components/log: add API header for logging library

TW6703

components/log/include/esp_log.h

@@ -0,0 +1,120 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef __ESP_LOG_H__
+#define __ESP_LOG_H__
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Logging library
+ *
+ * In each C file which uses logging functionality, define TAG variable like this:
+ *
+ *      static const char* TAG = "MyModule";
+ *
+ * then use one of logging macros to produce output, e.g:
+ *
+ *      ESP_LOGW(TAG, "Baud rate error %.1f%%. Requested: %d baud, actual: %d baud", error * 100, baud_req, baud_real);
+ *
+ * Log filtering happens both at compile time and at runtime.
+ *
+ * At compile time, filtering is done using CONFIG_ESP_LOG_LEVEL macro, set via menuconfig.
+ * All logging statments for levels higher than CONFIG_ESP_LOG_LEVEL will be removed by the preprocessor.
+ *
+ * At run time, all logs below CONFIG_ESP_LOG_LEVEL are enabled by default.
+ * esp_log_set function may be used to set logging level per tag.
+ *
+ *      esp_log_set("*", ESP_LOG_ERROR);        // set all components to ERROR level
+ *      esp_log_set("wifi", ESP_LOG_WARN);      // enable WARN logs from WiFi stack
+ *      esp_log_set("dhcpc", ESP_LOG_INFO);     // enable INFO logs from DHCP client
+ *
+ *
+ */
+
+
+typedef enum {
+    ESP_LOG_NONE,
+    ESP_LOG_ERROR,
+    ESP_LOG_WARN,
+    ESP_LOG_INFO,
+    ESP_LOG_DEBUG,
+    ESP_LOG_VERBOSE
+} esp_log_level_t;
+
+
+/**
+ * @brief Set log level for given tag
+ *
+ * If logging for given component has already been enabled, changes previous setting.
+ *
+ * @param tag Tag of the log entries to enable. Must be a non-NULL zero terminated string.
+ *            Value "*" means that all tags are affected.
+ *
+ * @param level  Selects log level to enable. Only logs at this and lower levels will be shown.
+ */
+void esp_log_set(const char* tag, esp_log_level_t level);
+
+/**
+ * @brief Write message into the log
+ *
+ * This function is not intended to be used directly. Instead, use one of
+ * ESP_LOGE, ESP_LOGW, ESP_LOGI, ESP_LOGD, ESP_LOGV macros.
+ */
+void esp_log_write(esp_log_level_t level, const char* tag, const char* format, ...) __attribute__ ((format (printf, 3, 4)));
+#ifndef CONFIG_ESP_LOG_LEVEL
+#define CONFIG_ESP_LOG_LEVEL ESP_LOG_NONE
+#endif
+
+#if (CONFIG_ESP_LOG_LEVEL < ESP_LOG_ERROR)
+#define ESP_LOGE( tag, format, ... )  esp_log_write(ESP_LOG_ERROR, tag, format, ##__VA_ARGS__)
+#else
+#define ESP_LOGE( tag, format, ... )
+#endif
+
+#if (CONFIG_ESP_LOG_LEVEL < ESP_LOG_WARN)
+#define ESP_LOGW( tag, format, ... )  esp_log_write(ESP_LOG_WARN, tag, format, ##__VA_ARGS__)
+#else
+#define ESP_LOGW( tag, format, ... )
+#endif
+
+#if (CONFIG_ESP_LOG_LEVEL < ESP_LOG_INFO)
+#define ESP_LOGI( tag, format, ... )  esp_log_write(ESP_LOG_INFO, tag, format, ##__VA_ARGS__)
+#else
+#define ESP_LOGI( tag, format, ... )
+#endif
+
+
+#if (CONFIG_ESP_LOG_LEVEL < ESP_LOG_DEBUG)
+#define ESP_LOGD( tag, format, ... )  esp_log_write(ESP_LOG_DEBUG, tag, format, ##__VA_ARGS__)
+#else
+#define ESP_LOGD( tag, format, ... )
+#endif
+
+#if (CONFIG_ESP_LOG_VERBOSE < ESP_LOG_ERROR)
+#define ESP_LOGV( tag, format, ... )  esp_log_write(ESP_LOG_VERBOSE, tag, format, ##__VA_ARGS__)
+#else
+#define ESP_LOGV( tag, format, ... )
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* __ESP_LOG_H__ */