From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26718 invoked by alias); 14 Feb 2003 19:24:48 -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 26696 invoked from network); 14 Feb 2003 19:24:47 -0000 Received: from unknown (HELO dberlin.org) (69.3.5.6) by 172.16.49.205 with SMTP; 14 Feb 2003 19:24:47 -0000 Received: from [192.168.1.34] (account dberlin HELO dberlin.org) by dberlin.org (CommuniGate Pro SMTP 4.0.5) with ESMTP-TLS id 2754389; Fri, 14 Feb 2003 14:24:47 -0500 Date: Fri, 14 Feb 2003 19:24:00 -0000 Subject: Re: Reference to .debug_loc Content-Type: text/plain; charset=US-ASCII; format=flowed Mime-Version: 1.0 (Apple Message framework v551) Cc: Michal Ludvig , gdb , gcc@sources.redhat.com To: Daniel Jacobowitz From: Daniel Berlin In-Reply-To: <20030214152619.GD30416@nevyn.them.org> Message-Id: Content-Transfer-Encoding: 7bit X-SW-Source: 2003-02/txt/msg00243.txt.bz2 On Friday, February 14, 2003, at 10:26 AM, Daniel Jacobowitz wrote: > On Fri, Feb 14, 2003 at 03:57:55PM +0100, Michal Ludvig wrote: >> Hi again, >> when location lists are in use, .debug_info looks like this: >> >> .section .debug_info >> .long 0x187 # Length of Compilation Unit Info >> .value 0x2 # DWARF version number >> .long .Ldebug_abbrev0 # Offset Into Abbrev. Section >> .byte 0x8 # Pointer Size (in bytes) >> .uleb128 0x1 # (DIE (0xb) DW_TAG_compile_unit) >> .long .Ldebug_line0 # DW_AT_stmt_list >> .quad .Letext0 # DW_AT_high_pc >> .quad .Ltext0 # DW_AT_low_pc >> .byte 0x1 # DW_AT_language >> [...] >> .uleb128 0x3 # (DIE (0x50) DW_TAG_formal_parameter) >> .long .LASF2 # DW_AT_name: "value" >> .byte 0x1 # DW_AT_decl_file >> .byte 0x2 # DW_AT_decl_line >> .long 0x8f # DW_AT_type >> .long .LLST0-.Ldebug_loc0 # DW_AT_location >> >> So, the reference to .debug_loc on the last line of the example >> (DW_AT_location) is an offset within that section, ie. it's 0 (NULL) >> for >> the first entry with a location list. However when I link several .o >> files together, each of them have DW_AT_location entries based at the >> same NULL. >> Err, why? If they are in different files, it should be adjusting the offsets when it merges the sections together, no? >> This time I realy can't see a way to find out at what position in the >> resulting (ie. linked from several ones) .debug_loc should I start >> reading for a given compilation unit. >> >> Should there be something more in the CU header? Something similar to >> .long .Ldebug_abbrev0 # Offset Into Abbrev. Section >> For example >> .long .Ldebug_loc0 # Offset Into Loclist Section >> No. >> Or is there another way? > > At a guess it should be like DW_AT_ranges: > .long .Ldebug_ranges0+0x0 # DW_AT_ranges > > I.E. dw2_asm_output_offset, rather than dw2_asm_output_delta, in GCC. > It's supposed to be the offset from the beginning of the debug_loc section. Will this do that? > -- > Daniel Jacobowitz > MontaVista Software Debian GNU/Linux Developer