Proposal for STT_GNU_IFUNC and R_*_IRELATIVE

[H.J. Lu]

On Wed, May 27, 2009 at 10:27 AM, Ulrich Drepper <drepper@redhat.com> wrote:
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> H.J. Lu wrote:
>> After looking another look, DT_* may be a good idea. STT_GNU_IFUNC
>> can be in DSO, dynamic executable and static executable. We need a way
>> to make it to work for all 3 cases.
>
> And?  Relocations of course also work in all the cases.
>
> It is a braindead idea to invent a new data structure every time some
> gets added.  Especially if there is already one which perfectly fits the
> bill.  There is no reason whatsoever to not use a relocation.  The
> introduction of a DT_* described data structure just makes things more
> complicated at runtime.
>
> The argument that only one thing for all architectures has to be changed
> is irrelevant.  The amount of work needed in the linker in negligible.
> On the other hand, there have to be completely different implementations
> for the fancy new data structure for different architectures if the
> function pointer implementation differs.
>
>
> Using R_*_IRELATIVE relocations is the right way to handle this.
>

How to do you handle R_*_PC32 relocation to a locally defined
STT_GNU_IFUNC symbol in dynamic and static executables?


-- 
H.J.