From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28444 invoked by alias); 11 May 2006 22:32:13 -0000 Received: (qmail 28434 invoked by uid 22791); 11 May 2006 22:32:12 -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; Thu, 11 May 2006 22:32:10 +0000 Received: from drow by nevyn.them.org with local (Exim 4.54) id 1FeJhY-00055n-4B; Thu, 11 May 2006 18:32:08 -0400 Date: Thu, 11 May 2006 22:32:00 -0000 From: Daniel Jacobowitz To: Jim Blandy Cc: gdb-patches@sourceware.org Subject: Re: [RFC] Move the frame zero PC check earlier Message-ID: <20060511223208.GA19492@nevyn.them.org> Mail-Followup-To: Jim Blandy , gdb-patches@sourceware.org References: <20060510180312.GA12606@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.8i 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: 2006-05/txt/msg00225.txt.bz2 On Thu, May 11, 2006 at 03:24:31PM -0700, Jim Blandy wrote: > > It looks good to me. I'm just curious why we even bother looking up > the frame type for the older frame whose PC is zero. (I understand > this test is inherited from the existing code.) You've gotta. It looks like this: #0 somefunc () #1 #2 0x00000000 in Nothing At All #3 function_which_calls_its_arg (arg = (void (*)()) 0x00000000) #4 main () There was a check for this at some point in the distant past - I believe it was committed, not just proposed - which didn't do this. Ergo signull.exp. Er... wait a second! You're talking about a different frame than I am, aren't you? Do you mean this? + if (prev_frame->level > 0 + && get_frame_type (this_frame) == NORMAL_FRAME + && get_frame_pc (prev_frame) == 0) In which case we could do this even earlier. Can there be sigtramp or dummy frames which have pc == 0? -- Daniel Jacobowitz CodeSourcery