This is the mail archive of the
mailing list for the GDB project.
Re: Debugging issue with gdbserver and a daemon on the target
- From: Laszlo Papp <lpapp at kde dot org>
- To: Pedro Alves <palves at redhat dot com>
- Cc: gdb at sourceware dot org
- Date: Wed, 20 Aug 2014 10:09:55 +0100
- Subject: Re: Debugging issue with gdbserver and a daemon on the target
- Authentication-results: sourceware.org; auth=none
- References: <CAOMwXhPxtfv7f=akjpuTh+HNCGDeEm0vxen1Kp3pPco++gvuLg at mail dot gmail dot com> <53F3743F dot 3000106 at redhat dot com> <CAOMwXhMmyXmHi9gZADtkTYb9mbF2hZRv2vHPC5AEcNWkE9duBg at mail dot gmail dot com> <53F3776D dot 2010705 at redhat dot com> <CAOMwXhOQkPH-6By+C0zcu3RAQMhWypC18ZsFrLK+ncdAcq3b0Q at mail dot gmail dot com> <53F4598D dot 8020208 at redhat dot com> <CAOMwXhO+Wr0WChhK7UCebEy7VMsOdYjzbKs+d569qwSMSFo8Kw at mail dot gmail dot com> <CAOMwXhNzTC6pgX0TKtagQoMB6tLGoCsDtkQRK2oF2qXkcx24RA at mail dot gmail dot com> <CAOMwXhM8D7UmLzhme=pG2h9+GwOsg_eGEHA+Y3hNbe1kuN_QAw at mail dot gmail dot com>
On Wed, Aug 20, 2014 at 9:39 AM, Laszlo Papp <firstname.lastname@example.org> wrote:
> On Wed, Aug 20, 2014 at 9:36 AM, Laszlo Papp <email@example.com> wrote:
>> On Wed, Aug 20, 2014 at 9:25 AM, Laszlo Papp <firstname.lastname@example.org> wrote:
>>> On Wed, Aug 20, 2014 at 9:17 AM, Pedro Alves <email@example.com> wrote:
>>>> On 08/19/2014 07:01 PM, Laszlo Papp wrote:
>>>>> Hmm, it seems that the stripped binary on the target and the one on
>>>>> the host were out-of-sync. This is really strange since I have not
>>>>> changed the source code. Seems different compilations still can get
>>>>> out-of-sync for the same code so that when I rebuild the same source
>>>>> code, I always need to update the binary on the target, too?
>>>> Ideally, if you used the exact same inputs, and the exact same tools,
>>>> and the same exact same tool options, the output is the same. You
>>>> can check that with md5sum, or some such.
>>> Thanks. I will check that next time.
>>>>> Anyway, now I only have problems with finding the sources file to view
>>>>> them in cgdb. I do not know why it is wrong, but it seems to be. As
>>>>> you can see the paths are set up for dwarf correctly:
>>>>> ... yet, gdb says src/bar.c cannot be found even though it should be
>>>>> in the aforementioned
>>>>> path, provided my sysroot setting is good above, but if that was not
>>>>> good, it would not load the binaries anyway, right?
>>>>> So, if I set that
>>>>> path one line above with the "-d" option to gdb, then the source file
>>>>> can be viewed. What may be going on here?
>>>> That sounds like the expected behavior, as the source directory knobs
>>>> are independent from the sysroot setting. See:
>>> Heh, coincidentally I started my day with reading that before, but
>>> thanks. At least, it is a confirmation that I am on the right track.
>>>>> Thanks in advance. I am so desperately lost. :(
>>>> I think I'm lost on which part you are lost. :-)
>>> Well, I am not sure why it does not work. Yocto generates the images
>>> for me, but that is not important here as long as the dwarf
>>> information looks correct after its operation in the provided readelf
>>> output. So, provided that the dwarf information looks correct, and the
>>> files are there, I am not sure why gdb cannot find src/bar.c in
>>> .../git/meh (path above). I will check "show directories" what gdb
>>> sees in my case, but if that does not help, I am not sure how to make
>>> it work. Got a clue?
>> It seems to just show the default:
>> (gdb) show directories
>> Source directories searched: $cdir:$cwd
>> (gdb) show substitute-path
>> List of all source path substitution rules:
>> To be detailed, this is the path to the source file in question:
>> -> ./tmp/work/foo-foo-linux-gnueabi/foo-core-image-dbg/1.0-r0/rootfs/usr/src/debug/foo-git/AUTOINC+0c2cbe33e653afa335ca25156d293552001228fa-r0/git/foo/foo.c
>> This is where gdb says:
>> (gdb) c
>> Breakpoint 1, foo (sp=0x5e968) at foo.c:99
>> 99 foo.c: No such file or directory.
>> (gdb) n
>> 100 in foo.c
>> Readelf says again:
>> -> e.g. /usr/src/debug/foo-git/AUTOINC+0c2cbe33e653afa335ca25156d293552001228fa-r0/git/foo
>> As you can see the two paths differ in
>> but that is set as sysroot when I run gdb. Do I also need to set this
>> as a substitute path, too, then?
> Oh, and more thing to provide as much information as possible to you:
> (gdb) info source
> Current source file is foo.c
> Compilation directory is
> Source language is c.
> Compiled with DWARF 2 debugging format.
> Does not include preprocessor macro info.
This made it work, but is it the best thing to do?
-ex "set substitute-path /usr/src/debug/
Also, can someone verify that it is also supposed to work if I just
use directories as claimed in here? I cannot because it does not work
in my version, but it is not the latest!
If yes, which one to use?