IAR 新版本打开老版本遇到的问题和解决方法 __nounwind和cannot open source file "core_cm3.h"

1.__nounwind

declaration is incompatible with "__nounwind __interwork __softfp unsigned int __iar_builtin_STREXB(unsigned char, unsigned char volatile *)

解决方法：右击工程进入options->C/C++Compiler->Preprocessor删除

$PROJ_DIR$\..\Libraries\CMSIS\CM3\CoreSupport

2.打不开”core_cm3.h”

cannot open source file "core_cm3.h" 

原因：没有选MCU型号
解决方法：右击工程进入options->General Options->Target选设备，选设备完后进入Library Configuration，勾选CMSIS内的Use CMSIS