X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=4dfcc13eeaab0984775fe1ca16f34a8d0b116fa2;hb=f4c9d2b23bd63b48566e0ca3b13c8bdfc4cd0c0b;hp=d7eaf76e2e5375763c7260f6754e333c7217b5df;hpb=f714e6b642fd614a9971717045ae47c3d871275e;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index d7eaf76..4dfcc13 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -6,7 +6,8 @@ \begin{code} module RnNames ( rnImports, importsFromLocalDecls, exportsFromAvail, - reportUnusedNames, mkModDeps, exportsToAvails + reportUnusedNames, reportDeprecations, + mkModDeps, exportsToAvails ) where #include "HsVersions.h" @@ -22,22 +23,23 @@ import LoadIface ( loadSrcInterface ) import TcRnMonad import FiniteMap -import PrelNames ( pRELUDE_Name, isBuiltInSyntaxName, isUnboundName, +import PrelNames ( pRELUDE_Name, 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 ) +import Name ( Name, nameSrcLoc, nameOccName, nameModuleName, isWiredInName, + nameParent, nameParent_maybe, isExternalName, nameModule, + isBuiltInSyntax ) import NameSet -import NameEnv -import OccName ( srcDataName, isTcOcc, OccEnv, +import OccName ( srcDataName, isTcOcc, occNameFlavour, OccEnv, mkOccEnv, lookupOccEnv, emptyOccEnv, extendOccEnv ) import HscTypes ( GenAvailInfo(..), AvailInfo, Avails, GhciMode(..), - IfaceExport, + IfaceExport, HomePackageTable, PackageIfaceTable, availName, availNames, availsToNameSet, unQualInScope, - Deprecs(..), ModIface(..), Dependencies(..) + Deprecs(..), ModIface(..), Dependencies(..), lookupIface, + ExternalPackageState(..) ) import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..), @@ -46,12 +48,13 @@ import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, Provenance(..), ImportSpec(..), isLocalGRE, pprNameProvenance ) import Outputable -import Maybes ( isJust, isNothing, catMaybes, mapCatMaybes ) +import Maybes ( isNothing, catMaybes, mapCatMaybes, seqMaybe ) import SrcLoc ( noSrcLoc, Located(..), mkGeneralSrcSpan, - unLoc, noLoc ) + unLoc, noLoc, srcLocSpan, combineSrcSpans, SrcSpan ) +import BasicTypes ( DeprecTxt ) import ListSetOps ( removeDups ) -import Util ( sortLt, notNull, isSingleton ) -import List ( partition, insert ) +import Util ( sortLe, notNull, isSingleton ) +import List ( partition ) import IO ( openFile, IOMode(..) ) \end{code} @@ -68,32 +71,32 @@ rnImports :: [LImportDecl RdrName] -> RnM (GlobalRdrEnv, ImportAvails) rnImports imports - = -- PROCESS IMPORT DECLS + = do { -- PROCESS IMPORT DECLS -- Do the non {- SOURCE -} ones first, so that we get a helpful -- warning for {- SOURCE -} ones that are unnecessary - getModule `thenM` \ this_mod -> - doptM Opt_NoImplicitPrelude `thenM` \ opt_no_prelude -> - let - all_imports = mk_prel_imports this_mod opt_no_prelude ++ imports - (source, ordinary) = partition is_source_import all_imports - is_source_import (L _ (ImportDecl _ is_boot _ _ _)) = is_boot - - get_imports = importsFromImportDecl this_mod - in - mappM get_imports ordinary `thenM` \ stuff1 -> - mappM get_imports source `thenM` \ stuff2 -> + this_mod <- getModule + ; opt_no_prelude <- doptM Opt_NoImplicitPrelude + ; let + all_imports = mk_prel_imports this_mod opt_no_prelude ++ imports + (source, ordinary) = partition is_source_import all_imports + is_source_import (L _ (ImportDecl _ is_boot _ _ _)) = is_boot + + get_imports = importsFromImportDecl this_mod + + ; stuff1 <- mappM get_imports ordinary + ; stuff2 <- mappM get_imports source -- COMBINE RESULTS - let + ; let (imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2) gbl_env :: GlobalRdrEnv gbl_env = foldr plusGlobalRdrEnv emptyGlobalRdrEnv imp_gbl_envs all_avails :: ImportAvails all_avails = foldr plusImportAvails emptyImportAvails imp_avails - in + -- ALL DONE - returnM (gbl_env, all_avails) + ; return (gbl_env, all_avails) } where -- NB: opt_NoImplicitPrelude is slightly different to import Prelude (); -- because the former doesn't even look at Prelude.hi for instance @@ -129,7 +132,7 @@ importsFromImportDecl :: Module importsFromImportDecl this_mod (L loc (ImportDecl loc_imp_mod_name want_boot qual_only as_mod imp_details)) = - addSrcSpan loc $ + setSrcSpan loc $ -- If there's an error in loadInterface, (e.g. interface -- file not found) we get lots of spurious errors from 'filterImports' @@ -180,7 +183,6 @@ importsFromImportDecl this_mod 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 } - mk_deprec = mi_dep_fn iface in -- Get the total imports, and filter them according to the import list @@ -190,26 +192,29 @@ importsFromImportDecl this_mod let -- Compute new transitive dependencies - orphans | is_orph = insert imp_mod_name (dep_orphs deps) + + orphans | is_orph = ASSERT( not (imp_mod_name `elem` dep_orphs deps) ) + imp_mod_name : dep_orphs deps | otherwise = dep_orphs deps (dependent_mods, dependent_pkgs) | isHomeModule imp_mod = -- Imported module is from the home package - -- Take its dependent modules and - -- (a) remove this_mod (might be there as a hi-boot) - -- (b) add imp_mod itself + -- Take its dependent modules and add imp_mod itself -- Take its dependent packages unchanged - ((imp_mod_name, want_boot) : filter not_self (dep_mods deps), dep_pkgs deps) + -- NB: (dep_mods deps) might include a hi-boot file for the module being + -- compiled, CM. Do *not* filter this out (as we used to), because when + -- we've finished dealing with the direct imports we want to know if any + -- of them depended on CM.hi-boot, in which case we should do the hi-boot + -- consistency check. See LoadIface.loadHiBootInterface + ((imp_mod_name, want_boot) : dep_mods deps, dep_pkgs deps) | otherwise = -- Imported module is from another package -- Dump the dependent modules -- Add the package imp_mod comes from to the dependent packages - -- from imp_mod - ([], insert (mi_package iface) (dep_pkgs deps)) - - not_self (m, _) = m /= this_mod_name + ASSERT( not (mi_package iface `elem` dep_pkgs deps) ) + ([], mi_package iface : dep_pkgs deps) import_all = case imp_details of Just (is_hiding, ls) -- Imports are spec'd explicitly @@ -224,7 +229,7 @@ importsFromImportDecl this_mod imports = ImportAvails { imp_qual = unitModuleEnvByName qual_mod_name avail_env, imp_env = avail_env, - imp_mods = unitModuleEnv imp_mod (imp_mod, import_all), + imp_mods = unitModuleEnv imp_mod (imp_mod, import_all, loc), imp_orphs = orphans, imp_dep_mods = mkModDeps dependent_mods, imp_dep_pkgs = dependent_pkgs } @@ -301,22 +306,15 @@ importsFromLocalDecls group -- The complaint will come out as "Multiple declarations of Foo.f" because -- since 'f' is in the env twice, the unQualInScope used by the error-msg -- printer returns False. It seems awkward to fix, unfortunately. - mappM_ (addErr . dupDeclErr) dups `thenM_` + mappM_ addDupDeclErr dups `thenM_` doptM Opt_NoImplicitPrelude `thenM` \ implicit_prelude -> let 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 @@ -339,10 +337,10 @@ importsFromLocalDecls group avails' | implicit_prelude = filter not_built_in_syntax avails | otherwise = avails - not_built_in_syntax a = not (all isBuiltInSyntaxName (availNames a)) + not_built_in_syntax a = not (all isBuiltInSyntax (availNames a)) -- Only filter it if all the names of the avail are built-in -- In particular, lists have (:) which is not built in syntax - -- so we don't filter it out. [Sept 03: wrong: see isBuiltInSyntaxName] + -- so we don't filter it out. [Sept 03: wrong: see isBuiltInSyntax] avail_env = mkAvailEnv avails' imports = emptyImportAvails { @@ -408,34 +406,37 @@ filterImports :: ModIface -> ImportSpec -- The span for the entire import decl -> Maybe (Bool, [Located (IE RdrName)]) -- Import spec; True => hiding -> [AvailInfo] -- What's available - -> RnM (AvailEnv, -- What's imported - GlobalRdrEnv) -- ...in two forms + -> RnM (AvailEnv, -- What's imported (qualified or unqualified) + GlobalRdrEnv) -- Same again, but in GRE form -- Complains if import spec mentions things that the module doesn't export -- Warns/informs if import spec contains duplicates. -mkGenericRdrEnv iface imp_spec avails - = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] False, - gre_deprec = mi_dep_fn iface name } - | avail <- avails, name <- availNames avail ] +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 iface imp_spec 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) -> + = mapAndUnzipM (addLocM get_item) import_items `thenM` \ (avails_s, gres) -> let - all_avails = foldr plusAvailEnv emptyAvailEnv avails - rdr_env = foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres + avails = concat avails_s in if not want_hiding then - returnM (all_avails, rdr_env) + return (mkAvailEnv avails, + foldr plusGlobalRdrEnv emptyGlobalRdrEnv gres) else - 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 iface imp_spec pruned_avails) + let + hidden = availsToNameSet avails + keep n = not (n `elemNameSet` hidden) + pruned_avails = pruneAvails keep total_avails + in + return (mkAvailEnv pruned_avails, + mkGenericRdrEnv imp_spec pruned_avails) + where import_fm :: OccEnv AvailInfo import_fm = mkOccEnv [ (nameOccName name, avail) @@ -446,24 +447,21 @@ filterImports iface imp_spec (Just (want_hiding, import_items)) total_avails -- in an import list map to TcOccs, not VarOccs. bale_out item = addErr (badImportItemErr iface imp_spec item) `thenM_` - returnM (emptyAvailEnv, emptyGlobalRdrEnv) - - mk_deprec = mi_dep_fn iface + returnM ([], emptyGlobalRdrEnv) - succeed_with :: Bool -> AvailInfo -> RnM (AvailEnv, GlobalRdrEnv) + succeed_with :: Bool -> AvailInfo -> RnM ([AvailInfo], GlobalRdrEnv) succeed_with all_explicit avail = do { loc <- getSrcSpanM - ; returnM (unitAvailEnv avail, + ; returnM ([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), - gre_deprec = mk_deprec 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) + get_item :: IE RdrName -> RnM ([AvailInfo], 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 @@ -477,16 +475,17 @@ filterImports iface imp_spec (Just (want_hiding, import_items)) total_avails 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 tc)) `thenM_` + ifOptM Opt_WarnDodgyImports (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 + -- Here the 'C' can be a data constructor + -- *or* a type/class, or even both = case catMaybes [check_item item, check_item (IEVar data_n)] of [] -> bale_out item - avails -> returnM (mkAvailEnv avails, emptyGlobalRdrEnv) + avails -> returnM (avails, emptyGlobalRdrEnv) -- The GlobalRdrEnv result is irrelevant when hiding where data_n = setRdrNameSpace n srcDataName @@ -574,9 +573,8 @@ type ExportAccum -- The type of the accumulating parameter of -- the main worker function in exportsFromAvail = ([ModuleName], -- 'module M's seen so far ExportOccMap, -- Tracks exported occurrence names - AvailEnv) -- The accumulated exported stuff, kept in an env - -- so we can common-up related AvailInfos -emptyExportAccum = ([], emptyOccEnv, emptyAvailEnv) + NameSet) -- The accumulated exported stuff +emptyExportAccum = ([], emptyOccEnv, emptyNameSet) type ExportOccMap = OccEnv (Name, IE RdrName) -- Tracks what a particular exported OccName @@ -587,7 +585,7 @@ type ExportOccMap = OccEnv (Name, IE RdrName) exportsFromAvail :: Bool -- False => no 'module M(..) where' header at all -> Maybe [Located (IE RdrName)] -- Nothing => no explicit export list - -> RnM Avails + -> RnM NameSet -- Complains if two distinct exports have same OccName -- Warns about identical exports. -- Complains about exports items not in scope @@ -610,33 +608,27 @@ exportsFromAvail explicit_mod exports exports_from_avail real_exports rdr_env imports } -exports_from_avail Nothing rdr_env - imports@(ImportAvails { imp_env = entity_avail_env }) +exports_from_avail Nothing rdr_env imports = -- Export all locally-defined things -- We do this by filtering the global RdrEnv, - -- keeping only things that are (a) qualified, - -- (b) locally defined, (c) a 'main' name - -- Then we look up in the entity-avail-env - return [ lookupAvailEnv entity_avail_env name - | gre <- globalRdrEnvElts rdr_env, - isLocalGRE gre, - let name = gre_name gre, - isNothing (nameParent_maybe name) -- Main things only - ] + -- keeping only things that are locally-defined + return (mkNameSet [ gre_name gre + | gre <- globalRdrEnvElts rdr_env, + isLocalGRE gre ]) exports_from_avail (Just export_items) rdr_env (ImportAvails { imp_qual = mod_avail_env, imp_env = entity_avail_env }) = foldlM (exports_from_litem) emptyExportAccum - export_items `thenM` \ (_, _, export_avail_map) -> - returnM (nameEnvElts export_avail_map) + export_items `thenM` \ (_, _, exports) -> + returnM exports where 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) + exports_from_item acc@(mods, occs, exports) ie@(IEModuleContents mod) | mod `elem` mods -- Duplicate export of M = do { warn_dup_exports <- doptM Opt_WarnDuplicateExports ; warnIf warn_dup_exports (dupModuleExport mod) ; @@ -649,23 +641,19 @@ exports_from_avail (Just export_items) rdr_env Just avail_env -> let - mod_avails = [ filtered_avail - | avail <- availEnvElts avail_env, - let mb_avail = filter_unqual rdr_env avail, - isJust mb_avail, - let Just filtered_avail = mb_avail] - - avails' = foldl addAvail avails mod_avails + new_exports = [ name | avail <- availEnvElts avail_env, + name <- availNames avail, + inScopeUnqual rdr_env name ] in + -- 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. + check_occs ie occs new_exports `thenM` \ occs' -> + returnM (mod:mods, occs', addListToNameSet exports new_exports) - foldlM (check_occs ie) occs mod_avails `thenM` \ occs' -> - returnM (mod:mods, occs', avails') - - exports_from_item acc@(mods, occs, avails) ie + exports_from_item acc@(mods, occs, exports) ie = lookupGlobalOccRn (ieName ie) `thenM` \ name -> if isUnboundName name then returnM acc -- Avoid error cascade @@ -684,41 +672,34 @@ exports_from_avail (Just export_items) rdr_env Just export_avail -> -- Phew! It's OK! Now to check the occurrence stuff! - checkForDodgyExport ie avail `thenM_` - check_occs ie occs export_avail `thenM` \ occs' -> - returnM (mods, occs', addAvail avails export_avail) + + let + new_exports = availNames export_avail + in + checkForDodgyExport ie new_exports `thenM_` + check_occs ie occs new_exports `thenM` \ occs' -> + returnM (mods, occs', addListToNameSet exports new_exports) } ------------------------------- -filter_unqual :: GlobalRdrEnv -> AvailInfo -> Maybe AvailInfo --- Filter the Avail by what's in scope unqualified -filter_unqual env (Avail n) - | in_scope env n = Just (Avail n) - | otherwise = Nothing -filter_unqual env (AvailTC n ns) - | not (null ns') = Just (AvailTC n ns') - | otherwise = Nothing - where - ns' = filter (in_scope env) ns - -in_scope :: GlobalRdrEnv -> Name -> Bool +inScopeUnqual :: GlobalRdrEnv -> Name -> Bool -- Checks whether the Name is in scope unqualified, -- regardless of whether it's ambiguous or not -in_scope env n = any unQualOK (lookupGRE_Name env n) +inScopeUnqual env n = any unQualOK (lookupGRE_Name env n) ------------------------------- -checkForDodgyExport :: IE RdrName -> AvailInfo -> RnM () -checkForDodgyExport (IEThingAll tc) (AvailTC _ [n]) = addWarn (dodgyExportWarn tc) +checkForDodgyExport :: IE RdrName -> [Name] -> RnM () +checkForDodgyExport (IEThingAll tc) [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 checkForDodgyExport _ _ = return () ------------------------------- -check_occs :: IE RdrName -> ExportOccMap -> AvailInfo -> RnM ExportOccMap -check_occs ie occs avail - = foldlM check occs (availNames avail) +check_occs :: IE RdrName -> ExportOccMap -> [Name] -> RnM ExportOccMap +check_occs ie occs names + = foldlM check occs names where check occs name = case lookupOccEnv occs name_occ of @@ -740,18 +721,77 @@ check_occs ie occs avail %********************************************************* %* * -\subsection{Unused names} + Deprecations +%* * +%********************************************************* + +\begin{code} +reportDeprecations :: TcGblEnv -> RnM () +reportDeprecations tcg_env + = ifOptM Opt_WarnDeprecations $ + do { (eps,hpt) <- getEpsAndHpt + ; 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 + = setSrcSpan (is_loc imp_spec) $ + addWarn (sep [ptext SLIT("Deprecated use of") <+> + 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 + | isWiredInName n -> 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) + -- 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_` - warnDuplicateImports dup_imps `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 @@ -764,28 +804,34 @@ 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 - - dup_imps = filter isDupImport defined_and_used - 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 @@ -809,12 +855,10 @@ 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. - add_name (GRE {gre_name = n, - gre_prov = Imported imp_specs _}) acc + add_name (GRE {gre_name = n, gre_prov = Imported imp_specs _}) acc = addToFM_C plusAvailEnv acc (is_mod (head imp_specs)) (unitAvailEnv (mk_avail n (nameParent_maybe n))) add_name other acc @@ -825,43 +869,37 @@ reportUnusedNames gbl_env mk_avail n Nothing | isTcOcc (nameOccName n) = AvailTC n [n] | otherwise = Avail n - add_inst_mod m acc - | m `elemFM` acc = acc -- We import something already - | otherwise = addToFM acc m emptyAvailEnv + add_inst_mod (mod,_,_) acc + | mod_name `elemFM` acc = acc -- We import something already + | otherwise = addToFM acc mod_name emptyAvailEnv + where + mod_name = moduleName mod -- Add an empty collection of imports for a module -- from which we have sucked only instance decls imports = tcg_imports gbl_env - direct_import_mods :: [ModuleName] - direct_import_mods = map (moduleName . fst) - (moduleEnvElts (imp_mods imports)) - - hasEmptyImpList :: ModuleName -> Bool - hasEmptyImpList m = - case lookupModuleEnvByName (imp_mods imports) m of - Just (_,Just x) -> not x - _ -> False + direct_import_mods :: [(Module, Maybe Bool, SrcSpan)] + -- See the type of the imp_mods for this triple + direct_import_mods = moduleEnvElts (imp_mods imports) -- unused_imp_mods are the directly-imported modules -- that are not mentioned in minimal_imports1 -- [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), - m /= pRELUDE_Name, - not (hasEmptyImpList m)] - -- hasEmptyImpList arranges not to complain about + unused_imp_mods = [(mod_name,loc) | (mod,imp,loc) <- direct_import_mods, + let mod_name = moduleName mod, + not (mod_name `elemFM` minimal_imports1), + mod_name /= pRELUDE_Name, + imp /= Just False] + -- The Just False part is not to complain about -- import M (), which is an idiom for importing -- instance declarations module_unused :: ModuleName -> Bool - module_unused mod = mod `elem` unused_imp_mods - + module_unused mod = any (((==) mod) . fst) unused_imp_mods -isDupImport (GRE {gre_prov = Imported imp_spec True}) = not (isSingleton imp_spec) -isDupImport other = False - +--------------------- warnDuplicateImports :: [GlobalRdrElt] -> RnM () warnDuplicateImports gres = ifOptM Opt_WarnUnusedImports (mapM_ warn gres) @@ -966,12 +1004,16 @@ exportClashErr global_env name1 name2 ie1 ie2 (gre:_) -> gre [] -> pprPanic "exportClashErr" (ppr name) -dupDeclErr (n:ns) - = vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr n), - nest 4 (vcat (map ppr sorted_locs))] +addDupDeclErr :: [Name] -> TcRn () +addDupDeclErr names + = addErrAt big_loc $ + vcat [ptext SLIT("Multiple declarations of") <+> quotes (ppr name1), + ptext SLIT("Declared at:") <+> vcat (map ppr sorted_locs)] where - sorted_locs = sortLt occ'ed_before (map nameSrcLoc (n:ns)) - occ'ed_before a b = LT == compare a b + locs = map nameSrcLoc names + big_loc = foldr1 combineSrcSpans (map srcLocSpan locs) + name1 = head names + sorted_locs = sortLe (<=) (sortLe (<=) locs) dupExportWarn occ_name ie1 ie2 = hsep [quotes (ppr occ_name),