From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7672 invoked by alias); 30 Dec 2009 13:45:27 -0000 Received: (qmail 7664 invoked by uid 22791); 30 Dec 2009 13:45:26 -0000 X-SWARE-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from NaN.false.org (HELO nan.false.org) (208.75.86.248) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 30 Dec 2009 13:45:20 +0000 Received: from nan.false.org (localhost [127.0.0.1]) by nan.false.org (Postfix) with ESMTP id B1A2E10DAA; Wed, 30 Dec 2009 13:45:18 +0000 (GMT) Received: from caradoc.them.org (209.195.188.212.nauticom.net [209.195.188.212]) by nan.false.org (Postfix) with ESMTP id 947CA10D9E; Wed, 30 Dec 2009 13:45:18 +0000 (GMT) Received: from drow by caradoc.them.org with local (Exim 4.69) (envelope-from ) id 1NPyrV-0003ua-RC; Wed, 30 Dec 2009 08:45:17 -0500 Date: Wed, 30 Dec 2009 13:45:00 -0000 From: Daniel Jacobowitz To: Ian Lance Taylor Cc: Mark Kettenis , brobecker@adacore.com, gdb-patches@sourceware.org Subject: Re: [RFC] frame_id_inner check and -fsplit-stack Message-ID: <20091230134517.GA14669@caradoc.them.org> Mail-Followup-To: Ian Lance Taylor , Mark Kettenis , brobecker@adacore.com, gdb-patches@sourceware.org References: <20091229190720.GE24363@adacore.com> <200912291948.nBTJmbCx011266@glazunov.sibelius.xs4all.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2009-12/txt/msg00438.txt.bz2 On Wed, Dec 30, 2009 at 12:06:09AM -0800, Ian Lance Taylor wrote: > Looking at DWARF, I see that there is a calling_convention enum which > can be added to the DW_TAG_subprogram for a function. I don't know all > that much about DWARF; does that seem like the right sort of thing to > do? No. The split-stack-ness doesn't affect how the function is called; the attribute's for cases like regparm. > That wouldn't help with the unwind info, though. There I think we could > add a new augmentation code for a split-stack function. The presence of > the augmentation would mean that the stack might be out of order when > unwinding through this function. I think that would work because > unwinders which didn't recognize it would simply ignore it. But again I > am far from being an expert in this area. An augmentation ought to work for this. Similarly, GDB could check for the prologue sequence if there is no unwind info. Didn't we have another report that the inner-than check was causing trouble, just a few months ago? I think it had to do with the Linux kernel, but I can't find the details. This check causes a lot of trouble. -- Daniel Jacobowitz CodeSourcery