Re: [PATCH 1/2] selftests: fix header dependency for pid_namespace selftests

[Shuah Khan <skhan@linuxfoundation.org>]

On 3/24/22 4:39 PM, Axel Rasmussen wrote:
> The way the test target was defined before, when building with clang we
> get a command line like this:
> 
> clang -Wall -Werror -g -I../../../../usr/include/ \
> 	regression_enomem.c ../pidfd/pidfd.h  -o regression_enomem
> 
> This yields an error, because clang thinks we want to produce both a *.o
> file, as well as a precompiled header:
> 
> clang: error: cannot specify -o when generating multiple output files
> 
> gcc, for whatever reason, doesn't exhibit the same behavior which I
> suspect is why the problem wasn't noticed before.
> 

Thank you fixing this.

> This can be fixed simply by using the LOCAL_HDRS infrastructure the
> selftests lib.mk provides. It does the right think and marks the target
> as depending on the header (so if the header changes, we rebuild), but
> it filters the header out of the compiler command line, so we don't get
> the error described above.
> 
> Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
> ---
>   tools/testing/selftests/pid_namespace/Makefile | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/testing/selftests/pid_namespace/Makefile b/tools/testing/selftests/pid_namespace/Makefile
> index dcaefa224ca0..edafaca1aeb3 100644
> --- a/tools/testing/selftests/pid_namespace/Makefile
> +++ b/tools/testing/selftests/pid_namespace/Makefile
> @@ -1,8 +1,8 @@
>   # SPDX-License-Identifier: GPL-2.0
>   CFLAGS += -g -I../../../../usr/include/
>   
> -TEST_GEN_PROGS := regression_enomem
> +TEST_GEN_PROGS = regression_enomem
>   
> -include ../lib.mk
> +LOCAL_HDRS += $(selfdir)/pidfd/pidfd.h
>   
> -$(OUTPUT)/regression_enomem: regression_enomem.c ../pidfd/pidfd.h
> +include ../lib.mk
> 

Will apply this for Linux 5.18-rc2

thanks,
-- Shuah