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

[shuah]

On 2/12/20 11:15 AM, shuah wrote:
> 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>
> > ---
> > Â tools/testing/selftests/futex/functional/Makefile | 2 +-
> > Â tools/testing/selftests/net/MakefileÂÂÂÂÂÂÂÂÂÂÂÂÂ | 4 ++--
> > Â tools/testing/selftests/rtc/MakefileÂÂÂÂÂÂÂÂÂÂÂÂÂ | 2 +-
> > Â tools/testing/selftests/timens/MakefileÂÂÂÂÂÂÂÂÂÂ | 2 +-
> > Â 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>

In the interest of getting this fix in, I applied it to

git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git 
fixes branch.

No need to do anything.

thanks,
-- Shuah