X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Frename%2FRnNames.lhs;h=8773732c6ddb16e406b9ec2872ce42503d1414cc;hb=3e12bb2d764b45563000ab3074dac61d22853321;hp=e043ab02a745f28ca0b0a9fc6d727b77b34bb156;hpb=b3fe66bb78fe11ee322f7442a5676e628f678b29;p=ghc-hetmet.git diff --git a/ghc/compiler/rename/RnNames.lhs b/ghc/compiler/rename/RnNames.lhs index e043ab0..8773732 100644 --- a/ghc/compiler/rename/RnNames.lhs +++ b/ghc/compiler/rename/RnNames.lhs @@ -14,8 +14,8 @@ module RnNames ( import CmdLineOpts ( DynFlag(..) ) import HsSyn ( IE(..), ieName, ImportDecl(..), LImportDecl, - ForeignDecl(..), HsGroup(..), - collectGroupBinders, tyClDeclNames + ForeignDecl(..), HsGroup(..), HsBindGroup(..), + Sig(..), collectGroupBinders, tyClDeclNames ) import RnEnv import IfaceEnv ( lookupOrig, newGlobalBinder ) @@ -38,9 +38,9 @@ import HscTypes ( GenAvailInfo(..), AvailInfo, GhciMode(..), IfaceExport, HomePackageTable, PackageIfaceTable, availNames, unQualInScope, Deprecs(..), ModIface(..), Dependencies(..), - lookupIface, ExternalPackageState(..), - IfacePackage(..) + lookupIface, ExternalPackageState(..) ) +import Packages ( PackageIdH(..) ) import RdrName ( RdrName, rdrNameOcc, setRdrNameSpace, GlobalRdrEnv, mkGlobalRdrEnv, GlobalRdrElt(..), emptyGlobalRdrEnv, plusGlobalRdrEnv, globalRdrEnvElts, @@ -75,9 +75,9 @@ rnImports imports -- Do the non {- SOURCE -} ones first, so that we get a helpful -- warning for {- SOURCE -} ones that are unnecessary this_mod <- getModule - ; opt_no_prelude <- doptM Opt_NoImplicitPrelude + ; implicit_prelude <- doptM Opt_ImplicitPrelude ; let - all_imports = mk_prel_imports this_mod opt_no_prelude ++ imports + all_imports = mk_prel_imports this_mod implicit_prelude ++ imports (source, ordinary) = partition is_source_import all_imports is_source_import (L _ (ImportDecl _ is_boot _ _ _)) = is_boot @@ -101,10 +101,10 @@ 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 no_prelude + mk_prel_imports this_mod implicit_prelude | this_mod == pRELUDE || explicit_prelude_import - || no_prelude + || not implicit_prelude = [] | otherwise = [preludeImportDecl] @@ -199,7 +199,7 @@ importsFromImportDecl this_mod (dependent_mods, dependent_pkgs) = case mi_package iface of - ThisPackage -> + HomePackage -> -- Imported module is from the home package -- Take its dependent modules and add imp_mod itself -- Take its dependent packages unchanged @@ -213,7 +213,7 @@ importsFromImportDecl this_mod -- check. See LoadIface.loadHiBootInterface ((imp_mod_name, want_boot) : dep_mods deps, dep_pkgs deps) - ExternalPackage pkg -> + ExtPackage pkg -> -- Imported module is from another package -- Dump the dependent modules -- Add the package imp_mod comes from to the dependent packages @@ -251,18 +251,29 @@ exportsToAvails :: [IfaceExport] -> TcRnIf gbl lcl NameSet exportsToAvails exports = foldlM do_one emptyNameSet exports where - do_one acc (mod, exports) = foldlM (do_avail mod) acc exports - do_avail mod acc (Avail n) = do { n' <- lookupOrig mod n; - ; return (addOneToNameSet acc n') } - do_avail mod acc (AvailTC n ns) = do { n' <- lookupOrig mod n - ; ns' <- mappM (lookup_sub n') ns - ; return (addListToNameSet acc (n':ns')) } + do_one acc (mod, exports) = foldlM (do_avail mod) acc exports + do_avail mod acc (Avail n) = do { n' <- lookupOrig mod n; + ; return (addOneToNameSet acc n') } + do_avail mod acc (AvailTC p_occ occs) + = do { p_name <- lookupOrig mod p_occ + ; ns <- mappM (lookup_sub p_name) occs + ; return (addListToNameSet acc ns) } + -- Remember that 'occs' is all the exported things, including + -- the parent. It's possible to export just class ops without + -- the class, via C( op ). If the class was exported too we'd + -- have C( C, op ) where - 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. + lookup_sub parent occ + = newGlobalBinder mod occ mb_parent noSrcLoc + where + mb_parent | occ == p_occ = Nothing + | otherwise = Just parent + + -- The use of newGlobalBinder here (rather than lookupOrig) + -- 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 may only suck in the interface 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, @@ -309,7 +320,7 @@ importsFromLocalDecls group -- printer returns False. It seems awkward to fix, unfortunately. mappM_ addDupDeclErr dups `thenM_` - doptM Opt_NoImplicitPrelude `thenM` \ implicit_prelude -> + doptM Opt_ImplicitPrelude `thenM` \ implicit_prelude -> let prov = LocalDef this_mod gbl_env = mkGlobalRdrEnv gres @@ -335,8 +346,8 @@ importsFromLocalDecls group -- Sigh. It doesn't matter because it only affects the Data.Tuple really. -- The important thing is to trim down the exports. filtered_names - | implicit_prelude = filter (not . isBuiltInSyntax) all_names - | otherwise = all_names + | implicit_prelude = all_names + | otherwise = filter (not . isBuiltInSyntax) all_names imports = emptyImportAvails { imp_env = unitModuleEnv this_mod $ @@ -369,12 +380,21 @@ getLocalDeclBinders mod (HsGroup {hs_valds = val_decls, -- an export indicator because they are all implicitly exported. 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) + + -- In a hs-boot file, the value binders come from the + -- *signatures*, and there should be no foreign binders + tcIsHsBoot `thenM` \ is_hs_boot -> + let val_bndrs | is_hs_boot = sig_hs_bndrs + | otherwise = for_hs_bndrs ++ val_hs_bndrs + in + mappM new_simple val_bndrs `thenM` \ names -> + + returnM (tc_avails ++ map Avail names) where - new_simple rdr_name = newTopSrcBinder mod Nothing rdr_name `thenM` \ name -> - returnM (Avail name) + new_simple rdr_name = newTopSrcBinder mod Nothing rdr_name + sig_hs_bndrs = [nm | HsBindGroup _ lsigs _ <- val_decls, + L _ (Sig nm _) <- lsigs] val_hs_bndrs = collectGroupBinders val_decls for_hs_bndrs = [nm | L _ (ForeignImport nm _ _ _) <- foreign_decls] @@ -742,8 +762,9 @@ gre_is_used used_names gre = gre_name gre `elemNameSet` used_names %********************************************************* \begin{code} -reportUnusedNames :: TcGblEnv -> RnM () -reportUnusedNames gbl_env +reportUnusedNames :: Maybe [Located (IE RdrName)] -- Export list + -> TcGblEnv -> RnM () +reportUnusedNames export_decls gbl_env = do { warnUnusedTopBinds unused_locals ; warnUnusedModules unused_imp_mods ; warnUnusedImports unused_imports @@ -793,8 +814,10 @@ reportUnusedNames gbl_env -- 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 -- into a bunch of avails, so they are properly grouped + -- + -- BUG WARNING: this does not deal properly with qualified imports! minimal_imports :: FiniteMap Module AvailEnv - minimal_imports0 = emptyFM + minimal_imports0 = foldr add_expall emptyFM expall_mods minimal_imports1 = foldr add_name minimal_imports0 defined_and_used minimal_imports = foldr add_inst_mod minimal_imports1 direct_import_mods -- The last line makes sure that we retain all direct imports @@ -821,6 +844,27 @@ reportUnusedNames gbl_env add_name other acc = acc + -- Modules mentioned as 'module M' in the export list + expall_mods = case export_decls of + Nothing -> [] + Just es -> [m | L _ (IEModuleContents m) <- es] + + -- This is really bogus. The idea is that if we see 'module M' in + -- the export list we must retain the import decls that drive it + -- If we aren't careful we might see + -- module A( module M ) where + -- import M + -- import N + -- and suppose that N exports everything that M does. Then we + -- must not drop the import of M even though N brings it all into + -- scope. + -- + -- BUG WARNING: 'module M' exports aside, what if M.x is mentioned?! + -- + -- The reason that add_expall is bogus is that it doesn't take + -- 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] @@ -843,6 +887,9 @@ reportUnusedNames gbl_env -- 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] + -- + -- BUG WARNING: does not deal correctly with multiple imports of the same module + -- becuase direct_import_mods has only one entry per module unused_imp_mods = [(mod,loc) | (mod,imp,loc) <- direct_import_mods, not (mod `elemFM` minimal_imports1), mod /= pRELUDE,