namespace-invasive CPP built-ins

[Neil Booth]

Jason R Thorpe wrote:-

> the LANGUAGE_* defines were recently brought to my attention by someone
> else in the context of MIPS, and so I started looking around and noticed
> them on Alpha, too.
> 
> The rub here is the "LANGUAGE_C" define ... it is namespace-invasive,
> and some targets (like NetBSD) try to keep stuff like that out of the
> namespace regardless of stdc options...
> 
> I guess it boils down to the fact that stuff like LANGUAGE_* is kind
> of OS-specific .. no all OSs use it in their headers or source code,
> and testing those defines certainly isn't portable in the general sense.
> 
> I'd like to figure out some way to sanely move these things out of
> TARGET_CPU_CPP_BUILTINS() and into some other construct.  Thoughts?

Making it OS-specific sounds like a good idea.  Possibly an empty
macro that is redefined to be non-empty by that OS' header?

Neil.