Re: [PATCH 8/8] btrfs: turn on -Wmaybe-uninitialized

Re: [PATCH 8/8] btrfs: turn on -Wmaybe-uninitialized

[Naresh Kamboju]

On Mon, 26 Dec 2022 at 09:47, Nathan Chancellor <nathan@kernel.org> wrote:
>
> On Fri, Dec 16, 2022 at 03:15:58PM -0500, Josef Bacik wrote:
> > We had a recent bug that would have been caught by a newer compiler with
> > -Wmaybe-uninitialized and would have saved us a month of failing tests
> > that I didn't have time to investigate.
> >
> > Signed-off-by: Josef Bacik <josef@toxicpanda.com>
>
> This needs to be moved to the condflags section, as
> -Wmaybe-uninitialized is a GCC only flag, so this breaks our builds with
> clang on next-20221226:
>
>   error: unknown warning option '-Wmaybe-uninitialized'; did you mean '-Wuninitialized'? [-Werror,-Wunknown-warning-option]

LKFT test farm also noticed these build breaks with clang on next-20221226.

Regressions found on arm64, riscv, s390 and powerpc

    - build/clang-lkftconfig
    - build/clang-15-lkftconfig
    - build/clang-15-defconfig-40bc7ee5
    - build/clang-15-defconfig
    - build/clang-nightly-defconfig
    - build/clang-15-lkftconfig-compat
    - build/clang-nightly-defconfig-40bc7ee5
    - build/clang-nightly-lkftconfig

make --silent --keep-going --jobs=8
O=/home/tuxbuild/.cache/tuxmake/builds/1/build LLVM=1 LLVM_IAS=1
ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- 'HOSTCC=sccache clang'
'CC=sccache clang'

error: unknown warning option '-Wmaybe-uninitialized'; did you mean
'-Wuninitialized'? [-Werror,-Wunknown-warning-option]
make[4]: *** [/builds/linux/scripts/Makefile.build:252:
fs/btrfs/super.o] Error 1


> I can send a patch on Tuesday unless the original commit can be amended.


ref:
https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20221226/testrun/13818773/suite/build/test/clang-15-defconfig/details/

- Naresh

Re: [PATCH 8/8] btrfs: turn on -Wmaybe-uninitialized

[David Sterba]

On Mon, Dec 26, 2022 at 07:34:51PM +0530, Naresh Kamboju wrote:
> On Mon, 26 Dec 2022 at 09:47, Nathan Chancellor <nathan@kernel.org> wrote:
> >
> > On Fri, Dec 16, 2022 at 03:15:58PM -0500, Josef Bacik wrote:
> > > We had a recent bug that would have been caught by a newer compiler with
> > > -Wmaybe-uninitialized and would have saved us a month of failing tests
> > > that I didn't have time to investigate.
> > >
> > > Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> >
> > This needs to be moved to the condflags section, as
> > -Wmaybe-uninitialized is a GCC only flag, so this breaks our builds with
> > clang on next-20221226:
> >
> >   error: unknown warning option '-Wmaybe-uninitialized'; did you mean '-Wuninitialized'? [-Werror,-Wunknown-warning-option]
> 
> LKFT test farm also noticed these build breaks with clang on next-20221226.

Fixed in our branch and for-next snapshot updated so the warnings will
be fixed once linux-next resumes.