esp-mqtt/include/mqtt_config.h

#ifndef _MQTT_CONFIG_H_
#define _MQTT_CONFIG_H_
#include "sdkconfig.h"
#include <stdio.h>

#ifdef CONFIG_MQTT_LOG_ERROR_ON
#define mqtt_error(format, ... ) printf( "[MQTT ERROR] " format "\n", ##__VA_ARGS__)
#else
#define mqtt_error( format, ... )
#endif
#ifdef CONFIG_MQTT_LOG_WARN_ON
#define mqtt_warn(format, ... ) printf( "[MQTT WARN] " format "\n", ##__VA_ARGS__)
#else
#define mqtt_warn( format, ... )
#endif
#ifdef CONFIG_MQTT_LOG_INFO_ON
#define mqtt_info(format, ... ) printf( "[MQTT INFO] " format "\n", ##__VA_ARGS__)
#else
#define mqtt_info(format, ... )
#endif

#ifndef CONFIG_MQTT_QUEUE_BUFFER_SIZE_WORD
#define CONFIG_MQTT_QUEUE_BUFFER_SIZE_WORD 1024
#endif

#endif