pr_log: a new module that provides a simple run-time controlled logging interface

[ccan] / ccan / pr_log / pr_log.h

diff --git a/ccan/pr_log/pr_log.h b/ccan/pr_log/pr_log.h
new file mode 100644 (file)
index 0000000..8e125b8
--- /dev/null
+++ b/ccan/pr_log/pr_log.h
@@ -0,0 +1,72 @@
+/* Licensed under LGPLv2.1+ - see LICENSE file for details */
+#ifndef CCAN_PR_LOG_H_
+#define CCAN_PR_LOG_H_
+
+#include <stdbool.h>
+#include <ccan/compiler/compiler.h>
+
+/*
+ * pr_emerg, pr_alert, pr_crit, pr_error, pr_warn, pr_notice, pr_info, pr_debug
+ *
+ * Each of these prints a format string only in the case where we're running at
+ * the selected debug level.
+ *
+ * Note that using these functions also causes a pre-pended log level to be
+ * included in the printed string.
+ *
+ * Log levels correspond to those used in syslog(3) .
+ */
+#define pr_emerg(...)  pr_log_(LOG_EMERG  __VA_ARGS__)
+#define pr_alert(...)  pr_log_(LOG_ALERT  __VA_ARGS__)
+#define pr_crit(...)   pr_log_(LOG_CRIT   __VA_ARGS__)
+#define pr_error(...)  pr_log_(LOG_ERROR  __VA_ARGS__)
+#define pr_warn(...)   pr_log_(LOG_WARN   __VA_ARGS__)
+#define pr_notice(...) pr_log_(LOG_NOTICE __VA_ARGS__)
+#define pr_info(...)   pr_log_(LOG_INFO   __VA_ARGS__)
+#define pr_debug(...)  pr_log_(LOG_DEBUG  __VA_ARGS__)
+
+#ifdef DEBUG
+# define pr_devel(...)  pr_debug(__VA_ARGS__)
+#else
+static PRINTF_FMT(1,2) inline void pr_check_printf_args(const char *fmt, ...)
+{
+       (void)fmt;
+}
+# define pr_devel(...) pr_check_printf_args(__VA_ARGS__)
+#endif
+
+#ifndef CCAN_PR_LOG_DEFAULT_LEVEL
+# define CCAN_PR_LOG_DEFAULT_LEVEL 6
+#endif
+
+#define LOG_EMERG  "<0>"
+#define LOG_ALERT  "<1>"
+#define LOG_CRIT   "<2>"
+#define LOG_ERROR  "<3>"
+#define LOG_WARN   "<4>"
+#define LOG_NOTICE "<5>"
+#define LOG_INFO   "<6>"
+#define LOG_DEBUG  "<7>"
+
+#ifndef CCAN_PR_LOG_DISABLE
+/**
+ * pr_log_ - print output based on the given logging level
+ *
+ * Example:
+ *
+ *     pr_log_(LOG_EMERG "something went terribly wrong\n");
+ *     pr_log_(LOG_DEBUG "everything is fine\n");
+ */
+void PRINTF_FMT(1,2) pr_log_(char const *fmt, ...);
+bool debug_is(int lvl);
+int debug_level(void);
+#else
+static PRINTF_FMT(1,2) inline void pr_log_(char const *fmt, ...)
+{
+       (void)fmt;
+}
+static inline bool debug_is(int lvl) { (void)lvl; return false; }
+static inline int debug_level(void) { return -1; }
+#endif
+
+#endif