From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca (simark.ca [158.69.221.121]) by sourceware.org (Postfix) with ESMTPS id 911703857C60 for ; Thu, 16 Jul 2020 15:41:10 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 911703857C60 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=simark.ca Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=simark@simark.ca Received: from [10.0.0.11] (173-246-6-90.qc.cable.ebox.net [173.246.6.90]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by simark.ca (Postfix) with ESMTPSA id B8A2D1E794; Thu, 16 Jul 2020 11:41:08 -0400 (EDT) Subject: Re: [PATCH V5] Fix issues with reading rnglists, especially from dwo files, for DWARF v5 To: Caroline Tice Cc: "H.J. Lu" , Eric Christopher , Tom Tromey , Caroline Tice via Gdb-patches References: <5eab18a1-c7e9-1a77-7f65-944eea10aa85@simark.ca> <5ccfe911-6049-e8f3-4874-9991b2649512@simark.ca> <4da310be-fa9f-9f21-8988-81af58ec73e3@simark.ca> From: Simon Marchi Message-ID: <804c1d3e-522f-f6bf-0106-330dcfd1fc50@simark.ca> Date: Thu, 16 Jul 2020 11:41:06 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: fr Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-3.5 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, KAM_NUMSUBJECT, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Jul 2020 15:41:11 -0000 On 2020-07-16 12:46 a.m., Caroline Tice wrote: > The attached patch has an updated commit message that explains how to > run the test and what version of clang was used. Other than that it > is identical to the previous patch. Thanks, I've now merged it. >> Just wondering, doesn't gcc emit at least *some* DWARF 5 by now? If so, >> can't the GNU assembler deal with it? >> > > Not that it matters for this patch, but I believe you are > misunderstanding the situation. GCC *does* emit some DWARF 5, but at > least the GCC version I'm using (Debian 9.3.0-8) does not seem to be > generating DWARF v5 line table sections; the line table section it > generates (when I compile with -gdwarf-5) is a DWARF v3 .debug_line > sections. > > In fact my gcc-generated binary has the following debug sections, > which are a mix of various dwarf versions: > > .debug_aranges (dwarf v2) > .debug_info (dwarf v5) > .debug_abbrev (dwarf v5) > .debug_line (dwarf v3) > .debug_str > .debug_addr (dwarf v5) > .debug_gnu_pubnames (dwarf v2) > .debug_gnu_pubtypes (dwarf v2) > .debug_rnglists (dwarf v5) I see. But if we generate a synthetic test case (using the DWARF assembler in the GDB testsuite) for the current issue, that deals with range lists, I don't think we even need a .debug_line section, do we? And if we do, we always have the option of generating a v3 one. > In contrast, here are the sections my clang compiler, when passed > -gdwarf-5 is generating dwarf v5 versions > of nearly all the sections: > > .debug_info (dwarf v5) > .debug_abbrev (dwarf v5) > .debug_line (dwarf v5) > .debug_str > .debug_addr (dwarf v5) > .debug_rnglists (dwarf v5) > .debug_str_offsets (dwarf v5) > .debug_gnu_pubnames (dwarf v2) > .debug_gnu_pubtypes (dwarf v2) > .debug_line_str (dwarf v5) > > So either the GNU assembler has not been updated to handle DWARF v5 > .debug_line file indices because GCC is not yet generating them; or > GCC is not yet generating them because the GNU assembler has not yet > been > updated to handle them. Take your pick. > > In any case, I hope my patch is now acceptable! :-) Simon