perf stat: Enhance option parse error message

Print related option help messages only when it failed to process
options.  While at it, modify parse_options_usage() to skip usage part
so that it can be used for showing multiple option help messages
naturally like below:

  $ perf stat -Bx, ls
  -B option not supported with -x

   usage: perf stat [<options>] [<command>]

      -B, --big-num         print large numbers with thousands' separators
      -x, --field-separator <separator>
                            print counts with custom separator

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Enthusiastically-Supported-by: Ingo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1383291195-24386-6-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 27 insertions, 15 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 1a9c95d270aa..0fc1c941a73c 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -1596,7 +1596,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
                 "perf stat [<options>] [<command>]",
                 NULL
         };
-        int status = -ENOMEM, run_idx;
+        int status = -EINVAL, run_idx;
         const char *mode;
 
         setlocale(LC_ALL, "");
@@ -1614,12 +1614,15 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
 
         if (output_name && output_fd) {
                 fprintf(stderr, "cannot use both --output and --log-fd\n");
-                usage_with_options(stat_usage, options);
+                parse_options_usage(stat_usage, options, "o", 1);
+                parse_options_usage(NULL, options, "log-fd", 0);
+                goto out;
         }
 
         if (output_fd < 0) {
                 fprintf(stderr, "argument to --log-fd must be a > 0\n");
-                usage_with_options(stat_usage, options);
+                parse_options_usage(stat_usage, options, "log-fd", 0);
+                goto out;
         }
 
         if (!output) {
@@ -1656,7 +1659,9 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
                 /* User explicitly passed -B? */
                 if (big_num_opt == 1) {
                         fprintf(stderr, "-B option not supported with -x\n");
-                        usage_with_options(stat_usage, options);
+                        parse_options_usage(stat_usage, options, "B", 1);
+                        parse_options_usage(NULL, options, "x", 1);
+                        goto out;
                 } else /* Nope, so disable big number formatting */
                         big_num = false;
         } else if (big_num_opt == 0) /* User passed --no-big-num */
@@ -1666,7 +1671,9 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
                 usage_with_options(stat_usage, options);
 
         if (run_count < 0) {
-                usage_with_options(stat_usage, options);
+                pr_err("Run count must be a positive number\n");
+                parse_options_usage(stat_usage, options, "r", 1);
+                goto out;
         } else if (run_count == 0) {
                 forever = true;
                 run_count = 1;
@@ -1678,8 +1685,10 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
                 fprintf(stderr, "both cgroup and no-aggregation "
                         "modes only available in system-wide mode\n");
 
-                usage_with_options(stat_usage, options);
-                return -1;
+                parse_options_usage(stat_usage, options, "G", 1);
+                parse_options_usage(NULL, options, "A", 1);
+                parse_options_usage(NULL, options, "a", 1);
+                goto out;
         }
 
         if (add_default_attributes())
@@ -1688,25 +1697,28 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
         perf_target__validate(&target);
 
         if (perf_evlist__create_maps(evsel_list, &target) < 0) {
-                if (perf_target__has_task(&target))
+                if (perf_target__has_task(&target)) {
                         pr_err("Problems finding threads of monitor\n");
-                if (perf_target__has_cpu(&target))
+                        parse_options_usage(stat_usage, options, "p", 1);
+                        parse_options_usage(NULL, options, "t", 1);
+                } else if (perf_target__has_cpu(&target)) {
                         perror("failed to parse CPUs map");
-
-                usage_with_options(stat_usage, options);
-                return -1;
+                        parse_options_usage(stat_usage, options, "C", 1);
+                        parse_options_usage(NULL, options, "a", 1);
+                }
+                goto out;
         }
         if (interval && interval < 100) {
                 pr_err("print interval must be >= 100ms\n");
-                usage_with_options(stat_usage, options);
-                return -1;
+                parse_options_usage(stat_usage, options, "I", 1);
+                goto out_free_maps;
         }
 
         if (perf_evlist__alloc_stats(evsel_list, interval))
                 goto out_free_maps;
 
         if (perf_stat_init_aggr_mode())
-                goto out;
+                goto out_free_maps;
 
         /*
          * We dont want to block the signals - that would cause