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Date:   Fri, 4 Dec 2020 09:41:12 +0000
From:   Brendan Jackman <jackmanb@google.com>
To:     Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc:     bpf <bpf@vger.kernel.org>, Alexei Starovoitov <ast@kernel.org>,
        Yonghong Song <yhs@fb.com>,
        Daniel Borkmann <daniel@iogearbox.net>,
        KP Singh <kpsingh@chromium.org>,
        Florent Revest <revest@chromium.org>,
        open list <linux-kernel@vger.kernel.org>,
        Jann Horn <jannh@google.com>
Subject: Re: [PATCH bpf-next v3 12/14] bpf: Pull tools/build/feature biz into
 selftests Makefile
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 <20201203160245.1014867-13-jackmanb@google.com>
 <CAEf4BzbEfPScq_qMVJkDxfWBh-oRhY5phFr=517pam80YcpgMg@mail.gmail.com>
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On Thu, Dec 03, 2020 at 01:01:27PM -0800, Andrii Nakryiko wrote:
> On Thu, Dec 3, 2020 at 8:07 AM Brendan Jackman <jackmanb@google.com> wrote:
> >
> > This is somewhat cargo-culted from the libbpf build. It will be used
> > in a subsequent patch to query for Clang BPF atomics support.
> >
> > Change-Id: I9318a1702170eb752acced35acbb33f45126c44c
> 
> Haven't seen this before. What's this Change-Id business?

Argh, apologies. Looks like it's time for me to adopt a less error-prone
workflow for sending patches.

(This is noise from Gerrit, which we sometimes use for internal reviews)

> > Signed-off-by: Brendan Jackman <jackmanb@google.com>
> > ---
> >  tools/testing/selftests/bpf/.gitignore |  1 +
> >  tools/testing/selftests/bpf/Makefile   | 38 ++++++++++++++++++++++++++
> >  2 files changed, 39 insertions(+)
> 
> All this just to detect the support for clang atomics?... Let's not
> pull in the entire feature-detection framework unnecessarily,
> selftests Makefile is complicated enough without that.

Then the test build would break for people who haven't updated Clang.
Is that acceptable?

I'm aware of cases where you need to be on a pretty fresh Clang for
tests to _pass_ so maybe it's fine.