Bug 1311346 - add cubeb_log.h to the tree

MozReview-Commit-ID: BHvbZzns6WK

media/libcubeb/src/cubeb_log.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright © 2016 Mozilla Foundation
+ *
+ * This program is made available under an ISC-style license.  See the
+ * accompanying file LICENSE for details.
+ */
+
+#ifndef CUBEB_LOG
+#define CUBEB_LOG
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern cubeb_log_level g_log_level;
+extern cubeb_log_callback g_log_callback;
+
+#ifdef __cplusplus
+}
+#endif
+
+#define LOGV(msg, ...) LOG_INTERNAL(CUBEB_LOG_VERBOSE, msg, ##__VA_ARGS__)
+#define LOG(msg, ...) LOG_INTERNAL(CUBEB_LOG_NORMAL, msg, ##__VA_ARGS__)
+
+#define LOG_INTERNAL(level, fmt, ...) do {                                   \
+    if (g_log_callback && level <= g_log_level) {                            \
+      g_log_callback("%s:%d: " fmt "\n", __FILE__, __LINE__, ##__VA_ARGS__); \
+    }                                                                        \
+  } while(0)
+
+#endif // CUBEB_LOG