_explicit_gre name : map mk_explicit_gre subs - _ -> - panic "mkGlobalRdrEltsFromIE" +gresFromIE :: ImpDeclSpec -> (LIE Name, AvailInfo) -> [GlobalRdrElt] +gresFromIE decl_spec (L loc ie, avail) + = gresFromAvail prov_fn avail where - mk_explicit_gre = mk_gre True - mk_implicit_gre = mk_gre False - - mk_gre explicit name = GRE { gre_name = name, - gre_prov = Imported [imp_spec] } - where - imp_spec = ImpSpec { is_decl = decl_spec, is_item = item_spec } - item_spec = ImpSome { is_explicit = explicit, is_iloc = loc } + is_explicit = case ie of + IEThingAll name -> \n -> n==name + other -> \n -> True + prov_fn name = Imported [imp_spec] + where + imp_spec = ImpSpec { is_decl = decl_spec, is_item = item_spec } + item_spec = ImpSome { is_explicit = is_explicit name, is_iloc = loc } + +mkChildEnv :: [GlobalRdrElt] -> NameEnv [Name] +mkChildEnv gres = foldr add emptyNameEnv gres + where + add (GRE { gre_name = n, gre_par = ParentIs p }) env = extendNameEnv_C (++) env p [n] + add other_gre env = env + +findChildren :: NameEnv [Name] -> Name -> [Name] +findChildren env n = lookupNameEnv env n `orElse` [] +\end{code} + +--------------------------------------- + AvailEnv and friends + +All this AvailEnv stuff is hardly used; only in a very small +part of RnNames. Todo: remove? +--------------------------------------- + +\begin{code} +type AvailEnv = NameEnv AvailInfo -- Maps a Name to the AvailInfo that contains it + +emptyAvailEnv :: AvailEnv +emptyAvailEnv = emptyNameEnv + +unitAvailEnv :: AvailInfo -> AvailEnv +unitAvailEnv a = unitNameEnv (availName a) a + +plusAvailEnv :: AvailEnv -> AvailEnv -> AvailEnv +plusAvailEnv = plusNameEnv_C plusAvail + +availEnvElts :: AvailEnv -> [AvailInfo] +availEnvElts = nameEnvElts + +addAvail :: AvailEnv -> AvailInfo -> AvailEnv +addAvail avails avail = extendNameEnv_C plusAvail avails (availName avail) avail + +mkAvailEnv :: [AvailInfo] -> AvailEnv + -- 'avails' may have several items with the same availName + -- E.g import Ix( Ix(..), index ) + -- will give Ix(Ix,index,range) and Ix(index) + -- We want to combine these; addAvail does that +mkAvailEnv avails = foldl addAvail emptyAvailEnv avails + +-- | combines 'AvailInfo's from the same family +nubAvails :: [AvailInfo] -> [AvailInfo] +nubAvails avails = nameEnvElts (mkAvailEnv avails) \end{code} @@ -663,9 +645,11 @@ it re-exports @GHC@, which includes @takeMVar#@, whose type includes \begin{code} type ExportAccum -- The type of the accumulating parameter of -- the main worker function in rnExports - = ([LIE Name], -- export items with Names + = ([LIE Name], -- Export items with Names ExportOccMap, -- Tracks exported occurrence names [AvailInfo]) -- The accumulated exported stuff + -- Not nub'd! + emptyExportAccum = ([], emptyOccEnv, []) type ExportOccMap = OccEnv (Name, IE RdrName) @@ -683,7 +667,7 @@ rnExports :: Bool -- False => no 'module M(..) where' header at all -- Complains about exports items not in scope rnExports explicit_mod exports - = do TcGblEnv { tcg_mod = this_mod, + = do TcGblEnv { tcg_mod = this_mod, tcg_rdr_env = rdr_env, tcg_imports = imports } <- getGblEnv @@ -706,10 +690,9 @@ rnExports explicit_mod exports -- ToDo: the 'noLoc' here is unhelpful if 'main' turns -- out to be out of scope - (exp_spec, avails) <- exports_from_avail real_exports rdr_env - imports this_mod - return (exp_spec, nubAvails avails) - -- combine families + (exp_spec, avails) <- exports_from_avail real_exports rdr_env imports this_mod + + return (exp_spec, nubAvails avails) -- Combine families exports_from_avail :: Maybe [LIE RdrName] -- Nothing => no explicit export list @@ -719,109 +702,97 @@ exports_from_avail :: Maybe [LIE RdrName] -> RnM (Maybe [LIE Name], [AvailInfo]) exports_from_avail Nothing rdr_env imports this_mod - = -- the same as (module M) where M is the current module name, + = -- The same as (module M) where M is the current module name, -- so that's how we handle it. let - names = [ gre_name gre | gre <- globalRdrEnvElts rdr_env, + avails = [ greAvail gre | gre <- globalRdrEnvElts rdr_env, isLocalGRE gre ] - avails = map (lookupNameEnv_NF (imp_parent imports)) names in return (Nothing, avails) exports_from_avail (Just rdr_items) rdr_env imports this_mod - = do traceRn (text "parent: " <> ppr (imp_parent imports)) - (ie_names, _, exports) <- foldlM do_litem emptyExportAccum rdr_items + = do (ie_names, _, exports) <- foldlM do_litem emptyExportAccum rdr_items return (Just ie_names, exports) where do_litem :: ExportAccum -> LIE RdrName -> RnM ExportAccum do_litem acc lie = setSrcSpan (getLoc lie) (exports_from_item acc lie) + kids_env :: NameEnv [Name] -- Maps a parent to its in-scope children + kids_env = mkChildEnv (globalRdrEnvElts rdr_env) + exports_from_item :: ExportAccum -> LIE RdrName -> RnM ExportAccum exports_from_item acc@(ie_names, occs, exports) - (L loc ie@(IEModuleContents mod)) - | mod `elem` mods -- Duplicate export of M + (L loc ie@(IEModuleContents mod)) + | let earlier_mods = [ mod | (L _ (IEModuleContents mod)) <- ie_names ] + , mod `elem` earlier_mods -- Duplicate export of M = do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ; warnIf warn_dup_exports (dupModuleExport mod) ; returnM acc } | otherwise - = case lookupUFM (imp_env imports) mod of - Nothing -> do addErr (modExportErr mod) - return acc - Just avails - -> do traceRn (text "mod avails: " <> ppr mod <+> ppr avails) - let avails' = filterAvails (inScopeUnqual rdr_env) $ - nubAvails avails - new_exps = concatMap availNames avails' - - occs' <- check_occs ie occs new_exps + = do { implicit_prelude <- doptM Opt_ImplicitPrelude + ; let gres = filter (isModuleExported implicit_prelude mod) + (globalRdrEnvElts rdr_env) + + ; warnIf (null gres) (nullModuleExport mod) + + ; occs' <- check_occs ie occs (map gre_name gres) -- This check_occs not only finds conflicts -- between this item and others, but also -- internally within this item. That is, if -- 'M.x' is in scope in several ways, we'll have -- several members of mod_avails with the same -- OccName. - return (L loc (IEModuleContents mod) : ie_names, - occs', avails' ++ exports) - where - mods = [ mod | (L _ (IEModuleContents mod)) <- ie_names ] + ; return (L loc (IEModuleContents mod) : ie_names, + occs', map greAvail gres ++ exports) } exports_from_item acc@(lie_names, occs, exports) (L loc ie) - = do new_ie <- lookup_ie ie - let ie_name = ieName new_ie - if isUnboundName ie_name + | isDoc ie + = do new_ie <- lookup_doc_ie ie + return (L loc new_ie : lie_names, occs, exports) + + | otherwise + = do (new_ie, avail) <- lookup_ie ie + if isUnboundName (ieName new_ie) then return acc -- Avoid error cascade else do - if isDoc new_ie -- deal with docs - then return (L loc new_ie : lie_names, occs, exports) - else do - traceRn (text "lookup_avail: " <> ppr (lookup_avail ie_name)) - let avail = filterAvailByIE new_ie (lookup_avail ie_name) - new_exports = case new_ie of - IEThingWith n ns -> n : ns - _ -> availNames avail - -- ^^^ an IEThingWith might contain duplicates - -- whereas the avail doesn't, but we want - -- duplicates to be noticed by check_occs below. - -- checkErr (not (null (drop 1 new_exports))) (exportItemErr ie) - checkForDodgyExport new_ie new_exports - occs' <- check_occs ie occs new_exports - return (L loc new_ie : lie_names, occs', avail : exports) - - lookup_avail :: Name -> AvailInfo - lookup_avail name = - case lookupNameEnv avail_env name of - Nothing -> pprPanic "rnExports:lookup_avail" (ppr name) - Just a -> a - where avail_env = imp_parent imports - lookup_ie :: IE RdrName -> RnM (IE Name) + occs' <- check_occs ie occs (availNames avail) + return (L loc new_ie : lie_names, occs', avail : exports) + + ------------- + lookup_ie :: IE RdrName -> RnM (IE Name, AvailInfo) lookup_ie (IEVar rdr) - = do name <- lookupGlobalOccRn rdr - return (IEVar name) + = do gre <- lookupGreRn rdr + return (IEVar (gre_name gre), greAvail gre) lookup_ie (IEThingAbs rdr) = do name <- lookupGlobalOccRn rdr - return (IEThingAbs name) + return (IEThingAbs name, AvailTC name [name]) - lookup_ie (IEThingAll rdr) + lookup_ie ie@(IEThingAll rdr) = do name <- lookupGlobalOccRn rdr - return (IEThingAll name) + let kids = findChildren kids_env name + when (null kids) + (if (isTyConName name) then addWarn (dodgyExportWarn name) + -- This occurs when you export T(..), but + -- only import T abstractly, or T is a synonym. + else addErr (exportItemErr ie)) + + return (IEThingAll name, AvailTC name (name:kids)) lookup_ie ie@(IEThingWith rdr sub_rdrs) = do name <- lookupGlobalOccRn rdr if isUnboundName name - then return (IEThingWith name []) + then return (IEThingWith name [], AvailTC name [name]) else do - let avail = lookup_avail name - env = mkOccEnv [ (nameOccName s, s) - | AvailTC _ subnames <- [avail], - s <- subnames ] - let mb_names = map (lookupOccEnv env . rdrNameOcc) sub_rdrs + let env = mkOccEnv [ (nameOccName s, s) + | s <- findChildren kids_env name ] + mb_names = map (lookupOccEnv env . rdrNameOcc) sub_rdrs if any isNothing mb_names then do addErr (exportItemErr ie) - return (IEThingWith name []) + return (IEThingWith name [], AvailTC name [name]) else do let names = catMaybes mb_names optIdxTypes <- doptM Opt_IndexedTypes when (not optIdxTypes && any isTyConName names) $ @@ -829,19 +800,18 @@ exports_from_avail (Just rdr_items) rdr_env imports this_mod . filter isTyConName $ names ) (text "in export list")) - return (IEThingWith name (catMaybes mb_names)) + return (IEThingWith name names, AvailTC name (name:names)) - lookup_ie (IEGroup lev doc) - = do rn_doc <- rnHsDoc doc - return (IEGroup lev rn_doc) - lookup_ie (IEDoc doc) - = do rn_doc <- rnHsDoc doc - return (IEDoc rn_doc) - lookup_ie (IEDocNamed str) - = return (IEDocNamed str) + lookup_ie ie = panic "lookup_ie" -- Other cases covered earlier - lookup_ie (IEModuleContents _) - = panic "rnExports:lookup_ie" -- caught earlier + ------------- + lookup_doc_ie :: IE RdrName -> RnM (IE Name) + lookup_doc_ie (IEGroup lev doc) = do rn_doc <- rnHsDoc doc + return (IEGroup lev rn_doc) + lookup_doc_ie (IEDoc doc) = do rn_doc <- rnHsDoc doc + return (IEDoc rn_doc) + lookup_doc_ie (IEDocNamed str) = return (IEDocNamed str) + lookup_doc_ie ie = panic "lookup_doc_ie" -- Other cases covered earlier isDoc (IEDoc _) = True @@ -850,21 +820,23 @@ isDoc (IEGroup _ _) = True isDoc _ = False ------------------------------- -inScopeUnqual :: GlobalRdrEnv -> Name -> Bool --- Checks whether the Name is in scope unqualified, --- regardless of whether it's ambiguous or not -inScopeUnqual env n = any unQualOK (lookupGRE_Name env n) - -------------------------------- -checkForDodgyExport :: IE Name -> [Name] -> RnM () -checkForDodgyExport ie@(IEThingAll tc) [n] - | isTcOcc (nameOccName n) = addWarn (dodgyExportWarn tc) - -- This occurs when you export T(..), but - -- only import T abstractly, or T is a synonym. - -- The single [n] is the type or class itself - | otherwise = addErr (exportItemErr ie) - -- This happes if you export x(..), which is bogus -checkForDodgyExport _ _ = return () +isModuleExported :: Bool -> ModuleName -> GlobalRdrElt -> Bool +-- True if the thing is in scope *both* unqualified, *and* with qualifier M +isModuleExported implicit_prelude mod (GRE { gre_name = name, gre_prov = prov }) + | implicit_prelude && isBuiltInSyntax name = False + -- Optimisation: filter out names for built-in syntax + -- They just clutter up the environment (esp tuples), and the parser + -- will generate Exact RdrNames for them, so the cluttered + -- envt is no use. To avoid doing this filter all the time, + -- we use -fno-implicit-prelude as a clue that the filter is + -- worth while. Really, it's only useful for GHC.Base and GHC.Tuple. + -- + -- It's worth doing because it makes the environment smaller for + -- every module that imports the Prelude + | otherwise + = case prov of + LocalDef -> moduleName (nameModule name) == mod + Imported is -> any unQualSpecOK is && any (qualSpecOK mod) is ------------------------------- check_occs :: IE RdrName -> ExportOccMap -> [Name] -> RnM ExportOccMap @@ -908,11 +880,9 @@ reportDeprecations dflags tcg_env -- Report on all deprecated uses; hence allUses all_gres = globalRdrEnvElts (tcg_rdr_env tcg_env) - avail_env = imp_parent (tcg_imports tcg_env) - - check hpt pit (GRE {gre_name = name, gre_prov = Imported (imp_spec:_)}) + check hpt pit gre@(GRE {gre_name = name, gre_prov = Imported (imp_spec:_)}) | name `elemNameSet` used_names - , Just deprec_txt <- lookupDeprec dflags hpt pit avail_env name + , Just deprec_txt <- lookupDeprec dflags hpt pit gre = addWarnAt (importSpecLoc imp_spec) (sep [ptext SLIT("Deprecated use of") <+> pprNonVarNameSpace (occNameSpace (nameOccName name)) <+> @@ -935,27 +905,23 @@ reportDeprecations dflags tcg_env -- interface lookupDeprec :: DynFlags -> HomePackageTable -> PackageIfaceTable - -> NameEnv AvailInfo -- parent info - -> Name -> Maybe DeprecTxt -lookupDeprec dflags hpt pit avail_env n - = case lookupIfaceByModule dflags hpt pit (nameModule n) of - Just iface -> mi_dep_fn iface n `seqMaybe` -- Bleat if the thing, *or - mi_dep_fn iface (nameParent n) -- its parent*, is deprec'd + -> GlobalRdrElt -> Maybe DeprecTxt +lookupDeprec dflags hpt pit gre + = case lookupIfaceByModule dflags hpt pit (nameModule name) of + Just iface -> mi_dep_fn iface name `seqMaybe` -- Bleat if the thing, *or + case gre_par gre of + ParentIs p -> mi_dep_fn iface p -- its parent*, is deprec'd + NoParent -> Nothing Nothing - | isWiredInName n -> Nothing + | isWiredInName name -> Nothing -- We have not necessarily loaded the .hi file for a -- wired-in name (yet), although we *could*. -- And we never deprecate them - | otherwise -> pprPanic "lookupDeprec" (ppr n) + | otherwise -> pprPanic "lookupDeprec" (ppr name) -- By now all the interfaces should have been loaded where - nameParent n = case lookupNameEnv avail_env n of - Just (AvailTC parent _) -> parent - _ -> n - -gre_is_used :: NameSet -> GlobalRdrElt -> Bool -gre_is_used used_names gre = gre_name gre `elemNameSet` used_names + name = gre_name gre \end{code} %********************************************************* @@ -975,32 +941,32 @@ reportUnusedNames export_decls gbl_env ; warnDuplicateImports defined_and_used ; printMinimalImports minimal_imports } where - used_names, all_used_names :: NameSet + used_names :: NameSet used_names = findUses (tcg_dus gbl_env) emptyNameSet -- NB: currently, if f x = g, we only treat 'g' as used if 'f' is used -- Hence findUses - avail_env = imp_parent (tcg_imports gbl_env) - nameParent_maybe n = case lookupNameEnv avail_env n of - Just (AvailTC tc _) | tc /= n -> Just tc - _otherwise -> Nothing - - all_used_names = used_names `unionNameSets` - mkNameSet (mapCatMaybes nameParent_maybe (nameSetToList used_names)) - -- A use of C implies a use of T, - -- if C was brought into scope by T(..) or T(C) - -- Collect the defined names from the in-scope environment defined_names :: [GlobalRdrElt] defined_names = globalRdrEnvElts (tcg_rdr_env gbl_env) -- Note that defined_and_used, defined_but_not_used -- are both [GRE]; that's why we need defined_and_used - -- rather than just all_used_names + -- rather than just used_names defined_and_used, defined_but_not_used :: [GlobalRdrElt] (defined_and_used, defined_but_not_used) - = partition (gre_is_used all_used_names) defined_names + = partition (gre_is_used used_names) defined_names + kids_env = mkChildEnv defined_names + -- This is done in mkExports too; duplicated work + + gre_is_used :: NameSet -> GlobalRdrElt -> Bool + gre_is_used used_names (GRE {gre_name = name}) + = name `elemNameSet` used_names + || any (`elemNameSet` used_names) (findChildren kids_env name) + -- A use of C implies a use of T, + -- if C was brought into scope by T(..) or T(C) + -- Filter out the ones that are -- (a) defined in this module, and -- (b) not defined by a 'deriving' clause @@ -1046,11 +1012,10 @@ reportUnusedNames export_decls gbl_env -- We've carefully preserved the provenance so that we can -- construct minimal imports that import the name by (one of) -- the same route(s) as the programmer originally did. - add_name (GRE {gre_name = n, gre_prov = Imported imp_specs}) acc - = addToFM_C plusAvailEnv acc (importSpecModule (head imp_specs)) - (unitAvailEnv (mk_avail n (nameParent_maybe n))) - add_name other acc - = acc + add_name gre@(GRE {gre_prov = Imported (imp_spec:_)}) acc + = addToFM_C plusAvailEnv acc + (importSpecModule imp_spec) (unitAvailEnv (greAvail gre)) + add_name gre acc = acc -- Local -- Modules mentioned as 'module M' in the export list expall_mods = case export_decls of @@ -1073,11 +1038,6 @@ reportUnusedNames export_decls gbl_env -- qualified imports into account. But it's an improvement. add_expall mod acc = addToFM_C plusAvailEnv acc mod emptyAvailEnv - -- n is the name of the thing, p is the name of its parent - mk_avail n (Just p) = AvailTC p [p,n] - mk_avail n Nothing | isTcOcc (nameOccName n) = AvailTC n [n] - | otherwise = Avail n - add_inst_mod (mod,_,_) acc | mod_name `elemFM` acc = acc -- We import something already | otherwise = addToFM acc mod_name emptyAvailEnv @@ -1263,9 +1223,6 @@ dodgyMsg kind tc ptext SLIT("suggests that") <+> quotes (ppr tc) <+> ptext SLIT("has constructor or class methods"), ptext SLIT("but it has none; it is a type synonym or abstract type or class") ] -modExportErr mod - = hsep [ ptext SLIT("Unknown module in export list: module"), quotes (ppr mod)] - exportItemErr export_item = sep [ ptext SLIT("The export item") <+> quotes (ppr export_item), ptext SLIT("attempts to export constructors or class methods that are not visible here") ] @@ -1310,6 +1267,9 @@ dupModuleExport mod quotes (ptext SLIT("Module") <+> ppr mod), ptext SLIT("in export list")] +nullModuleExport mod + = ptext SLIT("The export item `module") <+> ppr mod <> ptext SLIT("' exports nothing") + moduleDeprec mod txt = sep [ ptext SLIT("Module") <+> quotes (ppr mod) <+> ptext SLIT("is deprecated:"), nest 4 (ppr txt) ] |