On Mon, Dec 30, 2024 at 5:26 PM Ihor Solodrai <ihor.solodrai@xxxxx> wrote:
>
> > >
> > > #if STDC_VERSION < 202311L
> > > enum {
> > > false = 0,
> > > true = 1,
> > > };
> > > #endif
> > >
> > > Any drawbacks to this?
> >
> >
> > By special hacking this specific enum in bpftool ?
> > Feels like overkill when just adding -std=gnu17 will do.
>
> Yeah. I've tried both the flag and a btf_dump hack today, and the hack
> is indeed an overkill, assuming we don't care about generating
> C23-compilant vmlinux.h. To conditionalize the declarations both the
> enum and typedef _Bool have to be matched, so it's actually two hacks.
> Although we do use hacks like this, noticed an interesting example
> today [1].
>
> Regardless of how the bool-related error is fixed (with STDC_VERSION
> condition or std flag), I get the same int64 errors with GCC
> 15-20241229 when building selftests/bpf [2].
>
> [1] https://github.com/libbpf/libbpf/blob/master/src/btf_dump.c#L1198-L1201
This is more of a workaround for differences in gcc behavior.
There is no way to cure it with a flag.
While in this case -std will work. So use it.
No need for extra hacks.
There is no objective to produce c23 compliant vmlinux.h at the moment.
> [2] https://gist.github.com/theihor/7e3341c5a1e1209a744994143abd9e62
/usr/include/x86_64-linux-gnu/bits/stdint-intn.h
vs
/ci/workspace/bpfgcc.20241229/lib/gcc/bpf-unknown-none/15.0.0/include/stdint.h
looks like a configuration issue.
We can skip test_cls_redirect*.c for now.
