Feature request: improved build-id generation

[Andy Lutomirski]

On Thu, Mar 15, 2018 at 1:32 PM, Nick Clifton <nickc@redhat.com> wrote:
> Hi Mark,
>
>> That might be an interesting alternative. Could you use this for e.g.
>> inserting a .comment section fragment with an unique (version) string?
>> That would be stripped away, but should still count for the build-id
>> hash calculation.
>

...

>
>   % gcc hello.c -Wl,comment.t
>   % readelf -p.comment a.out
>
> String dump of section '.comment':
>   [     0]  GCC: (GNU) 7.3.1 20180130 (Red Hat 7.3.1-2)
>   [    2c]  GCC: (GNU) 7.2.1 20170915 (Red Hat 7.2.1-2)
>   [    58]  ABC
>
>   A simple perl or python script could be used to create the comment.t
>   linker script fragment.

When you say 'stripped away', do you mean that 'strip' would remove
it?  Neither plain strip nor 'strip -S' seem to be doing the job.

Sticking additional information in the object that affects the
build-id, shows up in the separate debug data, and does *not* show up
in the actual running ELF file seems quite handy.  Then there could be
a tool that would take an ELF file, find its debug info, and parse out
the Fedora package name and version :)

--Andy