How to find out if this preprocessor macro exists?

I want to know how to find out if the preprocessor macro __PRETTY_FUNCTION__ can be used with a given compiler (As it is supposed to be non-standard). How do I check this in a header file? What I want to do is something like:

#ifndef __PRETTY_FUNCTION__
   #define __PRETTY_FUNCTION__ __func__
#endif

But, I'm guessing what happens is the preprocessor defines the macro in place for each function so I wonder whether there's any meaning to __PRETTY_FUNCTION__ (Unlike __FILE__ or __LINE__) outside a function. Is this true or can I just use the code above? If not, how do I check for it?

EDIT: I tried it. __PRETTY_FUNCTION__ is undefined outside a function (I didn't check inside a class). So there has to be another way.

EDIT2: Actually a simple hack would be to do this :):

void Dummy()
{
    #ifndef __PRETTY_FUNCTION__
       #define __PRETTY_FUNCTION__ __func__
    #endif
}

The other method is to check for compiler as was suggested by others.