https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107980
--- Comment #12 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- The standard rule about not using extra arguments means that any warnings would need to avoid even converting those arguments from pp-tokens to tokens; it's OK for them to contain pp-tokens that cannot be converted to tokens. I think the accepted change to the standard was entirely clear about ignoring the extra arguments; it wasn't some obscure non-obvious consequence that such code would become valid.
