Function name variable within a non-trigger function

[Berend Tober <btober@xxxxxxxxxxxxxxxx>]

I know that within a trigger function the functin name can be referenced 
by the special variable TG_NAME, so I could include raise an exception 
that identified its source with a line like:

     RAISE EXCEPTION ''ERROR IN %'', TG_NAME;

Is there a similar set of special variables defined for "normal", i.e., 
non-trigger functions, too?