selftests: lib.mk: fix out-of-tree builds

  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 error: 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@linaro.org>
---
 tools/testing/selftests/lib.mk | 4 ++++
 1 file changed, 4 insertions(+)
  

This patch needs to go through mm tree as the commit which it fixes is in mm.

On 6/13/23 12:49 PM, 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 error: 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@linaro.org>
Please add fixes tag. ("selftests: error out if kernel header files are not
yet built")

Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>

> ---
>  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 := $(O)
> +endif
> +
>  ifneq ($(KBUILD_OUTPUT),)
>    # Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
>    # expand a shell special character '~'. We use a somewhat tedious way here.
  

On 13.06.23 10:16, Muhammad Usama Anjum wrote:
> This patch needs to go through mm tree as the commit which it fixes is in mm.
> 
> On 6/13/23 12:49 PM, 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 error: 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@linaro.org>
> Please add fixes tag. ("selftests: error out if kernel header files are not
> yet built")
> 
> Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>

This should get squashed into the original patch unless it's already in 
mm-stable (which it isn't) and we have a stable commit id.
  

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 error: 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@linaro.org>
> ---
>   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.)

thanks,
  

On Wed, 14 Jun 2023 at 04:23, John Hubbard <jhubbard@nvidia.com> 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@linaro.org>
> > ---
> >   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.
>
>
  

On 6/14/23 14:16, Anders Roxell wrote:
>> (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?
> 

Well, since you asked... :)

Yes. Given that the goal is to support two similar, related activities:
	a) make -C tools/testing/selftests
	b) make -C tools/testing/selftests/<subtest>

, we could move common functionality into common_vars.mk and
common_targets.mk, and include those from both the top level
tools/testing/selftests/Makefile, and the subtest Makefiles.

This allows deduplication in a fairly safe sort of way, because it also
simultaneously moves everything to a non-recursive Make design. That's
especially nice, because then dependencies work reliably, and you also
don't have to worry about propagating Make variables (via Make's export
directive).

I haven't done this, because a few years ago I somehow got the vague
impression that it would not be well-received. But maybe that's
pessimistic and/or obsolete--times change, after all!

***************************************************************
Contents of tools/testing/selftests/Makefile:

include common_vars.mk

include alsa/alsa.mk
include amd-pstate/amd-pstate.mk
include arm64/arm64.mk
...etc, there are 100+ subdirs

include common_targets.mk

(This is instead of doing "TARGETS += xxx" in the Makefile. Including
the subtest *.mk fragments allows each subtest to add features and
quirks as necessary, while also enabling full dependency checking via a
true non-recursive Make.)

***************************************************************
Contents of tools/testing/selftests/common_targets.mk:

all: kernel_headers
     ...

Other rules/targets here.

***************************************************************
Contents of tools/testing/selftests/common_vars.mk:

Common variables, some of which may be overridden by a Makefile.

***************************************************************

Using alsa as an example of a subtest:

***************************************************************
Contents of tools/testing/selftests/alsa/alsa.mk:
TARGETS += alsa

TEST* items

Plus: alsa-specific items, such as:
CFLAGS += $(shell pkg-config --cflags alsa)

***************************************************************
Contents of tools/testing/selftests/alsa/Makefile:

include ../common_vars.mk
include alsa.mk

...maybe very little else needs to go here.

include ../common_targets.mk


thanks,