https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121563
--- Comment #4 from Christopher Bazley <Chris.Bazley at arm dot com> --- In other words (continuing my previous comment), I prefer the behaviour of generating a diagnostic message for the second forward declaration of a parameter if you use ',' and think it is correct. The behaviour of not generating a diagnostic message for the second forward declaration of a parameter if you use ';' doesn't concern me because the paper that I wrote does not propose permitting that syntax in ISO standard C. I assume this syntax will continue to be supported by GCC as a compiler-specific extension, even if WG14 adopts my proposed specification. GCC can also keep the existing behaviour of not generating a diagnostic message.
