#defines for AIX versions & h/w architectures

[Vic Abell]

In article <1204 at ucl-cs.UUCP> J.Crowcroft at ucl-cs.UUCP writes:
>From: Jon Crowcroft <J.Crowcroft at uk.ac.ucl.cs>
>
>what predefineds (e.g. is cpp called with any by cc)

The porting guide, "Porting 4.3 BSD Programs to AIX Version 3.1" says:

	"In all cases, the AIXv3.1 C compiler defines the
	 following two tokens: _AIX, _IBMR2."

(You can find the porting guide in /usr/lpp/bos/bsdport.)

I don't believe that these predefines are established in the classical
cpp fashion.  Instead they are created by that part of XL C that handles
the stanzas of /etc/xlc.cfg.  There are several other reasons for doing
it this way:  1) more flexible; 2) there are two C preprocessors; and
3) no source code (yet) for cpp.