From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9413 invoked by alias); 26 Apr 2002 14:58:18 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 9356 invoked from network); 26 Apr 2002 14:58:16 -0000 Received: from unknown (HELO localhost.redhat.com) (24.112.240.27) by sources.redhat.com with SMTP; 26 Apr 2002 14:58:16 -0000 Received: from cygnus.com (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id 734FC3D5A; Fri, 26 Apr 2002 10:58:14 -0400 (EDT) Message-ID: <3CC96B06.3000302@cygnus.com> Date: Fri, 26 Apr 2002 07:58:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:0.9.9) Gecko/20020424 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Andrew Cagney Cc: gdb@sources.redhat.com Subject: Re: [rfc] frame->frame => frame->addr && frame->base() References: <3CB5F868.8070001@cygnus.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2002-04/txt/msg00461.txt.bz2 > Hello, > > This comes from DanielB's and my discussion about dwarf2 CFA and dwarf2's frame_base vs GDB's frame->frame. > > An executive summary is that the two dwarf2 frame concepts (CFA and frame_base) do not go into one GDB frame (frame->frame). > > Because of this, I'd like to propose that the frame object have both: > > struct frame_info > { > ... > > // An ISA/ABI specific address within the ``specified frame'' that is constant throughout the lifetime of the frame. This address is used by GDB as a handle to identify this frame. This field must be initialized as part of the creation of a frame object. (see dwarf2 CFA) > > CORE_ADDR addr; Hmm, MichaelS has pointed out (check the code for finding a frame) that all we know about the existing frame->frame is that it is going to fall somewhere in the range of stack addresses allocated to the function. Making for an even more in-exact science, this ``in'' has poorly defined boundary conditions - consider pre/post incr/decr SPs, ABIs that allocate beyond SP and the like. I guess, on the bright side, we now have it ``defined''. I'll update the comments then try to think of a next move (suggestions?). Andrew