此方法只适用于18,其他版本不知道
# ** Error: (vsim-19) Failed to access library 'cyclonev_ver' at "cyclonev_ver".
Error (12049): Can't compile duplicate declarations of entity "Fulladder" into library "work"
工图栏选择Tools->options->EDA Tool Options,如图所示
还要把之前工程路径下的work文件夹删掉
再次编译,simulation成功