Re: [PATCH v5 bpf-next 11/15] libbpf: don't use cxx to test_libpf target

From: Stanislav Fomichev
Date: Fri Nov 22 2019 - 11:32:18 EST


On 11/21, Andrii Nakryiko wrote:
> On Thu, Nov 21, 2019 at 1:42 PM Stanislav Fomichev <sdf@xxxxxxxxxxx> wrote:
> >
> > On 10/11, Ivan Khoronzhuk wrote:
> > > No need to use C++ for test_libbpf target when libbpf is on C and it
> > > can be tested with C, after this change the CXXFLAGS in makefiles can
> > > be avoided, at least in bpf samples, when sysroot is used, passing
> > > same C/LDFLAGS as for lib.
> > > Add "return 0" in test_libbpf to avoid warn, but also remove spaces at
> > > start of the lines to keep same style and avoid warns while apply.
> > Hey, just spotted this patch, not sure how it slipped through.
> > The c++ test was there to make sure libbpf can be included and
> > linked against c++ code (i.e. libbpf headers don't have some c++
> > keywords/etc).
> >
> > Any particular reason you were not happy with it? Can we revert it
> > back to c++ and fix your use-case instead? Alternatively, we can just
> > remove this test if we don't really care about c++.
> >
>
> No one seemed to know why we have C++ pieces in pure C library and its
> Makefile, so we decide to "fix" this. :)
It's surprising, the commit 8c4905b995c6 clearly states the reason
for adding it. Looks like it deserved a real comment in the Makefile :-)

> But I do understand your concern. Would it be possible to instead do
> this as a proper selftests test? Do you mind taking a look at that?
Ack, will move this test_libbpf.c into selftests and convert back to
c++.