官方例子main函数最后一段代码#ifdef USE_FULLASSERT 。。。。是什么意思？

flyheart · 发表于 2014-6-13 09:40:07

[mw_shl_code=c,true]#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[/mw_shl_code]

这段代码有什么作用？

xiaoyan · 发表于 2014-6-13 09:40:08

调试用的。在stm32f10x_conf.h文件中，有如下宏定义

#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 */

如果你定义了USE_FULL_ASSERT

就可以在assert_failed，加入：
printf("Wrong parameters value: file %s on line %d\r\n", file, line);
就可以使用assert_param(expr) 来判断当前参数是够正确，如果不正确，就会打印出错的文件，以及出错的行。
这样就可以方面调试信息了。