Xref: utzoo comp.sys.apollo:1567 comp.std.c:489
Path: utzoo!utgpu!attcan!uunet!ncrlnk!ncrcae!ece-csc!mcnc!uvaarpa!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn )
Newsgroups: comp.sys.apollo,comp.std.c
Subject: Re: Please include architecture define in cpp
Message-ID: <8855@smoke.BRL.MIL>
Date: 10 Nov 88 17:26:58 GMT
References: <17414@shemp.CS.UCLA.EDU> <3f6a319b.d5b2@apollo.COM> <17746@shemp.CS.UCLA.EDU>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 19

In article <17746@shemp.CS.UCLA.EDU> casey@cs.ucla.edu (Casey Leedom) writes:
>  But a question pops into my mind at this point: are these predefined
>defines defined anywhere?  That is, does ANSI C define them?  Obviously
>it couldn't define all of them because new architectures will be brought
>to market, etc.  A set of standard ANSI C predefined architecture defines
>would in fact almost seem to be the perfect thing to add to a new section
>of the Assigned Numbers RFC that the NIC maintains.  Does anyone have any
>information on this?

To provide a guarantee of purity of application-usable name spaces,
ANSI C forbids the implementation to predefine any macro names that
do not begin with a leading underscore followed by an upper-case
letter or a second underscore.  Thus a conforming implementation
cannot predefine symbols such as
	unix	vax	mc68000	u3b	apollo
However, _ISP__MC68K is permitted.

There is no known central registry for such implementation-supplied
names.  (It is certainly outside the scope of X3J11.)