Re: ideal visibility setting?

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Jay K <jay.krell@xxxxxxxxxxx> writes:

> Ian, I don't have to use -fPIC and go through GOT/PLT, in case my code will end up in a .so?
>  Well, it looks like you can do that -- omit -fPIC -- but then you get TEXTREL, not good.
>
>
> You know, x86 already has the ip-relative 0xE8 opcode.
> I'd like to just use that, directly to the function, have the linker generate a stub if it ends up imported (using GOT/PLT).
> But still whatever more complicated stuff is needed to reference data without TEXTREL.

That approach does not permit symbol interpositioning, which is a key
goal of ELF.  If you don't want to permit symbol interpositioning, you
can avoid the PLT if you with -fPIC, but link with -Bsymbolic.

That will still wind up using the GOT for global/static variables, but
I don't see how you can avoid that in position independent code.
There is no PC relative load instruction for 32-bit x86.  As far as I
can see you must either use a GOT or get a TEXTREL tag.

Ian


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