Re: [PATCH 1/2] perf, tools: Enable type checking for perf_evsel_config_term types

From: Arnaldo Carvalho de Melo
Date: Wed Nov 08 2017 - 10:41:00 EST


Em Tue, Oct 24, 2017 at 09:38:49AM +0200, Jiri Olsa escreveu:
> On Fri, Oct 20, 2017 at 01:27:54PM -0700, Andi Kleen wrote:
> > From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> >
> > Use a typed enum for the perf_evsel_config_term type enum.
> > This allows gcc to do much stronger type checks, and also
> > check for missing case statements.
> >
> > I removed the unused _MAX member from the number.
> >
> > It found one missing case. I'm not sure it's a real problem,
> > so I just turned it into a BUG_ON for now.
> >
> > Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> > ---
> > tools/perf/util/evsel.c | 2 ++
> > tools/perf/util/evsel.h | 5 ++---
> > 2 files changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > index f894893c203d..d1f63b93bf69 100644
> > --- a/tools/perf/util/evsel.c
> > +++ b/tools/perf/util/evsel.c
> > @@ -775,6 +775,8 @@ static void apply_config_terms(struct perf_evsel *evsel,
> > case PERF_EVSEL__CONFIG_TERM_OVERWRITE:
> > attr->write_backward = term->val.overwrite ? 1 : 0;
> > break;
> > + case PERF_EVSEL__CONFIG_TERM_DRV_CFG:
> > + BUG_ON(1);
> > default:
> > break;
> > }
> > diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> > index db658785d828..6728d8d6e513 100644
> > --- a/tools/perf/util/evsel.h
> > +++ b/tools/perf/util/evsel.h
> > @@ -37,7 +37,7 @@ struct cgroup_sel;
> > * It is allocated within event parsing and attached to
> > * perf_evsel::config_terms list head.
> > */
> > -enum {
> > +enum period_type {
>
> seems ok, but I'm puzzled with the 'period_type' name
> I think it should be more like 'term_type' or something

Ok, renamed it to term_type and added your Acked-by,

- ARnaldo

> jirka
>
>
> > PERF_EVSEL__CONFIG_TERM_PERIOD,
> > PERF_EVSEL__CONFIG_TERM_FREQ,
> > PERF_EVSEL__CONFIG_TERM_TIME,
> > @@ -48,12 +48,11 @@ enum {
> > PERF_EVSEL__CONFIG_TERM_OVERWRITE,
> > PERF_EVSEL__CONFIG_TERM_DRV_CFG,
> > PERF_EVSEL__CONFIG_TERM_BRANCH,
> > - PERF_EVSEL__CONFIG_TERM_MAX,
> > };
> >
> > struct perf_evsel_config_term {
> > struct list_head list;
> > - int type;
> > + enum period_type type;
> > union {
> > u64 period;
> > u64 freq;
> > --
> > 2.13.6
> >