Re: [PATCH -next 3/5] perf: Remove duplicate errbuf

[Chen Zhongjin]

Hi,

On 2022/9/27 3:54, Arnaldo Carvalho de Melo wrote:
> Em Mon, Sep 26, 2022 at 11:14:38AM +0800, Chen Zhongjin escreveu:
> > char errbuf[BUFSIZ] is defined twice in trace__run.
> >
> > However out_error_open is not cross to other out_error path, they can
> > share one errbuf together.
> >
> > Define the errbuf[BUFSIZ] at the beginning of function, and remove the
> > redefinations of them for code cleaning.
> Have you looked at the end result in the generated code? Just out of
> curiosity.

Good question. Because it is an auto reported warning of clang I didn't 
try it.

Just tried and found no different for 'objdump -d perf' on two version.


Best,

Chen

> - Arnaldo
>   
> > Signed-off-by: Chen Zhongjin <chenzhongjin@xxxxxxxxxx>
> > ---
> >   tools/perf/builtin-trace.c | 7 ++-----
> >   1 file changed, 2 insertions(+), 5 deletions(-)
> >
> > diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> > index 7ecd76428440..5660c0ee3507 100644
> > --- a/tools/perf/builtin-trace.c
> > +++ b/tools/perf/builtin-trace.c
> > @@ -3937,6 +3937,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
> >   	unsigned long before;
> >   	const bool forks = argc > 0;
> >   	bool draining = false;
> > +	char errbuf[BUFSIZ];
> >   
> >   	trace->live = true;
> >   
> > @@ -4027,8 +4028,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
> >   
> >   	err = bpf__apply_obj_config();
> >   	if (err) {
> > -		char errbuf[BUFSIZ];
> > -
> >   		bpf__strerror_apply_obj_config(err, errbuf, sizeof(errbuf));
> >   		pr_err("ERROR: Apply config to BPF failed: %s\n",
> >   			 errbuf);
> > @@ -4185,8 +4184,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
> >   	trace->evlist = NULL;
> >   	trace->live = false;
> >   	return err;
> > -{
> > -	char errbuf[BUFSIZ];
> >   
> >   out_error_sched_stat_runtime:
> >   	tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "sched", "sched_stat_runtime");
> > @@ -4213,7 +4210,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
> >   		evsel->filter, evsel__name(evsel), errno,
> >   		str_error_r(errno, errbuf, sizeof(errbuf)));
> >   	goto out_delete_evlist;
> > -}
> > +
> >   out_error_mem:
> >   	fprintf(trace->output, "Not enough memory to run!\n");
> >   	goto out_delete_evlist;
> > --
> > 2.17.1