https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107980
--- Comment #2 from Aaron Ballman <aaron at aaronballman dot com> --- (In reply to Andrew Pinski from comment #1) > Hmm from https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3054.pdf : > ``` > 7.16.1.4 The va_start macro > void va_start(va_list ap, ...); > > > Any additional arguments are not used by > the macro and will not be expanded or evaluated for any reason. > ``` > > > I would assume since it is `arguments` rather than additional argument, that > it could be more than one additional argument. Yes, the standard says "arguments" because there can be additional arguments due to using `...`. However, think about the user experience: ``` // This should always be happily accepted because it's // idiomatic C before C2x and it's valid C in C2x and later. va_start(list, some_arg); // This should be accepted in C2x mode and if you care // to do such things, warn the user that it's incompatible // with standards before C2x. Pre-C2x, this is an error. va_start(list); // Under what circumstances is this anything other than // programmer confusion? It's invalid before C2x and the // extra args are meaningless in C2x and later. va_start(list, 1, 2, 3, 4); ```
