https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110617
--- Comment #10 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
(In reply to Florian Weimer from comment #9)
> (In reply to Xi Ruoyao from comment #6)
> > (In reply to Richard Biener from comment #5)
> > > I think a -f... option to disable the code generation effects would make
> > > more sense than adding another attribute kind.
> >
> > Then maybe we'd just add a -D_GLIBC_NONNULL={0,1} (?) into Glibc cdefs.h
> > instead. Anyway I'm already too frustrated about this so I'll not continue
> > working on nonnull within Glibc headers. If you don't like this just close
> > it as WONTFIX.
>
> For those who are not following libc-alpha, glibc already disables __nonnull
> during its build, so it should be totally fine to use __nonnull in installed
> headers to improve diagnostics.
But Zack's reason against using __nonnull is __nonnull may cause unwanted
optimizations to *the user code*.
