在adc试验中添加timer.c 文件  在option中也设置了路径 但是编译出现下面错误  该怎么解决

..OBJADC.axf: Error: L6218E: Undefined symbol TIM_GetITStatus (referred from timer.o).
..OBJADC.axf: Error: L6218E: Undefined symbol TIM_ClearITPendingBit (referred from timer.o).
..OBJADC.axf: Error: L6218E: Undefined symbol TIM_Cmd (referred from timer.o).
..OBJADC.axf: Error: L6218E: Undefined symbol TIM_ITConfig (referred from timer.o).
..OBJADC.axf: Error: L6218E: Undefined symbol TIM_OC2Init (referred from timer.o).
..OBJADC.axf: Error: L6218E: Undefined symbol TIM_OC2PreloadConfig (referred from timer.o).
..OBJADC.axf: Error: L6218E: Undefined symbol TIM_TimeBaseInit (referred from timer.o).