objcopy --strip-debug breaks GROUP sections

[H.J. Lu]

On Tue, Feb 16, 2010 at 9:25 AM, Eirik Byrkjeflot Anonsen
<eirik@opera.com> wrote:
> Eirik Byrkjeflot Anonsen <eirik@opera.com> writes:
>
>> Using binutils 2.20, I find that running objcopy --strip-debug generates
>> "invalid" GROUP sections.  ("invalid" in the sense that ar complains and
>> the linker fails...  I haven't checked any specifications.)
>>
>>
>> It seems that what happens is that when sections are removed from the
>> object file, any references to that section within GROUP sections are
>> set to 0.
> [...]
>> So my immediate question is: Where in the code is the output GROUP
>> section data generated?  Or, in other words, what do I change to make
>> objcopy not output the null references?
>>
>> eirik
>
> Changing bfd_elf_set_group_contents() to shrink sh_size and skip the
> sections that will not be output seems to solve the problem.  Does
> anyone think that this is something I should try to clean up and submit
> a patch for?  Or am I doing something completely wrong?
>
> (I haven't been able to fully test this yet, as I now have problems with
> the .arm_vfe_vcallinfoi.* sections, I believe.  Probably objcopy doesn't
> renumber the section references in those sections.)
>

Please open a bug report with a self-contained testcase, which can
be reproduced with a cross binutils.

Thanks.

-- 
H.J.