From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Daniel Colascione Newsgroups: gmane.emacs.devel Subject: Re: Contributing LLVM.org patches to gud.el Date: Thu, 12 Feb 2015 09:42:46 -0800 Message-ID: <54DCE616.30607@dancol.org> References: <87mw4rxkzv.fsf@fencepost.gnu.org> <87y4oavxcy.fsf@fencepost.gnu.org> <87d25juy8m.fsf@fencepost.gnu.org> <83iofa8lu2.fsf@gnu.org> <87wq3qrvjz.fsf@fencepost.gnu.org> <83386d92ox.fsf@gnu.org> <874mqtsoqy.fsf@fencepost.gnu.org> <83y4o57lfj.fsf@gnu.org> <87oap1nmef.fsf@uwakimon.sk.tsukuba.ac.jp> <54DAD0C3.9040103@dancol.org> <8761b8raxh.fsf@fencepost.gnu.org> <54DB343D.5070008@dancol.org> <87h9usoa5r.fsf@uwakimon.sk.tsukuba.ac.jp> <838ug477ox.fsf@gnu.org> <83iof75c6e.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="MmQI6WjoqJjbrArcbsoWDhtqrdv56WxJs" X-Trace: ger.gmane.org 1423763000 12604 80.91.229.3 (12 Feb 2015 17:43:20 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 12 Feb 2015 17:43:20 +0000 (UTC) Cc: dak@gnu.org, emacs-devel@gnu.org To: Eli Zaretskii , stephen@xemacs.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Feb 12 18:43:10 2015 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1YLxnA-0003yN-DG for ged-emacs-devel@m.gmane.org; Thu, 12 Feb 2015 18:43:08 +0100 Original-Received: from localhost ([::1]:51534 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YLxn9-0005Ig-QG for ged-emacs-devel@m.gmane.org; Thu, 12 Feb 2015 12:43:07 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:56326) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YLxn4-0005I5-5H for emacs-devel@gnu.org; Thu, 12 Feb 2015 12:43:03 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YLxn3-00051S-5x for emacs-devel@gnu.org; Thu, 12 Feb 2015 12:43:02 -0500 Original-Received: from dancol.org ([2600:3c01::f03c:91ff:fedf:adf3]:42861) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YLxn2-00050p-RW; Thu, 12 Feb 2015 12:43:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=dancol.org; s=x; h=Content-Type:In-Reply-To:References:Subject:CC:To:MIME-Version:From:Date:Message-ID; bh=9xDsD4n2FmlzC4LaH1jDRgK7IPjOXKvVgvmStlkvpV8=; b=Dl7FPGn5OE0w1F4C+kZwWf81Vv95/apU708pVqWVioKocnTlMhkzZfVhVT2zf/lfynxq737hGZUsm8ZJw+wYQEBOWsNKGUN71Z2TRwA+v8YQODj3iyN9wptlCqf2GulRVnV6tnHHF5r8qG70RtATx7O+sjoD7Pzd6szuRLmcjiw6yWQVBILyH999q9yc7RJbts2XshLJmToCzEIVcf+HAqLjvCb5Y49Z3DWZfso65qwNjQ+iplzJv0P1lNxODZFP4/OX2VQTdl0YsWCIEEkFXQHceLMC/lo30rZVxpV2f4UcP63k68gz3osOYadm0PMNJ07Y8i7QSiztJ4XK15xcFQ==; Original-Received: from [2620:10d:c083:1004:7211:24ff:fe8c:b06d] by dancol.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84) (envelope-from ) id 1YLxmu-0006Sh-S0; Thu, 12 Feb 2015 09:42:52 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 In-Reply-To: <83iof75c6e.fsf@gnu.org> X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2600:3c01::f03c:91ff:fedf:adf3 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:182966 Archived-At: This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --MmQI6WjoqJjbrArcbsoWDhtqrdv56WxJs Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 02/12/2015 08:26 AM, Eli Zaretskii wrote: >> Date: Wed, 11 Feb 2015 18:07:42 +0200 >> From: Eli Zaretskii >> Cc: dancol@dancol.org, dak@gnu.org, emacs-devel@gnu.org >> >>> From: "Stephen J. Turnbull" >>> Cc: David Kastrup , >>> Eli Zaretskii , >>> emacs-devel@gnu.org >>> Date: Wed, 11 Feb 2015 22:22:24 +0900 >>> >>> Eli mentioned DWARF 2. The manual for GCC 4.8.4 says: >>> >>> -g >>> Produce debugging information in the operating system's native fo= rmat >>> (stabs, COFF, XCOFF, or DWARF 2). GDB can work with this debuggin= g >>> information. >>> >>> Later there is an option for specifying the version of DWARF, which >>> cautions that use of DWARF 4 "may require gdb 7 and >>> -fvar-tracking-assignments". I'll have to try that. >=20 > AFAIU, -fvar-tracking-assignments is automatically turned on when > compiling an optimized program. Maybe it's better these days. In some cases, we really can't reconstruct values. Consider something like this: unsigned x =3D foo(); unsigned y =3D x / 2; If y =3D=3D 4, we don't know whether x was 8 or 9. But that's not the case I've seen most. When debugging optimized code, though, I've run into far more annoying situations. Consider this code: void foo(void* context) { struct value* c =3D context; bar(c); } Say I'm broken into the program just before the call to bar and I want to inspect some field of c. I should be able to print c->field, right? Except GDB tells me that c is , even though context is right there and contains the same bits! --MmQI6WjoqJjbrArcbsoWDhtqrdv56WxJs Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBCAAGBQJU3OYXAAoJEN4WImmbpWBlzWYP/iCRC2aTZbz0F8XuE14uuZpU M9nfltUCM6lOIzO9mWbVqNc9r9cERQGTlSK3k7e7TCe8PTbgbHoOrb+vEXePLj0A N9/BzFz7cUmmvNaGfRyRQ+uGx9ZKtWMrLfc45+tOkuCkJ0Js9cLddHDnQq83kbBN qcqwuwj581r2YmijRFmruWr9ZhGPht5uScP4nvobyVGk/15wpzmt+5dQRx2KkwsJ fmPIkJJcqxNXMdePSoG+hNQrf1KoonPR1+wQ7tNefaq9eY22sCg4VpJSedMqywOS XSZyOA0vYKcgJuw/rgj8cAZ9L0rXJvx2U/if8rsTj2N1mjXQ2CaNcbmzawCzQuAF 5BRHGHGnwUF3nXUs/WBGz/tmbtWV4A81fRqt1yo2AosBYZTmR4IGN6cJsHAvhR2z zmMcaTxIQjvCRYK3giqSclwcluK/sxU4fFjxJxPbtIwq01QrixCz6Wmu9PuWWeUm pPBE+DlZIe8kkQfP05ZoF2XtIeH28PR8MrkS821U5Bl2hzXX5s0298x50/mgswyC BFFWpgHmzsHbRcUVNcLpva/o9Yi7rSk/ZLquCnu2Kw872EKJIILlkyINfDSpihPW ZsXceKHjCX7ll6bPCZdrcfHcCnYfnUQm/pjKPgbxC3VeIOD3eczeq5HBO9grhULy BWG7U6Efyn0vw4Yjvoi8 =5cmc -----END PGP SIGNATURE----- --MmQI6WjoqJjbrArcbsoWDhtqrdv56WxJs--