Re: GCJ Wiki

[Ranjit Mathew <rmathew at gmail dot com>]

Phil Shaw wrote:
> 
> Far from it, this answered background questions about GCJ I didn't 
> know I had! One aspect I would like to know more about is why GCJ and 
> Classpath are different and how they are being merged, and the 

GNU Classpath aims to provide a Free Java runtime for Free
JVMs, including GCJ, Kaffe, SableVM, IKVM, etc. Since the Java
runtime is *huge* and just keeps growing with each JDK release,
it makes sense for all these projects to share their Java
runtime, with perhaps minor VM-specific intentional differences.

Great volunteers like Michael Koch, Tom Tromey, Mark Wielaard,
et al constantly try to keep libgcj up-to-date with Classpath,
propagate fixes in libgcj to Classpath, etc. You can always
find the current status of libgcj v/s Classpath at:

  http://developer.classpath.org/compare/


> development process for GCJ with respect to GCC, which has come up on 
> the list recently.

GCJ provides the Java front-end in GCC as well as the
runtime standard library for Java (libgcj). As such,
GCJ is a part of GCC and is tied to its release process.

However, as explained by Mark Mitchell a couple of days
back, Java is not a release critical language for GCC.
This means that Java bugs will not block the release
of GCC, however critical they might be.

The Java front-end parses Java source files to an
intermediate representation and passes it on to the
*common* GCC middle-end which performs various
optimisations, etc. The middle-end passes the end
result to the machine-specific GCC backend which
performs various target-specific optimisations and
emits assembly code. This is then translated to a
binary object file by an assembler and then linked
into an executable by a linker.

Hope this answers your questions,
Ranjit.

-- 
Ranjit Mathew      Email: rmathew AT gmail DOT com

Bangalore, INDIA.    Web: http://ranjitmathew.hostingzero.com/