Repository : ssh://darcs.haskell.org//srv/darcs/ghc On branch : master
http://hackage.haskell.org/trac/ghc/changeset/a8ea80f19974abc4f1b18734013873292116fff5 >--------------------------------------------------------------- commit a8ea80f19974abc4f1b18734013873292116fff5 Author: Simon Peyton Jones <simo...@microsoft.com> Date: Mon Jan 7 17:50:57 2013 +0000 Rearrange the computation of unused imports; fixes Trac #7454 >--------------------------------------------------------------- compiler/rename/RnNames.lhs | 42 +++++++++++++++++++++++++++++------------- 1 files changed, 29 insertions(+), 13 deletions(-) diff --git a/compiler/rename/RnNames.lhs b/compiler/rename/RnNames.lhs index e4d21bd..1c44870 100644 --- a/compiler/rename/RnNames.lhs +++ b/compiler/rename/RnNames.lhs @@ -1362,25 +1362,41 @@ findImportUsage imports rdr_env rdrs import_usage = foldr (extendImportMap rdr_env) Map.empty rdrs unused_decl decl@(L loc (ImportDecl { ideclHiding = imps })) - = (decl, nubAvails used_avails, unused_imps) + = (decl, nubAvails used_avails, nameSetToList unused_imps) where used_avails = Map.lookup (srcSpanEnd loc) import_usage `orElse` [] -- srcSpanEnd: see Note [The ImportMap] - dont_report_as_unused = foldr add emptyNameSet used_avails - add (Avail n) s = s `addOneToNameSet` n - add (AvailTC n ns) s = s `addListToNameSet` (n:ns) + used_names = availsToNameSet used_avails + used_parents = mkNameSet [n | AvailTC n _ <- used_avails] + + unused_imps -- Not trivial; see eg Trac #7454 + = case imps of + Just (False, imp_ies) -> foldr (add_unused . unLoc) emptyNameSet imp_ies + _other -> emptyNameSet -- No explicit import list => no unused-name list + + add_unused :: IE Name -> NameSet -> NameSet + add_unused (IEVar n) acc = add_unused_name n acc + add_unused (IEThingAbs n) acc = add_unused_name n acc + add_unused (IEThingAll n) acc = add_unused_all n acc + add_unused (IEThingWith p ns) acc = add_unused_with p ns acc + add_unused _ acc = acc + + add_unused_name n acc + | n `elemNameSet` used_names = acc + | otherwise = acc `addOneToNameSet` n + add_unused_all n acc + | n `elemNameSet` used_names = acc + | n `elemNameSet` used_parents = acc + | otherwise = acc `addOneToNameSet` n + add_unused_with p ns acc + | all (`elemNameSet` acc1) ns = add_unused_name p acc1 + | otherwise = acc1 + where + acc1 = foldr add_unused_name acc ns -- If you use 'signum' from Num, then the user may well have -- imported Num(signum). We don't want to complain that - -- Num is not itself mentioned. Hence adding 'n' as - -- well to the list of of "don't report if unused" names + -- Num is not itself mentioned. Hence the two cases in add_unused_with. - unused_imps = case imps of - Just (False, imp_ies) -> nameSetToList unused_imps - where - imp_names = mkNameSet (concatMap (ieNames . unLoc) imp_ies) - unused_imps = imp_names `minusNameSet` dont_report_as_unused - - _other -> [] -- No explicit import list => no unused-name list extendImportMap :: GlobalRdrEnv -> RdrName -> ImportMap -> ImportMap -- For a used RdrName, find all the import decls that brought _______________________________________________ Cvs-ghc mailing list Cvs-ghc@haskell.org http://www.haskell.org/mailman/listinfo/cvs-ghc
