RT-Thread finsh源码分析: finsh_ops.c

/*
 *  operations for finsh shell.
 *
 * COPYRIGHT (C) 2006 - 2013, RT-Thread Development Team
 *
 *  This file is part of RT-Thread (http://www.rt-thread.org)
 *  Maintainer: bernard.xiong <bernard.xiong at gmail.com>
 *
 *  All rights reserved.
 *
 *  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 2 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, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2010-03-22     Bernard      first version
 */

//该文件用于栈操作，类似栈计算器实现

#include "finsh_ops.h"
#include "finsh_vm.h"

//字节操作，结果保存在栈中，栈指针减一
#define OP_BIN_BYTE(x)  do {\
        (finsh_sp - 2)->char_value = (finsh_sp - 2)->char_value x (finsh_sp - 1)->char_value; \
        finsh_sp--; \
    }while (0)

//字操作，结果保存在栈中，栈指针减一
#define OP_BIN_WORD(x)  do {\
        (finsh_sp - 2)->short_value = (finsh_sp - 2)->short_value x (finsh_sp - 1)->short_value; \
        finsh_sp--; \
    }while (0)

//双字操作，结果保存在栈中，栈指针减一
#define OP_BIN_DWORD(x)  do {\
        (finsh_sp - 2)->long_value = (finsh_sp - 2)->long_value x (finsh_sp - 1)->long_value; \
        finsh_sp--; \
    }while (0)

//空操作
/* --- noop --- */
void OP_no_op()
{
    /* none */
    return ;
}

//加
/* --- add --- */
void OP_add_byte()
{
    OP_BIN_BYTE(+);

    return ;
}

void OP_add_word()
{
    OP_BIN_WORD(+);

    return ;
}

void OP_add_dword()
{
    OP_BIN_DWORD(+);

    return ;
}

//减
/* --- sub --- */
void OP_sub_byte()
{
    OP_BIN_BYTE(-);

    return ;
}

void OP_sub_word()
{
    OP_BIN_WORD(-);

    return ;
}

void OP_sub_dword()
{
    OP_BIN_DWORD(-);

    return ;
}

//除
/* --- div --- */
void OP_div_byte()
{
    OP_BIN_BYTE(/);

    return ;
}

void OP_div_word()
{
    OP_BIN_WORD(/);