From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21634 invoked by alias); 15 Sep 2004 18:47:30 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 21627 invoked from network); 15 Sep 2004 18:47:30 -0000 Received: from unknown (HELO barry.mail.mindspring.net) (207.69.200.25) by sourceware.org with SMTP; 15 Sep 2004 18:47:30 -0000 Received: from user-119a90a.biz.mindspring.com ([66.149.36.10] helo=berman.michael-chastain.com) by barry.mail.mindspring.net with esmtp (Exim 3.33 #1) id 1C7eoT-0000yI-00; Wed, 15 Sep 2004 14:47:29 -0400 Received: from mindspring.com (localhost [127.0.0.1]) by berman.michael-chastain.com (Postfix) with SMTP id 5FEC94B102; Wed, 15 Sep 2004 14:47:24 -0400 (EDT) Date: Wed, 15 Sep 2004 18:47:00 -0000 From: Michael Chastain To: gdb@sources.redhat.com, cagney@gnu.org Subject: Re: Abort backtrace when consecutive zero PCs? Message-ID: <41488E3B.nailC0Y21J3UA@mindspring.com> References: <41487D1D.7040504@gnu.org> In-Reply-To: <41487D1D.7040504@gnu.org> User-Agent: nail 10.8 6/28/04 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-SW-Source: 2004-09/txt/msg00126.txt.bz2 Andrew Cagney wrote: > While we definitly need to allow a backtrace through a single zero PC > (for a NULL pointer call - signull.exp) should we make GDB abort when > two or more consecutive frames have a zero PC? Perhaps abort it after an identical frame is seen a second time? It's not the zero-ness that kills us, it's the repetition. The naive check would take O(n^2/2) time for n stack frames, but if you use a clever data structure, it would be O(n lg n) time. Michael