From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8500 invoked by alias); 20 May 2010 03:29:04 -0000 Received: (qmail 8487 invoked by uid 22791); 20 May 2010 03:29:04 -0000 X-SWARE-Spam-Status: No, hits=-5.7 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 20 May 2010 03:28:56 +0000 Received: from int-mx04.intmail.prod.int.phx2.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.17]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o4K3Smtk020704 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 19 May 2010 23:28:48 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx04.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o4K3SlRa014537; Wed, 19 May 2010 23:28:47 -0400 Received: from opsy.redhat.com (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id o4K3Sk4L008565; Wed, 19 May 2010 23:28:46 -0400 Received: by opsy.redhat.com (Postfix, from userid 500) id 2608037818E; Wed, 19 May 2010 21:28:46 -0600 (MDT) From: Tom Tromey To: Stan Shebs Cc: gdb-patches@sourceware.org, Jan Kratochvil Subject: Re: RFC: implement DW_OP_bit_piece References: <4BF327D2.3000802@codesourcery.com> <4BF48941.4090500@codesourcery.com> Reply-To: Tom Tromey Date: Thu, 20 May 2010 05:10:00 -0000 In-Reply-To: <4BF48941.4090500@codesourcery.com> (Stan Shebs's message of "Wed, 19 May 2010 17:58:41 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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: 2010-05/txt/msg00406.txt.bz2 >>>>> "Stan" == Stan Shebs writes: Stan> In theory, evaluation of the expression while examining a trace frame Stan> will just work, because the DWARF condition will evaluate to the same Stan> value as it would have when looking at the live state. My understanding is that tracepoint collection happens without GDB's intervention. I think this implies that either the conditions must be uploaded, or the AX code must over-collect data along all branches of the DWARF expression. Stan> But yeah, this is the kind of thing that gets us to start muttering Stan> again about the common compilation / evaluation pathway idea. Yeah. ISTR some other justifications for a big expression evaluator rewrite -- async function calls or something like that. But it seems like this can probably be done without that. Though, I haven't looked enough at ax.h to know whether it can represent all of DWARF... which reminds me, how much trouble is it to add to AX? Is it versioned so we can detect old remotes? Tom