From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30433 invoked by alias); 15 May 2006 19:06:53 -0000 Received: (qmail 30425 invoked by uid 22791); 15 May 2006 19:06:52 -0000 X-Spam-Check-By: sourceware.org Received: from sibelius.xs4all.nl (HELO sibelius.xs4all.nl) (82.92.89.47) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 15 May 2006 19:06:50 +0000 Received: from elgar.sibelius.xs4all.nl (root@elgar.sibelius.xs4all.nl [192.168.0.2]) by sibelius.xs4all.nl (8.13.4/8.13.4) with ESMTP id k4FJ6FCW026143; Mon, 15 May 2006 21:06:15 +0200 (CEST) Received: from elgar.sibelius.xs4all.nl (kettenis@localhost.sibelius.xs4all.nl [127.0.0.1]) by elgar.sibelius.xs4all.nl (8.13.6/8.13.6) with ESMTP id k4FJ6FAO010674; Mon, 15 May 2006 21:06:15 +0200 (CEST) Received: (from kettenis@localhost) by elgar.sibelius.xs4all.nl (8.13.6/8.13.6/Submit) id k4FJ6ERN027161; Mon, 15 May 2006 21:06:14 +0200 (CEST) Date: Mon, 15 May 2006 19:10:00 -0000 Message-Id: <200605151906.k4FJ6ERN027161@elgar.sibelius.xs4all.nl> From: Mark Kettenis To: drow@false.org CC: schwab@suse.de, gdb-patches@sourceware.org In-reply-to: <20060515161213.GE28924@nevyn.them.org> (message from Daniel Jacobowitz on Mon, 15 May 2006 12:12:13 -0400) Subject: Re: Use DWARF CFI frame unwinder on powerpc References: <20060515161213.GE28924@nevyn.them.org> 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: 2006-05/txt/msg00342.txt.bz2 > Date: Mon, 15 May 2006 12:12:13 -0400 > From: Daniel Jacobowitz > > Hi Andreas, > > I know we tried to do this once before, and ran into hiccups based on > the GCC numbering being inconsistent. Do we know which versions of GCC > this is likely to work with, and which are likely to make it fall down > horribly? I recall that GPRs were OK, but the numbering for LR was > ambiguous. > > It might have been this: > 2004-01-21 Alan Modra > > * config/rs6000/sysv4.h (DWARF2_FRAME_REG_OUT): Define. > * dwarf2out.c (output_cfi): Map regs using DWARF2_FRAME_REG_OUT. > * doc/tm.texi (DWARF_FRAME_REGNUM, DWARF2_FRAME_REG_OUT): Document. > > Yep, here's Mark K. and Alan discussing it: > http://gcc.gnu.org/ml/gcc/2004-01/msg00025.html > > I'm worried that since we don't currently use the "this is the unwind > column" to indicate where lr lives in the table, although we could, > we'll break on pre-3.4-ish(?) binaries. Just verified that Andreas' patch breaks GDB on OpenBSD/macppc 3.9 which uses GCC 3.3.5 :(. I'm afraid this means we can't unconditionally enable the dwarf2 unwinder on all powerpc targets. Selectively enabling them on platforms that are unlikely to have ever used GCC versions before 3.4 should be fine. I think all 64-bit powerpc targets should be fine. I'll have a look at what's needed to make things work for the old unwind information. Mark