On Tue, Jun 30, 2026 at 04:52:44PM -0600, Alex Williamson wrote: > On Tue, 30 Jun 2026 21:33:41 +0000 > David Matlack <[email protected]> wrote: > > > Mark test fixture objects __maybe_unused since they will not be used > > when there are fixture variants (the variants will be used instead). > > > > This fixes the VFIO selftest build with clang and -Werror: > > > > vfio_dma_mapping_mmio_test.c:106:1: error: variable > > '_vfio_dma_mapping_mmio_test_map_full_bar_object' set but not used > > [-Werror,-Wunused-but-set-global] > > 106 | TEST_F(vfio_dma_mapping_mmio_test, map_full_bar) > > | ^ > > ./../kselftest_harness.h:398:2: note: expanded from macro 'TEST_F' > > 398 | __TEST_F_IMPL(fixture_name, test_name, -1, > > TEST_TIMEOUT_DEFAULT) > > | ^ > > ./../kselftest_harness.h:470:33: note: expanded from macro '__TEST_F_IMPL' > > 470 | static struct __test_metadata > > *_##fixture_name##_##test_name##_object; \ > > | > > > > Fixes: ff556bd98348 ("vfio: selftests: Add -Wall and -Werror to the > > Makefile") > > Reported-by: Aaron Lewis <[email protected]> > > Signed-off-by: David Matlack <[email protected]> > > --- > > tools/testing/selftests/kselftest_harness.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/tools/testing/selftests/kselftest_harness.h > > b/tools/testing/selftests/kselftest_harness.h > > index 261e4df94d9d..29a19bc87084 100644 > > --- a/tools/testing/selftests/kselftest_harness.h > > +++ b/tools/testing/selftests/kselftest_harness.h > > @@ -467,7 +467,7 @@ static inline void __kselftest_memset_safe(void *s, int > > c, size_t n) > > !__atomic_test_and_set(_metadata->no_teardown, > > __ATOMIC_RELAXED)) \ > > fixture_name##_teardown(_metadata, self, variant); \ > > } \ > > - static struct __test_metadata *_##fixture_name##_##test_name##_object; \ > > + static struct __test_metadata *_##fixture_name##_##test_name##_object > > __maybe_unused; \ > > static void __attribute__((constructor(KSELFTEST_PRIO_TEST))) \ > > _register_##fixture_name##_##test_name(void) \ > > { \ > > > > base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482 > > Reviewed-by: Alex Williamson <[email protected]> > > Kees/Shuah, I can take this through the vfio tree if you prefer, it > fixes a commit that entered through vfio selftests. Thanks,
Not that it is a big deal or matters all too much but I do not think this fixes tag is entirely accurate. The blamed commit may have introduced the build warning/error in the VFIO code but that same warning could occur in any selftest code, as evidenced by the exact same patch submitted a month ago: https://lore.kernel.org/[email protected]/ clang made a change to -Wunused-but-set-variable (split out into its own subwarning, -Wunused-but-set-global) that exposes this. Personally, I find that change explains the problem better but this one makes it clear that it can become fatal with -Werror. -- Cheers, Nathan
