C++里面异常处理官方例程运行有错误

发布于 2020-11-17 17:04:41 浏览：1173 订阅该版

- 按照文章[在 STM32 上使用 C++ 指南](https://www.rt-thread.org/document/site/application-note/components/cplusplus/an0035-cpp/)的讲解
- 运行文档中给的C++测试例程出现错误：

> 程序为
> ```
> #include <math.h>
> #include <stdlib.h>
> 
> #define MIN_VALUE                 (1e-4)
> #define IS_DOUBLE_ZERO(d)         (abs(d) < MIN_VALUE)
> 
> double div_func(double x, double y)
> {
>     if (IS_DOUBLE_ZERO(y))
>     {
>         throw y;                                           /* throw exception */
>     }
> 
>     return x / y;
> }
> void throw_exceptions(void *args)
> {
>     try
>     {
>         div_func(6, 3);
>         rt_kprintf("there is no err\n");
>         div_func(4, 0);                                   /* create exception*/
>         rt_kprintf("you can run here\n");
>     }
>     catch(double)                                         /* catch exception */
>     {
>         rt_kprintf("error of dividing zero\n");
>     }
> }
> 
> MSH_CMD_EXPORT(throw_exceptions, throw cpp exceptions);
> ```
> 运行时报错为
> ```
> \ | /
> - RT -     Thread Operating System
>  / | \     4.0.3 build Nov 17 2020
>  2006 - 2020 Copyright by rt-thread team
> RTT Control Block Detection Address is 0x200024b0
> msh >throw_exceptions
> there is no err
> thread:tshell   abort!
> 
> ```
- 经过调试发现，程序中throw的y没被catch，转而执行到rtthread/components/libc/compliers/newlib/syscalls.c中的abort函数
```
void abort(void)
{
    if (rt_thread_self())
    {
        rt_thread_t self = rt_thread_self();

rt_kprintf("thread:%-8.*s abort!\n", RT_NAME_MAX, self->name);
        rt_thread_suspend(self);

rt_schedule();
    }

while (1);
}
```
- 请问是为什么？