Re: [PATCH 1/3] perf tools: Move callchain help messages to callchain.h

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Fri, Oct 23, 2015 at 11:59:32AM +0200, Ingo Molnar escreveu:
> Btw., another usability detail I noticed yesterday is that when I typed 'perf 
> report -h' I got so much output that I couldn't find the specific option I was 
> looking for, because there's no apparent ordering of the output:
> 
> triton:~/tip> perf report -h 2>&1 | grep -e ' -[a-Z],'
>     -i, --input <file>    input file name
>     -v, --verbose         be more verbose (show symbol address, etc)
>     -D, --dump-raw-trace  dump raw trace in ASCII
SNIP:
>     -C, --cpu <cpu>       list of cpus to profile
>     -I, --show-info       Display extended information about perf.data file
>     -M, --disassembler-style <disassembler style>
>     -b, --branch-stack    use branch records for per branch histogram filling
> 
> Such (alphabetic) ordering would be easier to navigate:
> 
>     -b, --branch-stack    use branch records for per branch histogram filling
>     -c, --comms <comm[,comm...]>
>     -C, --cpu <cpu>       list of cpus to profile

Try the patch below:


>From 182ec8d7c105e331884def4f98f56b4f876a4f1d Mon Sep 17 00:00:00 2001
From: Arnaldo Carvalho de Melo <acme@redhat.com>
Date: Fri, 23 Oct 2015 11:23:28 -0300
Subject: [PATCH 1/1] perf tools: Show tool command line options ordered

When asking for a listing of the options, be it using -h or when an
unknown option is passed, order it by one-letter options, then the ones
having just long names.

Suggested-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-41qh68t35n4ehrpsuazp1dx8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/parse-options.c | 42 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/tools/perf/util/parse-options.c b/tools/perf/util/parse-options.c
index 8aa7922397a9..47fb1405df7e 100644
--- a/tools/perf/util/parse-options.c
+++ b/tools/perf/util/parse-options.c
@@ -2,6 +2,7 @@
 #include "parse-options.h"
 #include "cache.h"
 #include "header.h"
+#include <linux/string.h>
 
 #define OPT_SHORT 1
 #define OPT_UNSET 2
@@ -642,9 +643,44 @@ static void print_option_help(const struct option *opts, int full)
 	fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
 }
 
+static int option__cmp(const void *va, const void *vb)
+{
+	const struct option *a = va, *b = vb;
+	int sa = tolower(a->short_name), sb = tolower(b->short_name), ret;
+
+	if (sa == 0)
+		sa = 'z' + 1;
+	if (sb == 0)
+		sb = 'z' + 1;
+
+	ret = sa - sb;
+
+	return ret ?: strcmp(a->long_name, b->long_name);
+}
+
+static struct option *options__order(const struct option *opts)
+{
+	int nr_opts = 0;
+	const struct option *o = opts;
+	struct option *ordered;
+
+	for (o = opts; o->type != OPTION_END; o++)
+		++nr_opts;
+
+	ordered = memdup(opts, sizeof(*o) * (nr_opts + 1));
+	if (ordered == NULL)
+		goto out;
+
+	qsort(ordered, nr_opts, sizeof(*o), option__cmp);
+out:
+	return ordered;
+}
+
 int usage_with_options_internal(const char * const *usagestr,
 				const struct option *opts, int full)
 {
+	struct option *ordered;
+
 	if (!usagestr)
 		return PARSE_OPT_HELP;
 
@@ -661,11 +697,17 @@ int usage_with_options_internal(const char * const *usagestr,
 	if (opts->type != OPTION_GROUP)
 		fputc('\n', stderr);
 
+	ordered = options__order(opts);
+	if (ordered)
+		opts = ordered;
+
 	for (  ; opts->type != OPTION_END; opts++)
 		print_option_help(opts, full);
 
 	fputc('\n', stderr);
 
+	free(ordered);
+
 	return PARSE_OPT_HELP;
 }
 
-- 
2.1.0