Re: [Tinycc-devel] x86_64: shared libs

[Michael Matz]

Hi,

On Fri, 4 Apr 2014, grischka wrote:

> Question apropos:
>
> On linux x86_64 there is still the ugly
>    "runtime_plt_and_got"
> hack which is a replacement for PLT in the "tcc -run" case
> to forward 32bit calls to extern libraries.
>
> On win64 the same problem is solved by building the IAT
> (import address table) also in the -run case.
>
> From your estimation, would it be possible to do the same on ELF?
> That is build the PLT/GOT as if we were making an executable and
> then use that with tcc -run?

Yes, that's something on my TODO.  Theoretically having 
runtime_plt_and_got makes code emission a tiny bit faster because having a 
proper PLT and GOT also for -run means first creating and second applying 
intermediate relocations (the _GLOB_DAT and _JUMP_SLOT relocs), which is 
cut short with the hack.  OTOH removing the hack would remove deviation 
depending on output type, so I think it's a good idea nevertheless.


Ciao,
Michael.