[Openmcl-devel] slet/rlet with C functions?

[Phil]

> A call like (#_CGRectIntegral r2 r) has already been transformed (no
> later than read-time) so that the structure-return syntax has been
> replaced with the structure-pointer-as-first-argument and that
> argument's been made explicit.  The expansion of the form returned by
> the reader macro is:
>
> (EXTERNAL-CALL "_CGRectIntegral" :ADDRESS R2 :<CGR>ECT R :VOID)
>
> and there isn't much information there that SLET could use to  
> determine
> that the :ADDRESS R2 was introduced to to hide the structure return.
> If the introduction of that first argument was more explicit - maybe
> something like
>
> (EXTERNAL-CALL "_CGRectIntegral" (:ADDRESS-FOR-STRUCTURE- 
> RETURN :<CGR>ECT) R2 :<CGR>ECT R :VOID)
>
> it'd be easier for SLET to see that a structure-return was  
> involved.  (The (:ADDRESS-FOR-STRUCTURE-RETURN :<CGR>ect) would  
> presumably get macroexpanded
> down to something simpler if this wasn't inside an SLET.)
>
> Unless that sort of annotation happened, I'm not sure that SLET could
> reasonably recognize/provide sugar for structure-returning ff-calls.

Would an alternative be to provide an alternate call path (i.e.  
rather than using the reader macro) using a function/macro like  
(EXTERNAL-FUNCTION-CALL "CGRectIntegral" R)?   Other than the  
additional effort to produce, do you see any problems with the idea?