Re: [PATCH] selftests: use LDLIBS for libraries instead of LDFLAGS

[shuah]

On 2/12/20 7:00 AM, Dmitry Safonov wrote:
> While building selftests, the following errors were observed:
> > tools/testing/selftests/timens'
> > gcc -Wall -Werror -pthread  -lrt -ldl  timens.c  -o tools/testing/selftests/timens/timens
> > /usr/bin/ld: /tmp/ccGy5CST.o: in function `check_config_posix_timers':
> > timens.c:(.text+0x65a): undefined reference to `timer_create'
> > collect2: error: ld returned 1 exit status
>
> Quoting commit 870f193d48c2 ("selftests: net: use LDLIBS instead of
> LDFLAGS"):
>
> The default Makefile rule looks like:
>
> $(CC) $(CFLAGS) $(LDFLAGS) $@ $^ $(LDLIBS)
>
> When linking is done by gcc itself, no issue, but when it needs to be passed
> to proper ld, only LDLIBS follows and then ld cannot know what libs to link
> with.
>
> More detail:
> https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html
>
> LDFLAGS
> Extra flags to give to compilers when they are supposed to invoke the linker,
> âldâ, such as -L. Libraries (-lfoo) should be added to the LDLIBS variable
> instead.
>
> LDLIBS
> Library flags or names given to compilers when they are supposed to invoke the
> linker, âldâ. LOADLIBES is a deprecated (but still supported) alternative to
> LDLIBS. Non-library linker flags, such as -L, should go in the LDFLAGS
> variable.
>
> While at here, correct other selftests, not only timens ones.
>
> Reported-by: Shuah Khan <skhan@xxxxxxxxxx>
> Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx>
> ---
>   tools/testing/selftests/futex/functional/Makefile | 2 +-
>   tools/testing/selftests/net/Makefile              | 4 ++--
>   tools/testing/selftests/rtc/Makefile              | 2 +-
>   tools/testing/selftests/timens/Makefile           | 2 +-
>   4 files changed, 5 insertions(+), 5 deletions(-)


Looks good. Thanks for fixing it quickly.

Please split these into 4 patches and send one for each test.

For timens:

Tested-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>

thanks,
-- Shuah