GNAT for Apple iMac

[Ellis N. Thomas]

I have for some time been trying to obtain a GNAT Ada compiler  
suitable for the Apple
iMac (Intel based, running Mac OS X).

The main obstacle is the need for an existing GNAT, as stated in http://gcc.gnu.org/install/prerequisites.html 
:

"GNAT
	In order to build the Ada compiler (GNAT) you must already have GNAT  
installed because portions of the Ada frontend are written in Ada  
(with GNAT extensions.)  Refer to the Ada installation instructions  
for more specific information."

I have been unable to determine where a suitable binary for the iMac  
is available that would enable the latest sources (4.6.2) to be  
compiled.

The details from the uname -mrsv command for this machine are:

Darwin 9.8.0 Darwin Kernel Version 9.8.0: Wed Jul 15 16:55:01 PDT  
2009; root:xnu-1228.15.4~1/RELEASE_I386 i386

If some sort of cross-compilation for the iMac would be possible, I  
might be able to call
on colleagues who were previously involved in Ada compiler development  
to use another
host system.  I have some familiarity with cross-compilation, as I  
worked some years ago
on the development of the XD-Ada (Ada83) compiler on the DEC Vax host.

Any help with this would be appreciated.

	Thanks,
		Ellis N. Thomas.