[pypy-dev] JVM backend - status and future work possibilities?

[Dario Bertini]

2011/5/11 Michał Bendowski <michal at bendowski.pl>:
> Welcome everyone :)
>
> I was wondering what is the current status of the JVM backend. I'm
> asking because I am considering working on it for my master's thesis -
> I was inspired by a call to action from the "Features" page of
> pypy.org. Unfortunately it's unclear to me how much work needs to be
> done here. I understand that RPython translation is already
> implemented (although might need some care, for the build process to
> succeed more easily[1]), but the JIT backend is missing. There is also
> no integration with JVM libraries - am I right? On the other hand
> there already is a "reference" CLI implementation and a whole thesis
> about it.

Hi, I'm in a similar situation here :)

I'm planning as well to work on the jvm backend for my master thesis:
I contacted just today one of my professors who seems to be willing to
mentor me, but I haven't started any work yet

the integration with JVM libraries basically is a prerequisite for
starting the work on the JIT backend, I'm not sure and I don't
actually know your university program, but here at my university for
the master thesis we have something like 15 ects... so something like
the integration with the JVM alone may very well be on the upper side
of what effort we could be expect to put in the thesis

You're right about the CLI implementation, but after a huge
refactoring inside pypy it wasn't functional anymore... Antonio Cuni
(who is the author of the CLI backend we're talking about) fixed it,
but I think that the ability to access CLI assemblies and class still
has some issues...

btw, I'm very new to this project as well, and from what I gathered
until now, Antonio seems to be the guy to ask to for questions about
the OO type system :)

As a starting point: he suggested me to start looking into JPype and Jtool

http://jpype.sourceforge.net/
http://blog.meresco.org/2010/03/11/integrating-java-in-python-with-jtool/

this kind of tools are needed for calling JVM code from CPython, thus
letting us to try/debug the JVM integration when running pypy
interpreted on top of CPython ( pypy/bin/py.py )

>
> I'm not familiar with pypy internals at the moment, nor am I a
> compiler expert (yet!). I will be very grateful for any advice, as to
> whether taking care of the JVM backend is a suitable amount of work,
> and whether it can "scale", i.e. be divided into smaller parts that I
> can implement along the way and stop if I'm out of time (I imagine I
> can always find more work in PyPy).
>

I would also like to know if this kind of work would be feasible to
tackle in parallel for 2 students like us :)

(btw, my presence on the irc channel has been quite lacking
nowadays... I'll try to be more present in the next days)

byebye

:Dario