https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79082
--- Comment #4 from Franz Sirl <sirl at gcc dot gnu.org> --- Hmm, %hhd is not usable on some of our platforms and also only really helpful with exact %x outputs: snprintf(buffer, 3, "%02hhx", val); What about: snprintf(buffer, 4, "%03hx", val & 0xfff); Here the 'h' modifier doesn't help at all and also in my eyes 'val & 0xfff' or 'abs(val % 100)' would be much more natural range limiters for warning suppression. It's a pity there isn't at least a minimum "arguments-only-VRP" even at -O0. Can't we have another level or two for -Wformat-truncation that only warns when VRP is active? Note that I believe that snprintf(buffer, 3, "%2d", (val < 0) ? -(val % 100) : val % 100); shouldn't warn when VRP is active. Seems to be a minor deficiency in VRP.
