perf tools: Add the bash completion for listing subsubcommands of perf data

The bash completion does not support listing subsubcommands for 'perf
data <TAB>', so fix it.

Example:

Before this patch:

 $ perf data <TAB>
 $

As shown above, the subsubcommands of perf data does not come out.

After this patch:

 $ perf data <TAB>
 convert

As shown above, the subsubcommands of perf data can come out now.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1426685758-25488-8-git-send-email-yunlong.song@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-data.c

@@ -22,7 +22,9 @@ static const struct option data_options[] = {
 	OPT_END()
 };
 
-static const char * const data_usage[] = {
+static const char * const data_subcommands[] = { "convert", NULL };
+
+static const char *data_usage[] = {
 	"perf data [<common options>] <command> [<options>]",
 	NULL
 };
@@ -98,7 +100,7 @@ int cmd_data(int argc, const char **argv, const char *prefix)
 	if (argc < 2)
 		goto usage;
 
-	argc = parse_options(argc, argv, data_options, data_usage,
+	argc = parse_options_subcommand(argc, argv, data_options, data_subcommands, data_usage,
 			     PARSE_OPT_STOP_AT_NON_OPTION);
 	if (argc < 1)
 		goto usage;

tools/perf/perf-completion.sh

@@ -143,7 +143,7 @@ __perf_main ()
 		__perfcomp_colon "$evts" "$cur"
 	else
 		# List subcommands for perf commands
-		if [[ $prev_skip_opts == @(kvm|kmem|mem|lock|sched) ]]; then
+		if [[ $prev_skip_opts == @(kvm|kmem|mem|lock|sched|data) ]]; then
 			subcmds=$($cmd $prev_skip_opts --list-cmds)
 			__perfcomp_colon "$subcmds" "$cur"
 		fi