IcedTea6 1.2 Released!

[Anthony Green]

Mark Wielaard wrote:
> Hi Anthony,
>
> On Wed, 2008-07-09 at 19:26 -0700, Anthony Green wrote:
>   
>> I got on my flight that day and looked at the IcedTea src tree for the 
>> first time, then quickly realized I wasn't going to be able to do this 
>> in a vacuum.
>>
>> First question for the IcedTea hackers:  where in the tree should my 
>> source code live?  It looks like there are a few viable spots.
>>     
>
> Yes, there are indeed a couple of ways to extend icedtea/openjdk
> depending on how big and how invasive your change is.
>   

Thanks for explaining this, Mark.  I'm proceeding with the overlay 
approach.  It's taking some time to figure out the build system.  Any 
tips?  Builds take forever.... and I don't know how to test my changes 
without starting the build pretty much from scratch.

AG



> For smaller changes the simplest way is to just add a patch under
> patches/icedtea-your-cool-hack.patch and then add that to the
> ICEDTEA_PATCHES in the Makefile.am. Your change will then be applied
> against the openjdk sources before any other building starts and then be
> build as if the change was already part of openjdk itself.
>
> For larger changes that mainly involve new classes/files/packages it is
> easier to use the overlay mechanism. This is used by Gervill for
> example, and is easier when you need to patch/override binary files
> (like the color profiles). This seems most appropriate to your case. You
> put your files under overlays/openjdk/jdk/src/share/classes/com/package
> that either completely overrides the existing classes there or that adds
> completely new files. If it is a new package then it is necessary to
> combine it with a small patches/icedtea-your-package.patch file to
> adjust the build system to pick up your new package
> (icedtea-gervill.patch and icedtea-rhino.patch give some examples of
> this).
>
> Finally you can build your extension after the core icedtea has been
> build, using the just build icedtea and then adding the extension to the
> jdk-image. This is how the gcjwebplugin applet and netx webstart support
> are done. This does mean that you are basically responsible for the
> build of your extension yourself in a separate target in Makefile.am
> that you then add as a dependency of stamps/icedtea.stamp. And in that
> target you then copy over the results into the correct image dirs. See
> the ICEDTEAPLUGIN_TARGET in Makefile.am for an example or the
> extra-lib/about.jar for a java extension. If you don't like the previous
> solution, then this might be the one to use, although it is a bit more
> work, but gives you more flexibility.
>
> There are some other things to take care for if your change is actually
> replacing the runtime, like the cacao, zero and shark integration, or
> when it is needed in the bootstrap phase (but perhaps not during the
> phase after that). Then you have to instruct configure.ac to pick up the
> right build pieces and then passing them to the rest of the build
> through the ICEDTEA_ENV and/or ICEDTEA_ENV_ECJ in Makefile.am. But those
> don't apply to your case.
>
> Cheers,
>
> Mark
>
>