From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23548 invoked by alias); 4 Apr 2002 19:40:15 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 23520 invoked from network); 4 Apr 2002 19:40:14 -0000 Received: from unknown (HELO nevyn.them.org) (128.2.145.6) by sources.redhat.com with SMTP; 4 Apr 2002 19:40:14 -0000 Received: from drow by nevyn.them.org with local (Exim 3.35 #1 (Debian)) id 16tD5b-0002rg-00; Thu, 04 Apr 2002 14:40:07 -0500 Date: Thu, 04 Apr 2002 11:40:00 -0000 From: Daniel Jacobowitz To: Elena Zannoni Cc: Michael Elizabeth Chastain , Andrew Cagney , gdb-patches@sources.redhat.com Subject: Re: [RFA] import drow dbxread.c fix to branch Message-ID: <20020404144007.A10769@nevyn.them.org> Mail-Followup-To: Elena Zannoni , Michael Elizabeth Chastain , Andrew Cagney , gdb-patches@sources.redhat.com References: <200204040536.g345a6t30923@duracef.shout.net> <20020404010112.A13460@nevyn.them.org> <15532.43273.686279.120593@localhost.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15532.43273.686279.120593@localhost.redhat.com> User-Agent: Mutt/1.3.23i X-SW-Source: 2002-04/txt/msg00117.txt.bz2 On Thu, Apr 04, 2002 at 02:27:05PM -0500, Elena Zannoni wrote: > Daniel Jacobowitz writes: > > On Wed, Apr 03, 2002 at 11:36:06PM -0600, Michael Elizabeth Chastain wrote: > > > DanielJ writes: > > > > Only shows on GCC 3.1, eh? I'll try to look at it later, but I have no > > > > post-3.0 toolchain installed right now. Actually, I should > > > > investigate, to make sure it isn't a 3.1 regression... > > > > > > On the next spin, I'll make a special report of regressions for gcc > > > 3.0.4 versus gcc-3_1-branch. You can already look at "difference by gcc" > > > in the regular report if you want to pick up a hot spot or two. > > > > > > BTW my test harness now saves the whole test directory, including all > > > the executable files. In fact I'll just throw some tarball up in my > > > ftp directory in case it might help someone: > > > > > > ftp://ftp.shout.net/pub/users/mec/gdb/for-pr-gdb-381.tar.gz > > > ftp://ftp.shout.net/pub/users/mec/gdb/for-pr-gdb-381-src.tar.gz > > > > Thanks. It does help - that was pretty easy, actually :). I've found > > the bug; mi-cmd-disassemble does not recognize '0' line numbers, and it > > needs to. I don't know why only 3.1 triggers this. Probably a > > function padding thing; the end of the previous function seems to share > > a PC with the beginning of the one being listed. Here's a patch; > > Andrew, how's this look? > > > > Take a look at the way gdbtk does it, in > gdbtk/generic/gdbtk-cmd.c:gdb_disassemble_driver(). > Can we adopt that solution? > > (I really can't wait until we can get rid of this duplication/triplication of > disassembly code. I think I'll start cleaning some things up). I'm not sure. That code assumes a different meaning of line==0 than the one we're using. Particularly, if I understand correctly, the meaning in gdbtk comes from a set of Cygnus-internal stabs for handling live range splitting, which never made it into any public GCC and are completely obsoleted by DWARF-2. I prefer: > + /* Skip any end-of-function markers. */ > + if (le[i].line == 0) > + continue; > + to: /* GCC sometimes emits line directives with a linenumber of 0. It does this to handle live range splitting. This may be a bug, but we need to be able to handle it. For now, use the previous instructions line number. Since this is a bit of a hack anyway, we will just lose if the bogus sline is the first line of the range. For functions, I have never seen this to be the case. */ if (le[i].line != 0) { mle[newlines].line = le[i].line; } else { if (newlines > 0) mle[newlines].line = mle[newlines - 1].line; } i.e. skip the line, not fake up a line number for it. It's a special-purpose marker, not a generic line number. If you agree with me, want me to update gdbtk's version to match? Does this same code exist in a third location? -- Daniel Jacobowitz Carnegie Mellon University MontaVista Software Debian GNU/Linux Developer