Re: [PATCH] selftests/futex: fix build for clang

[Ricardo Cañuelo <ricardo.canuelo@xxxxxxxxxxxxx>]

On mié, sep 14 2022 at 11:53:34, André Almeida <andrealmeid@xxxxxxxxxx> wrote:

> Hi Ricardo :)

Hey Tony! Long time, haha. I hope you're doing fine.

> Could you share how I can test this patch?

Simply running `make CC=clang' in tools/testing/selftest/futex with and
without the patch on should highlight the differences:

Without the patch:

    $ make CC=clang
    make[1]: Entering directory '/root/linux-kselftest/tools/testing/selftests/futex/functional'
    make --no-builtin-rules ARCH=x86 -C ../../../../.. headers_install
    make[2]: Entering directory '/root/linux-kselftest'
      INSTALL ./usr/include
    make[2]: Leaving directory '/root/linux-kselftest'
    clang  -g -O2 -Wall -D_GNU_SOURCE -pthread -I../include -I../../ -I../../../../../usr/include/     futex_wait_timeout.c ../include/futextest.h ../include/atomic.h ../include/logging.h -lpthread -lrt -o /root/linux-kselftest/tools/testing/selftests/futex/functional/futex_wait_timeout
    clang: error: cannot specify -o when generating multiple output files
    make[1]: *** [../../lib.mk:152: /root/linux-kselftest/tools/testing/selftests/futex/functional/futex_wait_timeout] Error 1
    make[1]: Leaving directory '/root/linux-kselftest/tools/testing/selftests/futex/functional'


With the patch:

    $ make CC=clang
    make[1]: Entering directory '/root/linux-kselftest/tools/testing/selftests/futex/functional'
    make --no-builtin-rules ARCH=x86 -C ../../../../.. headers_install
    make[2]: Entering directory '/root/linux-kselftest'
      INSTALL ./usr/include
    make[2]: Leaving directory '/root/linux-kselftest'
    clang  -g -O2 -Wall -D_GNU_SOURCE -pthread -I../include -I../../ -I../../../../../usr/include/     futex_wait_timeout.c -lpthread -lrt -o /root/linux-kselftest/tools/testing/selftests/futex/functional/futex_wait_timeout
    clang  -g -O2 -Wall -D_GNU_SOURCE -pthread -I../include -I../../ -I../../../../../usr/include/     futex_wait_wouldblock.c -lpthread -lrt -o /root/linux-kselftest/tools/testing/selftests/futex/functional/futex_wait_wouldblock
    ...

I'm testing this with Clang v11, by the way.

Cheers,
Ricardo