From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16491 invoked by alias); 2 Apr 2003 20:38:01 -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 16459 invoked from network); 2 Apr 2003 20:38:00 -0000 Received: from unknown (HELO crack.them.org) (65.125.64.184) by sources.redhat.com with SMTP; 2 Apr 2003 20:38:00 -0000 Received: from nevyn.them.org ([66.93.61.169] ident=mail) by crack.them.org with asmtp (Exim 3.12 #1 (Debian)) id 190ntk-0000CP-00; Wed, 02 Apr 2003 13:27:48 -0600 Received: from drow by nevyn.them.org with local (Exim 3.36 #1 (Debian)) id 190ntd-0006v9-00; Wed, 02 Apr 2003 14:27:41 -0500 Date: Wed, 02 Apr 2003 20:38:00 -0000 From: Daniel Jacobowitz To: gdb@sources.redhat.com, binutils@sources.redhat.com, nickc@redhat.com Subject: Re: gdb.mi/mi-cli.exp failures Message-ID: <20030402192740.GA3021@nevyn.them.org> Mail-Followup-To: gdb@sources.redhat.com, binutils@sources.redhat.com, nickc@redhat.com References: <3E89AB79.1060700@redhat.com> <3E89C7DB.3080906@redhat.com> <20030401182249.GB24160@nevyn.them.org> <20030402172825.GA32596@nevyn.them.org> <20030402180505.GA29974@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.1i X-SW-Source: 2003-04/txt/msg00032.txt.bz2 On Wed, Apr 02, 2003 at 10:53:08AM -0800, Ian Lance Taylor wrote: > Daniel Jacobowitz writes: > > > > > Well, do you have another suggestion for how to approach this? We're > > > > not actually linking; but I need to get the symbols from the input file > > > > into a symbol table with forged offsets in order to apply relocations > > > > against them. > > > > > > Well, I don't really know the context. If you're not linking, then it > > > seems to me that you'll be better off avoiding the linking calls. The > > > add_symbols() call is the first phase of a link, and is expected to be > > > followed by the second phase of a link; despite the name > > > add_symbols(), it doesn't just add symbols to a hash table. > > > > > > If you really just want to put the symbols into a hash table, can you > > > just get the symbol table generically and add them to a hash table > > > yourself? > > > > IIRC, then we may get a different kind of hash table than the > > platform's relocation application functions expect. It's been a little > > while though. > > > > The context is in bfd/simple.c if you want to look at it. The > > intention is to use this code for both gdb and objdump (they do use it > > now, to be more accurate) to relocate the contents of debug sections. > > This is necessary for the general cases of debugging shared objects and > > unlinked object modules. > > In principle, bfd_get_relocated_section_contents() should not expect > to see the exact same sort of hash table that is generated by > add_symbols(). It should work with any type of linker hash table. If > it doesn't work, then linking to a different object file format will > not work. The same applies to the HOWTO functions, of course. > > Of course, in practice linking to a different object file format may > not be supported. But in general the HOWTO functions can't expect to > see a linker hash table, since they are also called by the assembler. > And there is no reason to write get_relocated_section_contents() to > see a particular type of hash table, because it will never be called > if you use add_symbols() and final_link(). > > So while I'm perfectly willing to believe that there is a problem, I > don't know what it is. It seems to me that the simple.c code ought to > be able to call _bfd_generic_link_add_symbols(), and we could make > some guarantees about that specific function. If that doesn't work, > then why doesn't it? It appears to work, and fixes one of the two problems. I'll post a patch in a little while. This doesn't solve the question of freeing the symbol table; I suppose that using bfd_alloc for it may be the way to go. Note that this still isn't ideal, because the symbol table is not clearly cached in the BFD anywhere; so we'll get a new one each time we relocate a section. What we really need is to cache the canonicalized symbol table, I suppose. Really, BFD isn't set up to work the way I want it to for this functionality. I don't know what to do to make it better. -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer