Xref: utzoo comp.unix.wizards:16662 comp.lang.c:19172
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!apple!desnoyer
From: desnoyer@Apple.COM (Peter Desnoyers)
Newsgroups: comp.unix.wizards,comp.lang.c
Subject: Re: Needed:  A (Portable) way of setting up the arg stack
Keywords: 1/varargs, callg
Message-ID: <32256@apple.Apple.COM>
Date: 5 Jun 89 17:12:46 GMT
References: <708@mitisft.Convergent.COM> <32208@apple.Apple.COM> <10354@smoke.BRL.MIL> <11830@bloom-beacon.MIT.EDU>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 15

In article <11830@bloom-beacon.MIT.EDU> scs@adam.pika.mit.edu (Steve Summit) writes:
> [routine called va_call that takes a function pointer, an argument
> count, and an array of arguments]
>
>va_call can be implemented in one line of assembly language...
>A routine such as va_call MUST be written in assembly language; it
>is one of the handful of functions I know of that cannot possibly
>be written in C.

Almost correct. In Turbo C there are pseudo-variables for the stack
pointer, etc.  You can also access these registers (warning -
approaching gross kludge) by doing a setjmp and knowing the jmp_buf
format. 

				Peter Desnoyers