Re: [HACKERS] Checking if a system is ELF

Thus spake Tom Lane
> "D'Arcy" "J.M." Cain <darcy@druid.net> writes:
> > So grep will find "__ELF__" in the output on druid proving that it is an
> > a.out system.  On smaug, __ELF__ is defined as "1" so grep fails to find
> > the string "__ELF__" proving it to be an ELF system.
> 
> Seems to me that this is a test for __ELF__ being defined, but not for
> exactly what it is defined as.  Mightn't a non-ELF system define it as 0?

Hard to imagine.  Pre-ELF systems wouldn't know about it one way or
another.  However, it is certainly a theoretical possibility.

> Also, I think there are prefab test macros in Autoconf for checking
> whether a #define symbol exists ... you shouldn't have to do anything
> as grotty as writing out an explicit test program ...

This is why I didn't send in diffs.  I don't know enough about autoconf.
Is anyone looking at this discussion planning to incorporate something?

-- 
D'Arcy J.M. Cain <darcy@{druid|vex}.net>   |  Democracy is three wolves
http://www.druid.net/darcy/                |  and a sheep voting on
+1 416 424 2871     (DoD#0082)    (eNTP)   |  what's for dinner.