Date: Mon, 22 Nov 2004 18:18:30 -0500
From: Jakub Jelinek <jakub@redhat.com>
To: Bill Davidsen <davidsen@tmr.com>
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>, linux-kernel@vger.kernel.org
Subject: Re: var args in kernel?
Message-ID: <20041122231828.GX10340@devserv.devel.redhat.com>
Reply-To: Jakub Jelinek <jakub@redhat.com>
References: <20041122113328.GQ10340@devserv.devel.redhat.com> <41A25D53.9050909@tmr.com>
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On Mon, Nov 22, 2004 at 04:42:43PM -0500, Bill Davidsen wrote:
> Assignment of struct to struct has been a 
> part of C since earliest times. I used it in ~1990 in code which ran on 
> Z80, Multics, M68k, VAX and Cray2, and it worked without any ifdefs (for 
> that, there were "just a few" for other issues like 8 vs. 9 bit char, etc).

It is not a struct on those arches, but array of structs.
Just try:
#include <stdarg.h>

void foo (int x, ...)
{
  va_list ap, ap2;
  va_start (ap, x);
  ap2 = ap;
  va_end (ap);
}
on say x86_64 or ppc32 and you'll see what I mean:
test.c:7: error: incompatible types in assignment

That's why the standard has va_copy so that you can do the
copying portably.

	Jakub
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