ada.h _ECHO

[andrew.m.goth@l-3com.com]

Today I happened across something that made me scratch my head. 
Perhaps you can help me understand.  Or maybe it's a bug. 

ada.h contains the following preprocessor juju:

#ifdef __STDC__
#define CAT(A,B) A##B
#else
#define _ECHO(A) A
#define CAT(A,B) ECHO(A)B
#endif

For the non-__STDC__ case, why is the macro called _ECHO on one line and
ECHO on the next? 

See for yourself:

http://gcc.gnu.org/viewcvs/trunk/gcc/ada/gcc-interface/ada.h?view=markup

-- 
Andy Goth
   <amgoth@link.com>