Re: [PATCH] perf record: Remove the '--(null)' long_name for --list-opts

From: Ingo Molnar
Date: Wed Feb 18 2015 - 12:56:20 EST



* Yunlong Song <yunlong.song@xxxxxxxxxx> wrote:

> If the long_name of a 'struct option' is defined as NULL, --list-opts
> will incorrectly print '--(null)' in its output. As a result, '--(null)'
> will finally appear in the case of bash completion, e.g. 'perf record --'.
>
> Example:
>
> Before this patch:
>
> $ perf record --list-opts
>
> --event --filter --pid --tid --realtime --no-buffering --raw-samples
> --all-cpus --cpu --count --output --no-inherit --freq --mmap-pages
> --group --(null) --call-graph --verbose --quiet --stat --data
> --timestamp --period --no-samples --no-buildid-cache --no-buildid
> --cgroup --delay --uid --branch-any --branch-filter --weight
> --transaction --per-thread --intr-regs
>
> After this patch:
>
> $ perf record --list-opts
>
> --event --filter --pid --tid --realtime --no-buffering --raw-samples
> --all-cpus --cpu --count --output --no-inherit --freq --mmap-pages
> --group --call-graph --verbose --quiet --stat --data --timestamp
> --period --no-samples --no-buildid-cache --no-buildid --cgroup --delay
> --uid --branch-any --branch-filter --weight --transaction --per-thread
> --intr-regs
>
> Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx>
> ---
> tools/perf/util/parse-options.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/parse-options.c b/tools/perf/util/parse-options.c
> index 4ee9a86..2bfe0b3 100644
> --- a/tools/perf/util/parse-options.c
> +++ b/tools/perf/util/parse-options.c
> @@ -505,7 +505,8 @@ int parse_options_subcommand(int argc, const char **argv, const struct option *o
> break;
> case PARSE_OPT_LIST_OPTS:
> while (options->type != OPTION_END) {
> - printf("--%s ", options->long_name);
> + if (options->long_name)
> + printf("--%s ", options->long_name);

There seems to be another 'perf record --list-opts' bug as
well:

comet:~/tip> perf record --list-opts
--event --filter --pid --tid --realtime --no-buffering
--raw-samples --all-cpus --cpu --count --output
--no-inherit --freq --mmap-pages --group --(null)
--call-graph --verbose --quiet --stat --data --timestamp
--period --no-samples --no-buildid-cache --no-buildid
--cgroup --delay --uid --branch-any --branch-filter
--weight --transaction --per-thread --intr-regs comet:~/tip>

Note the lack of newline at the end of the printout.

Thanks,

Ingo
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