On Mon, Apr 26, 2021 at 8:59 AM Toke Høiland-Jørgensen [off-list ref] wrote:

Andrii Nakryiko [off-list ref] writes:

quoted

On Mon, Apr 26, 2021 at 1:06 AM Lorenz Bauer [off-list ref] wrote:

quoted

On Sat, 24 Apr 2021 at 00:36, Andrii Nakryiko [off-list ref] wrote:

quoted

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?

I honestly don't see the point. OK_PTR is special, it checks NULL and
the special ERR_PTR() variants, which is a lot of hassle to check
manually. While for FD doing ASSERT_GE(fd, 0) seems to be fine and
just mostly natural. Also for some APIs valid FD is > 0 and for other
cases valid FD is plain >= 0, so that just adds to the confusion.

-Toke