It works not as it says. I think it's a bug. Why not let it does as it introduced?
-- Summary: -Wall Product: gcc Version: 4.0.3 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: followait at 163 dot com GCC build triplet: all GCC host triplet: ubuntu GCC target triplet: all http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30256