https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108674
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Roman Lebedev from comment #0) > I believe in the version 12, a new instance of such intentional wraparound > was introduced into libstdc++: https://godbolt.org/z/rq153fxKW No, that code is from 2014-12-19. > I understand that there is no UB there. > I understand that you are doing this intentionally. > The problem is that it is happening in a header, > so it's effectively dictating everyone > that they should not use that sanitizer. Well, they shouldn't use it *and expect everybody else's code to never rely on unsigned wraparound*. If they want to write their own code to never rely on that guaranteed feature of the language, that's fine. They don't get to force that choice on everybody else. > Silencing this kind of thing from user side is possible, > but it's somewhat cumbersome: it requires compiling with > `-fsanitize-recover=integer`, and supplying a run-time suppressions file. > > On the other hand, suppressing this in-source is trivial: > https://godbolt.org/z/E7sEnvvrT > ... all it would take is applying > `__attribute__((no_sanitize("unsigned-integer-overflow")))` > to `_S_compare` on line 483 in `basic_string.h`. > > I have tried that locally, and it works, but it seems it needs to be > wrapped into `#if defined(__clang__)` preprocessor check: > https://godbolt.org/z/5a7ox4EWv > > Forwarded from https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1029970 So provide a patch then, instead of asking other people to work around this sanitizer for you.
