X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=656d13116b756f14a007eebace30720121474e5e;hb=d191be5da8d2934a5c50bdbc605784d6a9043b6f;hp=eb87208c4134bb199a0f64f23f46b43d00e04cd8;hpb=a195d525eb3ad5fd60a8797191c31907e6d9bfb0;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index eb87208..656d131 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -6,37 +6,40 @@ \begin{code} module RnNames ( rnImports, importsFromLocalDecls, exportsFromAvail, - reportUnusedNames, mkModDeps, exportsToAvails + reportUnusedNames, reportDeprecations, + mkModDeps, exportsToAvails ) where #include "HsVersions.h" import CmdLineOpts ( DynFlag(..) ) -import HsSyn ( IE(..), ieName, ImportDecl(..), +import HsSyn ( IE(..), ieName, ImportDecl(..), LImportDecl, ForeignDecl(..), HsGroup(..), - collectLocatedHsBinders, tyClDeclNames + collectGroupBinders, tyClDeclNames ) -import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, main_RDR_Unqual ) import RnEnv import IfaceEnv ( lookupOrig, newGlobalBinder ) import LoadIface ( loadSrcInterface ) import TcRnMonad import FiniteMap -import PrelNames ( pRELUDE_Name, isBuiltInSyntaxName, isUnboundName ) +import PrelNames ( pRELUDE_Name, isBuiltInSyntaxName, isUnboundName, + main_RDR_Unqual ) import Module ( Module, ModuleName, moduleName, mkPackageModule, moduleNameUserString, isHomeModule, unitModuleEnvByName, unitModuleEnv, lookupModuleEnvByName, moduleEnvElts ) import Name ( Name, nameSrcLoc, nameOccName, nameModuleName, - nameParent, nameParent_maybe, isExternalName ) + nameParent, nameParent_maybe, isExternalName, nameModule ) import NameSet import NameEnv -import OccName ( OccName, srcDataName, isTcOcc ) +import OccName ( srcDataName, isTcOcc, occNameFlavour, OccEnv, + mkOccEnv, lookupOccEnv, emptyOccEnv, extendOccEnv ) import HscTypes ( GenAvailInfo(..), AvailInfo, Avails, GhciMode(..), - IsBootInterface, IfaceExport, + IfaceExport, HomePackageTable, PackageIfaceTable, availName, availNames, availsToNameSet, unQualInScope, - Deprecs(..), ModIface(..), Dependencies(..) + Deprecs(..), ModIface(..), Dependencies(..), lookupIface, + ExternalPackageState(..) ) import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..), @@ -45,10 +48,12 @@ import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, Provenance(..), ImportSpec(..), isLocalGRE, pprNameProvenance ) import Outputable -import Maybes ( isJust, isNothing, catMaybes, mapCatMaybes ) -import SrcLoc ( noSrcLoc ) +import Maybes ( isJust, isNothing, catMaybes, mapCatMaybes, seqMaybe ) +import SrcLoc ( noSrcLoc, Located(..), mkGeneralSrcSpan, + unLoc, noLoc ) +import BasicTypes ( DeprecTxt ) import ListSetOps ( removeDups ) -import Util ( sortLt, notNull ) +import Util ( sortLt, notNull, isSingleton ) import List ( partition, insert ) import IO ( openFile, IOMode(..) ) \end{code} @@ -62,7 +67,7 @@ import IO ( openFile, IOMode(..) ) %************************************************************************ \begin{code} -rnImports :: [RdrNameImportDecl] +rnImports :: [LImportDecl RdrName] -> RnM (GlobalRdrEnv, ImportAvails) rnImports imports @@ -70,12 +75,11 @@ rnImports imports -- Do the non {- SOURCE -} ones first, so that we get a helpful -- warning for {- SOURCE -} ones that are unnecessary getModule `thenM` \ this_mod -> - getSrcLocM `thenM` \ loc -> doptM Opt_NoImplicitPrelude `thenM` \ opt_no_prelude -> let - all_imports = mk_prel_imports this_mod loc opt_no_prelude ++ imports + all_imports = mk_prel_imports this_mod opt_no_prelude ++ imports (source, ordinary) = partition is_source_import all_imports - is_source_import (ImportDecl _ is_boot _ _ _ _) = is_boot + is_source_import (L _ (ImportDecl _ is_boot _ _ _)) = is_boot get_imports = importsFromImportDecl this_mod in @@ -97,39 +101,43 @@ rnImports imports -- NB: opt_NoImplicitPrelude is slightly different to import Prelude (); -- because the former doesn't even look at Prelude.hi for instance -- declarations, whereas the latter does. - mk_prel_imports this_mod loc no_prelude + mk_prel_imports this_mod no_prelude | moduleName this_mod == pRELUDE_Name || explicit_prelude_import || no_prelude = [] - | otherwise = [preludeImportDecl loc] + | otherwise = [preludeImportDecl] explicit_prelude_import - = notNull [ () | (ImportDecl mod _ _ _ _ _) <- imports, - mod == pRELUDE_Name ] + = notNull [ () | L _ (ImportDecl mod _ _ _ _) <- imports, + unLoc mod == pRELUDE_Name ] -preludeImportDecl loc - = ImportDecl pRELUDE_Name +preludeImportDecl + = L loc $ + ImportDecl (L loc pRELUDE_Name) False {- Not a boot interface -} False {- Not qualified -} Nothing {- No "as" -} Nothing {- No import list -} - loc + where + loc = mkGeneralSrcSpan FSLIT("Implicit import declaration") \end{code} \begin{code} importsFromImportDecl :: Module - -> RdrNameImportDecl + -> LImportDecl RdrName -> RnM (GlobalRdrEnv, ImportAvails) importsFromImportDecl this_mod - (ImportDecl imp_mod_name want_boot qual_only as_mod imp_details iloc) - = addSrcLoc iloc $ + (L loc (ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details)) + = + addSrcSpan loc $ -- If there's an error in loadInterface, (e.g. interface -- file not found) we get lots of spurious errors from 'filterImports' let + imp_mod_name = unLoc loc_imp_mod_name this_mod_name = moduleName this_mod doc = ppr imp_mod_name <+> ptext SLIT("is directly imported") in @@ -169,11 +177,18 @@ importsFromImportDecl this_mod -- import {-# SOURCE #-} A( AType ) -- -- then you'll get a 'B does not export AType' message. Oh well. + + qual_mod_name = case as_mod of + Nothing -> imp_mod_name + Just another_name -> another_name + imp_spec = ImportSpec { is_mod = imp_mod_name, is_qual = qual_only, + is_loc = loc, is_as = qual_mod_name } in - exportsToAvails filtered_exports `thenM` \ avails -> - -- Filter the imports according to the import list - filterImports imp_mod want_boot imp_details avails `thenM` \ (filtered_avails, explicits) -> + -- Get the total imports, and filter them according to the import list + exportsToAvails filtered_exports `thenM` \ total_avails -> + filterImports iface imp_spec + imp_details total_avails `thenM` \ (avail_env, gbl_env) -> let -- Compute new transitive dependencies @@ -204,24 +219,10 @@ importsFromImportDecl this_mod _ -> Nothing -- Everything is imported, -- (or almost everything [hiding]) - qual_mod_name = case as_mod of - Nothing -> imp_mod_name - Just another_name -> another_name - -- unqual_avails is the Avails that are visible in *unqualified* form -- We need to know this so we know what to export when we see -- module M ( module P ) where ... -- Then we must export whatever came from P unqualified. - imp_spec = ImportSpec { is_mod = imp_mod_name, is_qual = qual_only, - is_loc = iloc , is_as = qual_mod_name } - mk_deprec = mi_dep_fn iface - gres = [ GRE { gre_name = name, - gre_prov = Imported [imp_spec] (name `elemNameSet` explicits), - gre_deprec = mk_deprec name } - | avail <- filtered_avails, name <- availNames avail ] - gbl_env = mkGlobalRdrEnv gres - - avail_env = mkAvailEnv filtered_avails imports = ImportAvails { imp_qual = unitModuleEnvByName qual_mod_name avail_env, imp_env = avail_env, @@ -309,15 +310,8 @@ importsFromLocalDecls group mod_name = moduleName this_mod prov = LocalDef mod_name gbl_env = mkGlobalRdrEnv gres - gres = [ GRE { gre_name = name, gre_prov = prov, gre_deprec = Nothing} + gres = [ GRE { gre_name = name, gre_prov = prov} | name <- all_names] - -- gre_deprecs = Nothing: don't deprecate locally defined names - -- For a start, we may be exporting a deprecated thing - -- Also we may use a deprecated thing in the defn of another - -- deprecated things. We may even use a deprecated thing in - -- the defn of a non-deprecated thing, when changing a module's - -- interface - -- Optimisation: filter out names for built-in syntax -- They just clutter up the environment (esp tuples), and the parser @@ -361,9 +355,8 @@ importsFromLocalDecls group %* * %********************************************************* -@getLocalDeclBinders@ returns the names for a @RdrNameHsDecl@. It's -used for both source code (from @importsFromLocalDecls@) and interface -files (@loadDecl@ calls @getTyClDeclBinders@). +@getLocalDeclBinders@ returns the names for an @HsDecl@. It's +used for source code. *** See "THE NAMING STORY" in HsDecls **** @@ -384,15 +377,15 @@ getLocalDeclBinders mod (HsGroup {hs_valds = val_decls, new_simple rdr_name = newTopSrcBinder mod Nothing rdr_name `thenM` \ name -> returnM (Avail name) - val_hs_bndrs = collectLocatedHsBinders val_decls - for_hs_bndrs = [(nm,loc) | ForeignImport nm _ _ _ loc <- foreign_decls] + val_hs_bndrs = collectGroupBinders val_decls + for_hs_bndrs = [nm | L _ (ForeignImport nm _ _ _) <- foreign_decls] new_tc tc_decl = newTopSrcBinder mod Nothing main_rdr `thenM` \ main_name -> mappM (newTopSrcBinder mod (Just main_name)) sub_rdrs `thenM` \ sub_names -> returnM (AvailTC main_name (main_name : sub_names)) where - (main_rdr : sub_rdrs) = tyClDeclNames tc_decl + (main_rdr : sub_rdrs) = tyClDeclNames (unLoc tc_decl) \end{code} @@ -406,77 +399,93 @@ getLocalDeclBinders mod (HsGroup {hs_valds = val_decls, available, and filters it through the import spec (if any). \begin{code} -filterImports :: Module -- The module being imported - -> IsBootInterface -- Tells whether it's a {-# SOURCE #-} import - -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hiding +filterImports :: ModIface + -> ImportSpec -- The span for the entire import decl + -> Maybe (Bool, [Located (IE RdrName)]) -- Import spec; True => hiding -> [AvailInfo] -- What's available - -> RnM ([AvailInfo], -- What's imported - NameSet) -- What was imported explicitly + -> RnM (AvailEnv, -- What's imported + GlobalRdrEnv) -- ...in two forms -- Complains if import spec mentions things that the module doesn't export -- Warns/informs if import spec contains duplicates. -filterImports mod from Nothing imports - = returnM (imports, emptyNameSet) - -filterImports mod from (Just (want_hiding, import_items)) total_avails - = mappM get_item import_items `thenM` \ avails_w_explicits_s -> +mkGenericRdrEnv imp_spec avails + = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] False } + | avail <- avails, name <- availNames avail ] + +filterImports iface imp_spec Nothing total_avails + = returnM (mkAvailEnv total_avails, mkGenericRdrEnv imp_spec total_avails) + +filterImports iface imp_spec (Just (want_hiding, import_items)) total_avails + = mapAndUnzipM (addLocM get_item) import_items `thenM` \ (avails, gres) -> let - (item_avails, explicits_s) = unzip (concat avails_w_explicits_s) - explicits = foldl addListToNameSet emptyNameSet explicits_s + all_avails = foldr plusAvailEnv emptyAvailEnv avails + rdr_env = foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres in - if want_hiding then - let -- All imported; item_avails to be hidden - hidden = availsToNameSet item_avails - keep n = not (n `elemNameSet` hidden) - in - returnM (pruneAvails keep total_avails, emptyNameSet) + if not want_hiding then + returnM (all_avails, rdr_env) else - -- Just item_avails imported; nothing to be hidden - returnM (item_avails, explicits) + let -- Hide stuff in all_avails + hidden = availsToNameSet (availEnvElts all_avails) + keep n = not (n `elemNameSet` hidden) + pruned_avails = pruneAvails keep total_avails + in + returnM (mkAvailEnv pruned_avails, mkGenericRdrEnv imp_spec pruned_avails) where - import_fm :: FiniteMap OccName AvailInfo - import_fm = listToFM [ (nameOccName name, avail) + import_fm :: OccEnv AvailInfo + import_fm = mkOccEnv [ (nameOccName name, avail) | avail <- total_avails, name <- availNames avail] -- Even though availNames returns data constructors too, -- they won't make any difference because naked entities like T -- in an import list map to TcOccs, not VarOccs. - bale_out item = addErr (badImportItemErr mod from item) `thenM_` - returnM [] + bale_out item = addErr (badImportItemErr iface imp_spec item) `thenM_` + returnM (emptyAvailEnv, emptyGlobalRdrEnv) - get_item :: RdrNameIE -> RnM [(AvailInfo, [Name])] - -- Empty list for a bad item. - -- Singleton is typical case. + succeed_with :: Bool -> AvailInfo -> RnM (AvailEnv, GlobalRdrEnv) + succeed_with all_explicit avail + = do { loc <- getSrcSpanM + ; returnM (unitAvailEnv avail, + mkGlobalRdrEnv (map (mk_gre loc) (availNames avail))) } + where + mk_gre loc name = GRE { gre_name = name, + gre_prov = Imported [this_imp_spec loc] (explicit name) } + this_imp_spec loc = imp_spec { is_loc = loc } + explicit name = all_explicit || name == main_name + main_name = availName avail + + get_item :: IE RdrName -> RnM (AvailEnv, GlobalRdrEnv) + -- Empty result for a bad item. + -- Singleton result is typical case. -- Can have two when we are hiding, and mention C which might be -- both a class and a data constructor. - -- The [Name] is the list of explicitly-mentioned names - get_item item@(IEModuleContents _) = bale_out item + get_item item@(IEModuleContents _) + = bale_out item - get_item item@(IEThingAll _) + get_item item@(IEThingAll tc) = case check_item item of Nothing -> bale_out item Just avail@(AvailTC _ [n]) -> -- This occurs when you import T(..), but -- only export T abstractly. The single [n] -- in the AvailTC is the type or class itself - ifOptM Opt_WarnMisc (addWarn (dodgyImportWarn mod item)) `thenM_` - returnM [(avail, [availName avail])] - Just avail -> returnM [(avail, [availName avail])] + ifOptM Opt_WarnMisc (addWarn (dodgyImportWarn tc)) `thenM_` + succeed_with False avail + Just avail -> succeed_with False avail get_item item@(IEThingAbs n) | want_hiding -- hiding( C ) -- Here the 'C' can be a data constructor *or* a type/class = case catMaybes [check_item item, check_item (IEVar data_n)] of - [] -> bale_out item - avails -> returnM [(a, []) | a <- avails] - -- The 'explicits' list is irrelevant when hiding + [] -> bale_out item + avails -> returnM (mkAvailEnv avails, emptyGlobalRdrEnv) + -- The GlobalRdrEnv result is irrelevant when hiding where data_n = setRdrNameSpace n srcDataName get_item item = case check_item item of Nothing -> bale_out item - Just avail -> returnM [(avail, availNames avail)] + Just avail -> succeed_with True avail check_item item | isNothing maybe_in_import_avails || @@ -488,7 +497,7 @@ filterImports mod from (Just (want_hiding, import_items)) total_avails where wanted_occ = rdrNameOcc (ieName item) - maybe_in_import_avails = lookupFM import_fm wanted_occ + maybe_in_import_avails = lookupOccEnv import_fm wanted_occ Just avail = maybe_in_import_avails maybe_filtered_avail = filterAvail item avail @@ -496,7 +505,7 @@ filterImports mod from (Just (want_hiding, import_items)) total_avails \end{code} \begin{code} -filterAvail :: RdrNameIE -- Wanted +filterAvail :: IE RdrName -- Wanted -> AvailInfo -- Available -> Maybe AvailInfo -- Resulting available; -- Nothing if (any of the) wanted stuff isn't there @@ -558,23 +567,23 @@ type ExportAccum -- The type of the accumulating parameter of ExportOccMap, -- Tracks exported occurrence names AvailEnv) -- The accumulated exported stuff, kept in an env -- so we can common-up related AvailInfos -emptyExportAccum = ([], emptyFM, emptyAvailEnv) +emptyExportAccum = ([], emptyOccEnv, emptyAvailEnv) -type ExportOccMap = FiniteMap OccName (Name, RdrNameIE) +type ExportOccMap = OccEnv (Name, IE RdrName) -- Tracks what a particular exported OccName -- in an export list refers to, and which item -- it came from. It's illegal to export two distinct things -- that have the same occurrence name -exportsFromAvail :: Maybe Module -- Nothing => no 'module M(..) where' header at all - -> Maybe [RdrNameIE] -- Nothing => no explicit export list +exportsFromAvail :: Bool -- False => no 'module M(..) where' header at all + -> Maybe [Located (IE RdrName)] -- Nothing => no explicit export list -> RnM Avails -- Complains if two distinct exports have same OccName -- Warns about identical exports. -- Complains about exports items not in scope -exportsFromAvail maybe_mod exports +exportsFromAvail explicit_mod exports = do { TcGblEnv { tcg_rdr_env = rdr_env, tcg_imports = imports } <- getGblEnv ; @@ -586,13 +595,12 @@ exportsFromAvail maybe_mod exports -- in interactive mode ghci_mode <- getGhciMode ; let { real_exports - = case maybe_mod of - Just mod -> exports - Nothing | ghci_mode == Interactive -> Nothing - | otherwise -> Just [IEVar main_RDR_Unqual] } ; - + | explicit_mod = exports + | ghci_mode == Interactive = Nothing + | otherwise = Just [noLoc (IEVar main_RDR_Unqual)] } ; exports_from_avail real_exports rdr_env imports } + exports_from_avail Nothing rdr_env imports@(ImportAvails { imp_env = entity_avail_env }) = -- Export all locally-defined things @@ -610,13 +618,15 @@ exports_from_avail Nothing rdr_env exports_from_avail (Just export_items) rdr_env (ImportAvails { imp_qual = mod_avail_env, imp_env = entity_avail_env }) - = foldlM exports_from_item emptyExportAccum + = foldlM (exports_from_litem) emptyExportAccum export_items `thenM` \ (_, _, export_avail_map) -> returnM (nameEnvElts export_avail_map) where - exports_from_item :: ExportAccum -> RdrNameIE -> RnM ExportAccum + exports_from_litem :: ExportAccum -> Located (IE RdrName) -> RnM ExportAccum + exports_from_litem acc = addLocM (exports_from_item acc) + exports_from_item :: ExportAccum -> IE RdrName -> RnM ExportAccum exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod) | mod `elem` mods -- Duplicate export of M = do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ; @@ -665,7 +675,7 @@ exports_from_avail (Just export_items) rdr_env Just export_avail -> -- Phew! It's OK! Now to check the occurrence stuff! - warnIf (not (ok_item ie avail)) (dodgyExportWarn ie) `thenM_` + checkForDodgyExport ie avail `thenM_` check_occs ie occs export_avail `thenM` \ occs' -> returnM (mods, occs', addAvail avails export_avail) } @@ -688,22 +698,22 @@ in_scope :: GlobalRdrEnv -> Name -> Bool -- regardless of whether it's ambiguous or not in_scope env n = any unQualOK (lookupGRE_Name env n) - ------------------------------- -ok_item (IEThingAll _) (AvailTC _ [n]) = False +checkForDodgyExport :: IE RdrName -> AvailInfo -> RnM () +checkForDodgyExport (IEThingAll tc) (AvailTC _ [n]) = addWarn (dodgyExportWarn tc) -- This occurs when you import T(..), but -- only export T abstractly. The single [n] -- in the AvailTC is the type or class itself -ok_item _ _ = True +checkForDodgyExport _ _ = return () ------------------------------- -check_occs :: RdrNameIE -> ExportOccMap -> AvailInfo -> RnM ExportOccMap +check_occs :: IE RdrName -> ExportOccMap -> AvailInfo -> RnM ExportOccMap check_occs ie occs avail = foldlM check occs (availNames avail) where check occs name - = case lookupFM occs name_occ of - Nothing -> returnM (addToFM occs name_occ (name, ie)) + = case lookupOccEnv occs name_occ of + Nothing -> returnM (extendOccEnv occs name_occ (name, ie)) Just (name', ie') | name == name' -- Duplicate export @@ -721,17 +731,72 @@ check_occs ie occs avail %********************************************************* %* * -\subsection{Unused names} + Deprecations +%* * +%********************************************************* + +\begin{code} +reportDeprecations :: TcGblEnv -> RnM () +reportDeprecations tcg_env + = ifOptM Opt_WarnDeprecations $ + do { hpt <- getHpt + ; eps <- getEps + ; mapM_ (check hpt (eps_PIT eps)) all_gres } + where + used_names = findUses (tcg_dus tcg_env) emptyNameSet + all_gres = globalRdrEnvElts (tcg_rdr_env tcg_env) + + check hpt pit (GRE {gre_name = name, gre_prov = Imported (imp_spec:_) _}) + | name `elemNameSet` used_names + , Just deprec_txt <- lookupDeprec hpt pit name + = addSrcSpan (is_loc imp_spec) $ + addWarn (sep [ptext SLIT("Deprecated use of") <+> + text (occNameFlavour (nameOccName name)) <+> + quotes (ppr name), + (parens imp_msg), + (ppr deprec_txt) ]) + where + name_mod = nameModuleName name + imp_mod = is_mod imp_spec + imp_msg = ptext SLIT("imported from") <+> ppr imp_mod <> extra + extra | imp_mod == name_mod = empty + | otherwise = ptext SLIT(", but defined in") <+> ppr name_mod + + check hpt pit ok_gre = returnM () -- Local, or not used, or not deprectated + -- The Imported pattern-match: don't deprecate locally defined names + -- For a start, we may be exporting a deprecated thing + -- Also we may use a deprecated thing in the defn of another + -- deprecated things. We may even use a deprecated thing in + -- the defn of a non-deprecated thing, when changing a module's + -- interface + +lookupDeprec :: HomePackageTable -> PackageIfaceTable + -> Name -> Maybe DeprecTxt +lookupDeprec hpt pit n + = case lookupIface 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 + Nothing -> pprPanic "lookupDeprec" (ppr n) + -- By now all the interfaces should have been loaded + +gre_is_used :: NameSet -> GlobalRdrElt -> Bool +gre_is_used used_names gre = gre_name gre `elemNameSet` used_names +\end{code} + +%********************************************************* +%* * + Unused names %* * %********************************************************* \begin{code} reportUnusedNames :: TcGblEnv -> RnM () reportUnusedNames gbl_env - = warnUnusedModules unused_imp_mods `thenM_` - warnUnusedTopBinds bad_locals `thenM_` - warnUnusedImports bad_imports `thenM_` - printMinimalImports minimal_imports + = do { warnUnusedTopBinds unused_locals + ; warnUnusedModules unused_imp_mods + ; warnUnusedImports unused_imports + ; warnDuplicateImports dup_imps + ; printMinimalImports minimal_imports } where used_names, all_used_names :: NameSet used_names = findUses (tcg_dus gbl_env) emptyNameSet @@ -744,27 +809,34 @@ reportUnusedNames gbl_env 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 defined_and_used, defined_but_not_used :: [GlobalRdrElt] - (defined_and_used, defined_but_not_used) = partition is_used defined_names - - is_used gre = gre_name gre `elemNameSet` all_used_names + (defined_and_used, defined_but_not_used) + = partition (gre_is_used all_used_names) defined_names - -- Filter out the ones that are - -- (a) defined in this module, and - -- (b) not defined by a 'deriving' clause - -- The latter have an Internal Name, so we can filter them out easily - bad_locals :: [GlobalRdrElt] - bad_locals = filter is_bad defined_but_not_used - is_bad :: GlobalRdrElt -> Bool - is_bad gre = isLocalGRE gre && isExternalName (gre_name gre) + -- Find the duplicate imports + dup_imps = filter is_dup defined_and_used + is_dup (GRE {gre_prov = Imported imp_spec True}) = not (isSingleton imp_spec) + is_dup other = False + + -- Filter out the ones that are + -- (a) defined in this module, and + -- (b) not defined by a 'deriving' clause + -- The latter have an Internal Name, so we can filter them out easily + unused_locals :: [GlobalRdrElt] + unused_locals = filter is_unused_local defined_but_not_used + is_unused_local :: GlobalRdrElt -> Bool + is_unused_local gre = isLocalGRE gre && isExternalName (gre_name gre) - bad_imports :: [GlobalRdrElt] - bad_imports = filter bad_imp defined_but_not_used - bad_imp (GRE {gre_prov = Imported imp_specs True}) + unused_imports :: [GlobalRdrElt] + unused_imports = filter unused_imp defined_but_not_used + unused_imp (GRE {gre_prov = Imported imp_specs True}) = not (all (module_unused . is_mod) imp_specs) -- Don't complain about unused imports if we've already said the -- entire import is unused - bad_imp other = False + unused_imp other = False -- To figure out the minimal set of imports, start with the things -- that are in scope (i.e. in gbl_env). Then just combine them @@ -788,7 +860,6 @@ reportUnusedNames gbl_env -- There's really no good way to detect this, so the error message -- in RnEnv.warnUnusedModules is weakened instead - -- 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. @@ -824,7 +895,7 @@ reportUnusedNames gbl_env -- unused_imp_mods are the directly-imported modules -- that are not mentioned in minimal_imports1 - -- [Note: not 'minimal_imports', because that includes direcly-imported + -- [Note: not 'minimal_imports', because that includes directly-imported -- modules even if we use nothing from them; see notes above] unused_imp_mods = [m | m <- direct_import_mods, isNothing (lookupFM minimal_imports1 m), @@ -837,6 +908,15 @@ reportUnusedNames gbl_env module_unused :: ModuleName -> Bool module_unused mod = mod `elem` unused_imp_mods +--------------------- +warnDuplicateImports :: [GlobalRdrElt] -> RnM () +warnDuplicateImports gres + = ifOptM Opt_WarnUnusedImports (mapM_ warn gres) + where + warn (GRE { gre_name = name, gre_prov = Imported imps _ }) + = addWarn ((quotes (ppr name) <+> ptext SLIT("is imported more than once:")) + $$ nest 2 (vcat (map ppr imps))) + -- ToDo: deal with original imports with 'qualified' and 'as M' clauses printMinimalImports :: FiniteMap ModuleName AvailEnv -- Minimal imports @@ -896,19 +976,18 @@ printMinimalImports imps %************************************************************************ \begin{code} -badImportItemErr mod from ie - = sep [ptext SLIT("Module"), quotes (ppr mod), source_import, +badImportItemErr iface imp_spec ie + = sep [ptext SLIT("Module"), quotes (ppr (is_mod imp_spec)), source_import, ptext SLIT("does not export"), quotes (ppr ie)] where - source_import = case from of - True -> ptext SLIT("(hi-boot interface)") - other -> empty + source_import | mi_boot iface = ptext SLIT("(hi-boot interface)") + | otherwise = empty -dodgyImportWarn mod item = dodgyMsg (ptext SLIT("import")) item -dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item +dodgyImportWarn item = dodgyMsg (ptext SLIT("import")) item +dodgyExportWarn item = dodgyMsg (ptext SLIT("export")) item -dodgyMsg kind item@(IEThingAll tc) - = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr item), +dodgyMsg kind tc + = sep [ ptext SLIT("The") <+> kind <+> ptext SLIT("item") <+> quotes (ppr (IEThingAll 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") ]