Re: [PATCH v1 bpf-next 17/18] selftests/bpf: Enable bpf_scan_ir in the config

[Anton Protopopov]

On 26/11/06 09:35PM, bot+bpf-ci@xxxxxxxxxx wrote:
> > selftests/bpf: Enable bpf_scan_ir in the config
> 
> TL;DR: Commit message only: the list of cases where Kconfig ignores the plugin
> options looks incomplete (other arches, missing matching llvm-config), so "CI
> builds and tests it" may not hold and fmodret_retval may silently skip.
> 
> >     selftests/bpf: Enable bpf_scan_ir in the config
> >
> >     The bpf_scan_ir plugin is off by default. Without it bpf_testmod has no
> >     fixtures for the plugin and fmodret_retval skips. Enable the plugin in
> >     the selftests config, so CI builds and tests it. Kconfig ignores the
> >     options with GCC and with clang older than 19.
> >     Signed-off-by: Anton Protopopov <a.s.protopopov@xxxxxxxxx>
> 
> Is the list of conditions in the last sentence complete?  The commit message
> says Kconfig ignores the options "with GCC and with clang older than 19", and
> that CI "builds and tests it".
> 
> scripts/llvm-plugins/Kconfig has more conditions.  LLVM_PLUGINS needs
> CC_IS_CLANG, a working $(LLVM_CONFIG), an llvm-config with the same major
> version as $(CC), and a $(HOSTCXX) that accepts the LLVM headers.
> CLANG_PLUGIN_BPF_SCAN_IR needs X86_64 || ARM64, DEBUG_INFO_BTF, !LTO_CLANG and
> CLANG_VERSION >= 190000.
> 
> So config.s390x, config.ppc64el and config.riscv64 never get the plugin, and a
> clang >= 19 host without a matching llvm-dev drops both options silently.  In
> those cases the build succeeds, bpf_testmod is built without the
> bpf_testmod_retval*.o objects, and fmodret_retval reports SKIP.
> 
> Could the message list the full set of conditions, or say that "CI builds and
> tests it" only holds when a matching llvm-config is available?

Yes, thanks, will rephrase it.

> 
> ---
> AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
> See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
> 
> CI run summary: https://github.com/kernel-patches/bpf/actions/runs/42294987431