[Bug sanitizer/87884] ubsan causes wrong -Wformat-overflow warning

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87884

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
             Status|UNCONFIRMED                 |NEW
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=82076,
                   |                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=79265
     Ever confirmed|0                           |1

--- Comment #4 from Martin Sebor <msebor at gcc dot gnu.org> ---
The sanitizer inserts a lot of tests some of which then interfere with
subsequent analyses (for some related examples, see pr82076 and pr79265). 
Ideally, it would be possible to use both the sanitizer and late warnings at
the same time, but we're not there yet.  Until then, the guidance has been to
avoid mixing the two.  Let me add something to the manual.

I agree that the null destination pointer warning should be controlled by an
option separate from -Wformat-overflow such as -Wnonnull.  That should make it
easier to avoid the sanitizer problem.  Let me adjust that.