Re: [PATCH v2 1/3] selftests: ublk: kublk: build with -Werror iff WERROR!=0

Ming Lei
2025-04-30T00:09:29Z

On Tue, Apr 29, 2025 at 04:41:03PM -0600, Uday Shankar wrote:
> Compiler warnings can catch bugs at compile time; thus, heeding them is
> usually a good idea. Turn warnings into errors by default for the kublk
> build so that anyone making changes is forced to heed them. Compiler
> warnings can also sometimes produce annoying false positives, so provide
> a flag WERROR that the developer can use as follows to have the build
> and selftests run go through even if there are warnings:
>
> make WERROR=0 TARGETS=ublk kselftest

I thought WERROR is 0 default, but actually the default value is 1.

Just tried gcc 14/15 and clang 18/20, looks everything works fine.

For kernel selftests, I guess the usual way is to do it explicitly
by passing 'make -C tools/testing/selftests TARGETS=ublk'.

Even though the build fails for people who is running the test on purpose,
or doling whole kernel selfests, they still can:

- report the failure

- skip ublk test by adding 'SKIP_TARGETS=ublk' to command line

Also this ways has been used by perf, lib/api, lib/subcmd and lib/sysmbol in
linux kernel tools/, so I feel the change should be doable, but let Jens decide
if it is fine to pass -Werror at default:

Reviewed-by: Ming Lei <ming.lei@redhat.com>

Otherwise, it still can be enabled conditionally with default off.

Thanks,
Ming