x15/kern/log.h

/*
 * Copyright (c) 2017-2019 Richard Braun.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 * System logging.
 */

#ifndef KERN_LOG_H
#define KERN_LOG_H

#include <stdarg.h>

#include <kern/init.h>
#include <kern/stream.h>

enum
{
  LOG_EMERG,
  LOG_ALERT,
  LOG_CRIT,
  LOG_ERR,
  LOG_WARNING,
  LOG_NOTICE,
  LOG_INFO,
  LOG_DEBUG,
  LOG_NR_LEVELS,
};

/*
 * Generate a message and send it to the log thread.
 *
 * The arguments and return value are similar to printf(), with
 * these exceptions :
 *  - a level is associated to each log message
 *  - processing stops at the first terminating null byte or newline
 *    character, whichever occurs first
 *
 * This function may safely be called in interrupt context.
 */
int log_msg (unsigned int level, const char *format, ...)
  __attribute__ ((format (printf, 2, 3)));

int log_vmsg (unsigned int level, const char *format, va_list ap)
  __attribute__ ((format (printf, 2, 0)));

// Convenience wrappers.

#define log_emerg(format, ...)   \
  log_msg (LOG_EMERG, (format), ##__VA_ARGS__)

#define log_alert(format, ...)   \
  log_msg (LOG_ALERT, (format), ##__VA_ARGS__)

#define log_crit(format, ...)   \
  log_msg (LOG_CRIT, (format), ##__VA_ARGS__)

#define log_err(format, ...)   \
  log_msg (LOG_ERR, (format), ##__VA_ARGS__)

#define log_warning(format, ...)   \
  log_msg (LOG_WARNING, (format), ##__VA_ARGS__)

#define log_notice(format, ...)   \
  log_msg (LOG_NOTICE, (format), ##__VA_ARGS__)

#define log_info(format, ...)   \
  log_msg (LOG_INFO, (format), ##__VA_ARGS__)

#define log_debug(format, ...)   \
  log_msg (LOG_DEBUG, (format), ##__VA_ARGS__)

/*
 * The bulletin returned by this function is used to notify the initial log
 * dump so that console output is well ordered.
 */
struct bulletin* log_get_bulletin (void);

// Get the logger stream for a particular level.
struct stream* log_stream (unsigned int level);

// Accesors for the above.

#define log_stream_emerg()     log_stream (LOG_EMERG)
#define log_stream_alert()     log_stream (LOG_ALERT)
#define log_stream_crit()      log_stream (LOG_CRIT)
#define log_stream_err()       log_stream (LOG_ERR)
#define log_stream_warning()   log_stream (LOG_WARNING)
#define log_stream_notice()    log_stream (LOG_NOTICE)
#define log_stream_info()      log_stream (LOG_INFO)
#define log_stream_debug()     log_stream (LOG_DEBUG)

/*
 * This init operation provides :
 *  - message logging
 *
 * The log thread isn't yet started and messages are merely stored in an
 * internal buffer.
 */
INIT_OP_DECLARE (log_setup);

#endif