måndag 12 januari 2015 12.11.17 skrev H.J. Lu:
> On Mon, Jan 12, 2015 at 12:03 PM, Jeff Law <l...@redhat.com> wrote:
> > On 01/12/15 12:59, H.J. Lu wrote:
> >> I don't know if -pg will work PIE on any targets. For Linux/x86
> >> the choices of crt1.o are
> >>
> >> %{!shared: %{pg|p|profile:gcrt1.o%s;pie:Scrt1.o%s;:crt1.o%s}}
> >>
> >> -shared, -pg and -pie are mutually exclusive. Those crt1 files are
> >> only crt1 files provided by glibc. You can't even try -pg -pie on
> >> Linux without changing glibc.
> >
> > You're totally missing the point. What I care about is *why*.
> >
With -pg it use gcrt1.o object file and that file is not compile with -fPIC.
When you build a shared lib on x86_64 all the objects files need to be buiit
with -fPIC else you get a error like that one abow and it is the same problems
when you build bin with -fPIE and linke with -pie.
Glibc do not provide one that is compile with -fPIC
> > Showing me spec file fragments is totally unhelpful. What is the
> > technical
> > reason why pg and pie are mutually exclusive?
>
> What kind of "technical" reason are you looking for? glibc doesn't
> provide the right crt1 file for GCC to support this combination. You
> can't define GNU_USER_TARGET_STARTFILE_SPEC to support
> -pg and -pie.
>
> If you are asking "why" glibc doesn't provide one, my guess is no
> one has requested one before.
