Comparing objc method arguments in checker plugin


I’m a bit lost in the clang docs and the existing checker don’t help me anymore at this point.

I’m trying to create a checker plugin which analyzes a function call, if it uses a certain argument:

So far I come to this point(everything works except matching the arguments):

if(S.isUnarySelector() && S.getIdentifierInfoForSlot(0) == IISetSecurityLevel){
      SVal arg = msg.getArgSVal(0);
  //want to check the arg here

I understand that getArgSVal gives me the value of the argument, but how can I compare it to another SVal I want to set?

I’m using this in an "checkPreObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const“ call

I hope somebody can help me

Best Regards