Re: [PATCH] selftests: lib.mk: fix out-of-tree builds

[Anders Roxell]

On Wed, 14 Jun 2023 at 04:23, John Hubbard <jhubbard@xxxxxxxxxx> wrote:
>
> On 6/13/23 00:49, Anders Roxell wrote:
> > Since commit ("selftests: error out if kernel header files are not yet
> > built") got merged, the kselftest build correctly because the
> > KBUILD_OUTPUT isn't set when building out-of-tree and specifying 'O='
> > This is the error message that pops up.
> >
> > make --silent --keep-going --jobs=32 O=/home/anders/.cache/tuxmake/builds/1482/build INSTALL_PATH=/home/anders/.cache/tuxmake/builds/1482/build/kselftest_install ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- V=1 CROSS_COMPILE_COMPAT=arm-linux-gnueabihf- kselftest-install
> > make[3]: Entering directory '/home/anders/src/kernel/next/tools/testing/selftests/alsa'
> >
> > -e  [1;31merror [0m: missing kernel header files.
> > Please run this and try again:
> >
> >      cd /home/anders/src/kernel/next/tools/testing/selftests/../../..
> >      make headers
> >
> > make[3]: Leaving directory '/home/anders/src/kernel/next/tools/testing/selftests/alsa'
> > make[3]: *** [../lib.mk:77: kernel_header_files] Error 1
> >
> > Fixing the issue by assigning KBUILD_OUTPUT the same way how its done in
> > kselftest's Makefile. By adding 'KBUILD_OUTPUT := $(O)' 'if $(origin O)'
> > is set to 'command line'. This will set the the BUILD dir to
> > KBUILD_OUTPUT/kselftest when doing out-of-tree builds which makes them
> > in its own separete output directory.
> >
> > Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
> > ---
> >   tools/testing/selftests/lib.mk | 4 ++++
> >   1 file changed, 4 insertions(+)
> >
> > diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
> > index b8ea03b9a015..d17854285f2b 100644
> > --- a/tools/testing/selftests/lib.mk
> > +++ b/tools/testing/selftests/lib.mk
> > @@ -44,6 +44,10 @@ endif
> >   selfdir = $(realpath $(dir $(filter %/lib.mk,$(MAKEFILE_LIST))))
> >   top_srcdir = $(selfdir)/../../..
> >
> > +ifeq ("$(origin O)", "command line")
> > +  KBUILD_OUTPUT := $(O)
> > +endif
> > +
>
> Thanks for fixing this up! This looks correct.
>
> (It's too bad that we have all this duplication between the Makefile
> and lib.mk.)

I agree, also the duplication of get_sys_includes in bpf, hid and net Makefile's
Do you have any idea how we can remove the duplication?

Cheers,
Anders

>
> thanks,
> --
> John Hubbard
> NVIDIA
>
> >   ifneq ($(KBUILD_OUTPUT),)
> >     # Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
> >     # expand a shell special character '~'. We use a somewhat tedious way here.
>
>