diff options
Diffstat (limited to 'ghc/compiler/rename')
| -rw-r--r-- | ghc/compiler/rename/RnEnv.lhs | 5 | ||||
| -rw-r--r-- | ghc/compiler/rename/RnNames.lhs | 86 |
2 files changed, 55 insertions, 36 deletions
diff --git a/ghc/compiler/rename/RnEnv.lhs b/ghc/compiler/rename/RnEnv.lhs index 2fb2549cfc..bdaa9f156e 100644 --- a/ghc/compiler/rename/RnEnv.lhs +++ b/ghc/compiler/rename/RnEnv.lhs @@ -42,7 +42,8 @@ import RdrName ( RdrName, rdrNameModule, isQual, isUnqual, isOrig, isExact_maybe, isSrcRdrName, GlobalRdrElt(..), GlobalRdrEnv, lookupGlobalRdrEnv, isLocalGRE, extendLocalRdrEnv, elemLocalRdrEnv, lookupLocalRdrEnv, - Provenance(..), pprNameProvenance, ImportSpec(..) + Provenance(..), pprNameProvenance, + importSpecLoc, importSpecModule ) import HscTypes ( availNames, ModIface(..), FixItem(..), lookupFixity ) import TcRnMonad @@ -751,7 +752,7 @@ warnUnusedName (name, prov) where (loc,msg) = case prov of Just (Imported is) - -> (is_loc imp_spec, imp_from (is_mod imp_spec)) + -> (importSpecLoc imp_spec, imp_from (importSpecModule imp_spec)) where imp_spec = head is other -> (srcLocSpan (nameSrcLoc name), unused_msg) diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index 6eaf8f41f2..71073a2e6c 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -45,8 +45,8 @@ import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..), emptyGlobalRdrEnv, plusGlobalRdrEnv, globalRdrEnvElts, extendGlobalRdrEnv, lookupGlobalRdrEnv, unQualOK, lookupGRE_Name, - Provenance(..), ImportSpec(..), - isLocalGRE, pprNameProvenance ) + Provenance(..), ImportSpec(..), ImpDeclSpec(..), ImpItemSpec(..), + importSpecLoc, importSpecModule, isLocalGRE, pprNameProvenance ) import Outputable import Maybes ( isNothing, catMaybes, mapCatMaybes, seqMaybe, orElse ) import SrcLoc ( Located(..), mkGeneralSrcSpan, @@ -180,8 +180,8 @@ importsFromImportDecl this_mod 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, is_explicit = False } + imp_spec = ImpDeclSpec { is_mod = imp_mod_name, is_qual = qual_only, + is_dloc = loc, is_as = qual_mod_name } in -- Get the total imports, and filter them according to the import list ifaceExportNames filtered_exports `thenM` \ total_avails -> @@ -378,7 +378,7 @@ available, and filters it through the import spec (if any). \begin{code} filterImports :: ModIface - -> ImportSpec -- The span for the entire import decl + -> ImpDeclSpec -- The span for the entire import decl -> Maybe (Bool, [Located (IE RdrName)]) -- Import spec; True => hiding -> NameSet -- What's available -> RnM (NameSet, -- What's imported (qualified or unqualified) @@ -387,14 +387,16 @@ filterImports :: ModIface -- Complains if import spec mentions things that the module doesn't export -- Warns/informs if import spec contains duplicates. -mkGenericRdrEnv imp_spec names +mkGenericRdrEnv decl_spec names = mkGlobalRdrEnv [ GRE { gre_name = name, gre_prov = Imported [imp_spec] } | name <- nameSetToList names ] + where + imp_spec = ImpSpec { is_decl = decl_spec, is_item = ImpAll } -filterImports iface imp_spec Nothing all_names - = returnM (all_names, mkGenericRdrEnv imp_spec all_names) +filterImports iface decl_spec Nothing all_names + = returnM (all_names, mkGenericRdrEnv decl_spec all_names) -filterImports iface imp_spec (Just (want_hiding, import_items)) all_names +filterImports iface decl_spec (Just (want_hiding, import_items)) all_names = mappM (addLocM get_item) import_items `thenM` \ gres_s -> let gres = concat gres_s @@ -407,7 +409,7 @@ filterImports iface imp_spec (Just (want_hiding, import_items)) all_names keep n = not (n `elemNameSet` specified_names) pruned_avails = filterNameSet keep all_names in - return (pruned_avails, mkGenericRdrEnv imp_spec pruned_avails) + return (pruned_avails, mkGenericRdrEnv decl_spec pruned_avails) where occ_env :: OccEnv Name -- Maps OccName to corresponding Name @@ -419,7 +421,7 @@ filterImports iface imp_spec (Just (want_hiding, import_items)) all_names sub_env :: NameEnv [Name] sub_env = mkSubNameEnv all_names - bale_out item = addErr (badImportItemErr iface imp_spec item) `thenM_` + bale_out item = addErr (badImportItemErr iface decl_spec item) `thenM_` returnM [] succeed_with :: Bool -> [Name] -> RnM [GlobalRdrElt] @@ -428,10 +430,11 @@ filterImports iface imp_spec (Just (want_hiding, import_items)) all_names ; returnM (map (mk_gre loc) names) } where mk_gre loc name = GRE { gre_name = name, - gre_prov = Imported [imp_spec'] } + gre_prov = Imported [imp_spec] } where - imp_spec' = imp_spec { is_loc = loc, is_explicit = explicit } - explicit = all_explicit || isNothing (nameParent_maybe name) + imp_spec = ImpSpec { is_decl = decl_spec, is_item = item_spec } + item_spec = ImpSome { is_explicit = explicit, is_iloc = loc } + explicit = all_explicit || isNothing (nameParent_maybe name) get_item :: IE RdrName -> RnM [GlobalRdrElt] -- Empty result for a bad item. @@ -678,7 +681,7 @@ reportDeprecations 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) $ + = setSrcSpan (importSpecLoc imp_spec) $ addWarn (sep [ptext SLIT("Deprecated use of") <+> occNameFlavour (nameOccName name) <+> quotes (ppr name), @@ -686,7 +689,7 @@ reportDeprecations tcg_env (ppr deprec_txt) ]) where name_mod = nameModule name - imp_mod = is_mod imp_spec + imp_mod = importSpecModule 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 @@ -767,8 +770,8 @@ reportUnusedNames export_decls gbl_env unused_imports :: [GlobalRdrElt] unused_imports = filter unused_imp defined_but_not_used unused_imp (GRE {gre_prov = Imported imp_specs}) - = not (all (module_unused . is_mod) imp_specs) - && any is_explicit imp_specs + = not (all (module_unused . importSpecModule) imp_specs) + && or [exp | ImpSpec { is_item = ImpSome { is_explicit = exp } } <- imp_specs] -- Don't complain about unused imports if we've already said the -- entire import is unused unused_imp other = False @@ -801,7 +804,7 @@ reportUnusedNames export_decls gbl_env -- 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 (is_mod (head imp_specs)) + = addToFM_C plusAvailEnv acc (importSpecModule (head imp_specs)) (unitAvailEnv (mk_avail n (nameParent_maybe n))) add_name other acc = acc @@ -887,13 +890,14 @@ warnDuplicateImports gres , pr <- redundants imps ] where warn name (red_imp, cov_imp) - = addWarnAt (is_loc red_imp) + = addWarnAt (importSpecLoc red_imp) (vcat [ptext SLIT("Redundant import of:") <+> quotes pp_name, ptext SLIT("It is also") <+> ppr cov_imp]) where - pp_name | is_qual red_imp = ppr (is_as red_imp) <> dot <> ppr occ + pp_name | is_qual red_decl = ppr (is_as red_decl) <> dot <> ppr occ | otherwise = ppr occ occ = nameOccName name + red_decl = is_decl red_imp redundants :: [ImportSpec] -> [(ImportSpec,ImportSpec)] -- The returned pair is (redundant-import, covering-import) @@ -904,26 +908,40 @@ warnDuplicateImports gres -- "red_imp" is a putative redundant import -- "cov_imp" potentially covers it - -- This test decides - covers red_imp cov_imp + -- This test decides whether red_imp could be dropped + -- + -- NOTE: currently the test does not warn about + -- import M( x ) + -- imoprt N( x ) + -- even if the same underlying 'x' is involved, because dropping + -- either import would change the qualified names in scope (M.x, N.x) + -- But if the qualified names aren't used, the import is indeed redundant + -- Sadly we don't know that. Oh well. + covers red_imp@(ImpSpec { is_decl = red_decl, is_item = red_item }) + cov_imp@(ImpSpec { is_decl = cov_decl, is_item = cov_item }) | red_loc == cov_loc = False -- Ignore diagonal elements - | not (is_as red_imp == is_as cov_imp) + | not (is_as red_decl == is_as cov_decl) = False -- They bring into scope different qualified names - | not (is_qual red_imp) && is_qual cov_imp + | not (is_qual red_decl) && is_qual cov_decl = False -- Covering one doesn't bring unqualified name into scope - | is_explicit red_imp - = not cov_explicit -- Redundant one is explicit and covering one isn't + | red_selective + = not cov_selective -- Redundant one is selective and covering one isn't || red_later -- Both are explicit; tie-break using red_later | otherwise - = not cov_explicit -- Neither import is explicit - && (is_mod red_imp == is_mod cov_imp) -- They import the same module + = not cov_selective -- Neither import is selective + && (is_mod red_decl == is_mod cov_decl) -- They import the same module && red_later -- Tie-break where - cov_explicit = is_explicit cov_imp - red_loc = is_loc red_imp - cov_loc = is_loc cov_imp + red_loc = importSpecLoc red_imp + cov_loc = importSpecLoc cov_imp red_later = red_loc > cov_loc + cov_selective = selectiveImpItem cov_item + red_selective = selectiveImpItem red_item + +selectiveImpItem :: ImpItemSpec -> Bool +selectiveImpItem ImpAll = False +selectiveImpItem (ImpSome {}) = True -- ToDo: deal with original imports with 'qualified' and 'as M' clauses printMinimalImports :: FiniteMap Module AvailEnv -- Minimal imports @@ -983,8 +1001,8 @@ printMinimalImports imps %************************************************************************ \begin{code} -badImportItemErr iface imp_spec ie - = sep [ptext SLIT("Module"), quotes (ppr (is_mod imp_spec)), source_import, +badImportItemErr iface decl_spec ie + = sep [ptext SLIT("Module"), quotes (ppr (is_mod decl_spec)), source_import, ptext SLIT("does not export"), quotes (ppr ie)] where source_import | mi_boot iface = ptext SLIT("(hi-boot interface)") |