perf test: Suppress libtraceevent warnings

Currently libtraceevent emits warning on unsupported event formats.
However it'd be better to see them only -v option is given.  To do that,
it needs to override the warning() function which is used in the
libtracevent.  Thus add set_warning_routine() same as set_die_routine()
and check the verbose flag in our warning routine.

Before:
  # perf test 5
   5: parse events tests                                       :
    Warning: [kvmmmu:kvm_mmu_get_page] bad op token {
    Warning: [kvmmmu:kvm_mmu_sync_page] bad op token {
    Warning: [kvmmmu:kvm_mmu_unsync_page] bad op token {
    Warning: [kvmmmu:kvm_mmu_prepare_zap_page] bad op token {
    Warning: [kvmmmu:fast_page_fault] function is_writable_pte not defined
    ...
   Ok

After:
  # perf test 5
   5: parse events tests                                       : Ok

Signed-off-by: Namhyung Kim <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

tools/perf/tests/parse-events.c

@@ -5,6 +5,7 @@
 #include <api/fs/fs.h>
 #include "tests.h"
 #include "debug.h"
+#include "util.h"
 #include <linux/hw_breakpoint.h>
 #include <api/fs/fs.h>
 
@@ -1753,6 +1754,17 @@ static int test_pmu_events(void)
 	return ret;
 }
 
+static void debug_warn(const char *warn, va_list params)
+{
+	char msg[1024];
+
+	if (!verbose)
+		return;
+
+	vsnprintf(msg, sizeof(msg), warn, params);
+	fprintf(stderr, " Warning: %s\n", msg);
+}
+
 int test__parse_events(void)
 {
 	int ret1, ret2 = 0;
@@ -1764,6 +1776,8 @@ do {							\
 		ret2 = ret1;				\
 } while (0)
 
+	set_warning_routine(debug_warn);
+
 	TEST_EVENTS(test__events);
 
 	if (test_pmu())

tools/perf/util/usage.c

@@ -50,6 +50,11 @@ void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN)
 	die_routine = routine;
 }
 
+void set_warning_routine(void (*routine)(const char *err, va_list params))
+{
+	warn_routine = routine;
+}
+
 void usage(const char *err)
 {
 	usage_routine(err);

tools/perf/util/util.h

@@ -145,6 +145,7 @@ extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)))
 
 
 extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
+extern void set_warning_routine(void (*routine)(const char *err, va_list params));
 
 extern int prefixcmp(const char *str, const char *prefix);
 extern void set_buildid_dir(const char *dir);