From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9483 invoked by alias); 9 Jun 2006 17:20:24 -0000 Received: (qmail 9423 invoked by uid 22791); 9 Jun 2006 17:20:21 -0000 X-Spam-Check-By: sourceware.org Received: from nevyn.them.org (HELO nevyn.them.org) (66.93.172.17) by sourceware.org (qpsmtpd/0.31.1) with ESMTP; Fri, 09 Jun 2006 17:20:17 +0000 Received: from drow by nevyn.them.org with local (Exim 4.54) id 1Fokeb-0000W3-L2; Fri, 09 Jun 2006 13:20:13 -0400 Date: Fri, 09 Jun 2006 17:20:00 -0000 From: Daniel Jacobowitz To: Eli Zaretskii Cc: Jim Blandy , julian@codesourcery.com, gdb-patches@sourceware.org Subject: Re: [PATCH] Accept DWARF 3-format debug info Message-ID: <20060609172013.GA1751@nevyn.them.org> Mail-Followup-To: Eli Zaretskii , Jim Blandy , julian@codesourcery.com, gdb-patches@sourceware.org References: <4488A920.9090705@codesourcery.com> <20060609122532.GA24240@nevyn.them.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11+cvs20060403 X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2006-06/txt/msg00099.txt.bz2 On Fri, Jun 09, 2006 at 07:41:54PM +0300, Eli Zaretskii wrote: > > On Fri, Jun 09, 2006 at 10:28:07AM +0300, Eli Zaretskii wrote: > > > In this case, what will happen when GDB sees a DWARF-3 feature it > > > doesn't yet support? I think we should make sure it displays a > > > warning message, instead of throwing an internal error (or some > > > similar fatal reaction). > > > > Same thing that happens when we see a DWARF-2 feature we don't support > > ;-) > > Which is -- what? (I really don't know.) It depends. We try to ignore it. However, often debugging information relies on some new construct in place of an older, less expressive one. Syntactically, GDB will cope with most unrecognized constructs just fine. Semantically, however, if it doesn't recognize something it may not cope well with debugging. This is already very true for DWARF-2; some of the other patches Julian will be posting are along those lines. > > GCC is actually a DWARF-3 producer in almost all ways. It just didn't > > bump the version number, to avoid upsetting consumers, since most of > > the changes are forwards-compatible. > > Well, the same reasons GCC had to avoid upsetting consumers might be > relevant for us as well, don't you think? No, because we're a consumer of this information, not a producer. This is a "conservative in what you generate, liberal in what you accept" sort of situation. Strictly speaking, we're handling a lot of tags in DWARF-2 that aren't really part of DWARF-2 - but that's harmless. -- Daniel Jacobowitz CodeSourcery