perf tools: Show proper error message for wrong terms of hw/sw events

Show proper error message and show valid terms when wrong config terms
is specified for hw/sw type perf events.

This patch makes the original error format function formats_error_string()
more generic, which only outputs the static config terms for hw/sw perf
events, and prepends pmu formats for pmu events.

Before this patch:

  $ perf record -e 'cpu-clock/freqx=200/' -a sleep 1
  invalid or unsupported event: 'cpu-clock/freqx=200/'
  Run 'perf list' for a list of valid events

   usage: perf record [<options>] [<command>]
      or: perf record [<options>] -- <command> [<options>]

      -e, --event <event>   event selector. use 'perf list' to list available events

After this patch:

  $ perf record -e 'cpu-clock/freqx=200/' -a sleep 1
  event syntax error: 'cpu-clock/freqx=200/'
                                 \___ unknown term

  valid terms: config,config1,config2,name,period,freq,branch_type,time,call-graph,stack-size

  Run 'perf list' for a list of valid events

   usage: perf record [<options>] [<command>]
      or: perf record [<options>] -- <command> [<options>]

      -e, --event <event>   event selector. use 'perf list' to list available events

Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1443412336-120050-2-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

4 files changed, 45 insertions, 24 deletions

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 9dc3fb6ee81e..ea64ec0720ca 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -656,6 +656,9 @@ do {									   \
                 CHECK_TYPE_VAL(STR);
                 break;
         default:
+                err->str = strdup("unknown term");
+                err->idx = term->err_term;
+                err->help = parse_events_formats_error_string(NULL);
                 return -EINVAL;
         }
 
@@ -1875,3 +1878,29 @@ void parse_events_evlist_error(struct parse_events_evlist *data,
         err->str = strdup(str);
         WARN_ONCE(!err->str, "WARNING: failed to allocate error string");
 }
+
+/*
+ * Return string contains valid config terms of an event.
+ * @additional_terms: For terms such as PMU sysfs terms.
+ */
+char *parse_events_formats_error_string(char *additional_terms)
+{
+        char *str;
+        static const char *static_terms = "config,config1,config2,name,"
+                                          "period,freq,branch_type,time,"
+                                          "call-graph,stack-size\n";
+
+        /* valid terms */
+        if (additional_terms) {
+                if (!asprintf(&str, "valid terms: %s,%s",
+                              additional_terms, static_terms))
+                        goto fail;
+        } else {
+                if (!asprintf(&str, "valid terms: %s", static_terms))
+                        goto fail;
+        }
+        return str;
+
+fail:
+        return NULL;
+}
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index ffee7ece75a6..c7b904a49189 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -156,5 +156,6 @@ int print_hwcache_events(const char *event_glob, bool name_only);
 extern int is_valid_tracepoint(const char *event_string);
 
 int valid_event_mount(const char *eventfs);
+char *parse_events_formats_error_string(char *additional_terms);
 
 #endif /* __PERF_PARSE_EVENTS_H */
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 936d566f48d8..c29832bce496 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -174,7 +174,7 @@ modifier_bp	[rwx]{1,3}
 
 <config>{
         /*
-         * Please update formats_error_string any time
+         * Please update parse_events_formats_error_string any time
          * new static term is added.
          */
 config                  { return term(yyscanner, PARSE_EVENTS__TERM_TYPE_CONFIG); }
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 89c91a1a67e7..ac42c97be9e4 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -626,38 +626,26 @@ static int pmu_resolve_param_term(struct parse_events_term *term,
         return -1;
 }
 
-static char *formats_error_string(struct list_head *formats)
+static char *pmu_formats_string(struct list_head *formats)
 {
         struct perf_pmu_format *format;
-        char *err, *str;
-        static const char *static_terms = "config,config1,config2,name,"
-                                          "period,freq,branch_type,time,"
-                                          "call-graph,stack-size\n";
+        char *str;
+        struct strbuf buf;
         unsigned i = 0;
 
-        if (!asprintf(&str, "valid terms:"))
+        if (!formats)
                 return NULL;
 
+        strbuf_init(&buf, 0);
         /* sysfs exported terms */
-        list_for_each_entry(format, formats, list) {
-                char c = i++ ? ',' : ' ';
-
-                err = str;
-                if (!asprintf(&str, "%s%c%s", err, c, format->name))
-                        goto fail;
-                free(err);
-        }
+        list_for_each_entry(format, formats, list)
+                strbuf_addf(&buf, i++ ? ",%s" : "%s",
+                            format->name);
 
-        /* static terms */
-        err = str;
-        if (!asprintf(&str, "%s,%s", err, static_terms))
-                goto fail;
+        str = strbuf_detach(&buf, NULL);
+        strbuf_release(&buf);
 
-        free(err);
         return str;
-fail:
-        free(err);
-        return NULL;
 }
 
 /*
@@ -693,9 +681,12 @@ static int pmu_config_term(struct list_head *formats,
                 if (verbose)
                         printf("Invalid event/parameter '%s'\n", term->config);
                 if (err) {
+                        char *pmu_term = pmu_formats_string(formats);
+
                         err->idx  = term->err_term;
                         err->str  = strdup("unknown term");
-                        err->help = formats_error_string(formats);
+                        err->help = parse_events_formats_error_string(pmu_term);
+                        free(pmu_term);
                 }
                 return -EINVAL;
         }