From mboxrd@z Thu Jan  1 00:00:00 1970
Path: news.gmane.org!not-for-mail
From: Eli Zaretskii <eliz@gnu.org>
Newsgroups: gmane.emacs.devel
Subject: Re: valid_pointer_p
Date: Sat, 12 Aug 2006 14:06:25 +0300
Message-ID: <uac6adxhq.fsf@gnu.org>
References: <u64hgd7us.fsf@gnu.org> <m3odv82bzu.fsf@kfs-l.imdomain.dk>
	<uirlfbx3w.fsf@gnu.org> <m3d5bm4u7t.fsf@kfs-l.imdomain.dk>
	<ud5bmo3vz.fsf@gnu.org> <m3zmeq6tcp.fsf@kfs-l.imdomain.dk>
	<u64h7l4fd.fsf@gnu.org> <m3zmeiu92l.fsf@kfs-l.imdomain.dk>
	<uvep6k0e0.fsf@gnu.org> <m364gy283m.fsf@kfs-l.imdomain.dk>
Reply-To: Eli Zaretskii <eliz@gnu.org>
NNTP-Posting-Host: main.gmane.org
X-Trace: sea.gmane.org 1155380803 20459 80.91.229.2 (12 Aug 2006 11:06:43 GMT)
X-Complaints-To: usenet@sea.gmane.org
NNTP-Posting-Date: Sat, 12 Aug 2006 11:06:43 +0000 (UTC)
Cc: emacs-devel@gnu.org
Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Aug 12 13:06:41 2006
Return-path: <emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org>
Envelope-to: ged-emacs-devel@m.gmane.org
Original-Received: from lists.gnu.org ([199.232.76.165])
	by ciao.gmane.org with esmtp (Exim 4.43)
	id 1GBrK9-0006L9-Qe
	for ged-emacs-devel@m.gmane.org; Sat, 12 Aug 2006 13:06:38 +0200
Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43)
	id 1GBrK9-0007xS-BT
	for ged-emacs-devel@m.gmane.org; Sat, 12 Aug 2006 07:06:37 -0400
Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1GBrJw-0007vG-Ac
	for emacs-devel@gnu.org; Sat, 12 Aug 2006 07:06:24 -0400
Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1GBrJu-0007qm-J3
	for emacs-devel@gnu.org; Sat, 12 Aug 2006 07:06:23 -0400
Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1GBrJu-0007qZ-9H
	for emacs-devel@gnu.org; Sat, 12 Aug 2006 07:06:22 -0400
Original-Received: from [192.114.186.73] (helo=heller.inter.net.il)
	by monty-python.gnu.org with esmtp (Exim 4.52) id 1GBrPF-0004gV-DV
	for emacs-devel@gnu.org; Sat, 12 Aug 2006 07:11:53 -0400
Original-Received: from HOME-C4E4A596F7 (IGLD-80-230-154-186.inter.net.il
	[80.230.154.186]) by heller.inter.net.il (MOS 3.7.3a-GA)
	with ESMTP id AFB36471 (AUTH halo1);
	Sat, 12 Aug 2006 14:06:19 +0300 (IDT)
Original-To: storm@cua.dk (Kim F. Storm)
In-reply-to: <m364gy283m.fsf@kfs-l.imdomain.dk> (storm@cua.dk)
X-BeenThere: emacs-devel@gnu.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: "Emacs development discussions." <emacs-devel.gnu.org>
List-Unsubscribe: <http://lists.gnu.org/mailman/listinfo/emacs-devel>,
	<mailto:emacs-devel-request@gnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/emacs-devel>
List-Post: <mailto:emacs-devel@gnu.org>
List-Help: <mailto:emacs-devel-request@gnu.org?subject=help>
List-Subscribe: <http://lists.gnu.org/mailman/listinfo/emacs-devel>,
	<mailto:emacs-devel-request@gnu.org?subject=subscribe>
Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org
Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org
Xref: news.gmane.org gmane.emacs.devel:58311
Archived-At: <http://permalink.gmane.org/gmane.emacs.devel/58311>

> Cc: emacs-devel@gnu.org
> From: storm@cua.dk (Kim F. Storm)
> Date: Sat, 12 Aug 2006 00:58:05 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Well, I figured that much.  But we do know the length of each object,
> > so we could validate exactly what is needed, right?  Just add another
> > argument to valid_pointer_p that tells it how many bytes to validate.
> 
> The problem is that you have to deref the pointer to know the length
> of the object...

??? Don't we have macros, like INTEGERP, SUBRP, etc. to do that
without dereferencing?  The length of the primitive Lisp types is
known, right?

Even if you are right, dereferencing a pointer accesses a region in
memory whose length is known in advance, so at most we will need to
call valid_pointer_p twice.