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>
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 9dc3fb6..ea64ec07 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -656,6 +656,9 @@
 		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 @@
 	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;
+}