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Date: Wed, 16 Sep 2020 13:46:38 +0000 (UTC)
From: Michael Matz <matz@suse.de>
To: Florian Weimer <fweimer@redhat.com>
cc: Jozef Lawrynowicz <jozef.l@mittosystems.com>, gnu-gabi@sourceware.org
Subject: Re: [RFC] SHF_GNU_RETAIN ELF Section Flag
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Hello,

On Wed, 16 Sep 2020, Florian Weimer via Gnu-gabi wrote:

> * Jozef Lawrynowicz:
> 
> > I suppose the most compelling use cases for SHF_GNU_RETAIN are when the
> > dependency cannot be expressed with references to ELF sections. You
> > can't use SHF_GROUP because there is nothing to group the section with.
> 
> But if there is nothing to group the section with, why would the link
> editor load the object?
> 
> That's the part I don't understand.

Hmm?  By putting it on the command line:

% ld --gc-sections needed.o

should retain the RETAIN sections from needed.o, even if otherwise not 
seemingly referenced.

(I'm not sure if doing this via a group flag, or via a section flag would 
be better here.  In a way I find the section flag more appealing, it's the 
less complicated way to state "don't GC this section").


Ciao,
Michael.