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- 2017-7-25
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- 129 小时
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5金钱
Rebuild target 'CAN'
compiling main.c...
main.c(14): warning: #1295-D: Deprecated declaration gets19file - give arg types
u8 gets19file();
main.c(23): warning: #177-D: variable "recback" was declared but never referenced
u8 feedback1,recback;
main.c(26): warning: #550-D: variable "res" was set but never used
u8 res;
main.c(29): warning: #550-D: variable "data_ff_fe" was set but never used
u8 data_ff_fe[8];
main.c(115): warning: #940-D: missing return statement at end of non-void function "gets19file"
}
main.c(72): warning: #550-D: variable "res" was set but never used
u8 res;
main.c(75): warning: #550-D: variable "data" was set but never used
u8 data[24];
main.c(77): warning: #550-D: variable "data_ff_fe" was set but never used
u8 data_ff_fe[8];
main.c: 8 warnings, 0 errors
compiling stm32f4xx_it.c...
compiling system_stm32f4xx.c...
compiling led.c...
compiling lcd.c...
compiling key.c...
compiling can.c...
compiling delay.c...
compiling sys.c...
compiling usart.c...
assembling startup_stm32f40_41xxx.s...
compiling misc.c...
compiling stm32f4xx_gpio.c...
compiling stm32f4xx_fsmc.c...
compiling stm32f4xx_rcc.c...
compiling stm32f4xx_syscfg.c...
compiling stm32f4xx_usart.c...
compiling stm32f4xx_can.c...
linking...
Program Size: Code=8368 RO-data=424 RW-data=48 ZI-data=1832
FromELF: creating hex file...
"..\OBJ\CAN.axf" - 0 Error(s), 8 Warning(s).
Build Time Elapsed: 00:00:16
编译为什么会出现这种警告,定义的变量在程序中有用到,为什么编译后说我没有用到呢,那位大神可以给我解释一下吗,谢谢
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最佳答案
查看完整内容[请看2#楼]
就是定义的是一个局部变量,用来存储接收数据,编译器认为这个变量不需要,优化掉了,所以仿真是你也看不到这个变量,换成全局变量就没这种问题了
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