Hi Mark,
> Am 29.03.2017 um 22:15 schrieb Torsten Polle <torsten.po...@gmx.de>:
>
> Hi Mark,
>
>> Am 27.03.2017 um 22:45 schrieb Mark Wielaard <m...@klomp.org>:
>>
>> Hi Torsten,
>>
>> On Sun, Mar 26, 2017 at 08:35:50PM +0200, Torsten Polle wrote:
>>> I observed that readelf and elfutils sometimes report different results.
>>
>> Do you have an example of this? It would be good to have a testcase.
>>
>>> PFA a patch that corrects this. I’m not sure whether the way I tackled
>>> the problem is acceptable.
>>
>> I see why you are proposing this. The DWARF spec does say about the
>> include_directories "Each path entry is either a full path name or is
>> relative to the current directory of the compilation". So your patch
>> does make sense.
>>
>> But it does depend on what users of dwarf_getsrclines expect.
>> Or any use of Dwarf_Line/Dwarf_Files. I think those users expect that
>> the returned file names can be relative. And that they should make them
>> absolute using index zero or the comp_dir themselves.
>>
>> So if you do have an example where the expected output isn't what you
>> believe it should be we should examine if there is some other way to
>> do the right thing.
>>
>> Cheers,
>> Mark
>
> thanks for the answer. I’ll come back with an example, which is SystemTap
> based. :-)
>
> Please allow for some delay. I expect to provide an example in about two
> weeks.
>
> Regards,
> Torsten
Sorry for coming back so late. Please find attached my reproduction.
I compile the simple program relative.c:
int main()
{
return 0;
}
with the command "gcc -g ../2017-05-03-elfutils/relative.c -o relative“.
When I run systemtap with the command
/opt/tooling/adit/systemtap/bin/stap -g -a i386 -B
CROSS_COMPILE=i586-poky-linux- -r
/home/polle/work/build/poky/build/tmp/work/qemux86-poky-linux/linux-yocto/4.8.12+gitAUTOINC+926c93ae07_021b4aef55-r0/build
--sysroot=/home/polle/work/build/poky/build/tmp/work/qemux86-poky-linux/core-image-sato/1.0-r0/rootfs
-L 'process("/bin/relative").function("main").call‘
I get the following output:
process("/bin/relative").function("main@../2017-05-03-elfutils/relative.c:1").call
But running nm returns the following.
nm -l | grep relative
080483eb T main
/home/polle/work/issues/2017-05-03-elfutils/../2017-05-03-elfutils/relative.c:1
I hope this helps.
Kind Regards,
Torsten
