Messages in this thread | | | From | Ian Rogers <> | Date | Wed, 21 Jun 2023 00:05:34 -0700 | Subject | Re: [PATCH] tools lib subcmd: Show parent options in help |
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On Thu, May 25, 2023 at 3:09 PM Namhyung Kim <namhyung@kernel.org> wrote: > > I've just realized that help message in a subcommand didn't show one > in the parent command. Since the option parser understands the parent, > display code should do the same. For example, `perf ftrace latency -h` > should show options in the `perf ftrace` command too. > > Before: > > $ perf ftrace latency -h > > Usage: perf ftrace [<options>] [<command>] > or: perf ftrace [<options>] -- [<command>] [<options>] > or: perf ftrace {trace|latency} [<options>] [<command>] > or: perf ftrace {trace|latency} [<options>] -- [<command>] [<options>] > > -b, --use-bpf Use BPF to measure function latency > -n, --use-nsec Use nano-second histogram > -T, --trace-funcs <func> > Show latency of given function > > After: > > $ perf ftrace latency -h > > Usage: perf ftrace [<options>] [<command>] > or: perf ftrace [<options>] -- [<command>] [<options>] > or: perf ftrace {trace|latency} [<options>] [<command>] > or: perf ftrace {trace|latency} [<options>] -- [<command>] [<options>] > > -a, --all-cpus System-wide collection from all CPUs > -b, --use-bpf Use BPF to measure function latency > -C, --cpu <cpu> List of cpus to monitor > -n, --use-nsec Use nano-second histogram > -p, --pid <pid> Trace on existing process id > -T, --trace-funcs <func> > Show latency of given function > -v, --verbose Be more verbose > --tid <tid> Trace on existing thread id (exclusive to --pid) > > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > --- > tools/lib/subcmd/parse-options.c | 26 ++++++++++++++++++-------- > 1 file changed, 18 insertions(+), 8 deletions(-) > > diff --git a/tools/lib/subcmd/parse-options.c b/tools/lib/subcmd/parse-options.c > index 9fa75943f2ed..41de97671c72 100644 > --- a/tools/lib/subcmd/parse-options.c > +++ b/tools/lib/subcmd/parse-options.c > @@ -806,18 +806,28 @@ static int option__cmp(const void *va, const void *vb) > > static struct option *options__order(const struct option *opts) > { > - int nr_opts = 0, nr_group = 0, len; > - const struct option *o = opts; > - struct option *opt, *ordered, *group; > + int nr_opts = 0, nr_group = 0, nr_parent = 0, len; > + const struct option *o, *p = opts; > + struct option *opt, *ordered = NULL, *group; > > - for (o = opts; o->type != OPTION_END; o++) > +retry:
Why use "goto retry" and not compute the size with the parent upfront?
> + for (o = p; o->type != OPTION_END; o++) > ++nr_opts; > > - len = sizeof(*o) * (nr_opts + 1); > - ordered = malloc(len); > - if (!ordered) > + len = sizeof(*o) * (nr_opts + !o->parent);
It'd be nice to comment on why the "!o->parent" here.
Thanks, Ian
> + group = realloc(ordered, len); > + if (!group) > goto out; > - memcpy(ordered, opts, len); > + ordered = group; > + memcpy(&ordered[nr_parent], p, sizeof(*o) * (nr_opts - nr_parent)); > + > + if (o->parent) { > + p = o->parent; > + nr_parent = nr_opts; > + goto retry; > + } > + /* copy the last OPTION_END */ > + memcpy(&ordered[nr_opts], o, sizeof(*o)); > > /* sort each option group individually */ > for (opt = group = ordered; opt->type != OPTION_END; opt++) { > -- > 2.41.0.rc0.172.g3f132b7071-goog >
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