assert_param始终不明白这个函数是怎么检查参数的，郁闷！

只看该作者 · 2012-3-16 15:30

assert_param 固件库里有好多这个函数可是我总是不明白它具体是怎么检查参数的，呜呜....

只看该作者 · 2012-3-16 15:46

也刚学:
看平台不同,全固件库搜:
"assert_param"
发现N多用"assert_param(....."
的几个: #define assert_param(expr) ....
其实就两个:
在stm32f10x_conf.h的69行和73行

#ifdef  USE_FULL_ASSERT

/**
  * @brief  The assert_param macro is used for function's parameters check.
  * @param  expr: If expr is false, it calls assert_failed function which reports
  *       the name of the source file and the source line number of the call
  *       that failed. If expr is true, it returns no value.
  * @retval None
  */
  #define assert_param(expr) ((expr) ? (void)0 : assert_failed((uint8_t *)__FILE__, __LINE__))
/* Exported functions ------------------------------------------------------- */
  void assert_failed(uint8_t* file, uint32_t line);
#else
  #define assert_param(expr) ((void)0)
#endif /* USE_FULL_ASSERT */

但:void assert_failed(uint8_t* file, uint32_t line);
这个是库里全程的Main定义的一个函数:(如下)
#ifdef  USE_FULL_ASSERT

/**
  * @brief  Reports the name of the source file and the source line number
  *       where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t* file, uint32_t line)
{
  /* User can add his own implementation to report the file name and line number,
   ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
}
#endif

主要是我看不懂:
assert_failed((uint8_t *)__FILE__, __LINE__))
后面的参数是怎来的