Re: [PATCH 2/2] tools: do not include scripts/Kbuild.include

[Paolo Bonzini]

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

Paolo

> Link: https://lore.kernel.org/lkml/86dadf33-70f7-a5ac-cb8c-64966d2f45a1@xxxxxxxxxxxxx/
> Fixes: d9f4ff50d2aa ("kbuild: spilt cc-option and friends to scripts/Makefile.compiler")
> Reported-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
> Reported-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
> ---
>
>   tools/testing/selftests/bpf/Makefile          |  3 ++-
>   tools/testing/selftests/kvm/Makefile          | 12 +++++++++++-
>   .../selftests/powerpc/pmu/ebb/Makefile        | 11 ++++++++++-
>   tools/thermal/tmon/Makefile                   | 19 +++++++++++++++++--
>   4 files changed, 40 insertions(+), 5 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index 044bfdcf5b74..d872b9f41543 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -1,5 +1,4 @@
>   # SPDX-License-Identifier: GPL-2.0
> -include ../../../../scripts/Kbuild.include
>   include ../../../scripts/Makefile.arch
>   include ../../../scripts/Makefile.include
>   
> @@ -476,3 +475,5 @@ EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(SCRATCH_DIR) $(HOST_SCRATCH_DIR)	\
>   	prog_tests/tests.h map_tests/tests.h verifier/tests.h		\
>   	feature								\
>   	$(addprefix $(OUTPUT)/,*.o *.skel.h no_alu32 bpf_gcc bpf_testmod.ko)
> +
> +.DELETE_ON_ERROR:
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index a6d61f451f88..8b45bc417d83 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -1,5 +1,15 @@
>   # SPDX-License-Identifier: GPL-2.0-only
> -include ../../../../scripts/Kbuild.include
> +
> +TMPOUT = .tmp_$$$$
> +
> +try-run = $(shell set -e;		\
> +	TMP=$(TMPOUT)/tmp;		\
> +	mkdir -p $(TMPOUT);		\
> +	trap "rm -rf $(TMPOUT)" EXIT;	\
> +	if ($(1)) >/dev/null 2>&1;	\
> +	then echo "$(2)";		\
> +	else echo "$(3)";		\
> +	fi)
>   
>   all:
>   
> diff --git a/tools/testing/selftests/powerpc/pmu/ebb/Makefile b/tools/testing/selftests/powerpc/pmu/ebb/Makefile
> index af3df79d8163..d5d3e869df93 100644
> --- a/tools/testing/selftests/powerpc/pmu/ebb/Makefile
> +++ b/tools/testing/selftests/powerpc/pmu/ebb/Makefile
> @@ -1,5 +1,4 @@
>   # SPDX-License-Identifier: GPL-2.0
> -include ../../../../../../scripts/Kbuild.include
>   
>   noarg:
>   	$(MAKE) -C ../../
> @@ -8,6 +7,16 @@ noarg:
>   CFLAGS += -m64
>   
>   TMPOUT = $(OUTPUT)/TMPDIR/
> +
> +try-run = $(shell set -e;		\
> +	TMP=$(TMPOUT)/tmp;		\
> +	mkdir -p $(TMPOUT);		\
> +	trap "rm -rf $(TMPOUT)" EXIT;	\
> +	if ($(1)) >/dev/null 2>&1;	\
> +	then echo "$(2)";		\
> +	else echo "$(3)";		\
> +	fi)
> +
>   # Toolchains may build PIE by default which breaks the assembly
>   no-pie-option := $(call try-run, echo 'int main() { return 0; }' | \
>           $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -no-pie -x c - -o "$$TMP", -no-pie)
> diff --git a/tools/thermal/tmon/Makefile b/tools/thermal/tmon/Makefile
> index 59e417ec3e13..92a683e4866c 100644
> --- a/tools/thermal/tmon/Makefile
> +++ b/tools/thermal/tmon/Makefile
> @@ -1,6 +1,21 @@
>   # SPDX-License-Identifier: GPL-2.0
> -# We need this for the "cc-option" macro.
> -include ../../../scripts/Kbuild.include
> +
> +TMPOUT = .tmp_$$$$
> +
> +try-run = $(shell set -e;		\
> +	TMP=$(TMPOUT)/tmp;		\
> +	mkdir -p $(TMPOUT);		\
> +	trap "rm -rf $(TMPOUT)" EXIT;	\
> +	if ($(1)) >/dev/null 2>&1;	\
> +	then echo "$(2)";		\
> +	else echo "$(3)";		\
> +	fi)
> +
> +__cc-option = $(call try-run,\
> +	$(1) -Werror $(2) $(3) -c -x c /dev/null -o "$$TMP",$(3),$(4))
> +
> +cc-option = $(call __cc-option, $(CC),\
> +	$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2))
>   
>   VERSION = 1.0
>