From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 43720 invoked by alias); 23 Aug 2018 21:12:45 -0000 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 Received: (qmail 43081 invoked by uid 89); 23 Aug 2018 21:12:44 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-0.0 required=5.0 tests=BAYES_20,KAM_SHORT,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=he'll, DW_AT_location, dw_at_location, showissuephp 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 ESMTP; Thu, 23 Aug 2018 21:12:43 +0000 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2FE69C050DE4; Thu, 23 Aug 2018 21:12:42 +0000 (UTC) Received: from pinnacle.lan (ovpn-116-27.phx2.redhat.com [10.3.116.27]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E9D47308BE72; Thu, 23 Aug 2018 21:12:41 +0000 (UTC) Date: Thu, 23 Aug 2018 21:12:00 -0000 From: Kevin Buettner To: gdb-patches@sourceware.org Cc: Tom de Vries , Richard Biener , Jakub Jelinek Subject: Re: [PATCH 1/3] Add support for DW_OP_GNU_variable_value Message-ID: <20180823141240.577345e0@pinnacle.lan> In-Reply-To: <93529546-71b0-4268-880a-79b00062ecd2@suse.de> References: <20180802210405.5c04ca7a@pinnacle.lan> <20180802211754.40a529c2@pinnacle.lan> <87o9ej1emk.fsf@tromey.com> <20180818133158.7e5b4dcb@pinnacle.lan> <93529546-71b0-4268-880a-79b00062ecd2@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2018-08/txt/msg00584.txt.bz2 On Wed, 22 Aug 2018 17:35:23 +0200 Tom de Vries wrote: > On 08/18/2018 10:31 PM, Kevin Buettner wrote: > > This patch adds support for DW_OP_GNU_variable_value to GDB. > > > > Jakub Jelinek provides a fairly expansive discussion of this DWARF > > expression opcode in his GCC patch... > > > > https://gcc.gnu.org/ml/gcc-patches/2017-02/msg01499.html > > > > It has also been proposed for addition to the DWARF Standard: > > > > http://www.dwarfstd.org/ShowIssue.php?issue=161109.2 > > Hi, > > AFAIU from the discussion here ( > https://gcc.gnu.org/ml/gcc-patches/2018-08/msg01351.html ) if: > - a DW_OP_GNU_variable_value refers to a die 'a', and > - there's a die 'b' with abstract_origin 'a' that does have a > DW_AT_location, and > - die 'b' is 'in scope' in an evaluation context, > then the evaluation of DW_OP_GNU_variable_value 'a' should return the > value found at the DW_AT_location of die 'b'. > > I've written a gcc demonstrator patch to generate code like this for > VLAs, and found that gdb master (containing this patch series) does not > support this. > > Is this further support of DW_OP_GNU_variable_value something you're > currently working on, or plan to work on? Tom and I discussed this briefly on IRC. Tom says that he'll take a look at it... Kevin