keil WARNING L1 : UNRESOLVED EXTERNAL SYMBOL 和 WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL

keil编译出现如下警告：

WARNING L1: UNRESOLVED EXTERNAL SYMBOL

SYMBOL:  UART0

MODULE:  .\obj\app_uart0.obj (APP_UART0)

WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL

SYMBOL:  UART0

MODULE:  .\obj\app_uart0.obj (APP_UART0)

ADDRESS: 31ACH

解决办法：L1和L2是同一问题，是Uart0在程序中使用了，但是没定义；

如下：uart.h文件中结构体

typedef struct
{
   u8 RxOk;
}USART_DEF;
extern USART_DEF Uart0;

uart.c中需要定义下USART_DEF Uart0;

标签：UNRESOLVED,obj,SYMBOL,UART0,WARNING,EXTERNAL
来源： https://blog.csdn.net/fenhong91/article/details/115655453