X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=eb87208c4134bb199a0f64f23f46b43d00e04cd8;hb=a195d525eb3ad5fd60a8797191c31907e6d9bfb0;hp=74d183c3ab5c0a98851d14ae1f13319a50b8b4f0;hpb=753d8919d892ed0f62fae63241f09610b1eda67e;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index 74d183c..eb87208 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -6,46 +6,47 @@ \begin{code} module RnNames ( rnImports, importsFromLocalDecls, exportsFromAvail, - reportUnusedNames, mkModDeps, main_RDR_Unqual + reportUnusedNames, mkModDeps, exportsToAvails ) where #include "HsVersions.h" -import {-# SOURCE #-} RnHiFiles ( loadInterface ) - import CmdLineOpts ( DynFlag(..) ) - import HsSyn ( IE(..), ieName, ImportDecl(..), ForeignDecl(..), HsGroup(..), collectLocatedHsBinders, tyClDeclNames ) -import RdrHsSyn ( RdrNameIE, RdrNameImportDecl ) +import RdrHsSyn ( RdrNameIE, RdrNameImportDecl, main_RDR_Unqual ) import RnEnv +import IfaceEnv ( lookupOrig, newGlobalBinder ) +import LoadIface ( loadSrcInterface ) import TcRnMonad import FiniteMap -import PrelNames ( pRELUDE_Name, mAIN_Name, isBuiltInSyntaxName ) -import Module ( Module, ModuleName, ModuleEnv, moduleName, +import PrelNames ( pRELUDE_Name, isBuiltInSyntaxName, isUnboundName ) +import Module ( Module, ModuleName, moduleName, mkPackageModule, moduleNameUserString, isHomeModule, - emptyModuleEnv, unitModuleEnvByName, unitModuleEnv, - lookupModuleEnvByName, extendModuleEnvByName, moduleEnvElts ) -import Name ( Name, nameSrcLoc, nameOccName, nameModule, isExternalName ) + unitModuleEnvByName, unitModuleEnv, + lookupModuleEnvByName, moduleEnvElts ) +import Name ( Name, nameSrcLoc, nameOccName, nameModuleName, + nameParent, nameParent_maybe, isExternalName ) import NameSet import NameEnv -import OccName ( OccName, dataName, isTcOcc ) -import HscTypes ( Provenance(..), ImportReason(..), GlobalRdrEnv, - GenAvailInfo(..), AvailInfo, Avails, - IsBootInterface, - availName, availNames, availsToNameSet, - Deprecations(..), ModIface(..), Dependencies(..), - GlobalRdrElt(..), unQualInScope, isLocalGRE, pprNameProvenance +import OccName ( OccName, srcDataName, isTcOcc ) +import HscTypes ( GenAvailInfo(..), AvailInfo, Avails, GhciMode(..), + IsBootInterface, IfaceExport, + availName, availNames, availsToNameSet, unQualInScope, + Deprecs(..), ModIface(..), Dependencies(..) ) -import OccName ( varName ) -import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, lookupRdrEnv, rdrEnvToList, - emptyRdrEnv, foldRdrEnv, rdrEnvElts, mkRdrUnqual, isQual, mkUnqual ) +import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, + GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..), + emptyGlobalRdrEnv, plusGlobalRdrEnv, globalRdrEnvElts, + unQualOK, lookupGRE_Name, + Provenance(..), ImportSpec(..), + isLocalGRE, pprNameProvenance ) import Outputable -import Maybe ( isJust, isNothing, catMaybes, fromMaybe ) -import Maybes ( orElse, expectJust ) +import Maybes ( isJust, isNothing, catMaybes, mapCatMaybes ) +import SrcLoc ( noSrcLoc ) import ListSetOps ( removeDups ) import Util ( sortLt, notNull ) import List ( partition, insert ) @@ -62,7 +63,7 @@ import IO ( openFile, IOMode(..) ) \begin{code} rnImports :: [RdrNameImportDecl] - -> TcRn m (GlobalRdrEnv, ImportAvails) + -> RnM (GlobalRdrEnv, ImportAvails) rnImports imports = -- PROCESS IMPORT DECLS @@ -85,7 +86,7 @@ rnImports imports let (imp_gbl_envs, imp_avails) = unzip (stuff1 ++ stuff2) gbl_env :: GlobalRdrEnv - gbl_env = foldr plusGlobalRdrEnv emptyRdrEnv imp_gbl_envs + gbl_env = foldr plusGlobalRdrEnv emptyGlobalRdrEnv imp_gbl_envs all_avails :: ImportAvails all_avails = foldr plusImportAvails emptyImportAvails imp_avails @@ -120,35 +121,38 @@ preludeImportDecl loc \begin{code} importsFromImportDecl :: Module -> RdrNameImportDecl - -> TcRn m (GlobalRdrEnv, ImportAvails) + -> RnM (GlobalRdrEnv, ImportAvails) importsFromImportDecl this_mod - (ImportDecl imp_mod_name is_boot qual_only as_mod imp_spec iloc) + (ImportDecl imp_mod_name want_boot qual_only as_mod imp_details iloc) = addSrcLoc iloc $ + + -- If there's an error in loadInterface, (e.g. interface + -- file not found) we get lots of spurious errors from 'filterImports' let + this_mod_name = moduleName this_mod doc = ppr imp_mod_name <+> ptext SLIT("is directly imported") in + loadSrcInterface doc imp_mod_name want_boot `thenM` \ iface -> - -- If there's an error in loadInterface, (e.g. interface - -- file not found) we get lots of spurious errors from 'filterImports' - tryM (loadInterface doc imp_mod_name (ImportByUser is_boot)) `thenM` \ mb_iface -> + -- Compiler sanity check: if the import didn't say + -- {-# SOURCE #-} we should not get a hi-boot file + WARN( not want_boot && mi_boot iface, ppr imp_mod_name ) - case mb_iface of { - Left exn -> returnM (emptyRdrEnv, emptyImportAvails ) ; - Right iface -> + -- Issue a user warning for a redundant {- SOURCE -} import + -- NB that we arrange to read all the ordinary imports before + -- any of the {- SOURCE -} imports + warnIf (want_boot && not (mi_boot iface)) + (warnRedundantSourceImport imp_mod_name) `thenM_` let - imp_mod = mi_module iface - avails_by_module = mi_exports iface - deprecs = mi_deprecs iface - is_orph = mi_orphan iface - deps = mi_deps iface - - avails :: Avails - avails = [ avail | (mod_name, avails) <- avails_by_module, - mod_name /= this_mod_name, - avail <- avails ] - this_mod_name = moduleName this_mod + imp_mod = mi_module iface + deprecs = mi_deprecs iface + is_orph = mi_orphan iface + deps = mi_deps iface + + filtered_exports = filter not_this_mod (mi_exports iface) + not_this_mod (mod,_) = mod /= this_mod_name -- If the module exports anything defined in this module, just ignore it. -- Reason: otherwise it looks as if there are two local definition sites -- for the thing, and an error gets reported. Easiest thing is just to @@ -165,10 +169,11 @@ importsFromImportDecl this_mod -- import {-# SOURCE #-} A( AType ) -- -- then you'll get a 'B does not export AType' message. Oh well. - in + exportsToAvails filtered_exports `thenM` \ avails -> + -- Filter the imports according to the import list - filterImports imp_mod is_boot imp_spec avails `thenM` \ (filtered_avails, explicits) -> + filterImports imp_mod want_boot imp_details avails `thenM` \ (filtered_avails, explicits) -> let -- Compute new transitive dependencies @@ -182,7 +187,7 @@ importsFromImportDecl this_mod -- (a) remove this_mod (might be there as a hi-boot) -- (b) add imp_mod itself -- Take its dependent packages unchanged - ((imp_mod_name, is_boot) : filter not_self (dep_mods deps), dep_pkgs deps) + ((imp_mod_name, want_boot) : filter not_self (dep_mods deps), dep_pkgs deps) | otherwise = -- Imported module is from another package @@ -193,10 +198,11 @@ importsFromImportDecl this_mod not_self (m, _) = m /= this_mod_name - import_all = case imp_spec of - (Just (False, _)) -> False -- Imports are spec'd explicitly - other -> True -- Everything is imported, - -- (or almost everything [hiding]) + import_all = case imp_details of + Just (is_hiding, ls) -- Imports are spec'd explicitly + | not is_hiding -> Just (not (null ls)) + _ -> Nothing -- Everything is imported, + -- (or almost everything [hiding]) qual_mod_name = case as_mod of Nothing -> imp_mod_name @@ -206,12 +212,17 @@ importsFromImportDecl this_mod -- 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 - - mk_prov name = NonLocalDef (UserImport imp_mod iloc (name `elemNameSet` explicits)) - gbl_env = mkGlobalRdrEnv qual_mod_name (not qual_only) - mk_prov filtered_avails deprecs - imports = ImportAvails { + imports = ImportAvails { imp_qual = unitModuleEnvByName qual_mod_name avail_env, imp_env = avail_env, imp_mods = unitModuleEnv imp_mod (imp_mod, import_all), @@ -228,13 +239,35 @@ importsFromImportDecl this_mod ) `thenM_` returnM (gbl_env, imports) - } -mkModDeps :: [(ModuleName, IsBootInterface)] - -> ModuleEnv (ModuleName, IsBootInterface) -mkModDeps deps = foldl add emptyModuleEnv deps - where - add env elt@(m,_) = extendModuleEnvByName env m elt +exportsToAvails :: [IfaceExport] -> TcRnIf gbl lcl Avails +exportsToAvails exports + = do { avails_by_module <- mappM do_one exports + ; return (concat avails_by_module) } + where + do_one (mod_name, exports) = mapM (do_avail mod_name) exports + do_avail mod_nm (Avail n) = do { n' <- lookupOrig mod_nm n; + ; return (Avail n') } + do_avail mod_nm (AvailTC n ns) = do { n' <- lookupOrig mod_nm n + ; ns' <- mappM (lookup_sub n') ns + ; return (AvailTC n' ns') } + where + mod = mkPackageModule mod_nm -- Not necessarily right yet + lookup_sub parent occ = newGlobalBinder mod occ (Just parent) noSrcLoc + -- Hack alert! Notice the newGlobalBinder. It ensures that the subordinate + -- names record their parent; and that in turn ensures that the GlobalRdrEnv + -- has the correct parent for all the names in its range. + -- For imported things, we only suck in the binding site later, if ever. + -- Reason for all this: + -- Suppose module M exports type A.T, and constructor A.MkT + -- Then, we know that A.MkT is a subordinate name of A.T, + -- even though we aren't at the binding site of A.T + -- And it's important, because we may simply re-export A.T + -- without ever sucking in the declaration itself. + +warnRedundantSourceImport mod_name + = ptext SLIT("Unnecessary {- SOURCE -} in the import of module") + <+> quotes (ppr mod_name) \end{code} @@ -253,7 +286,7 @@ Complain about duplicate bindings \begin{code} importsFromLocalDecls :: HsGroup RdrName - -> TcRn m (GlobalRdrEnv, ImportAvails) + -> RnM (GlobalRdrEnv, ImportAvails) importsFromLocalDecls group = getModule `thenM` \ this_mod -> getLocalDeclBinders this_mod group `thenM` \ avails -> @@ -273,12 +306,12 @@ importsFromLocalDecls group doptM Opt_NoImplicitPrelude `thenM` \ implicit_prelude -> let - mod_name = moduleName this_mod - mk_prov n = LocalDef -- Provenance is local - - unqual_imp = True -- Want unqualified names in scope - gbl_env = mkGlobalRdrEnv mod_name unqual_imp mk_prov avails NoDeprecs - -- NoDeprecs: don't complain about locally defined names + mod_name = moduleName this_mod + prov = LocalDef mod_name + gbl_env = mkGlobalRdrEnv gres + gres = [ GRE { gre_name = name, gre_prov = prov, gre_deprec = Nothing} + | 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 @@ -300,8 +333,9 @@ importsFromLocalDecls group -- defn of gbl_env 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. Sigh. - -- It doesn't matter because it only affects the Data.Tuple really. + -- 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. avails' | implicit_prelude = filter not_built_in_syntax avails @@ -309,7 +343,7 @@ importsFromLocalDecls group not_built_in_syntax a = not (all isBuiltInSyntaxName (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. + -- so we don't filter it out. [Sept 03: wrong: see isBuiltInSyntaxName] avail_env = mkAvailEnv avails' imports = emptyImportAvails { @@ -334,7 +368,7 @@ files (@loadDecl@ calls @getTyClDeclBinders@). *** See "THE NAMING STORY" in HsDecls **** \begin{code} -getLocalDeclBinders :: Module -> HsGroup RdrName -> TcRn m [AvailInfo] +getLocalDeclBinders :: Module -> HsGroup RdrName -> RnM [AvailInfo] getLocalDeclBinders mod (HsGroup {hs_valds = val_decls, hs_tyclds = tycl_decls, hs_fords = foreign_decls }) @@ -343,18 +377,22 @@ getLocalDeclBinders mod (HsGroup {hs_valds = val_decls, -- permanently bound into the TyCons and Classes. They don't need -- an export indicator because they are all implicitly exported. - mappM new_tc tycl_decls `thenM` \ tc_avails -> - mappM new_bndr (for_hs_bndrs ++ val_hs_bndrs) `thenM` \ simple_bndrs -> - - returnM (tc_avails ++ map Avail simple_bndrs) + mappM new_tc tycl_decls `thenM` \ tc_avails -> + mappM new_simple (for_hs_bndrs ++ val_hs_bndrs) `thenM` \ simple_avails -> + returnM (tc_avails ++ simple_avails) where - new_bndr (rdr_name,loc) = newTopBinder mod rdr_name loc + 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] - new_tc tc_decl = mappM new_bndr (tyClDeclNames tc_decl) `thenM` \ names@(main_name:_) -> - returnM (AvailTC main_name names) + 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 \end{code} @@ -372,7 +410,7 @@ filterImports :: Module -- The module being imported -> IsBootInterface -- Tells whether it's a {-# SOURCE #-} import -> Maybe (Bool, [RdrNameIE]) -- Import spec; True => hiding -> [AvailInfo] -- What's available - -> TcRn m ([AvailInfo], -- What's imported + -> RnM ([AvailInfo], -- What's imported NameSet) -- What was imported explicitly -- Complains if import spec mentions things that the module doesn't export @@ -407,7 +445,7 @@ filterImports mod from (Just (want_hiding, import_items)) total_avails bale_out item = addErr (badImportItemErr mod from item) `thenM_` returnM [] - get_item :: RdrNameIE -> TcRn m [(AvailInfo, [Name])] + get_item :: RdrNameIE -> RnM [(AvailInfo, [Name])] -- Empty list for a bad item. -- Singleton is typical case. -- Can have two when we are hiding, and mention C which might be @@ -433,7 +471,7 @@ filterImports mod from (Just (want_hiding, import_items)) total_avails avails -> returnM [(a, []) | a <- avails] -- The 'explicits' list is irrelevant when hiding where - data_n = setRdrNameSpace n dataName + data_n = setRdrNameSpace n srcDataName get_item item = case check_item item of @@ -529,41 +567,45 @@ type ExportOccMap = FiniteMap OccName (Name, RdrNameIE) -- that have the same occurrence name -exportsFromAvail :: Maybe [RdrNameIE] -> TcRn m Avails +exportsFromAvail :: Maybe Module -- Nothing => no 'module M(..) where' header at all + -> Maybe [RdrNameIE] -- 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 exports +exportsFromAvail maybe_mod exports = do { TcGblEnv { tcg_rdr_env = rdr_env, tcg_imports = imports } <- getGblEnv ; - exports_from_avail exports rdr_env imports } + + -- If the module header is omitted altogether, then behave + -- as if the user had written "module Main(main) where..." + -- EXCEPT in interactive mode, when we behave as if he had + -- written "module Main where ..." + -- Reason: don't want to complain about 'main' not in scope + -- 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] } ; + + exports_from_avail real_exports rdr_env imports } exports_from_avail Nothing rdr_env imports@(ImportAvails { imp_env = entity_avail_env }) - = do { this_mod <- getModule ; - if moduleName this_mod == mAIN_Name then - exports_from_avail (Just [IEVar main_RDR_Unqual]) rdr_env imports - -- Behave just as if we'd said module Main(main) - -- This is particularly important if we compile module Main, - -- but then use ghci to call it... we jolly well expect to - -- see 'main'! - else - -- 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 [ avail - | (rdr_name, gres) <- rdrEnvToList rdr_env, - isQual rdr_name, -- Avoid duplicates - GRE { gre_name = name, - gre_parent = Nothing, -- Main things only - gre_prov = LocalDef } <- gres, - let avail = expectJust "exportsFromAvail" - (lookupAvailEnv entity_avail_env name) - ] - } + = -- 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 + ] exports_from_avail (Just export_items) rdr_env (ImportAvails { imp_qual = mod_avail_env, @@ -573,7 +615,7 @@ exports_from_avail (Just export_items) rdr_env returnM (nameEnvElts export_avail_map) where - exports_from_item :: ExportAccum -> RdrNameIE -> TcRn m ExportAccum + exports_from_item :: ExportAccum -> RdrNameIE -> RnM ExportAccum exports_from_item acc@(mods, occs, avails) ie@(IEModuleContents mod) | mod `elem` mods -- Duplicate export of M @@ -605,17 +647,14 @@ exports_from_avail (Just export_items) rdr_env returnM (mod:mods, occs', avails') exports_from_item acc@(mods, occs, avails) ie - = lookupGRE (ieName ie) `thenM` \ mb_gre -> - case mb_gre of { - Nothing -> addErr (unknownNameErr (ieName ie)) `thenM_` - returnM acc ; - Just gre -> - + = lookupGlobalOccRn (ieName ie) `thenM` \ name -> + if isUnboundName name then + returnM acc -- Avoid error cascade + else -- Get the AvailInfo for the parent of the specified name let - parent = gre_parent gre `orElse` gre_name gre - avail = expectJust "exportsFromAvail2" - (lookupAvailEnv entity_avail_env parent) + parent = nameParent name + avail = lookupAvailEnv entity_avail_env parent in -- Filter out the bits we want case filterAvail ie avail of { @@ -629,7 +668,7 @@ exports_from_avail (Just export_items) rdr_env warnIf (not (ok_item ie avail)) (dodgyExportWarn ie) `thenM_` check_occs ie occs export_avail `thenM` \ occs' -> returnM (mods, occs', addAvail avails export_avail) - }} + } ------------------------------- @@ -647,10 +686,7 @@ filter_unqual env (AvailTC n ns) in_scope :: GlobalRdrEnv -> Name -> Bool -- Checks whether the Name is in scope unqualified, -- regardless of whether it's ambiguous or not -in_scope env n - = case lookupRdrEnv env (mkRdrUnqual (nameOccName n)) of - Nothing -> False - Just gres -> or [n == gre_name g | g <- gres] +in_scope env n = any unQualOK (lookupGRE_Name env n) ------------------------------- @@ -661,7 +697,7 @@ ok_item (IEThingAll _) (AvailTC _ [n]) = False ok_item _ _ = True ------------------------------- -check_occs :: RdrNameIE -> ExportOccMap -> AvailInfo -> TcRn m ExportOccMap +check_occs :: RdrNameIE -> ExportOccMap -> AvailInfo -> RnM ExportOccMap check_occs ie occs avail = foldlM check occs (availNames avail) where @@ -681,13 +717,6 @@ check_occs ie occs avail returnM occs } where name_occ = nameOccName name - ----------------------------- -main_RDR_Unqual :: RdrName -main_RDR_Unqual = mkUnqual varName FSLIT("main") - -- Don't get a RdrName from PrelNames.mainName, because - -- nameRdrNamegets an Orig RdrName, and we want a Qual or Unqual one. - -- An Unqual one will do just fine \end{code} %********************************************************* @@ -697,39 +726,28 @@ main_RDR_Unqual = mkUnqual varName FSLIT("main") %********************************************************* \begin{code} -reportUnusedNames :: TcGblEnv - -> NameSet -- Used in this module - -> TcRn m () -reportUnusedNames gbl_env used_names - = warnUnusedModules unused_imp_mods `thenM_` - warnUnusedTopBinds bad_locals `thenM_` - warnUnusedImports bad_imports `thenM_` +reportUnusedNames :: TcGblEnv -> RnM () +reportUnusedNames gbl_env + = warnUnusedModules unused_imp_mods `thenM_` + warnUnusedTopBinds bad_locals `thenM_` + warnUnusedImports bad_imports `thenM_` printMinimalImports minimal_imports where - direct_import_mods :: [ModuleName] - direct_import_mods = map (moduleName . fst) - (moduleEnvElts (imp_mods (tcg_imports gbl_env))) - - -- Now, a use of C implies a use of T, - -- if C was brought into scope by T(..) or T(C) - really_used_names :: NameSet - really_used_names = used_names `unionNameSets` - mkNameSet [ parent - | GRE{ gre_name = name, - gre_parent = Just parent } - <- defined_names, - name `elemNameSet` used_names] + used_names, all_used_names :: NameSet + used_names = findUses (tcg_dus gbl_env) emptyNameSet + 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 - -- Look for the qualified ones only, else get duplicates defined_names :: [GlobalRdrElt] - defined_names = foldRdrEnv add [] (tcg_rdr_env gbl_env) - add rdr_name ns acc | isQual rdr_name = ns ++ acc - | otherwise = acc + defined_names = globalRdrEnvElts (tcg_rdr_env gbl_env) defined_and_used, defined_but_not_used :: [GlobalRdrElt] - (defined_and_used, defined_but_not_used) = partition used defined_names - used gre = gre_name gre `elemNameSet` really_used_names + (defined_and_used, defined_but_not_used) = partition is_used defined_names + + is_used gre = gre_name gre `elemNameSet` all_used_names -- Filter out the ones that are -- (a) defined in this module, and @@ -737,14 +755,16 @@ reportUnusedNames gbl_env used_names -- 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) bad_imports :: [GlobalRdrElt] bad_imports = filter bad_imp defined_but_not_used - bad_imp (GRE {gre_prov = NonLocalDef (UserImport mod _ True)}) = not (module_unused mod) - bad_imp other = False + bad_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 -- 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 @@ -772,10 +792,10 @@ reportUnusedNames gbl_env used_names -- 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_parent = p, - gre_prov = NonLocalDef (UserImport m _ _)}) acc - = addToFM_C plusAvailEnv acc (moduleName m) - (unitAvailEnv (mk_avail n p)) + 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 = acc @@ -790,21 +810,37 @@ reportUnusedNames gbl_env used_names -- 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 + -- unused_imp_mods are the directly-imported modules -- that are not mentioned in minimal_imports1 -- [Note: not 'minimal_imports', because that includes direcly-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] + m /= pRELUDE_Name, + not (hasEmptyImpList m)] + -- hasEmptyImpList arranges not to complain about + -- import M (), which is an idiom for importing + -- instance declarations - module_unused :: Module -> Bool - module_unused mod = moduleName mod `elem` unused_imp_mods + module_unused :: ModuleName -> Bool + module_unused mod = mod `elem` unused_imp_mods -- ToDo: deal with original imports with 'qualified' and 'as M' clauses printMinimalImports :: FiniteMap ModuleName AvailEnv -- Minimal imports - -> TcRn m () + -> RnM () printMinimalImports imps = ifOptM Opt_D_dump_minimal_imports $ do { @@ -829,7 +865,7 @@ printMinimalImports imps to_ies (mod, avail_env) = mappM to_ie (availEnvElts avail_env) `thenM` \ ies -> returnM (mod, ies) - to_ie :: AvailInfo -> TcRn m (IE Name) + to_ie :: AvailInfo -> RnM (IE Name) -- The main trick here is that if we're importing all the constructors -- we want to say "T(..)", but if we're importing only a subset we want -- to say "T(A,B,C)". So we have to find out what the module exports. @@ -837,18 +873,19 @@ printMinimalImports imps to_ie (AvailTC n [m]) = ASSERT( n==m ) returnM (IEThingAbs n) to_ie (AvailTC n ns) - = loadInterface (text "Compute minimal imports from" <+> ppr n_mod) - n_mod ImportBySystem `thenM` \ iface -> + = loadSrcInterface doc n_mod False `thenM` \ iface -> case [xs | (m,as) <- mi_exports iface, m == n_mod, AvailTC x xs <- as, - x == n] of - [xs] | all (`elem` ns) xs -> returnM (IEThingAll n) - | otherwise -> returnM (IEThingWith n (filter (/= n) ns)) - other -> pprTrace "to_ie" (ppr n <+> ppr (nameModule n) <+> ppr other) $ - returnM (IEVar n) + x == nameOccName n] of + [xs] | all_used xs -> returnM (IEThingAll n) + | otherwise -> returnM (IEThingWith n (filter (/= n) ns)) + other -> pprTrace "to_ie" (ppr n <+> ppr n_mod <+> ppr other) $ + returnM (IEVar n) where - n_mod = moduleName (nameModule n) + all_used avail_occs = all (`elem` map nameOccName ns) avail_occs + doc = text "Compute minimal imports from" <+> ppr n + n_mod = nameModuleName n \end{code} @@ -891,15 +928,9 @@ exportClashErr global_env name1 name2 ie1 ie2 ppr_export ie name = nest 2 (quotes (ppr ie) <+> ptext SLIT("exports") <+> quotes (ppr name) <+> pprNameProvenance (get_gre name)) - -- get_gre finds a GRE for the Name, in a very inefficient way - -- There isn't a more efficient way to do it, because we don't necessarily - -- know the RdrName under which this Name is in scope. So we just - -- search linearly. Shouldn't matter because this only happens - -- in an error message. + -- get_gre finds a GRE for the Name, so that we can show its provenance get_gre name - = case [gre | gres <- rdrEnvElts global_env, - gre <- gres, - gre_name gre == name] of + = case lookupGRE_Name global_env name of (gre:_) -> gre [] -> pprPanic "exportClashErr" (ppr name)