On Thu, Apr 15, 2021 at 4:40 PM Paolo Bonzini [off-list ref] wrote:

On 15/04/21 09:27, Masahiro Yamada wrote:

quoted

Since commit d9f4ff50d2aa ("kbuild: spilt cc-option and friends to
scripts/Makefile.compiler"), some kselftests fail to build.

The tools/ directory opted out Kbuild, and went in a different
direction. They copy any kind of files to the tools/ directory
in order to do whatever they want to do in their world.

tools/build/Build.include mimics scripts/Kbuild.include, but some
tool Makefiles included the Kbuild one to import a feature that is
missing in tools/build/Build.include:

  - Commit ec04aa3ae87b ("tools/thermal: tmon: use "-fstack-protector"
    only if supported") included scripts/Kbuild.include from
    tools/thermal/tmon/Makefile to import the cc-option macro.

  - Commit c2390f16fc5b ("selftests: kvm: fix for compilers that do
    not support -no-pie") included scripts/Kbuild.include from
    tools/testing/selftests/kvm/Makefile to import the try-run macro.

  - Commit 9cae4ace80ef ("selftests/bpf: do not ignore clang
    failures") included scripts/Kbuild.include from
    tools/testing/selftests/bpf/Makefile to import the .DELETE_ON_ERROR
    target.

  - Commit 0695f8bca93e ("selftests/powerpc: Handle Makefile for
    unrecognized option") included scripts/Kbuild.include from
    tools/testing/selftests/powerpc/pmu/ebb/Makefile to import the
    try-run macro.

Copy what they want there, and stop including scripts/Kbuild.include
from the tool Makefiles.

I think it would make sense to add try-run, cc-option and
.DELETE_ON_ERROR to tools/build/Build.include?

To be safe, I just copy-pasted what the makefiles need.
If someone wants to refactor the tool build system, that is fine,
but, to me, I do not see consistent rules or policy under tools/.

-- 
Best Regards
Masahiro Yamada