ObjFW runtime: Add objc_msg_lookup(_super)_{fp,st}ret

[Eli Friedman]

On Fri, Jul 19, 2013 at 7:09 AM, Jonathan Schleifer <js at webkeks.org> wrote:
> Am 19.07.2013 um 03:02 schrieb Eli Friedman:
>
>> Ah, I figured out what's happening.  The other invocation is the one
>> that's failing.  Try changing your "STRET" prefix to "HASSTRET". :)
>
> Interesting. At one point, I tried WITHSTRET and WITHOUTSTRET, but that wouldn't help. Now it indeed works, though I wonder why it worked when I manually invoked it and didn't when it was invoked using llvm-lit.
>
> Anyway, this means the last missing piece is the documentation. I looked at LanguageExtensions.rst, but this does not seem like the right place to document it, considering it is such a small change. What would be a good place to document __has_feature(objc_msg_lookup_stret)? (Btw, I thought some more about a better name and came to the conclusion that anything containing forwaring, like objc_stret_forwarding, is completely wrong, as that is a feature the runtime / framework has to support. The objc_msg_lookup_stret call just makes it possible for the runtime / framework to correctly implement stret forwarding).

That's the place where every single other __has_feature is documented.
 I mean, if it's important enough to add a __has_feature name for it,
it's surely important enough to document the feature in question.

-Eli