https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95359
Martin Liška <marxin at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |marxin at gcc dot gnu.org Last reconfirmed| |2020-05-27 Ever confirmed|0 |1 Status|UNCONFIRMED |WAITING --- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> --- With GCC you see: gcc pr95359.c -c -O2 -Wall -Wextra pr95359.c: In function ‘f’: pr95359.c:3:22: warning: zero-length gnu_printf format string [-Wformat-zero-length] 3 | __builtin_printf("", 2); | ^~ or: gcc pr95359.c -c -O2 -Wall -Wextra pr95359.c: In function ‘f’: pr95359.c:3:22: warning: too many arguments for format [-Wformat-extra-args] 3 | __builtin_printf("aa", 2); | ^~~~ Does it really worth doing an optimization?