From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32255 invoked by alias); 23 Sep 2011 17:58:54 -0000 Received: (qmail 32239 invoked by uid 22791); 23 Sep 2011 17:58:52 -0000 X-SWARE-Spam-Status: No, hits=-2.0 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from smtp-out.google.com (HELO smtp-out.google.com) (216.239.44.51) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Fri, 23 Sep 2011 17:58:36 +0000 Received: from wpaz33.hot.corp.google.com (wpaz33.hot.corp.google.com [172.24.198.97]) by smtp-out.google.com with ESMTP id p8NHwZbh032383 for ; Fri, 23 Sep 2011 10:58:35 -0700 Received: from ywf9 (ywf9.prod.google.com [10.192.6.9]) by wpaz33.hot.corp.google.com with ESMTP id p8NHwYtD002121 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for ; Fri, 23 Sep 2011 10:58:34 -0700 Received: by ywf9 with SMTP id 9so3453265ywf.36 for ; Fri, 23 Sep 2011 10:58:34 -0700 (PDT) Received: by 10.100.237.8 with SMTP id k8mr3467350anh.64.1316800714547; Fri, 23 Sep 2011 10:58:34 -0700 (PDT) MIME-Version: 1.0 Received: by 10.100.237.8 with SMTP id k8mr3467335anh.64.1316800714228; Fri, 23 Sep 2011 10:58:34 -0700 (PDT) Received: by 10.100.249.7 with HTTP; Fri, 23 Sep 2011 10:58:34 -0700 (PDT) In-Reply-To: References: Date: Fri, 23 Sep 2011 17:58:00 -0000 Message-ID: Subject: Re: RFC: DWARF Extensions for Separate Debug Info Files ("Fission") From: Cary Coutant To: Jason Molenda Cc: dwarf-discuss@lists.dwarfstd.org, gcc@gcc.gnu.org, gdb@sourceware.org, Doug Evans , Paul Pluzhnikov , Sterling Augustine Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-System-Of-Record: true X-IsSubscribed: yes Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org X-SW-Source: 2011-09/txt/msg00258.txt.bz2 > The Apple approach has both the features of the Sun/HP implementation as = well as the ability to create a standalone debug info file. Thanks for the clarifications. I based my comments on a description you sent me a couple of years ago, and I apologize for any oversimplifications I introduced. > The compiler puts DWARF in the .o file, the linker adds some records in t= he executable which help us to understand where files/function/symbols land= ed in the final executable[1]. Did you intend to add a footnote? > =A0If the user runs our gdb or lldb on one of these binaries, the debugge= r will read the DWARF directly out of the .o files on the fly. =A0Because t= he linker doesn't need to copy around/update/modify the DWARF, link times a= re very fast. =A0If the developer decides to debug the program, no extra st= eps are required - the debugger can be started up & used with the debug inf= o still in the .o files. We're trying to achieve something very similar, but we have the additional goal of separating the info from the .o files because of our distributed build environment. I also wanted to attempt to standardize the approach, instead of having each vendor go in separate directions. Thanks, -cary