Modern C for Fedora (and the world)

It might *help*, but it's probably not foolproof either, as a newer GCC release might have improved the -Wfoo diagnostics path to catch cases that the older release didn't catch. Of course you could, in principle at least, split the enhanced version into a separate -Wfoo-gcc-XY, or something like that, which is only activated when -Wall=gcc-XX isn't enabled. But I suspect GCC wouldn't want to commit itself to such a level of backward compatibility in the warnings. And of course if there's ever any refactoring of some particular warning, requiring to provide perfect backward compatibility for the previous 27 major releases would probably be prohibitive.