[PATCH v2 4/4] libtraceevent: Increase libtraceevent logging when verbose

[Ian Rogers]

libtraceevent has added more levels of debug printout and with changes
like:
https://lore.kernel.org/linux-trace-devel/20210507095022.1079364-3-tz.stoyanov@xxxxxxxxx
previously generated output like "registering plugin" is no longer
displayed. This change makes it so that if perf's verbose debug output
is enabled then the debug and info libtraceevent messages can be
displayed.
The code is conditionally enabled based on the libtraceevent version as
discussed in the RFC:
https://lore.kernel.org/lkml/20210610060643.595673-1-irogers@xxxxxxxxxx/

v2. Is a rebase and handles the case of building without
    LIBTRACEEVENT_DYNAMIC.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/util/debug.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index 2c06abf6dcd2..c7a9fa0ffae9 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -24,6 +24,16 @@
 #include "util/parse-sublevel-options.h"
 
 #include <linux/ctype.h>
+#include <traceevent/event-parse.h>
+
+#define MAKE_LIBTRACEEVENT_VERSION(a, b, c) ((a)*255*255+(b)*255+(c))
+#ifndef LIBTRACEEVENT_VERSION
+/*
+ * If LIBTRACEEVENT_VERSION wasn't computed then set to version 1.1.0 that ships
+ * with the Linux kernel tools.
+ */
+#define LIBTRACEEVENT_VERSION MAKE_LIBTRACEEVENT_VERSION(1, 1, 0)
+#endif
 
 int verbose;
 int debug_peo_args;
@@ -228,6 +238,15 @@ int perf_debug_option(const char *str)
 	/* Allow only verbose value in range (0, 10), otherwise set 0. */
 	verbose = (verbose < 0) || (verbose > 10) ? 0 : verbose;
 
+#if MAKE_LIBTRACEEVENT_VERSION(1, 3, 0) <= LIBTRACEEVENT_VERSION
+	if (verbose == 1)
+		tep_set_loglevel(TEP_LOG_INFO);
+	else if (verbose == 2)
+		tep_set_loglevel(TEP_LOG_DEBUG);
+	else if (verbose >= 3)
+		tep_set_loglevel(TEP_LOG_ALL);
+#endif
+
 	return 0;
 }
 
-- 
2.33.0.464.g1972c5931b-goog