Undefined symbols for architecture x86_64:
"___gxx_personality_v0", referenced from:
-[NSData(MD5Related) qcloud_MD5String] in QCloudCore(QCloudEncryt.o)
_QCloudEncrytNSDataMD5Base64 in QCloudCore(QCloudEncryt.o)
_internalEncrytFileMD5(NSString) in QCloudCore(QCloudEncryt.o)
_QCloudEncrytFileMD5Base64 in QCloudCore(QCloudEncryt.o)
_internalEncrytNSDataMD5(NSData) in QCloudCore(QCloudEncryt.o)
_QCloudEncrytNSDataMD5 in QCloudCore(QCloudEncryt.o)
_QCloudEncrytFileMD5 in QCloudCore(QCloudEncryt.o)
...
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Undefined symbols for architecture x86_64: "___gxx_personality_v0", referenced from: -[NSData(MD5Related) qcloud_MD5String] in QCloudCore(QCloudEncryt.o) _QCloudEncrytNSDataMD5Base64 in QCloudCore(QCloudEncryt.o) _internalEncrytFileMD5(NSString) in QCloudCore(QCloudEncryt.o) _QCloudEncrytFileMD5Base64 in QCloudCore(QCloudEncryt.o) _internalEncrytNSDataMD5(NSData) in QCloudCore(QCloudEncryt.o) _QCloudEncrytNSDataMD5 in QCloudCore(QCloudEncryt.o) _QCloudEncrytFileMD5 in QCloudCore(QCloudEncryt.o) ... ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation)
引入项目报这个错误是什么原因?