los_cppsupport.c

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/*
 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of
 *    conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
 *    of conditions and the following disclaimer in the documentation and/or other materials
 *    provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
 *    to endorse or promote products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
#include "los_cppsupport.h"
#include "los_printf.h"
/**
 * @brief @file los_cppsupport.c
 * @verbatim 
    基本概念
        C++作为目前使用最广泛的编程语言之一，支持类、封装、重载等特性，是在C语言基础上
        开发的一种面向对象的编程语言。
 
    运作机制
        STL（Standard Template Library）标准模板库，是一些“容器”的集合，也是算法和其他
        一些组件的集合。其目的是标准化组件，使用标准化组件后可以不用重新开发，直接使用现成的组件。
 
    开发流程
        通过make menuconfig使能C++支持。
        使用C++特性之前，需要调用函数LOS_CppSystemInit，初始化C++构造函数。
        C函数与C++函数混合调用。在C++中调用C程序的函数，代码需加入C++包含的宏：
        #ifdef __cplusplus
        #if __cplusplus
        extern "C" {
        #endif /* __cplusplus * /
        #endif /* __cplusplus * /
        /* code * /
        ...
        #ifdef __cplusplus
        #if __cplusplus
        }
        #endif /* __cplusplus * /
        #endif /* __cplusplus * /
 * @endverbatim
 */
 
typedef VOID (*InitFunc)(VOID);
 
/**
 * @brief 使用C++特性的前置条件 初始化C++构造函数
 * @param initArrayStart init_array段的起始地址
 * @param initArrayEnd init_array段的结束地址
 * @param flag 标记调用C++特性时的场景
 * @return LITE_OS_SEC_TEXT_MINOR 
 */
LITE_OS_SEC_TEXT_MINOR INT32 LOS_CppSystemInit(UINTPTR initArrayStart, UINTPTR initArrayEnd, INT32 flag)
{
    UINTPTR *start     = (UINTPTR *)initArrayStart;
    InitFunc initFunc   = NULL;
 
    for (; start != (UINTPTR *)initArrayEnd; ++start) {
        initFunc = (InitFunc)(*start);
        initFunc();
    }
 
    return 0;
}