Re: [PATCH bpf-next 1/5] selftests/bpf: add remaining ASSERT_xxx() variants

["Toke Høiland-Jørgensen" <toke@redhat.com>]

Andrii Nakryiko <andrii.nakryiko@gmail.com> writes:

> On Mon, Apr 26, 2021 at 1:06 AM Lorenz Bauer <lmb@cloudflare.com> wrote:
>>
>> On Sat, 24 Apr 2021 at 00:36, Andrii Nakryiko <andrii@kernel.org> wrote:
>> >
>> > Add ASSERT_TRUE/ASSERT_FALSE for conditions calculated with custom logic to
>> > true/false. Also add remaining arithmetical assertions:
>> >   - ASSERT_LE -- less than or equal;
>> >   - ASSERT_GT -- greater than;
>> >   - ASSERT_GE -- greater than or equal.
>> > This should cover most scenarios where people fall back to error-prone
>> > CHECK()s.
>> >
>> > Also extend ASSERT_ERR() to print out errno, in addition to direct error.
>> >
>> > Also convert few CHECK() instances to ensure new ASSERT_xxx() variants work as
>> > expected. Subsequent patch will also use ASSERT_TRUE/ASSERT_FALSE more
>> > extensively.
>> >
>> > Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
>> > ---
>> >  .../selftests/bpf/prog_tests/btf_dump.c       |  2 +-
>> >  .../selftests/bpf/prog_tests/btf_endian.c     |  4 +-
>> >  .../selftests/bpf/prog_tests/cgroup_link.c    |  2 +-
>> >  .../selftests/bpf/prog_tests/kfree_skb.c      |  2 +-
>> >  .../selftests/bpf/prog_tests/resolve_btfids.c |  7 +--
>> >  .../selftests/bpf/prog_tests/snprintf_btf.c   |  4 +-
>> >  tools/testing/selftests/bpf/test_progs.h      | 50 ++++++++++++++++++-
>> >  7 files changed, 56 insertions(+), 15 deletions(-)
>> >
>> > diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dump.c b/tools/testing/selftests/bpf/prog_tests/btf_dump.c
>> > index c60091ee8a21..5e129dc2073c 100644
>> > --- a/tools/testing/selftests/bpf/prog_tests/btf_dump.c
>> > +++ b/tools/testing/selftests/bpf/prog_tests/btf_dump.c
>> > @@ -77,7 +77,7 @@ static int test_btf_dump_case(int n, struct btf_dump_test_case *t)
>> >
>> >         snprintf(out_file, sizeof(out_file), "/tmp/%s.output.XXXXXX", t->file);
>> >         fd = mkstemp(out_file);
>> > -       if (CHECK(fd < 0, "create_tmp", "failed to create file: %d\n", fd)) {
>> > +       if (!ASSERT_GE(fd, 0, "create_tmp")) {
>>
>> Nit: I would find ASSERT_LE easier to read here. Inverting boolean
>> conditions is easy to get wrong.
>
> You mean if (ASSERT_LE(fd, -1, "create_tmp")) { err = fd; goto done; } ?
>
> That will mark the test failing if fd >= 0, which is exactly opposite
> to what we wan't. It's confusing because CHECK() checks invalid
> conditions and returns "true" if it holds. But ASSERT_xxx() checks
> *valid* condition and returns whether valid condition holds. So the
> pattern is always

There's already an ASSERT_OK_PTR(), so maybe a corresponding
ASSERT_OK_FD() would be handy?

-Toke