On Mon, Jul 31, 2023 at 06:19:15PM +0800, Julian Waters via Gcc-help wrote: > Quick question, how does one define a new warning that accepts different > levels like Wformat? Right now I have the following: See c-family/c.opt, the block that starts Wformat= Here the whole thing, it's short anyway: Wformat= C ObjC C++ ObjC++ Joined RejectNegative UInteger Var(warn_format) Warning LangEnabledBy(C ObjC C++ ObjC++,Wall, 1, 0) IntegerRange(0, 2) Warn about printf/scanf/strftime/strfmon format string anomalies. > I don't quite understand what the syntax or each setting following the > warning definition means, https://gcc.gnu.org/onlinedocs/gccint/Options.html > nor how to check for warning levels in the > corresponding code for the warning The "warn_format" variable is set to 0..2, and you can check that however you want. > (Eg what does Joined do?), so some > pointers would be appreciated for that "Joined" means you write the argument as part of the option, while "Separate" means it is a separate arg. As in "-Wformat=2" is Joined, while "-Wformat 2" would be separate. Segher
