https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119429
--- Comment #28 from Jonathan Wakely <redi at gcc dot gnu.org> --- Indeed. I /think/ __attribute__((no_sanitize("undefined"))) would work on that kind of function. It doesn't work on the subject of this PR, but maybe that's because the "overflow" happens in a default argument so clang decides happens in the caller, and the attribute doesn't apply there. Or it's just broken, I dunno.