https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64504
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Andrey Vihrov from comment #2) > , and there is no warning without -fwhole-program. Of course, I can get the > same effect by making everything "static", but this depends on me > remembering to do it, so this option is better in this regard. -flto doesn't > have the same effect. This is not what -fwhole-program is for, you're just using it for a side-effect that happens as a result of making everything static. So my suggestion would be "don't do that". If you have a single file how hard can it be to remember to make your globals static? How many of them do you have?! Just enclosing them in an anonymous namespace would work, and then all you have to remember to do is add new globals inside that scope, not elsewhere in the file.
