From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28045 invoked by alias); 9 Jun 2004 14:12:57 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 28023 invoked from network); 9 Jun 2004 14:12:54 -0000 Received: from unknown (HELO faui10.informatik.uni-erlangen.de) (131.188.31.10) by sourceware.org with SMTP; 9 Jun 2004 14:12:54 -0000 Received: from faui1d.informatik.uni-erlangen.de (faui1d [131.188.31.34]) by faui10.informatik.uni-erlangen.de (8.9.3p3/8.1.9-FAU) with ESMTP id QAA04320; Wed, 9 Jun 2004 16:12:53 +0200 (CEST) From: Ulrich Weigand Received: (from weigand@localhost) by faui1d.informatik.uni-erlangen.de (8.9.3p3/8.1.6-FAU) id QAA01440; Wed, 9 Jun 2004 16:12:53 +0200 (CEST) Message-Id: <200406091412.QAA01440@faui1d.informatik.uni-erlangen.de> Subject: Re: [PATCH] Fix frame ID comparison problem on s390 To: cagney@gnu.org (Andrew Cagney) Date: Wed, 09 Jun 2004 14:12:00 -0000 Cc: weigand@i1.informatik.uni-erlangen.de (Ulrich Weigand), drow@false.org (Daniel Jacobowitz), gdb-patches@sources.redhat.com In-Reply-To: <40B24476.6070605@gnu.org> from "Andrew Cagney" at May 24, 2004 02:52:38 PM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-SW-Source: 2004-06/txt/msg00173.txt.bz2 Andrew Cagney wrote: > Symbol table code often returns 0 to indicate a failed lookup (here a > search for the function containing pc). That zero can end up in the > frame ID. Look at calls to get_frame_func / frame_func_unwind (which > I've proposed eliminating). > > From memory architectures that do not implement dummy ID unwind also > end up with wild-card IDs (fortunatly the dummy-frame code works around > this). > > Broken tramp unwinders often leave the .code address zero (see paragraph > #1 for why). So, what would you recommend to solve the problem of 'wildcard zero pc' being confused with 'NULL pointer call'? Is my original back-end hack OK with or, or do you have another target-independent suggestion? Thanks, Ulrich -- Dr. Ulrich Weigand weigand@informatik.uni-erlangen.de