feat(lnm): add logging framework

lnm/include/lnm/log.h

@@ -0,0 +1,47 @@
+#ifndef LNM_LOG
+#define LOG
+
+#include <stdarg.h>
+
+#include "lnm/common.h"
+
+typedef struct lnm_logger lnm_logger;
+
+typedef enum lnm_log_level {
+  lnm_log_level_debug = 0,
+  lnm_log_level_info,
+  lnm_log_level_notice,
+  lnm_log_level_warning,
+  lnm_log_level_error,
+  lnm_log_level_critical
+} lnm_log_level;
+
+extern const char *lnm_log_level_names[];
+
+/**
+ * Initialize the global logger.
+ */
+lnm_err lnm_log_init_global();
+
+/**
+ * Register stdout as one of the streams for the global logger.
+ */
+lnm_err lnm_log_register_stdout(lnm_log_level level);
+
+void lnm_log(lnm_log_level level, const char *section, const char *fmt, ...)
+    __attribute__((format(printf, 3, 4)));
+
+#define lnm_ldebug(section, fmt, ...)                                          \
+  lnm_log(lnm_log_level_debug, section, fmt, __VA_ARGS__)
+#define lnm_linfo(section, fmt, ...)                                           \
+  lnm_log(lnm_log_level_info, section, fmt, __VA_ARGS__)
+#define lnm_lnotice(section, fmt, ...)                                         \
+  lnm_log(lnm_log_level_notice, section, fmt, __VA_ARGS__)
+#define lnm_lwarning(section, fmt, ...)                                        \
+  lnm_log(lnm_log_level_warning, section, fmt, __VA_ARGS__)
+#define lnm_lerror(section, fmt, ...)                                          \
+  lnm_log(lnm_log_level_error, section, fmt, __VA_ARGS__)
+#define lnm_lcritical(section, fmt, ...)                                       \
+  lnm_log(lnm_log_level_critical, section, fmt, __VA_ARGS__)
+
+#endif