Re: [PATCH 05/26] perf tools: Add build_id__is_defined function

Namhyung Kim
2020-09-14T05:44:51Z

On Mon, Sep 14, 2020 at 6:05 AM Jiri Olsa <jolsa@kernel.org> wrote:
>
> Adding build_id__is_defined helper to check build id
> is defined and is != zero build id.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> tools/perf/util/build-id.c | 11 +++++++++++
> tools/perf/util/build-id.h | 1 +
> 2 files changed, 12 insertions(+)
>
> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> index 31207b6e2066..bdee4e08e60d 100644
> --- a/tools/perf/util/build-id.c
> +++ b/tools/perf/util/build-id.c
> @@ -902,3 +902,14 @@ bool perf_session__read_build_ids(struct perf_session *session, bool with_hits)
>
> return ret;
> }
> +
> +bool build_id__is_defined(const u8 *build_id)
> +{
> + static u8 zero[BUILD_ID_SIZE];
> + int err = 0;
> +
> + if (build_id)
> + err = memcmp(build_id, &zero, BUILD_ID_SIZE);
> +
> + return err ? true : false;
> +}

I think this is a bit confusing.. How about this?

bool ret = false;
if (build_id)
ret = memcmp(...);
return ret;

Or, it can be a oneliner..

Thanks
Namhyung

> diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
> index aad419bb165c..1ceede45c231 100644
> --- a/tools/perf/util/build-id.h
> +++ b/tools/perf/util/build-id.h
> @@ -14,6 +14,7 @@ extern struct perf_tool build_id__mark_dso_hit_ops;
> struct dso;
> struct feat_fd;
>
> +bool build_id__is_defined(const u8 *build_id);
> int build_id__sprintf(const u8 *build_id, int len, char *bf);
> int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id);
> int filename__sprintf_build_id(const char *pathname, char *sbuild_id);
> --
> 2.26.2
>