One issue that showed up as test failures with a default of -std=gnu23 is that -std=gnu23 -Wtraditional produces a "traditional C rejects ISO C style function definitions" warning for function definitions with empty parentheses, as they are treated like (void) in C23, so resulting in failure of several -Wtraditional tests.
Clearly that's a bug (that warning should only be given for literal (void), not for () meaning (void)) and wouldn't be hard to fix. But is there actually any current use for the -Wtraditional option? It seems extremely unlikely now that compatibility with pre-C89 compilers would be relevant. So maybe it would make more sense to remove -Wtraditional support (remove all the logic implementing the option, make it an option marked with Ignore in c.opt to do nothing so as not to break any build systems that hardcode this option) rather than fixing this bug with an option that's probably no longer useful. -- Joseph S. Myers josmy...@redhat.com
