log: do not drop debug logs at compile time

[dpdk.git] / lib / librte_eal / common / include / rte_log.h

diff --git a/lib/librte_eal/common/include/rte_log.h b/lib/librte_eal/common/include/rte_log.h
index 29f7d19..671e274 100644 (file)
--- a/lib/librte_eal/common/include/rte_log.h
+++ b/lib/librte_eal/common/include/rte_log.h
@@ -118,9 +118,8 @@ int rte_openlog_stream(FILE *f);
 /**
  * Set the global log level.
  *
- * After this call, all logs that are lower or equal than level and
- * lower or equal than the RTE_LOG_LEVEL configuration option will be
- * displayed.
+ * After this call, logs with a level lower or equal than the level
+ * passed as argument will be displayed.
  *
  * @param level
  *   Log level. A value between RTE_LOG_EMERG (1) and RTE_LOG_DEBUG (8).
@@ -184,9 +183,8 @@ int rte_log_cur_msg_logtype(void);
  * The level argument determines if the log should be displayed or
  * not, depending on the global rte_logs variable.
  *
- * The preferred alternative is the RTE_LOG() function because debug logs may
- * be removed at compilation time if optimization is enabled. Moreover,
- * logs are automatically prefixed by type when using the macro.
+ * The preferred alternative is the RTE_LOG() because it adds the
+ * level and type in the logged string.
  *
  * @param level
  *   Log level. A value between RTE_LOG_EMERG (1) and RTE_LOG_DEBUG (8).
@@ -217,8 +215,8 @@ int rte_log(uint32_t level, uint32_t logtype, const char *format, ...)
  * not, depending on the global rte_logs variable. A trailing
  * newline may be added if needed.
  *
- * The preferred alternative is the RTE_LOG() because debug logs may be
- * removed at compilation time.
+ * The preferred alternative is the RTE_LOG() because it adds the
+ * level and type in the logged string.
  *
  * @param level
  *   Log level. A value between RTE_LOG_EMERG (1) and RTE_LOG_DEBUG (8).
@@ -239,15 +237,8 @@ int rte_vlog(uint32_t level, uint32_t logtype, const char *format, va_list ap)
 /**
  * Generates a log message.
  *
- * The RTE_LOG() is equivalent to rte_log() with two differences:
-
- * - RTE_LOG() can be used to remove debug logs at compilation time,
- *   depending on RTE_LOG_LEVEL configuration option, and compilation
- *   optimization level. If optimization is enabled, the tests
- *   involving constants only are pre-computed. If compilation is done
- *   with -O0, these tests will be done at run time.
- * - The log level and log type names are smaller, for example:
- *   RTE_LOG(INFO, EAL, "this is a %s", "log");
+ * The RTE_LOG() is a helper that prefixes the string with the log level
+ * and type, and call rte_log().
  *
  * @param l
  *   Log level. A value between EMERG (1) and DEBUG (8). The short name is
@@ -263,7 +254,31 @@ int rte_vlog(uint32_t level, uint32_t logtype, const char *format, va_list ap)
  *   - Negative on error.
  */
 #define RTE_LOG(l, t, ...)                                     \
-       (void)((RTE_LOG_ ## l <= RTE_LOG_LEVEL) ?               \
+        rte_log(RTE_LOG_ ## l,                                 \
+                RTE_LOGTYPE_ ## t, # t ": " __VA_ARGS__)
+
+/**
+ * Generates a log message for data path.
+ *
+ * Similar to RTE_LOG(), except that it is removed at compilation time
+ * if the RTE_LOG_DP_LEVEL configuration option is lower than the log
+ * level argument.
+ *
+ * @param l
+ *   Log level. A value between EMERG (1) and DEBUG (8). The short name is
+ *   expanded by the macro, so it cannot be an integer value.
+ * @param t
+ *   The log type, for example, EAL. The short name is expanded by the
+ *   macro, so it cannot be an integer value.
+ * @param ...
+ *   The fmt string, as in printf(3), followed by the variable arguments
+ *   required by the format.
+ * @return
+ *   - 0: Success.
+ *   - Negative on error.
+ */
+#define RTE_LOG_DP(l, t, ...)                                  \
+       (void)((RTE_LOG_ ## l <= RTE_LOG_DP_LEVEL) ?            \
         rte_log(RTE_LOG_ ## l,                                 \
                 RTE_LOGTYPE_ ## t, # t ": " __VA_ARGS__) :     \
         0)