[Buildroot] [PATCH v3 1/1] package/bpftool: revert bpf_cookie patch to allow building

[Shahab Vahedi]

On 6/16/22 01:27, James Hilliard wrote:
> On Wed, Jun 15, 2022 at 5:10 AM Shahab Vahedi via buildroot
> <buildroot at buildroot.org> wrote:
>>
>> On 6/14/22 19:14, Arnout Vandecappelle wrote:
>>>
>>> On 14/06/2022 11:31, Shahab Vahedi wrote:
>>>> Building bpftool on Debian 11 (bullseye) with kernel v5.10 and clang-11
>>>
>>>  How do you build host-bpftool with clang in Buildroot context? HOSTCC is set to gcc in the Makefile... Do you supply an explicit HOSTCC= on the Buildroot command line? I'm not sure if we are really interested in carrying fixes for such exotic and not-really-supported situations...
>>
>> No, I don't do any sort of trickery to build bpftool on my end. The
>> bootstrapping, if becomes available for your configuration, uses clang
>> and only clang. I tried to explain this in v4 of the patch [1], the
>> second paragraph of the commit message.
> 
> I think clang/llvm support isn't going to work correctly yet since we only have
> version 9.0.1, there's a series bumping to version 11.1.0 that should fix that:
> https://patchwork.ozlabs.org/project/buildroot/list/?series=291585
> 
> Minimum clang/llvm version for libbpf co-re is version 10:
> https://github.com/libbpf/libbpf*bpf-co-re-compile-once--run-everywhere

You're right about the clang version, but it doesn't have anything to do
with Buildroot's clang. The build process uses the clang that is installed
on the host. For Debian bullseye, that is clang 11.

To emphasise, I am cross-building bpftool for my "arc-linux" target, and yet
the bootstrap part of bpftool, uses the x86 clang of the Debian machine.


-- 
Shahab