iOS 获取调用堆栈并打印

+ (void)deleteKeyPair {

    NSLog(@"deleteKeyPair调用堆栈: %@",[NSThread callStackSymbols]);

    [NSData  deleteKeyPairWithTag:VP_ECDHPrivateKey];

    [NSData  deleteKeyPairWithTag:VP_ECDHPublicKey];

    [NSData  deleteSharedKeyInKeychain:VP_ECDHSharedSecretKey];

    [[NSUserDefaults standardUserDefaults] setObject:**nil** forKey:VP_ECDHSharedSecretKey];

}