REFERENCE MADE TO UNRESOLVED EXTERNAL.

本文解释了一种常见的编程错误——使用未定义的外部变量。这种错误通常发生在声明了 extern 变量但在其他文件中未实际定义该变量的情况。文章详细介绍了这种错误的原因及常见场景。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

REFERENCE MADE TO UNRESOLVED EXTERNAL. 原因

使用了一个未定义的外部变量.(经常是在当前文件中声明了 extern xxx , 但其实在其它的文件中没有定义这个变量)

Rebuild target 'Target 1' assembling STARTUP.A51... compiling main.c... compiling delay.c... compiling uart.c... linking... *** WARNING L1: UNRESOLVED EXTERNAL SYMBOL SYMBOL: COUNT MODULE: .\Objects\main.obj (MAIN) *** WARNING L1: UNRESOLVED EXTERNAL SYMBOL SYMBOL: RECV MODULE: .\Objects\main.obj (MAIN) *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: COUNT MODULE: .\Objects\main.obj (MAIN) ADDRESS: 00E2H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: COUNT MODULE: .\Objects\main.obj (MAIN) ADDRESS: 00E4H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: COUNT MODULE: .\Objects\main.obj (MAIN) ADDRESS: 00E6H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: COUNT MODULE: .\Objects\main.obj (MAIN) ADDRESS: 00EEH *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: COUNT MODULE: .\Objects\main.obj (MAIN) ADDRESS: 00F0H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: COUNT MODULE: .\Objects\main.obj (MAIN) ADDRESS: 00F4H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: COUNT MODULE: .\Objects\main.obj (MAIN) ADDRESS: 00F9H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: RECV MODULE: .\Objects\main.obj (MAIN) ADDRESS: 004AH *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: RECV MODULE: .\Objects\main.obj (MAIN) ADDRESS: 004CH *** WARNING L1: UNRESOLVED EXTERNAL SYMBOL SYMBOL: RECV MODULE: .\Objects\uart.obj (UART) *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: RECV MODULE: .\Objects\uart.obj (UART) ADDRESS: 001DH Program Size: data=12.0 xdata=0 code=393 creating hex file from ".\Objects\mcu51"... ".\Objects\mcu51" - 0 Error(s), 13 Warning(s). Build Time Elapsed: 00:00:02
最新发布
07-31
*** ERROR L104: MULTIPLE PUBLIC DEFINITIONS SYMBOL: MAIN MODULE: .\Objects\main.obj (MAIN) *** WARNING L16: UNCALLED SEGMENT, IGNORED FOR OVERLAY PROCESS SEGMENT: ?PR?MAIN?MAIN *** WARNING L1: UNRESOLVED EXTERNAL SYMBOL SYMBOL: I2CRECEIVEBYTE MODULE: .\Objects\iic.obj (IIC) *** WARNING L1: UNRESOLVED EXTERNAL SYMBOL SYMBOL: I2CSTART MODULE: .\Objects\iic.obj (IIC) *** WARNING L1: UNRESOLVED EXTERNAL SYMBOL SYMBOL: _I2CSENDACK MODULE: .\Objects\iic.obj (IIC) *** WARNING L1: UNRESOLVED EXTERNAL SYMBOL SYMBOL: _I2CSENDBYTE MODULE: .\Objects\iic.obj (IIC) *** WARNING L1: UNRESOLVED EXTERNAL SYMBOL SYMBOL: I2CWAITACK MODULE: .\Objects\iic.obj (IIC) *** WARNING L1: UNRESOLVED EXTERNAL SYMBOL SYMBOL: I2CSTOP MODULE: .\Objects\iic.obj (IIC) *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: I2CSTART MODULE: .\Objects\iic.obj (IIC) ADDRESS: 0EDDH *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: _I2CSENDBYTE MODULE: .\Objects\iic.obj (IIC) ADDRESS: 0EE2H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: I2CWAITACK MODULE: .\Objects\iic.obj (IIC) ADDRESS: 0EE5H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: _I2CSENDBYTE MODULE: .\Objects\iic.obj (IIC) ADDRESS: 0EEAH *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: I2CWAITACK MODULE: .\Objects\iic.obj (IIC) ADDRESS: 0EEDH *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: I2CSTART MODULE: .\Objects\iic.obj (IIC) ADDRESS: 0EF0H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: _I2CSENDBYTE MODULE: .\Objects\iic.obj (IIC) ADDRESS: 0EF5H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: I2CWAITACK MODULE: .\Objects\iic.obj (IIC) ADDRESS: 0EF8H *** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL SYMBOL: I2CRECEIVEBYTE MODULE: .\Objects\iic.
04-03
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值