On Tue, Aug 29, 2023 at 5:20 PM Quentin Monnet <quentin@xxxxxxxxxxxxx> wrote:
>
> On 09/07/2023 03:56, Yafang Shao wrote:
> > Add new functions and macros to get perf event names. These names except
> > the perf_type_name are all copied from
> > tool/perf/util/{parse-events,evsel}.c, so that in the future we will
> > have a good chance to use the same code.
> >
> > Suggested-by: Jiri Olsa <olsajiri@xxxxxxxxx>
> > Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> > Reviewed-by: Quentin Monnet <quentin@xxxxxxxxxxxxx>
> > Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> > ---
> > tools/bpf/bpftool/link.c | 67 ++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 67 insertions(+)
> >
> > diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c
> > index a4f5a436777f..8e4d9176a6e8 100644
> > --- a/tools/bpf/bpftool/link.c
> > +++ b/tools/bpf/bpftool/link.c
>
> [...]
>
> > +#define perf_event_name(array, id) ({ \
> > + const char *event_str = NULL; \
> > + \
> > + if ((id) >= 0 && (id) < ARRAY_SIZE(array)) \
>
> Hi Yafang,
>
> I'm observing build warnings when building bpftool after you series:
>
> link.c: In function ‘perf_config_hw_cache_str’:
> link.c:86:18: warning: comparison of unsigned expression in ‘>= 0’ is always true [-Wtype-limits]
> 86 | if ((id) >= 0 && (id) < ARRAY_SIZE(array)) \
> | ^~
> link.c:320:20: note: in expansion of macro ‘perf_event_name’
> 320 | hw_cache = perf_event_name(evsel__hw_cache, config & 0xff);
> | ^~~~~~~~~~~~~~~
> [... more of the same for the other calls to perf_event_name ...]
>
> (using GCC 11.4.0)
>
> Could you please send a follow-up to suppress them? We're always passing
> unsigned, so it should be safe to drop the check on (id) >= 0.
>
Thanks for your report.
will send a fix soon.
--
Regards
Yafang
