[LLVMdev] Generating PIC object files from the LLVM API

[Josh Klontz]

Thanks for the quick response. I was able fix the problem by generating the
target machine like llc does with:

    TargetRegistry::lookupTarget(<...>)->createTargetMachine(<...>)

Working backwards from there, it became apparent that the cause of the
issue was EngineBuilder's default code model was CodeModel::JITDefault but
what I needed for static code generation was CodeModel::Default.

Is there any documentation on CodeModel? I couldn't find any in the usual
places.

Cheers,
Josh


On Wed, Jan 8, 2014 at 3:22 AM, Tim Northover <t.p.northover at gmail.com>wrote:

> > This novice developer thought that the solution would be:
> >
> >     engineBuilder.setRelocationModel(Reloc::PIC_);
>
> Hmm. That's exactly what I'd expect too. I don't suppose you're
> calling setRelocationModel after selectTarget or something odd like
> that?
>
> The only other wrinkle I see is that COFF targets (only Windows, I
> believe) don't seem to support PIC yet (from a very cursory reading of
> X86TargetMachine.cpp). You seem to be using ld so this is a long shot,
> but are you trying to use a COFF triple?
>
> Another possibility (which I assume you've checked) is that the
> absolute relocations might not be coming from a bog-standard
> addressing situation that -fPIC would fix. I'd take a quick look at
> the exact section and function ld is telling you about to make sure
> there's nothing odd going on there.
>
> If neither of those apply, I'd start delving into a debugger: put a
> break-point on X86TargetMachine's constructor and see where the value
> for the Reloc::Model comes from (and whether it is actually PIC).
>
> Cheers.
>
> Tim.
>
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