On Thu, May 02, 2024 at 06:58:20PM -0700, John Hubbard wrote:
> First of all, in order to build with clang at all, one must first apply
> Valentin Obst's build fix for LLVM [1]. Once that is done, then when
> building with clang, via:
>
> make LLVM=1 -C tools/testing/selftests
>
> ...the following error occurs:
>
> clang: error: cannot specify -o when generating multiple output files
>
> This is because clang, unlike gcc, won't accept invocations of this
> form:
>
> clang file1.c header2.h
>
> While trying to fix this, I noticed that:
>
> a) selftests/lib.mk already avoids the problem, and
>
> b) The binderfs Makefile indavertently bypasses the selftests/lib.mk
> build system, and quitely uses Make's implicit build rules for .c files
> instead.
>
> The Makefile attempts to set up both a dependency and a source file,
> neither of which was needed, because lib.mk is able to automatically
> handle both. This line:
>
> binderfs_test: binderfs_test.c
>
> ...causes Make's implicit rules to run, which builds binderfs_test
> without ever looking at lib.mk.
>
> Fix this by simply deleting the "binderfs_test:" Makefile target and
> letting lib.mk handle it instead.
>
> [1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/
>
> Fixes: 6e29225af902 ("binderfs: port tests to test harness infrastructure")
> Cc: Christian Brauner <[email protected]>
> Signed-off-by: John Hubbard <[email protected]>
> ---
Reviewed-by: Christian Brauner <[email protected]>
On 5/3/24 03:10, Christian Brauner wrote:
> On Thu, May 02, 2024 at 06:58:20PM -0700, John Hubbard wrote:
>> First of all, in order to build with clang at all, one must first apply
>> Valentin Obst's build fix for LLVM [1]. Once that is done, then when
>> building with clang, via:
>>
>> make LLVM=1 -C tools/testing/selftests
>>
>> ...the following error occurs:
>>
>> clang: error: cannot specify -o when generating multiple output files
>>
>> This is because clang, unlike gcc, won't accept invocations of this
>> form:
>>
>> clang file1.c header2.h
>>
>> While trying to fix this, I noticed that:
>>
>> a) selftests/lib.mk already avoids the problem, and
>>
>> b) The binderfs Makefile indavertently bypasses the selftests/lib.mk
>> build system, and quitely uses Make's implicit build rules for .c files
>> instead.
>>
>> The Makefile attempts to set up both a dependency and a source file,
>> neither of which was needed, because lib.mk is able to automatically
>> handle both. This line:
>>
>> binderfs_test: binderfs_test.c
>>
>> ...causes Make's implicit rules to run, which builds binderfs_test
>> without ever looking at lib.mk.
>>
>> Fix this by simply deleting the "binderfs_test:" Makefile target and
>> letting lib.mk handle it instead.
>>
>> [1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/
>>
>> Fixes: 6e29225af902 ("binderfs: port tests to test harness infrastructure")
>> Cc: Christian Brauner <[email protected]>
>> Signed-off-by: John Hubbard <[email protected]>
>> ---
>
> Reviewed-by: Christian Brauner <[email protected]>
>
Thank you. Applied to linunx-kselftest next for Linux 6.10-rc1
thanks,
-- Shuah