Re: gcc generated memcpy calls symbol version

[Tom Mason <wheybags at wheybags dot com>]

I'm not entirely sure I understand that issue. From what I understand,
calls to a function in a shared library should always use the PLT?
Also, I don't understand the purpose of applying hidden visibility to an
extern symbol,
But anyway, doesn't matter terribly much if I understand :p

On Fri, Jan 26, 2018 at 8:37 PM, H.J. Lu <hjl.tools@gmail.com> wrote:

> On Fri, Jan 26, 2018 at 12:29 PM, Tom Mason <wheybags@wheybags.com> wrote:
> > Hi,
> > I've got a project here: https://github.com/wheybags/
> glibc_version_header
> > which uses .symver directives to link to a specified version of glibc, so
> > long as it's older than the version on your system.
> > This works, but a problem I'm having is that gcc itself will sometimes
> > insert calls to memcpy (or memmove, memset and memcmp), as documented
> here:
> > https://gcc.gnu.org/onlinedocs/gcc/Standards.html
> > When it does so, it doesn't respect the .symver directives, and uses the
> > default version.
> > Is there any way for me to force the version for these symbols aswell?
> > I'm aware that I can disable the whole mechanism with -freestanding, but
> I
> > don't want to cripple the optimiser.
>
> I think this is related to:
>
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67220
>
> --
> H.J.
>