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From: "H.J. Lu" <hjl.tools@gmail.com>
To: Alan Modra <amodra@gmail.com>, Florian Weimer <fweimer@redhat.com>
Cc: Binutils <binutils@sourceware.org>
Subject: Re: [PATCH] elf: Don't set VER_FLG_WEAK
Date: Wed, 26 Jan 2022 05:26:34 -0800	[thread overview]
Message-ID: <CAMe9rOpwRavqZN4sT8CqY=7wN-cMegmuA4=Apc6i0N4f4ZB0Pg@mail.gmail.com> (raw)
In-Reply-To: <YfC7BqARPrvVRrgz@squeak.grove.modra.org>

On Tue, Jan 25, 2022 at 7:07 PM Alan Modra <amodra@gmail.com> wrote:
>
> On Tue, Jan 25, 2022 at 04:19:53PM -0800, H.J. Lu via Binutils wrote:
> > On Solaris, VER_FLG_WEAK indicates a weak version definition with no
> > symbols associated with it.  It is used to verify the existence of a
> > particular implementation without any symbol references to the weak
> > version.  Don't set VER_FLG_WEAK since it is unused in binutils.
>
> Can you tell me why the presence of this flag is bad?  I don't see it
> affecting anything in binutils or glibc.  VER_FLG_WEAK in version refs
> does affect resolution of symbol, but I can't see how a VER_FLG_WEAK
> in a version def can transfer over to a ref if the def is unused.

Florian,  can you share the reason why Linux doesn't want
VER_FLG_WEAK on the empty version?

Thanks.

> >       PR ld/28814
> >       * elflink.c (bfd_elf_size_dynamic_sections): Don't set
> >       VER_FLG_WEAK.
> > ---
> >  bfd/elflink.c | 4 ----
> >  1 file changed, 4 deletions(-)
> >
> > diff --git a/bfd/elflink.c b/bfd/elflink.c
> > index 2677561478d..ffb4506958f 100644
> > --- a/bfd/elflink.c
> > +++ b/bfd/elflink.c
> > @@ -6921,10 +6921,6 @@ bfd_elf_size_dynamic_sections (bfd *output_bfd,
> >
> >             def.vd_version = VER_DEF_CURRENT;
> >             def.vd_flags = 0;
> > -           if (t->globals.list == NULL
> > -               && t->locals.list == NULL
> > -               && ! t->used)
> > -             def.vd_flags |= VER_FLG_WEAK;
> >             def.vd_ndx = t->vernum + (info->create_default_symver ? 2 : 1);
> >             def.vd_cnt = cdeps + 1;
> >             def.vd_hash = bfd_elf_hash (t->name);
> > --
> > 2.34.1
>
> --
> Alan Modra
> Australia Development Lab, IBM



-- 
H.J.

  reply	other threads:[~2022-01-26 13:27 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-26  0:19 H.J. Lu
2022-01-26  3:07 ` Alan Modra
2022-01-26 13:26   ` H.J. Lu [this message]
2022-01-31 16:47     ` Florian Weimer
2022-01-31 18:19       ` H.J. Lu
2022-02-01  8:44 Nick Clifton

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