Re: [PATCH] perf tools: report initial event parsing error

[Jiri Olsa]

On Fri, Nov 08, 2019 at 10:15:33AM -0800, Ian Rogers wrote:
> Record the first event parsing error and report. Implementing feedback
> from Jiri Olsa:
> https://lkml.org/lkml/2019/10/28/680
> 
> An example error is:
> 
> $ tools/perf/perf stat -e c/c/
> WARNING: multiple event parsing errors
> event syntax error: 'c/c/'
>                        \___ unknown term
> 
> valid terms: event,filter_rem,filter_opc0,edge,filter_isoc,filter_tid,filter_loc,filter_nc,inv,umask,filter_opc1,tid_en,thresh,filter_all_op,filter_not_nm,filter_state,filter_nm,config,config1,config2,name,period,percore
> 
> Initial error:
> event syntax error: 'c/c/'
>                     \___ Cannot find PMU `c'. Missing kernel support?
> Run 'perf list' for a list of valid events
> 
>  Usage: perf stat [<options>] [<command>]
> 
>     -e, --event <event>   event selector. use 'perf list' to list available events
> 
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
>  tools/perf/arch/powerpc/util/kvm-stat.c |  9 ++-
>  tools/perf/builtin-stat.c               |  2 +
>  tools/perf/builtin-trace.c              | 16 ++++--
>  tools/perf/tests/parse-events.c         |  3 +-
>  tools/perf/util/metricgroup.c           |  2 +-
>  tools/perf/util/parse-events.c          | 76 ++++++++++++++++++-------
>  tools/perf/util/parse-events.h          |  4 ++
>  7 files changed, 84 insertions(+), 28 deletions(-)
> 
> diff --git a/tools/perf/arch/powerpc/util/kvm-stat.c b/tools/perf/arch/powerpc/util/kvm-stat.c
> index 9cc1c4a9dec4..30f5310373ca 100644
> --- a/tools/perf/arch/powerpc/util/kvm-stat.c
> +++ b/tools/perf/arch/powerpc/util/kvm-stat.c
> @@ -113,10 +113,15 @@ static int is_tracepoint_available(const char *str, struct evlist *evlist)
>  	struct parse_events_error err;
>  	int ret;
>  
> -	err.str = NULL;
> +	bzero(&err, sizeof(err));
>  	ret = parse_events(evlist, str, &err);
> -	if (err.str)
> +	if (err.str) {
>  		pr_err("%s : %s\n", str, err.str);
> +		free(&err->str);
> +		free(&err->help);
> +		free(&err->first_str);
> +		free(&err->first_help);

it's used in other places, so it's better to put it in
parse_events_error__exit or such..

jirka