GCJ with OpenJDK Java API instead of GNU Classpath

Thu May 7 20:24:00 GMT 2009

Andrew Haley wrote:
> It's all GPL + exception, so there are no licence difficulties.
>> This would be an excellent thing to do, but it would be difficult. In
> particular, class loading and class initialization are done in very
> different ways, and this would all need to be rewritten.
>> I'd love someone to do this, but I don't want them to be under any illusion
> about how difficult it might be.
>> Andrew.
>
So it should be challenging then, great :)
Thanks for all the feedback, I'm glad to hear there are others who seem 
to like the idea as well. I wasn't sure if this hadn't been started yet 
due to some legal issues, or otherwise. Sounds like its just something 
that needs a little elbow grease.
I started some preliminary work - just to get a feel for what might be 
entailed. What I was thinking as a general plan of attack:
	1) - Obtain/extract a copy of the Java sources from a standard/official 
Sun release. Just to start working from a clean slate since it is an 
effort towards maximum compatibility. I've noticed that not all classes 
are actually from a simple source-tree extract, some are generated by 
the build process (so I'm still trying to get through this...)
	2) - Isolate a subset of the sources to get gcj-openjdk port started. 
possibly: java.lang.* (and all dependancies) at first, then the other 
fundamental things; java.io.*, java.util.* etc. Although open for 
suggestions here of course.
	3) - Compile the pieces from 2) with GCJ, add in more packages as 
things build.
	4) - Somehow, maintain releases for it all as things progress, so 
people can grab current work and collaborate. I can do so much as to 
zip/upload snapshots when stuff starts working... but maybe others have 
much better ideas or resources here? I've got a feeling it won't be an 
overnight process, so it would be a big help to allow for as many hands 
on deck as possible.
--
I'm currently trying to make it all the way through the openjdk build 
process, to get at the .java sources, and isolate the JNI parts needed 
for a working library. Possibly if anyone has already done this let me 
know - as it doesn't seem other parts are very critical - (hotspot, 
etc.) to get running, since we're just replacing Classpath initially.
Looking forward to any ideas/comments!
Thanks much,
- Sal