Re: [PATCH v3] selftests: harness: Mark test fixture objects __maybe_unused

[David Matlack]

On Mon, Jul 6, 2026 at 11:32 AM David Matlack <dmatlack@xxxxxxxxxx> wrote:
>
> Mark _##fixture_name##_##test_name##_object __maybe_unused since it may
> not ever be read. This pointer is only read in XFAIL_ADD(), which tests
> are not required to use.
>
> clang made a change to -Wunused-but-set-variable (split out into its own
> subwarning, -Wunused-but-set-global) that causes this warning to be
> emitted for various selftests and can be upgraded to an error in
> selftest that set -Werror.
>
> VFIO selftests have been broken since commit ff556bd98348 ("vfio:
> selftests: Add -Wall and -Werror to the Makefile"), and the net
> selftests builds have been noisy due to -Wall.
>
> Fixes: 24cf65a62266 ("selftests/harness: Share _metadata between forked processes")
> Reported-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
> Reported-by: Aaron Lewis <aaronlewis@xxxxxxxxxx>
> Reviewed-by: Alex Williamson <alex@xxxxxxxxxxx>
> Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
> Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx>

Kees and Shuah, is it ok if Alex takes this through the VFIO tree? [1]
This fixes a bug exposed by recent VFIO selftests commit ff556bd98348
("vfio: selftests: Add -Wall and -Werror to the Makefile").

[1] https://lore.kernel.org/linux-kselftest/20260630165244.0d013bbc@xxxxxxxxxxx/