[RFC] SHF_GNU_RETAIN ELF Section Flag

[Florian Weimer]

* Jozef Lawrynowicz:

> On Tue, Sep 15, 2020 at 02:09:22PM +0200, Florian Weimer wrote:
>> * Jozef Lawrynowicz:
>> 
>> > I'd like to propose a new ELF section flag, SHF_GNU_RETAIN, for addition
>> > to the GNU gABI.
>> >
>> > This flag instructs the linker to "retain" the section in the output
>> > file, even if garbage collection would remove it because it appears
>> > unused.
>> 
>> How does this flag interaction with libraries (.a files)?
>
> If a section in a library has SHF_GNU_RETAIN set, and that library gets
> searched by the linker for some undefined symbol, then the
> SHF_GNU_RETAIN section will also be pulled into the program, and
> retained in the linked output file.

Sorry, that's not quite what I meant.  What happens if the .o file with
SHF_GNU_RETAIN in an .a library is not otherwise referenced and thus
never loaded by the link editor?  How would the link editor realize that
it is even there?

Thanks,
Florian
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