Joseph Myers via Gcc <gcc@gcc.gnu.org> writes: > 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.
Given the other messages in the thread, I'd like to share some anecdotal data: * I see 0 instances of -Wtraditional appearing in my cache of build logs; * I see 0 non-trivial (e.g. comments or bundled autoconf macros) references to -Wtraditional in my collection of repositories; * There are some, but not many, references on Debian code search: <https://codesearch.debian.net/search?q=Wtraditional&literal=1&perpkg=1>. Note that a chunk of the references are the kind of macros I mentioned, copies of GCC, or NEWS/ChangeLogs; * Not to say that such warnings are useless to ever attempt, but people who need compatibility with such compilers should really test with them anyway, so this is merely a convenience thing. It's not like it actually guarantees such compilers will work (to give another example, -std=gnu89 still lets you use headers which weren't in C89).
