perf tools: Search for more options when passing args to -h

Recently 'perf <tool> -h' was made aware of arguments and would show
just the help for the arguments specified, but that required a strict
form, i.e.:

  $ perf -h --tui

worked, but:

  $ perf -h tui

didn't.

Make it support both cases and also look at the option help when neither
matches, so that he following examples works:

  $ perf report -h interface

   Usage: perf report [<options>]

    --gtk    Use the GTK2 interface
    --stdio  Use the stdio interface
    --tui    Use the TUI interface

  $ perf report -h stack

   Usage: perf report [<options>]

    -g, --call-graph <print_type,threshold[,print_limit],order,
                      sort_key[,branch]>
      Display call graph (stack chain/backtrace):

        print_type:  call graph printing style (graph|flat|fractal|none)
        threshold:   minimum call graph inclusion threshold (<percent>)
        print_limit: maximum number of call graph entry (<number>)
        order:       call graph order (caller|callee)
        sort_key:    call graph sort key (function|address)
        branch:      include last branch info to call graph (branch)

      Default: graph,0.5,caller,function
        --max-stack <n>   Set the maximum stack depth when parsing the
                          callchain, anything beyond the specified depth
                          will be ignored. Default: 127
  $

Suggested-by: Ingo Molnar <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brendan Gregg <[email protected]>
Cc: Chandler Carruth <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 14 insertions, 1 deletions

diff --git a/tools/perf/util/parse-options.c b/tools/perf/util/parse-options.c
index 230e771407a3..9fca09296eb3 100644
--- a/tools/perf/util/parse-options.c
+++ b/tools/perf/util/parse-options.c
@@ -695,8 +695,21 @@ static bool option__in_argv(const struct option *opt, const struct parse_opt_ctx
 	for (i = 1; i < ctx->argc; ++i) {
 		const char *arg = ctx->argv[i];
 
-		if (arg[0] != '-')
+		if (arg[0] != '-') {
+			if (arg[1] == '\0') {
+				if (arg[0] == opt->short_name)
+					return true;
+				continue;
+			}
+
+			if (opt->long_name && strcmp(opt->long_name, arg) == 0)
+				return true;
+
+			if (opt->help && strcasestr(opt->help, arg) != NULL)
+				return true;
+
 			continue;
+		}
 
 		if (arg[1] == opt->short_name ||
 		    (arg[1] == '-' && opt->long_name && strcmp(opt->long_name, arg + 2) == 0))