From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27725 invoked by alias); 17 Mar 2016 21:14:58 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 27708 invoked by uid 89); 17 Mar 2016 21:14:57 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=jose, Jose, unwinding X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Thu, 17 Mar 2016 21:14:57 +0000 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id 9142B8AE72; Thu, 17 Mar 2016 21:14:55 +0000 (UTC) Received: from anchor.twiddle.net (vpn-231-20.phx2.redhat.com [10.3.231.20]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u2HLEsDW019988; Thu, 17 Mar 2016 17:14:55 -0400 Subject: Re: [PATCH][SPARC] sparc: switch -fasynchronous-unwind-tables on by default. To: "Jose E. Marchesi" , Eric Botcazou References: <1456435447-23676-1-git-send-email-jose.marchesi@oracle.com> <10333302.PFiANu1Ugm@polaris> <87h9grcy85.fsf@oracle.com> Cc: gcc-patches@gcc.gnu.org From: Richard Henderson Message-ID: <56EB1E4D.4050505@redhat.com> Date: Thu, 17 Mar 2016 21:17:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <87h9grcy85.fsf@oracle.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2016-03/txt/msg01050.txt.bz2 On 02/29/2016 07:50 AM, Jose E. Marchesi wrote: > The backtrace(3) implementation for sparc contains a simple unwinder > that works well in most cases, but that unwinder is not used if > libgcc_s.so can be dlopened and it provides _Unwind_Backtrace. There's no reason that simple unwinder can't be put into MD_FALLBACK_FRAME_STATE_FOR. Currently we only use that for unwinding through signal stacks, but it could be used for anything that the dwarf2 unwinder doesn't have data for. Given sparc register windows, this seems particularly reliable. r~