[llvm-dev] [LLD] Is there any reason to add _GLOBAL_OFFSET_TABLE_ to .dynsym?

[Rui Ueyama via llvm-dev]

I think that there's no reason to add that symbol to .dynsym. If it is
causing a problem, we should remove that.

On Mon, Feb 8, 2016 at 6:22 AM, Simon Atanasyan <simon at atanasyan.com> wrote:

> When LLD builds a shared library for x86_64 it puts
> _GLOBAL_OFFSET_TABLE_ to the both .symtab and .dynsym and defines it
> as a GLOBAL symbol. If later this shared library participates in
> executable file linking and GNU BFD linked is used for that, this
> linker shows an error:
>
> /usr/bin/ld: a.out: hidden symbol `_GLOBAL_OFFSET_TABLE_' in
> /usr/lib/x86_64-linux-gnu/crt1.o is referenced by DSO
>
> Gold linker does not show any error, but it is anyway strange that we
> make _GLOBAL_OFFSET_TABLE_ globally visible and add it to dynamic
> symbol table.
>
> Both BFD and Gold linker do not put _GLOBAL_OFFSET_TABLE_ to the
> dynamic symbol table and defines this symbol as follows:
>
> BFD:
> Num:    Value          Size Type    Bind   Vis      Ndx Name
>  42: 0000000000200990     0 OBJECT  LOCAL  DEFAULT  ABS
> _GLOBAL_OFFSET_TABLE_
>
> Gold:
> Num:    Value          Size Type    Bind   Vis      Ndx Name
>  19: 0000000000001a18    40 OBJECT  LOCAL  HIDDEN    19
> _GLOBAL_OFFSET_TABLE_
>
> --
> Simon Atanasyan
>
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