[llvm] r323297 - Don't assume a null GV is local for ELF and MachO.

[Rafael Avila de Espindola via llvm-commits]

Brooks Moses <bmoses at google.com> writes:

> On Fri, Feb 9, 2018 at 6:54 AM, Rafael Avila de Espindola <
> rafael.espindola at gmail.com> wrote:
>
>> Brooks Moses <bmoses at google.com> writes:
>> > Thanks for the quickly-implemented fix!  Honestly, I'm not sure how to
>> > fully test that this boots, but one of our grub developers has offered to
>> > test things for me if needed, so I'll give this a quick try tomorrow
>> > morning to make sure it builds in our build system, and then hand it off
>> to
>> > him for testing.  Hopefully we can let you know tomorrow afternoon if
>> this
>> > works and get you unblocked on re-committing the patch.
>> >
>> > If this is indeed the extent of the change required for grub, I agree
>> with
>> > your analysis that this shouldn't be a blocker.
>>
>> Any news? I would really like to recommit the patch.
>>
>> It seems unreasonable to hold back a llvm patch because another software
>> has an incomplete linker implementation, specially when a patch is
>> available.
>>
>
> Sorry for the delay -- my colleague reports that he's testing this now.  (I
> think he was out yesterday.)
>
> Do you have a reference for the part of the ELF ABI that describes why the
> PLT32 references should be treated as PC32 references here?

It comes from the definition of the plt in the PSABI:

https://github.com/hjl-tools/x86-psABI/wiki/intel386-psABI-1.1.pdf

Since the final function is know, calling the plt is the same is calling
the final function.

Cheers,
Rafael