Why does casting a function generate a run-time abort?

[Zack Weinberg]

Ziemowit Laski <zlaski@apple.com> writes:

> Right; there is an ugly 'if(!c_dialect_objc())' in front of the whole
> thing.  Although I do see that an abort is indeed permitted under the
> circumstances, I'm still mystified as to why this became an issue in
> the first place.  Why not just construct a function call using the
> signature specified in the cast?  Aside from not being able to inline
> the call, I'm not quite sure what the problem is...

A desire to flush out buggy code that *will* fail on platforms with
more complicated ABIs, I think, is the main motivation.

Lemme ask you why Objective-C message dispatch needs this.  It's
impossible to get "right" on IA64 and a few others.

zw