llvm dev - Apr 2015 - [LLVMdev] C API for hooking MCJIT's resolving of out-of-module references?

I am trying to port the Kaleidoscope tutorials to use the C API.

This worked up to part 3, but the code for part 4 (where MCJIT support is
added), creates a custom memory manager, in C++, that is then added with
setMCJITMemoryManager().

The custom memory manager is used in order to resolve references from a module
to symbols outside the module, e.g. to symbols representing code jitted in other
modules.

So, how can I hook the way MCJIT resolves out-of-module references, using only
the C API? Alternatively, is there some other way to handle cross module
references?

I briefly looked at the WebKit FTL code. They (mostly) use the C API but I could
not see how symbol references were handled.

(I use the C API because the surrounding application is written in C, so adding
my own C wrappers for unexposed functionality is not an attractive option.)

Thanks in advance,


Per Mildner
Per.Mildner at sics.se

Hi Per,

It doesn't look like there's any way to do this with the existing C-API.
I
suspect this isn't an issue for the FTL developers as they resolve most
(perhaps all?) of their symbols at the IR level.

I think it would be possible to extend the C-API to support symbol
resolution callbacks: We could add a new variant of the
LLVMCreateSimpleMCJITMemoryManager function which also takes a symbol
resolution callback.

Cheers,
Lang.

On Fri, Apr 24, 2015 at 3:17 AM, Per Mildner <Per.Mildner at sics.se>
wrote:
> I am trying to port the Kaleidoscope tutorials to use the C API.
>
> This worked up to part 3, but the code for part 4 (where MCJIT support is
> added), creates a custom memory manager, in C++, that is then added with
> setMCJITMemoryManager().
>
> The custom memory manager is used in order to resolve references from a
> module to symbols outside the module, e.g. to symbols representing code
> jitted in other modules.
>
> So, how can I hook the way MCJIT resolves out-of-module references, using
> only the C API? Alternatively, is there some other way to handle cross
> module references?
>
> I briefly looked at the WebKit FTL code. They (mostly) use the C API but I
> could not see how symbol references were handled.
>
> (I use the C API because the surrounding application is written in C, so
> adding my own C wrappers for unexposed functionality is not an attractive
> option.)
>
> Thanks in advance,
>
>
> Per Mildner
> Per.Mildner at sics.se
>
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
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