/**
Copyright (c) 2014 Alex Tsui

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOL
/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011,2012,2013 Giovanni Di Sirio.

    This file is part of ChibiOS/RT.

    ChibiOS/RT 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.

    ChibiOS/RT 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/>.
*/

/**
 * @file    chdebug.c
 * @brief   ChibiOS/RT Debug code.
 *
 * @addtogroup debug
 * @details Debug APIs and services:
 *          - Runtime system state and call protocol check. The following
 *            panic messages can be generated:
 *            - SV#1, misplaced @p chSysDisable().
 *            - SV#2, misplaced @p chSysSuspend()
 *            - SV#3, misplaced @p chSysEnable().
 *            - SV#4, misplaced @p chSysLock().
 *            - SV#5, misplaced @p chSysUnlock().
 *            - SV#6, misplaced @p chSysLockFromIsr().
 *            - SV#7, misplaced @p chSysUnlockFromIsr().
 *            - SV#8, misplaced @p CH_IRQ_PROLOGUE().
 *            - SV#9, misplaced @p CH_IRQ_EPILOGUE().
 *            - SV#10, misplaced I-class function.
 *            - SV#11, misplaced S-class function.
 *            .
 *          - Trace buffer.
 *          - Parameters check.
 *          - Kernel assertions.
 *          - Kernel panics.
 *          .
 * @note    Stack checks are not implemented in this module but in the port
 *          layer in an architecture-dependent way.
 * @{
 */

#include "ch.h"

/*===========================================================================*/
/* System state checker related code and variables.                          */
/*===========================================================================*/

#if CH_DBG_SYSTEM_STATE_CHECK || defined(__DOXYGEN__)

/**
 * @brief   ISR nesting level.
 */
cnt_t dbg_isr_cnt;

/**
 * @brief   Lock nesting level.
 */
cnt_t dbg_lock_cnt;

/**
 * @brief   Guard code for @p chSysDisable().
 *
 * @notapi
 */
void dbg_check_disable(void) {

  if ((dbg_isr_cnt != 0) || (dbg_lock_cnt != 0))
    chDbgPanic("SV#1");
}

/**
 * @brief   Guard code for @p chSysSuspend().
 *
 * @notapi
 */
void dbg_check_suspend(void) {

  if ((dbg_isr_cnt != 0) || (dbg_lock_cnt != 0))
    chDbgPanic("SV#2");
}

/**
 * @brief   Guard code for @p chSysEnable().
 *
 * @notapi
 */
void dbg_check_enable(void) {

  if ((dbg_isr_cnt != 0) || (dbg_lock_cnt != 0))
    chDbgPanic("SV#3");
}

/**
 * @brief   Guard code for @p chSysLock().
 *
 * @notapi
 */
void dbg_check_lock(void) {

  if ((dbg_isr_cnt != 0) || (dbg_lock_cnt != 0))
    chDbgPanic("SV#4");
  dbg_enter_lock();
}

/**
 * @brief   Guard code for @p chSysUnlock().
 *
 * @notapi
 */
void dbg_check_unlock(void) {

  if ((dbg_isr_cnt != 0) || (dbg_lock_cnt <= 0))
    chDbgPanic("SV#5");
  dbg_leave_lock();
}

/**
 * @brief   Guard code for @p chSysLockFromIsr().
 *
 * @notapi
 */
void dbg_check_lock_from_isr(void) {

  if ((dbg_isr_cnt <= 0) || (dbg_lock_cnt != 0))
    chDbgPanic("SV#6");
  dbg_enter_lock();
}

/**
 * @brief   Guard code for @p chSysUnlockFromIsr().
 *
 * @notapi
 */
void dbg_check_unlock_from_isr(void) {

  if ((dbg_isr_cnt <= 0) || (dbg_lock_cnt <= 0))
    chDbgPanic("SV#7");
  dbg_leave_lock();
}

/**
 * @brief   Guard code for @p CH_IRQ_PROLOGUE().
 *
 * @notapi
 */
void dbg_check_enter_isr(void) {

  port_lock_from_isr();
  if ((dbg_isr_cnt < 0) || (dbg_lock_cnt != 0))
    chDbgPanic("SV#8");
  dbg_isr_cnt++;
  port_unlock_from_isr();
}

/**
 * @brief   Guard code for @p CH_IRQ_EPILOGUE().
 *
 * @notapi
 */
void dbg_check_leave_isr(void) {

  port_lock_from_isr();
  if ((dbg_isr_cnt <= 0) || (dbg_lock_cnt != 0))
    chDbgPanic("SV#9");
  dbg_isr_cnt--;
  port_unlock_from_isr();
}

/**
 * @brief   I-class functions context check.
 * @details Verifies that the system is in an appropriate state for invoking
 *          an I-class API function. A panic is generated if the state is
 *          not compatible.
 *
 * @api
 */
void chDbgCheckClassI(void) {

  if ((dbg_isr_cnt < 0) || (dbg_lock_cnt <= 0))
    chDbgPanic("SV#10");
}

/**
 * @brief   S-class functions context check.
 * @details Verifies that the system is in an appropriate state for invoking
 *          an S-class API function. A panic is generated if the state is
 *          not compatible.
 *
 * @api
 */
void chDbgCheckClassS(void) {

  if ((dbg_isr_cnt != 0) || (dbg_lock_cnt <= 0))
    chDbgPanic("SV#11");
}

#endif /* CH_DBG_SYSTEM_STATE_CHECK */

/*===========================================================================*/
/* Trace related code and variables.                                         */
/*===========================================================================*/

#if CH_DBG_ENABLE_TRACE || defined(__DOXYGEN__)
/**
 * @brief   Public trace buffer.
 */
ch_trace_buffer_t dbg_trace_buffer;

/**
 * @brief   Trace circular buffer subsystem initialization.
 * @note    Internal use only.
 */
void _trace_init(void) {

  dbg_trace_buffer.tb_size = CH_TRACE_BUFFER_SIZE;
  dbg_trace_buffer.tb_ptr = &dbg_trace_buffer.tb_buffer[0];
}

/**
 * @brief   Inserts in the circular debug trace buffer a context switch record.
 *
 * @param[in] otp       the thread being switched out
 *
 * @notapi
 */
void dbg_trace(thread_t *otp) {

  dbg_trace_buffer.tb_ptr->se_time   = chVTGetSystemTimeX();
  dbg_trace_buffer.tb_ptr->se_tp     = currp;
  dbg_trace_buffer.tb_ptr->se_wtobjp = otp->p_u.wtobjp;
  dbg_trace_buffer.tb_ptr->se_state  = (uint8_t)otp->p_state;
  if (++dbg_trace_buffer.tb_ptr >=
      &dbg_trace_buffer.tb_buffer[CH_TRACE_BUFFER_SIZE])
    dbg_trace_buffer.tb_ptr = &dbg_trace_buffer.tb_buffer[0];
}
#endif /* CH_DBG_ENABLE_TRACE */

/*===========================================================================*/
/* Panic related code and variables.                                         */
/*===========================================================================*/

#if CH_DBG_ENABLED || defined(__DOXYGEN__)
/**
 * @brief   Pointer to the panic message.
 * @details This pointer is meant to be accessed through the debugger, it is
 *          written once and then the system is halted.
 */
const char *dbg_panic_msg;

/**
 * @brief   Prints a panic message on the console and then halts the system.
 *
 * @param[in] msg       the pointer to the panic message string
 */
void chDbgPanic(const char *msg) {

  dbg_panic_msg = msg;
  chSysHalt();
}
#endif /* CH_DBG_ENABLED */

/** @} */