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

[Richard Henderson]

On Fri, Jun 18, 2004 at 02:13:11PM -0700, Ziemowit Laski wrote:
> Yes, I think that what you suggest could work, albeit at the cost of 
> having to add additional machinery to GIMPLE.

Not so much as you'd think, I'll warrent.  In addition, you may be
able to devirtualize some calls entirely.

>     {
>       extern foo_id objc_msgSend(foo_id, char *, blort, blort);
>       obj0 = objc_msgSend (obj0, "foo message", foo, bar);
>     }

No.

>     {
>       extern foo_id __objc_msgSend_local_nnnn(foo_id, char *, blort, 
> blort) asm("objc_msgSend");
>       obj0 = __objc_msgSend_local_nnnn (obj0, "foo message", foo, bar);
>     }

No.

How about

	<CALL_EXPR <METHOD_EXPR obj0 message> (obj0, "message", foo, bar)>
	
perhaps rendered in the pretty printer as

	obj0 = METHOD<obj0, message>(obj0, "message", foo, bar)

wherein METHOD_EXPR has type "foo_id ()(foo_id, const char *, blort, blort)"
and expands (during rtl) to objc_msgSend.

I think you definitely want to NOT think about things you could sort-of
represent with C.

I'd want to think about how this might be used in C++ and Java before
settling the semantics of METHOD_EXPR, but I think something like this
could work well.


r~