llvm dev - Aug 2008 - [LLVMdev] LLVM JIT: How to install a callback for a function loaded in at runtime

Hello,

This is probably a bit of a beginner's question but I am new to LLVM
I have been examining the possibility of constructing something similar to the
JnJVM for a language which supports dynamic class loading. The problem I am
having is determining how the JIT system allows for dynamic loading of functions
into the JIT. The paper indicates the JnJVM use some sort of callback when the
JIT hits a call it cannot yet resolve. How do I install such a handler?

Thanks in advance,

Carter.

lib/System/DynamicLibrary.cpp is a good place to look.

Evan

On Jul 31, 2008, at 12:41 PM, Carter Cheng wrote:
> Hello,
>
> This is probably a bit of a beginner's question but I am new to LLVM
> I have been examining the possibility of constructing something  
> similar to the JnJVM for a language which supports dynamic class  
> loading. The problem I am having is determining how the JIT system  
> allows for dynamic loading of functions into the JIT. The paper  
> indicates the JnJVM use some sort of callback when the JIT hits a  
> call it cannot yet resolve. How do I install such a handler?
>
> Thanks in advance,
>
> Carter.
>
>
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev

Hi Carter,

Carter Cheng wrote:
> Hello,
>
> This is probably a bit of a beginner's question but I am new to LLVM
> I have been examining the possibility of constructing something similar to
the JnJVM for a language which supports dynamic class loading. The problem I am
having is determining how the JIT system allows for dynamic loading of functions
into the JIT. The paper indicates the JnJVM use some sort of callback when the
JIT hits a call it cannot yet resolve. How do I install such a handler?
>
>   
You need to implement your own ModuleProvider and specialize the 
materialzeFunction function to do the dynamic loading.  In vmkit, you 
can take a look at lib/JnJVM/VMCore/JnjvmModuleProvider.cpp file.

Nicolas
> Thanks in advance,
>
> Carter. 
>
>
>       
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>

Thanks. I didnt realize that this particular function was a virtual inherited
from the Module Provider interface. Out of curiousity what applications does the
materializeModule function have and when does it get invoked?

Regards,

Carter.



--- On Thu, 7/31/08, Nicolas Geoffray <nicolas.geoffray at lip6.fr> wrote:
> From: Nicolas Geoffray <nicolas.geoffray at lip6.fr>
> Subject: Re: [LLVMdev] LLVM JIT: How to install a callback for a function
loaded in at runtime
> To: carter_cheng at yahoo.com, "LLVM Developers Mailing List"
<llvmdev at cs.uiuc.edu>
> Date: Thursday, July 31, 2008, 5:42 PM
> Hi Carter,
> 
> Carter Cheng wrote:
> > Hello,
> >
> > This is probably a bit of a beginner's question
> but I am new to LLVM
> > I have been examining the possibility of constructing
> something similar to the JnJVM for a language which supports
> dynamic class loading. The problem I am having is
> determining how the JIT system allows for dynamic loading of
> functions into the JIT. The paper indicates the JnJVM use
> some sort of callback when the JIT hits a call it cannot yet
> resolve. How do I install such a handler?
> >
> >   
> 
> You need to implement your own ModuleProvider and
> specialize the 
> materialzeFunction function to do the dynamic loading.  In
> vmkit, you 
> can take a look at lib/JnJVM/VMCore/JnjvmModuleProvider.cpp
> file.
> 
> Nicolas
> 
> > Thanks in advance,
> >
> > Carter. 
> >
> >
> >       
> > _______________________________________________
> > LLVM Developers mailing list
> > LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
> >