Is it possible for a macro to tell file/namespace scope from other scopes?

[Patrick Horgan <phorgan1@xxxxxxxxx>]

On the subject of the difference in behavior in #pragma GCC diagnostic 
before 4.6 when they had to be at file/namespace scope, and 4.6 and 
later when they could be included at any scope, is there any way to 
determine if you are or are not at file/namespace scope in a test from a 
preprocessor macro?  I'm guessing not, but if there was it could make 
for a beautiful solution to using these things, in that you could have 
GCC_DIAG_ON/OFF(x) macros that would have appropriate implementations 
for appropriate scopes automagically.  So, anyone able to dispel my 
preconceptions and tell me it's possible?

Patrick