Question

I have a logger in a c++ application that uses defines as follows:

#define FINEST(...) Logger::Log(FINEST, _FILE, __LINE, __func, __VA_ARGS_)

However what I would like to do is to be able to switch off these logs since they have a serious performance impact on my system. And, it’s not sufficient to simply have my Logger not write to the system log. I really need to get rid of the code produced by the logs.

In order to do this, I changed the define to:

#define FINEST(...)

Which works, but this produces a whole bunch of warning in my code since variables are unused now. So what I would like to have is a sort of NULL FUNCTION that would not actually exist, but would not produce warnings for the unused variables.

So, said another way, I would like it to compile with no warnings (i.e. the compiler thinks that the variables are used for a function) but the function does not actually exist in the application (i.e. produces no performance hit).

Is this possible?

Thanks!

Answer 1

You could define an empty function with unnamed parameters:

void nullFunc(int, int, int, const char*, ...) {
}

Then redefine your macro to call this function:

#define FINEST(...) nullFunc(FINEST, _FILE, __LINE, __func, __VA_ARGS_)