selftests/bpf doesn't compile

[Shuah Khan]

Hi Alexei and Daniel,

bpf test depends on clang and fails to compile when

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make -C tools/testing/selftests/bpf run_tests


make: clang: Command not found
Makefile:39: recipe for target '.linux-kselftest/tools/testing/selftests/bpf/test_pkt_access.o' failed
make: *** [./linux-kselftest/tools/testing/selftests/bpf/test_pkt_access.o] Error 127
make: Leaving directory '.linux-kselftest/tools/testing/selftests/bpf'

With "make TARGETS=bpf kselftest" it fails earlier:


make[3]: Entering directory './linux-kselftest/tools/lib/bpf'
Makefile:40: tools/scripts/Makefile.arch: No such file or directory
Makefile:84: tools/build/Makefile.feature: No such file or directory
Makefile:143: tools/build/Makefile.include: No such file or directory
make[3]: *** No rule to make target 'tools/build/Makefile.include'.  Stop.
make[3]: Leaving directory '.linux-kselftest/tools/lib/bpf'
Makefile:34: recipe for target './linux-kselftest/tools/testing/selftests/bpf/libbpf.a' failed
make[2]: *** [./linux-kselftest/tools/testing/selftests/bpf/libbpf.a] Error 2
make[2]: Leaving directory './linux-kselftest/tools/testing/selftests/bpf'
Makefile:69: recipe for target 'all' failed
make[1]: *** [all] Error 2
Makefile:1190: recipe for target 'kselftest' failed
make: *** [kselftest] Error 2

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Is bpf test intended to be run in kselftest run? The clang dependency might
not be met on majority of the systems. Is this a hard dependency??

Would it make sense to create a special target for bpf test? We do have a few
tests that do that now. 

TARGETS_HOTPLUG = cpu-hotplug
TARGETS_HOTPLUG += memory-hotplug

I could add a special target for bpf TARGET_BPF perhaps and exclude it from
the run_tests.

Please let me know your thoughts on this.

thanks,
-- Shuah